NAMS 2002 Workshop - ICOM 2008

ICOM 2008 Oral Presentation Proceedings
Sheraton Waikiki Hotel
Honolulu, Hawaii, USA
http://www.icom2008.org
Hosted by:
Membrane Technology and Research, Inc.
The University of Texas at Austin
The University of California, Los Angeles
Meeting Chair:
Ingo Pinnau
Membrane Technology and Research, Inc.
1360 Willow Road, Suite 103
Menlo Park, CA 94025
Tel: (650) 328-2228 x 113
Fax: (650) 328-6580
E-mail: ipin@mtrinc.com
Meeting Co-Chair:
Benny Freeman
Dept. of Chemical Eng.
University of Texas at Austin
10100 Burnet Road, Building 133
Austin, TX 78758
Tel: (512) 232-2803
Fax: (512) 232-2807
E-Mail: freeman@che.utexas.edu
International Congress
on Membranes and
Membrane Processes
Honolulu, Hawaii
July 12-18, 2008
Meeting Co-Chair:
Yoram Cohen
Dept. of Chemical & Biomolecular Eng.
University of California, Los Angeles
BOX 951592, 5531 BH
Los Angeles, CA 90095-1592
Tel: (310) 825-8766
Fax: (310) 206-4107
E-Mail: yoram@ucla.edu

The organizers of ICOM 2008 gratefully
acknowledge the generous sponsorship of the
meeting by the following organizations:

Professor Yoram Cohen
Professor John Pellegrino
Professor Douglas Gin
Organizing Committee:
University of
California,
Los Angeles
University of
Colorado at Boulder
University of
Colorado at Boulder
Professor Albert Kim University of Hawaii
Sponsorship
Committee Chair
Student Award
Manager, Poster
Session
Food Coordinator
Onsite Logistics
Manager/Sponsorship
Committee, Poster
Session
Professor Glenn Lipscomb University of Toledo Website Manager
Dr. Ed Sanders Air Liquide Workshop Coordinator
Dr. Richard Ubersax
Onsite Logistics and
Technical Support,
Poster Session

ICOM International Advisory Board:
Pierre Aimar.................................................France
Paul Armistead ................................................ USA
Richard Baker ................................................. USA
Georges Belfort ............................................... USA
Neal Chung............................................. Singapore
Wookjin Chung.............................................. Korea
Enrico Drioli ....................................................Italy
Eric Favre ....................................................France
Francesc Giralt .............................................. Spain
Michael Guiver ............................................Canada
Akon Higuchi............................................... Taiwan
Anita Hill .................................................. Australia
Yong Soo Kang.............................................. Korea
Albert Kim ...................................................... USA
Sung Soo Kim ............................................... Korea
Hidetoshi Kita ............................................... Japan
Bill Koros........................................................ USA
Young Moo Lee.............................................. Korea
TorOve Leiknes ...........................................Norway
Jerry Lin......................................................... USA
Glenn Lipscomb............................................... USA
Andrew Livingston ............................................. UK
Jim McGrath ................................................... USA
Kazukiyu Nagai ............................................. Japan
Richard Noble ................................................. USA
Yoram Oren .................................................. Israel
Don Paul ........................................................ USA
Klaus-Viktor Peinemann............................. Germany
Peter Pintauro ................................................. USA
Giulio Sarti .....................................................Italy
Raphael Semiat ............................................. Israel
Kamalesh Sirkar .............................................. USA
Tae Moon Tak ............................................... Korea
Richard Ubersax .............................................. USA
Tadashi Uragami ........................................... Japan
Matthias Wessling........................... The Netherlands
Yuri Yampolskii............................................. Russia
Andrew Zydney ............................................... USA

ICOM 2008 Staff:
The University of Texas at Austin
Student Administrative Staff
Mr. Brandon Rowe Ms. Elizabeth Van Wagner
Mr. Geoff Geise Mr. Victor Kusuma
The University of Texas at Austin
Student Staff
Ms. Katrina Czenkusch Mr. Tom Murphy
Ms. Lauren Greenlee Mr. Grant Offord
Mr. Hao Ju Dr. Claudio Ribeiro
Mr. James Kyzar Ms. Alyson Sagle
Mr. Hua (Richard) Li Mr. Kevin Tung
Mr. Bryan McCloskey Ms. Yuan-Hsuan Wu
Mr. Dan Miller Mr. Wei Xie
The University of Texas at Austin
Administrative Assistant
Ms. Kumi Smedley
The University California, Los Angeles
Student Staff
Mr. Alex Bartman Mr. Eric Lyster
Centennial Conferences
Annett D’Antonio
Sheraton Hotel Staff:
Mr. Robert Morishige ..................... Convention & catering service manager
Mrs. Julene Davis.......................... Sales manager
Mr. Jeff Gionet.............................. Director of telecommunications
Mrs. Shirley Yamamoto.................. Director of convention services

Sheraton Waikiki Map:

ICOM 2008 Workshop Schedule:
Saturday, July 12
-Workshop: Membrane-Based Gas Separations (O’ahu) .................... 8:00am
-Professor Benny Freeman, University of Texas at Austin
-Professor Glenn Lipscomb, University of Toledo
-Dr. Hans Wijmans, Membrane Technology Research, Inc.
-Workshop: Fuel Cells (Honolulu) ..................................................... 8:00am
-Professor Peter Pintauro, Case Western Reserve
-Professor Ryszard Wycisk, Case Western Reserve
-Workshop: Polymeric and Inorganic Membrane Materials
and Membrane Formation (Wailua) ........................... 8:00am
-Professor Jerry Y. S. Lin, Arizona State University
-Dr. Michael D. Guiver, National Research Council of Canada, Ottawa
-Workshop: Measurement Methods for Membranes
(Kahuku).................................................................. 8:00am
-Professor John Pellegrino, University of Colorado at Boulder
Sunday, July 13
-Workshop: Emerging Membrane Materials
and Manufacturing Methods (Wai’anae)..................... 8:00am
-Dr. Klaus V. Peinemann, GMT Membrantechnik GmbH
-Dr. Suzanna P. Nunes, GKSS, Germany
-Professor Bruce Hinds, University of Kentucky
-Workshop: Membrane Desalination Technology
(Kohala/Kona).......................................................... 8:00am
-Dr. Craig Bartels, Hydranautics
-Dr. Rich Franks, Hydranautics
ICOM 2008 Social and Business Schedule:
Sunday, July 13
-Opening Reception (Ocean Terrace/Pool Area) .......................6:30pm – 9:30pm
Monday, July 14
-Elsevier Reception (Ballroom Foyer).......................................5:30pm – 6:30pm
-Poster Session I (Lana’i Ballroom)..........................................6:30pm – 9:30pm
Tuesday, July 15
-NAMS Business Meeting (Wai’anae) .......................................5:30pm – 6:30pm
-Poster Session II (Lana’i Ballroom) ........................................6:30pm – 9:30pm
Wednesday, July 16
-ICOM Banquet (Hawai’i Ballroom) ........................................ 6:00pm – 10:00pm
Thursday, July 17
-Poster Session III (Lana’i Ballroom) .......................................6:30pm – 9:30pm

Monday, July 14 – Morning Sessions
8:00AM Plenary I (Hawai’i Ballroom):
Professor James E. McGrath (Virginia Tech, Blacksburg, Virginia, USA)
Fuel Cell Polymer Electrolyte (PEM) Derived from Disulfonated Random and Block Poly(arylene ether) Copolymer System
9:00AM Coffee Break (Ballroom Foyer)
Gas Separation I
(Kaua’i)
Chair: Don Paul, The University of
Texas at Austin, USA
Co-Chair: Giulio Sarti, Universita
Degli Studi Di Bologna, Italy
9:30AM Beyond Inorganic-Organic
Nanocomposites for Molecular
Separations
Wessling, University of Twente, The
Netherlands
10:15AM Tailor Made Polymeric Membrane based
on Segmented Block Copolymer for CO 2
Separation
Car, Stropnik, University of Maribor,
Slovenia
Yave, Peinemann, Institute of Polymer
Research, GKSS Research Centre
Geesthacht GmbH, Germany
10:45AM Segmented Block Copolymers: A
Molecular Toolbox to Tailor the Mass
Transport Properties of Polymeric
Nanocomposites
Reijerkerk, University of Twente, The
Netherlands
11:15AM
Gas Separation Using Ionic Liquid
Polymers
Noble, Gin, Bara, Carlisle, Voss, Finotello,
University of Colorado, Boulder, Colorado,
USA
11:45AM Development of High Temperature CO 2-
Selective Porous Ceramic Membranes
Ku, Ramaswamy, Ruud, Willson, Narang,
GE Global Research, Niskayuna, New
York, USA
12:15PM Solubility and Diffusivity of Organic
Vapors in Mixed Matrix Membranes
Formed By High Free Volume Glasses
Loaded with Fumed Silica
Sarti, Ferrari, De Angelis, Galizia,
University of Bologna, Italy
Merkel, MTR- Membrane Technology and
Research, Menlo Park, California, USA
Drinking and
Wastewater
Applications I
(Maui)
Chair: Dibakar Bhattacharyya,
University of Kentucky, USA
Co-Chair: Maria Norberta de Pinho,
Instituto Superior Tecnico, Portugal
Reuse/Recycle Water Opportunities and
Challenges in Food/Bio Processing
Industry Using Membrane Technology:
Is this Myth or Reality?
Muralidhara, Cargill Inc., Savage,
Minnesota, USA
Integrated Membrane System for Waste
Water Reuse with Innovative PVDF UF
Membrane and Low Fouling RO
Membrane
Kitade, Takagi, Kantani, Taniguch,
Uemura, TORAY Industries, Inc., Otsu,
Shiga, Japan
Impact of Seasonal Water Quality
Changes on Low Pressure Membrane
Filtration of an Activated Sludge-Lagoon
Effluent
Roddick, Nguyen, Fan, Harris, RMIT
University, Melbourne, Australia
Investigating and Evaluating Different
Concepts of Membrane-Based
Technologies for a Cleaner Production
in the Automotive Industry
Lyko, Wintgens, Buchmann, Melin, RWTH
Aachen University, Germany
Herse, Ford-Werke GmbH, Germany
Membranes in Clean Technologies
Koltuniewicz, University of Technology,
Wroclaw, Poland
Drioli, Professor in Istituto per la
Tecnologia Delle Membrane, Italy
Oxygen and Carbon Dioxide Control by
Membrane Contactors in Desalination
Criscuoli, Carnevale, Institute on
Membrane Technology, ITM-CNR, Italy
Mahmoudi, ,University of Chlef, Algeria
Gaeta, Lentini, Reggiani, GVS S.P.A., Italy
Drioli, University of Calabria, Italy
Polymeric Membranes I
(Moloka’i)
Chair: Klaus-Viktor Peinemann,
GKSS, Germany
Co-Chair: Chris Cornelius, Sandia
National Laboratories, USA
Layer-by-Layer Assembly in Membrane
Pores for Ion Separations and
Biocatalysis
Bhattacharyya, Hollman, Butterfield,
Smuleac, Datta University of Kentucky,
Lexington, Kentucky, USA
Unusual Temperature Dependence of
Positron Lifetime in a Polymer of
Intrinsic Microporosity
Rätzke, De Miranda, Kruse, Faupel,
Technische Fakultät der CAU, Kaiserstr,
Germany
Fritsch, Abetz, Institut für
Polymerforschung, Germany
Budd, Selbie, Univ. of Manchester,
Manchester, United Kingdom
McKeown, Ghanem, Cardiff University,
Cardiff, United Kingdom
Macrovoid Formation in Polymeric
Membranes and Critical Factors in
Fabricating Macrovoid-Free Hollow
Fiber Membranes
Chung, Peng, Wang, National University of
Singapore, Singapore
Preparation of Porous Poly (ether ether
ketone) Membranes
Ding, Bikson, PoroGen Corporation,
Woburn, Massachusetts, USA
Design of New Membranes Assisted By
Block Copolymer Assembly
Deratani, Querelle, Quémener, Université
Montpellier, France
Ellouze, Ecole Nationale d'Ingénieur de
Tunis, France
Phan, Gigmes, Bertin, University Aix-
Marseille, France
Effect of Network Structure
Modifications of Cross-linked
Poly(ethylene oxide) Membranes on Gas
Separation Properties
Kusuma, Freeman, The University of Texas
at Austin, Austin, Texas, USA
Danquah, Borns, Comer, Kalika, University
of Kentucky, Lexington, Kentucky, USA
Biomedical and
Biotechnology I
(Honolulu/Kahuku)
Chair: Robert van Reis, Genentech,
Inc., USA
Co-Chair:Andrew Zydney, The
Pennsylvania State University, USA
Fouling Characteristics of Virus
Filtration Membranes
Zydney, Bakhshayeshi, The Pennsylvania
State University, University Park,
Pennsylvania, USA
Kuriyel, Jackson, PALL Life Sciences, USA
Mehta, Paley, Genentech, USA
Developments in Membrane Affinity
Chromatography for Monoclonal
Antibody Recovery
Sarti, Dimartino, Boi, University of Bologna,
Bologna, Italy
Bioactive Membranes for Liver Tissue
Engineering
De Bartolo,Salerno, Piscioneri, Morelli,
Rende, Campana, Drioli, Institute on
Membrane Technology, National Research
Council of Italy, ITM-CNR, Italy
Separation and Purification of
Hematopoietic Stem Cells from Human
Blood through Surface-modified
Membranes
Higuchi, Nat. Central Univ. & Nat. Res.
Institute for Child Health & Development,
Tokyo, Japan
Chang, Christian University, Taoyuan,
Taiwan
Ruaan, Chen, National Central University,
Taoyuan, Taiwan
Membrane Chromatography: Protein
Purification Using Newly Developed,
High-Capacity Adsorptive Membranes
Bhut, Husson, Clemson University,
Clemson, South Carolina, USA
Wickramasinghe, Colorado State
University, Fort Collins, Colorado, USA
Using Micro-Dialysis to Monitor Tissue
Production
Wu, University of Durham, Durham, United
Kingdom
Field, University of Oxford, Oxford, United
Kingdom
Membrane Fouling –
General Topics
(O’ahu)
Chair: Robert H. Davis, University
of Colorado, USA
Co-Chair: Isabel Escobar, University
of Toledo, USA
Protein Fouling of Polymeric
Membranes: Modeling and Experimental
Studies Using Ultrasonic Frequency-
Domain Reflectometry
Hernandez, Kujundzic, Cobry, Greenberg,
University of Colorado at Boulder, Boulder,
Colorado, USA
Ho, Li, University of Cincinnati, Cincinnati,
Ohio, USA
Assessment of Ultrasound as Fouling
Control Technique in Crossflow
Microfiltration for the Treatment of
Produced Water
Silalahi, Leiknes, Norwegian University of
Science and Technology, Norwegian
Impact of Diluate Solution Composition
in Protein and Magnesium on Membrane
Fouling During Conventional ED
Pourcelly, Institut Europeen des
Membranes, France
Casademont, University Laval, Québec,
Canada
Bribiesca, Farias, Bazinet, Institut
Nutraceutiques et Aliments Fonctionnels,
Québec, Canada
MBR Activated Sludge Filterability
Alteration in Stress Circumstances
Geilvoet, Graaf, NIeuwenhuijzen, Delft
University of Technology, The Netherlands
Scale-up of Lab Investigations on
Fouling in MBR Potentials and
Limitations
Kraume, Schaller, Iversen, Drews,
Technische Universität, Germany
Wedi, Engineering Office ATM, Germany
Torre, Berlin Centre of Competence for
Water, Germany
Visual Characterization of Fouling
Behavior By Activated Sludge Model
Solutions
Le-Clech, Marselina, Stuetz, Chen,
University of New South Wales, Sydney,
Australia
Membrane Modeling I
– Fundamental
Approaches
(Waialua)
Chair: Albert Kim, University of
Hawaii at Manoa, USA
Co-Chair: David Ford, University of
Massachusetts, USA
Membrane Analysis and Simulation
System (MASS)
Faibish, Pointer, Roux, Tentner, Argonne
National Laboratory, Argonne, Illinois, USA
Development of Novel Molecular
Modeling Technique for Membrane
Fouling in Water Treatments
Takaba, Suzuki, Sahnoun, Koyama,
Tsuboi, Hatakeyama, Endou, Carpio, Kubo,
Miyamoto, Tohoku University, Japan
Kawakatsu, Nishida, Watanabe, Kurita
Water Industries Ltd., Tochigi, Japan
Electroosmotic Flow in a Lysozyme
Crystal: Molecular Dynamics Simulation
Jiang, Hu, National University of
Singapore, Singapore
Theoretical Analysis of the Theoretical
Analysis of Effects of Asymmetric
Membrane Structure on Fouling during
Microfiltration
Ho, Li, University of Cincinnati, Cincinnati,
Ohio, USA
Duclos-Orsello, Millipore Corp., Billerica,
Massacheusetts, USA
Modeling Virus Filtration: A Population
Balance Approach
Abbas, Pavanasam, Chen, University of
Sydney, Australia
Ansumali, Nanyang Technological
University, Singapore
Direct Simulation of Particle Migration in
Cross-Flow Microfiltration
Fujita, Oda, Akamatsu, Nakao, The
University of Tokyo, Tokyo, Japan

Monday, July 14 – Afternoon Sessions
12:45PM Lunch Break
2:15PM
3:00PM
3:30PM
4:00PM
4:30PM
5:00PM
Hybrid and Novel
Processes I
(Kaua’i)
Chair: Glenn Lipscomb, University
of Toledo, USA
Co-Chair: Hans Wijmans, Membrane
Technology & Research, Inc., USA
Scaleable Membrane Separations for
the Lignocellulosic-to-Ethanol
Biorefinery?
Pellegrino, Colyar, Gutierrez-Padilla,
University of Colorado at Boulder,
Boulder, Colorado, USA
Hettenhaus, cea Inc., Charlotte, North
Carolina, USA
Schell, National Renewable Energy
Laboratory, Golden, Colorado, USA
Reducing the Energy Demand of Bio-
Ethanol Through Salt-Extractive
Distillation and Electrodialysis
Pfromm, Hussain, Kansas State
University, Manhattan, Kansas, USA
Membrane Separation Techniques in
the Continuous Fermentation and
Separation of Butanol
Du, Beitle, Clausen, Carrier, Hestekin,
University of Arkansas, Fayetteville,
Arkansas, USA
Power Generation by Reverse
Electrodialysis
Dlugolecki, Nymeijer, Metz, Wessling,
University of Twente, The Netherlands
Reverse Electrodialysis: Energy
Recovery from Controlled Mixing
Salt and Fresh Water
Post, Hamelers, Buisman, Wageningen
University, Wetsus, The Netherlands
Electrocatalytic Membranes for
Glucose/O 2 Biofuel Cell
Géraldine, Sophie, Marc, Marc,
Christophe, European Membrane
Institute, France
Nanofiltration and
Reverse Osmosis I -
Membranes
(Maui)
Chair: Andrew Livingston, Imperial
College, United Kingdom
Co-Chair: Isabel Escobar, University
of Toledo, USA
Development of Reverse Osmosis
FT-30 Membranes with Polyethylene
Oxide Brush Modified Antifouling
Surface
Mickols, Niu, Thorpe, Abaye, Dow
Water Solutions, Edina, Minnesota,
USA
Desalination Membranes Based on
Directly Sulfonated Poly(arylene
ether sulfone) Copolymers
Park, University of Ulsan, Ulsan, Korea
Xie, Freeman, University of Texas at
Austin, Austin, Texas, USA
Paul, Lee, Macromolecules and
Interfaces Institute and Department of
Chemistry, Blacksburg, Virginia, USA
Riffle, McGrath, Virginia Polytechnic
Institute and State University,
Blacksburg, Virginia, USA
Structure-Property Relationships in
PEG-Based Hydrogel Membrane
Coatings
Sagle, Ju, Freeman, Sharma, The
University of Texas at Austin, Austin,
Texas, USA
Engineering Molecular Weight Cut-
Off of Organic Solvent Nanofiltration
(OSN) Membranes for Natural
Product Fractionation
Sereewatthanawut, Lim, Boam,
Membrane Extraction Technology Ltd,
London, United Kingdom
See Toh, Livinston, Imperial College,
London, United Kingdom
High-Temperature Nanofiltration
Using Porous Titania Membranes
Tsuru, Ogawa, Yoshioka, Hiroshima
University, Higashi-Hiroshima, Japan
Polypyrrole Modified Solvent
Resistant Nanofiltration Membranes
Li, Vandezande, Vankelecom, Centre
for Surface Chemistry and Catalysis,
Faculty of Bioscience Engineering,
Leuven, Belgium
Nanostructured
Membranes I
(Moloka’i)
Chair: Peter Budd, University of
Manchester, USA
Co-Chair: Detlev Fritsch, GKSS
Research Centre, Germany
Novel Polymers of Intrinsic
Microporosity (PIMs): Towards an
Understanding of Structure-Property
Relationships
McKeown, Ghanem, Msayib, Cardiff
University, Cardiff, United Kingdom
Budd, Univesity of Manchester,
Manchester, United Kingdom
Fritsch, GKSS, Germany
Physical Aging and Mixed-Gas
Transport Properties of Microporous
Polymers for Gas Separation
Applications
Thomas, Pinnau, Membrane
Technology and Research, Inc., Menlo
Park, California, USA
Guiver, Du, Song, Institute for Chemical
Process and Environmental
Technology, National Research
Council, Ottawa, Ontario, Canada
Polymers of Intrinsic Microporosity:
New Copolymers, Syntheses,
Properties and Applications.
Fritsch, Heinrich, Bengtson, Pohlmann,
GKSS Research Centre, Germany
Characterizing the Pore Size
Distribution in Nanostructured
Membranes
Hill, CSIRO, Australia
Polymers of Intrinsic Microporosity
in the Application of Organic Solvent
Nanofiltration
Heinrich, Fritsch, Merten, Bengtson,
Dargel, GKSS Research Centre,
Germany
An Efficient Method for Preparing
High Molecular Weight Polymers of
Intrinsic Microporosity (PIM)s with
Cyclic-Free Structure via Fast
Polycondensation
Du, Robertson, Song,Guiver, Institute
for Chemical Process and
Environmental Technology, National
Research Council, Ottawa, Ontario,
Canada
Thomas, Pinnau, Membrane
Technology and Research, Menlo Park,
California, USA
Fuel Cell Membranes I
(Honolulu/Kahuku)
Chair: Susanna Nunes, GKSS –
Forschungszentrum, Germany
Co-Chair: Peter N. Pintauro, Case
Western Reserve University, USA
Polyoxadiazole Nanocomposite Fuel
Cell Membranes Operating above
100°C
Nunes, Gomes, GKSS Research
Centre, Germany
Nanocomposite Membranes with
Low Methanol Permeability for the
Direct Methanol Fuel Cell
Ladewig, Martin, Costa, Lu, The
University of Queensland, Australia
Proton Conducting Graft Copolymer
Electrolyte Membranes for Fuel Cells
Kim, Koh, Park, Roh, Yonsei University,
Seoul, Korea
Nanocomposite Proton Exchange
Membranes for Hydrogen Fuel Cells:
Self-Humidification, Molecular
Nucleation and Dynamic Simulation
Zhang, Gao, Hong Kong University of
Science and Technology, Hong Kong,
China
Sulfonated Polyimide Membranes for
Polymer Electrolyte Fuel Cells
Okamoto, Matsuda, Hu, Chen, Endo,
Higa, Yamaguchi University, Ube,
Yamaguchi, Japan
Syntheses and Physical Properties
of Novel Polymer Electrolyte
Membranes Comprising
Poly(diphenylacetylene)s
Ito, Yamamoto, Akiyama, Takeda,
Yokota, EBARA Research Co. Ltd.,
Kanagawa, Japan
Nagase, School of Engineering, Tokai
University, Kanagawa, Japan
Desalination I
(O’ahu)
Chair: Raphael Semiat, Technion -
Israel Institute of Technology, Israel
Co-Chair: Eric Hoek, University of
California at Los Angeles, USA
Energy Cost Optimization in RO
Desalting and the Thermodynamic
Restriction
Zhu, Christofides, Cohen, University of
California, Los Angeles, Los Angeles,
California, USA
Characterizing RO Membrane
Performance when Desalinating High
pH Produced Water from the Oil
Extraction Process
Franks, Bartels, Hydranautics,
Oceanside, California, USA
Submerged Hollow Fiber Pre-
Treatment to RO in Seawater
Applications
Ye, Sim, Chen, Fane UNESCO Center
for Membrane Science and
Technology, Sydney, Australia
RO Membrane Desalting in a Feed
Flow Reversal Mode
Uchymiak, Alex, Christofides, Cohen,
University of California, Los Angels, Los
Angeles, California, USA
Daltrophe, Weissman, Gilron, Ben-
Gurion University, Beer Sheva, Israel
Rallo, Universitat Rovira i Virgili,
Tarragona, Catalunya, Spain
Evaluating the Performance of
Single-Pass RO and Multi-Pass
NF/RO Systems for Seawater
Desalination
Tanuwidjaja, Hoek, University of
California, Los Angeles, Los Angeles,
California, USA
Performance Testing of a Large
Seawater RO Desalination Plant
Khawaji, Royal Commission for Jubail &
Yanbu, Yanbu Al-Sinaiyah, Saudi
Arabia
Wie, Saudi Arabian Parsons Limited,
Yanbu Al-Sinaiyah, Saudi Arabia
Composite Polymeric
Membrane Formation
(Waialua)
Chair: Richard Baker, Membrane
Technology & Research Inc., USA
Co-Chair: Klaus-Vikton Peinemann,
GKSS, Germany
A New Method to Fabricate
Membranes using Glassy Self
Assembly Templating
Ho, Feng, Co, University of Cincinnati,
Cincinnati, Ohio, USA
Ultra-Thin Polymeric Interpenetration
Network with Enhanced Separation
Performance Approaching Ceramic
Membranes for Biofuel
Jiang, Chung, National University of
Singapore, Singapore
Jean, Chen, University of Missouri-
Kansas City, Kansas City, Missouri,
USA
PTFE-Polyamide Thin-Film
Composite Membranes from
Interfacial Polymerization for
Pervaporation Dehydration of
Alcohol-Water Mixtures
Jeng, National Chung Hsing University,
Taichung, Taiwan
Yu, Liu, Lai, Chung Yuan University,
Chung-Li, Taoyuan, Taiwan
Preparation of Poly(vinyl alcohol)
Composite Reverse Osmosis and
Nanofiltration Membranes
Ramos, Cristiano, Federal University of
Rio de Janeiro, Brazil
Experimental Verification of Effect of
Support on Membrane Performance
Takagi, Shukugawa Gakuin College,
Nishinomiya, Japan
Pihlajamäki, Nyström Lappeenranta
University of Technology,
Lappeenranta, Finland
Shintani, Nitto Denko Corporation,
Osaka, Japan
Study on Improvement of Composite
Reverse Osmosis Membranes
Gao, Zhou, Yu, Wu, The Development
Center of Water Treatment Technology,
Hanzhou, China
An, College of Materials Science and
Chemistry, Zhejiang University,
Hangzhou, China

8:15AM
8:50 –
9:15AM
NAMS Alan S.
Michaels Award
(Kaua’i)
Chair: Greg Fleming, Air Liquide,
USA
Co-Chair: Rich Ubersax, Air
Liquide, USA
Some Reflections and Projections
Based on Thirty Five Years in
Membranes
Koros, Georgia institute of Technology,
Atlanta, Georgia, USA
A Versatile Membrane System for Bulk
Storage and Shipping of Produce in a
Modified Atmosphere
Paul, Kirkland, University of Texas at
Austin, Austin, Texas, USA
Clarke, Landec Corporation, Menlo Park,
California, USA
Nanofiltration and Reverse
Osmosis II – Imaging and
Characterization
(Maui)
Chair: Ho Bum Park, University of Ulsan, Korea
Co-Chair: Andrew Livingston, Imperial College,
United Kingdom
8:15AM On the Correlation Between MWCO
Values for Nanofiltration Membranes
and Quantitative Porosity Analysis
Using Variable Energy Positron
Beams
De Baerdemaeker, Ghent University,
Gent, Belgium
Boussu, Bruggen, KU Leuven, Leuven,
Belgium
Weber, Lynn, Washington State
University, Pullman Washington, USA
Tuesday, July 15 – Morning Sessions
Nanostructured
Membranes II
(Moloka’i)
Chair: Bruce Hinds, University of
Kentucky, USA
Co-Chair: Anita Hill, CSIRO,
Australia
Nanofiltration of Electrolyte Solutions
by Sub-2nm Carbon Nanotube
Membranes
Fornasiero, Park, Holt, Stadermann,
Noy, Bakajin, Lawrence Livermore
National Laboratory, Livermmore,
California, USA
Kim, University of California at Davis,
Davis, California, USA
In, Grigoropoulos, University of California
at Berkeley, Berkeley, California, USA
9:00AM Coffee Break (Ballroom Foyer)
9:30AM
9:55AM
10:20AM
10:45AM
Enhancing Natural Gas Purification
with Advanced Polymer/Molecular
Sieve Composites
Miller, Vu, Chevron Energy Technology
Company, Richmond, California, USA
High Performance Ultrafiltration: What
Can We Learn from the Gas
Separations Experts?
Zydney, The Pennsylvania State
University, University Park,
Pennsylvania, USA
Membranes and Reactors and
Integration, Oh My!
Rezac, Kansas State University,
Manhattan, Kansas, USA
Membranes for Energy Efficiency and
Sustainability
Murphy, Air Products, St. Louis, Missouri,
USA
11:10AM On the Time Scales of Sorption
Induced Plasticization
Wessling, University of Twente, The
Netherlands
11:35AM Recent Developments in Membranes
for Gas Separation Applications
Pinnau, Membrane Technology and
Research, Inc., Menlo Park, California,
USA
12:00PM Various Poly(dimethylsiloxane)
Membranes for Removal of Volatile
Organic Compounds from Water
Uragami, Ohshima, Miyata, Kansai
University, Suita, Osaka, Japan
9:30AM
10:00AM
10:30AM
11:00AM
11:30AM
Positron Annihilation Spectroscopy
(PAS): A New Powerful Technique to
Study Membrane Structure
Cano-Odena, Vandezande, Hendrix,
Zaman, Vankelecom, Katholieke
Universiteit Leuven, Leuven, Belgium
Mostafa, Baerdemaeker, NUMAT
(Nuclear Methods in Materials Science),
Gent, Belgium
Characterization of Biofouling
Development of Spiral Wound
Membrane Systems: The First NMR
Study
Vrouwenvelder, Loosdrecht, Wetsus,
Delft University of Technology, The
Netherlands
Schulenburg, Johns, University of
Cambridge, Cambridge, United Kingdom
Kruithof, Wetsus, The Netherlands
Probing Polyamide RO Membrane
Surface Charge, Energy, and Potential
With Advanced Contact Angle
Titrations
Hurwitz, Hoek, University of California,
Los Angeles, Los Angeles, California,
USA
Removal of Emerging Organic
Contaminants by High-Pressure
Membranes: Mechanisms, Monitoring,
and Modeling
Drewes, Sonnenberg, Colorado School
of Mines, Golden, Colorado, USA
Bellona, Carollo Engineers, Broomfield,
Colorado, USA
Evidence of Change in the Top
Surface Layer Structure of
Nanofiltration Membranes due to
Operating Temperature Variation
Andre, Université Montpellier, France,
Nihel, Saidani, Ecole Nationale des
Ingénieurs de Tunis, France
John, Université Paul Sabatier, France
12:00PM Characterization of the Polyamide
Active Layer in NF/RO Membranes
Using Gold Nanoparticles
Pacheco, Reinhard, Leckie, Stanford
University, Stanford, California, USA
Aligned Carbon Nanotube
Membranes: Transport Enhancement
and Gatekeeper Activity
Hinds, Wu, Kiess, Majumder, University
of Kentucky, Lexington, Kentucky, USA
Hybrid Biomimetic Membranes: Past,
Present and Beyond
Barboiu, Institut Europeen des
Membranes, France
Nanostructured Polymers with
Uniform d1 nm Pores Based on
Cross-linked Lyotropic Liquid
Crystals for Molecular Size-Selective
Separations
Gin, Zhou, Lu, Hatakeyama, Noble,
University of Colorado at Boulder,
Boulder, Colorado, USA
Elliott, TDA Research, Inc., Wheat Ridge,
Colorado, USA
Track-Etched Polymer Membranes as
Tool to Investigate Grafted Stimuli-
Responsive and Other Functional
Polymers for Smart Nano- and Micro-
Systems
Ulbricht, Friebe, Tomicki, Unv. Duisburg-
Essen, Germany
Fixed-Charge Group-Like Behavior of
the Captured Ion by Crown Ether and
Its Effect on the Response of a
Molecular Recognition Ion Gating
Membrane
Ito, Yamaguchi, Chemical Resources
Laboratory, Tokyo Inst. of Tech.,
Yokohama, Japan
Multifunctional Ultrathin TiO 2
Nanowire Ultrafiltration Membrane for
Water Treatment
Du, Zhang, Pan, Sun, Nanyang
Technological University, Singapore
Leckie, Stanford University, Stanford,
California, USA
Pervaporation and
Vapor Permeation I
(Honolulu/Kahuku)
Chair: Leland Vane, US EPA,
USA
Co-Chair: Ivy Huang, Membrane
Technology and Research, Inc.,
USA
Bioethanol Production Using
Pervaporation and Vapor Permeation
Membranes
Huang, Baker, Membrane Technology &
Research, Menlo Park, California, USA
Vane, The U.S. EPA, Cincinnati
Laboratory, Cincinnati, Ohio, USA
Dewatering Ethanol with Chemically
and Thermally Resistant
Perfluoropolymer Membranes
Majumdar, Stookey, Nemser, Compact
Membrane Systems, Inc., Newport,
Delaware, USA
Modelling and Process Integration of
Membranes for Ethanol Dehydration
Friedl, Schausberger, Bosch, Vienna
University of Technology, Vienna, Austria
Boontawan, Suranare University of
Technology, Institute of Agricultural
Technology, Sc, Nakhon Ratchasima,
Thailand
Performance of a New Hybrid
Membrane in High Temperature
Pervaporation
Van Veen, Kreiter, Engelen, Rietkerk,
Vente, Energy Research Centre of the
Netherlands, The Netherlands
Castricum, Elshof, Univ. of Twente, The
Netherlands
Investigation of the Fundamental
Differences Between Polyamide-Imide
(PAI) and Polyetherimide (PEI)
Membranes for Isopropanol
Dehydration via Pervaporation
Wang, Jiang, Chung, Goh, Nat. Univ. of
Singapore, Singapore
Matsuura, University of Ottawa, Ottawa,
Ontario, Canada
Preparation of Asymmetric
Polyetherimide Membranes for
Molecular Liquid Separations
Favre, El-Gendi, Roizard, LSGC-CNRS,
Nancy Université, France
Preparation of a Novel Styrene-
Butadiene-Styrene Block Copolymer
(SBS) Asymmetric Membrane for VOC
Removal by Pervaporation
Figoil, Drioli, Institute on Membrane
Technology (ITM-CNR), Italy
Sikdar, Burckle, US EPA, Cincinnati,
Ohio, USA
Osmotically Driven
Membrane Processes
(O’ahu/Waialua)
Chair: Jeff McCutcheon, Stony
Brook Water Purification Co., USA
Co-Chair: Klaus-Viktor
Peinemann, GKSS, Germany
Characterization of Solute Transport
in Osmotically Driven Membrane
Processes
Hancock, Cath, Colorado School of
Mines, Golden, Colorado, USA
Forward-Osmosis Using Ethanol for
Concentrate Minimization
Pellegrino, Mendoza, University of
Colorado at Boulder, Golden, Colorado,
USA
McCormick, Denver Water Department,
Denver, Colorado, USA
A Novel Hybrid Forward Osmosis
Process for Drinking Water
Augmentation Using Impaired Water
and Saline Water Sources
Lundin, Cath, Drewes, Colorado School
of Mines, Golden, Colorado, USA
Osmotic Membrane Bioreactor and
Pressure Retarded Osmotic
Membrane Bioreactor for Wastewater
Treatment and Water Desalination
Achilli, Marchand, Childress, University
of Nevada, Reno, Reno, Nevada, USA
Cath, Colorado School of Mines, Golden,
Colorado, USA
Osmotic Power - A New, Renewable
Energy Source
Skilhagen, Dugstad, Statkraft AS,
Norway
Holt, SINTEF, Scandinavia
Influence of Membrane Support Layer
Hydrophobicity on Water Flux in
Osmotically Driven Membrane
Processes
McCutcheon, Stony Brook Water
Purification Co., East Setauket, New
York, USA
Elimelech, Yale University, New Haven,
Connecticut, USA
Developing Permeation Enhanced
Nanofiltration Hollow Fiber
Membranes Used in Forward Osmosis
Wang, Yang, Chung, National University
of Singapore, Singapore
Gin, Centre for Advanced Water
Technology, Singapore
Asymmetric Polymeric
Membrane Formation
(Wai’anae)
Chair: Max Ekiner, Air Liquide,
USA
Co-Chair: Christiano Borges,
Universidade Federal de Rio de
Janeiro, Brazil
Manipulation of Block Copolymer
Nanostructure in Membranes
Prepared by Solvent Evaporation and
Non-Solvent Induced Phase
Separation
Yave, Boschetti-de-Fierro, Garamus,
Peinemann, Abetz, Simon, Institute of
Polymer Research, GKSS Research
Centre, Germany
Synthesis and Characterization of
Nanoporous Polycaprolactone
Membranes for Controlled Drug
Release
Yen, Lee, Ho, Ohio State University,
Columbus, Ohio, USA
He, Nanoscale Science and Engineering
Center for Affordable Nanoengineering,
Columbus, Ohio, USA
Catalytic PVDF Microcapsules for
Application in Fine Chemistry
Figoli, ITM-CNR c/o UNICAL, Italy
Buonomenna, ITM-CNR c/o University of
Calabria, Italy
Spezzano, Drioli, ITM-CNR, Italy
The Impact of Solvent on the
Microstructure of Integrally Skinned
Polyimide Nanofiltration Membranes
before and after Casting
Patterson, Costello, Havill, Turner, The
University of Auckland, Auckland, New
Zealand
See-Toh, Livingston, Imperial College,
London, United Kingdom
Nanofiltration Membranes for Polar
Aprotic Solvents
Lim, Sereewatthanawut, Boam,
Membrane Extraction Technology Ltd.,
London, United Kingdom
See-Toh, Livinston, Imperial College
London, London, UK
Phase Separation Microfabrication
Bikel, Lammertink, Wessling, University
of Twente, The Netherlands
In-Line and In-Situ Determination of
Non-Solvent, Solvent and Polymer
Composition within a Film-Forming
System prior to Phase Separation
during VIPS
Bouyer, Werapun, Pochat-Bohatier,
Dupuy, Université Montpellier,
Montpellier, France
Deratani, CNRS, Montpellier, France

Tuesday, July 15 – Afternoon Sessions
12:30PM Lunch Break
2:15PM
3:00PM
3:30PM
4:00PM
4:30PM
5:00PM
Gas Separations II
(Kaua’i)
Chair: Yuri Yampolski, Topchiev
Institute of Petrochemical Synthesis,
Russia
Co-Chair: Kazu Nagai, Meiji
University, Japan
Highly Gas-Permeable Substituted
Polyacetylenes: Recent Advances
Masuda, Kyoto University, Kyoto,
Japan
Modelling Molecular-Scale Gas
Separation
Thornton, Hill, CSIRO, Clayton,
Australia
Hilder, Hill, University of Wollongong,
Wollongong, Australia
Physical Aging in Thin Glassy
Polymer Films: A Variable Energy
Positron Annihilation Lifetime
Spectroscopy Study
Rowe, Freeman, Paul, University of
Texas at Austin, Austin, Texas, USA
Hill, Pas, CSIRO, Clayton, Australia
Suzuki, AIST, Ibaraki, Japan
Gas Permeation Parameters and
Other Physicochemical Properties of
a Polymer With Intrinsic
Microporosity (PIM-1)
Budd, University of Manchester, United
Kingdom
McKeown, Ghanem, Msayib, Cardiff
University, United Kingdom
Fritsch, GKSS, Germany
Starannikova, Belov, Sanofirova,
Yampolskii, Institute of Petrochemical
Synthesis, Russia
Shantarovich, Institute of Chemical
Physics, Russia
Addition-Type Polynorbornene with
Si(CH3) 3 Side Groups: Detailed Study
of Gas Permeation and
Thermodynamic Properties
Yampolskii, Starannikova, Pilipenko,
Belov, Gringolts, Finkelshtein, Institute
of Petrochemical Synthesis, Russia
Analysis of the Size Distribution of
Local Free Volume in Hyflon® AD
Perfluoropolymer Gas Separation
Membranes by Photochromic Probes
Jansen, Tocci, De Lorenzo, Drioli, ITM-
CNR, Renda (CS), Italy
Macchione, Universitia della Calábria,
Rende (CS), Italy
Heuchel, GKSS Research Center,
Teltow, Germany
Drinking and
Wastewater
Applications II
(Maui)
Chair: Chuyang Tang, Nanyang
Technological University, China
Co-Chair: Dibakar Bhattacharyya,
University of Kentucky, USA
Analysis of RO Membrane
Performance for Municipal
Wastewater Treatment
Bartels, Franks, Gourley, Hydranautics,
Oceanside, California, USA
Adsorption Behavior of
Perfluorinated Compounds on Thin-
Film Composite Membranes
Kwon, Leckie, Stanford University, Palo
Alto, California, USA
Shih, University of Hong Kong, Hong
Kong, China
Tang, Nanyang Technological
University, Singapore
RO Reject Recovery - A Challenge
Towards Sustainable Water
Reclamation
Viswanath, Tao, Kekre, CAWT,
Singapore Utilities International Pte Ltd,
Singapore
Ng, Lee, National University of
Singapore, Singapore
Seah, Public Utilities Board Board of
Singapore, Singapore
Effects of Organic Fouling on the
Removal of Trace Chemicals in
Nanofiltration Membrane Processes
Le-Clech Foo, Mcdonald, Khan,
University of New South Wales,
Sydney, Australia
Drewes, Colorado School of Mines,
Colorado, USA
Nghiem, University of Wollongong,
Wollongong, Australia
Emergency Water Purification
Device Using Gravity Driven
Membrane Filtration
Jiang, Cui, University of Oxford, Oxford,
United Kingdom
Membrane Defects and Bacterial
Removal Efficiency: Effect of
Alterations of the Skin and of the
Macroporous Support
LeBleu Causserand, Roques, Aimar,
Université de Toulouse, Toulouse,
France
Inorganic Membranes I
(Moloka’i)
Chair: Richard Noble, University of
Colorado, USA
Co-Chair: Hidetoshi Kita,
Yamaguchi University, Japan
Inorganic Membranes also Swell
Falconer, Yu, Lee, Funke, Noble,
University of Colorado, Boulder,
Colorado, USA
Synthesis and Characterization of
SAPO-34 Zeolite Crystals and
Membranes Employing Crystal
Growth Inhibitors
Carreon Venna, University of Louisville,
Louisville, Kentucky, USA
Effects of Electroless Plating
Conditions on the Synthesis of Pd-
Ag Hydrogen Selective Membranes
Bhandari, Ma, Worcester Polytechnic
Institute, Worchester, Massachusetts,
USA
Upgrading of a Syngas Mixture for
Pure Hydrogen Production in a Pd-
Ag Membrane Reactor
Barbieri, Brunetti, Institute for
Membrane Technology, Rende (CS),
Italy
Drioli, University of Calabria, Rende
(CS), Italy
Preparation and Characterization of
Hollow Fibre Carbon Membranes
based on a Cellulosic Precursor
He, Lie, Sheridan, Hagg, Norwegian
University of Science and Technology,
Norway
High-Density, Vertically-Aligned
Carbon Nanotube Membranes with
High Flux
Yu, Funke, Falconer, Noble, University
of Colorado, Boulder, Colorado, USA
Membrane Fouling –
UF & Water Treatment
(Honolulu/Kahuku)
Chair: Vicki Chen, UNESCO,
University of New South Wales,
Australia
Co-Chair: Robert H. Davis,
University of Colorado, USA
Fouling Mechanisms and Fouling
Control By Membrane Surface
Modification in Ultrafiltration of
Aqueous Solutions Containing
Polymeric Natural Organic Matter
Ulbricht, Peeva, Sustano, Universität
Duisburg-Essen, Germany
A Mechanistic Study on the Coupled
Organic and Colloidal Fouling of
Nanofiltration Membranes
Harris, Li, Rice University, Houston,
Texas, USA
Kim, University of Hawaii at Monoa,
Honolulu, Hawaii, USA
Effect of Crossflow on the Fouling
Rate of Spiral Wound Elements
Eriksson, GE W&PT, Vista, California,
USA
Exploiting Local Fouling Phenomena
in Dead-End Hollow Fiber Filtration:
The Partial Backwash Concept
van de Ven, Zwinnenburg, Kemperman,
Wessling, University of Twente, The
Netherlands
Fouling Resistant Coatings for
Oil/Water Separation
Wu, McCloskey, Kusuma, Ju, Freeman,
The University of Texas at Austin,
Austin, Texas, USA
Park, University of Ulsan, Korea
On the Representativeness of Model
Polymers in Fouling Research
Drews, TU Berlin, Berlin, Germany
Shammay, Chen, Le Clech, UNESCO
Centre UNSW, Sydney, Australia
Membrane Modeling II
– Gas Separation
(O’ahu/Wailua)
Chair: Albert Kim, University of
Hawaii at Manoa, USA
Co-Chair: Giulio Sarti, Universita
Degli Studi Di Bologna, Italy
Modeling Approaches for the Design
of High Performance Polymer Glassy
Membranes for Small Gas Molecule
Separations
Pullumbi, Air Liquide, Juoy-en-Josas,
France
Tocci, ITM-CNR, Rende (CS), Italy
Heuchel, Pelzer, GKSS, Teltow,
Germany
Molecular Modeling of Free Volume
in Poly (pyrrolone-imide)
Copolymers
Wang, University of California,
Berkeley, Berkeley, California, USA
Sanchez, Freeman, University of Texas
at Austin, Austin, Texas, USA
Development of a Microscopic Free
Volume Theory for Molecular Self-
Diffusivity Prediction in Polymeric
Systems
Ohashi, University of Tokyo, Tokyo,
Japan
Ito, Yamaguchi, Tokyo Institute of
Technology, Tokyo, Japan
A Molecular Pore Network Model for
Nanoporous Materials
Rajabbeigi, Elyassi, Tsotsis, Sahimi,
University of Southern California,
California, USA
Modeling and Performance
Assessment of Pd- and Pd/Alloy-
Based Catalytic Membrane Reactors
for Hydrogen Production
Ayturk, Kazantzis, Ma, Worcester
Polytechnic Institute, Worchester,
Massachusetts, USA
Free-Volume Holes in Amorphous
Polymers for Solvent Diffusion:
Reconsideration of the Free-Volume
Theory By Equation-of-State, Group
Contribution Method, PALS
Measurement and Molecular
Simulation
Lv, Wang, Yang, Tsinghua University,
China
Membrane and Surface
Modification I
(Wai’anae)
Chair: Young Moo Lee, Hanyang
University, China
Co-Chair: Mathias Ulbricht,
University of Duisburg-Essen,
Germany
New Chemically Modified
Membranes in Bioseparations
Melzner, Faber, Satorius Biotech,
Goettingen, Germany
Surface-Initiated Atom Transfer
Radical Polymerization: A New Tool
to Produce High-Capacity
Adsorptive Membranes
Bhut, Husson,Clemson University,
Clemson, South Carolina, USA
Wickramasinghe, Colorado State
University, Fort Collins, Colorado, USA
Gas and Liquid Permeation Studies
on Modified Interfacial Composite
Reverse Osmosis and Nanofiltration
Membranes
Louie, Reinhard, Stanford University,
Palo Alto, California, USA
Pinnau, Membrane Technology and
Research, Menlo Park, California, USA
Study of a Hydrophilic-Enhanced
Ultrafiltration Membrane
Gullinkala, Escobar, University of
Toledo, Toledo, Ohio, USA
Crosslinked Poly(ethylene oxide)
Fouling Resistant Coating Materials:
Synthesis, Characterization, and
Application
Ju, McCloskey, Sagle, Freeman,
University of Texas at Austin, Austin,
Texas, USA
Dopamine: Biofouling-Inspired Anti-
Fouling Coatings for Water
Purification Membranes
McCloskey, Freeman, The University of
Texas at Austin, Austin, Texas, USA
Park, University of Ulsan, Korea

Wednesday, July 16 – Morning Sessions
8:00AM Plenary II (Hawai’i Ballroom):
Professor Young Moo Lee (Hanyang University, Seoul, Korea)
Thermally Rearranged Polymer Membranes with Cavities Tuned for Fast Transport of Small Molecules
9:00AM Coffee Break (Ballroom Foyer)
Gas Separation III
(Kaua’i)
Chair: Keith Murphy, Air Products
and Chemicals, USA
Co-Chair: Ed Sanders, Air Liquide,
USA
9:30AM Membrane Engineering Progresses
and Potentialities in Gas Separations
Drioli, Research Institute on Membrane
Technology, ITM-CNR, Italy
10:15AM Evolution of Natural Gas Treatment
with Membrane Systems
White, Wildemuth, W.R. Grace & Co.,
Littleton, Colorado, USA
10:45AM CO 2 Permeation With Pebax-Based
Membranes for Global Warming
Reduction
Nguyen, Sublet, Rouen University,
France
Langevin, Chappey, Valleton, CNRS,
France
Schaetzel, CAEN University, France
11:15AM A Membrane Process to Capture CO 2
from Power Plant Flue Gas
Merkel, Lin, Thompson, Daniels,
Serbanescu, Baker, Membrane
Technology and Research, Menlo Park,
California, USA
11:45AM
Membranes and Post Combustion
Carbon Dioxide Capture: Challenges
& Prospects
Favre, LSGC CNRS, Nancy, France
12:15PM The Effect of Sweep Uniformity on
Gas Dehydration Modules
Hao, Lipscomb, The University of
Toledo, Toledo, Ohio, USA
Drinking and
Wastewater
Applications III
(Maui)
Chair: Maria Norberta de Pinho,
Instituto Superior Tecnico, Portugal
Co-Chair: Daniel Yeh, University of
South Florida, USA
Membranes and Water: the Role of
Hybrid Processes
Fane, Director, Singapore Membrane
Technology Centre, Singapore
Coagulation-Ceramic Microfiltration
Hybrid System Effectively Removes
Virus that is Difficult to Remove in
Conventional Coagulation-
Sedimentation-Sand Filtration
Process
Matsushita, Shirasaki, Matsui, Kobuke,
Urasaki, Ohno, Hokkaido University,
Sapporo, Japan
Membrane Enhanced Ultraviolet
Oxidation of Polyethylene Glycol
Wastewaters
Patterson, Vranjes, University of
Auckland, Auckland, New Zealand
Improvement of Swimming Pool
Water Quality by Ultrafiltration -
Adsorption Hybrid Process
Barbot, Moulin, Aix-Marseille University,
France
Processing of Low- and
Intermediate- Level Radioactive
Wastes from Medical and Industrial
Applications by Membrane Methods
Zakrzewska-Trznadel, Institute of
Nuclear Chemistry and Technology,
Warszawa, Poland
Removal of Natural Organic Matter in
Coagulation-Microfiltration-GAC
Adsorption Systems for Drinking
Water Production
Ahn, KAIST, Daejeon, Korea
Lee, University of Suwon, Gyeonggi-do,
Korea
Bae, Daejeon University, Daeion, Korea
Min, Samsung Construction, Kyunggi-
Do, Korea
Shin, KAIST, Daejeon, Korea
Polymeric Membranes
II
(Moloka’i)
Chair: Mary Rezac, Kansas State
University, USA
Co-Chair: Xiao-Lin Wang, Tsinghua
University, China
Optical Resolution with Chiral
Polymaide Membranes
Yoshikawa, Ikeuchi, Nakagawa, Kyoto
Institute of Technology, Kyoto, Japan
Dehydration of Alcohols By
Pervaporation Through Polyimide
Matrimid® Asymmetric Hollow
Fibers with Various Modifications
Jiang, Chung, Rajagopalan, National
University of Singapore, Singapore
New Cross-Linked Membranes For
Solvent Resistant Nanofiltration
Vanherck, Aldea, Vandezande,
Vankelecom, Centre for Surface
Chemistry and Catalysis, Katholieke
Universiteit Leuven, Heverlee, Belgium
Properties and Potential of
Polymeric Nanofiber Membranes for
Liquid Filtration Applications
Singh, Kaur, Ramakrishna, National
University of Singapore, Singapore
Wun Jern, Nanyang Technological
University, Singapore
Matsuura, University of Ottawa, Ottawa,
Canada
Perfluoropolymer Membranes for
Gasoline Vapor Emissions
Reductions
Bowser, Majumdar, Compact
Membrane System, Inc., Wilmington,
Delaware, USA
Universal Membranes for Solvent
Resistant Nanofiltration (SRNF) and
Pervaporation (PV) Based on
Segmented Polymer Network (SPN)
Li, Basko, Vankelecom, Centre for
Surface Chemistry and Catalysis,
Belgium
Du Prez, Ghent University, Belgium
Biomedical and
Biotechnology II
(Honolulu/Kahuku)
Chair: Akon Higuchi, National
Central University, Taiwan
Co-Chair: Ranil Wickramasinghe,
Colorado State University, USA
Macroporous Membrane Adsorbers:
Correlations Between Materials
Structure, Separation Conditions
and Performance in Bioseparations
Ulbricht, Wang, Universität Duisburg-
Essen, Germany
Dismer, von Lieres, Hubbuch, Institut
für Biotechnologie, Forschungszentrum,
Jülich, Germany
Integrated Membrane-Based Sample
Prep Approach for Viral and Microbe
Capture, Lysis, and Nucleic Acid
Purification From Complex Samples
Baggio, Souza, Murrell, Mullin, Avsola,
Lindsay, Gagne, Martin, Millipore
Corporation, Bedford, Massachusetts,
USA
Morphological and Funcational
Features of Neurons Isolated from
Hippocampus on Different
Membrane Surfaces
De Bartolo, Rende, Morelli, Salerno,
Piscioneri, Gordano, Drioli, Institute on
Membrane Technology National
Research Council of Italy, ITM-C,
Rende, Italy
Giusi, Canonaco, Comparative
Neuroanatomy Lab, Italy
Membrane Emulsification
Technology to Enhance Phase
Transfer Biocatalyst Properties and
Multiphase Membrane Reactor
Performance
Giorno, Mazzei, Bazzarelli, Drioli,
Institute on Membrane Technology,
ITM-CNR, Rende, Italy
Piacentini, University of Calabria,
Rende, Italy
Anti-Biofouling Membrane Surface
with Grafted Zwitterionic
Polysulfobetaine for Improved Blood
Compatibility
Chang, R&D Center for Membrane
Technology, Taiwan
Supported Liquid Membranes with
Strip Dispersion for the Recovery of
Cephalexin
Vilt, Ho, Ohio State University,
Columbus, Ohio, USA
Membrane Modeling III
– Process Simulations
(O’ahu/Waialua)
Chair: Albert Kim, University of
Hawaii at Manoa, USA
Co-Chair: Matthias Wessling,
University of Twente, The
Netherlands
Biopolymer Transport in
Ultrafiltration: Role of Molecular
Flexibility
Zydney, Molek, Latulippe, The
Pennsylvania State University,
University Park, Pennsylvania, USA
Effects of Long-Term Membrane
Fouling on the Dynamic Operability
of an Industrial Whey Ultrafiltration
Process
Yee, Wiley, UNESCO Centre for
Membrane Science and Technology,
Sydney, Australia
Bao, School of Chem. Sciences and
Eng., Sydney, Australia
CFD Modeling for the Concentration
of Soy Protein in an Ultrafiltration
Hollow Fiber Membrane System
Using Resistance-in-Series Model
Rajabzadeh, Moresoli, University of
Waterloo, Waterloo, Canada
Marcos, Universite de Sherbrooke,
Quebec, Canada
Hydrodynamic CFD Simulation of
Mixing in Full-Scale Membrane
Bioreactors with Field Experimental
Validation
Wang, Brannock, Leslie, The University
of New South Wales, Sydney, Australia
Hybrid Modeling: An Alternative Way
to Predict and Control the Behavior
of Cross-Flow Membrane Filtration
Processes
Curcio, Calabro, Iorio, University of
Calabria, Rende, Italy
Artificial Neural Networks Analysis
of RO Process Performance: RO
Plant Performance and Organic
Compound Passage
Giralt, Rallo, Libotean, Giralt,
Universitat Rovira i Virgili, Catalunya,
Spain
Cohen, University of California, Los
Angeles, Los Angeles, California, USA
Ultra- and
Microfiltration I -
Transport
(Wai’anae)
Chair: Tony Fane, University of New
South Wales, Australia
Co-Chair: Willem Kools, Millipore,
Inc., USA
Dynamic Microfiltration:
Investigation of Critical Flux
Measurement Methods and Improved
Macromolecular Transmission
Beier, Jonsson, CAPEC Technical
University, Lyngby, Denmark
An Integral Analysis of Crossflow
Filtration
Field, University of Oxford, Oxford,
United Kingdom
Wu, University of Durham, Durham,
United Kingdom
Flux Recovery During Infrasonic
Frequency Backpulsing of Micro-
and Ultrafiltration Membranes
Fouled with Dextrin and Yeast
McLachlan, Shugman, Sanderson,
UNESCO Assoc Centre for
Macromolecules, Stellenbosch, South
Africa
Electrostatic Contributions in Binary
Protein Ultrafiltration
Wang, Rodgers, University of California
Riverside, Riverside, California
Membrane Separation of High Added
Value Milk Proteins
Mier, Ibanez, Ortiz, University of
Cantabria, Spain
Tuning of the Cut-Off Curves By
Dynamic Ultrafiltration
Jonsson, Technical University of
Denmark, Lyngby, Denmark

8:15AM
8:35AM
EMS Barrer Prize
(Maui)
Chair: Andrew Livingston,
Imperial College, United Kingdom
Co-Chair: Tor Ove Leiknes,
Norwegian University of Science
and Technology, Norway
My Membrane World
Strathmann, Professor, Germany
Climbing Membranes and Membranes
Operations
Drioli ,Institute on Membrane Technology
of the Italian National Research Council,
Rende, Italy
Gas Separation IV
(Kaua’i)
Chair: Juin-Yih Lai, Chung Yuan Christian
University, Taiwan
Co-Chair: Tai-Shung (Neal) Chung, National
University of Singapore, Singapore
8:15AM
Thursday, July 17 – Morning Sessions
Polymer-Based Multicomponent
Membranes for Gas Separation
Peinemann, GKSS-Forschungszentrum,
Geesthacht, Germany
Ultra- and
Microfiltration II -
Processes
(Moloka’i)
Chair: Andrew Zydney, The
Pennsylvania State University,
University Park, Pennsylvania,
USA
Co-Chair: Tony Fane, University
of New South Wales, Sydney,
Australia
Membranes Applications in the Pulp
and Paper Industry: New
Developments and Case Studies
Lipnizki, Alfa Laval Product Centre
Membranes, Soborg, Denmark
Perrson, Jonsson, Lund University, Lund,
Sweden
9:00AM Coffee Break (Ballroom Foyer)
9:30AM
9:55AM
Membrane Separation of Nitrogen
from High-Nitrogen Natural Gas: A
Case Study from Membrane Synthesis
to Commercial Deployment
Baker, Membrane Technology and
Research Inc., USA
Molecular Simulations of Membrane
Transport Processes
Vegt, Max Planck Institute for Polymer
Research, Mainz, Germany
10:20AM Beyond Academic Research
Koops, GE Water, Burlington, Ontario,
Canada
10:45
New Challenges in Membrane
Preparation by Phase Inversion
Technique
Figoli, ITM-CNR, Rende, Italy
11:10AM Considerations for Normal Flow
Filtration: Fouling Models, Modules
and Systems
Kools, Millipore Coportation, Billerica,
Massachusetts, USA
11:35AM Dialysis Membranes - Continuous
Improvements
Krause, Storr, Gohl Gambro Dialysatoren
GmbH
12:00PM On the Origin of the Overlimiting
Current in Electrodialysis
Wessling, University of Twente,
Netherlands
9:30AM
Gas Separation Properties of
C/SiO 2/Alumina Composite
Membranes for CO 2 Separation
Han, Kim, Lee, Hanyang University,
Seoul, Korea
Park, University of Ulsan, Ulsan, Korea
10:00AM Gas Transport Properties of
Hyperbranched Polyimide Silica
Hybrid Membranes
Yamada, Kyoto Institute of Technology,
Kyoto, Japan
Itahashi, Suzuki, Nagoya Institute of
Technology, Nagoya, Japan
10:30AM Carbon Membranes Tackling the
Aging Issue
Sheridan, Lie, He, Hagg, Norwegian
University of Science and Technology,
Trondheim, Norway
11:00AM Glassy Perfluoropolymer - Zeolite
Hybrid Membranes for Gas and Vapor
Separations
Golemme, Univ. Della Calabria; ITM-
CNR; and INSTM, Rende, Italy
Muoio, De Luca, Bruno, Manes, Univ.
della Calabrai, Rende, Italy
Choi, Tsapatsis, Universtiy of Minnesota,
Minneapolis, Minnesota
11:30AM Development and Characterization of
PPO-based Emulsion Polymerized
Mixed Matrix Membranes
Kruczek, Wang, Tremblay, University of
Ottawa, Ottawa, Ontario, Canada
Sadeghi, Natural Resources Canada,
Varennes, Quebec, Canada
12:00PM Novel Semi-IPN Carbon Membranes
Fabricated by a Low-Temperature
Pyrolysis for C3H6/C3H8 Separation
Chng, Xiao, Chung, National University
of Singapore, Singapore
Toriida, Tamai, Mitsui Chemicals, Inc. ,
Japan
PAA and Thiol Functionalized MF/UF
Membranes for Surfactant Separation
and High Value Metal Capture:
Experimental Results and Modeling
Ladhe, Frailie, Bhattacharyya, University
of Kentucky, Lexington, Kentucky, USA
Assuring Biodiesel Quality via
Selective Membrane Filtration
Gutierrez-Padilla, Downs, Pellegri o,
University of Colorado, Boulder,
Colorado, USA
Bzdek, Sybios Technology, LLC, Fort
Collins, Colorado, USA
High Oxidative Resistant PVDF UF
Membrane for Metal-CMP Wastewater
Treatment
Shiki, Furumoto, Asahi Kasei Chemicals,
Suizuoka, Japan
Hygienic Barrier Efficiency of a
Coupled Coagulation / Flocculation
and Ceramic Microfiltration System
for Potable Water Production
Meyn, Leiknes, Norwegian University of
Science and Technology, Trondheim,
Norway
Konig, Technical University Berlin, Berlin,
Germany
Pioneering Explorations of Rooting
Causes for Morphology and
Performance Differences in Hollow
Fiber Kidney Dialysis Membranes
Spun From Linear and Hyperbranched
Polyethersulfone
Yang, Chung, National University of
Singapore, Singapore
Weber, Warzelhan, BASF
Aktiengesellschraft
Pressurized Porous Nanocrystalline
Silicon Membranes Exhibit High
Permeability to Water and Gas
Gaborski, Fang, Striemer, Kavalenka,
Snyder, Hoffman, DesOrmeaux,
McGrath, University of Rochester,
Rochester, New York, USA
Fauchet, SIMPore, West Henrietta, New
York, USA
Drinking and
Wastewater
Applications IV
(Honolulu/Kahuku)
Chair: Chuyang Tang, Nanyang
Technological University,
Singapore
Co-Chair: Maria Norberta de
Pinho, Instituto Superior Técnico,
Portugal
Optimization of Bubbly Flow in Flat
Sheet Membrane Modules
Prieske, Drews, Kraume, Technische
Universität , Berlin, Germany
Removal of Organic Micropollutants
with NF/RO Membranes: Derivation
and Validation of a Rejection Model
Verliefde, van Dijk, Delft University of
Technology, Delft, The Netherlands
Cornelissen, Heijman, Kiwa Water
Research, Nieuwegein, The Netherlands
Amy, UNESCO-IHE, Delft, The
Netherlands
Van der Bruggen, University of Leuven,
Leuven, Belgium
Anaerobic Membrane Bioreactor
(AnMBR) for Landfill Leachate
Treatment and Removal of Hormones
Yeh, Do, Prieto, University of South
Florida, Tampa, Florida, USA
Comparison of Multi-Parameter
Optimization Strategies for the
Development of Nanofiltration
Membranes for Salt and
Micropollutants Removal
Cano-Odena, Vandezande, Cools,
Vanderschoot, De Grave, Ramon, De
Raedt, Vankelecom, Katholieke
Universiteit Leuven, Leuven, Belgium
Study of an External MBR for
Degradation of Endocrine Disrupter
17(alpha)-ethinylestradiol
Clouzot, Marrot, Doumenq, Roche,
University of Aix-Marseille, France
Pressurized and De-pressurized
Membrane Photoreactors for Removal
of Pharmaceuticals from Waters
Molinari, Caruso, Argurio, Poerio,
University of Calabria, Rende, Italy
Mechanisms Governing the Effects of
Membrane Fouling on the
Nanofiltration of Micropollutants
Nghiem, Espendiller, University of
Wollongong, Wollongong, Australia
Braun, University of Applied Science
Cologne, Cologne, Germany
Inorganic Membranes
II
(O’ahu/Waialua)
Chair: Yi Hua (Ed) Ma, Worcester
Polytechnic Institute, Worchester,
Massachusetts, USA
Co-Chair: Weishen Yang,
Chineese Academy of Science,
China
High Temperature Gas Permeation
Characteristics of MFI and DDR Type
Zeolite Membranes
Lin, Kanezashi, O’Brien, Zhu, Arizona
State University, Tempe, Arizona, USA
Adding Ion-Selective Functionality to
Desalination Membranes with Unique
Charge and Structural Properties of
MFI Silicalite and ZSM-5 Zeolites
Duke, Victoria University, Melbourne,
Australia
Lin, Arizona State University, Tempe,
Arizona, USA
Diniz da Costa, The University of
Queensland, St. Lucia, Australia
Carbonate-Ceramic Dual-Phase
Membrane for High Temperature
Carbon Dioxide Separation
Anderson, Lin, Arizona State University,
Tempe, Arizona, USA
High Quality Tubular Silica
Membranes for Gas Separation
Luiten, Huiskes, Kruidhof, Nijmeijer,
University of Twente, The Netherlands
Recent Developments on the
Preparation and Modeling of
Nanoporous Silicon Carbide
Membranes for Gas Separation
Applications
Mourhatch, Elyassi, Chen, Sahimi,
Tsotsis, University of Southern
California, Los Angeles, California, USA
Preparation and Gas Separation
Performance of Carbon Hollow Fiber
Membrane Module
Yoshimune, Haraya, AIST, Tsukuba,
Japan
Viability of ITM Technology for
Oxygen Production and Oxidation
Processes: Material, System and
Process Aspects
den Exter, Haije, Vente, Energy research
Centre of the Netherlands, Petten, The
Netherlands
Fuel Cells II
(Wai’anae)
Chair: Michael Guiver, National
Research Council of Canada,
Canada
Co-Chair: Peter N. Pintauro, Case
Western Reserve University,
Cleveland, Ohio, USA
Fuel Cell Membranes from Nanofiber
Composites
Wycisk, Choi, Lee, Pintaruo, Case
Western Reserve University, Cleveland,
Ohio, USA
Mather, Syracuse University, Syracuse,
New York, USA
Hybrid Nanocomposite Membranes
for PEMFC Applications
Lafitte, Niepceron, Bigarre, Galiano,
Commissariat à l’Energie Atomique,
Monts, France
Hybrid Self-Organized Membranes:
New Strategies for Promising Fuel
Cell Energy Applications
Barboiu, Michau, Institut Europeen des
Membranes, Montpellier, France
Ion-Exchange Membranes from Side-
Chain Sulfonated Poly(arylene ether)s
Meier-Haack, Schlenstedt, Butwilowski,
Vogel, Leibniz Institute of Polymer
Research Dresden, Dresden, Germany
Ionomer Blend Membranes for Low T
and Intermediate T Fuel Cells
Kerres, Schoenberger, Schaefer,
Chromik, Krajinovic, University of
Stuttgart, Stuttgart, Germany
Gogel, Jorissen, Zentrum fur
Sonnenenergie- und Wasserstoff-
Forschung, Ulm, Germany
Li, Jensen, Bjerrum, Technical University
of Denmark, Lyngby, Denmark
Hygrothermal Aging of Nafion
Thominette, Collette, ENSAM, Paris,
France
Gebel, CEA, Grenoble, France
Automotive Hydrogen Fuel Cell
Membrane Applications
Brenner, Coms, Gittleman, Jiang, Lai,
Nayar, Schoeneweiss, Zhang, General
Motors, Honeoye Falls, New York, USA

Thursday, July 17 – Afternoon Sessions
12:30PM Lunch Break
2:15PM
3:00PM
3:30PM
4:00PM
4:30PM
5:00PM
Hybrid and Novel
Processes II
(Kaua’i)
Chair: Glenn Lipscomb, University
of Toledo, USA
Co-Chair: Hans Wijmans, Membrane
Technology & Research, USA
Cyclic Hybrid Adsorbent-Membrane
Reactor (HAMR) Studies for Hydrogen
Production
Tsotsis, Harale, Hwang, Liu, Sahimi,
University of Southern California, Los
Angeles, California, USA
Nanoparticle-Enhanced Microfiltration
for Low Energy Metal Removal from
Water
Jawor, Hoek, University of California Los
Angeles, Los Angeles, California, USA
Crystallization in Hollow Fiber Devices
Zarkadas, Shering, Plough Institute, Union,
New Jersey, USA
Sirkar, New Jersey Institute of Technology,
Newark, New Jersey, USA
Selectivity between Potassium, Sodium,
and Calcium Ions in Synthetic Media
and Juice Media Using Water Enhanced-
Electrodeionization
Ho, Cross, Hestekin, Kurup, Universtiy of
Arkansas, Arkansas, USA
Capillary ElectroChromatography and
Membrane Technology: Merging the
Advantages
Kopec, Stamatialis, Wessling, University of
Twente, The Netherlands
Chitosan Chiral Ligand Exchange
Membranes for Sorption Resolution of
Amino Acids
Chu, Wang, Xie, Yang, Song, Sichuan
University, Sichuan, China
Niu, University of Seaskatchewan,
Saskatoon, Canada
Membrane Fouling –
RO & Biofouling
(Maui)
Chair: Isabel Escobar, University of
Toledo, USA
Co-Chair: Vicki Chen, UNESCO,
University of New South Wales,
Australia
Biofouling of Spiral Wound
Nanofiltration and Reverse Osmosis
Membranes: A Feed Spacer Problem
Vrouwenvelder, Van Loosdrecht, Wetsus,
Delft University of Technology, Delft, The
Netherlands
Graf von der Schulenburg, Johns,
University of Cambridge, Cambridge,
United Kingdom
Kruithof, Westus Centre of Excellence for
Sustainable Water Technology,
Leeuwarden, The Netherlands
Microbial-Sensing Membranes
Functionalized with a Temperature
Sensitive Polymer Film
Gorey, Escobar, Gruden, University of
Toledo, Toledo, Ohio, USA
Modification of Microfiltration
Membranes: Implications for Biofouling,
Flux Recovery and Antibacterial
Properties
Malaisamy, Jones, Howard University,
Washington, District of Columbia, USA
Holder, Raskin, Berry, University of
Michigan, Ann Arbor, Michigan, USA
Lepak, Cornell University, Ithaca, New
York, USA
Role of Seawater Chemistry in Algal
Biopolymer Fouling of Seawater RO
Membranes
Jin, Hoek, University of California Los
Angeles, Los Angeles, California, USA
Effect of Surface Charge and pH on
Fouling and Critical Flux of MF
Membranes during Protein Filtration
Meier-Haack, Leibniz Institute of Polymer
Research Dresden, Dresden, Germany
Synthesis and Evaluation of Novel
Biocidal Coatings to Reduce Biofouling
on Reverse Osmosis Membranes
Hibbs, McGrath, Altman, Sandia National
Laboratories, Albuquerque, New Mexico,
USA
Cornelius, Virginia Polytechnic Institute and
State University, Blacksburg, Virginia, USA
Kang, Adout, Elimelech, Yale University,
New Haven, Connecticut, USA
Pervaporation and
Vapor Permeation II
(Moloka’i)
Chair: Richard Baker, Membrane
Technology & Research, USA
Co-Chair: Tadashi Uragami, Kansai
University, Japan
Aromatics Control in Refining with
Pervaporation
White, Harding, W.R. Grace & Co.-Conn.,
Columbia, Maryland, USA
Membrane Based Liquid Fuels
Desulfurization Process for Point-of-Use
Applications
Aagesen, Swamy, Intelligent Energy Inc.,
Long Beach, California, USA
Ion-containing Polyimide Membranes :
A Way of Overcoming the Trade-off
Permeability in Pervaporation?
Jonquieres, Awkal, Clement, Lochon,
Nancy Universite, France
Study of the Effect of Framework
Substitution on the Pervaporation of
Xylene Isomers Through MFI-type
Zeolite Membranes
O'Brien-Abraham, Lin, Arizona State
University, Tempe, Arizona, USA
On the Unusual Transport Phenomena
of Vapours in Amorphous Glassy
Perfluoropolymer Membranes with High
Fractional Free Volume
Jansen, Tocci, Drioli, Institute on
Membrane Technology, Rende, Italy
Friess, Institute of Chemical Technology,
Prague, Czech Republic
Pervaporation Performance of PDMSgrafted
Aromatic Polyamide Membrane
Exhibiting High Durability and
Processability
Yun, Nagase, Tokai University
Desalination II
(Honolulu/Kahuku)
Chair: Eric Hoek, UCLA, Los
Angeles, USA
Co-Chair: Raphael Semiat, Technion
– Israel Inst. of Tech., Israel
Memstill: A Near-Future Technology for
Sea Water Desalination
Dotremont, Ho, Keppel Environmental
Technology Centre
Kregersman, Puttemans, Keppel Seghers
Belgium NV, Williebroek, Belgium
Hanemaaijer, TNO Science and Industry,
The Netherlands
Parameters Affecting Osmotic
Backwash
Sagiv, Avraham, Dosoretz, Semiat, Grand
Water Research Institute, Technion, Haifa,
Israel
Fabrication of High Performance Dual
Layer Hydrophilic-Hydrophobic Hollow
Fiber Membranes for Membrane
Distillation Process
Bonyadi, Chung, National University of
Singapore, Singapore
A New Niche for Electrodialysis:
Improving Recovery from RO
Desalination
Lawler, Kim, Walker, University of Texas,
Austin, Texas, USA
A Novel Three-Stage Treatment for
Brackish Water Reverse Osmosis
Concentrate: Parameter Effects on and
Feasibility of Antiscalant Oxidation
Greenlee, Lawler, Freeman, The University
of Texas at Austin, Austin, Texas, USA
Marrot, Moulin, Universite Paul Cezanne,
France
Sustainable Seawater Desalination:
Small Scale Windmill and RO-System
Heijman, Rabinovitch, van Diijk, Delft
University of Technology, Delft, The
Netherlands
Membrane and Surface
Modification II
(O’ahu/Waialua)
Chair: Sung Soo Kim, Kyunghee
University, Korea
Co-Chair: Young Moo Lee, Hanyang
University, Korea
Macroporous Membrane Adsorbers with
Tailored Affinity and High Capacity via
Photo-Initiated Grafting-of Functional
Polymer Layers
Ulbricht, He, Wang, Yang, Yusof,
Universität Duisburg-Essen, Essen,
Germany
Surface Modification of Pervaporation
Membrane by UV-Radiation and
Application of Shear Stress
Izák, Institute of Chemical Process
Fundamentals, Prague, Czech Republic
Godinho, Crespo, Universidade Nova de
Lisboa, Portugal
Brogueira, Figueirinhas, Instituto Superior
Tecnico, Portugal
Microstructured Hollow Fiber
Membranes for Ultrafiltration
Wessling, Culfaz, Jani, Lammertink,
University of Twente, The Netherlands
High Performance Surface Nano-
Structured RO/NF Membranes
Lin, Lewis, Kim, Cohen, University of
California, Los Angeles, California, USA
Characterization of Commercial Reverse
Osmosis Membrane Performance and
Surface Modification to Enhance
Membrane Fouling Resistance
Van Wagner, Freeman, Sharma, University
of Texas at Austin, Austin, Texas, USA
Hydrophobic Modified Ceramic
Membranes for Gas Separation and
Desalination
Cerneaux, Condom, Persin, Prouzet,
Larbot, Institut Européen des Membranes,
Montpellier, France
Hybrid Membranes
(Wai’anae)
Chair: William J. Koros, Georgia
Institute of Technology, USA
Co-Chair: Tim Merkel, Membrane
Technology & Research, USA
Polymer-Zeolite 4A Mixed-Matrix
Nanocomposite Gas Separation
Membranes
Tantekin-Ersolmaz, Kertik, Agil, Atalay-
Oral, Istanbul Technical University,
Istanbul, Turkey
Hollow Fillers For Flux Enhancement In
Mixed Matrix Membranes
Vanherck, Aldea, Aerts, Martens,
Vankelecom, Katholieke Universiteit
Leuven, Heverlee, Belgium
Elaboration and Characterization of a
Hybrid Membrane Based on Hydrophilic
Polymer/Ceramic Membrane for Metal
Affinity Chromatography
Paolucci-Jeanjean, Dubois, Muvdi Nova,
Belleville, Rivallin, Barboiu, Institut
Européen des Membranes, Montpellier,
France
Bacchin, Laboratoire de Genie Chimique,
Toulouse, France
Optimization of SRNF Membranes Cast
from Emulsified Polyimide Solutions:
Comparison of a Traditional Approach
with a High Throughput/Combinatorial
Approach
Vandezande, Vanlelecom, Katholieke
Universiteit Leuven, Leuven, Belgium
Gevers, Flemish Institute for Technological
Research, Mol, Belgium
Weyens, Department of Chemistry-Biology-
Geology, Diepenbeek, Belgium
Crosslinking and Stabilization of MgO
Filled PTMSP Nanocomposite
Membranes for Gas Separation
Shao, Hagg, Norwegian University of
Science and Technology, Trondheim,
Norway
Preparation High Performance
Microporous/Mesoporous Hybrid
Membranes for Gas Separation
Liu, Zhao, Wang, Liu, Qiu, Dalian
University of Technology, Dalian, China
Cao, Dalian Institute of Chemical Physics,
Dalian, China

Friday, July 18 – Morning Sessions
8:00AM Plenary III (Hawai’i Ballroom):
Dr. William E. Mickols (DOW Water Solutions, Edina, Minnesota, USA)
The Development of Reverse Osmosis and Nanofiltration through Modern Times
9:00AM Coffee Break (Ballroom Foyer)
Gas Separation V
(Kaua’i)
Chair: Tai-Shung (Neal) Chung,
National University of Singapore,
Singapore
Co-Chair: Juin-Yih Lai, Chung Yuan
Christian University, Taiwan
9:30AM Designing Membranes for Future
Membrane Gas Separation
Applications
Baker, Membrane Technology and
Research, Inc., Menlo Park, California,
USA
10:15AM Sorption and Dilation of Crosslinked
Poly(ethylene oxide) Membranes by
Carbon Dioxide and Ethane
Ribeiro, Freeman, University of Texas
at Austin, Austin, Texas, USA
10:45AM
Kinetic Sorption and Permeation
Behavior of Water Vapor in
Polymeric Membranes
Nymeijer, Potreck, Nymeijer, Wessling,
University of Twente, The Netherlands
Van Marwijk, Heijboer, KEMA, The
Netherlands
11:15AM Natural Gas Purification Using High
Performance Crosslinked Hollow
Fiber Membranes: Effects of High
Pressure CO2 and Toluene Feed
Omole, Koros, Georgia Inst. of Tech.,
Atlanta, Georgia, USA
Miller, Richmond, California, USA
11:45AM Synthesis and Gas Permeability of
Hyperbranched Polyimide
Membranes
Nagai, Meiji University, Kawasaki,
Japan
12:15PM The Effect of Water on the Gas
Separation Performance of
Polymeric Membranes for Carbon
Dioxide Capture
Kentish, Scholes, Hasan, Stevens,
CRC for Greenhouse Gas
Technologies, Victoria, Australia
Nanofiltration and
Reverse Osmosis III -
Applications
(Maui)
Chair: William Mickols, Dow Water
Solutions, USA
Co-Chair: Ho Bum Park, Ulsan
University, Korea
Fundamental Study and
Performance Advancement of
Seawater RO Membrane
Henmi, Tomioka, Kawakami, Kurihara,
Toray Industries, Inc., Shiga, Japan
Development and Testing of a High-
Capacity, Mobile Desalination
System
Miller, Shalewitz, U.S. Army TARDEC,
Port Hueneme, California, USA
Chapman, Bureau of Reclamation,
Denver, Colorado, USA
Barley, Blumenstein, NSF International,
Ann Arbor, Michigan, USA
Investigation of Amphoteric
Polybenzimidazole (PBI)
Nanofiltration Hollow Fiber
Membrane for Both Cation and
Anion Removal
Wang, Lv, Chung, National University
of Singapore, Singapore
Nanofiltration of Ferric and Ferrous
Cations in Acidic Solutions
Bernat, Stuber, Bengoa, Fabregat,
Font, Universitat Rovira i Virgili,
Tarragona, Spain
Fortuny, Universitat Politecnica de
Catalunya, Barcelona, Spain
Treatment of the Groundwater
Contaminated by High Concentration
of Arsenic
Alizadehfard, WorleyParsons, Australia
Alizadehfard, Curtin University, Bentley,
Australia
Purification of Glucose/Sodium
Lactate Solutions by Nanofiltration:
Selectivity Improvement by the
Addition of a Mineral Salt
Roux-de Balmann, Galier, Université de
Toulouse, Toulouse, France
Umpuch, Kanchanatawee, Nakhon
Ratchasima, Thailand
Membrane Fouling –
RO & Desalination
(Moloka’i)
Chair: Vicki Chen, UNESCO,
University of New South Wales,
Australia
Co-Chair: Pierre Le-Clech,
UNESCO, University of New South
Wales, Australia
Studies on CaSO4 and CaCO3 Scaling of Membranes in
Desalination by DCMD
Sirkar, He, New Jersey Institute of
Technology, Newark, New Jersey, USA
Gilron, Zuckerberg Institute for Water
Research, Beer-Sheva, Israel
Development of Fouling Index to
Access Colloidal Fouling in Reverse
Osmosis Unit for Water Reclamation
Sim, Ye, Chen, Fane, UNESCO Center
for Membrane Science and
Technology, Sydney, Australia
The Effect of Membrane Body
Conductance on the Zeta Potential of
Clean and Fouled Polymer
Membranes
Luxbacher, Anton Paar GmbH, Austria
Comerton, Andrews, University of
Toronto, Toronto, Canada
Bagley, University of Wyoming,
Laramie, Wyoming, USA
Mechanisms of Marine Bacteria
Adhesion to Seawater RO
Membranes
Huang, Hoek, University of California
Los Angeles, Los Angeles, California,
USA
Optical Monitoring and Real-Time
Digital Image Analysis of Mineral
Scale Formation on RO Membranes
Kim, Lyster, Cohen, University of
California Los Angeles, Los Angeles,
California, USA
Effect of Foulant-Foulant Interaction
on the Limiting Flux for RO and NF
Membranes during Organic Fouling
Model Development and AFM
Adhesion Force Measurement
Tang, Nanyang Tech. Univ., Thailand
Nam Kwon, Leckie, Stanford University,
Palo Alto, California, USA
Membrane and Surface
Modification III
(Honolulu/Kahuku)
Chair: Mathias Ulbricht, Lehrstuhl
fur Technische, Germany
Co-Chair: Sung Soo Kim, Kyunghee
University, Korea
Modification of Polyethersulfone
Nanofiltration Membranes
Bruggen, Schols, Boussu, K.U.Leuven,
Heverlee, Belgium
Development and Characterization of
Ceramic Microfiltration Membrane
Devices for Biomolecule Separation
Malaisamy, Jones, Howard University,
Washington DC, USA
Lepak, Spencer, Cornell University,
Ithaca, New York, USA
Solvent Resistant Nanofiltration with
Partially Hydrolyzed Asymmetric
Polyacrylonitrile Membranes
Vandezande, Li, Vanderschoot,
Willems, Vankelecom, Centre for
Surface Chemistry and Catalysis,
Belgium
Hydrophilic Modification of
Polypropylene Hollow Fiber
Membrane
Kim, Kim, Kim, Kyung Hee University,
Gyeonggido, Korea
Effect of Surface Modifying
Macromolecules Stoichiometric
Ratio on Composite
Hydrophobic/Hydrophilic
Membranes Characteristics and
Performance in Membrane
Distillation
Qtaishat, Matsuura, University of
Ottawa, Ottawa, Canada
Khayet, University of Complutense
Madrid, Madrid, Spain
Surface Modification of an Aromatic
Polyamide Membrane by Self-
Assembly of Polyethyleneimine on
the Membrane Surface
Zhou, Feng, University of Waterloo,
Waterloo, Canada
Yu, Zhejiang Sci-Tech University, China
Gao, The Development Center of Water
Treatment Technology, China
Inorganic Membranes
III
(O’ahu/Waialua)
Chair: Jerry Y. S. Lin, Arizona State
University, USA
Co-Chair: Yi Hua (Ed) Ma,
Worcester Polytechnic Institute, USA
Silica Network Engineering For
Highly Permeable Hydrogen
Separation Membranes
Tsuru, Yada, Kanezashi, Hiroshima
University, Hiroshima, Japan
Development of Novel CO 2 Affinity-
Enhanced Carbon Membranes:
Characterization and CO 2 Separation
Performance
Kai, Kazama, Fujioka, Research
Institute of Innovative Technology for
the Earth (RITE), Kyoto, Japan
Electronic Conduction and Oxygen
Permeation Through Mixed-
Conducting SrCoFeO(x) Membranes
Kniep, Lin, Arizona State University,
Tempe, Arizona, USA
Micro-Structured Inorganic
Membrane Reactor
Liu, Wang, Elliott, Li, Johnson, Zheng,
Pacific Northwest National Lab,
Richland, Washington, USA
Selective Gas Transfer and Catalytic
Processes in Nano-Channels of
Ceramic Catalytic Membranes
Teplyakov, Tsodikov, A.V.Topchiev
Institute of Petrochemical Synthesis,
RAS, Moscow, Russia
Moiseev, Kurnakov Institute of General
and Inorganic Chemistry, RAS,
Moscow, Russia
The Oxidative CO 2 Reforming of
Methane to Syngas in a Thin Tubular
Mixed-Conducting Membrane
Reactor
Zhang, Dong, Jin, Xu, Nanjing
University of Technology, China
Facilitated Transport
Membranes
(Wai’anae)
Chair: Yong-Soo Kang, Hanyang
University, Korea
Co-Chair: Jongok Won, Sejong
University, Korea
Facilitated Transport Membrane for
Selective Separation of CO2 from
CO2-H2 Mixtures at Elevated
Temperatures and Pressures
Teramoto, Yegani, Matsuyama, Kobe
University, Kobe, Japan
Okada, Renaissance Energy Research
Co., Osaka, Japan
Explorative Investigation of Cu(II)
Facilitated Transportation Through
Supported Liquid Membrane and Its
Derivatively Successful Story
Yang, Chung, Jiang, Kocherginsky,
National University of Singapore,
Singapore
Ionic Liquid Membranes for Carbon
Dioxide Separation
Myers, Pennline, Luebke, US DOE,
National Energy Technology
Laboratory, Pittsburgh, Pennsylvania,
USA
Ilconich, Parsons, South Park,
Pennsylvania, USA
CO 2 Capture: Reduction in
Greenhouse Gas Levels
Trachtenberg, Smith, Cowan,
Carbozyme, Inc., Monmouth Junction,
New Jersey, USA
Novel Olefin Carrier for Facilitated
Transport Membranes: Partially
Polarized Surface of Silver
Nanoparticles by Electron Acceptor
Kang, Kang, Hanyang University, Korea
Selectivity and Stability of Facilitated
Transport Membranes Containing
Silver Nanoparticles for Propylene
Separation
Pollo, Habert, Borges, Federal
University of Rio de Janeiro, Rio de
Janeiro, Brazil

Friday, July 18 – Afternoon Sessions
12:45PM Lunch Break
2:15PM
3:00PM
3:30PM
4:00PM
4:30PM
Pervaporation and
Vapor Permeation III
(Kaua’i)
Chair: Tadashi Uragami, Kansai
University, Japan
Co-Chair: Ivy Huang, Membrane
Technology and Research, Inc., USA
Vapor Permeation and Pervaporation
as Efficient Alternatives in the
Recovery of Fruit Aroma
Compounds
Ortiz, Diban, Urtiaga, University of
Cantabria, Stantander, Spain
Monitoring and Modelling of Aroma
Recovery from Fermentation Media
Using Pervaporation and
Fractionated Condensation
Brazinha, Teodoro, Crespo,
Universidade Nova de Lisboa,
Caparica, Portugal
Effect of Feed Solution
Characteristics on Flavour
Concentration by Pervaporation
Overington, Wong, Harrison, Institute of
Food, Nutrition and Human Health,
Massey University, Palmerston North,
New Zealand
Ferreira, Fonterra Co-Operative Group,
Ltd., Auckland, New Zealand
Concentration of Bioethanol by
Porous Hydrophobic Membranes
Uragami, Kansai University, Osaka,
Japan
Treatment of Gas Containing
Hydrophobic VOCs by a Hybrid
Absorption-Pervaporation Process:
The Case of Toluene
Carretier, Moulin, Université Paul
Cézanne Aix Marseille, Provence,
France
Heymes, Manno-Demoustier, Fanlo,
LGEI, Ecole des Mines d’Ales, Ales,
France
Drinking and
Wastewater
Applications V
(Maui)
Chair: Daniel Yeh, University of
South Florida, USA
Co-Chair: Chuyang Tang, Nanyang
Technological University, Singapore
The Development of a Household
Ultrafiltration System for Developing
Countries
Peter-Varbanets, Vital, Hammes,
Pronk, Eawag - Swiss Federal Institute
of Aquatic Science and Technology,
Duebendorf, Switzerland
Treatment Performance and
Detoxification of Coke Plant
Wastewater Using an Anaerobic-
Anoxic-Oxic Membrane Bioreactor
System
Zhao, Huang, Lee, He, Division of
Water Environment, Department of
Environmental Science and
Engineering, Taiwan
Time Course of Sub-Micron Organic
Matter in MBRs: Relation to
Membrane Fouling in MBRs
Kimura, Yamato, Miyoshi, Naruse,
Watanabe, Hokkaido University,
Sapporo, Japan
On the Lookout for A Fouling
Indicator A Critical Evaluation of
Various Methods for Fouling
Characterisation in MBR
Drews, TU Berlin, Berlin, Germany
Importance of Membrane Reactor
Design for Membrane Performance
in Biofilm-MBR
Ivanovic, NTNU- Norwegian University
of Science and Technology, Trondheim,
Norway
Fuel Cells III
(Moloka’i)
Chair: James McGrath, Virginia
Tech, USA
Co-Chair: Michael Guiver, National
Research Council of Canada, Canada
Crystalline Order and Membrane
Properties in Perfluorosulfonate
Ionomers for PEMFC Applications
Moore, Virginia Tech, Blacksburg,
Virginia, USA
Model Studies of the
Characterization of the Durability of
Nafion® Membranes and
Nafion/Inorganic Oxide
Nanocomposite Membranes
Mauritz, Hassan, Patil, Rhoades,
University of Southern Mississippi
PBI Polymers for High Temperature
PEM Fuel Cells
Benicewicz, University of South
Carolina, USA
Novel Electrolytes for Fuel Cell
Electrodes
Muldoon, Hase, Toyota Motor
Engineering & Manufacturing, Ann
Arbor, Michigan, USA
Pintauro, Lin, Wycisk, Case Western
Reserve University, Cleveland, Ohio,
USA
Effect of Hydrocarbon Ionomer on
Electrochemical Performance of
MEA for Direct Methanol Fuel Cell
(DMFC)
Lee, Lee, Lee, School of Chemical
Engineering, Hanyang University,
Korea
Ultra- and
Microfiltration III -
Membranes
(Honolulu/Kahuku)
Chair: Willem Kools, Millipore, Inc.,
USA
Co-Chair: Andrew Zydney, The
Pennsylvania State University, USA
Pilot-scale Integrity Monitoring of
Microfiltration Processes Using a
Novel Multi-membrane Sensor
Wong, Wai, Su, Advanced Water and
Membrane Centre, Institute of
Environmental Science, Singapore
Fane, Nanyang Tech. Univ., Singapore
Phattanarawik, Norwegian Univ. of Sci.
and Tech., Norway
Integrity Monitoring for Membrane
Bioreactor Systems through
Turbidity and SDI Measurement
Zha, Kippax, Phelps, Nguyen, Siemens
Water Techologies, South Windsor,
Australia
Membrane Characterisation :
Assessment of the Bacterial
Removal Efficiency
LeBleu, Causserand, Roques, Aimar,
Université de Toulouse, Toulouse,
France
Pore Size Determination of UF and
MF Membranes By Streaming
Potential Measurement
Nakamura, Yokohama National
University, Yokohama, Japan
Acoustic Investigation of Porous and
Membrane Structures
Wyart, Bonnet, Moulin, Université Paul
Cézanne Aix Marseille, Provence,
France
Leoni, Allouche, Ecole Centrale,
Marseille, France
5:00PM Ellipsometric Observation of
Ceramic Membranes
Wyart, Tamime, Siozade, Deumie,
Moulin, Université Paul Cézanne Aix
Marseille, Provence, France
Membrane Contactors
(O’ahu/Waialua)
Chair: Pierre Cote, Vaperma, Canada
Co-Chair: Kitty Nijmeijer,
University of Twente, The
Netherlands
Modelling Aroma Stripping Under
Various Forms of Membrane
Distillation Processes
Jonsson, Technical University of
Denmark, Lyngby, Denmark
Membrane Extraction for Acetic Acid
and Lignin Removal from Biomass
Hydrolysates
Wickramasinghe, Grzenia, Colorado
State University, Fort Collins, Colorado,
USA
Schell, National Renewable Energy
Laboratory, Golden, Colorado, USA
Operational Flexibility of Gas-Liquid
Membrane Contactors for CO 2
Separation
Fischbein, Nijmeijer, Wessling,
University of Twente, Enschede, The
Netherlands
Effect of Spacer, Baffled and
Modified Hollow Fiber Geometries in
the Membrane Distillation Process
Chung, Bonyadi, Teoh, National
University of Singapore, Singapore
Gryta, Szczecin University of
Technology, Szczecin, Poland
Direct Contact Membrane
Distillation: Studies on Novel Hollow
Fiber Membranes, Devices,
Countercurrent Cascades and
Scaling
Sirkar, Song, Lee, He, Li, Kosaraju,
New Jersey Institute of Technology,
Newark, New Jersey, USA
Gilron, Zuckerberg Institute for Water
Research, Beer-Sheva, Israel
Ma, Liao, Irish, United Technologies
Research Center, East Hartford,
Connecticut
MEMFRAC - A New Approach to
Membrane Distillation
Sanchez, TNO (Netherlands
Organisation for Applied Scientific
Research), Delft, The Netherlands
Packaging and Barrier
Materials
(Wai’anae)
Chair: Anne Hiltner, Case Western
Reserve University, USA
Co-Chair: Eric Baer, Case Western
Reserve University, USA
New Developments in the
Measurement of Multi-Component
Sorption in Barrier Polymer
Materials: A Key Step Towards the
Modeling of Fuel Tank Permeability
Jonquieres, Clement, Kanaan, Lenda,
Lochon, Nancy Universite, Nancy
France
Brule, Arkema, Serquigny, France
Fundamental Exploration of Metal-
Catalyzed Oxidation in Styrene-
Butadiene-Styrene Block
Copolymers
Tung, Ferrari, Li, Ashcraft, Freeman,
Paul, The University of Texas at Austin,
Austin, Texas, USA
The Effect of Reaction Conditions on
Oxidation of Metal-catalyzed
Poly(1,4-butadiene)
Li, Tung, Freeman, The University of
Texas at Austin, Austin, Texas, USA
Stewart, Jenkins, Global PET
Technology, Eastman Chemical
Company, Kingsport, Tennessee, USA
On the Nature of Gas Barrier of
Ethylene Vinyl Alcohol Copolymers
Nazarenko, Chigwada, Brandt, Olson,
University of Southern Mississippi,
Hattiesburg, Mississippi, USA
Jamieson, Case Western Reserve
University, Cleveland, Ohio, USA
Confined Crystallization of PEO in
Nanolayered Films for Improved Gas
Barrier
Wang, Hiltner, Baer, Case Western
Reserve University, Cleveland, Ohio,
USA
Freeman, The University of Texas at
Austin, Austin, Texas, USA
Relationship between Biaxial
Orientation and Oxygen Permeability
of Polypropylene Film
Lin, Dias, Hiltner, Baer, Case Western
Reserve University, Cleveland, Ohio,
USA
Chen, The Dow Chemical Company,
Freeport, Texas, USA

Oral Presentation
Abstracts
Morning Session
Monday, July 14, 2008

Plenary Lecture I
Monday July 14, 8:00 AM-9:00 AM, Hawai’i Ballroom
Fuel Cell Polymer Electrolyte (PEM) Derived from Disulfonated Random
and Block Poly(Arylene Ether) Copolymer System
Professor James E. McGrath, Virginia Tech, Blacksberg, VA, USA
Our research group has been engaged in the past few years in the synthesis of
biphenol based partially disulfonated poly(arylene ether sulfone) random
copolymers as potential PEMs.
This series of polymers has been named as BPSH-xx, where BP stands for
biphenol, S stands for sulfonated, H stands for acidified and xx represents the
degree of disulfonation. All of these sulfonated copolymers phase separate to
form nano scale hydrophilic and hydrophobic morphological domains. The
hydrophilic phase containing the sulfonic acid moieties causes the copolymer to
absorb water. Water confined in hydrophilic pores in concert with the sulfonic
acid groups serve the critical function of proton (ion) conduction and water
transport in these systems. Both Nafion and BPSH show high proton conductivity
at fully hydrated conditions. However proton transport is especially limited at low
hydration level for the BPSH random copolymer. It has been observed that the
diffusion coefficients of both water and protons change with the water content of
the pore. This change in proton and water transport mechanisms with hydration
level has been attributed to the solvation of the acid groups and the amount of
bound and bulk-like water within a pore. At low hydration levels most of the
water is tightly associated with sulfonic groups and has a low diffusion coefficient.
This results in an isolated domain morphology. Thus, although there may be
significant concentrations of protons, the transport is limited by the discontinuous
morphological structure.
Hence the challenge lies in how to modify the chemistry of the copolymers to
obtain significant protonic conductivity at low hydration levels. This has been
possible by altering the chemical structure to afford nanophase separated ion
containing block or segmented copolymers. Unlike the BPSH statistical or
random copolymers, where the sulfonic acid groups are randomly distributed
along the chain, the multi block copolymers feature an ordered sequence of
hydrophilic and hydrophobic segments. Connectivity is established between the
hydrophilic domains in these multi-block copolymers, they will not need as much
water, and hence will show much better protonic conductivity than the random
copolymers (with similar degree of sulfonation, or IEC) at partially hydrated
conditions. This is particularly valuable for H2/air systems and the self assembling
nanophase also has potential for direct methanol fuel cells (DMFC) for portable
power. The systhesis and characterization of these materials and their potential
applications will be described.

Gas Separation I – 1 – Keynote
Monday July 14, 9:30 AM-10:15 AM, Kaua’i
Beyond Inorganic-Organic Nanocomposites for Molecular Separations
M. Wessling (Speaker), University of Twente, the Netherlands, M.Wessling@tnw.utwente.nl
Over the past two decades, hybrid materials comprising a polymer matrix with
embedded micrometer sized inorganic particles have been developed with
respect to their mass transport properties. The particles may be permeable as in
the case of zeolites and have a beneficial effect on the separation properties.
Impermeable particles often improve barrier properties. Smaller sub-micron sized
impermeable particles, such as nano-sized silica, increase the free-volume at the
particle-polymer interface, which results in an increase of permeability and socalled
inverse selective separation properties.
This presentation focuses on the molecular separation properties of nanocomposite
materials other than inorganic-organic. Three systems will be
discussed in detail: * fullerene-modified polyphenylene oxide PPO: Why is
binding better than dispersing? * Dendrimer-modified polymers: a supramolecular
toolbox with benefits? * Segmented block-copolymers: how does the interface of
the soft and hard blocks influence molecular separations? The presentation will
reflect on other nanocomposite materials and their potential for molecular
separations.

Gas Separation I – 2
Monday July 14, 10:15 AM-10:45 AM, Kaua’i
Tailor Made Polymeric Membrane Based on Segmented Block Copolymer
for CO2 Separation
A. Car (Speaker), University of Maribor, Faculty of Chemistry and Chemical Engineering,
Slovenia, anja.car@uni-mb.si
C. Stropnik, University of Maribor, Faculty of Chemistry and Chemical Engineering, Slovenia
W. Yave, Institute of Polymer Research, GKSS Research Centre Geesthacht GmbH, Germany
K. Peinemann, Institute of Polymer Research, GKSS Research Centre Geesthacht GmbH,
Germany
The use of polymers in applications that require control of gas transport is rapidly
growing. For many of them, it may be desirable to utilize heterogeneous polymer
blends or block copolymers in which one component provides desired
permeability characteristics, while the other improves material properties (e.g.,
modulus or impact strength). Heterogeneous block copolymers provide the
potential for creating new materials for applications with mechanical and
transport properties superior to those of the parent homopolymers. Morphological
features of microphase- separated block copolymers that can affect small
molecules transport, include the small size and narrow size distribution of
domains. Knowledge of the relationships between block copolymer morphology
and the diffusion and permeation processes is essential for successful
manufacturing and usage of heterogeneous polymers and their blends.
Poly(ethylene(oxide)-poly(butylene terephthalate) (PEO-PBT) multiblock
copolymers are found under the commercial name Polyactive®, and they are
considered as semicrystalline polymers [1] . In these copolymers, PEO block is the
permeable amorphous phase and PBT is the rigid crystalline phase, considered
as impermeable for gas transport [2, 3] .
This paper reports the design of a tailor made polymeric membrane by using
PEO-PBT multi- block copolymers. Their properties are controlled by the fraction
of PEO phase and its molecular weight, thus a structural manipulation in order to
obtain a material with desired transport properties is possible. From selected
PEO-PBT copolymers, blend membranes with PEG are tailored in order to
design membranes with high performance for CO2 separation. One focus of this
work was the development of a membrane material, which can effectively
separate CO2 and H2. This is an industrially important separation, e.g. for the
coal gasification process. Membranes with a preferred CO2-permeability are
especially attractive, because the hydrogen remains on the high-pressure side.
Blends of Polyactive® comprise 50 wt. % of PEG 200 were still mechanically
stable and showed a CO2/H2- solubility selectivity of 78. This was counteracted
by a CO2/H2-diffusivity selectivity of 0.17 (faster diffusion of hydrogen). The

esulting permeability selectivity of 13 (at room temperature) is still very attractive
especially when taking into account the high permeability of the hybrid material.
A study of these copolymers with different molecular weight and fraction of the
PEO block have been carried out in order to develop new membrane materials
for gas separation. Details on the different copolymer/PEG blends will be
presented in this lecture and first machine-made membranes will be shown as
well.
[1] A.A. Deschamps, D. W. Grijpma, J.Feijen, Poly (ethylene oxide)/poly(butylene terephthalate)
segmented block copolymers: the effect of copolymer composition on physical properties and
degradation behavior, Polymer 42 (2001) 9335- 9345.
[2] S. J. Metz, M. H. V. Mulder, M. Wessling, Gas- permeation properties of poly(ethylene oxide)
poly (butylene terephthalate) block copolymers, Macromolecules 37 (2004) 4590-4597.
[3] B. Gebben, A water vapor-permeable membrane from block copolymers of poly(butylene
terephthalate) and poly(ethylene oxide), J. Membr. Sci. 113 (1996) 323-329.

Gas Separation I – 3
Monday July 14, 10:45 AM-11:15 AM, Kaua’i
Segmented Block Copolymers: A Molecular Toolbox to Tailor the Mass
Transport Properties of Polymeric Nanocomposites
S. Reijerkerk (Speaker), University of Twente, The Netherlands, s.r.reijerkerk@utwente.nl
A. IJzer, University of Twente, The Netherlands
A. Araichimani, University of Twente, The Netherlands
R. Gaymans, University of Twente, The Netherlands
K. Nymeijer, University of Twente, The Netherlands
M. Wessling, University of Twente, The Netherlands
The removal of CO2 from light gas mixtures such as H2, N2 and CH4 is an
important application in industry, for instance in synthesis gas, flue gas and
natural gas processing. Poly(ethylene oxide) (PEO) based block copolymers
have been studied extensively as membrane material for these CO2/light gas
separations. In general, block copolymers contain a phase separated
morphology in which the hard segments (usually polyamides, polyurethanes or
polyimides) provide mechanical stability and the soft segments control the gas
transport properties. The polar ether oxygen linkages in PEO interact favorable
with the quadrupolar CO2, resulting in high CO2/light gas solubility selectivities.
Simultaneously the flexible ether oxygen linkages ensure high CO2 diffusivities
and thus high CO2 permeabilities.
Incorporation of high concentrations of PEO is however difficult due to its strong
tendency to crystallize, which is detrimental for the permeation properties. This is
especially evident at ambient and sub ambient temperatures. Crystallization at
sub ambient temperatures is especially disadvantageous for CO2/CH4
separations, as these separations often occur offshore and because higher
hydrocarbons in natural gas are usually removed by condensation at low
temperatures, thus reducing the need for reheating such a gas stream.
Furthermore, the non-uniform nature of the hard segments usually used, leads to
inefficient phase separation of the soft and hard segments, which has reduced
the CO2 permeability and the mechanical strength. High hard segment
concentrations (> 30 wt%) are thus required to guarantee mechanical strength,
but at the same time reduce the gas permeability.
Here, we report the synthesis, characterization and gas permeation properties of
a series of segmented block copolymers based on a soft segment containing a
random distribution of 75 mol% PEO and 25 mol% poly(propylene oxide) (PPO)
with strongly improved phase separation and a significant reduction in
crystallinity of the soft segment. The crystallization of the ethylene oxide units is
suppressed due to the presence of the methyl side groups of PPO, that are
randomly distributed along the polymer backbone and which prevent regular

chain packing. To ensure a well phase separated morphology a hard segment
containing uniform tetra-amide units is used.
The soft segment length is varied between 1.000 - 10.000 g/mol, enabling soft
phase concentrations up to 89 wt%. Crystallinity of the uniform hard segment is
high (~ 80%) and the phase separation is very efficient, leading to a pure, flexible
and highly permeable soft phase. Crucial in this case is the fact that PEO
crystallization is absent in all materials at temperatures as low as -5°C.
Pure gas permeabilities are determined using the constant volume, variable
pressure method in a temperature range from -10°C to 50°C at an upstream
pressure of 4 bars. CO2 gas permeabilities at 35°C ranged from 126 Barrer
(1.000 g/mol) to approximately 500 Barrer (10.000 g/mol), while gas selectivity
values are as high as 10 for CO2/H2, 45 for CO2/N2 and 13 for CO2/CH4. These
gas selectivities are comparable with a typical PEO containing block copolymer
like PEBAX® 1074, while permeability is increased with a factor four. At a
temperature of -10°C the CO2 permeability remained high with a value of 235
Barrer for a soft segment length of 10.000 g/mol. At this temperature CO2/H2,
CO2/N2, and CO2/CH4 selectivities reached values of respectively 19, 99 and 31.
Compared to the block copolymer systems described in literature the CO2 gas
permeability is tremendously increased (> 300 Barrer increase) while the
CO2/light gas selectivity is unaffected. The operating window of block copolymers
for CO2 gas separation is thus expanded to the low temperature region which is
interesting for CO2/CH4 as well as CO2/H2 separations.
In the present work we prove that segmented block copolymers are a successful
molecular toolbox to tailor the mass transport properties of polymeric
nanocomposites. A random distribution of 25 mol% PPO within a PEO oligomer
suppresses PEO crystallization in PEO based segmented block copolymers. In
addition, the use of a uniform hard segment results in block copolymers
containing a very pure and flexible soft phase. Combined, their use enhances the
CO2 gas permeability tremendously (up to a fourfold increase) over conventional
PEO based block copolymers without sacrificing selectivity. To our knowledge
these results are the best reported values to date for polyether based block
copolymer systems.

Gas Separation I – 4
Monday July 14, 11:15 AM-11:45 AM, Kaua’i
Gas Separation Using Ionic Liquid Polymers
R. Noble (Speaker), University of Colorado, Boulder, CO, USA, nobler@colorado.edu
D. Gin, University of Colorado, Boulder, CO, USA
J. Bara, University of Colorado, Boulder, CO, USA
T. Carlisle, University of Colorado, Boulder, CO, USA
B. Voss, University of Colorado, Boulder, CO, USA
A. Finotello, University of Colorado, Boulder, CO, USA
The objectives of this research are to fabricate new membrane structures based
on polymerizable ionic liquids; and characterize their fundamental gas and vapor
transport properties. Room temperature ionic liquids (RTILs) with polymerizable
groups can be readily converted into solid-state, poly(RTILs) for use as gas
separation membranes. The membranes will be fabricated from ILs (which will
act as the active component to provide high selectivity for the target agents) and
polymerizable ILs (which can be formed directly into solid, mechanically stable
and tunable polymeric solids). The use of polymerizable lyotropic liquid crystals
(LLCs) as a blendable additive to these IL materials provides a means to obtain
specific nanoporous morphologies that provide the potential for enhanced
sorption capacity in the resulting films or particles. LLC systems have the ability
to form ordered, phase-segregated nanoporous structures and incorporate the IL
into the ordered hydrophilic regions to generate very high surface area materials.
Separately, the addition of inorganic NPs to IL-based sorbent systems will allow
formation of solid-state materials, and provide additional surface area and
adsorption capacity for the target agents. Regular solution theory has been
shown to accurately predict the solubility of various gases and vapors in ionic
liquids and polymers. The IL solubility parameter can be tailored to minimize the
difference between the target agent and IL solubility parameters which
maximizes the solubility. A functional group contribution method to determine the
solubility parameter can be used to guide the detailed molecular design of the
ionic liquid. This method provides a theoretical framework to interface with the
material synthesis and characterization. Polymerizable ILs have already been
shown to have properties that exceed the upper bound on a Robeson plot for
CO2/N2 separation. The use of various additives can further enhance the
permeation while maintaining the high selectivity. Results will be shown for a
variety of materials.

Gas Separation I – 5
Monday July 14, 11:45 AM-12:15 PM, Kaua’i
Development of High Temperature CO2-Selective Porous Ceramic
Membranes
A. Ku (Speaker), GE Global Research, Niskayuna, NY, USA, kua@research.ge.com
V. Ramaswamy, GE Global Research, Niskayuna, NY, USA
J. Ruud, GE Global Research, Niskayuna, NY, USA
P. Willson, GE Global Research, Niskayuna, NY, USA
K. Narang, GE Global Research, Niskayuna, NY, USA
Because of their mechanical durability and thermal and chemical stability,
inorganic membranes have the potential to increase the efficiency of industrial
processes by enabling efficient separation of process gas streams into their
constituents. Numerous industrial processes, including hydrocarbon processing,
steam methane reforming, water gas shift, and CO2 capture from power
generation systems, would benefit from gas separation membranes that operate
at elevated temperatures. Selectivity is a key requirement for membranes. In
general, porous membranes are more selective for the smaller or lighter
molecules in a gas mixture. However, the mechanism of selective surface
transport, due to gas adsorption on the pore walls, can increase the flux of the
heavier molecule resulting in a reverse selective membrane.
Surface transport of adsorbed CO2 can lead to CO2-selectivity in porous
membranes, but is believed to be a low temperature effect because of desorption
of the gas upon heating. We will describe efforts to develop porous ceramic
membranes with enhanced surface transport of CO2 at elevated temperatures.
Based on a conceptual framework that allows screening for promising materials
through chemisorption properties, we identified several promising candidate
oxides and fabricated supported microporous membranes. We will report the gas
permeation and separation properties of our oxide membranes against a
microporous silica benchmark with substantial room temperature CO2/H2
selectivity.
Acknowledgement: This material is based partly upon work that was supported
by the U.S. Department of Energy under award number DE-FC26-05NT42451.

Gas Separation I – 6
Monday July 14, 12:15 PM-12:45 PM, Kaua’i
Solubility and Diffusivity of Organic Vapors in Mixed Matrix Membranes
Formed by High Free Volume Glasses Loaded with Fumed Silica
M. Ferrari, University of Bologna, Bologna, Italy
M. De Angelis, University of Bologna, Bologna, Italy
M. Galizia, University of Bologna, Bologna, Italy
T. Merkel, MTR- Membrane Technology and Research, Menlo Park, CA, USA
G. Sarti (Speaker), University of Bologna, Bologna, Italy, giulio.sarti@unibo.it
Solubility and diffusivity of mixed matrix membranes based on amorphous
Teflon® AF 2400 or PTMSP loaded with different amounts of nanoscale fumed
silica (FS) have been studied at 25°C. For such systems filler addition induces
variations in density as well as in sorptive capacity that do not obey an additive
rule, at any filler contents. The solubility isotherms of different hydrocarbons in
mixed matrices (MM) with different FS loadings up to 40 wt % are presented and
discussed in some detail, together with the dependence of the apparent
diffusivity on penetrant concentration and filler loading. Remarkably, with
increasing the FS content the penetrant diffusivity increases as well as the
apparent solubility in the polymer phase, in spite of the fact that the filler is
impermeable and endowed with an adsorption capacity smaller than that of the
pure polymers considered. In view of the complex behavior observed, the
characterization of the permeability of the mixed matrix and its selectivity towards
components in mixed gases seem to require an extensive experimental work in
which use is made of different penetrants as well as of different matrices at
various filler contents. Remarkably, analysis of the experimental data collected
clearly indicates that the study of the mixed matrix behavior, i.e. solubility,
diffusivity and permeability, can be greatly simplified and rationalized as follows:
i) consider first a test penetrant and measure the solubility isotherms for the
different mixed matrices at different filler contents; ii) calculate the solubility
isotherms in the polymer phase alone of the MM, by considering that the
adsorption contribution onto the FS surface remains the same as on the pure FS
particles; iii) calculate the effective density of the polymer phase of the MM, or
equivalently calculate the fractional free volume (FFV) of the polymer phase, by
using the NELF model for the solubility in glassy polymers; iv) finally, use the
latter value (density of the polymer phase or FFV) to calculate in a predictive way
the solubility isotherms in the same MM of other penetrants of interest. The
procedure indicated above has been followed in some detail, using n-butane as
test penetrant; the effects of filler content on the polymer FFV and density of the
different MM considered was calculated. From those values the solubility
isotherms of other hydrocarbon vapors (CH4, C2, C3, and C5) and of gases (N2)
were calculated from the Nelf model and the predicted values match in a rather

satisfactory way the corresponding solubility isotherms measured experimentally.
The values of the FFV thus obtained have also been used to correlate the
dependence of the apparent diffusivities in the MM. In fact it was observed that
the infinite dilution apparent diffusivity follows a well known exponential
dependence on the FFV of the polymer matrix. In conclusion the experimental
data presented indicate that it is possible to foresee the permeability of different
penetrants in MM membranes based on simple analysis of a reference penetrant.

Drinking and Wastewater Applications I – 1 – Keynote
Monday July 14, 9:30 AM-10:15 AM, Maui
Reuse/Recycle Water Opportunities and Challenges in Food/Bio
Processing Industry Using Membrane Technology: Is this Myth or Reality?
H. Muralidhara (Speaker), Cargill Inc., Savage, MN, USA, Hs_Murali@cargill.com
The food processing industry uses an enormous amount of water. The water is
used as a reactive ingredient during processing as a cleaning agent for heating
and cooling/chilling, and for transportation. The amount of water used has been
increasing for a variety of reasons during the last few years. Scarcity of quality
water will be a major issue in the upcoming years.
Water availability is arguably the most pressing resource issue in the world.
Fresh water is key to sustainable development. An inadequate water supply
reduces opportunity for food production/processing, and also has a detrimental
effect on the environment. With the advent of biofuels, the balancing act is
absolutely essential. Membrane technology should be explored to mitigate this
problem.
The pressure posed by lack of fresh water supplies portends rising water costs,
which makes apparent the urgent need to improve water use efficiency.
Recycle/reuse of water, if achieved economically, will provide greater operational
flexibility and more competitive cost structure in a water-stressed world. There is
indeed a dire need to address this issue.
Ninety-five percent of the U.S. fresh water is underground. North America s
largest aquifer, the Ogallala, is being depleted at a rate of 12 billion cubic meters
per year. The Ogallala stretches from Texas to South Dakota and irrigates
approximately one-fifth of the country’s farmland. There are also several foodmanufacturing
plants along the aquifer, and the water stress could have major
impact on many of these operations.
This keynote will address the importance of recycle/reuse opportunities for water
in the food and bio processing industries to promote sustainable development. I
will focus on actual case histories to demonstrate efficiency improvements of
water usage in processing, using membranes that have also had a significant
impact on energy efficiency. High performing membranes with longer lifetime will
expand the scope of recycling/reuse opportunities around the globe. I will
conclude by discussing some of the most important future challenges and
opportunities in the field on a global basis.

Drinking and Wastewater Applications I – 2
Monday July 14, 10:15 AM-10:45 AM, Maui
Integrated Membrane System for Waste Water Reuse with Innovative PVDF
UF Membrane and Low Fouling RO Membrane
T. Kitade (Speaker), TORAY Industries, Inc., Otsu, Shiga, Japan,
Tamotsu_Kitade@nts.toray.co.jp
R. Takagi, TORAY Industries, Inc., Otsu, Shiga, Japan
S. Kantani, TORAY Industries, Inc., Otsu, Shiga, Japan
M. Taniguchi, TORAY Industries, Inc., Otsu, Shiga, Japan
T. Uemura, TORAY Industries, Inc., Otsu, Shiga, Japan
Abstract In these years, the serious water shortage and pollution are being
tangible in the world. In order to secure sustainable water resources with small
environmental impact, the waste water reuse (WWR) systems have been
focused, and many large-scale (WWR) plants were constructed and started
operation. One of the promising WWR systems is combined with micro-filtration
(MF) membrane or ultra-filtration (UF) membrane followed by the reverse
osmosis (RO) process, which is called as ‘Integrated Membrane System (IMS)’.
This IMS has a lot of advantage such as cost saving and high product quality, but
one problem is sometimes appeared, which is the fouling of the membranes. In
this study, the authors focused on the principle and the prevention of fouling, and
has developed optimized IMS for WWR with high efficiency and anti-fouling
operation.
1) MF/UF Fouling of MF and UF membranes at the filtration of the secondary
effluent of waste water is mainly caused by the high concentration organic
matters in the feed water. In order to solve this problem, we tried to utilize our
innovative poly (vinylidene fluoride) (PVDF) hollow fiber MF/UF membranes.
These series of membranes were developed by applying the thermally induced
phase inversion technology, and had high chemical resistance and physical
strength, which enabled various physical and chemical cleaning for the stable
operation with wide ranges of feed water composition. At first, we have tested the
permeance, permeate quality and fouling properties of three PVDF hollow fiber
membranes whose structures, pore sizes and permeabilities were different, and
selected one type of membranes whose name was HFU and had 150,000
dartons as the nominal molecular weight cut off size, due to the best anti-fouling
property and the highest permeate water quality. Then, in order to achieve higher
flux operation of the filtration process with HFU, it was tried to apply and optimize
the combination of the coagulation and improved Chemical Enhanced
Backwashing (CEB) technique, which was much more effective than
conventional method. Firstly, the coagulation condition was focused, and then it
was found out that the membrane cleaning efficiency was related to the zeta
potentials of coagulated flocs and the membrane surface, and the coagulation

condition was optimized. Secondly, the investigation was conducted for the
improved Chemical Enhanced Backwashing (CEB) in order to remove more
effectively the organic matters from membrane surface and inside of the micropores.
As a result of the investigations above, the HFU filtration process
achieved the extremely higher flux 167 LMH (4.0 m/d) than before (1.0~1.5 m/d),
which could reduce the operational cost as well as the initial equipment cost. 2)
RO The major difficulty in the RO operation for WWR is the membrane fouling
due to the chemical and biological reasons. In this study, by using some organic
matters measurement in order to correlate the RO feed water composition with
chemical fouling property, it was found the specific organic matters were related
to the chemical fouling. Based on the analyses and comparison of various RO
membranes, it was confirmed that the low fouling RO membrane had the
excellent performance for chemical fouling. As for the bio-fouling, the
bactericides are usually used in order to prevent bio-fouling. However, it is
difficult to select appropriate and effective bactericide dosing conditions. In this
study, we have successfully developed the modified bio-film formation rate (BFR)
technique with more accurate ATP measurement and the newly developed test
column consisting of the actual RO membrane. This technique enabled to obtain
the bio-fouling potentials in shorter time. By using this modified BFR technique,
the bio-fouling potentials of the various RO feed water were easily measured,
and the most effective bactericide dosing condition could be decided.
References
Minegishi, S., Tanaka, Y., Henmi, M., and Uemura, T., 2007, "Advanced Fouling Resistant PVDF
Hollow Fiber Membrane Modules for Drinking Water Treatment ", The 2007 IWA Leading Edge
Conference on Water and Wastewater Technologies, Singapore
Minegishi, S., Henmi, M., Matsuka, N., and Kurihara, M., 2003, "Newly Designed PVDF Hollow
Fiber and Flat Sheet Membrane for Drinking Water Production and Wastewater Reuse ",
ICOM2005, Korea
J.S. Vrouwenvelder, D. van der Kooij, 2001, "Diagnosis, prediction and prevention of biofouling of
NF and RO membranes ", Desalination 139, 65- 71

Drinking and Wastewater Applications I – 3
Monday July 14, 10:45 AM-11:15 AM, Maui
Impact of Seasonal Water Quality Changes on Low Pressure Membrane
Filtration of an Activated Sludge-Lagoon Effluent.
F. Roddick (Speaker), RMIT University, Melbourne, Australia, felicity.roddick@rmit.edu.au
T. Nguyen, RMIT University, Melbourne, Australia
L. Fan, RMIT University, Melbourne, Australia
J. Harris, RMIT University, Melbourne, Australia
Increasing demands on Melbourne’s water resources due to population growth
and drought have emphasized the need for multiple use of water, including the
treatment and recycling of wastewater. Western Treatment Plant (WTP) treats
approximately 52% of Melbourne’s sewage, a total of approximately 485 million
liters/day, using a sequential activated sludge-lagoon (AS- lagoon) process. WTP
employs two AS-lagoon systems in which sewage is treated by passing through
ponds and an activated sludge plant with anoxic and aeration zones. The
biologically treated effluent then passes through a clarifier and a chain of lagoons
before it is transferred to the head of the road storage pond (HORS). The
recycled water is currently used for various on-site and off-site purposes,
however, due to catchment issues such as industrial waste input and saline
aquifer infiltration, it contains salt which limits its long term use for some
applications, such as agriculture, without additional management practices. Pilotscale
trials, which utilized microfiltration (MF) or ultrafiltration (UF) as a pretreatment
prior to reverse osmosis (RO), demonstrated that the product water
was suitable for various applications including agriculture and domestic use.
Since the effluent from WTP contains algae and algal products from the lagoon
process, as well as some residual products from the AS process, the resultant
membrane fouling and permeate properties may be more problematic and differ
from those arising from separate AS and lagoon processes. As the performance
can vary, and the lagoons are subject to algal blooms over the warmer months,
the aim of this study was to characterize the properties of the AS-lagoon effluent
and to determine their influence on the performance of the MF and UF processes
to determine the impact of seasonal variation. These data will be used as a basis
for the development of a fouling mitigation strategy. The filterability was
measured as specific permeate volume at a final flux rate of 55 L m h- 1 using a
dead-end stirred cell fitted with 0.22 µm PVDF or PES (100 kDa MWCO)
membranes.
The trends for a range of feed parameters over the eighteen month sampling
period were established and their influence on MF and UF filterability statistically
analyzed. During this period, there was a major algal bloom with consequential

greatly elevated total suspended solids (TSS), turbidity and dissolved organic
carbon (DOC). The MF and UF filterability trends were statistically analyzed
including and excluding the data for this sample.
The turbidity, total algal count and TSS levels showed greater variation over
October 06-March 07 (ie., the warmer months) than for the April 07-December 07
period. Some correlation between these parameters and DOC was apparent.
There was a trend for lower turbidity over the April 07-August 07 period, and
similarly, although to a lesser extent, for total algal count.
TDS and conductivity levels were fairly consistent over the February-December
07 period, although slightly lower levels in July-August may be indicative of a
minor seasonal trend.
The MF filterability of HORS samples was generally higher for the March-
December 07 period and this was reasonably consistent with their relatively low
turbidity, TSS, algal contents and low DOC. TSS level was the major determinant
of MF flux, MF filterability decreased to varying extents with increasing levels of
these parameters in the order TSS > turbidity > total algal count > DOC whether
an algal bloom was present or not.
The UF filterability of HORS samples was also generally higher for the March-
December 07 period. UF filterability decreased to varying extents with increasing
levels of TSS, turbidity, algal count and DOC such that the effect of DOC > TSS
> turbidity > total algal count. When data pertaining to the presence of an algal
bloom was included this order changed so that the effect of TSS level was
greater than DOC concentration on UF flux.
Seasonal water quality changes had a greater impact on MF rather than UF
filterability, which implies that UF is a better choice than MF for pre-treatment for
RO in terms of consistent performance. Pre-treatment of the feed would improve
water quality and thus filterability, particularly during algal bloom events, enabling
more consistent membrane performance.

Drinking and Wastewater Applications I – 4
Monday July 14, 11:15 AM-11:45 AM, Maui
Investigating and Evaluating Different Concepts of Membrane-Based
Technologies for a Cleaner Production in the Automotive Industry
S. Lyko (Speaker), RWTH Aachen University, Department of Chemical Engineering, Germany,
Sven.Lyko@avt.rwth-aachen.de
T. Wintgens, RWTH Aachen University, Department of Chemical Engineering, Germany
A. Buchmann, RWTH Aachen University, Department of Chemical Engineering, Germany
T. Melin, RWTH Aachen University, Department of Chemical Engineering, Germany
C. Herse, Ford-Werke GmbH, Germany
Introduction
The German automotive industry as the most stable employment sector is
committed to the development and application of novel environmental
technologies (VDA, 2007). The advanced treatment of its heavily concentrated
wastewater streams with environmental relevance flows is nontrivial but
necessary for a more frequent use of water during the production process and
the minimization of wastewater discharges.
The aim of this study was to evaluate and to assess the potential of membrane
processes for a modern water management in the automotive industry. By
combining chemical processes (precipitation and flocculation) with porous and
dense membrane processes (ultrafiltration, nanofiltration) the achievable
permeate quality and the operation performance were investigated in lab and
pilot scale and provided the basis for the evaluation of the recycling potential.
The production site Cologne (FORD-Werke GmbH) was selected as case study
as it provided a local situation with all relevant production processes of the
automotive industry in use.
Methodology
The first step was a comprehensive status analysis of the local situation followed
by the definition of three reliable treatment concepts covering the two
fundamental strategies of production integrated (Cleaner production) and end-ofpipe
technologies (EOP): Concept 1a: Production integrated measures (Cleaner
production) Concept 1b: EOP treatment of the painting wastewater Concept 2:
EOP treatment of the collected wastewater from the production area
To identify and evaluate the current situation the collection of existing data was
enhanced by composite wastewater samples over a 24-hours period for the
wastewater streams. Thereby the wastewater composition can be summarized

y high concentrations of COD, heavy metals, oil and surfactants. Furthermore,
the widespread application of biocides during various production processes
resulted in unfavorable COD/BOD ratios between 7 and 10. Thus, a biological
treatment was impossible and the investigated concepts were based on pressure
driven membrane processes in crossflow mode.
In a comprehensive lab-scale study a coagulation agent and a membrane
screening was conducted. Furthermore optimal process conditions in terms of
permeate quality and filtration performance and the effect of various influencing
factors (e.g. temperature, pH) were determined.
To prove these lab-scale findings and to evaluate the filtration performance and
operational reliability a set of different pilot plants was installed and operated
over a period of 6 months: -An ultrafiltration plant with polymeric membranes
(total membrane area: 15 m²) treating the collected wastewater from the paint
shop -An ultrafiltration plant with ceramic membranes (total membrane area: 7
m²) treating the collected wastewater from the mechanical production areas -A
nanofiltration plant treating the process water of the phosphating department
within the pre-treatment of the paint shop -A reverse osmosis plant for the
advanced treatment of the nanofiltration permeate -An ultrafiltration plant treating
the process water of the degreasing step within the paint shop pre-treatment -An
ultrafiltration plant treating the rinsing bath water of the degreasing step within
the paint shop pre-treatment
Results
The results revealed a better performance of the ceramic ultrafiltration plant in
comparison to the polymeric ultrafiltration plant characterized by lower total
filtration resistances and comparable retention properties. Due to the high fouling
potential of the wastewater submerged hollow fibre membranes (PURON®, Koch
Membrane Systems, Germany) were irreversibly blocked after the production of
2.2 m³ permeate per m² membrane area. Porous ultrafiltration membranes in
combination with pre-coagulation are able to reduce the heavy metal content to a
level below the environmental legislation. The molar mass distribution of the
wastewater showed the largest fraction (> 90%) with a molar mass lower than
1,500 Da. This finding was proved by the incomplete COD retention of the
crossflow- ultrafiltration. Therefore advanced treatment processes (powdered
activated carbon, nanofiltration) to decrease the organic content as a prerequisite
for the recirculation into the process were investigated and the results will be
presented. The production integrated nanofiltration within the phosphating
department provided a sufficient removal of heavy metals. The organic content
(TOC) was identified as remarkable parameter affecting the filtration performance
adversely.
Overall a broad set of data was generated and allows the presentation of a
quantitative comparison of different membrane-based treatment technologies for

an adjusted water management in the automotive industry with respect to
permeate quality, process performance and economical feasibility.

Drinking and Wastewater Applications I – 5
Monday July 14, 11:45 AM-12:15 PM, Maui
Membranes in Clean Technologies
A. Koltuniewicz (Speaker), Professor in University of Technology, Wroclaw, Poland,
akolt@interia.pl
E. Drioli, Professor in Istituto per la Tecnologia Delle Membrane, Italy
The clean technologies are based on effective separation of various
contaminants ‘at the source’ (e.g. before any dissipation takes place) to remove,
recover, reuse, or recycle them, which forms a closed cycle processes. The
paper reveals the new applications of membrane processes that offer efficient,
innovative pathways of reengineering and retrofitting different industrial sectors.
Recovery, recycling, reuse of water and valuable components play a dominant
role in saving costs resources energy, and protection of environment. The
Commission of the European Communities put the definition of Clean
Technologies as "any technical measures taken at various industries to reduce or
even eliminate at source the production of any nuisance, pollution, or waste, and
to help saving raw materials, natural resources and energy. The main attributes
of Clean Technologies were precisely formulated as:
1. Conservation of raw materials 2. Optimization of production processes 3.
Rational use of raw materials 4. Rational use of energy 5. Rational use of water,
6. Disposal or recycling of unavoidable waste 7. Accident prevention 8. Risk
management to prevent major pollution 9. and restoring sites after cessation of
activities.
Almost all attributes of the clean technologies may be fulfilled by using
membrane processes.
Conservation and rational use of raw materials is possible by application of
membrane processes for recovery, reuse, and recycling of unreacted substrates,
water and production media such as catalysts, solvents, surfactants, adsorbents,
cooling agents etc. Diluted metal ions may be gained from waste streams, mining
waters, tailings, leachates, seawaters etc. Diluted organic compounds may be
concentrated during pervaporation or membrane distillation, which additionally
takes advantage of and utilizes a waste heat. Thus membrane processes open a
new unexploited source of raw materials.
Membranes play an important role in optimization of production process and
rational use of energy in many ways, e.g. by the substitution of less energy
consuming membrane alternatives or their combination with conventional unit
processes which are known as ‘hybrid processes’. Membranes also open a new

prospect for new energy sources as fuel cells, new fuels. Conventional Energetic
sector uses large scale membrane plants for water recycling. Oil, gas and
petrochemical industries use membrane processes for products fractionation and
purification. Membranes may contribute in huge energy savings thanking to new
solutions of work, pressure, and energy recovery systems.
Water scarcity on the Earth is less harmful thanks to the exploitation of new
water resources. Desalination of brackish waters, sea waters and mining waters
by means of reverse osmosis and nanofiltration is matured practice. A rational
use of water during industrial processes may be attained by means of multiple
use and appropriate management of water and wastewater streams. In these
cases the proper adjusting of water quality to particular needs of each consumer
(within one water network) may be attained by membrane application for the
removal of all types of contaminants, e.g.: suspended solids, colloids, soluble
components, ions organic components. The disposal or recycling of unavoidable
waste streams may be achieved by a variety of membrane separations, which
enable to fractionate the wastewaters onto valuable pure materials that can be
subsequently reused as a resources or valuable by-products. The water
recovered by such separation can be recycled to the production processes.
Membrane processes reduce chemicals consumption during the regeneration of
ion exchange resins during water softening in power stations, and other
pollutants. Membranes enable the avoidance of the overdosing of fertilizers and
all kinds of chemicals used in agriculture, such as herbicides, and pesticides, by
means of controlled release. Insecticides are replaced by pheromones that are
also delivered precisely by means of membranes.
The aim of the paper is to:
1. Deliver up-to-date information about successful applications of membrane
based clean technologies in variety of industrial sectors, which may be a pattern
and stimulus for further development.
2. Present methodology of membrane implementation in clean technologies by
comparison of different alternative solutions and factors for evaluating their
effectiveness
3. Anticipate new potential area of membrane applications in clean technologies
basing on actual achievements and trends in development of membrane
processes.

