Specialist Group on Use of Macrophytes in Water Pollution ... - IWA

<strong>Specialist</strong> <strong>Group</strong> on 

Use of Macrophytes in Water Pollution Control 

Newsletter No. 38 

June 2011 

Edited by: Dr Suwasa Kantawanichkul 

Department of Environmental Engineering 

Faculty of Engineering 

Chiang Mai University 

Chiang Mai 50200 

Thailand 

Email: suwasa@eng.cmu.ac.th 

<strong>Group</strong> organisation 

Chair: Dr Jan Vymazal (vymazal@yahoo.com) 

Secretary: Dr Suwasa Kantawanichkul (suwasa@eng.cmu.ac.th) 

Regional Coordinators 

ASIA: Dr Zhai Jun (zhaijun99@126.com; zhaijun@cqu.edu.cn) 

Dr Suwasa Kantwanichkul (suwasa@eng.cmu.ac.th) 

AUSTRALIA: Dr Margaret Greenway (m.greenway@mailbox.gu.edu.au) 

NEW ZEALAND: Dr Chris C Tanner (c.tanner@niwa.co.nz) 

EUROPE: Dr Jan Vymazal (vymazal@yahoo.com) 

Professor Reimund Harberl (raimund.haberl@boku.ac.at) 

Dr Guenter Langergraber (guenter.langergraber@boku.ac.at) 

Professor Brian Shutes (b.shutes@mdx.ac.uk) 

Dr Fabio Masi (masi@iridra.com) 

Mr Heibert Rustige (rustige@akut-umwelt.de) 

MIDDLE EAST: Professor Michal Green (agmgreen@tx.technion.ac.il) 

NORTH AMERICA: Dr Otto Stein (ottos@ce.montana.edu) 

SOUTH AMERICA: Dr Gabriela Dotro (gdotro@gmail.com) 

AFRICA: Professor Jamidu H.Y.Katima (jkatima@udsm.ac.tz) 

Dr Akintunde Babatunde (akintunde.babatunde@ucd.ie) 

Disclaimer: This is not a journal, but a Newsletter issued by the IWA <strong>Specialist</strong> <strong>Group</strong> on Use of 

Macrophytes in Water Pollution Control. Statements made in this Newsletter do not necessarily 

represent the views of the <strong>Specialist</strong> <strong>Group</strong> or those of the IWA. The use of information supplied in the 

Newsletter is at the sole risk of the user, as the <strong>Specialist</strong> <strong>Group</strong> and the IWA do not accept any 

responsibility or liability. 

____________________________________________________________________________________________________ 

IWA <strong>Specialist</strong> <strong>Group</strong> on Use of Macrophytes in Water Pollution Control: Newsletter No. 38 1

CONTENTS 

Message from the Chair .............................................................................................................. 3 

First announcement: 13th International Conference on Wetland Systems in Water Pollution 

Control, 25–29 November 2012, Murdoch University, Perth, Australia 

Frank van Dien ........................................................................................................................... 4 

Interviewing Prof.Otto Stein 

Frank van Dien ........................................................................................................................... 8 

Application of Vertical Flow Treatment Wetland Systems in The Netherlands: Part 2 

Frank van Dien ......................................................................................................................... 11 

Nutrient release from integrated constructed wetlands sediment 

Yu Dong, Birol Kayranli, Miklas Scholz, Devi Prasad Tumula and Rory Harrington ............ 17 

Constructed wetlands as part of ecosan systems: 10 years of experiences in Uganda 

Elke Muellegger and Markus Lechner ...................................................................................... 23 

Area and energy requirements: comparison between CEPT-CWL, tidal flow CWL and 

French design CWL systems for the removal of organics and nitrogen compounds 

Eilon Guthman, Sheldon Tarre and Michal Green ................................................................... 31 

Design and performance of the wetland wreatment system at the Buffalo Niagara 

International Airport 

Scott Wallace and Mark Liner .................................................................................................. 36 

Treatment of sisal wastewater using constructed wetlands in Tanzania 

Nuru R. Mziray.......................................................................................................................... 43 

Wetland for water pollution control in China: Recent experiences 

J. Zhai, H.W. Xiao, J. Liu.......................................................................................................... 46 

<strong>Specialist</strong> Symposium: Bringing Together Science and Policy to Protect and Enhance 

Wetland Ecosystem Services in Agricultural Landscapes, Rotorua, New Zealand ................. 52 

The Constructed Wetland Association...................................................................................... 54 

News from IWA Headquarters ................................................................................................. 57 

New from IWA Publishing ....................................................................................................... 60 

___________________________________________________________________________ 

2 IWA <strong>Specialist</strong> <strong>Group</strong> on Use of Macrophytes in Water Pollution Control: Newsletter No. 37

MESSAGE FROM THE CHAIR 

Dear Members, 

I am happy to announce that the 13th Biennial Conference on Wetland Systems in Water 

Pollution Control has been approved by IWA headquarters and the conference will take place 

at Murdoch University, Perth, Western Australia, on 25–29 November 2012. I had a chance 

to participate in the conference on Integrated Water Management this February organized by 

Murdoch University and it was a great event. I have no doubts that our conference next year 

will be a success as well. The first announcement for this conference is on pages 4–7. 

It is apparent that the information on constructed treatment wetlands published in 

international journals is still growing and at this point I would like to draw your attention to 

three recently published journal special issues which contain papers on the use of wetlands 

for water quality improvement: 

Special Issue of Ecological Engineering: Enhancing ecosystem services on the landscape 

with created, constructed and restored wetlands 

Volume 37, Issue 1, pages 1–98 (January 2011) 

(based on papers presented during the INTECOL Wetland Conference in Cuiabá, Brazil, 

2008), edited by Jan Vymazal 

Special Issue of Ecological Engineering: Advances in pollutant removal processes and 

fate in natural and constructed wetlands 

Volume 37, Issue 5, pages 663–806 (May 2011) 

Based on papers presented during the WETPOL Conference in 2009 in Barcelona, Spain, 

edited by Joan García. 

Special issue of International Journal of Environmental Analytical Chemistry: 

Proceedings of the 3rd Conference on Wetland Pollutant Dynamics and Control 

Volume 91, Issue 7 and 8, pages 599–810 (2011) 

Based on papers presented during the WETPOL Conference in 2009 in Barcelona, Spain, 

edited by Josep M. Bayona 

Jan Vymazal 

<strong>Group</strong> Chair 

____________________________________________________________________________________________________ 


First Announcement and Call for Abstracts 

13 th International Conference in 

Wetland Systems for 

Water Pollution Control 

25-29 November 2012 

The biennial meeting of the IWA <strong>Specialist</strong> <strong>Group</strong> on the 

Use of Macrophytes in Water Pollution Control 

Hosted and Organised by 

Murdoch University 

Perth, Western Australia 

in collaboration with IWA and AWA 

discoverers welcome

The Proposers 

The Environmental Technology Centre (ETC) at Murdoch 

University is the lead organiser behind this proposal. 

Background and purpose 

The use of constructed wetlands in water pollution control has been 

a matter of considerable interest and research from the early eighties. 

While most of the work has focused on the use of wetlands as 

polishing systems and on removal of nutrients, metals and pathogens, 

research has also revealed their application for primary wastewater 

treatment (“French systems”) and sludge stabilisation. 

Reuse of wastewater and stormwater for non-potable purposes 

has become necessary due to increasing demand on high quality 

water. Wetlands have proven to reliably achieve efficient treatment 

processes, satisfying non potable reuse requirements. This is of extreme 

importance in the Australian context, where most of the water is used 

in agriculture. Besides, population pressure and declining rainfall 

patterns in some areas have led to depreciation of natural wetlands 

and groundwater dependent ecosystems. 

Treatment wetlands are now a well established technology. There are 

several thousand wetland systems treating municipal, agricultural 

and industrial wastewaters in North America and Europe and a 

rising number of systems treating point source and non-point source 

pollution globally. These wetland systems have a wide variety of 

engineering designs, wetted areas, flow rates, influent and effluent 

quality, hydraulic properties and monitoring requirements. The 

information from this operational treatment experience can be used 

to form design guidelines for wetland systems. Research is necessary 

in areas of system longevity, pollutant removal process dynamics and 

system modelling. 

The major aim of the Conference is to bring together researchers and 

professionals to discuss new developments and exchange experiences 

in the field of constructed wetland systems. The Conference will 

highlight the latest improvements and achievements in the treatment 

of urban storm water runoff, domestic and municipal wastewaters, 

agricultural and industrial effluents. 

The success of several IWA Conferences organised by the ETC 

demonstrates our capacity to organise the 13th International 

Conference on Wetlands Systems for Water Pollution Control. We have 

long been encouraging and disseminating research on treatment 

wetlands. Murdoch organised an International Workshop on Wetland 

Systems for Wastewater Treatment in 1996. We have published papers 

in the field of Constructed Wetlands, Decentralised Systems and 

Environmental Technologies. 

Conference date 

Considering the date of previous conferences in the series, and in the 

hope of ensuring that participants have a pleasant stay, we have chosen 

the week from 25-29 November 2012. This period is a non-teaching 

time at the University and all the facilities of the University will be 

available. Weather-wise November is an excellent period to organise a 

conference, as the weather is generally consistently warm and pleasant. 

Conference venue 

The Conference will take place at Murdoch University. There are 

modern lecture theatres available at the University. The Environmental 

Technology Centre will display sustainable technologies at their location 

on the University campus. The participants of the conference will have 

the privilege to visit the centre. 

Conference language 

The official language of the conference will be English. There will 

be oral and poster presentations, with pre-printed abstracts of 

conference papers. 

Technical Tours 

A technical tour is proposed for the Tuesday 27 November 2012. The 

tour is an integral part of the conference. The tour will include the 

following wetlands systems: CSBP Ltd. Kwinana – Industrial effluent; 

Point Fraser (CBD) – Stormwater treatment, Wharf + Liege street 

(Cannington) – Stormwater treatment; Peppermint Grove Library 

– Stormwater (rainwater use, urine separation) and other wetland 

facilities in Perth. 

An additional pre/post conference tour highlighting natural and 

constructed wetland systems in the scenic Margaret River Region in 

South Western WA is also being proposed.

Conference Topics 

• Process Dynamics 

• Management and Control 

• Case studies 

• Design criteria 

• Economics 

• Environmental issues and operation policies 

• CW Components 

• Modelling of wetland treatment processes 

• Systems with enhanced/active aeration 

• Floating emergent macrophyte wetlands 

• Suitability of treatment wetlands for developing countries 

• Removal of pharmaceuticals, heavy metals, surfactants and 

other emerging pollutants 

• Stormwater and industrial wastewater treatment 

Conference Planning Schedule 

Our organisation schedule is as follows: 

First Announcement and Call for Abstracts July 2011 

Deadline for Abstracts May 2012 

Date for notifying successful authors June 2012 

Date for full written papers to be received Sept 2012 

Web Hot Registration Fee Before 31 Jul 2012 

Early Registration Fee Before 30 Sept 2012 

Conference takes place Nov 2012 

Executive Committee 

1. Stewart Dallas (Murdoch University, Chair) 

2. Goen Ho (Murdoch University) 

3. Martin Anda (Murdoch University) 

4. Sergio Domingos (Murdoch University) 

5. Kathy Meney (Syrinx Environmental PL) 

6. Peter Adkins (Swan River Trust) 

7. David Oldmeadow (Parsons Brinkerhoff) 

8. Andrew Bruce (WA Local Government Association) 

9. Ken McIntosh (Department of Water) 

10. Suzanna Brown (Water Corporation ) 

11. Jane Chambers (Murdoch university) 

12. Cath Miller (Australian Water Association) 

National Committee 

• Margaret Greenway (Griffith University, QLD) 

• John Bavor (University of Western Sydney, NSW) 

• Phil Geary (University of New Castle, NSW) 

• Leigh Davison (Southern Cross University, NSW) 

• David Pont (Water and Carbon <strong>Group</strong>, VIC) 

• Mark Bayley (Australian Wetlands Consulting, NSW) 

• Peter Breen (Monash University, VIC)

MD6677-5-11 Printed on environmentally friendly paper 

International Advisory 

Committee 

• Fabio Masi (Italy) 

• Suriptono (Indonesia) 

• Raimund Haberl (Austria) 

• Jamidu Katima (Tanzania) 

• Pascal Molle (France) 

• Trond Maelhum (Norway) 

• Suzette Martins-Dias (Portugal) 

• Ramesh Reddy (USA) 

• Brian Shutes (UK) 

• Robert Kadlec (USA) 

• Akintunde Babatunde (Ireland) 

• Heribert Rustige (Germany) 

• Otto Stein (USA) 

• Florent Chazarenc (France) 

• Jaime Nivala (Germany) 

• Joan Garcia (Spain) 

• Carlos Arias (Denmark) 

For Further Information: 

Dr Kuruvilla Mathew or Dr Stewart Dallas 

Faculty of Science and Engineering 

Murdoch University 

Perth, Western Australia 

Phone: +61 (08) 9360 2896 

Mobile: 0406 644 947 

K.Mathew@murdoch.edu.au 

S.Dallas@murdoch.edu.au 

CRICOS Provider Code 00125J 

International Programme 

Committee 

• Hans Brix (Denmark) 

• Chris Tanner (NZ) 

• Scott Wallace (USA) 

• Gunter Langergraber (Austria) 

• Jan Vymazal (Czech Republic) 

• Suwasa Kantawanichkul (Thailand) 

• Tom Headley (Germany) 

• Michal Green (Israel) 

• Mark Nelson (Global) 

• Joseph V. Thanikal (Oman) 

• Jacques Brisson (Canada) 

Keynote speakers 

• Suwasa Kantawanichkul (Thailand) 

• Jan Vymazal (Chezh Republic) 

• Margaret Greenway (Australia) 

• Kathy Meney (Australia) 

• Scott Wallace (USA) 

• Gunter Langergraber (Austria) 

• Tom Headley (Germany) 

• Chris Tanner (NZ) 

• Keith Bolton (Australia) 

• Joan Garcia (Spain) 

• Robert kadlec (USA 

• Ulo Mander (Estonia) 

• Brian Shutes (UK) 

discoverers welcome

INTERVIEWING PROFESSOR OTTO STEIN 

Probably most people know you as the professor of SSF CW 

processes, Otto Stein from Montana State University in the USA. 

But many may also know you as a joyful person at our conferences, 

often photographed and always in for a laugh. The serious professor 

seems to be hidden, maybe in the research papers or in your works 

in Kenya? Maybe it‘s time to find out more about you. For starters, 

I wonder: 

Where in your life did things definitely turn in the direction that resulted in this position? 

