Dually charged polyamide nanofiltration membranes fabricated by microwave-assisted grafting for heavy metals removal

Heavy metals pollution is an urgent problem that seriously hazards human health and ecosystems. Herein, dually charged nanofiltration (NF) membranes were prepared via a facile modification with diethylenetriamine (DETA) after interfacial polymerization. More amine groups were imported after grafting and a polyamide layer with opposite charges was constructed. The as-prepared membranes had a pure water permeability of 17.0 L m−2 h−1 bar−1 and maintained ideal rejection for both Na2SO4 (98.2%) and MgCl2 (94.1%), illustrating dually charged property. In addition, the dually charged NF membranes had high rejection to a series of heavy metals, showing good application potential in heavy metals removal.