Drinking and Wastewater Applications I – 6
Monday July 14, 12:15 PM-12:45 PM, Maui
Oxygen and Carbon Dioxide Control by Membrane Contactors in
Desalination
A. Criscuoli (Speaker), Institute on Membrane Technology, ITM-CNR, Italy, a.criscuoli@itm.cnr.it
M. Carnevale, Institute on Membrane Technology, ITM-CNR, Italy
H. Mahmoudi, Sciences & Engineering Sciences Faculty,University of Chlef, Algeria
S. Gaeta, GVS S.P.A., Italy
F. Lentini, GVS S.P.A., Italy
S. Reggiani, GVS S.P.A., Italy
E. Drioli, Department of Chemical Engineering and Materials, University of Calabria, Italy
In a desalination plant the content of oxygen and carbon dioxide has to be
controlled because it is responsible of corrosion problems in pipelines and of the
pH and the conductivity of the water. Moreover, the pH of the water can influence
the precipitation and scaling phenomena, so an adequate control becomes
essential for reducing fouling issues inside the plant. Chemical agents are often
used for adjusting the pH while vacuum/stripping towers have traditionally been
used to remove dissolved gasses. More recently, membrane contactors have
been proposed as alternative systems for water deoxygenation (particularly for
the semiconductor industry and boilers). The aim of this work is to apply
membrane contactors for the oxygen removal, as well as the pH control in a
desalination plant. Experimental tests have been carried out in a lab set-up with a
flat membrane module of 40 cm 2 of membrane area, by feeding in a countercurrent
mode the liquid stream and a gas stream (consisting of CO2 or N2). The
liquid stream was recycled to the module while the gas stream was sent in
continuous. Different parameters have been varied, such as the temperature, the
streams flow rates, the liquid composition. In particular, the liquid streams sent to
the system were distilled water and synthetic solutions, prepared for simulating
the reverse osmosis permeate and brine and the nanofiltration permeate. In this
way, the performance of the membrane contactor in different parts of a
desalination plant has been studied in terms of oxygen removal and pH
variations. Five different flat hydrophobic membranes of 0.2 mm were tested and
compared: PVDF, PVDF-treated, acrylic-based, PTFE and PP membranes.
Before tests, all membranes have been characterized by swelling, CAM and
SEM analysis. The oxygen removals were higher at higher temperatures and
higher liquid flow rates, varying slightly with the gas flow rates. Higher removals
were achieved for the more concentrated streams, due to the ‘salting-out effect’.
Both CO2 and N2 gas streams were able to strip, in a similar extent, the dissolved
oxygen from the liquid solutions. However, the final pH of the water decreased
after the tests with CO2, whereas increasing or remaining constant after using
N2, depending on the solution treated. This result is of extreme interest,
because, depending on the specific needs, it will be possible to couple the

oxygen removal to the desired pH. Concerning the performance of membranes,
the highest oxygen removal from distilled water has been obtained with the PTFE
membrane; however, during tests with saline solutions the removal decreased,
probably due to a reduction of the open structure, as observed by SEM.
Acknowledgements The authors acknowledge the financial support of the European Commission
within the 6th Framework Program for the grant to the Membrane-Based Desalination: An
Integrated Approach project (acronym MEDINA). Project no.: 036997.

Polymeric Membranes I – 1 – Keynote
Monday July 14, 9:30 AM-10:15 AM, Moloka’i
Layer-by-Layer Assembly in Membrane Pores for Ion Separations and
Biocatalysis
D. Bhattacharyya (Speaker), University of Kentucky, Lexington, KY, USA, db@engr.uky.edu
A. Hollman, University of Kentucky, Lexington, KY, USA
A. Butterfield, University of Kentucky, Lexington, KY, USA
V. Smuleac, University of Kentucky, Lexington, KY, USA
S. Datta, University of Kentucky, Lexington, KY, USA
The development of new-generation materials that extend the industrial
applications of membrane processes will require a high level of control of both
the characteristics of the base polymeric or inorganic support layer, as well as, its
corresponding surface properties. Current research in membrane science is now
focusing more on the modification of surface physical along with chemical
properties using techniques like plasma or radiation-induced polymer grafting,
immobilization of reactive ligands, layer-by-layer assembly, etc. Membranes
functionalized with appropriate macromolecules can indeed provide applications
ranging from tunable flux and separations, toxic metal capture, to nanoparticle
synthesis for toxic organic dechlorination. Microfiltration membranes (eg,
cellulosics, silica, polysulfone, polycarbonate, PVDF) can be functionalized with a
variety of reagents. Depending on the types of functionalized groups (such as,
chain length, charge of groups, biomolecule, etc.) and number of layers, these
microfiltration membranes could be used in applications ranging from metal (or
oxyanions) separation to biocatalysis. The dependence of conformation
properties of polyelectrolytes on pH also provides tunable separation and flux
control.
Layer-by-layer (LBL) assembly technique, most commonly conducted by
intercalation of positive and negative polyelectrolytes or polypeptides, is a
powerful, versatile and simple method for assembling supramolecular structures .
Non-stoichiometric immobilization of charged polyelectrolyte assemblies within
confined pore geometries leads to an enhanced volume density of ionizable
groups in the membrane phase. This increase in the effective charge density
allows for Donnan or charge-based exclusion of ionic species using porous
materials characterized by hydraulic permeability values well beyond
conventional membrane processes. Multilayer assemblies were fabricated using
both PLGA (poly-L-glutamic acid)/PLL(poly-L-Lysine) and synthetic
polyelectrolytes (poly(styrene sulfonate)/poly(allylamine)) in an attempt to
compare the level of adsorption and separation properties of the resulting
materials. The role of salt concentration in the carrier solvent on overall
polyelectrolyte adsorption was examined to determine its effect on both solute

(Cl - , SO4 2- , As(V)) and water transport. This type of assembly has shown that >
95% arsenic can be removed from water even at 1-3 bar operations. Constriction
of the pore size induced by multilayer propagation was monitored through
permeability measurements and dextran rejection studies at each stage of the
deposition process.
Multilayer assemblies of polyelectrolytes can also be created within the
membrane pore domain for enzyme immobilization and catalysis. Functionalized
membranes were created by two different approaches. In the first approach,
alternative attachment of cationic and anionic polyelectrolytes was carried out
using LBL assembly technique within nylon based microfiltration (MF)
membrane. In the second approach, hydrophobic poly-vinylidene fluoride (PVDF)
MF membrane was functionalized by in-situ polymerization of acrylic acid. The
enzyme, glucose oxidase (GOX), was then electrostatically immobilized inside
the functionalized membrane domains to study the catalytic oxidation of glucose
to gluconic acid and H2O2. Characterization of the functionalized membranes, in
terms of polyelctrolyte / polymer domains and permeate flux was also studied.
Kinetics of H2O2 formation are studied, along with the effects of residence time
and pH on the activity of GOX. Stability and reusability of the electrostatically
immobilized enzymatic system were also established. Applications also include
other bio-catalytic reaction systems. This research is supported by the NIEHS-
SBRP program

Polymeric Membranes I – 2
Monday July 14, 10:15 AM-10:45 AM, Moloka’i
Unusual Temperature Dependence of Positron Lifetime in a Polymer of
Intrinsic Microporosity
K. Rätzke (Speaker), Technische Fakultät der CAU, Lehrstuhl für Materialverbunde, Kaiserstr. 2,
Germany, kr@tf.uni-kiel.de
R. Lima De Miranda, Technische Fakultät der CAU, Lehrstuhl für Materialverbunde, Kaiserstr. 2,
Germany
J. Kruse, Technische Fakultät der CAU, Lehrstuhl für Materialverbunde, Kaiserstr. 2, Germany
F. Faupel, Technische Fakultät der CAU, Lehrstuhl für Materialverbunde, Kaiserstr. 2, Germany
D. Fritsch, Institut für Polymerforschung, GKSS-Forschungszentrum Geesthacht, Germany
V. Abetz, Institut für Polymerforschung, GKSS-Forschungszentrum Geesthacht, Germany
P. Budd, School of Chemistry, The University of Manchester, Manchester, UK
J. Selbie, School of Chemistry, The University of Manchester, Manchester, UK
N. McKeown, School of Chemistry, Cardiff University, Cardiff, UK
B. Ghanem, School of Chemistry, Cardiff University, Cardiff, UK
The performance of glassy polymeric membranes for gas separation is mainly
determined by the availiability of free volume. Polymers of intrinsic microporosity
are interesting candidates due to the high abundance of accessible free volume.
Positron annihilation lifetime spectroscopy (PALS) is a generally accepted
method for investigation of free volume in polymers due to the so-called standard
model developed by Tao and Eldrup. This simple quantum mechanical model
assumes the Ps to be confined to spherical holes with infinitely high walls and
gives a direct relationship between pick-off lifetime of orthopositronium and the
size of the free volume holes. Since hole sizes in amorphous polymers are
relatively broadly distributed, the discrete o-Ps lifetime obtained from fits to
lifetime spectra and hence the hole radius has to be regarded as an average
value.
We performed measurements of the temperature dependence of PALS in two
polymers of intrinsic microporosity (PIM-1 and PIM-7) in the range from 143 to
523 K [1] . The mean value of the free volume calculated from the orthopositronium
life time is in the range of typical values for high free volume
polymers. However, the temperature dependence of the local free volume is nonmonotonous
in contrast to the macroscopic thermal expansion. The tentative
explanation is linked to the spirocenters in the polymer. The intensity shows no
anomalous temperature behavior, but is dependent on the pretreatment of the
samples. Experiments are underway to clarify this unusual behavior and will be
presented on the conference.

[1] R. Lima de Miranda, J. Kruse, K. Rätzke, D. Fritsch, V. Abetz, P. M. Budd, J. D. Selbie, N. B.
McKeown, B. S. Ghanem and F. Faupel, pss-rapid research letters, phys. stat. sol. (RRL) 1, No.
5, 190-192 (2007)

Polymeric Membranes I – 3
Monday July 14, 10:45 AM-11:15 AM, Moloka’i
Macrovoid Formation in Polymeric Membranes and Critical Factors in
Fabricating Macrovoid-free Hollow Fiber Membranes
N. Peng, Department of Chemical & Biomolecular Engineering, National University of Singapore,
Singapore
T. Chung (Speaker), Department of Chemical & Biomolecular Engineering, National University of
Singapore, Singapore, chencts@nus.edu.sg
K. Wang, Department of Chemical & Biomolecular Engineering, National University of Singapore,
Singapore
The origins of macrovoids and the ways to eliminate them have received great
attention and heavy debates during the last five decades, but no convincing and
agreeable comprehension has been achieved. Recently, due to resource
depletion, record high oil prices, and clean water shortage, the development of
macrovoid-free hollow fibers for water production and recycle, energy and
medical applications has received tremendous attention worldwide in the
membrane companies. This work will systematically investigate the key factors to
form macrovoid-free hollow fiber membranes. We have observed there should be
critical values of polymer concentration, air gap distance and take-up speed, only
above all of which the macrovoid-free hollow fibers can be successfully
produced. This observation was confirmed for hollow fibers spun from different
polymer materials such as polysulfone, P84 and cellulose acetate, and may be
even universally applicable for other polymers. The major mechanisms why
these critical parameters can effectively suppress macrovoids will be elaborated.
The most important of all, the concept of acceleration of stretch has been
proposed to quantitatively correlate the critical polymer concentration, critical
take-up speed and critical air gap distance in the formation of macrovoid-free
hollow fiber membranes for a polymer/solvent binary system. A linear relationship
can be reasonably observed between the square root of the number of
macrovoids per unit area and the acceleration of stretch. Even though this
mathematical description is still in its early stage and requires further
investigation due to the complexity of spinning process, this model does provide
some fundamental understanding of material related and process related
tendency of macrovoid formation, as well as implies there may be a universal
scaling to characterize a two- component polymer solution to fabricate
macrovoid-free hollow fiber membranes in consideration of extension viscosity,
Weissenberg number and die swell phenomena.

Polymeric Membranes I – 4
Monday July 14, 11:15 AM-11:45 AM, Moloka’i
Preparation of Porous Poly (ether ether ketone) Membranes
Y. Ding (Speaker), PoroGen Corporation, Woburn, MA, USA, yding@porogen.com
B. Bikson, PoroGen Corporation, Woburn, MA, USA
Membrane separation processes can be energy efficient as compared to
distillation since components do not undergo phase change during separation. In
order to replace the energy intensive distillation and evaporation separation
technologies utilized by numerous industries, including the energy sector and the
pharmaceutical industry, with a membrane process, a membrane system that is
capable of operation in the presence of various organics and at elevated
temperatures is required. Most conventional commercially available polymeric
membranes are prepared by solution based processes and thus do not provide
the desired solvent and/or chemical resistance. Inorganic membranes can
operate in a broad range of organic solvents and at elevated temperatures but
typically do not have sufficient hydrolytic stability and can be cost prohibitive.
Poly(ether ether ketone), PEEK, is a semi-crystalline high performance
engineering polymer, that is well known for its solvent/ chemical resistance and a
high temperature operating capability. The excellent chemical and physical
characteristics of PEEK make it an ideal candidate for the preparation of the next
generation of polymeric membranes that can combine inorganic membrane
performance capability with polymeric membrane price. Herein, we report
successful preparation of porous PEEK membranes and their applications for
fluid separation at high temperatures and in organic solvent media.
Porous PEEK membranes were prepared by a melt extrusion process from
compatible PEEK/polyimide blends. The polyimide served as a porogen and was
removed quantitatively to form the target porous PEEK membrane. Membrane
morphology and pore size was controlled by the blend composition and
processing conditions. The methodology is highly flexible and provides for
preparation of both flat sheet and hollow fiber membranes. PEEK exhibits
thermo-mechanical properties superior to almost all engineering polymers
currently in use in membrane preparation. Porous PEEK membranes are semicrystalline
with the crystalline fraction typically higher than 35%. This degree of
crystallinity is comparable to that of dense (non- porous) PEEK articles produced
by melt extrusion. Consequently, porous PEEK membranes are highly solvent
resistant and can operate at high temperatures. These characteristics enable the
use of PEEK membranes in aggressive fluid environments and at high operating
temperatures. These characteristics also enable preparation of PEEK
membranes with modified surface characteristics by functionalizing the surface
without altering membrane morphology or durability.

Porous PEEK membranes with controlled pore size in the range of 5 to 500 nm
were prepared. The methodology allows for preparation of porous materials with
a high pore volume and very high surface area. Porous membranes with a
surface area as high as 250 m 2 /g were prepared as measured by nitrogen
adsorption BET.
Hollow fiber membranes with broad range of dimensions ranging from 250 nm to
2 mm in diameter were prepared and showed stable filtration performance in a
broad range of solvents including chlorinated hydrocarbons, aprotic solvents,
aromatic solvents, alcohols and ketones.
Surface functionalization was utilized to further tailor membrane characteristics
towards target separation application. Hydrophilic PEEK membranes were
prepared by modifying porous PEEK membrane surface with hydroxyl groups
(~OH) through selective ketone group reduction or by grafting hydroxyl group
containing molecules to porous PEEK membrane surface through imine group
formation. This methodology allows for preparation of hydrophilic membranes
with the surface energy as high as 65 dyne/cm. Highly hydrophobic porous
membranes are prepared by grafting porous PEEK membrane surface with
perfluorohydrocarbons. Porous membranes with very low surface energy that do
not wet by alcohols can be prepared.
Porous PEEK hollow fibers can serve as an ideal substrate for preparation of
composite membranes. Nanofiltration membranes and gas separation
membranes can be prepared by depositing a surface separation layer by solution
coating or by surface grafting. PEEK based nanofiltration membranes with
molecular weight cut-off of 2000 Dalton capable of stable operation in solvents
was prepared. Composite gas separation membranes capable of high
temperature operation were also prepared. Stable continuous operation in air for
more than 500 hours at 200 ºC was demonstrated.
Acknowledgements: The work was supported in part by DOE Invention and
Innovation Program, DOE SBIR Program and USDA SBIR program.

Polymeric Membranes I – 5
Monday July 14, 11:45 AM-12:15 PM, Moloka’i
Design of New Membranes Assisted By Block Copolymer Assembly
S. Querelle, Université Montpellier, France
F. Ellouze, Ecole Nationale d'Ingénieur de Tunis, France
D. Quémener, Université Montpellier, France
A. Deratani (Speaker), Université Montpellier, France, Andre.Deratani@iemm.univ-montp2.fr
T. Phan, University Aix-Marseille, France
D. Gigmes, University Aix-Marseille, France
D. Bertin, University Aix-Marseille, France
Block copolymers enable well-defined micro- and nano-structure design thanks
to their excellent properties to self-assemble. This building bricks can be used in
Membrane Science in order to control membrane morphology. It is assumed that
heterogeneous structure (high polydispersity of the pore size) could be
reorganized in homogeneous structure by using block copolymers. In this
contribution, our last results in this field will be discussed, showing that block
copolymers, pure or in blend, can help in the production of membrane with
controlled architecture and interfacial properties.

Polymeric Membranes I – 6
Monday July 14, 12:15 PM-12:45 PM, Moloka’i
Effect of Network Structure Modifications of Cross-linked Poly(ethylene
oxide) Membranes on Gas Separation Properties
V. Kusuma (Speaker), University of Texas at Austin, Austin, TX, USA, kusuma@che.utexas.edu
B. Freeman, University of Texas at Austin, Austin, TX, USA
M. Danquah, University of Kentucky, Lexington, KY, USA
M. Borns, University of Kentucky, Lexington, KY, USA
A. Comer, University of Kentucky, Lexington, KY, USA
D. Kalika, University of Kentucky, Lexington, KY, USA
Cross-linked poly(ethylene oxide) (XLPEO) was recently identified as a promising
material to remove polar and acid gases, such as CO2, from mixtures with light
gases [1] . Prepared by cross-linking low molecular weight poly(ethylene glycol)
diacrylate with other poly(ethylene oxide) acrylates, XLPEO exhibits good
separations properties thanks to the ethylene oxide group interaction with CO2
and elimination of crystallinity due to the presence of cross-links.
This talk will discuss recent efforts aimed at exploring other cross-linkable
poly(ethylene oxide) containing acrylates to improve separations performance of
XLPEO. In particular, we will explore the effects of copolymerizing poly(ethylene
glycol) diacrylate with monoacrylates with a variety of functional groups. This
modification results in substantial changes in polymer free volume and chain
mobility, which, in turn, affects the transport properties of the materials. Dynamic
mechanical analysis results will be presented along with transport properties
measurement results to correlate the changes in network structure with the
changes in transport properties.
[1] H. Lin, T. Kai, B. D. Freeman, S. Kalakkunnath, D. S. Kalika, The Effect of Crosslinking on
Gas Permeability in Crosslinked Poly(ethylene glycol diacrylate), Macromolecules 2005, 38,
8381-8393.

Biomedical and Biotechnology I – 1 – Keynote
Monday July 14, 9:30 AM-10:15 AM, Honolulu/Kahuku
Fouling Characteristics of Virus Filtration Membranes
M. Bakhshayeshi, The Pennsylvania State University, University Park, PA, USA
R. Kuriyel, PALL Life Sciences, USA
N. Jackson, PALL Life Sciences, USA
A. Mehta, Genentech, USA
O. Paley, Genentech, USA
A. Zydney (Presenting), The Pennsylvania State University, University Park, PA, USA,
zydney@engr.psu.edu
Virus filtration provides a robust, size-based method for virus removal that
compliments other unit operations to achieve the very high levels of viral
clearance required for the production of therapeutic proteins. Several
manufacturers make membranes specifically targeted for virus filtration
applications, each having very different pore morphologies. A critical challenge
for all virus filtration membranes is protein fouling, which can severely limit the
membrane capacity and may even contribute to incomplete virus retention. The
objective of this study was to examine the fundamental mechanisms governing
protein transport and fouling during virus filtration.
Experiments were performed with Pall Ultipor DV20 virus filters made from a
hydrophilic PVDF membrane, with Bovine Serum Albumin and Human
Immunoglobulin G used as model proteins. Data were obtained for operation at
both constant pressure and constant flux, with the protein size distribution
analyzed using high performance size exclusion chromatography. Results for the
flux decline (for operation at constant pressure) and pressure rise (for operation
at constant flux) were analyzed using available fouling models. The effects of
fouling on the membrane were examined from both buffer permeability and
dextran sieving measurements obtained with the clean and fouled membranes.
Protein recovery was essentially 100% under all conditions, with no measurable
retention of protein monomers or dimers. Stirring had almost no affect on the flux
(at constant pressure) or the transmembrane pressure (at constant flux),
indicating that concentration polarization effects were negligible in this system.
The rate of fouling for the DV20 filters was quite low compared to prior results
obtained with Viresolve membranes, which appears to be due to differences in
the membrane permeability and underlying pore structure. Fouling caused a
small shift in the dextran sieving profiles, consistent with a reduction in the
effective membrane pore size. The membrane capacity appears to be a complex
function of the bulk protein concentration, with the capacity passing through a
maximum at an intermediate protein concentration under some conditions. These

esults provide important insights into the design and operation of virus filtration
systems for the production of therapeutic proteins.

Biomedical and Biotechnology I – 2
Monday July 14, 10:15 AM-10:45 AM, Honolulu/Kahuku
Developments in Membrane Affinity Chromatography for Monoclonal
Antibody Recovery
S. Dimartino, University of Bologna, Bologna, Italy
C. Boi, University of Bologna, Bologna, Italy
G. Sarti (Speaker), University of Bologna, Bologna, Italy, giulio.sarti@unibo.it
The great number of process development for monoclonal antibodies, presently
in development stage, has emphasized the capability limits of the biotech
industry. The recent improvements of cultivation technology, allow also to
achieve high titers of monoclonal antibody in cell supernatants, and the present
bottleneck for MABs’s production is associated to the downstream process
required for product recovery. Bead-based affinity chromatography with Protein A
is widely used in the primary capture stage. Membrane affinity chromatography
has not yet experienced extensive application due to the lower capacity of
membrane supports compared to chromatographic beads, yet it has several
advantages deserving serious attention. This work is focused on the purification
of Immunoglobulin G (IgG) with affinity membranes. A new Protein A affinity
membrane (Sartorius, Göettingen, Germany), as well as affinity membranes
prepared with synthetic ligands have been characterized in detail in batch and
dynamic experiments. The membranes have been analysed by using pure
solutions of polyclonal IgG, to determine their binding capacity, as well as a cell
supernatant containing monoclonal IgG, to investigate their selectivity and
general behavior. The influence of process conditions like flow rate and feed
concentration on adsorption and elution have been studied to obtain indications
for the optimal process conditions. The affinity membrane purification process
was also simulated with a mathematical model which was validated by using the
experimental data obtained. The model can simulate adsorption, washing and
elution steps by taking into account all the relevant transport phenomena.

Biomedical and Biotechnology I – 3
Monday July 14, 10:45 AM-11:15 AM, Honolulu/Kahuku
Bioactive Membranes for Liver Tissue Engineering
L. De Bartolo (Speaker), Institute on Membrane Technology, National Research Council of Italy,
ITM-C, Italy, l.debartolo@itm.cnr.it
S. Salerno, Institute on Membrane Technology, National Research Council of Italy, ITM-C, Italy
A. Piscioneri, Institute on Membrane Technology, National Research Council of Italy, ITM-C, Italy
S. Morelli, Institute on Membrane Technology, National Research Council of Italy, ITM-C, Italy
M. Rende, Institute on Membrane Technology, National Research Council of Italy, ITM-C, Italy
C. Campana, Institute on Membrane Technology, National Research Council of Italy, ITM-C, Italy
E. Drioli, Institute on Membrane Technology, National Research Council of Italy, ITM-C, Italy
Biomaterials in tissue engineering and regenerative medicine should provide the
necessary support for cells to proliferate and maintain their differentiated
functions. The use of polymeric semipermeable membranes with different
physico-chemical and transport properties is appealing in tissue engineering and
bioartificial organs since these and biomembranes share similarities such as the
selective transport of molecules, resistances and protection. Furthermore,
synthetic membranes can easily be mass produced modulating their
morphological and physico-chemical properties for specific applications.
Semipermeable membranes for their characteristics of selectivity, stability and
biocompatibility could provide a support for the maintenance of hepatocyte
phenotype and differentiated functions. In this study we report on the synthesis of
novel semipermeable membranes able to support the long-term maintenance
and differentiation of human liver cells and on the strategies to optimise cellbiomaterial
interactions in biohybrid systems. We developed membrane biohybrid
system constituted by membranes made from a polymeric blend of modified
polyetheretherketone and polyurethane (PEEK-WC-PU) and human hepatocytes.
This membrane combines the advantageous properties of the polymers (i.e.,
biocompatibility, biostability and biofunctionalities) with those of membranes such
as permeability, selectivity and well-defined geometry. Molecular modifications of
the membrane elicit specific interactions with cell receptors and thereby enhance
liver functions. Human hepatocytes organize in a 3D structure in the membrane
biohybrid system maintaining a polygonal shape, which would lead to better
functional maintenance, so many of the features of the liver in vivo are
reconstituted. Liver specific functions investigated in terms of urea synthesis,
albumin production and total protein secretion are maintained at high levels.
Hepatocytes are able to biotransform diazepam, which is an anti anxiety agent
(benzodiazepines), through the formation of its typical metabolites including
temazepam, N-desmethyl-diazepam and oxazepam. This engineered liver
construct is able to promote adhesion and to provide a microenvironment able to
elicit specific cellular responses.

Acknowledgments The Authors acknowledge European Commission through the Livebiomat
project, Contract No. NMP3-CT-2005-013653.

Biomedical and Biotechnology I – 4
Monday July 14, 11:15 AM-11:45 AM, Honolulu/Kahuku
Separation and Purification of Hematopoietic Stem Cells from Human
Blood through Surface-modified Membranes
A. Higuchi (Speaker), Nat. Central Univ. & Nat. Res. Institute for Child Health & Develop., Tokyo,
Japan, higuchi@ncu.edu.tw
Y. Chang, Chung Yuan Christian University, Taoyuan, Taiwan
R. Ruaan, National Central University, Taoyuan, Taiwan
W. Chen, National Central University, Taoyuan, Taiwan
Efficient cell separation is important for the successful isolation and purification of
blood cells, stem cells and specific tissue cells. Techniques such as
centrifugation, affinity column chromatography, and fluorescence activated cell
sorting (FACS), magnetic cell selection, and membrane filtration are typically
employed for cell separation. The centrifugal separation of cells is a typical
method employed to isolate platelets, leukocytes, mononuclear cells, red blood
cells and non-blood cells. Highly purified cellular preparations are obtained using
FACS or a magnetic cell selection system in conjunction with a fluorescentlylabeled
antibody as the cell-surface marker. Cell separation through membrane
filtration was recently reported by several researchers. Leukocyte removal filters
are commercially available cell separation filters. The stem cells that form blood
and immune cells are known as hematopoietic stem cells. Hematopoietic stem
and progenitor cells bear the CD34 cell surface marker. These cells are thought
to be responsible for the reconstitution of hematopoiesis. Therefore, the
transplantation of CD34+ cells is essential in the therapy of patients with acute
myeloid leukemia, myelodysplastic syndromes, chronic myeloid leukemia and
systemic mastocytosis. In a previous investigation (A. Higuchi et al., J. Biomed.
Mater. Res. 68A, 34 (2004)), cell separation from peripheral blood at fixed blood
permeation speeds (1 ml/min) was investigated using surface-modified
polyurethane (PU) membranes with a fixed pore size of 5 mm, carrying different
functional groups. However, optimal conditions for the purification of CD34+ cells
from blood using membrane filtration were still undetermined. In this study, we
prepared several of the membranes, and conducted further experiments on the
separation of CD34+ cells using the membranes.
Cell separation from peripheral blood was investigated using polyurethane (PU)
foam membranes having 5.2 mm pore size and coated with Pluronic F127 or
hyaluronic acid. The permeation ratio of hematopoietic stem cells (CD34+ cells)
and lymphocytes through the membranes was lower than for red blood cells and
platelets. Adhered cells were detached from membrane surfaces using human
serum albumin solution after permeation of blood through the membranes,
allowing isolation of CD34+ cells in the permeate (recovery) solution. High- yield

isolation of CD34+ cells was achieved using Pluronic-coated membranes. This
was because the Pluronic coating dissolved into the recovery solution at 4oC,
releasing adhered cells from the surfaces of the membranes during permeation
of human serum albumin solution through these membranes. Dextran and/or
bovine serum albumin solutions were also evaluated for use as recovery
solutions after blood permeation. A high recovery ratio of CD34+ cells was
achieved at 4oC in a process using 20% dextran solution through polyurethane
(PU) membranes having carboxylic acid groups. CD34+ (hematopoietic stem)
cells were efficiently recovered (85% recovery ratio) through PU-COOH
membranes in a process using 20 wt% aqueous dextran as the recovery
solution. This indicated that dextran solution was preferable to HSA and BSA
solutions during the recovery process.
Forraz et al. (Stem Cells 22, 100 (2004)) reported that negative-isolated cells,
which depleted umbilical cord blood mononuclear cells from blood cells
expressing mature hematopoietic markers (glycophorin A, CD2, CD3, CD7,
CD16, CD33, CD38, CD45 and CD56), lineage- negative cells, enriched longterm
culture- initiating cells. The lineage-negative cells maintained and expanded
more primitive hematopoietic stem and progenitor cells than CD34+ and CD133+
cells, and expressed higher levels of the cell-adhesion molecule CD162
[expression ratio (ER) = 16.0%] and CD164 (ER = 96.7%) involved in
hematopoietic progenitors forming bone marrow than CD34 (ER = 14.4%) and
CD133 (ER = 7.0%). Therefore, primitive hematopoietic stem and progenitor cells
tend to adhere to polyurethane (PU) membrane surfaces, due to their expression
of these cell-adhesion molecules on their surfaces.
The exact surface marker for primitive hematopoietic stem and progenitor cells
remains unclear at the current time. Isolating such cells by membrane filtration of
umbilical cord or bone marrow is thought to be more effective than magnetic
bead or flow cytometry sorting methods, because cell separation in membrane
filtration is based not only on cell size, but also on the intensity of cell adhesion to
the membrane surface. Of all methods, membrane separation is likely to provide
the most sanitary and simple isolation of primitive hematopoietic stem and
progenitor cells.

Biomedical and Biotechnology I – 5
Monday July 14, 11:45 AM-12:15 PM, Honolulu/Kahuku
Membrane Chromatography: Protein Purification using Newly Developed,
High-Capacity Adsorptive Membranes
B. Bhut (Speaker), Clemson University, Clemson, SC, USA, shusson@clemson.edu
S. Wickramasinghe, Colorado State University, Fort Collins, CO, USA
S. Husson, Clemson University, Clemson, SC, USA
Considering that the total cost of protein therapeutics is shifting from cell culture
to downstream purification, high productivity and high resolution separation
techniques are in demand by the biopharmaceutical industry. Membrane
chromatography offers several advantages over resin-based media, such as low
pressure drop and facile scale up and set up. High dynamic capacities are
needed to meet productivity demands. The objective of this research was to
investigate dynamic adsorption capacities and protein fractionation behavior of
newly developed adsorptive membranes. High dynamic capacity (>50 mg/ml
BSA) ion-exchange membranes were produced by grafting functional polymer
nanolayers from commercially available regenerated cellulose membranes using
atom transfer radical polymerization. Separation parameters and dynamic
adsorption capacities were measured using polymerization time as independent
variable. Flow effects on dynamic binding capacity and separation efficiency
were studied using an Akta purifier.

Biomedical and Biotechnology I – 6
Monday July 14, 12:15 PM-12:45 PM, Honolulu/Kahuku
Using Micro-Dialysis to Monitor Tissue Production
J. Wu (Speaker), University of Durham, Durham, UK, junjie.wu@durham.ac.uk
R. Field, University of Oxford, Oxford, UK
Diseased or damaged tissues as well as tissue degeneration are common to all
living organisms. Tissue engineering has the potential to address tissue failure by
providing functional biological substitutes grown in vitro that are able to integrate
with host tissues and remodel in vivo after implantation. There is a growing
interest in using large pore size probes for microdialysis of macromolecular
markers to monitor cell and tissue functions, and to determine the optimal
conditions for the design and manufacture of scalable bioprocessing system for
the regeneration of three-dimensional tissue that behaves similarly to their
biological counterparts.
Fluid balance could be an important issue when using such probes and Li et al
(JMS 2008) studied three modes of operation. The pumping systems generated
either push or pull or push-and-pull modes of flow. It was found that the relative
recovery of small solutes is not affected much by the applied pumping method
but that the relative recovery of macromolecules is significantly influenced.
Through use of the Krogh cylinder assumption analytical expressions are
obtained which contribute towards an explanation of this finding. Also a
comparison is made between the concentration distribution of tracers that are
added to the nutrient feed and the concentration distribution of produced
material. There can be a significant difference between the two depending upon
the selectivity of the microdialysis probe.

Membrane Fouling - General Topics – 1 – Keynote
Monday July 14, 9:30 AM-10:15 AM, O’ahu
Protein Fouling of Polymeric Membranes: Modeling and Experimental
Studies Using Ultrasonic Frequency-Domain Reflectometry
E. Kujundzic, University of Colorado at Boulder Department of Mechanical Engineering, Boulder,
CO, USA
K. Cobry, University of Colorado at Boulder Department of Mechanical Engineering, Boulder, CO,
USA
C. Ho, University of Cincinnati, Department of Chemical and Materials Engineering, Cincinnati,
OH, USA
W. Li, University of Cincinnati, Department of Chemical and Materials Engineering, Cincinnati,
OH, USA
A. Greenberg, University of Colorado at Boulder Department of Mechanical Engineering, Boulder,
CO, USA
M. Hernandez (Speaker), University of Colorado at Boulder Department of Civil, Architectural
and Engineering, Boulder, CO, USA, mark.hernandez@colorado.edu
Biofouling is a major problem associated with membrane separation processes
that causes decreased performance and altered selectivity. Biofouling typically
occurs either on the membrane/feed solution (external) surface or within the
pores that are internal to the membrane structure. Accurate characterization of
protein fouling as it occurs is crucial for an improved understanding of fouling
mechanisms with respect to biofouling control and membrane cleaning
optimization. A promising approach for achieving these objectives involves the
application of fouling models, which can be validated using data from noninvasive,
real-time monitoring of relevant membrane separations. Clearly, there
are significant benefits in employing real-time, non- destructive methods that can
resolve changes in accumulating mass on membrane surfaces and/or to the
materials that fill membrane pores, where these markedly different fouling
mechanisms can be isolated from each other. The only practical methodology
that currently satisfies these criteria is ultrasonic reflectometry (UR). Recent
reports have described the ability of UR to monitor the development of biofilms
on the surfaces of flat- sheet and hollow-fiber membranes used for drinking water
treatment. We describe the use of novel signal-processing protocols to extend
the sensitivity of UR for real-time in-situ monitoring of MF membrane fouling
during protein separations and purification.
Different commercial MF membranes with a nominal pore size of 0.2µm were
challenged using bovine serum albumin (BSA) and well-characterized bacterial
amylase as model proteins. Biofouling induced by these proteins was observed
in flat- sheet cells operating in a laminar, cross-flow regime. Membranes were
fouled by challenging these units with solutions containing BSA or amylase at
levels high as 1g/L. Baseline conditions were established by running ultrapure
water thorough the system for at least 24h. In a series of independent trials, the

membranes were then challenged with different protein formulations (pH, ionic
strength, protein mass) for 5 to 25h depending on the fouling response. During all
tests, the in-situ detection of proteins associating with the membranes used
ultrasonic frequency- domain reflectometry (UFDR) integrated with a fast Fourier
transform protocol to process the signals. Time-domain signals of acoustic scans
from ultrasonic transducers mounted on cross-flow cells were transformed into
amplitude versus frequency distributions. From these distributions, reflected
power was obtained, and standard statistical indices were used to report and
characterize the distributions. Following cross-flow cell tests, membrane samples
were analyzed using ESEM, and the proteins associated with the membranes
were determined using a bicinchoninic protein assay.
Depending on the fouling challenge conditions, permeate flow-rate decreased in
a range between 40-90%. Permeate flow-rate responses, and patterns of
corresponding acoustic reflection power changes, indicated that both internal
membrane and surface deposition occurred, and could be identified as separate
fouling mechanisms during some challenge conditions. The permeate-flow rate
decline data can be described using the combined pore blockage, pore
constriction, and cake filtration model. The best fit model parameters can be
independently obtained based on the property of the feed and membrane
characteristics. In some instances however, transducers were unable to detect
reflected power changes even after significant permeate-flow rate decline
occurred. This phenomenon could be explained by the fact that permeate flowrate
observations are derived from overall membrane behavior, whereas UFDR
is applied in a sentinel format, which reports acoustic responses of small area
(point) observations on a very short timescales. In addition, membrane-
associated protein deposits are visco-elastic, and can (and likely do) reposition
on or through a membrane during the course of a fouling challenge; this can
manifest in a wide variability of reflected power changes as protein density
changes on a local scale during a test. Biochemical assays of protein
concentrations associated with membranes and ESEM micrographs confirmed
that a significant heterogeneity of protein deposition was in part responsible for
the fouling behavior and local density changes observed by UFDR. Where
protein concentration on the membrane varied between 5 to 100µg/cm 2 , ESEM
observations showed non- uniformity of protein deposition in a capricious patchy
array, with a significant amount of clean membrane area exposed; beyond this
range however (100µg/cm 2 ), continuous protein layers were observed on
challenged membrane surfaces.
The use of fouling models in combination with non-invasive, real-time monitoring
provides a unique capability to improve the fundamental understanding and
control of MF membrane fouling by commercially significant proteinaceous
biopolymers.

Membrane Fouling - General Topics – 2
Monday July 14, 10:15 AM-10:45 AM, O’ahu
Assessment of Ultrasound as Fouling Control Technique in Crossflow
Microfiltration for the Treatment of Produced Water
S. Silalahi (Speaker), Norwegian University of Science and Technology, Norwegian,
sumihar.silalahi@ntnu.no
T. Leiknes, Norwegian University of Science and Technology, Norwegian
Produced water is contaminated water containing residual concentrations of
chemical additives, dispersed oil in water (o/w) emulsions, dissolved organic
compounds, traces of heavy metals and inorganic compounds, which is extracted
during oil and gas drilling operations. In 2005, the total amount of produced water
discharged to the North Sea was about 177 million m 3 , resulting in approximately
2800 m 3 of oil being discharged to the sea. Regulations that govern the allowable
discharge of oil into sea from offshore installation on the Norwegian Continental
Shelf (NCS) were 40 mg/l of oil in water (up to end of 2006) and is currently 30
mg/l. More stringent regulations are expected in the future.
Membrane separation has the potential for very effective separation of oil from
water. It has been applied for the treatment of produced water and oily
wastewaters. The major drawback of membrane technology is the fouling
phenomena, which in the long term will cause a progressive decrease of flux and
induce a loss of separation efficiency. Fouling mitigation has been approached
by; feed pre-treatment, modified membrane surface material, flow manipulations
(i.e. backpulsing, flow reversal, turbulence promoters etc.), applying additional
force fields (i.e. electrical fields and ultrasound fields). Fouling can also be limited
by operating the membrane under certain hydrodynamic conditions.
Ultrasound is a potential technique that can be used for membrane fouling
control and cleaning. The advantages of US to control membrane fouling are no
chemical use and no interruption during filtration. US dislodges fouling layers
formed on the membrane due to effects such as acoustic streaming,
microstreaming, microstreamers, microjets, and shock waves. The objective of
this study is to asses US for fouling control for treatment of produced water. The
effectiveness of ultrasound-assisted membrane filtration was determined by
various parameters i.e. ultrasound frequency and power, feed properties,
membrane properties and operation condition.
An analogue produced water was prepared by dispersing oil in surfactant and
water. Solid particles, scaling and corrosion inhibitor were also added to make-up
the analogue for Ceramic Al2O3 membrane with pore sizes of 0.1, 0.2 and 0.5µm

in crossflow mode operation were investigated. US with frequencies 25, 45, and
100 kHz respectively and power intensity of 600W were tested.
The effect of power intensity, frequency, mode of US operation (continuous vs.
intermittent) for different membrane pore sizes will be presented. Tests are done
with different feed properties. An optimum power intensity and frequency to
control the fouling was observed. Presence of particles plays a significant role to
reduce the performance by attenuating the ultrasound power.
Keywords: Produced water, microfiltration, fouling, ultrasound

Membrane Fouling - General Topics – 3
Monday July 14, 10:45 AM-11:15 AM, O’ahu
Impact of Diluate Solution Composition in Protein and Magnesium on
Membrane Fouling During Conventional ED
G. Pourcelly (Speaker), Institut Europeen des Membranes, France,
gerald.pourcelly@iemm.univ-montp2.fr
C. Casademont, University Laval, Québec, Canada
E. Ayala Bribiesca, Institut Nutraceutiques et Aliments Fonctionnels, Québec, Canada
M. Araya Farias, Institut Nutraceutiques et Aliments Fonctionnels, Québec, Canada
L. Bazinet, Institut Nutraceutiques et Aliments Fonctionnels, Québec, Canada
Fouling formation is among the most important limitations in electrodialysis (ED)
processes. Build- up of fouling film causes an increase in resistance, which
deteriorates the performance of process and can eventually lead to membrane
integrity alteration [1] . Numerous studies have been done on the identification of
species causing fouling [2-3] , but most of these works are directly related to anion-
exchange membrane (AEM), since their fouling susceptibility is higher than that
of cation- exchange membrane (CEM). But recently, the formation of a mineral
fouling on CEM and AEM has been reported during conventional ED of different
solutions of CaCl2 and Na2CO3 [2] . Furthermore, during the production of high
purity bovine milk casein isolates from skim milk by bipolar membrane
electroacidification (BMEA), a further step in the ED process evolution, where
bipolar membranes allow the dissociation of water molecules in protons and
hydroxyl ions under an electric field, two types of fouling were observed. A
mineral fouling identified as a mixture of CaCO3 and Ca(OH)2 was observed on
both sides and inside the CEM as well as a slight protein fouling on the CEM. For
the CaCO3 mineral fouling, it was suggested that nucleation would be the
controlling step, since crystallization occurred when the nuclei were formed and
the solution was supersaturated [4] and that Mg, present in milk at an average
concentration of 105 mg/kg would initiate and structure the formation of CaCO3 [5-
6] . However the impact of Mg on the formation of a CaCO3 fouling at the interface
of a CEM has never been studied. In addition, not much work characterizing
protein-caused fouling of ED membranes has been found.
The aim was to study the effect of the concentrate solution pH, the composition
in calcium, carbonate, magnesium (at different ratios of Mg/Ca) and protein of the
diluate solution to be treated by conventional ED on the fouling of ion- exchange
membranes. Conductivity, system resistance, pH of the diluate and cation
migration were monitored to follow the evolution of the demineralization. Acidic
and neutral conditions led to protein film formation over the diluate side of the
AEM, but basic conditions prevented its formation. Protein fouling on CEM was
not visually apparent. CEM presented mineral fouling only in basic concentrate
conditions when calcium was present, which would precipitate as calcium

hydroxide. For Mg/Ca = 0, the fouling observed on the surface in contact with the
basified concentrate was only formed by Ca(OH)2. As soon as Mg was
introduced into the solution treated, CaCO3 was observed. Furthermore, the Xray
diffraction results also identified the CaCO3 observed as calcite. From Mg/Ca
= 1/20 to 1/5, the amount of calcite increased with the Mg concentration. For
Mg/Ca > 1/5, an undesired fouling appeared on each side of the CEM and on the
concentrate side of the AEM whereas, under this ratio, no fouling was detected
on AEM and only on the CEM concentrate side. The membrane fouling mainly
affected the ED efficiency in basic conditions. Starting from Mg/Ca = 1/5, the
CEM permselectivity was significantly affected and a drastic decrease in the
current efficiency occurred. The direct consequence of this alteration was the
migration of hydroxyl ions through the CEM toward the anode. The hydroxyl
leaching also explains the mineral deposit observed on the diluate side of the
CEM. Mineral fouling on the concentrate side of AEM was due to recirculation
and mixture of both anion and cation-receiving streams. The stack configuration
used allowed calcium to migrate through CEM and, by recirculation, to be in
contact with the AEM and thus to precipitate on its surface, as CaCO3 and
Ca(OH)2.
According to these results, the separation of the concentrate stream in two
different loops would prevent formation of both, mineral and protein foulings. An
acidic or neutral pH condition should be maintained for the cation-receiving
stream in order to prevent mineral fouling on the concentrate side of CEM. This
loop must remain independent to the anion receiving one. A basic pH should be
maintained for the latter to prevent formation of a protein film over the AEM
surface. Mineral fouling on AEM will no longer form, as calcium will not enter in
contact with the concentrate side of such membrane.
[1]: M.Bleha, G.Tishchenko, V.Sumberova, V.Kudeala, Desalination 86(1991)73
[2]: L.Bazinet, M.Araya-Farias, J.Colloïd Interface Sci., 286(2005)639
[3]: E. Ayala-Bribiesca, G.Pourcelly, L.Bazinet, J.Colloid Interf Sci, 308(2007)182
[4]: T.H.Chong, R.Sheikholeslami, Chemical Engineering Sci., 56(2001)5391
[5]: F.C.Meldrum, S.T.Hyde, J. Crystal Growth, 231(2001)544
[6]: E.Loste, R.M.Wilson, R.Seshadri, F.C.Meldrum, J. Crystal Growth, 254(2003)206

Membrane Fouling - General Topics – 4
Monday July 14, 11:15 AM-11:45 AM, O’ahu
MBR Activated Sludge Filterability Alteration in Stress Circumstances
S. Geilvoet (Speaker), Delft University of Technology, The Netherlands, s.p.geilvoet@tudelft.nl
J. Van der Graaf, Delft University of Technology, The Netherlands
A. Van NIeuwenhuijzen, Delft University of Technology, The Netherlands
Fouling in membrane bioreactor (MBR) systems is an extensively investigated
research topic. Significant progress has been made in understanding fouling, but
nevertheless it still is a major point of attention in full-scale MBR operation and
many questions still remain unanswered. Simply stated the fouling potential in a
membrane bioreactor (MBR) system is depending on three factors: membrane
properties, membrane operation and activated sludge properties. Because in
practice every MBR plant has its own unique combination of these three factors,
it is difficult to determine which factor(s) is/are responsible in case of fouling
problems. Delft University of Technology has developed a filtration
characterization method that aims at determining the role of sludge
characteristics in the filtration process. Sludge samples collected from different
full-scale MBR plants or under different circumstances are filtrated with the same
membrane under exact identical operational circumstances with the Delft
Filtration Characterization method (DFCm). In this way differences in filterability
can be related exclusively to the quality of the sludge sample.
Several researchers demonstrated that when activated sludge is experiencing
stress conditions severe fouling problems can occur. In this research two
different stress conditions were simulated. Activated sludge samples collected
from full-scale MBR Heenvliet in the Netherlands were exposed to a long period
without aeration and to a short period of high shear stress conditions induced by
a centrifugal pump. Goal of the research was to examine the effect of these
stress conditions on the sludge filterability and characteristics and the ability of
the sludge to recover from it. The filtration characterization experiments were
accompanied by several sludge quality analyses: the concentration Soluble
Microbial Products (SMP), Particle Size Distribution (PSD) in the submicron
range of the free water and sludge viscosity were measured.
The results show that exposing the sludge to stress conditions lead to
deflocculation of the sludge which was expressed in the release of SMP and of
colloidal particles in the free water and a deterioration of the filterability. When
the sludge was subsequently preserved in continuous aerated conditions, it
showed a strong ability to recover from the stress circumstances. The sludge
quality deterioration which was obtained in approximately three days of anoxic
circumstances was undone in a period of only several hours. Together with the

improvement of filterability also the SMP concentrations and the number of
colloidal particles in the free water decreased. From this research it was
concluded that flocculation is a very important parameter for sludge filtration.
Looking after favorable flocculation conditions in MBR as soon as the sludge
reaches the membrane tank is an important aspect for good MBR operation.

Membrane Fouling - General Topics – 5
Monday July 14, 11:45 AM-12:15 PM, O’ahu
Scale-up of Lab Investigations on Fouling in MBR Potentials and
Limitations
M. Kraume (Speaker), Technische Universität Berlin, Chair of Chemical Engineering, Germany,
matthias.kraume@tu-berlin.de
D. Wedi, Engineering Office ATM
T. de la Torre, Berlin Centre of Competence for Water
J. Schaller, Technische Universität Berlin, Chair of Chemical Engineering, Germany
V. Iversen, Technische Universität Berlin, Chair of Chemical Engineering, Germany
A. Drews, Technische Universität Berlin, Chair of Chemical Engineering, Germany
Objective Despite the large number of publications, membrane fouling still is not
well understood due to the complexity of the interacting phenomena and the
multitude of module and reactor configurations as well as wastewaters and
operating conditions. To reduce the number of influencing factors, often lab trials
are carried out where only the parameter of interest is to be varied. These are
either filtration experiments (e.g., filtration mechanisms, fouling rate) carried out
with real or model feeds, biological investigations (e.g., soluble microbial
products (SMP) occurrence), a combination of both (e.g., fouling propensity of
SMP formed under different conditions) or concern suited cleaning protocols.
However, the outcomes of such studies are frequently inconsistent or even
contradictory. The representativeness of conclusions drawn from such trials is
thus highly questionable - both quantitatively and qualitatively. In the light of such
contradictions, this paper aims at answering the question how representative of
full scale operation lab trials are or indeed can be, i.e., what can be expected
from them at all considering their inherent differences from technical operating
conditions. Summarizing the different experiences, guidelines for a ‘good
laboratory practice’ will be derived concerning appropriate experimental set-ups
and corresponding test protocols.
Results
Initially, types of experiments and distinct differences are analyzed. In the
second part, results from own experiences in lab (1-140 L), pilot (1.5 m³) and full
scale (250-9,200 p.e.) together with data from literature are exemplarily
discussed to highlight potentials and limitations of different experimental
approaches. In general, lab scale experiments are an indispensable tool for
fundamental fouling research. With regards to their value and applicability to full
scale it will be stated that: · Properly done short-term experiments based on
suited protocols can be used to characterize the filterability and the relative
fouling propensity of different sludges. The absolute values of measured fouling
rates, however, are never appropriate to describe long-term operation in full

scale where fouling rates are commonly at least one order of magnitude lower.
The discrimination whether the reason for a sudden permeability decrease in full
scale is a low filterability of the activated sludge or, e.g., module sludging can be
realised on this basis. Hence a regular monitoring of sludge behaviors in full
scale plants is hereby possible. To some extent, data can be used for model
identification to analyse the mechanisms that are responsible for the observed
fouling rates. Due to the interactions of ambient conditions in full scale, defined
lab studies are the only way to independently study influences on biological
kinetics. Cleaning success can be transferred qualitatively to full scale but also
not quantitatively. Thus, it will be demonstrated that lab scale experiments can be
meaningful for full scale operation only if the following preconditions are fulfilled:
Hydrodynamics must be comparable to achieve qualitatively comparable fouling.
Aeration rate, crossflow velocity and geometry (channel width etc.) must be the
same in both scales. Due to the fluid-structure interactions this can hardly be
achieved for hollow fibres. Operating conditions (constant TMP/constant flux)
must be identical to achieve comparable quality of the fouling layer. Even such
alleged banalities like test cell orientation must be carefully considered. Fresh
sludge from the full scale plant must be used or in-situ experiments must be
carried out in order to avoid effects due to starvation/disintegration etc. of the
sludge during sludge storage and shipment. If any of these stipulations is not
met, researchers and operators should be aware that the inherently limited
representativeness of results gained in lab scale is restricted even further.

Membrane Fouling - General Topics – 6
Monday July 14, 12:15 PM-12:45 PM, O’ahu
Visual Characterization of Fouling Behaviour By Activated Sludge Model
Solutions
Y. Marselina, University of New South Wales, Sydney, Australia
P. Le-Clech, (Speaker) University of New South Wales, Sydney, Australia
R. Stuetz, University of New South Wales, Sydney, Australia
V. Chen, University of New South Wales, Sydney, Australia, v.chen@unsw.edu.au
Fouling can be easily characterized with the hydraulic performances of the
membrane, such as transmembrane pressure (TMP), flux and resistances. Better
insight of fouling can also be obtained by using visualization methods, which
include invasive and non-invasive techniques. The non-invasive techniques
provide some advantages over the invasive techniques, by analyzing the
membrane without removing it from its membrane module. Direct observation
(DO), which consists of modified crossflow module, microscope and video
camera, is one of the non-invasive techniques that can be used to visualize the
fouling deposition and removal on the hollow fibre membrane.
In this paper, the DO technique will be used to further characterize the fouling
behaviour for extracellular polymeric substances (EPS) in activated sludge for
membrane bioreactor (MBR) application. Recent research based on the effect of
the feed on MBR fouling has been conducted by using model solutions to mimic
the major foulants found in the mixed liquor. The bentonite particulate can be
used to approximate the behaviour of biomass particles and flocs. The alginate
and xanthan gum can be used to model the carbohydrate fraction and bovine
serum albumin (BSA) used to model the protein fraction of the EPS material in
the biomass. The glycerol was used to change the viscosity property of the fluid
and model the Newtonian fluid. Moreover, the xanthan gum was used to model
the non-Newtonian fluid.
During the filtration of the bentonite - alginate mixture, the fouling deposition
mechanisms were showed by the formation of the stagnant and fluidised layer on
the membrane surface. When the concentration of alginate in the bentonite -
alginate mixture was increased, the TMP and specific cake resistance increased
but the stagnant fouling thickness (Hc) decreased, indicating dense fouling layer.
Although the Hc decreased with the alginate concentration in the mixture, the
cleaning time required to remove most of the reversible fouling increased. This
showed that the addition of alginate contributed to the changes in the fouling
layer morphology by increasing the cohesion bonding between deposited
foulants and the adhesion bonding between foulants and membrane. It was
observed that the fouling removal mechanisms in the presence of alginate were

observed in two subsequence phenomena: (1) cake expansion and gradual
erosion, followed by (2) gradual erosion and removal in agglomerates.
The effects of different biopolymer natures and feed viscosities on particulate
fouling were also studied by observing the fouling deposition and removal of the
mixtures in the presence of bentonite, alginate, BSA, glycerol and xanthan gum.
The cake properties were better characterized with the TMP, resistances,
visualization during fouling deposition and removal. The observation during
fouling removal showed how the cohesivity of the fouling structures formed
during the filtration.
The presentation of this work will include videos of the fouling deposition and
removal obtained during our experiments.

Membrane Modeling I - Fundamental Approaches – 1 – Keynote
Monday July 14, 9:30 AM-10:15 AM, Waialua
Membrane Analysis and Simulation System (MASS)
R. Faibish (Speaker), Argonne National Laboratory, Argonne, IL, USA, rfaibish@anl.gov
D. Pointer, Argonne National Laboratory, Argonne, IL, USA
B. Roux, Argonne National Laboratory/University of Chicago, Argonne, IL, USA
A. Tentner, Argonne National Laboratory, Argonne, IL, USA
The MASS project is aimed to develop a novel and innovative simulation tool to
predict membrane properties and performance. The simulation tool will be
sufficiently robust to a-priori describe the fundamental membrane properties and
their relationship to membrane processes. The tool will integrate interactions
from the molecular level through their macroscopic impacts. It will guide the
prediction of membrane properties and performance and ultimately be a valuable
resource for predictive economics of a wide range of separations. The tool will
utilize computational fluid dynamics, lattice Boltzmann method modeling,
molecular dynamic modeling, user guidance feedback (UGF) based on artificial
intelligence (‘thinking model’), and system analysis. Upon appropriate input, the
model will then yield information on the feasibility of the desired separation,
materials selection, recommended operating parameters, and overall process
economics, among other possible outputs. The proposed ‘full picture’ modeling
tool will provide integrated macro- and micro-scale predictions to guide selection
of the proper membrane process, materials, and overall system for the desired
separation. There are three scales at which to attempt solutions: 1) Process
optimization using existing, characterized membranes; 2) Design of new
membranes based upon macroscopic, empirical characterization of membrane
materials; 3) Predict the behavior of a membrane from atomistic scale principles.
The paper will present the results and progress to date.

Membrane Modeling I - Fundamental Approaches – 2
Monday July 14, 10:15 AM-10:45 AM, Waialua
Development of Novel Molecular Modeling Technique for Membrane
Fouling in Water Treatments
H. Takaba (Speaker), Tohoku University, Sendai, Japan, takaba@aki.che.tohoku.ac.jp
A. Suzuki, Tohoku University, Sendai, Japan
R. Sahnoun, Tohoku University, Sendai, Japan
M. Koyama, Tohoku University, Sendai, Japan
H. Tsuboi, Tohoku University, Sendai, Japan
N. Hatakeyama, Tohoku University, Sendai, Japan
A. Endou, Tohoku University, Sendai, Japan
C. Del Carpio, Tohoku University, Sendai, Japan
M. Kubo, Tohoku University, Sendai, Japan
T. Kawakatsu, Kurita Water Industries Ltd., Tochigi, Japan
I. Nishida, Kurita Water Industries Ltd., Tochigi, Japan
Y. Watanabe, Kurita Water Industries Ltd., Tochigi, Japan
S. Nakao, The University of Tokyo, Tokyo, Japan
A. Miyamoto, Tohoku University, Sendai, Japan
Novel molecular modeling technique for investigation of fouling mechanism in
water treatments using membranes based on quantum molecular dynamics was
developed. The developed technique enables to calculate interactions between
soluble organic compounds and a membrane surface in aqueous condition so
that it is applicable to predict molecular behaviors of organic compounds in
UF/NF/RO membrane processes. In this technique, the interaction in aqueous
condition was represented by potential of mean force (PMF). Novel scheme of
molecular dynamics using the PMF has an advantage of computational cost in
evaluating interaction from water bulk, which makes possible a large scale
calculation. We applied this technique to the simulation of various surfactants
coagulation and adsorption on aromatic poly-amide RO membrane and revealed
the membrane fouling mechanism by the surfactant in treated water from
atomistic level.

Membrane Modeling I - Fundamental Approaches – 3
Monday July 14, 10:45 AM-11:15 AM, Waialua
Electroosmotic Flow in a Lysozyme Crystal: Molecular Dynamics
Simulation
Z. Hu, National University of Singapore, Singapore
J. Jiang (Speaker), National University of Singapore, Singapore, chejj@nus.edu.sg
The electroosmotic flow of electrolyte solution (mixed NaCl and CaCl2) in a
lysozyme crystalline membrane is investigated using nonequilibrium molecular
dynamics simulation. The stability of lysozyme is observed to slightly decrease
upon exposure to the electric field. Water molecules align preferentially parallel to
the electric field, and ions exhibit layered structures near the protein surface. The
hydration numbers of ions and the coordination Cl- numbers of cations are found
to be electric-field independent. The drift velocities of ions vary with the ion
charge and the electric-field strength, and are affected by the stream of
oppositely charged ions. Nonequilibrium and equilibrium simulations give a close
electrical conductivity for the system.

Membrane Modeling I - Fundamental Approaches – 4
Monday July 14, 11:15 AM-11:45 AM, Waialua
Theoretical Analysis of the Effects of Asymmetric Membrane Structure on
Fouling during Microfiltration
W. Li, University of Cincinnati, Cincinnati, OH, USA
C. Duclos-Orsello, Millipore Corp., Billerica, MA, USA
C. Ho (Speaker), University of Cincinnati, Cincinnati, OH, USA, chiachiho1@gmail.com
There is growing interest in the use of both asymmetric and composite
membranes for microfiltration and ultrafiltration processes. This includes particle
removal applications in the semiconductor industry and virus clearance in
biopharmaceutical applications. Filter fouling plays an important role in these
processes. Though flux decline models have been developed for homogeneous
membranes, the effects of asymmetric membrane structure on flux decline
behavior remains poorly understood on a fundamental level. Here, we develop a
theoretical model to describe the effects of asymmetric membrane structure on
flux decline. The asymmetric structure was described by the spatial variation in
Darcy permeability in the directions normal to and parallel to the membrane
surface. The velocity profile and flux decline due to pore blockage were
described using Darcy s law and a pore blockage and cake filtration model. Flux
decline data were obtained using pseudo-composite membranes with highly
interconnected polyvinylidene fluoride membranes (PVDF) and straight through
pore polycarbonate track etched membranes (PCTE). Model composite
membranes were formed by layering PCTE or PVDF membranes with different
pore sizes on top of each other. Flux decline data for the composite membrane
were in good agreement with model calculations. The results provide important
insights into the effects of asymmetric membrane pore structures on flux decline.

Membrane Modeling I - Fundamental Approaches – 5
Monday July 14, 11:45 AM-12:15 PM, Waialua
Modeling Virus Filtration: A Population Balance Approach
A. Pavanasam, University of New South Wales, Australia
A. Abbas (Speaker), University of Sydney, Australia, alia@usyd.edu.au
S. Ansumali, Nanyang Technological University, Singapore
V. Chen, University of New South Wales, Australia
Background: Ultrafiltration (UF) is proving to be a promising operation in the
biopharmaceutical industry for both virus purification and clearance operations. In
this paper, we present a detailed model for virus UF that is based on population
balance theory. The proposed model is validated experimentally.
Modeling: Numerous process models have been presented in the literature that
describes the performance of UF operations [1-6]. Typically UF models predict
permeate flux decline, the percent rejection and solute concentration in the
retentate under varying feed concentrations, membrane fouling and changes in
pressure drop. The model of this work addresses these variables interactions
and further takes into account particle suspension properties, more specifically
particle polydispersity parameters. Population balance theory lays the foundation
for this model where a discrete set of equations can be written to describe the
population density of each particle size class of the permeate (or retentate).
The developed population balance equation (PBE) is accompanied by a specific
initial condition, mass balance and other constitutive relations together forming
the population balance model (PBM). In developing the PBM, several
assumptions are considered including: tangential flow, laminar flow in pores,
monodisperse pore sizes, constant feed flow and concentration. The model is
solved using gPROMS package (Process Systems Enterprise, UK).
Model Validation: Experiments were conducted for the purpose of model
validation. In all the experiments, the temperature was set to 25C and specially
prepared 0.1% Latex particles at various pump speeds were used. The latex
particles were used to simulate the real virus ones. Samples (from permeate and
retentate) were collected at regular time intervals. These samples were analyzed
for the particle size distribution using dynamic laser particle size measurement.
Results: Preliminary modeling results are promising indicating that the mechanics
of the PBM, which are to a large extent statistical in nature, are close to the
region of the experimental data. The existing mismatch between the model and
the experimental data is attributable to the simplifications of the assumptions
involved. The PBM is simple yet serves as a powerful predictive tool for the study

of the impact of the operating parameters on the permeate particle phase viz.
quality of permeate. Particle mean size as well as other particle characteristics
like particle size distribution etc can be derived from the PBM leading to better
understanding of the underlying UF interactions and mechanisms.
References:
[1] Y Lee, M M Clark, Modeling of flux decline during crossflow ultrafiltration of colloidal
suspensions, J. Membrane Sci., 149 (1998), 181.
[2] M M Sharma and Y C Yortsos, Transport of particulate suspensions in porous media: Model
formulation, AIChe J, 33 (1987), 1636.
[3] G A Denisov, Theory of concentration polarization in cross-flow Ultrafiltration: Gel layer model
and osmotic pressure model, J. Membrane Sci., 91 (1994), 173.
[4] G L Baruah, A Venkiteshwaran, and G Belfort, Global Model for Optimizing Crossflow
Microfiltration and Ultrafiltration Processes: A New Predictive and Design Tool, Biotechnology
Prog., 21 (2005), 1013.
[5] J.G.Wijmans, S.Nakao and C.A.Smolders, Flux Limitation in Ultrafiltration: Osmotic Pressure
Model and Gel Layer Model, J. Membrane Sci., 20 (1984), 115.
[6] M.N.Tekic, J Kurjacki and Gy Vatai, Modeling of batch Ultrafiltration, Chemical Engg. Journal,
61 (1996), 157.

Membrane Modeling I - Fundamental Approaches – 6
Monday July 14, 12:15 PM-12:45 PM, Waialua
Direct Simulation of Particle Migration in Cross-Flow Microfiltration
M. Fujita (Speaker), The University of Tokyo, Tokyo, Japan, masahiro@chemsys.t.u-tokyo.ac.jp
K. Oda, The University of Tokyo, Tokyo, Japan
K. Akamatsu, The University of Tokyo, Tokyo, Japan
S. Nakao, The University of Tokyo, Tokyo, Japan
A direct simulation of particle migration due to a shear-induced lift force in a
cross-flow microfiltration is carried out without any analytical or empirical models
of the lift force. Both the motion of particles and the flow of liquid are
simultaneously computed based on a Newtonian dynamics and the fluctuating
Navier-Stokes equation that contain a variety of particle-to-particle interactions
and particle-to-liquid hydrodynamic interaction. The hydrodynamic interaction is
accurately calculated because pressure and viscous stress on the particle
surface are evaluated on the computational lattice whose spacing is quite smaller
than the particle size. The present simulation can resolve not only lift force
exerted on a single particle but also lift forces exerted on concentrated many
particles in the vicinity of a membrane surface. The simulation result shows the
relationship between the particle size and the velocity of particle migration in a
range of particle concentration.

Oral Presentation
Abstracts
Afternoon Session
Monday, July 14, 2008

Hybrid and Novel Processes I – 1 – Keynote
Monday July 14, 2:15 PM-3:00 PM, Kaua’i
Scaleable Membrane Separations for the Lignocellulosic-to-Ethanol
Biorefinery?
J. Pellegrino (Speaker), University of Colorado, Boulder, CO, USA,
john.pellegrino@colorado.edu
K. Colyar, University of Colorado, Boulder, CO, USA
M. Gutierrez-Padilla, University of Colorado, Boulder, CO, USA
J. Hettenhaus, cea Inc., Charlotte, NC, USA
D. Schell, National Renewable Energy Laboratory, Golden, CO, USA
There are many challenges to realizing a significant biomass-to-fuels industry
based on lignocellulosic feedstocks in the US. One of the significant issues is
how to economically address highly distributed, low density feedstock supplies
that arise from agricultural (such as, corn stover) and forestry waste material. In
addition, ways to recover and recycle fertilizer micronutrients (inculcated wthin
the biomass) back to the fields, and bring the farming community further along
the value chain, are all important criteria for successful growth of this important
industry. To these ends, we will present a brief overview of the opportunities for
membrane processes within the lignocellulosic biorefinery and ways that these
processes may potentially mitigate the economic penalties associated with small
scale plants. We will report bench-scale studies on leaching of micronutrients
from stored wet stover, co-harvested with the corn in a cooperative, and the
recovery and recycle of fertilizer anions and cations, as well as the water. We will
also present the broad results from several other membrane processes that
recover and recycle water, and/or fractionate by-products from this stover as it
undergoes pre-hydrolysis using a novel reactor designed for small scale
processing. And from the ethanol fuel product side, we have performed
separation studies on the removal of small organic molecules, which provide
inhibition of the fermentative organisms, in order to recycle water back to the
ethanol fermentor from the beer column. A variety of commercial membranes
have been considered for all these operations, and initial figures-of-merit have
been obtained and will be discussed within the context of desirable
improvements in materials and/or process configurations.

Hybrid and Novel Processes I – 2
Monday July 14, 3:00 PM-3:30 PM, Kaua’i
Reducing the Energy Demand of Bio-Ethanol through Salt-Extractive
Distillation and Electrodialysis
P. Pfromm (Speaker), Kansas State University, Manhattan, KS, USA, pfromm@ksu.edu
M. Hussain, Kansas State University, Manhattan, KS, USA
Bio-ethanol from corn currently consumes about 34,000 BTU in form of natural
gas to produce one gallon of ethanol representing 76,000 BTU as lower heating
value (U.S. industrial practice data, 2007). Separating ethanol from water
consumes about 40% of the natural gas demand cited above. Saline extractive
distillation of alcohol-water mixtures and fermentation broth has been considered
elsewhere and fairly comprehensive experimental data, thermodynamic data,
and simulations are available. Potentially very significant energy savings and
process simplifications have been found. However, the recovery and recycling of
the salt used to facilitate distillation has not been addressed. Electrodialysis is
uniquely suited for salt recovery from the saline extractive distillation column
bottoms since salt is selectively removed from the solution (no water is
evaporated) and the electrodialysis membranes and overall fluid handling are
tolerant to fermentation broth and even to entrained particulate matter. Concepts,
modeling, and experimental data for electrodialysis-enabled salt extractive
ethanol distillation will be shown. Aqueous/aqueous and aqueous/ethanol
electrodialysis will be discussed.

Hybrid and Novel Processes I – 3
Monday July 14, 3:30 PM-4:00 PM, Kaua’i
Membrane Separation Techniques in the Continuous Fermentation and
Separation of Butanol
J. Du (Speaker), University of Arkansas, Fayetteville, AR, USA
R. Beitle, University of Arkansas, Fayetteville, AR, USA
E. Clausen, University of Arkansas, Fayetteville, AR, USA
J. Carrier, University of Arkansas, Fayetteville, AR, USA
J. Hestekin, University of Arkansas, Fayetteville, AR, USA, jhesteki@uark.edu
Butanol is an excellent substitution of gasoline, which can use in the interior
combustion engine without any modification of engine. About 50 years ago, the
acetone-butanol-ethanol fermentation process, employing bacterium Clostridium
acetobutylicum to convert biomass to butanol, was the most popular way to
produce butanol. But this process has some drawbacks in that many bi-products
are produced. Besides butanol, the fermentation also produces acetic, butyric
and lactic acids when fermentation passes through acidogenesis phase..
In this project, we propose a continuous two stage fermentation/membrane
separation system that is based on the work of Ramey (1998) where two
organisms, Clostridium acetobutylicum and Clostridium tyrobutyricum, are used
in tandem to produce butyric acid (with lactic and acetic) in the first fermentation
and butanol (with acetone and ethanol) in the second fermentation. Ramey
(1998) proposed liquid-liquid extraction for product removal, but this process has
problems with solvent entrainment and selectivity. We are working to
demonstrate that selective removal of butyric acid from the first stage by a novel
membrane technique that will produce higher yields and productivity than current
technology.
The technology that we are exploring for this separation is electrodeionization
(EDI) which is connected to a continuous fermentation with cell recycle of the
Clostridium tyrobutyricum. EDI is a technology that has been used for pure water
purification, but is relatively unexplored in product separation, especially selective
removal of ions. Early results show that EDI is more selective than electrodialysis
(>2X increased selectivity of butyrate over lactate as compared to ED) and can
operate to a lower concentration (Arora et al., 2007), thus making the whole
process more attractive. We will demonstrate the first continuous production of
butyric acid by Clostridium tyrobutyricum with EDI product separation and show
the effects of reduced inhibition, substrate recycling, and media recycling. We will
also demonstrate a comprehensive model on the EDI fermentation process.
References

Arora, M.B., J.A. Hestekin, S.W. Snyder, E.J. St. Martin, M.I. Donnelly, C. Sanville-Millard and
Y.J. Lin, ‘The Separative Bioreactor: A Continuous Separation Process for the Simultaneous
Production and Direct Capture of Organic Acids’, Separation Science Technology, 42, 2519-
2538, 2007.
Ramey, D.E., ‘Continuous, Two Stage, Dual Path Anaerobic Fermentation of Butanol and Other
Organic Solvents Using Two Different Strains of Bacteria’, U.S. Patent 5,753,474, May 19, 1998.

Hybrid and Novel Processes I – 4
Monday July 14, 4:00 PM-4:30 PM, Kaua’i
Power Generation by Reverse Electrodialysis
P. Dlugolecki (Speaker), University of Twente, Wetsus, The Netherlands,
piotr.dlugolecki@wetsus.nl
K. Nymeijer, University of Twente, The Netherlands
S. Metz, University of Twente, Wetsus, The Netherlands
M. Wessling, University of Twente, The Netherlands
Introduction Membrane technology provides an opportunity to gain sustainable
energy from salinity gradients via reverse electrodialysis [1-4] . RED can be applied
where two solutions of different salinity gradient mix, e.g. where river water flows
into the sea. Ion-exchange membrane properties (resistance, selectivity, ion
exchange capacity, structure and thickness) affect the performance of the RED
process. Up to now it is not known which membranes properties are important for
the RED process. Therefore, we determined the membrane properties of several
commercial membranes and compared them for their RED performance with a
theoretical model [4] .
Theory In RED, a concentrated salt solution and a fresh water are brought into
contact through an alternating series of anion exchange membranes (AEM) and
cation exchange membranes (CEM). Anions migrate through the AEM towards
the anode and cations move through the CEM towards the cathode. The
difference in chemical potential between both solutions is the driving force for this
process. Electrons migrate from anode to cathode through an external electrical
circuit in order to maintain electro-neutrality in the cathode and anode
compartment. This electron migration can be used to generate electrical power.
The theoretical value of the chemical potential for an aqueous monovalent
electrolyte can be calculated using the Nerst equation. Results and discussion
The theoretical membrane model for reverse electrodialysis was used to predict
the theoretical power density obtainable using experimental membrane
characterization data. Results show that large increases in power density can be
obtained by decreasing the membrane resistance and the thickness of the river
water compartment. Improvement of membrane properties has only a significant
effect if such small membrane spacing is applied. When the membrane spacing
is 150µm the membrane resistance becomes a dominant factor to generate
energy. When 600µm spacer was applied the membrane selectivity seems to
play an equal role with the membrane resistance. However, with this stack
configuration membrane performance has less influence on obtained power
density. According to membrane model is feasible to reach the power density up
to 5 W/m 2 with commercial available membranes. Tailor-made membranes can
improve this performance even further more.

Conclusions Reverse electrodialysis is a non-polluting, sustainable technology to
generate direct electricity from the mixing of fresh and salt water. The ion
exchange membranes are the key elements in RED. Based on the results, the
best benchmarked commercially available anion exchange membranes reach a
power density of more than 5 W/m 2 whereas the best cation exchange
membranes show a theoretical power density of more than 4 W/m 2 . According to
the membrane model calculations power densities higher than 6 W/m 2 could be
obtained by using thin spacers and tailor made membranes with low membrane
resistance and high permselectivity especially designed for reverse
electrodialysis. This makes RED a potentially attractive and alternative for
sustainable energy production.
Reference
1. R.E. Pattle, Production of Electric Power by mixing Fresh and Salt Water in the Hydroelectric
Pile, Nature, 174 (1954) 660.
2. J.W. Post, J. Veerman, H.V.M. Hamelers, G.J.W. Euverink, S.J. Metz, K. Nymeijer, C.J.N.
Buisman, Salinity-gradient power: Evaluation of pressure- retarded osmosis and reverse
electrodialysis, Journal of Membrane Science, 288 (2007) 218.
3. J. Veerman, J.W. Post, M. Saakes, S.J. Metz, G.J. Harmsen, Reducing power losses caused
by ionic shortcut currents in reverse electrodialysis stacks by a validated model, Journal of
Membrane Science, 310 (2008) 418-430.
4. P. Dlugolecki, K. Nymeijer, S. Metz, M. Wessling, Current status of ion exchange membranes
for power generation from salinity gradients, Journal of Membrane Science, (2008) Submitted.
5. J.N. Weinstein, F.B.J.W. Leitz, Electric power from differences in salinity: the dialytic battery,
Science, 191 (1976) 557.

Hybrid and Novel Processes I – 5
Monday July 14, 4:30 PM-5:00 PM, Kaua’i
Reverse Electrodialysis: Energy Recovery from Controlled Mixing Salt and
Fresh Water
J. Post (Speaker), Wageningen University, Wetsus, The Netherlands
H. Hamelers, Wageningen University, Wetsus, The Netherlands, bert.hamelers@wur.nl
C. Buisman, Wageningen University, Wetsus, The Netherlands
The global potential to obtain clean energy from mixing river water with sea water
is considerable. The gross power potential of this unconventional energy source
was estimated to be 2.4-2.6 TW [1, 2] when the average discharges of all rivers
were used. It was assumed [1, 3] that from each cubic meter of river water that
flows into the sea, 2.3 MJ of work could be made available. A main question is
how much of this salinity-gradient energy can be converted into sustainable
electricity. Recently, we reviewed literature on two membrane-based techniques
that can be used for this conversion [4] , namely pressure-retarded osmosis and
reverse electrodialysis, and found that actually hardly attention was paid to the
energetic efficiency. In the papers concerning reverse electrodialysis, for
instance, we descried more-or-less founded estimates for the obtainable energy
recovery ranging from 0.35 MJ per m 3 of river water [5] to 0.6 MJ per m 3 of river
water [6] . These are not quite attractive numbers, especially not when the costs of
pre-treatment are taken into account. From this point of view, the absence of
experimental investigations regarding the obtainable energy recovery is a
peculiar gap in the field of reverse electrodialysis. The aim of our study [7] ,
therefore, was to investigate the energy recovery that can be obtained.
In our experimental setup, two batches of salt solutions with same volumes (550
mL each) were recycled over a reverse electrodialysis stack, namely 0.5 M NaCl
(‘sea water’) and 0.005 M NaCl (‘river water’). The available work from mixing is
then 0.80 kJ (i.e. 1.36 MJ per m 3 of river water, which is considerably lower but
more realistic then the mentioned 2.3 MJ). The mixing process was carried out at
different current densities (5, 10&25 A/m 2 ). During the mixing process, the stack
voltage was measured. From this measurement, the energy yield can be
calculated. For a reverse electrodialysis stack with 0.5 mm inter-membrane
distance which was operated with a current density of 5 A/m 2 , the energy yield
after complete mixing was 0.65 kJ (an energy recovery of 83%). Obviously, the
energy recovery was lower at higher current densities.
Theoretically, the internal losses could be minimized by reducing the intermembrane
distance, especially from the compartments filled with the lowconducting
river water. It was found, however, that a reduction of the
compartment thickness from 0.5 mm to 0.2 mm resulted in an almost equal

energy recovery. This is a remarkable result, and for this reason the losses were
analyzed into more detail: firstly the losses due to non-ideality of the membranes
and secondly the losses associated with charge transfer. It was supposed that
besides the compartment thickness, also the geometry of the spacer affects the
internal resistance.
In conclusion, this study shows that reverse electrodialysis is able to obtain a
high energy recovery from mixing sea water and river water. The obtainable
energy recovery is more than 80% which means an energy yield of >1.2 MJ per
m 3 of river water. From this study can also be concluded that in the development
of reverse electrodialysis, special attention should be given to the development of
the compartments between the membranes.
[1] J. N. Weinstein, F. B. Leitz, Electric-Power From Difference In Salinity - Dialytic Battery,
Science 191 (4227) (1976) p557-559.
[2] G. L. Wick, W. R. Schmitt, Prospects For Renewable Energy From Sea, Marine Technology
Society Journal 11 (5-6) (1977) p16-21.
[3] R. S. Norman, Water Salination: a Source of Energy, Science 186 (1974) p350-352.
[4] J. W. Post, J. Veerman, H. V. M. Hamelers, G. J. W. Euverink, S. J. Metz, D. C. Nymeijer, C.
J. N. Buisman, Salinity-gradient power: Evaluation of pressure-retarded osmosis and reverse
electrodialysis, Journal of Membrane Science 288 (2007) p218-230.
[5] C. Forgacs, Recent Developments In The Utilization Of Salinity Power, Desalination 40 (1-2)
(1982) p191-195.
[6] J. Jagur-Grodzinski, R. Kramer, Novel Process For Direct Conversion Of Free-Energy Of
Mixing Into Electric-Power, Industrial & Engineering Chemistry Process Design And Development
25 (2) (1986) p443-449.
[7] J. W. Post, H. V. M. Hamelers, C. J. N. Buisman, Energy recovery from controlled mixing salt
and fresh water with a reverse electrodialysis system, Environ Science Technology (Submitted
2008-02-12)

Hybrid and Novel Processes I – 6
Monday July 14, 5:00 PM-5:30 PM, Kaua’i
Electrocatalytic Membranes for Glucose/O2 Biofuel Cell.
M. Géraldine (Speaker), European Membrane Institute, France,
T. Sophie, European Membrane Institute, France, sophie.tingry@iemm.univ-montp2.fr
R. Marc, European Membrane Institute, France
C. Marc, European Membrane Institute, France
I. Christophe, European Membrane Institute, France
The constant increase in energy consumption in our modern society and the
significant environmental impact involved in the use of non- renewable energy
sources will shortly force us to find an alternative method of energy production. A
fuel cell usually relies on hydrogen as carburant and oxygen as oxidant to
generate power through the electrochemical conversion of fuels directly into
electricity. Because electrical energy is generated without combustion, fuel cells
are an extremely attractive option from an environmental standpoint. The
incurred redox reactions generate electrons at the electrodes and consequently a
voltage, accompanied by the production of water and heat. Biofuel cells use
biocatalysts, to convert chemical energy into electrical energy at room
temperature and under physiological conditions. The development of these
systems focuses on the different methods of enzyme immobilisation and the
establishment of their electrical connection to the electrodes. Efficient connection
is achieved by the use of appropriate redox mediators which can shuttle
electrons between the active site of the enzymes and the electrode surfaces.
Surface-immobilized mediators and enzymes are the key factors to improving
electron transfer at the electrode interface. Some approaches have been devised
to construct a glucose/O2 biofuel cell by exploiting the oxidation of glucose
coupled to the reduction of dissolved oxygen. Glucose is electrooxidized at the
anode to gluconolactone by glucose oxidase and dioxygen is reduced to water at
the cathode by specific enzymes such as laccase [1] The recent investigations in
biofuel cells [2] are devoted to miniature and implantable cells that appear to be
alternative methods of producing low power energy. This research field is
currently under extensive development at an international level. The objective is
the construction of a glucose/O2 biofuel cell, both efficient and stable. The
application of this device is to generate electrical current to supply micro-
machines, biosensors, or even implantable sources.
The originality of our work, compared to literature, concerns the structure and the
porous nature of the electrodes. Carbon porous tubes were used as original
conducting membrane support for enzyme incorporation and for transport of
dissolved dioxygen solution via convective flow, through the porosity. This
membrane allows the enzymatic reaction with dioxygen and the electrochemical

eaction with mediator due to the conductivity of the support. Various enzyme
immobilisation techniques on porous supports have been developed [3] . On the
other hand, the elaboration of a matrix polymer based on polypyrrole obtained by
electrochemistry is a manufacturing technique, well mastered in the IEM [4] to
allow for producing stable conductive interfaces. At the cathode, oxygen is
directly reduced to water by laccase or BOD and at the anode glucose is oxidised
in gluconolactone by glucose oxidase, in the presence of their respective redox
mediators 2,2-azinobis(3- ethylbenzothiazoline-6-sulfonate) and 8-
hydroxyquinoline-5-sulfonic acid. The enzyme/mediator couples were
immobilized by covalent linkage via an N-substituted polypyrrole matrix
beforehand electrodeposited on carbon porous electrodes.
Experiments were conducted to determine the activity and the stability of the
enzymes immobilized on the electrocatalytic membrane. Operational conditions
and performances of the electrocatalytic membrane have been studied by
electrochemistry. These electrochemical studies will be carried out in model
conditions [5,6] in a physiological environment. The feasibility of each enzyme
contactors was demonstrated by chronoamperometry and current voltage
measurements using electrochemical halfs cells. Performances of the glucose/O2
biofuel cell were demonstrated by current voltage curves operating at variable
external loads.
The electrocatalytic membrane presented good and stable current densities that
established the feasibility of the co- immobilization of both enzyme and its
mediator on the electropolymerized films and of an operative glucose/O2 biofuel
cell.
1. G. Tayhas, R. Palmore, H.H. Kim, J. Electroanal. Chem. 1999, 464, 110
2. Kendall K., Nature Materials, 2002, 1, 211
3. G. Merle, L. Brunel, S. Tingry, M. Cretin, M. Rolland, K. Servat, C. Jolivalt, C. Innocent, P.
Seta, Mat. Sci. Eng C. (in press)
4. A.Naji, C. Marzin, G. Tarrago, M. Cretin, C. Innocent, M. Persin, J. Sarrazin, J. Applied
Electrochem. 31, 2001, 547-557
5. K. Servat, S. Tingry, L. Brunel, S. Querelle, M. Cretin, C. Innocent, C. Jolivalt and M. Rolland,
J. Appl. Electrochem. 37, 23007, 121
6. L. Brunel, J. Denele, K. Servat, K.B. Kokoh, C. Jolivalt, C.Innocent, M Cretin, M. Rolland and
S. Tingry, Electrochem. Comm. 9, 2007, 331

Nanofiltration and Reverse Osmosis I - Membranes – 1 – Keynote
Monday July 14, 2:15 PM-3:00 PM, Maui
Development of Reverse Osmosis FT-30 Membranes with Polyethylene
Oxide Brush Modified Antifouling Surface
J. Niu (Speaker), The Dow Chemical Company, Edina, MN, USA
B. Mickols, The Dow Chemical Company, Edina, MN, USA, wemickols@dow.com
J. Thorpe, The Dow Chemical Company, Edina, MN, USA
A. Abaye, The Dow Chemical Company, Edina, MN, USA
Many applications that use membranes processes could benefit from a wide
range of polymer chemistries that would resulting in better performance and be
more chemically robust, low fouling, and less expense than current polymers.
Breakthroughs in membrane robustness, in particular improved durability and
cleanability would significantly reduce the cost of operation of reverse osmosis
(RO)/nanofiltration (NF) water systems. This would extend the economic viability
and growth of reverse osmosis technology. As a consequence, surface
modification of our already widely used polymers become more and more
important for the improvement of thin film composite membranes. We’ll show
how we have designed specific polymers to surface modify FilmTec’s FT-30
membranes to improve operation in fouling waters (biofilm, oil and soap). The
polymerization of poly(ethylene oxide) (PEO) brush from PEO methacrylate and
a functional co-monomer (epoxy, maleic anlydride, etc.) using radicals or atom
transfer in this synthesis is very well suited for making the crosslinkable
macromolecules. Reacting these polymers with the surface of FT-30 membranes
improved our ability to clean these membranes. These PEO brushes, which have
a comb-like architecture, have proven to be very efficient in preventing both
formation of biofilms and fouling from oil and soap. Such novel PEO based
antifouling polymer may provide long-term control of surface fouling in the
physiologic, marine and industrial environments. The synthetic diversity of these
water-soluble polymers was explored to better understand the fundamental
relationship between fouling resistance and polymer chemical composition.

Nanofiltration and Reverse Osmosis I - Membranes – 2
Monday July 14, 3:00 PM-3:30 PM, Maui
Desalination Membranes Based on Directly Sulfonated Poly(arylene ether
sulfone) Copolymers
H. Park (Speaker), University of Ulsan, Ulsan, Korea, hbpark@ulsan.ac.kr
W. Xie, University of Texas at Austin, Austin, TX, USA
B. Freeman, University of Texas at Austin, Austin, TX, USA
M. Paul, Macromolecules and Interfaces Institute and Department of Chemistry, Blacksburg, VA,
USA
H. Lee, Macromolecules and Interfaces Institute and Department of Chemistry, Blacksburg, VA,
USA
J. Riffle, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA
J. McGrath, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA
We have synthesized and characterized a systematic series of new sulfonated
copolymer membranes, for use as desalination membranes, based on chemistry
that is entirely different from the conventional post-polymerization sulfonation
technique. Using direct copolymerization of sulfonated and other monomers,
reproducible sulfonated copolymer membranes can be prepared as various
polymer structures and compositions at different levels of sulfonation. This
synthesis method overcomes the problems of conventional sulfonation
technology such as molecular weight reduction during sulfonation. This study will
discuss the preparation and evaluation of several families of sulfonated polymers
such as random or segmented multiblock copolymers in terms of desalination
characteristics (e.g., water permeability (or permeance), salt permeability and
salt rejection). These sulfonated polymers or their thin-film composite
membranes exhibit high tolerance to chlorine attack, which is in contrast to
conventional desalination membranes such as those based on aromatic
polyamides or cellulose acetate. They also exhibit high water flux and good salt
rejection. To delineate structure-property relations for these materials, solubility
and diffusivity of water and various salts were also evaluated for a series of
sulfonated polymers. These intrinsic properties were compared with those of
commonly used cellulose acetate and polyamide membranes. This fundamental
and systematic study of structure-property relations regarding newly synthesized
sulfonated copolymer membranes provides guidelines regarding material
selection for new reverse osmosis membranes.

Nanofiltration and Reverse Osmosis I - Membranes – 3
Monday July 14, 3:30 PM-4:00 PM, Maui
Structure-Property Relationships in PEG-Based Hydrogel Membrane
Coatings
A. Sagle (Speaker), University of Texas at Austin
H. Ju, University of Texas at Austin
B. Freeman, University of Texas at Austin, freeman@che.utexas.edu
M. Sharma, University of Texas at Austin
The search for new water resources continues as demand for fresh water
increases worldwide. One potential resource is produced water, a byproduct of
oil and natural gas production, which is a complex emulsion composed of oil and
other organics, salts, and particulate matter. Currently, 92% of produced water is
reinjected, but cost-effective treatment could provide new water resources for
beneficial uses in applications such as irrigation, power generation, and even
human consumption.
Reverse osmosis (RO) membranes are a potential option to purify produced
water because they are capable of removing up to 99.9% of monovalent salts as
well as particulates and emulsified oil. However, RO membranes foul strongly in
the presence of oily feed waters. One proposed solution to reduce membrane oil
fouling is to apply a hydrophilic coating to the membrane surface. An ideal
coating would be hydrophilic, resist oil droplet adhesion, and minimally impact
the water flux and salt rejection of the underlying desalination membrane.
As a first step towards preparing fouling-resistant coatings for RO membranes,
three series of copolymer hydrogel networks were synthesized using
poly(ethylene glycol) diacrylate (PEGDA) as the crosslinker and acrylic acid (AA),
2-hydroxyethyl acrylate (HEA), or poly(ethylene glycol) acrylate (PEGA) as
comonomers. Materials were prepared using varying amounts of PEGDA and
comonomer. Glass transition temperatures in these materials obeyed the Fox
equation. Both water and NaCl transport properties were studied, and ethylene
oxide content and crosslink density influenced these transport properties. For
example, the volume fraction of water sorbed by a 100 mole% PEGDA hydrogel
was 0.61. However, introducing comonomers into the network reduced hydrogel
crosslink density, and in hydrogels having the same ethylene oxide content,
water sorption increased as crosslink density decreased. Water permeability
increased systematically with increasing water sorption, and water permeability
coefficients ranged from 10 - 26 L micron/(m 2 hr bar). NaCl partition coefficients
ranged from 0.36 to 0.53 (g NaCl/cm 3 hydrogel)/(g NaCl/cm3 solution) and
correlated strongly with water sorption. NaCl diffusion coefficients varied little
with polymer composition; in this regard, diffusion coefficient values ranged from

4.3x10 -6 to 7.4x10 -6 cm 2 /s. Based on contact angle measurements using n
decane in water, oil exhibited a low affinity for the surfaces of these polymers.
Composite membranes using these materials and a commercial RO membrane
as a substrate were prepared using spin coating. Initial studies show composite
membrane behavior to follow trends predicted by a flux resistance model. The
influence of the coating on salt rejection is also examined using a resistance
model.

Nanofiltration and Reverse Osmosis I - Membranes – 4
Monday July 14, 4:00 PM-4:30 PM, Maui
Engineering Molecular Weight Cut-Off of Organic Solvent Nanofiltration
(OSN) Membranes for Natural Product Fractionation
I. Sereewatthanawut (Speaker), Membrane Extraction Technology Ltd, issara.s@imperial.ac.uk
Y. See Toh, Imperial College London
F. Lim, Membrane Extraction Technology Ltd
A. Boam, Membrane Extraction Technology Ltd
A. Livingston, Imperial College London
In recent decades there has been an increase in consumers’ concerns over the
quality and safety of many products including food, medicines and cosmetics.
Consumer’s preference has strongly moved to products produced from natural
sources as opposed to synthetic sources. As a result of this market demand, the
production of natural products has rapidly expanded and become a global
industry.
The production of natural products mainly involves separation processes. In
general, the most challenging aspect of natural compounds production are the
purification and fractionation steps. Current state-of-the-art technologies for
separation and purification involve the use of either distillation technology (shortpath
or conventional distillation), or conventional preparative liquid
chromatography. In recent years, membrane technology, particularly organic
solvent nanofiltration (OSN), has attracted a great deal of attention as an
alternative molecular separation technology. The main advantage of employing
OSN for purification of natural extracts is that by selecting suitable molecular
weight cut-off (MWCO) membranes, this technology can be used to fractionate
molecules of similar molecular weight (e.g. in the 200 to 1000 Da range) at a
much lower operating temperature compared to conventional processing
operations. In addition to the large saving in energy costs, natural products are
often susceptible to thermal damage and thus the milder operating conditions of
a membrane process can minimize the nutritive value loss from thermal
degradation.
The key aspect of employing this technology in natural product purification is
therefore to tailor and control the MWCO of OSN membranes. This study reports
the successful development of a robust technique for producing OSN
membranes with tuneable molecular weight [1] . We have found that through
careful control of the membrane formation conditions, it is possible to generate a
family of membranes with MWCO in the nanofiltration range, i.e. 200 to 1000 Da.
We have also shown that these membranes can be produced at pilot scale and
used to form spiral wound elements.

The development of these membranes and their application to natural products
processing, including the Solvent Extraction Membrane Separation (SEMS)
process [2] (in which different MWCO OSN membranes are used to fractionate
free fatty acids from glycerides in natural oils), will be presented and discussed in
this presentation.
[1] See Toh, Y H, et al., Engineering molecular weight cut off curves for highly solvent stable
nanofiltration membranes, Journal of Membrane Science, manuscript submitted.
[2] International Patent No.WO/2008/002154.

Nanofiltration and Reverse Osmosis I - Membranes – 5
Monday July 14, 4:30 PM-5:00 PM, Maui
High-Temperature Nanofiltration Using Porous Titania Membranes
T. Tsuru (Speaker), Hiroshima University, tsuru@hiroshima-u.ac.jp
K. Ogawa, Hiroshima University
T. Yoshioka, Hiroshima University
Nanofiltration is conventionally operated at ambient temperatures for water
treatment such as desalination and purification of land water. Rapid increase in
membrane applications will expand the operation of nanofiltration at high
temperatures such as water treatment in sugar industries and textile industries [1,
2] . However, polymeric nanofiltration membranes, which are mostly prepared
from polyamide, can be used in a limited range of temperatures lower than 60 °C
due to the glass transition [1] . On the other hand, ceramic membranes, especially
titania membranes, show excellent thermal stability as well as chemical
resistance, and can be used in both acidic and basic pHs [3, 4] . In this paper,
nanoporous titania membranes with controlled pore sizes in the range of 1-3nm
were successfully prepared by sol-gel processing, and the transport performance
was evaluated in the temperature range from 30 to 90C.
Two types of titania sol solutions were prepared for the preparation of
nanoporous membranes: colloidal and polymeric sols. In the polymeric sol route,
hydrolysis and condensation reactions of titanium tetra-isoproxide (TTIP) were
carried out with a small amount of water (molar ratio of H2O/Ti = 3~5) in
isopropanol solutions [5] . On the other hand, in peptization method, an excess
amount of water was added at the hydrolysis step at 60-70C for complete
hydrolysis, resulting in milky aggregated sols. After adding an acid such as nitric
acid, the milky sol was peptized to colloidal sol solutions, which were transparent
and bluish. Sol sizes in both cases could be controlled by the molar ratio of the
composition (acid concentration, water/Ti, etc.), temperature, aging time. Titania
sols were coated on a-alumina capillary (pore size: 150 nm, outer diameter 3
mm, thickness 0.36mm) and fired at 350-650C.
Average pore sizes of TiO2 membranes determined by nanopermporometry [6]
were successfully controlled from 2- 5 nm using colloidal sols and from 0.7-2 nm
using polymeric sols, by controlling the sol preparation conditions (pH,
temperature, concentration) and firing temperatures. TiO2 membranes showed
molecular weight cut-offs (MWCO) of 500-2,000 and pure water permeability (Lp)
of 10 -11 to 10 -10 m 3 m - 2 s -1 Pa -1 .
With an increase in permeation temperatures from 30 to 90C, the water
permeability increased 2-3 times depending on the pore sizes. Corrected water

permeability, defined as water permeability multiplied by viscosity in bulk water,
was not constant and increased with a decrease in pore sizes, that is, the water
permeation mechanism was found to be different from the viscous flow. This is
probably because water molecules, which are tightly bound to the hydrophilic
surface of TiO2 membranes and were confirmed by measuring non-freezing and
bound water in TiO2 powders, shows different temperature dependence from
that in bulk.
Rejection of neutral solutes (raffinose, PEG1000) decreased with temperature in
the range of 30-90 C, while that of electrolytes(MgCl2, NaCl) were approximately
constant. Based on Spiegler-Kedem equation, reflection coefficients for both
solutes were successfully fitted to be independent of permeation temperatures.
Permeability coefficients (P) of electrolytes were found to show the same
temperature dependence as Lp, that is, P increased almost linearly to Lp. On the
other hand, P of neutral solutes showed larger temperature dependence than Lp,
that is the neutral solutes were found to be transported in activated diffusion. The
transport mechanism of neutral and electrolyte solutes, which are molecular
sieving and charge effect, respectively, are found to be responsible for the
temperature dependence.
[1] N. Amar, H. Saidani, A. Deratani, J. Palmeri, Langmuir, 23(2007) 2937.
[2] T. Tsuru, S. Izumi, T. Yoshioka, M. Asaeda, AIChE Journal, 46 (2000) 565-574.
[3] T. Tsuru, Separation and Purification Methods, 30 (2001) 191-220.
[4] T. Tsuru, J. Sol-Gel Sci., Tech., in press.
[5] T. Tsuru, D. Hironaka, T. Yoshioka, M. Asaeda, Sep. Purif. Tech., 25 (2001) 307-314.
[6] T. Tsuru, T. Hino, T. Yoshioka, M. Asaeda, J. Membr. Sci., 186 (2001) 257-265.

Nanofiltration and Reverse Osmosis I - Membranes – 6
Monday July 14, 5:00 PM-5:30 PM, Maui
Polypyrrole Modified Solvent Resistant Nanofiltration Membranes
X. Li (Speaker), Centre for Surface Chemistry and Catalysis, Faculty of Bioscience Engineering,
Leuven, Belgium
P. Vandezande, Centre for Surface Chemistry and Catalysis, Faculty of Bioscience Engineering,
Leuven, Belgium
I. Vankelecom, Centre for Surface Chemistry and Catalysis, Faculty of Bioscience Engineering,
Leuven, Belgium, ivo.vankelecom@biw.kuleuven.be
Nanofiltration (NF) is a process in which feeds are separated over a membrane
by means of pressures between 5 and 20 bars. Permeation takes place through
the very small pores present in the membranes, or sometimes even through the
available polymer free volume only.1 Large scale applications currently exist in
waste water treatment and drinking water production. A major challenge these
days is to broaden the range of NF- applications to organic feeds (SRNF).2-3 A
more widespread use requires solvent-resistant membranes that preserve their
separation characteristics under more aggressive conditions of strongly swelling
solvents and elevated temperatures. Solvent stable polymers mostly contain
aromatic structures and hardly possess functional groups. Since some affinity
between membrane polymer and permeating solvent is needed, the few
commercial SRNF-membranes currently available are limited to applications in
apolar solvents. Moreover, being uncrosslinked, the existing polymeric
membranes dissolve in aprotic solvents. Polypyrrole (PPy) is a chemically
extremely resistant polymer, being insoluble in any organic solvent. Shaped as
nanoparticles, it has received considerable attention in catalysis,
chromatography, controlled drug release and pigment applications.4-5 Compared
with conventional polymers, PPy has a high surface energy, as well as good
electro-conductive and acid-base properties. In the membrane field, PPy based
membranes have been already mentioned for in the gas separation and
pervaporation but not for nanofiltration (NF) and solvent resistant nanofiltration
(SRNF) applications. Most of PPy based membranes were prepared by
interfacial polymerization. Pyrrole monomer vapour then first goes through the
membranes and reaches the other side of membranes, which was contacted with
oxidant and then polymerizes on the surface of the membranes. In the presented
work, the special properties of PPy will be used to enhance the SRNF
performance of membranes. Due to the poor solubility of PPy, an in-situ
polymerization method was adopted to modify the existing membranes. In this
method, the pyrrole monomer was first introduced on the surface of the
membrane support, which was immersed in an oxidant solution to initiate the
polymerization. The density of PPy can be controlled by the concentration of the
pyrrole solution. To confirm the versatility of this method different membranes

supports including charged (PSF/SPEEK, hydrolyzed PAN), none charged (PSF,
PI) were modified by PPy.
The research showed that this method is versatile and simple method to prepare
SRNF membranes. PPy modified membranes show a very high retention for
negatively charged Rose Bengal in different solvents system, comparable to
those of the MPF-50 and STARMEM 122 commercial membranes, but at a flux
that is much higher. The extended filtration experiment with PPy modified
membranes in DMF showed a stable permeability and retention over 30 hours.
References:
1. M. Mulder, Basic Principles of Membrane Technology, Kluwer Academic, Dordrecht, The
Netherlands 1991, 89-140.
2. I. F. J. Vankelecom and L. E. M. Gevers Pressure- driven membrane processes Chapter in
Green separation processes C.A.M. Afonso, J.G. Crespo (Eds), Wiley-VCH, Weinheim,
Germany, 2005.
3. P. Vandezande, L. E. M. Gevers and I. F. J. Vankelecom, Chem. Soc. Rev. 2008, DOI:
10.1039/b610848m.
4. M. Yuasa, A. Yamaguchi, H. Itsuki, K. Tanaka, M. Yamamoto, and K. Oyaizu, Chem. Mater.
2005, 17, 4278.
5. X. T. Zhang, J. Zhang, Z. F. Liu and C. Robinson, Chem. Commun. 2004, 1852.

Nanostructured Membranes I – 1 – Keynote
Monday July 14, 2:15 PM-3:00 PM, Moloka’i
Novel Polymers of Intrinsic Microporosity (PIMs): Towards An
Understanding of Structure-Property Relationships.
N. McKeown (Speaker), Cardiff University, Cardiff, UK, mckeownnb@cardiff.ac.uk
B. Ghanem, Cardiff University, Cardiff, UK
K. Msayib, Cardiff University, Cardiff, UK
P. Budd, Univesity of Manchester, Manchester, UK
D. Fritsch, GKSS, Germany
Polymers of Intrinsic Microporosity (PIMs) are materials that combine the
processability of polymers with a high degree of microporosity arising from their
rigid and non-planar structures that cannot fill space efficiently [1] . The rigidity is
enforced by the polymer backbone being composed solely of fused-rings and the
necessary sites of contortion are typically provided by spiro-centres or
triptycenes. PIMs can be prepared either as highly insoluble network polymers or
as soluble polymers (e.g. PIM-1, Fig. 1a and b) that are suitable for the
fabrication of self-standing films, submicron coatings or fibres a unique
advantage over conventional microporous materials. Their unique combination of
properties (microporosity, thermal stability, solubility and structural diversity)
makes them attractive for several applications [2] but they are particularly
promising as membrane materials. In particular, a number of published examples
of PIMs [3] display gas permeability data that lie above the Robeson plot [4] for the
separation of important gas pairs (e.g. O2/N2, CH4,CO2), showing that they have
good selectivity as well as high permeability. This presentation will describe
recent work at Cardiff that has the objective of preparing new PIMs to afford a
better understanding of polymer structure-property relationships. These PIMs are
derived from the chemical synthesis of novel monomers based on triptycenes,
spiro-bisindane and hexaazatrinaphthylene subunits, which are designed to
possess greater microporosity and/or binding sites for the inclusion of metals as
catalysts or for facilitated transport across the membrane. Attempts will be made
to correlate the structure of the PIM with the degree of microporosity achieved,
as assessed by low temperature gas adsorption, and their gas permeabilities.
[1] P. M. Budd, B. S. Ghanem, S. Makhseed, N. B. McKeown, K. J. Msayib, C. E. Tattershall,
Chemical Communications 2004, 230.
[2] A recent review on PIMs: N. B. McKeown, P. M. Budd, Chemical Society Reviews 2006, 35,
675.
[3] P. M. Budd, K. J. Msayib, C. E. Tattershall, B. S. Ghanem, K. J. Reynolds, N. B. McKeown, D.
Fritsch, Journal of Membrane Science 2005, 251, 263.

[4] L. M. Robeson, Journal of Membrane Science 1991, 62, 165.

Nanostructured Membranes I – 2
Monday July 14, 3:00 PM-3:30 PM, Moloka’i
Physical Aging and Mixed-Gas Transport Properties of Microporous
Polymers for Gas Separation Applications
S. Thomas (Speaker), Membrane Technology and Research, Inc., Menlo Park, CA, USA
I. Pinnau, Membrane Technology and Research, Inc., Menlo Park, CA, USA, ipin@mtrinc.com
M. Guiver, Institute for Chemical Process and Environmental Technology, National Research
Council, Ottawa, Ontario, Canada
N. Du, Institute for Chemical Process and Environmental Technology, National Research Council,
Ottawa, Ontario, Canada
J. Song, Institute for Chemical Process and Environmental Technology, National Research
Council, Ottawa, Ontario, Canada
Membrane-based gas separation has been practiced as an economically viable
separation technology during the past 30 years. Progress in this field resulted
from significant improvements in materials science, development of high-
performance membranes, and optimization in process design. Important
applications include: a) nitrogen production from air, b) hydrogen recovery in
petrochemical operations, c) removal of acid gases from natural gas, and d)
recovery of condensable, high-value organic vapors from a variety of waste-gas
streams. This presentation will focus on novel, intrinsically microporous glassy
polymers, which may find applications in a wide variety of commercially important
applications. The first generation of microporous glassy polymers was based on
ultra-high free-volume glassy polyacetylene-based polymers, which exhibit the
highest organic vapor/permanent gas selectivties coupled with the highest
organic vapor permeabilities of all known polymers. However, a significant
disadvantage of this class of materials is their inherent poor physical and
chemical instability when operated under industrial conditions. Recently, Budd et
al. reported that a new class of rigid, glassy ladder polymers, so called ‘polymers
with intrinsic microporosity’ (PIM) may offer advantages over microporous
polyacetylene-based polymers for membrane separations. This presentation will
compare the transport properties of these two classes of microporous polymers
for membrane separations. This study includes, for the first time, long-term gas
permeability data of PIM-based materials. We studied the pure-gas permeation
properties of PIM for over one year and the polymer’s properties are exceptional.
The initial oxygen permeability dropped from 1,535 Barrer to 700 Barrer after one
year of operation. On the other hand, the initial oxygen/nitrogen selectivity
increased from 3.7 to 5.2. These are unmatched permeation properties for air
separation, which lie far beyond the typical Robeson permeability/selectivity
trade-off. In addition, PIM is stable in hydrocarbon environment with very high
mixed-gas selectivity and permeability. For example, PIM-1 has a mixed- gas nbutane/hydrogen
selectivity of 30-50 depending on the feed composition. In
summary, microporous glassy polymers exhibit properties, which are unmatched

y conventional polymers and provide a window to broaden possible applications
for membranes used for gas separations.

Nanostructured Membranes I – 3
Monday July 14, 3:30 PM-4:00 PM, Moloka’i
Polymers of Intrinsic Microporosity: New Copolymers, Syntheses,
Properties and Applications.
D. Fritsch (Speaker), GKSS Research Centre Geesthacht GmbH, Germany, fritsch@gkss.de
K. Heinrich, GKSS Research Centre Geesthacht GmbH, Germany
G. Bengtson, GKSS Research Centre Geesthacht GmbH, Germany
J. Pohlmann, GKSS Research Centre Geesthacht GmbH, Germany
Since the discovery of polymers of intrinsic microporosity (PIM polymers) in 2004
[1] their superior properties and applicability in membrane separation processes
were detected [2, 3] . Besides very recently reported polyimides based on the PIM
concept [4] in this paper new copolymers of the PIM family with excellent film
forming properties will be reported. As detected by modeling of PIM-1 [5] the site
of contortion of the spirobisindane unit and the ether bonds attached to the
dicyanobenzene are somewhat deformed in the packed model, thus showing
more flexibility than expected. We concentrated our work on increasing the
stiffness of the site of contortion by synthesizing new tetrahydroxymonomers and
applying 2,3,5,6- tetrafluoro-4-cyanopyridine to introduce basic tertiary nitrogen
to eventually shift the properties. The syntheses and basic gas data, such as
permeability, diffusivity and solubility, will be reported for the first time. From
these properties the microporosity of the new polymers may be presumed. To
verify this hypothesis, a simple test applying PIM membranes for separation of
methanol/Ar mixtures fitted to a mass spectrometer as detector was performed.
Starting from gas/vapor-free thick membranes of about 100 µm, the pore filling
process could be monitored by (1) fast increase of the argon signal according to
the time-lag and (2) with increase of the methanol signal, accompanied by the
methanol condensation in the micropores, a marked decrease of the argon signal
was observed. This effect attributed to microporosity was validated further by
measuring well known high free volume, microporous polymers of the
polyacetylene family. In addition, thin-film composite membranes on different
polymeric supports were prepared and the properties measured, including
durability measurements for gases and in nanofiltration.
[1] P.M. Budd, B.S. Ghanem, S. Makhseed, N.B. McKeown, K.J. Msayib, C.E. Tattershall,
Polymers of intrinsic microporosity (PIMs): robust, solution- processable, organic nanoporous
materials, Chem. Commun., 2004, 230-231.
[2] P.M. Budd, E.S. Elabas, B.S. Ghanem, S. Makhseed, N.B. McKeown, K.J. Msayib, C.E.
Tattershall and D. Wang, Solution- processed, organophilic membrane derived from a polymer of
intrinsic microporosity , Adv. Mater., 2004, 16, 456-459.

[3] P.M. Budd, K.J. Msayib, C.E. Tattershall, B.S. Ghanem, K.J. Reynolds, N.B. McKeown and D.
Fritsch, Gas separation membranes from polymers of intrinsic microporosity, J. Membr. Sci.,
2005, 251, 263-269.
[4] B.S. Ghanem, N.B. McKeown, P.M. Budd and D. Fritsch, Polymers of intrinsic microporosity
(PIMs) derived from bis(phenazyl) monomers, Macromolecules, in print.
[5] M. Heuchel, D. Fritsch, P.M. Budd, N.B. McKeown, D. Hofmann, Atomistic packing model and
free volume distribution of a polymer with intrinsic microporosity (PIM-1), J. Membr. Sci., in print.

Nanostructured Membranes I – 4
Monday July 14, 4:00 PM-4:30 PM, Moloka’i
Characterizing the Pore Size distribution in Nanostructured Membranes
A. Hill (Speaker), CSIRO, Australia, anita.hill@csiro.au
Selective transport of small molecules through membranes is significantly
influenced by the distribution of pore sizes not only at the surface but also
throughout the bulk of the material. In the past few years with our collaborators,
we have focussed on the development of methods of pore size manipulation,
methods to measure pore size distribution (PSD), and methods to model and
predict PSD. Underpinning our work are advanced characterisation tools for
measuring internal and external porosity from 0.1 to 10 nm (positron
spectroscopy), ~1 nm and above (small angle X-ray scattering) and from 10 to
100 nm (phase contrast X-ray imaging). This talk will cover examples of our work
on tailoring and measuring pore size distribution in nanostructured membranes
such as nanocomposites, polymers with intrinsic microporosity, molecular sieve
silicas, and thermally rearranged polymers.

Nanostructured Membranes I – 5
Monday July 14, 4:30 PM-5:00 PM, Moloka’i
Polymers of Intrinsic Microporosity in the Application of Organic Solvent
Nanofiltration
K. Heinrich (Speaker), GKSS Research Centre Geesthacht GmbH, Germany
D. Fritsch, GKSS Research Centre Geesthacht GmbH, Germany, fritsch@gkss.de
P. Merten, GKSS Research Centre Geesthacht GmbH, Germany
G. Bengtson, GKSS Research Centre Geesthacht GmbH, Germany
S. Dargel, GKSS Research Centre Geesthacht GmbH, Germany
Nanofiltration of aqueous solutions is a well developed method in industrial
applications because it saves energy and costs. For non- aqueous, i.e., organic
solvent nanofiltration (OSN) only a very few membranes are on the market
available. Widely in use nanofiltration membranes for reverse osmosis are not
stable against organic solvents. New kinds of polymers are the polymers of
intrinsic microporosity (PIM polymers) [1] which shows superior properties
concerning OSN. These are ladder-type poly(ether)s with a stiff backbone and a
contorted structure that cannot pack closely and lead to a high free volume
accompanied by a high surface area. They are only soluble in tetrahydrofurane
and some halogenated solvents and are stable against many organic solvents
without cross-linking. In this work composite membranes of PIM-1 and newly
synthesized co-polymers were tested. The PIMs were prepared by
polycondensation reaction from dicyanotetrafluorobenzene and
tetrahydroxytetramethylspirobisindane [2] . Co- polymers were synthesized by
analogous polycondensation with of a variety of new co- monomers. The
synthesized polymers were characterized by size exclusion chromatography
(SEC), NMR, IR, elemental analysis, density and permeability measurements.
The fractional free volume was calculated from the density data. For preparation
of composite membranes different membrane supports were applied, such as,
poly(acrylonitrile) (PAN), cross-linked poly(acrylonitrile-co-glycidyl methacrylate)
(PANGMA) and poly(vinyliden-fluoride) PVDF. Fillers were added to improve the
nanostructered materials. Hexaphenylbenzene (HPB, MW = 534,71g/mol) was
used as a model compound to test the retention in different solvents. The results
show high fluxes in the range of 5 to 10 l/m²hbar and retentions up > 90%.
[1] Peter M. Budd et al., Adv. Mater. 2004, 16, 456.
[2] Kricheldorf et al., J. Polym. Sci. Part A.: Polym. Chem. 2006, 44, 5344 -5352.

Nanostructured Membranes I – 6
Monday July 14, 5:00 PM-5:30 PM, Moloka’i
An Efficient Method for Preparing High Molecular Weight Polymers of
Intrinsic Microporosity (PIM)s with Cyclic-Free Structure via Fast
Polycondensation
N. Du (Speaker), Institute for Chemical Process and Environmental Technology, National
Research Council, Ottawa, Ontario, Canada
G. Robertson, Institute for Chemical Process and Environmental Technology, National Research
Council, Ottawa, Ontario, Canada
J. Song, Institute for Chemical Process and Environmental Technology, National Research
Council, Ottawa, Ontario, Canada
S. Thomas, Membrane Technology and Research, Menlo Park, CA, USA
I. Pinnau, Membrane Technology and Research, Menlo Park, CA, USA
M. Guiver, Institute for Chemical Process and Environmental Technology, National Research
Council, Ottawa, Ontario, Canada, michael.guiver@nrc-cnrc.gc.ca
Recently, a British research group, reported on the syntheses of a number of
wholly aromatic glassy ladder polymers, referred to as Polymers of Intrinsic
Microporosity (PIM)s, via irreversible polycondensations at 65°C for 72 h. These
polymers have attracted great interest as an outstanding class of advanced
polymeric materials for membrane-based gas separation due to their rigid and
contorted zig-zag chain structure and loose chain packing that is capable of
generating very high free volume. In our work, a successful synthetic approach to
high molecular weight linear ladder polymers with few low molecular weight cyclic
species was carried out at elevated temperature and high monomer
concentration. In contrast with previously reported conditions for preparing these
PIM materials, the reaction could be completed within a few minutes. The
polymer properties were characterized by GPC, 1 HNMR, 13 CNMR, FNMR, FT-IR,
and MALDI-TOF MS. This procedure can also be used for the general synthesis
of other ladder polymers by irreversible polycondensation of tetraphenols with
activated tetrafluoro aromatics. Gas permeability coefficients (P) were measured
for helium, hydrogen, carbon dioxide, oxygen, methane and nitrogen. PIM-1
exhibits high gas permeability coupled with moderate selectivity. For example,
the oxygen permeability of PIM-1, made by the new synthetic method, is 1,650
Barrer coupled with an oxygen/nitrogen selectivity of 3.3.

Fuel Cells I – 1
Monday July 14, 2:15 PM-3:00 PM, Honolulu/Kahuku
Polyoxadiazole Nanocomposite Fuel Cell membranes operating above
100°C
D. Gomes, GKSS Research Centre Geesthacht GmbH, Germany
S. Nunes (Speaker), GKSS Research Centre Geesthacht GmbH, Germany, nunes@gkss.de
Among the high temperature polymer electrolyte membranes that have been
developed so far, phosphoric acid doped polybenzimidazole [1] , which contains
amphoteric nitrogen groups, is certainly the most investigated system with high
proton conductivity. Here, for the first time the use of a fluorinated polyoxadiazole
doped with phosphoric acid as a proton-conducting membrane is reported for fuel
cell operation at temperatures above 100 °C and low humidities. An advantage of
polyoxadiazoles in comparison to the polybenzimidazoles is the lower reaction
temperature (and time) required for synthesis [2] . The fluorinated polymer is very
stable even in mixtures of sulfuric acid and oleum (20-65 % SO3) [3] .
Protonated polyoxadiazole membranes with a doping level much lower than that
usually applied for polybenzimidazole (0.34 mol of phosphoric acid per
polyoxadiazole unit, 11.6 wt.% H3PO4) had proton conductivity at 120°C and
RH=100% in the order of magnitude of 10 -2 S cm -1 . When experiments are
conducted at low external humidity (relative humidity of 1%), still a high value of
proton conductivity (6 x 10 -3 S cm -1 ) was obtained at 150°C. Higher phosphoric
acid doping levels were possible with the incorporation of sulfonated silica
containing oligomeric fluorinated oxadiazole segments [4] . The functionalized
silica has thermal stability up to 160 °C. With the addition of functionalized silica
not only doping level but also water uptake increased. For the nanocomposite
membranes prepared with the functionalized silica, higher proton conductivity in
all range of temperatures up to 120°C and RH=100% (in the order of magnitude
of 10 -3 S cm -1 ) was observed when compared to the plain membrane (in the
order of magnitude of 10 -5 S cm -1 ).
[1] Q. Li, R. He, J.O. Jensen, d N.J. Bjerrum, Chem. Mater., 15 (2003) 4896-4915.
[2] D. Gomes, C. Borges, J.C. Pinto, Polymer, 45 (2004) 4997-5004.
[3]D. Gomes, S.P. Nunes, Journal of Membrane Science, in press
(http://dx.doi.org/10.1016/j.memsci.2007.11.041).

[4] D. Gomes, I. Buder, S.P. Nunes, Journal of Polymer Science Part B: Polymer Physics 44
(2006) 2278-2298.

Fuel Cells I – 2
Monday July 14, 3:00 PM-3:30 PM, Honolulu/Kahuku
Nanocomposite Membranes with Low Methanol Permeability for the Direct
Methanol Fuel Cell
B. Ladewig (Speaker), The University of Queensland, Australia, b.ladewig@uq.edu.au
D. Martin, The University of Queensland, Australia
J. Diniz da Costa, The University of Queensland, Australia
M. Lu, The University of Queensland, Australia
Current perfluorinated polymer membranes for the direct methanol fuel cell allow
an unacceptably high level of methanol crossover from the anode to the cathode
during operation, leading to decreased cell potential, fuel utilization efficiency and
power output. It is therefore desirable to develop a new class of membrane
materials with low methanol permeability, while maintaining high proton
conductivity, and chemical, thermal and mechanical stability.
A range of silicon alkoxide precursors have been used with in-situ sol gel
synthesis to prepare nanocomposite Nafion 117/inorganic membranes. The
resulting nanocomposite membrane transport properties show a very strong
dependence on the surface chemistry of the incorporated nanoparticles. In
particular, using 3-mercaptopropyl trimethoxysilane as a precursor leads to a sixfold
reduction in the methanol permeability, albeit with a slight decrease in proton
conductivity.
Future directions for the development of robust DMFC membranes in our centre
will be discussed with respect to current developments in the field.

Fuel Cells I – 3
Monday July 14, 3:30 PM-4:00 PM, Honolulu/Kahuku
Proton Conducting Graft Copolymer Electrolyte Membranes for Fuel Cells
J. Koh, Yonsei University, Seoul, Korea
J. Park, Yonsei University, Seoul, Korea
D. Roh, Yonsei University, Seoul, Korea
J. Kim (Speaker), Yonsei University, Seoul, Korea, jonghak@yonsei.ac.kr
A series of proton conducting comb copolymer membranes consisting of
poly(vinylidene fluoride- co-chlorotrifluoroethylene) backbone and poly (styrene
sulfonic acid) side chains, i.e. P(VDF- co-CTFE)-g-PSSA were synthesized using
atom transfer radical polymerization (ATRP). 1H NMR, FT-IR spectroscopy, wide
angle X-ray scattering (WAXS) and transmission electron microscopy (TEM)
results present the successful ‘grafting from’ method using ATRP and the welldefined
microphase-separated structure of the polymer electrolyte membranes.
All the properties of ion exchange capacity (IEC), water uptake and proton
conductivity for the membranes continuously increased with increasing PSSA
contents. The results of thermal gravimetric analysis (TGA) also showed that all
the membranes were stable up to 300 o C. After terminated chlorine atoms were
converted to end-functional azide groups (P (VDF-co-CTFE)-g-PSSA-N3), the
polymer electrolyte membranes were crosslinked under UV irradiation. The
crosslinked P(VDF-co-CTFE)-g- PSSA membrane with 73 wt% of PSSA content
exhibited the reduced water uptake from 300 to 83 %, the increased tensile
strength from 21.1 to 26.2 MPa and the slightly reduced proton conductivity from
0.074 to 0.068 S/cm at room temperature compared to the uncrosslinked
membrane.

Fuel Cells I – 4
Monday July 14, 4:00 PM-4:30 PM, Honolulu/Kahuku
Nanocomposite Proton Exchange Membranes for Hydrogen Fuel Cells:
Self-humidification, Molecular Nucleation and Dynamic Simulation
W. Zhang (Speaker), Hong Kong University of Science and Technology, Hong Kong, China
P. Gao, Hong Kong University of Science and Technology, Hong Kong, China
Nafion membranes, consisting of a polytetrafluoroethylene (PTFE) backbone with
sulfonic acid groups substituted at intervals along the chain, are the most widely
used proton exchange membrane (PEM) materials for hydrogen fuel cell
batteries. Their major drawback, however, is their inability to conduct protons at
low water content levels. Both the external humidifier and physical seal of the
fixture in commercial products increase the cost and complexity of the whole
system. Therefore, we have developed a novel Pt-clay/Nafion nanocomposite
membrane with significantly enhanced proton conductivity than the pristine
Nafion membranes. Monolayers of Pt nanoparticles of diameters of 2-3 nm with a
high crystallinity were successfully anchored onto exfoliated nanoclay surfaces
using a novel chemical vapor deposition process. Chemical bonding of Pt to the
oxygen on the clay surface ensured the stability of the Pt nanoparticles, and
hence, no leaching of Pt particles was observed after a prolonged ultrasonication
and a rigorous mechanical agitation of Pt-clay in the Nafion solution during the
membrane casting process. Systematic analysis using WAXD and TEM showed
that the recasting process produced a new self- humidifying exfoliated Ptclay/Nafion
nanocomposite membrane with a high crystallinity and proton
conductivity. In situ water production for humidification of the dry membranes
without any external humidification was characterized by a combined water
uptake and FTIR analysis of the as-prepared membrane after a single cell testing
without using electrodes. The power density at 0.5 V of a single cell made of a
Pt-clay/Nafion nanocomposite membrane was 723 mW/cm 2 , which is 170 %
higher than that made of a commercial Nafion 112 membrane of similar
thickness.
Durability is another major obstacle for the PEM fuel cell commercialization as
the membrane is the most fragile component. Hydrophobic PTFE backbones of
Nafion membranes were believed to aggregate and form the crystallites inside
the matrix. These crystallites, acting as physical crosslinks, are crucial for the
mechanical and thermal robustness. However their size has been estimated to
range between 3 to 5 nm, which is much smaller than the traditional nucleation
agents. (eg. SiO2, CaCO3, TiO2 et al.) Thus, an aromatic molecule (3, 4dimethylbenzaldehyde)
was selected as the nucleation agent for these special
nano-crystallites in Nafion. In this study, molecular dynamic simulation was firstly
carried out using the Discover and Amorphous Cell modules of Materials Studio,

which was developed by Accelrys Software Inc. The motivation for conducting an
atomistic model for Nafion membranes was to investigate the effects of the
nucleation agent on the dynamic behaviors of the backbones of Nafion in the
casting process at the atomistic level. Simulation results shown that the
backbones of Nafion with the presence of the nucleation agent were clearly
found to be energetic at the temperature above Tg whereas be confined tightly at
room temperature. Given that the activation and frozen phenomena were greatly
alleviated in the model for the pristine Nafion, these tiny aromatic molecules were
supposed to be self- assemble among the PTFE backbones of Nafion, promote
their aggregation and consequently facilitate the crystallization. Accordingly, this
nucleation agent was introduced into Nafion solution to cast membrane in the
experimental investigation. The crystallinity of recast Nafion membrane with 3
wt% 3, 4- dimethylbenzaldehyde impregnated was estimated to be 26 % using
WAXD, which ranges between 5 to 20 % for the commercial Nafion membranes
at equivalent weight of 1100.
The project was sponsored by the Research Grant Council of Hong Kong with an earmarked
grant for research, grant no. 612805.

Fuel Cells I – 5
Monday July 14, 4:30 PM-5:00 PM, Honolulu/Kahuku
Sulfonated Polyimide Membranes for Polymer Electrolyte Fuel Cells
K. Okamoto (Speaker), Yamaguchi University, Ube, Yamaguchi, Japan, okamotok@yamaguchiu.ac.jp
K. Matsuda, Yamaguchi University, Ube, Yamaguchi, Japan
Z. Hu, Yamaguchi University, Ube, Yamaguchi, Japan
K. Chen, Yamaguchi University, Ube, Yamaguchi, Japan
N. Endo, Yamaguchi University, Ube, Yamaguchi, Japan
M. Higa, Yamaguchi University, Ube, Yamaguchi, Japan
Polymer electrolyte membrane (PEM) is the key component of polymer
electrolyte fuel cell (PEFC). Many sulfonated hydrocarbon polymer membranes
have been developed as alternatives for sulfonated perfluoropolymer
membranes. Sulfonated polyimides (SPIs) are one of the promising candidates
for PEMs because of their low fuel permeation, good film-forming ability and
excellent mechanical, thermal and chemical properties. However, they have a
disadvantage of rather easy hydrolysis of imide ring. We investigated the
relationship between the chemical structure of SPIs and the water stability of
their membranes, and developed SPI membranes with reasonably high water
stability and high PEFC performance. In this presentation, we report on
preparation of novel sulfonated polyimide membranes with excellent water
stability and their applications for PEFCs.
SPIs bearing sulfophenoxy side groups were successfully prepared from 1,4,5,8naphthalene-tetracarboxylic
dianhydride (NTDA), 2,2-bis(4sulfophenoxy)benzidine
(2,2-BSPOB) and a non-sulfonated diamine such as 4,4bis(4-aminophenoxy)biphenyl.
The dry SPI membranes in proton form were
immersed into the medium of phosphorous pentoxide/methanesulfonic acid to
form cross-linking. Their uncross-linked and cross-linked membranes were
evaluated as polymer electrolyte membranes for polymer PEFCs.
They maintained high mechanical strength and high proton conductivity after
aging in water at 130 °C for 500 h, indicating their high water stability. PEFCs
with the SPI membranes showed high performances at 90 °C and 0.3 MPa with
air supply; for example, a cell voltage of 0.67 V at 0.5 A/cm 2 under 85 %RH.
They also showed fairly high performances even at a low humidity of 30%RH due
to the back diffusion of water formed at the cathode, for example, a cell voltage
of 0.63 V at 0.5 A/cm 2 . PEFCs with the cross-linked SPI membranes were
operated under a constant current density of 0.5 A/cm 2 at 90 °C and 85 %RH for
1600 h without any reduction in cell performance, indicating their high fuel cell
durability. The SPI membranes have high potential for PEFCs at higher
temperatures above 80 °C.

Fuel Cells I – 6
Monday July 14, 5:00 PM-5:30 PM, Honolulu/Kahuku
Syntheses and Physical Properties of Novel Polymer Electrolyte
Membranes Comprising Poly(diphenylacetylene)s
H. Ito (Speaker), EBARA Research Co. Ltd., Kanagawa, Japan, itoh.hitoshi@er.ebara.com
R. Yamamoto, EBARA Research Co. Ltd., Kanagawa, Japan
E. Akiyama, EBARA Research Co. Ltd., Kanagawa, Japan
K. Takeda, EBARA Research Co. Ltd., Kanagawa, Japan
H. Yokota, EBARA Research Co. Ltd., Kanagawa, Japan
Y. Nagase, School of Engineering, Tokai University, Kanagawa, Japan
The fuel cell, particularly, proton exchange membrane fuel cell (PEMFC) is a
promising technology to reduce dependence on petroleum oil and decrease
emission of carbon dioxide and to actualize a hydrogen-based energy economy.
The large part of the developing systems uses a perfluorinated ionomer, such as
Nafion, as a proton exchange membrane. In present, Nafion and perfluorinated
polymers have an advantage in durability compared with non-fluorinated
polymers. However, these perfluorinated polymers exhibited low glass transition
temperatures at around 393 K. Therefore, the operating temperature of a PEMFC
system is restricted at 333-353 K. If a new polymer electrolyte which can be used
at high temperature is available, the operating temperature of the system can be
raised. As a result, a tank of hot water can be downsized and an oxidation
process of carbon monoxide can be simplified. These simplifications will
contribute to the cost reduction of the PEMFC system. Therefore, the
development of a low-cost polymer electrolyte operational at high temperature is
expected. On the other hand, numerous hydrocarbon ionomers have been
studied for a proton exchange membrane. Generally speaking, the hydrocarbon
ionomers synthesized in the past contained aromatic groups in their polymer
main-chain in order to reinforce durability for oxidation. Especially, the wholly
aromatic polymers, such as poly(phenylene), poly(arylene ether) and poly (aryl
ether ether ketone) are studied energetically. However, the processability,
particularly, film formation property of these polymers is not enough for practical
use. We have much attention on poly (diphenylacetylene)s (PDAs) for a novel
polymer electrolyte because of their good film formation property. In addition, this
polymer has no hydrogen in its polymer main-chain; therefore, a hydrogen
abstraction reaction which caused the degradation of the proton exchange
membranes must not occur. On the other hand, these polymers have been
known as one of the highest gas permeability synthetic polymers. This high gas
permeability is undesirable for a proton exchange membrane because the gas
cross over of hydrogen or oxygen will occur in a fuel cell. In addition, if the double
bonds in the polymer main-chain show high reactivity, this polymer might be
decomposed by hydrogen, oxygen and other gases during the operation.
Therefore, the chemical stability for oxidation or reduction of the PDAs were

investigated at first. As a result, it was suggested that these polymers are stable
at both of oxidative and reductive conditions. Then, we synthesized sulfonated
PDAs by soaking a membrane of PDA with trimethylsilyl groups in sulfuric
acid/ethyl acetate solution. The physical properties such as gas permeability
coefficients, ion-exchange capacity and tensile strength were investigated with
these membranes. As a result, membranes of the sulfonated PDAs exhibited
lower gas permeability compared with those of non-sulfonated PDAs, and
oxygen gas permeability coefficient of the sulfonated PDA membranes were
around 1.0 x 10 -8 barrer. This gas permeability coefficient was as same as that of
Nafion 115. This result indicated that the introduction of the sulfonic acid groups
reduced the gas permeability. The sulfonated membranes showed good proton
conductivity, 1.0 x 10 -2 S/cm at 363 K, 90 % RH. Then, single cell performance
was measured at 353 K, 90 %RH, and almost same performance was obtained
compared with that of Nafion 115. The degradation ratio of the cell voltage was
also estimated by holding at OCV condition for several hundred hours as the
accelerating durability test. The average degradation ratio was about -150 uV/h.
From these results, this novel proton exchange membrane comprising the PDAs
will be candidate for the membrane to actualize high temperature operating of
PEMFCs.

Desalination I – 1 – Keynote
Monday July 14, 2:15 PM-3:00 PM, O’ahu
Energy Cost Optimization in RO Desalting and the Thermodynamic
Restriction
R. Zhu (Speaker), University of California, Los Angeles, Los Angeles, CA, USA
P. Christofides, University of California, Los Angeles, Los Angeles, CA, USA
Y. Cohen, University of California, Los Angeles, Los Angeles, CA, USA, yoram@ucla.edu
Modern RO and NF membranes can be operated at remarkably low pressures.
However, these pressures are still significantly above the thermodynamic
osmotic pressure. Although various studies have advanced a variety of
approaches to evaluate the energy cost of reverse osmosis membrane
desalination, such studies have not offered a simple mathematical formalism that
considered the effect of the lower bound on the feed pressure on energy cost
optimization. In the present study, a rigorous theoretical formalism was
developed that clarifies the thermodynamic restriction on RO energy cost and
provides a basis for RO process optimization. The present approach enables
direct analytical solution for the minimum specific energy cost with respect to
water recovery, feed and permeate flow rate. The additional impact of pressure
drop within the membrane module, energy recovery devices, membrane
hydraulic permeability and brine disposal cost were incorporated into the
theoretical model. Specific results will be presented for simple RO configurations
to demonstrate the impact of multi-stage RO operation on energy efficiency in
relation to membrane cost. In addition, an analytical approach was developed to
enable optimization, with respect to energy efficiency, for multi-pass RO and NF
membrane desalting. The implications of the present work to lowering RO
desalination cost by optimization of process configuration will be presented with
reference to specific recently developed large-scale process configurations.

