Photocatalysis and PMS activation caused by CuO/TiO2 photocatalyst coated on PVDF membrane for mitigating membrane fouling

Abstract

BackgroundOne direction to mitigate membrane fouling is to create anti-fouling photocatalytic membranes. The photocatalysts’ hydrophilicity reduces the interaction of the membrane with hydrophobic foulants and the photocatalysis decomposes membrane fouling. Another noteworthy point is that PMS (peroxymonosulfate) can be activated by photocatalysts to decompose foulants and membrane fouling more intensely. MethodsThe CuO/TiO2 was prepared by deposition of Cu(OH)2 onto TiO2 followed by heat treatments. Their catalytic performances were tested by the degradation of Acid Blue 260 by photocatalysis and PMS activation. The best CuO/TiO2 was then coated onto PVDF membranes through a PAA binding layer. Their antifouling performance was examined through simulated foulants such as sodium alginate. The photocatalysts and membranes were characterized using FTIR, SEM-EDS, TEM, XRD, BET, UV–Vis DRS, XPS, ESR, and AFM. Significant FindingsThe CuO/TiO2 possessed a lower bandgap, high surface area (60.7 m2/g), and low particle sizes (30–60 nm). The 25%CuO/TiO2 possesses the highest photocatalytic degradation efficiency of 39.0% under UV irradiation; further PMS activation caused the removal efficiency to reach 90.0%. The degradation efficiency by the membrane was 100% after five cycles. The membranes indicated a decrease of 18.9% in water flux but remained very high. The membrane flux recovery ratio (FRR) was 98.8%.