High-efficiency capture and recovery of anionic perfluoroalkyl substances from water using PVA/PDDA nanofibrous membranes with near-zero energy consumption

Abstract

Poly- and perfluoroalkyl substances (PFASs) have caused severe public concerns due to their toxicity and extensive occurrence in the aquatic environment. This study reports a highly porous amine-functionalized membrane for the rapid capture of GenX and other anionic PFASs [e.g., perfluorooctanesulfonate (PFOS) and perfluorooctanoic acid (PFOA)] from contaminated water with near-zero energy consumption. The optimized membrane, prepared by electrospinning of polydiallyldimethylammonium chloride using cross-linked poly(vinyl alcohol) as a binder, had a high water permeability of ∼2700 L m–2 h–1 kPa–1. This high permeability enabled rapid gravity-driven filtration of contaminated water with a merely 5 cm water head, corresponding to an estimated energy consumption of as little as 2.7 × 10–4 kWh/m3. Meanwhile, the membrane showed highly efficient capture of GenX (>97%), PFOS (>99%), and PFOA (>99%). A large capture capacity of 1.2 × 106 μg/m2 was demonstrated for GenX. The captured GenX was recovered and concentrated with a small-volume NaCl/methanol solution, which simultaneously regenerated the membrane for its reuse. Over a 12-cycle capture–recovery test, the membrane demonstrated a high GenX recovery ratio of 94% and a volumetric concentration factor of 40. Our study provides a promising strategy for effective capture and recovery of GenX to enable its sustainable control and remediation.