Desalination I – 2
Monday July 14, 3:00 PM-3:30 PM, O’ahu
Characterizing RO Membrane Performance when Desalinating High pH
Produced Water from the Oil Extraction Process
R. Franks (Speaker), Hydranautics, Oceanside, CA, USA, rfranks@hydranautics.com
C. Bartels, Hydranautics, Oceanside, CA, USA
Produced water is water brought to the surface as part of a high temperature oil
and gas extraction process. Produced water can range in salinity and
composition depending on its original source, but due to the nature of the
produced water, the subsequent treatment steps, particularly the desalination of
the produced water by reverse osmosis, faces unique challenges not
encountered in the treatment of typical surface or well waters. For this reason, an
improved understanding of the effect produced water has on RO membrane
performance is required. The purpose of this study is to characterize the water
transport, salt transport, and longevity of an RO membrane for the treatment of
produced water.
The typical method for dealing with produced water is deep well injection. But oil
production is limited by the well’s capacity to receive the produced water. For this
reason, a combination of technologies is used to treat produced water for
environmental, industrial, and agricultural reuse. Among these technologies is
desalination by reverse osmosis. Specifically, reverse osmosis membranes are
used in the final treatment step after oil, grease, solids and hardness removal
and pH elevation. The RO step is designed to remove the remaining dissolved
salts and organics, including sodium, silica and boron.
Due to the nature of the oil extraction process, produced water contains a unique
mixture of dissolved salts and organics. The passage of salt through the RO
membrane treating produced water at an elevated pH is distinctive from the
common RO performance of many municipal and industrial applications
operating at a neutral pH. A better understanding of salt passage is achieved by
comparing the performance of membranes treating produced water with their
performance on more typical feed waters and synthetic waters.
To do this, a review of the theories governing salt passage is first considered,
including the variation in salt passage with increasing pH. The salt transport
theories, along with years of accumulated data from RO systems treating more
common feeds, are used to predict ion passage in a produced water system.
To compare theoretical and actual performance, samples from an RO membrane
treating produced water in the field were analyzed. The analysis considered

specific ions such as chloride, sodium, silica, and boron as well as the passage
of organics by analyzing TOC. An analysis of the water transport coefficient was
also conducted. In general, the membrane performed as expected. The water
transport coefficient was found to be accurate and the salt passage of most ions
supported the theoretical results. However, the passage of sodium was found to
be significantly higher than the projected passage. The permeate pH also failed
to conform to theoretical predictions. Instead of seeing a decrease in permeate
pH relative to feed pH as is typical in RO systems operating at neutral pH, the
permeate pH was found to increase relative to the high feed pH.
Additional controlled studies were conducted in the lab in an effort to better
understand the differences between theoretical and actual performance. The
studies were conducted on synthetic waters, typical surface waters, and
produced water collected from the field. The passage of ions associated with the
different mixtures, including sodium passage, was analyzed at different pH
levels.
In addition of understanding salt passage when treating produced water, a better
understanding of membrane longevity is necessary considering the high pH and
high temperature operation associated with some produced water treatment
processes. Operation at high pH can mitigate organic fouling of the RO and act
as a kind of continuous cleaning. But exposure to high pH can also adversely
affect the integrity of the membrane. Both the polyamide layer and the
membrane’s polyester backing can be degraded by a combination of high
temperatures and high pH. For this reason, the polyester backing, RO
membrane, and RO elements were exposed to high pH solutions for extended
periods. Strength testing was performed on the backing material and wet testing
was done at one month intervals to quantify the increase in salt passage and the
change in water permeability.
The theoretical data, field analysis, and laboratory tests compiled in this study will
be used to better predict specific ion passage at high pH on both typical waters
and on produced waters. The results of this study will also be used to better
understand the long term behavior of an RO membrane when treating produced
water.

Desalination I – 3
Monday July 14, 3:30 PM-4:00 PM, O’ahu
Submerged Hollow Fibre Pre-treatment to RO in Seawater Applications
Y. Ye (Speaker), UNESCO Center for Membrane Science and Technology, School of Chemical
Science, Sydney, Australia
L. Sim, UNESCO Center for Membrane Science and Technology, School of Chemical Science,
Sydney, Australia
V. Chen, UNESCO Center for Membrane Science and Technology, School of Chemical Science,
Sydney, Australia, v.chen@unsw.edu.au
A. Fane, UNESCO Center for Membrane Science and Technology, School of Chemical Science,
Sydney, Australia
Since reverse osmosis membranes are very sensitive to foulants such as
colloids, inorganic scale and biofouling, proper pre-treatment process therefore
becomes a critical factor for a successful long-run seawater reverse osmosis
(SWRO) plants. Recently, low pressure membrane has been successfully used
in the pre-treatment for wastewater reclamation by reverse osmosis (RO). This is
because membrane pre-treatment offers several advantages such as smaller
plant footprint, better quality of feed water for RO unit and less chemical
consumption. As a result, the use of low pressure membrane is now being
considered as a viable solution for pre-treatment to SWRO plants but further
improvements in membrane configurations and operations need to be
investigated to reduce fouling and energy consumption.
The aim of this study is to investigate the efficiency of pre-treatment using MF
and UF submerged hollow fibre system by varying the operation parameters.
Three different type of hollow fibre (0.22um polypropylene (PP) membrane and
two 0.04um polyvinylidene fluoride (PVDF) membranes with different fibre outer
diameters) were used for the pre-treatment of the synthetic seawater. Three
different modes of filtration: continuous, relaxation and backwash mode of
filtration were investigated. For all three membranes used, it was found that,
during the relaxation mode of filtration, TMP only decreased slightly after 40s of
relaxation in each filtration circle (1hr). The decrease of TMP was also observed
after each backwash (3560s filtration, 40s backwash where the backwash flux is
twice of the permeate flux). However, the rate of TMP increase during each
filtration circle for the backwash mode is much higher than that in the relaxation
mode of filtration. Consequently, it leads to higher final TMP value in the end of
20 hr’s backwash mode filtration when compared to the relaxation mode.
Meanwhile, comparing different membranes fibres, it appears that bigger pore
size PP hollow fibre has higher dTMP/dt in each cycle of filtration after backwash
than those observed for smaller pore size PVDF membranes. All these indicate
that inappropriate backwash might even accelerate the membrane fouling. The
further characterization of the membranes using different mode of filtration is

eing carried out. In addition, the parameters of backwash/ relaxation such as
filtration time, backwash/relaxation time and backwash strength are investigated
to optimize the filtration performance.
Acknowledgements
The authors acknowledge the financial support of Department of Education, Science and
Training, Australia via the International Linkage program. The project is collaboration with the
European Union 6th Framework project, Membrane-Based Desalination: An Integrated Approach
(MEDINA). The authors also acknowledge Memcor Australia Pty. Ltd. for membrane supply.

Desalination I – 4
Monday July 14, 4:00 PM-4:30 PM, O’ahu
RO Membrane Desalting in a Feed Flow Reversal Mode
M. Uchymiak (Speaker), University of California, Los Angels
B. Alex, University of California, Los Angeles
P. Christofides, University of California, Los Angeles
N. Daltrophe, Ben-Gurion University, Beer Sheva, Israel
M. Weissman, Ben-Gurion University, Beer Sheva, Israel
J. Gilron, Ben-Gurion University, Beer Sheva, Israel
R. Rallo, Universitat Rovira i Virgili, Tarragona, Catalunya, Spain
Y. Cohen, University of Calironia, Los Angeles, yoram@ucla.edu
The growing demand for potable water, coupled with increasing salinity levels of
traditional water sources, has led to a fast growth of membrane RO desalination
as a potential solution to upgrading the quality of water supplies, as well as a
solution for exploiting underutilized non-traditional water sources, especially
brackish groundwater. However, product water recovery is often limited for inland
water desalination due to membrane scaling by sparingly soluble mineral salts
(e.g., calcium sulfate, calcium carbonate, barium sulfate) as well as silica.
Several methods are currently used to prevent scale formation; addition of
antiscalant chemicals to the feed or flushing the membrane units with low-TDS
(total dissolved solids) permeate water are two common procedures to
accomplish this task. These current methods of scale mitigation have several
disadvantages, antiscalants add to the cost of desalination, and the addition of
excess amounts can encourage membrane biofouling and even promote scaling
in some cases. In the case of permeate flush, the reverse osmosis operation
must be halted to allow for the flushing cycle, thereby reducing permeate
production, and using valuable permeate water. In the preset work, an automated
novel technique of feed flow reversal has been developed, which can prevent
mineral scaling without the addition of expensive chemicals or periods of system
downtime. In the present process configuration, a system of electronically
actuated valves is configured specifically to enable periodic reversal of the feed
flow direction through the RO modules. This reversal of the feed flow also
reverses the axial salt concentration profile at the surface of the membrane,
effectively "resetting the crystallization induction clock. The feed flow reversal,
when activated just after the first crystals have formed, also allows a substantial
portion of scale deposited on the membrane surface to re-dissolve into solution.
In order to automate the flow-reversal mode of operation, a novel ex-situ scale
observation detector (EXSOD) system was developed with the hardware and
software to allow for direct monitoring of the onset of scaling in RO processes.
The EXSOD system was coupled with model-predictive control algorithms that

were developed to enable feed-flow reversal operation. Open-loop and closedloop
simulations demonstrated non-linear model-predictive control strategies that
transition from the high-flow to low-flow steady-states in an optimal way while
subjected to plant-model mismatch on the feed concentration, actuator
constraints, and sampled measurements. The EXSOD detection of scale is
based on direct surface imaging, whereby the appearance of surface crystals is
analyzed in real-time using novel image analysis algorithms. Upon the detection
to the onset of surface scaling, a control signal is sent to the RO plant PLC to
initiate flow reversal. The flow reversal approached was successfully
demonstrated in both laboratory bench-scale studies and in RO pilot plant
studies demonstrating the ability to maintain constant permeate flux, without the
use of antiscalants, even under conditions of supersaturation. The study has the
demonstrated that the cost of water desalination can be reduced, whenever there
is propensity for mineral scaling, by using the feed flow reversal approach, both
due to eliminating the need for antiscalants and expected reduction in the
frequency of membrane cleaning.

Desalination I – 5
Monday July 14, 4:30 PM-5:00 PM, O’ahu
Evaluating the Performance of Single-Pass RO and Multi-Pass NF/RO
Systems for Seawater Desalination
D. Tanuwidjaja (Speaker), University of California, Los Angeles, Los Angeles, CA, USA, ,
dian@seas.ucla.edu
E. Hoek, UCLA CEE Dept/CNSI/WaTeR Center, Los Angeles, CA, USA
In recent years, reverse osmosis (RO) seawater (SW) desalination technology
has undergone a remarkable transformation. The number and capacity of large
SWRO plants and pilot facilities have increased significantly. An emerging
approach to seawater desalination is the use of complex, integrated multi-stage
and multi-pass systems [1] . Energy required to drive conventional single-pass
SWRO process comprises ~40 percent of the total cost of water produced. The
RO product water recovery cannot be driven beyond about 50-60 percent
because increasing retentate osmotic pressure at high recovery produces a
diminishing economic benefit. In addition, the higher retentate concentration
increases salt passage, as well as fouling and scaling concerns. Two novel
approaches to reduce energy consumption in seawater desalination include: (1)
the use of seawater RO membranes with different permeability to balance flux
and pressure through the system (e.g., the ‘Dow-FimTec’ method [2] ) and (2) the
use of a two-pass seawater nanofiltration (NF) membrane system (e.g., the ‘Long
Beach’ method [3] ).
We hypothesize that nanofiltration of seawater (using conventional NF
membranes) could dramatically reduce the fouling and scaling potential of the
feed, and the foulant-free seawater desalted by RO membranes operating at
much higher flux and recovery without significantly increasing specific energy
consumption; thus, reducing the overall cost of water produced. Additional
benefits of NF pretreatment include the fact that NF membranes are relatively
stable against chlorine attack allowing for better bio-growth control, plus NF
membranes almost completely reject dissolved organic matter, which may be a
critical foulant during algal blooms. Further, the RO process can be operated at
high pH due to reduced scaling concerns, which should enhance boron rejection.
Finally, NF pre-treatment creates options for NF concentrate demineralization
and recycling back to the plant feed, further increasing recovery and reducing
brine discharge.
Objectives of this study are: (1) create a model to assess product water quality
and specific energy consumption in single-pass and multi-pass NF/RO systems,
(2) determine the optimal theoretical NF/RO membrane properties needed to
optimize product water quality and specific energy consumption, (3) and evaluate

model results with bench-scale studies of seawater desalination using
commercially available NF/RO membranes. We have created a simple analytical
model that estimates full-scale NF/RO system product water quality and specific
energy consumption considering a membrane’s water permeability and TDS
rejection, feed water concentration, total system flux, and concentration
polarization. In addition, we have developed a bench scale NF/RO seawater
desalination simulator for testing real NF/RO membrane performances in the
modeled scenarios.
Model results for single-pass SWRO systems suggest the theoretical minimum
specific energy consumption is not yet realized, the effects of concentration
polarization are non-negligible, and increasing SWRO membrane permeability
beyond that of modern BWRO membranes may yield little benefit. These results
may have important implications and could be used to guide future efforts to
engineer better performing SWRO membranes and modules. These results and
their implications will be discussed in the presentation. Model simulations are
also performed to elucidate the optimal combination of first and second pass
NF/RO membrane rejections for a two-pass system. Simulations consider three
scenarios in which (a) membrane resistance and CP are neglected, (b)
membrane resistance is neglected, CP is considered, and (c) membrane
resistance and CP are considered. These results highlight the important role of
membrane resistance and CP in multi-pass system performance. Finally, three
scenarios have been tested in the laboratory: (a) two-pass NF membrane
followed by a high-rejection BWRO membrane, (b) two-pass seawater NF
(SWNF) membrane followed by another SWNF membrane, and (c) a one-pass
SWRO membrane. All three scenarios give desalination performance that may
have practical value. In this presentation we will present details of our modeling
and experimental results, and discuss the implications for single-pass and multipass
NF/RO seawater systems.
Reference:
1.Sauvet-Goichon, B., Ashkelon desalination plant -- A successful challenge. Desalination, 2007.
203(1-3): p. 75.
2.Lomax, I., Experiences of Dow in the field of seawater reverse osmosis. Desalination, 2008.
224(1-3): p. 111.
3.Harrison, C.J., et al., Bench-scale testing of nanofiltration for seawater desalination. Journal of
Environmental Engineering-Asce, 2007. 133(11): p. 1004-1014.

Desalination I – 6
Monday July 14, 5:00 PM-5:30 PM, O’ahu
Performance Testing of a Large Seawater RO Desalination Plant
A. Khawaji (Speaker), Royal Commission for Jubail & Yanbu, Yanbu Al-Sinaiyah, Saudi Arabia
J. Wie, Saudi Arabian Parsons Limited, Yanbu Al-Sinaiyah, Saudi Arabia,
JongMihn.Wie@parsons.com
Yanbu Industrial City in Saudi Arabia depends upon seawater desalination for its
entire fresh water supply. The fresh water is supplied by a desalination complex
that consists of a multi- stage flash distillation plant with a capacity of 95,760
m 3 /day and a reverse osmosis (RO) plant with a capacity of 50,400 m 3 /day. The
RO plant was constructed recently by the Royal Commission for Jubail & Yanbu.
This seawater RO plant is made up of six 8,400 m 3 /day permeate trains. The
plant consists of five basic components: seawater supply, feedwater
pretreatment, high pressure pumping, RO membranes, and permeate posttreatment.
The RO plant is designed to desalt the seawater with total dissolved
solids (TDS) of 46,400 ppm at 22 °C seawater temperature. RO feedwater is
treated with various chemicals such as sulfuric acid, ferric chloride, sodium
bisulfite, and sodium hypochlorite. Filtration is carried out in two stages with dual
media filters and cartridge filters. The multistage high pressure centrifugal pumps
are operated at 64 to 76 kg/cm 2 g. The high pressure pumps are coupled to
energy recovery turbines for energy recovery from the concentrated brine stream
to reduce electrical pumping costs. The RO membranes are made of cellulose
triacetate using the hollow fine fiber configuration. The plant is installed with
1,824 RO membrane elements. Salt rejection by the membranes is
approximately 99.4%. The plant produces permeate with a maximum TDS of 500
ppm at a minimum recovery ratio of 35% for the single pass permeators. The
plant is equipped with a distributed control system using state-of-the-art
computerized technology. This paper presents the major plant design features
and the results of the testing conducted to determine whether the plant
performance guarantee described in the contract technical specifications can be
met. The performance testing includes normalized permeate flow rates,
permeate water quality, recovery rates, chemicals consumption, power
consumption, silt density index values and residual chlorine concentrations of
seawater and filtered water, permeate pHs, and bacteriological tests of product
water.

Composite Polymeric Membrane Formation – 1 – Keynote
Monday July 14, 2:15 PM-3:00 PM, Waialua
A New Method to Fabricate Membranes using Glassy Self Assembly
Templating
G. Feng, University of Cincinnati, Cincinnati, OH, USA
C. Ho (Speaker), University of Cincinnati, Cincinnati, OH, USA
C. Co, University of Cincinnati, Cincinnati, OH, USA, cco@alpha.che.uc.edu
Ultrafiltration and microfiltration membranes play an integral part in downstream
processing operations in biotechnology and pharmaceutical industries.
Ultrafiltration membranes are traditionally manufactured by air casting,
immersion, or melt casting of polymer solutions. In almost all cases however, the
pores as defined by the percolated nodules of polymer, are very polydisperse
and geometrically ill-defined. As a result, most ultrafiltration membranes have
relatively broad molecular-weight cut-offs and sub-optimal hydraulic permeability.
A promising approach for manufacturing ultrafiltration membranes with uniform
pores relies on the polymerization of self-assembled surfactant nanostructures.
Many research groups have investigated polymerizing bicontinuous surfactant
structures. However, instead of forming ultrafiltration membranes with nanometer
size pores, membranes with micron-size pores much larger than that of the
surfactant template are consistently reported following polymerization. This is
due to breakthrough of the surfactant templates, which typically rearrange on a
time scale faster than the polymerization. To overcome this challenge in an
economical and practical way, the approach proposed here replaces water in
traditional self-assembled surfactant templates with glassy sugars. Successful
polymerization of these templates would potentially lead to membranes with
highly uniform and finely tunable nanometer-size pores whose dimensions are
dictated by the quasi-equilibrium thermodynamics of the glassy sugar/surfactant
template. After polymerization, the sugar and surfactant can be readily rinsed off
with water and recycled, thereby foregoing the use of toxic solvents prevalent in
traditional membrane manufacturing processes.

Composite Polymeric Membrane Formation – 2
Monday July 14, 3:00 PM-3:30 PM, Waialua
Ultra-Thin Polymeric Interpenetration Network with Enhanced Separation
Performance Approaching Ceramic Membranes for Biofuel
L. Jiang (Speaker), National University of Singapore, Singapore
Y. Jean, University of Missouri- Kansas City, Kansas City, MO, USA, chencts@nus.edu.sg
H. Chen, University of Missouri- Kansas City, Kansas City, MO, USA
T. Chung, National University of Singapore, Singapore
In this study, we report the discovery of novel molecular engineering and
membrane fabrication that can synergistically produce polymeric membranes
exhibiting separation performance approaching ceramic membranes in biofuel
dehydration. Biofuel has emerged as one of the most strategically important
sustainable fuel sources. The success of biofuel development is not only
dependent on the advances in genetic transformation of biomass into biofuel, but
also on the breakthroughs in separation of biofuel from biomass. The ‘separation’
alone currently accounts for 60 to 80% of the biofuel production cost. There
mainly exist two kinds of materials applied for biofuel separation by
pervaporation, namely, ceramic membranes and polymer membranes. Ceramic
membranes made of sophisticated processes have shown separation
performance far superior to polymeric membranes. Nevertheless, ceramic
membranes seriously suffers fragility and high fabrication cost, and polymeric
membrane with excellent flexibility is still attractive. For the polymeric membrane,
extensive studies exist on how to fine tune the membrane’s pore structure
including it’s cross-section morphology by the selection of polymer solvents and
non-solvents, additives, residence times and other parameters during nonsolvent
induced phase separation. The key for the performance is the very thin
‘skin’ layer which enables a high permeability. The newly discovered membranes
in current work are fabricated by dual-layer co-extrusion technology in just one
step through phase inversion. The best performance obtained was a total flux of
~3.9 kg/m 2 -hr with a separation factor of ~800 in tert-butanol dehydration. The
combined molecular engineering and membrane fabrication approach may
revolutionize future membrane research and development for purification and
separation in energy, environment, and pharmaceuticals.

Composite Polymeric Membrane Formation – 3
Monday July 14, 3:30 PM-4:00 PM, Waialua
PTFE-Polyamide Thin-Film Composite Membranes from Interfacial
Polymerization for Pervaporation Dehydration of Alcohol-Water Mixtures
C. Yu, Chung Yuan University, Chung-Li, Taoyuan, Taiwan
R. Jeng (Speaker), National Chung Hsing University, Taichung, Taiwan
Y. Liu, Chung Yuan University, Chung-Li, Taoyuan, Taiwan, ylliu@cycu.edu.tw
J. Lai, Chung Yuan University, Chung-Li, Taoyuan, Taiwan
Thin-film composite (TFC) membranes are attractive in membrane separations.
The thin selective layers of TFC membranes warrant their high fluxes and high
selectivitity in separation. Consideration of the superior chemical resistance,
good thermal stability, and high mechanical strength of poly (tetrafluoroethylene)
(PTFE), in this work we report attempts on preparation of PTFE-polyamide (PA)
TFC membranes by interfacial polymerization. The pervaporation dehydration
performance of the prepared membranes on alcohol- water mixtures is also
examined. The compatibility between the PTFE substrates and the monomer
solutions in interfacial polymerization is the key issue in the preparation of PTFE-
PA TFC membranes. We demonstrated several modification approaches on
PTFE surfaces and the modified PTFE films are applied to preparation of TFC
membranes. It has been found that incorporation of an amine- terminated layer
on the PTFE surface provides good compatibility and adhesion to PTFE/PA
interfaces by increases in hydrophilicity and formation of covalent linkages
between PTFE and PA. The amine-terminated layer is introduced to PTFE
surfaces via both of surface-initiated polymerization and surface plasma
deposition polymerization. Chemical structure characterizations are performed.
The morphology of the TFC membranes are also observed with electron
microscopy. The composite membranes are applied to pervaporation dehydration
processes on a 70 wt% isopropanol aqueous solution. The membranes are
stable under the pervaporation dehydration operations and show a high
permeation flux of 1720 g/h.m2 and a separation factor of 177. These PTFEbased
thin-film composite membranes are potentially useful in pervaporation
separation for other organic mixtures.

Composite Polymeric Membrane Formation – 4
Monday July 14, 4:00 PM-4:30 PM, Waialua
Preparation of Poly(vinyl alcohol) Composite Reverse Osmosis and
Nanofiltration Membranes
G. Ramos (Speaker), Federal University of Rio de Janeiro, PEQ, Chemical Engineering, Brazil,
gaby@peq.coppe.ufrj.br
B. Cristiano, Federal University of Rio de Janeiro, PEQ, Chemical Engineering, Brazil
Nowadays, in reverse osmosis (RO) and nanofiltration (NF) processes, the thinlayer
composite polyamide (PA) membrane is accepted as a reference system.
These PA membranes are widely commercialized for these processes due to
their excellent saline rejection and hydraulic permeability. However, one of the
major factors reducing the overall performance of the RO and NF processes is
fouling. Membrane fouling can cause irreversible loss of system productivity.
Among the types of fouling, biofouling is the one of the most serious fouling
problems and polyamide membranes are particularly susceptible to it.
In addiction, the major concern with PA membranes is their lost of performance
when exposed to oxidizing agents, such as aqueous chlorine, commonly used in
water disinfection. It is known that after an exposition to chorine of 500 to 2,000
ppm.h membranes salt rejection decreases and the water flux increase. In order
to protect the membrane, the chlorine should be completely removed in the pretreatment
stage, increasing costs and allowing the growth of microorganisms
throughout the system and, especially, the formation of biofilm on the surface of
the membrane. Also, sodium bi-sulfite, added to remove chlorine, attacks the PA
membrane under presence of heavy metals, such as Cu, Co, etc.
New polymer material with enhanced resistance to fouling and oxidation is
subject of many research works. By far, the simplest technique to prepare a
composite membrane is the dip-coating using a diluted polymer solution, which
allows the use of several polymers to prepare the top layer. Poly(vinyl alcohol)
(PVA) is an attractive material because it is an hydrophilic polymer with low
fouling potential, has chemical stability, low cost and it can be easily deposit on
top of many existing porous supports. Furthermore, the hollow fibers have
advantages in relation to the flat membranes: they are self supported and
appropriated for compact modules with large area of membrane.
The aim of this work is to investigate the synthesis of reverse osmosis and
nanofiltration composite membranes by using PVA as top layer, prepared by dip
coating technique. The molecular packing density of PVA dense layer was varied
by choosing the parameters that affect the crosslinking reaction of PVA
molecules. The PVA 80 and 99% hydrolyzed was crosslinked by using different

crosslinking agents, citric acid, oxalic acid and maleic acid, and different
temperatures: 60, 80, 100 and 150°C. The characterization of the crosslinked
PVA was performed by DSC, TGA and FTIR analysis, as well as water swelling
degree.
Ultrafiltration poly(ether sulfone) hollow fibers with cut-off of 50 kDa were used as
porous support for a selective layer of PVA. The composite fibers were
characterized by SEM and by permeation of sodium sulfate solution in a lab setup.
The transport properties in combination with morphological analysis allow
establishing criteria for selection of the best conditions to prepare PVA composite
membranes for RO and NF processes.
The results with these composite membranes showed salts rejection were
around 95%. To evaluate the chlorine resistance, PVA films were analyzed by
FTIR after immersion in chlorine solution. Results indicate that it is a promising
method to produce chlorine resistant membranes.

Composite Polymeric Membrane Formation – 5
Monday July 14, 4:30 PM-5:00 PM, Waialua
Experimental Verification of Effect of Support on Membrane Performance
R. Takagi (Speaker), Shukugawa Gakuin College, Nishinomiya, Japan, takagi@shukugawac.ac.jp
A. Pihlajamäki, Lappeenranta University of Technology, Lappeenranta, Finland
T. Shintani, Nitto Denko Corporation, Osaka, Japan
M. Nyström, Lappeenranta University of Technology, Lappeenranta, Finland
Generally, a membrane is a composite, made by forming a skin layer on a
support. The ion permeability coefficient of the support is generally different from
that of the skin layer. Thus, the characteristic properties of the support also affect
membrane performance. The effect of the support on the membrane
performance has been theoretically studied. It is already reported that the
variation of membrane charge, pore radius, porosity and thickness of the support
affect the ion flux and, then, affect the rejection of the membrane. It is very
important to know the effect of the support on the membrane performance to
design a new membrane. Unfortunately, it is very difficult to verify the effect of
the support experimentally. It will be possible to verify the effect of the support
experimentally, if the characteristic properties of the skin layer and the support
are known separately. It is possible to characterize the support as a separate
membrane experimentally. However, it is very difficult to experimentally
characterize the skin layer as a separate membrane, since the skin layer is very
thin and it is almost impossible to obtain the skin layer as a separate membrane.
In this paper, a potential way to experimentally verify the effect of the support is
discussed. The composite membrane will be asymmetric with respect to
membrane charge, since the porosity and the pore radius of the support are
different from those of the skin layer. It is theoretically reported that the
membrane potential of the asymmetric membrane with respect to membrane
charge varies by changing the membrane setting from (bulk solution 1|skin layer |
support | bulk solution 2) to (bulk solution 1| support | skin layer | bulk solution 2).
The membrane potential is an electric potential difference generated between the
bulk solutions when the membrane separates two bulk solutions with different
concentration of electrolyte or different kind of electrolyte. Then, if the skin layer
and the support are homogeneously charged and the membrane potential of the
composite membrane varies by changing the membrane setting, it shows that the
membrane is asymmetric with respect to membrane charge. It means that the
effect of the support is not negligibly small and that the support affects the
membrane performance.

Commercial polymeric membranes are used as the composite membranes. The
skin layer of commercial polymeric membranes is about 0.1~0.2μm in thickness.
It is reasonable to assume that the skin layer is homogeneously charged, since it
is very thin. The charge density of the skin layer will be higher than that of the
support, since the pore radius of the skin layer is smaller than that of the support.
On the other hand, the support of commercial polymeric membranes is about
150μm in thickness (PSF 50μm and nonwoven 100 μm) and has a nonhomogeneous
structure. If the membrane potential of the support as a separate
membrane does not vary by changing the membrane setting, it means
experimentally that the support is homogeneous with respect to membrane
charge. Thus, it will be an experimental evidence that the support affects the
membrane performance, if the membrane potential of the support as a separate
membrane does not vary by changing the membrane setting and the membrane
potential of the commercial membrane varies by changing the membrane setting.
The membrane potential was measured using NaCl as the electrolyte, keeping
the bulk concentration ratio as two. The membrane potential of the support as a
separate membrane did not vary by changing the membrane setting. It means
that the support is homogeneous with respect to membrane charge, regardless
of its geometric structure. On the other hand, the membrane potential of the
commercial membranes (Nitto Denko Corporation CPA3 and ES10-D4) varied by
changing the membrane setting. This fact verifies experimentally that the support
affects the membrane performance of composite membranes such as the
commercial membranes studied here.

Composite Polymeric Membrane Formation – 6
Monday July 14, 5:00 PM-5:30 PM, Waialua
Study on Improvement of Composite Reverse Osmosis Membranes
C. Gao (Speaker), The Development Center of Water Treatment Technology, Hanzhou, China,
gaocjie@mail.hz.zj.cn
Y. Zhou, The Development Center of Water Treatment Technology, Hanzhou, China
Q. An, College of Materials Science and Chemistry, Zhejiang University, Hangzhou, China
S. Yu, The Development Center of Water Treatment Technology, Hanzhou, China
L. Wu, The Development Center of Water Treatment Technology, Hanzhou, China
The current worldwide expansion of the RO application has resulted from the
introduction of thin-film-composite (TFC) membranes by interfacial
polycondensation. The TFC membranes are composed of thin skin layers and
supporting substrates. Some studies have been carried out recent years on the
improvements of both the skin layers and supporting substrates. For the
improvements of supporting substrates, the relationship between cloud point,
zero viscosity and rheological properties of casting solution and structure and
performance of membrane was analyzed. The formation mechanism of phase
inversion membrane was investigated. The supporting PSF membranes with
cross-section structures of sponge-like with density gradient were obtained. For
the improvements of thin skin layers, a few of functional monomers such as
SMPD, HDA, ICIC and CFIC, for interfacial polymerization were synthesized. The
effect of compositions of water phase (diamine) and oil phase (carbonyl chloride)
on membrane performance were investigated. The procedure and parameter
control of membrane preparation were optimized. The post treatment of obtained
TFC membrane was conducted for further improvement. The relation between
among performance and chemical structure, morphology of membranes was
investigated. The composite membranes with high flux, high rejection and antifouling
property were produced comparing with original membranes.

Oral Presentation
Abstracts
Morning Session
Tuesday, July 15, 2008

NAMS Alan S. Michaels Award – 1a
Tuesday July 15, 8:15 AM-8:50 AM, Kaua’i
Some Reflections and Projections Based on Thirty Five Years in
Membranes
W. Koros (Speaker), Georgia Institute of Technology, Atlanta, GA, USA, wjk@chbe.gatech.edu

NAMS Alan S. Michaels Award – 1b
Tuesday July 15, 8:50 AM-9:15 AM, Kaua’i
A Versatile Membrane System for Bulk Storage and Shipping of Produce in
a Modified Atmosphere
S. Kirkland, University of Texas at Austin, Austin, TX, USA
R. Clarke, Landec Corporation, Menlo Park, CA, USA
D. Paul (Speaker), University of Texas at Austin, Austin, TX, USA, drp@che.utexas.edu
After harvesting, fruits and vegetables continue to respire, i.e., consuming
oxygen and giving off carbon dioxide. Such produce will retain freshness and
market value much longer if the respiration process is slowed down, e.g., by
refrigeration. Produce shelf life can be extended further by storage in an
appropriate gaseous atmosphere, e.g., oxygen and carbon dioxide composition,
within an optimal range specific to each type of produce. Modified atmosphere
packing, MAP, employs membranes to achieve the specific atmosphere needed;
commercial application of this concept is growing rapidly for small, disposable
retail packages. Membrane technology can also be used to create appropriate
atmospheres in reusable large-scale bulk containers for storage and shipping of
produce. However, this approach would be even more widely used if a versatile
system could be designed to accommodate the requirements of different types of
produce without altering the hardware, i.e., one membrane system could be used
to create different compositions of oxygen and carbon dioxide, depending on
what produce is being shipped or stored at a given time. A scheme is proposed
here that uses a selective membrane and a non-selective membrane acting in
parallel. The relative amount of gas exchange through the non-selective
membrane can be adjusted by varying the volumetric air feed rate to its upstream
surface; this will, in turn, adjust the steady state composition of the gas around
the produce. A quantitative model for this scheme and sample calculations are
presented to illustrate the concept and how to design such a system where the
atmosphere created can be set to the desired range by adjusting the air feed
rate.

NAMS Alan S. Michaels Award – 2
Tuesday July 15, 9:30 AM-9:55 AM, Kaua’i
Enhancing Natural Gas Purification with Advanced Polymer/Molecular
Sieve Composites
S. Miller (Speaker), Chevron Energy Technology Company, Richmond, CA, USA
D. Vu, Chevron Energy Technology Company, Richmond, CA, USA, devu@chevron.com
Membranes have been of continuing interest to the petroleum and chemical
industries for gas separations. While glassy, polymeric membranes have
provided efficient performance to date, significant improvements over current
membrane technology will likely require novel materials. This paper will review
the development and status of a new technology based on composite
membranes, termed mixed matrix membranes, of polymer matrices in which
molecular sieves are dispersed to give enhanced separation of natural gas from
its impurities compared to membranes of the polymer alone.
The technology is particularly of interest to the separation of natural gas from its
impurities, such as CO2 and H2S.
In laboratory testing, the composite membranes, composed of molecular sieves
in commercial membrane polymer matrices, showed significant improvement in
both selectivity and flux compared to membranes of the polymers alone for the
separation of CO2 from natural gas. Enhancements were obtained using both
carbon molecular sieves and small pore zeolites.
While membranes have been of interest due to their compactness, light weight,
and ease of operation, there has not been widespread application due to low
selectivity and flux, and limited robustness. This has led researchers to study
molecular sieve membranes, including carbon molecular sieve and zeolitic
materials. While these membranes offer very attractive properties, their cost,
difficulty of commercial scale manufacture, and brittleness remain major
challenges. Mixed membrane technology, which combines benefits of molecular
sieves with the ease and low cost of processing polymer membranes, offers a
potential solution to these challenges.

NAMS Alan S. Michaels Award – 3
Tuesday July 15, 9:55 AM-10:20 AM, Kaua’i
High Performance Ultrafiltration: What Can We Learn from the Gas
Separations Experts?
A. Zydney (Speaker), The Pennsylvania State University, University Park, PA, USA,
zydney@engr.psu.edu
Historically, there has been relatively little interaction between researchers and
practitioners working on ultrafiltration and gas separation membranes. Not only
are these application areas very different, the fields use very different
terminology and theoretical frameworks to describe the performance of the
membrane processes. For example, ultrafiltration membranes are typically
characterized in terms of the nominal molecular weight cut-off, a poorly-defined
term that provides relatively limited information on membrane performance. In
contrast, gas separation membranes are typically characterized using a Robeson
plot, which provides a quantitative framework for comparing the performance of
different membrane materials. This presentation will examine a new approach for
understanding the behavior of ultrafiltration membranes that draws directly from
the gas separations literature, including much of the work done by Bill Koros'
group over the past 20 years.
Solute transmission through semipermeable ultrafiltration membranes is
proportional to the solute partition coefficient between the bulk solution and the
membrane pores and to the rate of hindered solute convection along the pore
length, which is in many ways analogous to the solution - diffusion analysis used
to describe transport through gas separation membranes. This suggests that it
should be possible to describe the performance of ultrafiltration membranes
using a "selectivity - permeability" trade-off plot, analogous to the classical
Robeson plot used for gas separation membranes. Experimental data for
traditional ultrafiltration processes and for high performance ultrafiltration for
protein separations have been successfully analyzed in terms of this selectivity -
permeability tradeoff, providing a quantitative framework for comparing the
performance of different ultrafiltration membranes. The results clearly show the
presence of an "upper bound" for the performance of commercial ultrafiltration
membranes, analogous to the upper bound seen with gas separation
membranes. The theoretical underpinnings for this upper bound are discussed
using appropriate models for the protein partition coefficient and the hindrance
factor for convection. High performance ultrafiltration membranes have been
developed by altering the solute partition coefficient into the membrane pores,
analogous to the development of solubility- selective gas separation membranes.
These results highlight some of the underlying similarities between ultrafiltration
and gas separation membranes, and they demonstrate that there are real

opportunities for improving membrane performance by drawing from leading
developments in both fields.

NAMS Alan S. Michaels Award – 4a
Tuesday July 15, 10:20 AM-10:45 AM, Kaua’i
Membranes and Reactors and Integration, Oh My!
M. Rezac (Speaker), Kansas State University, Manhattan, KS, USA, rezac@ksu.edu
Catalytic reactors are employed to convert a substrate to a product. Frequently,
the conversion is incomplete and not perfectly selective. This requires the use of
more or less complicated down-stream separation processes to recover the
desired pure product. Membrane reactors offer the opportunity to control the
reaction environment resulting in a more desirable product mixture. In this
presentation, we’ll examine several forms of membrane reactors with an
evaluation of the status of each and any remaining barriers to commercialization.
The overall results achieved with these systems include: (1) conversions wellbeyond
the conventional equilibrium limitation, (2) reaction rates and product
selectivities significantly altered by control of the reaction media, and (3)
selective addition of hydrogen via a membrane reactor can positively influence
reaction product composition.
The impact of processing conditions and membrane properties on the reaction
product spectrum will be discussed in this presentation.

NAMS Alan S. Michaels Award – 4b
Tuesday July 15, 10:45 AM-11:10 AM, Kaua’i
Membranes for Energy Efficiency and Sustainability
K. Murphy (Speaker), Air Products, St. Louis, MO, USA, murphymk@airproducts.com
Among of the most significant attributes of a great teacher is the ability to inspire
others. This presentation was inspired by the efforts of Professor William J.
Koros, the 2008 Alan Michaels Award honoree. Bill has spoken widely to foster
recognition of the contributions that membrane science and technology make to
the enhanced energy efficiency of large-scale industrial processes. Bill has
encouraged others to contribute meaningfully to a more sustainable future
worldwide.
Membranes applied to many separation and purification applications have
contributed, and can in the future contribute, significantly to more efficient
processes in a wide variety of industries. Bill’s efforts have encouraged the
membrane community and others to recognize that very large-scale societal
problems can be meaningfully addressed by what we collectively do. Membrane
processes positively impact society in many ways, from purifying drinking water,
to improving efficiency in production of agricultural fertilizers for food crop
production, to enhancing food stuffs’ distribution, to improving efficiencies of a
variety of processes for the production and utilization of energy resources.
Looking to the future, significant opportunities and challenges remain, where
improved membrane technologies could make substantial further contributions to
energy efficiency and sustainability.
This presentation is an overview, designed to provide perspective within a
worldwide context. It will use a diverse range of application examples to
demonstrate utility and potential of membrane technology to serve society’s
growing needs. The intent of the presentation is to reflect on the past in hopes of
inspiring current and next generations of engineers and scientists to help achieve
that better future.
Among his many contributions, through his substantial technical work and his
training of many top-notch graduates, Bill has done much to further the
attainment of a better future. Many people would be proud to leave such a
legacy. Bill’s message includes an implicit urging that we look beyond the
parochial to the larger view, of how we impact the larger world by our actions.
This presenter sincerely hopes to honor the 2008 Alan Michaels Award winner,

Bill Koros, by furthering his vision that all of us in the membrane community can
contribute meaningfully to a better future.

NAMS Alan S. Michaels Award – 5
Tuesday July 15, 11:10 AM-11:35 AM, Kaua’i
On the Time Scales of Sorption Induced Plasticization
M. Wessling (Speaker), University of Twente, The Netherlands, m.wessling@utwente.nl
This contribution focuses on the phenomenon of sorption induced plasticization.
The term plasticization is frequently used to describe a variety of experimental
observations ranging from for instance (a) time-independent but concentration
dependent diffusion coefficients to (b)very slow (relaxational) changes in volume
dilation and dynamic weight uptake.
The presentation focuses on the plasticization phenomena in three different
polymers: 1. A glassy polyimide (Matrimid) 2. A glassy ionomer (sulphonated
PEEK) 3. A segmented block-copolymer PEBAX
Dynamic sorption studies are carried out for a variety of different gases and
vapors such as noble gases, hydrocarbons and water.
These data are used to reflect on the time-scales of polymer dynamics as
compared to the time-scales of penetrant motion in order to explain plasticization
in rubbery as well as glassy polymers.

NAMS Alan S. Michaels Award - 6
Tuesday July 15, 11:35 AM-12:00 AM, Kaua’i
Recent Developments in Membranes for Gas Separation Applications
I. Pinnau (Speaker), Membrane Technology and Research., Inc., Menlo Park, CA, USA,
ipin@mtrinc.com
Gas separation-based membrane processes were introduced about thirty years
ago. The first membrane types were i) integrally-skinned asymmetric cellulose
acetate membranes, ii) silicone thin-film composite membranes, and multilayer
polysulfone/silicone composite membranes. These membrane types were
successfully applied in petrochemical and natural gas applications as well as
production of nitrogen from air and recovery of organic vapors from a variety of
waste gas streams. Ideal membranes for gas separation applications must fulfill
the following requirements: a) high gas permeance to minimize membrane area
requirements, b) high selectivity to provide high product purity and c) good
tolerance to contaminants in the feed gas. In the past decade many polymers
with improved permeability and selectivity were developed; however, very few
were scaled up as high-performance membranes for commercial applications.
This presentation will highlight some of Bill Koros' achievements in the field of
gas separation membranes, including: materials science aspects, development
of ultrathin-skinned asymmetric membranes, and mixed-matrix polymer/inorganic
hybrid membranes.

NAMS Alan S. Michaels Award - 7
Tuesday July 15, 12:00 AM-12:25 AM, Kaua’i
Various Poly(dimethylsiloxane) Membranes for Removal of Volatile Organic
Compounds from Water
T. Uragami (Speaker), Kansai University, Suita, Osaka, Japan, uragami@ipcku.kansai-u.ac.jp
T. Ohshima, Kansai University, Suita, Osaka, Japan
T. Miyata, Kansai University, Suita, Osaka, Japan
In this study, five kinds of polymer membranes such as poly(methyl
methacrylate) (PMMA) and poly (dimethylsiloxane) (PDMS) graft copolymer
membranes (Membrane A), PFA-g-PDMS/PMMA-g-PDMS membranes surfacemodified
with a fluorine- containing graft copolymer (PFA) (Membrane B),
CA/PMMA-g-PDMS membranes added calixarene (CA) to PMMA-g-PDMS
(Membrane C), PDMS dimethylmethacrylate (PDMSDMMA) membranes cross-
linked with various cross-linkers (Membrane D), and CA/cross-linked
PDMSDMMMA membranes added CA into cross-linked PDMADMMM
(Membrane E) were prepared for the removal of volatile organic compounds
(VOCs) from water. Permeation and separation characteristics for an aqueous
solution of dilute VOC through the above membranes during pervaporation (PV)
are discussed from the viewpoints of chemical and physical characteristics of
those membranes.
Membrane A increased benzene/water selectivity and permeation rate with
increasing DMS content. The benzene/water selectivity and permeation rate of
membrane A increased dramatically at a DMS content of more than about 40
mol%. It was recognized by transmission electron microscopy (TEM) that
Membrane A had a microphase-separated structure, and a continuous PDMS
phase in the microphase-separated structure of Membrane A played an
important role for the benzene/water selectivity of an aqueous solution of dilute
benzene through this membrane.
In Membrane B, it was confirmed by the contact angle and X-ray photoelectron
spectroscopy measurements that PFA was localized on the air- side surface of
membrane. It became apparent from TEM that adding a PFA of less than 1.2
wt% did not affect the morphology of the microphase- separated Membrane A,
but adding PFA over 1.2 wt% resulted in a morphology change from a continuous
PDMS phase to a discontinuous PDMS phase. The addition of a small amount of
PFA into the microphase-separated Membrane A enhanced both the permeability
and selectivity for a dilute aqueous solution of benzene.
On the other hand, in Membrane C both the permeability and the benzene/water
selectivity were enhanced by increasing the CA content, due to the affinity of the

CA for benzene. TEM observations and differential scanning calorimetry
measurements revealed that Membrabe C had a microphase-separated structure
consisting of a PMMA phase and a PDMS phase containing CA.
On the basis of the above results, Membranes D, which has a continuous PDMS
phase in the whole of membrane, were prepared. In Membrane D, both the
permeability and benzene/water selectivity of the membranes were enhanced
with increasing divinyl compound content as the cross-linker, and were
significantly influenced by the kind of divinyl compound. PDMSDMMA
membranes cross- linked with divinyl perfluoro-n-hexane (DVF) showed very
high membrane performance during PV.
Membrane E also increased both the permeation rate and the benzene/water
selectivity with increasing CA content.
The membrane performance for the removal of VOCs of these membranes was
in the order of Membrane E > Membrane D > Membrane C > Membrane B >
Membrane A. The membrane performance of modified PDMS membrane added
CA of 0.4 wt% to PDMSDMMA membrane cross-linked with DVF of 90 mol% in
the membrane (Membrane D) was very excellent; the normalized permeation
rate and the separation factor for an aqueous solution of 0.05 wt% benzene were
1.86 [10 -5 kgm/(m 2 h)] and 5027, respectively.

Nanofiltration and Reverse Osmosis II - Imaging and Characterization – 1 –
Keynote
Tuesday July 15, 8:15 AM-9:00 AM, Maui
On the Correlation Between MWCO Values for Nanofiltration Membranes
and Quantitative Porosity Analysis Using Variable Energy Positron Beams.
J. De Baerdemaeker (Speaker), Ghent University, Gent, Leuven, Belgium,
jeremie.debaerdemaeker@ugent.be
K. Boussu, KU Leuven, Leuven, Belgium
B. Van der Bruggen, KU Leuven, Leuven, Belgium
M. Weber, Washington State University, Pullman WA, USA
K. Lynn, Washington State University, Pullman WA, USA
Correlations between the MWCO (Molecular Weight Cut Off) and the pore size in
the skin layer of nanofiltration membranes is still under debate due to the lack of
independent techniques to determine in a quantitative way the porosity of the
skin layer. It might even be stated that progress in nanofiltration (NF) is tempered
by the lack of knowledge of fundamental properties such as porosity.
Using positron and positronium spectroscopy, valuable information can be
gained regarding the true influence of porosity on the transport of molecules
through nanofiltration membranes (NFM). The use of variable energy positron
beams enables depth profiling of the porosity in NFM. By measuring the lifetime
of the positronium in the skin layer of the membrane the size and distribution of
the pores can be determined. This techniques has only very recently been
introduced into the nanofiltration field[1,2,3].
As will be demonstrated complementary information is gained by comparing the
depth profile porosity evolution with high resolution cross section images using a
dualbeam FIB/SEM (Focused Ion Beam - Scanning Electron Microscope).
The results presented within the scope of this research focuse on the correlation
of MWCO values measured for different commercial nanofiltration membranes
with positron results. This comparison not only indicates that the absolute size of
the pores does not seem to be the crucial parameter for the understanding of NF
but presents strong evidence on how the pore distribution determines the
selectivity in these membranes.
This implies that the current models which describe NF should be reexamined.
These findings are crucial for the modeling of NF and might open the path to the
final goal of NF, the production of tailor made NFM. This new study should also
stimulate the membrane community to consider and use positronium

spectroscopy as a novel research tool for the fundamental understanding of
porosity in membranes used in different technologies.
[1]K. Boussu at al. ChemPhysChem 2007, 8, 370.
[2]H. Chen et al. Macromolecules 2007, 40, 7542.
[3]D. Cagill at al. MRS Bulletin January 2008.

Nanofiltration and Reverse Osmosis II - Imaging and Characterization - 2
Tuesday July 15, 9:30 AM-10:00 AM, Maui
Positron Annihilation Spectroscopy (PAS): A New Powerful Technique to
Study Membrane Structure
A. Cano-Odena (Speaker), Center for Surface Chemistry and Catalysis, Katholieke Universiteit
Leuven, Leuven, Belgium
P. Vandezande, Center for Surface Chemistry and Catalysis, Katholieke Universiteit Leuven,
Leuven, Belgium
K. Hendrix, Center for Surface Chemistry and Catalysis, Katholieke Universiteit Leuven, Leuven,
Belgium
R. Zaman, Center for Surface Chemistry and Catalysis, Katholieke Universiteit Leuven, Leuven,
Belgium
K. Mostafa, NUMAT (Nuclear Methods in Materials Science), Dept Subatomic and Radiation,
Gent, Belgium
J. De Baerdemaeker, NUMAT (Nuclear Methods in Materials Science), Dept Subatomic and
Radiation, Gent, Belgium
I. Vankelecom, Center for Surface Chemistry and Catalysis, Katholieke Universiteit Leuven,
Leuven, Belgium, ivo.vankelecom@biw.kuleuven.be
Introduction Positron annihilation spectroscopy (PAS) is a nondestructive
technique used to study defects and open volumes in materials based on the
analysis of the ³-ray radiation emitted due the annihilation of positrons (antimatter
counterpart of the electron) with electrons of the material. Positrons injected in a
polymer sample can either annihilate freely or capture an electron forming a
meta-stable bound state positronium(Ps) with two possible states depending on
the relative orientations of the spins of the electron and the positron:ortho-
positronium(o-Ps) and para-positronium(p-Ps). The use of a variable low energy
positron beam enables the study of the characteristic annihilation of the
positronium from the surface down to a couple of micron. Hence with a positron
beam a depth profile of the porosity is measured. O-Ps has a longer lifetime in
vacuum and gets preferentially localized in the free volume of the polymer. In
positron annihilation lifetime spectroscopy (PALS) the decrease in o- Ps lifetime
is related to free volume cavities radius. Despite clear benefits over more indirect
characterization techniques PAS has only recently been applied in membrane
research [1,2]. Its use will be here extended to an in- depth characterization of
the morphology of the polymeric structure allowing to correlate physical defects
at atomic scale (free volume) with membrane performance (permeability,
selectivity).
Thanks to increased environmental concerns and the search for cleaner and
energy-efficient technologies, solvent resistant nanofiltration (SRNF)[3] has
received enhanced attention as a promising technique, offering a sustainable
alternative for conventional energy-intensive and waste-generating separations.
SRNF holds a vast potential in food, (fine-)chemical, pharmaceutical and

petrochemical industries. In view of the expected growth of the SRNF market and
the relatively limited number of commercial membranes, a clear need still exists
to develop robust membranes to solve separation problems in existing industrial
processes and open new application areas. Polar aprotic solvents (NMP, DMF,
DMSO) are frequently applied in pharmaceutical and chemical processes.
Chemical cross-linking with diamines allows preparing chemically stable
asymmetric polyimide (PI)- based SRNF membranes that have been successfully
applied in polar aprotic solvents and THF[4].
Objectives -Characterize skin layer thicknesses, densities, differences in porosity
and porosity evolution between skin layers and sublayers of of polyimide (PI)based
membranes prepared by phase inversion with PA(L)S. -Correlate the
information obtained through PA(L) S with performance data in laboratory-made
and commercial PI membranes (Starmem") and other characterization
techniques to study the influence of synthesis parameters (polymer
concentration, evaporation time) and post- treatment conditions (chemical crosslinking)
on the performance of asymmetric PI (P84) based membranes in
filtrations of Rose Bengal (RB, 1017 Da) in 2-propanol (IPA), DMF and THF.
Results and discussion As expected, an increase of the initial polymer
concentration in the casting solution, containing P84 in a NMP/THF mixture
improves RB retention but decreases the permeability. It can be related, to the
formation of a denser skin layer, also observed from PAS profiles and confirmed
by SEM. Increasing the evaporation time prior immersion in the coagulation bath
drops IPA and THF permeabilities but no significant changes in the RB retention
were observed. The longest evaporation times have no effect in performance and
no differences were observed in PAS profiles. For membranes chemically crosslinked,
a 90% flux drop was noticed as compared to uncross-linked ones together
with better retentions. Solvent fluxes followed the order THFDMFHIPA. The
chemical cross-linking involves the transformation of imide bonds to amide
bonds, reducing the interstitial space among chains and thus the free volume,
which results in a decrease in the top layer thickness, as confirmed by PAS.
Conclusions laboratory-prepared P84-based SRNF membranes showed higher
fluxes compared to the commercial ones. From the analysis of profiles of the
energy of annihilation, differences in porosities between top and support layers in
membranes and different evolution from the skin layer to the mesoporous regions
can be estimated and be related to the performance results from filtration
experiments.
References
[1] K. Boussu at al. ChemPhysChem 2007, 8, 370.
[2] H. Chen et al. Macromolecules 2007, 40, 7542.
[3] P. Vandezande et al. Chem. Soc. Rev. 2008, 37, 365.

[4] K. Vanherck et al. Accepted for publication in J. Membr. Sci.

Nanofiltration and Reverse Osmosis II - Imaging and Characterization – 3
Tuesday July 15, 10:00 AM-10:30 AM, Maui
Characterization of Biofouling Development of Spiral Wound Membrane
Systems: The First NMR Study
D. Graf von der Schulenburg, University of Cambridge, Cambridge, UK
J. Vrouwenvelder (Speaker), Wetsus, Delft University of Technology, Deft, The Netherlands,
hans.vrouwenvelder@wetsus.nl
J. Kruithof, Wetsus, The Netherlands
M. Van Loosdrecht, Delft University of Technology, Deft, The Netherlands
M. Johns, University of Cambridge, Cambridge, UK
High quality drinking water can be produced with membrane filtration processes
like reverse osmosis and nanofiltration. A disadvantage of membrane filtration
processes is membrane fouling, resulting in higher costs. A major fouling type is
biofouling caused by biofilm accumulation in membrane elements [1]. Biofouling
development in time is difficult to study because of the construction of spiral
wound membrane modules. There is a need for in-situ non destructive
quantitative measurements on the accumulation of biomass in spiral wound
membranes. Nuclear magnetic resonance (NMR) is a potential powerful tool to
study membrane fouling, since it is a quantitative potentially, real-time, noninvasive
measurement/imaging technique that is readily applied to opaque
samples.
The objective of this study was thus to determine if NMR is a suitable technique
to study biofouling of spiral wound membranes.
Biofilm development and velocity distribution images were determined using an
appropriate NMR spectrometer as a function of time in a spiral wound membrane
module and a flow cell containing spacers and membranes. The flow cell had the
same construction as the membrane fouling simulator [3], utilizing sheets of
membrane and spacers. The development of pressure drop in time was
monitored and the accumulated material on the membranes was analyzed for
fouling diagnosis. The feed water was supplemented with a biodegradable
compound to stimulate biofilm formation.
The presented NMR protocols allow (i) the extraction of the spatial biofilm
distribution in the membrane module, (ii) the velocity field and its evolution with
biofouling and (iii) propagators, that is distributions of molecular displacement of
a passive tracer (e.g. salts, organic molecules) in the membrane module. Despite
the opaque nature of the membrane design, NMR provides a non-invasive, nondestructive
and spatially resolved in-situ measurement of biofouling and its
impact on hydrodynamics and mass transport. In a spiral wound membrane
module, biofilm accumulation and velocity fields were observed over time. Biofilm

accumulation had a strong effect on the velocity distribution profile. The pressure
drop measurements and membrane autopsy confirmed that membrane biofouling
occurred. In a flow cell containing feed spacer and membranes, biofilm
accumulation and a strong change in velocity distribution was observed as well.
The observations of the NMR biofilm imaging matched the visual observations
using the sight glass of the membrane fouling simulator, which emphasis the
potential of NMR in membrane (bio)fouling studies. Limited biofilm accumulation
had great impact on the velocity distribution profile. The measured channeling of
the water flow in the NMR studies matched visual observations during membrane
autopsies. NMR was thus able to measure the biofilm development and the effect
of biofilm formation on the velocity profile.
In summary, NMR is an ideal tool to non- invasively study biofouling development
in spiral wound membranes. The NMR enables in-situ real- time non-invasive
quantitative measurements for (combinations of) 2D/3D imaging, velocity
imaging, and propagators [2].
Literature
[1] Ridgway, H.F. (2003). Biological fouling of separation membranes used in water treatment
applications, AWWA research foundation.
[2] Graf von der Schulenburg, D.A., Vrouwenvelder, J.S., Creber, S.A., Van Loosdrecht, M.C.M.,
Gladden L.F., Johns, M.L. (to be submitted). Nuclear Magnetic Resonance microscopy studies of
membrane biofouling.
[3] Vrouwenvelder, J.S. van Paassen, J.A.M., Wessels, L.P., van Dam A.F., Bakker, S.M. (2006).
The Membrane Fouling Simulator: a practical tool for fouling prediction and control. Journal of
Membrane Science. 281, 316-324.

Nanofiltration and Reverse Osmosis II - Imaging and Characterization – 4
Tuesday July 15, 10:30 AM-11:00 AM, Maui
Probing Polyamide RO membrane Surface Charge, Energy, and Potential
With Advanced Contact Angle Titrations
G. Hurwitz (Speaker), University of California, Los Angeles, Los Angeles, CA, USA
E. Hoek, University of California, Los Angeles, Los Angeles, CA, USA, hoek@seas.ucla.edu
Contact angle titrations are performed to evaluate surface charge, surface
tension, and surface potential of a polyamide reverse osmosis (RO) membrane.
Contact angle titration involves measuring equilibrium contact angles for both
buffered and unbuffered aqueous drops over a range of pH values. The buffered
titration gives the fractional ionization of surface functional groups and the
effective pKa. The unbuffered titration gives the maximum surface charge density
of the membrane. These measured parameters are then combined with the
Grahame equation to estimate the membrane surface (zeta) potential. Zeta
potentials calculated from the contact angle titrations compare well with those
calculated from streaming potential measurements across a range of ionic
strength and pH values.
In addition to direct surface titrations, contact angles of a non-aqueous polar
liquid and an apolar liquid are measured to enable calculation of Lifshitz-van der
Waal, electron-donor, and electron-acceptor surface tensions. These contact
angle measurements are augmented by measured contact angles of various
aqueous electrolytes to provide further insight into how specific ion interactions
influence electron-donor/acceptor components of surface tensions for polyamide
RO membranes. The polyamide membrane becomes more hydrophilic as NaCl
concentration increases from 0 to 1 M. The higher hydrophilicity results from a
larger ratio of electron-donor to electron-acceptor functionality being expressed
as the contact angle droplet ionic strength increases. Hydrophilicity also
increases with increasing solution pH and in the presence of a few millimoles of
divalent cations. However, there are no discernable differences among calcium,
barium, magnesium, and strontium at a fixed concentration.
In summary, these results suggest that contact angle analyses can be used to
probe membrane surface chemistry to a greater degree than is traditionally
pursued. Contact angle titrations may be combined with multiple probe liquid
contact angle analyses to elucidate membrane surface charge, tension, and
potential. In a more practical sense, the polyamide membrane evaluated
becomes more hydrophilic as pH, ionic strength, and minerals content increase.
Increased membrane hydrophilicity will no doubt have significant impacts on
membrane transport and surface fouling phenomena. Additional research is
needed to determine if this behavior is reproducible for other RO membranes

and, if so, to develop correlations between solution chemistry, membrane
properties, and membrane performance.

Nanofiltration and Reverse Osmosis II - Imaging and Characterization – 5
Tuesday July 15, 11:00 AM-11:30 AM, Maui
Removal of Emerging Organic Contaminants by High-Pressure
Membranes: Mechanisms, Monitoring, and Modeling
J. Drewes (Presenting), Colorado School of Mines, Golden, CO, USA
C. Bellona, Carollo Engineers, Broomfield, CO, USA
M. Sonnenberg, Colorado School of Mines, Golden, CO, USA
The rejection of emerging organic micropollutants is an important issue where
recycled water is used to augment drinking water supplies. The focus of this
research study was to explore alternatives of an integrated membrane system
involving nanofiltration (NF) and ultra-low pressure reverse osmosis (ULPRO) in
place of conventional reverse osmosis (RO) representing a more cost-effective
system because of potentially lower pressure requirements and the greater
selectivity for organic micropollutants as compared to removal of total dissolved
solids (TDS).
The organic micropollutants studied in this research included disinfection byproducts
(e.g., trichloroacetic acid, chloroform, bromoform, Nnitrosodimethylamine),
pesticides, endocrine disrupting compounds (e.g., 17²estradiol,
testosterone, bisphenol A), pharmaceutical residues (e.g., ibuprofen,
naproxen, gemfibrozil, carbamazepine, primidone), and chlorinated flame
retardants. These compounds have a broad range of physicochemical properties,
and are associated with potential adverse effects for human health and aquatic
life. Uncertainty regarding the rejection of certain solutes, justifies the
development of modeling approaches to predict the removal of contaminants by
RO and NF. A successful predictive model would eliminate the need for pilotscale
evaluation of trace organic contaminant removal, and eliminate uncertainty
regarding permeate water quality. After pre-screening over 15 potential NF and
ULPRO products during laboratory-scale membrane rejection experiments, three
candidate membranes were selected and pilot tested using a 68 L/min
membrane pilot skid for at least 1,300 hours on microfiltered feed water at two
full-scale facilities. State-of-the-art membrane characterization tools were used to
describe the fouling behavior of NF/ULPRO membranes and determine the role
of fouling on operation (e.g., flux decline) and rejection.
Past studies on modeling membrane performance have resulted in several
methods and sets of equations that can be used to model the rejection of
inorganic and organic solutes. However, simple yet robust solution-diffusion
models do not directly apply to membranes in which pore phenomena including
physical sieving and Donnan exclusion are important for solute rejection.
Transport equations developed to describe the transport of electrolytes through

non-porous and porous membranes are often hindered by the complexity of the
calculations as well as the numerous descriptive parameters required. Although
significant advances in membrane modeling have been made in order to optimize
the separation of mixtures of inorganic ions and ionic organic solutes, little work
has been conducted to satisfactorily quantitatively predict the rejection of organic
solutes. Rejection studies at laboratory-, pilot- and full-scale were developed into
a model framework to reliably predict - a priori - rejection of organic
micropollutants by RO, NF and ULPRO membranes taking into account
physicochemical properties of solutes and membranes as well as key operational
conditions affecting solute rejection.
Findings of this research clearly demonstrated that a single model does not
currently exist that is capable of describing the mass transport of organic
micropollutants during high-pressure membrane treatment. Since
physicochemical properties of the solutes are the key factors determining
rejection, they need to be properly considered and put in context with relevant
membrane properties so that rejection can be quantitatively predicted. A number
of approaches were assessed to quantitatively describe and predict the rejection
of non-ionic and ionic compounds of concern: Spiegler-Kedem model,
hydrodynamic model, extended Nernst-Planck equation model(s), and hybrid
models combining statistical approaches with membrane transport models. The
Spiegler-Kedem model and hydrodynamic model were determined to be only
marginally accurate for describing the rejection of a wide variety of non-ionic
solutes by a conventional RO, an ULPRO and an NF membrane. However,
predictive accuracy was improved by using statistical approaches to determine
model parameters as a function of solute properties. For ionic solutes, the
Spiegler-Kedem model underpredicted rejection as expected since electrostatic
and dielectric exclusion are difficult to integrate into the model. A linearized
version of the Donnan Steric Pore model was more suitable for modeling
transport of ionic solutes and preliminary results suggest that this modeling
approach describes rejection for ionic micropollutants more accurately.

Nanofiltration and Reverse Osmosis II - Imaging and Characterization – 6
Tuesday July 15, 11:30 AM-12:00 PM, Maui
Evidence of Change in the Top Surface Layer Structure of Nanofiltration
Membranes Due to Operating Temperature Variation
H. Saidani, Ecole Nationale des Ingénieurs de Tunis, France
B. Nihel, Ecole Nationale des Ingénieurs de Tunis, France
P. John, Université Paul Sabatier, France
D. Andre (Speaker), Université Montpellier 2, France, Andre.Deratani@iemm.univ-montp2.fr
The applications of nanofiltration (NF) in the treatment of water and wastewater
is developing very quickly. Of special concern for this application is the influence
of temperature on the performances of NF membranes, because water to be
treated can be at temperatures higher than 40°C. The temperature effect is not
yet well understood [1] and is usually described through a simple correction
factor applied to the water permeability. The present report shows the influence
of operating temperature variation on the permeability and the rejection of neutral
and charged solutes. Two commercial NF membranes were used in the course
of this study, the DESAL DK (GE Water Technologies -USA) and NF90 (Dow /
Filmtec - USA).
The results obtained show an important variation of membrane performances
with temperature change both in terms of flux and rejection. Interestingly, while
the DESAL DK exhibits the expected flux increase (due to a decrease in solution
viscosity) and rejection decrease with increasing temperature, the NF90 shows
the opposite trend. Moreover, it was observed that this variation becomes
irreversible if the operating temperature exceeds a critical temperature (Tc),
which depends on the membrane type.
To understand these phenomena, the thermal behavior of the top surface layer
for each NF membrane was investigated. It was found that Tc corresponds to the
glass transition temperature Tg of the polymer constituting the membrane top
active layer. The pore size and effective layer thickness were estimated using the
Nanoflux® NF modeling software [2].
The NF data are interpreted in terms of structural changes occurring during
temperature cycles that are intimately related to the intrinsic thermal properties of
the polymeric materials.
[1] Nihel Ben Amar, Hafedh Saidani, André Deratani, John Palmeri, Effect Of Temperature On
The Transport Of Water And Neutral Solutes Across Nanofiltration Membranes, Langmuir 23,
2937 (2007).

[2] Palmeri, J., Sandeaux, R. Sandeaux, X. Lefebvre, P. David, C. Guizard, P. Amblard, J.F. Diaz,
B. Lamaze, Modeling of multi-electrolyte transport in charged ceramic and organic nanofilters
using the computer simulation program NANOFLUX, Desalination 147 231 (2002).

Nanofiltration and Reverse Osmosis II - Imaging and Characterization – 7
Tuesday July 15, 12:00 PM-12:30 PM, Maui
Characterization of the Polyamide Active Layer in NF/RO Membranes Using
Gold Nanoparticles
F. Pacheco (Speaker), Stanford University, Stanford, CA, USA, fpacheco@stanford.edu
M. Reinhard, Stanford University, Stanford, CA, USA
J. Leckie, Stanford University, Stanford, CA, USA
The goal of this project was to investigate the deposition of nanoparticles during
filtration to better understand how transport and rejection mechanisms occur
within the active layer of a RO membrane. The active layer in state of the art RO
membranes consists of cross-linked networks of fully aromatic polyamide, with
an average thickness of approximately 200 nm and a very heterogeneous
structure that confers the membrane a relatively rough surface, also described in
the field as the peak-and-valley structure. Because of the thinness of this layer,
characterization at the microscale is extremely difficult and as result knowledge
of the transport and separation mechanisms is incomplete. Experiments were
performed with gold nanoparticles in a dead-end filtration system without stirring
at a pressure of 4.8 bar (70 psi). The membrane investigated was a commercial
low pressure RO membrane with a fully aromatic polyamide layer featuring the
characteristic peak- and-valley rough structure.
The ability to separate the polyamide layer from the underlying polysulfone
support was used to develop a novel TEM based technique that allowed us to
image the spatial distribution of the gold nanoparticles with respect to the
projected surface area of the polyamide layer. The resulting images show that
the particles did not accumulate uniformly over the surface of the membrane, but
instead formed distinct clusters around the areas where the polyamide layer was
the thickest, i.e. the areas near the peaks. TEM images of polyamide cross
sections, as well as SEM images of the membrane surface, confirmed that the
particles accumulated preferentially on the peaks rather than in the valleys of the
polyamide structure. Although the deposited nanoparticles only covered about
30% of the projected surface area of the membrane, water flux was significantly
reduced. These results suggest that there are areas within the polyamide layer
that have higher permeability to water and that are the most sensitive to fouling.
The effects of particle size and concentration, pH and ionic strength were
investigated.
The use of nanoparticles in combination with advanced microscopic imaging
techniques can be used to examine which sections of the polyamide layer in NF
and RO membranes are actively involved in the transport and rejection
mechanisms, as well as those that are highly sensitive to the initial stages of

fouling. Information obtained from these experiments can also be useful to better
understand how membranes will perform with feeds containing other kinds of
nanoparticles.

Nanostructured Membranes II – 1 – Keynote
Tuesday July 15, 8:15 AM-9:00 AM, Moloka’i
Nanofiltration of Electrolyte Solutions by Sub-2nm Carbon Nanotube
Membranes
F. Fornasiero (Speaker), Lawrence Livermore National Laboratory, Livermore CA, USA,
fornasiero1@llnl.gov
H. Park, Lawrence Livermore National Laboratory, Livermore CA, USA
J. Holt, Lawrence Livermore National Laboratory, Livermore CA, USA
M. Stadermann, Lawrence Livermore National Laboratory, Livermore CA, USA
S. Kim, University of California at Davis, Davis, CA, USA
J. In, University of California at Berkeley, Berkeley, CA, USA
C. Grigoropoulos, University of California at Berkeley, Berkeley, CA, USA
A. Noy, Lawrence Livermore National Laboratory, Livermore CA, USA
O. Bakajin, Lawrence Livermore National Laboratory, Livermore CA, USA
MD simulations have shown that liquid and gas flow through carbon nanotubes
with nanometer size diameter is exceptionally fast compared to the predictions of
continuum hydrodynamic theories and, also, compared to conventional
membranes with pores of similar size, such as zeolites. This unique property has
been attributed to their exceptionally smooth pore walls allowing nearly
frictionless transport, and to fluid molecular ordering at nanoscale. Recently, the
availability of membranes made of well-aligned carbon-nanotube (CNT) arrays
embedded in an impermeable filling matrix has allowed experimental
confirmation of MD predictions on a laboratory scale. For applications in
separation technology, selectivity is required together with fast flow. In particular,
for water desalination, coupling the enhancement of the water flux with selective
ion transport could drastically reduce the cost of brackish and seawater
desalting.
In this study, we use pressure-driven filtration experiments, coupled with capillary
electrophoresis analysis of permeate and feed to quantify ion exclusion in silicon
nitride/CNT composite membranes as a function of solution ionic strength, pH,
and ion valence. The pores of the membranes used in this study are sub-2-nm
diameter CNTs whose entrance is decorated by negatively charged carboxylic
groups.
We show that carbon nanotube membranes exhibit significant ion exclusion that
can be as high as 98% under certain conditions. Our results support a Donnantype
rejection mechanism, dominated by electrostatic interactions between fixed
membrane charges and mobile ions, while steric and hydrodynamic effects
appear to be less important. Comparison with commercial nanofiltration
membranes for water softening reveals that our carbon nanotube membranes
provides far superior water fluxes for similar ion rejection capabilities.

This work performed under the auspices of the U.S. Department of Energy by
Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.
UCRL-ABS-236106

Nanostructured Membranes II – 2
Tuesday July 15, 9:30 AM-10:00 AM, Moloka’i
Aligned Carbon Nanotube Membranes: Transport Enhancement and
Gatekeeper Activity
M. Majumder, Univ. of KY, Lexington KY, USA
K. Kiess, Univ. of KY, Lexington KY, USA
J. Wu, Univ. of KY, Lexington KY, USA
B. Hinds (Speaker), Univ. of KY, Lexington KY, USA, bjhinds@engr.uky.edu
Carbon nanotubes have three key attributes that make them of great interest for
novel membrane applications 1) atomically flat graphite surface allows for ideal
fluid slip boundary conditions 2) the cutting process to open CNTs inherently
places functional chemistry at CNT core entrance and 3) CNT are electrically
conductive allowing for electrochemical reactions and application of electric fields
gradients at CNT tips. Towards this goal, a composite membrane structure
containing vertically aligned carbon nanotubes passing across a polystyrene
matrix film have been fabricated. Fabrication steps, material characterization and
ionic diffusion transport properties are described. Plasma oxidation during the
fabrication process introduces carboxylic acid groups on the CNT tips that are
modified using carbodiimide mediated coupling between carboxylic acid on the
CNTs and accessible amine groups of the functional molecule. To explore the
hypothesis of “Gatekeeper” selectivity, the entrances to CNT’s cores were
functionalized with aliphatic amines of different lengths, charged dye molecule
and an aliphatic amine elongated by spacers containing poly-peptides. The
simultaneous permeation of two differently sized but equally charged molecules
(ruthenium bi-pyridine [Ru-(bipy)3 +2 ] and methyl viologen [MV +2 ]) was studied and
relative selectivity of was seen to vary from 1.9 to 3.6 as a function of tipfunctionalization
chemistry. Anionic charged functional groups are seen to
sharply increase flux of cationic permeates. This effect is reduced at higher
solution ionic strength consistent with shorter Debye screening length screening
attractive charge at the CNT core entrance. Using a hindered diffusion to model
observed selectivities was consistent only with a geometry of only CNT tip
functionalization, not along the length of CNT core. Bio-chemical gating of CNTs
is also seen by tethering desthiobiotin to CNT tips with the reversible binding to
streptavidin. The complete ATP cycle (phosphylation/dephosphylation) can be
performed on CNT tips with corresponding modulation of flux across CNT
membrane. Strong electrostatic effects of binding protein are seen with enhanced
cationic flux seen for the relativel open anioic protein binding at CNT tip entrance.
The functional density of tethered charge molecules can be substantially
increased by the use of electrochemical grafting of diazonium salts. Functionality
can be forced to occur at the CNT tip entrances by fast fluid flow of an inert
solvent through the core during electrochemical functionalization. The selectivity

etween Ru(bi-pyridine)3 2+ and methyl viologen 2+ flux is found to be as high as
23 with -130mV bias applied to the membrane with tethered anionic dye
molecule. Changes in the flux and selectivity support a model where charged
tethered molecules at the tips are drawn into the CNT core at positive bias
hindering/gating flux across the membrane. Applications towards controlled
transdermal drug delivery are discussed. In general, the transport mechanisms
through CNT membrane are a) ionic diffusion is near bulk expectation with no
enhancement from CNT b) gas flow is enhanced by ~1-2 order of magnitude due
to specular reflection off of flat graphitic surface c) and pressure driven flux of a
variety of solvents (H2O, hexane, decane ethanol, methanol) are 4-5 ORDERS
OF MAGNITUDE FASTER than conventional Newtonian flow due to atomically
flat graphite planes inducing nearly ideal slip conditions.

Nanostructured Membranes II – 3
Tuesday July 15, 10:00 AM-10:30 AM, Moloka’i
Hybrid Biomimetic Membranes: Past, Present and Beyond
M. Barboiu (Speaker), Institut Europeen des Membranes, France,
mihai.barboiu@iemm.univ-montp2.fr
Many fundamental biological processes appear to depend on unique properties
of molecular recognition or self-assembled domains of the biomolecules. Such
behaviour is illustrated by the functional complexity of self-organized membrane
proteins, which may assist in proton and ion translocation through membranes.
Gramicidin A and KCsA K + ionic channels, Aquaporin water channels are well
known non-exclusive examples of functional systems in which protons, ions and
water molecules are envisioned to diffuse along a directional pathways according
to different relaying and migration mechanisms. Numerous artificial transport
systems utilizing carriers, channel-forming or self-organized polymeric
superstructures able to orient, to select and to pump the ionic transport across
membranes have been developed in the last decades. Artificial membrane
materials are the subject of various investigations, offering great potentialities as
well on the level of their chemical composition or organization as to that of the
concerned applications. Of special interest is the structure- directed function of
biomimetic and bioinspired membrane materials and control of their build-up from
suitable units by self-organisation. The main interest focus on functional
biomimetic membranes in which the recognition-driven transport properties could
be ensured by a well-defined incorporation of receptors of specific molecular
recognition and self-organization functions, incorporated in a hybrid dense or
mesopourous materials. We are therefore proposing to review the membrane
facilitated transport properties of such supramolecular membrane materials. The
first part begins with a survey of different methods and processes which can be
used for the generation of molecular recognition-based hybrid materials. Then
basic working principles of self-organized membranes are provided in order to
better understand the requirements in material design for the generation of
functional membrane materials.These results describe the simple synthetic
hybrid biomaterials which successfully formed molecular recognition devices,
transport patterns so as to enable efficient translocation events. Finally actual
and potential applications of such self-organized systems presenting combined
features of structural adaptation in a specific nanospace will be presented. From
the conceptual point of view these membranes express a synergistic adaptative
behaviour: the addition of the fittest solute drives a constitutional evolution of the
membrane toward the selection and amplification of a specific transporting
superstructure in the presence of the solute that promoted its generation in a first
time. This is the interesting example of dynamic evolutive membranes, where a
solute induces the upregulation of (prepares itself) its own selective membrane.

[1] M. Barboiu, C. Luca, C. Guizard, N. Hovnanaian, L. Cot, G. Popescu, J. Membrane Sci., 1997,
129, 197-207.
[2] M. Barboiu , N. Hovnanian, C. Luca, L. Cot, Tetrahedron, 1999, 55, 9221-9232.
[3] M. Barboiu, C. Guizard, J. Palmeri, C. Reibel, C. Luca, L. Cot, J. Membrane Sci. 2000, 172,
91-103.
[4] C. Guizard, A. Bac, M. Barboiu, N. Hovnanian, Sep. Tech. Pur. 2001, 25, 167-180.
[5] M. Barboiu, G. Vaughan, A. van der Lee, Org. Lett. 2003, 5, 3073-3076.
[6] M. Barboiu, J. Incl. Phenom. Mol. Rec. 2004, 49, 133-137.
[7] M. Barboiu, S. Cerneaux, G. Vaughan, A. van der Lee, J. Am. Chem. Soc. 2004, 126 3545-
3550.
[8] C. Arnal-Herault, M. Barboiu, E. Petit, M. Michau, and A. van der Lee, New J. Chem., 2005,
29, 1535-1539.
[9] A. Cazacu, A. Pasc-Banu, M. Barboiu, Macromol. Symposia, 2006, 245-246, 435-438.
[10] A. Cazacu, C. Tong, A. van der Lee, T.M. Fyles, M. Barboiu, J. Am. Chem. Soc. 2006,
128(29), 9541-9548.
[11] C. Arnal-Herault, A. Pasc-Banu, M. Michau, M. Barboiu, Angew. Chem. Int. Ed. 2007, 46,
8409- 8413.
[12] C. Arnal-Hérault, M. Barboiu, A. Pasc, M. Michau, P. Perriat, A. van der Lee, Chem. Eur. J.
2007, 13, 6792
[13] M. Michau, M. Barboiu, R. Caraballo, C. Arnal- Hérault, A. van der Lee, Chem. Eur.J. 2007,
in press.
[14] C. Arnal-Herault, A. Pasc-Banu, M. Barboiu A. van der Lee, Angew. Chem. Int. Ed. 2007, 46,
4268-4272.

Nanostructured Membranes II – 4
Tuesday July 15, 10:30 AM-11:00 AM, Moloka’i
Nanostructured Polymers with Uniform d1 nm Pores Based on Crosslinked
Lyotropic Liquid Crystals for Molecular Size-Selective Separations
D. Gin (Speaker), University of Colorado at Boulder, Boulder, CO, USA, gin@spot.colorado.edu
M. Zhou, University of Colorado at Boulder, Boulder, CO, USA
X. Lu, University of Colorado at Boulder, Boulder, CO, USA
E. Hatakeyama, University of Colorado at Boulder, Boulder, CO, USA
R. Noble, University of Colorado at Boulder, Boulder, CO, USA
B. Elliott, TDA Research, Inc., Wheat Ridge, CO, USA
The ability to fabricate porous polymer membrane materials that can separate
molecular mixtures cleanly based solely on differences in molecular size or
shape is one of the long-sought after goals in membrane science. The design of
ordered, nanoporous polymers based on cross-linked lyotropic (i.e., surfactant)
liquid crystals (LLCs) for molecular size-selective separations of gases and
aqueous solutions will be presented. First-generation LLC membranes of this
type are based on an inverted hexagonal (HII) phase architecture and contain
monodisperse, ionic, cylindrical channels that are ca. 1.2 nm in diameter.
Supported HII membranes are able to completely reject water-soluble molecules
and ions greater than or equal to the nanopore diameter, allowing them to cleanly
separate molecular mixtures straddling this size threshold. The same HII
materials copolymerized with butyl rubber afford highly selective, "breathable"
vapor barrier materials for chemical warfare agent protection. They exhibit good
water vapor permeability but are still able to reject mustard agent simulants to a
large degree, whereas pure cross-linked butyl rubber shows slightly lower
chemical warfare agent simulant permeability and no water vapor transport.
Preliminary studies also showed that these HII polymers have interesting
sorption and permeation properties for light gases that are dependent on the
nanostructure. The only caveats with these first-generation LLC membranes is
that (1) they exhibit low water flux due to lack of control over bulk alignment of
the cylindrical nanopores; and (2) they have nanopores that are too large to
reject solutes smaller than 1 nm in size. More recently, second-generation crosslinked
LLC materials based on a bicontinuous cubic (Q) phase have been
developed that contain a 3-D interconnected water layer manifold system with a
uniform gap size of less than 1 nm. These LLC membranes are able to cleanly
size-exclude hydrated salt ions and small organic solutes < 1 nm in size from
water with good permeabilities and excellent performance stability. The potential
of these unique, sub-1-nm ultrafiltration materials for biologically relevant
separations will be discussed. LLC-butyl rubber composite membranes based on
this Q-phase material also show over an order of magnitude improvement in
water vapor flux, and water vs. chemical warfare agent simulant selectivity,
compared to the first-generation HII-phase materials.

Nanostructured Membranes II – 5
Tuesday July 15, 11:00 AM-11:30 AM, Moloka’i
Track-Etched Polymer Membranes as Tool to Investigate Grafted Stimuli-
Responsive and Other Functional Polymers for ‘Smart’ Nano- and
Microsystems
M. Ulbricht (Speaker), Lehrstuhl für Technische Chemie II, Universität Duisburg-Essen,
Germany, mathias.ulbricht@uni-due.de
A. Friebe, Lehrstuhl für Technische Chemie II, Universität Duisburg-Essen, Germany
F. Tomicki, Lehrstuhl für Technische Chemie II, Universität Duisburg-Essen, Germany
There is an increasing scientific and technical interest in the functionalization of
materials surfaces with thin grafted polymer layers. The focus in this field is now
on synthesis methods which allow a precise control of grafted layer architecture
(grafting density, grafted chain length at low polydispersity, type and distribution
of functional groups), and on the detailed evaluation of correlations between
structure and properties of such functional polymer layers. In the recent years,
our group has systematically explored track-etched membranes (TEM) from
poly(ethylene terephthalate) (PET) as versatile base materials to investigate
various surface functionalization chemistries and the consequences for
composite material’s functions, such as selective barrier, selective adsorber or
catalytic reactor [1]. More recently, we have demonstrated that with a
comprehensive characterization of the pore structure of an isoporous base
membrane (pore diameter and pore density from combination of SEM analysis,
gas flow / pore dewetting permporometry and liquid permeability under welldefined
conditions) as basis, and the confirmation of even coverage of the entire
membrane (pore) surface (from contact angle and trans-membrane zeta potential
measurements), the effective grafted layer thickness (in the range of a few to
several hundreds nanometers) under different conditions (e.g., pH, temperature)
can be deduced from liquid permeability data [2].
Here we will focus on our recent work on surface- initiated atom transfer radical
polymerization (ATRP) within the pores of PET TEM (pore diameters between
100 and 1000 nm). In our first paper on that topic [3], we had confirmed that
grafted temperature-responsive poly-N- isopropylacrylamide (PNIPAAm) with a
“brush” structure (polymer density in swollen state ~0.4 g/cm3, swelling /
deswelling ratios of ~3) has been achieved, and that a reduction of grafting
density was possible via the conditions during solid-phase synthesis for
introduction of the ATRP initiator (this leads to lower polymer densities and
higher swelling / deswelling ratios). The reaction conditions for ATRP had been
optimized so that ‘living’ polymerization is now established for NIPAAm and
various other functional monomers (e.g., tert.- butyl acrylate /tBA/, N,Ndimethylaminoethyl
methacrylate, or polyethyleneglycol methacrylate), and this is

confirmed by highly efficient re- initiation and successful synthesis of block
copolymers (at preserved high polymer density in swollen state). Influences of
membrane pore diameter, grafting density and chain lengths are currently
systematically investigated, and the results will be discussed and compared with
data of other groups who use non-porous SAM-coated planar inorganic or metal
substrates. The potential of the obtained systems as functional devices will also
be illustrated. For example, by combining temperature-responsive PNIPAAm with
pH- responsive poly(acrylic acid) (as grafted block copolymers, prepared via
grafted poly(tBA)), membrane pores with four distinctly different effective pore
sizes as function of the combination of temperature (25°C vs. 40°C) and pH (2
vs. 7) could be prepared, and those membranes were evaluated with respect to
their barrier properties in diffusion and filtration experiments.
In conclusion, we will demonstrate that the pore space of membranes can be
controlled by grafted functional polymer layers having densities and thicknesses
(between a few to several 100s nanometers), which are pre-determined by well-
defined ‘grafting-from’ reactions such as surface- initiated ATRP. An important
feature is the response of those layers to stimuli, and this can be used to create
‘gates’ or ‘valves’ in the nano- or microscale. The binding to functional groups in
those layers (e.g., immobilization or reversible binding of biomolecules) provides
additional attractive options. The knowledge gained from our model studies with
TEM on the correlations between synthesis, structure and function of such
tailored grafted polymer layers can be transferred to other porous membranes,
and this will enable the preparation of novel membrane-based materials for
advanced separations, controlled release, catalysis and other applications.
[1] M. Ulbricht, Polymer 2006, 47, 2217-2262.
[2] C. Geismann, A. Yaroshchuk, M. Ulbricht, Langmuir 2007, 23, 76-83.
[3] A. Friebe, M. Ulbricht, Langmuir 2007, 23, 10316-10322.

Nanostructured Membranes II – 6
Tuesday July 15, 11:30 AM-12:00 PM, Moloka’i
Fixed-Charge Group-like Behavior of the Captured Ion By Crown Ether and
Its Effect on the Response of a Molecular Recognition Ion Gating
Membrane
T. Ito (Speaker), Chemical Resources Laboratory, Tokyo Institute of Technology, Yokohama,
Japan
T. Yamaguchi, Chemical Resources Laboratory, Tokyo Institute of Technology, Yokohama,
Japan, yamag@res.titech.ac.jp
We have suggested the concept of a molecular recognition ion gating membrane,
which can open and close its pores automatically in response to the specific ion
signals such as Ba 2+ and K + , and have showed various functions of the gating
effect to control pressure-driven permeation, osmotic pressure, and diffusion.
These response behaviors of the gating membrane mainly depend on the
swelling and shrinking of the grafted poly- NIPAM(N-isopropylacrylamide)-co-
BCAm (Benzo- [18]-crown-6-acrylamide). The grafted copolymer have crown
ether moieties, which can capture specific ion species and trigger the swelling of
the grafted polymer. This swelling and shrinking of the grafted copolymer also
accompany the change of water hydration onto the copolymer. These
phenomena were thought to control the membrane responses. However, we
recently found some interesting gating behaviors, which can’t be explained by
swelling and shrinking only. For instance, the permeability change of a small
molecular weight drug in response to ion stimulations was larger than that of high
molecular weight drug. The difference between these drugs was whether the
drugs have charges or not. Second, ion concentration gradient through the gating
membrane generated osmotic pressure, even though the size of ions was small
enough and water content of the grafted copolymer was high enough. Based on
these phenomena, the captured ions by crown ether moieties behave like fixed-
charge groups, and the molecular recognition ion gating membrane has the
aspect of a charged membrane, which can change its fixed charge density in
response to the specific ion signals. We conclude that combination of hydration
effect and charge effect of the grafted copolymer can make the sophisticated
functions of the molecular recognition ion gating membrane.

Nanostructured Membranes II - 7
Tuesday July 15, 12:00 PM-12:30 PM, Moloka’i
Multifunctional ultrathin TiO2 Nanowire Ultrafiltration Membrane for Water
Treatment
X. Zhang (Speaker), Nanyang Technological University, Singapore
A. Du, Nanyang Technological University, Singapore
J. Pan, Nanyang Technological University, Singapore
D. Sun, Nanyang Technological University, Singapore, ddsun@ntu.edu.sg
J. Leckie, Stanford University, Stanford, CA, USA
For the last two decades, micro/ultra filtration membranes have been used as an
advanced water treatment process for producing high quality drinking water with
small footprint 1 . Recently, inorganic membranes have attracted considerable
attention due to their excellent thermal, chemical, mechanical stability 2 . Among
the materials used for the preparation of inorganic membranes, TiO2 is unique
due to its excellent performance under UV irradiation on mineralization of virtually
all organic compounds 3, 4 . So, TiO2 membrane can provide concurrent filtration
and photocatalytic oxidation. Recently various morphologies of 1 dimensional
(1D) nanostructured TiO2, including nanowires, nanofibers, nanorods and
nanotubes, have been prepared by means of chemical or physical methods 5-11 .
These nanostructured TiO2 photocatalysts exhibit superior photocatalytic
efficiency relative to conventional bulk materials as a result of its larger surface
area and presence of quantum size effect.
In this paper, a new kind of multifunctional ultrathin TiO2 nanowire UF membrane
was fabricated using a method of hydrothermal syntheses-filtration. The
fabricated UF membrane has a supporting layer of glass fiber and a funcational
layer of ultrafine TiO2 nanowire. These TiO2 nanowires had typical diameter of
several micrometers. Beside of good performance on separation, the TiO2
membrane exited excellent photocatalytic activity on degradation of methylene
blue (MB). The nanowire membrane has shown unusual potentials for
environmental purification.
Ultrathin TiO2 nanowires were systhesized by hydrothermal reaction. These TiO2
nanowires were assembled on glass filter by filtration with surfactant assistant.
The photocatalytic activity of the TiO2 nanowire membrane were evaluated with
MB and humic acid (HA) as model pollutants.
FESEM observation revealed that the TiO2 nanowire functional layer of the
membrane was formed by overlap and interpenetration of long TiO2 nanowires
with typical lengths of several micrometers. The surface of membrane was very
flat. TEM observations revealed that the diameters of TiO2 nanowires were less

than 10 nm. XRD data suggest that the crystal phase of TiO2 nanowire depends
on the calcination temperature. The pure anatase phase (JCPDS 21-1272) was
gained at 600 °C.
From the FESEM images of the TiO2 nanowire membrane, the size of pore
formed in the functional layer is less than 10 nm suggesting that it was an UF
membrane. The MWCO of the TiO2 nanowire membrane was determined with
different molecular weight of PEG (400, 1K, 4K, 6K, 10K and 35K). According to
the results of filtration, the MWCO of the TiO2 nanowire of membrane was about
10K.
The photocatalytic activity of TiO2 nanowire membrane was evaluated by the
photocatalytic oxidation of MB under UV irradiation. Finger prints of aqueous MB
(1.0 × 10 -4 mol/L) were made onto the TiO2 nanowire membrane and a
commercial glass fiber membrane. Both membranes were exposed to UV
irradiation. After 30 min of irradiation, no remarkable change was found to the
mark on the SiO2 fiber membrane. However, the MB mark on TiO2 nanowire
membrane completely disappeared, which indicated that the TiO2 nanowire
membrane has good photocatalytic activity.
To investigate the concurrent capacity of separation and photocatalytic oxidation
of the TiO2 nanowire membrane, HA solution of 20 mg/L was filtered using the
TiO2 nanowire membrane in continuous operation mode under UV irradiation.
The membrane flux was kept a constant for a long time. The removal rates of HA
and TOC by the two processes are almost 100% abd 95.1%, respectively. It
clearly indicates excellent performance on concurrent filtration and photocatalytic
degradation.
Reference
1. Cho, J.; Amy, G.; Pellegrino, J. Journal of Membrane Science 2000, 164, (1-2), 89-110.
2. Choi, H.; Sofranko, A. C.; Dionysious, D. D. Advanced Functional Materials 2006, 16, 1067-
1074.
3. Hoffmann, M. R.; Martin, S. T.; Choi, W.; Bahnemann, D. W. Chem. Rev. 1995, 95, (1), 69-96.
4. Fujishima, A.; Rao, T. N.; Tryk, D. A. Journal of Photochemistry and Photobiology C:
Photochemistry Reviews 2000, 1, (1), 1-21.
5. Jung, J. H.; Kobayashi, H.; van Bommel, K. J. C.; Shinkai, S.; Shimizu, T. Chem. Mater. 2002,
14, (4), 1445-1447.
6. Yao, B. D.; Chan, Y. F.; Zhang, X. Y.; Zhang, W. F.; Yang, Z. Y.; Wang, N. Applied Physics
Letters 2003, 82, (2), 281-283.
7. Kasuga, T.; Hiramatsu, M.; Hoson, A.; Sekino, T.; Niihara, K. Langmuir 1998, 14, (12), 3160-
3163.

8. Tian, Z. R.; Voigt, J. A.; Liu, J.; McKenzie, B.; Xu, H. J. Am. Chem. Soc. 2003, 125, (41),
12384-12385.
9. Yoshida, R.; Suzuki, Y.; Yoshikawa, S. Journal of Solid State Chemistry 2005, 178, (7), 2179-
2185.
10. Yuan, Z.-Y.; Su, B.-L. Colloids and Surfaces A: Physicochemical and Engineering Aspects
2004, 241, (1-3), 173-183.
11. Chen, Y.; Crittenden, J. C.; Hackney, S.; Sutter, L.; Hand, D. W. Environ. Sci. Technol. 2005,
39, (5), 1201-1208.

Pervaporation and Vapor Permeation I – 1 – Keynote
Tuesday July 15, 8:15 AM-9:00 AM, Honolulu/Kahuku
Bioethanol Production Using Pervaporation and Vapor Permeation
Membranes
I. Huang (Speaker), Membrane Technology & Research, Menlo Park, CA, USA,
ihuang@mtrinc.com
R. Baker, Membrane Technology & Research, Menlo Park, CA, USA
L. Vane, The U.S. EPA, Cincinnati laboratory, Cincinnati, OH, USA
Bioethanol production for use as a renewable energy resource is booming driven
by climate change concerns and soaring oil prices. Conventional
distillation/molecular sieve drying of bioethanol uses about 20% of the energy
content of the ethanol produced. Alternative technologies which consume less
energy to dehydrate ethanol are of considerable interest to the bioethanol
industry. The existing membrane technology for ethanol/water separations uses
pervaporation. The first industrial-scale pervaporation unit was installed in Brazil
by GFT (now Sulzer Chemtech) in 1982 to dehydrate ethanol from a cane sugar
fermentation plant. Despite this early success, pervaporation has not been widely
used in bioethanol production, primarily because the membrane modules used
were too expensive and were susceptible to slow degradation, leading to
excessive replacement costs.
In this paper, the application of pervaporation and vapor permeation to
bioethanol membrane separations is described. Novel, low energy process
designs require membrane modules able to operate at high temperatures with
high water concentration ethanol solutions. The requirements for membrane
properties are discussed. The processes described showed significant energy
savings compared to the conventional distillation/molecular sieve drying process.

Pervaporation and Vapor Permeation I – 2
Tuesday July 15, 9:30 AM-10:00 AM, Honolulu/Kahuku
Dewatering Ethanol with Chemically and Thermally Resistant
Perfluoropolymer Membranes
S. Majumdar (Speaker), Compact Membrane Systems, Inc., Newport, DE, USA,
smajumdar@compactmembrane.com
D. Stookey, Compact Membrane Systems, Inc., Newport, DE, USA
S. Nemser, Compact Membrane Systems, Inc., Newport, DE, USA
Bio-based ethanol is a renewable energy source. Ethanol from agricultural
sources has many potential advantages including development of fuel
independence and reduction in greenhouse gas generation. However, the energy
costs associated with converting fermentation ethanol to dry fuel grade ethanol
are substantial. Ethanol as derived through fermentation from biomass contains a
significant amount of water. Dehydration is an essential process step that is
complicated by the ethanol-water azeotrope.
CMS is currently investigating highly permeable, chemically and thermally
resistant perfluoropolymer membranes to selectively remove water from waterethanol
mixtures. These membranes are hydrophobic and organophobic and yet
have high water vapor permeation flux. Basic data in combination with
preliminary economic and engineering analysis show that a process scheme that
includes CMS membranes can improve the overall economics for dewatering and
producing fuel-grade ethanol. This presentation discusses the application of this
novel perfluoropolymer membrane-based technology for the production of fuelgrade
ethanol.

Pervaporation and Vapor Permeation I – 3
Tuesday July 15, 10:00 AM-10:30 AM, Honolulu/Kahuku
Modeling and Process Integration of Membranes for Ethanol Dehydration
P. Bösch, Vienna University of Technology, Vienna, Austria, peter.boesch@tuwien.ac.at
P. Schausberger, Vienna University of Technology, Vienna, Austria
A. Boontawan, Suranare University of Technology, Institute of Agricultural Technology, Sc,
Nakhon Ratchasima, Thailand
A. Friedl (Speaker), Vienna University of Technology, Vienna, Austria
To capitalize on economy of scale effects ethanol for fueling vehicles is produced
in facilities with a yearly output of >100.000 t/a. Although the plants are
economical viable, the ecology of the overall process is in doubt. This is mostly
due to the distances the feed crop travels, the fertilizer required during crop
cultivation and also on the used energy source for the process. Therefore a
feasibility study on small scale ethanol production (

The authors gratefully acknowledge the support by “Energy Systems of Tomorrow”, a
subprogram of the Federal Ministry of Transport, Innovation and Technology (BMVIT) in
cooperation with the "Austrian Industrial Research Promotion Fund" (FFG).

Pervaporation and Vapor Permeation I – 4
Tuesday July 15, 10:30 AM-11:00 AM, Honolulu/Kahuku
Performance of a New Hybrid Membrane in High Temperature
Pervaporation
H. van Veen (Speaker), Energy research Centre of the Netherlands, ECN, The Netherlands,
vanveen@ecn.nl
R. Kreiter, Energy research Centre of the Netherlands, ECN, The Netherlands
C. Engelen, Energy research Centre of the Netherlands, ECN, The Netherlands
M. Rietkerk, Energy research Centre of the Netherlands, ECN, The Netherlands
H. Castricum, Univ. of Twente, The Netherlands
A. ten Elshof, Univ. of Twente, The Netherlands
J. Vente, Energy research Centre of the Netherlands, ECN, The Netherlands
Thermal separation processes like distillation consume a large amount of energy
in the process industry. Replacing these processes by membrane pervaporation
will lead to much lower energy consumption. The expected high chemical and
thermal stability of inorganic membranes compared to polymer membranes has
resulted in a growing research activity with the first aim of replacing polymer
membranes with inorganic ones. The superior separation performance, i.e.
selectivity and flux, of silica-based membranes in the dehydration of alcohols and
solvents at elevated temperatures has raised the interest even further. The
application depends on a reliable and good long-term performance.
Unfortunately, information on this topic is still very limited. We have shown that
silica and methylated silica membranes are not stable at temperatures above
100°C and the application window of state-of-the-art Me-SiO2 membranes for use
in dehydration processes is limited to 95°C [1]. For methanol separation from
organic solvents the Me-SiO2 membranes can be used at higher temperatures
[2].
Hybrid silica materials are expected to have a much higher hydrothermal stability
than (methylated) silica. The superior separation performance, i.e. selectivity and
flux, of these hybrid membranes in the dehydration of alcohols and solvents at
elevated temperatures has raised the interest [3]. High flux performance is
required to decrease the membrane area needed and thereby the price to
become competitive against the well know distillation technique. It is proven that
the required water flux of at least 3 kg/m 2 h, for the dehydration of 5wt.% water in
butanol as a representative standard application, can be achieved easily. The
profitable application of the membranes depends on a reliable, stable long-term
behaviour and the broad applicability especially at temperatures above 100°C.
We will report on the development of organic/inorganic hybrid silica membranes
with selectivities and fluxes, that are comparable with the silica based
membranes in dehydration by pervaporation. Details of test results will be given
in different dehydration applications up to 150°C including the dehydration of

aprotic solvents. Further, results will be given on long term stability testing up to
150°C and up to 2 years of continuous operation in the dehydration of organic
mixtures. The results show that a completely new class of hybrid materials is
available that opens new markets for dehydration processes by pervaporation.
Acknowledgement Part of this work was supported with a grant from the Dutch
Ministry of Economic Affairs via the EOS- LT (Long term energy research
subsidy) programme, managed by SenterNovem.
References
[1] J. Campaniello, C.W.R. Engelen, W.G. Haije, P.P.A.C. Pex and J.F. Vente, Long-term
performance of microporous methylated silica membranes, Chem.Comm. (2004), p.834-835.
[2] J.F. Vente, H.M. van Veen and P.P.A.C. Pex, Microporous sol-gel membranes for molecular
separations, Ann.Chim.Sci.Mat. (2007),Vol. 32, No.2, 231-244.
[3] H.L. Castricum, A. Sah, R. Kreiter, D.H.A. Blank, J.F. Vente and J.E. ten Elshof, Chem.Comm.
(2008), DOI:10.1039/B718082A.

Pervaporation and Vapor Permeation I – 5
Tuesday July 15, 11:00 AM-11:30 AM, Honolulu/Kahuku
Investigation of the Fundamental Differences between Polyamide-imide
(PAI) and Polyetherimide (PEI) Membranes for Isopropanol Dehydration via
Pervaporation
Y. Wang (Speaker), National University of Singapore, Singapore
L. Jiang, National University of Singapore, Singapore
T. Chung, National University of Singapore, Singapore
T. Matsuura, University of Ottawa, Ottawa, Ontario, Canada
S. Goh, National University of Singapore, Singapore
Polyimides (PI) are recently emerging as a promising material for pervaporation
dehydration of alcohols because of their excellent thermal, chemical and
mechanical stabilities. In this study, two kinds of polyimides, Torlon 4000TF
polyamide- imide (PAI) and Ultem 1010 polyetherimide (PEI) membranes are
investigated as membrane materials for the pervaporation dehydration of
isopropanol. Generally, PAI membranes are found to have higher separation
performance than PEI membranes. The physicochemical properties of these two
materials and the as-fabricated membranes are investigated and correlated to
the pervaporation performance through different characterizations (DSC, TGA,
Goniometery, X-ray diffraction, gas permeation, and water sorption). PAI
membranes exhibited better pervaporation performance which is attributed to the
greater hydrophilicity, higher glass transition temperature, narrower d-space,
higher density and higher water uptake. Compared with PEI dense membranes,
PAI dense membranes show a much higher separation factor (up to 3000 at 60
°C) and comparable flux. PAI membranes also showed higher O2/N2 selectivity
than PEI with comparable gas permeability. The results showed that, for the
fabrication of the asymmetric membranes, the dope concentration is a very
important factor on its pervaporation performance. For both PAI and PEI
membranes, dope concentrations equal to or higher than their critical
concentrations are essential to produce useful pervaporation membranes. In
addition, heat treatment is an effective way to reduce defects and enhance
separation performance. This is because the molecular chain packing of the top
dense layer becomes denser with increasing dope concentration or thermal
treatment temperature of the membrane. Further increase of the dope
concentration or thermal treatment temperature may cause an increased
substrate resistance, which leads to the decrease of the selectivity.
Pervaporation process using different operation modes is also studied. The
separation using a membrane with porous structure facing against the feed
solution shows a much higher separation factor with only a slight decrease of
flux. This important phenomenon can be explained in terms of the balance

etween two major contradictory effects: concentration polarization and dense
layer swelling.

Pervaporation and Vapor Permeation I – 6
Tuesday July 15, 11:30 AM-12:00 PM, Honolulu/Kahuku
Preparation of Asymmetric Polyetherimide Membranes for Molecular Liquid
Separations
A. El-Gendi, LSGC-CNRS, Nancy Université, France
D. Roizard, LSGC-CNRS, Nancy Université, France, Denis.Roizard@ensic.inpl-nancy.fr
E. Favre (Speaker), LSGC-CNRS, Nancy Université, France
The aromatic polyimides are a well-known class of polymer materials, which
have been widely studied for over 20 years in the field of membrane separation.
As glassy polymers, they possess remarkable mechanical and chemical
properties for organic materials, but in general their permeability coefficients are
limited because of their rigid carbon skeleton and low available free volume;
hence their application to molecular separation is limited to gas separations.
To circumvent this problem, and to broaden the scope of these very stable
polymers, we have studied the properties of a block-ether aromatic polyimide
series comprising a flexible block and we prepared asymmetrical films with the
aim of achieving liquid-liquid separations. Using various experimental conditions
of phase inversion, either totally opened microstructures typical of microfiltration
membranes or asymmetric microstructures with a thin dense top surface could
be obtained and then tested for the fractionation by pervaporation of model liquid
mixtures, such as toluene - heptane or water - ethanol. As an interesting
outcome, it was found that some copolyether-imide aromatic membranes could
indeed present high permeation fluxes and fairly good selectivities. Thus, it is
expected that the development of these new asymmetric block copolyimide
membranes might give rise to high performance membrane systems for
applications in liquid-liquid separations.

Pervaporation and Vapor Permeation I – 7
Tuesday July 15, 12:00 PM-12:30 PM, Honolulu/Kahuku
Preparation of a Novel Styrene-Butadiene-Styrene Block Copolymer (SBS)
Asymmetric Membrane for VOC Removal by Pervaporation
A. Figoli (Speaker), Institute on Membrane Technology (ITM-CNR), Italy, a.figoli@itm.cnr.it
S. Sikdar, USEPA, Cincinnati, OH, USA
J. Burckle, USEPA, Cincinnati, OH, USA
E. Drioli, Institute on Membrane Technology (ITM-CNR), Italy
Pervaporation (PV) is often applied to the separation of volatile organic
chemicals (VOCs) from water. This process provides a cost effective means to
achieve the removal of VOC's in the 50 to 150's ppm range concentrating by a
factor of 10 to 7000 times or more, permitting recovery in a concentrated form for
recycle and reuse or disposal. The economic application of pervaporation is
highly dependent upon the efficiencies of the membranes developed for
pervaporation applications. Most of the commercial systems use standard
polydimethylsiloxane (PDMS) membranes. In literature, PDMS membranes
employed in trichloroethane (TCA) removal from water by PV showed a
selectivity in the range of 2000-3000 and flux of 15 g/m 2 h [1-2]. Other
elastomeric polymers such as EPDM (ethylene-propylene-diene) terpolymer,
NBR (nitrile butadiene rubber), PEBA (polyether-block-polyamide) have also
shown promising results. Sikdar, et al. [3] studied the potentiality of a different
material, styrene-butadiene-styrene block copolymer (SBS), for VOCs removal
from water. The SBS coated on polymeric material lead to a significant
improvement in the selectivity (TCA/H2O) in the range of 3000-5000, while
retaining a relatively high flux. On the basis of such results, in this work we report
the preparation of novel asymmetric SBS membranes prepared by the nonsolvent
induced phase inversion technique (NIPS) [4]. This technique allows
tailoring the morphology of the prepared membrane and obtaining a resistant
membrane with a thin active layer in a single step. The success of the
preparation of asymmetric elastomeric membranes leads to an easier membrane
production at lower cost with respect to the composite membrane production and
to the possibility to tailor the membrane morphology. Different membrane
structures were obtained by using different non-solvent/solvent pairs. The
influence of several parameters on the membrane film formation, such as the
composition of the polymer solution (concentration, type of solvent), composition
of the coagulation bath, the exposure time before immersion in the coagulation
bath, casting knife thickness, was investigated. Using small amount of polymer
non- solvent (up to 5wt.%) into the solvent polymer solution asymmetric porous
membranes were obtained (instantaneous demixing). Addition of solvent to the
coagulation bath partially suppressed the porous formation and yielded
membranes with a dense top-layer. In particular, the THF(solvent)/ethanol or

ethanol/butanol (non solvent) combination allowed the formation of asymmetric
membranes with a dense skin layer, suitable for pervaporation applications. A
thicker dense layer was made increasing the polymer concentration (10wt.% to
25wt.%) in the casting solution. The surface and the cross-section of the
prepared membranes were analysed using a Scanning Electron Microscopy
(SEM). Gas and water permeability experiments have been also performed to
evaluate the pore size diameter, porosity, and transport property of the active
layer of the SBS asymmetric membranes. The asymmetric SBS flat membrane
was successfully tested for VOCs removal from water by PV in a pilot setup, TCA
was used as model VOCs species. Several process conditions, such as feed flow
rate, temperature, vacuum pressure have been deeply investigated. From the
experimental tests, the flux and separation factor obtained were higher than
those achieved with commercial membranes. In particular, the best performance
of the SBS asymmetric flat membrane showed a selectivity of about 4600 and a
TCA flux of about 18 g/m 2 h at a temperature of 34 °C and 40 Torr [4].
References
1) W. Ji, S.K. Sikdar, S.T. Hwang, Modeling of multicomponent pervaporation for removal of
volatile organic compounds from water, J. Membr. Sci. 93 (1994) 1.
2) I. Abou-Nemeh, S. Majumdar, A. Saraf, S.K. Sirkar, L.M. Vane, F.R. Alvarez, L. Hitchens,
Demonstration of pilot-scale pervaporation systems for volatile organic compound removal from a
surfactant enhanced aquifer remediation fluid II. Hollow fiber membrane modules, Environmental
Progress,20, issue 1 (2001) 64-73.
3) B.K. Dutta, S.K. Sikdar, Separation of volatile organic compounds from aqueous solutions by
pervaporation using S-B-S block copolymer membranes. Environ Sci Technol 33 (1999) 1709.
4) S.K. Sikdar, J.O. Burckle, B.K. Dutta, A. Figoli, E. Drioli, Method for Fabrication of Elastomeric
Asymmetric Membranes from Hydrophobic Polymers,U.S. Patent 11/598,840; publish in May,
2008.

Osmotically Driven Membrane Processes – 1 – Keynote
Tuesday July 15, 8:15 AM-9:00 AM, O’ahu/Waialua
Characterization of Solute Transport in Osmotically Driven Membrane
Processes
N. Hancock (Speaker), Colorado School of Mines, Golden, CO, USA
T. Cath, Colorado School of Mines, Golden, CO, USA, tcath@mines.edu
Osmotically-driven membrane processes are emerging water treatment
technologies that have come under renewed interest and subjected to numerous
investigations in recent years. These studies have mostly focused on novel
applications of the forward osmosis process to augment and improve existing
water treatment methods. Recent studies have focused on characterizing
concentration polarization phenomena and its affect on the non-linearity of
osmotically-driven processes and on the effect of forward osmosis membrane
structure on process performance. However, osmotically-driven membrane
processes have yet to undergo any exhaustive or focused studies to determine
solute transport characteristics through the membrane. In the current study, we
focus on characterization of the bi-directional diffusion of solutes in osmotically
driven membrane processes.
Recent studies by Cath, et al. and Halloway, et al. have suggested utilizing
forward osmosis as a pretreatment for reverse osmosis (RO) in order to enhance
the treatment of various types of waste streams. These studies demonstrated
that forward osmosis is an effective pretreatment for RO due to its ability to
effectively treat severely impaired water with minimal membrane fouling and
simple maintenance. Forward osmosis has a reduced fouling potential because
of the membrane’s hydrophilicity (resulting in a lower fouling tendency from
organic matter) and its operation with very low hydraulic pressure. Recent
research, funded by the US Bureau of Reclamation and conducted by Martinetti,
Childress, and Cath for Eastern Municipal Water District (EMWD) of Southern
California demonstrated that forward osmosis can effectively augment existing
brackish water desalination operations by enhancing water recovery.
In this process, forward osmosis is used to pretreat the concentrate from an
existing brackish water desalination processes. The highly concentrated stream,
rich in sparingly soluble solutes, contacts the active side of the forward osmosis
membrane. Water diffuses through the membrane into a highly concentrated
draw solution of controlled composition. The high selectivity of the forward
osmosis membrane generates a moderately dilute draw solution. Yet, very slow
diffusion of solutes also occurs in both directions during the process. Commonly,
an RO process is used to produce a stream of purified water and a stream of reconcentrated
draw solution to sustain the forward osmosis process. Using

forward osmosis, the RO process is thus protected from scaling and fouling of
any constituents present in the source of impaired water.
An important caveat of the forward osmosis process is that its membrane, like all
synthetic semi-permeable membranes, is not perfectly selective. Sparingly
soluble solutes, toxic metals, and other emerging contaminants of concern
present in the feed solution, as well as the draw solution solutes, will inevitably
diffuse across the forward osmosis membrane. The introduction of sparingly
soluble solutes into the final RO stage may subsequently scale the RO
membrane, while the diffusion of draw solution solutes against flow of water
represents inefficiency in the system because lost solutes will have to be
replenished. Despite the multi-barrier treatment obtained by such a system, there
is still concern that toxic metals and other containments of interest will cross both
the forward osmosis and RO membranes and contaminate the product stream.
In the current study, multiple tests were performed to elucidate the diffusion of
solutes across two different cellulose triacetate forward osmosis membranes.
These studies were performed with the aid of a novel supervisory control and
data acquisition (SCADA) system developed by the authors. Using the SCADA
system, the authors were able to conduct experiments at very steady conditions
including constant temperatures, flux, and draw solution concentrations. These
studies utilized feed solutions containing both single salts and synthetic brackish
water to characterize specific and competitive solute diffusion through the
forward osmosis membranes. Samples from these experiments were analyzed
by ion chromatography (IC) and inductively coupled plasma (ICP) to determine
solute transport across the membranes. Data collected from this analysis was
used to determine the individual solute’s permeation tendency through the
membrane.

Osmotically Driven Membrane Processes – 2
Tuesday July 15, 9:30 AM-10:00 AM, O’ahu/Waialua
Forward-Osmosis Using Ethanol for Concentrate Minimization
J. Pellegrino (Speaker), University of Colorado, Boulder, CO, USA,
john.pellegrino@colorado.edu
P. McCormick, Denver Water Department, Denver, CO, USA
A. Mendoza, University of Colorado, Boulder, CO, USA
Ethanol has several compelling features for use as a "draw" agent for forward
osmosis-based separation of water from aqueous electrolytes. Due to the high
osmotic gradients available, it can be used in crystallization processes and
therefore provide a method for overall concentrate minimization as part of an
inland desalination strategy. We have previously presented the transport
properties of several membrane materials (IEX and PVA) with respect to EtOH,
H2O, and NaCl under diffusive transport conditions. Also, rudimentary process
design analysis has been done to identify approaches for recovery of recycle
draw solution and product water. In this work, we have performed batch
crystallization experiments using model electrolyte mixtures and have measured
the integrated transport properties for the several species in a flow system, and
the crystallization kinetics and speciation results.

Osmotically Driven Membrane Processes – 3
Tuesday July 15, 10:00 AM-10:30 AM, O’ahu/Waialua
A Novel Hybrid Forward Osmosis Process for Drinking Water
Augmentation using Impaired Water and Saline Water Sources
C. Lundin (Speaker), Colorado School of Mines, Golden, CO, USA
T. Cath, Colorado School of Mines, Golden, CO, USA, tcath@mines.edu
J. Drewes, Colorado School of Mines, Golden, CO, USA
As water resources become more contaminated and over allocated, new sources
of water must be developed. While many coastal areas are turning to reverse
osmosis (RO) desalination, the energy requirements can be a large drawback.
The large amounts of energy required for RO desalination is mainly due to the
need to overcome the osmotic pressure of seawater. The high osmotic pressure
of seawater limits the maximum recovery possible by RO systems. There are
only a few ways of reducing the energy required, one of which is by reducing the
osmotic pressure of the feed water, for example through dilution, thereby
reducing the needed applied high pressure.
Concurrently in many coastal areas, treated wastewater effluent is being
discharged to the ocean without providing any beneficial use; wasting a valuable
resource. In some areas the effluent is put into non-potable reuse systems, and
recently, some very progressive utilities have started using reclaimed water for
indirect potable reuse. Indirect potable reuse can work well in some areas, but it
requires a large natural water storage area (lakes or aquifer) and further
treatment after extraction from the aquifer and before ultimate potable use. Thus,
it might be more efficient to pursue direct potable reuse in certain circumstances.
The two problems of energy demand and wasted reclaimed water could be
synergistically solved if the impaired water stream could be safely used to dilute
seawater before RO desalination.
In a newly patented approach, forward osmosis (FO) uses a saline stream
(seawater or brackish water concentrate) to extract purified water from a source
of impaired water. FO uses an osmotic pressure differential as the driving force;
drawing water through a semi-permeable membrane and rejecting almost all
dissolved contaminants in the process. Because FO uses only osmotic pressure
as a driving force, its energy demand is very low. The diluted seawater is then
processed through an RO desalination system which provides rejection of salts,
as well as further rejection of dissolved contaminants that may have crossed the
FO membrane from the impaired water source. Most importantly, because the
saline water is diluted during FO, the energy required for subsequent RO
desalination of the diluted saline water is reduced. Thus, the energy demand of

the desalination plant is lessened and two significant barriers are in place to
reject contaminants present in the impaired/reclaimed stream.
Recent progress in research has demonstrated that FO can be successfully
implemented in a wide range of applications including wastewater treatment
(e.g., landfill leachate, anaerobic digester sludge, and life support systems),
desalination (e.g., seawater and brackish water), and pharmaceutical and food
industries. Yet, very limited research has been conducted on the direct
combination of desalination and impaired water reclamation; specifically with
regards to trace organic rejection. Therefore, the main objectives of the currently
AwwaRF-funded study are threefold: (1) investigate the performance (e.g., water
flux; solute and solid rejections) and potential limitations of FO membranes for
pretreatment of impaired/reclaimed water, (2) investigate the mechanisms behind
the mass transport of organic contaminants across the membrane, and (3)
develop recommendations and cost estimates for a FO/RO hybrid for the
simultaneous treatment of impaired and saline water.
The process is tested on both bench and pilot scale. The bench scale setup is
comprised of a custom built flat sheet FO membrane cell (0.07 m 2 ), and a SEPA-
CF flat sheet RO membrane cell for desalination of seawater. Following the
bench-scale study, pilot-scale testing of the process is conducted in several
wastewater reclamation facilities. Several water quality parameters are being
measured including TOC (Shimatzu HTCO), anions (IC), and cations (ICP).
Because measuring the rejection of specific micropollutants is difficult in highly
saline solutions, an existing HPLC method is being modified using solid phase
extraction.

Osmotically Driven Membrane Processes – 4
Tuesday July 15, 10:30 AM-11:00 AM, O’ahu/Waialua
Osmotic Membrane Bioreactor and Pressure Retarded Osmotic Membrane
Bioreactor for Wastewater Treatment and Water Desalination
A. Achilli (Speaker), University of Nevada, Reno, Reno, Nevada, USA, aachilli@unr.edu
T. Cath, Colorado School of Mines, Golden, CO, USA
E. Marchand, University of Nevada, Reno, Reno, Nevada, USA
A. Childress, University of Nevada, Reno, Reno, Nevada, USA
More stringent regulations and the ability to produce high quality effluent make
membrane bioreactors (MBRs) an attractive process for domestic and industrial
wastewater treatment. In a conventional MBR, microfiltration (MF) or ultrafiltration
(UF) membranes are utilized and water is commonly filtered through the
membranes using pressure. Suspended solids are completely rejected and
substantial removal of organic carbon and nutrients can be achieved [1]. MBRs
replace two pivotal stages of conventional activated sludge systems
(biotreatment and clarification) with a single, integrated process. MBR effluent
may be suitable for use as irrigation water, process water, or a source of potable
water. For potable reuse (e.g., indirect reuse through aquifer recharge),
advanced treatment such as reverse osmosis (RO), nanofiltration (NF), or
chemical oxidation is necessary after the MBR [2]. The advantages of MBRs over
conventional treatment have been thoroughly reviewed and include product
consistency, reduced footprint, reduced sludge production due to a high biomass
concentration in the bioreactor, and complete suspended solids removal from the
effluent [3].
A novel MBR system that utilizes a submerged forward osmosis (FO) membrane
in the bioreactor is investigated in the current study. In forward osmosis, water
diffuses across a selectively permeable membrane from a solution of higher
water chemical potential (lower osmotic pressure) to a solution of lower water
chemical potential (higher osmotic pressure); in this application, water diffuses
from the bioreactor into a controlled draw solution (DS). The FO membrane acts
as a barrier to solute transport and provides high rejection of contaminants
present in the wastewater stream. The diluted DS is reconcentrated using RO or
distillation, and being reused in the FO process; the permeate is a high-quality
product water. Thus, in most wastewater treatment applications, FO is not the
ultimate process but rather a high-level pretreatment step before an ultimate
reconcentration/desalination process.
Compared to the MF or UF process in a conventional MBR, the FO process in
the osmotic membrane bioreactor (OMBR) offers the advantages of much higher
rejection (semi-permeable membrane versus microporous membrane) without

the need of applying pressure to withdraw the permeate. FO membranes are
also likely to have lower fouling propensity compared to high pressure
membranes [4].
Preliminary results from experiments conducted with a flat-sheet cellulose
triacetate FO membrane and an NaCl solution as the DS demonstrated high
sustainable water flux. Membrane fouling was minimal and controlled with
osmotic backwashing. The FO membrane was found to reject 98% of organic
carbon and 90% of ammonium; the OsMBR process was found to remove 99.8%
of organic carbon and 97.7% of ammonium.
In certain situations, when a stream of concentrated brine from a desalination
facility is available, an open-loop OsMBR could be used. In this configuration, the
brine from a nearby desalination facility would be used as the DS and the diluted
DS would be discharged to the sea. Sea discharge of the diluted DS would be
environmentally favorable over direct discharge of the brine because the diluted
DS concentration would be closer to that of seawater.
Further application of the OsMBR process is its possible utilization in osmotic
power generation through pressure-retarded osmosis (PRO). PRO utilizes the
FO principle as a basis for its operation. In PRO the DS is at elevated hydraulic
pressure, lower than the osmotic pressure difference between the feed and the
DS streams. The optimal hydraulic pressure at which the system should operate
is a function of the osmotic pressures of the feed and DS streams and the
membrane characteristics. The water that diffuses through the membrane is
depressurized in a turbogenerator to recover beneficial energy. When OMBR is
operated in PRO mode in order to recover energy, the process is referred to as
the pressure retarded OMBR (ProMBR). Other novel combination of ProMBR will
be introduced. Computer modeling performed with ideal systems demonstrated
that ProMBR can potentially be a viable source of renewable energy.
References
[1] S. Judd, The MBR Book: Principles and Applications of Membrane Bioreactors in Water and
Wastewater Treatment, Elsevier, 2006.
[2] P. Lawrence, S. Adham and L. Barro, Ensuring water re-use projects succeed - institutional
and technical issues for treated wastewater re-use, Desalination, 152 (2002) 291-298.
[3] T. Stephenson, S. Judd, B. Jefferson and K. Brindle, Membrane bioreactors for wastewater
treatment, IWA Publishing, 2000.
[4] A. Achilli, T.Y. Cath, E.A. Marchand and A.E. Childress, The forward osmosis membrane
bioreactor: A low fouling alternative to MBR processes, Desalination, Accepted for publication.

Osmotically Driven Membrane Processes – 5
Tuesday July 15, 11:00 AM-11:30 AM, O’ahu/Waialua
Osmotic Power - A New, Renewable Energy Source
S. Skilhagen (Speaker), Statkraft AS, Norway
T. Holt, SINTEF, Scandinavia
J. Dugstad, Statkraft AS, Norway, jon.dugstad@statkraft.com
Osmotic power is a relatively new energy conversion concept even though
osmosis has been known for several hundred years. Only 30-35 years ago, Prof.
Sidney Loeb and his team at UCLA utilised the natural knowledge and proposed
methods for the utilisation of osmotic pressure in power generation using
membranes.
In the eighties and nineties, membrane technology was introduced successfully
in many industrial applications and efficient semi-permeable membranes became
available. In the late nineties the efficient transfer of mechanical energy be-
tween fluids was also made possible. All the basic technology components
necessary for efficient osmotic power production are therefore in principle
available. New and more energy efficient membrane technology has been
developed during the last few years.
During the last decades the increased global energy consumption, together with
increased focus on the environment, demands for new soruces of
environmentaly friendly energy. Osmotic power can represent one of the
solutions for these challenges.
Statkraft, a North European electricity generator, is now planning to build an
osmotic power plant prototype to further verify the osmotic power system.
Throughout the last 10 years, developments has led to believe that it is possible
to develop the necessary membrane technology and the construction of the first
osmotic power prototype will be completed in 2008. The commercial potential of
osmotic power is identified and a wide R&D programme involving research
centres and commercial developers on three continents are currently in progress.

Osmotically Driven Membrane Processes – 6
Tuesday July 15, 11:30 AM-12:00 PM, O’ahu/Waialua
Influence of Membrane Support Layer Hydrophobicity on Water Flux in
Osmotically Driven Membrane Processes
J. McCutcheon (Speaker), Stony Brook University, East Setauket, NY, USA,
jeff@stonybrookpure.com
M. Elimelech, Yale University, New Haven, CT, USA
Osmotically driven membrane processes, such as forward osmosis (FO) and
pressure retarded osmosis (PRO), rely on the utilization of large osmotic
pressure differentials across semi-permeable membranes to generate water flux.
Previous investigations on these two processes have demonstrated how
asymmetric membrane structural characteristics, primarily of the support layers,
impact water flux performance. In this investigation, we demonstrate that support
layer hydrophilicity, or wetting, plays a crucial role in water flux across
asymmetric semi-permeable membranes. The results show that the polyester
(PET) nonwoven and polysulfone supports typically present in thin-film composite
(TFC) reverse osmosis (RO) membranes do not wet fully when exposed to water,
thereby resulting in a marked decrease in water flux. A cellulosic RO membrane
exhibited modestly higher water fluxes due to its more hydrophilic support layer.
Removal of the PET layers from the cellulosic and TFC RO membranes resulted
in an increased water flux for the cellulosic membrane and very little change in
flux for the TFC membrane. Pretreatment with hydraulic pressure (RO mode),
feed solution degassing, and use of surfactants were used to further elucidate
the wetting mechanisms of the different support layers within each membrane.
The importance of considering membrane support layer chemistry in further
development of membranes tailored specifically for osmotically driven membrane
processes is discussed.

Osmotically Driven Membrane Processes – 7
Tuesday July 15, 12:00 PM-12:30 PM, O’ahu/Waialua
Developing Permeation Enhanced Nanofiltration Hollow Fiber Membranes
Used in Forward Osmosis
K. Wang (Speaker), National University of Singapore, Singapore
Q. Yang, National University of Singapore, Singapore
T. Chung, National University of Singapore, Singapore, chencts@nus.edu.sg
J. Gin, Centre for Advanced Water Technology, Singapore
Osmosis is the natural diffusion of water that permeating through a semipermeable
membrane from a solution containing a low concentration of dissolved
species to a solution having a higher concentration of dissolved species. Instead
of employing hydraulic pressure as the driving force for separation in the reverse
osmosis process, forward osmosis (FO) employs the osmotic pressure gradient
to induce a net flow of water through the membrane into the draw solution (with
high osmotic pressure), thus effectively separating the feed water from dissolved
solutes. The main advantages of using FO in seawater desalination are that FO
membrane has high rejection to a wide range of contaminants, and it may have a
lower membrane fouling propensity than other pressure-driven membrane
processes. The membranes used in FO process play a vital role on the FO
performance of separation and productivity. Up to now, available commercial
reverse osmosis membranes were employed in almost all FO processes. It is
necessary to develop special FO membranes that can adapt for the forward
osmosis application. Nanofiltration membranes may have potential applications
in the realization of FO for their molecular-size pores on the selective layer to
reject larger molecules, such as salts, sugars, starches, proteins, viruses,
bacteria, and parasites. In this study, polybenzimidazole (PBI) hollow fiber
membranes through dry-jet wet phase inversion were fabricated with different
structures, for instances, wall thickness and porosity in order to investigate the
effects of membrane morphology on the membrane performance during FO
process. The support layer structure may have the important effect on the water
transport due to the serious concentration polarization in the porous support
layer. It is found that operating temperature also has an important influence on
the permeation flux due to its effect on the solution viscosity.

Asymmetric Polymeric Membrane Formation – 1 – Keynote
Tuesday July 15, 8:15 AM-9:00 AM, Wai’anae
Manipulation of Block Copolymer Nanostructure in Membranes Prepared
by Solvent Evaporation and Non-Solvent Induced Phase Separation
W. Yave (Speaker), Institute of Polymer Research, GKSS Research Centre Geesthacht GmbH,
Germany, Wilfredo.Yave.Rios@gkss.de
A. Boschetti-de-Fierro, Institute of Polymer Research, GKSS Research Centre Geesthacht
GmbH, Germany
V. Garamus, Institute of Materials Research, GKSS Research Centre Geesthacht GmbH,
Germany
K. Peinemann, Institute of Polymer Research, GKSS Research Centre Geesthacht GmbH,
Germany
V. Abetz, Institute of Polymer Research, GKSS Research Centre Geesthacht GmbH, Germany
P. Simon, Institute of Polymer Research, GKSS Research Centre Geesthacht GmbH, Germany
Self-assembly of macromolecular components is considered as a key for the
fabrication of periodically nanostructured materials [1]. Block copolymers, having
two or more polymer blocks chemically bound to each other have received great
attention due to their chemical functionality and physical properties [2, 3]. These
copolymers have the ability to self-assemble into microdomains, and the
manipulation of these patterns by a variety of physical and chemical methods has
been the challenge of many scientists.
For membrane technology, block copolymers showing a perpendicular cylindrical
structure at the surface combined with the simplicity of membrane preparation is
of special interest [4, 5]. In our previous work we combined the self-assembly of
a block copolymer with the well established non- solvent induced phase
separation technique. An asymmetric membrane with an extremely well ordered
top-layer was obtained [5]. After the first works it was noticed that not only the
typical parameters as composition of copolymer solution, evaporation time and
precipitation conditions are essential for the final membrane structure, but also
the age of copolymer solution due to the structure formation in solution.
Therefore, we prepared microphase separated films by evaporation of block
copolymer solutions, after storing them for different times. Small angle neutron
scattering experiments carried out on these solutions indicated structural
changes as a function of time. The time dependence on the final nanostructure of
the cast films will be discussed.
The process described above was then combined with the phase inversion
process, and nanostructured asymmetric membranes could be produced. By
using block copolymers of different compositions and different casting conditions,
the quality of the self-assembly in the top layer could be controlled.

References:
[1] Stupp, S. I.; Lebonheur, V. ; Walker, K.; Li, L.S.; Higgins, K.E.; Kesser, M.; Amstutz, A.
Science 1997, 276, 384.
[2] Bates, F. S. Science 1991, 251, 898.
[3] Abetz, V. ed. Block Copolymer I and II Vol. 189 and 190, Springer Publisher Heidelberg
(2005).
[4] Kim, S.H.; Misner, M.J.; Xu, T.; Kimura, M.; Russell, T.P. Advanced Materials 2004, 16, 226.
[5] Peinemann, K.-V.; Abetz, V.; Simon, P.F.W. Nature Materials 2007, 6, 992 .

Asymmetric Polymeric Membrane Formation – 2
Tuesday July 15, 9:30 AM-10:00 AM, Wai’anae
Synthesis and Characterization of Nanoporous Polycaprolactone
Membranes for Controlled Drug Release
C. Yen (Speaker), The Ohio State University, Columbus, OH, USA
H. He, Nanoscale Science and Engineering Center for Affordable Nanoengineering of, Columbus,
OH, USA
L. Lee, The Ohio State University, Columbus, OH, USA
W. Ho, The Ohio State University, Columbus, OH, USA
Polycaprolactone (PCL) has recently drawn a lot of attention in the biomedical
applications. PCL, a semicrystalline polymer, has several advantages including
low cost, biocompatiblitiy, and biodegradability. Moreover, PCL is a U.S. Food
and Drug Administration approved material for implantable devices, such as
suture. Thus, PCL is a superior material to fabricate an affordable and
implantable drug delivery device.
The porous membranes play an important role in a variety of drug delivery
systems. Several factors, including porosity, turtuosity, and pore size, have
critical effects on controlling the rate of drug diffusion through the membranes.
Currently, porous PCL membranes can be prepared by solvent-cast-leaching
method, bi- axial stretching, thermally-induced phase separation, and
nonsolvent-induced phase separation. However, state-of-the-art, porous PCL
membranes which are prepared via above methods have pore size still on a
micron scale that is too large. The mechanism governing diffusion phenomena
could be free diffusion, leading to an undesirable burst effect. Therefore, micronsize
porous membranes might not be a proper means to achieve the desirable
zero-order drug release rate. It appears that nanoporous PCL membranes could
be an ideal system to achieve the desirable release rate for implantable drug
delivery devices.
In this study, nanoporous PCL membranes have been prepared successfully via
the combination of thermally and nonsolvent induced phase separations. In the
membrane formation, the effects arisen from the thermally-induced phase
separation on the membrane formation have been investigated. In the membrane
preparation, the cast-film on a glass plate was immersed into a coagulation
(water) bath at a different constant temperature. When water bath temperature
was 5° C, the pore size at membrane top side was approximately 50 nm, and the
porosity was about 73%. However, while water temperature increased, the pore
size would also increase but the porosity would decrease. As coagulation bath
temperature increased to 35°C, the pore size at top side of the membrane would
be about 1 µm, and the porosity was about 56%. Lower coagulation

temperatures might bring about the enlarged phase-separation and crystallization
areas. Based on the 3-phase diagram, the composition path may cross the
bimodal line and move into the crystallization area. Therefore, crystallization
could suppress pore coalescence to ensure a well-connected pore structure.
Moreover, the use of nonsolvent, water, in the wet process of the nonsolvent
induced phase separation would produce nanopores at the top side of
membranes. Also, the influence of coagulation composition on the membrane
structure will be discussed. Various coagulation bath compositions would bring
about a different pore size on the top side of the membrane. By understanding
the fundamental parameters related to the formation of membrane structure,
nanoporous membrane-based implantable drug delivery devices with the
preprogrammed drug release rate would be developed.