When anyone has been in academia as long as I have, your career will necessarily take a few 

unanticipated turns, but my getting into wetlands was rather 

accidental, but perhaps fate driven. I was hired into and 

Agricultural Engineering position here at MSU right after 

completing my PhD in Civil Engineering (hydraulics) with a 

focus on erosion and sediment transport; I think because I had 

a Master‘s degree in Agronomy and a BS in Environmental 

Science. But the program (like many agricultural engineering 

programs in the USA) had few students. So one of my first 

charges was to revive the program and I felt that it was 

important to move away from a very traditional irrigation and 

machinery focus to a focus on ‗rural water issues‘. I convinced 

my chair that I should teach a course on rural water quality 

engineering rather than agricultural structural design since I 

didn‘t (and still don‘t) know anything about that. The problem 

was that I didn‘t know anything about rural water quality 

either! To learn more, I enrolled in a two-week short course 

on the topic, which ended up having a major focus on treatment wetlands. While there, I 

convinced myself that my diverse academic training with hydraulics, soil science, organic 

chemistry, plant science and microbiology was a asset and since the TW field was so new (I think 

that was in 1992) I decided to look at research opportunities as well as incorporate TW into the 

What does this world need most at 

the moment? More time to get to 

know the rest of the people on our 

planet. It is really hard to vilify folks 

you know, and most of our 

problems would go away. 

What does our own (waste) water 

world need most at the moment? 

More composting toilets. 

1958: born in Philadelphia, 

Pennsylvania 

1990: PhD in Civil Engineering 

from Colorado State University 

and Assistant Professor Montana 

State University 

1996: first wetland research grant 

1998: first wetland publication 

2006: promoted to Professor 

2006: Faculty Advisor to 

Engineers Without Borders 

new class. That eventually lead to a grant that was funded in 

1996 and my career started moving away from erosion to 

wetlands. In 2000, when I went to my first IWA wetlands 

meeting in Orlando, Florida. I finally met all the people 

whose papers I had been reading. I also realized that not only 

were they great scientists and engineers with much to learn 

from, but they really knew how to have fun too … Well I 

knew then that I had found ‗my people‘ and I was going to 

make a commitment to keep returning. I haven‘t missed a 

meeting since and have never been disappointed in the 

learning or camaraderie that goes on �. 

___________________________________________________________________________ 


You mention Kenya, and I should talk about that a little too. We have a big undergraduate 

teaching commitment at MSU and back in 2006 one of my advisees convinced me that I should 

become the advisor to the MSU chapter of Engineers Without Borders. The organization which is 

modelled after Doctors Without Borders, was founded in 2001 (I think, but I am getting old and 

my memory is not what it used to be) and our chapter got a project to bring potable water and 

sanitation facilities to 58 primary schools in the Khwisero Region of Western Kenya. While the 

region is blessed with fertile soil and good rains, the 120,000 or so inhabitants live primarily by 

subsistence agriculture and most water comes from shallow wells and springs, or is decanted 

directly from the streams, and sanitation is almost exclusively via pit latrines. Needless to say, 

there are health issues with this system not to mention the social and educational issues 

surrounding the female students fetching water from distance sources for the schools. So our 

chapter has been very successful in raising funds to alleviate this situation and we have used that 

funding to (so far) drill 7 deep (~70m) bore holes and construct 6 composting latrines and one 

biogas latrine at various schools. We have also had about 75 MSU students visit Khwisero and 23 

more will be headed there to help construct two more composting toilets, a distribution pipeline 

from one of the previously-drilled boreholes to several more schools, a health centre and a 

market. I first went there personally ‗on my way‘ to the conference in Indore, India in 2008 and 

had the opportunity to return for a month last summer. In addition I have been busy trying to 

incorporate all this activity into the academic curriculum of what has become quite a big and 

diverse group of students. We have about 60 students actively involved representing majors from 

engineering to soil science to English Literature to film making. Somehow we seem to find an 

active role for all and recently the success of the chapter has brought us several awards. While it 

is the students that do so much of the work, I am really proud of the success the group has had 

and the difference we seem to be making in the world. Not only is the group helping people in 

Kenya, but it is also giving the students the opportunity to live and interact with people of another 

culture and bring that perspective back to other Americans. 

It is not hard to imagine that it feels great to see such a thing develop into something of 

that importance. But I understand that you haven’t (yet) come to installing treatment 

wetlands there? 

Well no, and the good news is that hopefully we will never need treatment wetlands or any 

other ‗end of pipe‘ treatment systems in Khwisero. Something that perhaps those of us in the 

developed world could learn from rural Africa is that we don‘t have to flush our waste away 

with water, saving us the trouble of having to separate them to make the water useful a 

second time. Wouldn‘t it be great if we could make the term ‗wastewater‘ obsolete? 

Ha ha, you ask me, the interviewer? You know what: I’ll add it to the standard 

questions, I think you’re on to something! But back to you: what do you prefer as a 

‘name’: Constructed Wetland or Treatment Wetland? 

Well, I definitely prefer ‗treatment wetland‘ for wetlands designed to remediate contaminated 

water. To me the term ‗constructed wetland‘ is broader and includes ‗created wetlands‘ and 

‗mitigation wetlands‘ which would be wetlands created for the main purpose of wildlife 

habitat development, the latter case as a legal requirement to replace wetlands lost due to 

development. In the US at least, I think ‗treatment wetland‘ causes less confusion to the 

general scientist. 

____________________________________________________________________________________________________ 


Do you see treatment wetlands as an ultimate solution for waste water? And if so, in 

general or just occasional, i.e. when no sewer system is available? 

I think the ultimate solution for wastewater would be to stop using water as a means to convey 

our waste away from us, but I don‘t expect much headway on that in our lifetimes, so we are 

kind of stuck with the system we have, at least in the developed world. Otherwise it depends on 

the goals. I think treatment wetlands are the best option when flow rates are small enough that a 

conventional system, i.e. activated sludge with advanced nutrient removal and anaerobic sludge 

digestion, is too expensive. I don‘t think any other ‗alternative‘ or ‗natural‘ or extensive‘ or 

‗low tech‘ system can compare performance-wise (BTW I don‘t like any of those terms, but 

have never been able to come up with a better one). But for big flow rates or applications in 

highly urbanized areas, I think the trade-off on land requirements for TWs makes conventional 

systems the more logical option. I do worry about the carbon footprint cost for power required 

to run a conventional system though. It would be an interesting exercise to do a life cycle 

analysis between wetlands and conventional systems, hum ... next project �? 

Here’s a daring question for you! Do you think the horizontal system is superior to the 

vertical or is it the other way around or do we simply need them both? 

Let‘s not forget our free water surface or floating island friends in this debate! I think there is 

an appropriate application for everyone of those systems. But since you asked, for domestic 

wastewater I like the hybrid system with a vertical flow (two stage??) followed by a 

horizontal flow system, especially in the USA where we typically have nitrate limits as well 

as TN and BOD and SS and …. everything else. The idea of taking raw WW to US discharge 

standards using nothing but a wetland is really intriguing to me. And if we could do it in a 

climate like Montana‘s, well even better. 

Is there, to your knowledge, a TW that is an example for us all? 

I think I just answered that. I like the hybrid systems with a primary first stage that I have 

seen. I have to admit that I was a complete sceptic when I first heard them described at our 

conference in Arusha, Tanzania, as I couldn‘t see how a system like that could possibly work 

without plugging. But when I had the chance to see a few on the tour during the Avignon, 

France conference, I was completely convinced. That is what made me realize that a TW 

could be the complete system, raw wastewater to surface discharge. 

Well, here you get close to what I actually meant: What physical wetland is an example 

for us all? Are you talking about the Roussillon wetland, built by SINT (Dirk Esser) in 

1998, we visited during that conference? 

Ha, you are really trying to put me on the spot for my favourite system, and there are so many 

good ones to choose from! But yeah, I do like the system I saw in Roussillon but I think for 

US discharge standards we need to add an HF component on the back end to knock down the 

nitrate that is generated, and there is also that sticky issue of long-term phosphorous removal. 

One concern for that type of system to meet Montana discharge standards would be whether 

there is enough organic carbon carryover from the VF component or production in the HF 

component to drive denitrification. My research group is currently looking into that. 

And the last question: who would you like to be interviewed the next time? 

I would really like to know more about the views of one of our more experienced group 

members: Paul Cooper. And finally, I want to thank you for the opportunity to ‗chat‘ with 

you. I think this is great addition to the newsletter. 

Interview by Frank van Dien 

___________________________________________________________________________ 


APPLICATION OF VERTICAL FLOW TREATMENT WETLAND SYSTEMS IN THE 

NETHERLANDS (PART 2) 

Frank van Dien 

Owner of ECOFYT 

Designer and contractor of constructed wetlands in Holland 

(In the last newsletter you could read part 1 of this presentation; this is the last part of it.) 

In November 2010 I had the honour to be invited to the public PhD defence of Nathalie 

Fonder, in Gembloux, Belgium. She managed to turn this event into quite an international 

occasion: she organized a sanitaion day around it, for which she invited speakers from 

Belgium, France, Denmark, the Netherlands and the US. And a field trip to some projects 

she‘d been involved with. I was invited to talk about ‗The application of Vertical Flow 

Treatment Wetland Systems in the Netherlands‘. Dr. Fonder considered me a suitable person 

in this group, having seventeen years of experience as a contractor in Constructed Wetlands 

in Holland. 

But I had to give it some thought: what could be my contribution to this event, concerning the 

‗Dutch Views On The Topic‘. I started my lecture with saying that we, Dutchmen, have quite 

a history with water. And I gave examples, from how ‗we‘ sailed the seas; how the Dutch 

traded goods to and fro, all over the world ... And how we also had to fight the seas, 

especially as far as our shores are concerned. And that we, in the mean time, had to fight with 

rivers and with groundwater tables as well living at the end of several great rivers in what 

was nothing more than a delta. And that, all in all, over the years our *knowledge* of water 

had become part of what we have to trade. 

But not where wetlands are concerned ... 

So, I told the audience: basically, my presentation has three topics: 

1) What is the sanitation situation in the Netherlands? 

Holland will not easily be a world leader in the field of treatment wetlands. 

And there is a simple explanation for it: before this green technology started to get known, 

the Dutch were close to ready with connecting any point of discharge to the sewer system... 

I did a little survey on ‗what is the actual sanitation situation in the Netherlands‘. 

2) And what is the wetland situation in the Netherlands? 

Is it because we first had to dry our country, in order to be able to live there... that we started 

a little late with treatment wetlands? How many do we have? 

Especially for this occasion, I started a survey on that as well. 

And finally: 

____________________________________________________________________________________________________ 


3) What does the typical Dutch wetlands look like? 

In a moment you will see that there are many more vertical Flow Constructed Wetlands in 

Holland than all other varieties. There‘s a reasonably simple explanation for that, too. 

This time the last part, topic number three: 

3) What do Dutch wetlands look like... 

... and why are there so many more VF TW‘s over other systems? 

There‘s this funny thing in Wetlandia: we manage to form friendships all over the world. We 

like each others work and want to hear about it. We love the conferences on wetlands and 

will travel around the globe to attend them. It must be because we all share the same passion 

for the topic ... On the other hand, I noticed that we do not act in the same way. We tend to 

keep to what we‘re used to: 

The English, they stick to gravel based, horizontal subsurface flow systems. 

(and worry a bit about the clogging they encounter) 

The Americans, they stick to gravel based, subsurface flow systems. 

(maybe they add a little aeration to it) 

Zee Frenzj, zey want to smazj zee waste water raw on zeyr fields 

(And don‘t worry a thing about the smells it may produce) 

And we Dutch stick to fertical flow, srough fine send 

(and just look a bit confused when told that this is expensive) 

How come? 

I cannot answer this question for all of us, I‘ll stick to my turf: and let me start by telling you 

that this is somewhat more of an anecdote, rather than official facts ... 

Back in 1994, there had been two or three relatively large pilots of Surface Flow Treatment 

wetlands built in Holland and a couple of private, Do-It-Yourself wetlands by some pioneers 

– but that was about it. 

Then, Dion van Oirschot and I put our heads together to see if we 

could earn a living with this unknown technique called contructed 

wetlands. 

Dion had already read several documents on the topic (and please 

don‘t forget, internet was just born then, that was not yet the usual 

way to get your information, we read BOOKS!) 

And I had some experience in construction, all sorts of it, which 

of course comes in handy. 

___________________________________________________________________________ 


So we knew: 

1. We wanted to do something useful for the environment (that had already been the red 

thread through both our careers). 

2. There were still quiet some remote locations where people produced waste water but a 

connection to the sewer system would not be affordable. 

3. Wetlands had been constructed to mimic nature - and their results 

were impressive. 

4. There were books on that item by Abby Rockefeller, 

Dr. Käthe Seidel, Prof. Kickuth ... 

– And a very readable book by Klaus Bahlo and Gert Wach (in German but okay ...) 

Without any bias, Dion and I discussed the pros and cons of all known systems. Our goal was 

waste water treatment, so Surface Flow was not really part of the discussion. 

And – with ground being expensive in Holland – a system that claimed to need less surface 

would probably win the race. 

And filling such a system with fine material would result in far more treatment surface... - but 

too fine material could result in clogging - that‘s a lesson learned from Kickuth. 

And transporting water through the media, mainly by gravity – it makes sense! 

So we kind of adopted this German system - and changed it to our liking concerning 

drainage, lining, injection techniques ... Just by common sense, not by any tradition… 

And suddenly (well, we spent one year of talking before we had our first client) we had a 

system that worked, that was monitored by a waterboard and people got really enthusiastic! 

A dozen wetlands later, more people entered ‗the business‘ and the discussion was raised 

among waterboards and townships: ‗Next we have a couple of hundred wetlands built by who 

knows who ... How are we going to control that?‘ 

So the idea of certifying systems was born and well, being first in the business, Dion and I 

played our part in that discussion. We DID know what we were talking about and could 

defend many ins and outs of what WE had come up with. So what we initially considered a 

proper way of treating waste water sort of became the standard in Holland. Parties that later 

entered the market often hardly knew about other treatment systems; if you wanted to deliver 

the best small scale treatment system, you‘d take a helofytenfilter – and they meant: a VF 

TW (which of course stands for a Vertical Flow Treatment Wetland). 

Funny thing is that for Dion and me, this never has been the final, golden rule. Although our 

collaboration only lasted a couple of years (Dion later moved to Belgium and continued 

building wetlands there), for both of us the first rule is to ask yourself: What is to be treated 

(how much water and how dirty)? 

____________________________________________________________________________________________________ 


And what is the best suitable solution? So – though the emphasis lies on VF – we designed 

HF and SF (Surface Flow) or FEM (Floating Emergent Macrophyts) systems - as we pleased. 

Or as it pleased us. 

