Simultaneous removal of Cu2+ and bisphenol A by a novel biochar-supported zero valent iron from aqueous solution: Synthesis, reactivity and mechanism

Abstract

In this study, a novel biochar-supported zero valent iron (BC-nZVI) was synthesized through a green method. A high performance on the simultaneous removal of Cu²⁺ and bisphenol A (BPA) by a combination of BC-nZVI with persulfate (BC-nZVI/PS) system was successfully achieved. The simultaneous efficiencies of Cu²⁺ and BPA could reach 96 and 98% within 60 min, respectively. Both HO• and SO₄^•- were two major reactive species in BC-nZVI/PS system, and SO₄^•- was primary radical responsible for the degradation of BPA. Four kinds of Cu species, such as Cu(OH)₂, CuO, Cu₂O and Cu⁰ were generated via the adsorption and reduction of the BC-nZVI, whereas six kinds of products of BPA including p-isopropenyl phenol and 4-isopropylphenol were generated via the combined oxidation of SO₄^•- and HO•. The possible reaction mechanism for the simultaneous removal of Cu²⁺ and BPA by BC-nZVI/PS system contained a synergistic effect between the reduction of Cu²⁺ and the oxidation of BPA. This is the first report on the feasibility of the remediation of coexistence of heavy metal and organic compound in aquatic environment using the BC-nZVI/PS system.

Keywords: Biochar; Bisphenol A; Cu(2+); Persulfate; nZVI.