Asymmetric Polymeric Membrane Formation – 3
Tuesday July 15, 10:00 AM-10:30 AM, Wai’anae
Catalytic PVDF Microcapsules for Application in Fine Chemistry
M. Buonomenna, ITM-CNR c/o UNiversity of Calabria, Italy, mg.buonomenna@itm.cnr.it
A. Figoli (Speaker), ITM-CNR c/o UNICAL, Italy
I. Spezzano, ITM-CNR, Italy
E. Drioli, ITM-CNR, Italy
Microcapsules have found numerous applications in various fields, such as
pharmaceutical, chemical, textile, biomedical, environmental, petroleum and
pesticide industries, and so on [1,2]. In particular, in the field of catalysis, when
encapsulating a catalyst or enzyme, a potentially high interfacial specific area is
created and the recovery of the catalyst is facilitated. The selective sorption
through the membrane can further increase catalytic performances. In this study,
we report on the preparation, characterization and use of new catalytic polymeric
microcapsules for application in fine chemistry. The catalyst, ammonium
molybdate tetrahydrate, was entrapped inside PVDF polymeric microcapsules
during their preparation. Common techniques for fabricating hollow
microcapsules with dense or porous membranes include interfacial
polymerization, in situ polymerization [3-5], and phase inversion [6-8]. In
particular, using phase inversion method, microcapsule membranes based on
cellulose acetate (CA), ethylcellulose (EC) [9,10], polyethersulphone (PES) [11]
and PEEKWC [12] characterized by pore microstructure both straight and packed
throughout the whole membrane thickness were prepared. These morphological
properties were obtained by using additives in the polymeric solutions as LiCl,
PVP and PEG400 or acetone, alcohol, glycerin, or TEC in various ratio, that are
responsible for an increase of demixing rate and for a more porous structure. In
this communication, we will report on new PVDF catalytic microcapsules
prepared by means of phase inversion induced by non-solvent without use of
additives in the polymeric solutions to prevent catalyst deactivation. The
developed catalytic microcapsules are featured with a reservoir-type porous
microcapsule membrane structure and with numerous straight microchannels
across the membrane. The hollow structure provided large space for
immobilizing the catalyst inside the proposed microcapsule, and the straight
microchannel structure across the membrane significantly reduced the mass
transfer resistance [13]. The chemical-physical analysis of the new PVDF
catalytic microcapsules was carried out by means of SEM, EDX, IR, DSC and
XRD techniques. Catalytic activity of the PVDF catalytic microcapsules has been
evaluated in the oxidation of aromatic alcohols to corresponding aldehydes in
solvent free conditions. The polymeric microcapsules “keep in contact” the two
phases: the organic phase, containing the substrate and the product, and the
aqueous phase with the oxidant, H2O2. In this way, every microcapsule works as
a catalytic membrane reactor with both the catalytic and contactor functions.

References
[1] S. Benita, Microencapsulation: Methods and Industrial Applications, Marcel Dekker, New York,
1996.
[2] A. Kondo, Microcapsule Processing and Technology, Marcel Dekker, New York, 1979.
[3] L.-Y. Chu, S.-H. Park, T. Yamaguchi, S. Nakao, Langmuir 18 (2002) 1856.
[4] Suryanarayana, P.S. Sai Prasad, Catal. Commun. 7 (2006) 245.
[5] L. Yuan, G.Z. Liang, J.Q. Xie, L. Li, J. Guo, J. Mater. Sci 42 (2007) 4390.
[6] C.Y. Wang, H.O. Ho, L.H. Lin, Y.K. Lin, M.T. Sheu, Int. J. Pharm. 297 (2005) 89.
[7] A.G. Thombrea, J.R. Cardinal, A.R. DeNoto, S.M. Herbig, K.L. Smith, J. Control. Release 57
(1999) 55.
[8] G.J. Wang, L.Y. Chu, M.Y. Zhou, W.M. Chen, J. Membr. Sci. 284 (2006) 301.
[9] C.Y. Wang, H.O. Ho, L.H. Lin, Y.K. Lin, M.T. Sheu, Int. J. Pharm. 297 (2005) 89.
[10] A.G. Thombrea, J.R. Cardinal, A.R. DeNoto, S.M. Herbig, K.L. Smith, J. Control. Release 57
(1999) 55.
[11] G.J. Wang, L.Y. Chu, M.Y. Zhou, W.M. Chen, J. Membr. Sci. 284 (2006) 301.
[12] A.Figoli, G. De Luca, E. Longavita, E.Drioli, Sep. Sci. Technol.42 (2007) 2809.
[13] M.G. Buonomenna, A.Figoli, I. Spezzano, M. Davoli, E.Drioli, Applied Catalysis B:
Environmental 80 (2008) 185.

Asymmetric Polymeric Membrane Formation – 4
Tuesday July 15, 10:30 AM-11:00 AM, Wai’anae
The Impact of Solvent on the Microstructure of Integrally Skinned
Polyimide Nanofiltration Membranes before and after casting
D. Patterson (Speaker), Department of Chemical and Materials Engineering, The University of
Auckland, Auckland, New Zealand, darrell.patterson@auckland.ac.nz
S. Costello, Department of Chemical and Materials Engineering, The University of Auckland,
Auckland, New, Zealand
A. Havill, Department of Chemical and Materials Engineering, The University of Auckland,
Auckland, New, Zealand
Y. See-Toh, Department of Chemical Engineering and Chemical Technology, Imperial College,
London, UK
A. Livingston, Department of Chemical Engineering and Chemical Technology, Imperial College,
London, UK
A. Turner, School of Biological Sciences, The University of Auckland, Auckland, New Zealand
Due to their excellent resistance to a range of solvents, integrally skinned
polyimide membranes have been used as nanofiltration membranes to achieve
selective separations in a range of industrial and lab-scale chemical operations.
These include: homogeneous catalyst recycle, petrochemical dewaxing, solvent
exchange and chiral resolutions. However, despite the widening scope of use of
these membranes, there is still little understanding of how different casting and
filtration solvents affect their microstructure and how this impacts on membrane
separation performance. Part of this question arises because the microstructure
of nanofiltration membranes are typically characterised using dry membranes.
However, during a filtration, the structure of the membrane changes when in
contact with the solvent to be used, especially due to swelling. Therefore,
although imaging a membrane outside of a solvent (dry) may give an indication
of the initial microstructure prior to filtration, in order to understand how the
microstructure affects the transport mechanism and thus membrane separation
performance when it is being used, the membrane must be imaged when in
solvent (wet).
As a first step towards answering the above question, integrally skinned
nanofiltration membranes were fabricated by phase inversion using Lenzing P84
polyimide. A range of P84 membranes were fabricated, varying three formation
parameters: doping solution solvents, evaporation time and post heat treatment
temperature. The doping solvents used were n-methyl-2-pyrrolidone, dimethyl
sulfoxide, dimethylformamide, 1,4-dioxane and acetone. The evaporation times
varied were 10 seconds, 30 seconds and 60 seconds. The heat treatment
temperatures were 100°C, 150°C and 200°C. The effect these parameters had
on the membrane microstructure, filtration performance and mechanical strength
were then characterised. The microstructure of these membranes, dry and in

solvent, were investigated (where appropriate) by scanning electron microscope
(SEM), transmission electron microscope (TEM) and environmental scanning
electron microscope (ESEM). The membrane performance was determined by
measuring the flux from a dead-end filtration cell using ethanol as the filtration
solvent. The mechanical strength was determined from a tensile test.
SEM and TEM imaging of dry membranes revealed that this type of polyimide
membrane has three microstructurally distinct polyimide layers, not the two
indicated in prior literature. The top skin layer consists of closely packed polymer
nodules. The middle layer is a microstructure transition region where the
microstructure changes with the densely packed polymer nodules slowly
becoming more interconnected and less densely packed further from the
membrane surface. The bottom layer is a uniformly porous support layer
consisting of an interconnected polyimide network. Furthermore, TEM images
reveal nano-sized pores in the polyimide structure, which indicate that the
transport mechanism for these membranes is probably neither only solutiondiffusion
nor only pore-flow.
The different casting solvents used changed the microstructural characteristics of
these three layers. In particular, it was found that acetone had the effect of
increasing the density of the membrane skin layer and increasing the thickness
of the membrane skin layer by 50nm. This was attributed to the fact that acetone
is a more volatile solvent than the other solvents used. Increasing the
evaporation time from 10 seconds to 30 seconds and 60 seconds increased the
density of the skin layer also, leading to smaller nano-sized pores in the
membrane skin layer. An increase in heat treatment temperature also increased
the skin layer density. This could be attributed to the heat treatment allowing the
polymer chains to align in a more thermodynamically stable arrangement.
ESEM imaging showed that when saturated in ethanol, the microstructure of the
membranes changes: it is wispy and thus quite different to the more solid
polymer nodules and interconnected polymer network observed in the dry
membranes. Thus, transport and separation mechanisms based on the structure
of the dry membranes may not be completely accurate. Membranes cast with
acetone as a solvent swelled the most in ethanol. The 200°C heat treated
membrane did not swell excessively, perhaps indicating that the
thermodynamically stable arrangement of polymer chains impeded solvent entry.
Overall, these results indicate that the current theory used to describe polyimide
membrane mass transfer and separation performance must be rethought.
Furthermore, as currently there is no definitive definition for the thickness of the
skin layer of these membranes, based on the dry morphology observed here, it is
proposed that the dry skin layer thickness be defined as the length perpendicular
from the top surface of the membrane to the point where these pores become
interconnected.

Asymmetric Polymeric Membrane Formation – 5
Tuesday July 15, 11:00 AM-11:30 AM, Wai’anae
Nanofiltration Membranes for Polar Aprotic Solvents
F. Lim (Speaker), Membrane Extraction Technology Ltd., Fulham, London, UK,
fui@membrane-extraction-technology.com
Y. See-Toh, Imperial College London, London, UK
I. Sereewatthanawut, Membrane Extraction Technology Ltd., Fulham, London, UK
A. Boam, Membrane Extraction Technology Ltd., Fulham, London, UK
A. Livingston, Imperial College of London, Membrane Extraction Technology Ltd., Fulham,
London, UK
This paper will present new work undertaken as a collaboration between Imperial
College and Membrane Extraction Technology Ltd. This has resulted in the
development of the first reported polymeric nanofiltration membranes which are
stable in aggressive solvents such as methylene chloride (DCM), tetrahydrofuran
(THF), dimethyl formamide (DMF) and n-methyl pyrrolidone (NMP) [1]. These
membranes have been further developed into spiral wound elements, which are
also stable in these aggressive liquids.
The recent advent of commercial Organic Solvent Nanofiltration (OSN)
membranes has opened up a wide range of potential applications. OSN allows
economic and efficient separation of molecules in the range 200 - 1000 g mol -1
and can be employed in many sectors including the petrochemical, food and
beverage, biotechnology and pharmaceutical industries. The majority of OSN
membranes are either composites comprising a polydimethylsiloxane (PDMS)
separating layer on a polyacrylonitrile (PAN) support, or integrally skinned
asymmetric membranes made of polyimides (PI). Although PAN shows good
chemical resistance in many solvents, the PDMS separating layer swells
appreciably in many solvents resulting in limited solvent stability. Commercial PI
OSN membranes have been shown to give good performances in several
organic solvents (e.g. toluene, methanol, ethyl acetate etc. [2]) but are however
unstable in some amines and have generally poor stability and performance in
polar aprotic solvents such as DCM, THF, DMF and NMP, in which most of these
membranes are soluble. Inorganic membranes have been developed which offer
good stability in organic solvents, but they are often more expensive and difficult
to handle. To date, there are few reports of OSN in aggressive solvents such as
THF, DMF and NMP.
Crosslinking of polymeric membranes has been shown to increase their chemical
and thermal stability [3]. However, this is often at the expense of a decrease in
permeability. Several crosslinking strategies for polyimide (PI) have been
proposed including the use of radical initiated (thermally or via the use of UV)
and chemical crosslinks [4]. Post casting modification of polymer films provides

ease of manipulation as this allows the desired morphology of the membranes to
be attained via phase inversion followed by further crosslinking on the pre-formed
membrane to maintain this morphology in aggressive conditions. In OSN, where
membrane stability of the under-layer is as critical as the separating layer,
effective and uniform crosslinking of the whole membrane must be achieved.
This suggests the use of radical initiated methods which would have difficulty of
achieving crosslinking throughout the whole membrane. Instead, we chose
chemical crosslinking as the preferred method to achieve uniform crosslinking
throughout the membranes. Several chemical crosslinking strategies for use in PI
membranes have been proposed and include the use of di/poly-amines in a ring
opening reaction [4] and the inclusion of condensable crosslinking sites during
polymer preparation.
A range of solvent stable organic solvent nanofiltration membranes were
prepared through the chemical crosslinking of preformed integrally skinned PI
membranes using aliphatic diamines. The resultant membranes had a spongy
structure and were stable in many organic solvents including toluene, methanol,
acetone, DCM, THF, DMF and NMP. The further development of the membrane
into spiral wound elements was undertaken, involving scaling up the membrane
production process and then developing spiral wound elements that are stable in
aggressive solvents. Extended periods of both flat-sheet and spiral-wound
element testing in DMF and THF for e120 h showed that the membranes and
elements have a stable flux and good separation performance, with DMF
permeability in the range of 1-8 L m -2 h -1 bar -1 and Molecular Weight Cut-Off
(MWCO) between 250-1000 g mol -1 . However possible re- imidization and loss of
crosslinking at elevated temperatures limits their range of application to
temperatures

Asymmetric Polymeric Membrane Formation – 6
Tuesday July 15, 11:30 AM-12:00 PM, Wai’anae
Phase Separation Microfabrication
M. Bikel (Speaker), Membrane Technology Group - University of Twente, The Netherlands
R. Lammertink, Membrane Technology Group - University of Twente, The Netherlands,
r.g.h.lammertink@utwente.nl
M. Wessling, Membrane Technology Group - University of Twente, The Netherlands
Phase Separation Micro Fabrication (PSuF) entails the phase separation of
polymer solutions that are cast onto structured supports which serve as molds. In
this way, microstructured membranes can be obtained without the use of
cleanroom technology. The replication of the pattern on the mold makes these
membranes asymmetric from a structural point of view, as one side is flat and the
other one is structured. The structural asymmetry can be obtained independently
from the morphological one. Here, we focus on the effects of this pattern and
other variables on the final structural and morphological asymmetry of
membranes obtained from a PES/PVP/NMP/water system.
Many kinds of features can be replicated down to the micron range, even with
high aspect ratios. These features can be indentations into the membrane
surface as well as protrusions of polymeric material emerging from the patterned
surface. With small adaptations, this process is extendable to the structuring of
hollow fibers, whether be it for structuring the outside of the fiber, its lumen or
both.
By means of introducing different features on the molds, the phase separation
mechanism could be studied and changed. The presence of a small amount of
features allowed us to study the process by observing the effect of the final
morphology on the replication of the features. Several types of distortion were
observed when the polymeric matrix shrunk away from the mold walls. Generally,
indentations on the membranes were larger than the features and polymeric
protrusions, smaller.
An increase in the number or total area of the features decreased the
deformation of the replicas to a minimum. In this case, the pattern has an effect
on the morphology. This has to do with the lack of access to the space between
the mold and the polymer solution, implying that less non-solvent comes directly
in contact with the features. Instead, the whole phase separation takes place
through the diffusion of the non-solvent through the polymer solution, yielding
membranes with a different morphology. To further analyze this, we used a third
mold with deeper features. In this case, local thinning of the film above the
features was observed. This can be related to pulling forces during shrinkage.

Horizontal shrinkage does not have an effect as high as that of vertical
shrinkage. This is due to the different interaction of the layers in each direction,
which leads to different levels of accumulation of these effects. As a rule of
thumb, the relative vertical shrinkage is uniform, whereas the lateral one is not.
This happens because when shrinking, each layer is impeded by the layers
directly above it which have already solidified.
Coagulation baths with increasing NMP to water ratios were tried, finding
minimum values for macrovoid suppression. Their effect on the solidification of
the membrane was also assessed. The inclusion of a vapor bath before
immersion precipitation was studied for creating a skin that slowed down the
exchange of solvent and non-solvent. For systems where a critical casting
thickness can be found, it has been seen that macrovoids tend to accumulate
inside the features, where the membrane is thicker.
Tunability of the porosity of the membrane is an interesting feature since the
inner structure of the membrane is also of high importance for the different
applications. Therefore, a methodical study of the PES/PVP/NMP/water system
was carried out. Variations in the compositions of both the casting solution and
the coagulation bath were tested for influence on the thickness, extent of
shrinkage and porosity of the final membrane. This has shown that the final
morphology of the membrane can be modified, including the appearance of the
skin layer.
The study of PSuF has clarified several aspects of the phase separation process.
The tests we have performed have provided us with tools to foresee and work
around potential challenges when patterning membranes for future applications.

Asymmetric Polymeric Membrane Formation – 7
Tuesday July 15, 12:00 PM-12:30 PM, Wai’anae
In-Line and In-Situ Determination of Non-Solvent, Solvent and Polymer
Composition within a Film-Forming System prior to Phase Separation
during VIPS
W. Werapun, Université Montpellier, Montpellier, France
D. Bouyer (Speaker), Université Montpellier, Montpellier, France, denis.bouyer@univ-montp2.fr
C. Pochat-Bohatier, Université Montpellier, Montpellier, France
A. Deratani, CNRS, Montpellier, France
C. Dupuy, Université Montpellier, Montpellier, France
Two processes can be used to promote the transfer of the non-solvent into the
polymer solution: immersion wet casting into a coagulation bath (Non-Solvent
Induced Phase Separation), and exposure to a non-solvent vapor atmosphere,
usually humid air (VIPS). The main interest for using the VIPS process consists
of reduction in mass transfer kinetics. The obtained membranes are
characterized by a more homogeneous morphology. Furthermore, there has
been a growing interest in VIPS process because when it is applied prior to the
immersion in a coagulation bath it could prevent the formation of the macrovoids
generally obtained by a direct immersion. VIPS has been studied mainly during
the last decade, through experimental works and also modeling approaches.
Recently, different mathematical descriptions were developed to describe the
mass transfer kinetics related to VIPS. Nevertheless, the experimental validation
of such models appears quite difficult, and the models have not been validated
by experimental results, but with global gravimetric measurements. The main
objective of this work consists in using the Near Infra-Red Spectroscopy (NIRS)
for following in-line, i.e. during the VIPS process, and in-situ, i.e. directly in the
polymer solution, the concentration evolution of the three components. The
polymer solution was placed into a rectangular cuvette and then exposed to nonsolvent
vapor. The solution composition was followed at different depths using
NIRS during the VIPS under monitored RH, temperature and hydrodynamics
conditions.
The experiments were conducted using different polymer/solvent systems and
the water was the non-solvent in each case. The polymers used in this study
were PEI (poly(bisphenol A-co-4- nitrophtalic anhydride-co-1,3phenylenediamine,
Sigma Aldrich) and Poly(EtherSulfone) (PES) (Ultrason
E6020P, BASF). Each polymer was dissolved in two different solvents:
dimethylacetamide (DMAc) and (NMP) for PEI and dimethylformamide (DMF)
and NMP for PES. The composition of each polymer/solvent systems was initially
12/88 in mass fraction (wt-%).

Absorption of water was determined both by gravimetric and by NIRS
measurements. Experiments were carried out in a static mode, i.e. without any
air circulation. The open cell was placed in a closed vessel at 40°C with an
atmosphere with fixed RH controlled by a saturated salt solution (NaCl for 75%
RH).
Fourier transform NIRS in a transmission mode was used to measure the
transfer of water within an elementary volume of polymer solution. NIR spectra
were recorded each 30 min using a Perkin Elmer Spectrum One NTS equipped
with a tungsten- halogen lamp with a quartz envelope and a deuterated triglycine
sulfate (DTGS) detector. The instrument was controlled via the software
Spectrum v3.02 from Perkin Elmer, which permits acquisition and processing of
spectra. Four scans were averaged at a 4 cm -1 resolution in the range of 2600-
10000 cm -1 . The size of the laser spot was set equal to 2.5 mm diameter, and the
analyses were performed at 7 mm under the air/solution interface. Gravimetric
measurements were used as a reference method to evaluate the NIR method.
The NIR measurements performed on different systems during VIPS exhibit the
following points:
The composition of the solution, in terms of polymer, solvent and non-solvent
local concentration has been successfully followed in- line and in-situ. Before the
phase separation takes place, whatever the system the evolution curves
representing the local concentration of water gradually increase whereas the
solvent concentration decreases and the concentration of the polymer remains
almost constant.
The concentration of the three components can be followed not only before but
also after the phase separation has occurred at the top surface of the polymer
solution, since the points of measurement are placed under the top surface. This
aspect is of special interest for studying the mass transport phenomena at
different stages of the membrane formation. Nevertheless, as soon as the
solution phase separates at the point of measurement, the NIR analysis is no
more possible.
The time needed for reaching the phase separation at the top surface of the
polymer solution can be easily determined from the experimental curves. Indeed,
demixing leads to a drastic change in the mass transport phenomena due to the
formation of a polymer precipitated surface layer. The penetration rate of nonsolvent
is also reduced resulting in a change of slope in the absorption curves,
the critical point indicating complete surface phase separation.
Using three points of measurements within the polymer solution, concentration
profiles can be plotted during time. These results could help validating numerical
mass transfer model using the VIPS process. In addition, the method allows the
apparent diffusion coefficients to be determined.

Oral Presentation
Abstracts
Afternoon Session
Tuesday, July 15, 2008

Gas Separation II – 1 – Keynote
Tuesday July 15, 2:15 PM-3:00 PM, Kaua’i
Highly Gas-Permeable Substituted Polyacetylenes: Recent Advances
T. Masuda (Speaker), Kyoto University, Kyoto, Japan - masuda@adv.polym.kyoto-u.ac.jp
Polyacetylenes having various substituents (substituted polyacetylenes) can be
synthesized by use of metathesis catalysts (W, Mo, Ta, and Nb) [1-3]. Among
those polymers, poly[1-(trimethylsilyl)-1-propyne] [poly(TMSP)] exhibits higher
gas permeability than any known synthetic polymers. Its oxygen permeability
coefficient (Po2) varies depending on preparation and measuring conditions, but
its typical value is ca. 10,000 barrers at 25 °C [4,5]. In-depth reviews of
poly(TMSP) are available [1,3,5].
Apart from poly(TMSP), pretty many substituted polyacetylenes are now known
to be more gas-permeable than poly(dimethylsiloxane), the most permeable
commercial membrane material. One of them is poly[1-phenyl-2-(ptrimethylsilylphenyl)acetylene]
[poly(p-Me3Si-DPA)] [6], whose oxygen
permeability is around 1,500 barrers.
More, recently, the polymerization of 1-(1,1,3,3-tetramethylindan-5-yl)-2phenylacetylene
(1), 1-(1,1,2,2,3,3-hexamethylindan-5-yl)-2-phenylacetylene (2),
and 1-(1,1,4,4-tetramethyl-1,2,3,4-tetrahydronaphthalene-6-yl)-2-phenylacetylene
(3) was carried out with TaCl5-n-Bu4Sn catalyst [7]. All the monomers gave high
molecular weight polymers (Mw ~1,000,000) in good yields. The formed
polymers were soluble in common solvents including cyclohexane, toluene,
CHCl3, and THF. Free-standing membranes of poly(1) -poly(3) were fabricated
by casting toluene solution. According to thermogravimetric analysis (TGA)
measured in air, these polymers exhibited excellent thermal stability (T0 ~400
°C). The membranes of these polymers showed extremely high gas permeability
(Po2 4,000-14,000 barrers); especially the Po2 value of poly(1) reached 14,000
barrers. The PO2/PN2 ratios were in a range of 1.24-1.44.
Derivatives 4-6 of monomer 1 that have a para-halo-substituent [1-(1,1,3,3tetramethylindan-5-yl)-2-(4-X-phenyl)acetylenes;
1: X = H, 4: X = F, 5: X = Cl, 6:
X = Br] were polymerized with TaCl5-n-Bu4Sn catalyst to give high molecular
weight polymers (Mw ~1,000,0000) in moderate yields [8]. Poly(4) -poly(6) were
soluble in common organic solvents, and gave free-standing membranes by
solution casting. These polymers possessed excellent thermal stability according
to TGA (T0 ~410 °C). The membranes of these polymers displayed high gas
permeability (Po2 5,000-17,900 barrers). In particular, the oxygen permeability of

poly(4) reached up to 17,900 barrers, which is even larger than that of the so far
most permeable PTMSP.
Poly(diphenylacetylene) [poly(DPA)] membrane was successfully prepared by
desilylation of poly(p-Me3Si-DPA) membrane catalyzed by trifluoroacetic acid.
This is quite interesting because poly(DPA) membrane cannot be fabricated
directly because of the insolubility of the polymer [9,10]. The membrane of
poly(DPA) is fairly permeable to oxygen (Po2 = ca. 1,000 barrers) in spite of the
absence of any spherical substituents.
It is impossible to directly obtain substituted polyacetylenes having polar groups
such as hydroxy groups because of catalyst deactivation during polymerization,
but this has been achieved by an indirect method. Namely, poly[1-p-(tbutyldimethylsiloxyphenyl)-2-phenylacetylene]
was at first synthesized, and then
its membrane was treated with CF3COOH/H2O to provide poly[1-(phydroxyphenyl)-2-phenylacetylene]
membrane. This oxygen-containing polymer
also shows fairly high oxygen permeability (250 barrers), and more interestingly it
shows large CO2 permselectivity (PCO2 110 barrers; PCO2/PN2 46) [11].
1. T. Masuda and K. Nagai, in ‘Materials Science of Membranes for Gas and Vapor Separation’,
Yu. Yampolskii, I. Pinnau, B. D. Freeman, Eds., Wiley, Chichester, Chapter 8 (2006).
2. T. Masuda, J. Polym. Sci., Part A: Polym. Chem., 45, 165 (2007).
3. K. Nagai, Y.-M. Lee, and T. Masuda, in ‘Macromolecular Engineering: Precise Synthesis,
Materials Properties, Applications’, K. Matyjaszewski, Y. Gnanou, and L. Leibler, Eds., Wiley-
VCH, Weinheim, Vol. 4, Chapter 12 (2007).
4. T. Masuda, E. Isobe, T. Higashimura, and K. Takada, J. Am. Chem. Soc., 105, 7473 (1983).
5. K. Nagai, T. Masuda, T. Nakagawa, B. D. Freeman, and I. Pinnau, Prog. Polym. Sci., 26, 721
(2001).
6. K. Tsuchihara, T. Masuda, and T. Higashimura, J. Am. Chem. Soc., 113, 8548 (1991).
7. Y. Hu, M. Shiotsuki, F. Sanda, and T. Masuda, Chem. Commun., 4269 (2007).
8. Y. Hu, M. Shiotsuki, F. Sanda, B. D. Freeman, and T. Masuda, J. Am. Chem. Soc., submitted.
9. M. Teraguchi and T. Masuda, Macromolecules, 35, 1149 (2002).
10. T. Sakaguchi, K. Yumoto, Y. Shida, M. Shiotsuki, F. Sanda, and T. Masuda, J. Polym. Sci,
Part A Polym. Chem., 44, 5028 (2006).
11. Y. Shida, T. Sakaguchi, M. Shiotsuki, and T. Masuda, Macromolecules, 38, 4096 (2005).

Gas Separation II – 2
Tuesday July 15, 3:00 PM-3:30 PM, Kaua’i
Modeling Molecular-Scale Gas Separation
A. Thornton (Speaker), CSIRO, Clayton, Australia - aaron.thornton@csiro.au
T. Hilder, University of Wollongong, Wollongong, Australia - tah429@uow.edu.au
A. Hill, CSIRO, Clayton, Australia - anita.hill@csiro.au
J. Hill, University of Wollongong, Wollongong, Australia- jhill@uow.edu.au
The ability to separate gas mixtures is a vital skill in a world that emits excess
carbon dioxide into the atmosphere, needs purified water, wants artificial kidneys,
requires hydrogen for energy alternatives and demands many more
improvements and developments. Gas separation membranes are composed of
nano- sized pores which may be designed to separate a gas mixture. In this
paper we employ mathematical modeling using the Lennard-Jones interactions
between the gas molecule and the pore wall to determine an ideal pore radius in
terms of efficiently separating molecules. The method adopted is closely related
to carbon nanotube forest-based membranes and can also be used to explain
the performance of polymer membranes such as thermally rearranged (TR), poly
(trimethylsilylpropyne) (PTMSP) and conventional dense polymers. All the
nanotubes in a carbon nanotube forest have the same radius enabling a more
deterministic separation outcome. While polymers on the other hand have a
distribution of pore sizes and therefore have an inbuilt capacity to perform
various separations. This investigation reveals the acceptance radius and the
radius of pores which provide a maximum suction energy for gases He, H2, CO2,
O2, N2 and CH4. By assuming there are three different separation mechanisms
namely blockage, suction and freeway, we may qualitatively explain the
separation outcomes of TR, PTMSP and conventional polymer membranes.

Gas Separation II – 3
Tuesday July 15, 3:30 PM-4:00 PM, Kaua’i
Physical Aging in Thin Glassy Polymer Films: A Variable Energy Positron
Annihilation Lifetime Spectroscopy Study
B. Rowe (Speaker), The University of Texas at Austin, Austin, Texas, USA -
rowe@che.utexas.edu
A. Hill, CSIRO, Clayton, Australia - Anita.Hill@csiro.au
S. Pas, CSIRO, Clayton, Australia - Steven.Pas@csiro.au
R. Suzuki, AIST, Ibaraki, Japan - r-suzuki@aist.go.jp
B. Freeman, The University of Texas at Austin, Austin, Texas, USA - freeman@che.utexas.edu
D. Paul, The University of Texas at Austin, Austin, Texas, USA - drp@che.utexas.edu
Most gas separation membranes are formed from glassy polymers because of
their exceptional permeability-selectivity properties. However, glassy polymers
are non-equilibrium materials that will spontaneously, but usually slowly, change
over time towards an equilibrium state by a process known as physical aging.
The physical aging rate becomes orders of magnitude more rapid if the thickness
of the film is decreased below about one micron. 1 This phenomenon is an
intrinsically fascinating scientific issue, and understanding physical aging has
broad impacts in several technologies including the gas separation industry.
New insight regarding the mechanisms behind physical aging can be gained by
studying the free volume profile in polymer films during the aging process.
Positron annihilation lifetime spectroscopy (PALS) is a powerful tool capable of
determining the size and concentration of free volume sites in polymer systems
by measuring the lifetime of injected positrons. 2 The coupling of PALS with a
variable mono-energetic positron beam source has resulted in a relatively new
technique which allows the energy of the incident positron beam, and, therefore,
penetration depth, to be controlled. 3 This research will help provide a better
fundamental scientific understanding of why aging rate depends on thickness,
particularly at the molecular level.
The effect of physical aging on free volume and its distribution across the
thickness of thin (l ~ 450 nm) polysulfone (PSF) films was investigated using
variable energy PALS. This study is the first reported physical aging study using
variable energy PALS. Previous work has typically been completed using films
without well defined thermal histories. The concentration and average size of free
volume elements were measured at 18 different energies, probing across the
entire thickness of each sample. The data show the average free volume
element size is reduced near the film surface (up to 50 nm deep) as compared to
the interior of the film. Reduced free volume size near the surface indicates that
the near-surface layer has aged more rapidly than the film interior. The overall
free volume size decreases with aging, with no significant changes in their

concentration. These results are consistent with accelerated physical aging in
thin films tracked by gas permeability measurements. The influence of high
pressure CO2 on the film free volume properties was also examined.
(1)Huang, Y.; Paul, D. R. Polymer 2004, 45, 8377- 8393.
(2)Mallon, P. E. In Positron & Positronium Chemistry; Jean, Y. C.; Mallon, P. E.; Schrader, D. M.,
Eds.: World Scientific, New Jersey, 2003; pp 253-280.
(3)Jean, Y. C.; Cao, H.; Dai, G. H.; Suzuki, R.; Ohdaira, T.; Kobayashi, Y.; Hirata, K. Applied
Surface Science 1997, 116, 251-255.

Gas Separation II – 4
Tuesday July 15, 4:00 PM-4:30 PM, Kaua’i
Gas Permeation Parameters and Other Physicochemical Properties of a
Polymer With Intrinsic Microporosity (PIM-1)
P. Budd (Speaker), University of Manchester, United Kingdom - Peter.Budd@manchester.ac.uk
N. McKeown, Cardiff University, United Kingdom - mckeownnb@Cardiff.ac.uk
B. Ghanem, Cardiff University, United Kingdom - mckeownnb@Cardiff.ac.uk
K. Msayib, Cardiff University, United Kingdom - mckeownnb@Cardiff.ac.uk
D. Fritsch, GKSS, Germany - detlev.fritsch@gkss.de
L. Starannikova, Institute of Petrochemical Synthesis, Russia - Luda@ips.ac.ru
N. Belov, Institute of Petrochemical Synthesis, Russia - Belovna@gmail.com
O. Sanfirova, Institute of Petrochemical Synthesis, Russia - Belobna@gmail.ru
Y. Yampolskii, Institute of Petrochemical Synthesis, Russia - Yampol@ips.ac.ru
V. Shantarovich, Institute of Chemical Physics, Russia - shant@chph.ras.ru
Polymers with intrinsic microporosity (PIMs) and PIM- polyimides form a new
class of advanced materials for membrane gas separation. They are
distinguished by several excellent properties: a good combination of permeability
and permselectivity (the data points are above Robeson upper bounds for
various gas pairs: O2/N2, CO2/CH4, CO2/N2), relatively high gas permeability (e.g.
P(O2)=1600 Barrer), the largest reported gas and vapor solubility coefficients,
large free volume, unusual possibility to control their transport parameters by film
casting protocol, good film forming properties. In the presentation a survey of
different transport and thermodynamic parameters in these polymers will be
disclosed and discussed: relative contribution of solubility and diffusion
coefficients to permeability, temperature dependence of the permeability
coefficients, the effects of chloroform, methanol and water on the observed
permeability, the results of the study of sorption thermodynamics in these
polymers using the inverse gas chromatographic method, free volume study by
means of positron annihilation lifetime spectroscopy.

Gas Separation II – 5
Tuesday July 15, 4:30 PM-5:00 PM, Kaua’i
Addition-Type Polynorbornene with Si(CH3)3 Side Groups: Detailed Study
of Gas Permeation and Thermodynamic Properties
L. Starannikova, Institute of Petrochemical Synthesis, Russia - Luda@ips.ac.ru
M. Pilipenko, Institute of Petrochemical Synthesis, Russia - Luda@ips.ac.ru
N. Belov, Institute of Petrochemical Synthesis, Russia - belovna@gmail.ru
Y. Yampolskii (Speaker), Institute of Petrochemical Synthesis, Russia - Yampol@ips.ac.ru
M. Gringolts, Institute of Petrochemical Synthesis, Russia - gringol@ips.ac.ru
E. Finkelshtein, Institute of Petrochemical Synthesis, Russia - fin@ips.ac.ru
Polymerization of norbornene bearing Si(CH3)3 groups in the 5 position with the
opening of double bonds results in creation of a novel high free volume, highly
permeable polymer addition type poly(trimethylsilyl norbornene) (PTMSN). By
accurate selection of the ratios catalyst/co-catalyst and monomer/catalyst the
samples with increased molecular mass (about 400,000) and good film forming
properties can be obtained. Transport parameters of PTMSN were measured
using the gas chromatographic and mass spectrometric methods for different
gases (H2, He, O2, N2, CO2, CH4, C2H6, C3H8, n-C4H10). Temperature
dependence of the permeability coefficients (P) indicated that low activation
energies of permeation (EP) and diffusion (ED) are characteristic for PTMSN. In
some cases (CO2, C2H6) negative EP values were observed. Thermodynamics of
vapor sorption in this polymer was studied using the inverse gas chromatography
method. It was shown that PTMSN is characterized by very large solubility
coefficients S similar to those of poly(trimethylsilyl propyne) (PTMSP). The
comparison of the P, D, and S values of these highly permeable polymers
showed that the greater permeability of PTMSP is determined by the larger D
values. Application of different approaches for the determination of the size of
microcavities in PTMSN indicated that this polymer is characterized by large size
of microcavity (800- 1200 Angstroms 3 ). Possible applications of this novel
polymer as a material for gas separation membranes will be considered.

Gas Separation II – 6
Tuesday July 15, 5:00 PM-5:30 PM, Kaua’i
Analysis of the Size Distribution of Local Free Volume in Hyflon® AD
Perfluoropolymer Gas Separation Membranes by Photochromic Probes
J. Jansen (Speaker), ITM-CNR, Rende (CS), Italy - jc.jansen@itm.cnr.it
E. Tocci, ITM-CNR, Rende (CS), Italy - e.tocci@itm.cnr.it
M. Macchione, Università della Calabria, Rende (CS), Italy - marmach@unical.it
L. De Lorenzo, ITM-CNR, Rende (CS), Italy - Ldelore@unical.it
M. Heuchel, GKSS Research Center, Teltow, Germany - matthias.heuchel@gkss.de
E. Drioli,ITM-CNR, Rende (CS), Italy - e.drioli@itm.cnr.it
This paper reports on the first successful application of the photochromic probe
technique for the evaluation of the free volume distribution (FVD) in the
amorphous glassy perfluorpolymer Hyflon® AD, a copolymer of 2,2,4- trifluoro-5trifluorometoxy-1,3-dioxole
and tetrafluoroethylene. Hyflon AD is highly
permeable to permanent gases, offering interesting perspectives for use in gas
separation membranes [1,2], especially because of its high thermal, chemical,
ageing and weather resistance and excellent inertness to most organic solvents.
As in other amorphous perfluoropolymers [3], the high gas permeability of Hyflon
is related to the high Fractional Free Volume (FFV), usually estimated by Bondi's
group contribution method [1,4-6]. Besides the total FFV, knowledge of its
distribution is important for the understanding of the transport properties of the
Hyflon membranes.
The aim of the present work is to use the photochromic probe method and
molecular dynamics (MD) simulations to determine the size distribution of local
free volume elements in Hyflon AD membranes and to correlate this to their
transport properties. Experimentally, photochromic probing is relatively simple
compared to other probing methods, like 129-Xe NMR spectroscopy and
Positron Annihilation Lifetime Spectroscopy (PALS). It is based on the principle
that photo-isomerizable molecules require a certain free volume to undergo
isomerisation when dispersed in the polymer matrix [7]. Using a series of probe
molecules with different size, spectrophotometric analysis of the degree of
isomerisation of each probe will yield the FVD.
In the case of perfluoropolymers a major technical difficulty is the sample
preparation, because the hydrocarbon probe molecules are usually insoluble in
the fluorinated solvent for the polymer and the polymer is insoluble in the solvent
for the probes. The main challenge of the present work is therefore to find a
suitable method to obtain a homogeneous dispersion of the dye molecules in
Hyflon AD films, to be subjected to subsequent spectrophotometric analysis. It

will be shown that homogeneous films could be obtained successfully by the
clever choice of mutually miscible fluorinated and non-fluorinated solvents.
Dense membranes, doped with a series of stilbene and azobenzene
photochromic probe molecules with different sizes, were thus prepared by
solution casting. The cis-trans isomerisation reaction was found to be completely
reversible and repeatable over numerous cycles when irradiating at 440 nm and
350 nm, respectively. The ratio of the degree of probe isomerisation at the
photostationary state in the solid polymer film, compared to that in a solution, is a
quantitative measure of the availability of free volume elements of the
corresponding size. A plot of this ratio as a function of the total isomerisation
volume of the probe molecules represents the FVD in the polymer. For two
different grades of Hyflon AD the experimentally determined FVD curve shows a
typical sigmoidal shape. The free volume size ranges from about 250 to 520 Å 3 in
Hyflon AD60X and from about 380 to 600 Å 3 in Hyflon AD80X. This is in
agreement with the higher gas permeability of Hyflon AD80X and with data
obtained by 129-Xe NMR spectroscopy and PALS. For the molecular dynamics
simulations, several independent atomistic bulk models were constructed. The
cavity size distribution was investigated by the particle insertion grid method [8].
It will be shown that the molecular modelling approach offers additional insight
into the free volume distribution compared to the experimental method, for
instance on the pore-interconnectivity.
References
1. R.S. Prabhakar, B.D. Freeman, I. Roman, Macromolecules, 37 (2004) 7688.
2. M. Macchione, J.C. Jansen, G. De Luca, E. Tocci, M. Longeri and E. Drioli, Polymer 48 (2007)
2619.
3. T.C. Merkel, I. Pinnau, R. Prabhakar, B.D. Freeman, Gas and Vapor transport properties of
perfluorpolymers, in: Yu. Yampolskii, I. Pinnau, B.D. Freeman, B.D. (Eds.), Materials Science of
Membranes for Gas and Vapor Separation, John Wiley & Sons, Chichester, 2006, pp.251-270.
4. V. Arcella, P. Colaianna, P. Maccone, A. Sanguineti, A. Gordano, G. Clarizia, E. Drioli, J.
Membr. Sci., 163 (1999) 203.
5. A. Bondi, J. Phys. Chem., 68 (1964) 441.
6. D.W. van Krevelen, Properties of Polymers, Elsevier, Amsterdam, 1976.
7. J.G Victor, J.M. Torkelson, Macromolecules 20 (1987) 2241.
8. D. Hoffmann, M. Heuchel, Yu. Yampolskii, V. Khotimskii, V. Shantarovich, Macromolecules, 35
(2002) 2129.

Drinking and Wastewater Applications II – 1 – Keynote
Tuesday July 15, 2:15 PM-3:00 PM, Maui
Analysis of RO Membrane Performance for Municipal Wastewater
Treatment
C. Bartels (Speaker), Hydranautics, Oceanside, California, USA - cbartels@aol.com
R. Franks, Hydranautics, Oceanside, California, USA - rfranks@hydranautics.com
P. Gourley, Hydranautics, Oceanside, California, USA - pgourley@hydranautics.com
Reclamation of wastewater has become a key means to augment local water
supplies in water stressed areas. Reclamation technology varies from
conventional filtration and UV- advanced oxidation processes to membrane
processes combined with UV and advanced oxidation processes. The selection
of the type of process depends on the planned use of the reclaimed water. For
indirect potable and industrial use, reverse osmosis (RO) has proven to be an
essential wastewater treatment technology. RO membranes are a physical
barrier that can ensure the significant reduction of dissolved inorganic solids,
total organic carbon (TOC), pharmaceuticals, endocrine disruptor compounds
(EDC), and other potentially harmful chemicals. The effective pore size of RO
membrane is on the order of a few angstroms or molecular weight cut-off values
on the order of 70 Daltons. As a result of the large number of plants using RO,
there is a growing amount of detailed information about the removal rates of
these compounds. Experience has shown that there are two critical parameters
which determine if the effectiveness of the membrane system - stable water
permeability and high rejection of contaminants. This paper will present analysis
of these factors from a variety of operating plants.
A typical advanced wastewater treatment plant may consist of activated sludge
treatment process, UF or MF membrane treatment, RO, and then UV and/or
advanced oxidation process. To achieve stable RO operation, the plant must be
operated within certain defined guidelines. Some of the key parameters include
operating at a flux of 10-12 gfd, a recovery of 75-80%, maintaining a chloramine
residual of 2-4 ppm, and utilization of RO membranes that show resistance to
organic fouling. When the system is operated well, it is possible to achieve 3 to 6
years of membrane life.
Even when systems are operated with careful attention to detail and within
recommended guidelines, it is still certain that their will be fouling. Due to the
broad variety and complexity of organic compounds, there are many compounds

which can adsorb on the surface of the membrane and reduce water flow. In a
typical RO plant, the normalized flow may drop by 15 to 25% in the first 60 days
of operation. In subsequent months, though, the decline may only be a few
percent. Cleaning can often recover a good portion of this loss. Detailed
operating data will be shown to examine this.
Although much progress has been made in controlling fouling, further research is
needed to understand and minimize this fouling. This paper will present some
detailed studies of membranes analyzed during the initial 30 days of operation
and characterize the organic material which leads to membrane fouling. It will
also evaluate common foulants found in commercial systems that can degrade
membrane performance.
High rejection of contaminants is the key to the use of RO processes. The
membrane which is selected must produce water that meets the water quality
targets. Depending on the use of the water, these targets can vary significantly.
For applications such as those in Singapore where the water is primarily used in
the wafer fabrication industry, it is critical to have low concentrations of organics,
as well as hardness and other salts. These very strict limits cannot be met by all
membranes. Typically, high rejection, low pressure composite polyamide
membranes, such as the Hydranautics ESPA2 membrane, have found much
use, since they give adequate rejection and operate at the lowest possible
pressure.
A recent survey of commercial plants shows that hardness ions are very highly
rejected, with rejections ranging from 99.88 to 99.99%. Similar rejection would be
seen for most ionized metals such as iron or manganese. Likewise the divalent,
negatively charged sulfate molecule has similar rejection rates. Monovalent ions
such, as sodium and chloride, have much lower rejection rates, in the range of 99
to 99.3%, and nitrate, which has a smaller hydrated radius, is the lowest rejected
anion, at about 94-97% rejection. These rejection rates are still much higher than
the values seen for brackish water treatment. Rejection of TOC is mostly in the
range of 99.6 to 99.7%. This is important for places such as Singapore, where
the permeate must contain less than 100 ppb of TOC. It is apparent, that these
membranes can easily achieve such values for a feed stream containing 10-15
ppm of TOC. From recent plant data, a detailed analysis of the rejection of
various compounds will be presented, and how these are meeting the recent
stringent demands of the end user.

Drinking and Wastewater Applications II – 2
Tuesday July 15, 3:00 PM-3:30 PM, Maui
Adsorption Behavior of Perfluorinated Compounds on Thin-film Composite
Membranes
Y. Kwon (Speaker), Stanford University, Palo Alto, California, USA - kwonyn@stanford.edu
K. Shih, University of Hong Kong, Hong Kong, China
C. Tang, Nanyang Technological University, Singapore
J. Leckie, Stanford University, Palo Alto, California, USA
Perfluorinated compounds (PFCs), emerging contaminants, are globally
distributed due to their persistent and bioaccumulative characteristics. The static
adsorption behavior of PFCs on BW30, NF90, and NF270 membranes and the
effect of the physico-chemical properties of the membranes and structure of
Perfluorinated compounds (PFCs) on interactions between them have been
thoroughly investigated. Two classes of PFCs were evaluated: perfluorosulfonic
acid (PFOS) and perfluoroalkanoic acid with 5, 7, 9, and 11 carbon atoms.
Adsorption of PFCs increased with increasing ionic strength, and decreasing pH
due to decreased electrostatic repulsion between membrane surfaces and PFCs.
The extent of PFOS adsorption on each membrane was higher than the extent of
comparable perfluorononanoic acid (PFNA) adsorption. This is attributed to the
easy migration of PFOS to the membrane surface from aqueous solution
compared with PFNA. The adsorption of PFCs on thin-film composite
membranes strongly depended on the material composing the active layer of the
membranes. NF270 membranes (a piperazine based membrane) showed higher
adsorption of PFOS and PFNA compounds compared with BW30 and NF90
membranes (polyamide based membranes). The BW30 polyamide membrane,
which has a coating layer with aliphatic carbon and hydroxyl groups, had less
interaction with PFOS and PFNA than the NF90 polyamide membrane.
Increased chain length of PFCs increased adsorption.
This research shows that the adsorption behavior of PFCs on commercial thinfilm
composite membranes depends on the electrostatic interaction of both
membranes and PFCs as a function of the applied solution chemistry, the active
layer material of the membranes, and the chain length/functional group of PFCs.

Drinking and Wastewater Applications II – 3
Tuesday July 15, 3:30 PM-4:00 PM, Maui
RO Reject Recovery - A Challenge Towards Sustainable Water Reclamation
B. Viswanath (Speaker), CAWT, Singapore Utilities International Pte Ltd, Singapore -
Bviswanath@cawt.sui.com.sg
G. Tao, CAWT, Singapore Utilities International Pte Ltd, Singapore - Ghtao@cawt.sui.com.sg
K. Kekre, CAWT, Singapore Utilities International Pte Ltd, Singapore - Kakekre@cawt.sui.com.sg
H. Ng, Env. Sci. & Eng. Division, National University of Singapore, Singapore
L. Lee, Env. Sci. & Eng. Division, National University of Singapore, Singapore -
eselly@nus.edu.sg
H. Seah, Public Utilities Board of Singapore, Singapore - Harry_SEAH@pub.gov.sg
Recovery of RO reject is an important part in sustaining the water reclamation
practices. RO reject generated from water reclamation contains high
concentration of both organic and inorganic compounds. Cost-effective
technologies for treatment of RO reject are still relatively unexplored. This study
aims to determine a feasible treatment process for removal of both organic and
inorganic compounds in RO reject generated from NEWater production.
NEWater is treated used water that has undergone stringent purification and
treatment processes using advanced dual-membrane (microfiltration and reverse
osmosis) and ultraviolet technologies. With the increasing demand of NEWater,
the amount of brine generated will also be increased. It is therefore envisaged
that there will be a need to treat the brine stream generated, at a later stage,
before it is being discharged it to sea.
The organics present in the RO reject are soluble microbial products (SMPs),
which comprises of mainly extra-cellular polymeric substances (EPS), such as
polysaccharides and proteins. For reject disposal in inland water bodies, these
organics have to be removed prior to discharge. Currently, there is little
knowledge on (i) the characteristics of SMPs in the RO reject, and ii) effective
technology for removal of the moderate to high concentration of organics present
in the reject (brine). Besides organics, inorganic compounds with total dissolved
solids (TDS) concentration typically higher than 2,000 ppm have to be removed
too prior to reject disposal. Cost-effective technologies for treatment of RO reject
are still unexplored. The reject generated from water reclamation contains both
moderate to high concentration of organics and inorganic compounds. The
reverse osmosis (RO) process has been a widely applied technology for water
reclamation of secondary effluent due to its affordable cost and reliability. High
quality permeate suitable for indirect potable or direct non-potable use after
disinfection is produced from RO process while another stream, RO reject, is
also generated simultaneously. The aim of this study is to determine the
feasibility of the combined BAC and CDI process for removal of both organic and
inorganic compounds in RO reject generated from NEWater production.

The integrated system comprises of a biological activated carbon (BAC) column
for organic removal, followed by capacitive deionization (CDI) process with and
without microfiltration/ultrafiltration as the pre-treatment step for the CDI process.
The biological activated carbon (BAC) process consists of both activated carbon
adsorption and biodegradation of organics by microorganisms. The advantages
of combining adsorption and biodegradation in BAC are: activated carbon can be
partially regenerated by biochemical activities while the carbon bed is in
operation (Rodman et al., 1978; Rice and Robson, 1982); less biodegradable
organics can be adsorbed on the carbon first, and are then slowly degraded by
microorganisms (Weber and Ying, 1978; Rice and Robson, 1982); and biological
reaction rates become higher on activated carbon due to an enrichment of the
organics by carbon adsorption (Weber and Ying, 1978). With these
characteristics, BAC may be potentially useful for removal of organics in RO
reject, which consists of less biodegradable organics.
The CDI process cycle consists of purification phase, regeneration phase and
purge phase. During purification phase, an electrical field with a potential
difference of about 1.2 - 1.5 volts (direct current) between the two electrodes
removes the dissolved ions from the water as its passes through the electric field.
The anions and cations are attracted to the opposite charge and directed to the
respective electrode until saturation occurs. During purification phase, permeate
with lower conductivity is generated as product water. Regeneration then takes
place by reversing the potential. Hence, the ions are expelled into the rinse water
and eventually purge out from the cell into a concentrate stream. In practice,
more than 80% of water can be recovered with CDI process. CDI process
generally has lower energy consumption as compared with membrane process
as high pressure pumps are not required to achieve the treatment process in.
This study will provide an alternative treatment technology for water utilities to
manage the brine streams generated from their water reclamation systems. This
process shows the potential of increased water recovery in the reclamation
process while volume for disposal can be further minimized.

Drinking and Wastewater Applications II – 4
Tuesday July 15, 4:00 PM-4:30 PM, Maui
Effects of Organic Fouling on the Removal of Trace Chemicals in
Nanofiltration Membrane Processes
S. Foo, University of New South Wales, Sydney, Australia
J. Mcdonald, University of New South Wales, Sydney, Australia
J. Drewes, Colorado School of Mines, Colorado, USA
L. Nghiem, University of Wollongong, Wollongong, Australia
S. Khan, University of New South Wales, Sydney, Australia
P. Le-Clech (Speaker), University of New South Wales, Sydney, Australia - p.leclech@unsw.edu.au
Trace chemicals, like endocrine disrupting compounds (EDCs), pharmaceutically
active compounds (PhACs) and personal care products (PCPs), present in
wastewater effluents are known to potentially cause detrimental effects to human
health and to the biotic environment if not removed during the treatment process.
High-pressure membrane processes such as nanofiltration (NF) can be used
efficiently in applications where a high water quality is required. Previous
research indicated that the fouling layer formed on the membrane surface during
filtration could significantly affect the rejection of trace chemicals and could either
improve or jeopardize the quality of the treated water. Conflicting results on the
exact effect of fouling on rejection have indeed been reported and the
mechanisms and physicochemical interactions occurring during the rejection of
the trace chemicals by fouled NF membrane are, so far, limited.
Accelerated organic fouling was achieved on a NF270 membrane (from DOW) by
using a variety of natural organic matter (NOM) fractions ranging from humic
acids, extracted from river water and from soil, surface water, protein (bovine
serum albumin) solution, and wastewater effluent from a tertiary treatment
process (membrane bioreactor). Different concentrations of NOM and operating
modes (such as constant flux and constant pressure operation) were considered.
A mixture of 18 trace chemicals representing a wide range of different
physicochemical properties was added at the nanogram per liter (ng/L) range to
the different feed water qualities and their level of rejection was assessed by a
gas chromatography-mass spectrometry (GC-MS). According to their
characteristics, the trace chemicals were grouped into three categories: (1)
hydrophilic non-ionic, (2) hydrophilic ionic, and (3) hydrophobic non-ionic.
Variations in hydraulic resistance, membrane surface charge, roughness and
relative hydrophobicity were measured for each experiment. Preliminary results
indicated that the feed matrices and operational modes were the major factors
governing the trace chemicals rejection. Under constant flux operation, it was
found that the rejection of contaminants increased after fouling, as compared to
those obtained under constant transmembrane pressure. Changes of the

membrane surface characteristics due to the formation of an organic fouling layer
were clearly confirmed by the observed increased hydrophobicity and decreased
surface charge, which could explain the rejection mechanisms of compounds
detected in this study: (1) the main rejection mechanism for the hydrophilic nonionic
compounds was size exclusion, as their rejection remains relatively
constant throughout the experiments. (2) In the case of the hydrophilic ionic
chemicals, the initial rejection mechanism was electrostatic exclusion, which
became offset by size exclusion as fouling occurred. This was explained by the
rejection performances of small compounds declining by 10%, while rejection of
larger chemicals decreased only by 2%. (3) Hydrophobic non-ionic compounds
presented high initial rejection due to their adsorption on the membrane surface.
During long-term operation, their rejection decreased as they were able to diffuse
through the hydrophobic fouling layer.

Drinking and Wastewater Applications II – 5
Tuesday July 15, 4:30 PM-5:00 PM, Maui
Emergency Water Purification Device Using Gravity Driven Membrane
Filtration
Y. Jiang (Speaker), University of Oxford, Oxford, United Kingdom - yu.jiang@eng.ox.ac.uk
Z. Cui, University of Oxford, Oxford, United Kingdom - zhanfeng.cui@eng.ox.ac.uk
An emergency water purification device capable of purifying water to potable
standard after natural disasters, such as floods, has been developed in this
study. This device is based on ultrafiltration (UF), and the filtration is driven by
gravity and hence no external power is required for the operation.
The paper reports results from prototype testing. A commercial hollow fiber UF
cartridge was used in this study. Key design papameters were first identified and
their effect on membrane performance was tested experimentally, including feed
flowrate, membrane mounting angle, transmembrane pressure (TMP) and feed
concentration, etc. A pure water flux of around 14 l/m 2 h has been obtained under
0.1 bar, approximate pressure generated by 1 m water head. This shows that the
selected cartridge has great potential to meet drinking water requirements in
emergencies and the gravity driven concept could be feasible. Additionally,
through filtration tests of betonite solutions, the flux dependency on TMP and
feed concentration were determined. It was also found that the cartridge placed
vertically performed well giving higher permeate flux over longer period of time.
Based on the obtained design parameters, a laboratory prototype, which
generated TMP by water gravity, was fabricated to further confirm and optimize
the design and operation. Experiments on the behavior of gravity driven feed
flowrate, fouling tendency over time, the effect of manual backflushing on
permeate flux and device lifetime, etc. were carried out. The investigation of 8hour
fouling tendency of this cartridge using diverse concentration betonite
solutions shows that manual backflushing with the treated water is needed for
high productivity and will perform better if applied in the first couple of hours. An
optimal backflushing scheme was determined. It was confirmed that the device
can produce 8 l portable water per hour on average. This is enough to meet
drinking water needs of a group up to 30 people every day. Additionally, a long
term test demonstrates that the device can repeat its performance every day by
simple manual backflushing for at least 30 days.

Drinking and Wastewater Applications II – 6
Tuesday July 15, 5:00 PM-5:30 PM, Maui
Membrane Defects and Bacterial Removal Efficiency: Effect of Alterations
of the Skin and of the Macroporous Support.
N. LEBLEU (Speaker), Université de Toulouse, Toulouse, France - lebleu@chimie.ups-tlse.fr
C. CAUSSERAND, Université de Toulouse, Toulouse, France - caussera@chimie.ups-tlse.fr
C. ROQUES, Université de Toulouse, Toulouse, France - christine.roques@cict.fr
P. AIMAR, Université de Toulouse, Toulouse, France - aimar@chimie.ups-tlse.fr
In the context of potable water production, one of the major concerns to water
treatment remains the microbiological water safety which is ensured by final
disinfection step. In principle and according to its membrane pore size
distribution, ultrafiltration is able to remove very efficiently waterborne pathogens
and thus to meet drinking water requirements. Nevertheless, that may not be the
case any more if membrane integrity is compromised. As for an example,
imperfections may be generated during membranes manufacturing (such as
abnormally large pores) or the membrane porous structure may be altered
overtime by chemical and mechanical ageing [1,2]. In function of their
characteristics (number, size, depth,&), such imperfections are likely to allow
microogarnisms through the membranes [3,4].
The objective of the work presented here is to address, via an experimental
study, the following question : which characteristics of such defects allow
bacterial leakages and lead to the contamination of the distributed water ?
Challenge tests were performed on flat-sheet regenerated cellulose membrane
the integrity of which was deliberately altered. The MWCO of the uncompromised
membrane is 30 kD and its effective area is 13.4 cm 2 . These membranes were
chosen for their asymmetrical structure (skin with low porosity and macroporous
support) and because they are initially totally retentive for E. coli. In such
conditions, bacterial concentration in permeate samples is directly linked to their
transfer through the defect. The membrane porous structure was altered by
perforating the surface by means of various techniques, depending on the
required characteristics of the defect. At first, defects of 200 µm diameter with a
perfect cylindrical geometry were created with ultrashort laser pulses. Then, in
order to approximate those which are more likely to be generated during
membrane ageing, holes of same diameter were punched with a sharp tungsten
tip. Finally, a microhardness tester allowed us to create defects across one
fraction of the membrane skin thickness. Once these imperfections have been
made, dead-end filtration experiments were carried out in a stirred cell device.
The feed solution consists of a bacterial suspension of E. coli at 104 CFU/mL
and the transmembrane pressure was set to 0.5 bar. Steadily, permeate samples

were collected, the viable bacteria were enumerated. Influence of the
characteristics of the defect upon the microorganism retention, i.e. the log
reduction value (LRV), was analysed in order to assess the impact of a defect
which alters only the skin in comparison with a defect crossing the whole
membrane structure.
Experimental results confirmed the leading part of the selective skin towards
bacterial removal : as long as the selective skin is not altered on its whole
thickness, the altered membrane keeps a retention efficiency equivalent to the
one of an uncompromised membrane (LRV > 7). Nevertheless, the skin is not the
only part of the membrane occuring in the retention mechanisms. For
membranes with a fully punched skin but with an uncompromised macroporous
support, the bacterial tranfer through the defect is highly limited by the support
since a log reduction value of 4 log may be attributed to this part of the
membrane structure. In order to get a better understanding of the retention
mechanisms provided by the macroporous support, a comparison between the
two types of defects altering the whole thickness of the membrane was done.
Here, the log reduction value is around 2 log when the support was punched by
the tip to be compared to 0.3 log in the case of a membrane altered with a defect
of same diameter made by burning the whole support with the femtosecond laser
beam. The observed discrepancy between those two results is analysed as the
swelling of the macroporous structure under the selective skin owing to the
applied transmembrane pressure. This change in material structure leads to the
partial clogging of the punched defect which was confirmed by scanning electron
microscopy observations. Under such conditions, we conclude that the
macroporous support works as quite an efficient fibrous particles collector.
To conclude, a highly compromised membrane (one defect of 200 µm diameter
for an effective area of 13.4 cm 2 ) is likely to keep a non negligible bacterial
removal efficiency thanks to the part taken by the macroporous support in
bacteria retention mechanisms. To complete this study, experiments with smaller
defects are still in progress. However, by gradually decreasing the size of the
defects until the range of the microorganisms size, we will have to cope with
bacterial specific behaviour such as their deformation under mechanical stress.
References
[1] Kobayashi et al. 1998 J Membr Sci vol.140 p.1.
[2] Causserand et al. 2006 Desal vol.199 p.70.
[3] Urase et al. 1996 J Membr Sci vol.115, p.21.
[4] Gitis et al. 2006 J Membr Sci vol.276 p.199.

Inorganic Membranes I – 1 – Keynote
Tuesday July 15, 2:15 PM-3:00 PM, Moloka’i
Inorganic Membranes also Swell
M. Yu, University of Colorado, Boulder, Colorado, USA
J. Lee, University of Colorado, Boulder, Colorado, USA
H. Funke, University of Colorado, Boulder, Colorado, USA
R. Noble, University of Colorado, Boulder, Colorado, USA
J. Falconer (Speaker), University of Colorado, Boulder, Colorado, USA -
john.falconer@colorado.edu
MFI zeolite membranes swell when some molecules adsorb in the MFI pores.
Although the amount of swelling is small compared to polymer membranes, it has
dramatic effects on the membrane permeation and separation properties.
Adsorbate-induced swelling can essentially seal off defects in MFI membranes.
Thus, MFI membranes with significant flow through defects can be selective for
some separations because certain molecules, when they adsorb in the MFI
pores, expand the crystals and shrink the defect pores. This adsorbate-induced
swelling dramatically changes the membrane permeation properties. A
combination of permporosimetry, pervaporation, vapor permeation, single gas
permeation, and binary mixture separations were used to demonstrate these
behaviors on membranes with different fractions of their flow through defects.
Permporosimetry measurements, in which the flux of helium was measured as a
function of the activity of a molecule adsorbed in the MFI pores, depended on
which molecule was adsorbed.
A membrane that had 90% of its flow through defects at room temperature, as
determined by benzene permporosimetry, had an H2/SF6 ideal selectivity of 250.
For the same membrane, n-hexane permporosimetry showed that only 0.14% of
the helium flux at room temperature was through defects. Thus, MFI membranes
can be self-sealing for many separation mixtures. The sizes of the defects were
estimated from capillary condensation to be approximately 2 nm in this
membrane, but this size decreased dramatically following adsorption of some
molecules, such as n-hexane. These measurements show that many of the
techniques that have been used for MFI membrane characterization in previous
studies do not determine if the membrane has significant flow through defects.
Permporosimetry with n-hexane, H2/SF6 and n-butane/i-butane ideal selectivities,
n-propane/H2, n-butane/i-butane, and n-hexane/2,2-dimethylbutane separation
selectivities have all been used to estimated membrane quality. However, all
these methods used molecules that cause MFI crystal expansion, and thus these
methods do not provide an good indication of membrane quality. Instead,
pervaporation of molecules too large to fit into MFI pores (such as isooctane and
2,2-dimethylbutane), vapor permeation of these molecules as a function of feed

pressure, and permporosimetry with benzene present a consistent picture of
membrane properties.
Permporosimetry, temperature-programmed desorption, and pervaporation of
mixtures clearly show that propane, n-butane, i-butane, n-pentane, n-hexane, noctane,
and SF6 all decrease the size of defects in MFI membranes by swelling
MFI crystals when they adsorb. Although XRD and optical microscopy studies
show that crystal expansion is less than 0.5% linearly for MFI crystals, such
expansion can essentially seal 2-nm membranes. For the membrane with 90% of
its helium flow through defects, n-hexane adsorption decreased the helium flow
almost three orders of magnitude. This membrane also had a 2,2-dimethylbutane
flux during pervaporation that was 160 times its n-hexane flux; that is, the larger
molecule permeated 160 times faster because the defects that it permeated
through were almost sealed off by n-hexane adsorption. The defects were sealed
at much less than saturation loadings in the MFI crystals. The loading required to
decrease the flux through defects by more than two orders of magnitude
increased as the number of carbon atoms in the alkane decreased. These results
may explain many inconsistencies for MFI permeation in the literature. They also
indicate that flow through defects can be more important at higher feed
concentrations, and show that characterizations at high feed concentrations
provide a better indication of membrane quality.

Inorganic Membranes I – 2
Tuesday July 15, 3:00 PM-3:30 PM, Moloka’i
Synthesis and Characterization of SAPO-34 Zeolite Crystals and
Membranes Employing Crystal Growth Inhibitors
S. Venna, University of Louisville, Louisville, Kentucky, USA
M. Carreon (Speaker), University of Louisville, Louisville, Kentucky, USA -
macarr15@louisville.edu
The separation of CO2 from natural gas is an important environmental and
energy issue. Improved membranes for separating CO2 from CH4 would reduce
considerably the costs of natural gas purification. Since polymeric membranes
have limitations based on operating temperature and high pressures that cause
their degradation, small pore zeolites such as SAPO-34 with pore size ~0.38 nm
are preferred to effectively separate CO2/CH4 mixtures. Here, we present the
hydrothermal synthesis of SAPO- 34 employing crystal growth inhibitors (CGI)
such as polyoxyethylene lauryl ether, polyethylene glycol, and methylene blue for
both crystal and membrane preparation. The incorporation of these CGI during
gel synthesis resulted in 1-2.5 ¼m seeds with narrow crystal size distribution and
unprecedented high surface areas (up to 700 m2/g). CO2 and CH4 adsorption
isotherms indicated improved CO2/CH4 selectivities for the crystals prepared with
CGI. Membranes were grown by in-situ crystallization on ±-alumina porous tubes
and evaluated for CO2/CH4 gas separation.

Inorganic Membranes I – 3
Tuesday July 15, 3:30 PM-4:00 PM, Moloka’i
Effects of Electroless Plating Conditions on the Synthesis of Pd-Ag
Hydrogen Selective Membranes
R. Bhandari (Speaker), Worcester Polytechnic Institute, Worchester, Massachusetts, USA -
rajb@wpi.edu
Y. Ma, Worcester Polytechnic Institute, Worchester, Massachusetts, USA - yhma@wpi.edu
Pd-Ag membranes are better suited for H2 separation applications than pure Pd
membranes because of their higher H2 permeability (23 Ag wt%). The
morphology of the Pd-Ag deposits plays an important role in the synthesis of a
thin H2 selective membrane. The electroless plating conditions have radical
effects on the deposit morphology. The electroless deposition involves redox
reactions, therefore electrochemical technique such as linear sweep voltammetry
(LSV) could be very useful to understand the effect of the plating conditions on
the deposit morphology. The objective of this study was to investigate the plating
conditions and their effect on the morphology of the deposits using the LSV
technique in order to determine suitable plating conditions to synthesize H2
selective Pd-Ag membranes.
The electroless plating bath used in this study consisted of Pd or Ag ions and
N2H4 as the reducing agent and porous stainless steel coupons were used as
the substrate. The deposits were characterized by using SEM, EDX and X-ray
differactometer. The stainless steel wires deposited with Pd or Ag were used in
the LSV study. The LSV scans were obtained using the BAS 110B/W
electrochemical station. Based on the results of LSV study, two Pd-Ag
membranes (M-1 and M-2) supported on porous Inconel tubes were synthesized
using the multilayer Pd-Ag sequential deposition and then annealed at 550 °C
(24 h) in H2 atmosphere and characterized further for the H2 permeation in 300-
500 °C range.
The Ag bath LSV polarization curve showed the fast reduction kinetics for the
metal and within 15-25 mV electrode over potential, the overall deposition
process was limited by the diffusion of Ag ions in the solution. However large
over potential (400- 500 mV) was observed for the Pd deposition. Also the Pd
surface showed higher catalytic activity for the N2H4 oxidation and at electrode
potential of 0 mV, the current associated with the oxidation of N2H4 on the Pd
surface was an order of magnitude higher than that on the Ag surface. The
morphology study of the Pd deposits (N2H4/Pd = 5.6/16) showed good Pd pore
penetration. However for the Ag deposits (N2H4/Ag = 5.6/3), poor Ag pore
penetration was observed. Further, the Ag deposits (N2H4/Ag = 5.6/3) showed
dendritic morphology on the substrate covered with the Pd deposits, therefore

not suitable for the Pd-Ag membrane synthesis. The poor penetration of the Ag
deposits (N2H4/Ag = 5.6/3) could be due to the overall Ag deposition significantly
controlled by the diffusion of Ag ions in the solution. Therefore, the lower
N2H4/Ag ratio in the bath (N2H4/Ag = 4/20) could avoid Ag deposition occurring
at electrode potential where overall deposition was controlled by the diffusion of
Ag ions. The deposits obtained with (N2H4/Ag = 4/20) showed good pore
penetration and no dendritic characteristics, therefore suitable for the synthesis
of Pd-Ag membrane.
Both the Pd plating condition with N2H4/Pd = 5.6/16 and Ag plating condition with
N2H4/Ag = 4/20 showed deposits with uniform growth and good pore penetration
and hence were used to synthesize the Pd-Ag membranes.
Negligible He flow was observed for as synthesized membranes (M-1 thickness =
7.4 µm, M-2 thickness = 8.8 µm). After annealing at 550 °C both membranes
showed increase in the H2 permeance due to the alloying of Pd-Ag layers. The
membranes after annealing showed low activation energy (AE) for the H2
permeation (M-1 = 3.2 kJ/mole, M-2 = 8.6 kJ/mole) than pure Pd (14.9 kJ/mole).
The H2 permeability was product of its diffusivity and solubility in Pd. The alloying
of Pd with Ag decreased the H2 diffusivity and increased the H2 solubility in Pd.
The net effect was increase in the H2 permeance and corresponding decrease in
the AE for H2 peremance up to 23 wt% Ag. The low AE of Pd-Ag membranes
indicated that the H2 permeability in Pd-Ag membranes decreased at lesser rate
than that of Pd, making Pd-Ag membranes more effective for the H2 separation
at lower temperatures. The M-1 showed the H2 permeability (m 3 -µm/m 2 -h-atm 0.5 )
of 466, 428 and 366 while the corresponding pure Pd foil values were 525, 374
and 237 at 500, 400 and 300 °C respectively. For the M-2, the H2 permeability
values were 451, 348 and 245 m 3 -µm/m 2 -h- atm 0.5 at 500, 400 and 300 °C
respectively. The EDX analysis showed the average value of 20 and 31 wt% in
M-1 and M-2 respectively. The lower H2 permeability of M-2 than that of M-1
could be attributed to its higher than optimum (23) Ag wt%. Both membranes
showed decline in H2/He selectivity with time with the final selectivity (ΔP=1atm)
of 335 (M-1) and 151 (M-2) at 500 °C.
It can be concluded that thin and He dense Pd-Ag membranes could be
synthesized using the suitable plating conditions based on the LSV study. The
annealing time of 24 h at 550 °C was sufficient to form the Pd-Ag alloy. The
prepared membranes were more effective for H2 separation than the pure Pd
membranes at lower temperatures.

Inorganic Membranes I – 4
Tuesday July 15, 4:00 PM-4:30 PM, Moloka’i
Upgrading of a Syngas Mixture for Pure Hydrogen Production in a Pd-Ag
Membrane Reactor
A. Brunetti, National Research Council - Institute for Membrane Technology, Rende (CS), Italy -
a.brunetti@itm.cnr.it
G. Barbieri (Speaker), National Research Council - Institute for Membrane Technology Rende
(CS), Italy - g.barbieri@itm.cnr.it
E. Drioli, University of Calabria, Rende CS, Italy, e.drioli@itm.cnr.it
In integrated plants for hydrogen production a fundamental step is the upgrading
of stream outletting reformers. These streams contain H2 (50%), CO2, N2 etc. and
about 10-15% of CO which could be converted producing in the meantime more
hydrogen. In a traditional reactor (TR), the presence of hydrogen in the feed
stream depletes CO conversion owing to the constraint imposed by the
thermodynamics. In the temperature range of interest (220-330°C) the maximum
achievable conversion could not be higher than 25%. In Pd-Ag membrane
reactor (MR), the selective removal of hydrogen allows the thermodynamics
limitation of a TR to be overcome and hence CO conversion might be
significantly higher. This value depends on the MR extractive capacity which is a
function of the operating conditions and particularly of the permeation driving
force. In this work it was realized by feed and permeate pressures and no sweep
gas was used. CO conversion in this MR was measured 4-5 times higher than
that of equilibrium of a TR. Hydrogen recovered as a pure permeate stream is
about 80% of the total present in the feed stream and also produced by (water
gas shift) reaction. The hydrogen produced was fed to a PEMFC for energy
production which showed stable performance not depending on the MR
operating conditions and equal to that measured feeding hydrogen from a
cylinder.

Inorganic Membranes I – 5
Tuesday July 15, 4:30 PM-5:00 PM, Moloka’i
Preparation and Characterization of Hollow Fibre Carbon Membranes
based on a Cellulosic Precursor
X. He (Speaker), Norwegian University of Science and Technology, Norway -
xuezhong@chemeng.ntnu.no
J. Lie, Norwegian University of Science and Technology, Norway - jonarvid@nt.ntnu.no
E. Sheridan, Norwegian University of Science and Technology , Norway-
sheridan@chemeng.ntnu.no
M. Hägg, Norwegian University of Science and Technology, Norway - maybritt.hagg@chemeng.ntnu.no
A selected cellulosic precursor was spun as hollow fibres based on the dry-wet
spinning method. The influences of the different variables in the spinning process
on the final quality of the fibre were studied and discussed (spinning rate,
coagulation bath temperature, air gap, take-up speed, and others).
Documentation of the quality of the resulting fibres was done by SEM-pictures.
The carbon membranes were fabricated from the cellulosic fibre precursor under
a multi-dwell carbonization protocol with inert purge gas, a heating rate of
1°C/min and a final temperature and soak time of 650°C and 2h, respectively. A
weight loss of approximately 75% and a longitudinal shrinkage of 32% were
found. The structure and morphology of the prepared hollow fibre carbon (HFC)
membranes were also characterized by SEM. The diameter and thickness of the
HFC membranes were identified by an optical microscope. The HFC membranes
were mounted in a module for testing, and five different gases (H2, N2, CH4, CO,
CO2) were measured using a single gas permeation test setup. The permeation
tests of the HFC membranes were run at the same feed temperature and
pressure (30°C and 2bar). Four different recipes were used for post-treatment of
the hollow fibre precursors before carbonization. The results indicated clearly the
relationship between the separation performance and the post-treatment
conditions of the fibres. The separation performance of the HFC membranes
could thus be optimised with respect to the conditions for the post-treatment of
the hollow fibres. The permeance (m 3 (STP)/m 2 .h.bar) for H2 and CO2 was 0.045
and 0.006 respectively, and the ideal selectivity for the gas pairs CO2/N2,
CO2/CO and H2/CH4 was found to be 47, 19 and 2800. The five gases were
chosen due to the potential of using this membrane for separation of pressurized
flue gas (CO2-N2-CO), pre-combustion separation (CO2-H2 at high temperature
and pressure) or upgrading of biogas (CO2-CH4). Further work on optimisation is
ongoing to increase separation performance.

Inorganic Membranes I – 6
Tuesday July 15, 5:00 PM-5:30 PM, Moloka’i
High-Density, Vertically-Aligned Carbon Nanotube Membranes with High
Flux
M. Yu (Speaker), University of Colorado, Boulder, Colorado, USA - miao.yu@colorado.edu
H. Funke, University of Colorado
J. Falconer, University of Colorado
R. Noble, University of Colorado
Several studies have reported carbon nanotube (CNT) membranes that consist
of aligned nanotubes sealed in a polymer or inorganic matrix 1-3 . These
membranes had single gas selectivities that were approximately Knudsen, and
they had high permeation fluxes for liquid and gas feeds in nanotubes. Because
the aligned CNTs grew with a low density (~ 1011 CNTs per cm 2 of surface
area), only a few percent (0.08 ~ 2.7) of the membrane consisted of CNTs; most
of it was the sealing material. Thus, although the fluxes per cm 2 of CNT area
were orders of magnitude higher than other types of membranes, the fluxes per
actual membrane area (CNTs plus polymer or inorganic sealant) were much
lower.
We have prepared vertically-aligned CNT membranes with a CNT density of 2.9
x 1012 CNTs/cm 2 , which is approximately 20 times higher than these previous
studies by eliminating the need for a polymer or inorganic filler. Aligned CNTs
were grown on a silicon wafer with catalyst thin films 1-nm Fe/10-nm Al2O3 that
were formed by e-beam evaporation, the nanotubes were removed from the
silicon surface by in-situ water etching, and the nanotubes were collapsed to
about 5% of their original area by solvent evaporation. The tops of the CNT
membrane are expected to be open due to water etching 4, 5 , and the bottoms are
also expected to be open because the silicon wafers can be reused for several
times for CNT growth after detaching the CNT arrays. This preparation is much
simpler than that used for composite membranes, and the membranes have
much higher fluxes because of the much higher CNT density and additional
interstitial transport pathway between nanotubes. These membranes exhibit light
gas selectivities that are equal to or greater than Knudsen selectivities, but their
permeances are not independent of pressure. Instead, for most gases the
permeances decrease with increasing pressure. The permeance at 1 bar
pressure drop for N2 through a membrane that was 750 mm thick was 1.2 x 10 -4
mol/m 2 -s-Pa. This corresponds to a permeability of 27 cc (STP)/ m 2 -s-atm. Thus,
these permeabilities are one to four orders of magnitude higher than those
reported for composite membranes.

Because these membranes do not contain a filler, the spaces between the
nanotubes must also be available for transport, but apparently the CNTs are
close enough together that the flux through these spaces has similar behavior to
the flux through nanotubes. The flux of liquid n-hexane through these
membranes was approximately 1,500 kg/m 2 -h at 1 bar pressure drop, which is 3
to 4 orders of magnitude higher than the flux of n-hexane through MFI zeolite
membranes, even though these membranes are thicker (750 mm). The
nanotubes were approximately 3 nm in diameter, as determined by TEM and
calculated from N2 desorption isotherms at 77 K. The average space between
nanotubes is appropriately 3 nm with a distribution from 1.4 to 7 nm, as
calculated by the BJH method from N2 desorption isotherms at 77 K.
1.Hinds, B. J.; Chopra, N.; Rantell, T.; Andrews, R.; Gavalas, V.; Bachas, L. G. Science 2004,
303(5654), 62-65. 2.Holt, J. K.; Park, H. G.; Wang, Y. M.; Stadermann, M.; Artyukhin, A. B.;
Grigoropoulos, C. P.; Noy, A.; Bakajin, O. Science 2006, 312(5776), 1034-1037. 3.Kim, S.;
Jinschek, J. R.; Chen, H.; Sholl, D. S.; Marand, E. Nano Lett 2007, 7(9), 2806-2811. 4.Ci, L. J.;
Manikoth, S. M.; Li, X. S.; Vajtai, R.; Ajayan, P. M. Adv Mater 2007, 19(20), 3300-+. 5.Zhu, L. B.;
Xiu, Y. H.; Hess, D. W.; Wong, C. P. Nano Lett 2005, 5(12), 2641-2645.

Membrane Fouling - UF & Water Treatment – 1 – Keynote
Tuesday July 15, 2:15 PM-3:00 PM, Honolulu/Kahuku
Fouling Mechanisms and Fouling Control By Membrane Surface
Modification in Ultrafiltration of Aqueous Solutions Containing Polymeric
Natural Organic Matter
M. Ulbricht (Speaker), Lehrstuhl für Technische Chemie II, Universität Duisburg-Essen,
Germany - mathias.ulbricht@uni-due.de
P. Peeva, Lehrstuhl für Technische Chemie II, Universität Duisburg-Essen, Germany -
polina.peeva@uni-due.de
H. Susanto, Lehrstuhl für Technische Chemie II, Universität Duisburg-Essen, Germany -
heru.susanto@uni-due.de
Because membrane processes are increasingly used for separations of mixtures
with high complexity, the focus of fouling studies in ultrafiltration (UF) has also
been shifted from using well-studied foulants such as proteins [1], to more
complicated and less-defined substances, i.e. colloidal natural organic matter
(NOM) [2]. Relevant foulants in such systems are humic acids, polysaccharides
or polyphenols. The strongest motivation for such work is certainly based on the
success of membrane separations and membrane bioreactors (MBR) for water
and wastewater treatment.
With respect to the identification of foulants for UF membranes, we had
demonstrated that the combination of a detailed analysis of the membrane
surface structure with adsorption and UF experiments can give valuable
quantitative information about causes, extent and consequences of membrane
fouling, also for previously less investigated foulants such as the polysaccharide
dextran [3]. Surface modification of the membranes is gaining increasing
importance for minimizing membrane fouling [4]. Very recently, new thin layer
hydrogel composite (TLHC) UF membranes, based on commercial
polyethersulfone (PES) membranes, have been prepared via photo- initiated
graft copolymerization of monomers containing side groups with “kosmotropic”
properties along with controlled chemical cross-linking during grafting. The
antifouling properties of those new membranes had been evaluated using a
limited set of adsorption and UF experiments with the model foulants myoglobin
and humic acid [5]. TLHC membranes with adjusted surface chemistry had also
shown promising performance in UF of NOM- containing water [6].
This work describes the fouling behaviour of protein, humic acid, polysaccharide,
polyphenol and their mixtures by investigation of membrane-solute interactions
(adsorptive fouling) and membrane- solute-solute interactions (UF fouling).
Surface and fouling characterization was also supported by measurements of
contact angle and zeta potential and by FTIR-ATR spectroscopy. Myglobin,
bovine serum albumin, humic acid from Aldrich, alginate, dextran, and

polyphenol from green tea (Sigma) were used as model foulants. Three
commercial PES UF membranes with nominal cut-off of 10, 30 and 100 kg/mol
and a TLHC membrane, synthesized by photo-initiated graft copolymerization of
poly(ethylene glycol) methacrylate (PEGMA) onto the 100 kg/mol PES UF
membrane and having a cut-off of 10 kg/mol (cf. [5]) were used. The effects of
foulant concentration, pH, ionic content and proportions between different
foulants in the solution onto fouling were investigated. The results showed that
significant water flux reductions and changes in membrane surface property were
observed after static adsorption for PES membranes for all feed solution
conditions. At moderate concentrations (up to 0.1 g/L), the polyphenol was a
strongest foulant. Synergistic effects between polysaccharide and protein with
respect to forming a mixed fouling layer with stronger reduction of flux than for
the individual solutes under the same conditions have also been verified for PES
UF membranes. UF experiments using a stirred dead- end UF indicated that both
reversible and irreversible fouling contributed to the overall fouling. Standard
fouling models were used to distinguish between pore blocking and constriction,
and cake formation. The water flux after UF and external washing for the PES
membrane with a cut- off of 10 kg/mol was between 20 and 70% of the original
water flux. The pronounced antifouling efficiency of the TLHC membrane has
been demonstrated for the strong foulants polyphenol, alginate and the model
proteins as well as for foulant mixtures, with respect to both adsorptive and
ultrafiltration fouling. In particular, the regeneration of flux after UF was much
easier, even simple external rinsing with water removed most of the fouling layer
and lead to more than 90% of the original water flux.
The results of this work with respect of the individual and combined effects of
polymeric model foulants for NOM and the high antifouling efficiency of tailored
hydrogel-based composite membranes for UF have also implications for other
applications of ultrafiltration, for instance in the food and beverage or in the
pharmaceutical industries.
[1] R. Chan, V. Chen, J. Membr. Sci. 2004, 242, 169-188.
[2] A. R. Costa, M. N. de Pinho, M. Elimelech, J. Membr. Sci. 2006, 281, 716-725.
[3] H. Susanto, S. Franzka, M. Ulbricht, J. Membr. Sci. 2007, 296, 147-155.
[4] M. Ulbricht, Polymer 2006, 47, 2217-2262.
[5] H. Susanto, M. Ulbricht, Langmuir 2007, 23, 7818-7830.
[6] H. Susanto, M. Ulbricht, Water Research 2008, accepted.

Membrane Fouling - UF & Water Treatment – 2
Tuesday July 15, 3:00 PM-3:30 PM, Honolulu/Kahuku
A Mechanistic Study on the Coupled Organic and Colloidal Fouling of
Nanofiltration Membranes
A. Harris (Speaker), Rice University, Houston, Texas, USA, harrisa@rice.edu
A. Kim, University of Hawaii at Manoa, Honolulu, Hawaii, USA - albertsk@hawaii.edu
Q. Li, Rice University, Houston, Texas, USA - qilin.li@rice.edu
Various types of foulants present in natural and waste waters, such as colloids,
dissolved organic matter, electrolyte ions, and microorganisms, contribute to
membrane flux decline through different mechanisms. Separately the fouling
mechanisms of each are relatively well understood, and models are available to
predict respective fouling behaviors. However, little is understood about the
interactions between these foulants and how they impact membrane fouling
mechanisms in filtration of natural and waste waters. This study focuses on the
coupled effect of dissolved organic and colloidal foulants on the permeate flux of
nanofiltration (NF) membranes. The role of common organic macromolecules in
natural and waste waters on the deposition of silica colloids on NF membrane
surface was investigated.
Bovine serum albumin (BSA), sodium alginate, dextran, and a standard natural
organic matter Suwannee River NOM were chosen to represent naturally
occurring organic matter of different molecular properties in natural and waste
waters. The impact of the model organic compounds on the physicochemical
properties, i.e., particle size, surface zeta potential, and suspension stability, of
silica colloids (60 nm in diameter) was thoroughly characterized by dynamic light
scattering (DLS) and electrophoretic mobility measurements. The four model
organic compounds showed distinct impact on silica-silica interactions. For
example, measurements of colloidal silica properties in the presence of dextran
showed little impact compared to silica alone, while BSA, alginate and NOM
demonstrated different levels of impacts on silica colloid properties through
adsorption onto the silica surface at sufficiently high concentrations. Quartz
crystal microbalance with dissipation monitoring (QCM-D) was employed to
quantitatively characterize particle-particle interactions in the presence and
absence of the model organic compounds using a quartz crystal sensor coated
with SiO2. The QCM-D technique was also used to quantify the impact of the
model organic compounds on the deposition of the silica colloids on polymer
surfaces with similar surface chemistry as the membranes. This technique was
shown to be a useful tool for evaluating membrane fouling potential of a complex
suspension. The effect of solution chemistry, e.g., pH and Ca 2+ concentration,
was also studied. The impact of Ca 2+ was very complex due to its interaction with
both the organic macromolecule and the silica colloid. Bridging between

macromolecules adsorbed on neighboring silica colloid surface was
hypothesized to be the cause of the greatly enhanced deposition of silica colloids
in the presence of Ca 2+ . Monte-Carlo simulations of the BSA silica system are
currently being performed to better understand how BSA or other
macromolecules affect silica aggregation and deposition behaviors.
Results from these molecular-level characterizations were combined with those
from a series of cross-flow filtration experiments to reveal the mechanisms
involved in the combined effect of model organic and colloidal foulants on NF flux
decline. The enhanced deposition of silica colloids observed in the QCM-D
experiments agreed well with the increased initial flux decline rate during crossflow
filtration of the colloid-organic mixture compared to the additive sum of the
effects of the two individual foulants.
In addition to changing the deposition rate of silica colloids and hence increasing
the initial fouling rate, adsorption of organic macromolecules also alters the
structure of the colloidal cake layer. Transmission electron microscopy (TEM)
imaging of fouled membranes was employed to visualize the structure of the
fouling layer formed with and without the model organic macromolecules. This
effect was manifested at a later stage of the filtration process. Although BSA was
found to significantly increase initial membrane fouling rate, higher quasi-steady
state flux was observed in the presence of BSA due to a more porous fouling
layer.
Results from this study clearly demonstrate that different organic
macromolecules affect colloidal fouling differently. The overall fouling potential of
a complex suspension may not be predicted based on the fouling potential of
each individual foulant.

Membrane Fouling - UF & Water Treatment – 3
Tuesday July 15, 3:30 PM-4:00 PM, Honolulu/Kahuku
Effect of Crossflow on the Fouling Rate of Spiral Wound Elements
P. Eriksson (Speaker), GE W&PT, Vista, California, USA - peter.eriksson@ge.com
Four spiral wound ultrafiltration elements (0.3 m (12”) long) operated on an
oil/water emulsion for 140 h at 207 kPa (30 psi) feed gage pressure, each at a
different feed flow rate, which corresponded to 0.1-0.4 m/s superficial velocities
and 11-138 kPa/m (1.7-20 psi/m) pressure drops. The feed channel spacer was
diamond shaped with a thickness of 0.86 mm (0.034”). During the first 3 hours of
operation, the permeate flux vs. feed flow rate followed the normal curve for
applications where the permeate flux at low crossflow rates is limited by the
boundary layer resistance. The permeate flux increased from 28 lmh (17 gfd) at
the lowest flow rate to 134 lmh (79 gfd) at the highest flow rate, with the slope of
the flux vs. flow curve steepest at the lowest flow rate to almost level out at the
highest flow rates. After 15 hours of operation the permeate flux had decreased
30-50 percent for the two middle flow rates and much less for the lowest and
highest flow rates. This trend continued during the rest of the test, so at the end,
the permeate flux was 9.3, 12, 21 and 77 lmh (5.5, 7.0, 12, and 46 gfd) for the
respective element listed in order from the lowest to the highest feed flow rate.
Between 55 to 79 hours operating time, the flow rate for the element with the
lowest flow rate was temporarily increased to give a pressure drop of 115 kPa/m,
which was between those for the two elements with the highest flow rates. This
increased the permeate flux of the element to slightly above that of the initially
next highest feed flow rate element, but the flux was still less than half of that of
the element with the highest feed flow rate. These results imply that the
permeate flux was affected both by the boundary layer resistance, which was
reversible, and a membrane fouling part that was not reversible. The irreversible
membrane fouling rate was not much affected by the feed flow rates at the lowest
three levels, but was greatly decreased at the highest flow rate level, which
indicates that for the used feed water solution, there was a threshold feed flow
rate, above which membrane fouling was greatly reduced.
A two-stage RO unit with 8” diameter spiral wound elements operating on city tap
water experienced after one week of operation a steadily increasing feed side
pressure drop with time. Cleanings were required every 4-8 weeks to keep the
pressure drop not to exceed the maximum allowed. The main problem was
biofouling. All six elements in one of the housings in the first stage, and the first
and last element in a housing in the second stage were taken out and tested
individually. The feed side pressure drop at a constant feed flow rate was about
4.5 times the nominal one for the first three elements in the upstream housing,
and then decreased for each element in the downstream direction to be less than

1.5 times the nominal one for the last element in the second stage. The water
permeability was 30 percent below nominal for the first element in the first stage,
to increase with increasing position in the downstream direction, to reach the
nominal water permeability for the first element in the second stage. During
normal operation in the first stage housing, the feed flow superficial velocity
decreased from about 0.2 m/s for the first element to about 0.1 m/s for the last
element. The fouling rate was much higher for the first element than for the last
element, despite double as high feed flow rate to the first one. Most likely, the
high fouling rate for the first element was not caused by the initially higher
permeate flux for this one, because later in operation, the permeate flux would be
as high for the last element in the housing as for the first one. It is possible that
the RO elements were very good at trapping the microbes, and the that formed
biofilm was very good at catching the nutrients in the feed solutions, so it took a
long time for the downstream elements to build up a thick biofilm.

Membrane Fouling - UF & Water Treatment – 4
Tuesday July 15, 4:00 PM-4:30 PM, Honolulu/Kahuku
Exploiting Local Fouling Phenomena in Dead-End Hollow Fiber Filtration:
The Partial Backwash Concept
W. van de Ven (Speaker), Membrane Technology Group, University of Twente, The Netherlands,
w.j.c.vandeven@utwente.nl
A. Zwijnenburg, Wetsus, centre for sustainable water technology, The Netherlands,
arie.zwijnenburg@wetsus.nl
A. Kemperman, Membrane Technology Group, University of Twente, , The Netherlands,
a.j.b.kemperman@utwente.nl
M. Wessling, Membrane Technology Group, University of Twente, The Netherlands,
m.wessling@utwente.nl
Introduction Fouling of hollow fiber membranes during the filtration of natural
organic matter (NOM) is a complex issue due to the largely unknown composition
of the NOM. The particle size ranges from the nanometer to the micrometer scale
and interaction with the membrane varies for the different NOM components.
Due to the low axial flow that is present in a large part of the fiber in dead-end
ultrafiltration, the fouling is not necessarily homogenous over the entire length of
the fiber. In this work, we will discuss the axial distribution of fouling layers in
hollow fiber ultrafiltration membranes and the application of a partial backwash
concept, based on these results.
Local fouling phenomena We used two methods to assess the location of
membrane fouling in dead-end ultrafiltration. The firts method visualized that the
retention of a humic acid solution is significantly lower at the end of the module.
In a second set of experiments, filtration performance was studied for individual
modules by using five small modules in series. The results confirmed the visual
observation that membrane fouling takes places mainly at the end of the module.
Very high flux and retention (>95%) values are obtained in the initial part of the
module, while very low retention (even negative retentions are possible) are
found at the end of the module. The axial distribution is a result of the interplay
between the low crossflow velocity, high diffusion of the humic matter, and the
charge repulsion between the membrane and the matter.
The concept of partial backwashing The result of the experiments can be used to
optimize hollow fiber filtration processes. We present the concept of partial
backwashing. Instead of backwashing the complete module, only the part of the
module that is fouled is backwashed, increasing the overall recovery of the
process.

Results The partial backwash concept was studied for humic acid solutions with
and without the addition of calcium. The results show clearly that partial
backwashing is as effective as conventional full module backwashing when no
calcium is added, obtaining an 80% reduction in backwash water use. However,
when calcium is added to the feed solution, partial backwashing is not
successful. Addition of calcium leads to aggregation of the humic material,
increasing NOM particle size and enhancing humic acid- membrane interactions.
This leads to deposition of the material over the entire length of the fiber.
Conclusion Our work shows that the unique properties of hollow fiber dead-end
filtration and feedwater can result in a fouling layer that is inhomogeneous over
the length of the fiber. This is especially evident when particles are small and
interaction with the membrane is low. When material deposits primarily at the end
of the fiber, partial backwashing is an interesting way to reduce backwash water
use.

Membrane Fouling - UF & Water Treatment – 5
Tuesday July 15, 4:30 PM-5:00 PM, Honolulu/Kahuku
Fouling Resistant Coatings for Oil/Water Separation
Y. Wu (Speaker), University of Texas, Austin, Austin, Texas, USA –
B. McCloskey, University of Texas, Austin, Austin, Texas, USA
V. Kusuma, University of Texas, Austin, Austin, Texas, USA
H. Ju, University of Texas, Austin, Austin, Texas, USA
H. Park, University of Ulsan, Korea
B. Freeman, University of Texas, Austin, Austin, Texas, USA – Freeman@che.utexas.edu
The shortage of pure water is one of the world's most serious concerns.
Consequently, water reuse and management is increasingly important. Produced
water, often containing salts, heavy metals, emulsified oil and other organics, is
the single largest waste stream in oil and gas production. If the organic content
and salinity of produced water could be reduced to acceptable limits, produced
water would represent a potential new water source with a wide variety of uses.
Although membranes may be an effective tool for treating water from oil and gas
production, membrane fouling is a serious problem that limits the efficiency of
water purification.
The objective of this research was to find a method of preparing the thin-film
composite membranes using N-vinyl-2-pyrrolidone crosslinked with N,N'methylenebisacrylamide
as the coating layer and an ultrafiltration membrane
(i.e., polysulfone) as the support membrane to reduce fouling in oil/water
emulsions. Three different prepolymerization compositions containing 50, 60 and
70 wt% water (labeled as 50H, 60H and 70H, respectively) and a fixed 85/15
ratio of NVP/MBAA were used as coating solutions. Thin-film composite
membranes were successfully made, and their permeation and fouling properties
were studied.
The thin-film composite membranes were characterized using several
techniques. Fourier Transform Infrared Spectroscopy (FTIR-ATR) is a convenient
tool for monitoring the conversion of the polymer coating solution and the
existence of a coating layer. Based on ATR-FTIR studies of composite
membranes, the coating layer is thin. Calculations based on the penetration
depth of the infrared beam indicates that the coating layer is thinner than 1.2
micrometers. Scanning electron microscopy (SEM) was used to determine the
existence and the thickness of coating layer, which was 1.3 ± 0.5 micrometers
when using 50H as the coating solution and 0.2 ± 0.05 micrometers when 60H
was used as the coating solution. However, for the 70H solution, the coating
layer was too thin to be detected by SEM. As the water content in the

prepolymerization mixture increases, the coating layer thickness decreases
significantly.
To characterize their permeation and fouling properties, composite membranes
were tested using oil/water emulsion crossflow filtration tests. After 24 hours
permeation with oil/water emulsions used as model foulants, the uncoated PSF
flux was down to 10 L/m 2 hr, while thin-film composite membranes with 70H
coating solution had a flux 8 times higher, demonstrating good oil fouling
resistance. The oil rejection of thin-film composite membranes with all three
coating solutions-50H, 60H and 70H-was as high as 99.5 %, and rejection
remained constant, indicating that the PSF was thoroughly coated with the
coating layer. From the pure water flux before and after the oil/water emulsion
crossflow filtration test, the irreversible fouling index was calculated (i.e.,
permeance after oil water filtration divided by permeance before oil water
filtration). 70H has a higher initial flux but a low irreversible fouling resistance;
50H exhibits lower initial flux but high irreversible fouling resistance. There is a
trade-off between pure water flux and internal fouling in the thin-film composite
membrane.

Membrane Fouling - UF & Water Treatment – 6
Tuesday July 15, 5:00 PM-5:30 PM, Honolulu/Kahuku
On the Representativeness of Model Polymers in Fouling Research
A. Drews (Speaker), TU Berlin, Berlin, Germany - anja.drews@tu-berlin.de
A. Shammay, UNESCO Centre UNSW, Sydney, Australia
V. Chen, UNESCO Centre UNSW, Sydney, Australia
P. Le Clech, UNESCO Centre UNSW, Sydney, Australia
Objectives In an attempt to track down the culprit components or conditions, labscale
fouling experiments where the complexity of the interacting phenomena is
reduced are carried out by many groups all over the world. Such experiments
often involve small-scale (test cell) membrane filtration experiments with either
real feed suspensions, supernatants or model substances such as xanthan gum
or alginate (e.g. [1]). In reducing the complexity, the representativeness of
conclusions drawn from these trials becomes highly questionable - not only
quantitatively but also qualitatively. During such investigations under allegedly
more defined conditions a number of problems can be encountered, concerning
both filtrations conditions (different fouling mechanisms occur at constant flux
and constant pressure, respectively, or by lack of air scour in test cells [2]) and
composition of the feed suspension. For the filtration of real feeds, it is known
that even a few hours, which often elapse between sampling and filtration tests,
can lead to potentially unrepresentative fouling behaviour [2]. Model polymers
are assumed to be more stable - generally without proof - and more defined but
might still be unrepresentative due to the following: a) The form in which they are
obtained or prepared (completely dissolved or particulate) will affect their
fouling/adsorption potential [3], b) the chemical structure of the substance might
be largely different from that found in the real feed, c) the absence of the solids
matrix might cause largely different fouling mechanisms, and d) fouling might not
always mainly be caused by biopolymers. This study aims at elucidating the
representativeness of model foulant experiments in fundamental fouling
research.
Methods Test cell experiments (J = const, air-sparged, MF and UF membranes)
were carried out with suspensions or solutions of alginate, xanthan gum, BSA,
yeast, and bentonite (pure and spiked with BSA and/or alginate) under sub- and
supercritical flux conditions. A new membrane was used for each trial. To
determine the influence of “aging” of the model suspension on filtration results,
experiments were repeated after several hours of stirring and pumping through
the set-up. SMP, EPS and TOC were analysed in the feed and permeate [4, 5].
Results were compared to data obtained with sludge.

Results It was found that not only feed protein, carbohydrate and TOC
concentrations obviously differed strongly from those measured in sludge, but
also that permeate concentrations generally were much higher than in sludge
filtration. This indicates that polymer sizes or also fouling effects are quite
different. TMP increase was also different for the investigated suspensions,
however, irreversible fouling resistance could be correlated with TOC of the SMP
for a number of suspensions indicating that TOC might a relevant measure of
fouling. Regarding the aging effect, model foulant solutions were also subject to
changes over time which can be due to continuous shear in pumps and in the
vicinity of stirrers, temperature changes, or indeed even degradation. Initial TMP
increase was reproducible but acceleration occurred up to 40% earlier after
already 5 hours of feed conditioning. Temperature, which was deliberately
allowed to rise over time (pumping power input) has an effect not only on
viscosity but also on model substance properties like adsorption potential or
‘stickiness’ of the cake [6]. In a yeast + alginate suspension, especially
carbohydrates and TOC decreased over time showing that potential foulants
disappear or change during the course of successive trials.
Conclusions Results showed that like in sludge experiments, filterability and
other properties of model suspensions can change over time. In order to be able
to use model substances as defined foulants, fresh suspensions should be
prepared regularly. Permeate concentration and rejection can give valuable
information on the state of the solution. At the conference, more results will be
presented on model-based analyses of data which yield more information on
fouling mechanisms than permeability data in its raw form. Thus, improved
protocols for model foulants experiments in fundamental research will be
identified.
Acknowledgements Anja Drews gratefully acknowledges the financial support by the Deutsche
Forschungsgemeinschaft (DFG DR763/2-1) and by the University of New South Wales.
References
[1] Ye Y, Le Clech P, Chen V, Fane AG, Jefferson B (2005) Desal 175, 7-20.
[2] Kraume M, Wedi D, Schaller J, Iversen V, Drews A (2008) Desal (in press).
[3] Nataraj S, Schomäcker R, Kraume M, Mishra IM, Drews A (2007) J Membr Sci 308 (2008),
152-161.
[4] Dubois M, Gilles KA, Hamilton JK, Rebers PA, Smith F (1956) Anal Chemistry 28, 350-356.
[5] Frolund B, Palmgren R, Keiding K. Nielsen PH (1996) Water Res, 1749-1758.
[6] Drews A, Mante J, Iversen V, Lesjean B, Vocks M, Kraume M (2007) Water Res 41, 3850-
3858.

Membrane Modeling II - Gas Separation – 1 – Keynote
Tuesday July 15, 2:15 PM-3:00 PM, O’ahu/Waialua
Modeling Approaches for the Design of High Performance Polymer Glassy
Membranes for Small Gas Molecule Separations
P. Pullumbi (Speaker), Air Liquide, Jouy-en-Josas, France - pluton.pullumbi@airliquide.com
E. Tocci, Institute for Membrane Technology ITM-CNR, Rende (CS), Italy
M. Heuchel, GKSS, Teltow, Germany
S. Pelzer, GKSS, Teltow, Germay
The need to shorten the research cycle of novel materials used in gas
separations technologies by coupling several computational approaches with
experimental techniques has been the driving force for the recent developments
in molecular modeling technology. Modeling of gas transport through polymer
membranes is not straightforward because of the complexity of phenomena
involved. In this study we propose a methodology composed out of several
computational methods combining atomistic modelling of models of polymer
membrane materials with Molecular Dynamics (MD) calculations as well as
transition state theory (TST) simulation of transport properties of small gas
molecules in these models followed by Quantitative Structure Activity
Relationship (QSAR) analysis for the design of new polymer materials. The
quality of the predicted transport properties of small gas molecules through
membrane models strongly depends on the quality of these last ones. The large
scatter often observed in simulated values of small gas molecule diffusion
coefficient and solubility in the same glassy polymer membrane is related to the
methodology applied for generating reproducible packing models of the
membrane. In order to reduce this scatter, numerical analysis of structural
features of the membrane model has been used for pre-selecting only the
realistic ones for further use in simulations by means of transition state theory
(TST) approach. In this study more than 200 polymer membrane packing models
corresponding to more than 60 different polymers have been prepared.
Simulated values via TST of Solubility and Diffusion coefficients for small gas
molecules have been predicted for each packing model. Detailed Free Volume
analysis has been carried out for each cell of the data set. A multi- level QSAR
approach has been adopted in order to determine, first, the relevant descriptors
(including information of free volume distribution and dynamics) and second,
determine of the specific weight of each descriptor. Several “separated” QSAR
studies (QSAR-monomers, QSAR-chain, QSAR- Cell) have been carried out and
several descriptors have been selected for the composed study. The proposed
computational methodology in this study whose validation is under progress,
contributes to the joint experimental-theoretical efforts towards the rational
design of membranes with improved properties.
The authors acknowledge the European Community for its partial support (Project: NMP3-CT-
2005- 013644 MULTIMATDESIGN ).

Membrane Modeling II - Gas Separation – 2
Tuesday July 15, 3:00 PM-3:30 PM, O’ahu/Waialua
Molecular Modeling of Free Volume in Poly (pyrrolone-imide) Copolymers
X. Wang (Speaker), University of California Berkeley, Berkeley, California, USA -
xywangz@berkeley.edu
I. Sanchez, University of Texas at Austin, Austin, Texas, USA
B. Freeman, University of Texas at Austin, Austin, Texas, USA
Poly (pyrrolone-imide) copolymers, ultra-rigid polymers which can mimic
molecular sieves, have the potential to be used in the separation of olefin and
paraffin gases in the petrochemical industry. The conventional separation of
olefin and paraffin gases is done using energy intensive low temperature
distillation. Using atomistic models, average cavity sizes and cavity size (free
volume) distributions of poly (pyrrolone-imide) copolymers are calculated using
the Cavity Energetic Sizing Algorithm (CESA). Cavity size distributions of poly
(pyrrolone-imide) copolymers are consistent with the wide angle x-ray diffraction
measurements.

Membrane Modeling II - Gas Separation – 3
Tuesday July 15, 3:30 PM-4:00 PM, O’ahu/Waialua
Development of a Microscopic Free Volume Theory for Molecular Self-
Diffusivity Prediction in Polymeric Systems
H. Ohashi (Speaker), The University of Tokyo, Tokyo, Japan - yamag@res.titech.ac.jp
T. Ito, Tokyo Institute of Technology, Tokyo, Japan
T. Yamaguchi, Tokyo Institute of Technology, Tokyo, Japan
Molecular diffusivity in polymer matrices is an important dynamic physical
property for membrane transports. Prediction of the diffusivity using some
theoretical models is favorable, and thus, several diffusion models for polymeric
systems have been proposed up to now. However, diffusivity prediction model
without adjustable parameter has not been proposed yet because microscopic
phenomena are not taken into account in the previous models.
Microscopically, molecular self-diffusion originates in the common mechanisms
of molecular collisions and random walk motion in polymer systems as well as in
simple liquids. Therefore, we developed a novel model for molecular diffusion in
polymer by incorporating these two notions into the free volume theory. The free
volume theory for polymeric systems contains two unknown parameters, so we
introduced a newly developed concept, “shell-like free volume” around a
molecule, and “random walk movement into neighbor free volume hole” into both
of the unknown parameters. Incorporation of these microscopic concepts
provides a predictive model, which can calculate self-diffusivity of mixing property
using only pure component properties derived from experimental viscoelasticity
and quantum chemical calculation.
Using this model, we can predict self-diffusivity of various molecules in polymer
matrices without using any adjustable parameter. Our model can be applied to
molecules having various shapes and molecular types of gas, solvent, and solute
in several polymeric systems. The predictive ability of our model was found to be
fairly acceptable in every case and thus, the model can be a useful tool for
polymeric membrane designs.

Membrane Modeling II - Gas Separation – 4
Tuesday July 15, 4:00 PM-4:30 PM, O’ahu/Waialua
A Molecular Pore Network Model for Nanoporous Materials
N. Rajabbeigi (Speaker), University of Southern California, California, USA - rajabbei@usc.edu
B. Elyassi, University of Southern California, California, USA
T. T. Tsotsis, University of Southern California, California, USA
M. Sahimi, University of Southern California, California, USA
A new molecular pore network model for the structure of nanoporous materials,
and in particular membranes, has been developed. The construction of the model
starts with a three- dimensional (3D) box in which the atoms that constitute the
material are distributed, either in crystalline form, or as an amorphous material
which is obtained by annealing. The box is then tesselated using the Voronoi
algorithm that partitions the space into irregular 3D polyhedra. A fraction of the
polyhedra is then designated as the pores of the material, and all the atoms
inside such polyhedra, as well as the dangling (singly-connected) atoms are
removed. The size distribution of pore polyhedra can be tuned to match
experimental data for the pore size distribution (PSD) of a given nanoporous
material with any correlation function. Since the pore polyhedra are
interconnected, the model takes into account the effect of the pore connectivity.
Because the material is randomly tesselated and the dangling atoms are
removed, the pores have rough internal surface, which is consistent with what is
known experimentally. To test the model, we simulate adsorption isotherms for
nitrogen, using equilibrium molecular dynamics simulations, in three silicon
carbide (SiC) membranes by adjusting the average pore size of the model to the
experimental data. Good agreement was obtained between the simulated and
measured isotherms. The experimentally-validated model was then used for
modeling transport of gaseous mixtures in the SiC membrane under a variety of
conditions.

Membrane Modeling II - Gas Separation – 5
Tuesday July 15, 4:30 PM-5:00 PM, O’ahu/Waialua
Modeling and Performance Assessment of Pd- and Pd/Alloy-based
Catalytic Membrane Reactors for Hydrogen Production
M. Ayturk (Speaker), Worcester Polytechnic Institute, Worchester, Massachusetts, USA
N. Kazantzis, Worcester Polytechnic Institute, Worchester, Massachusetts, USA
Y. Ma, Worcester Polytechnic Institute, Worchester, Massachusetts, USA - yhma@wpi.edu
As global competition for oil supplies steadily intensifies, transforming today’s oil
dominated energy and transportation system to one running on hydrogen,
represents one of the most daunting challenges. The production of hydrogen via
natural gas steam reforming (MSR) and/or water-gas shift (WGS) reaction of the
coal-derived syngas in Pd- and sulfur tolerant Pd/Alloy-based catalytic
membrane reactors (CMRs) is an attractive technology which generates further
interest primarily due to its great potential for process intensification. Motivated
by the above considerations, the main objective of the present study is to
develop a systematic and comprehensive modeling framework for the
assessment of the impact of operating conditions on Pd-based CMR
performance, as well as appropriately define indicators representing quantitative
criteria for the attainment of key process intensification objectives (efficiencies in
the use of material and energy resources, cost and “waste management” for a
given production capacity target).
An isothermal mathematical steady-state model of an industrial size CMR for the
MSR, WGS and methanation reactions was developed and a comparative
performance assessment of the CMR versus a conventional packed bed reactor
(PBR) was conducted. The temperature dependence of the reaction rate
parameters, equilibrium and adsorption constants and the intrinsic reaction
kinetics for the MSR and WGS reactions on a supported Ni catalyst were
adopted from the detailed experimental study conducted by Xu and Froment.
Based on the available literature data, an average hydrogen permeability for the
pure-Pd films has been determined via linear regression analysis and used to
estimate the rate of hydrogen removal in the CMR model. The Matlab® software
was utilized to numerically integrate the set of process model equations via a 4th
order Runga-Kutta algorithm. In particular, the model is structurally comprised of
the requisite set of independent mass balance equations that describe the
steady-state profiles of product distribution and total methane conversion along
the lengths of both the tubular CMR as well as the PBR.
Validation of the CMR model was accomplished by simulating both the Pd-based
CMR and the conventional PBR conditions reported in the literature. A detailed
literature benchmarking showed that the models developed in this study

predicted total methane conversion within 99% of the experimental values
reported in the literature. The performance analysis was conducted by simulating
the reactor model equations within a broad range of operating conditions,
including reactor temperature, reaction- and permeate-side pressures, steam-tomethane
ratio, membrane thickness, permeate-side sweep gas flow rate,
effectiveness factor and bed porosity. In all simulation studies conducted, the Pdbased
CMRs demonstrated superior performance over the traditional PBRs.
From a traditional process intensification perspective, CMRs exhibit considerable
advantages over traditional reformers including the elimination of high and low
temperature shift reactors, pre-Ox and hydrogen separator, thus enabling
reaction, separation and product concentration processes to take place in a
single unit operation. In order to develop a concrete quantitative performance
evaluation framework for CMRs coupled with progress assessment towards the
attainment of key process intensification objectives, a set of indicators are
proposed that can be readily evaluated by simulating the aforementioned CMR
model. In particular, the proposed reactor performance criteria and process
intensification indicators are realized in terms of conversion, hydrogen recovery,
membrane selectivity, reaction temperature and catalyst lifetime, process
modularity, as well as energy and fuel savings and effective use of resources.

Membrane Modeling II - Gas Separation – 6
Tuesday July 15, 5:00 PM-5:30 PM, O’ahu/Waialua
Free-Volume Holes in Amorphous Polymers for Solvent Diffusion:
Reconsideration of the Free-Volume Theory By Equation-of-State, Group
Contribution Method, PALS Measurement and Molecular Simulation
H. Lv (Speaker), Tsinghua University, China
B. Wang, Tsinghua University, China - bgwang@tsinghua.edu.cn
J. Yang, Tsinghua University, China
In many processes such as gas separation, pervaporation and vapor permeation
with a polymeric dense membrane, solvent diffusion behaviors in polymer matrix
have attracted much attention, since the diffusivity is normally the rate- limiting
step. Prediction of solvent diffusivity is of fundamental importance in the
development of polymeric membrane design methodology for organic mixture
separation [1-3]. In the past decades, the free-volume theory, which emphasizes
the amount of free-volume vacancies as the dominant factor for diffusion, has
served as the main basis for the correlation of diffusion behaviors in polymersolvent
systems. The model proposed by Vrentas and Duda is the representative
of free-volume theory, in which most parameters can be obtained from pure
component properties and no adjustable parameters are used [4-8]. However,
free-volume parameters of polymer are usually determined by fitting the results
from measurement of polymer viscoelasticity, meaning a great deal of time and
cost consumption [9-11]. Moreover, the relationship between detailed information
about the atomic-scale holes, which collectively constitute the free volume in
polymers, and solvent transport properties still remains uncertainty. In order to
remove these shortcomings, this study proposes four approaches to estimate
polymer free volume and compare with the original model both theoretically and
experimentally.
The first two approaches are equation-of-state (EOS) and group contribution
method, both of which are based on macroscopic viewpoint of the free volume.
For the former, the Simha-Somcynsky hole theory EOS is introduced into the
free-volume theory; for the latter, the universal constant of the van der Waals
volume of functional groups in polymer repeating units is introduced. Both of the
modified models provide agreeable prediction of infinite dilution diffusion
coefficients and solvent self-diffusion coefficients in several polymer- solvent
systems without measuring polymer viscoelasticity. Furthermore, the individual
predominance of these two approaches is discussed. In the EOS-modified
model, the influence of pressure on solvent diffusivity in dilute polymer solutions
can be included. In the group contribution-modified model, since all the
parameters related to polymer can be determined only based on the knowledge
of polymer structural units, a real process of membrane design with polymer

functional groups becomes available. The third approach is positron annihilation
lifetime spectroscopy (PALS) technique, which can measure the mean size and
size distribution of subnanometer-size vacancies in polymers. The published
mean hole volume detected by PALS is employed to predict solvent diffusion
coefficients with the help of the EOS. The predictions are generally consistent
with published diffusion data. In addition, the analysis of hole size distribution can
prove the reliability of the EOS-approach and group contribution-approach. The
fourth approach is molecular simulation, which can investigate free- volume holes
from microscopic point of view. The simulation is performed on PVAc and PMA,
which are structural isomers of each other. The quantitative relation between the
simulation and the free volume defined by the Simha-Somcynsky EOS, PALS
measurements and free-volume theory is given. The infinite dilution diffusion
coefficients in PVAc are predicted using simulation method, and the predictions
are in good agreement with experimental data.
This study provides a consistent feature to describe solvent transport in polymer
matrix with both macro- and microscopic structure. The prediction ability of the
original free-volume theory is improved by introducing the EOS and group
contribution method. Therefore, the modified model is useful to understand mass
transport in polymeric dense membranes and to develop a novel approach for
membrane materials design.
Acknowledgement The authors gratefully acknowledge the financial assistance
from the Major State Basic Research Development Program of China (973
Program) (No. 2003CB615701) and the National Natural Science Foundation of
China (No. 20676068).
References
[1] Yamaguchi T, Miyazaki Y, Nakao SI, Tsuru T, Kimura S. Ind Eng Chem Res, 1998, 37, 177.
[2] Wang BG, Miyazaki Y, Yamaguchi T, Nakao SI. J Membr Sci, 2000, 164, 25.
[3] Wang BG. Membrane design for organic mixture separation [Ph.D. Dissertation]. University of
Tokyo, Japan, 2000.
[4] Vrentas JS, Duda JL. J Polym Sci Polym Phys Ed, 1977, 15, 403.
[5] Zielinski JM, Duda JL. AIChE J, 1992, 38, 405.
[6] Hong SU. Ind Eng Chem Res, 1995, 34, 2536.
[7] Vrentas JS, Vrentas CM. Macromolecules, 1994, 27, 4684.
[8] Yamaguchi T, Wang BG, Matsuda E, Suzuki S, Nakao SI. J Polym Sci Polym Phys, 2003, 41,
1393.
[9] Lv HL, Wang BG. J Polym Sci Polym Phys, 2006, 44, 1000.

[10] Wang BG, Lv HL, Yang JC. Chem Eng Sci, 2007, 62, 775.
[11] Lv HL, Wang BG, Yang JC. Polym J, 2007, 39, 1167.

Membrane and Surface Modification I – 1 – Keynote
Tuesday July 15, 2:15 PM-3:00 PM, Wai’anae
New Chemically Modified Membranes in Bioseparations
D. Melzner (Presenting), Sartorius Stedim Biotech GmbH, Goettingen, Germany -
dieter.melzner@sartorius-stedim.com
R. Faber, Sartorius Stedim Biotech GmbH, Goettingen, Germany
Chemically modified membranes are meanwhile widely used in bioseparations.
Especially in the downstream processing of monoclonal antibodies and vaccines
the membrane chromatography is established as an important unit operation.
To obtain optimal separation results in specific process steps and to compete
with alternative techniques, intensive further development in optimization of the
membrane properties and extension of available ligands is necessary.
The work has been done by identifying the critical membrane properties for an
optimal fit to the corresponding application and transfer of these results into the
optimal chemical structure.
New Membranes are presented, which fulfil optimal the needs for separation and
purification of biomolecules like monoclonal antibodies or other proteins. The
membrane structures in relation to the separation properties are discussed.
The results are discussed under consideration of the device construction and
process design., because both have substantial influence on the performance of
the whole purification process.
Examples of polishing of monoclonal antibodies solutions, virus removal and
virus harvesting are shown.

Membrane and Surface Modification I – 2
Tuesday July 15, 3:00 PM-3:30 PM, Wai’anae
Surface-Initiated Atom Transfer Radical Polymerization: A New Tool to
Produce High-Capacity Adsorptive Membranes
B. Bhut (Speaker), Clemson University, Clemson, South Carolina, USA
S. Wickramasinghe, Colorado State University, Fort Collins, Colorado, USA
S. Husson, Clemson University, Clemson, South Carolina, USA - SHUSSON@CLEMSON.EDU
When used as chromatography media, synthetic microporous or macroporous
membranes offer advantages over resin-based media, such as low pressure
drop, high production rate, and facile scale up and set up. In this presentation,
we will describe how to surface modify commercially available regenerated
cellulose membrane by atom transfer radical polymerization to produce high-
capacity (>50 mg/ml) ion-exchange membranes for protein chromatography. The
monomer 2- dimethylaminoethyl methacrylate was polymerized from cellulose
membranes to convert them into weak anion-exchange membranes.
Physicochemical properties of surface-modified membranes were studied as a
function of polymerization time with various analytical measurement techniques
that include scanning electron microscopy, atomic force microscopy, and
attenuated total reflectance FTIR. Performance properties that were measured
include buffer permeability and static protein adsorption capacities.

Membrane and Surface Modification I – 3
Tuesday July 15, 3:30 PM-4:00 PM, Wai’anae
Gas and Liquid Permeation Studies on Modified Interfacial Composite
Reverse Osmosis and Nanofiltration Membranes
J. Louie (Speaker), Stanford University, Palo Alto, California, USA - jlouie@stanford.edu
I. Pinnau, Membrane Technology and Research, Inc., Menlo Park, California, USA
M. Reinhard, Stanford University – Palo Alto, California, USA
Surface coating is a simple technique to modify water treatment membranes for
enhanced fouling resistance. However, the conditions of the modification process
and interactions between the membrane and the coating can impact membrane
performance. A selection of reverse osmosis and nanofiltration membranes were
coated with a thin water-permeable polyether-polyamide block copolymer layer
(PEBAX 1657) to reduce the rate of fouling, and thereby increase cumulative
flux. Improved fouling resistance was observed when treating an oil-watersurfactant
emulsion with a PEBAX-coated seawater membrane, relative to an
uncoated sample. However, pure-water flux values for some of the coated
membrane types were lower than for uncoated membranes, and the reductions
exceeded the predicted declines based on the series resistance model. Gas
permeation tests were performed to assess how membrane modification
procedures affect the separating layer morphology of thin-film composite reverse
osmosis membranes. Selectivity data provided evidence for the presence of
nanoscale separating layer defects in dry samples of six commercial membrane
types. These defects were eliminated when the membrane surface was coated
with a polyether-polyamide block copolymer (PEBAX 1657), as indicated by a 25fold
decrease in gas permeance and at least a two-fold increase in most
selectivity values. Treatment with n-butanol reduced water flux and gas flux by
30% and 75%, respectively, suggesting that it negatively affects the membrane
during the coating process. The results of this study demonstrate that gas
permeation measurements can be used to detect morphological changes that
impact membrane flux. It also demonstrates the need to evaluate incidental
effects of modification procedures on membrane structure and performance.

Membrane and Surface Modification I – 4
Tuesday July 15, 4:00 PM-4:30 PM, Wai’anae
Study of a Hydrophilic-Enhanced Ultrafiltration Membrane
T. Gullinkala (Speaker), University of Toledo, Toledo, Ohio, USA - tgullink@eng.utoledo.edu
I. Escobar, University of Toledo, Toldeo, Ohio, USA
Different approaches of grafting poly (ethylene glycol) chains to commercially
available cellulose acetate ultrafiltration membrane were considered and
compared with respect to permeate flux, solute rejection and fouling prevention.
Grafting was attained by forming reactive radicals on the membrane surface by
using oxidation agent. Persulfate was used as the oxidizing agent due to its ease
of use in aqueous phase. Formation of free radicals was confirmed by their
reaction with sulfate ions and consecutive sulfur mapping images. Low molecular
weight PEG chains were attached to the membrane surface through the reaction
with these free radicals. Low molecular weight PEG was chosen to reduce the
chance of cross linking on the membrane surface. The propagating PEG chains
were capped by a chain transfer agent after optimum reaction time. Chain
termination was achieved by the chain transfer agent. The function of chain
transfer agent was established by SEM mapping.
Optimum reaction times for the modification were 10 minutes for oxidizing agent,
5 minutes for the monomer and 2.5 minutes for the chain transfer agent. These
contact times were used in the two different approaches used to perform the
modification. In one method, called bulk method membrane samples were
immersed in the liquid reagents associated with vigorous stirring. Samples were
dissolved first in oxidizing agent then in aqueous PEG solution and finally in
chain transfer agent for the above mentioned reaction times. In another method
called drop method, a membrane sample was placed flat on a glass sample
holder and solutions containing the oxidizing agent were added to the membrane
sheet drop wise so that the entire sample sheet was filled with the persulfate
solution. After ten minutes the oxidizing solution was replaced by PEG solution
for chain propagation and then chain transfer agent was added drop wise for
controlling chain length. Modification was confirmed by FTIR spectra and SEM
mapping.
Two different feed solutions were used to characterize the modification. Dextran
solution was used to determine the effect of modification on uncharged
particulate matter and modeled sea water to determine the influence of graft
polymerization on natural organic matter during filtration through cellulose
acetate membranes. In these experiments sea water was simulated by forming
an aqueous solution composed of 2 mg/l of each Suwannee River Fulvic and
Humic Acids, along with 0.1 mM CaCl2 as a representative of divalent cations,

0.1 mM NaHCO3 as buffer system,1M NaCl as background electrolyte and 1 mg/l
of SiO2.
Drop method modification of the membrane resulted in better flux than bulk
modified and virgin membranes during ultrafiltration of dextran solution. It also
resulted in 10% increase in the rejection capacity than that of virgin membrane.
Drop modification of membrane also led to modest decrease in the roughness of
the membrane which reduces the membrane susceptibility to fouling. Only bulk
modification was used to polymerize the membranes in the case of ultrafiltration
of modeled sea water for the ease of use. Different sets of filtration runs were
performed such as 1 minute, 5 minutes, 15 minutes and up to 6 hours to
determine the fouling patterns due to natural organic matter such as humic and
fulvic acids present in the feed solution. In this case modification led to the
increase in the permeability of the membrane and finer fouling patterns during
filtratuion.

Membrane and Surface Modification I – 5
Tuesday July 15, 4:30 PM-5:00 PM, Wai’anae
Crosslinked Poly(ethylene oxide) Fouling Resistant Coating Materials:
Synthesis, Characterization, and Application
H. Ju (Presenting), University of Texas at Austin, Austin, Texas, USA
B. McCloskey, University of Texas at Austin , Austin, Texas, USA
A. Sagle, University of Texas at Austin , Austin, Texas, USA
B. Freeman, University of Texas at Austin, Austin, Texas, USA – freeman@che.utexs.edu
Various crosslinked poly(ethylene glycol) diacrylate (XLPEGDA) materials were
synthesized via free-radical photopolymerization of poly(ethylene glycol)
diacrylate (PEGDA) solutions. These materials have potential as fouling-resistant
coatings for commercial ultrafiltration (UF) membranes. PEGDA chain length
(n=10~45) and water content in the prepolymerization mixture (0~80 wt.%) were
varied in synthesizing the XLPEGDA materials, and their water transport ability
and solute sieving properties were characterized. Water permeability increased
with increasing water content in the prepolymerization mixture and with
increasing PEGDA chain length. However, solute rejection decreased with
increasing prepolymerization water content or PEGDA chain length. Finally, the
fouling resistance of XLPEGDA materials was evaluated with static protein
adhesion experiments, and less BSA accumulated onto XLPEGDA surfaces
when the film was prepared at higher prepolymerization water content or using
longer PEGDA chains. When XLPEGDA materials were applied to polysulfone
(PSF) UF membranes to form coatings on the surface of the PSF membranes,
the coated PSF membranes had water flux values 400% higher than that of an
uncoated PSF membrane after 24 hours of operation, and the coated
membranes had higher organic rejection than the uncoated membranes in
oil/water crossflow filtration experiments.

Membrane and Surface Modification I – 6
Tuesday July 15, 5:00 PM-5:30 PM, Wai’anae
Dopamine: Biofouling-Inspired Anti-Fouling Coatings for Water Purification
Membranes
B. McCloskey (Speaker), The University of Texas at Austin, Austin, Texas, USA
H. Park, University of Ulsan, Korea
B. Freeman, The University of Texas at Austin, Austin, Texas, USA – freeman@che.utexas.edu
One of the main issues facing water purification membrane technology is
membrane fouling, which is the deposition of organic contaminants on the
membrane surface or in its pore structure. Fouling leads to a catastrophic
decrease in water flux which, in turn, results in high operating costs and short
membrane lifetime. Many methods have been studied to combat membrane
fouling, most of which focus on two general techniques: introducing high fluid
shear on the feed stream side, such as backpulsing, dean vortices, and air
sparging, and altering the surface properties of the membranes, either through
surface grafting/coating, plasma treatment, or other chemical modifications.
Although feed flow instabilities increase flux in some MF and UF membrane
applications, fouling is still a concern. Furthermore, combining surface modified
membranes with increased surface shear will lead to higher membrane efficiency
over using one of the two techniques. Therefore, this study focuses on producing
a simple chemical modification technique that uses a strongly bound, hydrophilic
ad-layer, which is stable under even the most extreme fluid shear environments.
Dopamine has been recently used to mimic a mussel s adhesive plaque. In
alkaline solutions, dopamine will self-polymerize (polydopamine) and deposit on
virtually any surface with which it comes into contact. By using this simple
deposition technique, polydopamine is “coated” onto polysulfone (PSf)
ultrafiltration (UF) membranes and polyamide (PA) reverse osmosis (RO)
membranes. Polydopamine was found to increase a membrane s surface
hydrophilicity and therefore increase its resistance to fouling. After one day of oilemulsion
fouling, the polydopamine-coated PSf membrane showed a flux over 8
times higher than that of the unmodified PSf membrane, and a polydopaminemodified
PA RO membrane exhibited a 30% flux increase over the unmodified
membrane. Furthermore, organic rejection of the modified membranes is similar
to that of the unmodified membranes.

Oral Presentation
Abstracts
Morning Session
Wednesday, July 16, 2008

Plenary Lecture II
Wednesday July 16, 8:00 AM-9:00 AM, Hawai’i Ballroom
Thermally Rearranged Polymer Membranes With Cavities Tuned for Fast
Transport of Small Molecules
Professor Young Moo Lee, Hanyang University, Seoul, Korea - ymlee@hanyang.ac.kr
We demonstrate that polymers with an intermediate cavity size, a narrow cavity
size distribution and a shape reminiscent of bottlenecks connecting adjacent
chambers, such as those found elegantly in Nature in the form of ion channels
and aquaporins, yield both high permeability and high selectivity [1]. Central to
our approach for preparing these intermediate sized cavities is controlled free
volume element formation via spatial rearrangement of the rigid polymer chain
segments in the glassy phase. It is known that a rearrangement, such as
intramolecular cyclization, in glassy polymers could lead to changes in polymer
structure for gas transport [2]. For this purpose, aromatic polymers
interconnected with heterocyclic rings (e.g., benzoxazole, benzithiazole,
polypyrrolone and benzimidazole) are of interest because phenylene-heterocyclic
ring units in such materials have a flat, rigid-rod structure with high torsional
energy barriers to rotation between two rings [3]. The stiff, rigid ring units in such
flat topologies pack efficiently, leaving very small penetrant-accessible free
volume elements. This tight packing is also promoted by intersegmental
interactions such as charge transfer complexes between heteroatoms containing
lone electron pairs (e.g., O, S and N). The genesis of these materials was the
demand for highly thermally and chemically stable polymers. However, their
application as gas separation membranes was frustrated by their lack of solubility
in common solvents, which effectively prevents them from being prepared as thin
membranes by solvent casting, which is the most widely practiced method for
membrane preparation. Most of all, the greatest benefit of these Thermally
Rearranged (TR) polymers is the ability to tune the cavity size and distribution for
specific gas applications including CO2 from flue gas by using various templating
molecules and heat treatments, using one starting material.
References
1. H.B. Park, C.H. Jung, Y.M. Lee, A.J. Hill, S.J. Pas, S.T. Mudie, E. Van Wagner, B.D.
Freeeamn, D.J. Cookson, Science 318, 214 (2007).
2. I.K. Meier, M. Langsam, H.C. Klotz, J. Membr. Sci. 94, 195 (1994).
3. V.J. Vasudevan, J.E. McGrath, Macromolecules 29, 637 (1996).

Gas Separation III – 1 – Keynote
Wednesday July 16, 9:30 AM-10:15 AM, Kaua’i
Membrane Engineering Progresses and Potentialities in Gas Separations
E. Drioli (Speaker), Research Institute on Membrane Technology, ITM-CNR, Italy -
e.drioli@itm.cnr.it
Membrane processes for gaseous mixture separations are today a well
consolidated technique competitive in various cases with the traditional
operations [1]. Separation of air components, natural gas dehumidification,
separation and recovery of CO2 from biogas and natural gas, and of H2 from
refinery industrial gases are some examples in which membrane technology is
applied already at industrial level. The separation of air components or oxygen
enrichment has advanced substantially during the past 10 years. The oxygen-
enriched air produced by membranes has been used in various fields, including
chemical and related industries, the medical field, food packaging, etc. The
possibility of utilizing membrane technology in solving problems such as the
greenhouse effect related to CO2 production has also been suggested.
Membranes able to remove CO2from air, having a high CO2/N2 selectivity, might
be used at any large-scale industrial CO2source as power station in
petrochemical plants. The CO2separated might be converted by reacting it with
H2 in methanol, starting a C1 chemistry cycle. A membrane reactor might be
ideally used to carry out hydrogenation reactions for chemical production using
CO2 recovered from exhaust gases by membrane separation. The separation
and recovery of organic solvents from gas streams is also rapidly growing at the
industrial level. Polymeric rubbery membranes that selectively permeate organic
compounds (VOC) from air or nitrogen have been used. Such systems typically
achieve greater than 99% removal of VOC from the feed gas and reduce the
VOC content of the stream to 100 ppm or less. The significant positive results
reached in gas separation membrane systems are however still far away to
realize the potentialities of this technology. Problems related to the pretreatments
of the streams, to the membranes life time, to their selectivity and permeability
still exist slowing down the growth of large scale industrial applications. New
polymeric inorganic and hybrid materials are under investigation in different
laboratories around the world. The possibility to realize also new mass transport
mechanisms as the ones characterizing the perovskites membranes is becoming
of interest. The case of O2 and H2 transport in these membranes might be
extended to other species by realizing new specific materials. Molecular
dynamics studies, fast growing in this area, might contribute to the design of
these new inorganic materials or to the appropriate functionalization of existing
polymeric membranes. Amorphous perfluoropolymers might be utilized for
casting asymmetric composite membranes [2] with interesting selectivity and
permeabilities for various low molecular species. Their cost is however a

negative aspect. With the introduction of process intensification strategy also in
to the petrochemical industry, a large new areas will be open for gas separation
membrane systems. The possibility to realize integrated membrane operations in
the ethylene process, for example, has been studied and is under investigations
[3]. Some of the drawbacks of the membrane operations such as the necessity of
accurate pre- treatments, might be solved by combining, as already done in
water treatments, various membrane operations in the same industrial process.
The recent studies on carbon nanotubes with the unexpected very high
permeability and selectivities, the progresses in zeolite membranes and in hybrid
membranes where polymers and specific absorbers are combined, are offering
interesting new opportunities for making membrane operations dominant also in
gas separations and gas conversions.
References
[1] Drioli, E: Gas Separation Membranes: A Potential Dominant Technology. Special Issue.
Trends in Gas Separation Membranes. (Membrane) 31, (2), 000- 000 (2006)
[2] Baker RW, Wijmans JG, Kaschemekat JH: ’The Design of Membrane Vapor-Gas Separation
Systems’, Journal of Membrane Science, , 55-62 (1998)
[3] Bernardo P, Criscuoli A, Clarizia G, Barbieri G, Drioli E, Fleres G, Picciotti M : Applications of
membrane unit operations in Ethylene Process, Clean Technologies and Environmental Policy, 6,
(2) 78 (2004)

Gas Separation III – 2
Wednesday July 16, 10:15 AM-10:45 AM, Kaua’i
Evolution of Natural Gas Treatment with Membrane Systems
L. White (Speaker), W.R. Grace & Co.-Conn., Littleton, Colorado, USA -
lloyd.s.white@grace.com
C. Wildemuth, Grace Davison Membranes, Littleton, Colorado, USA
Membrane treatment of natural gas to produce pipeline quality feedstock was
commercially introduced in the early 1970’s. Cellulose acetates (CA) were found
to be the polymer of choice for these early systems. Polyimides were identified
by the 1980;s as a next generation polymer for natural gas treatment. But despite
the remarkable properties exhibited by the polyimides the CA based systems are
today still competitive in real world separations.
Remaining of key interest are the effects of impurities in the natural gas stream
on the membranes. Interactions with condensable hydrocarbons are different
between CA and polyimide membranes.
Since these technologies continue to improve, this paper will explore some of the
key aspects in the evolution of membrane performance, packaging, and
engineering of large-scale systems for natural gas processing. Will current trends
toward large-scale installations be maintained in the future?

