Greener synthesis of thin-film nanocomposite membranes with varied nanofillers for enhanced organic micropollutant removal

Abstract

Nowadays, the green process in membrane science is essential for industrial applications. The nanofiltration (NF) membrane developed by a green approach with effective separation of micropollutant from aqueous media makes it possible. Here, we designed a series of thin-film nanocomposite membranes prepared with structurally and morphologically different nanofillers, such as graphene oxide (GO)–NH2, arginine (Arg)-MMT and cloisite (C) MMT-NH2. The vapour-phase interfacial polymerisation (VP-IP) process is used to prepare highly selective and permeable thin-film nanocomposite (TFN) membranes. The polymerization reaction was done on the surface of the polysulfone (PSf) support membrane between an aqueous phase solution of 3,5-diaminobenzoic acid (DABA) and vapours of trimesoyl chloride (TMC). The nanomaterials' and prepared membranes' chemical and physical properties were determined using different characterization techniques. The TFN membranes (TFN-1, TFN-2 and TFN-3) prepared using three different nanomaterials (GO-NH2, Arg-MMT, CMMT-NH2) were compared for their separation against pharmaceutical compounds sulfamethoxazole (SMZ), triclosan (TRI), diclofenac (DIC) and cephalexin (CEP). The membranes demonstrated good hydrophilicity and antibacterial activity, resulting in a reasonable permeate flux rate. The fabricated membranes showed excellent selectivity for pharmaceutical compounds. Still, the TFN-3 membrane embedded with CMMT-NH2 nanomaterial recorded the highest rejection rate (> 99%) compared to the TFN-2 (Arg-MMT) and TFN-1 (GO-NH2) membranes. In contrast, the permeate flux rates for the individual TFN membranes showed slight variation. The developed TFN membranes via green and sustainable vapour-phase interfacial polymerization process demonstrated the possibility of being utilized for removing organic micropollutants from water to prevent the terrible devastation of our environment and aquatic systems.