A double-crosslinked cyclodextrin-based porous polymer for effective removal of bisphenol A: Preparation, adsorption behavior and mechanism

As a sort of typical endocrine-disrupting chemical, bisphenol A (BPA) brings potential harm to the aquatic ecosystem and human health. Cyclodextrin-based polymer adsorbents have attracted increasing attention due to their high affinity for BPA. In this study, we demonstrated a double cross-linking adsorbent BDE-T-CDP(B) prepared at an optimal ratio, which was green synthesized by simultaneous ring-opening and nucleophilic substitution reaction of beta-cyclodextrin (beta-CD), a rigid crosslinker (tetrafluoroterephthalonitrile, TFTPN) and a flexible crosslinker (1,4-butanediol diglycidyl ether, BDE) in the alkaline aqueous system, avoiding the involvement of organic solvents. The combined effects of cavity inclusion, pi-pi interaction, and hydrogen bonding endowed BDE-T-CDP(B) to exhibit superior adsorption capacity (71.30 mg & sdot;g(-1)) toward grabbing BPA, which was visualized by IGM analysis. BDE-T-CDP(B) with porous structures was found to rapidly achieve adsorption equilibrium governed by the pseudo-second-order kinetic model (R-2 > 0.99) within 30 min. Besides, BDE-T-CDP (B) could still reach 94.7% of the saturated adsorption capacity after five successive regeneration cycles. Further, during the treatment of practical plastic factory wastewater with trace BPA pollutants, the satisfactory adsorption performance of BDE-T-CDP(B) was evidently observed. Thus, BDE-T-CDP(B) is a promising engineering adsorbent owing to its green preparation, excellent adsorption performance, and good recyclability.