Gas Separation III – 3
Wednesday July 16, 10:45 AM-11:15 AM, Kaua’i
CO2 Permeation With Pebax-Based Membranes for Global Warming
Reduction
Q. Nguyen (Speaker), Rouen University, France - trong.nguyen@univ-rouen.fr
J. Sublet, Rouen University, France
D. Langevin, CNRS, France
C. Chappey, CNRS, France
J. Valleton, CNRS, France
P. Schaetzel, CAEN University, France
Carbon dioxide extraction from nitrogen- rich gas streams produced by fossil-
fuel- based power plants is of growing interest, both within industry and
government, for the gas sequestration in a global warming reduction strategy.
The classical gas- scrubbing process is energy- voracious and source of extra-
pollution due to the need of regeneration of amines, the absorbent. Membrane
processes may offer attractive alternatives to reduce the emission of this
greenhouse effect source, due to their well-known advantages from the
environmental and energetic viewpoints. The success of a gas permeation
process relies on the possibility of obtaining membranes with high- performances
and good mechanical/ thermal stabilities. Composite membranes consisting of an
asymmetric glassy membrane whose surface defects are sealed with a thin
polymer layer are generally the preferred structure, because of their
technological feasibility. Sofar, such a concept of composite membranes with a
gutter silicone layer has been successfully used for separation membranes e.g.
for the hydrogen recovery or oxygen/ nitrogen production from air. The
performances of the composite membranes depend critically on the gas nature
and on the intrinsic properties of the composite layers. Contrary to hydrogen and
other gases of very low normal boiling points, CO2 is a polar gas of similar
molecular size to nitrogen, that can significantly interacts with certain chemical
groups. We followed Lin and Freeman's approach* in developing new polymer
materials for the membrane selective layer. The approach consists of selecting
polymers of high CO2 solubility and CO2/light gas solubility selectivity by
introducing polar groups in polymers. Ether oxygens in polyethylene oxide (PEO)
appeared to be the most useful groups*. Commercial Pebax® copolymer
containing "soft" PEO /PTMO and "hard" polyamide (6 or 12) blocks were chosen
as the base polymers in this study because the compromise they provide
between a high content of PEO and good mechanical properties. Membranes
made of extruded and solvent- cast Pebax® block copolymers of different
structures were studied by gas permeation, DSC and AFM. The change in the
transport characteristics with the Pebax®- type appeared to be complex, due to
multiphase structure of the materials: EO content is not the sole factor that
controls the membrane performances. The best Pebax® material for CO2/N2

separation was next blended with different ethylene oxide- containing polymers
and studied in gas permeation. In general, the CO2/N2 separation performances
of the blends were depressed by blending, except for the blend with liquid
polyethylene glycol (PEG) of low molecular weight. For the latter blend, both the
permeability and the selectivity were improved, probably due to the high mobility
of the PEG chain and absence of its crystallinity. Such materials, which derive
from commercially available products, can be easily combined with a
microporous support to yield a composite membrane for the CO2 abatement.
*Haiqing Lin and Benny D. Freeman, Materials selection guidelines for membranes that remove
CO2 from gas mixtures J. Molec. Struct., 739 (2005) 57-74
Q. T. Nguyen, J. Sublet, D. Langevin, C. Chappey, J. M. Valleton and P. Schaetzel*, UMR 6522,
CNRS- Rouen University, 76821 Mont St Aignan Cedex- France * Laboratoiry of material
processes, Caen University, 14032 Caen Cedex- France Corresponding author:
trong.nguyen@univ- rouen.fr

Gas Separation III – 4
Wednesday July 16, 11:15 AM-11:45 AM, Kaua’i
A Membrane Process to Capture CO2 from Power Plant Flue Gas
T. Merkel (Speaker), Membrane Technology and Research, Menlo Park, California, USA -
tcmerkel@mtrinc.com
H. Lin, MTR, Menlo Park, California, USA
S. Thompson, MTR, Menlo Park, California, USA
R. Daniels, MTR, Menlo Park, California, USA
A. Serbanescu, MTR, Menlo Park, California, USA
R. Baker, MTR, Menlo Park, California, USA
The use of coal as fuel to make power inevitably produces carbon dioxide (CO2)
as a byproduct. In the future, this CO2 must be captured and sequestrated. A
number of technologies are being evaluated for CO2 capture. Membrane
technology is an attractive approach because of its inherent advantages such as
high energy efficiency, a small footprint, environmentally friendly operation (no
chemicals), mechanical simplicity, and good reliability.
We have developed new CO2 selective membranes and process designs to
recover CO2 from power plant flue gas. These membranes have CO2
permeances 10 times higher than conventional commercial membranes
combined with high CO2/N2 selectivities. Bench scale test results on the
membrane and modules will be discussed. Sensitivity studies will illustrate the
optimal membrane properties for this application. System designs and
simulations for a 500 MWe power plant will be shown to illustrate the effect of
operating conditions (such as required CO2 recovery) on the cost of CO2 capture.
Based on the best system design developed, achieving 90% CO2 recovery
requires 18% of the power produced by the power plant.
In general, removal of CO2 from coal power flue gas is technically feasible with
current membranes, but remains economically challenging. Higher flux
membranes and low-cost ways of packaging them in large modules will improve
the competitiveness of this separation approach. Also key to further development
of this technology will be collaboration of membrane system producers and coal
power plant designers.

Gas Separation III – 5
Wednesday July 16, 11:45 AM-12:15 PM, Kaua’i
Membranes and Post Combustion Carbon Dioxide Capture: Challenges &
Prospects.
E. Favre (Speaker), LSGC CNRS, Nancy, France - Eric.Favre@ensic.inpl-nancy.fr
CCS (Carbon Capture & Sequestration) is a key issue in the reduction of
greenhouse gases emissions. The capture step, which corresponds to the most
expensive part of the technological chain, can be potentially achieved thanks to
different processes. Numerous strategies are currently explored in order to
identify the most efficient and less expensive process, which could reach a high
CO2 capture ratio (typically 80 % or more), together with the production of a
carbon dioxide stream of high purity (typically a volume fraction of 0.8 or more)
[1]. From the energy requirement point of view, the EU has fixed 2 GJ per ton of
carbon dioxide captured as a target [2]. Surprisingly, gas separation membranes
are often discarded for this application [3].
This presentation intends to give an overview of the different strategies which
can be proposed in order to use gas separation membranes for post combustion
carbon capture in an industrial context (e.g. power plants, steel or cement
manufacturing).
In a first step, challenges for membrane materials will be analysed. The major
targets of the capture process in terms of selectivity, energy requirement and
productivity will be reviewed and compared to membrane performances
(permeability / selectivity / permeance). An up to date review of the various
membrane materials which could potentially be proposed (polymers, mineral
membranes, mixed matrix membranes, fixed site carrier membranes, liquid
membranes) will be critically discussed according to these requirements.
In a second step, novel process strategies will be proposed, in order to minimize
the energy requirement. Reverse selective materials, pressurised combustion,
water entrainment and concentrated CO2 post combustion streams will be briefly
exposed. A novel hybrid process will be more specifically detailed [4]. The key
concept is based on the minimal work of concentration. A capture framework
which combines an oxygen enrichment step before combustion and a CO2
capture step from flue gas has been investigated. The potentialities of this hybrid
process from the energy requirement point of view are discussed. It is shown that
the hybrid process can lead to a 35% decrease of the energy requirement
(expressed in GJ per ton or recovered CO2) compared to the standard capture
technology (i.e. oxycombustion), providing that optimal operating conditions are
chosen. These promising performances can be achieved with a membrane

selectivity of 50 or more, which is realistic for the CO2/N2 mixture. Applications of
this concept to biogas power plants appear to be extremely attractive.
[1] Davidson, O., Metz, B. (2005) Special Report on Carbon Dioxide Capture and Storage,
International Panel on Climate Change , Geneva, Switzerland, (www. ipcc.ch).
[2] Deschamps P., Pilavachi, P.A. (2004) Research and development actions to reduce CO2
emissions within the European Union. Oil & Gas Science and Technology 59 (3) : 323-33
[3] Favre, E. (2007) Carbon dioxide recovery from post combustion processes: Can gas
permeation membranes compete with absorption? Journal of Membrane Science, 294, 50-59.
[4] Favre, E., Bounaceur, R., Roizard, D. (2008) A hybrid process combining enriched oxygen
combustion and membrane separation for carbon dioxide post combustion capture. International
Journal of Greenhouse Gas Control, submitted

Gas Separation III – 6
Wednesday July 16, 12:15 PM-12:45 PM, Kaua’i
The Effect of Sweep Uniformity on Gas Dehydration Modules
P. Hao (Speaker), The University of Toledo, Toledo, Ohio, USA
G. Lipscomb, The University of Toledo, Toledo, Ohio, USA - glenn.lipscomb@utoledo.edu
Air dehydration membranes offer a simple, cost effective solution to humidity
control. Membrane units may be installed in-line and require no- auxiliary utilities
- only a portion of the feed gas is lost and a small pressure drop is incurred.
To produce desired dew points, a portion of the product gas typically is used as
sweep in the module. Sweep lowers the water concentration in the permeate to
permit sufficient reduction of the water concentration in the retentate (non-
permeate) stream.
The literature reports numerous ways to create the sweep stream including: 1)
making the fibers non-selective at the product end, 2) introducing the sweep from
an external collar around the module, and 3) inserting tubes through the
tubesheet that allow communication between the product header and the shell of
the module.
We report simulations of the sweep distribution within the shell and its effect on
module performance. Two types of simulations are considered: 1) simulations
that explicitly predict flow fields within the shell based on how the sweep gas is
introduced and 2) simulations that assume the sweep flow around each fiber is
distributed in a Gaussian manner.
The use of fibers that are non-selective at the product end is most efficient based
on module capacity and dry gas recovery. Introducing the sweep through an
external collar or internal tubes is poorer due to poorer gas distribution in the
shell.
Predictions based on explicit calculation of shell flow fields are in good
agreement with those based on a Gaussian sweep distribution using a standard
deviation in sweep flow equal to ~15% of the average sweep flow rate. We
believe the results of this work may be used to evaluate alternative methods
providing sweep in a module.

Drinking and Wastewater Applications III – 1 – Keynote
Wednesday July 16, 9:30 AM-10:15 AM, Maui
Membranes and Water: the Role of Hybrid Processes
A. Fane (Speaker), Director, Singapore Membrane Technology Centre, NTU, Singapore -
AGFane@ntu.edu.sg
Membrane technology now has a major role in water and wastewater treatment.
In many cases the membrane does not operate alone but is coupled with other
unit operations, giving us Hybrid Membrane Processes. Further, in the majority of
cases the membrane process is low pressure microfiltration or ultrafiltration and
the hybrid component allows greater removals to be achieved. Submerged
membrane systems provide a simple concept with the ‘unit operation’ in the tank
and the membranes providing both inventory control and separation.
This presentation discusses a number of hybrid processes including adsorption,
photocatalysis [1] and combined adsorption and photocatalysis for water
treatment. In these examples the membrane plays an inventory management
role but provides little solute separation; typically fouling is a minor concern. For
wastewater treatment the submerged MBR is the dominant hybrid and fouling is
the dominant issue. The MBR fouling ‘roadmap’ [2] is revisited with an eye on
recent developments. In the MBR the membrane may provide partial ‘solute’
removal as well as complete particle removal. Finally a novel MBR [3] involving
membrane distillation provides an approach to complete solute retention of
solutes. The challenges faced by the MDBR concept are outlined.
[1] S. S. Chin, T. M. Lim, K. Chiang and A. G. Fane, Factors affecting the performance of a lowpressure
submerged membrane photocatalytic reactor., Chem Eng J., 131 (2007) 53-63.
[2] J. Zhang, H. C. Chua, J. Zhou and A. G. Fane, Factors affecting the membrane performance
in submerged membrane bioreactors, Journal of Membrane Science, 284 (2006) 54-66.
[3] A. G. Fane, J. Phattaranawik and F. S. Wong, Contaminated inflow treatment with membrane
distillation bioreactor, PCT/SG2006/000165 Filing date 16 June 2006 (2006).

Drinking and Wastewater Applications III – 2
Wednesday July 16, 10:15 AM-10:45 AM, Maui
Coagulation-Ceramic Microfiltration Hybrid System Effectively Removes
Virus that is Difficult to Remove in Conventional Coagulation-
Sedimentation-Sand Filtration Process
N. Shirasaki, Hokkaido University, Sapporo, Japan
T. Matsushita (Speaker), Hokkaido University, Sapporo, Japan - taku-m@eng.hokudai.ac.jp
Y. Matsui, Hokkaido University, Sapporo, Japan
M. Kobuke, Hokkaido University, Sapporo, Japan
T. Urasaki, Hokkaido University, Sapporo, Japan
K. Ohno, Hokkaido University, Sapporo, Japan
INTRODUCTION Ceramic membranes have attracted attention in the field of
drinking water treatment in Japan. However, in general, ceramic membranes are
microfiltration (MF) devices, so their pore sizes are not small enough to exclude
particles with diameters less than tens of nanometers. Included among such
small particles are some of the pathogenic waterborne viruses. These viruses
cannot be excluded by ceramic membranes alone. To compensate for this
disadvantage, it was proposed that coagulation, which is usually employed to
destabilize and aggregate small particles and then to remove them under gravity,
be used in combination with ceramic MF. Our group has already reported the
usefulness of the coagulation- ceramic MF hybrid system for virus removal.
However, evaluation of treatment processes in terms of virus removal is
generally based on virus concentration quantified by plaque forming unit (PFU)
method; our previous report also evaluated the hybrid system by the method.
Judging from its measurement principle, the PFU method detects infectious virus
alone, but does not detect inactivated one. Therefore, quantification of virus in
the MF permeate by the PFU method might underestimate the potential risk of
virus, because a part of the virus is inactivated during the treatment process. If
the temporarily inactivated virus recovers its infectivity after the process, it might
pollute our drinking water. In this meaning, investigating removal of virus
including inactivated one as well as infectious one is very important for the
evaluation of treatment processes. Accordingly, the objectives of the present
study are to investigate the removal of virus regardless of its infectivity by using
polymerase chain reaction (PCR) method, and to compare the removals during
the coagulation-ceramic MF hybrid system and the conventional coagulationsedimentation-sand
filtration process for confirming superiority of the hybrid MF
system in virus removal.
MATERIALS AND METHODS (1) Virus used Bacteriophage MS2, whose
diameter is 23 nm, was used as a model virus. Virus was quantified by both the
PFU and PCR methods. The PFU method quantifies infectious virus, while the
PCR method quantifies total virus particles regardless of their infectivity.

(2) Coagulation-sedimentation-sand filtration tests Virus was added to river water
at around 10 8 pfu/mL. PACl (polyaluminum chloride, 1.08 mg- Al/L) was injected
to the water as a coagulant. The water was stirred rapidly for 2 min, slowly for 28
min, and then left at rest for 20 min, allowing the generated floc to settle down.
After settling, the supernatant was pumped into a small column with an infill of
silica sand at a constant flow rate (5000 LMH).
(3) Coagulation-ceramic MF hybrid system The river water was spiked with virus
at around 10^8 pfu/mL. The river water was pumped into the system at a
constant flow rate (83 LMH). After PACl was injected to the water at 1.08 mg-
Al/L, the water was fed into the ceramic MF module (pore size: 100 nm) in deadend
mode.
RESULTS AND DISCUSSION (1) Virus removal during conventional process
Removal of infectious virus was 3.6 log, indicating that a certain level of removal
of infectious virus was achieved during the conventional process. In contrast,
removal of virus particles was only 2.1 log, which is smaller than that of infectious
virus. In other words, over 30 times more virus particles were leaked from the
process than the value expected from the result obtained by the PFU method.
Although most of the virus particles which were just eluted from the sand column
lost their infectivity (97%), they might recover their infectivity after the process. In
this meaning, the conventional process does not ensure the high-efficient
removal of virus.
(2) Virus removal during coagulation-ceramic MF hybrid system The hybrid MF
system successfully removed infectious virus: the removal was 4 to 6 log. This
value was higher than that in the conventional process, because the microfloc,
which enmeshed virus particles, was not removed by the conventional process
owing to its small size, but was removed by the hybrid MF process. The hybrid
MF system also achieved high removal of virus particles: the removal was 4-5
log, which is more than 2 log higher than that by the conventional process. In this
way, high removal was achieved by the hybrid MF system not only for infectious
virus but also for virus particles including inactivated virus.
CONCLUSION (1) Although relatively high removal of infectious virus was
achieved by the conventional treatment process (3.6 log), the removal of virus
particles was only 2.1 log. Inactivated virus particles were leaked from the
process. (2) In contrast, coagulation-ceramic MF hybrid system successfully
removed virus particles regardless of their infectivity: 4-5 log for infectious virus
and 4-6 log for virus particles. Superiority in virus removal of the hybrid MF
system was demonstrated.

Drinking and Wastewater Applications III – 3
Wednesday July 16, 10:45 AM-11:15 AM, Maui
Membrane Enhanced Ultraviolet Oxidation of Polyethylene Glycol
Wastewaters
D. Patterson (Speaker), Laboratory for Green Process Engineering, University of Auckland,
Auckland, New Zealand - darrell.patterson@auckland.ac.nz
T. Vranjes, Laboratory for Green Process Engineering, University of Auckland, Auckland, New
Zealand
Ultraviolet (UV) advanced oxidation is a commonly used system used to degrade
biologically recalcitrant wastewaters. It typically consists of a non selective flow-
through reactor containing ultraviolet lamps irradiating a wastewater, into which
an oxidant is dosed. The UV energy is sufficient to generate the strongly
oxidising hydroxyl free radical (HO") from the water and oxidant, which
mineralises the organic compounds in the wastewater via a series of radical
reactions. Standard UV oxidation systems do not give an efficient treatment, as
they can be non- selective and wasteful of the oxidant and other active radicals
because they have no method of ensuring that only fully oxidised compounds
leave in the effluent. This can have dire consequences: If the oxidation
technology is the sole means of treating the water, untreated waste may exit the
system, contravening the discharge consent. If the water is being pre- treated by
the oxidation technology to make it more biodegradable, then the more refractory
compounds may not be adequately oxidised, leaving them biologically
recalcitrant. Finally, the radicals (which destroy the organic waste) are always
lost with the treated effluent, creating a severe process inefficiency.
A new technology, called Membrane Enhanced Oxidation (MemOx), could
overcome these limitations. If the compounds in the water streams undergo an
order of magnitude change in size when oxidised, ionize, or change polarity, then
a membrane may be applied to selectively retain the unoxidised molecules in the
UV reactor. The membrane is chosen so that unoxidised molecules cannot
permeate through the membrane, whilst the smaller, sufficiently oxidised
molecules permeate and are discharged in the effluent. Also, by recycling
partially oxidised molecules back into the reactor, this technology can increase
the rate of reaction by synergistic rate acceleration. This is because the recycled,
unoxidised effluent contains radical species, which increase the radical
concentration in the reactor, thereby increasing the rate of reaction.
This paper will outline the preliminary work conducted at the University of
Auckland developing the MemOx process. PEG1500 was chosen as the model
organic pollutant and UV oxidised using solutions at 1 to 2 g/L using hydrogen
peroxide (at varying concentrations) as the oxidant. The oxidation was carried

out with UV light supplied by a 254nm low pressure mercury lamp. All membrane
filtration experiments were conducted using a dead-end stainless steel cell with
an effective membrane area of 13.9 cm 2 pressurised by nitrogen gas at 3000
kPa. A Filmtec nanofiltration membrane was used in all tests. Dead-end cell
rejection tests showed that that the Filmtec membrane was able to give a
rejection of 96.4% of 2g/L PEG1500 in deionised water, and so was able to retain
unoxidised PEG1500. All concentrations were determined by HPLC and pH was
measured during all oxidation experiments. To determine the feasibility of the
MemOx system, successive batch oxidation and filtration experiments were
carried out to simulate a continuous reactor with a recycle. In this, a batch UV
oxidation was firstly conducted. The reactor contents were then filtered, fresh
feed was added to the retentate to make it up to the original volume and this
solution was recycled back to the UV oxidation reactor and then the process
repeated. A new disc of membrane was used for each filtration to minimise the
effects of membrane fouling.
Results showed that when compared to standard UV oxidation for the equivalent
time period, the rate of oxidation in these batch membrane recycle experiments
was at least twice as fast, indicating that the membrane recycle produced a
synergistic rate acceleration. On average the pH dropped by 0.3 over 1 hour
during every oxidation, indicating that acidic species were being produced. HPLC
traces confirmed that these molecules were more polar than PEG1500, indicating
that they were most likely the recalcitrant volatile fatty acids produced in such
oxidations (such as formic and acetic acid). In all successive batch oxidation and
filtration experiments a steady state organic concentration was reached in the
reactor which changed with different operating conditions. The UV intensity,
temperature, oxidation time, oxidant concentration and recycle ratio therefore
need to be optimised in each new application to ensure the permeate (effluent)
from the MemOx system is sufficiently oxidised.
Consequently, this preliminary work has demonstrated that a Membrane
Enhanced UV oxidation is more effective than standard UV oxidation of
wastewater streams, allowing the oxidation system to operate at a higher
reaction rate and select a narrower range of molecules into the effluent.

Drinking and Wastewater Applications III – 4
Wednesday July 16, 11:15 AM-11:45 AM, Maui
Improvement of Swimming Pool Water Quality by Ultrafiltration -
Adsorption Hybrid Process
E. Barbot (Speaker), Aix-Marseille University, UMR 6181, France - elise.barbot@univ-cezanne.fr
P. Moulin, Aix-Marseille University, UMR 6181, France
Disinfection by-products can be rapidly formed when organic matter is in contact
with chlorine (i.e. disinfection of drinking water). Among those compounds,
trihalomethanes and haloacetic acids are primarily formed. Since the current
standard swimming pool water treatment method involves disinfection by
chlorinated compounds, pools are highly susceptible to these reactions.
Swimmers introduce a non negligible amount of organic matter, coming from
body fluids, skin, hair and cosmetics. Nitrogenous compounds, typically
originating from urine and sweat, easily react with hypochlorous acid and lead to
the formation of chloramines (NH2Cl and NCl3). The presence of carbonaceous
compounds leads to the formation of trihalomethanes, especially chloroform and
chloroacetic acids. Chloroform and chloramines are toxic and highly volatile,
which means they can rapidly pollute not only the water but also the atmosphere
of the pool. Chloramines concentration has been reported to reach 1.85 mg.m -3
in pool air, when the standard long term exposure value is leveled at 0.5 mg.m -3 .
This chemical pollution is of great concern for the swimming pool staff, who can
suffer from pulmonary or ocular irritation and asthma. Early age children are also
highly exposed, especially through baby swimmer activities. Specific conditions,
such as higher temperature of the water and high pool usage, coupled with
physiological characteristics of babies (i.e. very permeable skin) mean that a
baby can absorb as much chloroform in one hour than a lifeguard in three weeks.
Thus, this study develops a new process for swimming pool water treatment to
meet the three legislation standards of water quality: bacteriological, visual and
chemical. Ultrafiltration by hollow fiber was chosen because of its ability to both
clarify the water by simultaneously removing bacteria and viruses without
chemical compound addition. Molecular weight cut-off (MWCO) of ultrafiltration
hollow fiber membrane does not enable the retention of the major part of organic
matter introduced into the water, nor the disinfection by-products. Thus it was
necessary to couple the ultrafiltration process with an additional one, which could
retain organic matter or chlorinated compounds. Adsorption on a specific
activated carbon was the process selected for that purpose. Experiments were
performed for 18 months in a municipal swimming pool located in Marseille
(France). During that time the 100 m 3 pool was subjected to a high usage
frequency, aquagym and baby swimmer activities. An industrial ultrafiltration unit,
with a 115 m 2 membrane surface and cellulose acetate hollow fibers was set on

the current treatment line. A lab-scale adsorption unit followed the filtration.
Chlorine components were monitored; in particular, combined chlorine was
measured, which gave the concentration of disinfection by-products in the water.
Chemical water quality was followed depending on the number of swimmers and
activity. It appears that disinfection by-products concentration increases rapidly
with pool usage. However with the high variability of the number of swimmers
and the difficulty of quantifying their activity, no correlation was found between
those parameters. Combined chlorine concentration at the end of the day often
exceeds the French standard legislation, showing the non efficiency of the
classical treatment. Pool usage also has a high influence on the membrane
permeability. A constant and high number of swimmers during one day or baby
swimmer activity during 4 hours can involve a permeability decrease of 2.4 L h -1
m -2 bar -1 with each hour of filtration. After 18 months, optimal ultrafiltration
operating conditions were found to be at a transmembrane pressure (TMP) of
0.45 bar and a filtration time (Tf) of 60 min for the entire range of each water
quality parameter studied. Backwashes appear to be sufficient to maintain
membrane permeability when pollution is introduced during a short period. The
closure of the pool during night and holidays when combined with
filtration/backwashes cycles can lead to the full recovery of permeability. On the
contrary, when the pool is subjected to a constant high usage, like during the
summer months, backwashes are not sufficient and the permeability constantly
decreases. However, permeability never decreased less than 160 L h -1 m -2 bar -1 .
The adsorption step limited the concentration of combined chlorine in water to
0.35 ppm, well below the limit given by the French legislation (0.6 ppm). When
the adsorption material is fresh, active chlorine is readily adsorbed to the surface,
but after 24 hours this effect is reduced to less than 50% and the active chlorine
standard is maintained.
This hybrid ultrafiltration adsorption process responds well to all the three
required criteria of swimming pool water treatment by disinfecting and clarifying
while simultaneously reducing the concentration of combined chlorine.

Drinking and Wastewater Applications III – 5
Wednesday July 16, 11:45 AM-12:15 PM, Maui
Processing of Low- and Intermediate- Level Radioactive Wastes from
Medical and Industrial Applications by Membrane Methods
G. Zakrzewska-Trznadel (Speaker), Institute of Nuclear Chemistry and Technology, Warszawa,
Poland - gzakrzew@ichtj.waw.pl
The processing of radioactive wastes before ultimate disposal is important taking
into account the potential hazard of radioactive substances to human health and
surrounding environment. The choice of appropriate technology depends on
capital and operational costs, wastes amount and their characteristics, appointed
targets of the process, e.g. the values of decontamination factors and volume
reduction coefficients. The conventional technologies applied for radioactive
waste processing, such as precipitation coupled with sedimentation, ion
exchange and evaporation have many drawbacks. These include high energy
consumption and formation of secondary wastes, e.g. the sludge from sediment
tanks, spent ion exchange adsorbents and regeneration solutions. Membrane
processes as the newest achievement of the process engineering can
successfully supersede many non-effective, out of date methods. But in some
instances they can also complement these techniques whilst improving the
parameters of effluents and purification economy. The paper presents the own
research data on the application of recent achievements in the area of
membrane processes for solving selected problems in nuclear technology in
Poland. Particular attention was paid to the pressure- driven processes, e.g.
ultrafiltration and reverse osmosis, which were studied on a laboratory and pilot
scale. Verification of the potential application of reverse osmosis on an industrial
scale for treatment of liquid low- and intermediate-level radioactive wastes has
been carried out with the installation designed and constructed for Radioactive
Waste Management Plant at Swierk (Poland). The thin-layer composite
membranes made from a cross-linked aromatic polyamide of high retention of
NaCl (99,4-99,7%) were applied in this process. It has been proved that a threestage
installation enables the radioactive waste of specific radioactivity below
105 Bq/dm3 to be cleaned down to 10 Bq/dm3 in permeate, with simultaneous 7-
15-fold reduction of the activity in the concentrate. The results of the own studies
concerning the removal of selected radionuclides from model aqueous solutions
and radioactive wastes with ultrafiltration enhanced by complexation and sorption
were also presented in this work. In these cases, the mineral (ceramic) porous
membranes made from alpha-alumina, titanium and zirconium oxides were
applied. These membranes exhibited a high resistance against ionizing radiation,
aggressive chemical environment and high temperatures. The high effectiveness
of removal of the main components of liquid radioactive waste like 134Cs,
137Cs, 60Co, 124Sb, 85Sr, 152Eu and 154Eu with a hybrid

ultrafiltration/complexation process has been experimentally proved. The effects
of this type of complexing agent, its concentration and pH of the processed
solution on the complexation effectiveness have been studied. Effectiveness of
the method was tested with real radioactive wastes. The paper performs results
of the studies on membrane distillation which has been proposed for processing
of liquid radioactive wastes, and the analysis of its applicability for nuclear
desalination and the production of pure water for power industry purposes. The
membranes made from polytetrafluoroethylene and polypropylene were used in
the case of membrane distillation. It was proved that membrane distillation is an
efficient process in radioactive waste processing, enabling complete purification
of the effluent and high volume reduction. The flow- sheet of integrated system
for the purification of low and medium level radioactive wastes, combined with
nuclear desalination by the membrane distillation method for the purpose of
nuclear power plant, has been elaborated. The final conclusions comprise the
characteristics and comparison of the applied membrane methods and the
evaluation of their efficiency.

Drinking and Wastewater Applications III – 6
Wednesday July 16, 12:15 PM-12:45 PM, Maui
Removal of Natural Organic Matter in Coagulation-Microfiltration-GAC
Adsorption Systems for Drinking Water Production
Y. Ahn (Speaker), KAIST, Daejeon, Korea - ytahn@kaist.ac.kr
C. Lee, University of Suwon, Gyeonggi-do, Korea
B. Bae, Daejeon University, Daeion, Korea
S. Min, Samsung Construction, Kyunggi-Do
H. Shin, KAIST, Daejeon, Korea
As the limitations of conventional water treatment processes to meet increasingly
stringent drinking water regulations become more apparent, membrane
processes are gaining support within water treatment industry as a better means
of addressing existing and anticipated regulatory requirements. Generally, the
low pressure driven membrane techniques such as microfiltration and
ultrafiltration have been considered as indispensable treatment methods in the
water treatment applications to remove specific pollutants which cannot be
removed by the conventional process. MF and UF are excellent in removing
microparticles, microorganisms, macromolecules, colloids and most bacteria.
However, they can only partially remove color and dissolved organic matter and
synthetic organic compounds. Therefore, the membrane hybrid systems such as
membrane-adsorption and coagulation- membrane filtration system are regarded
as an alternative way to achieve a high removal efficiency of natural NOM
(natural organic matter) and SOC (synthetic organic chemical) in a cost-effective
manner (Lebeau et al., 1998). In this study, coagulation and GAC (granular
activated carbon) adsorption are applied as a pre- and post treatment process for
the microfiltration process. The aim of this study is to minimize disinfection byproduct
formation potential through the precursor removal and maximize the
efficiency of the whole system through NOM characterization. The complicated
characteristics of NOM were assessed by various analytical techniques to
evaluate their removal efficiency in each process.
The experiments were carried out in laboratory using a bench scale reactor
treating 40 litre of surface water per day, and the surface was taken from Wol-
Pyeong water treatment plant in Korea. The MF membrane made of PTFE
(polytetrafluoroethylene) having a nominal pore size of 0.1 um was submerged in
the rectangular basin. Apparent molecular weight distribution was determined
using ultrafiltration membranes with a Amicon® cell device (Model 8200,
Millipore, USA). The dissolved organic carbon and UV absorbance at a
wavelength of 254 nm (UVA254) were measured using a total organic carbon
analyzer (Phoenix 8000, USA) and UV-VIS spectrophotometer (DU650,
Beckman, USA), respectively

Preferential removal of hydrophobic NOM fraction was achieved by GAC
adsorption compared to transphilic and hydrophilic fractions. This is in agreement
with the reported result that the humic fraction (hydrophobic NOM) was
preferentially removed by GAC adsorption to the non-humic fraction (Krasner and
Amy, 1995). A significant difference in NOM removal between coagulation and
the GAC adsorption was found in terms of hydrophobic rejection: less than 30%
by coagulation vs. 80% by GAC adsorption. Also small MW fraction of NOM was
removed by GAC adsorption, while large MW fraction was mostly removed by
membrane filtration. Unlike the coagulation results, medium molecular weight
NOM (1k ~ 3k Da) was also effectively removed by GAC filter, which might be
caused by the sieving mechanism of filter bed. In terms of disinfection by-product
formation potential (DBPFP) removal, both of THMFP (trihalomethane formation
potential) and HAAFP (haloacetic acid formation potential) were more effectively
removed in the GAC column than coagulation or microfiltration membrane.
Especially, the removal of bromide combined DBP (dichlorobromomethane,
dibromo- chloromethane) was achieved only in the GAC adsorption due to the
low molecular weight of their precursors.
When plotting the ultraviolet absorbance at 254 nm, correlations appeared
between the dissolved organic carbon concentration and DBPFP. Both of DOC
and THMFP concentration profile showed a similar trend, also the most of
organic carbon and THMFP were preferentially removed by GAC adsorption.
These correlations can be used for the selective operation of post treatment for
microfiltration effluent with high DBPFP. The low R2 value (0.6) of correlation
between UVA254 and DBPFP might be due to the low DOC/UVA value
(22.8~86.7 mg/L/cm-1) of tested water compared to the previously reported
values (Kim et al., 2007). Summarizing the experimental results, coagulation and
GAC adsorption are playing a different role in NOM removal. Coagulation
preferentially removed hydrophilic, large molecular weight, and THMFP related
NOM, while GAC adsorption was responsible for hydrophobic, small molecular
weight, and HAAFP related NOM removal. Therefore, combination of coagulation
and GAC adsorption seemed to be an essential process to minimize the DBP
concentration of treated water in membrane coupled drinking water treatment
process.

Polymeric Membranes II – 1 – Keynote
Wednesday July 16, 9:30 AM-10:15 AM, Moloka’i
Optical Resolution with Chiral Polymaide Membranes
M. Nakagawa, Kyoto Institute of Technology, Kyoto, Japan
Y. Ikeuchi, Kyoto Institute of Technology, Kyoto, Japan
M. Yoshikawa (Speaker), Kyoto Institute of Technology, Kyoto, Japan - masahiro@kit.ac.jp
Chirality plays an important role in biological processes. Production of
enantiomerically pure compounds has attracted much attention in pharmaceutical
industry, agrochemical applications, perfume production, food preparation, and
so forth. There are a couple of ways to obtain optically pure enantiomers; one is
asymmetric synthesis, the other resolution of racemates. In spite of the advances
in asymmetric synthesis of pure enantiomers, the resolution of racemates is still
the main method for the production of pure enantiomers in industry. Among chiral
separation technologies, membrane processes are regarded as economically
and ecologically competitive to other conventional chiral separation technologies.
With the exception of optical activity, enantiomers show identical
physicochemical properties. From this, physical stereoselectivity is an important
factor for chiral recognition and chiral separation. To this end, novel polyamides
with chiral environment were synthesized from aromatic diamines and the
derivative of glutamic acids. Membranes with chiral environment were prepared
from the present chiral polyamides. They showed chiral separation ability. Those
abilities were dependent on the absolute configuration of constitutional repeating
unit of chiral polyamides. The present results suggest that chiral polyamide
membranes have potential to separate racemic enantiomers. The present results
indicate the great possibility for practical applications.

Polymeric Membranes II – 2
Wednesday July 16, 10:15 AM-10:45 AM, Moloka’i
Dehydration of Alcohols By Pervaporation Through Polyimide Matrimid®
Asymmetric Hollow Fibers with Various Modifications
L. Jiang (Speaker), National University of Singapore, Singapore
T. Chung, National University of Singapore, Singapore - chencts@nus.edu.sg
R. Rajagopalan, National University of Singapore, Singapore
Membrane development involving material selection and membrane fabrication is
the heart for the successful development of pervaporation system applied in high
temperature and corrosive environment. Among various polymers applied,
polyimide is promising material that has already adopted by some commercial
fiber producers for gas separation due to its good thermal and chemical stability.
Nevertheless, intensive investigation of its asymmetric membrane, a more
favorable structure, for pervaporation application is quite limited.
In this study, Matrimid® polyimide asymmetric hollow fibers have been fabricated
and applied for pervaporation dehydration of isopropanol. The effectiveness of
thermal annealing at high temperatures and/or chemical crosslinking using 1, 3propane
diamine (PDA) on the separation property of these fibers has been
investigated. It is found that an increase in the cross-linking degree results in an
increase in separation factor and a decrease in flux. This mainly arises from the
restricted polymer chain mobility and redistributed free volume size and number
induced by the crosslinking process. XRD characterization confirms a tighter
polymer networking in hollow fibers with the crosslinking modification. Thermal
annealing alone has failed to improve hollow fiber performance due to the cracks
caused by inhomogeneous shrinkage in heating process. Nevertheless,
appropriate application of thermal annealing as a pretreatment for crosslinking
can produce fibers with the optimal performance. It is believed that the formation
of charge transfer complexes (CTCs) within the polymer matrix during heat
treatment not only assists polymeric chain packing and rigidification but also
facilitates more efficient PDA crosslinking, thus results in higher size and shape
discrimination in pervaporation. Apparently, PDA molecules could also fill up and
seal the non-selective cracks (defects). Experimental results indicate the
combined thermal and chemical modification possibly is an effective method
independent of the initial status of the hollow fiber (e.g. defective or defective
free) in revitalizing and enhancing the membrane performance. Comparison
between the dehydration of different alcohols reveals that a better separation
performance could be obtained for alcohols having a larger molecular crosssection.

Polymeric Membranes II – 3
Wednesday July 16, 10:45 AM-11:15 AM, Moloka’i
New Cross-linked Membranes for Solvent Resistant Nanofiltration
K. Vanherck (Speaker), Centre for Surface Chemistry and Catalysis, Katholieke Universiteit
Leuven, Heverlee, Belgium
S. Aldea, Centre for Surface Chemistry and Catalysis, Katholieke Universiteit Leuven, Heverlee,
Belgium
P. Vandezande, Centre for Surface Chemistry and Catalysis, Katholieke Universiteit Leuven,
Heverlee, Belgium
I. Vankelecom, Centre for Surface Chemistry and Catalysis, Katholieke Universiteit Leuven,
Heverlee, Belgium - ivo.vankelecom@biw.kuleuven.be
No commercial membranes exist yet for applications in certain demanding
solvents such as the aprotic solvents N,N-dimethylformamide (DMF), Nmethylpyrrolidinone
(NMP), N,N-dimethylacetamide (DMAc) and
dimethylsulfoxide (DMSO). For solute recovery and solvent purification,
industries that commonly use these aprotic solvents generally rely on
conventional separation techniques such as energy-consuming distillations or
waste-generating extractions. The development of a solvent resistant
nanofiltration (SRNF) membrane with a high flux and a low molecular weight cutoff
(MWCO) in the aprotic solvents can provide a sustainable alternative for these
processes by lowering the economical and environmental costs. Since NMP,
DMF, DMAc and DMSO are all good solvents for many polymers, the membraneforming
polymer should be chosen so that it can be modified to be able to
withstand these solvents.
The effects of the chemical cross-linking of phase-inversion Matrimid® based
membranes on the SRNF performance in different aprotic solvents were
investigated. Since it is known that addition of inorganic fillers can significantly
improve membrane performance, Matrimid® based membranes filled with nanosized
zeolite precursors were prepared as well. The effect of the filler on the
cross-linking reaction was studied.
Cross-linking of this polyimide material was done by immersing the membrane in
a bath of 100g/l p-xylylenediamine in methanol. To prevent drying out and
collapsing of the pores, the membranes went through a solvent exchange
procedure before drying. Pieces of the dried cross-linked membranes were
immersed in DMF, NMP, DMAc and DMSO for several days. Filtration tests in
IPA with these immersed pieces of membrane showed that 60 minutes of crosslinking
time was sufficient to create stable membranes. This was confirmed by
ATR measurements, showing a near-to-complete conversion of the imide bonds
into amide bonds after 60 minutes immersion in the cross-linking bath. Since this
was the case for both the filled and unfilled membranes, the cross-linking

eaction didn t seem to be influenced by the fillers. Both types of membranes
had previously been optimized for applications in alcohol such as isopropanol.
These optimal membranes were reproduced, crosslinked and tested for their
performance in DMF, NMP, DMAC, DMSO and THF. The cross-linked
membranes showed a remarkable performance in DMF with permeabilities at 6
bar ranging from 0,7 to 5,4 l/m² bar h. Rejections of rose Bengal (1017Da) up to
99% and of methyl orange (327,2 Da) up to 97% were found. Permeability of
DMF, NMP and DMAc of filled and unfilled membranes dropped considerably at
higher pressures (up to 40 bar), most probably due to compaction of the
membrane. This may be resolved by further optimization and fine-tuning of the
membrane composition. The long term stability was estimated by 10 h lasting
dead end filtrations in DMF, DMSO and THF. The results showed that rejections
and permeabilities remained virtually constant after an initial stabilizing period of
about one hour.
Overall, these are very promising results. Modified polyimide membranes were
created that are stable in a range of aprotic solvents. Both the unfilled polyimide
membranes and those filled with nano-sized zeolite precursors have high
permeabilities and a good MWCO in these solvents. The easy methodology may
allow for a straightforward upscaling of these membranes.

Polymeric Membranes II – 4
Wednesday July 16, 11:15 AM-11:45 AM, Moloka’i
Properties and Potential of Polymeric Nanofiber Membranes for Liquid
Filtration Applications
G. Singh (Speaker), National University of Singapore, Singapore - nnigs@nus.edu.sg
S. Kaur, National University of Singapore, Singapore
S. Ramakrishna, National University of Singapore, Singapore
N. Wun Jern, Nanyang Technological University, Singapore
T. Matsuura, University of Ottawa, Ottawa, Canada
Membrane technology has been hailed as a promising solution in addressing the
global water challenges. With increasing costs of fuel and concerns about
environmental impacts of various technologies, their energy requirement is
becoming an important focal point for governments and industrialists. The future
of membrane technology requires the development of more efficient and energysaving
membranes. These next generation membranes should result in better
performance i.e. permeation rate or flux at better or the same quality of the
permeate i.e. selectivity. Nanofiber membranes represent a new class of
membranes, which we have been developing and studying in the last few years.
There is good potential for these membranes to be used for liquid filtration. In this
paper, the properties of nanofiber membranes are explored and its performance
compared with a top-end commercial membrane is evaluated.
Through nanotechnology, it has become possible to produce polymeric fibers in
the nanometer range (

An interesting surface property of the nanofiber membranes is its higher water
contact angle as compared to conventional polymeric films made of the same
materials. A PVDF nanofiber membrane has an average static contact angle of
145°. In comparison the contact angle of a PVDF film is only about 60-90°. We
believe that the surface roughness of the nanofibers and trapped air pockets,
given the high porosity of the nanofiber membrane contribute to this increased
hydrophobicity. This hydrophobic characteristic of the nanofiber membrane is
particularly important in some liquid filtration applications e.g. membrane
distillation.
Nanofiber membranes when produced may not have suitable mechanical
strength to be used in liquid filtration processes. We have conducted extensive
studies on the effect of heat treatment on the nanofiber properties. Tensile
strength tests were conducted on two nanofibrous membranes, with one
undergoing further heat treatment at 150°C for 3 hours. The heat treated
membrane exhibited much higher mechanical strength with an ultimate tensile
strength of 8.5 MPa for the heat treated membrane as compared to 0.4 MPa for
the non-heat treated membrane. The mechanical strengthening of the heat
treated nanofiber membranes, suggests that the structure of the nanofiber
membranes changes after heat treatment. Differential scanning calorimetric
profiles for the heat treated membranes indicate two peaks unlike the single peak
found for non-heat treated PVDF nanofiber membranes. This signaled the
presence of a more ordered fiber structure as a result of heat treatment. It was
further found that when the heat applied is below the melting point (Tm) of the
polymeric material used, it results in the overlapping nanofibers fusing together.
The produced PVDF nanofiber membranes have a pore size distribution of
between 4-10.6 µm. This is too large to be compared with commercial
microfiltration and ultrafiltration membranes. To reduce the pore size of the
nanofiber membranes but still maintain the nanofiber architecture, plasmainduced
graft copolymerization of poly(metharcylic acid) on the PVDF nanofiber
membrane was carried out. The pore size distribution of the grafted PVDF
nanofiber membrane was then found to be similar to a commercial hydrophilic
MF membrane of pore size 0.45 µm (HVLP, Millipore). The surface contact
angles of both the grafted nanofiber membrane and the commercial hydrophilic
membrane were the same at approximately 60°. This allowed a fairer comparison
between the membranes. Both membranes were tested for filtration flux using
distilled water and the nanofiber membrane had a higher flux compared with the
commercial membrane at all pressures tested. The grafted nanofiber membrane
had on average fluxes that were 1.6-2.0 times that of the commercial membrane.
The higher flux of the nanofiber membrane indicates its potential to be used as a
new next generation membrane material for water filtration.

Polymeric Membranes II – 5
Wednesday July 16, 11:45 AM-12:15 PM, Moloka’i
Perfluoropolymer Membranes for Gasoline Vapor Emissions Reduction
J. Bowser (Speaker), Compact Membrane Systems, Inc., Wilmington, Delaware, USA -
jbowser@compactmembrane.com
S. Majumdar, Compact Membrane Systems, Inc., Wilmington, Delaware, USA
The California Air Resources Board (CARB) has required that the 13,000
gasoline stations in California install vapor processing equipment to become
compliant with new air quality regulations. The only technology currently certified
by CARB for installation in 90% of these stations is an air/vapor separation
process based on amorphous perfluoropolymer membranes.
This paper discusses why this class of membrane is ideal for abatement of
gasoline vapor emissions and similar applications requiring the separation of
volatile organic compounds from atmospheric gasses. Design of the vapor
processor for optimal use of the membrane's characteristics will also be
discussed.

Polymeric Membranes II – 6
Wednesday July 16, 12:15 PM-12:45 PM, Moloka’i
Universal membranes for Solvent resistant nanofiltration (SRNF) and
Pervaporation (PV) based on segmented polymer network (SPN)
X. Li (Speaker), Centre for Surface Chemistry and Catalysis, Belgium
M. Basko, Centre for Surface Chemistry and Catalysis, Belgium
P. Du Prez, Ghent University, Ghent, Belgium
I. Vankelecom, Centre for Surface Chemistry and Catalysis, Belgium -
ivo.vankelecom@biw.kuleuven.be
Segmented polymer networks (SPN) are two- component networks of covalently
interconnected hydrophilic/hydrophobic phases of co-continuous morphology. In
the case of amphiphilic SPNs, their swelling properties can be easily tuned
through their composition and the covalent bonding of the hydrophilic phases to
the hydrophobic ones limits the maximal swelling to prevent the swollen network
from disintegrating. This mechanical stability together with their particular tunable
swelling behavior, crosslinking degree and nano-separated morphology offers a
unique combination of properties to use them in membrane applications. In the
present work, hydrophilic bisacrylate terminated poly(ethylene oxide) was used
as crosslinker for different types of hydrophobic polyacrylates in the synthesis of
amphiphilic SPNs. Composite membranes with thin SPN toplayers were
prepared by in-situ polymerization. As the support consisted of hydrolyzed
polyacrylonitrile, the high chemical resistance of the composite membrane
allowed applications of the SPN based membranes in solvent resistant
nanofiltration (SRNF) and pervaporation (PV). The membranes show very high
retention on Rose Bengal (1017 Da) RB in different solvents, especially in strong
swelling solvents such as tetrahydrofuran (THF) and dimethylformamide (DMF).
In THF, the membranes have nearly 100% retention for RB. The membranes
were used in pervaporation for dehydration of ethanol and isopropanol (IPA) as
well. The selectivity of the membranes proved to be greatly dependent on the
ratio of hydrophilic and hydrophobic phases of the SPN.
References
1. Koros, W. J.; Ma, Y. H.; Shimidzu, T.; J. Membr. Sci. 1996, 120, 149-159.
2. Vandezande, P.; Gevers, L. E. M.; Vankelecom, I. F. J.; Chem. Soc. Rev. 2008, DOI:
10.1039/b610848m.
3. Bhanushali, D.; Bhattacharyya, D.; Ann. N.Y. Acad. Sci. 2003, 984, 159-177.
4. Shao, P.; Huang, R. Y. M.; J. Membr. Sci. 2007, 287, 162-179.

5. Erdodi, G.; Kennedy, J. P.; Prog. Polym. Sci. 2006, 31, 1-18

Biomedical and Biotechnology II – 1 – Keynote
Wednesday July 16, 9:30 AM-10:15 AM, Honolulu/Kahuku
Macroporous Membrane Adsorbers: Correlations between Materials
Structure, Separation Conditions and Performance in Bioseparations
M. Ulbricht (Presenting), Lehrstuhl für Technische Chemie II, Universität Duisburg-Essen,
Germany - mathias.ulbricht@uni-due.de
J. Wang, Lehrstuhl für Technische Chemie II, Universität Duisburg-Essen, Germany
F. Dismer, Institut für Biotechnologie, Forschungszentrum, Jülich, Germany
E. von Lieres, Institut für Biotechnologie, Forschungszentrum, Jülich, Germany
J. Hubbuch, Institut für Biotechnologie, Forschungszentrum, Jülich, Germany
Separations with membrane adsorbers are a very attractive and rapidly growing
field of application for functional macroporous membranes [1,2]. The key
advantages in comparison with conventional porous adsorbers (particles,
typically having a diameter of >50 µm) result from the pore structure of the
membrane which allows a directional convective flow through the majority of the
pores; thus, the characteristic distances (i.e., times) for pore diffusion will be
drastically reduced. The separation of substances is based on their reversible
binding on the functionalized pore walls; the most frequently used interactions
are ion- exchange and various types of affinity binding. However, there is still a
large interest in improvement of performance for established membranes and in
development of novel membranes with higher selectivity [2]. Further, for a better
understanding of the complex interplay between mass transfer and reversible
binding, a more comprehensive analysis of the (coupled) influences of pore
structure and functional binding layer as well as their interactions with the mobile
phase, all as function of flow rate, is strongly needed. Here we will present our
recent efforts to elucidate influences of the materials and the process conditions
onto resulting separation performance.
First, a detailed analysis of pore structure and protein binding in commercial
cation-exchange membrane adsorbers (Sartobind®) by conventional and
environmental scanning electron microscopy (ESEM) as well as confocal laser
scanning microscopy (CLSM) has been performed [3]. The binding of mono-Cy5labelled
lysozyme inside fluoresceine-labelled and unlabelled Sartobind®
membranes was monitored by CLSM. The characteristic fluorescence intensity
distributions indicated that protein binding takes place predominately in a layer
which is anchored to a fine cellulose fiber network. Due to the limited thickness of
this binding layer, a significant fraction of the macropores remained free of
protein. Protein binding as function of concentration and incubation times was
also monitored by CLSM and discussed related to the binding isotherms for the
membranes. For the first time, the binding and breakthrough of (dye-labelled)
protein within a (dye-labelled) membrane adsorber has been monitored in situ
and on-line by using CLSM. Distinctly different breakthrough times have been

observed for different locations in the x-y plane, and this can presumably help to
explain the observed significant dispersion for the same protein in the same
membrane in conventional chromatographic experiments (performed in an Äkta
system).
Second, various types of new cation-exchange membrane adsorbers with threedimensional
binding layers on macroporous support membranes from
regenerated cellulose with 0.45, 1 and 3~5 µm pore diameter had been prepared
via photo- initiated graft copolymerization [4]. A well-defined chemical crosslinking
of the functional binding layer via addition of a cross-linker monomer
during photo-grafting lead to a markedly improved separation performance
because higher permeability and lower susceptibilities of permeability to salt
concentration than with linear grafted polymer had been combined with high
protein binding capacities.
Third, the system dispersion curves (using inert tracer and/or unmodified base
membranes) and breakthrough curves (using proteins of various sizes) have
been measured for the commercial and the various newly prepared porous
membrane adsorbers (with varied pore structure and binding layer). The results
will be interpreted in the frame of two models, a macroscopic ‘dead-volume’
model describing the influence of flow distribution in the membrane module, and
a ‘dynamic binding’ model describing the interplay between convection through
the membrane pores and the binding in three-dimensional (several 100s nm
thick) functional layers on the pore walls.
In conclusion, the combination of advanced microscopy with detailed
investigations of static and dynamic protein binding provides a better
understanding of the coupling between mass transfer and reversible binding in
membrane adsorbers onto separation performance, and it yields valuable guidelines
for the development of improved membrane adsorbers and separations
based on such materials.
[1] R. van Reis, A. Zydney, J. Membr. Sci. 2007, 297, 16-50.
[2] M. Ulbricht, Polymer 2006, 47, 2217-2262.
[3] J. Wang, F. Dismer, J. Hubbuch, M. Ulbricht, J. Membr. Sci. 2007, submitted.
[4] J. Wang, M. Ulbricht, J. Chromatogr. A 2008, submitted.

Biomedical and Biotechnology II – 2
Wednesday July 16, 10:15 AM-10:45 AM, Honolulu/Kahuku
Integrated Membrane-Based Sample Prep Approach for Viral and Microbe
Capture, Lysis, and Nucleic Acid Purification From Complex Samples
R. Baggio (Speaker), Millipore Corporation, Bedford, Massachusetts, USA -
rick_baggio@millipore.com
K. Souza, Millipore Corporation, Bedford, Massachusetts, USA
J. Murrell, Millipore Corporation, Bedford, Massachusetts, USA
L. Mullin, Millipore Corporation, Bedford, Massachusetts, USA
M. Aysola, Millipore Corporation, Bedford, Massachusetts, USA
J. Lindsay, Millipore Corporation, Bedford, Massachusetts, USA
G. Gagne, Millipore Corporation, Bedford, Massachusetts, USA
C. Martin, Millipore Corporation, Bedford, Massachusetts, USA
The detection of microbial and viral contamination in a timely, simple, and
effective manner is a concern of high interest to bioprocess workflows. Anaerobic
bacterial and mycoplasma detection based on growth and viral detection based
on infectivity assays are notoriously slow, labor intensive, and costly. Our
laboratory has developed an integrated membrane-based approach coupled to
quantitative PCR (qPCR) for the detection of Pseudomonas aeruginosa,
Propionobacter acnes, Mycoplasma hyorhinis,and Minute Virus of Mouse (MVM)
in both simple and Chinese Hamster Ovary (CHO) cell loaded samples at levels
as low as 100 CFU. In the sample preparation described in this work all cells in
the sample are captured and processed. By configuring prefilters, retentive
membranes, and affinity membranes in single or stacked interlocking devices
more aseptic processing could also be realized. The closed devices have been
engineered to be capable of multiple process work involving multiple and
discontinuous solution handling. By configuring size exclusion membranes and
affinity-based retentive membranes in sequential order, multiple process steps
are simultaneously carried out. The approach simplifies sample preparation steps
by combining size excluision chromatography and affinity chromatogarphy in a
unified membrane-based format. The separate steps of microbe capture, microbe
lysis, and nucleic acid purification are all performed in the devices, providing a
simplified method of preparation for challenging samples. These results
demonstrate the utility of an integrated method for sample preparation from
samples that mimic the complex bioreactor environment.

Biomedical and Biotechnology II – 3
Wednesday July 16, 10:45 AM-11:15 AM, Honolulu/Kahuku
Morphological and Functional Features of Neurons Isolated from
Hippocampus on Different Membrane Surfaces
L. De Bartolo (Presenting), Institute on Membrane Technology, National Research Council of
Italy, ITM-C, Italy - l.debartolo@itm.cnr.it
M. Rende, Institute on Membrane Technology, National Research Council of Italy, ITM-C, Italy
S. Morelli, Institute on Membrane Technology, National Research Council of Italy, ITM-C, Italy
G. Giusi, Comparative Neuroanatomy Laboratory, Department of Ecology, University of C, Italy
S. Salerno, Institute on Membrane Technology, National Research Council of Italy, ITM-C, Italy
A. Piscioneri, Institute on Membrane Technology, National Research Council of Italy, ITM-C, Italy
A. Gordano, Institute on Membrane Technology, National Research Council of Italy, ITM-C, Italy
M. Canonaco, Comparative Neuroanatomy Laboratory, Department of Ecology, University of C,
Italy
E. Drioli, Institute on Membrane Technology, National Research Council of Italy, ITM-C, Italy
Biomaterials such as membranes have become of great interest, since they offer
the advantage of developing neuronal tissue that may be used for in vitro
simulation of brain function. In an attempt to develop a membrane biohybrid
system constituted of membranes and neurons the behaviour of neurons isolated
from the hippocampus of the hamster Mesocricetus auratus were studied on
membranes with different morphological properties. Polymeric membranes in
polyester (PE), modified polyetheretherketone (PEEK-WC), fluorocarbon (FC)
and polyethersulfone (PES) coated with poly- L-lysine with different
morphological surface properties (e.g., pore size, porosity and roughness) were
used as substrate for cell adhesion. Confocal and SEM analyses of cells cultured
on the different surfaces demonstrated that in response to varying the roughness
of the membrane surface, hippocampal neurons exhibited a different
morphology. Indeed cells grown on smoother membranes differentiated with a
large number of neuritis with consequent formation of bundles. As a
consequence while a very complex network was formed on FC membrane, cells
tend to, instead, form aggregates and most of the processes are developed
inside the pores of the membranes when rougher PEEK-WC surfaces were used.
Metabolic results in terms of glucose consumption, lactate production and BDNF
secretion confirmed the effect of roughness on the cell behaviour: neurons
exhibited BDNF secretion at high levels on FC membranes with respect to the
other membranes. Taken together these results suggest the pivotal role played
by membrane roughness in the adhesion and differentiation of the hippocampal
neurons and may thus constitute a valuable approach for future neurobiological
studies.

Biomedical and Biotechnology II – 4
Wednesday July 16, 11:15 AM-11:45 AM, Honolulu/Kahuku
Membrane Emulsification Technology to Enhance Phase Transfer
Biocatalyst Properties and Multiphase Membrane Reactor Performance
L. Giorno (Speaker), Institute on Membrane Technology, ITM-CNR, Rende, Italy -
l.giorno@itm.cnr.it
E. Piacentini, University of Calabria, Rende, Italy
R. Mazzei, Institute on Membrane Technology, ITM-CNR, Rende, Italy
F. Bazzarelli, Institute on Membrane Technology, ITM-CNR, Rende, Italy
E. Drioli, Institute on Membrane Technology, ITM-CNR, Rende, Italy
Membrane emulsification is a relatively new technology; it has been developed in
the last 20 years and nowadays it can be considered at a good stage of
acceptance by stakeholders, with several applications being constantly
developed. It is well recognized as a sustainable and efficient technology for
precision making of droplets and particles with uniform and controlled size
distribution.
In this paper, new feature of direct membrane emulsification will be emphasized.
In particular, the droplet formation mechanism of membrane emulsification
applied to assist the optimal distribution of phase transfer biocatalysts at the oilwater
interface of stable and uniform oil droplets will be discussed. The process
is carried out at room temperature, atmospheric pressure and very low shear
stress, i.e. conditions that preserve the functional stability of labile
macromolecules such as enzymatic proteins.
The process allowed fine and regular dispersion of the enzyme at the interface
leading to a very efficient catalyst formulation to the point that unprecedented
improved intrinsic catalytic properties are observed. Furthermore, the
methodology is accurate enough to allow basic parameters evaluation. For
example, the hydrodynamic diameter of macromolecule at the interface could be
evaluated and compared to the molecular diameter calculated from
crystallographic data.
The unique performance of the formulated biocatalyst were also applied to
implement two- separate phase enzyme-loaded membrane reactors. In
particular, enantiocatalytic selectivity and stability could be improved and mass
transfer of polar/non-polar molecules through the membrane could be modulated.
The methodology opens for a large variety of process implementation in
biotechnology, biomedicine, food, waste water treatment. Some major cases

applied in the first two fields will be outlined to illustrate the technological
perspectives.

Biomedical and Biotechnology II – 5
Wednesday July 16, 11:45 AM-12:15 PM, Honolulu/Kahuku
Anti-Biofouling Membrane Surface with Grafted Zwitterionic
Polysulfobetaine for Improved Blood Compatibility
Y. Chang (Speaker), R&D Center for Membrane Technology and Department of Chemical
Engineering, Taoyuan, Taiwan - yungchang0307@gmail.com
One of the most important requirements for membranes in biomedical
applications is to reduce the nonspecific adsorption of biomolecules when living
systems encounter membrane surfaces. Biofouling of membranes prepared from
hydrophobic materials will lead to a change in biomolecular structure selectively
decreasing the permeate flux with time, especially in the filtration of protein,
platelet, or cell-containing solutions. In general, ester group in poly(ethylene
glycol) (PEG)- based material is the ideal choice of surface functional moiety with
anti-biofouling characteristics. However, it has been recognized that PEG
decomposes in the presence of oxygen and transition metal ions found in most
biochemically relevant solutions. Whereas, PEG exhibits an excellent nonfouling
capability, but it faces the problem of long-term stability for biomedical uses.
Therefore, materials containing zwitterionic phosphotidylcholine headgroups
have become one of the popular synthetic materials for developing anti-biofouling
surfaces. Recently, our works have shown that material surfaces containing
similar zwitterionic structure to phosphorylcholine, such as sulfobetaine are ideal
for resisting protein adsorption when the surface density and chain length of
zwitterionic groups is controlled. In our current research, it was further
demonstrated that a surface with well-packed grafted zwitterionic
polysulfobetaine performs highly stable anti- biofouling properties for plasma
protein repulsion. This work is aimed at addressing two important issues for
polysulfobetaine (PSBMA) stability, i.e., (i) protein adsorption on PSBMA
surfaces at different ionic strengths, solution pH values, and temperatures, (ii)
PSBMA blood compatibility in the human body temperature. The results were
systematically studied by surface plasmon resonance and will be summarized in
the first part of the giving talk. This work concluded that zwitterionic PSBMA
provides a significant impact and opportunity in searching for alternative stable
nonbiofouling materials other than PEG. In this extended study, the strategy for
creating zwitterionic PSBMA surface will be introduced to prepare anti-biofouling
membranes. The general idea was performed by two different surface
modification approaches for the case of segmented polyurethane (SPU)
membrane, which will be presented in the second part of the giving talk. For the
first case system, interpenetrating polymer networks (IPNs) on the prepared
membrane surface were prepared by the modification of a SPU with a crosslinked
sulfobetaine methacrylate (SBMA) polymer. The IPN membrane surfaces
that were prepared can effectively resist nonspecific protein adsorption when the

distribution of SBMA units within the SPU membrane is well controlled, and they
retain high mechanical strengths inherent from the base SPU membranes. In this
case system, various parameters governing the formation of IPNs containing
SBMA were studied. The amount of adsorbed proteins on the IPN membrane
was determined by an enzyme-linked immunosorbent assay. Results show that
the amount of adsorbed proteins on the IPN membranes depends on the
incubation conditions, including solvent polarity, incubation time, SBMA monomer
ratio, and incubation concentration. It appears that the IPN membranes prepared
in a mixed solvent of higher polarity with long incubation time lead to very low
protein adsorption. For the second case system, SPU membranes grafted with
PSBMA via surface- activated ozone treatment and thermally induced graft
copolymerization. Blood compatibility of the modified SPU membranes was
evaluated by the biofouling property of the platelet adhesion observed by
scanning electron microscopy (SEM) and the plasma protein adsorption
determined by an enzyme-linked immunosorbent assay (ELISA). This study not
only determines the grafting quality with PSBMA, but also provides a
fundamental understanding of various grafting density governing the effects on
the correlation of surface hydration and plasma proteins adoption.

Biomedical and Biotechnology II – 6
Wednesday July 16, 12:15 PM-12:45 PM, Honolulu/Kahuku
Supported Liquid Membranes with Strip Dispersion for the Recovery of
Cephalexin
M. Vilt (Speaker), The Ohio State University, Columbus, Ohio, USA
W. Ho, The Ohio State University, Columbus, Ohio, USA - ho@chbmeng.ohio-state.edu
Cephalexin is an important and widely used semi- synthetic cephalosporin.
Cephalosprorins along with penicillins are Beta-lactam antibiotics, which account
for the majority of the antibiotic world market. Cephalexin is traditionally produced
by a 10-step chemical synthesis. An enzymatic synthesis for Cephalexin has
been developed, and offers several advantages over the classical route. The
enzymatic synthesis reduces energy and solvent waste, but has been used in
industrial production on a limited basis. The enzymatic reaction mixture contains
Cephalexin, side products, and unconverted reactants, which are similar in
structure, are difficult to separate. Liquid membranes, in particular supported
liquid membranes (SLMs), are a promising solution to the separation. Reactive
extraction with the quaternary ammonium compound Aliquat 336 has been
demonstrated for Cephalexin and other semi-synthetic cephalosporins. SLMs are
still not used industrially, as they still plagued with problem of long term
instability. The SLM with strip dispersion has been a recent development to solve
the issue of stability.
SLM with strip dispersion can be described when an aqueous strip solution is
dispersed in an organic membrane solution by a mixer, and passed on one side
of a membrane support. When a microporous hydrophobic support is used, the
organic phase of the dispersion becomes imbedded in the pores of the support,
forming a stable SLM. Stability is maintained by having a constant supply of
organic membrane solution to the pores.
In this study, Cephalexin has been separated and concentrated from an aqueous
solution using the SLM with strip dispersion. Experiments used a Liqui-Cel®
hollow fiber module as a microporous support. The organic membrane solution of
the SLM consisted of Aliquat 336, Isopar L (isoparaffinic hydrocarbon solvent),
and 1- decanol. The aqueous strip solution was composed of potassium chloride
and citrate buffer. The following key parameters were investigated: feed and strip
dispersion flowrate, strip dispersion mixing rate, carrier concentration, counter ion
concentration, pH, and volume of aqueous strip solution. High extraction and
recovery rates were achieved when maintaining a proper pH in the aqueous strip
solution combined with an excess of potassium chloride. An enrichment factor of
up to 3.2 was observed in the aqueous strip solution while achieving over 99%
extraction and 96.2% total recovery. In this case, the aqueous feed solution of

5500 ppm (15 mM) was lowered to 30 ppm when using an organic membrane
solution containing 2.5% Aliquat 336. The resulting overall mass transfer
coefficient was 1.6 x 10 -5 cm/sec. The mass flux of Cephalexin for this system
was found to be independent of aqueous feed and strip dispersion flowrates,
suggesting a major mass transfer resistance due to chemical reaction kinetics,
which is supported by calculated individual mass transfer resistances. The pH of
the aqueous strip phase was found to play a more significant role when trying to
achieve higher enrichment ratios. It was observed that the highest stripping
efficiency occurs when the pH of the aqueous strip phase is between the values
of 5 and 6.

Membrane Modeling III - Process Simulations – 1 – Keynote
Wednesday July 16, 9:30 AM-10:15 AM, O’ahu/Waialua
Biopolymer Transport in Ultrafiltration: Role of Molecular Flexibility
A. Zydney (Speaker), The Pennsylvania State University, University Park, Pennsylvania, USA -
zydney@engr.psu.edu
J. Molek, The Pennsylvania State University, University Park, Pennsylvania, USA
D. Latulippe, The Pennsylvania State University, University Park, Pennsylvania, USA
Ultrafiltration is used extensively for the purification and concentration of a wide
range of biomolecules including natural proteins, enzymes, diagnostic antibodies,
and therapeutic proteins. These proteins typically have a dense hydrophobic
core, giving them a highly globular structure with relatively little molecular
flexibility. Consequently, the transport characteristics of these biomolecules are
traditionally described using a hard sphere analysis accounting for the steric,
hydrodynamic, and long-range (electrostatic) interactions in the membrane
pores. In contrast, polymer transport in membrane systems has typically been
described using models that account for the flow-induced elongation of the
flexible polymer chain. There is growing interest in second generation
biotherapeutics including PEGylated proteins, in which one or more long
polyethylene glycol (PEG) chains are covalently attached to a therapeutic
protein, as well as plasmid DNA, with the latter of interest in both gene therapy
applications and for DNA-based vaccines. These molecules have more complex,
and potentially flexible, morphologies. The objective of this study was to examine
the role of molecular flexibility in the transport of these novel biomolecules
through semipermeable ultrafiltration membranes.
PEGylated alpha-lactalbumin was produced by covalent attachment of an
activated polyethylene glycol, having molecular weight of 5, 10, or 20 kDa. A 3.0
kilobase pair plasmid was obtained from Stratagene and prepared by Aldevron.
Ultrafiltration experiments were performed in a stirred cell using composite
regenerated cellulose membranes provided by Millipore. Biomolecule
transmission was evaluated as a function of both filtrate flux and stirring speed to
independently control the degree of concentration polarization and flow-induced
elongation. Data were analyzed using both hydrodynamic models for hardsphere
solutes and flow-induced elongation models for flexible polymers.
The extent of plasmid transmission was a very strong function of the filtrate flux,
with minimal transmission below a critical value of the flux. This critical flux was
in good agreement with theoretical models accounting for the flow-induced
plasmid elongation, suggesting that these large plasmids behave as nearly
infinitely flexible polymers. In contrast, transmission of the PEGylated proteins at
low flux was dominated by hard-sphere interactions, with the polyethylene glycol

increasing the effective size of the biomolecule. However, there was clear
evidence for elongation of the PEGylated proteins at high flux, causing the
transmission to depend on both the total molecular weight and the number of
polyethyleneglycol chains. These results provide the first quantitative
demonstration of the importance of biopolymer flexibility on the ultrafiltration
characteristics of these important second-generation biotherapeutics.

Membrane Modeling III - Process Simulations – 2
Wednesday July 16, 10:15 AM-10:45 AM, O’ahu/Waialua
Effects of Long-Term Membrane Fouling on the Dynamic Operability of an
Industrial Whey Ultrafiltration Process
K. Yee (Speaker), UNESCO Centre for Membrane Science and Technology, Sydney, Australia
J. Bao, School of Chemical Sciences and Engineering, Sydney, Australia
D. Wiley, UNESCO Centre for Membrane Science and Technology, Sydney, Australia -
d.wiley@unsw.edu.au
1. Introduction
In the production of whey protein concentrate (WPC) by ultrafiltration (UF), the
flowrate and composition of the fresh whey feed often fluctuate. Automatic
feedback controllers are implemented in industry to maintain the WPC product
within its desired specifications. The manipulated variables of the automatic
controllers include the ratios of the retentate and permeate streams that are
recycled and mixed with the fresh feed, as well as the amount of diafiltration
water added to the process. By adjusting the manipulated variables, the
automatic controllers are able to mitigate the effects of fluctuations in feed
flowrate and composition.
In order to achieve an optimal economic return from WPC production, the
achievable control performance from a given process design needs to be
determined before the actual feedback controller is implemented. This intrinsic
property of the process design towards automatic control is called dynamic
operability. Based on the dynamic behaviour of manipulated variables from an
industrial whey UF process, the effects of the number of stages of the process
and recycle streams on dynamic operability have been investigated by the
authors [1, 2]. However, given that industrial whey UF processes usually operate
for 16 hours every day, the effects of long-term membrane fouling on dynamic
operability is not well understood. The aim of this study is therefore to investigate
the effects of long-term fouling on the dynamic operability of an industrial whey
UF process, and the implications on process operation. The study is based on
dynamic models of an industrial whey UF process developed by the UNSECO
Centre for Membrane Science and Technology.
2. Results and Discussion
Dynamic operability of the industrial whey UF process indicates that the required
adjustments in manipulated variables to deliver the same level of control
performance increase with time during the 16 hours of operation. Given the
physical constraints of the manipulated variables (e.g. recycle ratios are bounded

etween 0 and 1), the automatic feedback controllers are not able to mitigate
flucutations in feed flowrate and composition experienced by the whey UF
process when long-term fouling becomes significant after long hours of
operation.
While mid-run washing is often used during the industrial production of WPC to
ensure that the desired specifications of WPC can be delivered in steady state,
dynamic operability of the whey UF process suggests that mid-run washing is
crucial to maintain the performance of automatic feedback controllers, especially
after long hours of process operation.
Modifications in process design, such as the installation of a buffer tank to
dampen the flucations of the fresh whey feed before supplying to the UF process,
can also improve the achievable control performance of the automatic controllers
when long-term fouling is significant. By studying the dynamic operability of the
modified design, improvements on the achievable control performance can be
assessed even before the modification is actually implemented.
References
[1] K.W.K. Yee, A. Alexiadis, J. Bao and D.E. Wiley, Effects of recycle ratios on process dynamics
and operability of a whey ultrafiltration stage, Proceedings of IMSTEC 07, 5 9 November
2007, Sydney, Australia.
[2] K.W.K. Yee, A. Alexiadis, J. Bao and D.E. Wiley, Effects of multiple-stage membrane process
designs on the achievable performance of automatic control, submitted to the Journal of
Membrane Science.

Membrane Modeling III - Process Simulations – 3
Wednesday July 16, 10:45 AM-11:15 AM, O’ahu/Waialua
CFD Modeling for the Concentration of Soy Protein in an Ultrafiltration
Hollow Fiber Membrane System Using Resistance-in-Series Model
A. Rajabzadeh (Speaker), University of Waterloo, Waterloo, Canada
B. Marcos, Genie Chimique, Universite de Sherbrooke, Quebec, Canada
C. Moresoli, University of Waterloo, Waterloo, Canada - cmoresol@cape.uwaterloo.ca
Computational Fluid Dynamics (CFD) is a robust technique for solving
conservation equations for momentum (Navier-Stokes), mass (continuity), and
heat (energy) simultaneously with minimal simplifications. Detailed local
information on the fouling mechanism in hollow fiber ultrafiltration and
microfiltartion membrane systems requires a rigorous analysis that CFD can
provide. In this study, a CFD model was developed to investigate local flow
behavior, concentration profile, and membrane fouling for unsteady-state
ultrafiltration concentration operation of soy protein in a hollow fiber membrane. A
new resistance model based on the local protein concentration comprising the
reversible and irreversible fouling components is proposed. The effects of pH,
feed velocity, as well as Trans Membrane Pressure (TMP) on the permeate flux
were investigated and results were validated with experimental data for two types
of soy proteins, pH 6 and pH 9. The hollow fiber ultrafiltration membrane module
was 30 cm in length with 50 fibers of 1mm inner diameter. The retentate was
returned back to the feed tank which agitated the feed solution and provided
homogenous mixing. The viscosity and the diffusivity of the solution were
considered as a function of concentration and pH, respectively. The membrane
was assumed to be fully retentive for proteins. Fouling was considered to have
no consequence on the flow conditions. Two ordinary differential equations
representing the changes in the solution volume and the protein concentration in
the feed tank were incorporated to the model. The model predictions and the
experimental data revealed that the global resistance for the pH 6 soy protein
extract is one order of magnitude larger than for the pH 9 extract. The variation of
TMP, pH, and feed velocity will also be discussed in details during the
presentation.

Membrane Modeling III - Process Simulations – 4
Wednesday July 16, 11:15 AM-11:45 AM, O’ahu/Waialua
Hydrodynamic CFD Simulation of Mixing in Full-Scale Membrane
Bioreactors with Field Experimental Validation
Y. Wang (Speaker), The University of New South Wales, Sydney, Australia
M. Brannock, The University of New South Wales, Sydney, Australia
G. Leslie, The University of New South Wales, Sydney, Australia - yuanw@student.unsw.edu.au
Membrane bioreactors (MBR) represent the ‘state of the art’ for the treatment of
municipal wastewater. The optimisation of MBR units requires knowledge of
biological treatment, membranes and hydrodynamics/mixing. Good mixing can
ensure the effective use of the entire reactor volume and can affect nutrient
removal efficiency. The degree of mixing and membrane configuration (e.g. flat
sheets and hollow fibres) affects the output response describing the system’s
flow regimes and expressed by the residence time distribution (RTD) profiles.
The authors’ research group has investigated the mixing efficiency of pilot scale
MBRs [1] and full-scale MBRs [2] with different membrane configurations via
RTD analysis. Recently, we have developed a CFD model that has been
validated with field experiments to show how membrane configurations can affect
mixing conditions in the reactor.
CFD simulations were conducted using the commercial software package
Fluent® on a 2.2 MLD hollow fibre membrane MBR in Sydney and a 2.5 MLD
double deck flat sheet membrane MBR in South Australia. A 3-dimensional flow
field consisting of the interacting phases of water and air were computed using
the Eulerian-Eulerian multiphase model. The simulation results showed good
agreement with the measured field RTD data. The hollow fibre MBR has a Peclet
number of 0.24 and number of completely mixed tanks in series of 1.08, while the
flat sheet MBR has a Peclet number of 0.37 and 1.13 of completely mixed tanks
in series, which showed that the two MBRs were both close to completely mixed
conditions. However, the mixing energy contributed by the mixer, bioreactor and
membrane aeration, and recirculation pumps was 55.8 kW in total of the flat
sheet MBR while 42.9 kW of the hollow fibre MBR, which indicated that the use
of flat sheet membranes was 20% higher in mixing energy to create the same
degree of mixing.
In conclusion, the development of MBR CFD model can provide the access to
evaluate the effects of membrane configurations on energy consumption with the
view of achieving the optimum mixing conditions at the lowest possible energy
inputs for the design of large installations.

References:
[1] Y. Wang, K. W. Ong, M. Brannock, and G. Leslie, Evaluation of Membrane Bioreactor
Performance via Residence Time Distributions: Effects of Membrane Configuration and Mixing,
Water Science & Technology, 57(3)
[2] M. Brannock, B. Kuchle, Y. Wang, and G. Leslie, Evaluation of Membrane Bioreactor
Performance via Residence Time Distributions Analysis: Effects of Membrane Configuration,
Presented at the 2nd IWA National Young Water Professional Conference, 4-5 June 2007, Berlin,
Germany

Membrane Modeling III - Process Simulations – 5
Wednesday July 16, 11:45 AM-12:15 PM, O’ahu/Waialua
Hybrid Modeling: An Alternative Way to Predict and Control the Behavior of
Cross-Flow Membrane Filtration Processes
S. Curcio (Speaker), University of Calabria, Rende, Italy
V. Calabro', University of Calabria, Rende, Italy
G. Iorio, University of Calabria, Rende, Italy - gabriele.iorio@unical.it
The aim of the present paper is to develop a hybrid model predicting the behavior
of ultrafiltration process, performed in pulsating conditions. The hybrid model
actually consists of two different components: a fundamental, theoretical model
describing the unsteady-state transport of both momentum and mass in the
module channel and through the membrane, and a very simple cause- effect
model, based on an artificial neural network (ANN). The theoretical model,
described by a system of partial differential equations solved by Finite Elements
Method (FEM), allows predicting the time evolution of concentration polarization
and of permeate flux decay as a function of process input variables. The neural
model, instead, is used to determine, in a wide range of operating conditions, the
functional relationship existing between the concentration of the rejected species
adsorbed on the membrane surface and the additional resistance due to the
membrane fouling. The main advantage of hybrid modeling actually regards the
possibility to describe some well-assessed phenomena, such as concentration
polarization phenomena and their dependence on the operating conditions, by
means of a fundamental theoretical approach. Some others, like the complex
interactions existing between the adsorbed solute(s) and the membrane surface,
could be very difficult to interpret and, therefore, to express in terms of proper
mathematical relationships. An artificial neural network can make up for this
limited knowledge of complex physical phenomena with the identification of
rather simple single input single output (SISO) models, based on ANN. The
observed reliability of hybrid model predictions suggested the possibility of
implementing an advanced control system that could generate proper trans-
membrane pressure and feed flow rate pulsations, thus promoting polarized layer
disruption and, consequently, membrane performance enhancement. This
feedback control system has been developed by the integration of different
computational environments, thus resulting in the manipulation of the UF
experiments operating conditions as control variables, according to the hybrid
model suggestions for a permeate flux enhancement. In particular, the effects of
proportional, integral and derivative control actions on the responses of the
controlled process have been examined.

Membrane Modeling III - Process Simulations – 6
Wednesday July 16, 12:15 PM-12:45 PM, O’ahu/Waialua
Artificial Neural Networks Analysis of RO Process Performance: RO Plant
Performance and Organic Compound Passage
F. Giralt (Speaker), Universitat Rovira i Virgili, Catalunya, Spain - fgiralt@urv.cat
R. Rallo, Universitat Rovira i Virgili, Catalunya, Spain
D. Libotean, Universitat Rovira i Virgili, Catalunya, Spain
J. Giralt, Universitat Rovira i Virgili, Catalunya, Spain
Y. Cohen, University of California, Los Angeles (UCLA)
A neural network based modeling approach was investigated as a means of
developing data-driven models for describing RO process performance in terms
of flux and salt rejection in addition to evaluating the suitability of RO membranes
for rejecting a broad range of organic compounds. The concept of plant
memory time interval was introduced to capture the time-variability of plant
performance. The time interval, for the present case of relatively short-term plant
performance variability, was introduced as a unique input variable, along with
basic input process operating parameters. ANN model training was carried out
with the normalized permeate flux and salt passage for various model
architectures and time intervals. Model results demonstrated that plant
performance could be described to a reasonable level of accuracy (absolute
average errors of less than one percent) with respect to both permeate flux and
salt passage with a plant memory time interval. Forecasting of plant performance
was also shown to be feasible and with good accuracy with a reasonable
memory time interval (as high as ~ 48 hrs). The current approach is providing the
basis for developing and incorporating neural network data-driven models in a
control strategy and early-warning system of the deterioration of RO plant
performance. In this regard, the passage of organics through RO membranes is
particularly critical for applications that involve RO membranes in water treatment
plants. Neural network models can be effective in generating Quantitative
Structure-Property Relations (QSPR) for the organic passage (P), sorption (S)
and rejection (R) using the most relevant set of molecular descriptors. In the
present work, the approach was demonstrated based on an experimental data
set of 50 organics with four different RO membranes. A number of feature
selection methods were employed. Pre-screening was carried out, with Principal
Components Analysis and SOM of the chemical domain for the study chemicals,
as defined by chemical descriptors, to identify the applicability domain and
chemical similarities. The QSPR models predicted organic passage, rejection,
and sorption within the range of the standard deviations of measurements for the
experimental data set of fifty compounds. The application for the approach for
compounds of interest, for which experimental data were not available,
demonstrated reasonable mass balance closures. The quality of the QSPR/NN

models developed suggests that there is merit in extending the present approach
to develop a comprehensive tool for assessing RO plant performance (with
respect to both salt and organic solute removal) in RO water treatment
processes.

Ultra- and Microfiltration I - Transport – 1 – Keynote
Wednesday July 16, 9:30 AM-10:15 AM, Wai’anae
Dynamic Microfiltration: Investigation of Critical Flux Measurement
Methods and Improved Macromolecular Transmission
S. Prip Beier (Speaker), CAPEC/Department of Chemical and Biochemical Engineering,
Technical University, Lyngby, Denmark
G. Jonsson, CAPEC/Department of Chemical and Biochemical Engineering, Technical University,
Lyngby, Denmark - gj@kt.dtu.dk
Introduction: Membrane fouling can be irreversible, such as adsorption [1], or
reversible, such a concentration polarization and cake formation, or a
combination. I) Fouling increases the hydraulic resistance of the membrane.
Increasing the cross-flow velocity can minimize fouling, but this is expensive due
to pumping costs. II) Fouling can change the membrane pore size distribution
which can affect the transmission of certain components.
Our dynamic microfiltration set-up is constructed to handle both problems. I)
Pumping energy is lowered because the shear at the membrane surface is
disconnected from the feed suspension velocity by vibrations. II) The vibrations
maintain the pore size distribution. Thus, an initial high transmission of
macromolecules can be sustained when the flux is below the critical flux.
The dynamic microfiltration system, which has earlier been tested in filtration of
yeast cell suspensions [2] and in separation of alpha-amylase enzymes from
yeast cells [3], is tested using different critical flux measurement methods and
constant flux experiments. ‘Fouling rate’ and macromolecular transmission are
evaluated.
Experimental: The module consists of microfiltration hollow fibers with the skin
layer on the outside placed vertically in a bundle. The module can be vibrated
vertically at variable frequency and amplitude. The average pore sizes are 0.45E-
6 m and the system operates at constant flux. Bakers yeast suspensions and
bovine serum albumin (BSA) solutions are used. Results and Discussion: The
critical flux determination ‘step-up-down’ method along with a ‘step-up’ method
has been investigated. Parameters such as step height, step length and start
level are varied and investigated in order to identify and improve a proper
procedure for determining a critical flux. For a 8 g/l dry weight yeast cell
suspension vibrated at 20 Hz and 1.375 mm amplitude (average surface shear
rate around 1200 s -1 ) the average critical flux value for the different determination
procedures is 32 L/(m 2 h) with a standard deviation of 8 L/(m 2 h). Thus, because of
the relatively large standard deviation it is seen that the determination methods
including their operational parameters such as step height, step length and flux

start level has a huge impact on the critical flux level determined. The
experimental critical flux determination methods are further evaluated by running
5-6 hours constant flux experiments below, at and above the experimentally
determined critical fluxes. Based on our earlier defined acceptable fouling rate
limit of 40 mbar/h [2,3] at the critical flux, the step-up method seem to be the
most appropriate. Low flux start level (~ 7 L/(m 2 h)), a step-height of ~ 2 L/(m 2 h)
and a step length of 5-10 minutes should be applied in order to determine critical
fluxes at which operation slightly below makes long term constant flux operation
without exceeding a fouling rate of 40 mbar/h possible.
The effect of module vibrations on the transmission of BSA macromolecules has
also been investigated. For pure BSA solutions of 0.4 wt%, constant flux
filtrations at 20 L/(m 2 h) yielded a constant BSA transmission around 85 %
whereas the transmission without module vibration decreased from an initial
value of 67 % to around 45 % after 6 hours of constant flux filtration at 20
L/(m 2 h). The BSA transmission was also investigated in the separation from
yeast cells. A 8 g/L dry weight yeast cell suspension with 0.4 wt% BSA was
filtrated at 20 L/(m 2 h). It was possible to retain yeast cells completely and obtain
a BSA containing permeate with a constant BSA transmission of around 70 %.
Conclusion: A step-up method with a flux start level of around 7 L/(m 2 h), a step
height of around 2 L/(m2h) and a step length between 5-10 minutes is
appropriate for critical flux determination. This method yield critical fluxes that
when running constant flux filtrations for 5-6 hours slightly below the critical flux
do not exceed a defined critical flux fouling rate limit. Module vibrations facilitate
constant BSA transmission and the ability to completely separate yeast cells from
BSA with a constant BSA transmission of around 70 %. Overall the dynamic
microfiltration system is able to reduce fouling problems and enhance the critical
flux by module vibrations. Thus, pumping energy consumption is reduced.
Furthermore, constant and high macromolecular transmission is possible.
References:
[1] S.P. Beier, A.D. Enevoldsen, G.M. Kontogeorgis, E.B. Hansen, G. Jonsson, Adsorption of
Amylase Enzyme on Ultrafiltration Membranes, Langmuir 23 (2007) 9341-9451.
[2] S.P. Beier, G. Jonsson, M. Guerra, A. Garde, Dynamic Microfiltration with a Vibrating Hollow
Fiber Membrane Module; Filtration of Yeast Suspensions, J. Membr. Sci. 281 (2006) 281-287.
[3] S.P. Beier, G. Jonsson, Separation of Yeast Cells and Enzymes with a Vibrating Hollow Fiber
Membrane Module, Sep. Purif. Technol. 53 (2007) 111-118.

Ultra- and Microfiltration I - Transport – 2
Wednesday July 16, 10:15 AM-10:45 AM, Wai’anae
An Integral Analysis of Crossflow Filtration
R. Field (Speaker), University of Oxford, Oxford, United Kingdom
J. Wu, University of Durham, Durham, United Kingdom - junjie.wu@durham.ac.uk
Hermia’s analysis of dead-end filtration (in which he introduced four values of n,
(n-2 complete pore blocking; n=1.5 standard pore blocking; n=1 incomplete pore
blocking; n=0 cake filtration) was extended by Field et al (JMS 1995) to crossflow
filtration who linked the removal terms to the concept of critical flux. However
equating the critical flux to the steady-state flux needs to be questioned; the
removal term during initial fouling will not be the same as that after a cake has
formed. This mode of analysis also has one other fault and that is the use of flux
(J) and time (t) plots. Distinguishing between one form of fouling on the basis of
fits to J-t data can be problematic. Although the use of dJ/dt data should in
principal be very informative, the noise in typical data is a major problem.
Besides examining the theoretical basis of the terms employed, a novel integral
analysis is introduced for crossflow data. It is based upon combinations of
volume collected per unit area (V), time (t) and functions of J. The plots that are
created enable one to distinguish much more clearly between the various forms
of fouling. Linear behaviour is found if the fouling corresponds to a given mode of
fouling. Switches in the mode of fouling can readily be identified. A number of
examples including yeast filtration, protein filtration and oily-water filtration will be
covered.
The advantages and (fewer) disadvantages of this new approach will be
discussed with candor.

Ultra- and Microfiltration I - Transport – 3
Wednesday July 16, 10:45 AM-11:15 AM, Wai’anae
Flux Recovery During Infrasonic Frequency Backpulsing of Micro- and
Ultrafiltration Membranes Fouled with Dextrin and Yeast
D. McLachlan (Speaker), UNESCO Assoc Centre for Macromolecules, Shellenbosch, South
Africa - davidsm@sun.ac.za
E. Shugman, UNESCO Assoc Centre for Macromolecules, Shellenbosch, South Africa
R. Sanderson, UNESCO Assoc Centre for Macromolecules, Shellenbosch, South Africa
The fouling of micro and ultra membrane filters during the filtration process
necessitates that they be cleaned regularly. Back pulsing cleaning, as presented
in this paper, has the advantage that the plant does not have to be shut down
and that there are no soaps to dispose of.
In this paper Micro and Ultra membranes (Alpha Laval polysulphone 0.1 micron
and 100 000 MWCO) are first fouled, using a feed pressure of 100 kPa, in a flat
cell, with Dextrin or Yeast. After this infrasound backpulsing, directly into the
permeate space, was used to clean the membrane. During the cleaning, the RO
feed pressure remained at100 kPa and the cross flow rate at 30lt/hr. The back
pulsing was done using permeate water and at peak pressures of 90, 140 and
180 kPa. The results to be given in the presentation show that flux values of over
80% of the clean water value, can be restored by this procedure. These results
also show that when applied correctly regular and frequent backpulsing can
maintain an overall higher flux.
The purpose of this work is to explore the efficiency of cleaning, various
combinations of membrane materials and foulants, using backpulsing in flat cells,
where changes can easily be effected. Work is done in conjunction with these
experiments, is the use of backpulsing to clean spiral wrap elements (see R D
Sanderson et al-these proceedings.)

Ultra- and Microfiltration I - Transport – 4
Wednesday July 16, 11:15 AM-11:45 AM, Wai’anae
Electrostatic Contributions in Binary Protein Ultrafiltration
Y. Wang (Speaker), University of California Riverside, Riverside, California
V. Rodgers, University of California Riverside, Riverside, California - vrodgers@engr.ucr.edu
The objective of the current research is to investigate the important electrostatic
effects on binary protein ultrafiltration (UF) performance via factors such as
system pH and ionic strength. Four proteins were used in this study: alphalactalbumin
(aLA, 15 kDa), hen egg lysozyme (HEL, 15 kDa), cytochrome C
(CytC, 15 kDa) and bovine serum albumin (BSA, 69 kDa). Cross-flow UF
experiments (with diafiltration) were conducted for three binary protein systems:
aLA/BSA, CytC/BSA and HEL/BSA. These systems were chosen due to their
similar protein/protein size ratio however different charge properties, so they
were ideal systems to study the non-solute-size effects, especially electrostatic
effects, in binary protein UF. The membrane used in all experiments was 30,000-
MWCO composite regenerated cellulose (CRC) membrane. This type of
membrane has been known for its low extent of fouling, therefore, membrane
fouling contributions can be minimized in the current research. The experiments
were conducted at various pH values (pH 4.7, pH 6, pH 7, pH 8 and pH 10), and
low to moderate ionic strengths (0.0015 M, 0.015 M and 0.15 M). During the
experiments, the applied operating hydraulic pressure was varied randomly in the
range from 0 to 145 kPa, and the permeate flux versus pressure dependence
profiles, as well as the corresponding protein sieving behaviors, were recorded.
The pH and ionic strength dependences of the permeate flux were first observed
in the single BSA UF experiments that served as controls. The permeate flux
generally increased with increasing pH (which corresponds to the increase of
BSA net charge), and decreased with increasing ionic strength. For the binary
protein UF experiments, the permeate flux behaviors differed largely from system
to system, as expected. For the aLA/BSA system in which aLA was similarly
charged as BSA at all pH values studied, the flux-pressure behaviors were
almost identical to those of the control experiments with BSA only. On the other
hand, for the HEL/BSA system consisting two proteins that were always
oppositely charged at the pH values studied, the permeate flux-pressure
behaviors differed largely from control experiments. At lower ionic strengths, the
significant pH dependence as well as unusual patterns in the permeate fluxpressure
profiles strongly suggested reversible formation of HEL-BSA complex
caused by electrostatic interaction. Though less significantly, the CytC/BSA
system showed similar flux behaviors as the HEL/BSA system. The observed
sieving coefficient (as a function of the permeate flux) of the 15 kDa proteins for

all three binary protein UF systems also demonstrated clear pH and ionic
strength dependences, as well as system dependence.
The free solvent-based model (FSB) previously developed by our group, which
successfully predicts and characterizes of the flux behavior in protein UF with
moderate electrostatic screening, was modified to include electrostatic
contributions, and was applied to the theoretical modeling of the observed
experimental observations. The FSB model uses the free-solvent model for
osmotic pressure [Ref. 1] coupled with the Kedem-Katchalsky model and film
theory, and in a paradigm shift, this model reestablishes the significance of
osmotic pressure by examining its contribution to permeate flux behavior in the
framework of the free-solvent model. The modified film theory [Ref. 2], which
includes a permeate flux contribution resulted from the electrostatic forces on the
solute particles in the concentration polarization layer, was used to study the pH
and ionic strength dependences observed in single BSA UF flux behaviors.
Through this approach, the regressed protein surface potential values for each
solution condition agreed with the literature reasonably well; however, the
limitations of this approach were also recognized. Hindered transport theory [Ref.
3] with electrostatic contribution was used to study the electrostatic interaction
effects on the sieving behaviors in binary protein UF. For the aLA/BSA system
that only contains repulsive interactions, the model calculations agreed well with
the experimental observations. For the other two systems that contain attractive
interactions, theoretical modeling is currently on-going.
In summary, the effects of electrostatic contributions in the UF performance of
binary protein UF experiments were systematically studied. Theoretical
approaches have also demonstrated preliminary success. Results will be
discussed.
Ref. 1: M.A. Yousef, R. Datta, and V.G.J. Rodgers, J. Colloid Interface Sci., 197 (1998) 108-118.
Ref. 2: R.M. McDonogh, A.G. Fane, and C.J.D. Fell, J. Membr. Sci., 43 (1989) 69-85.
Ref. 3: W.M. Deen, AIChE Journal, 33 (1987) 1409-1425.

Ultra- and Microfiltration I - Transport – 5
Wednesday July 16, 11:45 AM-12:15 PM, Wai’anae
Membrane Separation of High Added Value Milk Proteins
M. Mier (Speaker), University of Cantabria, Spain
R. Ibáñez, University of Cantabria, Spain
I. Ortiz, University of Cantabria, Spain - ortizi@unican.es
High Performance Tangential Flow Filtration (HPTFF) is an emerging technology
that employs a new kind of porous membranes of recent development [1, 2]. The
novelty of these membranes is the fact that they have a net charge either positive
or negative. HPTFF claims to be a two-dimensional purification method that
exploits differences in both size and charge characteristics of molecules [3], thus,
enhancing the efficiency of difficult separations.
First applications of HPTFF dealt with the separation of biomolecules similar in
size but different in charge as BSA / Fab; IgG / BSA or myoglobin. [2, 3]. HPTFF
is expected to be a good alternative to traditional protein purification processes
due to its unique characteristics and its ability to separate molecules with,
virtually, the same size taking advantage of their differences in charge. The
increasing interest of the food and pharmaceutical industry in the separation of
pure protein fractions with nutraceutical properties motivates the development of
new membrane separation technologies and the introduction of more efficient
processes including different membrane technologies working in conjunction.
In previous works carried out by our research group, the suitability of
electrodialysis with bipolar membrane technology (EDBM) for pH control of liquid
fluids without the employment of chemical reagents have been demonstrated [4 -
6]. In this basis, this work aims to achieve the pH control of a organic matrix
solution (milk) prior the HPTFF processing so that, taking advantage of both
membrane technologies, the separation of minor whey proteins into different pure
fractions can be achieve minimizing the use of chemicals.
In a first stage the evaluation of the performance of HPTFF membrane
technology in the separation of minor whey proteins is studied. Commercial
available membranes and prototype charged membranes are tested in order to
determine the viability of using HPTFF for difficult separations as similar size
protein mixtures but different in their isoelectric point (pI). In a second stage,
EDBM is used in combination with HPTFF to achieve selective separation. Using
solutions containing mixtures of proteins the solution pH is changed by means of
EDBM allowing the selective protein fractionation performed by HPTFF.

Synthetic solutions of ±-lactalbumin (140kDa - pIH4.5), bovine serum albumin
(BSA) (69kDa - pIH4.8) and lactoferrin (78kDa - pIH8) are used in this study.
EDBM experiments are carried out by means of a laboratory scale plant
purchased by Elektrolyse Project (Netherlands). Commercial anionic and cationic
(Ralex AMH and CMH) and bipolar membranes (NEOSEPTA BP-1) are used.
HPTFF experiments are carried out by means of a laboratory scale plant from
Millipore using BIOMAX and prototype membranes from Millipore.
Finally, a hybrid process combining both membrane technologies, EDBM and
HPTFF, will be proposed and tested for the separation of whey proteins.
Bibliography
[1] R. van Reis, S. Gadam, L.N. Frautschy, S. Orlando, E.M. Goodrich, S. Saksena, R. Kuriyel,
C.M. Simpson, S. Pearl, A.L. Zydney, High performance tangential flow filtration, Biotechnology
and Bioengineering 56 (1997) 71-82.
[2] R. van Reis, J.M. Brake, J. Charkoudian, D.B. Burns, A.L. Zydney, High-performance
tangential flow filtration using charged membranes, Journal of Membrane Science 159 (1999)
133-142.
[3] C. Christy, G. Adams, R. Kuriyel, G. Bolton, A. Seilly, High-performance tangential flow
filtration: a highly selective membrane separation process, Desalination 144 (2002) 133-136.
[4] M.P. Mier, R. Ibáñez, I. Ortiz, Influence of ion concentration on the kinetics of electrodialysis
with bipolar membranes, Separation and Purification Technology 59 (2008) 197 - 205.
[5] M.P. Mier, R. Ibáñez, I. Ortiz, Electrodialysis with bipolar membranes as an efficient method
for the obtention of milk proteins, Récents Progrès en Génie des Procédés 94 (2007).
[6] M.P. Mier, R. Ibáñez, I. Ortiz, Influence of process variables on the separation of casein from
milk by Electrodialysis with Bipolar Membranes, Biochemical Engineering Journal DOI:
10.1016/j.bej.2007.12.023.

Ultra- and Microfiltration I - Transport – 6
Wednesday July 16, 12:15 PM-12:45 PM, Wai’anae
Tuning of the Cut-Off Curves By Dynamic Ultrafiltration
G. Jonsson (Speaker), Technical University of Denmark, Lyngby, Denmark - gj@kt.dtu.dk
Ultrafiltration is mainly used to concentrate macromolecules and removing salts
and smaller molecules through the membrane. Sharp separation is rarely seen
which is partly due to the coupling of solute and water transport and the
concentration polarization at the membrane surface. In case of real fractionation
of macromolecules, a decoupling of the solute transport from the water transfer
together with a minimization of the concentration polarization of the larger
molecules, have to take place. Using hollow fiber membranes under high-
frequency backflushing the concentration polarization can be minimized due to
the non- steady state operation. The build-up of the polarized highly concentrated
layer at the membrane surface takes typically 10-30 seconds why it is possible to
obtain a dynamic layer with a substantially reduced surface concentration
thereby increasing the selectivity of the membrane. The paper describes the
modeling of the dynamics of the concentration polarization and how it influences
the membrane selectivity and productivity. The modeling is further supported by
experiments fractionating dextrans and proteins on a hollow fiber system using
backflushing intervals from 1 to 30 seconds and backflushing times from 0,1 to 5
seconds.

Oral Presentation
Abstracts
Morning Session
Thursday, July 17, 2008

Gas Separation IV – 1 – Keynote
Thursday July 17, 8:15 AM-9:00 AM, Kaua’i
Polymer-based Multicomponent Membranes for Gas Separation
K. Peinemann (Speaker), GKSS-Forschungszentrum Geesthacht GmbH, Geesthacht, Germany
- klaus-viktor.peinemann@gkss.de
In spite of significant developments of polymeric membranes for gas separation it
seems that the race for better tailor made organic polymers with improved
performance has slowed down during the last years. New developments in the
area of hybrid materials (inorganic/organic, organic/organic) have instead
stimulated membrane research. In recent years the phrases nanocomposites and
nanostructured membrane materials have become the magic formula to attract
attention. Some of the scientific achievements, which have been made in this
field, will be highlighted. But in spite of these achievements very few (any?) of the
sophisticated new materials have found their way into technical applications.
Some will but many will never, because they are too complicated for large scale
applications. This will be discussed using the example of carbon dioxide
capturing. Nanostructured fixed-carrier membranes e.g. show fascinating
performance in lab scale experiments but it is highly unlikely that they will be
used for natural gas or flue gas treatment. Crossing the Robeson line should not
the main criterion for development of a successful gas separation membrane.
The author will discuss simple approaches for manufacturing nanocomposites for
gas separation.

Gas Separation IV – 2
Thursday July 17, 9:30 AM-10:00 AM, Kaua’i
Gas Separation Properties of C/SiO2/alumina Composite Membranes for
CO2 Separation
S. Han (Speaker), Hanyang University, Seoul, Korea
S. Kim, Hanyang University, Seoul, Korea
H. Park, University of Ulsan, Ulsan, Korea
Y. Lee, Hanyang University, Seoul, Korea ymlee@hanyang.ac.kr
Membrane-based gas separation is one of the promising separation technologies
due to its high energy efficiency as well as excellent separation property. During
the last several decades, polymer materials like polysulfone, poly (ether sulfone),
and polyimide have been used for gas separation membrane. Recently, many
researchers have shown interests in carbon membranes rendered from
polymeric precursors as good candidate materials for gas separation with their
superior separation performances, highly excellent stabilities for vapor and
condensable gases, and extraordinary durability in heated and corrosive
circumstance. In our previous study, we developed carbon-silica(C/SiO2)
membranes for enhanced permeabilities of small gas molecules. The C/SiO2
membranes derived from poly(imide siloxane) copolymers were composed of the
dispersed silica domains to give higher permeable region as well as the
continuous carbon matrix to retain the selectivities of common carbon
membranes. We have modified the C/SiO2 materials by UV treatment, by
changing the ratio of siloxane domain to polyimide region, by adding sol-gel
solution of alkoxysilane, or, by partial oxidation of siloxane domain in pyrolysis to
obtain the most suitable membrane for CO2 separation. Furthermore, we have
studied to develop the composite membrane coated on porous supports for large
areas of inorganic membrane and practical applications. Here, we would like to
demonstrate the gas permeation properties of supported carbon composite
membrane modules prepared from polyimide and poly(imide siloxane) to
fabricate a large inorganic membrane and to test their CO2/N2 separation
properties for CO2 sequestration in flue gases. For preparing poly(imide siloxane)
as polymeric precursors, a calculated amount of pyromellitic dianhydride(PMDA)
was dropped to equimolar 4,4'- oxydianiline(ODA) and aminopropyl
dimethylsiloxane (PDMS, Mw=900) solution in 1- methylpyrrolidinone (NMP) and
tetrahydrofuran (THF). The alumina support(O.D. = 4.8 mm, I.D. = 3.0 mm,
length = 400 mm) purchased from Nanoporous materialsTM were slip-casted by
boehmite sol and calcinated at 700 C to prepare mesoporous intermediate layer.
The prepared polymeric precursors were coated on the alumina supports
modified by alumina layer, and the composite membranes were carbonized at

600 C in a tubular furnace. Finally, a carbon membrane module was fabricated
by sustainable stainless (SUS 316) housing and VitonTM O-ring for permeation
test at high temperature. The effective area of carbon membrane module
composed of 19 composite membranes was 1002.8 cm 2 . Gas permeation
properties of pure gases were recorded to GPU unit by MFCs (mass flow
controllers) and Baratron manometers at 1 to 5 atm. Mixed gas separation
experiments were conducted by using binary gas mixtures(21% O2/79% N2, 15%
CO2/85% N2, 50% CO2/50% CH4), and the compositions of permeate and
retentate flow were measured with different stage-cuts by gas chromatography
(GC- 2010 ATF, Shimadzu Co. Ltd., Japan) at room temperature to 150oC. The
uniform mesoporous ³- alumina layer and defect-free carbon layer coated on the
alumina support were 1-2 μm and 2-3 μm thick. Gas permeances of He, H2, CO2,
O2, N2, CH4 were 207, 310, 169, 39, 6.1, and 2.7 GPU(1GPU=10 - 6 cm 3 -cm -2 -seccmHg),
respectively. Ideal gas selectivities of the composite membrane were 7
and 27 to O2/N2 and CO2/N2 at 298 K, similarly with the factors calculated from
gas permeabilities of flat carbon membranes by time- lag method in our previous
study. The gas permeances increased at higher temperature, whereas the
selectivities slightly decreased. For binary gas mixtures, composition (yi : conc. at
inlet, yp : conc. at permeate, yr : conc. at retentate) and flux (Vi : flux at inlet, Vp :
flux at permeate, Vr : flux at retentate) were recorded to calculate the stage-cut
and recovery ratio. Stage-cut, the ratio of permeate flux(Vp) divided by inlet
flux(Vi), provides information related to the capacity of a membrane module. The
larger stage-cut indicates that large amount of feed gas can be supplied at a
constant pressure, while the enrichment of the permeate stream should drop
proportionally to the increasing stage-cut. Recovery ratio, the ratio of the
recovered gas flux per supplied gas flux at inlet stream, is the value of stage-cut
multiplied by the permeate concentration. Therefore, the recovery ratio
approaches to 1 at higher stage-cut. In CO2/N2 separation test, the enriched CO2
concentration dropped from 85 to 15% at the stage-cut of 0 to 1, while the
recovery ratio of CO2 approached from 0 to 1. At the optimized stage-cut of 0.25,
the recovery ratio and the permeate composition were 0.9 and 60% CO2.

Gas Separation IV – 3
Thursday July 17, 10:00 AM-10:30 AM, Kaua’i
Gas Transport Properties of Hyperbranched Polyimide-Silica Hybrid
Membranes
Y. Yamada (Speaker), Kyoto Institute of Technology, Kyoto, Japan - y-yamada@kit.ac.jp
K. Itahashi, Nagoya Institute of Technology, Nagoya, Japan
T. Suzuki, Nagoya Institute of Technology, Nagoya, Japan
Physical and gas transport properties of hyperbranched polyimide silica hybrid
membranes were investigated. Hyperbranched polyamic acids as precursors was
prepared by polycondensation of a triamine, 1,3,5-tris(4-aminophenoxy) benzene
(TAPOB), and commercially available dianhydrides, and subsequently modified a
part of end groups by 3-aminopropyltrimethoxysilane (APTrMOS). The
hyperbranched polyimide silica hybrid membranes were prepared by sol-gel
reaction using the polyamic acids, water, and various alkoxysilanes. 5 % weightloss
temperature of the hybrid membranes increased with increasing silica
content, indicating effective crosslinking at polymer silica interface mediated by
APTrMOS moiety. On the other hand, glass transition temperature of the hybrid
membranes prepared with methyltrimethoxysilane (MTMS) showed a minimum
value at low silica content region, suggesting insufficient formation of threedimensional
Si-O-Si network compared to the hybrid membranes prepared with
tetramethoxysilane (TMOS). CO2, O2, N2, and CH4 permeability coefficients of
the hybrid membranes increased with increasing silica content. Especially for
TMOS/MTMS combined system, the hybrid membranes showed simultaneous
enhancements of gas permeability and CO2/CH4 separation ability. It was
concluded that the hyperbranched polyimide-silica hybrid membranes have high
thermal stability and excellent CO2/CH4 selectivity, and are expected to apply to
high-performance gas separation membranes.

Gas Separation IV – 4
Thursday July 17, 10:30 AM-11:00 AM, Kaua’i
Carbon Membranes - Tackling the Aging Issue
E. Sheridan (Speaker), Norwegian University of Science and Technology, Trondheim, Norway
J. Lie, Norwegian University of Science and Technology, Trondheim, Norway
X. He, Norwegian University of Science and Technology, Trondheim, Norway
M. Hägg, Norwegian University of Science and Technology, Trondheim, Norway - maybritt.hagg@chemeng.ntnu.no
Carbon membranes are generally found to out- perform polymeric membranes in
relation to selectivity, permeability and stability in highly corrosive and high
temperature environments hence making them suitable candidates for processes
such as pre-combustion separation of CO2 from natural gas and biogas
upgrading. Although carbon membranes have been intensively researched over
recent years, the development for commercially application has been hampered
somewhat due to the high cost of commonly used precursor materials such as
polyimides, the energy demanding carbonization process and the deterioration of
performance over time due to membrane aging. The production of carbon
membranes as hollow fibres offers a real potential for commercialisation although
the major problem of membrane aging must first be addressed.
Our current work attempts to overcome some of the practical problems, by
producing carbon hollow fibres by a dry-wet spinning process using a relatively
cheap cellulosic precursor and investigating techniques to overcome membrane
aging while enhancing membrane performance. Two approaches to defeating the
aging effect on carbon membranes are examined. Firstly, the effect of carrying
out the carbonization process in different gas atmospheres is investigated.
Secondly, the investigation of electrothermal regeneration of the carbon
membrane fixed in a module is presented. Results have shown that a carbon
membrane may be restored to within 90-100% of its original permeability after
this regeneration compared with a loss of 40% for the non-treated membrane.
Additional considerations concerning a suitable module design to facilitate
electrothermal regeneration are also presented.
The enhancement of the lifetime of carbon membranes through techniques such
as regeneration is a key factor in commercialisation of these membranes. In
addition, if the above issues are resolved, carbon membranes could surpass the
usefulness of polymeric membranes due to their durability in harsh, high
temperature environments.

Gas Separation IV – 5
Thursday July 17, 11:00 AM-11:30 AM, Kaua’i
Glassy Perfluoropolymer - Zeolite Hybrid Membranes for Gas and Vapor
Separations
G. Golemme (Speaker), Univ. della Calabria; ITM-CNR; and INSTM, Rende (CS), Italy -
ggolemme@unical.it
J. Jansen, ITM - CNR
D. Muoio, Univ. della Calábria, Rende, Italy
G. De Luca, Univ. della Calábria, Rende, Italy
A. Bruno, Univ. della Calábria, Rende, Italy
R. Manes, Dip, Univ. della Calábria, Rende, Italy
J. Choi, University of Minnesota, Minneapolis, Minnesota
M. Tsapatsis, University of Minnesota, Minneapolis, Minnesota
This paper reports on the successful preparation of hybrid membranes of glassy
perfluoropolymer and MFI zeolites, with significantly improved transport
properties compared to the pure polymers. Perfluoropolymers withstand easily
temperatures beyond 100°C, organic solvents and aggressive chemicals. As a
result of the unusual sorption properties of glassy and amorphous
perfluoropolymers, the permeability-selectivity combinations of some gas pairs
exceed the Robeson upper bound [1,2]. Nanoscale fumed silica as a filler of
highly permeable, stiff backbone polymers (Teflon AF 2400, PMP, PTMSP) was
found to increase the free volume due to the disruption of the packing ability of
the organic phase [3-6]; in Teflon AF 2400 and PMP, the increased free volume
in turn was responsible of a higher permeability, especially for the most
condensable species, and therefore, at the same time, of a better n-butane/CH4
separation factor.
Since porous fillers may have an even better effect on the performance of hybrid
membranes than dense fumed silica, the scope of the present work was to study
the separation capabilities of Teflon AF and Hyflon hybrid membranes with
Silicalite-1 (MFI) crystals of different size. In the past it was demonstrated that
surface modified sub-micron zeolites can be effectively dispersed inside the
extremely hydrophobic matrix of glassy perfluoropolymer membranes [7]. Hybrid
membranes containing up to 42 wt % of fluorophilic MFI crystals (80 to 1500 nm)
were thus prepared. Their morphology was observed by SEM and TEM. Single
gas permeation experiments (O2, N2, H2, He, CH4, CO2, n-butane) were carried
out at 25°C and 1 bar of feed pressure in a constant volume - variable pressure
device [8]. The gas diffusion coefficients were derived from the time-lag, the
permeability from the steady state pressure increase rate, and the solubility from
the permeability-to-diffusion ratio.

Defect free membranes could be prepared in all cases. In Teflon AF 1600, the
noteworthy increase of the gas solubility (especially CO2, CH4 and N2) indicated
an active contribution of the MFI crystals to the transport of penetrants.
Experimental evidences indicated the presence of a polymer-zeolite interface
characterized by higher free volume and permeability. At the same time, the
surface of the crystals probably offers a resistance to transport.
MFI fillers improve the separation performance of the poorly selective Teflon AF
polymers. In fact the n-butane permeability of a membrane made of 1500 nm MFI
crystals (40 wt%) in Teflon AF 2400 was 2230 Barrer, with an ideal n-C4/CH4
separation factor of 2.4, and a solubility selectivity of 38. A comparable
membrane of the same polymer containing 40 wt% of amorphous silica, instead,
in the same conditions had a lower n-C4 permeability (690 Barrer) and an ideal n-
C4/CH4 separation factor of only 0.63 [3]. Mixed gas permeation experiments are
now in progress.
Also for the more selective and less permeable Hyflon AD 60X polymer, the main
effect of the MFI filler (1500 nm, 42 wt%) is the enhancement of solubility. A CO2
permeability of 500 Barrer and a CO2/CH4 ideal selectivity of 23 represent an
interesting combination for the sweetening of natural gas, thanks to the
resistance to plasticization of the polymer and also to the stabilizing effect of the
inorganic phase [3]. The permeability-selectivity combination of the N2/CH4 gas
pair (2.9 ideal selectivity, 63 Barrer for N2) also lies beyond the Robeson 1991
upper bound [2].
In conclusion, this study demonstrates that dispersing porous fillers in
perfluoropolymer membranes is a viable principle for the improvement of their
separation properties. For some gas pairs the original size selectivity of the pure
polymer may be transformed in solubility selectivity in the hybrid material, which
opens up new opportunities for the treatment of natural gas.
References
1. T. C. Merkel, I. Pinnau, R. Prabhakar, B. D. Freeman; "Gas and Vapor Transport Properties of
Perfluoropolymers", in Yu. Yampol'skii, I. Pinnau, B. D. Freeman, Eds., Materials Science of
Membranes for Gas and Vapor Separation; J. Wiley: Chichester (UK), 2006; Chapt. 9, pp. 251-
70.
2. L. M. Robeson, J. Membrane Science, 62 (1992) 165.
3. T. C. Merkel, Z. He, I. Pinnau, B. D. Freeman, P. Meakin, A. J. Hill; Macromolecules, 36 (2003)
8406.
4. T. C. Merkel, B. D. Freeman, R. J. Spontek, Z. He, I. Pinnau; Science, 296 (2002) 519.
5. Z. He, I. Pinnau, A. Morisato; Desalination, 146 (2002) 11.

6. T. C. Merkel, Z. He, I. Pinnau, B. D. Freeman, P. Meakin, A. J. Hill; Macromolecules, 36 (2003)
6844.
7. G. Golemme, A. Bruno, R. Manes, D. Muoio, Desalination, 200 (2006) 440.
8. M. Macchione, J. C. Jansen, G. De Luca, E. Tocci, M. Longeri, E. Drioli; Polymer, 48 (2007)
2619.

Gas Separation IV – 6
Thursday July 17, 11:30 AM-12:00 PM, Kaua’i
Development and Characterization of PPO-based Emulsion Polymerized
Mixed Matrix Membranes
Q. Wang, University of Ottawa, Ottawa, Ontario, Canada
F. Sadeghi, Natural Resources Canada, Varennes, Quebec, Canada
A. Tremblay, University of Ottawa, Ottawa, Ontario, Canada
B. Kruczek (Speaker), University of Ottawa, Ottawa, Ontario, Canada - bkruczek@uottawa.ca
Molecular level combination between organic polymers and inorganic materials
has been of interest for two decades and one of the major challenges in this field
is achieving the compatibility between the organic and inorganic phases, which is
critical for the synthesis of gas separation membranes.
In this presentation we will present a novel method for preparation of poly (2,6dimethyl-1,4-phenylene
oxide) (PPO)-based organic/inorganic membranes.
Essentially, an inorganic precursor, aluminium hydroxonitrate, contained in a
stable water-in-oil (W/O) emulsion was mixed with a polymer solution containing
a second inorganic precursor, tetraethyl orthosilicate (TEOS). Inorganic
polymerization occurred in or at the surface of the aqueous droplets of the W/O
emulsion. Subsequently, thin films were prepared by a spin coating technique,
and the resulting membranes were referred to as emulsion polymerized mixed
matrix (EPMM) membranes. The size of the inorganic particles, which greatly
affects their dispersion in a continues polymeric phase and determines whether
or not phase separation occurs, was controlled by an ultrasonic energy input into
the W/O emulsion. Such prepared membranes were characterized by EDX-Ray
measurements, SEM, TGA and DSC analyses. The permeability and selectivity
of the membranes were determined in air separation tests. The air separation
tests also confirmed achieving compatibility between the phases. The effect of
inorganic loading on the gas transport and physical properties of the PPO-based
EPMM membranes will also be presented and discussed.

Gas Separation IV – 7
Thursday July 17, 12:00 PM-12:30 PM, Kaua’i
Novel Semi-IPN Carbon Membranes Fabricated by a Low-Temperature
Pyrolysis for C3H6/C3H8 Separation
M. Chng (Speaker), National University of Singapore, Singapore
Y. Xiao, National University of Singapore, Singapore
T. Chung, National University of Singapore, Singapore- chencts@nus.edu.sg
M. Toriida, Mitsui Chemicals, Inc., Japan
S. Tamai, Mitsui Chemicals, Inc., Japan
One of the most important processes in petrochemical industries and petroleum
refining is the separation of hydrocarbon mixtures with close boiling points, such
as olefins and paraffins. At present, the separation of olefin and paraffin mixture
is mostly carried out using low temperature distillation which requires enormous
capital and large energy consumption. Membrane technology, which has the
advantages of both low cost and reduced energy consumption as compared to
the conventional separation processes, is potentially an attractive option,
although it is the largest challenge to find suitable membrane materials with both
high permeability and propylene/propane separation performance. Carbon
membranes are chemically strong materials and have tailorable gas transport
properties with high separation performance for gas pairs with very similar
molecular dimensions such as C3H6/C3H8 through a molecular sieving
mechanism. We will report a carbon membrane derived from Poly (aryl ether
ketone). Interpenetrating polymer networks (IPNs) are a unique polymer blend,
which is defined as a combination of two or more polymers in the form of network
with at least one of which is crosslinked in the immediate presence of the other.
IPNs successfully created polymeric nano-scale blends having new extraordinary
properties. Carbon membranes display superior permeabilities- selectivity
combination than polymeric membranes. Low pyrolysis temperature not only
keeps the membrane flexibility and toughness, but also tends to avoid excessive
closure of the main selective ultramicropores and hence increase the
permeability and selectivity. As a result, the newly developed carbon membranes
show a significantly enhanced olefin/paraffin separation performance due to the
molecular sieving mechanism.

EMS Barrer Prize – 1a
Thursday July 17, 8:15 AM-8:35 AM, Maui
My Membrane World
H. Strathmann (Speaker), Professor, Germany Heiner.Strathmann@t-online.de

EMS Barrer Prize – 1b
Thursday July 17, 8:35 AM-9:00 AM, Maui
Climbing Membranes and Membranes Operations
E. Drioli (Speaker), Institute on Membrane Technology of the Italian National Research Council,
Rende, Italy - e.drioli@itm.cnr.it
Membranes and membrane operations are today dominant technologies and
their visibility in large part of the public is growing continuously. The situation was
quite different not too many years ago. It is interesting and useful to revisit and
rediscuss some of the problems and efforts which researchers and engineers
had to overcome to reach their goals. The success of membrane science and
membrane engineering are mainly related to the work of researchers able to face
the basic problems related to the understanding the final morphology of dense
and microporous membranes, their transport mechanism, and to develop new
membrane operations, for molecular separation, chemical conversions, mass
and energy transfer between different phases.

EMS Barrer Prize – 2
Thursday July 17, 9:30 AM-9:55 AM, Maui
Membrane Separation of Nitrogen from High-Nitrogen Natural Gas: A Case
Study from Membrane Synthesis to Commercial Deployment
R. Baker (Speaker), Membrane Technology and Research, Inc., USA - rwbaker@mtrinc.com
Fourteen percent of U.S. natural gas contains excess nitrogen, and cannot be
sent to the national pipelines without treatment. Nitrogen is difficult to remove
economically from methane, by any technology. Currently, the only process used
on a large scale is cryogenic liquefaction and fractionation, but this technology
requires economies of scale to be practical. Many owners of small gas fields
cannot produce their gas for lack of suitable nitrogen separation technology.
This paper describes the development of selective membranes to treat natural
gas containing high concentrations of nitrogen. Membranes selectively permeate
either nitrogen or methane, the principal constituent of natural gas. Our work has
shown that methane-selective membranes are generally preferable. We have
produced membranes with high permeances and methane/nitrogen selectivities
of approximately 3-3.5. This selectivity is modest, so commercial systems often
require multi-stage or multi-step process designs. Despite the design complexity
and compression requirements, multi-step/multi-stage membrane systems are
the lowest cost nitrogen removal technology in many applications.
The development of this membrane technology to the commercial scale is
described. To date, nine membrane-based systems for nitrogen removal during
natural gas processing have been installed.

EMS Barrer Prize – 3
Thursday July 17, 9:55 AM-10:20 AM, Maui
Molecular Simulations of Membrane Transport Processes
N. van der Vegt (Speaker), Max Planck Institute for Polymer Research, Mainz, Germany -
vdervegt@mpip-mainz.mpg.de
In my talk I will discuss the use of molecular models in computer simulations of
membrane transport processes. Detailed models, which include nearly all
atomistic degrees of freedom, as well as less detailed, coarse-grained models, in
which several covalently linked atoms are lumped together into a single
interaction site, will be introduced. I will illustrate how these models can be used
in multiscale polymer simulations spanning a wide range of time and length
scales. These simulations permit describing relaxed (equilibrated) polymer
morphologies on length scales up to 0.1-1 micrometer and in a second step to
"zoom-in" down to Angstrom-scale resolution if atomistic details need to be
further understood. I will emphasize future perspectives for membrane transport
modeling by invoking this multiscale simulation approach. The examples
discussed in my talk include thin-layer protective coatings on a solid substrate;
predictive modeling of residual monomer diffusion in molten polystyrene with
coarse-grained models; and solubility of bulky penetrant molecules in large-size
simulation volumes of bulk polycarbonate calculated by means of fast-growth
thermodynamic integration.

EMS Barrer Prize – 4a
Thursday July 17, 10:20 AM-10:45 AM, Maui
Beyond Academic Research
G.-H. Koops (Speaker), GE Water & Process Technologies, Burlington, Ontario, Canada -
Geert.Koops@ge.com
This paper discusses some typical research questions that need to be answered
to bring a new UF hollow fiber membrane for water filtration from development to
commercial production.
Academic researchers typically report on relationships/effects between various
components in the polymer solution and their membrane properties. Or study the
effect of various spinning parameters on the membrane properties. Sometimes
exotic polymers are synthesized, polymers are modified, or membranes are
coated/post treated. Normally, all testing is done on small samples sizes,
reproducibility is often neglected and costs are not at all a consideration. This
makes academic research so much fun: there are no limitations, no CTQs!
In the industrial world this is quite different. Most new membrane introductions
start off with the same kind of academic research, but with significant restrictions
due to clear CTQs (Critical to Quality objectives). When this stage is passed and
a new chemistry has been developed many more development stages follow
before a new product makes it to the market. This paper addresses some
challenges that are normally not studied by academics, but are critical for new
product introductions. The challenges that will be addressed are: cost and
material choice, chemical resistance testing, fiber breaks, fiber fatigue testing,
scale up challenges, and performance testing.

EMS Barrer Prize – 4b
Thursday July 17, 10:45 AM-11:10 AM, Maui
New Challenges in membrane preparation by phase inversion technique
A. Figoli (Speaker), ITM-CNR, Rende, Italy - a.figoli@itm.cnr.it
The phase inversion technique allows producing both symmetric and asymmetric
(porous and dense) membranes. Prof. Heiner Strathmann gave his strong
contribution in this field, already in 1971, elaborating an original approach in
which the process of membrane formation is shown in a simplified way as a line
through the phase diagram [1-3]. Nowadays, the phase inversion technique still
represents the most used procedure for membranes preparation that are usually
employed in traditional separation processes from microfiltration/ ultrafiltration
(porous membranes) to nanofiltration/reverse osmosis/pervaporation/gas
separation (dense membranes). In this work, innovative polymeric membranes
prepared by this technique are presented for potential food, environmental,
pharmaceutical and chemical applications: a) a multilayer membrane film b)
polymeric capsules and c) elastomeric asymmetric SBS membranes. a) The
multilayer membrane was developed as an innovative antimicrobial food
packaging film [4-5]. The ´intelligent´ film should recognize the presence of
bacteria in the food and release an amount of antimicrobials suitable to inhibit
bacterial growth and prevent spoilage. The multilayer film is made of three layers:
1) an outer dense layer to control the exchange rate of gases and vapour
between the external and internal environment of the food packaging, 2) an
intermediate adhesive tie-layer which has also the function of reservoir of
antimicrobials, 3) a porous third layer, made by non-solvent induced phase
inversion (NIPS), which is able to control the release of antimicrobials to the food
in time. The release of antimicrobials can be adjusted changing the morphology
of the porous layer that can be controlled varying the phase inversion process
conditions. b) Polymeric capsules using a membrane process combined with the
phase inversion technique (NIPS) was exploited [6]. This method can be
identified as an integration between the traditional chemical capsule techniques
(coacervation or phase inversion) and the mechanical capsule technique
(pressure extrusion). It allows the formation of monodispersed polymer (modified
polyetheretherketone) micro-capsules with different morphologies. The capsule
morphology, porosity, size and shell thickness is easily adjusted changing the
ingredient parameters such as polymer concentration, solvent and non solvent
involved phases in the process. c) Novel asymmetric elastomeric SBS
membranes were prepared by NIPS [7] which allows to taylor the morphology of
the prepared membrane and to obtain a resistant membrane with a thin active
layer in a single step. The success of the preparation of asymmetric elastomeric
hydrophobic membranes leads to an easier membrane production at lower cost

with respect to the composite membrane traditionally produced for pervaporation
purposes.
References
1) H. Strathmann, P. Scheible, R.W. Baker ‘A rationale for the preparation of Loeb-Sourirajan
Type Cellulose Acetate Membranes’, J. Appl. Polymer Science, 15 (1971) 811.
2) M.T. So, F.R. Eirich, H. Strathmann, R.W. Baker, ‘Preparation of anisotropic Loeb-Sourirajan
Membranes’, Polymer Letters, 11 (1973) 201.
3) H. Strathmann, K.Kock, ‘The formation of mechanism of phase inversion membranes’,
Desalination, 21 (1977) 241.
4) A. Figoli, E. Drioli, J.Jansen, M.Wessling, Film antimicrobico per prolungare la shelf-life,
Rassegna dell Imballaggio, ISSN0033-9687, Nov. 2004, n.16, Year 25°.
5) J.C.Jansen, M.G.Buonomenna, A.Figoli, E.Drioli, Asymmetric membranes of modified
poly(ether ether ketone) with an ultra-thin skin for gas and vapour separations, Journal of
Membrane Science, 272 (2006) 188-197.
6) A. Figoli, G. De Luca, E. Longavita, E. Drioli, PEEKWC Capsules Prepared by Phase Inversion
Technique: A Morphological and Dimensional Study, Separation Science and Technology 42
(2007) 2809-2827.
7) S.K. Sikdar, J.O. Burkle, B. K. Dutta, A. Figoli, E. Drioli, Method for fabrication of Elastomeric
Asymmetric Membranes from Hydrophobic Polymers, US 11/598,840, filed 13 November 2006,
publish in May 2008.

EMS Barrer Prize – 5
Thursday July 17, 11:10 AM-11:35 AM, Maui
Considerations for Normal Flow Filtration: Fouling Models, Modules, and
Systems
W. Kools (Speaker), Millipore Corporation, Billerica, Massachusetts, USA -
willem_kools@millipore.com
Normal flow filtration processes in biotech processes are often batch processes
run at constant pressure. To consider implementation of membrane processes at
scale, several scales need to be considered: membrane performance, module
performance and system performance.
On a membrane disk level, several fouling models can be used to describe the
filtration behavior. Recently both in academic and commercial setting new
combined models are introduced based on older models. A quick retrospective
look and review of the newer models will be covered in this presentation.
Depending on the choices made during module design certain (in)efficiencies
can be realized. Scaling factors should be included in defining required areas on
a module level.
Finally, system considerations should be taken into account to make final
designs.
Sensitivities on fouling model choice, module construction and system
considerations are reviewed to identify implementation risks in sizing the required
surface areas.

EMS Barrer Prize – 6
Thursday July 17, 11:10 AM-11:35 AM, Maui
Dialysis Membranes – Continuous Improvements
B. Krause (Presenting), Gambro Dialysatoren GmbH, Hechingen, Germany -
Bernd.Krause@gambro.com
M. Storr, Gambro Dialysatoren GmbH, Hechingen, Germany
H. Göhl, Gambro Dialysatoren GmbH, Hechingen, Germany
Today, dialysis membranes are highly engineered separation devices and the
manufacturing processes are fully automated. More than 150 million dialyzers
having an average surface area of 1.8 m² are manufactured in 2007 world wide
to treat patients suffering from chronic kidney failure. The continuous request for
increased removal rates of uremic toxins and improved biocompatibility results in
new membrane generations. New generations of dialyzers combine different
separation principles and functions to increase separation performance and
reduce treatment complexity for customers. In addition to the standard dialysis
membranes more advanced High Cut-Off membranes have been developed that
allow effective removal of substances in the molecular weight range between 25
and 50 kDa (middle molecular weight substances). This unique development
gives access to a whole group of new extra-corporeal therapies. One example
are patients with multiple myeloma suffering from elevated serum concentrations
of monoclonal free light chains (FLCs), which can result in irreversible renal
failure secondary to cast nephropathy. Because, elimination of these middle
molecular weight compounds is limited by conventional dialysis membranes. We
have investigated the removal of FLC using a novel High Cut-Off membrane.
This membrane is characterized by a tailored pore size distribution and
separation characteristics compared with conventional dialysis membranes.
In the first part new developments with dialysis membrane towards
multifunctional and biological separation devices will be shown. In the second
part in-vitro and in-vivo results using the High-Cut-Off membrane will be
presented. Kappa and lambda FLC sieving coefficient and clearance were
studied in-vitro in hemodialysis and hemodiafiltration mode. The ability of the
membrane to reduce serum free light chain levels in-vivo was investigated in a
clinical pilot study with patients who presented with dialysis dependent renal
failure and multiple myeloma. With a kappa FLC sieving coefficient of 0.9
measured in human plasma the High Cut-Off membrane is effective in
eliminating FLCs. Clearance rates of both FLCs were many times higher using
the high cut-off membrane compared with a conventional High Flux dialysis
membrane. In patients with multiple myeloma very large quantities of FLCs were
removed with High Cut-Off dialysis. This resulted in post treatment reductions in
serum FLC concentrations of between 45 and 81%. The removal rates of other

therapy options have been modelled to confirm the advantages of the High-Cut-
Off concept. Patients who achieved a sustained reduction in serum FLCs of
greater than 65% became dialysis-independent following a mean treatment
period of 21 days. Moreover, is has been shown that the mortality of the High
Cut-Off membrane treated population decreases drastically.
Dialysis membrane research is path leading in the development of multifunctional
synthetic and hybrid separation devices. High cut-off membranes
exhibit a significant permeability for nephrotoxic free light chain proteins. High
cut-off hemodialysis treatments allowed a rapid reduction of serum FLC
concentrations in patients with multiple myeloma and dialysis dependent renal
failure. Preliminary clinical data suggests that this treatment modality can
improve renal outcomes in these patients.