But to come back to the true item of this topic, basically, the Dutch constructed wetlands (for 

waste water, that is) looks like this: 

From top to bottom we have: 

1. the visual part: the macrophytes (commonly reed); 

2. a gravel bed in which lie the main pressure pipe with its side branches; 

3. the actual substrate being fine sand (usually a D50 of a quarter millimeter); and finally 

4. at the bottom, below a root cloth, a gravel layer with drains and a connection pipe ... 

off to the surface water! 

In this top layer of (round) gravel, in which the pressure pipes are hidden, water is injected 

per every square meter… (And when the pump switches on, water is divided, over the entire 

surface, through the gravel, when the pump switches off, gravity makes the water to travel 

through the sandlayer). The gravel layer being thick enough to store the waste water in its 

pores: no puddles, no smells ... 

The actual working body consists of 1 m of fine sand ... 

We may use calcium carbonate and iron (in small sparticles) to try to bind phosphorous. And 

straw, as a carbon source for denitrification. Commonly we use 1 mm PE lining for water 

tightness. And some have artificial water levels in their systems, others just run dry. 

And in case you want to know something about the performances, I have some figures… 

___________________________________________________________________________ 


All these analysis were done by third parties, accredited labs, universities ... And it only 

concerns projects by ECOFYT, both domestic and dairy waste water treatment. 

So, as I said: maybe the Netherlands are not the county to wait for when it comes down to 

exciting developments. Often times it‘s the real urge that brings the best ideas. But good 

ideas may be born under circumstances without life threatening stress, as well. I can say that 

we have been involved in projects that could be defined as intellectually challenging. Like the 

self supporting houseboat called ‗geWOONboot‘, and its spin off: ‗BeauTark‘. Or ‗the most 

sustainable office of the Netherlands, the Bussummer watertoren‘ but maybe that‘s something 

for another story. 

I‘d like to finish with saying that we have this big tool box, so many systems to choose from, 

but that shouldn‘t mean that we should lay back and rest ... New developments are appealing, 

they are exciting! As I have heard Prof. Otto Stein say many times: ‗Engineers are good in 

doing what engineers have done before!‘ But it‘s way more fun to keep an open mind. (And I 

wish to understand that this is actually his point!) 

We have a heart for the environment, right? Then let me invite you to dive into the ideas like 

Cradle to Cradle! We‘re used to designing with materials that will do the job. But, since 

everything comes to an end, we should be much more aware of picking materials that - in the 

end – will be harmless as waste. 

____________________________________________________________________________________________________ 


Or even better: why not search for materials that – in the end – will be excellent new building 

material? In this line of thinking, ‗waste‘ simply doesn‘t exist. Materials simply are in 

transition, from one state to another, from one goal to another... Isn‘t that a beautiful thought? 

And if you now think: OK, tell me how! I‘m going to disappoint you: I cannot tell you yet … 

We‘ve just started the journey, I can only invite you to join us, let‘s find out together! 

Having a heart for the environment... Let me also invite you to dive into the idea of designing 

systems that do not simply try to eliminate the ‗dangerous substances‘ in our ‗waste‘ water. 

That basically, is what we have been doing so far, do you understand what I‘m saying? We 

try to eliminate BOD and COD and in the same line of thinking, we are used to trying to 

eliminate nitrogen and phosphorus. 

Recently we come to think that we have to invest (time and money) in winning back nitrogen 

and phosphorus. New sanitation, digesting faeces, making struvite … I do not yet know how 

Treatment Wetlands will play a role in that process. But we need to adjust our way of 

thinking into that direction. So we can reuse the nutrients which we now mainly manage to 

transform in nitrates, or bind to iron or calcium ... Collect it and give it a ‗second life‘ in 

agriculture, for which activity we now still mine these elements, knowing that it will come to 

a halt. In this line of thinking, ‗waste‘ simply doesn‘t exist. Materials simply are in transition, 

from one state to another, from one goal to another ... Isn‘t that a beautiful thought? 

___________________________________________________________________________ 


NUTRIENT RELEASE FROM INTEGRATED CONSTRUCTED WETLANDS 

SEDIMENT 

Yu Dong 1 , Birol Kayranli 1 , Miklas Scholz 1,2 , Devi Prasad Tumula 2 and Rory Harrington 3 

1 Institute for Infrastructure and Environment, School of Engineering, The University of 

Edinburgh, William Rankine Building, King’s Buildings, EH9 3JL, Edinburgh, UK 

2 Civil Engineering <strong>Group</strong>, School of Computing, Science and Engineering, The University of 

Salford, Newton Building, Salford M5 4WT, UK 

3 Water and Planning Division, Department of Environment, Heritage and Local Government, 

Waterford County Council, Ireland 

Email: y.dong@ed.ac.uk 

INTRODUCTION 

Wetland sediments mainly comprise of organic matter from wastewater, dead plants and 

minerals associated with soil erosion. Sediment may retain or release contaminants when 

environmental conditions change. 

METHODS 

Five horizontal free surface flow constructed wetland mesocosms (Figure 1) were set up at 

The University of Edinburgh to provide nutrient removal and/or accumulation within 

integrated constructed wetland (ICW) sediment. The laboratory room temperature was 

maintained at 15 ºC. Artificial light was provided by programmable controlled UV lights to 

simulate diurnal sunshine. The mesocosms were constructed using polyvinyl chloride 

drainage pipes with identical dimensions (height: 83 cm; diameter: 10 cm). Seven plastic taps 

were evenly placed around the circumference of the pipe for subsequent sample collection. 

The outlet valves were located at the centre of the bottom plate for each pipe. Outflow water 

was collected with vinyl tubing of 1.2 cm internal diameter. 

Of the five mesocosms (Figure 2), two were fed with farmyard runoff (mesocosms 1 and 2). 

Three mesocosms (mesocosms 3, 4 and 5) were fed with pre-treated domestic wastewater. 

Three planted experimental mesocosms (mesocosms 2, 3 and 4) were packed with four 

successive layers of aggregates (from bottom to top): 50 mm of small gravel (1.2–5.0 mm), 

50 mm of sand (0.6–1.2 mm), 250 mm of sodium bentonite clay (permeability of 10 -9 m/s) 

and 350 mm of core sediment (incorporating plants if applicable). These systems were 

flooded with inflow water up to the top. Core sediment samples were directly taken from the 

surface of ICW site 11 (cell 1), which were applied for the treatment of farmyard runoff for 

approximate ten years (Figure 3a). Further core sediment samples of domestic mesocosms 

were extracted from the surface of ICW site 7 (cell 1), which were constructed to treat 

domestic wastewater for approximate eight years (Figure 3b). Two control mesocosms 

(mesocosms 1 and 5) were set up to ensure the same flow conditions and saturation ratios. 

The soils and aggregates of the two control mesocosms (from bottom to top) contained 50 

mm of small gavel (1.2–5.0 mm), 50 mm of sand (0.6–1.2 mm), and 600 mm of sodium 

bentonite clay (permeability of 10 -9 m/s). 

____________________________________________________________________________________________________ 


Figure 1. Integrated constructed wetland experimental mesocosms 

Mesocosm 2 was planted with Phragmites australis; mesocosm 3 and 4 were planted with 

Phragmites australis and Agrostis stolonifera rhizomes respectively. The control mesocosms 

were left unplanted. 

Water samples (up to 100 ml each) were collected from top to bottom taps (Figure 2). The top 

tap (tap I) was used to collect horizontal free surface flow above the sediment layer (where 

applicable). Water samples were also taken from the oxidized sediment layers (tap II) and the 

reduced sediment layers (tap III). Virtually no water infiltrated into deeper layers due to the 

presence of bentonite and biomass. Therefore, water samples from the remaining other 

sampling points (below tap III) could not be collected. 

10 CM 

35 CM 

25 CM 

5 CM 

5 CM 

1 

TAP I 

TAP II 

2 

TAP I 

TAP III 

TAP II 

Figure 2. Schemes of experimental integrated constructed wetland mesocosms 

___________________________________________________________________________ 

18 IWA <strong>Specialist</strong> <strong>Group</strong> on Use of Macrophytes in Water Pollution Control: Newsletter No. 37 

3 

TAP I 

TAP III 

TAP II 

4 

Sediments 

TAP I 

TAP III 

5 

Clay 

Sand Gravel 

TAP I

Collected samples were analysed for temperature, pH, conductivity, total dissolved solids, 

redox potential, dissolved oxygen, suspended solids (SS), and chemical oxygen demand 

(COD) at The University of Edinburgh. Ammonia-nitrogen, nitrate-nitrogen, nitrite-nitrogen, 

total organic nitrogen, chloride, and molybdate reactive phosphorus (MRP, equivalent to 

soluble reactive phosphorus) were tested at the Waterford County Council water laboratory. 

Figure 3. Integrated constructed wetland near Waterford (Ireland); a: ICW site 11 treating 

farmyard runoff; b: ICW site 7 treating domestic wastewater. 

RESULTS 

Water treatment performance 

In this study, experiments were carried out in five column-scale horizontal free surface flow 

ICW systems. Mesocosms 1 and 2 were conducted between February 2009 and October 

2010. Whereas mesocosms 3, 4 and 5 were operated between May 2009 and October 2010. 

These results indicate that the mesocosms act as sources of COD rather than as sinks (Figures 

4 and 5). The sediments released substantially more organic matter in comparison to the 

amount of incoming organic matter that could be degraded. This can be explained by the fact 

that most organic matter accumulated at the interface between the sediment and clay layers 

due to the characteristics of slow organic matter decomposition and low permeability. In 

addition, due to relatively high concentrations of ammonia-nitrogen in influent, more than 

90% of the above-ground plants in mesocosms were dead after operation of approximately 

three months. This change in plant presence considerably affected the oxygen transfer 

capacity to the deeper sediment layers and aerobic decomposition processes were thus 

reduced. Therefore, the decomposition rate was most likely slower than the primary 

productivity rate, which resulted in a net accumulation of organic matter. 

In general, the ammonia-nitrogen concentrations at sampling points for all mesocosms were 

relatively higher than that of influent, in particular at tap III (Figures 4 and 5). This is 

probably because accumulated ammonia-nitrogen is bound loosely to the substrate such as 

sediment and subsequently released when water chemistry and other environmental factors 

change (e.g. oxygen shortage, low pH and temperature values, and high salinity 

concentration). In addition, kinetic ammonification (mineralization) of organic nitrogen 

proceeds more rapidly than nitrification, thus creating the potential for an increase in 

____________________________________________________________________________________________________ 


ammonium concentration in the outlet (Kadlec and Knight 1996). On the other hand, 

ammonia-nitrogen can be reduced by several processes, which include adsorption, plant 

uptake and volatilization. However, it is generally believed that the contribution of these 

processes is very limited (Lee et al. 2009). 

Experimental results also indicate that the wetland sediments were saturated with MRP, 

therefore, acting as a source for MRP (Figure 4 and 5). The alteration of environmental 

conditions triggered the phosphorus releasing process, resulting in a decrease of the removal 

efficiency. Moreover, the phosphate-accumulating microorganisms were sensitive to high 

salinity (Scholz 2006). The high chloride concentration possibly supported the release of 

phosphorus from the mature sediments. 

Concentration (mg/l) 

160 

140 

120 

100 

80 

60 

40 

20 

0 

COD Ammonia-N MRP 

Variables 

Influent 

___________________________________________________________________________ 


Tap I 

Tap II 

Tap III 

Figure 4. Water quality variables for farmyard runoff mesocosms. (Tap I: surface flow water; 

Tap II: oxidized sediment layer; Tap III: reduced sediment layer; COD: chemical oxygen 

demand; Ammonia-N: ammonia-nitrogen; MRP: molybdate reactive phosphorus).

Concentration (mg/l) 

160 

140 

120 

100 

80 

60 

40 

20 

0 

COD Ammonia-N MRP 

Variables 

Influent I-Tap I 

I-Tap II I-Tap III 

II-Tap I II-Tap II 

II-Tap III 

Figure 5. Water quality variables for domestic wastewater mesocosms (I: mesocosm 3; II: 

mesocosm 4; Tap I: surface flow water; Tap II: oxidized sediment layer; Tap III: reduced 

sediment layer; COD: chemical oxygen demand; Ammonia-N: ammonia-nitrogen; MRP: 

molybdate reactive phosphorus). 

Plant 

Concerning the two mesocosms treating domestic wastewater, mesocosm 3 had higher 

reduction removal efficiencies of COD, ammonia-nitrogen, MRP and SS to those of 

mesocosm 4. It suggests that the presence of Agrostis stolonifera in planted mesocosms has 

limited the diffusion of oxygen (as electron reception) to the lower sediment layers. 

Relatively low oxygen concentrations can be identified as the main contributor to the 

inadequate removal of COD and ammonia-nitrogen. 

Groundwater contamination 

An outlet valve was located on the base plate of each experimental mesocosm in to gauge the 

possibility of groundwater contamination by infiltration of the polluted water. However, no 

leachate was collected throughout the study period. The absence of measurable infiltration 

can be explained by the presence of a compact bentonite clay layer, acting as an excellent 

barrier to prevent nutrient transfer to potential aquifers. Furthermore, some of 

biogeochemical processes play important roles in clogging of the soil matrix. For example, 

biomass accumulation and/or insoluble biogas (i.e. methane) formation through soil microbes 

(Kellner et al. 2004; Tokida et al. 2005). 

Sediment management 

In March 2005, sediment accumulations were measured at six ICW sites in Waterford. The 

mean accumulation rates were approximately 3 cm per annum for moderately loaded 

systems. Previous research (Scholz 2007) indicated that the approximate sludge removal 

frequency of cell 1 within ICW site 11 would be nine years considering pond capacity. 

However, from the nutrient removal perspective, ICW cells require desludging every 5 to 6 

years. For some heavily loaded systems, more frequent desludging appears to be necessary. 

____________________________________________________________________________________________________ 


Since removed sediments contain some elements required for plant growth, they can be seen 

as a resource that can be put to beneficial use. The most appropriate solution would be land 

spreading on a farm in accordance with good farm management practice based on cost and 

feasibility considerations. 

CONCLUSION 

The frequent absence of an artificial liner such as bentonite clay makes ICW technology 

affordable. However, appropriate sediment management is paramount to protect groundwater 

and receiving watercourses during storm events. Wetland designers and operators should 

formally account for sediment accumulation rates. For similar operations, sediments should 

be removed from the first cell of an ICW system after approximately 5-6 years of operation to 

maintain high removal efficiencies. 

REFERENCES 

Kadlec, R. H. & Knight, R. L. (1996). Treatment Wetlands. CRC Press, Boca Raton, Florida. 

Kellner, E., Price, J. S. & Waddington, J. M. (2004) Pressure variations in peat as a result of 

gas bubble dynamics. Hydrological Processes 18(13), 2599–2605. 

Lee, C., Fletcher, T. D. & Sun, G. (2009). Nitrogen removal in constructed wetland systems. 

Engineering in Life Science 9(1), 11–22. 

