Copper nanoparticles incorporated membranes for comprehensive treatment of surface water: synthesis and characterization

Incorporating copper nanoparticles (Cu-NPs) in polymeric membranes has garnered significant attention for enhancing water treatment efficiency and mitigating biofouling. Copper boasts several desirable attributes, including excellent antimicrobial properties, abundant availability, cost-effectiveness, and various economically viable synthesis methods to produce materials with tunable features. This study investigates the antibacterial properties of copper (Cu) and copper oxide (Cu₂O) nanoparticles, synthesized using a chemical reduction method. These nanoparticles were integrated into 20% (by wt) polyethersulphone (PES) membranes at concentrations ranging from 0 to 0.75 g, resulting in membranes labeled M1 to M4, tailored for ultrafiltration of surface water. The synthesized nanoparticles and nanocomposite membranes (NCMs) were characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and energy-dispersive X-ray (EDX). Physicochemical and bacteriological parameters were analyzed for feed, permeate, and reject water samples. Among the membranes, M3, containing 0.5 g Cu-NPs, exhibited outstanding performance with a pure water flux of 175 L/m²/h, 100% bacterial filtration efficiency, 62.96% colour rejection, and 88.46% turbidity rejection, besides achieving complete removal of E. coli and common bacteria. All membranes demonstrated over 95% bovine serum albumin (BSA) rejection, with the M3 membrane achieving a 74.6% and the plain membrane 45.5% flux recovery ratio (FRR), indicating strong antifouling properties after the addition of NPs. These findings suggest that the developed NCMs hold significant potential for producing high-quality potable water through effective clarification and disinfection.