EMS Barrer Prize – 7
Thursday July 17, 9:30 AM-9:30 AM, Maui
On the Origin of the Overlimiting Current in Electrodialysis
M. Wessling (Speaker), University of Twente, Netherlands - m.wessling@utwente.nl
The origin of the current flow above the limiting current density has been a puzzle
ever since its discovery. Loss in membrane selectivity, gravitational convection,
and in particular enhanced water splitting have been used as arguments to
explain the occurrence of the overlimiting current. Yet another explaination is the
emergence of electro-convection. This presentation reflects on these theories,
but will present for the first time explicit experimental proof of the existance of
electro-convection.

Ultra- and Microfiltration II - Processes – 1 – Keynote
Thursday July 17, 8:15 AM-9:00 AM, Moloka’i
Membrane Applications in the Pulp and Paper Industry: New Developments
and Case Studies
F. Lipnizki (Presenting), Alfa Laval Product Centre Membranes, Soborg, Denmark -
frank.lipnizki@alfalaval.com
T. Persson, Lund University, Lund, Sweden
A.-S. Jönsson, Lund University, Lund, Sweden
Every year, 100,000 tons of dissolved hemicelluloses are discharge unused with
wastewater from thermomechanical pulp mills around the world. Isolation of
these hemicelluloses from the wastewater would not only reduce the treatment
costs for the pulp mills but would also provide an excellent raw material for high
value applications such as oxygen barriers in food packaging. The isolation of the
hemicelluloses can be combined with polishing of the wastewater by using
different filtration processes. The initial step in this combination is either a drum
filter or a microfiltration treatment to remove solid residues from the wastewater
followed by ultrafiltration to concentrate the hemicelluloses. The permeate from
the ultrafiltration can then be further polished by reverse osmosis before
recycling. The focus of this paper is on the optimisation of the ultrafiltration step
concentrating on the membrane selection and its impact on the process
economics. The membrane selection includes the newly developed commercial
UFX5 pHt membrane (Alfa Laval, Denmark) based on hydrophilised
polyethersulfone. The feed studied in this paper is process water from the
thermomechanical pulp mill Stora Enso Kvarnsveden (Sweden). The temperature
of this process stream is 75°C. To reduce the need for cooling and preserve the
energy, temperature tolerance is an important membrane selection parameter.
Further, since the process water contains resin and lignin, which tend to foul
membranes, the hydrophilicity of the membrane is another important selection
parameter. Based on this, five membranes with molecular weight cut- offs
(MWCOs) between 1 - 10 kD were pre-selected: (1) a hydrophilised fluoro
polymer membrane ETNA10PP, MWCO: 10 kD, (2) a hydrophilised fluoro
polymer membrane ETNA01PP, MWCO: 1 kD, (3) a hydrophilised
polyethersulfone membrane UFX5 pHt, MWCO: 5 kD (all Alfa Laval, Denmark),
(4) a regenerated cellulose membrane UC005, MWCO: 5 kD, and (5) a
polyethersulfone membrane UP005, MWCO: 5 kD (all Microdyn-Nadir,
Germany). The ETNA10PP, ETNA01PP, and UC005 are limited to a temperature
of 60/55°C and to a pH range of 1 to 11, whereas the UP005 and UFX5pHt can
be operated up to 75°C and in a pH range from 1 to 14/13. In the initial study, a
small flat test module was used to study the pure water fluxes and the fouling
behaviour of the membranes related to octanoic acid, a fouling substance which
represents a significant number of small hydrophobic substances. Based on this,

ETNA01PP, ETNA10PP, and UFX5pHt were selected for further experiments in
2.5 spiral wound modules using process water from Kvarnsveden pulp mill. In
these experiments, among others the flux decline with increasing concentration
of hemicelluloses at different transmembrane pressures and cross-flow velocities
as well as the retention of hemicelluloses under these conditions were studied.
The experimental results of ETNA10PP, ETNA01PP and UFX5pHt were then
used as basis for the development of a full-scale system to treat a feed stream of
100 m 3 /h with an initial feed temperature of 60/75ºC. Both investment and
operating costs were analysed as well as the impact of retention and operating
conditions on the ultrafiltration process. It was revealed that operating
temperature and membrane selection/retention had an impact on both the
investment and operating costs. In conclusion, the results show that ultrafiltration
is an attractive process unit in the hemicelluloses isolation process.

Ultra- and Microfiltration II - Processes – 2
Thursday July 17, 8:15 AM-9:00 AM, Moloka’i
PAA and Thiol Functionalized MF/UF Membranes for Surfactant Separation
and High Value Metal Capture: Experimental Results and Modeling
A. Ladhe (Speaker), University of Kentucky, Lexington, Kentucky, USA - abhayladhe@uky.edu
P. Frailie, University of Kentucky, Lexington, Kentucky, USA
D. Bhattacharyya, University of Kentucky, Lexington, Kentucky, USA
Modification of microfiltration membranes with desired functional groups and their
subsequent applications for selective separations is receiving increasing
attention. The desired membrane functionalization can be achieved through
chemical modification, graft copolymerization, covalent binding, layer by layer
attachment of polyelectrolytes etc. In this study two types of functionalized
microfiltration membranes were studied for surfactant separation from
hydrophobic solvent and high value metal capture from aqueous solutions.
Commercially available hydrophilized polyvinylidene fluoride (PVDF) MF
membrane (pore diameter 0.45 micrometer) was functionalized with poly(acrylic
acid) (PAA) with subsequent partial cross-linking by ethylene glycol at 110
degree celcius. Ethoxylated nonionic surfactant solution in siloxane based
solvent was permeated through this membrane to study surfactant separation.
PAA is known to form a complex with ethoxylated nonionic surfactants in
aqueous phase through hydrogen bonding between carboxyl groups of PAA and
ethylene oxide groups of the surfactants. Hydrophobic attraction between alkyl
chain of the surfactants and PAA also contributes towards the interaction. The
role of ethylene oxide content of surfactant molecule on the surfactant separation
was studied and it was observed that extent of separation increased by 20 fold
when ethylene oxide groups per surfactant molecule increased from 3 to 8. The
pH dependence of the membrane permeability due to ionization changes of the
functionalized PAA inside membrane pore was also studied. The membrane flux
decreased from 60E-4 to 2E-4 cm 3 /cm 2 -s (applied pressure = 2 bar) with
increasing pH from 1 to 6. The pH sensitivity of the surfactant-PAA complex was
useful for membrane regeneration. The successful regeneration and reuse of the
membrane is attractive in terms of process development for surfactant based
cleaning operations.
Another way of membrane functionalization is to incorporate solid inorganic
particles with desired functional groups inside membrane matrix. These types of
mixed matrix membranes (MMMs) have been studied extensively for gas
separations. Preparation of MMM by phase inversion method in order to have
highly interconnected porous UF type membranes opens new domain for

convective flow liquid phase applications. Silica particle functionalization by
silane chemistry is well studied in the literature. In this particular case, silica
particles were functionalized with 3-mercaptopropylsilane in order to obtain free
surface thiol groups and incorporated into polysulfone matrix. Thiol groups
strongly interact with various metals like Au, Hg, Ag etc which may be applied
advantageously in various applications like water treatment and high value metal
capture processes. In order to demonstrate applicability of the MMMs, silver ion
is selected as the target metal ion for separation from its aqueous silver nitrate
solutions. The silica-polysulfone MMMs were characterized by SEM and
permeability measurements. It was observed that membrane permeability
increased with increasing silica loading (weight fraction) in the membrane. The
effect of silica properties like particle size, specific surface area, and
porous/nonporous morphology on the silver ion capture capacity was studied.
Typical silver capture capacity was in the range of 1.5 to 2 mmole per gram of
silica (20E-4 mmole per square meter of particles). Dynamics of the silver
capture process were studied by performing experiments at various applied
transmembrane pressure. Initially, the dynamic silver capture capacity decreased
from 70% to 40% of equilibrium capacity with increasing membrane flux and
became flux independent thereafter. It was also demonstrated that the
membrane can capture silver selectively in presence of significant concentration
of other metal ions like calcium. One dimensional unsteady state model with
overall volumetric mass transfer coefficient was developed and solved to predict
silver ion concentration in liquid phase and silica phase along the membrane
thickness at varying time. The breakthrough curve data predicted using model
solution is comparable with the experimental observations. Furthermore,
fundamental silver ion thiol interaction was studied by QCM (Quartz Crystal
Microbalance) technique.
Peter Frailie was supported by the NSF-REU program.

Ultra- and Microfiltration II - Processes – 3
Thursday July 17, 10:00 AM-10:30 AM, Moloka’i
Assuring Biodiesel Quality via Selective Membrane Filtration
M. Gutierrez-Padilla (Speaker), University of Colorado, Boulder, Colorado, USA
J. Downs, University of Colorado, Boulder, Colorado, USA
J. Pellegrino, University of Colorado, Boulder, Colorado, USA - john.pellegrino@colorado.edu
J. Bzdek, Symbios Technologies, LLC, Fort Collins, Colorado, USA
Biodiesel is produced by transesterification/esterification of lipids derived from
vegetable oils and waste fats. As a transportation fuel, biodiesel has some
desirable end-use attributes (including particulate emissions) versus petrodiesel
and thermochemically produced "green" diesel, which support its continued use
as part of the "sustainable" transportation fuel infrastructure. Nonetheless,
commercial experience has shown infrequent incidents of formation of a cloudyhaze,
and vehicle filter clogging problems, presumably due to trace contaminant
species, which need to be resolved. There may be several causes for each of
these quality-related events, and due to the variable feedstock sources, a broad-
based processing approach merits consideration. We have studied crossflow
membrane filtration of biodiesel with a variety of membrane structures and
material chemistries. Besides obtaining some process design-related figures-ofmerit,
for example, the membrane permeances versus applied transmembrane
pressure, we assayed the streams using the modified ASTM 6217 test (aka the
"cold soak" test), which is used as a quality control metric for filterability. We will
report results from several membranes, icluding a polyethylene microfiltration
membrane; several ultrafiltration membranes made from polyethersulfone and
polyvinylidene fluoride, and a solvent resistant nanofiltration membrane. The
filtration process was performed continuously with a retentate recycle until
permeate recoveries of 30 to 75% were obtained. (NB. Commercial processing
can be done to much higher recovery, ~98-99%, using a feed-and-bleed design.)
The main effect we studied was the transmembrane pressure, which was in the
range of 34 to 207 kPa (5 to 30 psi). Membrane cleaning for some membranes
was performed after the filtration tests by running methanol or ethanol across the
top of the membrane. These membranes could be reused after the cleaning.
Permeances in the range of 1.3x10 -7 to 6x10 -8 m/s/kPa could be consistently
obtained with some of the UF membranes. The hazy feedstock and the retentate
from all trials failed the cold soak test, but the ultrafiltration permeates passed it.
The microfiltration membrane was not fully acceptable in assuring that the
permeate passed the cold soak test. In addition, we analyzed our samples using
GCMS to quantify the fatty acid methyl esters (FAME) profile in the original
feedstock (soybean oil-based) and permeate. We found that the filtration process

did not perceptibly change that profile. To date we have not been able to identify
the contaminants.

Ultra- and Microfiltration II - Processes – 4
Thursday July 17, 10:30 AM-11:00 AM, Moloka’i
High Oxidative Resistant PVDF UF Membrane for Metal-CMP Wastewater
Treatment
S. Shiki (Speaker), ASAHI KASEI CHEMICALS, Shizuoka, Japan - shiki.sb@om.asahikasei.co.jp
G. Furumoto, ASAHI KASEI CHEMICALS, Shizuoka, Japan
We developed a novel ultrafiltration (UF) hollow fiber membrane made of
polyvinylidenfluoride (PVDF) suitable for wastewater treatment including oxidants
and organic solutes. In this paper, we describe the membrane characteristics and
an example of filtration by using semiconductor industry wastewater including
turbidities and oxidative chemicals.
Recently, as it becomes high integration of semiconductor, the metal chemical
mechanical polishing (metal-CMP) process is spreading in the semiconductor
industry. This process puts out an oxidative wastewater including the polishing
slurry, and it is necessary to treat this wastewater. Conventionally, UF
membranes have been used for semiconductor industry wastewater, but for the
metal-CMP wastewater, the polymeric membranes are damaged by oxidants and
that leads to membrane breakage.
Asahi Kasei Chemicals is the pioneer on developing PVDF microfiltration (MF)
hollow fiber membrane, and because of its high mechanical strength and
chemical resistance, it has been used for many applications, especially for water
purification and membrane bioreactor (MBR). However, it is difficult to use MF
membrane for metal-CMP wastewater treatment because the slurry with a size of
about 10 to 100 nm, pass through the MF membrane pores.
The necessity of UF membrane for metal-CMP wastewater treatment has been
increasing, however, our existing UF membrane could not stably be used in that
application due to their low oxidant resistance. Therefore we developed the
epoch-making PVDF UF hollow fiber membrane. And also, there were no PVDF
UF hollow fiber membranes with high durability and good permeability because it
was difficult to make PVDF UF membrane due to its low processability.
Our new PVDF UF membrane has high permeability, sufficient mechanical
strength and high chemical resistance, especially to oxidants, compared to our
conventional polymeric membranes, such as those made of polysulfone and
polyacrylonitrile. In addition, we also found that chemical resistance of our novel
PVDF UF membrane was superior to other PVDF membranes and that the
difference in chemical resistance among PVDF membranes was derived from the

membrane structures, which would be determined by their different
manufacturing processes.
The result of long term filtration test, using semiconductor plant metal-CMP
wastewater, showed that the permeated water quality was good, for example Si:
100ppm (raw water) to 5 ppm (filtrate); TOC: 20 ppm to 0.4 ppm and filtration
was stable for over 5 months.

Ultra- and Microfiltration II - Processes – 5
Thursday July 17, 11:00 AM-11:30 AM, Moloka’i
Hygienic Barrier Efficiency of a Coupled Coagulation / Flocculation and
Ceramic Microfiltration System for Potable Water Production
T. Meyn (Speaker), Norwegian University of Science and Technology, Trondheim, Norway -
thomas.meyn@ntnu.no
A. König, Technical University Berlin, Berlin, Germany
T. Leiknes, Norwegian University of Science and Technology, Trondheim, Norway
Due to climatic and geographical conditions, Norway has an abundance of water
resources and about 90% of drinking water supplies are from surface water
sources, mostly lakes with very low turbidity. In general, the drinking water
sources are characterized by high concentrations of natural organic matter
(NOM), low pH, low alkalinity and low turbidity. Typical values are; colour of 30-
80 mg Pt/l, TOC 3-6 mg C/l, COD 4-8 mg Mn/l, turbidity < 1 NTU, alkalinity < 0,5
meq/l and hardness < 5 mg Ca/l. The removal of NOM is a primary treatment
concern since coloured water is unattractive to consumers, results in colouring of
clothes during washing, can cause odour and taste, increases corrosion and
biofilm growth in the distribution network, and is a precursor to the formation of
disinfection by-products (DBP) when water is disinfected. Coagulation /
flocculation coupled with a MF ceramic membrane filtration plant is a promising
alternative membrane process for the removal of NOM to produce potable water.
National regulations for drinking water production requires minimum of two
hygienic barriers and the object of this study has been to assess the hygienic
barrier efficiency of this treatment alternative.
Bacteria and viruses in drinking water can cause diseases among consumers.
These viruses belong to the group of adenoviruses, astroviruses, enteroviruses,
hepatitis-A and hepatitis-E viruses, noroviruses and rotaviruses. These human
pathogenic viruses mostly reproduce themselves in the gastrointestinal tract and
get together with the faeces in big amounts into wastewater and the environment.
This especially becomes important because viruses can be regularly found in the
effluent of conventional treatment plants and the fact that the portion of treated
waste water in rivers can be high.
The MF ceramic membrane filtration unit used in this study is based on dead-end
operation of multi-bore tubular membranes with a pore size of 0,1 µm. The
filtration pilot plant consists of three trains with an integrated flocculation step.
The membranes were operated at a flux of 140 LMH. Two different coagulation
agents, polyaluminium chloride and iron chloride were tested. The virus and
bacteria removal capacity was determined by using MS2-bacteriophage and
Escherichia coli respectively. Possible virus inactivation by the applied

coagulants was also investigated. The virus removal was examined in
dependence on the operational parameters of the coagulation step: pH-value,
coagulant dose and type and flocculator setup.
Without any flocculation nearly all viruses passed through the microfiltration
membrane. Even at low doses of coagulant the removal was improved
significantly. For example, at iron concentrations of 8 mg / L and alum
concentrations of 4 mg / L, virus concentrations of d 1 plaque forming units per
millilitre (pfu/mL) were observed in the permeate, depending on the operating
conditions and starting with a virus concentrations of 107 to 108 pfu/mL in the
raw water. More detailed results will be shown in the presentation.

Ultra- and Microfiltration II - Processes - 6
Thursday July 17, 11:30 AM-12:00 PM, Moloka’i
Pioneering Explorations of Rooting Causes for Morphology and
Performance Differences in Hollow Fiber Kidney Dialysis Membranes Spun
From Linear and Hyperbranched Polyethersulfone
Q. Yang (Speaker), National University of Singapore, Singapore
T. Chung, National University of Singapore, Singapore - chencts@nus.edu.sg
M. Weber, BASF Aktiengesellschaft
V. Warzelhan, BASF Aktiengesellschaft
The adoption of conventional polyethersulfone (PES) material with linear
structure for kidney dialysis membrane application has attracted intensive
attention due to its excellent stability under sterilization, superior bio-compatibility
after the polyvinylpyrrolidone (PVP) modification, and minimal degradation in
membrane performance over extended period of time. On the other hand,
polymers with highly branched structure have also witnessed gaining interests
during the past decade due to their large number of functional groups and high
surface reactivity in contrast to their linear analogues. Although much progress
has been achieved in the structural understanding and the synthesis of
hyperbranched polymers, fundamental understanding and especially industry
application of these hyperbranched polymers are still in infancy. In addition, there
were few studies conducted to systematically compare hyperbranched polymers
properties with their linear analogues, but not to speak of identifying the
differences between hollow fiber membranes spun with the linear and
hyperbranched counterparts.
First of all in this NUS-BASF joint research program, the science and engineering
of hollow fiber membrane formation by a dry-jet wet-spinning technique was
investigated in-depth in order to identify a membrane with desirable structure,
suitable pore size and pore size distribution for kidney dialysis applications. The
dual-bath coagulation technique has been employed for the first time in this study
for fabricating kidney dialysis membranes: with a weak coagulant isopropanol
(IPA) serving as the first external coagulation bath while water as the second
bath, the as-spun membrane can achieve a tight inner selective skin and loose
outer supporting layer structure. This is a desirable membrane structure for
removing low and middle molecular weight uremic toxins such as uric acid, urea,
creatinine, inulin and beta2-microglobulin but retaining proteins molecules during
hemodialysis.
In addition, we have identified that the addition of PVP into the polymer dope
(both linear and hyperbranched PES) during the hollow fiber membrane spinning
could not only provide a macrovoid-free and completely sponge-like structure but

also improve the resultant membrane’s hemocompatibility. After being treated in
8000 ppm NaOCl solution for 1 day, fibers show larger pore sizes and porosity in
both inner and outer surfaces, and thinner inner and outer layers than their asspun
counterparts. Based on SEM observations and solute rejection
performance, the further heat treated fibers in an aqueous solution is found to be
an effective way to fine tune membranes morphology and molecular weight cutoff
(MWCO) for kidney dialysis application.
Last but not the least, comprehensive comparisons of the linear and
hyperbranched PES, especially their as-spun hollow fiber kidney dialysis
membranes were conducted based on their physical, chemical, thermal and
rheological properties. The most significant differences between the
hyperbranched PES material and its linear analogue were identified by its higher
molecular weight, wider molecular weight distribution and a much more compact
structure. The molecular characteristics of hyperbranched PES led its as-spun
membrane with smaller pores, narrower pore size distribution, and a smaller
MWCO. In addition, hyperbranched PES bound stronger with the additive PVP
and their blend displayed a lower coefficient of thermal expansion (42.16μm/°C)
than that for linear PES (89.08μm/°C). Both factors resulted in a less
effectiveness of PVP leaching by the NaOCl solution and hot water. A higher
water temperature was required to tailor the as-spun hyperbranched PES hollow
fibers with the pore size and pore size distribution suitable for kidney dialysis
application. To our knowledge, this is the first work to reveal the morphologies
and solute separation performances differences between hyperbranched- and
linear- PES made membranes based on the comprehensive explorations and
fundamental understandings of these two polymer analogues properties.

Ultra- and Microfiltration II - Processes – 7
Thursday July 17, 12:00 PM-12:30 PM, Moloka’i
Pressurized Porous Nanocrystalline Silicon Membranes Exhibit High
Permeability to Water and Gas
T. Gaborski (Speaker), University of Rochester, Rochester, New York, USA
D. Fang, University of Rochester, Rochester, New York, USA
C. Striemer, University of Rochester, Rochester, New York, USA
M. Kavalenka, University of Rochester, Rochester, New York, USA
J. Snyder, University of Rochester, Rochester, New York, USA
M. Hoffman, University of Rochester, Rochester, New York, USA
J. DesOrmeaux, SiMPore Inc., West Henrietta, New York, USA
P. Fauchet, University of Rochester, Rochester, New York, USA
J. McGrath, University of Rochester, Rochester, New York, USA - jmcgrath@bme.rochester.edu
We recently introduced porous nanocrystalline silicon (pnc-Si) as a molecularly
thin membrane material capable of size and charged based separation of
proteins and other nanometer-sized solutes (Striemer et al. Nature, 2007). The
membranes can be produced in massive arrays with membranes freely
suspended over millimeter support spacings. Mechanical tests indicate surprising
strength with failure at or above 15 psi with no fatigue prior to rupture. Average
membrane pore sizes can be tuned between 5 nm to 100 nm with porosities
between 0.1-10%.
The structure of pnc-Si membranes suggests that they should display
extraordinary permeability to water and gas under pressure. To test this
prediction, we formatted membranes for easy assembly into gas pressure cells
and centrifuge tube inserts. For membranes with mean pore sizes ~ 20 nm and
porosities ~ 2%, we measured hydraulic permeabilities of nearly 2 x 10 -8 m/(s-Pa)
and air permeability in excess of 5 x 10 -5 (m/s-Pa). These values are at least
tenfold higher than the permeability values for commercial ultrafiltration
membranes measured in side-by-side comparisons. The permeabilities to air and
water are also more than one order higher than literature values for carbon
nanotube/polymer composite membranes. Because pores can be directly imaged
in electron microscopy, we employ known pore sizes and distributions to test
existing theories for gas and water permeability of ultrathin membranes (Tong et.
al. Nano Letters, 2004). For both water and air, we find that the existing theories
are predictive of the flow rates we measure through specific membranes.
Interestingly, native pnc-Si membranes are impermeable to water if one side of
the membrane is left dry, highlighting the significance of surface tension and high
curvature for liquid flow through nanoporous membranes.

Drinking and Wastewater Applications IV – 1 – Keynote
Thursday July 17, 8:15 AM-9:00 AM, Honolulu/Kahuku
Optimization of Bubbly Flow in Flat Sheet Membrane Modules
H. Prieske (Speaker), Technische Universität Berlin, Berlin, Germany
A. Drews, Technische Universität Berlin, Berlin Germany
M. Kraume, Technische Universität Berlin, Berlin, Germany - matthias.kraume@tu-berlin.de
Introduction and Aim
In the operation of membrane bioreactors for wastewater treatment, continuous
or intermittent air scour is applied to reduce cake layers and thus to minimise
fouling. Optimisation of module design and operating conditions (e.g., distance
between flat sheet membranes, crossflow velocity, aeration intensity, etc.)
requires knowledge of the most suited hydrodynamic conditions for the filtration
task. Especially the circulation velocity which is induced by the bubble movement
is of importance. However, many fundamentals of this gas/liquid flow are still
unknown and difficult to access experimentally. While a number of studies on the
influence of bubble motion have been carried out for hollow fibre membranes,
much less work has been published on bubbly flow in flat sheet modules. Thus,
the aim of this study is the fundamental investigation of gas/liquid flow between
flat plates and the corresponding wall shear stresses. Special attention is drawn
on the movement of differently sized single bubbles in the gap between plates.
Using experimental and numerical methods, the optimum bubble size and air
flow rate for fouling control in relation to the respective plate distance will be
determined.
Methods
The examined module was operated in airlift loop configuration with a circulating
flow induced by the aeration of the flat sheets (riser section) whereas the outer
area was not aerated and represented the downcomer section of the total airlift.
Experiments were carried out with water and air in a quasi two-dimensional MBR
model with 2.1 m height, 1.2 m width and 0.1 m depth. Particle Image
Velocimetry and an impeller anemometer were applied to measure the liquid
velocities. Bubble distributions were optically analyzed by video imaging through
the transparent walls of the tank. The movement of differently sized air bubbles
rising in stagnant water between differently spaced flat plates was recorded using
a highspeed camera. From this, the terminal bubble rise velocity was determined
which together with the observed bubble shape serves as a validation for the
numerical investigations. The velocity profile between the membrane plates was
calculated by a CFD code (CFX) based on the Eulerian-Eulerian approach for
two-phase flow. Additionally the flow field and especially the wall shear stresses

in the vicinity of the rising bubbles were simulated with CFD (Fluent) in
combination with the volume of fluid (VOF) method (constant surface tension,
time step 10 -6 - 10 -4 s). All these numerical simulations were also used to perform
parameter studies by varying geometrical values or operating conditions (e.g.
channel width, bubble diameter) studying their influence on the wall shear
stresses in order to minimise fouling.
Results
For the circulating flow the measured and simulated liquid velocities showed
good agreement. So CFD simulations are an appropriate tool for the optimisation
of module and filtration tank geometry. Furthermore typical problems in the
operation of flat sheet membrane modules became evident such as insufficient
aerated gaps in the outer region of the module. In practice this will lead to an
accelerated fouling in this area and a subsequent permeability reduction of the
total module. By an improved design of the gas sparger a more homogeneous
bubble distribution in the membrane module and an accelerated circulation was
achieved. The rise velocity of bubbles ascending between differently spaced
plates showed that small bubbles move like in an unconfined liquid. Above a
certain diameter, however, which is smaller for narrowly spaced walls, bubbles
briefly slow down as the deceleration effect caused by the walls becomes
dominant. With further increased size, the presence of the walls drastically
changes the bubble shape: they become elongated and flat cap bubbles. Due to
the thus decreased projected area, bubbles with a diameter above 10 mm
overcome the deceleration effect and even achieve higher rise velocities
between plates than in unconfined environments. Although this acceleration is
independent of channel width, the plate distance influences the maximum
possible stable bubble size. Even small bubbles disrupt due to the higher shear
in narrow channels. In order to optimize bubble size and wall distance for fouling
control, the shear rates must be known. From the CFD simulations the maximum
wall shear stresses have been deduced. As expected, highest shear can be
achieved for narrow channels which, however, would become clogged too easily
in sludge systems. For practical applications an optimum bubble size and
membrane gap of both 5 mm is suggested.

Drinking and Wastewater Applications IV – 2
Thursday July 17, 9:30 AM-10:00 AM, Honolulu/Kahuku
Removal of Organic Micropollutants with NF/RO Membranes: Derivation
and Validation of a Rejection Model
A. Verliefde (Speaker), Delft University of Technology, Delft, The Netherlands -
a.r.d.verliefde@tudelft.nl
E. Cornelissen, Kiwa Water Research, Nieuwegein, The Netherlands
B. Heijman, Kiwa Water Research, Nieuwegein, The Netherlands
G. Amy, UNESCO-IHE, Delft, The Netherlands
B. Van der Bruggen, University of Leuven, Leuven, Belgium
H. van Dijk, Delft University of Technology, Delft, The Netherlands
Drinking water utilities in Europe are facing a growing presence of organic
micropollutants in the water sources. Not only surface waters, but also ground
waters are increasingly contaminated with a wide range of organic pollutants,
such as pesticides, hormones, pharmaceutically active compounds and other
problematical substances, e.g. the fuel additive MTBE or the potent carcinogenic
NDMA. Even though these substances often only occur at low concentrations,
removal in the drinking water treatment is still desirable, since health effects
related to consumption of drinking water containing traces of these substances
are yet unknown. Nanofiltration (NF) and reverse osmosis (RO) as water
treatment processes are often considered as effective remediation techniques for
trace organic pollutants, since the molecular weight cut-off values of the
membranes are often in the range of the molecular weights of the organic
micropollutants. In some cases, however, organic solutes are still detected in the
permeate of NF/RO installations, indicating incomplete removal.
An integrated understanding of trace organic rejection mechanisms has begun to
emerge, which now includes the perspective of solute-membrane interactions
such as steric, electrostatic, and hydrophobic (solute-membrane affinity) effects.
These solute-membrane interactions are influenced by solute and membrane
properties, process conditions and feed water composition.
In this research, the effect of solute-membrane interactions on trace organics
transport through NF/RO membranes was studied and translated into
mathematical models. By carrying out selected rejection tests with model organic
solutes and different membranes on single 4-inch NF/RO membrane elements,
the effects of the different solute-membrane interactions on rejection could be
determined. With this knowledge, a rejection model for uncharged solutes was
developed, based on a convection- diffusion model, but extended with
parameters accounting for membrane-solute affinity (hydrophobic interactions).
Secondly, the influence of both solute and membrane charge (and the influence

of feed water ionic strength) on rejection was also investigated and incorporated
into the mathematical model. Results suggest that, in contrast to the rejection of
inorganic solutes, the Donnan-exclusion mechanism does not seem to play a role
in the rejection of charged organic solutes. The models for uncharged and
charged solutes were then combined into a general rejection model for organic
solutes in aqueous solutions. Using mass balances, this general rejection model
was then extended to a mathematical expression for the rejection of organic
solutes in full-scale installations.
The full-scale rejection model was tested and validated by spiking a cocktail of 25
pharmaceutically active compounds and pesticides on a 2 stage pilot installation.
The pilot scale installation contained 18 4-inch membrane elements (12 in the
first stage, 6 in the second stage) and was operated during 2 different runs at
75% and 83% recovery. During these runs, permeate samples of the different
stages and of the first and last membrane element were collected and analysed
for pharmaceuticals and pesticides. This way, rejection values at different
recoveries could be determined and compared to the modelled rejection values.
The modelled rejections seemed to correspond to the measured full-scale
rejection values at different recoveries quite well.
Results obtained in this study may prove to be very useful for future applications
of membrane filtration for potable water purposes. The derived models may
provide an a priori evaluation of the performance of a full-scale membrane
filtration plant: based on selected parameters of solute and membrane, the
rejection of an organic solute with a full-scale NF/RO plant can be estimated.

Drinking and Wastewater Applications IV – 3
Thursday July 17, 10:00 AM-10:30 AM, Honolulu/Kahuku
Anaerobic Membrane Bioreactor (AnMBR) for Landfill Leachate Treatment
and Removal of Hormones
A. Do, University of South Florida, Tampa, Florida, USA
A. Prieto, University of South Florida, Tampa, Florida, USA
D. Yeh (Speaker), University of South Florida, Tampa, Florida, USA - dhyeh@eng.usf.edu
To date, the majority of the studies on trace pharmaceuticals and endocrine
disrupting compounds (EDCs) have focused on their fate in sewage treatment
plants. However, EDCs can enter the landfill via several routes, including
household solid waste and sludge from wastewater treatment plants.
Increasingly, in light of the ineffectiveness of conventional wastewater treatment
systems to completely remove these contaminants, the public is instructed to
dispose of PPCP in household trash in the US. In a recent survey conducted in
the UK, two-thirds of the subjects disposed of unwanted or expired mediation
through household trash. With the maturing of the Baby Boom Generation and
our society's increasing reliance on mediation, there is good reason to anticipate
that states with high populations of the elderly, such as Florida, will receive high
loadings of EDCs to landfills in years to come. Even if the EDCs are disposed in
bags or containers, it is likely that they will be released once they enter the
general trash stream, either through mechanical compaction and breakage in the
garbage trucks or at the landfill. Additionally, containers can lose integrity in the
landfill from degradation, thereby enabling the contents to enter the general
contents of the landfill. In short, landfills can serve as a long-term source of
EDCs for soil and groundwater contamination.
To prevent environmental contamination and to comply with state and local
regulations, an effective method is needed for treating and removing xenobiotic
compounds from landfill leachate. Landfill leachates are among the most difficult
waste streams to treat, as they typically contain high concentrations of dissolved
and colloidal organics (much of which may be recalcitrant and hard to degrade),
inorganics (e.g., ammonium), heavy metals (e.g., arsenic, mercury, cadmium,
copper, and xenobiotic organic pollutants (e.g., chlorinated organics). Further,
constituents of the effluent can be toxic or inhibitory to many conventional
biological treatment processes. Although there is a growing trend to operate
landfills themselves as biological reactors, young landfills will rely most heavily
on an external leachate treatment system while the biological activity establishes
within the landfill itself.
The membrane bioreactor (MBR), in which biological waste treatment and
membrane separation (typically MF or UF) are synergistically-coupled, is a

technology that has gained growing popularity in the past fifteen years. To date,
MBRs are used primarily for the treatment of municipal and some industrial
wastewaters. While MBRs have been used with success for the treatment of
landfill leachate in Europe (more than 30 installations in Europe during the
1990's), there has been relatively few applications of such in the United States,
with only one full-scale plant commissioned in North America.
The objective of the present study is the development of an anaerobic MBR
technology to treat leachate. In the initial phase of the current research, a
laboratory-scale system was developed to treat simulated young landfill leachate
with comparable COD, ammonium, inorganic species, etc. A 5L anaerobic
membrane bioreactor is equipped with temperature and pH control, sensors and
automatic logging of bioreactor (total gas, methane, temperature, pH, ORP,
ammonium) and membrane (TMP and permeate flux) performance data. The
reactor includes dual external crossflow membrane system (with CIP) for parallel
comparison of membrane materials and operating conditions. We are testing
PVDF UF membranes (with and without anti-fouling coating) provided for this
study by Membrane Technology Research, Inc. (MTR, Menlo Park, CA). The
reactor was started with anaerobic digestion sludge from a local WWTP.
The target EDC is 17beta-estradiol (E2), a prevalent female hormone used for
contraceptives and hormone replacement therapy. Due to the nature of
packaging and widespread use in households, the entry of E2 into landfills is
highly likely. E2 has also been measured in leachate. The quantification of E2 in
this project is performed by the use of solid-phase microextraction (SPME) with
GC/MS. To facilitate E2 retention and removal by the AnMBR, as well as to
control membrane fouling, we added powder activated carbon (PAC) to the
reactor. Separate batch assays were conducted to determine the anaerobic
biodegradability of E2 as well as to measure the respective distribution
coefficients of E2 to PAC and sludge biomass. The biodegradation kinetics and
distribution coefficients were used to guide reactor operational conditions. In this
presentation, we will report on the reactor design, initial testings and startup
operation of the anaerobic MBR.

Drinking and Wastewater Applications IV – 4
Thursday July 17, 10:30 AM-11:00 AM, Honolulu/Kahuku
Comparison of Multi-Parameter Optimization Strategies for the
Development of Nanofiltration Membranes for Salt and Micropollutants
Removal
A. Cano-Odena (Speaker), Katholieke Universiteit Leuven, Leuven, Belgium
P. Vandezande, Katholieke Universiteit Leuven, Leuven, Belgium
I. Cools, Katholieke Universiteit Leuven, Leuven, Belgium
K. Vanderschoot, Katholieke Universiteit Leuven, Leuven, Belgium
K. De Grave, Katholieke Universiteit Leuven, Leuven, Belgium
J. Ramon, Katholieke Universiteit Leuven, Leuven, Belgium
L. De Raedt, Katholieke Universiteit Leuven, Leuven, Belgium
I. Vankelecom, Katholieke Universiteit Leuven, Leuven, Belgium -
ivo.vankelecom@biw.kuleuven.be
Introduction
The currently and since years growing water demand worldwide, together with
new and more strict regulations for potable and waste water levels, lead to the
need of better cleaning technologies to decrease the concentration of
micropollutants (pharmaceutical active compounds, endocrine disrupting
compounds,etc) in water streams, whose properties affect environmental and
human health. Membrane-based technologies (nanofiltration and reverse
osmosis) seem better positioned to remove trace contaminants than conventional
techniques.[1]
There are several parameters involved in membrane synthesis, including
compositional and non-compositional. Multi-parameter optimization strategies are
extremely useful in membrane technology to minimize time and material
consumption to develop better performing membranes. Combinatorial synthesis
refers to change in the nature of the compositional parameters. High-throughput
experimentation(HT) enables rapid and accurate collection of large data-sets
essential for the implementation of combinatorial synthesis together with
miniaturization (cost, waste reduction).[2] Combinatorial techniques have been
used already in the pharmaceutical industry, material development and catalysis
leading to successful implementation and great revolutionary impact. Its
combination with membrane technology is still incipient but promising to direct
membrane synthesis towards better separation properties (selectivity) of the
targeted compounds combined with useful fluxes.
Objectives

Optimize polymeric membranes for salt and micropollutants removal in aqueous
streams. Explore compositional and non-compositional parameters of membrane
synthesis in such membrane optimization strategies. Compare different multiparameter
optimization strategies and machine learning methods to optimize
membrane performance (permeability, selectivity) for these applications.
Evaluate which one leads to faster convergence and better results.
Methods
Polymeric NF membranes will be prepared via phase inversion. Their
performance will be evaluated to retain ibuprofen from water. Ibuprofen is
selected as one of the smallest molecules from relevant micropollutants currently
present in drinking water. Its succesful removal would most probably also allow
retention of all other possible micropollutants. High performance composite RO
membranes will be prepared by interfacial polymerzation for see or brackish
water desalination. The parameters to be optimized will refer to membrane
composition (polymer concentration, solvent) but also for first time, on the level of
the membrane synthesis process and post treatment (temperature, annealing
time), which via classical research have proven to have a great impact on
membrane performance.
Genetic Algorithms (GA), Artificial Neural Networks (ANN) and Active Learning
using Gaussian Processes (GP) are different multi- parameter optimization
techniques. GA, the combination (hybrid) of GA with ANN, and GP will be
compared to evaluate which approach leads faster to the best optimum. GAs are
stochastic search techniques inspired by the principles of natural evolution. If a
membrane is experimentally found to be more successful it will have more
offspring and more variants (generated by mutation and crossover) of it will be
tested in the following experiments. ANNs are data mining techniques used to
model complex functions in multidimensional spaces and can be trained using
earlier observations. A GA can be combined with an ANN in a hybrid process
where the neural network models the fitness of the individuals of the GA. The
model is used to avoid doing experiments defined as very unpromising by the
ANNS in the next generation. This hybrid approach has already shown
advantages over the use of only a GA[3] by reducing the population size and the
number of generations. Active learning has recently been introduced into the field
of function optimization using Gaussian Process regression as the underlying
predictive model. GPs are a fully Bayesian probabilistic modelling framework. A
key property of a GP model is that it provides both a prediction and an
uncertainty interval, hence allowing the active learning strategy to explicitly trade
off exploration of the search space against exploitation of the knowledge gained
through previous experiments. This results in finding the optimal points in a
smaller number of experiments.
[1] A.I. Schäfer, A.G. Fane, T.D. Waite, Nanofiltration principles and applications, Elsevier, 2003.

[2] P. Vandezande, L.E.M. Gevers, J.S. Paul, I. F.J. Vankelecom, P. A. Jacobs. Journal of
Membrane Science 250 (2005) 305-310. [3] J. M. Serra, A. Corma, S. Valero, E. Argente, V.
Botti. QSAR and Combinatorial Science 26 (2007) 11-26.

Drinking and Wastewater Applications IV – 5
Thursday July 17, 11:00 AM-11:30 AM, Honolulu/Kahuku
Study of an External MBR for Degradation of Endocrine Disrupter
17(alpha)-ethinylestradiol
L. Clouzot (Speaker), University of Aix-Marseille, France
B. Marrot, University of Aix-Marseille, France - benoit.marrot@univ-cezanne.fr
P. Doumenq, University of Aix-Marseille, France
N. Roche, University of Aix-Marseille, France
The xenobiotic 17±-ethinylestradiol (EE2), a common oral contraceptive
component, is an endocrine disrupter with fish feminization induced at
concentrations as low as 0.1 ng.L -1 . EE2 occurrence in the aquatic environment
(0.5-5 ng.L -1 ) is due to inefficient removal in municipal wastewater treatment
plants (WWTPs). EE2 biodegradation is achieved by nitrifying micro- organisms
(autotrophic biomass), characterized by slow growth. Therefore, EE2 removal
requires activated sludge (AS) with a high sludge retention time (SRT). However,
in WWTPs, there is often an incomplete separation of water and AS, resulting in
low biomass concentrations and low SRTs. Membrane bioreactors (MBRs), with
a complete physical retention of AS, are a promising solution to enhance EE2
degradation. During the past 10 years, an exponential increase in MBRs
research and literature has been observed worldwide. Membrane fouling is a key
issue that has slowed MBR technology commercialization; however, a significant
increase in the breadth of application areas is anticipated. The aim of this study
is to use MBR technology to improve EE2 elimination during municipal
wastewater treatment. First, nitrifying AS acclimation was developed to obtain a
specific biomass effective for EE2 degradation. Subsequently, purification of a
synthetic wastewater containing EE2 will be tested in an external MBR with the
acclimated AS. External MBR configuration has been selected because it results
in a more effective biomass, and fouling is easier to control. Compared to
immersed MBRs, floc size is smaller in external MBRs, providing a greater
exposed surface area. To limit fouling during purification experiments,
operational MBR conditions were optimized beforehand; hydrodynamics
parameters and flux were adjusted. Acclimation of nitrifying AS from municipal
WWTPs was developed in an 80 L immersed MBR with a SRT of 30 days. An
immersed MBR provides a less harsh environment for AS acclimation because
the bacteria are not recycled through a pump (as is the case for external MBRs).
Autotrophic characteristics of the biomass required a culture media composed of
NaHCO3 (inorganic carbon source), (NH4)2SO4 (energy and nitrogen source)
and mineral salt supplements (MgSO4, KH2PO4, CaCl2). The pH was controlled
at 7 by automatic titration with NaHCO3. Biodegradation experiments were
performed after 96 days of acclimation, with EE2 concentrations of 1 mg.L -1 , 500
µg.L -1 and 250 µg.L -1 . Sample analysis is currently underway. Membrane fouling

ehaviour was investigated in a 10 L external MBR (microfiltration), at constant
operating conditions. Initial permeability was fixed at 265 L.h -1 .m -2 .bar -1 , with a
relative standard deviation of 8%. A mixed liquor suspended solids (MLSS)
concentration of 10 g.L -1 was chosen. When MLSS was increased from 8 g.L -1 to
16 g.L -1 , at a transmembrane pressure (TMP) of 2.5 bar and a crossflow velocity
of 3 m.s -1 , there was a 20% decrease in permeate flux. Critical flux, defined as
the minimum flux that creates an irreversible deposit on the membrane [1], is the
key parameter used to predict fouling. However, MBRs are typically operated at
fluxes above the critical flux of the system. At 4 m.s -1 crossflow velocity, critical
flux appeared between 0.7 and 0.9 bar, with a permeate flux of 70-85 L.h -1 .m -2 .
Critical flux also depends on the membrane state. At 5 m.s -1 , a new membrane
had an irreversible fouling between 0.7 and 0.9 bar whereas a previously fouled
membrane had a critical flux below 0.7 bar. One method for reducing membrane
fouling consists of increasing the crossflow velocity. At a fixed TMP of 2.5 bar,
when crossflow velocities were increased from 2 to 5 m.s -1 , the permeate flux
increased from 142%. Backpulses can also be used to reduce membrane fouling.
For one-day experiments, with 2 and 4 m.s -1 crossflow velocities and 1 bar TMP,
1 s backpulses per minute did not improve flux permeate. A four-day experiment
at 5 m.s -1 and 1 bar gave the same result. Therefore, backpulses can influence
filtration but not during short term experiments. Previous research [2] has
indicated extracellular polymeric substances (EPS) as the most significant factor
affecting fouling in MBRs. EPS effects on fouling mechanisms occurring in the
external MBR are currently being investigated. First, experiments without the
membrane will show the effect of the pump shear stress on the EPS
concentration. The same type of experiments, performed with the membrane, will
show the effect of the membrane on the EPS concentration.
[1] Espinasse B, Bacchin P and Aimar P. On an experimental method to measure critical flux in
ultrafiltration. Desalination; 2002, 146:91-96.
[2] Le-Clech P, Chen V and Fane TAG. Fouling in membrane bioreactors used in wastewater
treatment. Journal of Membrane Science; 2006, 284:17-53.

Drinking and Wastewater Applications IV – 6
Thursday July 17 ,11:30 AM-12:00 PM, Honolulu/Kahuku
Pressurized and De-pressurized Membrane Photoreactors for Removal of
Pharmaceuticals from Waters
R. Molinari (Speaker), University of Calabria, Rende, Italy - r.molinari@unical.it
A. Caruso, University of Calabria, Rende, Italy
P. Argurio, University of Calabria, Rende, Italy
T. Poerio, University of Calabria, Rende, Italy
Pharmaceutically active compounds (PhACs) are an important group of toxic
organic contaminants that are not completely removed during conventional
wastewater treatments and, therefore, can be found with concentration levels up
to the µg L -1 in sewage, surface and groundwater [1, 2]. Because of drawbacks of
conventional purification methods, hybrid systems based on coupling
membranes and photocatalysis could represent an useful solution to these
problems [3, 4]. The photocatalytic process allows the complete degradation
(mineralization) of the organic molecules in harmless products and, at the same
time, using a suitable membrane, it is possible to retain the pollutant and its
degradation products in the reaction environment, the recovery and reuse of the
photocatalyst and the separation of clarified solution. Besides, an interesting
perspective is the possibility to use photocatalysis exploiting the solar light as
energy source [5], with significant energy saving. In this work the performance of
two configurations of catalytic membrane photoreactors (pressurized and depressurized)
in batch and continuous systems for the degradation of two
pharmaceuticals (Gemfibrozil and Tamoxifen), using TiO2 as suspended catalyst,
have been studied. With the aim to understand the influence of some parameters
on the efficiency of membrane photoreactors, the effects of pH of aqueous TiO2
suspensions, recirculation flow rate and membrane clean-up were previously
studied. In the experimental studies on membrane photoreactor two different
operative procedures were used: in the first one (closed membrane system) the
permeate was continuously recycled, with the aim to determine the ability of the
membrane to retain the drug and the oxidation products in the oxidant
environment, while in the second one, in order to simulate the continuous
photodegradation process that could be applied at industrial level, the removed
permeate was replaced by an equal volume of initial feed drug solution. The
achieved data showed that the photodegradation of the two selected drugs
resulted quick and complete with a drug abatement of 99 % in the first 20
minutes and a mineralization higher than 90 % in about 120 minutes in the batch
membrane system. Nevertheless a small or no- rejection to degradation products
of both the drugs was evidenced. Tests in the pressurized continuous system,
performed with Gemfibrozil solutions, underlined a good system operating
stability, reaching a steady state in ca. 120 minutes with a complete abatement of

the drug and values of mineralization (60 %) and permeate flux (38.6 L h -1 m -2 )
that remained constant until the end of a run. The TOC rejection of about 62 % at
steady state showed the need to identify a membrane with higher rejection to the
intermediate products, to maintain almost all of them in the reaction environment
for the necessary time to reach their complete degradation. One of the major
problems observed in the NF membrane photoreactor with the suspended
catalyst is the membrane flux decline due to catalyst deposition and membrane
fouling. To solve this problem our research has been addressed towards the use
of a different configuration of membrane photoreactor, the de- pressurized
(submerged) membrane system, in which the submerged membrane module was
located separately from the photoreactor and the oxygen was bubbled on the
membrane surface. The results obtained in this system confirmed that the
presence of the suspended catalyst allows a complete degradation of Gemfibrozil
in about 15 - 20 minutes and a partial mineralization of the organic intermediates
with a TOC value at steady- state in the retentate of about 4.2 ± 0.7 mg L -1 ,
though the no TOC rejection underlined the necessity to identify a membrane
selective to intermediate products. The submerged membrane photoreactor,
however, resulted more advantageous in terms of permeate flux, with values
almost two times (65.1 L h -1 m -2 ) greater than those measured with the
pressurized membranes. Actually, other types of membranes, more selective to
substrates and intermediates, are under consideration.
[1] M.J. Gòmez, M.J. Martìnez Bueno, S. Lacorte, A.R. Fernàndez-Alba, A. Aguera,
Chemosphere, 66 (2007) 993.
[2] L. Comoretto and S. Chiron, Sci. Total Environ., 349 (2005) 201.
[3] R. Molinari, F. Pirillo, V. Loddo, L. Palmisano, Catal. Today, 118 (2006) 205.
[4] R. Molinari, F. Pirillo, M. Falco, V. Loddo, L. Palmisano, Chem. Eng. Process., 43 (2004)
1103.
[5] V. Augugliaro, E. Garcia-Lopez, V. Loddo, S. Malato-Rodriguez, I. Maldonado, G. Marcì, R.
Molinari, L. Palmisano, Sol. Energy, 79 (2005) 402.

Drinking and Wastewater Applications IV – 7
Thursday July 17, 12:00 PM-12:30 PM, Honolulu/Kahuku
Mechanisms governing the effects of membrane fouling on the
nanofiltration of micropollutants
L. Nghiem (Speaker), University of Wollongong, Wollongong, Australia - longn@uow.edu.au
C. Espendiller, University of Wollongong, Wollongong, Australia
G. Braun, University of Applied Science Cologne, Cologne, Germany
The influence of membrane fouling on the retention of five micropollutants
namely sulfamethoxazole, ibuprofen, carbamazepine, bisphenol A, and triclosan
by nanofiltration membranes was investigated in this study. Humic acid, alginate,
bovine serum albumin, and silica colloids were selected as model foulants to
simulate various organic fractions and colloidal matter that are found in
secondary treated effluent and surface water. Membrane fouling was achieved
with foulant cocktails containing individual model organic foulants in a
background electrolyte solution. The effects of membrane fouling on the
separation process was delineated by comparing retention values of clean and
fouled membranes and relate them to the membrane properties (under both
clean and fouled conditions) as well as physicochemical characteristics of the
micropollutants. Results reported here indicate a strong correlation between
membrane fouling, foulant characteristics, and membrane properties. The effects
of fouling on retention were found to be membrane pore size dependent. It was
probable that the influence of membrane fouling on micropollutant retention could
be governed by four distinctive mechanisms: modification of the membrane
charge surface, pore constriction, cake enhanced concentration polarisation, and
modification of the membrane hydrophobicity. The presence of the fouling layer
could affect the retention behavior of charged solutes by altering the membrane
surface charge density. While the effect of surface charge modification was clear
for inorganic salts, it was less obvious for the negatively charged pharmaceutical
species (sulfamethoxazole and ibuprofen) examined in this investigation,
possibly due to the interference of the pore constriction mechanism. Behavior of
the very loose TFC-SR2 membrane was found dominated by pore constriction
and this membrane consistently showed an increase in retention under fouled
conditions. In contrast, evidence of the cake enhanced concentration polarisation
effect was observed with the smaller pore size NF-270 and NF-90 membranes,
particularly under colloidal fouling conditions. In addition, the fouling layer could
also interfere with the solute membrane interaction, and therefore, exerted
considerable influence on the separation process of the two hydrophobic
micropollutants bisphenol A and triclosan used in this study.

Inorganic Membranes II – 1 – Keynote
Thursday July 17, 8:15 AM-9:00 AM, O’ahu/Waialua
High Temperature Gas Permeation Characteristics of MFI and DDR type
Zeolite Membranes
J. Lin (Speaker), Arizona State University, Tempe, Arizona, USA - Jerry.Lin@ASU.EDU
M. Kanezashi, Arizona State University, Tempe, Arizona, USA
J. O'Brien-Abraham, Arizona State University, Tempe, Arizona, USA
X. Zhu, Arizona State University, Tempe, Arizona, USA
This presentation compares synthesis and gas permeation/separation properties
of two thermally stable zeolite membranes: intermediate pore MFI type and small
pore DDR type zeolite membranes. These membranes have minimized defects
and pinholes and exhibit unique gas separation and permeation properties for
separation and membrane reactor applications. Experimental data for permeation
of small gases such as hydrogen, helium, carbon dioxide and carbon monoxide
through these two zeolite membranes in the temperature range of 25-500°C will
be presented and analyzed by the translational gas permeation model. The
permeation and separation properties of these small gases at high temperatures
for these microporous membranes feature a combined Knudsen and activated
diffusion mechanisms, depending on the relative size of the diffusing gas to the
membrane pores and quality of the membranes. The experimental data show
that at high temperatures the molecules of these gases in the zeolite pores retain
their gas characteristics. For MFI type zeolite membranes, the permeance
decreases with increasing temperature and is determined by the molecular
weight, not the kinetic diameter of the molecules. Diffusion of small molecules in
the small pore DDR type zeolite membranes exhibits activated process, with
permeance decrease with increasing size of the molecules.

Inorganic Membranes II – 2
Thursday July 17, 9:30 AM-10:00 AM, O’ahu/Waialua
Adding Ion-Selective Functionality to Desalination Membranes with Unique
Charge and Structural Properties of MFI Silicalite and ZSM-5 Zeolites
M. Duke (Speaker), Victoria University, Melbourne, Australia - mikel.duke@vu.edu.au
J. Lin, Arizona State University, Tempe, Arizona, USA
J. Diniz da Costa, The University of Queensland, St. Lucia, Australia
Inorganic membranes such as zeolites have unique structural and surface
properties which can be tailored to achieve ion-selective desalination. In this
work we show how variation in the Si/Al ratio of MFI membranes influences not
only membrane flux, but also the ability for the membrane to selectively pass
specific ions in seawater. In membrane distillation, the pure silicalite membrane
exhibited NaCl rejection from 3.8 wt% seawater of 97%, but alumina containing
ZSM- 5 membranes showed outstanding rejections >99.5%. With most
membrane formulations, permeate flux decreased upon switching form fresh
water feeds to seawater, however the Si/Al = 100 membrane displayed a unique
potential to increase flux by 30% when seawater was introduced. Also, for the
same membrane, rejection was discovered to switch to negative values (-80%)
after increasing the feed pressure to 700kPa using 0.5 wt% seawater feeds. Ions
in seawater clearly influence the zeolite structure in ways which allow either total
rejection or salt enrichment through the membrane, serving niche ion- selective
applications, or potentially reducing the energy required for desalination.

Inorganic Membranes II – 3
Thursday July 17, 10:00 AM-10:30 AM, O’ahu/Waialua
Carbonate-Ceramic Dual-Phase Membrane for High Temperature Carbon
Dioxide Separation
M. Anderson (Speaker), Arizona State University, Tempe, Arizona, USA
J. Lin, Arizona State University, Tempe, Arizona, USA - jerry.lin@asu.edu
Carbon dioxide is produced as a byproduct in many industrial processes, such as
the generation of electricity via coal combustion. Flue gas from conventional
coal-burning power plants contains roughly 13% carbon dioxide, 73% nitrogen,
10% water, 3% oxygen and less than 1% various pollutants. It is of increasing
importance to find ways to effectively separate carbon dioxide because it is a
known greenhouse gas. In this work we report the synthesis of a novel
carbonate-ceramic dual-phase membrane for improved high temperature carbon
dioxide separation. The dual-phase membrane is composed of a ceramic (solid)
phase, which acts as a support for a molten carbonate (liquid) phase.
La(0.6)Sr(0.4)Co(0.8)Fe(0.2)O(3-delta) (LSCF) was chosen as the support
material to take advantage of its mixed conductivity and improved oxidation
resistance in comparison to the previously used metallic dual-phase membrane.
LSCF supports were prepared by pressing and sintering powder synthesized
using the citrate method at 900 C. The pore radius of the sintered LSCF supports
was determined to be approximately 330 nm via both steady state helium
permeance and mercury porosimetry measurements. Dual-phase membranes
were successfully prepared by direct infiltration of molten carbonate at 520
degrees C. Helium permeances of the LSCF support before and after infiltration
were on the order of 10 -6 and 10 -10 mol/s.m 2 .Pa respectively, indicating that the
membrane was completely infiltrated. High temperature carbon dioxide
permeation experiments were performed from 650-900 C by feeding carbon
dioxide and argon on the upstream side of the membrane, and using helium as a
sweep gas on the downstream side of the membrane. It was observed that
LSCF’s relatively high oxygen ion conductivity made it possible for the support to
provide oxygen ions and facilitate formation of CO3 = in accordance with the
following reaction: CO2 + O = �� CO3 = . Upon reaching the downstream side of
the membrane, the reverse reaction occurs, leading to separation of pure carbon
dioxide. The LSCF dual-phase membrane exhibited a high carbon dioxide
permeance of 3.6x10 -8 mol/s.m 2 .Pa at 900 C. Additionally, the amount of argon
present in the permeate was found to be lower than the detection limit (~10 -10
mol/s.m 2 .Pa) of the gas chromatograph, indicating an ideal separation factor of
carbon dioxide over argon of at least 360. The activation energy for this
membrane was found to be 75 kJ/mol, which is comparable to the values for the
activation energy of oxygen vacancy diffusion in this particular material. This

confirms that the carbon dioxide permeance through the dual-phase membrane
is largely controlled by oxygen ion conductivity of the ceramic phase. A
theoretical model was developed to predict the high temperature permeation
characteristics for the material studied. It was found that the experimental results
and theoretical predictions were in agreement, furthering proving the feasibility of
the carbonate-ceramic dual-phase membrane.

Inorganic Membranes II – 4
Thursday July 17, 10:30 AM-11:00 AM, O’ahu/Waialua
High Quality Tubular Silica Membranes for Gas Separation
M. Luiten (Speaker), University of Twente, The Netherlands - m.w.j.luiten@utwente.nl
C. Huiskes, University of Twente, The Netherlands
H. Kruidhof, University of Twente, The Netherlands
A. Nijmeijer, University of Twente, The Netherlands
Highly selective silica membranes have been made on repaired extruded
commercial ±-Al2O3 tubular supports with lengths of 10 and 55 cm. To decrease
the surface roughness of commercial extruded ±- Al2O3 tubular supports
Pervatech (Enter, Netherlands) developed a repairing technology. Silica
membranes coated on the inside of these repaired commercial ±- alumina tubes
(10 resp. 55 cm) have been prepared and analysed by using SEM,
permporometry, XPS and single gas permeance measurements. These
permeance measurements were carried out at temperatures between 100 and
450ºC. The hydrogen permeance (at 450ºC) was around 2x10 -6 mol m -2 s -1 Pa -1
and the permselectivity for hydrogen over light gases was very high; F(H2/CH4) >
1200, F(H2/CO2) >100 and the F(H2/N2) = 250. A long term (>2600 h) permeation
test shows that the permeance of hydrogen (at 200ºC and ΔP=3.8bar) was in the
range of 6-8x10 -7 mol m -2 s -1 Pa -1 . The excellent gas separation performance of
the silica membrane on a tube with a length of 55 cm indicates a large potential
for the future of these membranes as it opens the way for a large number of
industrial applications.

Inorganic Membranes II – 5
Thursday July 17, 11:00 AM-11:30 AM, O’ahu/Waialua
Recent Developments on the Preparation and Modeling of Nanoporous
Silicon Carbide Membranes for Gas Separation Applications
R. Mourhatch (Speaker), University of Southern California, Los Angeles, Califorinia, USA -
mourhatc@usc.edu
B. Elyassi, University of Southern California, Los Angeles, Califorinia, USA
F. Chen, University of Southern California, Los Angeles, Califorinia, USA
M. Sahimi, University of Southern California, Los Angeles, Califorinia, USA
T. Tsotsis, University of Southern California, Los Angeles, Califorinia, USA
Silicon carbide (SiC) is a material with very attractive chemical and physical
properties, which have made it a great candidate for membrane applications,
especially those related to gas separation and hydrogen production. The focus of
the present paper is on using two different approaches to prepare asymmetric
nanoporous silicon carbide membranes which are applicable in reactive
separations involving the water-gas shift and methane steam reforming
reactions, where the membrane has to function in the presence of hightemperature
steam. The first approach for the preparation of SiC microporous
membranes, involves the pyrolysis of thin allyl-hydridopolycarbosilane (AHPCS)
films coated, using a combination of slip-casting and dip-coating techniques, on
tubular SiC macroporous supports. Combining slip-casting with dip-coating
significantly improved the reproducibility in preparing high quality membranes.
The membranes were studied for their transport characteristics, and steam
stability. In addition, a novel method, based on the use of sacrificial interlayers,
was also developed for the preparation of nanoporous SiC membranes, which
involves periodic and alternate coatings of polystyrene sacrificial interlayers and
SiC AHPCS layers on the top of slip-casted tubular SiC supports. Membranes
prepared by this technique exhibit single gas ideal separation factors of He and
hydrogen over Ar in the range of (176-420) and (100-200), respectively, with
permeances that are typically two to three times higher than those of SiC
membranes prepared previously by the more conventional techniques.
Preparation of asymmetric nanoporous SiC membranes is also carried out using
chemical-vapor infiltration/chemical-vapor deposition (CVI/CVD) techniques. We
have used macroporous SiC disks and tubes as supports, and tri-isopropylsilane
as the precursor. We have also developed two dynamic models to describe the
preparation and the transport characteristics of the membranes by the CVD/CVI
technique. First, a coarse-grained pore network model was developed for the
membranes, that provides accurate predictions for the ideal selectivities, as well
as the transport of binary gas mixtures. A continuum model of the CVD/CVI
membrane preparation process has also been developed, which is validated by
the results of a comprehensive experimental study. The results of the model

indicate that the CVI/CVD process of the TPS on the SiC support continues only
so long as the pore sizes are larger than the molecular radius RTPS of the TPS.
Once the pores shrink to a size smaller than (or equal to) RTPS, the permeance
of argon no longer changes, even if one continues the deposition process.
Moreover, the model shows that, significant porosity changes occur mostly in the
region very close to the top surface. We have optimized the model in order to
achieve the best operating conditions for preparing high quality membranes.

Inorganic Membranes II – 6
Thursday July 17, 11:30 AM-12:00 PM, O’ahu/Waialua
Preparation and Gas Separation Performance of Carbon Hollow Fiber
Membrane Module
M. Yoshimune (Speaker), AIST, Tsukuba, Japan - m-yoshimune@aist.go.jp
K. Haraya, AIST, Tsukuba, Japan
We have studied carbon molecular sieve membranes derived from
poly(phenylene oxide) (PPO) as a new type of carbon precursor. Carbon hollow
fiber membranes are promising for the industrial use of membrane modules,
however, one of the main problems of carbon hollow fiber is brittleness. In this
study, a flexible carbon hollow fiber membrane derived from PPO derivative is
investigated and a membrane module containing hundreds of carbon hollow
fibers is successfully prepared. This carbon hollow fiber membrane module
showed not only better mechanical stability but excellent performance for the gas
separation such as CO2/CH4.

Inorganic Membranes II – 7
Thursday July 17, 12:00 PM-12:30 PM, O’ahu/Waialua
Viability of ITM Technology for Oxygen Production and Oxidation
Processes: Material, System and Process Aspects
M. den Exter (Speaker), Energy Research Centre of the Netherlands, Petten, The Netherlands -
denexter@ecn.nl
W. Haije, Energy Research Centre of the Netherlands, Petten, The Netherlands
J. Vente, Energy Research Centre of the Netherlands, Petten, The Netherlands
The threat of global warming due to increasing CO2 concentrations has been
recognized as one of the main environmental challenges of this century. To limit
atmospheric CO2 concentrations to acceptable levels, major changes in energy
consumption are required in the coming decades. Still, fossil fuels are widely
expected to remain the world’s major source of energy for well into the 21st
century. While supply of oil and gas is under threat due to political instability and
uncertainties on reserves, the use of coal is increasing, with concomitant higher
CO2 emissions. To meet the targets set for atmospheric CO2 concentrations, the
development of break through technologies is essential. Otherwise, it will proof to
be impossible to reach the dramatic decrease of the CO2 emission to the
atmosphere during the conversion of fossil fuels to other forms of energy, e.g.
electricity or hydrogen. Three main routes for mitigation of CO2 emissions in
electricity plants can be defined:
1. Post-combustion processes: CO2 is captured from the flue gases. 2. Precombustion
processes: The fuel (natural gas or coal) is converted into hydrogen
and CO2. The CO2 is separated and hydrogen is combusted in a gas turbine. 3.
Oxyfuel processes: Combustion is carried out using pure oxygen, resulting in a
flue gas that mainly contains H2O and CO2.
These routes are connected with carbon capture with subsequent sequestration.
An additional approach is to avoid the production of CO2 emissions altogether
through increased industrial energy efficiency and thus lower energy
consumption. Oxygen production is related to the last two points.
This contribution is devoted to the state of the art of ionic transport membrane
(ITM) technology as alternative for energy-demanding distillations in large-scale
oxygen production. The most important aspects in the development of high
temperature ceramic air separation membranes, based on perovskite as oxygen
conducting material, will be treated starting from membrane development to
module designs and process schemes. Development of (tubular) membranes will
be explained in terms of preparation methods and choice of perovskite-types.
The latter is based on physical and chemical properties such as oxygen

permeability, stability issues comprising kinetic phase demixing, creep, unwanted
phase transitions and manufacturing issues that come to for. Module concepts,
based on single-hole tubes, monoliths, hollow-fibers and plate-tube designs will
be shown and techno-economically evaluated, directing the choice of the most
desirable membrane configuration while sealing design options will be revealed,
based on chemical/physical issues and economical viability.
Additionally, fields of application of ITM technology will be discussed in terms of
oxygen consumption in chemical processes.

Fuel Cells II – 1 – Keynote
Thursday July 17, 8:15 AM-9:00 AM, Wai’anae
Fuel Cell Membranes from Nanofiber Composites
R. Wycisk (Speaker), Case Western Reserve University, Cleveland, Ohio, USA -
ryszard.wycisk@case.edu
J. Choi, Case Western Reserve University, Cleveland, Ohio, USA
K. Lee, Case Western Reserve University, Cleveland, Ohio, USA
P. Pintauro, Case Western Reserve University, Cleveland, Ohio, USA
P. Mather, Syracuse University, Syracuse, New York, USA
New generation of proton conducting membranes meeting the needs of the
emerging fuel cell industry will have to appear soon if fuel cells are to play an
important role in the transformation towards greener energy production. Those
membranes will combine the latest developments in both materials chemistry and
nanomorphology control.
The most obvious trend in sulfonic acid type membrane polymers is to increase
the sulfonation degree so as to maximize proton conductivity and water retention
capability, which are especially important for applications in hydrogen fuel cells.
Unfortunately, this approach leads to problems with membrane
dimensional/mechanical stability. Recent studies on the advantageous
nanomorphologies of multiblock sulfonic copolymers open up an interesting
avenue for improvements. Still this approach has limits imposed by the
monomer/oligomer reactivity, block stoichiometry and casting solvent availability.
An entirely new approach for fabricating fuel cell membranes has been
developed by the present authors. It can be universally applied to a wide range of
proton conducting materials. Briefly, a three-dimensional, interconnected network
of proton-conducting polymer nanofibers fabricated via electrospinning is
embedded in an inert/impermeable polymer matrix. The nanofiber network,
occupying about 40-70% of the dry membrane volume, is composed of a high
ion-exchange capacity sulfonic acid polymer to ensure high water affinity and a
high concentration of protogenic sites. The inert (hydrophobic) polymer matrix
controls water swelling of the nanofibers and provides overall mechanical
strength to the membrane. Unlike other fuel cell membranes, the role of the
mechanical support is decoupled from that of the proton conductor. This
composite structure is also free from the limitations imposed by the percolation
effects typical of classic phase-separated systems.
The talk will be on the experimental details of nanofiber composite membranes
fabrication. Water swelling, proton conductivity, and thermal/mechanical
properties of the resulting membranes will be discussed.

Fuel Cells II – 2
Thursday July 17, 9:30 AM-10:00 AM, Wai’anae
Hybrid Nanocomposite Membranes for PEMFC Applications
B. Lafitte (Speaker), Commissariat à l’Energie Atomique, Monts, France - benoit.lafitte@cea.fr
F. Niepceron, Commissariat à l’Energie Atomique, Monts, France
J. Bigarre, Commissariat à l’Energie Atomique, Monts, France
H. Galiano, Commissariat à l’Energie Atomique, Monts, France
Fuel cells[1,2] are important enabling technologies for the reduction of greenhouse
gases emissions, offering cleaner, more-efficient alternatives to
combustion of gasoline and other fossil fuels. Current Polymer Electrolyte
Membrane Fuel Cell (PEMFC) systems predominantly use perfluorosulfonic acid
based membranes, such as Nafion®. However, Nafion® membranes tend to
significantly dehydrate at high temperatures or at low relative humidity leading to
low proton conductivity and poor PEMFC performance under these conditions.
Thus, new proton exchange membrane (PEM) materials have been developed in
order to increase the performance over a large temperature window and at low
humidification.
These new materials[3-5] are based on a hybrid organic-inorganic formulation in
which the inorganic phase contributes to the enhancement of the water retention
properties around 100°C. In particular, the development of a new family of PEMs
where the proton conductive characteristics rely exclusively on the inorganic
phase gives promising results.[6] In the present contribution, a report of the
incorporation of original acid-functionalized inorganic nanoparticles in inert
membranes (low-cost polymer) is given. Membranes with different amounts of
inorganic particles have been prepared by evaporation and recasting techniques.
These membranes were tested for their proton conductivities and their
morphologies have been investigated. Finally, the performance of membraneelectrode
assemblies (MEAs), using selected hybrid membranes, was evaluated
by single cell fuel cell tests. Remarkably, such hybrid membrane systems
exhibited up to 1.2 W/cm 2 , at 80 °C using non-hydrated gas feeds.
ACKNOWLEDGEMENTS This work was carried within the framework of a Pan-H program
financed by the Agence Nationale pour le Recherche and co-supported by the Commissariat à
l’Energie Atomique and the Region Centre.
REFERENCES
1. Song, C. Catalysis Today 2002, 77, 17.
2. Costamagna, P.;Srinivasan, S. Journal of Power Sources 2001, 102, 242.

3. Shao, Z.-G.; Loghee, P.; Hsing, I.-M. Journal of Membrane Science. 2004, 229, 43.
4. Kwak, S.-H. Solid State Ionics 2003, 160, 309.
5. Chang, H. Y.; Lin, C. W. Journal of Membrane Science. 2003, 218, 295.
6. Bébin, P.; Caravanier, M.; Galiano, H. Journal of Membrane Science. 2006, 278, 35.

Fuel Cells II – 3
Thursday July 17, 10:00 AM-10:30 AM, Wai’anae
Hybrid Self-Organized Membranes: New Strategies for Promising Fuel Cell
Energy Applications
M. Michau, Institut Europeen des Membranes, Montpellier, France
M. Barboiu (Speaker), Institut Europeen des Membranes, Montpellier, France -
mihai.barboiu@iemm.univ-montp2.fr
Artificial membrane materials are the subject of various investigations,offering
great potentialities as well on the level of their chemical composition or
organization as to that of the concerned applications. Of special interest is the
structure-directed function of hybrid membrane materials and control of their
build-up from suitable units by self- organisation.
The main interest focus on functional hybrid membranes in which the recognitiondriven
transport properties could be ensured by a well- defined incorporation of
receptors of specific molecular recognition and self-organization functions,
incorporated in a hybrid dense materials.
Actual and potential applications of such self- organized systems can emerge for
new membrane materials presenting combined features of structural adaptation
in specific nanodomains randomly ordered in the hybrid matrix. These oriented
nanodomains are resulted from the controlled self-assembly of simple molecular
components that encodes the required information for ionic assisted-diffusion
within hydrophilic pathways. Our results simply that the control of molecular
interactions can define the self- organized supramolecular architectures
presenting a strong communication between the organic and the siloxane layers.
Although these pathways do not merge to cross the micrometric films, they are
well defined along nanometric distances. It results that these systems may
transport protons through structure diffusion under low-humidity conditions. In
addition some potential research directions for the development of new efficient
fuel cell PEMFC materials presenting enhanced conduction properties.
[1] A. Cazacu, C. Tong, A. van der Lee, T.M. Fyles, M. Barboiu, J. Am. Chem. Soc. 2006, 128
(29), 9541-9548.
[2] C. Arnal-Herault, A. Pasc-Banu, M. Michau, M. Barboiu, Angew. Chem. Int. Ed. 2007, 46,
8409- 8413.
[3] C. Arnal-Hérault, M. Barboiu, A. Pasc, M. Michau, P. Perriat, A. van der Lee, Chem. Eur. J.
2007, 13, 6792

[4] M. Michau, M. Barboiu, R. Caraballo, C. Arnal- Hérault, A. van der Lee, Chem. Eur. J. 2008,
14, 1776-1783.
[5] C. Arnal-Herault, A. Pasc-Banu, M. Barboiu A. van der Lee, Angew. Chem. Int. Ed. 2007, 46,
4268- 4272.

Fuel Cells II – 4
Thursday July 17, 10:30 AM-11:00 AM, Wai’anae
Ion-Exchange Membranes from Side-Chain Sulfonated Poly(arylene ether)s
J. Meier-Haack (Speaker), Leibniz Institute of Polymer Research Dresden, Dresden, Germany -
mhaack@ipfdd.de
K. Schlenstedt, Leibniz Institute of Polymer Research Dresden, Dresden, Germany
W. Butwilowski, Leibniz Institute of Polymer Research Dresden, Dresden, Germany
C. Vogel, Leibniz Institute of Polymer Research Dresden, Dresden, Germany
Polymer electrolyte membranes and in particular cation exchange membranes
are used in a broad field of applications such as low fouling membranes in water
and wastewater treatment, solid polymer electrolytes in electrochemical
processes (e.g. low temperature fuel cells) or as ion-selective membranes in
sensors.
Despite of some drawbacks, today poly(perfluoroalkylsulfonic acid)s such as
Nafion® and similar materials are still the standard membrane materials for
polymer electrolyte fuel cells (PEMFC). The disadvantages of these materials
and the demand for new energy conversion/production systems have initiated
world-wide research activities on the development of alternative membrane
materials for PEMFC. Among the various materials suggested, sulfonated
poly(arylene ether)s are seen as the most promising ones due to their
outstanding chemical and thermal stabilities, high glass transition temperature
(Tg) as well as their good solubility in dipolar aprotic solvents such as N-methyl-2pyrrolidone
(NMP), dimethylsulfoxide (DMSO) or N,N- dimethylacetamide
(DMAc) and film forming properties. However these materials have two main
disadvantages over Nafion-like materials, namely: (1) the hydrolytic instability of
aromatic sulfonic acids [1] and (2) the lower acidity of the sulfonic acid groups,
leading to lower conductivities at comparable ion-exchange capacities.
Vogel et al. reported on a surprisingly high hydrolytic stability of polystyrene
sulfonic acid [1]. First indications of hydrolysis were found only after treatment in
water at 200°C for 24h. On the other hand poly(styrene sulfonic acid) is not
suitable for applications in fuel cells due to its chemical instability arising from the
tertiary carbon in the polymer backbone. These results led us to the idea to
prepare chemically stable poly(arylene ethers) with a pending phenyl ring, which
can be sulfonated selectively, in order to mimic poly(styrene sulfonic acid).
Having the sulfonic acid group in the side chain has further advantages as has
been described in the literature by Lafitte et al. [2 - 4] or Guiver et al. [5].
Recently, we reported on poly(arylene ether)s prepared from bis-(4-
fluorophenyl)-sulfone bis-(4-hydroxyphenyl)- sulfone and phenylhydroquinone [6,
7], which can be selectively sulfonated at the external benzene ring. Secondly, to

support a phase separation between sulfonated and non-sulfonated domains,
block copolymers have been prepared. A block copolymer with short segments
showed similar or better transport properties as the random copolymer of same
composition. It is expected that blockcopolymers with longer blocksegments will
show better performance than their random counterparts. The properties will be
further discussed in terms of proton conductivities and PEMFC-performance.
[1] C. Vogel, J. Meier-Haack, A. Taeger, D. Lehmann, Fuel Cells 4, 320 (2004).
[2] B. Lafitte, L. E. Karlsson, P. Jannasch, Macromol. Rapid Commun. 23, 896 (2002).
[3] L. E. Karlsson, P. Jannasch J. Membr. Sci. 230, 61 (2004).
[4] B. Lafitte, P. Jannasch J. Polym. Sc.: Part A: Polym. Chem. 43, 273 (2005).
[5] B. Liu, G. P. Robertson, D.-S. Kim, M. D. Guiver, W. Hu, J. Zhenhua Macromolecules 40,
1934 (2007).
[6] J. Meier-Haack, C. Vogel, W. Butwilowski, K. Schlenstedt, D. Lehmann Pure and Applied
Chemistry 79, 2083 (2007).
[7] J. Meier-Haack, C. Vogel, H. Komber, W. Butwilowski, K. Schlenstedt, D. Lehmann Macromol.
Symp. 254, 322 (2007).

Fuel Cells II – 5
Thursday July 17, 11:00 AM-11:30 AM, Wai’anae
Ionomer Blend Membranes for Low T and Intermediate T Fuel Cells
J. Kerres (Speaker), University of Stuttgart, Stuttgart, Germany - jochen.kerres@icvt.unistuttgart.de
F. Schoenberger, University of Stuttgart, Stuttgart, Germany
M. Schaefer, University of Stuttgart, Stuttgart, Germany
A. Chromik, University of Stuttgart, Stuttgart, Germany
K. Krajinovic, University of Stuttgart, Stuttgart, Germany
V. Gogel, Zentrum für Sonnenenergie- und Wasserstoff-Forschung, Ulm, Germany
L. Jörissen, Zentrum für Sonnenenergie- und Wasserstoff-Forschung, Ulm, Germany
Q. Li, Technical University of Denmark, Lyngby, Denmark
J. Jensen, Technical University of Denmark, Lyngby, Denmark
N. Bjerrum, Technical University of Denmark, Lyngby, Denmark
This contribution comprises an overview about the work done by our research
group in the development of ionomers/ionomer (blend) membranes for
membrane fuel cells. The topics include the development of novel sulfonated
arylene main chain nonfluorinated and partially fluorinated homo polymers, block
and statistical copolymers by nucleophilic displacement polycondensation
procedures; the preparation of covalently or ionically cross-linked membranes
prepared by mixing these polymers with PBI Celazol or other basic polymers; the
application of these membranes to PEFC and DMFC, particularly up to a
temperature of 60°C under atmospheric pressure (air-breathing) for the
application in micro fuel cells; development of novel base-excess PBI/sulfonated
polymer/H3PO4 blend membranes, and test of these membranes in fuel cells at
intermediate fuel cell operation temperatures (170-200°C). From the sulfonated
ionomers, acid-excess ionically cross-linked membranes have been prepared by
mixing the sulfonated ionomer with the basic polymer PBI.Covalently cross-linked
blend membranes have been prepared by blending sulfonated arylene polymers
with PSU-sulfinate under cross-linking of the sulfinate groups with different crosslinkers
via sulfinate S-alkylation. These membranes have been tested in a DMFC
to investigate their suitability for the DMFC up to a temperature of 60°C under
atmospheric pressure which is interesting for the use of DMFC as power supply
for mobile electronic applications, under comparison with Nafion. The i/U
polarization curves of the membranes along with their MeOH permeability,
determined via monitoring the CO2 flux in the cathode effluent gas using an
optical IR CO2 sensor, showed a better performance than Nafion which is mainly
due to the lower meOH permeability of the arylene ionomer membranes,
compared to Nafion. Membrane-electrode assemblies (MEAs) using the new
ionomers have been built up using different methods: 1) by coating the
membranes with anode and cathode inks; 2) by building up the MEA from the
cathode; 3) by building up the MEA from the anode. Among all applied methods,

1) yielded the MEAs with the best DMFC performance. One of the MEAs was
tested for 4 weeks in a DMFC and showed continuously increasing performance
within this period of time. PBI/sulfonated polymer/H3PO4 blend membranes for
the application in intermediate T fuel cells have been developed as well. These
membranes showed good performance in fuel cells in the temperature range
170-200°C, their chemical stability being even better than that of pure PBI
membranes, which was ascertained by H2O2 and Fentons degradation test:
during H2O2 treatment, the base-excess base-acid PBI blend membranes
showed markedly less molecular weight degradation than pure PBI or sulfonated
polymer, as determined by gel permeation chromatography (GPC).

Fuel Cells II – 6
Thursday July 17, 11:30 AM-12:00 PM, Wai’anae
Hygrothermal Aging of Nafion
F. Thominette (Speaker), ENSAM, Paris, France - francette.thominette@paris.ensam.fr
F. Collette, ENSAM, Paris, France
G. Gebel, CEA, Grenoble, France
1. Introduction
Nafion membranes are mostly used in PEMFC fuel cell as an electrolyte. Nafion
molecular structure, in the acid form, consists of polytetrafluoroethylene
hydrophobic backbone with perfluorinated pendant chains terminated by
hydrophilic sulfonic groups. These hydrophilic end-groups permit water sorption,
contributing to protons transport and, thus, to ionic conductivity. Water and
temperature are viewed as systematically existing parameters in fuel cells in use.
Their influence on the polymer is reported in this study. Our aim is to study the
evolution of Nafion hydrophilicity properties with aging time and to link it with the
modifications of its chemical structure.
2. Experimental
Commercial perfluorinated sulfonic acid membranes Nafion® 112 membranes
were used as received for durability tests. Aging was done at 80° C, either at
0%RH or 80%RH. Samples were removed throughout aging and were
characterized by Dynamical Vapour Sorption (DVS), infrared spectroscopy and
nuclear magnetic resonance.
3. Results
For pristine sample, a sigmoidal isotherm is obtained by DVS. The concave part,
for low activities, is relative to water molecules fixed preferentially on sulfonic
acid groups. It corresponds to Langmuir population with strong interactions
caused by hydrogen bonds. The quasi linear region of the sorption isotherm can
be attributed to Henry mode sorption which corresponds physically to molecules
of water sorbed by an ordinary dissolution mechanism, in the hydrophilic phase.
At higher activities, the sorption isotherm displays a positive curvature that
corresponds to the clusters formation. With aging, the isotherms are significantly
modified. The most spectacular feature is the progressive disappearance of
Langmuir contribution. This implies that the proportion of water sorbed on the
Langmuir sites decreases with aging time, indicating that probably the number of
sulfonic acid sites decreases too. It is also observed that the concentration of
water at equilibrium decreases with aging time: At water activity of 0.9, for

samples aged at 80%RH, water concentration decreases from 15% to 6.5% up to
80 days and remains constant beyond. With aging, Nafion absorbs less water: It
becomes less hydrophilic.
Pristine and aged samples are analysed in parallel by infrared spectroscopy
(transmission mode). The most spectacular phenomenon is the appearance of a
new band at 1440 cm -1 which is clearly observed in all IR spectra of aged
samples. The intensity of this absorbance band increases with aging and
remains constant after exposure times very close to that observed from DVS
measurements.
19F NMR spectra show that aged Nafion backbone is not chemically altered by
aging but that the environment of chemical functions located on pendant chains
is slightly modified.
To follow the influence of aging on the sulfonic groups of Nafion, 1H NMR MAS
spectra of aged samples are observed in parallel of the 19F NMR spectra. In its
original state, Nafion pristine membrane displays only one protonated site. 1H
NMR spectra of Nafion aged in a climatic chamber display a second peak at
3.4ppm with aging. Heteronuclear correlation NMR experiments 1H- 13C did not
point out any interaction of these protons with the carbonated structure of Nafion.
This peak does not result from a chemical degradation of the polymer.
The same observations are done for samples aged at 80°C, 0%RH except that it
evolves more slowly (stabilization over 200 days).
4. Discussion
One of the most interesting features of Nafion aging is the decrease of Nafion
water uptake. After exposure at 80°C, Nafion becomes less hydrophilic as shown
by DVS. Aged Nafion isotherms do not display Langmuir contribution anymore:
water is no longer trapped by sulfonic acid end-groups as in pristine Nafion.
The apparition of an infrared absorption band at 1440 cm -1 strongly suggests
anhydride formation and will be considered as a degradation tracer. The
mechanism proposed here is a condensation of two sulfonic acids creating a
cross-link S-O-S between two side groups which is accompanied by loss of one
water molecule.
Modifications observed in 19F NMR reveals a change of the chemical
environment of the pendant chains as expected by the anhydride formation. With
aging, a new 1H NMR peak located at 3.4ppm appears after exposure at 0 or
80%RH. According to its chemical shift, this peak is attributed to non- acidic
water molecules located around anhydrides. The observation of the non-acidic
water peak at 3.4 ppm, on the 1H NMR spectra, can be considered as a tracer of
the polymer aging.

5. Conclusion
In this work, the evolution of Nafion chemical structure highlights sulfonic
anhydrides formation, creating a cross-link between two side chains. This leads
to the decrease of the polymer hydrophilicity with a proton conductivity drop off.
These changes are observed for all aged samples.

Fuel Cells II – 7
Thursday July 17, 12:00 PM-12:30 PM, Wai’anae
Automotive Hydrogen Fuel Cell Membrane Applications
A. Brenner (Speaker), General Motors, Honeoye Falls, New York, USA -
annette.brenner@gm.com
F. Coms, General Motors, Honeoye Falls, New York, USA
C. Gittleman, General Motors, Honeoye Falls, New York, USA
R. Jiang, General Motors, Honeoye Falls, New York, USA
Y. Lai, General Motors, Honeoye Falls, New York, USA
A. Nayar, General Motors, Honeoye Falls, New York, USA
M. Schoeneweiss, General Motors, Honeoye Falls, New York, USA
Y. Zhang, General Motors, Honeoye Falls, New York, USA
Automotive fuel cell systems have requirements that differ from other fuel cell
applications. The challenge is dynamic operation over the wide range of
operating conditions experienced by the vehicle during its 5500 hour target life.
How the vehicle requirements translate to membrane targets and related testing
is reviewed for two membrane focus areas within the automotive system: the
PEM fuel cell stack and humidification subsystem. The in-situ and ex- situ
measurements used to evaluate these membranes for use in commercial
automotive fuel cells will be described in addition to corresponding targets and
status.
Recovery of water from the cathode exhaust with a humidification membrane can
extend the durability and enhance performance of the PEM. Water transport and
gas separation are the key performance metrics of the humidification
membranes. The primary functions of the PEM membrane are proton transport,
gas separation and electrical insulation. The PEM can fail due to chemical
degradation, mechanical degradation or a combination. The humidification
membrane is subject to some similar factors contributing to mechanical
degradation, such as high temperatures and drier conditions. Cycling of humidity
and freeze and oxidative environments can also contribute to degradation.
Durability, performance, and processability of each membrane are critical to
meeting the cost, life, and performance targets of the fuel cell vehicle.

Oral Presentation
Abstracts
Afternoon Session
Thursday, July 17, 2008

Hybrid and Novel Processes II – 1 – Keynote
Thursday July 17, 2:15 PM-3:00 PM, Kaua’i
Cyclic Hybrid Adsorbent-Membrane Reactor (HAMR) Studies for Hydrogen
Production
A. Harale, University of Southern California, Los Angeles, California, USA
H. Hwang, University of Southern California, Los Angeles, California, USA
P. Liu, Media and Process Technology Inc., Pittsburg, Pennsylvania, USA
M. Sahimi, University of Southern California, Los Angeles, California, USA
T. Tsotsis (Speaker), University of Southern California, Los Angeles, California, USA -
tsotsis@usc.edu
1. Introduction
As a result of stricter environmental regulations worldwide, hydrogen is
progressively becoming an important clean energy source. For H2 to replace
fossil fuels in mobile applications, it will require the creation of a production and
delivery infrastructure equivalent to that currently existing for fossil fuels, which is
an immense task. As an alternative, and as an interim step towards the new
hydrogen economy, various groups are currently studying steam reforming of
methane (SRM) for the on- board generation of hydrogen, or for on site
production, in order to alleviate the need for compressed or liquid hydrogen gas
storage(1-4). Conventional technologies are, however, neither convenient nor
economical to apply for small-scale (on site or on-board) hydrogen generation.
Reactive separation processes have, as a result, been attracting renewed
interest for application in H2 production through SRM. One such technology is the
hybrid adsorbent-membrane reactor (HAMR) system, which couples reaction and
membrane separation steps with adsorption on the reactor and/or membrane
permeate side. The HAMR concept was originally proposed by our group(5,6) for
esterification reactions, and it was adapted recently for on-board or on-site
hydrogen production applications. Our early studies involved the development of
a mathematical model for the HAMR system (applied to hydrogen production
through SRM(7)); recently experimental investigations with the water-gas shift
reaction(8), using microporous membranes and CO2 hydrotalcite-type
adsorbents, were carried out in order to validate the HAMR design models.
Experimental data were compared with the model predictions, and found to be
consistent. In this paper we focus on the practical process design aspects of the
HAMR hydrogen production process. A continuous HAMR process scheme has
been investigated, both experimentally and through modeling studies. 2. HAMR
Cyclic Process The steps involved in the proposed cyclic HAMR process for the
direct production of pure H2 are described below. It consists of four steps:
1.Adsorption-Reaction-Membrane Separation Step. The reactor is initially presaturated
with H2 and steam at the desired reaction temperature and pressure. A
mixture of steam and CH4 (or CO) at a prescribed ratio are fed to the reactor, and

an essentially pure H2 product is collected at the permeate side. The reaction
step is continued up to the time needed for breakthrough to occur. This time
depends upon adsorbent and membrane characteristics, and membrane
parameters such as the residence time, and transmembrane pressure.At the
breakthrough point the feed is diverted into a second identical reactor. 2.Blowdown
Step. The reactor is depressurized to a lower pressure of PL
countercurrently to the feed flow direction. The effluent gas stream from this step
contains all the components left in the reactor at the end of Step 1, and can
either be recycled as a feed to another reactor or be used as fuel. 3. Purge
Step.The reactor is countercurrently purged with a weakly adsorbing gas such as
steam or H2 to desorb the CO2. The desorption step operates at PL. The
desorbed gas consists of CO, CH4, CO2, H2, and H2O and is either separated for
recycle or used as fuel. 4.Pressurization step. The reactor is countercurrently
pressurized to the reaction pressure (for Step 1) using a mixture of steam and H2.
At the end of this step, reactor regeneration, and the reactor is ready to undergo
a new cycle.
In our studies, a 24 min, 4-bed-4 step cycle was investigated for the water-gas
shift reaction. A H2- selective carbon molecular sieve membrane together with a
CO2-selective hydrotalcite adsorbent, and a commercial Cu/Zn catalyst was
used. Virtually 100% conversion is achieved during the reaction step, while
simultaneously 100% of CO2 is being captured during this step. Since the
membrane excludes CO, the hydrogen product in the permeate side is highly
pure, and ready to use in a fuel cell. A more detailed description of the
characteristics of the HAMR cyclic process will be discussed during the
conference presentation.
Acknowledgement: The support of the US Department of Energy and NASA is gratefully
acknowledged.
1.Y. Choi, H. Stenger, J. Power Source, 124, 432 (2003).
2.N. Darwish,N. Hilal, G. Versteeg, B. Heesink, Fuel, 83, 409 (2003).
3.Z. Liu, H.Roh, S.Park, , J. Power Sources, 111, 83. ( 2002)
4.T. A. Semelsberger, L. F. Brown, R. L. Borup, M. A. Inbody, Int. J. Hyd. Energ. 29, 1047. (2004)
5.B. Park, Ph.D. Thesis, University of Southern California, Los Angeles, California, (2001)
6.B. Park, T.T. Tsotsis, Chem. Eng. Proc. 43, 1171.(2004)
7.B. Fayyaz, A. Harale, B.G. Park, P.K.T. Liu, M. Sahimi, and T. T. Tsotsis, Ind. Eng. Chem.
Res., 44 (25), 9398 -9408, (2005)
8.A. Harale, H. Hwang, P.K. Liu, M. Sahimi, and T.T. Tsotsis, Chemical Engineering Science
62:4126- 4137(2007)

Hybrid and Novel Processes II – 2
Thursday July 17, 3:00 PM-3:30 PM, Kaua’i
Nanoparticle-Enhanced Microfiltration for Low Energy Metal Removal from
Water.
A. Jawor (Speaker), University Of California Los Angeles, Los Angeles, California, USA -
ajawor@ucla.edu
E. Hoek, University Of California Los Angeles, Los Angeles, California, USA
Polymer-enhanced ultrafiltration (PEUF) is highly effective for selectively
removing metal ions from water, but this process is difficult to implement in
practice because polymer gel formation and pore plugging lead to severe, often
irreversible flux decline. Recently, dendritic polymers (a.k.a., dendrimers) have
been proposed as a high-binding capacity, low-fouling alternative to traditional
polyelectrolytes. However, dendrimers are very expensive and require use of
tight, ultrafiltration membranes. Nanoparticle-enhanced microfiltration (NEMF) is
a hybrid membrane process, like PEUF, where a target contaminant selectively
reacts with nanoparticles added to a mixed reactor. Contaminant-nanoparticle
complexes are removed using low-pressure microfiltration membranes.
In this study, we evaluate nanoparticle-enhanced microfiltration using inorganic
nanoparticles. Our objective is to demonstrate selective removal of divalent metal
cations from simple and complex electrolytes through addition of metal-binding
nanoparticles followed by microfiltration. As a first step towards testing this
concept, we evaluate a traditional polyelectrolyte (polyacrylic acid), a succinic
and carboxylic acid functionalized PAMAM dendrimers, and a NaA zeolite
nanocrystals as metal-binding agents in combination with various microfiltration
and ultrafiltration membranes. Electron microscopy, light scattering, particle
electrophoresis, direct titrations, and contact angle analyses are used to
characterize nanoparticle size, shape, hydrodynamic radius, zeta potential,
charge density, and surface energy, respectively. Preliminary metal-binding
experiments are performed to elucidate nanoparticle binding kinetics, capacity
and strength (i.e., reversibility) using various divalent metal ions (Ca 2+ , Mg 2+ ,
Ba 2+ , Sr 2+ , Cd 2+ ). Nanoparticle rejections and flux decline are determined using
polysulfone- based UF and MF membranes ranging from molecular weight cut-off
(MWCO) of 5 kD up to a characteristic pore size of 100 nm. Mechanisms of
membrane fouling by polymers, dendrimers, and nanocrystals are elucidated by
fitting flux decline data with classical blocking filtration models. Clean and fouled
membrane surfaces are analyzed by SEM/EDX to confirm morphology and
composition of fouling layers formed. Additional membrane characterization
includes pure water permeability and zeta potential by electrolyte filtration
experiments, plus surface roughness and energy via AFM and contact angle
analyses.

In the presentation, we will present results from membrane filtration experiments
used to characterize (1) metal ion sequestration by the different binding agents,
(2) optimal membrane MWCO/pore size for nanoparticle filtration, and (3) the
extent, mechanisms, and reversibility of membrane fouling by each nanoparticle.

Hybrid and Novel Processes II – 3
Thursday July 17, 3:30 PM-4:00 PM, Kaua’i
Crystallization in Hollow Fiber Devices
D. Zarkadas (Speaker), Schering Plough Research Institute, Union, New Jersey, USA
K. Sirkar, New Jersey Institute of Technology, Newark, New Jersey, USA -
kamalesh.k.sirkar@njit.edu
Membrane based crystallization has recently attracted interest as an alternative
crystallization technique. Both hollow fiber and flat membrane devices have been
tested. This paper focuses on the use of hollow fiber devices for cooling and
antisolvent crystallization. Their compactness, high heat and mass transfer
volumetric efficiency, scalability and ease of operational control makes hollow
fiber devices ideal for the creation of homogeneous supersaturation conditions
and hence for tight crystal size distribution (CSD) control.
Cooling crystallization was studied in hollow fibers with solid, nonporous walls.
These devices are extremely efficient heat exchangers with a relatively flat radial
temperature profile inside the hollow fibers. Therefore, they can serve as
standalone crystallizers or supersaturation creation devices in combination with a
completely stirred tank. The performance of hollow fiber devices as standalone
crystallizers for aqueous KNO3 was characterized by broader CSDs and lower
reproducibility compared to literature data from Mixed Suspension Mixed Product
Removal (MSMPR) crystallizers due to generation of a large number of fines
causing slow filtration and localized growth on the filters. However, when the
hollow fiber module was used for supersaturation creation in combination with a
stirred tank, it yielded narrow and reproducible CSDs with mean sizes between
100-150 μm, 3-4 times lower than MSMPR crystallizers. Also, 90% of the crystals
were smaller than 370 μm compared to 550-600 μm for MSMPR crystallizers.
Further, the number of crystals generated per unit volume was 2-3 orders of
magnitude higher.
When hollow fiber devices were used as supersaturation creation devices in
combination with a static mixer for cooling crystallization of paracetamol in
ethanol, it was illustrated that the solution can be kept stable even 30-40oC
below published metastable zone values. This leads to the achievement of very
high nucleation rates and hence small crystal sizes. The nucleation rates were 2-
4 orders of magnitude higher than values obtained for potassium nitrate and
salicylic acid and reached values encountered only in impinging jet
crystallization. A qualitative comparison with existing literature data showed that
the CSD was confined to smaller sizes and a narrower range. Finally, a linear
relationship between the mean crystal size and the cooling medium temperature

was observed, indicative of the simplicity of CSD control available in solid hollow
fiber devices.
Porous hollow fiber antisolvent crystallization was tested for a well studied
biological molecule, L-asparagine monohydrate. The antisolvent for the aqueous
solution was isopropanol. The process proved to be successful despite the fact
that the geometrical design of the membrane hollow fiber crystallizers used was
not optimal. Mean crystal sizes between 34-86 μm and 33-40 μm were obtained
respectively in standalone membrane hollow fiber crystallizers (MHFC) and their
combinations with completely stirred tanks. The CSD was confined below 150
μm for the former and 70 μm for the latter, levels that are sufficient for most
pharmaceutical crystalline products, for which bioavailability and formulation
concerns dictate the desired CSD. In addition, porous hollow fiber devices
achieved 1-5 orders of magnitude higher nucleation rates compared to batch
stirred crystallizers. Considerable improvements can be obtained by carefully
designing membrane hollow fiber crystallizers.

Hybrid and Novel Processes II – 4
Thursday July 17, 4:00 PM-4:30 PM, Kaua’i
Selectivity between Potassium, Sodium and Calcium Ions in Synthetic
Media and Juice Media Using Wafer Enhanced- Electrodeionization
T. Ho (Speaker), University of Arkansas, Arkansas, USA
R. Cross, University of Arkansas, Arkansas, USA
J. Hestekin, University of Arkansas, Arkansas, USA - jhesteki@uark.edu
A. Kurup, University of Arkansas, Arkansas, USA
Wafer enhanced electrodeionization (WE-EDI) is a new technology that has been
shown to removal ions from fermentation broths to very dilute levels (Arora et al.,
2007). The novelty in the process is producing unique wafers, that transport ions,
and incorporating these into an electrodialysis stack. Although the technology
has been shown to be viable for dilute ion separations, areas such as selective
separations, wafer enhancement, and ion exchange bead selection have not
been explored. This paper is focused on the removal of sodium ion in the present
of other competing ions such as potassium and calcium. The purpose is to
produce low sodium juice for health purpose especially for low sodium tolerance
patients. Using WE-EDI technology would allow controlling the selectivity of the
ions. Moreover, WE-EDI will provide and attractive alternative to the use of
bipolar membranes in electrodialysis. The WE-EDI technology has been shown
to increase the performance of the membranes by increasing the transport of
ions through the system. For instance, early studies of removal of sodium and
potassium show up to a 40% reduction of power under certain conditions. WE-
EDI also may increase the life time of the membrane especially in high complex
media such as juice by allowing water dissociation on the surfaces of the resin
beads instead of on the surface of the membranes, which is violent and hard on
the surface layer. This paper addresses the characteristics of wafer: porosity and
capacity with different composition. We also propose a mathematical model that
provides a good prediction for product quality, especially for low sodium juice
production. The selectivity difference between sodium, potassium, and calcium
will be evaluated in order to optimizing the process performance. The
experimental will ensure the accuracies of the model as well as provides the
reason why WE-EDI technology has an economic advantage in comparison with
the bipolar membrane electrodialysis or conventional electrodialysis.

References
Arora, M.B., J.A. Hestekin, S.W. Snyder, E.J. St. Martin, M.I. Donnelly, C. Sanville-Millard and
Y.J. Lin, ‘The Separative Bioreactor: A Continuous Separation Process for the Simultaneous
Production and Direct Capture of Organic Acids’, Separation Science Technology, 42, 2519-
2538, 2007.

Hybrid and Novel Processes II – 5
Thursday July 17, 4:30 PM-5:00 PM, Kaua’i
Capillary ElectroChromatography and Membrane Technology: Merging the
Advantages
K. Kopec (Speaker), University of Twente, The Netherlands
D. Stamatialis, University of Twente, The Netherlands - d.stamatialis@utwente.nl
M. Wessling, University of Twente, The Netherlands
Introduction
Capillary ElectroChromatography (CEC) is a separation technique that is a hybrid
of capillary electrophoresis (CE) and high performance liquid chromatography
(HPLC). The flow of mobile phase is driven through the column by an electric
field (a phenomenon known as electroosmosis) generated by applying a high
voltage across the column. Application of electrical current, rather than pressure,
and presence of a stationary phase result together in fast separations that
combine the efficiency of capillary electrophoresis and the selectivity of liquid
chromatography. CEC with its precision, accuracy and possibility of separation of
complex mixtures is an eligible technique for dealing with biomolecules (proteins,
peptides) and pharmaceuticals. Currently three types of columns are used in
capillary electrochromatography: in-situ polymerized monoliths, capillaries
packed with particles and capillaries with inner coatings (open tubular). In each
case, the stationary phase is incorporated into fused silica capillary and in each
case manufacture of a CEC column is a time consuming and expensive process.
Experimental
In our approach, membrane technology is employed to produce porous polymer
fibers and apply them as stationary phase in CEC. Full, as well as, small borefibers,
both with uniform porosities are manufactured via phase inversion by
immersion precipitation spinning. In this work, fibres are prepared from two
different blends: poly-ether-sulphone (PES) with sulphonated poly-ether-etherketone
(S-PEEK), and polyimide P84 with S-PEEK. The sulphonation degree of
S-PEEK and the blend ratios of PES/S- PEEK and P84/S-PEEK are tailored to
achieve fibre with high charge density and mechanical stability. The sulphonic
functional groups of S-PEEK, which are ionized over a wide range of pH,
generate high electroosmotic flow.
Results and conclusions
The produced fibres have outer diameters ranging from 400 to 1000 micron,
small bores up to 60 micron and sizes of the pores from 0.5 to 15 micron. The

performance of fibers is analyzed and compared with commercially available
CEC columns in a home-built CEC set-up enabling testing of fibers with various
diameters and lengths. The characteristics of the polymeric fibers are not inferior
to the current stationary phases introduced into fused silica. This, together with
the ease and low cost of fabrication makes the polymer fiber competitive to the
silica capillary and allows scaling up of the separation process into massively
parallelized fashion.

Hybrid and Novel Processes II – 6
Thursday July 17, 5:00 PM-5:30 PM, Kaua’i
Chitosan Chiral Ligand Exchange Membranes for Sorption Resolution of
Amino Acids
H. Wang, Sichuan University, Sichuan, China
L. Chu (Speaker), Sichuan University, Sichuan, China - chuly@scu.edu.cn
R. Xie, Sichuan University, Sichuan, China
C. Niu, University of Saskatchewan, Saskatoon, Canada
M. Yang, Sichuan University, Sichuan, China
H. Song, Sichuan University, Sichuan, China
The concept of chiral ligand exchange is employed in the present study to
achieve the chiral resolution of tryptophan (Trp) enantiomers by using chitosan
(CS) membrane in a sorption resolution mode and copper(II) ion as the
complexing ion. CS porous membranes are prepared by freeze-drying method
(CS-LT) and sol-gel process at high temperature (CS-HT) respectively to
investigate their sorption resolution characteristics. The proposed CS chiral
ligand exchange membranes exhibit good chiral resolution capability. Meanwhile
the sorption selectivity of the CS membranes is found to be reversed from Lselectivity
at low copper(II) ion concentration to D-selectivity at high copper(II) ion
concentration, which is attributable to the competition between the copper(II)-Trp
complex behavior on the CS membrane and in the bulk solution as well as the
stability difference between the copper(II)-L-Trp and copper(II)-D-Trp complexes.
Moreover, the CS-HT membrane shows better performance with respect to both
sorption selectivity and sorption capability than the CS-LT membrane, which is
resulted from its more amorphous structures compared with the more crystalline
structures of the CS-LT membrane.

Membrane Fouling III - RO & Biofouling – 1 – Keynote
Thursday July 17, 2:15 PM-3:00 PM, Maui
Biofouling of Spiral Wound Nanofiltration and Reverse Osmosis
Membranes: A Feed Spacer Problem
J. Vrouwenvelder (Speaker), Wetsus, Delft University of Technology, Delft, The Netherlands -
hans.vrouwenvelder@wetsus.nl
D. Graf von der Schulenburg, University of Cambridge, Cambridge, United Kingdom
J. Kruithof, Wetsus Centre of Excellence for Sustainable Water Technology, Leeuwarden, The
Netherlands
M. Johns, University of Cambridge, Cambridge, United Kingdom
M. Van Loosdrecht, Delft University of Technology, Delft, The Netherlands
Biofouling - growth of biomass, i.e. biofilms - is a major fouling type in
nanofiltration and reverse osmosis membrane systems. Biofouling increases the
pressure drop, thereby increasing the process costs [1,2]. In spiral wound
membrane elements, two types of pressure drops can be discriminated: the feed
spacer channel pressure drop and the trans membrane pressure drop. The trans
membrane pressure drop is related to the membrane flux (permeation rate).
The objective of this study was to determine (i) the effect of biofouling on the feed
spacer channel pressure drop and trans membrane pressure drop and (ii) the
role of feed spacer on the pressure drop.
The development of feed spacer channel pressure drop and biofouling was
investigated with monitors (named membrane fouling simulators [3]), single
membrane element test rigs, a pilot and a full scale membrane filtration
installation, operated with NF and RO membranes with and without permeate
production. Additionally, the development of pressure drop and biofouling was
determined in monitors without feed spacer. The feed water used for the
laboratory studies was tap water with or/and without dosage of biodegradable
compounds to stimulate biofouling. The development of fouling was monitored by
(i) the pressure drop, (ii) in-situ real-time non- destructive observations such as
nuclear magnetic resonance (NMR [4]) and using the sight glass of the
membrane fouling simulator and (iii) analysis of coupons sampled from the
monitor or membrane modules. The parameters determined were adenosine
triphosphate (ATP), total direct cell counts and total organic carbon (TOC).
Biofilm accumulation affected the feed spacer channel pressure drop without
influencing the trans membrane pressure. The same feed channel pressure drop
development in time was observed in nanofiltration and reverse osmosis
membrane modules. Apparently, the membrane type was not influencing
biofouling development. From the observations it can be concluded that the
pressure drop increase due to biofouling is a feed spacer problem. This

conclusion is based on (i) in-situ observations on the fouling accumulation and
velocity distribution profiles using NMR, (ii) in-situ visual observations on the
fouling accumulation using the monitor sight glass and (iii) the development of
pressure drop and biomass in monitors with and without feed spacer.
In summary, biofouling is a feed spacer problem. The membrane fouling
simulator in combination with NMR measurements are suitable measurement
tools for in-situ, real-time and non-destructive studies of the biofouling formation
process in nanofiltration and reverse osmosis membranes. Biofouling research
should be focused on the feed spacer (channel) so that biomass accumulation
has low(er) impact on the feed channel pressure drop.
Literature
[1] Ridgway, H.F. (2003). Biological fouling of separation membranes used in water treatment
applications, AWWA research foundation.
[2] Characklis, W.G., Marshall, K.C. (1990) Biofilms. John Wiley & Sons, New York.
[3] Vrouwenvelder, J.S. van Paassen, J.A.M., Wessels, L.P., van Dam A.F., Bakker, S.M. (2006).
The Membrane Fouling Simulator: a practical tool for fouling prediction and control. Journal of
Membrane Science. 281, 316- 324.
[4] Graf von der Schulenburg, D.A., Vrouwenvelder, J.S., Creber, S.A., Van Loosdrecht, M.C.M.,
Gladden L.F., Johns, M.L. (to be submitted). Nuclear Magnetic Resonance microscopy studies of
membrane biofouling.

Membrane Fouling III - RO & Biofouling – 2
Thursday July 17, 3:00 PM-3:30 PM, Maui
Microbial-Sensing Membranes Functionalized with a Temperature Sensitive
Polymer Film
C. Gorey (Speaker), University of Toledo, Toldeo, Ohio, USA - cgorey50@yahoo.com
I. Escobar, University of Toledo, Toldeo, Ohio, USA
C. Gruden, University of Toledo, Toledo, Ohio, USA
The presence of microorganisms in feed water can further exacerbate fouling
due to the accumulation of microorganisms onto the membrane surface and on
the feed spacer between the envelopes, or biofouling. Microorganisms
transported to the membrane element can attach to the feed side of the
membrane and the spacer. Attachment depends on Van der Waals forces,
hydrophobic interactions and electrostatic interactions between the
microorganisms and the surface. Biofouling control has been attempted via
biocide additions; however, while a biocide may kill the biofilm organisms, it
usually will not remove the biofouling layer, and may cause bacteria that survive
disinfection to potentially become more resistant. Therefore, bacterial detection is
essential in determining biofouling potential. In situ detection of bacteria in
membrane-based water treatment systems is critical since biofouling can
significantly impact membrane efficiency. Moreover, there is a keen interest in
tracking and eliminating potential pathogens in these systems. With very few
exceptions, techniques for specific detection of bacteria in aqueous systems are
based on membrane filtration followed by culturing and phylogenetic or functional
analysis. Direct detection strategies, which eliminate the bias introduced in
culture-based methods, are gaining in popularity. Biorecognition molecules have
been designed to label characteristic artifacts (e.g., exocellular proteins, fatty
acids) and genomic material (e.g., nucleic acids). Methods based on the
detection of antibodies against microbial specific exocellular proteins (antigens)
are characterized by their simplicity, rapid response, and financial viability. For
specific detection, antibodies (Ab) can be immobilized on surfaces for
immunocapture of target bacterial species and subsequent separation of the
target species from complex matrices. Antibodies have been applied to target a
wide range of bacteria in various sample types including natural waters and
sediments. Support media for antibody-based sensors have included the
surfaces of magnetic beads, microplates, and glass slides. We propose to
produce a fouling-resistant membrane by attaching a stimuli-responsive polymer
film on the surface, which offers the potential to collapse or expand the polymer
film. The phase change arises from the existence of a lower critical solution
temperature (LCST) such that the polymer precipitates from solution as the
temperature is increased. This temperature is determined to be where the mass
is changing the fastest. This capability can be exploited to control

adsorption/desorption. We then will use the polymer film to act as the support
medium for bacterial sensing. To our knowledge, this is the first application of
conjugated polymers attached to membranes for bacterial sensing. While this
project will focus on developing fouling resistant membranes with in-situ bacterial
sensing, this technology can easily be translated to small membrane coupons.
The polymers being studied for this application are Hydroxypropyl Cellulose and
N-Isopropylacrylamide and have LCSTs in a usable temperature range.
Attachment to the Cellulose Acetate surface has been studied using a Primary
method, which involves building the film from the surface. The latest method we
have been attempting deals with the Secondary method, this synthesis works by
building the film first and then attaching it to the surface. Wetcell Atomic Force
Microscopy allows us the image the surface and do roughness analysis while
under different temperatures in an aqueous environment. This means we can
detect how rough the surface is at the low temperatures, where the film should
be extended; and at high temperatures, where the film should be collapsed. The
method of immunocapture uses antibodies and we attach those antibodies using
a carbodiimide acting as a zero-length linker to connect a hydroxyl group from
the HPC to the carboxyl group on the antibody. So far only work has been done
with HPC in this area. Exposure of the completely modified membrane to
bacteria has yielded successful capture of said bacteria which can be visualized
using fluorescence.

Membrane Fouling III - RO & Biofouling – 3
Thursday July 17, 3:30 PM-4:00 PM, Maui
Modification of Microfiltration Membranes: Implications for Biofouling, Flux
Recovery and Antibacterial Properties
R. Malaisamy (Speaker), Howard University, Washington, District of Columbia, USA -
malaisamy@gmail.com
D. Berry, University of Michigan, Ann Arbor, Michigan, USA
D. Holder, University of Michigan, Ann Arbor, Michigan, USA
L. Raskin, University of Michigan, Ann Arbor, Michigan, USA
L. Lepak, Cornell University, Ithaca, New York, USA
K. Jones, Howard University, Washington, District of Columbia, USA
Biofouling remains one of the most problematic issues surrounding membrane
based water treatment processes. Biofouling is likely to occur whenever
microorganisms are present in the feedwater. It is difficult to remove all
microorganisms prior to membrane filtration, and disinfectants have been shown
to deteriorate many membrane surfaces. A lot of research has been performed
on modifying membrane surfaces to prevent organic, inorganic and colloidal
fouling, however research on membrane modification for prevention of biofouling
is rather limited. We grafted an antibacterial quaternary ammonium acrylic
polymer onto polyethersulfone (PES) microfiltration membranes. A quaternary
salt of acrylic acid derivative, [2-(Acryloyloxy)ethyl]trimethylammonium chloride
(AETMA) was taken and the polymerization on the membrane surface was
carried out under a high energy UV radiation. We confirmed the chemical
modification on the membrane using ATR FT-IR spectroscopy by identifying a
peak at 1730 cm-1 corresponding to the carbonyl group of the co-polymer. The
degree of grafting was found to be proportional to the monomer concentration
and the time of irradiation. The streaming potential measurements showed that
the surface charge of the parent membrane was reversed from negative to
positive and the absolute value of zeta potential was almost constant irrespective
of the degree of modification. The water contact angle values reduced gradually
when the degree of grafting increased, showing that the membranes become
more and more hydrophilic. The permeability and pure water flux declined
proportionate to the degree of grafting and the scanning electron microscopic
pictures illustrated that the surface of the membrane and pores were covered by
the co-polymer that caused the flux decline. When the unmodified membranes
during filtration were subjected to a pure culture of Escherichia coli as the model
foulant, the permeate flux declined rapidly to about 30% of the initial flux, and
was recovered only to 70% upon hydraulic cleaning and completely recovered
only after chemical cleaning. For the modified membranes, the permeability
declined gradually as the degree of grafting increased. However, during filtration
with the E. coli suspension, the modified membranes did not undergo any flux
decline (irrespective of the degree of grafting), and the flux increased over 100%

after cleaning. Both hydraulic and chemical cleaning resulted in an unexpectedly
large flux improvement. In order to determine whether or not the modification
changed the basic membranes structure, both morphological and surface
characterizations by FTIR were conducted and the results confirmed the stability
of the co-polymer. Measuring the contact angle showed an improvement in
hydrophilicity after the fouling studies, which may have caused the flux
improvement. Another objective of this study was to accomplish lysis of bacterial
cells to further reduce the likelihood of bacterial growth on the membranes.
Fluorescence microscopic investigations showed that interactions on the surface
of the AETMA modified membrane surface damaged the bacterial cells. These
AETMA modified PES membranes when compared with acrylic acid modified
ones with the same extent of modification, perform better in terms of permeate
flux, recovery, and anti-bacterial activity.

Membrane Fouling III - RO & Biofouling – 4
Thursday July 17, 4:00 PM-4:30 PM, Maui
Role of Seawater Chemistry in Algal Biopolymer Fouling of Seawater RO
Membranes
X. Jin (Speaker), University of California Los Angeles, Los Angeles, California, USA -
jinxuesky@ucla.edu
E. Hoek, University of California Los Angeles, Los Angeles, California, USA
A major fouling concern in seawater reverse osmosis (SWRO) plants is the
increased biomass generated during algal blooms. Algae, bacteria, and their
exudates are present in high concentrations, and thus, have the potential to foul
RO membranes. Although, membrane fouling by colloids and dissolved organics
has been studied extensively for brackish and wastewater applications, fouling
behavior may be very different in seawater due to the high ionic strength and
suppression of electrical double layer interactions. We hypothesize that short-
range interfacial interactions will play a critical role in determining the rate and
extent of SWRO membrane fouling and that seawater chemistry will strongly
impact foulant-membrane interfacial interactions. As a first step towards
understanding the role of seawater chemistry in SWRO membrane fouling, we
have conducted a study of SWRO membrane fouling by algal biopolymers.
Commercially available SWRO membranes - FilmTec SWHR (Dow Chemicals,
Minneapolis, MN) and SWC3+ (Hydranautics, Oceanside, CA) - are used as
model SWRO membranes. The two membranes were selected because they
represent a relatively hydrophobic, rough membrane with significant carboxylic
acid functionality at its interface (Hydranautics SWC3+) and a relatively
hydrophilic, smooth membrane with relatively little carboxylic acid functionality at
its interface (FilmTec SWHR). The former is expected to be more fouling prone
due to attractive acid-base interactions and its rough, carboxylic acid rich
interface. The latter membrane is expected to be relatively resistant to fouling
due to repulsive acid-base interactions and its relatively smooth, non-
carboxylated interface.
Accelerated fouling experiments are carried out in a bench-scale SWRO
simulator with 6 parallel flat-sheet membrane cells. Alginic acid - an acidic
hetero-polysaccharide excreted by Brown algae - is spiked into synthetic
seawater solutions with constant total dissolved solid (TDS) concentrations of 32
g/L, but varied concentrations of major cations (e.g., sodium, magnesium,
calcium). In addition, a real seawater matrix (Instant Ocean®) was also
evaluated. Water flux and conductivity rejection are tracked with time. At the end
of fouling experiments, cleaning is performed first using laboratory de-ionized
(DI) water, followed by a 5 mM EDTA solution adjusted to pH 11 by NaOH

addition. Extensive characterization of clean and fouled membranes and alginic
acid are performed to evaluate material compositions, functionalities,
physicochemical properties, and alginate-membrane interfacial interactions.
Results from fouling experiments confirm that specific ions present in seawater
dramatically impact the rate, extent, and reversibility of flux decline. Alginic acid
does not cause much membrane fouling in NaCl solutions with pH of 6, whereas
it causes significant fouling in the real seawater matrix adjusted to pH 6. In
addition, there is significant fouling in NaCl solutions spiked with divalent cations
(Mg 2+ and Ca 2+ ) at concentrations identical to those in real seawater. However,
the effect of Ca 2+ on flux decline is much more pronounced than that of Mg 2+ .
The initial rates of flux decline (dJ/dt) for both membranes decrease as: pure
NaCl > Instant Ocean, pH6 > NaCl + MgCl 2 > NaCl + CaCl 2 . Physicochemical
characterization reveals the interfacial free energy of adhesion between both
membranes and alginic acid follow the same order of decline: pure NaCl >
Instant Ocean, pH6 > NaCl + MgCl 2 > NaCl + CaCl 2 , where a higher free energy
indicates smaller propensity for adhesion (or greater fouling resistance). In all
solution chemistries, SWC3+ appears more fouling prone than SWHR because
of its more hydrophobic, rough surface, which produces attractive interfacial
interactions.
Flux decline due to alginate fouling in the absence of Ca 2+ ions is almost
completely reversible using only DI water; however, DI water is almost
completely ineffective at recovering the initial flux if Ca 2+ ions are present.
Cleaning with an alkaline EDTA solution almost completely recovers the initial
flux, thus providing more evidence for the specificity of calcium-mediated fouling.
For the membrane samples fouled in the real seawater matrix, permeate flux is
poorly recovered after cleaning even when EDTA is employed, suggesting that
the more complex composition of seawater produces a more complex fouling
problem. In all cases, the initial flux of SWHR is more completely recovered by
cleaning than that of SWC3+. We believe this is due to its PVA coating, which
reduces calcium-carboxylate complex formation between alginate and the
polyamide material.

Membrane Fouling III - RO & Biofouling – 5
Thursday July 17, 4:30 PM-5:00 PM, Maui
Effect of surface charge and pH on fouling and critical flux of MF
membranes during protein filtration
Jochen Meier-Haack (Speaker), Leibniz Institute of Polymer Research Dresden, Dresden,
Germany - mhaack@ipfdd.de
Although subject to research for decades, fouling is still one of the major limiting
factors in membrane applications. Numerous methods have been suggested to
overcome this drawback, like crossflow filtration, backflushing, air sparging, all of
them in combination with chemical cleaning. However many of these techniques
imply off-production cycles, resulting in lower yield, shorter life-time of
membranes and therefore higher costs. In the mid-nineties Field et al. introduced
the concept of the -critical flux [1, 2] and which has been subject of a review
recently [3]. It defines a permeate flux below a critical value - the critical flux -
where no irreversible fouling occurs. The critical flux is determined by several
factors including hydrodynamic forces introduced by the crossflow velocity and
the transmembrane pressure, electrostatic interaction between feed components
and the membrane surface and others [3]. Although mainly important for large
molecules, we have focused our work on the effect of surface charges on fouling
and critical flux.
In static (non-filtration) adsorption experiments we observed a strongly reduced
protein adsorption at the surface in the case of repulsive electrostatic forces
between the membrane surface and feed components and vice-versa [4]. The
same effect was reported in dead-filtration using surface modified MFmembranes
[5]. We now extended our investigations on the effect of surface
modification on the critical flux. Surface modified microporous PP membranes
were obtained by grafting polyacrylic acid onto the surface using a so-called
macroinitiator [6, 7]. These modified membranes showed a strong influence of
pH on the filtration properties (stimuli-response membranes). The surface charge
was reversed by adsorption of a polycation (PDADMAC) onto the graft-layer.
Although the total amount of modificator on the membrane surface was
increased, a slight flux enhancement (at constant pressure) was observed
compared to the "one-layer" membrane. Simultaneously the response on pH
change was reduced dramatically, but still observable. Upon the adsorption of a
third polyelectrolyte layer (PAAc) the response to pH change was recovered to a
small extent while the permeate flux at constant pressure was unchanged (20
l/m 2 h at 1 bar) compared to the two-layer membrane. The surface modification
along with the introduction of surface charges has also a strong effect on the
critical flux. While for the unmodified membrane a critical flux of 20 l/m 2 h was

detected, this value increased with increasing number of polyelectrolyte layers
adsorbed to the membrane surface in the case when the feed components (here
bovine serum albumin) and the surface are equally charged (repulsive
electrostatic forces). For a three-layer membrane (PAAc/PDADMAC/PAAc) a
critical flux > 60 l/m2h was determined. In the case of attractive electrostatic
forces a dramatic fouling was observed.
[1] R. W. Field; D. Wu; J. A. Howell; B. B.Gupta; J. Membr. Sci. 100, 259 (1995)
[2] J. A: Howell; J: Membr. Sci. 107, 165 (1995)
[3] P. Bacchin, P. Aimar, R. W. Field; J. Membr. Sci. 281, 42 (2006)
[4] M. Müller et al.; Macromol. Rapid Commun. 19, 333 (1998)
[5] T. Rieser et al.; ACS Symposium Series 744, Edts. I. Pinnau. B. D. Freeman; ACS,
Washington (1999), p. 189
[6] T. Carroll, N. A. Booker, J. Meier-Haack; J. Membr. Sci. 203, 3 (2002) [7] J. Meier-Haack, S:
Derenko, J. Seng; Sep. Sci. Technol. 42, 2881 (2007)

Membrane Fouling III - RO & Biofouling – 6
Thursday July 17, 5:00 PM-5:30 PM, Maui
Synthesis and Evaluation of Novel Biocidal Coatings to Reduce Biofouling
on Reverse Osmosis Membranes
M. Hibbs (Speaker), Sandia National Laboratories, Albuquerque, New Mexico, USA -
mhibbs@sandia.gov
C. Cornelius, Virginia Poytechnic Institute and State University, Blacksburg, Virginia, USA
L. McGrath, Sandia National Laboratories, Albuquerque, New Mexico, USA
S. Altman, Sandia National Laboratories, Albuquerque, New Mexico, USA
S. Kang, Yale University, New Haven Connecticut, USA
A. Adout, Yale University, New Haven Connecticut, USA
M. Elimelech, Yale University, New Haven Connecticut, USA
Reverse osmosis (RO) is a membrane-based separation process that is
commonly used in industrial applications such as desalination and waste-water
treatment. The major problems associated with membrane-based separation
processes include fouling and high pressure loss, which decrease the efficiency
of the filtration while increasing operation costs. Quaternary ammonium
compounds (QACs) are among the most widely used antibacterial agents and
polymers containing ammonium salts have been shown to possess enhanced
antibacterial activity with reduced toxicity and prolonged lifetimes. An RO
membrane coated with such a polymer should prove resistant to biofouling and
thus more efficient over its useful lifetime.
Novel ionomers have been prepared from a poly(arylene ether sulfone) with
benzyl trialkylammonium groups randomly attached in a postpolymerization step.
The alkyl chain lengths were varied among the different ionomers because this
has been reported to be a crucial factor in establishing the biocidal activity of
QACs. All of the polymers were soluble in alcohols with the aid of a surfactant
and, unlike most polymers with quaternary ammonium groups, they were
insoluble in water. However, they were hydrophilic and swelled in water, key
features which allowed water to pass through them. The polymer solutions could
be sprayed onto RO membranes to form thin coatings. Contact angle, streaming
potential, and AFM interaction forces were measured for the coated surfaces.
Testing for cell adhesion and antibacterial properties with E. coli showed that all
of the coatings had significant biotoxicity. Results from accelerated biofouling
tests in a cross-flow RO system will also be discussed.
Sandia is a multi-program laboratory operated by Sandia Corporation, a Lockheed Martin
Company, for the United States Department of Energy under Contract DE-ACO4-94AL85000.

Pervaporation and Vapor Permeation II – 1 – Keynote
Thursday July 17, 2:15 PM-3:00 PM, Moloka’i
Aromatics Control in Refining with Pervaporation
R. Harding, W.R. Grace & Co.-Conn., Columbia, Maryland, USA
L. White (Speaker), W.R. Grace & Co.-Conn., Columbia, Maryland, USA -
lloyd.s.white@grace.com
Benzene, toluene, and xylenes (BTX) are commodity chemicals produced in
large volumes at refineries. Benzene, however, attracts regulatory interest due to
a carcinogenic nature and also has numerous other unique chemical properties.
We have seen that these aromatics (BTX) can interact strongly with
pervaporation membranes. Given that aromatic selective membranes can
selectively transport even low levels of benzene in pervaporation mode, Grace
has been able to demonstrate that benzene levels can easily be reduced to less
than 0.2% in refinery process streams. These new aromatic selective
membranes, part of the Aromem(TM) class, are being applied to real world
refining streams to selectively control benzene levels. This class of membranes,
built upon the S-Brane(TM) technology platform, is ready for commercial testing.
S-Brane and Aromem are trademarks of W.R. Grace.

Pervaporation and Vapor Permeation II – 2
Thursday July 17, 3:00 PM-3:30 PM, Moloka’i
Membrane Based Liquid Fuels Desulfurization Process for Point-of-Use
Applications
D. Aagesen (Speaker), Intelligent Energy Inc., Long Beach, California, USA -
diane.aagesen@intelligent-energy.com
D. Swamy, Intelligent Energy Inc., Long Beach, California, USA
In order to address the growing concern over sulfur oxides and particulate matter
emissions that adversely affect the environment and human health, Intelligent
Energy (IE) has recently developed a unique fuel desulfurization technology. The
process uses a polyimide membrane to fractionate fuels in a slip-stream point-ofuse
process. This technology can be applied to pre-treat fuels used by
transportation equipment such as locomotives, large ships and other off-road
equipment. The technology has the potential to significantly reduce pollutants
thus directly improving the quality of life for nearly 25 percent of the world’s
population. Furthermore, the technology can be used for the removal of
dibenzothiophene and heavier refractory sulfur compounds from logistic fuels
when placed upstream of adsorbent beds integrated with fuel cell auxiliary power
units (APU). This leads to increased sorbent capacity and life.
This paper discusses the process configuration, engineering aspects, test data
results from feedstock including Jet A, JP5, marine diesel oil (MDO) and
highlights the commercial drivers and applications for the point-of-use system.
Typical flux rates for the fuels tested ranged between 1-2kg/hr-m 2 with sulfur
reduction between 40-80% when stage-cuts (fraction of feed passed through the
membrane) of 5-20% are obtained. The parasitic power requirement of the
process can vary between 1-3% of the heating value of the cleaned fuel.

Pervaporation and Vapor Permeation II – 3
Thursday July 17, 3:30 PM-4:00 PM, Moloka’i
Ion-containing Polyimide Membranes: A Way of Overcoming the Trade-off
Permeability in Pervaporation ?
A. Jonquieres (Speaker), Nancy Universite, France - Anne.Jonquieres@ensic.inpl-nancy.fr
M. Awkal, Nancy Universite, France
R. Clement, Nancy Universite, France
P. Lochon, Nancy Universite, France
Two international patents [1,2] and also recent results [3] have shown that
polymeric membranes containing cationic groups are highly efficient for the
removal of protic species (e.g. alcohols) from organic mixtures by pervaporation,
with an important potential application for the purification of ethyl-tert-butyl ether
(ETBE). By appropriate fiscal privileges for the past ten years, the European
Union has been strongly inciting the large production of this alkyl ether from
agricultural ethanol. Thanks to its specific advantages and its much better
biodegradability than methyl-tert- butyl ether (MTBE), ETBE is currently
considered as one of the most promising bio-fuels [4,5]. Nevertheless, its
industrial synthesis process leads to an azeotropic mixture containing 20 wt % of
ethanol which has to be removed for ETBE purification. If the former polymer
membranes were well performing for this separation, the rather poor control of
their chemical structure did not allow any detailed analysis about the influence of
the cationic sites on their permeability.
Taking advantage of our former experience on polyimide copolymers for this
separation [6], we recently developed the synthesis and characterization of 3
families of new ion-containing polyimide copolymers, with a control of the number
of their cationic ammonium groups, the length of their alkyl side chain and the
type of their counter- ions [7,8]. In this new communication, the membranes
features of the 3 copolymer families will be discussed in terms of structureproperty
relationships on the basis of sorption and pervaporation results obtained
for the separation of the azeotropic mixture EtOH/ETBE. In particular, it will be
shown how simply changing the chemical structure of the cationic groups
enabled to increase sharply permeability with a very low impact on selectivity,
therefore overcoming the usual trade- off permeability/selectivity.
[1] H. Steinhauser, H. Brüschke, European Patent 0674940 B1 (1995).
[2] H. Steinhauser, H. Brüschke, US Patent 5,700,374 (1997).
[3] S. Touchal, D. Roizard, L. Perrin, Journal of Applied Polymer Science, Vol. 99 (2006) 3622.

[4] H. Noureddini, Book of Abstracts, 219th ACS National Meeting, San Francisco, CA, March 26-
30, 2000.
[5] R. Koenen, W. Puettmann, Grundwasser, Vol. 10 (2005) 227.
[6] A. Jonquieres, R. Clément, P. Lochon, Progress in Polymer Science, Vol. 27 (2002) 1803.
(review)
[7] M. Awkal, A. Jonquières, G. Creffier, R. Clément, P. Lochon, Macromolecules, Vol. 37 (2004),
684.
[8] M. Awkal, A. Jonquières, R. Clément, P. Lochon, Polymer, Vol. 47 (2006), 5724.

Pervaporation and Vapor Permeation II – 4
Thursday July 17, 4:00 PM-4:30 PM, Moloka’i
Study of the Effect of Framework Substitution on the Pervaporation of
Xylene Isomers through MFI-type Zeolite Membranes
J. O'Brien-Abraham (Speaker), Arizona State University, Tempe, Arizona, USA
J. Lin, Arizona State University, Tempe, Arizona, USA - jerry.lin@asu.edu
Changing conventional xylene separation techniques such as extractive or
azeotrophic distillation to continuous membrane processes has been the focus of
much research in recent years. Specifically, the use of pervaporation to efficiently
separate p-xylene (PX) from its isomers o-xylene and m-xylene (OX, MX) has
gained significant attention. The success of such technology will rely on the
ability of the membrane to provide significant flux and selectivity as well as good
thermal and chemical stability under desired operating conditions. Molecular
sieving inorganic membranes such as MFI-type zeolite show promise for this
application. MFI-type zeolite membranes possess a microporous structure
consisting of sinusoidal, elliptical channels (0.51 x 0.54 nm) interconnected with
straight, circular channels (0.54 x 0.56 nm). Apertures of these sizes suggest that
the membranes should be able to separate xylene isomers based solely on size
selectivity given that PX is the only isomer small enough to enter the zeolite
pores. However, for pervaporation applications saturated feed-side coverages
cause high adsorption loadings of the MFI crystals. Under these conditions, the
zeolite framework molecules shift to accommodate an entropically favorable
packing of the PX molecules which leads to overall distortion of the MFI pores.
This distortion allows for OX to be able to enter the pore structure causing
competitive adsorption between the isomers. Ultimately, these PX-framework
and PX-OX interactions reduce the ability of the membrane to separate the
isomers via size selectivity. Our findings show that membrane performance is
highly dependent on the relative concentration of isomers in the feed; the higher
the PX concentration the lower the selectivity observed. Although high selectivity
(~18) was observed at low PX concentration in the feed, it was not stable over
time. The focus of this work is to use membranes with isomorphously substituted
framework atoms in order to induce differences in both adsorption properties and
membrane microstructure. Specifically, the metal ion Boron (B) was substituted
into the MFI framework for Si. Boron was chosen because of its smaller size
(relative to Si) which causes a reduction in the unit cell volume; it is speculated
that this may induce some structural rigidity preventing the above mentioned
affect of framework distortion at high PX loadings. Additionally, because B is a
trivalent atom its presence in the microstructure will introduce acid sites that can
affect the membrane adsorption properties. B-ZSM5 membranes were
synthesized utilizing templated seeded growth methods and characterized via xray
diffraction (XRD) and scanning electron microscopy (SEM). Single and multi-

component (PX, OX) separation via pervaporation was performed at room
temperature under a variety of feed compositions on both silicalite and B-ZSM5
membranes to evaluate to effectiveness of the substituted B in reducing the
affects of framework flexibility and competitive adsorption at high loadings of PX.