Scholz, M. (2006). Wetland systems to control urban runoff. Elsevier, Amsterdam. 

Scholz, M., Harrington, R., Carroll, P. & Mustafa, A. (2007). The Integrated Constructed 

Wetlands (ICW) Concept. Wetlands 27(2), 337–354. 

Tokida, T., Miyazaki, T., Mizoguchi, M. & Seki, K. (2005). In situ accumulation of methane 

bubbles in a natural wetland soil. European Journal of Soil Science 56(3), 389–395. 

___________________________________________________________________________ 


CONSTRUCTED WETLANDS AS PART OF ECOSAN SYSTEMS: 10 YEARS OF 

EXPERIENCES IN UGANDA 

Elke Muellegger and Markus Lechner 

EcoSan Club Austria (http://www.ecosan.at) 

elke.muellegger@ecosan.at, markus.lechner@ecosan.at 

INTRODUCTION 

In 1999 the first vertical flow constructed wetland (CW) system was implemented in Uganda. 

It was constructed for St. Kizito Hospital Matany, a rural hospital in Western Uganda. Since 

then, six more CWs (2 horizontal and 4 vertical flow CWs, respectively) have been 

constructed for different institutions scattered all over the county. These seven CW systems, 

sizes ranging from 200 to 1000 person equivalents, are all a component of sustainable / 

ecological sanitation systems. These systems focus on water resources protection, in areas 

where water is very scarce, and reuse of sanitized human excreta and treated wastewater. 

The practise of reuse also bears risks to human beings, animals and the environment. To 

evaluate the actual health risk related to handling and use of treated wastewater and human 

excreta the study "Risk of Reuse - Study on the reuse of treated wastewater and sanitised 

human excreta in Uganda" (Muellegger, 2010) was conducted. Five Ugandan institutions, 

three hospitals, one health centre and one school, were part of this study. These institutions 

are using wastewater and products from human excreta in agriculture. 

The data presented in this paper focus on the performance of the 5 treatment systems (2 

vertical and 2 horizontal flow CWs and 1 waste stabilization pond). The risk assessment, 

which is based on the methodology adopted by the ―WHO Guidelines for the safe use of 

wastewater, excreta and greywater‖ (WHO, 2006), is not described here. 

MATERIALS AND METHODS 

Site descriptions 

Five Ugandan institutions were part of this study: St. Kizito Hospital Matany and Kanawat 

Health Centre, St. Mary‘s Hospital Lacor and Maracha Hospital and Kalungu Girls 

Secondary School. 

St. Kizito Hospital Matany is a rural hospital in the semiarid region of Karamoja, in eastern 

Uganda. The sanitation system is in operation since 1999. Wastewater from flush toilets is 

treated in a vertical flow constructed wetland system (Figure 1), with a capacity of 625 PE. 

The wetland is separated in three individual beds and planted with elephant grass (Pennistum 

purpureum). A three-chamber settling tank serves as wastewater pre-treatment and a 

distribution unit enables an intermittent distribution to the three beds. The treated wastewater 

is collected in a storage tank for irrigation. Furthermore dried sludge from septic tanks and pit 

latrines are used as soil conditioner. Both fractions are only used to fertilise trees. 

____________________________________________________________________________________________________ 


Figure 1. Vertical flow constructed wetland system in Matany Hospital. 

Kanawat Health Centre is located in the north-east of Karamoja. The sanitation system was 

completely replaced 2003 and 2004. Wastewater from flush toilets is treated in a horizontal 

flow constructed wetland system (Figure 2), with a capacity of 30 PE. The bed is planted with 

elephant grass. A three-chamber settling tank is pre-treating the wastewater and a sludge 

drying bed was constructed for sludge from the settling tank. An underground collection tank 

is storing the treated wastewater for irrigation of trees. Staff of the health centre is using urine 

diverting dry toilets, one block with four units. 

Figure 2. Horizontal flow constructed wetland in Kanawat Health Centre. 

Maracha Hospital is a rural hospital in north-western Uganda. The sanitation infrastructure 

was rehabilitated in 2001 / 2002. Wastewater is treated in a vertical flow constructed wetland, 

which has a capacity of 250 PE. The bed is planted with elephant grass. Two intermittently 

fed filter baskets are serving as pre-treatment (Figure 3) and a distribution chamber enables 

an evenly distribution to the beds. Treated wastewater is discharged to the environment. 

Additionally two blocks of urine diverting dry toilets, each with eight toilets, are in use. 

Sludge from the filter baskets and dried faeces from the urine diverting dry toilets are 

composted and used in the hospitals own vegetable garden and sold respectively. 

___________________________________________________________________________ 


Figure 3. Filter baskets as wastewater pre-treatment in Marcha Hospital. 

Kalungu Girls Secondary School is a rural boarding school in the tropical South of Uganda. 

The sanitation system is in operation since 2003. Wastewater is treated in a horizontal flow 

constructed wetland (for 165 PE), planted with elephant grass (Figure 4). The system is 

treating mainly greywater and a small share of blackwater from three flush toilets. The 

collected wastewater is pre-treated in a three-chamber settling tank. After treatment it is 

infiltrated into the ground and not reused as the amount of water is very little. For excreta 

management 45 single vault urine diverting dry toilets for pupils and one for teachers are in 

use. The collected faecal material is further treated in a composting area. Dried faeces and 

urine are used as fertiliser in the school garden. 

Figure 4. Horizontal flow CW in Kalungu. 

Lacor Hospital is a rural hospital in North-Uganda. A conventional pond system (Figure 5) 

for treatment of mixed wastewater is in operation since the 1990 th . In 2005 a ―natural filter‖ 

has been construction, because of insufficient treatment of wastewater. The ―natural filter‖ is 

a fenced area planted with elephant grass, aiming to increase the treatment efficiency of the 

system. Treated wastewater is not used. 

____________________________________________________________________________________________________ 


Figure 5. Inlet into the first pond in Lacor Hospital. 

Determination of quality parameters 

Sampling and analysis 

Grab samples have been taken 6 times between June 2004 and March 2006 from the effluents 

of the CWs. During the first three sampling rounds most of the wastewater parameters were 

analysed directly on spot with field testing equipment. Due to problems of transporting the 

testing equipment by bus, for the last three rounds the majority of parameters were analysed 

in the laboratory of the National Water and Sewage Corporation (Quality Control 

Department; Central Public Laboratories) in Kampala. 

The following physico-chemical parameters have been analysed: COD, BOD5, NH4-N, PO4- 

P, SO4-S, turbidity, pH-value, Electrical conductivity (EC) and temperature. Additionally the 

samples have been analysed for the following heavy metals: cadmium, chromium, copper, 

lead, nickel, zinc. 

Ugandan Discharge Regulation 

For the results of the data collection the Standards for discharge of effluent and wastewater in 

Uganda (Uganda Discharge Regulation, 1999) were used as reference level. Table 1 shows 

the discharge limits considered in this study: 

Table 1. The standards for discharge of effluent and wastewater in Uganda. 

___________________________________________________________________________ 


RESULTS AND DISCUSSION 

Physico-chemical parameters 

Vertical flow constructed wetlands 

Table 2 compares the results of the two vertical flow CWs which are both located in the 

semiarid part of Uganda. The CW in Matany is working since 12 years without problem 

which was confirmed by the low outflow concentrations. The CW in Matany is using a septic 

tank as pre-treatment unit, which is emptied once a year. The Maracha CW, on contrary, had 

continuous problems with the pipe valves of the distribution chamber. This was mainly due to 

the fact that maintenance of the system was neglected. The non-functional pipe valves are 

mainly responsible for a lack of oxygen thus resulting in a higher NH4-N effluent 

concentration. 

Table 2. Results from wastewater analysis of vertical flow CWs. 

Horizontal flow constructed wetlands 

Table 3 compares the results of the two horizontal flow CWs. Both are in operation since 

nearly eight years and are used mainly to treat greywater. The treatment system in Kanawat 

had only problems with too high NH4-N concentrations which could be attributed to 

unplanned urine discharge into the sewer system. The analysis in Kalungu showed very 

unsatisfactory results. The main reason is the instability of the hydraulic load, which 

fluctuates strongly over the year. Especially during holidays, the hydraulic load is reduced to 

a minimum and the wetland oversized. 

____________________________________________________________________________________________________ 


Table 3. Results of wastewater analysis of horizontal flow CWs. 

Vertical flow vs. horizontal flow CW 

The results presented in Tables 2 and 3 demonstrate the expected improved nitrification 

efficiency of vertical flow constructed wetlands. The untypically high NH4-N effluent 

concentration of the Maracha treatment plant is due to maintenance issues. Frequent 

problems with keeping the pipe valve, which controls the intermittent discharge to the filter 

beds, result in insufficiently equal distribution of the wastewater and lack of oxygen supply 

into the soil matrix. 

Pond system 

Table 4 shows the results of the pond system in Lacor. The results show significantly higher 

effluent concentrations for COD, BOD5 and NH4-N in comparison to constructed wetlands. 

Higher COD and BOD concentrations are probably at least partly due to algae which cannot 

be retained in the system (compare the lower COD/BOD ratio compared with constructed 

wetlands as well as higher turbidity) while the higher NH4-N concentration shows insufficient 

supply of oxygen for nitrification. 

Table 4. Results of wastewater analysis of pond system. 

___________________________________________________________________________ 


Heavy metals 

The analysis for heavy metals showed that in most samples the concentration was below the 

Ugandan standards, only few samples exceeded the limits. Scattered higher levels of copper, 

nickel, cadmium and lead have been measured. The main sources of high lead, cadmium and 

nickel concentrations in wastewater are discarded nickel–cadmium (WHO, 2003) and leadacid 

(WHO, 2008) batteries thrown into the toilets. High copper concentrations may cause 

from corrosion of interior copper plumbing, which may occur in standing water in copper 

pipes (WHO, 2008). 

Operation and maintenance (O&M) as key factor for sustainability 

Maximum benefit of an improved sanitation infrastructure can only be achieved when the 

facilities operate continuously and at full capacity in conformity with national standards of 

quantity and quality. In practice, O&M of sanitation systems, especially in developing 

countries, receives less attention compared to the design and construction phases, or it is even 

completely neglected (Muellegger et al. 2010). The CWs in Uganda prove these statements: 

1. Matany Hospital and Kanawat Health Centre have employees who are responsible for 

the CW systems. Beside the regular maintenance works they are also emptying the 

septic tank once a year, resulting in good performing CW systems. 

2. In Maracha Hospital also operators for the sanitation system are employed. However, 

the distribution chambers are not cleaned regularly thus the pipe valves are not 

working, resulting in poor performance. A similar problem exists in Kalungu, where 

the septic tank is not cleaned regularly. 

Recommendations for implementation of CWs in Uganda 

Commonly it is assumed that technical wastewater treatment plants are not applicable for 

(rural areas in) Uganda. The main reasons are unreliable power supply and lack of technical 

capacities for operation and maintenance. Therefore commonly stabilisation ponds are 

designed as a standard solution. However looking at National Standards (Uganda Discharge 

Regulation, 1999) and expected and measured performance of stabilisation ponds it is clear 

that as far as nitrification is concerned these standards cannot be reached. This study 

demonstrates that vertical flow constructed wetlands show a significantly better performance 

and can be a suitable alternative for wastewater treatment in particular for rural areas in 

Uganda. Still even minimal maintenance requirements of a vertical flow constructed wetland 

– in the case of the treatment plant in Maracha the pipe valve for intermittent discharge – can 

pose a problem. 

Nevertheless further research is required when it comes to nitrogen elimination as required 

according to Ugandan National Standards. Furthermore one major issue related to technical 

design is the quality of filter media available locally. While European design guidelines 

generally assume the availability of uniform filter media this is not the case in Uganda. 

Material which is available locally or at least within close vicinity has to be used. A design 

methodology therefore by necessity should take the characteristics of the material into 

consideration rather than assuming a certain quality. 

____________________________________________________________________________________________________ 


References 

Muellegger, E. (2010). Risk of Reuse – Study on the reuse of treated wastewater and 

sanitised human excreta in Uganda. Master thesis, University for Natural Resources and 

Applied Life Sciences, Vienna (BOKU University), Austria. 

Muellegger, E., Freiberger, E., McConville, J., Samwel, M., Rieck, C., Scott, P. 

Langergraber, G., (2010). Operation and maintenance of sustainable sanitation systems. 

Fact sheet SuSanA Working <strong>Group</strong> 10, Sustainable Sanitation Alliance (SuSanA), 

http://www.susana.org. 

Uganda Discharge Regulation (1999). Standards for Discharge of Effluent into Water or on 

Land Regulations, 1999. Statutory Instruments Supplement No.4. 12th February, 1999, 

Kampala, Uganda. 

WHO (2003). Nickel in Drinking-water. Background document for development of WHO 

Guidelines for Drinking-water quality, World Health Organisation, Geneva, Switzerland 

(http://www.who.int/water_sanitation_health/dwq/chemicals/nickel.pdf). 

WHO (2006). WHO Guidelines for the Safe Use of Wastewater, Excreta and Greywater. 

Volume II Wastewater use in Agriculture. World Health Organisation, Geneva, 

Switzerland. 

WHO (2008). Guidelines for Drinking-water Quality. Third edition, incorporating the first 

and second addenda, World Health Organisation, Geneva, Switzerland. 

___________________________________________________________________________ 


AREA AND ENERGY REQUIREMENTS: COMPARISON BETWEEN CEPT-CWL, 

TIDAL FLOW CWL AND FRENCH DESIGN CWL SYSTEMS FOR THE REMOVAL 

OF ORGANICS AND NITROGEN COMPOUNDS 

Eilon Guthman, Sheldon Tarre and Michal Green 

Technion, Israel Institute of Technology, Haifa, 32000 Israel 

Background 

In smaller communities the environmental friendly, low cost and long-lived technology of 

constructed wetlands becomes more and more important. However, the large land demand 

with the accompanying water loss and increased salinity due to the high evaporation rate 

typical to Mediterranean countries, limit the application of this technology, especially when 

effluent re-use is practiced or desired. Moreover, while the efficiency of constructed wetlands 

in the removal of BOD and TSS is very high, nitrogen removal in most of the present 

generation of operating wetland systems (predominantly horizontal flow beds) is deficient, 

mainly because of poor nitrification due to insufficient oxygen supply. Treated domestic 

wastewater without nutrient removal can be beneficial for agricultural use, but unfortunately, 

this water cannot be released uncontrolled to the environment due to their negative effect on the 

environment: eutrophication, contamination of groundwater, ammonia toxicity, etc. In Israel 

where currently about 70% of the wastewater produced is reclaimed for agricultural reuse, a 

new standard for unrestricted irrigation, known as Inbar regulations have been approved 

(Inbar, 2007). Among others, the regulations dictate (average values): COD=100 mg/l; 

TSS=10mg/l; TN=25 mg/l; NH4-N=20 mg/l; Total P=5 mg/l. 

