Performance comparison of thin-film nanocomposite polyamide nanofiltration membranes for heavy metal/salt wastewater treatment

For the treatment of wastewater and water resources, membrane technologies are rapidly developing. Also, water pollution by heavy metals, dyes, oil, medicinal, and salts leads to lower water quality and water shortages. In this research, thin-film nanocomposite nanofiltration (TFN) membranes were produced via the interfacial polymerization (IP) method between trimesoyl chloride (TMC) and m-phenylenediamine (MPD) monomers at the top surface of PES/(UF) membrane and modified by graphene oxide (GO) and aluminum fumarate (AlFu) metal-organic framework (MOF) nanostructures to remove heavy metal and (divalent and monovalent) salts. The FTIR, NMR, SEM, XRD, and zeta potential analyses investigated the modified thin-film nanocomposite membrane properties. Also, the hydrophilicity of the membrane was determined via contact angle analysis. Compared to the polyamide (PA) and PA/AlFu membranes, the as-synthesized TFN membrane contains 0.3 wt% GO had the highest water flux, 110.86 l/m²·h, rejection of Na₂SO₄ salt and Cr²⁺ about 98.94% and 97.5%, respectively. Generally, using nanostructures like GO and AlFu (MOF) opens a novel path to improve hydrophilicity, negative charge, water flux, and rejection of polyamide nanocomposite membrane.