Pervaporation and Vapor Permeation II – 5
Thursday July 17, 4:30 PM-5:00 PM, Moloka’i
On the Unusual Transport Phenomena of Vapours in Amorphous Glassy
Perfluoropolymer Membranes with High Fractional Free Volume
K. Friess, Institute of Chemical Technology, Prague, Czech Republic
J. Jansen (Speaker), Institute on Membrane Technology, Rende, Italy - jc.jansen@itm.cnr.it
E. Tocci, Institute on Membrane Technology, Rende, Italy
E. Drioli, Institute on Membrane Technology, Rende, Italy
In this paper the gas and vapour transport through four different high fractional
free volume amorphous glassy perfluoropolymers is studied. The idea of the
paper is to correlate the experimental transport parameters with the fractional
free volume (FFV) and with the molecular properties and activity of the different
penetrants. In particular, the scope of the work is to fit our results with commonly
used correlations, e.g. between the diffusion coefficient and the penetrant’s
critical volume, and to study how these correlations change for chemically
different species, which undergo for instance clustering and hydrogen- bonding,
or for sterically different penetrants.
Amorphous glassy perfluoropolymers are known for their good film forming
properties, high thermal and chemical stability, low tendency to swelling,
insolubility in common organic solvents and their strong hydrophobic character.
All such properties make them interesting for wet gas treatment where
conventional polymers might suffer from plasticization by condensable species or
chemical attach in corrosive environment. In spite of the low swelling, these
polymers are nevertheless remarkably permeable to some organic vapours
because of the high interconnected FFV, and therefore they have a certain
potential for specific organic-organic separations, reason for the present study.
Samples of flat membranes from copolymers of 2,2- bis(trifluoromethyl)-4,5difluoro-1,3-dioxole
with tetrafluoroethylene (Teflon AF®) and 2,2,4- trifluoro-5trifluorometoxy-1,3-dioxole
with tetrafluoroethylene (Hyflon® AD) were prepared
by solution casting, using 1-methoxy- nonafluorobutane as the solvent [1].
Samples were left overnight to allow slow evaporation of most of the solvent and
the films were further dried in a vacuum oven.
The permeability of the membranes was tested at 25°C in a fixed volumepressure
increase instrument for a series of different gases and vapours. The
diffusion coefficients of the penetrants were determined from the transient
behaviour (time lag method) and the permeability was calculated from the steady
state pressure increase rate. Assuming the validity of the solution-diffusion
model, the solubility was determined indirectly by the simple relation S=P/D.

Generally these results were in good agreement with the literature data
determined mostly by sorption measurements [2-4].
A log-log plot of the diffusion coefficient vs. critical volume of the penetrant
showed the commonly observed linear relationship for permanent gases and
linear hydrocarbons. However, large differences were found between the trends
of dissimilar species in molecular shape (e.g. linear vs. branched or ring
structures) or in molecular interactions (e.g. inert molecules vs. polar or hydrogen
bonding species which may exhibit clustering [4]). For instance, n-alcohols show
a similar trend as n- alkanes, but their diffusion is nearly half an order of
magnitude slower than that of alkanes with a comparable critical volume, or it is
similar to alkanes which have nearly twice their crucial volume. Similarly,
cyclohexane diffusion is over two orders of magnitude slower than hexane
diffusion and MTBE is 200 times slower than diethylether. The anomalous
behaviour of the lower alcohols is further illustrated by the highly unusual
transient in the methanol and ethanol permeation curves, suggesting the
presence of multiple diffusion coefficients.
The experimental results were discussed in terms of the penetrant’s molecular
properties and the free volume of the polymers. For this purpose the free volume
of the two Hyflon samples was studied by molecular dynamics (MD) simulations.
Several independent atomistic bulk models were constructed for each sample
and the cavity size distribution was investigated by the particle insertion grid
method [5]. It will be shown that the molecular modelling approach offers
important insight in the possible behaviour of the penetrants in the free volume
elements of the polymer.
References
1. M. Macchione, J.C. Jansen, G. De Luca, E. Tocci, M. Longeri and E. Drioli, Polymer 48 (2007)
2619-2635.
2. R.S. Prabhakar, B.D. Freeman, I. Roman, Macromolecules 2004, 37, 7688-7697.
3. A.Yu. Alentiev, Yu. P. Yampolskii, V.P. Shantarovich, S.N. Nemser, J. Membr. Sci 126 (1997)
123-132.
4. A. Tokarev, K. Friess, J. Machková, M. `ípek, Yu. Yampolskii, J. Polym. Sci. Part B, 44 (2006)
832-844.
5. D. Hoffmann, M. Heuchel, Yu. Yampolskii, V. Khotimskii, V. Shantarovich, Macromolecules, 35
(2002) 2129.

Pervaporation and Vapor Permeation II – 6
Thursday July 17, 5:00 PM-5:30 PM, Moloka’i
Pervaporation Performance of PDMS-grafted Aromatic Polyamide
Membrane Exhibiting High Durability and Processability
C. Yun (Speaker), Tokai University, Kanagawa, Japan
Y. Nagase, Tokai University, Kanagawa, Japan - yunagase@keyaki.cc.u-tokai.ac.jp
Pervaporation is a promising membrane technique for the removal of organic
molecules from their aqueous solutions. In earlier investigations, the
pervaporation process was applied to separate alcohol by water-selective
permeation through membranes, which has been already used in industries.
However, it is more practical to separate alcohol by using an alcohol-
permselective membrane, because alcohol is a minor component in the
fermentation product. Furthermore, if a practical organic-permselective
membrane is obtained, the pervaporation technique is expected to be an efficient
method for the removal or the recovery of organic components from waste fluid
or industrial drainage. To achieve the selective permeation of organic
components in the pervaporation of aqueous solutions of organic liquids, it is
very important to enhance the solubility of alcohol over water in a polymer
membrane because of the higher diffusivity of water as compared with alcohol. In
addition, the durability of the membrane against several organic solvents is more
important, because the organic component was concentrated in the inert of the
membrane during the permeation. A crosslinked polydimethylsiloxane (PDMS)
membrane, has been known to show a selective permeation of alcohol at the
pervaporation of an aqueous alcohol solution. Such a separation property of
PDMS membrane is due to the high hydrophobicity of the membrane surface and
the high permeability of vapors through the membrane. However, it is not a
practical membrane because an ultrathin membrane to achieve a high flux
cannot be prepared from the crosslinked material. Therefore, we have prepared
some soluble PDMS- grafted copolymers having a rigid backbone component
that showed an improved mechanical property and organic-permselectivity. In
our previous work, we have developed a siloxane-grafted polyamide (PA-g-
PDMS) by the polycondensation of 3,5-bis(4-aminophenoxy)benzyloxypropyl-
terminated polydimethylsiloxane (BAPB- PDMS) and terephthaloyl chloride,
which exhibited a high organic permselectivity in the pervaporation of aqueous
organic liquid solutions with a stable permeation. However, in the case of PA-g-
PDMS, when the reprecipitated polymers were filtered and dried in vacuo, they
became insoluble in all solvents. In other words, this membrane possessed poor
processability due to the chemical structure of the backbone component. In this
study, a chemical modification of the main chain structure of PDMS- grafted
polyamide has been investigated to enhance the processability of the copolymer,
with maintaining the durability to organic components. For this purpose, the

introduction of methyl groups into the main chain polyamide component was
carried out, in which a new macromonomer, 3,5-bis(4-amino-3-
methylphenoxy)benzyloxypropyl- terminated polydimethylsiloxane (BAMPB-
PDMS) was synthesized instead of BAPB- PDMS. Generally, it has been known
that the introduction of alkyl group into aromatic polyamides could achieve the
improvement of their solubility. The polycondensation of BAMPB-PDMS with
terephthaloyl chloride yielded the desired siloxane-grafted polyamide
copolymers, MPA-g-PDMS. The copolymer membranes were prepared by
solvent casting method, and the gas permeability and pervaporation property of
these membranes were evaluated. PA-g-PDMS was insoluble in any solvents
after the copolymer was dried in vacuo, however, MPA-g-PDMS was soluble in
solvents, such as tetrahydrofuran, chloroform and dichloromethane, even after it
was completely dried. Therefore, MPA-g- PDMS exhibited the higher
processability than PA-g-PDMS. Then, the measurement of stress-strain
behavior of copolymer membranes was carried out, and these copolymer
membranes showed the high mechanical strength. The gas permeability property
of PA-g-PDMS and MPA-g-PDMS membranes was as same as that of the PDMS
cross-linking membrane for all of the gases. In addition, gas permeability of these
membranes were increased as increase of PDMS segment length, and these
values of MPA-g-PDMS were slightly higher than those of PA- g-PDMS
containing the same PDMS segment length. From the results of pervaporation of
the dilute aqueous solutions of organic solvents, it was found that both of PA-g-
PDMS and MPA-g- PDMS exhibited the excellent permselectivity toward several
organic solvents, such as alcohols, acetone, tetrahydrofuran, chloroform,
dichloromethane and benzene with a high and stable permeation. Such a high
selectivity for organic liquids would be due to the hydrophobic surface covered
with PDMS segments and the high permeability of the PDMS continuous domain,
which were confirmed by transmission electron macrography (TEM). Therefore, it
is expected that MPA-g-PDMS membranes can be used effectively for the
removal of organic solvents from their aqueous mixtures due to their properties of
high mechanical strength, durability and processability.

Desalination II – 1 – Keynote
Thursday July 17, 2:15 PM-3:00 PM, Honolulu/Kahuku
Memstill: A Near-Future Technology for Sea Water Desalination
C. Dotremont (Speaker), Keppel Environmental Technology Centre, Singapore -
chris_dotremont@keppelseghers.com
B. Kregersman, Keppel Seghers Belgium NV, Williebroek, Belgium
S. Puttemans, Keppel Seghers Belgium NV, Williebroek, Belgium
P. Ho, Keppel Environmental Technology Centre, Singapore
J. Hanemaaijer, TNO Science and Industry, The Netherlands
The Memstill development history started some 10 years ago at TNO Science
and Industry - the Netherlands. In 2002, Keppel Seghers joined the R&D
consortium. Ten years of development work resulted in a box module concept
which is leakage-free, resistant to hot sea water and has a salt reduction factor >
10.000 in scaled-up modules of 300 m 2 membrane area.
Memstill is a membrane-based distillation technique which makes use of
hydrophobic membranes to separate sea water from pure distillate. In a
countercurrent flow process, the cold sea water enters the module and takes up
heat in the condenser channel through condensation of water vapour, after which
a small amount of (waste) heat is added, and flows counter currently back via the
membrane channel. Driven by the small added heat, water evaporates through
the membrane, and is discharged as cold condensate. The brine is disposed, or
further concentrated in a next module. A heat exchanger between the condenser
and membrane envelop supplies the necessary heat to the module. Because a
Memstill module houses a continuum of evaporation stages in an almost ideal
countercurrent flow process, a very high recovery of evaporation heat is possible:
Gained Output Ratios (GOR) of 15-30 are achievable.
This technology is especially attractive in case low grade waste steam or solar
heat is available, i.e. top temperatures between 60 and 90 degrees Celsius and a
temperature difference over the membrane/condenser of 5 to 10 degrees Celsius
are already sufficient to drive the process. In other words, memstill is energy/CO2
- neutral and is driven by relatively small quantities (100 - 200 MJ/m 3 ) of heat. If
operated in a once pass through system, memstill operates at recoveries of 5-
10%, without any additives like acids and anti-scalants, producing high quality
fresh water and a brine which is only 10% concentrated and with only 2 to 5
degrees Celsius increase in temperature, thus without any proven environmental
damage.
A first pilot plant - equipped with the first generation of modules - was operated
for 14 months in Singapore (March 2006 - June 2007). And although the intake of
sea water at the Strait of Johor was of low quality, the pilot showed good

separation quality (10 µS/cm) and module integrity; however flux performance
and energy efficiency were still quite low.
A second pilot - equipped with the second generation of modules - operated for 4
months at E.ON Benelux - in the Port of Rotterdam, the Netherlands (October
2006 - January 2007) with promising results. A mean distillate flux of 2.7 l/h.m 2 or
a distillate flow of 800 l/h (300 m 2 ) has been measured during the 4 months test
trial. At start-up, an energy consumption of 120-150 MJ/m 3 was registered,
increasing over time likely due to some fouling.
Currently, this pilot is being revamped for a third field test at the waste
incineration plant of AVR, again situated in the Port of Rotterdam, the
Netherlands. New modules were manufactured and installed - allowing higher
cross-flows and higher energy efficiency. In addition, this pilot trial will focus on
fouling issues and is scheduled for the coming six months, starting from March
2008 onwards. Preliminary cost assessments for large scale desalination show
that Memstill costs come close or even equal RO sea water desalination costs.
Because significant improvement of performance and decreasing production
costs can be expected in coming years, Memstill technology should be subject to
a further cost reduction. In addition, future increasing cost discrepancy can be
expected in favor of Memstill as electricity costs are assumed to rise steadily in
the coming years.
In this presentation an overview of the main results and improvements based on
previous & current pilot trials will be given. Performance data like flux, energy
consumption, distillate quality and fouling will be discussed. Finally, an outlook on
further development work, product improvement and the preparation of the
commercialization will be briefly presented.
Acknowledgement The Memstill development was supported by the Netherlands E.E.T. program.
The Memstill consortium comprises Keppel Seghers,TNO, EMF, WTH, Twente University, E.ON
Benelux,Heineken International, Evides, Amsterdam Waternet. The Memstill development was
also supported by the Public Utilities Board (PUB) and the National Environment Agency (NEA) of
Singapore.

Desalination II – 2
Thursday July 17, 3:00 PM-3:30 PM, Honolulu/Kahuku
Parameters Affecting Osmotic Backwash
N. Avraham, Grand Water Research Institute, Technion, Haifa, Israel
A. Sagiv (Speaker), Grand Water Research Institute, Technion, Haifa, Israel
C. Dosoretz, Grand Water Research Institute, Technion, Haifa, Israel
R. Semiat, Grand Water Research Institute, Technion, Haifa, Israel - cesemiat@technion.ac.il
The Reverse Osmosis (RO) membrane cleaning process is of great interest to
the desalination industry. The water volume needed for the backwash process
and the time duration of the wash process are key parameters that must be
considered in practice. Appropriate changes in feed and permeate applied
pressures across the membrane for a given concentration difference enable a
shift back and forth from the RO to the BW process with minimal intervention by
the RO desalination process. Effects of different parameters, including operation
pressure and salt concentration, were investigated experimentally in the present
study. Experiments were carried out, measuring the wash volume as a result of
different salt concentrations in the RO steady-state operation prior to the
backwash experiment and at different pressures on both sides of the membrane.
Results show that within the operated range of parameters, the wash volume is
basically independent of the initial pressure difference. Yet, as expected, it is
affected by the difference in concentrations across the membrane. It was found
that the wash volume increases with the concentration differences at the lower
range and decreases at the higher range. This result is explained by the two
opposite flux mechanisms discussed in a previous study of zero BW applied
pressure. The BW volume decreases with BW feed applied pressure, indicating a
decrease in BW driving pressure. For a similar reason, the BW volume increases
with increased permeate side pressure since it increases the BW driving
pressure.
Results of the present study provide an experimental basis for further
understanding the BW process under industrial conditions, and finding BW
characteristics necessary for the efficient design of RO-based desalination
plants.

Desalination II – 3
Thursday July 17, 3:30 PM-4:00 PM, Honolulu/Kahuku
Fabrication of High Performance Dual Layer Hydrophilic-Hydrophobic
Hollow Fiber Membranes for Membrane Distillation Process
S. Bonyadi (Speaker), National University of Singapore, Singapore
T. Chung, National University of Singapore, Singapore - chencts@nus.edu.sg
Hydrophilic-hydrophobic composite membranes have been considered as
promising membrane configurations to be applied as membrane contactors,
especially for flux enhancement in membrane distillation (MD) process. While
there are several reports in the literature demonstrating the fabrication of these
types of membranes in flat sheet geometries, however, there is no such report in
case of hollow fibers. Furthermore, most of the proposed approaches are either
expensive or inefficient in controlling membrane properties such as porosity and
pore-size distribution. For the first time in this paper, co-extrusion has been
applied as a novel approach to fabricate dual layer PAN (hydrophilic) - PVDF
(hydrophobic) composite membranes. The effect of different non-solvents on the
morphology of the PVDF membranes was investigated and it was found that
weak coagulants such as water/methanol (20/80, w/w) can induce a three
dimensional porous structure on PVDF membranes with high surface and bulk
porosities, big pore size, sharp pore size distribution, high surface contact angle
and high permeability but rather weak mechanical properties. In order to enhance
the membranes mechanical properties, hydrophobic and hydrophilic clay
particles were incorporated into the outer and inner layer dope solutions,
respectively. It was also found that the incorporation of clay particles in the fibers
inner layer reduces the shrinkage and reduces the delamination between the two
layers considerably. The fabricated fibers were characterized through pore size
distribution, gas permeation, porosity and contact angle measurement tests.
Ultimately they were tested for desalination through a direct contact membrane
distillation process and fluxes as high as 47 kg/m 2 hr, were achieved at 90 ºC. By
carrying out some modifications on the fabricated fibers the obtained flux was
increased to 70 kg/m 2 hr at 86 ºC, which is a superior flux compared to all the
data reported in the literature for hollow fiber membranes so far. The details
regarding the conducted modifications are under review by the AIChE Journal.

Desalination II – 4
Thursday July 17, 4:00 PM-4:30 PM, Honolulu/Kahuku
A New Niche for Electrodialysis: Improving Recovery from RO Desalination
D. Lawler (Speaker), The University of Texas at Austin, Austin, Texas, USA -
dlawler@mail.utexas.edu
Y. Kim, The University of Texas at Austin, Austin, Texas, USA
W. Walker, The University of Texas at Austin, Austin ,Texas USA
Desalination continues to grow in importance because freshwater supplies for
drinking water dwindle while demand grows with increasing population. Dramatic
improvements in membrane technology have made reverse osmosis (RO)
systems the industry standard for desalination. Nevertheless, RO is not the
universal panacea; in particular, when RO is used on inland brackish waters, the
recovery (the fraction of the influent water that becomes product) is rarely higher
that 80%. The other 20%, the concentrate, becomes a waste stream that is
expensive and environmentally troublesome to dispose.
One possible means to improve recovery of RO desalination systems is to use
electrodialysis (ED) as an interstage or post-treatment; that is, to treat the
existing concentrate of an RO system using ED and thereby increase the overall
recovery. The objectives of this paper are to present a simple mathematical
model of ED that helps define the niche for ED in this application and to reinforce
that model with laboratory experimental results.
In ED, alternating cation- and anion-exchange membranes create alternating
clean (diluate) and concentrate streams. For an ion to be transported from the
bulk solution in the feed stream to the bulk solution of the concentrate, it must
move through five separate regions: (i) the bulk solution on the diluate side of an
ion exchange membrane, (ii) a diffusion boundary layer on the diluate side of the
membrane, (iii) the membrane itself, (iv) a boundary layer on the concentrate
side, and (v) the bulk solution on the concentrate side. In each region,
electroneutrality must be maintained, so cations and anions do not act
independently of one another; slower moving ions tend to control the overall
transport. The ion concentrations and potential drop adjust in various parts of the
system to achieve the requirements of electroneutrality and equal electrical
current (ion flux) being carried in each step at steady state. The behavior in each
region is defined by the Nernst-Planck equation. Operating ED systems have a
critical or limiting current, and the actual current (and consequent potential drop)
must be held below this value.
In both bulk solutions and both membranes in a single-salt system, the
concentrations are uniform (so diffusion is zero) and the current and potential

drop are linearly related (although the diffusion coefficients in the membrane and
solution are not the same). The boundary layers are more complex, because
both electromigration and diffusion are operative. An analytical mathematical
model describing the relationships among concentration (profile), current density,
and potential gradient in the boundary layers for an ideal one-dimensional
system at steady state has been developed and solved, and this model illustrates
all of the important characteristics and limitations of real ED systems. The model
has been solved for both a single salt (one cation and one anion) and two salt
(one cation and two anions, or vice versa) situations; more complex mixtures
require numerical solutions which are under development at the time of writing.
To our knowledge, such a model has not previously been presented.
The analytical model elucidates the influence of several factors on ED design
and operation more directly than more complex numerical models. For example:
(i) The concentration for the single-salt solution varies linearly with distance in the
boundary layer, and the absolute value of the slope increases with increasing
current and decreasing diffusion coefficient of the selected ion. (ii) The
concentration decreases from either membrane to the bulk in the boundary
layers of the concentrate, and decreases from the bulk to the membrane in the
boundary layers of the diluate. (ii) The potential drop is expressed by a
logarithmic function with distance in the boundary layer, but the relevant
variables have similar functionality as in the concentration expressions. (iv) ED is
most efficient when the total dissolved solids (TDS) concentration of the influent
is much less than that of seawater and when the effluent TDS can be sufficiently
high to allow current passage; these conditions exactly fit brackish water RO
concentrate as a feedstock to create drinking water.
Along with development of the model, laboratory scale experiments are being
performed using a five cell-pair electrodialyzer from PCCell, GmbH (Heusweiler,
Germany). A computerized drive controls the flow rate, while a direct current
regulated power supply controls the applied potential (or current). Conductivity
and pH of the treatment streams are monitored continuously. A digital balance is
used in flow rate calibrations and osmosis quantification. A graphical user
interface and data acquisition system round out the system. A wide range of
experiments have been and will be performed, and a selection of results that test
and demonstrate the utility of the model will be presented.

Desalination II – 5
Thursday July 17, 4:30 PM-5:00 PM, Honolulu/Kahuku
A Novel Three-Stage Treatment for Brackish Water Reverse Osmosis
Concentrate: Parameter Effects on and Feasibility of Antiscalant Oxidation
L. Greenlee (Speaker), The University of Texas at Austin, Austin, Texas, USA -
lauren_greenlee@yahoo.com
D. Lawler, The University of Texas at Austin, Austin, Texas, USA
B. Freeman, The University of Texas at Austin, Austin, Texas, USA
B. Marrot, Université Paul Cézanne, France
P. Moulin, Université Paul Cézanne, France
In many locations, fresh water resources are insufficient for local needs, and
alternative sources with lesser water quality are being considered as drinking
water supplies. In particular, the United States has many inland regions with
untapped brackish water (500-10,000 mg/L total dissolved solids) resources.
Reverse osmosis (RO) membrane desalination is a feasible solution, but the
product recovery (volume of product water per volume of feed water) range is
only 75-90%; i.e., at least 10% of the feed water becomes the RO waste stream,
or concentrate. The costs and technical feasibility of concentrate disposal
severely limit the application of inland RO. This research was designed to reduce
the volume of brackish water RO concentrate.
In brackish water RO systems, recovery is limited by salt precipitation. Chemicals
called antiscalants are used to complex with problematic salts (CaCO3, CaSO4,
BaSO4, SrSO4, silica), delaying precipitation. However, salt concentration
increases with recovery, and eventually precipitation control is overcome. To
increase system recovery and decrease the concentrate volume, a new
approach is required.
Previous research using precipitation and separation to treat concentrate has
shown that significant increases in total system recovery are possible. However,
the presence and influence of antiscalants and natural organic matter (NOM)
during RO concentrate treatment have not been investigated.
This paper presents the development of a novel three-stage process to treat the
concentrate from a brackish water RO system. The process achieves
problematic salt removal through (I) antiscalant deactivation, (II) precipitation,
and (III) solid/liquid separation. Antiscalant deactivation is performed using ozone
(O3) and hydrogen peroxide (H2O2). pH elevation is used to precipitate salts, and
solid/liquid separation is achieved through sedimentation and filtration. While
technologies for solid/liquid separation are well-established, the combination of
antiscalant oxidation and precipitation represents a new system; research on

antiscalant oxidation has been limited, and the effect of ozonation on
precipitation has not been investigated.
The effects of several parameters, including pH, ozonation time, water
composition, antiscalant concentration and type, ozone dose (mg O3 per mg
dissolved organic carbon (DOC)), and [H2O2]/[O3] ratio (mole:mole), on
phosphonate antiscalant oxidation were evaluated. Increases in ozonation time,
pH, and ozone dose increased antiscalant oxidation. An increase in ozonation
time from 1 to 30 minutes increased fractional phosphate oxidation from 0.10 to
0.57 (pH 6), while a pH increase from 5 to 8 increased carbon oxidation from 36
to 86% (15 min ozone). Doubling the ozone dose increased oxidation by 40-90%
(1-10 min ozone). The addition of H2O2 ([H2O2]/[O3] = 0.2), for the same ozone
dose and pH, increased carbon oxidation by 25%. The effect of changing the
[H2O2]/[O3] ratio varied, depending on the water composition; however, the ratio
of 0.8 resulted in the most antiscalant degradation. Increasing the ratio from 0.2
to 0.8 increased fractional carbon oxidation by 33-250%. Changes in water
composition showed the scavenging effect of the carbonate system on
antiscalant oxidation; the addition of carbonate (pH 6, ozone dose = 2.6 mg
O3/mg DOC and [H2O2]/ [O3] = 0.8) increased complete carbon oxidation from 47
to 58%. The extent of oxidation was different for the two antiscalants tested;
differences in chemical structure affect oxidation.
The effect of oxidation on the precipitation and separation stages was then
studied. Parameters having a potential effect on the precipitation stage
(ozonation time, water composition, antiscalant type and concentration) were
varied. In all experiments, ozonation prior to precipitation allowed greater calcium
precipitation. Results showed phosphate produced during antiscalant oxidation
completely precipitated during the second stage. Tests with a simplified water
(containing only NaHCO3 and CaCl2) showed 97% calcium precipitation after 10
minutes ozonation, while antiscalant-dosed, non- ozonated samples showed
92% calcium precipitation. Similar results for calcium were obtained for a more
complex (but synthetic) water; calcium precipitation increased from 81 to 87%
with the addition of ozonation prior to precipitation. This calcium precipitation
increase would increase the achievable overall recovery, due to a greater
reduction in precipitation potential. A preliminary cost analysis showed a
concentrate disposal cost reduction of up to 90%. The research is ongoing, and
results from a natural brackish water will be presented to show the influence of
NOM.

Desalination II – 6
Thursday July 17, 5:00 PM-5:30 PM, Honolulu/Kahuku
Sustainable Seawater Desalination: Small Scale Windmill and RO-System
S. Heijman (Speaker), Delft University of Technology, Delft, The Netherlands -
S.G.J.Heijman@tudelft.nl
E. Rabinovitch, Delft University of Technology, Delft, The Netherlands
J. van Dijk, Delft University of Technology, Delft, The Netherlands
INTRODUCTION
In coastal areas with a shortage of fresh drinking water, but enough wind power,
the combination wind energy and reverse osmosis may provide a sustainable
way to produce drinking water. Especially in remote areas and with high water
prices the combination is cost effective. At the moment there are windmills
providing electricity for RO installations. But in these systems the wind energy is
first transferred to electricity and than transferred back to mechanical energy for
the high pressure pump. Often the electricity is also stored in order to overcome
periods of low wind speeds. The system is rather expensive because of the
energy loss and the storage of electricity. It is of course less expensive to store
the fresh water and drive the high pressure pump directly with wind energy.
OBJECTIVE
A commercial windmill, normally used for irrigation purposes, is converted with a
gearbox and a shaft running down to ground level. The windmill is driving a high
pressure piston pump. The piston pump is connected directly to the mill shaft
with the right rotation speed for the pump. An energy recovery system uses the
energy from the concentrate. The energy recovery is also securing a fixed
(water) recovery of 30% at different wind speed. The installation will produce
between 5 and 10 m 3 of fresh water a day. It produces only water if there is
enough wind energy, so a fresh water storage is very important. The installation
will also have a mechanical dry-run protection and both a low speed and a high
speed limitation.
RESULTS
The first prototype is ready in December 2007. It will be tested on salt water near
Delft University and shipped to Curacao in February 2008. The results will
include production of permeate as a function of the wind speed, fouling problems
as a function of the wind speed and biofouling. Of course the water price is
estimated by calculating the investment costs and estimating the yearly
production.

Membrane and Surface Modification II – 1 – Keynote
Thursday July 17, 2:15 PM-3:00 PM, O’ahu/Waialua
Macroporous Membrane Adsorbers with Tailored Affinity and High
Capacity via Photo-initiated Grafting-of Functional Polymer Layers
M. Ulbricht (Speaker), Universität Duisburg-Essen, Essen, Germany - mathias.ulbricht@unidue.de
D. He, Universität Duisburg-Essen, Essen, Germany
J. Wang, Universität Duisburg-Essen, Essen, Germany
Q. Yang, Universität Duisburg-Essen, Essen, Germany
A. Yusof, Universität Duisburg-Essen, Essen, Germany
Separations with membrane adsorbers are a very attractive and rapidly growing
field of application for functional macroporous membranes [1]. The key
advantages in comparison with conventional porous adsorbers result from the
pore structure of the membrane which allows a directional convective flow
through the majority of the pores; thus, the characteristic distances for pore
diffusion will be drastically reduced. The separation of substances is based on
their reversible binding on the functionalized pore walls; the most frequently used
interactions are ion-exchange and various types of affinity binding. However,
there is still a large interest in improvement of performance for established
materials and in development of novel materials. Specific aims are membrane
adsorbers with higher dynamic binding capacity and membrane adsorbers with
higher affinity and selectivity for certain target substances, especially via affinity
binding to robust chemical ligand architectures.
Via different surface-selective photo-grafting methods developed in our group [2],
various types of anion- and cation-exchange membrane adsorbers with threedimensional
binding layers had been prepared on different macroporous support
membranes, from regenerated cellulose with pore diameters (dp) of 0.45, 1 and
3~5 µm, from polypropylene with dp ~0.4 µm, or for model studies track-etched
poly(ethylene terephthalate) with dp of ~0.4 or ~0.8 µm. Functional monomers for
weak cation-exchange and strong anion- exchange membranes, respectively,
were acrylic acid [3] and 2-(methacryloyloxy)ethyl)- trimethylammonium chloride
[4], respectively. Copolymerization with hydrophilic diluent acrylamide monomers
was used to adjust the density of functional groups, and cross-linking with
bisacrylamides was used as another parameter for tailoring the grafted
architectures. The synergist immobilization method for photo-grafting [2,4] had
turned out to be especially versatile because the highest surface selectivity for
photo-grafting could be achieved. Dynamic evaluation of the membrane
adsorbers had been done by analysis of breakthrough curves for proteins of
different size and by separation of proteins based on their different isoelectric
points. In all cases, a well- defined chemical cross-linking of the grafted layer via
addition of a cross-linker monomer during photo-grafting lead to a markedly

improved separation performance because higher permeability and lower
susceptibilities of permeability to salt concentration than with linear grafted
polymer had been combined with high dynamic protein binding capacities, i.e. the
trade- off between high binding capacity and low permeability observed for linear
grafted polymer chains could be partially avoided.
Finally, we will report about two novel routes to protein-selective membrane
adsorbers where affinity binding occurs via multiple-site molecular recognition in
grafted functional copolymer layers. Recognition is either based on the
incorporation of monomers with receptor groups for specific amino acids (e.g.
arginine) on the protein surface [5] or on monomers with glycosidic groups for the
specific binding of a special group of proteins, the lectins [6].
[1] M. Ulbricht, Polymer 2006, 47, 2217-2262.
[2] D. M. He, H. Susanto, M. Ulbricht, Photo- irradiation for preparation, modification and
stimulation of polymeric membranes (Invited Review), Progr. Polym. Sci., 2007, submitted.
[3] A. H. M. Yusof, M. Ulbricht, J. Membr. Sci. 2008, 311, 294-305.
[4] D. M. He, M. Ulbricht, J. Membr. Sci. 2008, accepted.
[5] D. M. He, S. Wei, T. Schrader, M. Ulbricht, to be submitted.
[6] Q. Yang, A. Friebe, Z. K. Xu, M. Ulbricht, to be submitted.

Membrane and Surface Modification II – 2
Thursday July 17, 3:00 PM-3:30 PM, O’ahu/Waialua
Surface Modification of Pervaporation Membrane by UV-Radiation and
Application of Shear Stress
P. Izák (Speaker), Institute of Chemical Process Fundamentals, Prague, Czech Republic -
izak@icpf.cas.cz
H. Godinho, Universidade Nova de Lisboa, Portugal
P. Brogueira, Instituto Superior Técnico, Portugal
L. Figueirinhas, Instituto Superior Técnico, Portugal
J. Crespo, Universidade Nova de Lisboa, Portugal
At present, one of the main challenges in green chemistry is the selective
recovery of solutes from ionic liquids by clean membrane processing. Serious
problems are caused by concentration polarization, in particular during
pervaporation process, especially when green solvents with high viscosity (such
as ionic liquids) are used. Therefore we looked for ways to promote external
mass transfer in the binary mixture and thus minimize the concentration
polarization at the membrane surface. The surface modification of the
polyurethane (PU) and polybutadiene-diol (PBDO) membrane obtained by UVradiation
and application of shear stress allowed us to increase external mixing of
the liquid feed at the membrane surface. The formed microstructures increased
the enrichment factor and also permeation flux of solute. Additionally, when we
increased feed flow rate in pervaporation module we also improved the
pervaporation characteristics. This work demonstrates the potential of surface
modified dense membranes to enhance the pervaporation separation processes.
Acknowledgements
This research was supported by the post-doc grant (SFRH/BPD/9470/2002) and the projects
grants (POCTI/EQU/35437/2000 and POCTI/CTM/56382/2004) from Fundação para a Ciência e
a Tecnologia, Portugal, and to the Czech Science Foundation for grant No. 104/08/0600.

Membrane and Surface Modification II – 3
Thursday July 17, 3:30 PM-4:00 PM, O’ahu/Waialua
Microstructured Hollow Fiber Membranes for Ultrafiltration
P. Culfaz, University of Twente, The Netherlands
J. Jani, University of Twente, The Netherlands
R. Lammertink, University of Twente, The Netherlands - r.g.h.lammertink@utwente.nl
M. Wessling (Speaker), University of Twente, The Netherlands
Hollow fibers are used in many membrane processes from gas separation to
microfiltration. The fibers are most commonly made by the solution spinning
method and have a round shape. Through the use of silicon micromachining
technology, the spinnerets used for spinning hollow fibers can be modified to
produce microstructured fibers with convolutions on the outside [1]. This is done
by placing a silicon insert with a structured opening in the middle inside the
spinneret, such that the polymer solution flows through this structured annulus
instead of a circular annulus.
The increased surface area of the fibers is expected to result in increased flow
per fiber length if the selective layer is of comparable thickness. Convoluted
membranes are also suggested to cause turbulence around the convolutions,
which may decrease fouling and facilitate cleaning of the membranes [2].
In this study, ultrafiltration fibers of a PES-PVP blend were made using a dry-wet
spinning process. The fibers were made using a structured insert as well as a
round insert for comparison. The clean water fluxes were measured to compare
the throughput of the fibers. The molecular weight cut- offs were measured by
filtering a mixture of dextranes. The pore size distribution and skin layer
thickness will also be examined to have a complete comparison of the structured
and the round fibers made under identical conditions. The fouling behavior of the
fibers was evaluated in modules of ca. 140 cm 2 membrane area (5-7 fibers) by
filtering a 50 ppm humic acid solution. Fluxes from 20 - 100 L/h.m 2 were used.
The transmembrane pressure difference required to obtain the set flux was
measured and from this the membrane resistance was calculated.
First, structured fibers were made applying increasing air gaps between the
spinneret outlet and the coagulation bath. Using a solution of 20% PES, 5% PVP
K30, 5% PVP K90, 5% H2O and 65% NMP, the complete loss of the structure in
the fiber occurred within 60 mm of an air gap. When a 6 mm air gap was used,
the structured fiber had 80% higher surface area compared to the round fiber
made under the same conditions. For equal length of fiber subjected to the same
transmembrane pressure difference, the structured fiber had 90% higher
flowrate. The molecular weight cut-offs of the round and structured fibers were

oth 15±5 kDa, which suggests that the pore sizes of the round and structured
fibers are similar.
Using finite element methods, the evolution of the initial convoluted shape
towards a round shape could be simulated. The shape evolution is controlled by
the solution viscosity and surface tension. The outcome of the simulation fits the
actual behavior of the fiber quite well. Using these simulations new inserts which
can retain the structure longer in the air gap can be designed.
In the fouling tests, it was observed that the structured fibers showed no
irreversible fouling after the filtration of the humic acid solution, whereas the
round fibers did. The structured fibers used in these experiments had 55% higher
surface area than their round equivalents and the flowrate through these
structured fibers was 40% higher than the round fibers.
Using a modified spinneret to make structured hollow fibers appears to be a
promising method to enhance the throughput and reduce the fouling of
ultrafiltration membranes. While keeping the separation characteristics the same,
the throughput can be increased and fouling can be reduced.
References:
[1] Nijdam, W., De Jong, J., Van Rijn, C.J.M., Visser, T., Versteeg, L., Kapantaidakis, G., Koops,
G.-H., Wessling, M., 2005, Journal of Membrane Science 283, p. 209-215.
[2] Scott, K., Mahmood, A.J., Jachuck, R.J., Hu, B., 2000, Journal of Membrane Science 173, p.
1-16.

Membrane and Surface Modification II – 4
Thursday July 17, 4:00 PM-4:30 PM, O’ahu/Waialua
High Performance Surface Nano-Structured RO/NF Membranes
G. Lewis, University of California, Los Angeles, California, USA
N. Lin (Speaker), University of California, Los Angeles, California, USA
M. Kim, University of California, Los Angeles, California, USA
Y. Cohen, University of California, Los Angeles, California, USA - yoram@ucla.edu
Reverse Osmosis (RO) and Nanofiltration (NF) membranes used for surface and
groundwater desalination are susceptible to bio-organic fouling (i.e., proteins,
humic acid, fulvic acid), colloidal fouling and mineral salt scaling. Membrane
fouling and/or scaling not only results in a decreased membrane permeate flux
but also protein adhesion and mineral salt scale formation that may permanently
alter the physical features of the surface and lead to irreparable membrane
damage. Previous strategies for mitigating membrane fouling/scaling (i.e.,
polymer surface adsorption and UV, gamma irradiation, and low-pressure plasma
graft polymerization) have relied on alteration of the membrane surface chemistry
and topography by addition of a permselective polymer thin film that would act
both as a separation layer and a physical boundary to prevent adsorption of
organic and mineral salt species. In the present study, a novel atmospheric
pressure plasma-induced graft polymerization method was developed to enable
the generation of a high surface density of active surface sites for subsequent
graft polymerization using a suitable monomer. Surface graft polymerization was
then carried out to form a dense layer of grafted polymer chains that are
covalently and terminally bound to the surface. The chemical and physical
features of the resulting grafted polymer film may be tuned by altering the
monomer chemistry as well as the reaction conditions to achieve unique
architectures for effective advanced materials in membrane separations.
Using the above approach of atmospheric pressure plasma-induced graft
polymerization (APPIGP), a novel class of RO and NF membranes were
developed. Characterization of membrane bio-organic fouling studies were
conducted in a dilute aqueous feed stream of model proteins. Surface scaling
was evaluated by subjecting the surface structured membranes to a dilute
aqueous mineral salt solution with the onset of mineral scaling detected by a
novel scale-observation imaging system. The properties of the grafted polymer
on the RO and NF membranes, specifically the surface density, polymer chain
length, and monomer chemistry, were evaluated with respect to the membrane
performance (i.e., onset of mineral scaling, water permeate flux decline and
surface scale coverage) to determine the optimal surface structuring conditions
required reduce surface fouling/scaling. The properties of the grafted surfaces,
such as surface topology and surface feature uniformity, were evaluated by

Atomic Force Microscopy (AFM), and the surface chemistry was elucidated by
Fourier Transform Infrared (FTIR) Spectroscopy. The results suggest that
surface modification of both RO and NF membranes by plasma-induced graft
polymerization can be an effective tool for increasing membrane performance by
decreasing the propensity for scaling and fouling.

Membrane and Surface Modification II – 5
Thursday July 17, 4:30 PM-5:00 PM, O’ahu/Waialua
Characterization of Commercial Reverse Osmosis Membrane Performance
and Surface Modification to Enhance Membrane Fouling Resistance
E. Van Wagner (Speaker), The University of Texas at Austin, Austin, Texas, USA
B. Freeman, The University of Texas at Austin, Austin, Texas, USA – freeman@che.utexas.edu
M. Sharma, The University of Texas at Austin, Austin, Texas, USA
Thin-film composite reverse osmosis (RO) membranes have been studied for
nearly fifty years, gradually evolving to the high water flux, high salt rejection
(typically >98%) materials used today. However, the high throughput and
selectivity that make RO membranes viable candidates for desalination also
make measuring their properties difficult. Additionally, commercial RO
membranes are prone to fouling by contaminants present in potential alternative
water sources, making membrane surface modification a current area of
significant interest. This study was undertaken to identify some important
variables responsible for measured performance values (water flux and salt
rejection) of commercial RO membranes, and also to modify the commercial
membrane surfaces to make more fouling-resistant materials.
First, polyamide RO membranes obtained from Dow FilmTec (XLE and LE) were
characterized using carefully controlled testing conditions mimicking those of the
manufacturer. The measured water flux and salt rejection values were in good
agreement with the benchmarks. In addition, the effects of feed pH and
continuous feed prefiltration on membrane flux and rejection were studied.
Concentration polarization was accounted for in all experiments.
Surface modification of the well-characterized commercial RO membranes was
then performed. Short-chain molecules based on poly(ethylene glycol) diglycidyl
ethers or fluoroalkyl oxiranes were used to form chemical bonds between their
epoxide endgroups and free amines present on the RO membrane surface.
Variables including reaction method (dip or spin coating), time, temperature, and
molecular weight and concentration of grafting molecule were studied for their
effect on flux and rejection. The fouling resistance (i.e., flux decline) of modified
and unmodified membranes was compared in model foulant solutions.

Membrane and Surface Modification II – 6
Thursday July 17, 5:00 PM-5:30 PM, O’ahu/Waialua
Hydrophobic Modified Ceramic Membranes for Gas Separation and
Desalination
S. Cerneaux (Speaker), Institut Européen des Membranes, Montpellier, France -
cerneaux@iemm.univ-montp2.fr
S. Condom, Institut Européen des Membranes, Montpellier, France
M. Persin, Institut Européen des Membranes, Montpellier, France
E. Prouzet, Institut Européen des Membranes, Montpellier, France
A. Larbot, Institut Européen des Membranes, Montpellier, France
Ceramic membranes are hydrophilic by nature since hydroxyl groups are present
both on the surface and within inner pores of membranes. Hence, this
characteristic is highly suitable to perform membranes surface modification to
confer them a specific affinity depending on the targeted applications. For water
treatment and desalination, attention has been focused on membranes showing
a hydrophobic feature as it yields to the formation of a repellent barrier for liquid
water transfer in Membrane Distillation (MD) processes, which are driven by a
temperature difference across hydrophobic membranes and only allow water
vapor permeation. In gas separation, these hydrophobic membranes are also of
great interest as perfluorinated chains used in this work are well known to have a
specific affinity for the CO2 gas molecules.
To post-functionalize zirconia, alumina and titania ceramic materials with different
pore diameters, perfluoroalkyl alkoxysilane molecules CnF2n+1(CH2)2Si(OR)3
were used. Materials were chemically modified by reaction of the different
fluorinated alkoxysilanes in alcoholic media for 4h and efficiency of grafting was
evaluated by FTIR, TGA and solid-state 29Si NMR for corresponding modified
powders. The influence of the perfluorinated chain length on the hydrophobic
stage of the modified membranes was further evidenced by measuring the water
liquid entry pressure and the wettability, water contact angles higher than 140°
being obtained for n=6 and n=8. The pore diameters of the modified membranes
need to be considered in desalination and liquid separations as they represent
the limiting factor for rejection rate and flux in desalination. Modified zirconia
membrane with pore diameters of 50nm yielded to the highest flux and rejection
rates higher than 99%, while working in Direct Contact Membrane Distillation.
Preliminary results in CO2 separation using hydrophobic zirconia membranes
showed that a pure gas selectivity of 3 for CO2 against N2 can be achieved with a
CO2 permeance of 0.2 m 3 (STP)/m 2 .h.bar.

Hybrid Membranes – 1 – Keynote
Thursday July 17, 2:15 PM-3:00 PM, Wai’anae
Polymer-Zeolite 4A Mixed-Matrix Nanocomposite Gas Separation
Membranes
A. Kertik, Istanbul Technical University, Istanbul, Turkey
I. Agil, Istanbul Technical University, Istanbul, Turkey
C. Atalay-Oral, Istanbul Technical University, Istanbul, Turkey
S. Tantekin-Ersolmaz (Speaker), Istanbul Technical University, Istanbul, Turkey -
ersolmaz@itu.edu.tr
Polymer/zeolite mixed matrix composite (MMC) membranes are hybrid materials
offering the potential to overcome the permeability-selectivity trade-off limitation
of polymeric membranes. These hybrid membranes combine high selectivity of
zeolites and easy processability of polymers when proper polymer/zeolite pair is
selected and good adhesion is achieved at the polymer/zeolite interphase.
However, experimental studies in the literature have shown that when good
adhesion is ensured, permeability values decrease pointing out an interfacial
region around the zeolite particles showing more resistance to gas flow than the
polymeric matrix which is often described as chain rigidification around the
zeolite particle. The interphase effect in MMC membranes was investigated in
our earlier studies and a model (Modified Effective Medium Theory (EMT)) was
developed to include the interphase resistance [1,2].
Presence of an interphase surrounding zeolite particles contributing to the
effective permeability is especially important from an industrial perspective since
commercial application of membranes require asymmetric membrane
configuration with thin (

y single gas permeation experiments. The interfacial effect of zeolite particle
size on MMC membrane separation characteristics is investigated by comparing
the properties of membranes prepared with nanosize zeolites with an average
particle size of 200 nm and commercial zeolites with 2-5 microns particle size.
The experimental permeability data obtained in this study were also compared
with the effective permeability predictions of EMT and Modified EMT models. The
results indicated differences in the magnitude of chain rigidification between
different polymer-zeolite systems. The differences in the characteristics of the
polymeric phase change the behavior and the severity of the interphase
characteristics.
References
[1] Tantekin-Ersolmaz, S. B., Atalay-Oral, C., Tatlier, M., Schoeman, B., Sterte, J. (2000) Effect of
Zeolite Particle Size on the Performance of Polymer-Zeolite Mixed Matrix Membranes, J. Memb.
Sci.. 175:285-288.
[2] Erdem-Senatalar, A., Tatlier, M., Tantekin-Ersolmaz, S. B. (2001) Estimation of the Interphase
Thickness and Permeability in Polymer-Zeolite Mixed Matrix Membranes, Stud. Surf. Sci. Cat.
35:154.
[3] Mahajan, R. and Koros, W. J. (2000) Factors Controlling Successful Formation of Mixed-
Matrix Gas Separation Materials, Ind. Eng. Chem. Res. 39:2692-2696.

Hybrid Membranes – 2
Thursday July 17, 3:00 PM-3:30 PM, Wai’anae
Hollow Fillers For Flux Enhancement In Mixed Matrix Membranes
K. Vanherck (Speaker), Katholieke Universiteit Leuven, Heverlee, Belgium
S. Aldea, Katholieke Universiteit Leuven, Heverlee, Belgium
A. Aerts, Katholieke Universiteit Leuven, Heverlee, Belgium
J. Martens, Universiteit Leuven, Heverlee, Belgium
I. Vankelecom, Katholieke Universiteit Leuven, Heverlee, Belgium -
ivo.vankelecom@biw.kuleuven.be
Mixed matrix membranes (MMMs), consisting of an organic polymer (bulk phase)
and inorganic particle phases (dispersed phase), have the potential to combine
high selectivities with high membrane fluxes. Zeolites and carbon molecular
sieves have been most attractive as inorganic fillers in MMMs because their very
defined pore structure increases the selectivity. Zeolite-filled
polydimethylsiloxane (PDMS) membranes have already been developed for gas
separation, pervaporation, and nanofiltration. PDMS is known to be a chemically
and thermally stable polymer, but the excessive swelling and resulting selectivity
loss in certain organic solvents (e.g. toluene, DCM,&) limits its utility in these
solvents. The incorporation of zeolites reduces PDMS swelling via extra crosslinking,
without lowering the intrinsic fluxes. In previous research, composite
membranes were prepared with a PDMS top layer filled with zeolites ZSM-5 and
USY. Top layer thicknesses of approximately 8µm could be obtained, giving a
92% rejection for Wilkinson Catalyst in toluene at a permeability of 1,07 l/m² bar
h. Since a zeolite-filled PDMS top layer requires a certain minimal thickness to
remain free of defects, it is not easy to obtain higher fluxes.
To lower the minimal thickness of a zeolite-filled PDMS toplayer, two strategies
were explored in this research. Firstly, zeolites with a smaller crystal size, nanosized
silicalite-1 (NS), were used as fillers. Secondly, the incorporation in PDMS
of micron-sized hollow spheres (HS) with a zeolite shell was investigated. Hollow
spheres with a shell consisting of nano-sized silicalite crystals and a diameter of

PDMS toplayers were only partially cross-linked by the zeolites, explaining the
strong swelling and rejection loss in toluene and DCM. For the MMMs with a
toplayer of PDMS filled with HS, a high increase in permeability was expected
since the hollow fillers should allow a fast flow of the solvent. At the same time,
rejection should be maintained by the molecular sieving and cross-linking effect
of the silicalite-1 shell of the HS. The toplayer thickness that could be obtained
varied between 10 and 20 micron. The MMMs showed an increased flux
(normalized to a top layer thickness of 3 micron) in nanofiltration experiments
with isopropanol and Bengal rose (2,13 l/m² bar h) compared to the zeolite filled
PDMS (0,12- 0,67 l/m² bar h) and unfilled PDMS (0,25 l/m² bar h) without loss of
rejection (99%). In DCM and toluene, preliminary results were disappointing due
to a problematic adhesion between the PDMS toplayer and the polyimide
support. The improvement of this adhesion is still under study.
The described method should not be limited to hollow substances with zeolitic
shell nor to PDMS as a polymer. Any type of hollow compound with a shell
composed of inorganic material functional for the preparation of MMMs can be
used to improve permeabilities. It is expected that the described method will
improve fluxes not only in the nanofiltration field but also for pervaporation and
gas separation.

Hybrid Membranes – 3
Thursday July 17, 3:30 PM-4:00 PM, Wai’anae
Elaboration and Characterization of a Hybrid Membrane Based on
Hydrophilic Polymer/Ceramic Membrane for Metal Affinity Chromatography
M. Dubois, Institut Européen des Membranes, Montpellier, France
C. Muvdi Nova, Institut Européen des Membranes, Montpellier, France
D. Paolucci-Jeanjean (Speaker), Institut Européen des Membranes, Montpellier, France -
delphine.paolucci@iemm.univ-montp2.fr
M. Belleville, Institut Européen des Membranes, Montpellier, France
M. Rivallin, Institut Européen des Membranes, Montpellier, France
M. Barboiu, Institut Européen des Membranes, Montpellier, France
P. Bacchin, Laboratoire de Génie Chimique, Toulouse, France
Membrane chromatography was introduced as an integrative technology for the
purification of proteins several years ago. In general, the membrane process
could offer some advantages such as no intraparticle diffusion, short axial-
diffusion path, low pressure drop, no bed compaction, easier scale up, which are
usually limited in the conventional packed-column chromatographic systems [1].
Consequently, membrane chromatography is a promising large- scale separation
process for the isolation, purification, and recovery of proteins [2].
Almost all publications on membrane chromatography systems deal with organic
membranes which offer a large choice of functional chemical groups for ligand
grafting. In this study, an original hybrid membrane was chosen : a ceramic
support brings the mechanical and chemical strength required for industrial
applications whereas an organic layer brings the functional chemical groups
involved in the ligand grafting.
The elaboration of the hybrid metal affinity chromatography membrane involves 4
steps : i) coating of a polymer layer in order to functionalize the ceramic support,
ii) cross-linking and activation of the polymer layer, iii) grafting of a metal
chelating agent, iv) metal ion adsorption.
First, ceramic supports are functionalized by coating hydrophilic polymers on or
inside the membrane by tangential filtration of diluted chitosan or polyvinyl
alcohol (PVA) aqueous solutions in order to provide amine or hydroxyl groups
able to fix active compounds.
Then, functionalized membranes are cross-linked and activated with bisoxiranes
such as epichlorohydrin or 1,4-butanediol diglycidyl ether. On the one hand, this
step enables to stabilize the polymer layer (by cross-linking) and on the other
hand it provides epoxy groups for the metal- chelating-agent grafting. It is worth

noting that cross-linking agents constitute spacer arms which increase the ligand
accessibility and facilitate protein retention.
In the next step, iminodiacetic acid (IDA), a metal- chelating agent, is attached to
the epoxidized membranes.
Finally, Cu 2+ is chelated by IDA-grafted membranes during dead-end filtration of
a CuSO4 aqueous solution.
Different membranes are elaborated and the influence of several parameters
(polymer nature, cross-linking conditions, IDA grafting conditions) on Cu 2+
adsorption and thus protein retention is checked.
Cu 2+ adsorption capacities are estimated at 290 mg.m -2 for the chitosanmembrane
and 160 mg.m-2 for the PVA-membrane. These results are in the
same order of magnitude than those obtained for other organic membranes [3-5].
The PVA-membrane adsorbs a lower quantity of Cu 2+ than the chitosanmembrane
but as the adsorption is more specific, it remains attractive.
The hybrid affinity membranes obtained are then used for bovine serum albumin
and lysozyme retention.
Acknowledgement The authors acknowledge the French ANR (Agence Nationale pour la
Recherche) for the financial support of the PROMEMGEL project (ANR-05-JC05- 47316)
References
(1)E.Klein, Affinity membranes : a 10 years review, J Memb.Sci., 179, 2000, 1.
(2)C.Charcosset, Purification of proteins by membrane chromatography, J. Chem. Techn.
Biotech., 71, 1998, 95.
(3)T.C. Beeskow and W. Kusharyoto, Surface modification of microporous polyamide membranes
with hydroxyethyl cellulose and their application as affinity membranes, J. Chromatogr. A, 715,
1995, 49.
(4)Y.H. Tsai, M.Y. Wang and S.Y. Suen, Purification of hepatocyte growth factor using
polyvinyldiene fluoride-based immobilized metal affinity membranes: equilibrium adsorption study,
J. Chromatogr. B., 766, 2002, 133.
(5)C.Y. Wu, S.Y. Suen, S.C. Chen and J.H. Tzeng, Analysis of protein adsorption on regenerated
cellulose-based immobilized copper ion affinity membranes. J. Chromatogr. A., 996, 2003, 53.

Hybrid Membranes – 4
Thursday July 17, 4:00 PM-4:30 PM, Wai’anae
Optimization of SRNF Membranes Cast from Emulsified Polyimide
Solutions: Comparison of a Traditional Approach with a High
Throughput/Combinatorial Approach
P. Vandezande (Speaker), Katholieke Universiteit Leuven, Leuve, Belgium -
L. Gevers, Flemish Institute for Technological Research (VITO), Mol, Belgium
N. Weyens, Department of Chemistry-Biology-Geology, Diepenbeek, Belgium
I. Vankelecom, Katholieke Universiteit Leuven, Leuven, Belgium -
vo.vankelecom@biw.kuleuven.be
Solidification of Emulsified Polymer Solutions via Phase Inversion (SEPPI) has
recently been presented as a novel approach to create porous polymeric
structures with controlled porosity [1]. SEPPI involves the preparation of an
emulsified polymer solution through the addition of an organic suspension
containing nano-sized silicalite-1 particles [2]. This polymeric emulsion is
subsequently solidified by simple contact with a polymer non-solvent, with the
droplets acting as template for the final pores. A wide variety of polymers could
thus be turned into porous materials with tunable pore characteristics via a
number of easily accessible parameters at the level of the emulsion. Thanks to
the nano- dimensions of the particles and the insertion of an evaporation step
prior to solidification of the cast films, highly selective polyimide (PI) membranes
with thin top- layers could be prepared, which were successfully applied in
solvent resistant nanofiltration (SRNF) [3].
Being a membrane process able to separate organic mixtures down to a
molecular level at pressures between 5 and 20 bar, SRNF has a huge potential
in treating non-aqueous streams, mainly found in the food, petrochemical, finechemical
and pharmaceutical industries [3]. SRNF membranes are typically
applied to retain organic compounds with MWs ranging from 200 to 1000 g/mol.
Environmental and economical concerns explain the steadily increasing interest
in SRNF as a sustainable technique to treat solvent streams. In view of the
expected growth of the SRNF market, a clear need still exists to develop more
and better membranes to solve separation problems in existing industrial
processes and open new application areas.
As many parameters are involved in membrane synthesis, for instance via phase
inversion, testing and optimization of membranes has always been timeconsuming.
Using a traditional parameter- by-parameter approach, in which all
possible parameters are systematically, but independently screened, the
development of a new membrane with optimal properties would be extremely
slow, but also ineffective since it is very improbable to find the overall optimum of

such extended parameter space in this way. An important challenge in
developing and optimizing membranes is thus to find and implement more
efficient search strategies, which rapidly focus on the most promising spots within
the parameter space, thus increasing the chance on finding the membrane with
the best separation of the targeted compounds. The feasibility of high throughput
(HT) techniques and combinatorial search strategies in membrane research has
been demonstrated earlier with the successful optimization of PI based
asymmetric SRNF membranes in a 8- dimensional compositional parameter
space [4].
Similar to the latter study, asymmetric, nanozeolite-filled membranes, prepared
from emulsified PI solutions via the SEPPI method, were optimized here for their
performance in the separation of the low molecular weight dye rose Bengal (1017
g/mol) from IPA. All membranes were prepared and tested in a parallellized,
miniaturized and automated manner using laboratory- developed HT
experimentation techniques [4,5]. Only parameters related to the composition of
the casting solutions were investigated; all other synthesis conditions were kept
constant. Membranes were ranked according to their objective function, a fitness-
proportional numerical figure based on both permeance and retention values,
relative to predefined target and threshold performances. First, a preliminary
systematic screening was carried out, in which four constituents were used, i.e.
Matrimid® PI, NMP as solvent, THF as volatile co-solvent and NMP-based
nanozeolite sol as emulsifying agent. After, a combinatorial strategy, based on a
genetic algorithm and a self-adaptive evolutionary strategy, was applied to
optimize the membrane performance in an extended, 9- dimensional parameter
space, comprising two extra solvents (DMSO and DMAc), the two corresponding
nanozeolite suspensions, and another co-solvent (1,4-dioxane). Coupling with
HT techniques allowed to prepare three generations of casting solutions (176
compositions), resulting in 125 membranes. With IPA permeances up to 3.3 l. m-
2 .h -1 .bar -1 and RB rejections around 98%, the combinatorially optimized
membranes scored significantly better than the best membranes obtained in the
systematic screening. The most performant SEPPI membranes also showed
much higher IPA permeances than the commercial MPF- 50 and Starmem" 120
membranes, at similar or slightly lower RB rejections. Moreover, the
organomineral SEPPI membranes proved to be more compaction-resistant.
References
[1] P. Vandezande et al., accept. for public. in Chem. Mater.
[2] R. Ravishankar et al., J. Phys. Chem. B 1999, 103, 4960.
[3] P. Vandezande et al., Chem. Soc. Rev., 2008, 37, 365.
[4] M. Bulut et al., J. Comb Chem. 2006, 8, 168.
[5] P. Vandezande et al., J. Membr. Sci. 2005, 250, 305.

Hybrid Membranes – 5
Thursday July 17, 4:30 PM-5:00 PM, Wai’anae
Crosslinking and Stabilization of MgO Filled PTMSP Nanocomposite
Membranes for Gas Separation
L. Shao (Speaker), Norwegian University of Sci. and Tech., Trondheim, Norway
M. Hägg, Norwegian University of Sci. and Tech., Trondheim, Norway - maybritt.hagg@chemeng.ntnu.no
Poly(1-trimethysilyl-1-propyne)[PTMSP] is a stiff chain, high free volume glassy
polymer known for its very high gas permeability, but consequently then also
relatively low selectivity. The high gas permeability could be an advantage, but is
unstable over time. It has been reported that the oxygen permeability of PTMSP
decreased by 1 order of magnitude during storage at 25 °C for 30 days under
vacuum. The gas permeability in this polymer is also sensitive to processing
history. PTMSP undergoes significant physical aging which is caused by the
gradual relaxation of non-equilibrium excess free volume in glassy polymers.
Additionally, organic solvents may degrade PTMSP, and hence all these
disadvantages may compromise the practical use of this high permeation
polymer.
The current study investigates the effect of crosslinking PTMSP on transport
properties and physical aging. PTMSP has been crosslinked using bis azides to
improve its chemical and physical stability. Crosslinking PTMSP renders it
insoluble in good solvents for the uncrosslinked polymer. Gas permeability and
fractional free volume (FFV) decreased as crosslinker content increased, while
gas sorption was unaffected by crosslinking. Therefore, the reduction in
permeability upon crosslinking PTMSP was due to decreases in diffusion
coefficients. Compared to the pure PTMSP membrane, the permeability of the
crosslinked membrane is initially reduced for all gases tested due to the
crosslinking. By adding nanoparticles MgO, the permeability is again increased;
permeability reductions due to crosslinking could be offset by adding
nanoparticles to the membranes. Increased selectivity is documented for the gas
pairs O2/N2, CO2/N2, CO2/CH4 and H2/CH4 using crosslinking and addition of
nanoparticles. Crosslinking is successful in maintaining the permeability and
selectivity of PTMSP membranes and PTMSP/filler nanocomposites over time.

Hybrid Membranes – 6
Thursday July 17, 5:00 PM-5:30 PM, Wai’anae
Preparation High Performance Microporous/Mesoporous Hybrid
Membranes for Gas Separation
Q. Liu (Speaker), Dalian University of Technology, Dalian, China
X. Zhao, Dalian University of Technology, Dalian, China
T. Wang, Dalian University of Technology, Dalian, China - wangth@chem.dlut.edu.cn
S. Liu, Dalian University of Technology, Dalian, China
Y. Cao, Dalian Institute of Chemical Physics, Dalian, China
J. Qiu, Dalian University of Technology, Dalian, China
Carbon molecular sieving (CMS) membrane is considered to be one of the most
promising inorganic membrane materials for membrane-based gas separation
because of their excellent selectivity and thermal and chemical stability even
under harsh conditions, such as high pressure and high temperature. However,
the separation performance of this material still can not satisfy the practical
application requirement owing to their low permeability.
Herein, a novel carbon-based microporous/mesoporous hybrid membrane has
been successfully designed and prepared for gas separation. The as-synthesized
hybrid material is composed of continuous microporous carbon matrix and
dispersed mesoporous material SBA-15. It is well known that gas transport
through ordered mesoporous materials is governed by the Knudsen diffusion
mechanism with negligible contribution from viscous flow. Therefore, the gas
diffusion rate in the mesoporous materials is several orders of magnitude faster
than that in microporous materials. The incorporation of mesoporous material
SBA-15 will help to increase the gas diffusion rate in the membranes and
improve the gas separation performance.
The characterization results conducted by XRD, TEM and nitrogen sorption
analysis indicated that the mesoporous material SBA-15 was well dispersed in
the carbon matrix and the mesoporous structure of SBA-15existed in hybrid
membrane was not destroyed during pyrolysis. The gas permeation tests using
small molecules (H2, CO2, O2, N2 and CH4) showed that the hybrid membrane
exhibited outstanding permeability together with high selectivity, which indicated
that gas transport through the hybrid membranes was still controlled by the
molecular sieving effect. The correlation of the permeability versus the selectivity
for the hybrid membrane showed higher values than the Robeson upper bounds
for polymeric membranes. And the gas separation performance of the
membranes were also higher than the polyimide-derived carbon membranes.
The excellent gas separation performance for all tested gases makes the
microporous/mesoporous hybrid membrane an attractive material in gas
separation areas.

Oral Presentation
Abstracts
Morning Session
Friday, July 18, 2008

Plenary Lecture III
Friday July 18. 8:00 AM-9:00 AM, Hawai’I Ballroom
The Development of Reverse Osmosis and Nanofiltration through Modern
Times
William E. Mickols (Speaker), DOW Water Solutions, Edina, Minnesota - WEMickols@dow.com
The history of reverse osmosis (RO) began with the discovery of osmotic
pressure. Modern thermodynamics offered the explanation of how theoretical
chemical activity differences could be used to develop a physical pressure
difference. Further developments in stochastic theory showed how either a
physical pressure or a chemical concentration difference could be expressions of
the same effect. The actual proof of using pressure to develop a chemical
gradient was left to Loeb and Sourirajan. Their work on cellulose based
symmetric and asymmetric RO membranes amazed the scientific and popular
world. This mobilized the scientific world to convert their discovery from a
scientific curiosity to a viable method to desalinate water.
The development of RO was driven, in part, by considerations that 80% of the
world’s surface is covered with water too saline to drink. Recently we have found
that 60-80% of the remaining water is too contaminated to drink by World Health
Organization (WHO) standards. Of the remaining 20-30% drinkable water, much
of it is becoming contaminated and will require extensive remediation.
Modified celluloses were initially used to make asymmetric RO membranes.
Charged thermoplastics were also extensively studied. Modern RO membranes
began with asymmetric aromatic polyamides in the hollow fiber form. The recent
explosion in RO began with the development of interfacial synthesis of thin film
composites by John Cadotte at North Star research. Initial development used
polyimine based cross-linked polyamides (NS200). This began the parade of
remarkable high flux, high rejection reverse osmosis membranes.
With the development of interfacial synthesis of two new aromatic polyamides,
the concept of nanofiltration and RO was developed. The FilmTec NF-40
membrane (piperazine and TMC) and FT-30 (meta phenylene diamine and TMC)
launched the modern industry. Over the course of 20 years the water
permeability increased by a factor of eight and the salt permeability dropped by
almost a factor of twenty. Separations that required 400 psi now only require 50
psi and have better rejection. Modification of the surface of FT-30 has also
allowed RO to operate at very low ionic strengths. The altered charged surfaces
changed the ion rejection characteristics at low ionic strength. For high ionic
strength we’ve shown that by designing the membrane to fit the separation, the
efficiency of RO separations can be increased by a factor of over 50%. Modern

alteration of the structure of FT-30 includes designs for specific solute rejections.
This includes cutting the passage of neutral solutes like boric acid by 40%.
Contamination of water supplies with neutral solutes and difficult to remove
solutes has fueled recent advances in RO chemistry. General methods to reduce
solute passage are being developed across the globe. Continuing to redesign
RO membranes will allow us to improve the passage of other important solutes
which will drive further utilization of RO throughout the world.

Gas Separation V – 1 – Keynote
Friday July 18. 9:30 AM-10:15 AM, Kaua’i
Designing Membranes for Future Membrane Gas Separation Applications
R. Baker (Speaker), Membrane Technology and Research, Inc., Menlo Park, California, USA -
rwbaker@mtrinc.com
Using membranes for gas separation is now big business. Close to $500 million
of equipment is sold each year, 50,000-100,000 plants for separation of nitrogen
from air have been installed, and natural gas plants with membrane areas of
several hundred thousand square meters have been built. In this talk, the current
technical status of the gas separation membrane industry will be described. This
will be followed by a discussion of some membrane separations under
development: water from bioethanol, carbon dioxide from coal power plant flue
gas, and olefins from paraffins. The relationships between process design and
the type of membrane needed will be addressed.

Gas Separation V – 2
Friday July 18, 10:15 AM-10:45 AM, Kaua’i
Sorption and Dilation of Crosslinked Poly(ethylene oxide) Membranes by
Carbon Dioxide and Ethane
C. Ribeiro (Speaker), The University of Texas at Austin, Austin, Texas, USA
B. Freeman, The University of Texas at Austin, Austin, Texas, USA - freeman@che.utexas.edu
Carbon dioxide constitutes a common impurity that must be removed from
natural gas to improve its heating value. For low gas flow rates, membrane units
have already been installed to perform this separation instead of the traditional
process based on absorption in amine solutions. However, due to plasticization
by carbon dioxide and higher hydrocarbons, the selectivity and flux of current
commercial membranes, based on cellulose acetate and polyimides, are not high
enough to compete with amine systems for medium and large gas flow rates.
Therefore, new membrane materials for this separation are sought.
Crosslinked poly(ethylene oxide)-based (XLPEO) membranes have been
recently identified as a promising alternative for the selective removal of carbon
dioxide from light gas mixtures. Copolymers synthesized by photopolymerization
of different composition ratios of poly(ethylene glycol) diacrylate (PEGDA) and
poly(ethylene glycol) methyl ether acrylate (PEGMEA) exhibited excellent
separation performance for CO2/hydrocarbon mixtures in permeation
experiments carried out with both pure gases and gas mixtures [1, 2]. Contrary to
cellulose acetate and polyimides, XLPEO-based membranes are solubility
selective and, therefore, the determination of their sorption characteristics for
different gases is of considerable importance. Even though pure gas sorption
data for these materials are already available [3], these were all obtained
neglecting the effect of polymer dilation, which can be rather significant.
In the present contribution, pure gas dilation and sorption data for two different
XLPEO-based materials with carbon dioxide and ethane are reported at
temperatures ranging from -20 to 35 o C. The importance of taking polymer dilation
into account to determine the gas solubility in the polymer was clearly
demonstrated. In particular, the PEGMEA content, previously believed to have a
negligible effect on gas sorption [4], was shown to influence gas solubility
significantly. The amount of carbon dioxide sorbed in the polymer for a given gas
activity increased with decreasing temperature, whereas, in the case of ethane,
the opposite trend was observed. For each temperature, sorption and dilation
data were combined to calculate the respective partial molar volume of each gas
in the polymer and the results were compared with available literature data for
other rubbery polymers.

References:
[1] H. Lin, E. Van Wagner, R. Raharjo, B. D. Freeman, I Roman. High-performance polymer
membranes for natural-gas sweetening. Advanced Materials, 18, 39-44, 2006.
[2] S. Kelman, H. Lin, E. S. Sanders, B. D. Freeman. CO2/C2H6 separation using solubility
selective membranes. Journal of Membrane Science, 305, 57-68, 2007.
[3] H. Lin and B. D. Freeman. Gas and vapor solubility in cross-linked poly(ethylene glycol
diacrylate). Macromolecules, 38, 8394-8407, 2005.
[4] H. Lin, E. Van Wagner, J. S. Swinnea, B. D. Freeman, S. J. Pas, A. J. Hill, S. Kalakkunnath,
D. S. Kalika. Transport and structural characteristics of crosslinked poly(ethylene oxide) rubbers.
Journal of Membrane Science, 276, 145-161, 2006.

Gas Separation V – 3
Friday July 18, 10:45 AM-11:15 AM, Kaua’i
Kinetic Sorption and Permeation Behavior of Water Vapor in Polymeric
Membranes
H. Sybesma, University of Twente, The Netherlands
J. Potreck, University of Twente, The Netherlands
K. Nymeijer (Speaker), University of Twente, The Netherlands - d.c.nijmeijer@utwente.nl
R. van Marwijk, KEMA, The Netherlands
R. Heijboer, KEMA, The Netherlands
M. Wessling, University of Twente, The Netherlands
Objective
Coal-fired power plants produce electricity and in addition to that large volume
flows of flue gas, which mainly contains N2, O2, CO2 and water vapor, but also
pollutants such as nitric oxides (NOx), sulfur dioxide (SO2), and fly ash. As a
consequence of gas cleaning steps, the temperature of the flue gas decreases
and the gas stream becomes saturated with water vapor. This can easily lead to
condensation of water vapor in the stack of the power plant, which causes
corrosion. To prevent condensation, traditionally reheating of the flue gas is
required, resulting in extra energy consumption and additional costs.
Membrane technology is an attractive technology to remove part of the water
vapor to prevent condensation. The application of membranes for this separation
is especially attractive due to the possibility of re-use of the water and the
additional energy savings.
In the present work we present such a membrane system with extremely high
separation factors and fluxes for the removal of water vapor from flue gasses.
The work combines fundamental understanding of the kinetic sorption and
transport behavior of water vapor in macromolecular structures with more applied
knowledge to show the potential of the developed membranes for industrial flue
gas dehydration [1-3].
Kinetic sorption analysis
An economically viable membrane process for the dehydration of flue gasses
requires membranes with extremely high water vapor fluxes combined with a
very low non-condensable flux. Several materials were investigated and the
results clearly show the superior performance of sulfonated poly(ether ether
ketone) (SPEEK), especially at higher water vapor activities. Sorption isotherms
of water vapour in this glassy polymer were determined experimentally and the

elative contributions of Fickian diffusion and relaxational phenomena are
quantified as a function of the water concentration in the polymer using the
Hopfenberg-Berens model. The hydrophilic nature of the polymeric material,
especially for higher degrees of sulfonation, results in very high water vapour
sorption values, high swelling and subsequently high Fickian diffusion
coefficients. The results proof the occurrence of both Fickian sorption behaviour
and relaxation phenomena already at very low water concentrations in the
polymer matrix. With increasing water concentration, the glass transition
temperature of the swollen polymer decreases and the relative importance of
relaxation phenomena increases whereas that of Fickian diffusion decreases.
Mixed gas and water vapor permeation behavior
Composite hollow fiber membranes with a dense top layer of SPEEK were
developed and characterized in terms of their mixed water vapor/nitrogen
permeability and selectivity. Membrane modules were prepared and used for a
150 h experiment with artificial flue gas. 0.6 to 1 kg/m 2 hr of water with a
conductivity of 2 µS/cm was removed continuously and no visible changes in
membrane structure or morphology were observed.
The developed membranes were used for flue gas dehydration in long-term
exposure tests under real flue gas conditions in a 450 MW coal fired power plant.
The prepared membranes were placed directly into the aggressive flue gas
stream and the performance was monitored. To create a driving force for
permeation, the overcapacity of the condenser system already present in the
power plant could be used. An average water vapor removal rate of 0.2 to 0.46
l/m 2 h was obtained during a continuous period of 5300 hours.
Finally, the experimental data were used as input values for computer
simulations to identify the influence of the process parameters on the installed
membrane area. Simulations stress the importance of very high water vapor
permeabilities combined with very low inert gas fluxes for an economically viable
process.
Conclusions
In the present work we present a gas separation membrane with extremely high
separation factors and fluxes for the removal of water vapor from flue gasses.
The work combines fundamental understanding of the kinetic sorption and
transport behavior of water vapor in macromolecular structures with more applied
knowledge to show the potential of the developed membranes for industrial flue
gas dehydration.

References:
1. Hylke Sijbesma, Kitty Nymeijer, Rob van Marwijk, Rob Heijboer, Jens Potreck, Matthias
Wessling, Flue gas dehydration using polymer membranes, J. Membrane Sci. (2007),
doi:10.1016/j.memsci.2008.01.024.
2. J. Potreck, F. Uyar, H. Sijbesma, K. Nymeijer, D. Stamatialis, M. Wessling, Kinetic sorption
behavior of water vapor in sulfonated poly ether ether ketone, In preparation.
3. J. Potreck, T. Kosinski, K. Nymeijer, M. Wessling, Sorption, diffusion and transport phenomena
of water vapor in PEBAX®, In preparation.

Gas Separation V – 4
Friday July 18, 11:15 AM-11:45 AM, Kaua’i
Natural Gas Purification Using High Performance Crosslinked Hollow Fiber
Membranes: Effects of High Pressure CO2 and Toluene Feed.
I. Omole (Speaker), Georgia Institute of Technology, Atlanta, Georgia, USA
S. Miller, Chevron Energy Technology Company, Richmond, California, USA
W. Koros, Georgia Institute of Technology, Atlanta, Georgia, USA -
william.koros@chbe.gatech.edu
Natural gas is one of the fastest growing primary energy sources in the world
today. The increasing world demand for energy requires increased production of
high quality natural gas. For the natural gas to be fed into the mainline gas
transportation system, it must meet the pipe-line quality standards. Natural gas
produced at the wellhead is usually ‘sub-quality’ and contains various impurities
such as CO2, H2S, and higher hydrocarbons, which must be removed to meet
specifications.
Carbon dioxide is usually the largest impurity in natural gas feeds and high CO2
partial pressures in the feed can lead to plasticization, which causes loss of some
methane product and may ultimately render the membrane ineffective. Moreover,
the presence of highly sorbing higher hydrocarbons in the feed can further
reduce membrane performance.
Covalent crosslinking has been shown to increase plasticization resistance in
dense films by suppressing the degree of swelling and segmental chain mobility
in the polymer, thereby preserving the selectivity of the membrane. This research
focuses on extending the dense film success to asymmetric hollow fibers.
In this paper, the effect of high pressure CO2 (up to 400 psig CO2 partial
pressure) on CO2/CH4 mixed gas separation performance was investigated on
the hollow fiber membrane at different degrees of crosslinking. All the crosslinked
fibers were shown to exhibit good resistance to selectivity losses from CO2
induced plasticization, significantly more than the uncrosslinked fibers. Robust
resistance of the hollow fiber membranes in the presence of toluene (a highly
sorbing contaminant) was also demonstrated as the membranes showed no
plasticization even in toluene saturated feed streams.

Gas Separation V – 5
Friday July 18, 11:45 AM-12:15 PM, Kaua’i
Synthesis and Gas Permeability of Hyperbranched Polyimide Membranes
K. Nagai (Speaker), Meiji University, Kawasaki, Japan - nagai@isc.meiji.ac.jp
The mobility of polymer chains is larger for their polymer terminal chain ends as
compared to that for their polymer main chains. Therefore, gas-induced
plasticization may occur easily around the polymer chain ends as compared to
around the polymer main chains. Moreover, if the number of polymer chain ends
is minimized in a membrane, gas-induced plasticization would be prevented. In
order to reduce the number of polymer chain ends as well as their mobility,
hyperbranched polymer membranes were prepared, and the plasticization
resistance of their carbon dioxide (CO2) permeability was investigated. The base
polymers for hyperbranch were the polyimides based on 4,4'-
(hexafluoroisopropylidene)diphthalic anhydride (6FDA). The diamine used for
these polyimides was either 3,4-diaminodiphenyl ether (3,4DADE) or 2,3,5,6tetramethyl-1,4-phenylene
diamine (TeMPD). Both chain ends of the linear
6FDA- based polymer were capped with either 4-(2- phenylethynyl)phthalic
anhydride (PEPA) or p- aminostyrene. For example, in the case of 6FDA-
3,4DADE-PEPA, the hyperbranch structure was formed by the cycrotrimerization
of three acetylene groups in three PEPA groups in the presence of tantalum
chloride (V), which act as a catalyst. The linear base polyimide was soluble in
chloroform and so on, while the hyperbranched one showed poor solubility in the
same solvents. In addition, the hyperbranched polyimides had larger membrane
density than their base linear counterparts. During CO2 exposure at 40 atm and
at 35C, the CO2 permeability coefficient in the base linear polyimide membranes
increased with time, whereas in the hyperbranched one, the polyimide
membranes were stable, indicating resistance for CO2 plasticization.

Gas Separation V – 6
Friday July 18, 12:15 PM-12:45 PM, Kaua’i
The Effect of Water on the Gas Separation Performance of Polymeric
Membranes for Carbon Dioxide Capture.
C. Scholes, CRC for Greenhouse Gas Technologies, Victoria, Australia
R. Hasan, CRC for Greenhouse Gas Technologies, Victoria, Australia
S. Kentish (Speaker), CRC for Greenhouse Gas Technologies, Victoria, Australia -
sandraek@unimelb.edu.au
G. Stevens, CRC for Greenhouse Gas Technologies, Victoria, Australia
Polymeric gas separation membranes for natural gas, pre- and post-combustion
carbon dioxide capture must contend with water, which generally saturates the
feed gas. The presence of water competes with carbon dioxide in sorption into
the Langmuir volume of the polymeric membrane. This competitive sorption
generally results in decreased carbon dioxide permeability in the membrane
compared to dry gas, and therefore a loss in performance. Furthermore, the
presence of water can act as a plasticizer, and over time alter the polymeric
structure leading to time dependent ageing of the membrane, and possibly
failure. Here, the impact of water on a range of glassy polymeric membranes are
studied; polysulfone, Matrimid and 4,4-(hexafluoroisopropylidene) diphthalic
anhydride (6FDA-Durene), as well as the rubbery material poly dimethylsiloxane
(PDMS). The purpose of this work is to model the water affected carbon dioxide
separation performance under conditions that mimic real carbon capture
systems. Results will be compared to upcoming plant trials to be conducted
under the Energy Technology Innovation Strategy (ETIS) program for both pre-
and post- combustion carbon dioxide capture.
For all polymeric membranes, glassy and rubbery, a loss in carbon dioxide
permeability occurs upon exposure to wet feed gas, indicative of competition
from water. This behaviour is modelled for glassy membranes as competitive
sorption in the dual- sorption model; and used to evaluate the affinity of water for
the Langmuir volume within the membranes. Exposure over longer timescales
(hours) result in improved carbon dioxide permeability for both poly sulfone and
6FDA- Durene. This is a consequence of plasticization of the membranes by
water, altering the glassy polymeric matrix to a more rubbery state. This
behaviour is not observed for Matrimid, and is associated with the difference in
free volume of the polymeric membranes, and therefore their susceptibility to
plasticization.

Nanofiltration and Reverse Osmosis III - Applications – 1 – Keynote
Friday July 18, 9:30 AM-10:15 AM, Maui
Fundamental Study and Performance Advancement of Seawater RO
Membrane
M. Henmi (Speaker), Toray Industries, Inc., Shiga, Japan - Masahiro_Henmi@nts.toray.co.jp
H. Tomioka, Toray Industries, Inc., Shiga, Japan
T. Kawakami, Toray Industries, Inc., Shiga, Japan
M. Kurihara, Toray Industries, Inc., Shiga, Japan
In seawater reverse osmosis (SWRO) desalination field, boron removal is a
significant matter to be conquered since it is known to show male reproductive
tract per oral administration in laboratory animals. WHO has established the
boron concentration in drinking water to be below 0.5mg/L as a guideline value.
Boron exists as boric acid in seawater, and its concentration is 4 to 7 mg/L. Boric
acid is the typical substance which is difficult to be removed by RO membrane
since it is a very small molecule having about 0.4 nm in diameter. Although
conventional RO membrane elements have shown a little more than 90% of
boron rejection, it was still inadequate and necessary to use some supportive
processes to remove boron. Accordingly, high boron rejection membrane is
desirable for reducing the loading to such supportive processes. We have
recently been investigating SW RO membranes with focusing on high boron
removal, and its performance is getting better every year. The boron rejection
rates of the recent membranes have been improved up to 94 - 95 %, and
fundamental researches into the substance removal mechanism of RO
membrane have been carried out for the achievement of further excellent
performance.
Spectroscopic structure analyses for various RO membranes, which were
selected from those of having an aromatic polyamide separating functional layer
and different performance upon boron removal, but equal salt removal, were
performed to obtain the molecular structure information and the parameters
influencing to substance removal. Positron annihilation lifetime spectroscopy
(PALS) study with positron beam method nondestructively provided the
information of the pore sizes in the range of 5.6 - 7.0 angstroms for several
SWRO membranes as against of 50 - 70 angstroms for an NF membrane.
Consequently, the correlation between the measured pore size and the boron
removal performance in RO membranes was also revealed. Solid-state 13C
NMR spectroscopy demonstrated all the peaks of each chemical functional group
in separating functional layer of the RO membranes and the presumptive
molecular structures of the polyamide were estimated. Molecular dynamics
analyses based on the estimated molecular models were performed, and the
calculated pore sizes were well agreed with the measured ones. Transmission

Electron Microscopy (TEM) analyses of protuberance of RO membrane surface
shows the probability of membrane potential improvement. Through these
studies, special molecular design, which controls the pore size in RO membrane,
is needed to the development of further renovate membrane. In this presentation,
the prospect of attaining a new renovative high boron rejection membrane will be
discussed.

Nanofiltration and Reverse Osmosis III - Applications – 2
Friday July 18, 10:15 AM-10:45 AM, Maui
Development and Testing of a High-Capacity, Mobile Desalination System
M. Miller (Speaker), U.S. Army TARDEC, Port Hueneme, California, USA -
mark.c.miller@navy.mil
M. Chapman, Bureau of Reclamation, Denver, Colorado, USA
C. Barley, NSF International, Ann Arbor, Michigan, USA
M. Blumenstein, NSF International, Ann Arbor, Michigan, USA
B. Shalewitz, U.S. Army TARDEC, Port Hueneme, California, USA
In late 2002 a multidisciplinary team of U.S. military and government personnel
were enjoined in response to a congressional initiative to stimulate discovery and
invention in science and technology pertaining to water purification, and verify as
well as validate the utility of emerging state of the art science and technology in
water purification systems. The EUWP program was established to address two
principal objectives. The first was to fund research in the academic and
commercial sectors to further the state of desalination technology, while the
second was to develop a mobile, high-capacity desalination system intended to
showcase technological innovations that may have application for future military
water purification equipment. This presentation will address the development and
evaluation of the EUWP technology demonstrator.
The objective of the EUWP demonstrator is to develop a system that maximizes
production, yet achieves transportability requirements important to the military.
The primary design constraint for the equipment is that it be air transportable.
Achieving air transportability requires that the overall system weight and size be
minimized. This resulted in the incorporation of several technologies not used in
military water purification systems at the time, as well as a change in design
philosophy. Some examples include:
- Ultrafiltration with coagulant addition: Due to the mobile nature of the system
and feed water conditions that are expected to be encountered, the EUWP
utilizes ultrafiltration (UF) to be able to treat high turbidity water with minimal
footprint. In an effort to further reduce system size and weight, coagulant addition
is employed resulting in the ability to operate the UF system at higher flux rates
for extended periods of time. An additional benefit of UF is that the high quality
water provided can enable operating the reverse osmosis (RO) system at higher
flux and recovery rates. - Energy recovery: The incorporation of energy recovery
allows the system to produce more water with no additional power burden. In
addition, the size of the high-pressure pump and motor can be reduced resulting
in overall space and weight savings.

- Hybrid RO train: A hybrid RO train consisting of three different RO elements is
employed to provide a more balanced flux distribution between elements and an
increased production over a conventional RO train. Using a hybrid RO train
results in the need for fewer RO membranes and therefore a smaller package.
Pilot testing of the UF and RO systems was conducted prior to their incorporation
into the system design. These tests confirmed important performance
parameters and operational constraints prior to incorporation into the system.
Final evaluation of the system based on the EPA’s Environmental Technology
Verification (ETV) program was pursued in 2006 and 2007 due to the potential
employment of the system for use in disaster relief missions. ETV evaluations
were conducted on three different water sources to evaluate performance of the
entire system as well as several of the subsystems. Feed waters included
seawater, surface water and a secondary effluent with high biological content to
challenge the prefiltration system. The primary objective of the ETV testing was
to verify that the system meets water quality objectives; however the evaluation
of performance metrics pertaining to the UF and RO systems were also included
to evaluate membrane performance. ETV testing exceeded 2,000 hours.
The incorporation of the aforementioned technologies has resulted in arguably
the highest production system per unit volume and weight than any stand-alone
water purification system in existence. The EUWP has been successfully
deployed on three separate occasions.

Nanofiltration and Reverse Osmosis III - Applications – 3
Friday July 18, 10:45 AM-11:15 AM, Maui
Investigation of Amphoteric Polybenzimidazole (PBI) Nanofiltration Hollow
Fiber Membrane for both Cation and Anion Removal
J. Lv, National University of Singapore, Singapore
K. Yu Wang (Presenting), National University of Singapore, Singapore
T.-S. Chung, National University of Singapore, Singapore - chencts@nus.edu.sg
High levels of harmful ions in the surface and ground waters have become a
major health problem in many countries. Harmful anions removal can be
achieved by adsorption, precipitation and electrocoagulation, ion exchange and
extraction. Membrane separation processes have been proven to be a feasible
and promising option for the removal of toxic ion species. Using nanofiltration
(NF) membranes to remove toxic species of wastewater has also been carried
out. Generally, positively-charged NF membranes are only effective for cations
removal, whereas negatively- charged NF membranes are only effective for
anions removal. In this study, the removal of both anions (phosphate, arsenate,
arsenite and borate ions) and cations (copper ions) has been investigated by
employing a lab-developed amphoteric polybenzimidazole (PBI) nanofiltration
(NF) hollow fiber membrane. The amphoteric characteristics are due to the
imidazole group within PBI molecules that makes the PBI NF membrane having
an isoelectric point near pH 7.0 and shows different charge signs based on the
media pH. Investigations on the rejection capability of typical anions, e.g.
phosphate, arsenate, arsenite, borate anions and typical heavy metal cations,
e.g. copper ions, reveal that the PBI NF membrane exhibits impressive rejection
performance for various ion removals. However, their rejections are strongly
dependent on the chemical nature of electrolytes, solution pH and the feed
concentrations. The experimental results are analyzed by using the Speigler-
Kedem model with the transport parameters of the reflection coefficient and the
solute permeability (P) with the aid of molecular model and ion sizes. The PBI NF
membrane may have potential to be used in industrial removal of various
environmentally- unfriendly ion species.

Nanofiltration and Reverse Osmosis III - Applications – 4
Friday July 18, 11:15 AM-11:45 AM, Maui
Nanofiltration of Ferric and Ferrous Cations in Acidic Solutions
X. Bernat (Speaker), ETSEQ, Universitat Rovira i Virgili, Terragona, Spain
F. Stüber, ETSEQ, Universitat Rovira i Virgili, Terragona, Spain
A. Fortuny, Universitat Politècnica de Catalunya, Barcelona, Spain
C. Bengoa, Universitat Rovira i Virgili, Terragona, Spain
A. Fabregat, ETSEQ, Universitat Rovira i Virgili, Terragona, Spain
J. Font, ETSEQ, Universitat Rovira i Virgili, Terragona, Spain - jose.font@urv.cat
Ferric and ferrous ions are used as catalyst in advanced oxidation processes, in
conjunction with hydrogen peroxide, to accelerate oxidation reactions for partially
mineralizing organic biorefractory substances. Fenton process, Fe/H2O2, is the
most popular technique based in this principle. As a result, homogeneous iron
leaves the oxidation step with the treated wastewater posing potential
environmental and economical problems. Nanofiltration is being studied and
applied as a promising technology to recover multivalent ions and organic
compounds from aqueous polluted streams achieving additionally partial
softening of these waters. Several mechanisms such as charge repulsion
between the membrane and the targeted compound and sieving are involved in
the mechanisms allowing the retention of the targeted ions or compounds. In
addition, several operating variables may affect the efficiency of the separation
process by lowering the permeate fluxes during the operation. The
transmembrane pressure, the pH, the hydrodynamic conditions, the presence of
other species and still others may influence the retention, the permeate rate and
the fouling during the filtration process. In this work, the recovery of ferrous and
ferric ions from aqueous solution by nanofiltration is presented. The experiments
were conducted in a commercial batch stirred filtration cell. The effect of several
operating variables on both the iron retention and the permeate flux were
studied. NF, NF90 and NF270 membranes (manufactured by Dow Filmtec) were
selected for this work as they are commercially available membranes that
possess different isoelectric points and charge densities on their surfaces. The
solutions to be treated were adjusted at pH 2, which is typical pH for effluents
treated by Fenton process. The effect of the transmembrane pressure, the
stirring speed, the presence of NaCl and the iron concentration on the iron
retention and permeate flux decline is illustrated. The results show that low
permeate flux decline was achieved and high Fe (III) retention (up to 99.9%) was
obtained with all the tested membranes, assuring the final quality of the permeate
and the possibility of reusing the retentate in the oxidation reactor. When
comparing Fe (III) and Fe (II) performance, a lower iron charge caused a
decrease of the iron retention due to the poorer charge repulsion phenomena
between the charged membrane surface and the Fe (II) ions. NF90, which is a
specially designed membrane for the recovery of iron, showed the highest Fe (III)

etention but it also gives the lowest Fe (II) retention when compared to NF and
NF270. In addition, NF90 membrane exhibited remarkable permeate flux decline,
which make it not very attractive for this use. In turn, NF and NF270 membranes
showed very similar Fe (III) and Fe (II) retentions. However, permeate flux
decline of NF270 was higher than that of NF. As NF270 permeability is much
higher than that of NF, NF270 is considered the best option for the effective
recovery of ferrous and ferric ions from acidic solutions by nanofiltration and will
be further tested in Fenton treatment as means to confine the homogeneous
reaction and recover clean water.

Nanofiltration and Reverse Osmosis III - Applications – 5
Friday July 18, 11:45 AM-12:15 PM, Maui
Treatment of the Groundwater Contaminated by High Concentration of
Arsenic
M. R. Alizadehfard (Speaker), WorleyParsons, Australia -
reza.alizadehfard@worleyparsons.com
M. H. Alizadehfard, Curtin University, Bentley, Australia
Arsenic classified as Group 1 carcinogenic substance to humans based on
powerful epidemiological evidence. Arsenic cannot be destroyed; it can only be
transformed into different forms or combined with other elements to be converted
into insoluble compounds. Therefore, there is a tremendous demand for
developing expense efficient methods for arsenic removal from contaminated
groundwater and drinking water. In this work, the removal of arsenic from
contaminated groundwater by Membrane and Ligand technologies were
investigated. The suspended solids in contaminated groundwater were removed
by a 1 micron bag filter. Organic compounds in the contaminated groundwater
were removed by adsorption onto granular activated carbon. The Arsenic in the
groundwater, with the average initial concentration of 450 mg/l, was concentrated
by rejecting through a thin film composite reverse osmosis (RO) membrane unit.
The arsenic concentration in the final RO permeate was reduced to 2 mg/l by
passing two times through the two stages RO membrane pilot unit. The arsenic
concentration in RO concentrate was increased to 2500 mg/l prior to
Electrochemical (Ion Exchange membrane) unit. RO permeate was captured by
passing through a thin bed of zirconium hydroxide media. The arsenic
concentration in the final treatment was reduced to 0.05 ppm. Then, the
arsenite/arsenate mixture was removed from the media with an alkaline solution
forming sodium arsenite and sodium arsenate. This solution was treated by a
proprietary electrochemical process in a specially designed cell to plate the
arsenic as metalloid onto a cathode.

Nanofiltration and Reverse Osmosis III - Applications – 6
Friday July 18, 12:15 PM-12:45 PM, Maui
Purification of Glucose/Sodium Lactate Solutions By Nanofiltration:
Selectivity Improvement By the Addition of a Mineral Salt
C. Umpuch, Suranaree University of Technology, Nakhon Ratchasima, Thailand
S. Galier, Université de Toulouse, Toulouse, France
S. Kanchanatawee, Suranaree University of Technology, Nakhon Ratchasima, Thailand
H. Roux-de Balmann (Speaker), Université de Toulouse, Toulouse, France -
roux@chimie.ups-tlse.fr
Nanofiltration is expected to be adapted to the separation of neutral solutes, like
sugars, from charged ones, like organic acid salts depending on their molecular
weight. This is the case of glucose and sodium lactate for instance. Previous
work was thus devoted to the investigation of NF to purify glucose/sodium lactate
solutions. Indeed, it was considered that such solutions are representative of
those that can be encountered in the frame of the purification of lactic acid
fermentation broths, in which glucose would represent the residual sugar
impurities remaining after the fermentation stage.
The experimental study was carried out with an NF Desal DK membrane and
solutions of increasing complexity, i.e. single solutions of glucose or sodium
lactate on one hand and mixed ones, containing both solutes, on the other hand.
A good selectivity was expected from single solute solutions, since the retention
of glucose and sodium lactate were found to be about 80 and 20% respectively.
On the contrary, it was observed that the retention of glucose in mixed solution
was significantly decreased from 80 to 20%. As a result, the NF selectivity was
found to be very poor. Such an effect of the presence of charged species on the
retention of neutral ones was reported in different situations, with organic as well
as inorganic membranes and with different kind of solutes, like organic acid salts
and PEG for instance.
In this work, we try to investigate to what extend the ionic composition can
influence the selectivity of the glucose/sodium lactate separation by NF. Indeed,
thanks to the former results, one can expect that the addition of a third charged
species, like a mineral salt, affects the sugar and organic acid salt in different
manner. Then, a separation could be achieved for appropriate operating
conditions. An experimental study is thus reported in which the influence of the
fluid composition, and specially the mineral composition, on the selectivity of the
glucose/sodium lactate separation is investigated. This is done by adding
different mineral salts, like NaCl (0.1-1M) and Na2SO4 (0.1- 0.5M). It shows that,
in the lower flux region, the selectivity can be significantly improved by the
addition of a salt. This improvement depends on the mineral salt type and

concentration as well as on the sodium lactate concentration. From these results,
it is also possible to identify the limiting phenomena governing the retention of
the different solutes through the NF membrane. Finally, this can open new
possibilities for the application of NF as a purification process.

Membrane Fouling IV - RO & Desalination – 1 – Keynote
Friday July 18, 9:30 AM-10:15 AM, Moloka’i
Studies on CaSO4 and CaCO3 Scaling of Membranes in Desalination by
DCMD
F. He, New Jersey Institute of Technology, Newark, New Jersey, USA
J. Gilron, Zuckerberg Institute for Water Research, Beer-Sheva, Israel
K. Sirkar (Speaker), New Jersey Institute of Technology, Newark, New Jersey, USA -
Sirkar@ADM.njit.edu
Membrane distillation (MD) whether of the DCMD (direct contact membrane
distillation) or VMD (vacuum membrane distillation) variety can have a role to
play in desalting highly saline waters that have considerable osmotic pressures
where reverse osmosis (RO) operation becomes more expensive and
problematic. Using MD in this way would allow increased recovery and help
reduce the problem of concentrate disposal vexing inland desalination. To realize
this promise, MD must show itself to be more resistant to scaling than RO and
thus not limited by it in the way that RO is.
An analysis of the scaling potential in hollow fiber membrane-based crossflow
DCMD is presented in terms of the saturation index profiles throughout the
hollow fiber membrane module as a function of the location in the module for the
sparingly soluble salt, CaSO4 and CaCO3, individually or mixed together.
Modeling shows that the highest scaling potential is to be found at the high
temperature end of the module both due to the high brine temperature and
concentration polarization associated with high local fluxes. Concentration effects
are far more important than temperature, although concentration polarization
estimated in crossflow hollow fiber DCMD units is lower than that in spiral wound
modules in RO for similar flux values.
Scaling studies carried out in DCMD using CaSO4 as the scaling salt (at
saturation indices for gypsum ranging between 1.13 and 1.93) indicate that even
when there was significant precipitation of CaSO4, there was no effect on the
membrane vapor flux or brine pressure drop. The induction period for CaSO4
nucleation decreased with increased feed brine temperature (60-90°C) and
increasing level of the degree of supersaturation. We observed no flux reduction
inspite of extensive scaling deposits in solution. Similar results were obtained
with CaCO3 over a wide range of temperature and SI values (11 to 64). Mixed
CaCO3 + CaSO4 systems behaved similarly except the scaling deposits were
extensive and somewhat stickier. Scaling studies with CaSO4 on a polymeric
solid hollow fiber heat exchanger did not lead to a decrease in heat transfer
performance although there was a minor increase in pressure drop. Crossflow
with coated fibers prevented any flux reduction or distillate contamination by

scaling deposits in the DCMD device whereas parallel flow did not. Noncoated
fibers in a DCMD device were susceptible to faster nucleation.
As is well known, antiscalants are very effective in inhibiting scaling from
deposits during the reverse osmosis (RO) membrane process. The inhibition is
by physical rather than chemical mechanisms and involves adsorption
processes. Will the application of antiscalants help inhibit the scaling problem if
any in the membrane distillation process? This question has not been answered
yet. One potential source of concern is that the membrane micropores may be
wetted by its organic components. Thus, experiments were first arranged to
figure out whether the hydrophobic PP membrane would be wetted by antiscalant
solutions at a possible working concentration. Extensive scaling experiments with
the addition of antiscalant were conducted to see the effects of concentration and
different kinds of antiscalant on inhibiting scaling from deposits of CaSO4 and
CaCO3. The parameters of the induction period, calcium concentration and the
water vapor flux were investigated.

Membrane Fouling IV - RO & Desalination – 2
Friday July 18, 10:15 AM-10:45 AM, Moloka’i
Development of Fouling Index to Access Colloidal Fouling in Reverse
Osmosis Unit for Water Reclamation
L. Sim (Speaker), UNESCO Center for Membrane Science and Tech., Sydney, Australia
Y. Ye, UNESCO Center for Membrane Science and Tech., Sydney, Australia
V. Chen, UNESCO UNESCO Center for Membrane Science and Tech., Sydney, Australia -
v.chen@unsw.edu.au
A. Fane, UNESCO Center for Membrane Science and Tech., Sydney, Australia
Reverse osmosis technology is a promising method widely used in water
reclamation such as desalination of seawater and purification of domestic water.
However, due to the lack of reliable method in predicting fouling potential of the
RO feed water, the subsequent system suffers severe flux decline.
Consequently, intense chemical cleaning or membrane replacement becomes
necessary and leads to higher operating cost of a plant. Silt Density Index (SDI)
and Modified Fouling Index (MFI0.45) are the current approaches to measure the
fouling potential of reverse osmosis (RO) feed water. The major drawback of
these methods is that both methods do not account for the small particles in the
feed and the conditions of a real RO system are not well simulated, therefore, the
indices failed to represent the true fouling potential of that particular feed. In
response to the poor ability of both indices, a lot of efforts have been allocated in
developing better fouling index, for instance Modified Fouling Index -
Ultrafiltration (MFI-UF) where ultrafiltration membrane is used instead of
microfiltration membrane.
In this study, a new fouling index known as Crossflow Sampler - Modified Fouling
Index (CFS-MFI) was developed. This index was performed in a typical cross
flow filtration module followed by a dead-end MFI measuring device. Feed
solution is pumped through a crossflow cell in order to fractionate the feed
hydrodynamically. Permeate collected therefore consists of foulants that are
responsible for cake formation during RO filtration. Large pore size membrane, in
this study, 1.2um membrane was chosen in the CFS to ensure that any foulants
which come near to the crossflow membrane surface are able to permeate
through and hence are incorporated in MFI measurement. It is believed that,
these foulants are responsible for the fouling in the real RO system if the same
solution was used. The 10kDa PES membrane was used in the dead-end MFI
measuring device. In addition, in order to further simulate fouling condition in RO
system, the constant flux mode of filtration is selected in this study rather than
the constant pressure mode.

Silica colloidal solution with different particle sizes was used throughout.
Preliminary experimental results revealed that CFS-MFI is linearly dependent of
feed concentration as well as permeate flux. In a range of experiments where
22nm mono particle size silica solution was used, CFS-MFI values appeared to
be lower than MFI-UF values but only to a small extent, ranging from 200 to
500s/L 2 for operating flux of 25 to 120LMH. The influence of CFS is vaguely
shown in these experiments might be due to the narrow particle distribution. In
order to observe the clear effect of CFS on the MFI value, the silica mixture
solution of 50ppm of 22nm silica colloidal and 70nm to 100nm silica colloidal
suspension was used for another set of experiments. CFS-MFI shows significant
lower value than MFI-UF. Under constant flux of 52LMH, CFS-MFI was found to
be 76368s/L 2 whilst MFI-UF was 87878s/L 2 . The difference of MFI-UF and CFS-
MFI can range from 500 to 12000s/L 2 at permeate flux of 28 LMH, 52 LMH and
77 LMH. Results implied that the conventional method may have overestimated
the fouling propensity of the RO feed solution. The effects of other operating
variables such as feed composition, permeate flux and crossflow velocity were
also investigated in the study.
Acknowledgements
The authors would like to thank Department of Education, Science and Training, Australia for
their financial support and this study is collaborated with the European Union 6th Framework
project, Membrane-Based Desalination: An Integrated Approach (MEDINA).

Membrane Fouling IV - RO & Desalination – 3
Friday July 18, 10:45 AM-11:15 AM, Moloka’i
The Effect of Membrane Body Conductance on the Zeta Potential of Clean
and Fouled Polymer Membranes
T. Luxbacher (Speaker), Anton Paar GmbH, Austria - thomas.luxbacher@anton-paar.com
A. Comerton, University of Toronto, Toronto, Canada
R. Andrews, University of Toronto, Toronto, Canada
D. Bagley, University of Wyoming, Laramie, Wyoming, USA
The electrokinetic or zeta potential is an important property of charged solidliquid
interfaces and provides insight regarding the charging behaviour of solid
surfaces and colloidal particles immersed in a dielectric. Experimental methods
to determine the zeta potential include streaming potential, electrophoresis, or
electroacoustic techniques. The streaming potential method has become a
common tool to determine the zeta potential of macroscopic solid surfaces of
granular or fibrous substances as well as flat sheets. The application of the
streaming potential to the characterization of thin-film composite membranes for
water treatment is widely known. Beside the characterization of the active
membrane surface, the streaming potential gives information about the
interaction between the membrane and ions, organics, and surfactants, which
provides useful insights into the relationship between reverse osmosis (RO) and
nanofiltration (NF) membrane surface properties, separation performance and
membrane fouling.
Despite of the acceptance of the streaming potential method in the field of
membrane surface characterization, the effect of the electrical conductivity of the
membrane bulk on the charging behaviour of the membrane surface is often
underestimated. The streaming potential measurement is sensitive to surface
conductivity, which is likely to occur on NF and RO membranes, and allows the
determination of an apparent zeta potential only. In this paper we compare the
calculated zeta potential of commercial NF and RO membranes determined from
streaming potential measurements to that calculated from streaming current
results. The streaming current measurement is insensitive to effects like surface
conductivity or membrane body conductance and reveals the complete zeta
potential information. We extend the comparison of virgin membranes to NF and
RO membranes fouled with different sources for drinking water. The effect of
membrane fouling on the surface chemistry is monitored by the streaming current
measurement whereas the ratio between the apparent zeta potential and the
correct value is affected by the change in the membrane porosity.

Membrane Fouling IV - RO & Desalination – 4
Friday July 18, 11:15 AM-11:45 AM, Moloka’i
Mechanisms of Marine Bacteria Adhesion to Seawater RO Membranes
X. Huang (Speaker), University of California Los Angeles, Los Angeles, California, USA -
xiaofeih@ucla.edu
E. Hoek, University of California Los Angeles, Los Angeles, California, USA
Biofouling is among the most problematic issues for seawater desalination by
reverse osmosis (RO) membranes. It is particularly difficult for seawater
applications because continuous chlorination of polyamide RO membranes is not
possible and because algal blooms result in periodic upsets to seawater quality
bringing increased biomass and assimilable organics into the RO system. The
high ionic strength of seawater virtually eliminates electrostatic double layer
interactions among foulants and membranes; hence, van der Waals and shortrange
interactions (acid-base, roughness, steric, metal-complexation, etc.) may
govern adhesion of bacteria and organic matter. Previous research in fresh and
brackish water applications suggests that membrane surface chemistry and
morphology govern colloidal fouling of RO membranes. Other research suggests
that calcium forms complexes between carboxylic acid functionality on foulants
and polyamide RO membranes - exacerbating flux decline and making the
membranes difficult to clean. We hypothesize that calcium-complexation will be
important for the initial rate of bacterial adhesion to seawater RO (SWRO)
membranes.
Our objective in this study is to elucidate the relative importance of van der
Waals interactions, acid-base interactions, surface roughness, and calciumcomplexation
on bacterial adhesion to SWRO membranes. We have selected a
model system comprising Halomonas pacifica (GFP), a common marine
bacterium, and two commercial polyamide composite seawater RO membranes.
The two membranes were selected because they represent a relatively
hydrophobic, rough membrane with significant carboxylic acid functionality at its
interface (Hydranautics SWC3+) and a relatively hydrophilic, smooth membrane
with little carboxylic acid functionality at its interface (FilmTec SWHR). The
former is expected to produce higher bacterial deposition rates due to attractive
acid-base interactions and its rough, carboxylic acid rich interface. The latter
membrane is expected to be relatively resistant to bacterial adhesion due to
repulsive acid-base interactions and its smooth non-carboxylated interface. In
some experiments, bacteria are dispersed in a real seawater matrix. In other
experiments, solution chemistry is systematically controlled by addition of
calcium and magnesium ions to NaCl solutions at seawater ionic strengths.

We have systematically characterized H. pacifica physicochemical properties
using light scattering, particle electrophoresis, and contact angle titrations.
Membranes are characterized by atomic force microscopy, contact angle
titrations, and spectroscopic analyses. We employ direct microscopic observation
to visually monitor (in real-time) the deposition rates of bacteria cells onto the
membrane surfaces. In addition, we evaluate the strength of bacterial adhesion
by simulating membrane cleaning with various rinsing agents. Direct observation
experiments are designed to systematically investigate the influence of seawater
chemistry on bacterial adhesion, specifically, to identify the potential role of
calcium mediated bacterial adhesion. We interpret direct observation data
through an interfacial force model with inputs derived from rigorous
physicochemical characterization of bacteria cells and membranes.

Membrane Fouling IV - RO & Desalination – 5
Friday July 18, 11:45 AM-12:15 PM, Moloka’i
Optical Monitoring and Real-Time Digital Image Analysis of Mineral Scale
Formation on RO Membranes
M. Kim (Speaker), University of California Los Angeles, Los Angeles, California, USA
R. Rallo, Universitat Rovira i Virgili, Catalunya, Spain
E. Lyster, University of California Los Angeles
Y. Cohen, University of California Los Angeles - yoram@ucla.edu
Upgrading the water quality of inland brackish water by RO and NF memrmbane
processes is often limited in recovery due to the rise in the concentration of
sparingly soluble salts in the retentate stream to levels that exceed their solubility
limits. As a result, such mineral salts can precipitate in the retentate stream and
crystallize on the membrane surface resulting in surface scaling that reduces
permeate flux and ultimately damaging the membrane itself. Early detection of
membrane surface scaling and fouling is necessary for timely initiation of
fouling/scale mitigation steps. Present traditional measures of process
performance trends (primarily flux decline and salt passage) are used as indirect
indicators of the occurrence mineral scaling and fouling. Although numerous
methods of scale and fouling detection have been proposed, it is only recently
that real-time early detection of the onset of scale formation has become
possible. Direct visual observations and detection of mineral scale on RO/NF
membranes under high pressure have been made possible with an ex-situ scale
observation detector (EXSOD) along with digital image analysis. The EXSOD
system is an optically transparent high-pressure flat sheet membrane cell that
allows real-time digital imaging of the membrane surface under RO process
conditions. The EXSOD can be operated as a stand- alone laboratory RO system
or connected to an RO/NF plant such that the EXSOD receives a side- stream
from a tail element of the RO/NF plant and thus enable early detection of mineral
scale. In its stand-alone mode, the EXSOD system was recently redesigned to
enable real- time measurements of the kinetics of surface crystallization of
mineral salts and assessment of the efficiency of scale mitigation strategies. In
order to utilize the above approach, efficient on-line image analysis software was
developed assisted with neural networks algorithms to enhance image analysis
by providing image family groups to increase the accuracy of single crystal
analysis, surface area covered by scale and shape and thus crystal type
identification. Using the present approach, real-time evolution of surface scaling
was evaluated for RO/NF scaling by calcium sulfate and calcium carbonate.
Direct information on surface nucleation by mineral salt crystals and the rate of
single crystal growth was determined over a range of operating conditions and
different antiscalants, generating, for the first time, direct fundamental data on the
kinetics of surface mineral salt crystallization on RO/NF membranes. These

measurements, along with a comprehensive numerical concentration polarization
model, enabled evaluation of the direct relationship between the observed flux
decline and the surface area covered by mineral scale.

Membrane Fouling IV - RO & Desalination – 6
Friday July 18, 12:15 PM-12:45 PM, Moloka’i
Effect of Foulant-Foulant Interaction on the Limiting Flux for RO and NF
Membranes during Organic Fouling - Model Development and AFM
Adhesion Force Measurement
C. Tang (Speaker), Nanyang Technological University, Thailand - cytang@ntu.edu.sg
Y. Kwon, Stanford University, Palo Alto, California, USA
J. Leckie, Stanford University, Palo Alto, California, USA
A limiting flux model has been recently developed to predict the fouling behavior
of reverse osmosis and nanofiltration membranes by organic macromolecules
(Tang and Leckie, 2007). Several interesting results have been observed: a)
there was a maximum pseudo stable flux (the limiting flux) beyond which further
increase in applied pressure did not translate to a greater stable flux; b) all
membrane samples attained the limiting flux under constant pressure conditions
as long as their initial flux was greater than the limiting flux; c) the limiting flux did
not depend on the properties of membranes; d) the limiting flux had strong
dependence on the feedwater composition, such as pH, ionic strength, and
divalent ion concentration. The current study investigates the dependence of
limiting flux on intermolecular interaction between foulant molecules. It was
observed that the limiting flux was directly proportional to the intermolecular
electrostatic repulsive force and that conditions enhancing foulant-depositedfoulant
repulsion resulted in greater limiting flux values. Such observations agree
well with a theoretical model capturing both hydrodynamic and DLVO
interactions. Adhesion force measurements by atomic force microscopy (AFM)
were also performed. The limiting flux correlated well with AFM adhesion force
between the model foulant and the fouled membrane surface. Finally, membrane
fouling was primarily controlled by the initial-flux-over-limiting-flux ratio - a greater
ratio inevitably resulted in more severe flux reduction, greater foulant
accumulation, and greater density of the foulant layer.
Reference:
C. Y. Tang and J. O. Leckie, "Membrane independent limiting flux for RO and NF membranes
fouled by humic acid," Environ. Sci. Technol., vol. 41, pp. 4767-4773, 2007.

Membrane and Surface Modification III – 1 – Keynote
Friday July 18, 9:30 AM-10:15 AM, Honolulu/Kahuku
Modification of Polyethersulfone Nanofiltration Membranes
K. Boussu, Katholieke Universiteit Leuven, Heverlee, Belgium
K. Schols, Katholieke Universiteit Leuven, Heverlee, Belgium
B. Van der Bruggen (Speaker), Katholieke Universiteit Leuven, Heverlee, Belgium -
bart.vanderbruggen@cit.kuleuven.be
The top layer of commercial polymeric nanofiltration membranes for use in
aqueous applications is in most cases composed of polyamide or
polyethersulfone (PES). The main advantage of using PES membranes is the
very high chemical and thermal stability. However, these membranes also have a
high hydrophobicity (pernicious for membrane fouling) and a wide pore
distribution (pernicious for a distinct separation between two components). To
minimize these inadequacies, membrane modification is a valuable option, which
can be performed in two different ways: by working on the polymer used (e.g., by
sulfonating, chlorinating, addition of a copolymer) or by working on the existing
membrane top layer (e.g., by grafting, plasma treatment,..).
This study focuses on different modification (or more specifically hydrophilization)
techniques, applied on both commercial and laboratory-made PES nanofiltration
membranes. The surfaces of these membranes were hydrophilized by means of
the grafting technique, which implies that hydrophilic monomers (like acrylamide
or methacrylic acid) were grafted on active places on the membrane surface after
a redox reaction with K2S2O8 and K2S2O3. Moreover, in case of the laboratorymade
membranes, the polymer can also be hydrophilized, e.g. by sulfonating.
Starting from this hydrophilic polymer, a membrane was prepared by using the
DIPS technique (Diffusion Induced Phase Separation).
After modification, the membranes were characterized thoroughly for the
hydrophobicity (by contact angle measurements), the roughness (by AFM), the
chemical composition of the top layer (by ATR-FTIR) and the size of the pores. A
cross-flow nanofiltration set-up was used to study the performance (i.e., water
permeability and membrane fouling) of the modified membranes. By comparing
the characterization results of the unmodified with the modified membranes, the
degree of modification was checked. Moreover, for each characteristic, the
behaviour was followed as a function of time, to have an idea about the
modification mechanism (reversible or irreversible).

Membrane and Surface Modification III – 2
Friday July 18, 10:15 AM-10:45 AM, Honolulu/Kahuku
Development and Characterization of Ceramic Microfiltration Membrane
Devices for Biomolecule Separation
R. Malaisamy (Speaker), Howard University, Washington DC, USA - malaisamy@gmail.com
L. Lepak, Cornell University, Ithaca, New York, USA
M. Spencer, Cornell University, Ithaca, New York, USA
K. Jones, Howard University, Washington DC, USA
Conventional techniques for bioseparations are frequently being replaced by
membrane separation processes, owing to increased versatility and efficiency of
membranes. In this study, we are tailoring the surface properties of ceramic
(alumina) microfiltration membranes by spin coating thin layers of a protein,
collagen, for biomolecule separation applications. Commercial anodized alumina
membranes were sulfonated by heating in concentrated sulfuric acid for 15
minutes. A commercially available (US Biological) aqueous solution of 0.3%
bovine dermal collagen was spin deposited on the alumina membranes. Either 3
or 6 layers of collagen were spun and crosslinked into fibrils by immersing the
composite membrane in an aqueous solution of dilute glutaraldehyde for 10
minutes. The membranes were then rinsed by immersion in a series of dilute
aqueous buffers, and gradually dehydrated through immersion in a series of
dilutions of ethanol in preparation for critical point drying.
IR spectra were obtained for the modified dried membranes and confirmed the
presence of collagen protein on the substrate. When viewed by scanning
electron microscopy, the thin film composite membranes appeared to have
collagen fibrils spun uniformly on the alumina surface, covering the pores of the
alumina considerably. The water contact angle values for unmodified alumina
and sulfonated alumina membrane surfaces were measured to be 38±2° and
34±2° respectively, whereas the contact angle increased to 78±6° when collagen
was spun onto the membranes. The zeta potential (surface charge) of both pure
alumina and sulfonated alumina membranes at a pH of 5.5 using 1mM KCl
electrolyte solution was around 30 mV, where as it was around 20 mV for the
collagen modified membranes. The pure water permeability was found to lie
around 200 L/(m 2 .h.psi) for the sulfonated alumina base membrane, but declined
to 90 and 10 L/(m 2 .h.psi), when it was coated with 3 and 6 layers of collagen
respectively. The permeate flux value at 30 psi for sulfonated alumina was 5000
L/(m 2 .h), but the flux dropped by almost 50% for 3 layer coated membranes, and
was only 260 L/(m 2 .h) with 6 spun-on layers. These permeability and flux values
for the collagen coated membranes are comparable to ultrafiltration and loose
nanofiltration membranes, and are expected to be suitable for biomolecule
separation.

Membrane and Surface Modification III – 3
Friday July 18, 10:45 AM-11:15 AM, Honolulu/Kahuku
Solvent Resistant Nanofiltration with Partially Hydrolyzed Asymmetric
Polyacrylonitrile Membranes
P. Vandezande (Speaker), Center for Surface Chemistry and Catalysis, Katholieke Univ. Leuven,
Belgium
X. Li, Center for Surface Chemistry and Catalysis, Katholieke Univ. Leuven, Belgium
K. Vanderschoot, Centre Center for Surface Chemistry and Catalysis, Katholieke Univ. Leuven,
Belgium
I. Willems, Center for Surface Chemistry and Catalysis, Katholieke Univ. Leuven, Belgium
I. Vankelecom, Center for Surface Chemistry and Catalysis, Katholieke Univ. Leuven, Belgium -
ivo.vankelecom@biw.kuleuven.be
Over the last few years, new technical achievements and a growing acceptance
of membrane technology in industry have increased interest in membranes to
separate non-aqueous streams. Particularly solvent resistant nanofiltration
(SRNF), where organic mixtures are separated on a molecular level by simply
applying a pressure gradient, has experienced a significant growth, spurred by
increasing environmental concerns and energy prices [1]. Offering a sustainable
alternative for traditional separation techniques, SRNF holds a vast potential in a
vraiety of solvent-intensive processes were low molecular weight compounds
(typically 200-1000 g/mol) are to be separated from organic solvents. Such
applications are mainly found in the food, fine-chemical, pharmaceutical and
petrochemical industries.
In SRNF, an ideal membrane combines chemical, mechanical and thermal
stability with excellent rejections and high permeabilities. Unfortunately,
applications are yet difficult in certain demanding solvents such as the aprotic
solvents DMF, NMP, DMAc and DMSO, since none of the polymeric SRNF
membranes currently available on the market resists these solvents. Solute
recovery and solvent purification in industries that commonly use these aprotic
solvents therefore generally rely on conventional separation techniques such as
energy-consuming distillations or waste- generating extractions. The
development of SRNF membranes with a high flux and a low MWCO)in these
solvents can provide a sustainable alternative for these processes.
Since most polymers dissolve in aprotic solvents, the membrane-forming polymer
should be chosen so that it can be modified to be able to withstand these
solvents. Integrally skinned asymmetric polyimide membranes, prepared by
phase- inversion, have been chemically cross-linked with diamines to allow
applications in chemically rigorous environments, i.e. aprotic solvents and THF
[2,3].

Polyacrylonitrile (PAN) UF membranes are mainly used for water treatment, but
have also been applied as support for thin film composite SRNF membranes [1].
Despite their relatively good chemical stability, e.g. in hexane and toluene, PAN
membranes can not be used in more aggressive solvents such as DMF, DMSO
and THF. Moreover, due to the poor solubility of PAN in most solvents, it is
practically not feasible by phase-inversion only to reduce the pore size of PAN
membranes into the range needed for NF selectivity. Different modification
techniques, such as heat treatment in the presence of ZnCl2, and low
temperature plasma grafting of styrene, have been applied to transform PAN
based UF membranes in (SR)NF membranes [1]. These modifications did
however not imply chemical stability in aprotic solvents. Partial hydrolysis of the
nitrile groups of PAN membranes under alkaline conditions is frequently applied
to render the surface of the membranes hydrophilic and charged [4]. Membrane
Products Kiryat Weitzman patented a procedure for the synthesis of composite
SRNF membranes composed of an interfacially cross-linked top layer on top of a
PAN support which is on its turn cross-linked through immersion in a base,
followed by heat treatment [5]. These modified membranes clearly showed
improved stability in aprotic solvents.
The synthesis of partially hydrolyzed, asymmetric, purely PAN based SRNF
membranes and their use for selective separations in aprotic solvents has
however never been reported. In the presented work, PAN UF membranes were
prepared by casting DMSO/THF based PAN solutions and immersing the
obtained films in de-ionized water. These membranes were then immersed (1-60
min) in a concentrated (1-10 wt./vol.%) aqueous base solution (NaOH or
NaOCH3) at elevated temperatures (25-90°C). Hydrolysis resulted in a partial
conversion of the nitrile groups into carboxyl, amidine, acrylamide and other
functional groups [6], as observed via ATR-IR. This chemical change was
accompanied by an average decrease of the pore diameter in such a way that
selectivities in the NF range were obtained. While a minimal degree of crosslinking
was required for chemical stability in aprotic solvents, the membranes
completely dissolved in the base medium under more stringent hydrolysis
conditions due to their increased hydrophilicity. Effective cross-linking could thus
only be achieved in a relatively small stability window. Small dyes with MW
ranging from 300 to 1000 Da were successfully separated from DMF, NMP,
DMAc, DMSO and THF at high permeabilities. The cross-linked membranes
showed moreover excellent long-term stabilities.
References
[1] P. Vandezande et al., Chem. Soc. Rev. 2008, 37, 365.
[2] K. Vanherck et al., accept. for public. in J. Membr. Sci. (2008)
[3] Y.H. See Toh et al., J. Membr. Sci. 2007, 301, 3.
[4] Z. Wang et al., J. Membr. Sci. 2007, 304, 8.

[5] C. Linder et al., US Pat. 5 039 241 (1991) and US Pat. 5 032 282 (1991).
[6] A.D. Litmanovich et al., Macromol. Chem. Phys. 2000, 201, 2176.

Membrane and Surface Modification III – 4
Friday July 18, 11:15 AM-11:45 AM, Honolulu/Kahuku
Hydrophilic Modification of Polypropylene Hollow Fiber Membrane
S. Kim (Speaker), Kyung Hee University, Gyeonggido, Korea - sungkim@khu.ac.kr
H. Kim, Kyung Hee University, Gyeonggido, Korea
J. Kim, Kyung Hee University, Gyeonggido, Korea
Polypropylene hollow fiber membrane was hydrophilized by EVOH dip coating
followed by low temperature plasma treatment and UV irradiation. EVOH coating
attained high water flux without any pre-wetting treatment but its stability was not
guaranteed at high water permeation rate. Gradual flux decline was observed
due to swelling and delamination of the EVOH coating layer, which caused pore
blocking. However, plasma treatment reduced the swelling, which suppressed
delamination of the EVOH coating layer from PP support, which resulted in
relieving the flux decline. UV irradiation with hydrophilic monomers helped
crosslinking of the EVOH coating layer to enhance the performance at low water
permeation rate. FT-IR and XPS analyses revealed that EVOH dip coating
performed homogeneous coating not only on membrane surface but also into the
membrane matrix. Thermogram of EVOH film modified by plasma treatment and
UV irradiation showed the increase of crosslinking density of EVOH layer.
Chemical modification by plasma treatment and UV irradiation stabilized the
hydrophilic coating layer to increase the critical flux of the membrane, when it
was operated in submerged mode.

Membrane and Surface Modification III – 5
Friday July 18, 11:45 AM-12:15 PM, Honolulu/Kahuku
Effect of Surface Modifying Macromolecules Stoichiometric Ratio on
Composite Hydrophobic/Hydrophilic Membranes Characteristics and
Performance in Membrane Distillation
M. Qtaishat (Speaker), University of Ottawa, Ottawa, Canada - mrasool@eng.uottawa.ca
T. Matsuura, University of Ottawa, Ottawa, Canada
M. Khayet, University Complutense Madrid, Madrid, Spain
This study aims to develop novel hydrophobic/hydrophilic composite membranes
that are made specifically for membrane distillation (MD). The concept of
hydrophobic/hydrophilic composite membrane for MD was firstly proposed by
Khayet et al. [1,2]; where surface modifying macromolecules (SMMs) were
synthesized and blended with the host polyetherimide (PEI) to prepare composite
membranes. Those membranes were further tested for desalination by direct
contact membrane distillation (DCMD). The SMMs were prepared from
methylene bis-p-phenyl diisocyanate (MDI), diethylene glycol (DEG) and
oligomeric fluoroalcohol, Zonyl BA-LTM of average molecular weight 443 (BAL).
The stoichiometric ratio for SMMs synthesis was 3(MDI): 2(DEG): 2(BAL).
Suk et al. [3] later developed new surface modifying macromolecules (nSMM), in
which DEG in the earlier work was replaced by aminopropyl poly(dimethyl
siloxane) (PDMS). They used these nSMMs together with the host
polyethersulfone (PES) to prepare membranes for MD. It is worth mentioning that
blending DEG based SMM yielded better DCMD fluxes than blending nSMM [1-
3].
In this study further improvement of MD performance was attempted by changing
the nSMM structures. To this end, the stoichiometric ratio of nSMM components
was altered systematically in nSMM synthesis; i.e. nSMM1
2(MDI):1(PDMS):2(BAL); nSMM2, 3(MDI):2(PDMS):2(BAL); nSMM3:
4(MDI):3(PDMS):3(BAL).
The newly synthesized SMMs were characterized by the gel permeation
chromatography and the elemental analysis to know the molecular weight and
fluorine content, respectively. The results showed that fluorine content decreased
with increasing the PDMS stoichiometric ratio. Furthermore, the newly developed
SMMs were blended with PEI host polymer to prepare composite
hydrophobic/hydrophilic membranes. This was done in a single casting step by
the phase inversion method. The details of membrane casting are as follows. A
predetermined amount of PEI was dissolved in dimethylacetimide (DMAc)/gbutyrolactone
(GBL) mixture, into which nSMM was added. The composition of

the polymer dope was PEI (12 wt%), GBL (10 wt%) and nSMM (1.5 wt%) with a
balance of DMAc. The resulted mixtures were stirred in an orbital shaker at room
temperature for at least 48 h. The polymer dope was cast on a smooth glass
plate to a thickness of 0.30 mm using a casting rod at room temperature.
Subsequently, the cast film together with the glass plates was immersed for 1 h
in distilled water kept at room temperature. The membrane peeled off from the
glass plate spontaneously during gelation. All the membranes were then dried at
ambient conditions for 3 days.
The membranes were characterized using gas permeation test, measurement of
the liquid entry pressure of water (LEPw), scanning electronic microscopy (SEM),
and contact angle measurement. The effects of the SMM type on the membrane
morphology were identified, which enabled us to link the membrane morphology
to the membrane performance.
The membranes were further tested by DCMD for desalination of 0.5 M NaCl
solution and the results were compared to commercial polytetraflouroethylene
(PTFE) membranes (FGLP 1425, Millipore). nSMM2/PEI membrane yielded the
best performance among the tested membranes. In particular, it should be
emphasized that the above membrane was superior to the commercial one,
which was attributed to the fact that nSMM2/PEI had the highest pore
size/porosity ratio and the lowest LEPw among the laboratory made membranes.
It is worth mentioning that all the prepared membranes were tested successfully
for the desalination application. In other words, no NaCl was detected in the
permeate.
The SEM images showed that the laboratory made membranes had similar
finger-like structures regardless of the type of the nSMM used. The nSMM2/PEI
membrane exhibited macro-voids in the bottom layer, which might have
contributed to its DCMD flux that was the highest among all the tested
membranes.
A better and instructive understanding of hydrophobic/hydrophilic membrane
performance in MD has been obtained by finding the relationship between
membrane morphology and membrane performance. This will open a wide
avenue to the rational development of novel membranes for membrane
distillation.
References
1. M. Khayet, J.I. Mengual, T. Matsuura, J. Membr. Sci., 252 (2005), 101-113.
2. M. Khayet, T. Matsuura, M.R. Qtaishat, J.I. Mengual, Desalination, 199 (2006), 180-181.
3. D.E. Suk, T. Matsuura, H.B. Park, Y.M. Lee, J. Membr. Sci., 277 (2006), 177-185.

Membrane and Surface Modification III – 6
Friday July 18, 12:15 PM-12:45 PM, Honolulu/Kahuku
Surface Modification of an Aromatic Polyamide Membrane By Self-
Assembly of Polyethyleneimine on the Membrane Surface
Y. Zhou (Speaker), University of Waterloo, Waterloo, Canada
S. Yu, Zhejiang Sci-Tech University, China
C. Gao, The Development Center of Water Treatment Technology, China
X. Feng, University of Waterloo, Waterloo, Canada - xfeng@uwaterloo.ca
Reverse osmosis is now a well accepted technique for water and waste water
treatment, and interfacially polymerized thin film composite (TFC) polyamide
membranes are being used extensively for these applications. Because
polyamide membranes are negatively charged under typical operating conditions
(pH > 4) due to carboxyl groups on the membrane surface, they are vulnerable to
fouling by cationic contaminants. In this study, an aromatic polyamide TFC
membrane was modified by electrostatic self-assembly of polyethyleneimine on
the membrane surface, and the modified membrane showed significantly
improved anti- fouling properties. It was expected that the charge reversal on the
membrane surface due to the application of the polyethyleneimine layer would
increase the fouling resistance of the membrane to cationic foulants because of
the enhanced electrostatic repulsion, and the increased surface hydrophilicity
would help minimize the flux reduction. The effects of parameters involved in the
membrane surface modification (e.g., polyethyleneimine concentration and
deposition time) on the membrane performance were investigated in terms of
water permeation flux and salt rejection with and without the presence of
decyltrimethylammonium bromide (which is a common cationic surfactant
present in waste water). It was shown that the improved fouling resistance and
the increased surface hydrophilicity compensated for the reduction in membrane
permeability due to the deposition of the polyethyleneimine layer.

Inorganic Membranes III – 1 – Keynote
Friday July 18, 9:30 AM-10:15 AM, O’ahu/Waialua
Silica Network Engineering For Highly Permeable Hydrogen Separation
Membranes
T. Tsuru (Speaker), Hiroshima University, Hiroshima, Japan - tsuru@hiroshima-u.ac.jp
K. Yada, Hiroshima University, Hiroshima, Japan
M. Kanezashi, Hiroshima University, Hiroshima, Japan
Inorganic membranes are promising for possible application to high temperature
separation systems and membrane reactor systems [1-3]. Metal membranes,
which shows 100% selectivity to hydrogen and high permeances at
temperatures, have several disadvantages such as expensive cost, degradation
with hydrocarbon and acid gases, and hydrogen brittleness at low temperatures.
On the other hand, amorphous silica, which can be derived from the sol-gel
processing or CVD (Chemical vapor deposition), is a microporous material,
consisting of silica network which allows the permeation of small molecules such
as helium and hydrogen. In this paper, recent progress in the control and design
of silica network by sol-gel processing will be discussed to develop highly
permeable hydrogen separation membranes.
The sol-gel process is divided into two main routes: the polymeric sol-gel route
and the colloidal sol-gel route1). In the colloidal sol route where the hydrolysis
and condensation reaction of alkoxide (tetraethoxysilane (TEOS) for SiO2
membranes) is fast, the rapid condensation reaction causes particulate growth
and/or the formation of precipitates. In the polymeric sol route, the hydrolysis
reaction is slower, resulting in a partially hydrolyzed alkoxide and the formation of
a linear inorganic polymer. Pore sizes can be controlled by the void spaces
among the packed colloidal particles (i. e. interparticle pore) in the colloidal sol
route and by the size of the gel network in the polymeric gel route, respectively.
By controlling the preparation condition of silica sols (pH, temperature,
concentration, aging time etc.), pore sizes of SiO2 membranes were found to be
precisely tuned in the subnanometer range. SiO2 membranes showing highly
hydrogen selectivity over nitrogen [3], as well as showing a large H2 permeation
rate with low H2/N2 but high H2/SF6 separation factors, were successfully
prepared [1].
Another strategy to control silica network is the utilization of structured alkoxides,
such as (EtO)3-Si-(CH2)n-Si-(OEt)3 (n=1-6). Since the silicone atoms are more
distant with each other than the case of TEOS, due to the existence of -C2H4-,
the silica network can be expected to be formed more loosely than the case of
TEOS. Silica membranes prepared from bis(triethoxysilil)ethane (BTESE, n=2)

were found to show significantly high permeance (1x10 -5 mol m -2 s -1 Pa -1 ) and
high selectivity of H2/SF6 (> 1,000).
[1] T. Tsuru, J. Sol-Gel Sci. Tech., in press.
[2].T. Tsuru, T. Morita, T. Yoshioka, J. Membr. Sci., in press.
[3] R. Igi, T. Yoshioka, Y. Ikuhara, Y. Iwamoto, T. Tsuru, J. Am. Cer. Soc., submitted.

