NAMS 2002 Workshop - ICOM 2008

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