Construction of rGO@AuNPs incorporated antifouling nanofiltration membrane with elevated filtration performance

Abstract

Developing polymer membrane with high efficiency in purification of water containing high salinity and concurrently has better antibacterial property has drawn considerable attention in water treatment. In this study, rGO@AuNPs is uniformly deposited on the thin film nanocomposite (TFN) base membrane through vacuum filtration (6.0 bar), and then the membrane was constructed by the Polyethyleneimine (PEI) and trimesoyl chloride (TMC) interfacial polymerization (IP) reaction, which was greener and more effective compared with conventional methods. The impact of rGO@AuNPs on TFN membrane morphology, chemical composition, bond structure, salt separation, and anti-fouling of rGO@AuNPs-based TFN membrane were conducted and compared. The results indicated that PAN-4 membrane obtained by incorporating rGO@AuNPs (0.025 % wt%) exhibited excellent salt rejections (i.e., NaCl: 91.5 %, Na2SO4: 92.0 %, MgCl2: 96.2 %, and MgSO4: 96.5 %) and outstanding antibacterial rate (up to 100 %) than all other membranes. What was more, the PAN-4 membrane also displayed the strong ability to kill resistance gene Escherichia coli (E. coli, 99.6–99.8 %). The salt rejection and antibacterial property of the PAN-4 membrane had no obvious changes after 7 days of operation, which revealed its good reproducibility. The results indicated that rGO@AuNPs membrane has shown great potential application in treatment of typical wastewater containing high concentration of salts and E. coli (especially resistance genes).