Inorganic Membranes III – 2
Friday July 18, 10:15 AM-10:45 AM, O’ahu/Waialua
Development of Novel CO2 Affinity-Enhanced Carbon Membranes:
Characterization and CO2 Separation Performance
T. Kai (Speaker), Research Institute of Innovative Technology for the Earth (RITE), Kyoto, Japan
S. Kazama, Research Institute of Innovative Technology for the Earth (RITE), Kyoto, Japan -
kazama@mvc.biglobe.ne.jp
Y. Fujioka, Research Institute of Innovative Technology for the Earth (RITE), Kyoto, Japan
The concentration of carbon dioxide (CO2), a greenhouse gas, has been
increasing in the atmosphere. Several methods have been devised to reduce the
amount of CO2 emissions into the atmosphere. Among them, the sequestration
of CO2 underground or in the oceans is regarded as one of the promising means
to mitigate carbon dioxide emissions. One problem with the sequestration is the
cost of recovering CO2 from emissions. For example, chemical absorption, the
best-known method of separating and recovering CO2 to date, accounts for more
than seventy percent of the entire cost of carbon sequestration. One promising
means to lower the cost of CO2 separation is the development of new, high-
performance CO2 separation membranes that allow efficient CO2 recovery.
It is well known that carbon membranes shows good CO2/N2 separation
performance. To obtain higher separation performance using carbon
membranes, it is very important to control CO2 affinity on the pore surface as well
as pore size control. In this presentation, we will report on development of novel
carbon membranes with enhanced CO2 affinity for CO2 separation to obtain
higher CO2 separation performance by incorporating CO2 affinity materials in the
pores of the carbon membranes.
Polyimide was chosen as the precursor for carbon membranes. Tubular porous
a-alumina membrane (pore diameter: 150nm (symmetric), Outer- diameter:
10mm, inner-diameter: 7mm)) was purchased from Noritake Co., Limited., Japan,
and was used as the porous support. The precursor solution was coated on the
outer surface of the alumina support by the dip-coating method. After drying, the
precursor-coated membrane was carbonized under a N2 atmosphere at 600
degrees centigrade for 3 hours. Alkali metal carbonates (Na2CO3, K2CO3,
Rb2CO3, Cs2CO3) and an amine (DL- 2,3-Diaminopropionic acid hydrochloride
(DAPA)) were chosen as a CO2 affinity materials. Two preparation methods were
examined; Method A (Blend CO2 affinity materials with precursor solution) and
method B (Post-treatment, Dip- coating of carbon membranes).
From EDX spectra of the surface of Cs2CO3- incorporated carbon membrane
(method A), it was confirmed that the amount of incorporated Cs2CO3 increased

as the Cs2CO3 concentration in precursor solution increased. In other words, the
amount of incorporated Cs2CO3 could be controlled by the Cs2CO3 concentration
in precursor solution. From water vapor sorption experiments using carbon film
prepared from method A at 40 degrees centigrade, it was found that the shape of
sorption isotherm changed as the Cs2CO3 concentration in precursor solution
increased. It is suggested that the carbon pores became more hydrophilic by the
incorporation of Cs2CO3.
The separation performance was evaluated using a CO2/N2 gas mixture at 40
degrees centigrade. For both method A and method B, separation performance
was improved compared with that of the untreated carbon membrane under the
humidified conditions.

Inorganic Membranes III – 3
Friday July 18, 10:45 AM-11:15 AM, O’ahu/Waialua
Electronic Conduction and Oxygen Permeation Through Mixed-Conducting
SrCoFeO(x) Membranes
J. Kniep (Speaker), Arizona State University, Tempe, Arizona, USA
J. Lin, Arizona State University, Tempe, Arizona, USA - Jerry.Lin@asu.edu
The total conductivity and oxygen permeation properties of dense SrCoFeO(x)
membranes synthesized from the solid state method were studied in the
temperature range of 700 to 900 degrees C. SrCoFeO(x) powder has been
shown to have favorable oxygen adsorption and desorption rates as well as a
large oxygen sorption capacity above 800 degrees C. X ray diffraction analysis
verifies that the SrCoFeO(x) samples consist of an intergrowth Sr(4)Fe(6x)Co(x)O(13
+ or - delta), perovskite SrFe(1-x)Co(x)O(3-delta), and spinel Co(3x)Fe(x)O(4)
phase. SrCoFeO(x) exhibits n- type and p-type conduction at low
and high oxygen partial pressures, respectively, and has a total conductivity of
16.5 S/cm at 900 degrees C in air. SrCoFeO(x) membranes were structurally
stable during oxygen permeation experiments with one side exposed to air and
the other side exposed to either an inert gas or carbon monoxide. The oxygen
permeation fluxes with a carbon monoxide sweep gas were approximately two
orders of magnitude higher than the fluxes measured with an inert sweep gas.
The highest measured oxygen flux through a 0.80 mm thick SrCoFeO(x)
membrane with a carbon monoxide sweep was 4.8 ml/cm 2. min at 900 degrees C.
The oxygen flux through SrCoFeO(x) membranes was higher than the oxygen
flux through SrFeCo(0.5)O(x) membranes of the same thickness under the same
experimental conditions.
Asymmetical SrCoFeO(x) membranes consisting of a dense thin layer and a
porous support layer of the same material were made using a cold pressing
technique. Finely ground powder was used for the dense layer while larger
particle sized powder was used for the porous support. The thickness of the
dense layer was controlled by using varying amounts of the finely ground
powder, with the thinnest dense layer being approximately 150 micrometers.
When helium was used as the sweep gas, the critical thickness was determined
to be approximately 600 micrometers. When carbon monoxide was used as the
sweep gas, the oxygen flux continued to increase as the dense layer decreased
down to 150 micrometers due to the more favorable surface kinetics on the
sweep side.

Inorganic Membranes III – 4
Friday July 18, 11:15 AM-11:45 AM, O’ahu/Waialua
Micro-structured Inorganic Membrane Reactor
W. Liu (Speaker), Pacific Northwest National Lab, Richland, Washington, USA - wei.liu@pnl.gov
Y. Wang, Pacific Northwest National Lab, Richland, Washington, USA
D. Elliott, Pacific Northwest National Lab, Richland, Washington, USA
X. Li, Pacific Northwest National Lab, Richland, Washington, USA
B. Johnson, Pacific Northwest Naitonal Lab, Richland, Washington, USA
R. Zheng, Pacific Northwest National Lab, Richland, Washington, USA
Many catalytic reactions are limited by mass transfer or thermodynamic
equilibrium. Membranes can be used for in situ regulation of mass transfer rate of
reactants or products during a catalytic reaction process to enhance the
productivity and/or product yield. Inorganic membranes are suitable for
fabrication of membrane reactors due to its high thermal and chemical stability.
However, the conventional inorganic membranes made in a single tube or planar
disk form has low surface area packing density and is associated with challenges
of high cost per unit membrane surface area and low productivity per unit reactor
volume. Micro-structured membrane reactor design concepts and prototypes will
be discussed in this presentation. In the proposed design, small reaction
channels (0.5~3mm) are formed in macro-porous support matrix with the
membrane and/or catalyst layer being deposited on the channel wall. The porous
matrix plus membrane layer allows selective introduction of reactants from the
exterior of the reactor module into the reaction channel or selective withdrawal of
products from the reaction channel to the exterior of the reactor module. The
small channel enables efficient mixing of the reactants inside the channel and
rapid mass transport between the membrane surface and bulk channel fluid. Use
of the small channel also provides high membrane surface area packing density.
Performance benefits of the novel design will be illustrated with two different
types of reaction applications, gas-phase steam reforming for hydrogen
production, gas/liquid multiphase hydrogenation for biomass conversion.

Inorganic Membranes III – 5
Friday July 18, 11:45 AM-12:15 PM, O’ahu/Waialua
Selective Gas Transfer and Catalytic Processes in Nano-Channels of
Ceramic Catalytic Membranes
V. Teplyakov (Speaker), A.V.Topchiev Institute of Petrochemical Synthesis, RAS, Moscow,
Russia - tepl@ips.ac.ru
M. Tsodikov, A.V.Topchiev Institute of Petrochemical Synthesis, RAS, Moscow, Russia
I. Moiseev, Kurnakov Institute of General and Inorganic Chemistry, RAS, Moscow, Russia
Catalytic processes using of porous ceramics where catalytic coatings on the
microchannel walls are of modern interest for creation of high speed (residence
time is < 10 -3 sec) and compact membrane reactors, especially for C1 reactions.
Catalytic mesoporous inorganic membranes combining selective gas transport
and catalytic activity can be considered as ‘ensemble’ of nanoreactors and be
related to new direction of heterogeneous catalysis. The counter-diffusion
transport in catalyst particles is replaced by unidirectional transport with the
potential of intensified catalysis and increased selectivity.
Mesoporous ceramic membranes with variation of pore size as non-linear
gradient can play an important role for selective mass-transfer control in
membrane catalysis. Based on methanol decomposition and methane
conversion this paper presents the results demonstrating the intensification of
gas phase catalytic processes in nano-channels of ceramic catalytic membranes.
Oxidative condensation of methane was carried out with using tubular ceramic
membranes of "BUM" trademark based on titanium carbide with La- Ce/MgO
catalyst deposited inside the membrane pores. The methanol conversion was
studied using TRUMEM metal-ceramic membranes (TiO2/Stainless steel). For
this reaction a Cr2O3×Al2O3×ZnO catalytic coating formed inside the membrane
channels was prepared. In latter case additionally a mesoporous layer of single
phase oxide P0.03Ti0.97O2±d with a narrow pore size distribution in the range of
2 nm was coated on the top of the catalytic membrane. As a result asymmetric,
three- layer ceramic catalytic membranes with a pore gradient in the range of 2-
3000 nm were prepared.
It was found that such membranes possess "directed permeability" in relation to
H2, He, CO2, O2, CH4, Ar. The dehydration rate of methanol into formaldehyde
and hydrogen directly correlates with selective properties of directed
permeability. Productivity of hydrogen under methanol feeding in direction to
selective layer through large porous one practically in half-order higher then
under contrary direction. Such systems can be considered as membranecatalytic
"diode". Ceramic membranes BUM modified by La-Ce/MgO provide

improved activity and selectivity in syn-gas production by using partial oxidation
of methane under 550-650 o C.
It is found that combination of separation selectivity and catalytic activity of
ceramic membranes with gradient-porosity can provide intensification of catalytic
processes, particularly, for methanol decomposition, oxidative methane
conversion and methane gasification by CO2. The latter has good prospects for
creation of technology combining consumption of CO2 and methane conversion
in one process.

Inorganic Membranes III – 6
Friday July 18, 12:15 PM-12:45 PM, O’ahu/Waialua
The Oxidative CO2 Reforming of Methane to Syngas in a Thin Tubular
Mixed-Conducting Membrane Reactor
C. Zhang (Speaker), Nanjing University of Technology, China
X. Dong, Nanjing University of Technology, China
W. Jin, Nanjing University of Technology, China - wqjin@njut.edu.cn
N. Xu, Nanjing University of Technology, China
With the increasing global demand for cleaner energy, fuel cell hydrogen and
ultraclean gas-to- liquid (GTL) fuels are receiving a great deal of attention as
alternative energy sources. Mixtures of H2 and CO, known as synthesis gas,
serve as the intermediate between hydrocarbon feedstocks and both hydrogen
and GTL fuels. Synthesis gas can be produced by partial oxidation reactions or
reforming reactions (steam, CO2, and autothermal), all of which either require or
can benefit from pure oxygen as a reactor feed. Because of the high economic,
environmental and safety costs associated with pure oxygen, dense mixed-
conducting oxygen-permeable membranes have been explored as an alternative
oxygen source for methane oxidation process. In this work, the oxidative CO2
reforming of methane (OCRM) to syngas, involving coupling of exothermic partial
oxidation of methane (POM) and endothermic CO2 reforming (CRM) processes,
was studied on a thin tubular Al2O3 doped SrCo0.8Fe0.2O3-´ (SCFA) membrane
reactor packed with a Ni/Al2O3 catalyst. The influences of the temperature and
feed concentration on the membrane reaction performances were investigated in
detail. The methane conversion and the CO2 conversion were both found to
increase with increasing reaction temperature; however, exerted a larger
influence on the CO2 conversion. The H2 selectivity was also found to increase
with increasing reaction temperature. Depending on the temperature or H2O/CH4,
the OCRM process could be performed auto-thermally with idealized reaction
condition. Furthermore, OCRM reaction is a green chemistry process owing to its
utilization of two greenhouse gases (CO2 and CH4) as a feedstock.

Facilitated Transport Membranes – 1 – Keynote
Friday July 18, 9:30 AM-10:15 AM, Wai’anae
Facilitated Transport Membrane for Selective Separation of CO2 from CO2-
H2 Mixtures at Elevated Temperatures and Pressures
R. Yegani, Kobe University, Kobe, Japan
M. Teramoto (Speaker), Kobe University, Kobe, Japan
O. Okada, Renaissance Energy Research Company, Osaka, Japan
H. Matsuyama, Kobe University, Kobe, Japan - matuyama@kobe-u.ac.jp
A novel facilitated transport membrane consisting of Cs2CO3 as CO2 carrier and
poly (vinyl alcohol)/ poly (acrylic acid) gel (PVA/PAA gel) as support was
developed for the removal of CO2 from CO2/H2 mixtures at relatively high
pressures (up to 600kPa) and temperatures (125 - 200°C). For this membrane,
the presence of water in the membrane is indispensable for the CO2-carrier
reaction (overall reaction: CO2 + CO3 2- + H2O = 2HCO3-) to occur rapidly and also
for the gel layer to swell so that gas permeation is facilitated. Therefore, very
hygroscopic PVA/PAA gel was used as membrane material. The membrane was
prepared by casting an aqueous solution of Cs2CO3 and PVA/PAA copolymer
onto a hydrophilic microporous PTFE membrane followed by heat treatment. In
this membrane, the PTFE membrane pores are filled with the gel and its surface
is covered with the gel, which makes the membrane very stable. The membrane
performance was tested mainly at 160° C by the experiments on the selective
separation of CO2 from a mixture of 5% CO2, 45% H2 and 50% H2O with argon
as sweep gas. The sweep side pressure was usually 20kPa lower than the feed
side pressure. With increasing the feed side pressure, CO2 permeance increased
due to increased water content in the membrane gel layer caused by increased
H2O partial pressure. The highest CO2 permeance, 2x10 -4 mol/(m 2 s kPa), was
obtained at 160C when the Cs2CO3 concentration in the gel layer (dry basis) was
about 70wt%, and the CO2/H2 selectivity was 125. The highest CO2 permeance
and CO2/H2 selectivity were observed at 160C. This may be explained by slower
CO2-carrier reaction rate at lower temperatures and lower water content in the
gel as well as lower chemical equilibrium constant of the reaction at higher
temperatures. However, even at 200C, the observed CO2 permeance was still
high (1x10 -4 mol/(m 2 s kPa)) and the CO2/H2 selectivity was about 80. It was
found that the higher the humidity of the feed gas, the higher both CO2
permeance and CO2/H2 selectivity, which also suggests the importance of water
content in the membrane. Crosslinking of gel layer by glutaraldehyde was found
to be effective to decrease H2 permeation rate by minimizing the defect (pinhole)
formation. The highest CO2/H2 selectivity was as high as 650 with almost the
same CO2 permeance as that observed with the membrane without crosslinking.
This membrane was found to be stable during a long-term experiment for 350 h.
As far as we know, the resent membrane has the highest CO2 permeance and

CO2/H2 selectivity at high temperatures. This type of membrane has a potential
for use as CO2 selective membrane in a water-gas shift membrane reactor and
also for CO2/N2 separation at high temperatures such as CO2 separation from hot
flue gases.

Facilitated Transport Membranes – 2
Friday July 18, 10:15 AM-10:45 AM, Wai’anae
Explorative Investigation of Cu(II) Facilitated Transportation Through
Supported Liquid Membrane and Its Derivatively Successful Story
Q. Yang (Speaker), National University of Singapore, Singapore
T. Chung, National University of Singapore, Singapore - chencts@nus.edu.sg
J. Jiang, National University of Singapore, Singapore
N. Kocherginsky, National University of Singapore, Singapore
The initiative for this work is to develop a novel and more efficient supported
liquid membrane (SLM) based process to recover copper and regenerate spent
ammoniacal etchant solution with low operation cost and without generating
secondary waste for Printed Circuit Board (PCB) manufacturers. A
comprehensive study has been conducted in this work including 1) the quantum
chemical computations for selecting proper carrier for Cu(II) extraction in SLM
system; 2) the fundamental kinetics and mechanism of Cu(II) transport through
SLM system; 3) a successful lab-scale to pilot-scale spent etchant treatment
process.
First of all, a comparative study of two widely used Cu(II) extractants, namely
LIX54 and LIX84, and their impregnated SLM systems was carried out in this
work. Experimental and computational characterizations of LIX54/Cu(II) and
LIX84/Cu(II) complexes were investigated and the results agreed well in the
reaction mechanisms, complexes geometries and Cu(II) extraction strengths of
these two carriers. Cu(II) transmembrane fluxes at different conditions were
compared and the results showed that LIX54 had slightly higher copper removal
rate in the ammoniacal solution but much poorer copper loading in acidic media.
Much higher selective separation performances of Cu(II) over Zn(II) and Cd(II)
and no ammonia carry-over provide LIX54 significant advantages over LIX84 for
ammoniacal solutions treatment.
Subsequently, Cu(II) recovery from industrial ammoniacal wastewater using flat
sheet SLM system was investigated. LIX54 in kerosene was used as a carrier in
the liquid membrane phase to extract and transfer copper. Detailed theoretical
model for facilitated transport through flat membrane was developed, where
diffusion of copper complex with ammonia in aqueous stagnant layer and fast
reactions of the carrier and copper species in aqueous reaction layer have been
taken into account. This model, where the carrier moves slightly out from the
membrane in the reaction layer, then transfers from one aqueous phase to
another through the membrane, and finally moves back, is called Big Carrousel.
Mathematical model simulation demonstrated that only Big Carrousel model,
based on the ability of the carrier to leave the membrane and to react with copper

ammonia complexes in aqueous solutions, gives satisfactory quantitative
description of all experimental results, including the flux plateau at high feed
copper concentrations and the decrease of copper flux at lower pH of the feed
solutions. This is for the first time an experimental work demonstrating the
applicability of this transportation mechanism.
Relied on the above-mentioned fundamental studies, the successful bench scale
to pilot scale tests were accomplished. The treatment process based on SLM
technology resulted in Cu(II) removal from spent ammoniacal etching solution
and formation of saturated copper sulfate solution in sulfuric acid, used as a
striping phase. Composition of the regenerated etching solution and purity of
CuSO4‡5H2O crystals formed in the striping phase were comparable or even
better than their commercial analogues.

Facilitated Transport Membranes – 3
Friday July 18, 10:45 AM-11:15 AM, Wai’anae
Ionic Liquid Membranes for Carbon Dioxide Separation
C. Myers (Speaker), US DOE, National Energy Technology Laboratory, Pittsburgh,
Pennsylvania, USA - christina.myers@netl.doe.gov
J. Ilconich, Parsons, South Park, Pennsylvania, USA
H. Pennline, US DOE, National Energy Technology Laboratory, Pittsburgh, Pennsylvania, USA
D. Luebke, US DOE, National Energy Technology Laboratory, Pittsburgh, Pennsylvania, USA
Recent scientific studies are rapidly advancing novel technological improvements
and engineering developments that demonstrate the ability to minimize,
eliminate, or facilitate the removal of various contaminants and greenhouse gas
emissions in power generation. The Integrated Gasification Combined Cycle
(IGCC) shows promise for carbon dioxide mitigation not only because of its
higher efficiency as compared to conventional coal firing plants, but also due to a
higher driving force in the form of high partial pressure. One of the novel
technological concepts currently being developed and investigated is membranes
for carbon dioxide (CO2) separation, due to simplicity and ease of scaling. A
challenge in using membranes for CO2 capture in IGCC is the possibility of failure
at elevated temperatures and pressures. Our earlier research studies examined
the use of ionic liquids on various supports for CO2 separation over the
temperature range 37-300°C. The ionic liquid, 1-hexyl- 3methylimidazolium
Bis(trifluoromethylsulfonyl) imide, ([hmim][Tf2N]), was chosen for our initial
studies with the following supports: polysulfone (PSF), poly(ether sulfone) (PES),
and cross- linked nylon. The PSF and PES supports had similar performance at
room temperature, but increasing temperature caused the supported membranes
to fail. The ionic liquid with the PES support greatly affected the glass transition
temperature, while with the PSF, the glass transition temperature was only
slightly depressed. The cross-linked nylon support maintained performance
without degradation over the temperature range 37-300°C with respect to its
permeability and selectivity. However, while the cross-linked nylon support was
able to withstand temperatures, the permeability continued to increase and the
selectivity decreased with increasing temperature. Our studies indicated that
further testing should examine the use of other ionic liquids, including those that
form chemical complexes with CO2 based on amine interactions. The hypothesis
is that the performance at the elevated temperatures could be improved by
allowing a facilitated transport mechanism to become dominant. Several aminebased
ionic liquids were tested on the cross-linked nylon support. It was found
that using the amine- based ionic liquid did improve selectivity and permeability
at higher temperatures. The hypothesis was confirmed, and it was determined
that the type of amine used also played a role in facilitated transport. Given the
appropriate aminated ionic liquid with the cross-linked nylon support, it is

possible to have a membrane capable of separating CO2 at IGCC conditions.
With this being the case, the research has expanded to include separation of
other constituents besides CO2 (CO, H2S, etc.) and if they play a role in
membrane poisoning or degradation. This communication will discuss the
operation of the recently fabricated ionic liquid membranes and the impact of
gaseous components other than CO2 on their performance and stability.

Facilitated Transport Membranes – 4
Friday July 18, 11:15 AM-11:45 AM, Wai’anae
CO2 Capture: Reduction in Greenhouse Gas Levels
D. Smith, Carbozyme, Inc., Monmouth Junction, New Jersey, USA
R. Cowan, Carbozyme, Inc., Monmouth Junction, New Jersey, USA
M. Trachtenberg (Speaker), Carbozyme, Inc., Monmouth Junction, New Jersey, USA -
mct@cz-na.com
Separation of flue gas carbon dioxide (CO2) from natural gas, petroleum or coal
fired furnaces is the single most difficult and expensive step (>65% of total) in the
capture-transport-geologic storage scenario proposed by national and
international organizations focused on control of greenhouse gases. The object,
as laid out by the DOE National Energy Technology Laboratory (NETL), is to
extract 90% of the CO2 to yield 95% purity with an energy penalty of less than
20% for the stream derived from combustion of pulverized coal and to have the
scalability to manage a gas flow of thousands of cubic meters (hundreds of
thousands of cubic feet) each day.
We have been developing an enzyme-based, contained liquid membrane (CLM),
dual hollow fiber permeator for this purpose. The key next step is progressive
scale up of this design and testing with actual flue gas under development facility
conditions in anticipation of later, yet larger, pilot scale field trials. The design and
operation of the permeator is critical to maximizing performance. However, a
multiple hollow fiber design of the type we developed has not been demonstrated
before nor has it been manufactured commercially. Key elements to successful
design are: " Thermal regulation as the evaporation of large quantities of water
will affect operating temperature. Control of this temperature by circulating the
CLM will affect system selectivity and CO2 recovery. Lack of control of this
temperature will result in condensation within the hollow fibers and/or membrane
pores. " Uniformity of thermal management effects driving forces for system flow.
" Permeate pressure control is necessary to minimize the energy burden
imposed by the capture system. However this will effect CO2 recovery and have
an effect on selectivity.
Each of these issues has now been addressed. Process engineering studies and
system simulations provide the basis for size selection.
Modeling of the effect of pulverized coal fired flue gas components on the CLM
has been carried out to determine the flue gas component acceptance values as
well as the preferred gas flow rates, pressure and temperature. Modeling has
been used to design post-capture treatment to provide a stream that satisfies
pipeline acceptance values. Primary interest is on the micro components of PC

fired boiler flue gas, SOx and mercury. These components will have significant
effects on the permeator function and there control before admission to the
permeator is important. Acceptance criteria for them have been established.
To date, using smaller, laboratory scale devices, we have studied both analog
(ersatz) streams and flue gas derived from combusting methane or propane. The
feed gas CO2 concentration ranged from 0.05- 40% in air, and 6%-13% derived
from burning hydrocarbon fuels. Feed gas source or composition did not affect
CO2 permeance. The solubility of each non-reactive gas in the solvent liquid
alone determined the specific permeance and thus the selectivity. For coal
(natural gas) feed streams will contain about 13.8% (3.5%) CO2; the retentate,
returned to the stack, are expected to contain 1.6% (0.4%) CO2, while the dry
compressed product is 94.9% (89%) CO2 for a given permeator design. We are
in process of determining the actual operation values. The status will be
discussed.

Facilitated Transport Membranes – 5
Friday July 18, 11:45 AM-12:15 PM, Wai’anae
Novel Olefin Carrier for Facilitated Transport Membranes: Partially
Polarized Surface of Silver Nanoparticles by Electron Acceptor
Y. Kang (Speaker), Hanyang University, Korea - kangys@hanyang.ac.kr
S. Kang, Seoul National University, Korea
A new application of metallic silver nanoparticles as a novel olefin carrier for
facilitated olefin transport membranes was explored. The surfaces of silver
nanoparticles were chemically activated using electron acceptor such as pbenzoquinone.
The chemically activated surface is expected to form complexes
with olefin molecules resulting in olefin carrier for facilitated transport. Such
facilitated transport membranes were applied for separation of olefin/paraffin
mixtures such as propylene/propane mixtures. The separation performance for
the 50/50 (v/v) propylene/propane mixture through the 1/1/0.85 EPR/AgO/ pbenzoquinone
membrane showed the selectivity of 10 and the mixed gas
permeance of 0.5 GPU for up to 105 hrs. The change in the chemical
environment around the silver nanoparticles in EPR/Ago composite membranes
upon the incorporation of p-benzoquinone was investigated by XPS. The binding
energy of the d5/2 orbital of the silver particle in the EPR/Ago/p-benzoquinone
system increased gradually with increasing p-benzoquinone content. This
indicates that the binding energy of the valence electrons in the silver atoms
increased due to the interactions between the silver atoms and p-benzoquinone,
and that the surface of the silver nanoparticles was partially positively charged.
Quantum mechanical ab-initio calculations were conducted to confirm the
possible theoretical interactions between the surface of the silver nanoparticles
and olefin molecules. Ethylene molecules can interact with the upper edge, the
side, or the palm side of the silver nanoparticle with corresponding complexation
enthalpies (”H) of -4.48, -3.65 and -1.42 kcal/mol, respectively. These ab-initio
calculations suggest the presence of the interactions between the silver
nanoparticle and olefin molecules, with the most probable interaction of ethylene
with the upper edge of the silver nanoparticle. The complexation of propylene
with the surface of the silver nanoparticles was investigated using FT-IR
spectroscopy. The EPR/Ago composite without p-benzoquinone showed two
peaks at 1664 and 1640 cm -1 representing the C=C stretching vibration of
propylene (Å1 and Å2 of C=C in free propylene are 1664 and 1640 cm -1 ,
respectively), upon exposure to propylene. The positions of the peaks remained
unchanged as the exposure time was increased up to 30 minutes. The two
propylene peaks disappeared in the spectra following desorption of propylene for
5 minutes. These results suggest no interaction of propylene with the surface of
the silver nanoparticles in the EPR/Ago composite without p-benzoquinone as
the propylene absorption occurs only in the EPR matrix. On the other hand, the

EPR/Ago/p-benzoquinone composite showed peaks at 1664 and 1640 cm -1 right
after propylene exposure. The intensities of the both peaks at 1664 and 1640 cm -
1 decreased and a new peak at 1649 cm -1 became dominant with increasing
propylene exposure time. These results indicated that the new peak at 1649 cm -1
was presumably due to the partial electron transfer from the C=C bond of
propylene to the partially positively charged surface of the silver nanoparticles.
Conclusively this is the first attempt to use silver nanoparticles activated by an
electron acceptor such as p-benzoquinone as olefin carriers for facilitated
transport. The activated or partially positively charged surface of silver
nanoparticles caused interactions or complexation with olefin molecules, such as
propylene and ethylene, as supported by FT-IR spectroscopy and ab-initio
calculations.
Reference
(1) Y. S. Kang, S. W. Kang, H. Kim, J. H. Kim, J. Won, C. K. Kim, and K. Char, Advanced
Materials, 2007, 19, 475-479

Facilitated Transport Membranes – 6
Friday July 18, 12:15 PM-12:45 PM, Wai’anae
Selectivity and Stability of Facilitated Transport Membranes Containing
Silver Nanoparticles for Propylene Separation
L. Pollo (Speaker), Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
A. Habert, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
C. Borges, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil -
cristiano@peq.coppe.ufrj.br
Propylene is the key building block for the production of important petrochemical
products, such as polypropylene, acrylonitrile, propylene oxide, cumene, phenol,
isopropylic alcohol and many others. The worldwide demand for propylene has
been increasing at 5.7% a year since 1990, with a forecast of 84 million tons for
2010. To obtain propylene many successive stages of distillation are necessary,
the separation of propane and propylene being the most difficult and expensive.
With close molecular sizes and relative volatility, distillation towers must run at
high rates of reflux extreme pressure and temperature conditions, with a high
energy cost.
Polymeric membranes have long been used in the separation of mixtures, like
oxygen from air, carbon dioxide from methane, and the dehumidification of air
amongst others. Nevertheless, conventional polymeric membranes are not
competitive for the separation of olefin/paraffin mixtures, due to an unfavorable
tradeoff of selectivity and permeability. Similar physicochemical properties and
molecular size of these compounds are indeed limitations for membrane
separation based on sorption/diffusion mechanism. One alternative that has been
sought is a simultaneous increase of permeability and selectivity by incorporating
in the membrane matrix specific agents that interact reversibly with propylene but
not with propane. In this way, propylene permeation occurs by facilitated
transport mechanism.
Our research group has been investigating silver salts as propylene carriers,
obtaining very good results. However, silver salts have a low chemical stability
resulting in the loss of transport activity over long periods of time. In order to
overcome this problem, this work investigates the use of metallic silver
nanoparticles in polyurethane composite membranes. Metallic nanoparticles
have attracted much attention due to their unique physicochemical properties.
The silver nanoparticles were photogenerated in situ in the polyurethane matrix
using UV light radiation and AgCF3SO3 salt as precursor. The composite
membrane was prepared by coating a commercial microfiltration membrane of
nylon. It was observed an improved stability of silver nanoparticles, which may

elated to the presence of free electrons in functional groups of the polymer
chain. The membranes also showed excellent performance for
propylene/propane separation at 25ºC and 4 bar. A propylene/propane ideal
selectivity of 100 and propylene permeability of 4 GPU were obtained. After 180
hours of continuous permeation, the membrane performance still was
unchanged.

Oral Presentation
Abstracts
Afternoon Session
Friday, July 18, 2008

Pervaporation and Vapor Permeation III – 1 – Keynote
Friday July 18, 2:15 PM-3:00 PM, Kaua’i
Vapor Permeation and Pervaporation as Efficient Alternatives in the
Recovery of Fruit Aroma Compounds
N. Diban, University of Cantabria, Stantander, Spain
A. Urtiaga, University of Cantabria, Stantander, Spain
I. Ortiz (Speaker), University of Cantabria, Stantander, Spain - ortizi@unican.es
Flavours or aroma compounds are key components for the fruit juice industry.
They confer the characteristic scent and taste attributes to the product
determining the customers acceptance. During the concentration process, aroma
compounds are usually lost and they are recovered by distillation in order to add
them back to the final product. Nevertheless, the heat applied during this stage
may cause important degradation and losses of volatile aroma compounds,
additionally to the high energy consumption that this procedure implies.
Membrane processes are very attractive to be applied in aroma recovery
because they are simple and flexible, employ mild working temperatures and do
not need chemical additives. Moreover, they are characterised by low energy
consumption and easy scaling-up [1]. From the possible membrane- based
technologies, Pervaporation (PV) [2] and Vacuum Membrane Distillation (VMD)
[3] were selected.
Identification of the characteristic aroma compounds present on real fruit juices
has been made by means of GC-MS. From this analysis, supported by the
literature [5], it was determined that the impact aroma compound of pear was
ethyl 2, 4-decadienoate (DEC) and for bilberry, it was trans-2-hexen-1-ol (HEX).
They belong to different functional groups (esters and alcohols, respectively) and
own different characteristic properties (i.e., saturation pressure, solubility in
water, hydrophobicity).
While for PV, the membrane mass transfer across dense polymer material is
always due to a solution- diffusion phenomenon, in VMD, because of the porous
membrane, mass transfer can occur by vapour permeation through the porous
membrane and/or solid transport in the non-porous section of the membrane,
depending on the compound/membrane affinity.
In this work the comparative analysis of the behaviour of PV and VMD for the
separation and concentration of the mentioned two aroma compounds using
hydrophobic membranes has been made. PV of trans-2-hexen-1-ol on
polydimethylsiloxane (PDMS) membranes and VMD of ethyl 2, 4-decadienoate
on polypropylene (PP) membranes were studied for a ternary model system of

water/ethanol/aroma compound. Operational variables (aroma compound feed
concentration, feed flow rate, temperature and downstream pressure) affecting
the process performance (i.e. partial fluxes and enrichment factors) were studied.
Efforts were directed to the development of mathematical models that allow the
process design and simulation. The characteristic mass transfer mechanism and
parameters for each system, consisting on a membrane technology and an
aroma compound feed solution, were experimentally determined [6-8]. On one
hand, for the PV of HEX, the classical solution-diffusion mass transport
mechanism across the membrane was found and its characteristic solubility, Si,
and diffusivity, Ds,i, parameters were obtained. On the other hand, experimental
results showed that during the VMD of DEC, similarly to PV, solution and surface
diffusion of the aroma compound onto the PP membrane occurred, while for the
major components of the feed solution the mass transfer took place by means of
classical vapour permeation.
During the experiments of VMD for the concentration of DEC, the aroma
compound enrichment factor, bDEC, reached a value up to 15. Whereas in PV,
the bHEX achieved was approximately 200 at the most favourable experimental
working conditions. The mathematical models previously developed have been
used in the analysis of operative conditions and parameters in the comparative
behaviour of the technologies for the two study cases. Both technologies show
feasibility and a great potential for aroma compound recovery.
Acknowledgements Projects CTM2006-00317 and CTQ2005-02583 of the Spanish Ministry of
Education and Science and F.P.I. grant are gratefully acknowledged.
Literature
[1] V.Calabro, B.L.Jiao and E.Drioli, Theoretical and experimental study on membrane distillation
in the concentration of orange juice, Ind & Eng Chem Res, 33 (1994) 1803.
[2] C.C.Pereira, C.P.Ribeiro, R.Nobrega and C.P. Borges, Pervaporative recovery of volatile
aroma compounds from fruit juices. J Memb Sci 274 (2006) 1.
[3] R.Bagger-Jørgensen, A.S.Meyer, C.Varming and G.Jonsson, Recovery of volatile aroma
compounds from black currant juice by vacuum membrane distillation. J Food Eng 64 (2004) 23.
[4] I.D.Morton & A.J.Macleod. Food flavours. Part C. The flavour of fruits. Elsevier, Amsterdam,
1990.
[5] N.Diban, A.Urtiaga, I.Ortiz. Recovery of key components of bilberry aroma using a commercial
pervaporation membrane. Desal 224 (2008) 34.
[6] V.García, N.Diban, D.Gorri, R.Keiski, A. Urtiaga, I. Ortiz. Separation and concentration of
bilberry impact aroma compound from dilute model solution by pervaporation. JCTB, accepted.
[7] N. Diban, O.C. Voinea, A. Urtiaga,I. Ortiz. Vacuum Membrane Distillation of the main pear
aroma compound: experimental study and mass transfer modelling. J Mem Sci, under review.

Pervaporation and Vapor Permeation III – 2
Friday July 18, 3:00 PM-3:30 PM, Kaua’i
Monitoring and Modelling of Aroma Recovery from Fermentation Media
Using Pervaporation and Fractionated Condensation
C. Brazinha (Speaker), Universidade Nova de Lisboa, Caparica, Portugal -
carla.brazinha@dq.fct.unl.pt
O. Teodoro, Universidade Nova de Lisboa, Caparica, Portugal
J. Crespo, Universidade Nova de Lisboa, Caparica, Portugal
Introduction
Organophilic pervaporation has a high potential for aroma recovery from dilute
aqueous solutions because it involves a low energy input when compared with
other separation processes such as distillation. Also, it operates at mild
conditions allowing a direct recovery of aroma compounds from fermentation
processes or biological complex media.
Mass spectrometry (MS) proves to be a powerful analytical tool for studying the
recovery and fractionation of aromas using pervaporation-condensation systems
because it allows for on-line monitoring of the concentration of each vapour
present in the permeate stream. Due to its high sensitivity and precision, MS is
particularly suitable for on-line monitoring of aromas present in trace
concentrations. It also enables transient studies and reduces experimental
workload significantly when compared with conventional gas chromatography
analysis.
Previous work proved that MS can successfully on-line monitor pervaporation
processes under variable upstream conditions [1]. The present work aims to
extend the use of this technique for processes with variable temperature of
condensation and downstream pressure.
Aroma recovery both from fermentation media (e.g. for valorisation of aromas as
by-products of the bio-ethanol production) and also from other biological media is
not an easy task since aromas are usually dilute in a complex mixture (aroma
profile). Fractionation of aromas is important to consider when we are interested
in a particular aroma or group of aroma compounds. Aiming at defining suitable
strategies for recovery and fractionation of aromas, in order to obtain pre-defined
condensates, a mathematical model was developed and experimentally
validated. This model allows for optimisation of the temperature in first
condenser, in a pervaporation process using in-series condensation. This model
also applies successfully to media where ethanol and dissolved gases (carbon
dioxide) are present.

Experimental
The experimental set-up involves a pervaporation cell and two condensers in
series operated under controlled vacuum and temperature. A POMS-PEI
membrane gently provided by GKSS, Germany was used. For on-line MS
monitoring, the partial permeate pressure of each compound i is acquired in realtime.
The permeate is sampled through a split line with a needle valve.
Previously, independent mono component calibrations were obtained in order to
correlate the characteristic MS signal of compound i with its partial permeate
pressure.
Results
The experimental work developed for validation of the MS monitoring technique
was performed with the MS coupled to the pervaporation-condensation system,
varying the temperature in the first condenser. This work allowed to define
suitable operating conditions where the MS signals were sensitive, reproducible
and independent, validating the MS as an on-line monitoring tool.
The mathematical model we developed was based on phase equilibrium in the
condensers and it allowed us to obtain pre-defined condensates using
Pervaporation and Condensation-in-series under constant operating conditions,
such as upstream conditions and permeate pressure. The model allows for
prediction of the percentage of condensation of each compound and the
composition of the condensates in each condenser, at variable temperature in
the condenser. After an independent measurement of dissolved gases, the
model was firstly developed for systems with water and different amounts of
dissolved gas as feed solution, taking into account inert gas permeation. The
effect of inert gases on the performance of the condensation process are
discussed comprehensively and predicted mathematically. This model was also
applied to complex feed streams: dilute aroma compounds in aqueous solutions
and dilute aroma compounds in hydro alcoholic solutions, comprising different
amounts of dissolved gas. In all steps, with increasing complexity of the feed
solution, this modelling toolbox was experimentally validated and the results
obtained interpreted. As a final result, the model developed proved to be
adequate to all feed streams studied, including feed solutions with complex
composition, as happens in biological and fermentation media (with ethanol and
dissolved gases).
This model enables to predict correctly the degree of condensation of the
different feed components as a function of the condenser’s temperature, making
possible the design of the best strategies for aroma recovery and fractionation.
References
[1] T. Schäfer, J. Vital and J.G. Crespo, Coupled pervaporation/mass spectrometry for
investigating membrane mass transport phenomena, J. Membrane Sci., 2004, 241 (2004) 197.

Pervaporation and Vapor Permeation III – 3
Friday July 18, 3:30 PM-4:00 PM, Kaua’i
Effect of Feed Solution Characteristics on Flavour Concentration by
Pervaporation
A. Overington (Speaker), Institute of Food, Nutrition and Human Health, Massey University,
Palmerston North, New Zealand - Amy.Overington@fonterra.com
M. Wong, Institute of Food, Nutrition and Human Health, Massey University, Palmerston North,
New Zealand
J. Harrison, Institute of Fundamental Sciences, Massey University, Palmerston North, New
Zealand
L. Ferreira, Fonterra Co-operative Group Ltd., Auckland, New Zealand
Organophilic pervaporation can potentially be used in the food industry to recover
flavours that would otherwise be lost, and to create natural flavour concentrates.
Trials with model solutions often show that flavour compounds can be highly
enriched using pervaporation, but there has been little research on how the
process is affected by non-volatile substances found in foods, such as fat, protein
and carbohydrates. These components cannot pass through pervaporation
membranes, but they can interact with flavour compounds in the feed.
The driving force for pervaporation depends on the activity of each permeant on
the feed side of the membrane. Non-volatile feed components can either
increase or decrease permeant activities, following various mechanisms. In a
food product that contains fat, flavour compounds will partition between the
aqueous and fat phases. The partition coefficient between the two phases
depends on the compound. The portion of each compound in the fat phase is
effectively unavailable for pervaporation. Protein and carbohydrates can also
alter flavour compound volatility by different amounts depending on the
compound, thereby changing the driving force for pervaporation of these
compounds. The driving force of acidic compounds is also affected by the feed
pH.
To bridge the gap between model solution trials and pervaporation of real food
products, it is important to understand how feed solution characteristics affect
pervaporation. This presentation presents results from the pervaporation of
selected flavour compounds (homologous series of organic acids, esters and
ketones) in feed solutions containing dairy ingredients (cream, lactose and milk
protein).

Pervaporation and Vapor Permeation III – 4
Friday July 18, 4:00 PM-4:30 PM, Kaua’i
Concentration of Bioethanol By Porous Hydrophobic Membranes
T. Uragami (Speaker), Kansai University, Osaka, Japan - uragami@ipcku.kansai-u.ac.jp
Porous poly(dimethylsiloxane) (PDMS) membranes were prepared by freeze
drying aqueous emulsions of organopolysiloxane for the concentration of
aqueous solutions of dilute ethanol which are produced from the fermentation of
biomass. This paper introduces the preparation of porous PDMS membranes
and the development of a new membrane separation technique for the
concentration of bioethanol. Porous PDMS membranes were applied to a
temperature- difference controlled evapomeation (TDEV) method developed as a
new membrane separation technique that can be controlled temperatures of the
feed solution and the membrane surroundings. When the temperature of the feed
solution was kept constant but the temperature of membrane surroundings was
lowered, the ethanol/water selectivity increased remarkably and the permeation
rate decreased. The ethanol/water selectivity of a porous PDMS membrane in
TDEV operation was almost equal to that of a dense PDMS membrane in TDEV,
however, the permeation rate of the porous membrane was higher by three
orders of magnitude. The permeation and separation mechanisms for aqueous
ethanol solutions through porous PDMS membranes in TDEV were discussed as
follows.
When water and ethanol molecules, vaporized from the feed solution, come
close to the membrane surroundings kept at lower temperature in TDEV, the
water vapor aggregates much easier than the ethanol vapor, because the
freezing point of water molecules is much higher than that of ethanol molecules,
and the aggregated water molecules tend to be liquefied as the temperature of
the membrane surroundings becomes lower. On the other hand, because the
PDMS membrane has a relatively high affinity to the ethanol molecules, they are
sorbed inside the pores in a porous PDMS membrane and this sorbed layer of
the ethanol molecules is formed in an initial stage of the permeation. The
vaporized ethanol molecule may be able to permeate across the membrane by
surface diffusion on the sorbed layer of the ethanol molecules inside the pores.
Both the aggregation of the water molecules and the surface diffusion of the
ethanol molecules in the pores are responsible for the increase in the
ethanol/water selectivity through a porous PDMS membrane in TDEV. The
increase of the ethanol/water selectivity in TDEV can be attributed to both the
degree of aggregation of the water molecules on the membrane surroundings
and the thickness of the sorbed layer of the ethanol molecules inside the pores,
which are significantly governed by the temperature of the membrane

surroundings. When the temperature of the membrane surroundings becomes
lower, the degree of aggregation of the water molecules and the thickness of the
sorbed layer of the ethanol molecules are increased. Therefore, an increase in
the ethanol/water selectivity for aqueous ethanol solutions was observed with
decreasing temperature of the membrane surroundings.

Pervaporation and Vapor Permeation III – 5
Friday July 18, 4:30 PM-5:00 PM, Kaua’i
Treatment of Gas Containing Hydrophobic VOCs by a Hybrid Absorption-
Pervaporation Process: The Case of Toluene
F. Heymes, LGEI, Ecole des Mines d'Ales, Ales, France
P. Manno-Demoustier, LGEI, Ecole des Mines d'Ales, Ales, France
J. Fanlo, LGEI, Ecole des Mines d'Ales, Ales, France
E. Carretier (Speaker), Université Paul Cézanne Aix Marseille, Provence, France -
emilie.carretier@univ-cezanne.fr
P. Moulin, Université Paul Cézanne Aix Marseille, Provence, France
Recent legislation encourages industrialists to set up equipment for treating their
VOC-loaded gaseous effluents. For hydrophobic components such as toluene,
poor solubility in water requires specific absorbent. This work contributes to the
development of a hybrid absorption-pervaporation process to treat gases
containing hydrophobic compounds by coupling absorption and in-situ
membrane-based regeneration. The approach can be split into several parts. The
first part aimed to review hydrophobic absorption knowledge to determine an
efficient absorbent. Four chemical classes were tested (i) polyethylene glycols,
(ii) phthalates (iii) adipates and (iv) silicon oil. Experiments were performed to
check gas-liquid partitioning and viscosity. All missing experimental data were
determined, and this allowed selection of di(2- ethylhexyl) adipate (DEHA) as the
most attractive absorbent. Influence of temperature was correlated in the range
(20 to 70) °C. DEHA was shown to be efficient in other aromatic and chlorinated
VOCs. The second part examined the hydrodynamics and mass transfer of a
packed column fed with DEHA to eliminate the toluene from a medium-
concentration gaseous effluent (0.5-5g.m -3 ). The hydrodynamic study showed
that the viscosity of DEHA was not a technical obstacle to its implementation in
an industrial column. The absorption of toluene by DEHA showed the efficiency
of this process. But, this efficiency decreases quickly when the washing liquid
becomes loaded with toluene. From the point of view of mass transfer modelling,
we showed that mass transfer is limited by liquid-side resistance, which seems
logical since DEHA is a viscous absorbent. Our experimental results showed that
the kLa of the system depends on the liquid speed but also on the gas speed.
This behaviour has also been observed by the few authors who have used
viscous fluids in their experiments, but runs counter to all the authors who have
work on low-viscosity fluids: generally, they do not take into account the gas
speed. During the third pervaporation part, bibliographical research and a
preliminary theoretical evaluation led to the choice of PDMS for separating the
toluene / absorbent mixture, whatever the absorbent. PDMS has a high affinity
for toluene and a lower affinity for the different absorbents. The permeability of
the toluene was evaluated at 25°C and confirmed the potential of PDMS for
recovering toluene. Experiments led with the various pure absorbents showed

that no absorbent was detected in the filtrates. In the case of toluene-absorbent
mixtures (10 g.L -1 ), results led to the conclusion that DEHA would be the most
easily regenerable absorbent. Experimental pervaporation flows at low toluene
concentrations (< 10 g.L -1 ) were very low. The predominant effect of the liquid
boundary layer was highlighted. Liquid hydrodynamics upstream of the
membrane therefore seem to be the major parameter. The tubular module was
intended to study this question rigorously. Pervaporation was investigated to
regenerate a heavy absorbent containing toluene at low concentrations (< 10 g.L -
1 ). This process was chosen because of thermal decomposition of heavy
absorbents by distillation and absorbent loss by stripping. The resistance-inseries
theory allowed the impact of the boundary layer to be quantified. The flow
rates of toluene extraction from a DEHA solution were low and require improving
the pervaporation regeneration performance to use this kind of separation in an
industrial hybrid process. The hybrid process was coupled in function of three
values: flow rate, temperature, concentration. The concentration of toluene in the
absorbent has a determining effect on the efficiency of the overall process.
However, it is not a directly adjustable parameter, unlike temperature and flow
rate. Temperature has opposite effects on the efficiency of the two steps in the
process, which means either finding an optimum compromise or dithermal
operation (different temperatures for the absorption column and pervaporation
module). Important information was provided by formulating the equations of the
system and using the correlations determined. It was shown that there were
multiple possible membrane surface area / column height compromises for
treating a given gaseous effluent. Any increase in membrane surface area can
be compensated by a decrease in column height (operating at low global toluene
concentrations in the liquid phase). Inversely, a high column enables a lower
membrane surface area to be used (operating at high global toluene
concentrations in the liquid phase). Calculating the initial investment and
operating costs will enable the user to choose the best compromise between
column height and membrane surface area.

Drinking and Wastewater Applications V – 1 – Keynote
Friday July 18, 2:15 PM-3:00 PM, Maui
The Development of a Household Ultrafiltration System for Developing
Countries
M. Peter-Varbanets (Speaker), Eawag - Swiss Federal Inst. of Aquatic Science and Technology,
Duebendorf, Switzerland - maryna.peter@eawag.ch
M. Vital, Eawag - Swiss Federal Inst. of Aquatic Science and Technology, Duebendorf,
Switzerland
F. Hammes, Eawag - Swiss Federal Inst. of Aquatic Science and Technology, Duebendorf,
Switzerland
W. Pronk, Eawag - Swiss Federal Inst. of Aquatic Science and Technology, Duebendorf,
Switzerland
Global assessments by the WHO and UNICEF showed that one-sixth of the
world's population did not have access to safe water for drinking at the beginning
of 2000. A huge effort is required in order to reach the drinking water objectives
set out in the Millennium Development Goal: to half the proportion of population
without sustainable access to safe drinking water and sanitation by 2015 as
compared to 1990. A part of the solution is the application of decentralized Pointof-use
(POU) treatment systems. This solution is already practiced in some
areas, but available systems are often cost-intensive and require time consuming
maintenance. In principle, membrane technology is also attractive for such
applications because it provides absolute barriers for controlling hygiene hazards
and its modular construction allows implementation on all possible scales.
Furthermore, the costs of the membrane itself have decreased significantly in the
last decades. However, the application of UF technology in DC and TC is limited
by other factors. The basic principle of operation of traditional large scale UF
water treatment plant is to assure high flux avoiding large membrane surfaces.
Therefore, frequent chemical cleaning are usually applied and transmembrane
pressures are in the order of 0.5 - 1.0 bar. For application in households in
developing and transition countries, the application of pumps and chemicals, as
well as complex operation schemes should be avoided. Therefore, we focused
on developing a low-pressure, gravity-driven membrane system without the use
of cleaning chemicals. The system was operated at pressures between 40 and
110 mbar. This corresponds to a water column of 0.40 - 1.10 m, and such a
gravity- driven system can be easily implemented in households. A flat sheet
membrane module with a membrane surface of 0.0016 m 2 was operated in deadend
mode without any cross flow or backflushing.
For the experiments we used natural water from the Chriesbach river
(Dübendorf, Switzerland) with the following composition: Turbidity 0.2-1 NTU with
peak values of 30 NTU, and TOC 2-4 ppm. The membrane module was operated
at a transmembrane pressure of 110 mbar. The flux decreased within the first 2

days of filtration from 120 to 7-10 L/hm 2 and remained stable for the studied
period of 76 days independently on fluctuations of feed water quality. Upon
variations of the pressure, the flux varied temporarily, but afterwards stabilized
again to a value around 7-10 L/hm 2 . This implies that the permeability decreases
with increasing pressures. Sodium azide (1.5%) was added to the feed in order
to suppress biological activity without changing the NOM composition. The
results show that the initial flux decline was similar to the first experiment, but no
flux stabilization was observed and the flux continuously declined. From these
results it can be concluded that biological activity has an important influence on
the flux stabilization. Therefore, microbiological parameters were studied more in
detail. The bioactivity in the feed and on the membrane was measured using the
ATP method. The results show that the bioactivity on the membrane increases
within the first 2 days and then stabilizes. The ATP material balance shows that
during time the proportion of active cells on the membrane decreases, indicating
cell die-off in the depth of the fouling layer. In the presence of sodium azide,
biological activity (ATP) on the membrane was much lower. In the absence of
sodium azide, the concentration of assimilable organic carbon (AOC) was
determined in the feed water and it was observed that AOC correlates with the
activity on the membrane (ATP). Considering that during time increasing
amounts of suspended material from the feed water are deposited on the
membrane, the stabilizing flux implies that the specific resistance of the fouling
layer (m/m 2 ) decreases. Based on the results, we postulate that this is based on
biologically induced cell die-off, resulting in cavity formation and increased
porosity.
More detailed results which support these mechanisms will be presented.
In contrast to conventional membrane plants, neither the membrane surface nor
the capacity is a limiting factor for application of POU systems. While the
required productivity of POU system is approx. 20-50 L/day, and assuming the
flux of 7-10 L/hm 2 the required membrane surface to provide the required
capacity is 0.12-0.21 m 2 . Assuming a membrane price of 40 US$/m 2 , this
corresponds to US$ 4.8-8.4 of membrane costs per POU system. Thus, in case
the membrane life time is several years, the membrane costs are not prohibitive
for application in developing and transition countries. Moreover, the system can
be operated without pumps under hydrostatic pressure of 40 mbar or less,
without regular backflushing, any addition of chemicals or multi-stage
pretreatment.

Drinking and Wastewater Applications V – 2
Friday July 18, 3:00 PM-3:30 PM, Maui
Treatment Performance and Detoxification of Coke Plant Wastewater Using
an Anaerobic-Anoxic-Oxic Membrane Bioreactor System
W. Zhao (Speaker), Div. of Water Environment, Dept, of Environmental Science and Engineering,
China - xhuang@tsinghua.edu.cn
X. Huang, Div. of Water Environment, Dept, of Environmental Science and Engineering, China
D. Lee, Chemical Engineering Department, National Taiwan University, Taiwan
M. He, Div. of Water Environment, Dept, of Environmental Science and Engineering, China
Coke plant wastewater is a kind of complex industrial wastewater generated in
the iron and steel industry during coal carbonization and fuel classification. Its
quantity and quality may vary fairly widely, depending on coal quality, coking
temperature, and by-product recovery processes. The major contaminants in a
typical coke plant wastewater consist of high concentration ammonia, toxic
substances (such as cyanide, thiocyanate, phenols), and biologically inhibitory
organic compounds. The conventional activated sludge process is usually not
potent enough for removal and detoxification of these pollutants. Due to
increasingly stringent regulations for receiving water bodies and industrial
wastewater reuse strategies, achieving effective and safe control of this kind of
wastewater is imperative. In this study, an anaerobic-anoxic-oxic membrane
bioreactor (MBR) system was proposed to treat coke plant wastewater.
Treatment performance at different hydraulic retention times (HRTs) was
investigated. Acute toxicity test was applied to evaluate the toxicity change
during the MBR system, and transformation of organic pollutants in the system
was also analyzed.
The MBR system consisted of an anaerobic reactor (A1), an anoxic reactor (A2)
and an oxic reactor (O) with a submerged hollow fibre polythene membrane
(nominal pore size: 0.4 μm, membrane area: 0.2 m 2 , Mitsubishi, Japan). The
anaerobic reactor was packed with soft media. The anoxic and oxic reactors
were completely mixed tanks, and the mixed liquor recirculation was from the
oxic one to the anoxic one. Compared conventional anaerobic-anoxic-oxic
activated (CAS) system was operated at the same condition with MBR system.
Raw coke plant wastewater was collected from Beijing Steel Company. Acute
toxicity of wastewater was assessed by luminescent bacteria growth inhibition
test, using Zn 2+ as the toxicity reference substance. Transformation of organic
pollutants in the system was analyzed by fluorescence excitation- emission
matrix (EEM). The MBR process was operated in a constant mode. When the
transmembrane pressure (TMP) reached around 0.3MPa, off line physical (with
tap water) and chemical (with HCl, NaOH, NaClO) cleaning of the membrane

was performed to restore membrane flux and then reinstalled in the aeration tank
for continuous operation.
The MBR system was continuously operated for more than 500 days, employing
different HRTs. The optimal conditions were obtained when the HRT of
anaerobic, anoxic, and oxic reactors were 6.7, 13.3, and 20.0 h, respectively,
with constant flux of 4.5L/(m 2 .h), an intermittent suction of membrane with 8 min
on/ 2 min off, and recirculation ratio at 3:1. The MBR effluent average COD, NH3-
N, TN concentrations and turbidity were 248±32 mg/L, 0.2±0.1 mg/L, 120± 11
mg/L, and 1.1±0.2 NTU with removal efficiencies of 90.2±1.0%, 99.9±0.1%,
74.4± 1.1%, and 99.6±0.1%. The effluent of the MBR system was free of
suspended solids, and COD concentrations were lower than those from the CAS
system, especially at high COD loading rates. In terms of removing NH3-N and
TN, both MBR and CAS systems showed effective and no significant difference
in ammonia loading rate from 0.08 to 0.22 kg NH3-N/(m 3 .d) and TN loading from
0.12 to 0.31 kg TN/(m 3 .d).
Acute toxicity test indicated that coke plant wastewater was highly toxic and
79.4±0.4% luminescent bacteria growth inhibition was observed even in 10 times
dilution of raw wastewater compared with control solution, equal to toxicity of
9.60±0.12 mg/L Zn 2+ . Acute toxicity of wastewater decreased substantially
through treatment of MBR system, with the effluent toxicity of 34.2±0.9% growth
inhibition, equal to 0.19±0.01 mg/L Zn 2+ .
The contour maps of EEMs of the MBR influent and effluent revealed that two
fluorophores of the influent with Ex/Em of 220-230/275-325 nm and Ex/Em of
250-280/275-325 nm were ascribed to phenols which were presumedly
responsible for high toxicity of the raw coke plant wastewater. The other two
fluorophores with Ex/Em of 220- 240/330-425 nm and Ex/Em of 250-290/330-425
nm were much alike with the effluent. These peaks may be associated with
humic acid and fulvic acid, potentially refractory organic matters remained in
coke plant wastewater.

Drinking and Wastewater Applications V – 3
Friday July 18, 3:30 PM-4:00 PM, Maui
Time Course of Sub-Micron Organic Matter in MBRs: Relation to Membrane
Fouling in MBRs
K. Kimura (Speaker), Hokkaido University, Sapporo, Japan - kkatsu@eng.hokudai.ac.jp
N. Yamato, Hokkaido University, Sapporo, Japan
T. Miyoshi, Hokkaido University, Sapporo, Japan
T. Naruse, Hokkaido University, Sapporo, Japan
Y. Watanabe, Hokkaido University, Sapporo, Japan
Membrane fouling in MBRs is still a big obstacle for widespread use of MBRs. In
many previous researches, carbohydrates and/or proteins produced by
microorganism during their metabolic activities were pointed out as the major
foulants in MBRs. In this study, sub-micron carbohydrates and proteins in MBRs
were investigated in relation to the evolution of membrane fouling.
Three pilot-scale MBRs equipped with PVDF hollow-fiber MF membranes
(Mitsubishi Rayon Engineering, Tokyo, Japan) were installed at a municipal
wastewater treatment plant and fed with real municipal wastewater. Nominal pore
size of the membrane used was 0.4 µm. The three MBRs were operated with the
identical membrane flux (i.e., 25 LMH) and with different SRTs of 16, 65 and 117
days. Concentrations of carbohydrates and proteins in the three MBRs were
continuously and intensively monitored. Continuous operation of the three MBRs
was carried out for 120 days after acclimatization of biomass. Three size
fractions of organic matter (i.e.,

with the SRT of 65 days, no correlation between fouling trend and any fractions
of organic matter was seen although physically reversible fouling became
significant at the end of the continuous operation. Physically reversible fouling in
the MBR with the SRT of 65 days was presumably explained by development of
biofilms on the surface of membranes.
The rate of evolution of physically irreversible fouling significantly changed in the
MBR operated with SRT of 16 days while those in the other two MBRs were
relatively constant throughout the 140 days operation. It was suggested that time
course of carbohydrates with the size of

Drinking and Wastewater Applications V – 4
Friday July 18, 4:00 PM-4:30 PM, Maui
On the Lookout for a Fouling Indicator – A Critical Evaluation of Various
Methods for Fouling Characterization in MBR
A. Drews (Speaker), TU Berlin, Berlin, Germany - anja.drews@tu-berlin.de
T. de la Torre, Berlin Centre of Competence for Water, Berlin, Germany
V. Iversen, TU Berlin, Berlin, Germany
J. Schaller, TU Berlin, Berlin, Germany
J. Stüber, Berlin Centre of Competence for Water, Berlin, Germany
F. Meng, TU Berlin, Berlin, Germany
B. Lesjean, Berlin Centre of Competence for Water, Berlin, Germany
M. Kraume, TU Berlin, Berlin, Germany
Objectives Fouling still is a major issue in membrane research in general and in
MBR research in particular. A multitude of manuscripts on fouling are constantly
submitted. Despite all this effort, neither the culprit components nor the exact
mechanisms are known and results are even contradictory to some extent. The
main reasons for this are: 1) A wide variety of experimental, sample preparation
but also evaluation methods are used in different groups. E.g., critical flux in its
strictest form is agreed to be unattainable [1], so identification of the onset of the
so-called critical flux is rather arbitrary. 2) Due to the complexity of the systems,
researchers jumped to conclusions on observing any correlations at all. In the
light of this it is not surprising that plenty of different fouling indicators are in use.
The aim of this paper is not to add just another study on fouling but to step back
and evaluate ‘traditional’ and new characterisation methods. Using a large variety
of characterisation tools in a standardised way to monitor a number of different
plants over several months, a pool of data was gained that will lead to more
generally valid information on a) suited characterisation methods and b) suited
data evaluation methods and ‘ hopefully ‘ c) culprit fouling components.
Methods Fouling propensity and mixed liquor characteristics were monitored
regularly in 6 MBR plants (10 L to 250 p.e.) over a period of several months. In
total, 10 chemical and physical mixed liquor characterisation methods were
applied (polysaccharides and proteins in EPS and SMP [2, 3], CST, TTF,
biopolymers via LC/OCD), including the novel TEP (transparent exopolymer
particles) method [4] which yields information on a hitherto undetected fraction of
polymers, and 2 different filtration test cells (ex situ sidestream and a novel in situ
immersed). In the filtration experiments which were carried out to assess the
individual fouling propensity of different sludges in a comparative manner, 3
different critical flux protocols and 2 data evaluation methods were compared
(average TMP during each step and dTMP/dt [1]). This campaign is
supplemented by data gained with the DfCm method [5].

Results Critical flux measurements with sludges from 4 different plants showed
that critical flux varies over time but is surprisingly similar in the investigated
plants despite the fact that that chemical parameters like SMP and EPS differ by
more than 100%. The different evaluation methods yielded variations within the
range of normal change in feed behaviour (±20%). Due to the elimination of
unfed and unaerated feed transport from MBR to filtration test rig, in situ filtration
tests were thought to be superior [6]. Of the three protocols used, two gave a
similar outcome while the result of protocol I (without relaxation between flux
steps) was completely different. This shows the importance of standardising
critical flux protocols for comparison of data. On cross-evaluating several results
of chemical and physical analyses, no clear relationships could be observed.
CST as a first tentative measure of filterability only gave a correlation with TEP
concentrations [4]. While all other alleged chemical indicators vary quite a lot,
critical flux remains pretty stable (see above).
Conclusions The applied large variety of fouling characterisation methods based
on both physical and chemical analyses of the mixed liquor and supernatant
over several months of operation of various plants will allow a more generally
valid conclusion on the practical use of different assessment methods.
Comparative short-term filtration tests like critical flux trials were further improved
by an in situ set-up that eliminates unfed and unaerated sample storage. The
applicability of the novel TEP method has been shown. So far, ‘traditional’
indicators like SMP and EPS gave no clear correlation with filterability. At the
conference, more data of the ongoing campaign will be presented and crossevaluated.
Acknowledgements Parts of this study were funded by the European Commission (AMEDEUS,
REMOVALS, ENREM, MBR-TRAIN). Mr. Meng acknowledges the financial support through the
Alexander von Humboldt-Stiftung. The authors wish to thank Renata Mehrez, Adrien Moreau,
Moritz Mottschall and Djihan Beuter for their work, and BWB, A3 and Microdyn-Nadir for support
and free supply of membrane material.
References
[1] Le Clech P, Jefferson B, Chang IS, Judd SJ, J Membrane Sci 227, 2003, 81-93.
[2] Dubois M, Gilles KA, Hamilton JK, Rebers PA, Smith F, Anal Chemistry 28, 1956, 350-356.
[3] Frolund B, Palmgren R, Keiding K, Nielsen PH, Water Res, 1996, 1749-1758.
[4] De la Torre T, Lesjean B, Drews A, Kraume M, Talanta (submitted).
[5] Evenblij H, Geilvoet S, van der Graaf JHJM, van der Roest HF, Desal 178, 2005, 115-124.
[6] Kraume M, Wedi D, Schaller J, Iversen V, Drews A, Desal (in press).

Drinking and Wastewater Applications V – 5
Friday July 18, 4:30 PM-5:00 PM, Maui
Importance of Membrane Reactor Design for Membrane Performance in
Biofilm-MBR
I. Ivanovic (Speaker), Norwegian University of Sci. and Tech., Trondheim, Norway -
torove.leiknes@ntnu.no
T. Leiknes, Norwegian University of Sci. and Tech., Trondheim, Norway
A Biofilm-MBR is an alternative concept to activated sludge - MBR where a
biofilm reactor is employed instead an activated sludge reactor, and where the
membrane reactor is designed only as an enhanced particle separation unit.
Possible advantages of this concept lie in the fact that biomass is attached to
suspended carriers and there is no need for sludge (i.e. biomass) recirculation in
the system. Additionally, only small amounts of biomass that become detached
from biofilm carriers need to be separated in membrane reactor. [1]. A lower
amount of suspended matter that needs to be separated gives less fouling
potential with regard to cake formation on the membrane surface. However,
submicron particles and colloidal organic matter remain significant foulants as
reported in previous studies [2][3][4]. For this study a small-scale pilot plant was
operated, consisting of moving-bed- biofilm reactor (working volume of 260 L),
coupled with a submerged membrane reactor (MR) with Zenon ZW10 hollow
fiber membrane modules (membrane area 0.93m 2 ). Municipal wastewater was
fed to the pilot plant and operated under low organic loading conditions, giving on
average >90 % ammonium removal. The biofilm reactor was operated with a 4
hour hydraulic retention time. Suspended solids (SS) in the effluent from the
biofilm reactor varied between 90 - 150 mg L -1 , while COD and FCOD were
between 120-242 and 25.9-43.1 mg O 2 L -1 respectively. The membrane reactor
was operated in a 5 minute cycle with production flux 35 LMH, backwash flux 42
LMH and recovery 96%. Continuous air scouring of the membrane was
employed for all tests with specific aeration demand (SADm) set on
approximately 1 Nm 3 airm -2 membrane areah -1 .
Three membrane reactor designs were compared: 1) a completely mixed reactor
(CM-MR), 2) membrane reactor with integrated sludge pocket (SP-MR) and 3) a
membrane reactor with a modified sludge pocket (MSP-MR). Volumes of the
membrane reactors were 9, 25 and 41 L respectively. Preliminary results
showing that design i.e. geometry of the membrane reactor play an important
role in membrane performance. Steady state concentrations of MLSS around the
membrane area were ~3900, ~1000, ~400 mg/L giving fouling rates within
production cycle of 20, 6, and 3×10 -5 bar sec -1 , respectively. Lower
concentrations of MLSS and COD around the membranes as a function of the
modified rector designs results in a better membrane performance. Reduction in

MLSS is not directly proportional to a reduction of fouling rates (i.e. dTMP/dt).
The characteristics of suspended matter around the membrane play an important
role in membrane fouling, however, a reduction in these foulants by an enhanced
membrane reactor design is a significant contribution to controlling and
minimizing fouling of the membrane. Soluble matter (i.e. FCOD) was reduced by
~ 40% in MSP- MR compared to CM-MR. Particle size distribution analyzed in
membrane reactors showed that the differential number percentage of submicron
particles around the membrane in the reactors with a sludge pocket design (SP-
MR and MSP-MR) could be reduced by ~ 8 % and ~ 10 % respectively,
compared to a completely mixed design membrane reactor (CM-MR).
In the presentation will be given more in detail design characteristics of
compared reactors and analyzed their effects on membrane performance i.e.
membrane fouling.
References.
[1] Leiknes T.O. and Ødegaard H., (2007) The development of a biofilm membrane bioreactor ,
Desalination, 202:135-143
[2] Leiknes, T.O.; Ivanovic I.; Ødegaard H,(2006) Investigating the effect of colloids on the
performance of a bio lm membrane reactor (BF- MBR) for treatment of municipal wastewater.
Water S.A.
[3] Ivanovic I; Leiknes T.O.; Ødegaard H., (2006) Influence of loading rates on production and
characteristics of retentate from a biofilm membrane bioreactor (BF-MBR). Desalination ;199:490-
492
[4] Ivanovic I; Leiknes T.O.; (2008) Impact of aeration rates on particle colloidal fraction in the
biofilm membrane bioreactor (BF-MBR). In Press, Desalination

Fuel Cells III – 1 – Keynote
Friday July 18, 2:15 PM-3:00 PM, Moloka’i
Crystalline Order and Membrane Properties in Perfluorosulfonate Ionomers
for PEMFC Applications
R. Moore (Speaker), Virginia Tech, Blacksburg, Virginia, USA - rbmoore3@vt.edu
In this study, we explore the form and function of the crystalline domains in
perfluorosulfonate ionomer membranes. This fundamental project is aimed at
filling a critical void in our understanding of the form and function of polymeric
crystals produced by the ordered packing of backbone chains in modern fuel cell
membranes. While we have learned a great deal about the organization of the
proton-conducting ionic domains in functional polymers such as the
perfluorosulfonate ionomer (PFSI) Nafion, it is remarkable that we know very little
about the detailed structure and formation of the crystallites in these materials or
the spatial arrangement of these ordered features with respect to the proximity of
the ionic domains. In contrast to the vast majority of morphological studies of
these technologically important polymers, this project will be focused on the
‘other’ important morphological feature in these membranes, namely the critical
significance of the crystalline component.

Fuel Cells III – 2
Friday July 18, 3:00 PM-3:30 PM, Moloka’i
Model Studies of the Characterization of the Durability of Nafion®
Membranes and Nafion/Inorganic Oxide Nanocomposite Membranes
K. Mauritz (Speaker), University of Southern Mississippi, Hattiesburg, Mississippi -
kenneth.mauritz@usm.edu
M. Hassan, University of Southern Mississippi, Hattiesburg, Mississippi
Y. Patil, University of Southern Mississippi, Hattiesburg, Mississippi
D. Rhoades, University of Southern Mississippi, Hattiesburg, Mississippi
Selected results from the investigation of the degradation of Nafion
perfluorosulfonic acid membranes in the fuel cell environment will be presented.
The topics will include a detailed explanation of the use of the powerful technique
of modern broadband dielectric spectroscopy which can interrogate
macromolecular motions as well as charge motions over a vast range of time and
distance scales. Long range main chain motions associated with the glass
transition (² relaxation) as well as a higher temperature transition involving the
disruption of polar associations (± relaxation) are revealed. The shift in chain
dynamics of Nafion as seen through real-time in-cell dehydration, as well as postchemical
degradation will be discussed. It will also be explained how the
distribution of relaxation times is related to the shift in Nafion molecular weight
distribution with degradation by radicals issuing from peroxide decomposition.
Finally, the concept and rationale for the use of Nafion membranes that are
inorganically modified with membrane - in situ - synthesized sol-gel-derived
nanoscopic fillers, including a possible benefit of mitigating mechanical
degradation, will be presented. Viscoelastic relaxation studies of alteration of
mechanical properties through these inorganic modifications will be discussed.
Acknowledgments:
Funding for this work was provided by DuPont Fuel Cells and DOE Office of Energy Efficiency
and Renewable Energy; contract # DE-FC36-03GO13100 and DE-FG36-06GO86065.

Fuel Cells III – 3
Friday July 18, 3:30 PM-4:00 PM, Moloka’i
PBI Polymers for High Temperature PEM Fuel Cells
B. Benicewicz (Speaker), University of South Carolina, USA - benice@sc.edu
Polybenzimidazole (PBI) polymers are excellent candidates for PEM fuel cell
membranes capable of operating at temperatures up to 200°C. The ability to
operate at high temperatures provides benefits such as faster electrode kinetics
and greater tolerance to impurities in the fuel stream. In addition, PBI
membranes doped with phosphoric acid can operate efficiently without the need
for external humidification and the related engineering hardware to monitor and
control the hydration levels in the membrane. PBI membranes are currently being
investigated as candidates for portable, stationary, and transportation PEM fuel
cell applications. A new sol-gel process was developed to produce PBI
membranes loaded with high levels of phosphoric acid. This process, termed the
PPA process, uses polyphosphoric acid as the condensing agent for the
polymerization and the membrane casting solvent. After casting, absorption of
water from the atmosphere causes hydrolysis of the polyphosphoric acid to
phosphoric acid. The change in the nature of the solvent induces a sol-gel
transition that produces membranes with high loadings of phosphoric acid and a
desirable suite of physical and mechanical properties. The new membranes were
characterized through measurements of acid doping levels, ionic conductivity,
mechanical properties and fuel cell testing. The durability of these new
membranes in multiple operating environments is of particular importance for the
further development of practical fuel cell devices. Testing protocols have been
developed to examine the behavior of PBI membranes under both static and
cyclic conditions. The results of long-term testing under these conditions as well
as long term static testing will be presented.
The development of the PBI membranes has also led to major advances in
hydrogen separation, purification, pumping, and compression technologies.
Recent developments in polybenzimidazole (PBI) proton conducting membranes
have been applied to electrochemical hydrogen pumping. The basic properties of
these membranes as high temperature (>100°C) proton conductors, combined
with the well-known chemical stability, high tolerance to gas impurities, and
potential for low cost, provide the significant advancement in this enabling
technology for hydrogen purification. In this presentation, we will outline the basic
technology associated with this device and describe the applications of these
devices in both the future hydrogen economy and current industrial hydrogen gas
user markets.

Fuel Cells III – 4
Friday July 18, 4:00 PM-4:30 PM, Moloka’i
Novel Electrolytes for Fuel Cell Electrodes
J. Muldoon (Speaker), Toyota Motor Engineering & Manufacturing North America, Inc., Ann
Arbor, Michigan, USA - john.muldoon@tema.toyota.com
R. Wycisk, Case Western Reserve University, Cleveland, Ohio, USA
J. Lin, Case Western Reserve University, Cleveland, Ohio, USA
P. Pintauro, Case Western Reserve University, Cleveland, Ohio, USA
K. Hase, Toyota Motor Corporation, Japan
Fuel cells (FC) are attracting great attention due to their high energy conversion
efficiency and low pollution emission, relative to conventional combustion
engines. Among various types, proton exchange membrane fuel cells (PEMFC)
have emerged as promising power generators for portable, stationary, and
automotive applications. For hydrogen/air and direct methanol fuel cells, a typical
electrode binder is a perfluorsulfonic acid polymer such as Nafion" (DuPont)
which shows exceptional chemical stability, good mechanical strength, high
proton conductivity, and high gas permeability (oxygen/hydrogen). Unfortunately,
Nafion" is very expensive and poses a serious environmental threat of HF
release upon its decomposition under FC operating conditions and during
recycling of the catalyst, which would be avoided if a non-fluorinated polymer
were used. Polyphosphazenes are an attractive class of polymers with a
backbone composed of alternating phosphorus and nitrogen atoms. Through
appropriate functionalization of the backbone, the properties of these polymers
can be designed to an extent unachievable with other types of materials. Here
we report on the preparation and fuel cell performance of catalyst inks containing
sulfonated polyphosphazenes. The method of preparing membrane-electrodeassemblies
with polyphosphazene-based binders will be described and the
resulting hydrogen/air fuel cell performance plots will be contrasted to those
obtained with Nafion as the electrode binder.

Fuel Cells III – 5
Friday July 18, 4:30 PM-5:00 PM, Moloka’i
Effect of Hydrocarbon Ionomer on Electrochemical Performance of MEA for
Direct Methanol Fuel Cell (DMFC)
S. Lee (Speaker), School of Chemical Engineering, Hanyang University, Korea
C. Lee, School of Chemical Engineering, Hanyang University, Korea
Y. Lee, School of Chemical Engineering, Hanyang University, Korea - ymlee@hanyang.ac.kr
Direct methanol fuel cells (DMFCs) have been receiving much attention as clean
and alternative energy source owing to high energy efficiency and excellent
power density. The fuel cell performances are significantly affected by
electrochemical properties of membrane-electrode assemblies (MEAs) where the
electrochemical reactions take a place at the three-phase boundary zone
consisting of catalyst, catalyst binder and proton exchange membrane (PEM).
Hear, a catalyst binder acts as proton conductor as well as a mechanical
supporter in the catalyst layer. The binder also contributes to enhanced
dispersion of catalyst. A high-performance electrode requires good adhesion
between the membrane and electrode, uniform catalyst dispersion in the
electrode and good ion conduction. These properties are influenced by the
component materials and fabrication process of the electrode. In most cases,
Nafion® ionomer (EW=1,100) has been used as catalyst binder, irrespective of
membrane materials. A severe delamination in MEAs occurred between low-cost
hydrocarbon membrane and Nafion® ionomer owing to incompatibility between a
catalyst binder and a membrane material. MEA containing hydrocarbon
membrane needs a new hydrocarbon catalyst binder to reduce interfacial
resistance with catalyst layers. Unfortunately,only a little attention has been paid
so far to the catalyst binder compatible with the alternative electrolyte
membranes. In this study, a new type of hydrocarbon binder (B1) was designed
to fabricate a desirable MEA based on sulfonated polymer membrane. The
effects of B1 binder on MEA properties and also on its electrochemical cell
performance are investigated.

Ultra- and Microfiltration III - Membranes – 1 – Keynote
Friday July 18, 2:15 PM-3:00 PM, Honolulu/Kahuku
Pilot-scale Integrity Monitoring of Microfiltration Processes Using a Novel
Multi-membrane Sensor
F. Wong (Speaker), Advanced Water and Membrane Centre, Institute of Env. Sci. and Eng.,
Singapore - jincai@ntu.edu.sg
A. Fane, Nanyang Technological University, Singapore
J. Phattanarawik, Norwegian University of Sci. and Tech., Norway
M. Wai, Advanced Water and Membrane Centre, Institute of Env. Sci. and Eng., Singapore
J. Su, Advanced Water and Membrane Centre, Institute of Env. Sci. and Eng., Singapore
Effective contaminant removal in a membrane process is guaranteed only when
the membrane is intact. In practice, the performances of the membrane filters
may be compromised by presence of oversized pores, broken fibres or leaking
O- ring connectors. Membrane integrity monitoring is to verify whether membrane
filters are meeting the treatment objectives. The popular methods used for
membrane integrity monitoring are pressure decay test, particle counting and
particle monitoring, sonic testing, and turbidity measurement [1-3]. Unfortunately,
the currently available integrity monitoring techniques show some disadvantages,
i.e. labour- intensive, time-consuming, high cost, low sensitivity or requiring
highly skilled operator, which limit their application.
The work presented here is part of an on-going project on pilot-scale integrity
monitoring of filtration processes. Novel membrane integrity sensors developed
by Phattaranawik et al. were employed in the pilot trials [4]. The novel sensor is a
two-membrane device incorporating small-area membranes connected in series.
The permeate from the first membrane flows totally to the second membrane,
considered to be the retentate of the second membrane. Sensor parameter is
defined as the ratio of the trans- membrane pressures of the two membranes.
When there is the problem such as a breach, chemical degradation or biological
degradation of the filtration membrane or mechanical failure of O- rings or
gaskets, more particles in the filtrate will deposit on the surface of the first
membrane within the sensor, resulting in significant drop in the permeate
pressure of the first membrane. Consequently, increased trans- membrane
pressure of the first membrane and decreased trans-membrane pressure of the
second membrane are observed. The value of sensor parameter thus rises, and
an alarm will be sent to the operator if the sensor parameter exceeds certain
limit. Pilot testing of the integrity sensor would be performed at three different
water plants in Singapore. The source waters used would be MF treated
secondary effluent (plant 1), submerged membrane treated reservoir water (plant
2), and MBR treated municipal wastewater (plant 3). Several integrity sensors
would be installed at the three sites and the continuous online integrity testing
would last for several months.

Some preliminary results were obtained from the sensors installed at plant 1.
Using Millipore® membranes with pore size of 0.45μm, two sensors operated at
average filtrate pressures of 1.05 and 0.49 bar (gauge) gave average sensor
parameters of 0.79 and 0.24, respectively. It was observed that the values of
sensor parameter did not deviate too much from the average value at the higher
filtrate pressure whilst the values of sensor parameter were more dispersed at
the lower filtrate pressure. This may elucidate the sensitivity of sensor parameter
subjected to the fluctuation in filtrate pressure. The average values of sensor
parameter for these two sensors were constant and stable during the period of
observation, indicating that the microfiltration membranes were intact. One
sensor equipped with Millipore® membranes with pore size of 0.22μm gave an
average sensor parameter of 0.62 at an average filtrate pressure of 0.68 bar
(gauge). Slight decrease in the permeate pressure of the first membrane within
this sensor was observed. As a result, the value of sensor parameter increased a
little. This is an indication of increasing amount of particles in the MF treated
secondary effluent. The online monitoring is to be continued and further
observation would help to confirm whether MF membrane is still intact or not.
The installation work of the sensors is being carried out at plants 2 and 3, and
part of the results from the pilot trails would also be reported in due time.
References
G.F. Crozes, S. Sethi, B.X. Mi, J. Curl, B. Marinas. Improving membrane integrity monitoring
indirect methods to reduce plant downtime and increase microbial removal credit. Desalination
149 (2002) 493-497.
K. Glucina, Z. Do-Quang, J.M. Laine. Assessment of a particle counting method for hollow fiber
membrane integrity. Desalination 113 (1997) 183- 187. K. Farahbakhsh, D.W. Smith. Estimating
air diffusion contribution to pressure decay during membrane integrity tests Journal of Membrane
Science 237 (2004) 203-212.
J. Phattanarawik, A.G. Fane and F.S. Wong (2006). US Provisional Patent, ETPL Pat Ref:
SRC/p/04267/00/US, Filing date: 10 May 2006.

Ultra- and Microfiltration III - Membranes – 2
Friday July 18, 3:00 PM-3:30 PM, Honolulu/Kahuku
Integrity Monitoring for Membrane Bioreactor Systems through Turbidity
and SDI Measurement
F. Zha (Speaker), Siemens Water Techologies, South Windsor, Australia
V. Kippax, Siemens Water Technologies, South Windsor, Australia -
victoria.kippax@siemens.com
R. Phelps, Siemens Water Technologies, South Windsor, Australia
T. Nguyen, Siemens Water Technologies, South Windsor, Australia
Integrity of a membrane filtration system plays a critical role in the overall
permeate quality of the system. The water treatment industry has developed
methods to test membrane filter integrity, both direct and indirect. Direct methods
of integrity testing measure a breach in the membrane surface, such as diffusive
airflow and pressure decay (PDT) tests. Whereas, indirect methods of integrity
monitoring measure the resulting permeate from the membrane system,
including turbidity measurement, slit density index (SDI) and challenge tests.
The main index used to correlate the test methods to water quality is the log
reduction valve (LRV = Log(Cinf/Ceff). The PDT method has been widely used in
measuring the integrity of membrane system and results can be correlated with
the permeate quality, LRV.
It has traditionally been recommended to use the PDT method for integrity
monitoring for membrane bioreactor (MBR) systems; however, the suspended
solids (SS) concentration is many times higher than the feed water of other
membrane systems. This paper seek to investigate methods of integrity testing
and through the information presented demonstrate that turbidity measurement
and slit density index for RO pre-treatment is sensitive enough to monitor the
integrity of MBR systems and traditional direct methods may not accurately
predict the permeate quality.
Relationship between turbidity and MLSS concentration
Samples taken from activated sludge tanks were diluted to different suspended
solids concentrations and the turbidity was measured. The results demonstrate
that turbidity can be directly related to the MLSS concentration, with the bio-mass
sources having little influence; aerobic, anoxic or membrane tank. The
relationship of turbidity and MLSS concentration can be correlated as Turbidity
(NTU) = 0.916 [MLSS (mg/L)]0.968 (1)

MBR systems typically operate with a MLSS concentration ranging between
5,000 to 30,000 mg/L, a turbidity range of 3,500 to 20,000 NTU (eqn. 1).
Membrane directly filters such mixed liquor and produce clean permeate with a
turbidity of around 0.1 NTU, achieving LRV>4.5. The resolution of standard
turbidimeter is about 0.01 NTU, therefore with the meter it is easy to measure
LRV of 5.
Integrity monitoring in MBR
An integral membrane module consisting of 2000 fibers was used in MBR to filter
mixed liquor with a SS of 12,500 mg/L. The baseline turbidity was recorded as
0.06 NTU. Then 1, 2 and 5 fibers were cut respectively at the top end. The
results of this test are shown in the table below. From the PDT results, poor
permeate turbidity and fecal coliform results were expected. However, on-line
turbidity meter recording shows an initial surge in turbidity, but turbidity of
permeate rapidly dropped back to less than 0.2 NTU.
Number of cut fibers at top end 1 2 5 Loss of pressure in PDT (kPa/min) 30 60
~120 Peak turbidity(NTU) 1.993 1.349 2.4 Average turbidity 24h (NTU) 0.136
0.147 0.196 Fecal coliforms in permeate(cfu/100 mL)

Ultra- and Microfiltration III - Membranes – 3
Friday July 18, 3:30 PM-4:00 PM, Honolulu/Kahuku
Membrane Characterisation : Assessment of the Bacterial Removal
Efficiency
N. LeBleu (Speaker), Université de Toulouse, Toulouse, France
C. Causserand, Université de Toulouse, Toulouse, France
C. Roques, Université de Toulouse, Toulouse, France
P. Aimar, Université de Toulouse, Toulouse, France - aimar@chimie.ups-tlse.fr
The retention of microorganisms is one of the praised advantages of filtration
membranes used for bioprocesses, or water and waste water treatments.
Nevertheless, the removal efficiency of membranes or modules may be reduced
by the presence of a small number of abnormally large pores. The qualification of
such membranes, and the question of their integrity, which can be carried out by
various types of testing methods, have to be relevant and sensitive. However
several works show that membrane characterisation and integrity monitoring
based on tracers rejection and air tests are not sensitive enough to detect such
imperfections [1-3]. They provide at best information on defects larger than 3 µm
[4]. As a consequence, they are not adapted to predict the removal efficiency for
smaller microorganisms such as bacteria [5].
In this context, we have worked on a new approach for membrane
characterization, based on the specific behaviour of bacteria during filtration that
we revealed in a former experimental study [6]. It appears that the bacterial
transport through a porous membrane structure can be assisted by its
deformation and this phenomenon is governed by the structural characteristics of
the cell wall, namely the peptidoglycan layer. The more this layer is thin and
elastic, the more the bacteria will deform, and will likely pass through pores
smaller than its own size. As a consequence, rejection mechanisms based on
steric effects are inadequate to assess the membrane rejection capacity since
bacteria of equal size can exhibit different behaviours in filtration depending on
their deformability. The present study is divided in two parts : the description of
the characterisation methodology and its application to commercial membranes.
Challenge tests were performed on flat-sheet polycarbonate track-etched
microfiltration membranes of different nominal pore sizes (0.05 - 0.2 - 0.4 - 0.8 -
1.2 µm). This type of membrane was chosen as model due to their well-defined
pore geometry which allows breaking the bacterial transfer into elementary
mechanisms. For the following part of the study, we assume that the bacteria
transport trough one these pores is equivalent to the one through a small defect
or an abnormally large pore of an ultrafiltration membrane. Five bacterial strains
of various morphological and structural characteristics were selected in function

of the flexibility of their external membrane (Escherichia coli, Pseudomonas
aeruginosa, Staphylococcus aureus, Brevundimonas diminuta and Micrococcus
luteus). Dead-end filtration experiments, in a stirred filtration cell, were carried out
with bacterial suspensions of each strain at 104 CFU/mL as feed solutions.
Transmembrane pressure was set at 0.5 bar for all trials. Steadily, filtration flux
was measured and permeate samples were collected. Viable bacteria were then
enumerated after culture into solid nutrient agar medium (24 h at 37 °C).
According to the results of those trials, the assessment of the presence of
bacteria in the permeates has allowed to associate each strain to one only of the
homoporous membranes tested. The interesting feature is that there is not a
direct correspondence between the size of the pores (homoporous membranes)
and the size of the bacteria, and this because of the deformation of the latter
during the filtration process. Moreover, since when several bacteria are present
in a dispersion they do not exhibit the same rejection as when they are filtered
one by one, successive filtrations of each bacterial suspension are ncessary to
accurately assess the presence of the largest pores in the structure of a tested
membrane and to evaluate the range of their diameter.
For instance, if an unknown membrane fully retains Escherichia coli, we can
consider that defects of 0.4 µm in diameter are not enough numerous to alter the
membrane removal capacity. If this tested membrane leaks Pseudomonas
aeruginosa to some extent, one concludes that the presence of pores of at least
0.2 µm is not negligible. The application of this methodology to various
commercial ultrafiltration membranes and to membranes with a controlled
porosity will be presented.
To conclude, in complement to other characterisation tests, this methodology
could be a well-adapted tool to qualify filtration membranes or modules in terms
of bacterial removal efficiency and to carry out unbiased comparison between
membranes in a benchmarking context.
References
[1] Causserand et al. 2002 - Desal vol.149 p.485.
[2] Shinde et al. 1999 - J Membr Sci vol.162, p.9.
[3] Kobayashi et al. 1998 - J Membr Sci vol.140 p.1.
[4] Farahbakhsh 2003 - JAWWA vol.95 p.95.
[5] Urase et al. 1996 - J Membr Sci vol.115, p.21.
[6] Delebecque et al. 2006 - Desal vol.199 p.81.

Ultra- and Microfiltration III - Membranes – 4
Friday July 18, 4:00 PM-4:30 PM, Honolulu/Kahuku
Pore Size Determination of UF and MF Membranes By Streaming Potential
Measurement
K. Nakamura (Speaker), Yokohama National University, Yokohama, Japan - naka1@ynu.ac.jp
K. Matsumoto, Yokohama National University, Yokohama, Japan
The streaming potential of microporous membrane is used for characterization of
charge properties of pore surface while the streaming potential can depend not
only on surface charge of pore surface but also on ionic strength of solution and
membrane pore size. In this study the pore size characterization method of
MF/UF membranes based on the streaming potential measurement was
developed. The pore size characterized by the streaming potential measurement
was compared to AFM image or molecular weight cut off(M.W.C.O.), which was
measured using polyethylene glycol( PEG). The membranes used were
polysulfone UF membranes(M.W.C.O. 10k, 50k, 200k Da), aromatic polyamide
UF membrane(M.W.C.O.20k Da) and polycarbonate MF membranes(nominal
pore size 50, 100, 200 and 400nm). Potassium chloride solution was used as
electrolyte. The electrical potential difference across the membrane was
measured with Pt-black wire electrodes equipped to both sides of membrane. In
all membranes measured the streaming potential showed minus value and
increased with the increase in conductivity and approached to zero. The
experimental curve was well simulated by the calculation result of space charge
model except for lower conductivity region, which means the model is valid for
higher ionic strength region. By this analysis the pore radius rp and surface
charge density qp could be determined as fitting parameters. In order to confirm
the relationship between rp and actual retention performance M.W.C.O. for UF
membranes was measured with PEG. rp showed a good linear relation with
Stokes diameter estimated from M.W.C.O. values. In polycarbonate
microfiltration membranes rp showed a good linear relation with pore size
determined by AFM image. These results showed that the rp determined by
streaming potential measurements is useful for predict the separation
performance of UF/MF membranes.

Ultra- and Microfiltration III - Membranes – 5
Friday July 18, 4:30 PM-5:00 PM, Honolulu/Kahuku
Acoustic Investigation of Porous and Membrane Structures
S. Léoni, Ecole Centrale Marseille, Marseille, France
J. Bonnet, Université Paul Cézanne Aix Marseille, Provence, France
Y. Wyart (Speaker), Université Paul Cézanne Aix Marseille, Provence, France -
yvan.wyart@univ-cezanne.fr
J. Allouche, Ecole Centrale Marseille, Marseille, France
P. Moulin, Université Paul Cézanne Aix Marseille, Provence, France
The processes of membrane filtration are in the heart of actual and future
environmental challenges. Nevertheless, in order to increase the impact of
membrane separation techniques in industrial field, the phenomenon of
membrane fouling must be more understood. The membrane fouling can be
monitored by measuring the increase of transmembrane pressure when the
filtration is made at a constant flow rate. This procedure is a good indicator to
estimate the frequency of backwashes or chemical cleanings; but gives no
information about the kinetic of the fouling phenomenon, the fouling location (on
membrane surface or in the membrane bulk), the structure of the cake&
Moreover, it is well known that the membrane fouling depends on the structural
characteristics of the membrane. The aim of the study is to develop an acoustic
method to characterize first new membranes and secondly fouled membranes.
This method must be non- invasive to avoid the destructuration of the cake and
simple for an easy use.
The present work deals with acoustic characterisation of porous media and
membrane using impedance tube. This kind of materials is widely used
throughout industry to measure the sound absorption coefficient and other
acoustic properties of materials. Low frequency acoustic method is used to
determine porosity from acoustic sample properties. The experimental setup is
composed of a sound source, two microphones and a sample holder. The sound
source (speaker), placed at an extremity of a rigid walled tube, generates
incident plane waves which are partially reflected by the material sample, located
at the other extremity of the tube (sample holder). The incident and reflected
waves interfere and create a system of standing waves. For sufficiently low
frequencies, it is a plane wave which is propagated along the tube axis. The
lower limit frequency is dependent on the microphones limitation and on the
spacing between microphones. The higher limit is given by the cut off frequency
of the tube. Placed at the end of the tube, two microphones measure the acoustic
pressure in order to calculate the frequency response function (FRF). This FRF is
used to determine the complex acoustic surface impedance Z of the sample. The
method presented in this paper is based on the theories of Lafarge- Allard which
are based on a low frequency approximation. Using this assumption, porosity Phi

can be deduced from the imaginary part of the surface impedance Z of the
material according to the relation below:
Phi=(P0/we). Im(1/Z)
with, P0 the atmospheric pressure (Pa), w the angular frequency (rad.s-1) and e
the sample thickness.
The porosity is obtained by an average over a selected optimal frequency interval
where ¦ does not depend on the frequency. This acoustic method allows
accessing other porous media properties such as permeability, tortuosity&
Experimental procedure and data treatment need to be validated and calibrated.
For calibration, two products are used: cork and melamine. For porous media
characterisation, two different porous materials were investigated and different
results are obtained: open-celled metal foam and microfiltration plane membrane.
These two kinds of materials are very different in the cell topology and the
material made of, but exhibit similar porosity values ranged from 80 to 90%.
Metals foams are used as reference material for experimental set up validation.
Indeed, the geometrical parameters as well as the physicals properties (pore
diameter, porosity, material, permeability&) of each studied metal foam sample
were already finely characterized. In addition with the set up validation function,
data obtained lead to an improved understanding of sound absorption in opencelled
metal foams for noise control applications. With these results, we can
investigated the filtration of particles generated from the combustion of different
products (oil, fuel, municipal waste, biomass) more especially the the influence of
the metallic foam thickness on the retention. In fact, we have observed that the
particles flow is less and less important with the progression through volume of
the metallic foam and the retention becomes less efficient.
Tests were carried out using microfltration plane membrane. As these
membranes are very thin (0.1mm), a stack of several specimens layers are
required to better capture the physical of the material. In order to evaluate the
stack thickness impact on the determination of the membrane porosity, a first
tests series was performed for length varying in the range 1mm to 5mm. A good
agreement was obtained between our results and the porosity value given by the
manufacturer.
A second tests series concerned the impact of new membranes and fouled
membranes on the FRF; it is in progress and will be presented during ICOM
2008.

Ultra- and Microfiltration III - Membranes – 6
Friday July 18, 5:00 PM-5:30 PM, Honolulu/Kahuku
Ellipsometric Observation of Ceramic Membranes
R. Tamime, Université Paul Cézanne Aix Marseille
Y. Wyart (Speaker), Université Paul Cézanne Aix Marseille - yvan.wyart@univ-cezanne.fr
L. Siozade, Université Paul Cézanne Aix Marseille
C. Deumié, Université Paul Cézanne Aix Marseille
P. Moulin, Université Paul Cézanne Aix Marseille
The application of membrane processes in the industrial world is impeded by a
major drawback: membrane fouling. During the filtration steps, this fouling can
occur either on the surface or within the pores of the membrane. Where this
fouling occurs not only affects the permeate flux and/or the selectivity but is also
of crucial importance for the membrane regeneration step. The membrane
fouling corresponds to an accumulation of matter which occurs either on the
membrane surface or inside the porous matrix. The structural properties of
membranes (roughness, porosity) have an impact on fouling phenomenon and
must be characterized to develop a fouling control method.
In this work, the angle resolved scattering technique and the analysis of the
scattered wave polarization state using the technique of Ellipsometry of Angle
Resolved Scattering are used to characterize ultrafiltration and microfiltration
membranes and discriminate between them. The main objective of this work is to
show the potential of these recent optical techniques not well defined or used in
the domain of membrane processes. The information, obtained for ceramic
membranes, is compared for different cut-offs (300 kDa, 0.1 µm, 0.45 µm and the
corresponding support). The measurements are made using an instrument called
‘scatterometer’ which allows angular measurements for discrete wavelengths
ranging from UV (325 nm) to the mean IR (10.6 μm). Measurements at low angle
resolution (sampling interval of a few degrees) or at high angle resolution
(sampling interval of a few hundreds of degrees) can be performed. The
experimental setup is composed of a photomultiplier and a synchronous
detection apparatus. The beam is mechanically modulated (chopper). Part of the
beam is deviated upstream (reference) and measured together with the rest of
the beam to avoid the possible fluctuations of the light source power. The laser to
be used is selected through a system of mirrors mounted on a translation plate.
The optical signal is collected by a 1 mm diameter glass fiber that can move
throughout the entire space along the usual angular directions.
First, the angle resolved scattering technique was performed at low and high
resolution mode. For low resolution as well as for high resolution mode, it
appeared difficult to extract one parameter allowing the differentiation of the

membranes. The analysis of the light scattering intensity did not make it possible
to separate the bulk states of these components. That is why the polarimetric
behavior of each sample was studied. The analysis of the scattered wave
polarization state at low resolution measurements clearly revealed that the origin
of the light scattering lies essentially in the bulk. Indeed, the polarimetric phase
shift varies very quickly, which is representative of bulk scattering. With low angle
resolution, comparison of different membrane cut off is not significant. To analyze
statistically the oscillations of the polarimetric phase shift as a function of the
scattering angle, the same measurements were run at high angle resolution. By
representing the standard deviation of the polarimetric phase shift, it is possible
to identify a difference in membrane behavior. Logically, the phase shift standard
deviation increases with the porosity. To confirm this result, some theoretical
investigations were run. Simulations were performed using the differential
method, which is a rigorous method for the resolution of Maxwell’s equations.
The polarimetric phase shift of the wave scattered by a porous structure with a
defined volumic structure (pore size and material) was calculated. The
membranes were modeled by a volume 8 μm in width and 1 mm in depth, filled
with a mixture of air (optical refraction index:1) and zircone (optical refraction
index: 2.2, absorption neglected). In the case of membranes with porosities
ranging from 20 to 400 nm, modelling step shows that the standard deviation
increases with the sample porosity. These numerical calculations confirm the
evolution observed for the experimental results.
The ellipsometry of angle resolved scattering can be used for the structural
characterization of the organic membranes whatever the membrane geometry.
The study of these membranes must allow to develop a methodology in order to
improve the understanding of the fouling mechanisms, to correlate the
membrane properties (membrane cut- off, membrane material) to the fouling and
to minimize the membrane fouling.

Membrane Contactors – 1 – Keynote
Friday July 18, 2:15 PM-3:00 PM, O’ahu/Waialua
Modelling Aroma Stripping Under Various Forms of Membrane Distillation
Processes
G. Jonsson (Speaker), Technical University of Denmark, Lyngby, Denmark - gj@kt.dtu.dk
Concentration of fruit juices by membrane distillation is an interesting process as
it can be done at low temperature giving a gentle concentration process with little
deterioration of the juices. Since the juices contains many different aroma
compounds with a wide range of chemical properties such as volatility, activity
coefficient and vapor pressure, it is important to know how these aroma
compounds will eventually pass through the membrane.
Experiments have been made on an aroma model solution and on black currant
juice in a lab scale membrane distillation set up which can be operated in various
types of MD configurations: Vacuum Membrane Distillation, Sweeping Gas
Membrane Distillation, Direct Contact Membrane Distillation and Osmotic
Membrane Distillation. The influence of feed temperature and feed flow rate on
the permeate flux and concentration factor for different types of aroma
compounds have been measured for these MD configurations.
A general transport model for the flux of water and aroma compounds have been
derived and compared with the experimental data. A reasonable agreement
between the modelling and the experiments could be obtained. From the
modelling it was possible to explain the large different in permeate flux and
concentration factor that was observed for the different MD configurations. This is
highly related to the heat and mass transfer resistances in the membrane as well
as in the boundary layers adjacent to the membrane surface and how the driving
force develops along the length of the membrane.

Membrane Contactors – 2
Friday July 18, 3:00 PM-3:30 PM, O’ahu/Waialua
Membrane Extraction for Acetic Acid and Lignin Removal from Biomass
Hydrolysates
D. Grzenia, Colorado State University, Fort Collins, Colorado, USA
D. Schell, National Renewable Energy Laboratory, Golden, Colorado, USA
R. Wickramasinghe (Speaker), Colorado State University, Fort Collins, Colorado, USA -
wickram@engr.colostate.edu
A major obstacle to the large scale industrial use of biobased products and
biofuels is the lack of efficient, cost-effective separation methods. Separations
operations currently account for 60- 80% of the processing costs of most mature
chemical processes. Here we focus on the development of membrane extraction
as a low cost, robust separation process in future biorefineries. As membrane
extraction is non- dispersive it overcomes all of the disadvantages of
conventional extraction. Acetic acid is produced during thermochemical
pretreatment of lignocellulosic biomass. It is a weak acid that is strongly inhibitory
to microorganisms used for bioconversion of sugars. Removal of acetic acid
could be essential for increasing ethanol yields during fermentation. We have
conducted experiments using dilute sulfuric acid pretreated corn stover. Acetic
acid, in its protonated form, was extracted into an organic phase consisting of
octanol and Alamine 336, a tertiary amine, containing 8-10 carbon aliphatic
chains. Importantly, acetic acid removal is most efficient at pH values below 4.8,
the pKa of acetic acid, thus no pH adjustment is required after pretreatment.
Further as sulfuric acid is co- extracted the pH of the hydrolysate increases
during extraction. Our results indicate co- extraction of furfural,
hydroxymethylfurfural, acid soluble lignin and other phenolic compounds. Thus
addition of membrane extraction to remove acetic acid may simplify and/or
eliminate current hydrolysate detoxification technologies such as overliming.
Development of a practical membrane extraction process for removal of weak
acids such as acetic acid depends on carefully choosing the organic diluent and
extractant (octanol and Alamine 336 used here).

Membrane Contactors – 3
Friday July 18, 3:30 PM-4:00 PM, O’ahu/Waialua
Operational Flexibility of Gas-Liquid Membrane Contactors for CO2
Separation
K. Fischbein (Speaker), University of Twente, Enschede, The Netherlands -
k.fischbein@utwente.nl
K. Nijmeijer, University of Twente, Enschede, The Netherlands
M. Wessling, University of Twente, Enschede, The Netherlands
Objective CO2 is one of the major contributors to the greenhouse effect: the
power and industrial sectors combined, account for about 60% of global CO2
emissions [1]. To prevent the emissions of CO2, capture and sequestration of
CO2 from gas streams is essential. The traditional method of separating CO2
from other gases is amine scrubbing. Although high product yields and purities
can be obtained, the disadvantage of this method is its high energy consumption
- especially during desorption - in combination with a high liquid loss due to
evaporation of the solvent. Membrane technology is a promising method of
replacing conventional absorption technology. It has a high energy efficiency, is
easy to scale-up because of its modular design, and it has a high area-to-volume
ratio [2]. These advantages suggest that membrane separation is a viable
alternative to conventional gas separation techniques. In this work, we use a
membrane contactor to separate CO2 from natural gas. A membrane contactor
combines the advantages of membrane technology with those of an absorption
liquid. In a membrane contactor, CO2 diffuses from the feed gas side through the
membrane and is then absorbed in the selective absorption liquid. The loaded
liquid is circulated from the absorber to the desorber, which can be a traditional
desorber or a second membrane contactor, in which desorption of CO2 occurs.
The membrane acts as an interface between the feed gas and the absorption
liquid. The selectivity of the process is not only determined by the membrane, but
also the absorption liquid plays a significant role and contributes to the selectivity.
Gas-liquid membrane contactors offer a unique way to perform gas- liquid
absorption processes in a controlled fashion and they have a high operational
flexibility. In this work, we investigate the effect of these operating parameters on
the CO2/CH4 separation performance of the membrane contactor and identify the
operating window for such a process.
Experimental Part Porous polypropylene hollow fibers (Accurel S6/2, obtained
from Membrana GmbH, Germany) and asymmetric poly phenylene oxide
membranes (normally used for gas separation; kindly provided by Parker Gas
Separation, The Netherlands) were used as absorber and desorber in a
membrane contactor for the separation of CO2/CH4 (20/80 vol.%). The use of
asymmetric membranes with a dense top layer prevents penetration of the

absorption liquid in the pores of the membrane and leads to a reduction in the
loss of absorption liquid. Mono ethanol amine (MEA) - the traditional absorption
liquid for CO2 removal - was used as the absorption liquid. The effects of the flow
rate of the absorption liquid (72 - 315 ml/min), the feed gas pressure (1.2 - 3.5
bar) and the temperature difference between absorption and desorption
processes (T = 0 - 35°C) were investigated, and the operating window for the
membrane contactor process was identified.
Results The results of the multiple fiber contactor experiments show the effect of
the operating parameters on the CO2/CH4 separation performance of the
membrane contactor and identify the operating window for such a process. A
comparison between the porous and the asymmetric fiber modules shows
significant differences, especially concerning the pressure sensitivity. For the
porous fiber modules, an increase in the feed pressure immediately results in
increases in the permeabilities of both CO2 and - more especially - CH4, which
results in a tremendous decrease in CO2/CH4 selectivity. The asymmetric fiber
modules are more resistant to pressure fluctuations, and this thus increases the
performance and the operating window for the process significantly. Apart from
differences between the membranes types, some similar effects can be observed
for both types of membranes; for example, an increase in the temperature
difference between absorber and desorber significantly influences the process
performance. The temperature of the desorber is especially important, because
desorption is the limiting step in the process. With an increasing liquid flow rate, a
maximum in productivity can be observed. Below this maximum, the capacity of
the absorption liquid limits the process, whereas at higher flow rates mass
transport limitations determine the performance. The results of the various
experiments clearly show the influence of the different process parameters and
thus define the operating window for such a process to separate CO2 from CH4.
1. 1 IPCC Special Report on Carbon dioxide Capture and Storage;
http://www.ipcc.ch/activity/srccs/SRCCS_Chapter2.pdf.
2. B.D. Bhide, A. Voskericyan,S.A. Stern, Hybrid processes for the removal of acid gases from
natural gas, Journal of Membrane Science, 140 (1998) 27

Membrane Contactors – 4
Friday July 18, 4:00 PM-4:30 PM, O’ahu/Waialua
Effect of Spacer, Baffled and Modified Hollow Fiber Geometries in the
Membrane Distillation Process
M. Teoh (Speaker), National University of Singapore, Singapore
S. Bonyadi, National University of Singapore, Singapore
T. Chung, National University of Singapore, Singapore - chencts@nus.edu.sg
M. Gryta, Szczecin University of Technology, Szczecin, Poland
For about three decades, Membrane distillation (MD) has been considered as a
possible alternative for the conventional desalination technologies such as multistage
flash vaporization (MSFV) and reverse osmosis (RO). However, MD has
gained little acceptance and yet to be implemented in industry for several
reasons: barrier of suitable MD membrane and module design, membrane pore
wetting, low permeate flow rate & water flux (i.e., productivity) as well as
uncertain energetic and economic costs. In this respect, opportunities therefore
beckon membrane researchers to improve the permeate flux to bring MD closer
to commercialization. Based on the MD mechanism, the obtained flux in MD
depends both on the membrane permeation properties as well as the flow
geometry in the membrane modules. A good flow geometry maintaining
turbulence among the fibers can minimize the undesirable temperature
polarization which leads to a lower driving force across the membrane and
consequently a lower obtained flux. Therefore, research on the flux enhancement
in MD can be divided into two large areas: (1) the fabrication of highly permeable
membranes and (2) designing optimized membrane modules.
Because of the effect of temperature polarisation or temperature drop crossing
membrane, heat transfer across the boundary layer from the bulk to the
membrane surface often limits the rate of flux transfer in MD. Thus to improve
mass transfer of flux in MD, researchers must minimise this phenomenon. An
alternative approach to the flux enhancement in MD application lies in the
modification of module design by spacers/baffles/turbulence promoters and
modified hollow fiber geometries. By modeling the transport phenomena, the
application of baffles increase the feed-side heat-transfer coefficient, which
correspond to ~20% flux enhancements. Besides, it was observed that using
spacers among the fibers may prevent the fibers from sticking together hence
efficiently increase the effective membrane area ~33%. The un-straight geometry
of the hollow fibers (braided and twisted) may act as a static mixer for the shellside
flow which can increase the associated heat-transfer coefficients and led to
flux enhancements as high as 36% without inserting an external turbulent
promoter. In overall, greater flux enhancements with modified hollow fiber
membranes modules were achieved at higher feed temperatures.

Membrane Contactors – 5
Friday July 18, 4:30 PM-5:00 PM, O’ahu/Waialua
Direct Contact Membrane Distillation: Studies on Novel Hollow Fiber
Membranes, Devices, Countercurrent Cascades and Scaling
K. Sirkar (Speaker), New Jersey Institute of Technology, Newark, New Jersey, USA -
Sirkar@ADM.njit.edu
L. Song, New Jersey Institute of Technology, Newark, New Jersey, USA
H. Lee, New Jersey Institute of Technology, Newark, New Jersey, USA
F. He, New Jersey Institute of Technology, Newark, New Jersey, USA
J. Gilron, Zuckerberg Institute for Water Research, Beer-Sheva, Israel
B. Li, New Jersey Institute of Technology, Newark, New Jersey, USA
P. Kosaraju, New Jersey Institute of Technology, Newark, New Jersey, USA
Z. Ma, United Technologies Research Center, East Hartford, Connecticut
X. Liao, United Technologies Research Center, East Hartford, Connecticut
J. Irish, United Technologies Research Center, East Hartford, Connecticut
We have recently developed novel hollow fiber membranes and devices for
recovering pure water from hot brine via membrane distillation (MD). Hot brine
undergoes rectangular crossflow over the outer surface of highly porous
hydrophobic polypropylene hollow fibers whose outside surface was coated with
porous plasmapolymerized silicone-fluoropolymer coating to mitigate pore
wetting and distillate contamination. In direct contact membrane distillation
(DCMD) process using these fibers, cold distillate flows through the fiber bores
which are large; the thickness of the highly porous wall is considerably larger
than conventional membrane contactor hollow fibers. Brine crossflow, large fiber
wall thickness, large fiber bore and the porous coating have yielded very high
water vapor flux, high thermal efficiency, low temperature polarization and no
distillate contamination. The DCMD studies were carried out sequentially with
modules having a surface area of ~120 cm 2 , with larger modules having a
surface area of 0.286 m 2 and recently in a pilot plant at United Technologies
Research Center with modules each having 0.61-0.66 m 2 membrane surface
area. This DCMD pilot plant was operated with hot brine at different salt
concentration levels; sea water was also used. For brine feeds of 85-90 o C, water
vapor flux reached values of over 55 kg/m 2 -h independent of the scale of the
hollow fiber membrane membrane modules or the salt concentration (up to 10%).
Extended pilot scale operation demonstrated no salt leakage, stable and
repeatable performance.
Modeling the direct contact membrane distillation behavior in both small (each
having an area of 0.286 m 2 ) and large-scale modules (each having an area of
0.61-0.66 m 2 ) has been successfully implemented. A variety of module
configurations were studied; the primary variables investigated were brine flow

ate, distillate flow rate, inlet temperatures of the two streams, salt
concentrations, etc.
Cost-efficient desalination technology was also developed successfully by
integrating a countercurrent cascade of these novel crossflow hollow-fiber
membrane-based direct contact membrane distillation (DCMD) devices and solid
polymeric hollow fiber-based heat exchange (HX) devices. Each of the small
DCMD membrane modules used for the countercurrent cascade had a surface
area of 500 cm 2 . Studies were carried out in such a heat-integrated cascade
using 2-8 modules representing 2-8 stages. A comprehensive numerical
simulator was developed to successfully predict the experimentally observed
performance of such a cascade. The thermal efficiency achieved experimentally
in such a cascade was as high as 0.87. The highest GOR (gained output ratio)
achieved reached around 6; heat loss to the environment from the heat
exchanger limited so for the attainment of higher values. Fractional water
recovery per pass reached almost 7%. Modeling results provide a guidance to
cascade performance improvement. For example, unequal incoming brine and
distillate flow rates can yield a GOR as high as 12 for ten stages in a
countercurrent DCMD cascade unlike equal incoming brine and distillate flow
rates. Numerical simulations yield reasonable cost figures for desalination.
Scaling studies carried out in DCMD using CaSO4 as the scaling salt indicate that
even when there was significant precipitation of CaSO4, there was no effect on
the membrane vapor flux or brine pressure drop. The induction period for CaSO4
nucleation decreased with increased feed brine temperature (60-90°C) and
increasing level of the degree of supersaturation. We observed no flux reduction
inspite of extensive scaling deposits in solution. Similar results were obtained
with CaCO3 over a wide range of temperature and SI values (11 to 64). Mixed
CaCO3 + CaSO4 systems behaved similarly except the scaling deposits were
extensive and somewhat stickier. Scaling studies with CaSO4 on a polymeric
solid hollow fiber heat exchanger did not lead to a decrease in heat transfer
performance although there was a minor increase in pressure drop. Crossflow
with coated fibers prevented any flux reduction or distillate contamination by
scaling deposits in the DCMD device whereas parallel flow did not. Noncoated
fibers in a DCMD device were susceptible to faster nucleation.

Membrane Contactors – 6
Friday July 18, 5:00 PM-5:30 PM, O’ahu/Waialua
MEMFRAC - A New Approach to Membrane Distillation
E. Sanchez (Speaker), TNO (Netherlands Organisation for Applied Scientific Research), Delft,
The Netherlands - eva.sanchezfernandez@tno.nl
P. Koele, TNO (Netherlands Organisation for Applied Scientific Research), Delft, The Netherlands
E. Meuleman, TNO (Netherlands Organisation for Applied Scientific Research), Delft, The
Netherlands
Traditionally, membrane distillation uses macroporous hydrophobic membranes
as surface for contacting a vapor and a liquid phase. One of the requirements for
a membrane distillation process is that the membrane must not be wetted. Pore
wetting may happen when surface active components are in direct contact with
the membrane surface or when the pressure exceeds the liquid entry pressure.
TNO has developed MEMFRAC as a new approach to circumvent these
problems. MEMFRAC is an acronym of the words MEMbrane contactor and
FRACtionating. The principle of MEMFRAC is based on the use of highly
permeable dense membranes as a membrane contactor instead of using
macroporous membranes. The presented work demonstrates that membrane
contactors, based on dense asymmetric membranes, are a promising alternative
packing material for distillation. Major advantages of this system are long term
stability and no risk of pore wetting.
Within the present project several membrane types were tested. MEMFRAC
contactors are made of extreme hydrophobic porous membrane that repels
ethanol and water and mixtures thereof, poly (phenylene oxide) (PPO)
asymmetric hollow fiber membranes, dense hydrophilic sheets and dense
polypropylene asymmetric hollow fiber membranes. Based on extensive testing,
the project was focused on the PPO membranes, because they were
commercially available. The membrane structure consists of a macroporous
sublayer in the inside and a thin highly permeable dense layer on the outside.
This top layer prevents liquid penetration, while vapor can penetrate readily. The
total membrane thickness is about 100 microns and the fibers have an outer
diameter of about 0.5 mm. Special modules were developed for the purpose of
MEMFRAC. A typical MEMFRAC module contains 2300 fibers per module
resulting in a specific area as high as 3000 m 2 /m 3 . The performance of
MEMFRAC has been tested for different organic solvent - water mixtures. The
presentation will focus on the bench scale distillation plant for the separation of
ethanol from water. Experimental tests have been carried out with different
ethanol - water mixtures and operating at total reflux. The ethanol concentration
at the MEMFRAC contactor inlet varied from 40 wt% to 80 wt%. For the highest
concentrations, enrichments of about 19% are obtained. In this case the outlet

concentration approaches the azeotrope composition. At lower concentrations,
higher enrichments are obtained (up to 85%). Mass transfer efficiency has been
investigated at different vapor loads (i.e. F- factor: vapor velocity times the
square root of vapor density) ranging from 0.3 to 1 (m/s)(kg/m 3 ) 0.5 . High fluxes
can be obtained leading to an overall vapor phase mass transfer coefficient of
about 1 x 10 -3 m/s. The HETP increases slightly with increasing vapor loads,
being as low as 13 cm for low vapor loads and as high as 18 cm for high vapor
loads. Compared to random packings these values are substantially lower.
Results show high fluxes, robustness and long term stability in operation
(continuous stable operation of more than 240 hours). MEMFRAC shows great
potential especially in situations where small foot prints are beneficial (e.g.
distillation on platforms, off-shore applications).

Packaging and Barrier Materials – 1 – Keynote
Friday July 18, 2:15 PM-3:00 PM, Wai’anae
New Developments in the Measurement of Multi-Component Sorption in
Barrier Polymer Materials: A Key Step towards the Modeling of Fuel Tank
Permeability
A. Jonquieres (Speaker), Nancy Universite, Nancy, France -
Anne.Jonquieres@ensic.inpl-nancy.fr
R. Clement, Nancy Universite, Nancy, France
C. Kanaan, Nancy Universite, Nancy, France
B. Brule, Arkema, Serquigny, France
H. Lenda, Nancy Universite, Nancy, France
P. Lochon, Nancy Universite, Nancy, France
For different reasons including safety and weight reduction of vehicles, most of
the fuel tanks are currently made of multi-layer barrier polymer materials which
have to comply with ever more demanding environmental international
regulations [1]. These fuel tanks are so poorly permeable that the measurement
of their permeability usually requires almost one year, i.e. the time necessary to
reach the steady state in contact with the multi- component fuel mixture. In this
highly demanding context, the modelling of their permeability would allow to
bypass the measurement delay and to predict and optimize their permeation
properties, within a period of time compatible with the fast evolution of the
international regulations limiting the fuel emissions per vehicle.
According to the sorption-diffusion model [2], the permeation of a fuel mixture
through of a barrier polymer film involves two elementary steps. In the first
sorption step, a part of the fuel mixture is absorbed at the upstream side of the
film. In the second step, the absorbed species diffuse across the polymer film
according to their activity gradients defined by the sorption step. Therefore,
determining the sorption properties of the different barrier polymer materials of
fuel tanks is truly indispensable for modelling their permeability [3].
However, the barrier polymer materials used in fuel tanks are usually
characterized by very low sorption levels which can nevertheless vary by several
orders of magnitude depending on the absorbed solvent. Therefore,
quantitatively determining their sorption properties remains a true technical
challenge never taken up to the best of our knowledge. This communication
describes our last progress made in collaboration with the worldwide chemical
company Arkema for the quantitative determination of these multi-component
sorption properties.
A new semi-automated desorption experimental set-up was thus developed for
measuring the sorption properties of these barrier polymer materials in contact

with model fuel mixtures. This fairly complex apparatus combines a desorption
mini-oven with on-line gas chromatography (GC), to allow the on-line analysis of
the desorbed mixture during a given desorption cycle. By a proper optimization of
the measurement conditions in real time, in particular the GC sensitivity range
and the desorption temperature profile, a very high sensitivity (0.1 microgram)
was easily obtained for the measured weights.
This very high sensitivity eventually enabled to determine partial sorption data
differing by three orders of magnitude for the same experiment which, to the best
of our knowledge, has never been reported so far. Several examples for multi-
component sorption results will be discussed with a particular focus on two
leading polymer materials used in multi-layer fuel tanks (high density
polyethylene HDPE and an ethylene-vinyl alcohol copolymer EVOH) [4]. The
whole set of sorption data revealed opposite trends for their swelling in model
fuel mixtures ethanol/i-octane/toluene for a wide range of compositions typical for
the various types of fuels. While HDPE absorbed preferentially the apolar
hydrocarbons, EVOH displayed a very strong affinity towards ethanol. Another
striking fact was that both barrier materials showed very different affinities for
both hydrocarbons with a preferential sorption of toluene owing to its strong
polarizability, in good agreement with former observations made for related
permeability measurements [3].
References :
[1] T. McNally, G.M. McNally, S.B. Byrne, W.R. Murphy, and I. Gilpin, Annual Technical
Conference - ANTEC, Conference Proceedings, 3 (1998) 2642- 2646.
[2] J. Wijmans, R. Baker, Journal of Membrane Science 107 (1995) 1-21 (review).
[3] M. Nulman, A. Olejnik, M. Samus, E. Fead, and G. Rossi, Society of Automotive Engineers,
Special Publication, SP-1365 (1998) 41-48.
[4] R. Clément, C. Kanaan, B. Brulé, H. Lenda, P. Lochon, A. Jonquières, Journal of Membrane
Science 302 (2007) 95-101.

Packaging and Barrier Materials – 2
Friday July 18, 3:00 PM-3:30 PM, Wai’anae
Fundamental Exploration of Metal-Catalyzed Oxidation in Styrene-
Butadiene-Styrene Block Copolymers
K. Tung (Speaker), The University of Texas at Austin, Austin, Texas, USA
C. Ferrari, The University of Texas at Austin, Austin, Texas, USA
R. Li, The University of Texas at Austin, Austin, Texas, USA
K. Ashcraft, The University of Texas at Austin, Austin, Texas, USA
B. Freeman, The University of Texas at Austin, Austin, Texas, USA - freeman@che.utexas.edu
D. Paul, The University of Texas at Austin, Austin, Texas, USA
Barrier films are essential for packaging to prolong product shelf life, and films
that have exceptional oxygen barrier properties are valuable for food packaging.
One method to improve oxygen barrier properties is to incorporate reactive
groups in the membranes[1, 2]. In the presence of a transition metal catalyst,
these reactive groups capture, or scavenge O2 as it diffuses through a film.
The ultimate goal of this study is to investigate the performance of scavenging
polymers in the form of block copolymers containing a scavengable block, such
as polybutadiene, and a block, such as polystyrene, that might compatibilize the
material with a matrix barrier resin, such as polystyrene. This study will
eventually lead to the investigation of multi-layered systems of styrenebutadiene-styrene
(SBS) block copolymers and polystyrene.
The rate and amount of oxygen uptake as a function of metal catalyst
concentration, film thickness, and oxygen partial pressure were characterized
using an SBS block copolymer with the following characteristics: MW: 114,800,
12.5 % polystyrene, and 76 % vinyl structure. The experiments were performed
at 30 °C. Effect of metal-catalyzed oxidation on polymer morphology was also
studied through microscopic and spectroscopic characterization.
The experimental mass uptake data were used to characterize oxidation kinetics
as a function of catalyst (cobalt neodecanoate) loading. Induction periods were
observed in lower catalyst loadings. Mass uptake did not scale linearly with
catalyst concentration; there was an optimum catalyst loading. Different values of
optimum catalyst concentrations were found in homopolymers (i.e., poly(1,2butadiene)
and poly(1,4-butadiene)) and the SBS block copolymer. Film
thickness also had an effect on oxidation kinetics. Mass uptake values increased
as film thickness decreased; in other words, oxidation is more efficient as the film
becomes thinner. It was hypothesized that surface oxidation takes place as O2
molecules diffuse through SBS films. AFM images revealed a hard region, which
was rationalized to be the oxidized layer, at the film surface. Normalizing by film
surface area shows a close overlap of mass uptake data of various thicknesses,

supporting the hypothesis of surface oxidation. That is, the oxygen first oxidizes
the surface of the samples and then moves into the film, in the form of a front,
and gradually oxidizes the polymer deeper and deeper into the sample. In
oxygen partial pressure experiments, mass uptake increases as oxygen content
increases. A shrinking core mathematical model was developed to predict
oxygen concentration as a function of time and distance into the film.
Reference:
1. Cochran, M. A.; Folland, R.; Nicholas, J. W.; Robinson, M. E. R. Packaging. 5,639,815, 1997
2. Cochran, M. A.; Folland, R.; Nicholas, J. W.; Robinson, M. E. R. Packaging. 5,021,515, 1991

Packaging and Barrier Materials – 3
Friday July 18, 3:30 PM-4:00 PM, Wai’anae
The Effect of Reaction Conditions on Oxidation of Metal-catalyzed Poly(1,4butadiene)
H. Li (Speaker), The University of Texas at Austin, Austin, Texas, USA
K. Tung, The University of Texas at Austin, Austin, Texas, USA
B. Freeman, The University of Texas at Austin, Austin, Texas, USA - freeman@che.utexas.edu
M. Stewart, Global PET Technology, Eastman Chemical Company, Kingsport, Tennessee, USA
J. Jenkins, Global PET Technology, Eastman Chemical Company, Kingsport, Tennessee, USA
Oxygen scavenging polymers, which are polymeric materials that trap and
effectively immobilize oxygen, have potential for large applications in the
packaging industry. Incorporating an oxygen scavenging polymer into the
package wall can lead to a significant improvement in oxygen barrier properties.
However, there are very few studies of the fundamental structure/property
relations governing oxygen scavenging, and this research is focused on
addressing this shortcoming in the literature.
In this study, we used a simple, accurate instrument for testing large numbers of
samples. Oxygen mass uptake was determined by a non-invasive oxygen sensor
based system, and experiments were performed with metal-catalyzed poly(1,4butadiene)
films. For comparison, oxygen uptake was also measured using an
analytical balance, and similar results were obtained. Experimental results
showed that poly(1,4-butadiene) was oxidized under various storage conditions,
and a maximum of 30 weight percent oxygen uptake was observed. A highly
oxidized layer was found at the membrane surface after the reaction. The
oxidized layer thickness was determined by measuring the oxygen mass uptake
of film with different thicknesses.
This presentation also discusses the influence of reaction conditions on oxidation
rate and oxygen mass uptake of poly(1,4-butadiene). Specifically, the effect of
reaction temperature, oxygen partial pressure, and catalyst concentration on
oxygen mass uptake, oxidation rate, and change in membrane permeability will
be discussed. Experimental results reveal that by controlling the reaction
conditions, an efficient and long-term oxygen scavenging membrane can be
obtained. These results not only provide an understanding of oxidation in these
membranes, but also could lead to the development of new scavenging
packaging materials and prediction of their optimum working conditions.

Packaging and Barrier Materials – 4
Friday July 18, 4:00 PM-4:30 PM, Wai’anae
On the Nature of Gas Barrier of Ethylene Vinyl Alcohol Copolymers.
S. Nazarenko (Speaker), University of Southern Mississippi, Hattiesburg, Mississippi, USA -
Sergei.Nazarenko@usm.edu
G. Chigwada, University of Southern Mississippi, Hattiesburg, Mississippi, USA
J. Brandt, University of Southern Mississippi, Hattiesburg, Mississippi, USA
B. Olson, University of Southern Mississippi, Hattiesburg, Mississippi, USA
A. Jamieson, Case Western Reserve University, Cleveland, Ohio, USA
Ethylene vinyl alcohol copolymers (EVOH) play an important role in the food
packaging industry. These copolymers are typically produced via hydrolysis of
ethylene vinyl acetate random copolymers. Gas barrier of EVOH copolymers
depends on vinyl alcohol content. EVOH copolymers, especially with high vinyl
alcohol content, are excellent gas barriers primarily due to hydrogen bonding (Hbonding)
formed by the hydroxyl moieties. In turn, H-bonding results in the
increase of cohesive energy density (CED) of a polymer and decreases its free
volume. Both factors contribute to low gas diffusivity and high gas barrier of
EVOH copolymers. The fundamental role of free volume and CED on diffusion
behavior and their fundamental interrelationship, however, has not been
completely understood as yet. Because of its structural simplicity EVOH
copolymers is an excellent model system for studying the effect of H- bonding on
gas diffusion.
EVOH copolymers with various ethylene contents (0, 24, 27, 32, 38, 44, 48, 60,
75, 82 and 95 mol %), were used in this work. EVOH 0-60 mol % are commercial
products, EVOH 75-95% were prepared by hydrolysis of ethylene vinyl acetate
(EVA) copolymers. Thin films of the ethylene vinyl alcohol copolymers were
prepared by compression molding. Glass transition temperature of copolymers
was investigated by DSC. The crystallinity was investigated by WAXS. The state
of hydrogen bonding was determined by FTIR. Cohesive energy of the
copolymers was calculated using Hoy group contribution method as well as
determined by conducting molecular dynamics simulations using commercially
available software Accelrys. The free volume at various temperatures was
probed by Positron Annihilation Life-Time Spectroscopy (PALS). Oxygen
transport measurements were conducted using standard MOCON Oxtran-2/21
facility at 0%RH. Oxygen flux curves versus time were measured. The flux data
were fit to the solution of Ficks second law. Oxygen permeability (P) and
diffusivity (D) data were generated from the fit. Oxygen solubility coefficient (S)
was calculated from P and D. Activation energy for oxygen diffusivity for selected
copolymers, however covering the entire range of composition, was measured by
running the experiments at various temperatures above as well as below glass
transition temperature of the copolymers.

Historically, all the approaches describing gas diffusion in polymers can be
roughly divided in two categories, based on free volume model and the activation
molecular models based on Eyring transition state theory, which take into
account the cooperative penetrant polymer chain motions, chain rigidity and
intermolecular forces. Although gas transport characteristics exhibit a general
correlation with free volume, alone free volume can not adequately describe gas
barrier. The chain rigidity and the strength of intermolecular interaction are two
additional important factors which are manifested via activation energy.
Currently, there is a tendency towards unification of these two different
approaches as the process of diffusion in the glassy state indeed depends on
free volume while at the same time is a thermally activated process. The main
objective of this work was to develop fundamental understanding of gas diffusion
in EVOH copolymers as it is related to free volume characteristics and cohesive
energy density.

Packaging and Barrier Materials – 5
Friday July 18, 4:30 PM-5:00 PM, Wai’anae
Confined Crystallization of PEO in Nanolayered Films for Improved Gas
Barrier
H. Wang (Speaker), Case Western Reserve University, Cleveland, Ohio, USA
B. Freeman, The University of Texas at Austin, Austin, Texas, USA
A. Hiltner, Case Western Reserve University, Cleveland, Ohio, USA - pah6@case.edu
E. Baer, Case Western Reserve University, Cleveland, Ohio, USA
The goal of this project is to produce gas barrier materials for food packaging
with controlled atmosphere. Crystallization of polymer chains in a confined space
can generate unique morphologies and may impact the properties of the
polymeric material, such as the mechanical strength and gas barrier. Previously
confined polymer crystallization has been extensively studied in block
copolymers utilizing the nanoscale structure formed by their self-assembly. The
enabling technology of layer-multiplying coextrusion in the Center for Layered
Polymeric Systems (CLiPS) provides a unique opportunity to study the confined
crystallization of commercial polymers. In this study, assemblies of highly
crystalline poly (ethylene oxide) (PEO) layers with thickness ranging from 4
micron to 100nm were achieved by ‘forced assembly’ with ethylene-co-acrylic
acid copolymer (EAA). When the PEO layer thickness was in the micron scale (1-
4 micron), the PEO crystal orientation was isotropic and the gas barrier of PEO
layer was the same as the non- layered PEO. Upon further decreasing the PEO
layer thickness to around 100nm, atomic force microscopy and wide angle X-ray
diffraction showed that the long PEO lamellar crystals were aligned parallel to the
layer direction in these nanolayered films. The PEO/EAA nanolayered films
exhibited greatly improved gas barrier properties with the oxygen and carbon
dioxide permeability one order of magnitude lower than the microlayered films.
The improved barrier was attributed to the increased diffusion tortuosity in the
PEO layers because the long, impermeable PEO crystals were aligned
perpendicular to the gas diffusion direction. This observation reveals the potential
of making better barrier films from conventional polymeric materials.

Packaging and Barrier Materials – 6
Friday July 18, 5:00 PM-5:30 PM, Wai’anae
Relationship between Biaxial Orientation and Oxygen Permeability of
Polypropylene Film
Y. Lin (Speaker), Case Western Reserve University, Cleveland, Ohio, USA
P. Dias, Case Western Reserve University, Cleveland, Ohio, USA
H. Chen, The Dow Chemical Company, Freeport, Texas, USA
A. Hiltner, Case Western Reserve University, Cleveland, Ohio, USA - pah6@case.edu
E. Baer, Case Western Reserve University, Cleveland, Ohio, USA
Biaxially oriented polypropylene (BOPP) films were produced by simultaneous
and sequential biaxial stretching to various balanced and unbalanced draw
ratios. The BOPP films were characterized in terms of density, crystallinity,
refractive index, oxygen permeability and dynamic mechanical relaxation
behavior. It was found that the density and crystallinity of BOPP films decreased
as the area draw ratio increased. Sequential stretching led to a slightly lower
density than simultaneous stretching to the same draw ratio. Moreover,
sequential stretching produced lower orientation in the first stretch direction and
higher orientation on the second stretch direction compared to simultaneous
stretching. The study confirmed the generality of a one-to- one correlation
between the oxygen permeability of BOPP films and the mobility of amorphous
tie chains as measured by the intensity of the dynamic mechanical betarelaxation.
Moreover, the study established the correlation for commercially
important sequentially drawn BOPP films with an unbalanced draw ratio. For the
specific resin used in this study, the oxygen permeability also correlated with the
z- direction refractive index. Finally, the chain mobility in the stretch direction was
found to depend on the final stress during stretching.