Having in mind the main disadvantages of extensive systems in general and constructed 

wetlands (CWL) specifically, i.e. large land requirements, water loss and increased salinity 

and poor nutrients removal, and in order to comply with the Israeli Inbar regulations, a new 

CEPT-CWL system was investigated. This system is characterized by the main advantages of 

extensive systems (constructed wetlands) including simplification; cost effectiveness; and 

reliability, with the additional important advantages of nutrients (N, P) removal and minimal 

land requirement. The system consists of chemically enhanced primary treatment (CEPT) that 

significantly reduces the organic load on the succeeding units, followed by the use of 

constructed wetland units for nitrification and denitrification with recirculation between the 

two units. In addition to reducing the organic load, the removal of COD and suspended solids 

by CEPT results in an effluent with a C to N ratio more suited for nitrification and less prone 

to wetland clogging. The process is characterized by low energy input since the oxygen 

requirement for the removal of the organic matter is minimized (most of the residual COD is 

used as the electron donor for denitrification). 

This article focuses on the area and energy requirements of the CEPT-CWL system in 

comparison to two other well known CWL system variations claiming nitrogen removal: the 

‗tidal flow‘ wetland system (nitrification and denitrification) (Austin et al., 2003, 2006) and 

the ‗French design‘ system (nitrification with minimal denitrification) (Molle et al., 2008; 

Molle et al., 2005). 

____________________________________________________________________________________________________ 


The ‘French design’ system 

The pulse fed two stage vertical flow constructed wetland (VFCW) for the treatment of raw 

sewage is the most commonly design found in France for CWL (several hundreds of plants). 

The first stage in the VFCW is divided into three filters (one active bed and two under rest 

conditions receiving no flow), and the second stage is divided into two filters (one under 

resting conditions). All 5 filters are of equal area. Oxygen transfer occurs passively. Average 

values for the French small communities‘ wastewater are: COD= 733 mg/l; TSS=280 mg/l; 

and TKN= 87 mg/l (Molle et al, 2005). The above configuration allows more than 90% 

removal of COD and TSS, and about 85% nitrification, but only about 20% denitrification 

(Molle et al., 2005). 

The ‘tidal flow’ system 

The ‗tidal flow‘ system, designed for pre-settled wastewater, is comprised of multiple flood 

and drain (tidal) wetland cells where a flood and drain regime allows for efficient oxygen 

transfer. The cells‘ aggregate is characterized by a high CEC (>4 meq/100g) to allow for 

NH4 + adsorption. Nitrification occurs in drained wetland cells while denitrification occurs in 

flooded wetland cells. A model system with a flow rate of 1000 m 3 /d was evaluated by 

Austin and Nivala, (2009) with influent wastewater characteristics of 300 mg/L COD, 60 

mg/L TN. The system was based on three paired CW cells with reciprocating pumped flow in 

each cell pair and overflow drain to the next cell pair in series. The first stage rotates between 

three paired cells in parallel to allow for a rest phase (two pairs under rest conditions). The 

system achieves reliable tertiary treatment performance, with effluent BOD, TSS and TKN 

all about 10 mg/L. Design effluent ammonia is less than or equal to 1.0 mg/L. 

The CEPT–CWL system 

In the CEPT–CWL system, raw wastewater is pretreated with CEPT using a low dose of 

FeCl3 (10-13 mg/l) followed by a dual unit CWL. During the CEPT stage, removals of 69%, 

79% and 60% for CODT, TSS and P, respectively, were obtained resulting in effluent with 

average values of 230mg/L CODT; 73mg/L TSS; 2.3 mg/L PO4-P and 61 mg/L NH4-N. The 

large reduction in COD and suspended solids from the wastewater by CEPT allows for a 

much smaller CW footprint for the following treatment step. In addition, the phosphorus 

concentration of the CEPT effluent using a low dose of FeCl3 was much lower than that 

required by the Inbar regulations, leaving only residual COD and ammonia to be treated. The 

first bed of the dual unit CWL treating CEPT effluent is an anoxic saturated subsurface 

horizontal flow CW and the second bed is an unsaturated aerobic vertical flow CW similar to 

the French design described above. The two beds are interconnected by recirculation and the 

recycle to influent feed ratio is 2:1. 

Comparison of the Area and Energy requirements 

The comparison was based on a daily organic loading rate of 1 PE or 120 g COD/day and 

only operational electrical energy requirements were considered. 

___________________________________________________________________________ 


The ‘French design’ system. Based on results from hundreds of systems for small 

communities in France, 2 square meters are required per PE (120g COD, 150 liter, 10-12 g 

TN), i.e. 2 m 2 /120g COD or 60 gram per square meter per day. For more diluted wastewater 

where the hydraulic loading rate (HLR) becomes the limiting factor to allow for the required 

oxygen transfer, it is recommended that the HLR should not exceed 0.75m/day on the active 

cell (Molle et al., 2005). In the comparison made here, the area requirement was determined 

based on the organic loading rate as the limiting factor, typical for systems treating raw 

wastewater (COD>700 mg/l). As for the energy requirement, since the flow in the ‗French 

design‘ systems is designed for gravitation (slope site), zero energy is needed. 

The ‘tidal flow’ system. As outlined by Austin and Nivala (2009), a typical tidal system 

treating 1000 m 3 /day (300 mg/L COD, 60 mg/L NH4-N) requires an area of 5,000 m 2 . As in 

the French design system, the area required for the tidal system is one square meter per 60 

gram of COD per day. The design is based on COD loading limitations to avoid clogging 

from the growth of heterotrophs (first stage COD loading rate of 0.1 kg COD/m 2 /day). For 

the ‗tidal flow‘ wetland process, the energy requirement is the sum of the energy required for 

the pumps moving the wastewater from cell to cell. The calculated energy demand is 211 kW 

hr/day or 0.211 kW hr/m 3 as calculated by Austin and Nivala using the following equations: 

q� � � g � �H 

Ph 

� 

6 

3.6�10 Ph 

Ps 

� 

� 

p 

Ps 

Pe 

� 

� 

m 

where Ph is the hydraulic power, kW; Substituting in q = pump flow rate, m3/h; g = 9.81 

m/sec 2 ; ρ = 1000 kg/m 3 ; ΔH = total dynamic head, m; Ps is the Shaft power, kW; ηp is the 

pump efficiency (0.75); Pe is the electrical power, kW; ηm is the motor efficiency (0.9). 

The CEPT-CWL System: With regard to the CEPT-CWL system where the CEPT is 

followed by two CWL units with a recirculation ratio of 2:1, the same area as in both the 

‗French‘ and ‗tidal flow‘ designs of 1 m 2 for 60 g COD/day was required to achieve the 

desired (Inbar) effluent quality with regard to COD, NH4 and TN (Guthman et al., 2010). 

The energy requirement was calculated in the same manner as for the ‗tidal flow‘ system. 

The energy requirement for the CEPT–CWL system was found to be 0.037kWhr/m3 where 

the main difference is the much lower recirculation rate. The results of the comparison are 

given in Tables 1 and 2. 

Summarizing, the new generation of constructed wetlands will have to be designed to meet 

stricter regulations with the removal of nutrients. The relatively small footprint vertical flow 

CWL systems have already proved their ability for highly efficient nitrification. However, 

for complete inorganic nitrogen compounds removal energy input for recirculation is 

essential unless a prohibitive large area is used for denitrification. 

____________________________________________________________________________________________________ 


It is important to note that CEPT-CWL and ‗tidal flow‘ systems allow for much higher HLR 

(a direct result of recirculation) in comparison to that in the French system, because of the 

efficient denitrification (nitrate as the electron acceptor for a significant fraction of the 

influent COD). Due to the denitrification, oxygen demand is lower and therefore the lower 

oxygen transfer rates at higher HLR are permissible. 

Table 1. Effluent quality in each of the three treatment systems and the Israeli standard for 

unlimited irrigation 

Parameter (mg/l) New Israel standard CEPT-CWL ‗Tidal Flow‘ ‗French design‘ 

for unlimited 

VFCWL 

irrigation 

(Treating raw 

wastewater) 

COD 100 29.8±4.4 10 66±13 

TN* 25 9.41±2.1 8 

** 

68 

NO3 as N — 14.1±2.5 7 55 

NH4 as N 20 0.8±0.5 1 13 

TP 5 2.3±1.7 

*** 

TSS 10 0.6 14±5 

OLR (g COD/m 2 /d) 60 60 60 

N load (g N/m 2 /d) 12 12 6 

*TN=NO3-N + NH4-N; **assuming 25% denitrification; *** 40% reduction; from (Molle, 2005). 

Table 2. Summarized results of the area and energy requirements for the three treatment 

systems 

System Area 

m 2 Energy consumption 

/PE/day kWhr/m 3 Performance 

influent 

French design 2 0 High effluent TN due to limited denitrification. 

Tidal flow 2 0.211 High effluent quality with regard to TN, COD and 

TSS. Effluent complies with the Israeli standard 

for both: river discharge and unlimited 

irrigation, except for P concentration 

CEPT-CWL 2 0.037 High effluent quality with regard to COD, TSS, N 

compounds and P, complying with the Israeli 

standard for unlimited irrigation 

___________________________________________________________________________ 


References 

Austin D.C., Lohan E. and Verson E. (2003) Nitrification and denitrification in a tidal 

vertical flow wetland pilot. In: Proceedings of the WEFTEC 2003 National Conference, 

76th Annual Conference and Exhibition, Water Environment Federation, Alexandria, 

Virginia. 

Austin D.C (2006) Influence of cation exchange capacity (CEC) in a tidal flow, flood and 

drain wastewater treatment wetland. Ecol. Eng. 28(1), 35–43. 

Austin D.C. and Nivala J. (2009) Energy requirements for nitrification and biological 

nitrogen removal in engineered wetlands. Ecol Eng. 35(2), 184–192. 

Guthman E., Shachnai A., Beliavski M., Tarre S. and Green M. (2010) Wastewater treatment 

for unrestricted reuse: a decentralized, low cost and simple to operate system based on 

CEPT and constructed wetlands. In: Proceedings of the 12th IWA Conference for Wetland 

Systems for Water Pollution Control, Venice, Italy. 

Inbar, Y. (2007) New standards for treated wastewater reuse in Israel. In: Wastewater Reuse 

– Risk Assessment, Decision-Making and Environmental Security, M.K. Zaidi (ed.), 

Springer, pp.291–296. 

Molle P., Lienard A., Boutin C. and Iwema A. (2005) How to treat raw sewage with 

constructed wetlands: an overview of the French systems. Water Science & Technology 

51(9), 11–21. 

Molle P., Prost-Boucle S. and Lienard A. (2008). Potential for total nitrogen removal by 

combining vertical flow and horizontal flow constructed wetlands: a full-scale experiment 

study. Ecol. Eng. 34(1), 23–29. 

____________________________________________________________________________________________________ 


DESIGN AND PERFORMANCE OF THE WETLAND WREATMENT SYSTEM AT 

THE BUFFALO NIAGARA INTERNATIONAL AIRPORT 

Scott Wallace and Mark Liner 

Naturally Wallace Consulting, Vadnais Heights, Minnesota, USA 

(scott.wallace@naturallywallace.com, mark.liner@naturallywallace.com) 

Abstract 

The wetland treatment system at the Buffalo Niagara International Airport has been in 

operation for two years now, and represents one of the major applications of intensified 

wetlands for treatment of glycol-based deicing fluids. The full-scale system is designed to 

remove 4,500 kg/d of biochemical oxygen demand (BOD5). The wetland design was based 

on pilot testing conducted in 2007, which established degradation rate coefficients for both 

aerated and non-aerated modes of operation. 

Aeration was found to profoundly affect treatment performance. When aerated at 0.85 m 3 

air per hour (per m 3 of wetland bed), the volumetric (2TIS) BOD5 removal rate constant 

averaged 5.4 day −1 with a temperature coefficient (θ) of 1.03, based on experiments 

conducted at 22°C and 4°C. In contrast, the non-aerated wetland had a rate coefficient of 

0.55 day −1 . 

Operation of the full-scale system during the 2009/2010 deicing season revealed nutrientlimited 

conditions that resulted in polysaccharide slime formation within the wetland bed. A 

system for nutrient addition was updated and expanded for the 2010/2011 deicing season, 

which resulted in successful operation at BOD5 loadings of over 20,000 kg/d, which is 

almost five times greater than the original design. During the 2010/2011 deicing season, 

BOD5 removal averaged 98.3%. 

Keywords 

aircraft deicing, airport, ethylene glycol, propylene glycol, intensified wetland, subsurface 

flow wetland 

INTRODUCTION 

In addition to other contaminants found in stormwater and snowmelt at airports (e.g., fuel & 

lubricant residuals, oil & greases, airport stormwater runoff contains large amounts of aircraft 

de-icing fluids during periods when de-icing and anti-icing operations are carried out. The 

ADFs may be ethylene glycol (EG), or propylene glycol (PG) based and are applied as water 

solutions The volumes of de-icing fluids used depend on weather conditions and the type of 

aircraft involved (Higgins and Maclean, 2002). 

Controlling and treating stormwater runoff from airport facilities is a matter of increasing 

environmental concern and is now having a major effect on the design and operation of 

airports. Within the United States and Canada, new regulatory standards are being 

implemented for the management of de-icing fluids used to remove ice from aircraft during 

winter operations. Preferred chemicals are EG and PG, which in the 50% concentrations 

commonly used for aircraft de-icing and anti-icing, has a BOD5 of approximately 

200,000 mg/L. Although this is diluted by ice-melt, BOD5 concentrations in excess of 

20,000 mg/L are common. These high influent concentrations, combined with the inherently 

variable nature of winter storms and the low temperature of de-icing runoff, challenges the 

operation of conventional mechanical treatment plants. 

___________________________________________________________________________ 


Constructed wetlands are an attractive option for treatment of deicing runoff, because when 

operated in a subsurface mode, the risk to airfield operations is minimal and the systems 

require much less operation & maintenance than conventional systems. 

PILOT TESTING 

Pilot testing was carried out at Campus D‘Alfred of the University of Guelph in Ontario, 

Canada. . The tests were carried out indoors in 1 m 3 vessels configured as mixing tanks 

(containing mixers and heaters), open aerated basins (AB cells, simulating aerated tanks and 

containing fine bubble aeration spargers), non-aerated vertical subsurface flow (VSSF) 

constructed wetland cells and aerated VSSF intensified (IW) test cells. The wetland cells 

were vegetated with common reed (Phragmites sp.) taken from ditches near the test unit. Test 

runs were preceded by month-long calibration and acclimatization periods. 

