Synergistic dual-functionalities of starch-grafted-styrene hydrophilic porous resin for efficiently removing bisphenols from wastewater

Highly efficient remediation of bisphenols (BPs) contaminated wastewater by adsorption is intriguing but remains challenging. Herein, we present a starch-grafted-styrene hydrophilic porous resin (SGS-HPR) showing excellent BPs adsorption capacity, through simple graft copolymerization and then external knitting strategy. The typical influencing factors of graft copolymerization and external crosslinking processes were investigated systematically. A series of characterization experiments verified the successful fabrication of SGS-HPR and manifested that the optimum product, SGS-HPR7, possesses a hierarchical porous structure with strong hydrophilicity. The abundant presence of starch chain in SGS-HPR7, not only increased the hydrophilicity but also enhanced the adsorption affinity, making SGS-HPR7 exhibit remarkable removal ability toward BPs. The adsorption performance of SGS-HPR7 was studied systematically in static mode. The results showed that SGSHPR7 can adsorb BPs quickly with a stable ability irrespective of the varying aqueous environments. Besides, the continuous adsorption and regeneration experiments were conducted using bisphenol A (BPA) as the model BPs. The adsorbed BPA can be efficiently desorbed by ethanol elution, and the regenerated SGS-HPR7 showed great recyclability. Interestingly, SGS-HPR7 also retained the superior adsorption capacity and marvelous regeneration ability in the continuous adsorption experiments. Further, according to theoretical calculation studies, the hydrogen-bonding and pi-pi stacking interactions involved mechanism was uncovered clearly. Collectively, this work provides a new convenient strategy to fabricate new highly hydrophilic bio-based adsorbent for BPs removal.