Surface modified polymeric membranes to reduce (bio)fouling: a microbiological study using E. coli Original Research Article

Membrane (bio)fouling is the main problem during an operation of membrane elements for water treatment processes. In an attempt to reduce a bio(fouling) affinity, commercial polyvinilidene fluoride (PVDF) microfiltration membranes (Millipore) were surface modified via photoinitiated graft polymerisation with quatemized 2-(dimethylamino) ethyl metacrylate (gDMAEM) or 2-acrylamido-methyl-propane sulfonic acid (AMPS) as functional monomers. Membranes with different degrees of modification were obtained by varying the time of polymerisation and concentration of the monomer solution. Another set of PVDF membranes was modified using interfacial polymerisation between polyethyleneimine (PEI) and toluene diisocyanate. The affinity of modified membranes to biofouling was studied using E. coli bacteria. It was found that membrane samples modified with gDMAEM as well as with PEI have a strong bactericide effect towards E. coli. The possible mechanism of antimicrobial action of modified membranes has been discussed.