Preface - kmutt

KMUTT Annual Research Abstracts 2005
extract phenol derivatives from an aqueous
solution, was based on logP values. The logP
value of the hydrophobic solvent must be equal
or lower than the logP of phenolic compound to
be exacted. As a proof of principle test, 4-
chlorophenol was partitioned from aqueous
solution into a nitrobenzene electrode coating
and then oxidized at single wall carbon
nanotubes (SWNT) which were adsorbed on the
glassy carbon electrode. This was reduced the
fouling which usually occurs at glassy carbon
and enhanced the oxidation current. The
oxidation current to a 20 µM 4-chlorophenol
solution at the SWNT suspended in nitrobenzene
modified glassy carbon electrode was 1.02 µA
compared with 0.30 µA at an electrode modified
by only nitrobenzene and 0.09 µA at an unmodified
electrode. The detection limited and
sensitivity to 4-chlorophenol of SWNT
suspended in nitrobenzene modified electrode
was 3 x 10 -10 M and 6.60 x 10 -9 AM -1
respectively.
IC-343 DUAL BIOSENSOR FOR THE TOTAL
CONCENTRATION DETERMINATION OF
PHENOLS
Patsamon Rijiravanich, Mithran Somasundrum,
Werasak Surareungchai
The International Conference on
Bionanotechnology : A New Chapter of Life
(BioThailand 2005), November 2-4, 2005,
Queen Sirikit National Convention Center,
Bangkok, Thailand, p. 24
Phenolic compounds are considered as
an acute problem in environment. However, the
measurement of total phenols concentration with
an enzyme biosensor is failure. A biosensor for
total phenol determination was investigated,
based on a dual enzyme electrode. Three types
of enzyme, polyphenol oxidase (PPO), laccase
(LAC) and horseradish peroxidase (HRP), were
studied. PPO and LAC were immobilized by
electropolymerization of poly (pyrrole) on a
platinum electrode. HRP was bound by the
sequential immobilization of sulfonic thiol, HRP
and polystyrene sulfonate (PSS) onto a gold
electrode. The steady-state response of each
enzyme electrode was noted while varying
enzyme loading, rate of convection and pH.
Eight phenol derivatives were screened by each
biosensor. The different enzymes showed
different amperometric responses to the different
derivatives. Hence, a dual-biosensor, based on
197
PPO- and HRP-modified electrodes, was used
for total phenols measurement. The biosensor
could determine total phenol concentration in a
mixture of two to four derivatives with standard
error of 0.18 to 1.95 using, the proposed
mathematics model. However, passivation by
quinone derivatives limited the sensor stability.
IC-344 WATER MINIMIZATION IN THE
TAPIOCA STARCH PRODUCTION
INDUSTRY: A DECISION SUPPORT SYSTEM
Natthakan Rungraeng, Kanchana Saengchan,
Annop Nopharatana, Warinthorn Songkasiri
Starch Update 2005 : The 3 rd Conference on
Starch Technology (BioThailand 2005),
November 4-5, 2005, Queen Sirikit National
Convention Center, Bangkok, Thailand, p. 325
A Typical tapioca starch manufacturing
process consumes freshwater approximately 10
to 30 m 3 per ton of starch produced. The amount
of water consumption can be reduced
considerably by the recycle of wastewater. This
research utilizes a water pinch technology as a
tool to minimize water consumption in the
starch production process. The water pinch
decision support system, called the W-Pinch
program, was generated by the Starch
Engineering and Process Optimization (SEPO)
Program, King Mongkut's University of
Technology Thonburi (KMUTT). The W-Pinch
modelling system includes 7 composition
balances of water, starch, protein, pulp, sand,
peel, and sulfur. Water composition is correlated
to freshwater and wastewater calculations and
the moisture content of the product. Starch and
pulp compositions demonstrate the extractor
efficiency. Peel, sand, protein, and sulfur
compositions are the control parameters to
monitor and control the final product quality
after applying the water recycling patterns.
Each composition stream was balanced
for each unit in the starch production process,
i.e., root receiver, washer/cutter, rasper/grinder,
coarse extractor, fine extractor, separator I,
separator II, separator III, centrifugal dewater
unit, and flash dryer. A user inputs the removal
efficiency of each component and the maximum
allowable concentrations of each composition at
that specific unit into the W-Pinch input file.
Five recycling patterns were designed to
evaluate the water minimization in the starch
process. All the water streams do not require
the water treatment ire the reuse of water. In
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