Anti-biofouling effect of thin film nanocomposite membrane with functionalized carbon nanotube blended polymeric support layer

Abstract

In this research, we focus on the analysis of anti-biofouling effect of thin film nanocomposite (TFC) membrane with functionalized carbon nanotube blended polymeric support layer to determine the potential of application in forward osmosis (FO) and pressure retarded osmosis (PRO) process. We fabricated thin film nanocomposite membranes with functionalized carbon nanotube to mitigate microorganism attachment and growth on surface of membrane. Fabricated membranes are characterized by SEM, FTIR, Contact angle, AFM, Zeta potential analysis. Anti-biofouling effect of fabricated membrane is analyzed by attachment test, biofouling test in cross flow. In previous researches, carbon nanotube has been used to reduce biofouling by incorporating in active layer. However, in this study, we analyzed anti-biofouling effect of carbon nanotube incorporating in support layer of TFC membrane. The fabricated nanocomposite membrane with 0.5wt% fCNT has enhanced anti-biofouling property compared to bare TFC membrane in PRO mode - low roughness, high negative surface charge, hydrophilicity. Bacteria attachment on membrane decline approximately 35% compared to bare TFC membrane in PRO mode. In lab scale biofouling test, fCNT0.5-TFC membrane shows less flux decrease compared to bare TFC membrane. This biofouling reduction is due to the less accumulation of bacteria on membrane surface due to anti-biofouling property of membrane. Therefore, this research shows fCNT composite TFC membranes have high potential in overcoming the current biofouling problem in PRO process with increased water flux. Even so, complexity of anti-biofouling mechanism makes it hard to clarify main factor of anti-biofouling effect, it requires further study to understand main mechanism for anti-biofouling effect on fCNT composite TFC membrane. Also, weather antimicrobial property of fCNT inhibits bacteria growth or not.