Enhanced removal of short-chain perfluoroalkyl substance using aminated waste-derived sorbent

Per- and polyfluoroalkyl substances (PFAS) are persistent environmental pollutants threatening human health and ecosystems. This study examines the removal of perfluorooctanoic acid (PFOA) and perfluorobutanoic acid (PFBA), representing long-chain and short-chain PFAS respectively, from aqueous solutions using waste-derived char produced through co-pyrolysis of polyvinyl chloride (PVC) and layered double hydroxide (LDH) grown on cellulose (LDH@cellulose). LDH@cellulose incorporation enhanced the char's thermal stability and specific surface area. Adsorption kinetics revealed that PFBA exhibited faster equilibrium times and higher affinity for aminated sorbent, while PFOA showed a preference for pyrolyzed sorbent. These findings were attributed to the influence of PFAS chain length on their interactions with the surface properties of the sorbents. The used sorbents were regenerated using desorption solvents. Additionally, PFAS present in the eluate were found to be degradable in polar aprotic solvent environments. These findings highlight the importance of surface wettability in PFAS adsorption and emphasize the potential for removing PFAS present in solvents.