Kinetic and mechanistic insights into the oxidation of bisphenol A in Cu(II)-mediated Fenton-like oxidation process

The Fenton-based oxidation process is an effective wastewater treatment approach for degrading organic pollutants. However, it has limitations in terms of pH range and secondary pollution. Cu(II)-mediated Fenton-like oxidation presents a promising alternative for applications. In this work, experimental approaches were integrated with kinetic modeling analysis to understand the production, performance and reaction mechanism of active species during the Cu(II)/H 2 O 2 process. Chemical probe analysis and electron paramagnetic resonance information verified the presence and properties of ·OH and Cu(III) in the Cu(II)/H 2 O 2 process. By using the periodate colorimetric technique, the relationship between reaction conditions and the generation of Cu(III) was further clarified. Together with theoretical analysis, the contribution of ·OH and Cu(III) to the elimination of bisphenol A (BPA) in the Cu(II)/H 2 O 2 process was examined. Quantitative analysis demonstrated that ·OH played a pivotal role under acidic conditions, accounting for 54.06 % and 62.06 % of BPA removal at pH 4 and 6, respectively. However, a dramatic shift occurred under alkaline conditions, where ·OH contributions decreased substantially to·3.35 % and 0.89 % at pH 10 and 12, respectively. The kinetic model for the removal of BPA by Cu(II)/H 2 O 2 process was calculated as V= 0.236·[BPA] 0.173 ·[Cu(II)] 0.619 ·[H 2 O 2 ] 1.556 using one-eighth lifetime method. Furthermore, Cu(III) was found to be more reactive toward the benzene ring than ·OH. This work contributes to our understanding of the Cu(II)-mediated Fenton-like oxidation process, and it could offer a promising new method for treating refractory organic wastewater.