Activation of peroxymonosulfate by CuFe2O4-CoFe2O4 composite catalyst for efficient bisphenol a degradation: Synthesis, catalytic mechanism and products toxicity assessment

Abstract

In this research, the CuFe2O4-CoFe2O4 metallic oxides catalyst (donated as CCF) was synthesized by solvothermal method and applied to degrade bisphenol A (BPA) by activating peroxymonosulfate (PMS). The different influences containing initial PMS concentration, pH, catalyst dosage, coexisting ions and reaction temperature on the degradation efficiency of BPA were systematically investigated. The CCF exhibited 99.3% removal efficiency and 72.5% mineralization of BPA. Notably, compared with the reported metallic catalysts, CCF exhibited much lower amount of metal leaching during the degradation process. The superior catalytic activity and stability of CCF was attributed to the synergistic effects of Co2+/Co3+, Cu+/Cu2+ and Fe2+/Fe3+ redox cycles. The SO4•− and •OH were detected by chemical scavenging and electron paramagnetic resonance (EPR) tests while SO4•− might play a dominant role for BPA degradation. Furthermore, the catalytic mechanism was proposed and analyzed the toxicity of reaction system. The toxicity of BPA and its oxidation intermediates were predicted by ECOSAR model and activity inhibition experiments to demonstrate that BPA was ultimately mineralized as a non-toxic product. This study suggests that the prepared CCF is an efficient and environmentally friendly catalyst for activating PMS, which has an enormous potential application in practical waste water treatment.