Effect of surface properties of reverse osmosis membranes on biofouling occurrence under filtration conditions

Biofouling of reverse osmosis (RO) membranes, which occurs as a result of biofilm growth following initial bacterial adhesion, is well known as one of the most serious problems. Although membranes with surfaces resistant to bacterial adhesion are expected to have higher resistance to biofouling as well, our recent study reported that membrane surface properties have no significant relationship with biofouling under no filtration condition (Lee et al., 2010 [27]). The purpose of this study is to investigate the effects of surface properties of RO membranes (hydrophobicity, surface charge, and roughness) on biofouling under a lab-scale cross-flow RO membrane system using three commercial RO membranes with different surface properties. This study reports that the extent of biofouling, which was demonstrated through flux decline with time, appeared to remain constant despite the apparent difference in surface properties among the three commercial RO membranes selected. As a result, it seems that surface properties of RO membrane have no relationship with biofouling occurrence.

► Biofouling process is different from organic fouling.
► Surface properties of RO membrane appear to have no relationship with biofouling.
► Modified surface properties might be limited for biofouling control of RO membrane.