Hybridly charged NF membranes with MOF incorporated for removing low-concentration surfactants

Water pollution is a growing issue that requires remediation. Surfactants, used in many domestic and industrial applications, are one of the emerging contaminants that require immediate concern. Removing low-concentration surfactants using nanofiltration (NF) membrane is a study that deserves attention. In this case, a mixed polyamide-based NF membrane was fabricated via interfacial polymerization (IP) using polyethylenimine (PEI) and piperazine (PIP) as monomers in aqueous solution. UiO66-NH 2 and UiO66 were synthesized and incorporated into the polyamide layer to enhance the permeability of the prepared NF membranes. The pure water flux of the NF membranes reached 16.6 L m −2  h −1 bar −1 when UiO66-NH 2 concentration in aqueous solution is 0.005 wt%, and the membrane showed decent rejection to divalent salts, 96.5% to MgCl 2 and 85.6% to Na 2 SO 4 . The prepared membranes were utilized to remove surfactants with the concentration (100 mg L −1 ) below the critical micelle concentration (CMC) from water, and they showed good removal to both anionic and cationic surfactants . In addition, the durability of the fabricated NF membranes is acceptable. This work provides a feasible strategy for the fabrication of highly permeable NF membranes and demonstrates the capability of NF membrane for surfactants removal.