Renewable Magnetic NH₂-MIL-101(Fe) for the Efficient Removal of Bisphenol A from Aqueous Solutions

Bisphenol A (BPA) is extensively utilized as an industrial chemical in the production of certain plastics and epoxy resins. They are frequently found in environmental water and have the potential to cause risks to both the environment and human health. To efficiently remove the endocrine disruptor BPA from aqueous solutions, sea urchin-like magnetic material Fe₃O₄@PDA@NH₂-MIL-101 (Fe) was synthesized via hydrothermal methods. Fe₃O₄@PDA@NH₂-MIL-101 (Fe) has excellent adsorption performance, with a theoretical maximum adsorption capacity of 300.47 mg/g for BPA. The adsorption kinetics of BPA by Fe₃O₄@PDA@NH₂-MIL-101 (Fe) followed the pseudo-second-order kinetic model and Liu's isotherm model. Magnetic separation experiments reveal a high recovery efficiency, maintaining 94.82% of its initial adsorption capacity after five cycles. The primary adsorption mechanisms of Fe₃O₄@PDA@NH₂-MIL-101 (Fe) on BPA included pore filling, hydrogen bonding, π-π interaction, and Lewis acid-base interaction. Additionally, the material showed excellent removal performance of BPA, with a maximum adsorbed amount of 135.27 mg/g for total organic carbon (TOC) in the shale gas fracturing flowback fluid. These findings suggest that Fe₃O₄@PDA@NH₂-MIL-101 (Fe) holds significant potential as an adsorbent for BPA removal from actual wastewater, offering promising prospects for practical applications.