The pilot facility was configured as a mixing tank; two open-water AB cells; one non-aerated 

VSSF CW cell containing gravel 0.3 m deep and; and two aerated gravel-bed VSSF 

intensified wetland cells (IW1 and IW2) containing gravel 0.8 m deep. There were two 

separate sets of cells which, after initial calibration and acclimation periods at room 

temperature, operated in parallel at the two design basis target temperatures. The set-up for 

high temperature operations consisted of a mixing tank and an AB cell followed by parallel 

CW and IW cells. (These were considered as two separate trains.) The set up for low 

temperature operations consisted of an AB Cell and one IW cell in series. These latter two 

vessels were located inside a walk-in refrigerator at the Alfred Pilot Unit (Train 3). The initial 

configuration of the pilot facility is shown in Figure 1. 

SW from 

Storage Tanks 

ADF 

Mixing Tank 

AB Cell 

Lo Temp 

AB Cell 

Hi Temp 

Walk-in Refrigerator 

IW Cell 

Lo Temp 

CW Cell 

Hi Temp 

IW Cell 

Hi Temp 

Figure 1. Pilot test facility schematic 

Train 3 



Results from the four testing periods (Runs A, B, C, D) and the three process trains (Trains 1, 

2, 3) are summarized in Table 1 (Wallace et al., 2007). 

____________________________________________________________________________________________________ 


Table 1. Average BOD5 concentrations (mg/L); percent removal is listed in parenthesis 

Run Mixing 

Tank 

Influent 

Train 1 Train 2 Train 3 

AB Effluent 

High Temp. 

IW Effluent 

High Temp. 

AB Effluent 

High Temp. 

CW Effluent 

High Temp. 

AB Effluent 

Low Temp. 

IW Effluent 

Low Temp. 

A 1,491 542 (64) 8 (99) 542 (64) 212 (61) 649 (56) 27 (96) 

B 1,524 Not Used 56 (96) 257 (83) 119 (54) 679 (55) 21 (97) 

C 773 Not Used 25 (7) 177 (77) 29 (84) 325 (58) 10 (7) 

D 694 Not Used 4 (99) 130 (81) 34 (74) Not Used 24 (97) 

Since the different treatment trains were operated at different flow rates and temperatures, 

inspecting percent removals based on concentration (as summarized in Table 2) does not 

provide a complete understanding of treatment performance. The data were analyzed using a 

tanks-in-series (TIS) flow model using a relaxed parameter, P (Kadlec and Wallace, 2009) 

that accounts not only for the number of tanks but weathering of the BOD5 as the PG 

degraded into daughter products. 

Calculated rate coefficients for the aerated IW cells for the high temperature runs are 

summarized in Table 2, based on a flow model with P = 2 (this is an approximate value based 

on previous tracer testing of aerated intensified wetland cells): 

Table 2. Aerated intensified wetland rate coefficients for high temperature runs 

Average BOD5 (mg/L) 

Run Influent Effluent 

A 542.3 7.5 9.15 

B 1,524.0 55.7 5.17 

C 773.0 25.0 5.60 

D 694.0 4.0 14.84 

Average 8.69 

k2TIS(d −1 ) 

The higher results from Run D where the aeration rate was increased from 0.85 m 3 air per 

hour (per m 3 of wetland bed) to 2 m 3 of air per hour indicate that even further improvement 

of treatment could be possible. A similar set of BOD5 IW rate coefficient calculations were 

made for the low temperature operations and these are presented in Table 3: 

Table 3. Aerated intensified wetland rate coefficients for low temperature runs 



A 648.8 26.5 4.81 

B 679.3 21.0 5.72 

C 325.0 10.3 5.63 

D 694.0 23.5 5.41 

Average 5.39 

k2TIS(d −1 ) 

For Runs B and C, the data can be used to determine the Arrhenius constant, θ, based on the 

following equation: 

�T �20� 

k �k � 

T 

20 

where kT is the rate constant at temperature T = T°C and k20 is the rate constant at 20°C. 

Based on these results, the value of θ was calculated to be approximately 1.03. 

___________________________________________________________________________ 


The BOD5 removal rate coefficients for the non-aerated CW cell were also calculated based 

on a flow model with P = 4. A higher value of P was assumed because there is less internal 

mixing in non-aerated cells. Results are summarized in Table 4: 

Table 4. Non-aerated constructed wetland rate coefficients for high-temperature runs 



A 542.3 212.3 0.68 

B 257.0 119.0 0.27 

C 177.0 29.0 0.73 

D 129.5 33.5 0.51 

Average 0.55 

k2TIS(d −1 ) 

NUTRIENT LIMITATIONS 

Operation of the full-scale treatment wetland indicated that nutrient-limited conditions 

occurred during the 2009/2010 de-icing season, since propylene glycol (C3H8O2) and 

ethylene glycol (C2H6O2) do not contain nitrogen, phosphorus and other nutrients. The 

nutrient demands for bacterial growth can be estimated using the factors summarized in 

Table 5. 

Table 5. Approximate nutrient requirements for bacterial growth (Grady et al., 1999) 

Nutrient Approximate nutrient requirement 

(g/kg of biomass produced) 

Nitrogen 85 

Phosphorus 17 

Potassium 10 

Calcium 10 

Magnesium 7 

Sulfur 6 

Sodium 3 

Chloride 3 

Iron 2 

Zinc 0.2 

Manganese 0.1 

Copper 0.02 

Molybdenum 0.004 

Cobalt < 0.0004 

One major unknown parameter in treatment wetlands is the yield ratio of microbial growth, 

which can be defined as the fraction of the influent biochemical oxygen demand (BOD) 

converted to microbial biomass. For suspended-growth activated sludge systems, this 

parameter can be easily measured and is often quite high; in the range of 1.0 to 0.7. 

Treatment wetlands are attached-growth systems with a very long solids retention time where 

microbial predation would presumably substantially reduce the yield ratio. In one study of a 

pilot-scale, fill-and-drain subsurface flow wetland, the yield ratio was estimated to be 0.068 

(Austin et al., 2007). With such a low yield rate, this would imply that treatment wetlands 

would not require large amounts of nutrients to maintain a mature microbial community 

under steady-state conditions. 

____________________________________________________________________________________________________ 


Although the Buffalo design had anticipated the need for nutrient addition, establishment of 

effective treatment was slow, and the system began to experience foaming associated with the 

formation of polysaccharide slimes by the resident bacteria. Foaming and slime formation is 

known to occur at wastewater treatment plants subject to severe nutrient limitations (Arias et 

al., 2008; Ayati and Ganjidoust, 2008). 

Owing to the observed slime formation at Buffalo, estimates on the yield ratio had to revised 

upwards, and was finally estimated by the authors to be at least 0.3. This had profound 

implications on the rate of nutrient addition, as the Buffalo wetland was designed to process 

4,500 kg/d of BOD; a yield ratio of 0.3 implies 1,350 kg/d per day of microbial biomass 

production. Based on the information in Table 5, this amount of biomass production would 

require 115 kg/d of nitrogen and 23 kg/d of phosphorus, in addition to micronutrients. After 

feeding the appropriate amount of nutrients, slime formation ceased and treatment 

performance improved dramatically. 

FULL-SCALE OPERATION 

Operation of the full-scale treatment wetland was continued through the 2010/2011 de-icing 

season (with improved nutrient addition). The full-scale system consists of four subsurface 

flow wetland beds (saturated vertical downflow), each sized at 4,640 m 2 with a bed depth of 

1.5 m. The distribution piping is buried under an insulating level of compost such that no 

water is exposed during the treatment process (Figure 2). 

Figure 2. Full-scale treatment wetland at Buffalo Niagara International Airport. 

The subsurface vertical flow wetlands have an internal array of aeration tubes to enhance 

oxygen transfer as a means of intensification. The enhanced oxygen transfer rate allows for 

the aerobic degradation of glycol compounds. Each wetland can be supplied with air up to 

140 m 3 /min, which allows an oxygen transfer rate approximately 60 times greater than what 

would be supplied through passive atmospheric diffusion. 

___________________________________________________________________________ 


During the 2010/2011 de-icing season, influent BOD5 concentrations were in excess of 

15,000 mg/L. Generally, the system had very low effluent values, which averaged 77 mg/L 

(based on a correlation between online total organic carbon measurements and laboratory 

BOD5 values), as shown in Figure 3. 

Figure 3. Influent and effluent BOD5 values for the intensified wetland at Buffalo Niagara 

International Airport. 

The wetland system also experienced BOD5 loadings well in excess of the original design 

parameters. While the design was based on a BOD5 loading rate of 4,500 kg/d, actual 

loadings exceeded 20,000 kg/d. BOD5 removals remained in the range of 90 to 100% (with 

an average removal rate of 98.3%), and reductions in treatment efficiency were only observed 

at the heaviest organic loadings (Figure 4). 

Figure 4. BOD5 loadings and treatment efficiency for the intensified wetland at Buffalo 

Niagara International Airport 

____________________________________________________________________________________________________ 


CONCLUSIONS 

The Buffalo Niagara system has demonstrated that aerated, intensified subsurface flow 

wetlands are a viable technology for treatment of deicing runoff at airport facilities. The 

Buffalo system was successfully scaled up from pilot testing results, and has demonstrated 

high levels of treatment effectiveness even when subjected to organic loadings well in excess 

of the original design parameters. 

The Buffalo Niagara wetland has served as a template for the upgrade and refurbishment of 

existing treatment wetlands at London‘s Heathrow airport and the airport facility in 

Edmonton, Alberta. However, the Buffalo facility has also demonstrated that nutrient 

limitations in deicing runoff can be a significant impediment to treatment of deicing runoff, 

and that nutrient addition is necessary to reach the full potential of wetland treatment 

systems. 

REFERENCES 

Arias, C.A., Vollersten, J., Lange, K.H., Pedersen, J., Hallager, P., Bruus, A., Laustsen, A., 

Bundensen, V.W., Nielsen, A.H., Nielsen, N.H., Wium-Andersen, T., Hvitved-Jacobsen, 

T., Brix, H. (2008). Integrating constructed wetland filters and wet detention ponds for the 

treatment of urban stormwater runoff. In: Proceedings of the 11th International 

Conference on Wetland Systems for Water Pollution Control, 1-7 November 2008. Billore 

S.K., Dass P., Vymazal J. eds. Vikram University and IWA: Indore, India. pp. 781. 

Austin, D.C., Maciolek, D.J., Davis, B.M., Wallace, S.D. (2007). Damköhler number design 

method to avoid clogging of subsurface flow constructed wetlands by heterotrophic 

biofilms. Water Science and Technology 56(3), 7–14. 

Ayati, B., Ganjidoust, H. (2008). Investigation of pollution sources in Anzali reserved 

wetland. In: Proceedings of the 11th International Conference on Wetland Systems for 

Water Pollution Control, 1–7 November 2008. Billore S.K., Dass P., Vymazal J. eds. 

Vikram University and IWA: Indore, India. pp. 116-122. 

Higgins, J.P., Maclean, J. (2002). The use of a very large constructed sub-surface flow 

wetland to treat glycol-contaminated stormwater from aircraft de-icing operations. Water 

Quality Research Journal of Canada 37(4), 785–792. 

Kadlec, R.H., Wallace, S.D. (2009). Treatment Wetlands, second edition. Boca Raton, 

Florida: CRC Press. 

Wallace, S.D., Higgins, J., Liner, M.O., Diebold, J. (2007). Degradation of aircraft deicing 

runoff in aerated engineered wetlands. In: Multi Functions of Wetland Systems: An 

International Conference, 26-29 June 2007. University of Padova and International Water 

Association: Padova, Italy. 

___________________________________________________________________________ 


TREATMENT OF SISAL WASTEWATER USING CONSTRUCTED WETLANDS IN 

TANZANIA 

Nuru R. Mziray (Ph.D) 

University of Dar es Salaam, College of Engineering and Technology, P.O. Box 35131, 

Dar es Salaam, Tanzania. E-mail: nururessa@gmail.com 

Investigation of the sisal wastewater treatment by using constructed wetland was undertaken 

from October, 2007 to April, 2008 at Highlands Sisal Estate located in Coast Region of 

Tanzania. Two subsurface flow constructed wetlands (CW1- planted with Phragmites 

mauritianus and CW2-unplanted) of equal size (0.6 m long, 0.4m wide and 0.4 m high) were 

receiving pre-treated sisal wastewater from a Dynamic Roughing Filter (DRF) unit (0.42m 

long, 0.4m wide and 0.4 m high) at a continuous flow rate of 0.01 m 3 /day. For all three units 

gravels obtained from a nearby quarry, namely Msolwa were used as substrate (particle size 

ranged from 10-30 mm).The hydraulic retention time of the DRF and CW were 2 hrs and 7 

days, respectively. The system was operated at a water depth of 0.34 m leaving a freeboard 

allowance of 0.06 m and this system was used to treat only 1% of the wastewater produced 

per day but it can be scaled up in future research. 

Effluent samples were taken for analysis of BOD5, TSS and Turbidity (APHA, 2000) so as to 

quantify the treatment efficiencies. The respective observed percentage of pollutants removal 

for DRF, CW1 and CW2, were: BOD5 -30.96, 71.24 and 52.61; TSS- 35.04, 74.70 and 67.47; 

Turbidity- 34.65, 49.09 and 46.25. 

By using Stella II software (STELLA®8.1.1) and data from CW1 and CW2, a model for 

removal of organic carbon in the CW was developed, calibrated and validated. Model results 

indicated that the main processes for removal of organic carbon were uptake by plants and 

growth of heterotrophic bacteria (uptake), oxidation and sedimentation. The model developed 

can be used for predicting the future performance of the ecosystem. 

This study concluded that the use of subsurface flow constructed wetlands for treatment of 

pre-treated sisal wastewater is feasible (Mashauri et al., 2004). There was good performance 

in treatment of important parameters such as pH, BOD5, TSS and Turbidity (Brandon, 1949; 

Mponzi, 2005). However, it is recommended that for optimization of system treatment 

performance with respect to BOD5 and TSS removal, a primary treatment system need to be 

used prior to the CW in order to meet acceptable Tanzanian wastewater discharge standards, 

which are 30 mg/l and 50 mg/l, respectively. 

____________________________________________________________________________________________________ 


Inflow 

wastewater 

in open 

channel 

Screen Tank 

DRF 

Outflow 

in open 

channel 

Figure 1. Schematic diagram of the treatment system at Highlands sisal estate in Coast region, 

Tanzania. 

A B 

CW1 

CW2 

Figure 2. (A) Sisal decorticator and (B) sisal fibres at Highlands sisal estate in Coast region, Tanzania. 

A B 

Figure 3. (A) sisal wastewater and (B) Constructed wetlands for treatment of sisal wastewater at 

Highlands sisal estate in Coast region, Tanzania. 

___________________________________________________________________________ 


References 

APHA (2000). Standard Methods for the Examination of Water and Wastewater, 21st 

edition, American Public Health Association, Washington DC, USA. 

