Mitigation of membrane fouling in dye wastewater using a ternary WO3/CNT/ZnO composite photocatalytic membrane

Abstract

The membrane filtration has been widely utilized in the water reclamation due to its simplicity in operation and outstanding separation performance. Nevertheless, the membrane filtration always suffers from the fouling issue which deteriorate the permeability of membrane. This study targeted to diminish the membrane fouling using a photocatalytic membrane. A ternary tungsten trioxide/carbon nanotube/zinc oxide (WO3/CNT/ZnO) composite photocatalyst was applied to form a ternary WO3/CNT/ZnO composite photocatalytic membrane via a wet processing technique. The highest efficiency to photodegrade methylene blue (MB) were obtained using the M5 ternary composite photocatalytic membrane. The presence of CNT and WO3 intensifies the photocatalysis in the ternary photocatalytic membrane to degrade MB. The ternary composite photocatalyst in membrane form displayed a competitive effectiveness in degrading MB when compared to particle form. The ternary composite photocatalytic membrane demonstrated a decreased permeation flux, accompanied by an increased rejection toward the MB when increasing the loading of ternary composite photocatalyst in the photocatalytic membrane. The analysis on the antifouling behaviour of the ternary composite photocatalytic membrane showed that approximately 95% of flux recovery ratio (Rfr) and 5% of irreversible fouling ratio (Rif) were obtained.