Photocatalytic Reactive Ultrafiltration Membrane for Removal of Antibiotic Resistant Bacteria and Antibiotic Resistance Genes from Wastewater Effluent

Abstract

Biological wastewater treatment is not effective in removal of antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs). In this study, we fabricated a photocatalytic reactive membrane by functionalizing polyvinylidene fluoride (PVDF) ultrafiltration (UF) membrane with titanium oxide (TiO2) nanoparticles for the removal of ARB and ARGs from a secondary wastewater effluent. The TiO2 modified PVDF membrane provided complete retention of ARB and effective photocatalytic degradation of ARGs and integrons. Specifically, the total removal efficiency of ARGs (i.e., plasmid-mediated floR, sul1, and sul2) with TiO2 modified PVDF membrane reached similar to 98% after exposure to UV irradiation. Photocatalytic degradation of ARGs located in the genome was found to be more efficient than those located in plasmid. Excellent removal of integrons (i.e., intI1, intI2, and intI3) after UV treatment indicated that the horizontal transfer potential of ARGs was effectively controlled by the TiO2 photocatalytic reaction. We also evaluated the antifouling properties of the TiO2-UF membrane to demonstrate its potential application in wastewater treatment.