A novel way of activating peroxysulfate by zero-valent copper and ferroferric oxide co-modified biochar to remove bisphenol A in aqueous solution: Performance, mechanism and potential toxicity

Abstract

In view of the highly demanding in heterogeneous catalysts with intensive activity and stability in AOPs based water pollution treatment, a magnetically separable Cu0-Fe3O4@Biochar composite was prepared by citric acid combustion method and utilized to remove bisphenol A (BPA) in aqueous solution at a broad pH range via activation of peroxymonosulfate (PMS). A remarkable synergetic effect was observed between Cu0-Fe3O4 and Biochar. 5 mM NaHCO3 could increase the stability of Cu0-Fe3O4@Biochar(65%) and catalytic activity as well. Indicating by EPR and quenching experiment results, singlet oxygen which may come from the lattice oxygen of the composite based on XPS analysis was the main active species in the degradation system other than hydroxyl radicals and sulfate radicals. In accordance with the degradation efficiency results, electrochemical analysis verified that the capability of electron transfer was enhanced markedly once coupling Cu0-Fe3O4 and Biochar. The acute and chronic toxicities of intermediates produced were evaluated indicating dramatic reduction in toxic.