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Herein, we report a strategy to construct highly efficient perfluorooctanoic acid (PFOA) adsorbents by installing synergistic electrostatic/hydrophobic sites onto porous organic polymers (POPs). The constructed model material of PAF-1-NDMB (NDMB = N,N-dimethyl-butylamine) demonstrates an exceptionally high PFOA uptake capacity over 2000 mg g−1, which is 14.8 times enhancement compared with its parent material of PAF-1. And it is 32.0 and 24.1 times higher than benchmark materials of DFB-CDP (β-cyclodextrin (β-CD)-based polymer network) and activated carbon under the same conditions. Furthermore, PAF-1-NDMB exhibits the highest k2 value of 24,000 g mg−1 h−1 among all reported PFOA sorbents. And it can remove 99.99% PFOA from 1000 ppb to <70 ppt within 2 min, which is lower than the advisory level of Environmental Protection Agency of United States. This work thus not only provides a generic approach for constructing PFOA adsorbents, but also develops POPs as a platform for PFOA capture. The performance of adsorbents for perfluorooctanoic acid (PFOA) removal often suffers from long equilibrium times, weak binding affinities and poor stability. Here the authors report a highly efficient PFOA adsorbents by functionalizing porous organic polymers with electrostatic and hydrophobic binding sites. [ABSTRACT FROM AUTHOR]

Per- and polyfluoroalkyl substances (PFAS) are man-made environmental contaminants causing increasing global concern due to their adverse effect on environmental and human health. Conventional treatment methods are ineffective in removing short-chain PFAS because they are persistent and recalcitrant to treatment. This study evaluated the performance of a structurally-tunable and chemically-stable porous organic polymer (POP) for PFAS removal under realistic environmental conditions. The POP demonstrated an exceptionally high removal efficiency (>95%) within 15 min when the initial PFAS concentration was approximately 400 ng/L. The adsorption of PFAS on the POP was not significantly affected by changes in solution pH within the range of 5–9. The common co-contaminants in water competed with short-chain PFAS for active sites during the adsorption process following the order of natural organic matter (NOM), long-chain PFAS, and Cl−. The Freundlich-type model could predict the multicomponent interactions well with a R2 value above 0.91. The spent POP was effectively regenerated using a mixture of the 10% NaCl and 30% methanol solution and the PFAS removal maintained at 90% through five adsorption and desorption cycles. The characteristics of the designed POP make it a highly promising and stable absorbent. It enables fast and effective removal of short-chain PFAS. [Display omitted] • Cationic POP shows a fast adsorption rate and a high capacity for PFAS removal. • The designed POP maintained above 85% removal for PFBA at a pH range of 5–9. • The effect of the co-contaminants on PFBA removal followed the order of HA > PFOS > Cl−. • PFAS removal maintained at 90% in five consecutive adsorption/regeneration cycles. [ABSTRACT FROM AUTHOR]