Membrane biofouling control using polyvinylidene fluoride membrane blended with quaternary ammonium compound assembled on carbon material

Abstract

Widespread applications of membrane technology call for the development of antibiofouling membranes. For the in-situ membrane surface modification, the antibiofouling efficacy is always hindered by the inefficient presence of antimicrobial agents on membrane surface since they are blended with the polymers and distributed into the bulk membrane matrix. In this study, a compatible carbon carrier was adopted to assemble the quaternary ammonium compound (QAC@Carbon) for enhancing its surface segregation of polyvinylidene fluoride (PVDF) microfiltration membranes and simultaneously controlling QAC release, thereby improving the efficiency in mitigating biofouling. The results indicated that carbon carrier was capable of driving surface segregation of QAC without deteriorating the physicochemical properties of membranes. The QAC concentration on surface of the membrane modified by QAC@Carbon (MCQ) was 2.5-fold of membrane blended with QAC alone (MQ). Meanwhile, carbon carrier was capable of improving QAC stability in membrane matrix to ensure a lasting antibiofouling efficacy for engineering applications. Batch tests clearly exhibited that both MCQ and MQ had antibiofouling efficiency, while MCQ membrane under cross-flow filtration demonstrated better antibiofouling behaviors compared to MQ. This is mainly attributed to the reduced accumulation of microbial biomass and improved membrane physicochemical properties (higher permeability and porosity) compared to MQ. These findings highlight the potential of introducing QAC@Carbon into polymeric membranes as an effective strategy for fabricating antibiofouling membranes.