Activation of persulfate by a novel Fe(II)-immobilized chitosan/alginate composite for bisphenol A degradation

Abstract

In this study, a novel Fe(II) immobilized chitosan/alginate composite (Fe-Chitoal) was prepared via a simple crosslinking reaction to activate persulfate (PS) to degrade bisphenol A (BPA). The newly synthesized Fe-Chitoal was characterized by scanning electron microscopy, energy dispersive spectroscopy, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy, which indicated that Fe was successfully imprinted into the composite. The PS/Fe-Chitoal system demonstrated a much higher removal efficiency of BPA (99.5%) than the conventional PS/Fe(II) system (69.2%) with a negligible amount of Fe ions released into the solution. The effects of different experimental conditions, including the concentration of PS, concentration of Fe-Chitoal, and pH, on the removal of BPA were also investigated. The removal rate increased with increasing amounts of PS and Fe-Chitoal, and a high removal efficiency was maintained at a pH of 2–10. The PS/Fe-Chitoal system was rarely affected by high concentrations of anions (Cl−, SO42−, NO3−, and HCO3−), and the composite catalyst could be reused in a synthetic sewage solution. To simply separate the material, a Fe-Chitoal mesh bag was fabricated, which showed a consistent catalytic reactivity toward PS and BPA removal suggesting practical field applications.