Enhancing the Anti-biofouling Properties of Polyethersulfone Membrane Using Chitosan-Powder Activated Carbon Composite

Biofouling is one of the major challenges of membrane technology in water and wastewater treatments. In this work, we investigated the potential of chitosan/chitosan powder activated carbon (PAC) composite to reduce biofouling of membrane. Polyethersulfone (PES) membrane was modified with chitosan/chitosan-PAC composite and the performance of the modified membrane in river water treatment was evaluated. The effect of different concentration of polymer [(chitosan: 2.0% (w/v), 1.0% (w/v), 0.5% (w/v), 0.1% (w/v), and chitosan-PAC composite: 1.5% (w/v) − 1.0 (w/v), 0.5% (w/v) − 0.2% (w/v)] on the membrane performance was examined. The properties of the modified membrane such as roughness, morphology, surface functional groups wettability, swelling ration and contact angle were analyzed. The membrane water flux increased with increasing chitosan concentration from 0.1% (w/v) (7.36 mL/cm² m) to 1.0% (w/v) (9.46 mL/cm² m), but decreased at (2.0 w/v) (5.30 mL/cm² m). However, the water flux for chitosan-PAC-modified membrane was about 6.86 mL/cm² m, which was slightly lower than unmodified membrane (7.36 mL/cm² m). The chitosan-modified membrane resulted in 28% reduction in total coliform bacteria while the chitosan-PAC-modified membrane reduced 45% of the total coliform bacteria. These results indicated that chitosan and chitosan-PAC composite could enhance the anti-microbial properties of PES membrane, which would prevent biofilm formation during water treatment.