(313e) Superfine Activated Carbon-Functionalized Adsorptive Thin-Film Nanocomposite Membranes for Enhanced Pfas Removal from Water

Due to the widespread production and use of per- and polyfluoroalkyl substances (PFAS), as well as their ability to move and persist in the environment, surveys conducted by the Centers for Disease Control and Prevention (CDC) show significant human exposure to PFAS. Membrane filtration and adsorption process are the two main effective separation and removal methods for PFAS removal from water. Thin-film composite (TFC) nanofiltration (NF) membranes showed an acceptable (<90%) removal of PFAS. However, the presence of rejected PFAS in the concentrate stream needs another separation process. In this study, we report the fabrication of adsorptive thin-film nanocomposite (TFN) NF membranes functionalized with super fine ( <100 nm) activated carbon (SFAC) for enhanced PFAS removal by adsorption during the water filtration. The NF membrane was fabricated on a poly (ether sulfone) (PES) support layer with a polyamide (PA) selective layer functionalized by immobilization of AC inside the PA via interfacial polymerization. The isotherm adsorption of SPAC showed 93% removal of Perfluorooctanesulfonic acid (PFOS) in DI water. The bare NF membrane showed 12 (L.m^-2.h^-1.bar^-1) water permeability, around 60% NaCl rejection, more than 99% salt MgSO₄ rejection, and 90% PFAS removal. Based on the recorded results, the SPAC TFN membranes show enhanced PFAS removal due to the hybrid mechanism of size exclusion and adsorption without sacrificing the membrane permeability and antifouling properties.