Hybrid adsorption–photocatalysis properties of quaternary magneto-plasmonic ZnO/MWCNTs nanocomposite for applying synergistic photocatalytic removal and membrane filtration in industrial wastewater treatment

Abstract

A new multifunctional filtration membrane was prepared by twofold advantages of conventional polymeric-membrane as the supporting layer and magneto-plasmonic Ag-doped ZnO@Fe3O4/MWCNTs nanocomposite as the functional layer. Poly acrylic acid (PAA)-modified polyamide (PA) discs (PAA-PA) were applied to increase the hydrophilicity of prepared membrane and X-Ray diffraction (XRD) and scanning electron microscopy (SEM) techniques were used for characterization. The grafting yield of PAA in the pores and on the surface of PA was 17 wt.% and weigh difference between PAA-PA membrane before and after modifying with the photocatalyst was 8.7 mg. The amount of photocatalyst loading in the prepared membrane was obtained 6.49 g m−2. The synergistic effect of photocatalysis and membrane filtration was evaluated by investigating removal efficiency of amoxicillin (AMOX) as model pollutant using photocatalytic filtration concentration (CPF) parameter under a solar-simulated xenon lamp and the prepared photocatalyst-grafted PAA-PA membrane (PC-PAA-PA) was exhibited better removal ability than bare PA. The flux performance and antifouling property of the prepared membrane was investigated using pharmaceutical wastewater samples and the results revealed that the PC-PAA-PA exhibited good multifunctional characteristics such as high photocatalytic property, flux stability, and antifouling potential. The fouling process was performed in triplicate and the results demonstrated good stability of the photocatalyst on the membrane surface during operation. It can be concluded that by using a simple process for grafting of the photocatalyst to the membrane and the excellent antifouling ability of the resulting filter, an efficient reactor with antifouling characteristics can be constructed to produce cleaner water.