Rapid Removal of Perfluoroalkyl Substances from Water by Quaternized Amine-Functionalized Nanocellulose/Deacetylated Chitin Composite Aerogel

Per- and polyfluoroalkyl substances (PFAS) are emerging contaminants, and many chemical adsorbents have recently been utilized for their removal. In this study, we synthesized a quaternary amine-modified (QA-CNF/DAC) composite aerogel by simultaneous cross-linking and amination of two most abundant natural polymers: cellulose nanofiber (CNF) and deacetylated chitin (DAC). The characterization results confirmed successful modification of aerogel by yielding a high surface area and quaternized amine content of 64.5 m2/g and 0.598 mmol/g, respectively. The aerogel exhibited high adsorption capacities of 269.76 mg/g for perfluorooctanesulfonate at pH 6.78 and 83.20 mg/g for perfluorohexanoic acid at pH 4.1, with rapid equilibrium times of 0.5 and 3 min, respectively. Adsorption followed pseudo-second order kinetics and the Freundlich model, indicating multilayer exothermic interactions on a heterogeneous aerogel surface. The aerogel retained performance when tested over multiple cycles, showing high stability and reusability. These findings demonstrate that QA-CNF/DAC aerogel is sustainable and cost-effective material for efficient PFAS remediation.