Efficient removal of bisphenol-A from water and wastewater by Fe₂O₃-modified graphene oxide

Bisphenol-A (BPA) has been widely used as a plasticizer in modern society and persistently released into aquatic environments. Herein, a novel Fe₂O₃-graphene oxide (GO) hybrid containing 22.8% of GO was prepared to enhance BPA removal from contaminated water and wastewater. This hybrid material afforded outstanding BPA adsorption capacities of 3293.9 mg g^-1 under optimized conditions, which led to 1.9 times and 1.2 times of BPA removal as compared to GO and reduced GO (rGO), respectively. In addition, Fe₂O₃-GO showed higher thermal stability, greater solid/liquid separation performance, and better anti-fouling performance. Moreover, the coexistence of natural or effluent organic matter caused 6.7-16.8% decline in BPA adsorption capacity of Fe₂O₃-GO, which was lower than those of GO and rGO (11.8-39.4%). Further characterization experiments revealed that BPA removal by Fe₂O₃-GO was enhanced because of the formation of Lewis acid-base (AB) interactions between the active sites on Fe₂O₃ (Lewis base) and BPA anions (Lewis acid). The existence of the AB interaction is beneficial for practical application considering the low environmental concentrations of BPA in water and wastewater. Besides, the distinctly lowered GO content of the hybrid saved 77.2% of the adsorbent cost. In conclusion, this study demonstrated the potential of Fe₂O₃-GO as a novel material for the treatment of BPA-contaminated water and wastewater.