Removal of heavy metal from aqueous medium using novel high-performance, antifouling, and antibacterial nanofiltration polyethersulfone membrane modified with green synthesized Ni-doped Al2O3

This study used green synthesized nickel-alumina nanoparticles (NANPs) to fabricate antifouling, antibacterial, and high-performance polyethersulfone (PES) nanofiltration membranes for heavy metal ion removal. Scrophularia striata extract was used to synthesize NANPs and to modify PES membranes. FT-IR, SEM, TEM, EDS, AFM, XRD, and zeta potential instrumental analyses were used to characterize NANPs and the membranes. The membrane porosity increased from 62.6% to 71.6-83.8%, and mean pore radius data exhibited a similar trend (from 4.47 to 7.54-12.55 nm). The water contact angle of the membranes was reduced from 64.1 degrees to 57.3 degrees-47.1 degrees owing to functionalities of NANPs, which improved membrane hydrophilicity and wettability. The prepared membrane water flux improved from 20.38 to 44.11-78.34 kg/m(2)h. The results reveal the enhancement antifouling resistance parameters for the blended membranes due to NANPs functionalities hydrogen bonding, membranes surface negative charge, and the smoother surface of the modified membranes, which AFM analysis proved. NANPs/PES membranes exhibited potent heavy metal ion removal and in the best case (0.5 wt% NANPs/PES membrane) the heavy metal rejection was Pb2+: 99.27%, Zn2+: 99.15%, Fe2+: 98.91%, and Cu2+: 98.58%. All the blended membranes showed effective antibacterial resistance against Escherichia coli (35.8-93.17%) and Staphylococcus aureus (37.3-94.25%) due to the presence of nickel and functionalities of NANPs.