Brandon, T.W. (1949). Treatment and disposal of wastewaters from decortications of sisal. 

Journal of the East African Agriculture, 15. 

Mashauri D.A., Mbwette , T.S.A. and Kayombo, S. (2004). Report of field trip on 16th to 

19th December, 2004 to investigate the potential sites for constructed wetland units. 

‗‗Research project: Integrated Cost-effective Eco-Techniques for purification of 

wastewater‘‘, University of Dar es Salaam, Tanzania. 

Mponzi, S.A. (2005). Management of Wastewater from Sisal Processing Industry. 

Dissertation submitted for partial fulfilment of the requirement for the award of Bachelor 

of Science degree in environmental engineering of University College of lands and 

architecture studies, Tanzania. 

____________________________________________________________________________________________________ 


WETLAND FOR WATER POLLUTION CONTROL IN CHINA: 

RECENT EXPERIENCES 

J. Zhai, H.W. Xiao, J. Liu 

Chongqing University, Faculty of urban construction and environmental engineering, 

Chongqing 400045, P. R. China 

E-mail: zhaijun@cqu.edu.cn; xiaohaiwen99@163.com; liujiede87@yahoo.com.cn 

Environmental protection has aroused increasing awareness from citizens and government 

officials in china. Based on the current underdeveloped economic situation and low energy 

consumption concept, the wastewater treatment technologies with low investment and 

operation cost are favourable in China. Wetland, as a treatment technology with low 

construction and operation cost and great aesthetical value, has great potential on water 

pollution control. In recent years, more and more wetlands have been constructed in china. 

Generally, two types of wetlands are constructed in china, one is constructed wetland, and the 

other is converted natural wetland. Constructed wetland is usually utilized for urban 

municipal wastewater and rural wastewater treatment, polluted landscape water purification 

or non-point pollution control. Converted natural wetland is mostly used for purifying the 

runoff, buffering flood peak, creating the inhabitancy for creatures, and improving the urban 

ecological environment. And it is generally constructed into Wetland Park. This report 

presents a brief review of constructed wetlands (CWs) and converted natural wetlands 

(CNWs) applied in China in the last three years. 

1. Constructed wetlands 

Seven newly constructed wetlands in China are introduced in this report. The basic 

information for each of them, including the name and location, influent, and treatment 

capacity for the seven CWs, is illustrated in table 1. And table 2 lists the treatment process, 

HLR, plants in wetlands, and occupation area etc. 

From the two tables, the influent for all the CWs can be classified into three kinds, the urban 

municipal and rural wastewater for secondary treatment, the effluent of WWTP for advanced 

treatment, and the polluted landscape water. The CWs were all constructed between 2008 and 

2011, and the type of CW is all hybrids CW except Jiaoling CWs. The treatment capacity for 

the landscape water is the largest, for the municipal and rural wastewater is smaller and for 

the effluent of WWTP is smallest. 

CWs for urban municipal and rural wastewater treatment are widely used in china in the past 

three years. Because domestic wastewater accounts for most of the wastewater, the influent 

of urban wastewater and rural wastewater is not constant in quality and quantity, in which the 

concentration of SS is very high and organics are very low. Normally in south china, the 

indexes for urban wastewater are BOD/(mg.L −1 ) 55–153, COD/(mg.L −1 ) 78–578, 

SS/(mg.L −1 ) 22–541, NH3-N/(mg.L −1 ) 13–28, TN/(mg.L −1 ) 18–31, TP/(mg.L −1 ) 3–9. In most 

applied cases, the effluent can meet the requirements of Discharge Standard ClassⅠB 

(GB18918-2002)(COD 60 mgL −1 ; BOD 20 mg.L −1 ;SS 20 mg.L −1 ; NH3-N/(mg.L −1 ) 8; 

TN/(mg.L −1 ) 20; TP/(mg.L −1 ) 1) or even higher standard after treating by CWs. The treatment 

process of CWs includes stabilization pond or aeration pond, HSSF CW and VSSF CW etc. 

___________________________________________________________________________ 


CW is not only utilized for treating wastewater, but also for treating the effluent of WWTP, 

such as the Kunming sport center CWs and Chengbei CWs. According to the previous study 

result, CWs for advanced treatment can pose a good effect on removal of COD, NH3-N, TN, 

and Persistent organic pollutants etc. Generally, water quality for the effluent can be much 

better than the effluent without the CWs treatment. The general treatment process is 

Stabilization pond, FWS CW, and HSSF CW etc. CW has also been used as an advanced 

treatment technology to treat the effluent of some industrial wastewater, and the further 

removal effect for some kinds of leather wastewater and plating wastewater has been 

confirmed in china. 

As an ecological treatment technology, CW plays a positive role in urban landscape water 

purification in china, such as Jiuxi CWs, in Yuxi city, Yunnan province. The raw water is full 

of blue-green algae. The HLR for CW is 0.67 m 3 .m −2 .d −1 , which is quite high. It is also the 

largest CW with packing in the world, in which is filled with 150,000 m 3 gravels. The 

effluent water quality is quite good, all the indexes except NH3-N and P can meet the 

requirements of National Grade III of Surface Water Ambient Quality Standard, and the 

removal rate of blue-green algae is up to 99%. The treatment process, Stabilization pond, 

FWS CW, and HSSF CW, is also simple and effective. The project eliminates the danger of 

the portable water safety for Yuxi city. 

The function of CW in china has been diverse in the last three years. CW will be more and 

more used in decentralized wastewater treatment system, non-point pollution prevention, and 

industrial wastewater advanced treatment in the future. The hybrid CWs have been preferred, 

and which are usually combined with pretreatment and post-treatment. CWs constructed in 

urban area or communities have been in conformity with landscape, which is a plus for 

aesthetic value. In a word, the further scientific study and increasing design and operation 

experience for CW will push the wide utilization of CW in china. 

Figures 1 to 5 show some details of these CWs, the Fig 1 to Fig 5 successively corresponds to 

No.1 to 5 in Tables 1 and 2. 

Fig 1a. Fish of Kunming sport center CWs 

Fig 2a. Aeration tank of Zhouzhi CWs 

Fig 1b. Plants of Kunming sport center CWs 

Fig 2b. HSSF CW of Zhouzhi CWs 

____________________________________________________________________________________________________ 


Fig 3a. VSSF CW of Nankeng CWs 

Fig 4a. Waterfall aeration of Jiuxi CWs 

Fig 5a. Baffle CW in pre-operation period of 

Qinghe village CWs 

Fig 3b. HSSF CW of Nankeng CWs 

Fig 4b. HSSF CW of Jiuxi CWs 

Fig 5b. HSSF CW in pre-operation period of 

Qinghe village CWs 

Table 1. Basic information for seven CWs in China 

No. Name and Location Influent of CW 

CW 

type 

1 Kunming sport center CWs, Effluent of WWTP Hybrid 

Kunming, Yunnan province 

CWs 

2 Zhouzhi CWs, Xi‘an, Shanxi Municipal wastewater Hybrid 

province. 

CWs 

3 Nankeng CWs, Pingxiang, Municipal wastewater mixed Hybrid 

Jiangxi province. 

with non-point pollutants CWs 

4 Jiuxi CWs, Yuxi, Yunnan Lake water purification Hybrid 

province. 

CWs 

5 Qinghe village CWs, Chongqing Rural wastewater treatment Hybrid 

CWs 

6 Chengbei CWs, Wuxi, Jiangsu Effluent of WWTP Hybrid 

province 

CWs 

7 Jiaoling CWs, Meizhou, Municipal wastewater HSSF 

Guangdong province 

CWs 

Treatment 

capacity/m 3 .d −1 

2,000 

11,000 

5,000 

100,000 

___________________________________________________________________________ 


1500 

2,000 

10,000

Table 2. Process characteristics and design parameters for seven CWs in China 

No. Treatment process HLR/ 

m 3 m −2 d −1 

Occupation 

area/m 2 

Plants Time for 

completion 

1 Stabilization pond, 

0.50 4,000 Typha spp., Zizania caduciflora, 

2008.10 

FWS CW, HSSF CW 

Nymphaea tetragona, Eichornia crassipes 

2 Aeration tank, 

0.40 33,335 Phragmites australis, Typha spp., Scirpus 2010.05 

sedimentation tank, 

validus, Acorus calamus, Lythrum 

VSSFCW, HSSF CW 

salicaria 


0.56 9,000 Cyperus alternifolius, Eichhornia 2009.07 

HSSF CW, VSSF CW 

crassipes, Lythrum salicaria, Acorus 

calamus 


0.67 150,000 Cyperus alternifolius, Eichhornia 2008.05 

HSSF CW, VSSF CW 

crassipes, Arundo donax var, Versicolor, 

Pennisetum hybridum 


0.19 7,960 Phragmites australis, Cyperus 

2011.01 

Baffle CW, HSSF 

CW, observation pond 

alternifolius, Eichhornia crassipes 

6 Aeration tank, FWS 0.29 6,900 Typha spp., Phragmites australis, Canna 2008.05 

CW,VSSF CW, 

stabilization pond 

indica, Nymphaea tetragona, 

7 Aeration–flocculation 0.57 17,400 Phragmites australis, Cyperus 

2009.01 

tank, HSSF CW 

alternifolius, Arundo donax 

HLR, hydraulic load rate; the same number in Table 2 and Table 1 refers the same wetland. 

2. Converted natural wetlands 

Natural wetland, which is referred to as ―kidney of the Earth‖, is an area between land and 

water natural ecosystems. A great large number of natural wetlands are widely located in 

China. It is counted that natural wetlands in China accounts for 10% of the world. As china 

joined ―Convention on Wetlands‖, Urban Wetland Park as a converted natural wetland has 

been applied in a lot of Chinese cities. Since Chinese government encourages constructing 

Wetland Park in 2005, over 41 national wetland parks have been approved to build up to 

now. Fig 6 to 13 shows some details of the constructed National Urban Wetland Parks. The 

basic information for them can be detected in table 3. 

Take the Kunshan Urban Wetland Park for example, which is located in the west of Kunshan 

city in Jiangsu province. It has total area of 200 hectares, 58 hectares of which is water, and 

10 hectares is mud flat. The previous fish ponds, depression, and wasteland are fully utilized 

in the wetland park. The influent of the wetland park is purified through a series of physical, 

chemical and biological processes in reed marshes. Trees in the wetland function very well in 

water conservation, maintenance of regional water balance, regulation of regional climate, 

degradation of pollutants, conservation of biological diversity and landscaping surroundings. 

After constructed, the wetland park has insignificantly purified the water, increased the 

diversity of plants and animals, and beautified the urban environment. Especially in wild 

water birds, the kinds and numbers have been increased year by year. Currently, there are 57 

family 98 genus and 131 species plants and 70 kinds of wetland birds in the wetland park, 

which has been a good inhabitancy for plants and animals. 

As the urban wetland park has been successfully applied in some cities, they can become 

good study cases and provide more beneficial experience for the future ones. A lot of urban 

wetland parks will be built up in china, not only in big cities, but in medium and small cities. 

____________________________________________________________________________________________________ 


Fig 6. Kunshan National Urban Wetland Park 

Fig 8 .Bailu island Lake National Urban Wetland Park 

Fig 10. Lotus Lake National Urban Wetland Park 

Fig 12. Gucheng Lake National Urban Wetland Park 

Fig 7. Kongmu River National Urban Wetland Park 

Fig 9. Huaxi National Urban Wetland Park 

Fig 11. Qunli National Urban Wetland Park 

Fig 13. Weishui National Urban Wetland Park 

___________________________________________________________________________ 


Table 3. the basic information of the constructed National Urban Wetland Parks in China 

No Name and location 

Occupation area/ 

hectares 

Time of 

completion 

1 South Lake National Urban Wetland Park, Baicheng, Jilin province 356 2008.06 

2 Kunshan National Urban Wetland Park, Jiangsu province 200 2008.06 

3 Kongmu River National Urban Wetland Park, Xinyu, Jiangxi province 1564 2008.06 

4 Lvtang River National Urban Wetland Park, Zhanjiang, Guangdong province 34 2008.06 

5 Kanyang Lake National Urban Wetland Park, Taizhou, Zhejiang province 595 2009.12 

6 Pingxi Lake National Urban Wetland Park, Pingdingshan, Henan province 660 2009.12 

7 Bailu Island National Urban Wetland Park, Pingdingshan, Henan province 90 2009.12 

8 Huaxi National Urban Wetland Park, Guiyang, Guizhou province 460 2009.12 

9 Chengbei National Urban Wetland Park, Zhangye, Gansu province 4133 2009.12 

10 Lotus Lake National Urban Wetland Park, Tieling, Liaoning province 484 2009.12 

11 Qunli National Urban Wetland Park, Haerbin, Heilongjiang province 34 2009.12 

12 Bairang oasis National Urban Wetland Park, Weifang, Shandong province 1000 2010.07 

13 Gucheng Lake National Urban Wetland Park, Nanjing, Jiangsu province 6882 2011.01 

14 Weishui National Urban Wetland Park, Changyi, Shandong province 363 2011.01 

15 Xinlin Bay National Urban Wetland Park, Xiamen, Fujian province 3160 2011.01 

____________________________________________________________________________________________________ 


<strong>Specialist</strong> Symposium: Bringing Together Science and Policy to Protect and Enhance 

Wetland Ecosystem Services in Agricultural Landscapes. 

Rotorua, New Zealand 

Thursday, 22 September 2011 

in association with the 15 th IWA International Diffuse Pollution and Eutrophication 

Conference 

Symposium sponsored by the OECD Co-operative Research Programme 

Organisers: Chris Tanner and Clive Howard-Williams 

Wetland ecosystems operate at the cusp of hydrological and ecological functioning of 

agricultural landscapes. They provide a critical suite of ecosystem services to regulate 

and stabilize stream flow, intercept and attenuate diffuse pollutants, enhance 

biodiversity and nutrient cycling, sequester carbon, and provide aesthetic, spiritual, 

and recreational benefits for human culture. However, agricultural development has 

led to the drainage, degradation and loss of many wetlands that were once part of 

agricultural landscapes across the globe. Land pressures from human populations and 

the need to increase food production make it difficult to implement policies that 

restore wetland ecosystems. Yet, wetlands have the potential to provide critical 

services that directly provide security and livelihood for societies, such as mitigation 

of flooding and eutrophication of lakes and coastal waters that provide important 

recreational and fishery resources. Therefore it is critical to bring together science and 

policy to ensure that the ecosystem services provided by wetlands are properly 

recognized and appropriate efforts made to create, protect, and restore wetlands as 

integral components of sustainable agricultural landscapes. 

