Development of micropollutants removal process using thin-film nanocomposite membranes prepared by green new vapour-phase interfacial polymerization method

Abstract

The presence of emerging micropollutants in water bodies and potable water, has become a topic of great concern globally. In this study, a newly modified vapour-phase interfacial polymerization (VP-IP) method has been used to fabricate thin-film composite (TFC) and thin-film nanocomposite (TFN) nanofiltration (NF) membranes to study the removal of micropollutants, diclofenac (DIC) and triclosan (TRI) from water. The method used is an economically and environmentally greener method as the reaction takes place between the aqueous monomer solution and vapours of the organic phase, thereby avoiding the utilization of organic solvent hence named as vapour-phase interfacial polymerization (VP-IP) method. Polydopamine (PDA) coated polyethersulfone (PES) membranes were used to support the TFC and TFN membranes. The TFN membranes were incorporated with different concentrations of amine-functionalized cloisite Na+ 2D clay nanosheets (NH2-CMMT) to enhance the physicochemical properties of the TFN membranes. The performance study of the prepared TFN membranes based on different hours and pressures demonstrated an excellent rejection percentage of ∼99 ± 0.5% for both DIC and TRI compared to the TFC membrane. The membranes showed improved water permeate fluxes of ∼109 ± 5 Lm-2h-1 for DIC and ∼150 ± 5 Lm-2h−1 for TRI. The prepared TFN membranes demonstrated positive results for the antifouling test as well as exhibited antibacterial activity tested against Escherichia coli (E. coli) bacteria. The findings of this study show that our prepared TFN membranes combined with NH2-CMMT 2D clay nanosheets exhibit enhanced hydrophilicity, improved flux rate, excellent removal efficiency, antibacterial activity, and improved antifouling properties, indicating the potential to be used for removing emerging micropollutants from water.