This symposium will contribute to the sustainable management of agricultural 

landscapes by evaluating scientific understanding of ecosystem services accruing 

from wetlands in agricultural landscapes, and identifying policy approaches that 

support or deter appropriate wetland creation, restoration and protection. Sponsorship 

by the OECD Co-operative Research Programme has enabled a team of renowned 

experts from around the world to contribute to this Symposium: They include: 

� Prof. Edward Maltby, University of Liverpool, UK 

� Dr Bruna Gumiero, Bologna University, Italy 

� Dr Peter Groffman, Cary Institute of Ecosystem Studies, USA 

� Dr Richard Lowrance, USDA-ARS, USA 

� Dr George Lukacs, James Cook University, Australia 

� Prof. William Mitsch, The Ohio State University USA 

� Ms Shona Myers, Wildland Consultants, New Zealand 

___________________________________________________________________________ 


Dr Yosihiro Natuhara, Nagoya University, Japan 

Dr Chris Tanner, NIWA, New Zealand 

Dr Mark Tomer, USDA-ARS, USA 

Prof. Jos Verhoeven, Utrecht University, Netherlands 

Dr Stefan Weisner, Halmstad University, Sweden 

Mr Landon Yoder, The Environmental Law Institute, USA 

For further information please visit the conference website: 

http://on-cue.co.nz/dipcon/Wetlands%20Symposium.html 

____________________________________________________________________________________________________ 


THE CONSTRUCTED WETLAND ASSOCIATION 

The Constructed Wetland Association (CWA) is a professional association, representing all 

those who are interested in, and practising in the field of constructed wetland technology, The 

CWA promotes the application of Constructed Wetland technology for water pollution 

control including wastewater treatment, surface water run-off management, habitat 

enhancement and protection of our natural water resources. The CWA aim to provide quality 

assurance, establish and maintain the highest standards of design, installation, performance 

and maintenance of these systems through research, training, seminars, conferences, peer 

review and accreditation. 

The concept of the Constructed Wetland Association was initiated between David Cooper 

from ARM Ltd and Paul Cooper from WRc and discussed with Eric May from Portsmouth 

University at the 1998 IAWQ Wetland Conference in Brazil. During the 1990s, several 

international conferences established who the specialists involved in the development of 

wetland technology in the UK and internationally were. At that time this was a new 

technology and there were no established commercial practitioners. The Water Research 

Council (WRc) and water companies had resolved to monitor development of the technology 

in the UK and it seemed sensible to explore the possibility of concurrently developing an 

association of those who were already involved and those who were contemplating the 

development and exploitation potential of wetland technology. After several meetings, the 

CWA was fully established in early 2000 with the help of donations from Severn Trent and 

ARM Ltd. The CWA has now been going for 11 years and our members include students, 

academics, researchers, NPOs, companies and individual practitioners as well as those who 

have a general interest in constructed wetlands. 

Constructed wetlands continue to be a popular choice for a range of applications and take-up 

of the technology across Europe and other parts of the world is now quite extensive. As a 

result our experience of their design, operation and capabilities continues to grow. The CWA 

holds an annual conference. Last year‘s event even attracted speakers and delegates from 

across the globe including Jan Vymazal (Prague University/NGO ENKI), Scott Wallace 

(Naturally Wallace, USA), Paul Griffin (Severn Trent), Carlos Arias (Aarhus University, 

Denmark), Steen Nielsen (Orbicon, Denmark) and Stuart Widdowson (Coal Authority). The 

conference included a site visit to a number of wetlands. Paul Griffin from Severn Trent gave 

a really informative tour of their systems and was happy to discuss operational problems and 

practical solutions. Andrew MacDonald from Anglian Water gave a tour of the final 

constructed wetland in Welton. Delegates were shown the range of sites from those that had 

been recently renovated to those which were suffering from a high degree of clogging. This 

was a really practical interesting visit which was of real benefit to designers, installers and 

operators of wetland systems. 

This year‘s conference aims to share and promote best practice in the many applications for 

constructed wetlands in both the domestic and industrial sectors. As part of the conference, 

delegates will be taken on a tour of a treatment wetland onsite which was designed by the 

Coal Authority to treat mine water. Speakers at this year‘s events include Severn Trent, 

Cranfield University, ARM Ltd, Naturally Wallace, Aarhus University, Halcrow <strong>Group</strong> Ltd, 

WWT and Water Course Systems, and the Coal Authority. 

___________________________________________________________________________ 


Further details of this year‘s conference and programme can be found here: 

http://www.aquaenviro.com/images/stories/aett/conferencebrochures/cwa%20brochure%202 

011.pdf 

Further information about the CWA can be found at www.constructedwetland.co.uk or 

contact the CWA secretary at clodagh.murphy@armgroupltd.co.uk 

CWA Delegates at Fenny Compton sewage treatment works (Severn Trent), UK. 

Scott Wallace from Naturally Wallace presenting at the CWA conference in 2010. 

____________________________________________________________________________________________________ 


Paul Griffin (Severn Trent) giving an informative guided tour of Severn Trent‘s reed bed 

treatment. 

___________________________________________________________________________ 


NEWS FROM IWA HEADQUARTERS 

IWA Development Congress – Pioneering Water Solutions in Urbanising Areas 

21–24 November 2011 

Kuala Lumpur, Malaysia 

Low and middle income countries face unprecedented challenges to supply water and 

sanitation services to their citizens and to manage the entire water cycle wisely. Yet, tackling 

these challenges also provides them with significant opportunities to innovate, strengthen 

service provision and create new businesses. 

The IWA Development Congress aims to accelerate the uptake of these innovations to have 

impact at scale. It does so by bringing together utilities, NGOs, technology suppliers decision 

makers, scientists and engineers to share, debate and learn about pioneering solutions to 

urban water challenges. Be part of the solution and join us in Kuala Lumpur. Visit the 

Congress website for more information. 

www.iwa2011kl.org 

____________________________________________________________________________________________________ 


New from IWA – the IWA Water Wiki! 

Invitation to Participate 

www.iwawaterwiki.org 

The WaterWiki is a website providing a place for the water community to interact, share 

knowledge and disseminate information online. 

Since the site was launched, we have been working with IWA <strong>Specialist</strong> <strong>Group</strong>s, offering them the 

opportunity to set up their own group work spaces on the WaterWiki – we now have over 20 <strong>Group</strong>s 

using the site to communicate and network online. 

Want to get involved? We would like to invite members of the The use of macrophytes in water 

pollution control <strong>Specialist</strong> <strong>Group</strong> to set up their own private <strong>Group</strong> Space on the Wiki. 

WaterWiki <strong>Group</strong> Spaces – Why participate? 

Establishing a <strong>Group</strong> Space on the WaterWiki is excellent way share information within your group. 

You can: 

- Include contact details of key members in the group 

- Upload PDFS, Word documents, presentations etc. 

- Circulate minutes from meetings, events, conferences etc. 

- Plan upcoming events and webinars 

- Discuss research developments and group activities 

Once you have established your group space on the Wiki, members can add, remove, or edit 

content at anytime – and we have a dedicated support team on hand to answer any technical 

queries. 

If you are a member of the The Use of Macrophytes in Water Pollution Control IWA <strong>Specialist</strong> 

<strong>Group</strong> and would like to establish a <strong>Group</strong> Space on the WaterWiki, please contact Victoria Beddow 

(vbeddow@iwap.co.uk). 

Call for Contributions – New articles 

We are currently looking for new articles in your subject area. If you are able to write on any of the 

following subjects (about 600-1000 words), please do contact us: 

Biological Treatment Processes; Engineering and design; Pollution monitoring and control; Public 

participation in Environmental Management; Constructed ecosystems. 

Victoria Beddow 

IWA WaterWiki Community Manager 

vbeddow@iwap.co.uk 

___________________________________________________________________________ 


____________________________________________________________________________________________________ 


NEW FROM IWA PUBLISHING 

Southeast Asian Water Environment 4 

Editor: Kensuke Fukushi 

ISBN: 9781843393627 

September 2010 • 280 pages • Paperback 

IWA Members price: £ 73.50 / US$ 132.30 / € 99.23 

http://www.iwapublishing.com/template.cfm?name=isbn9781843393627 

This is the fourth volume in the series of books on the Southeast Asian water environment. 

The most important articles presented at the Sixth and Seventh International Symposiums on 

Southeast Asian Water Environment have been selected for this book. It covers water environment 

management, biological and physico-chemical processes in water and wastewater treatment, 

monitoring approaches, and water related health issues. This publication is the result of building an 

academic network among researchers of related fields from different regions to exchange 

information. 

This book will be an invaluable source of information for researchers, policy makers, NGOs, NPOs, 

and those who are concerned with achieving global sustainability within the water environment in 

developing regions. 

----- 

Treatment of Micropollutants in Water and Wastewater 

Authors: Jurate Virkutyte, Rajender S. Varma, Veeriah Jegatheesan 

ISBN: 9781843393160 

August 2010 • 520 pages • Hardback 



Over the last few years there has been a growing concern over the increasing concentration of 

micropollutants originating from a great variety of sources including pharmaceutical, chemical 

engineering and personal care product industries in rivers, lakes, soil and groundwater. As most of 

the micropollutants are polar and persistent compounds, they are only partially or not at all 

removed from wastewater and thus can enter the environment posing a great risk to the biota. It is 

hypothesized that wastewater is one of the most important point sources for micropollutants. 

Treatment of Micropollutants in Water and Wastewater will also enable readers to make 

well informed choices through providing an understanding of why and how micropollutants must be 

removed from water sources, and what are the most appropriate and available techniques for 

providing a cost and technologically effective and sustainable solutions for reaching the goal of 

micropollutant-free water and wastewater. 

This title belongs to Integrated Environmental Technology Series 

----- 

___________________________________________________________________________ 


Environmental Technologies to Treat Nitrogen Pollution 

Authors: Francisco J. Cervantes 

ISBN: 9781843392224 

Jul 2009• 432 pages • Hardback 



Environmental Technologies to Treat Nitrogen Pollution provides a thorough understanding of the 

principles and applications of environmental technologies to treat nitrogen contamination. The 

main focus is on water and wastewater treatment, with additional coverage of leachates and offgasses. 

The book brings together an up-to-date compilation of the main physical, chemical and biological 

processes demanded for the removal of nitrogenous contaminants from water, wastewater, 

leachates and off-gasses. It includes a series of chapters providing a deep and broad knowledge of 

the principles and applications required for the treatment of nitrogen pollution. Each chapter has 

been prepared by recognized specialists across the range of different aspects involved in the 

removal of nitrogenous contaminants from industrial discharges. 

This title belongs to Integrated Environmental Technology Series 

----- 

Water Technology: 

An Introduction for Environmental Scientists and Engineers 

Third Edition 

Author: N. F. Gray 

ISBN: 9781843393030 

July 2010 • 600 pages • Paperback 



Water science and technology is one of the world's largest and most interdisciplinary industries, 

employing chemists, microbiologists, botanists, zoologists as well as engineers, computer specialists 

and a range of different management professionals. 

This accessible student textbook covers the key concepts of water science and technology by 

explaining the fundamentals of water quality and regulation, policy and management, 

hydrobiology, water treatment and drinking water supply, and wastewater treatment. 

� The Water Framework Directive is the unifying theme for this new edition. 

� Deals with water quality assessment, management and treatment 

� Includes a new chapter on sustainability within water technology 

Co-Published with Elsevier/Butterworth Heinemann 

----- 

____________________________________________________________________________________________________ 


Sediments Contamination and Sustainable Remediation 

Authors: Catherine N. Mulligan, Masaharu Fukue and Yoshio Sato 

ISBN: 9781843393009 

February 2010 • 359 pages • Hardback 



The surface water environment can be considered to be an important part of 

the geo-environment. It is the recipient of not only liquid discharges from 

surface run-offs, rivers and groundwater but also waste discharges from land-based industry, 

municipal and other anthropogenic sources. It is also a vital element in the geo-environment that 

provides the base for life support systems and is a significant resource. The combination of these 

two large factors, with their direct link to human population, makes it an integral part of the 

considerations on the sustainability of the geo-environment and its natural resources. A healthy 

ecosystem ensures that aquatic plants and animals are healthy and that these do not pose risks to 

human health when they form part of the food chain. 

This book discusses the threats to the health of the sediments resulting from discharge of 

pollutants, excessive nutrients and other hazardous substances from anthropogenic activities. It 

examines the impacts observed as a result of these discharges including the presence of hazardous 

materials and the phenomenon of eutrophication. It also examines the remediation techniques 

developed to restore the health of the sediments and how to evaluate the remediation technologies 

using indicators. 

Co-Published with CRC Press 

----- 

Analytical Measurements in Aquatic Environments 

Editors: Jacek Namiesnik and Piotr Szefer 

ISBN: 9781843393061 

October 2009 • 503 pages • Hardback 



Over the past twenty years, the knowledge and understanding of wastewater treatment have Even 

a cursory perusal of any analytical journal will demonstrate the increasing important of trace and 

ultra-trace analysis. And as instrumentation continues to develop, the definition of the term "trace 

element" will undoubtedly continue to change. Covering the composition and underlying properties 

of freshwater and marine systems, Analytical Measurements in Aquatic Environments 

provides the basis for understanding both. It discusses all aspects of analytical protocols from the 

handling of representative samples to the metrological evaluation of specific steps and whole 

procedures. 

Ecotoxicological considerations and the effort to achieve an increasingly accurate description of the 

state of the environment challenge analytical chemists who need to determine increasingly lower 

concentrations of various analytes in samples that have complex and even non-homogenous 

matrices. The newly coined expression "analytics" emphasizes the interdisciplinary nature of 

available methods for obtaining information about material systems, with many methods that 

___________________________________________________________________________ 


exceed the strict definition of analytical chemistry. Drawing on the disciplines of chemistry, 

physics, computer science, electronics, material science, and chemometrics, this book provides in 

depth information on the most important problems in analytics of samples from aquatic 

ecosystems. 

Co-Published with CRC Press 

----- 

SELECTED RESEARCH REPORTS 

Improving the Efficacy of Wastewater-Polishing Reed Beds 

WERF Report DEC11U06 

Author(s): Thaddeus K. Graczyk 

Publication Date: 01 Dec 2011 • ISBN: 9781843395317 

Pages: 20 


Modeling Onsite Wastewater Systems at the Watershed Scale: A User's Guide 

WERF Report 04-DEC-6 

Authors: John McCray, Eileen P Poeter, Kyle E Murray, David S Morgan 

Publication Date: September 2009 • ISBN: 9781843395287 

Pages: 180 • Paperback 



----- 

For more information on IWA Publishing products or to buy online visit 

www.iwapublishing.com. Or contact one of IWA Publishing‘s distributors: 

UK, Europe and Rest of World: 

Portland Customer Services 

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Email: order@bookmasters.com 

____________________________________________________________________________________________________ 


IWA Head Office: 

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General e-mail: water@IWAhq.org 

___________________________________________________________________________

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