Catalytic ozonation of Bisphenol A in aqueous solution by Fe3O4-MnO2 magnetic composites: Performance, transformation pathways and mechanism

In this study, Fe3O4-MnO2 magnetic composites were prepared and used as catalyst for the catalytic ozonation of BPA in aqueous solution. First, characterization results proved that Fe3O4-MnO2 magnetic composites were prepared successfully. Meanwhile, the advantage of Fe3O4-MnO2/O-3 system was demonstrated by control experiments. The degradation efficiency of BPA in Fe3O4-MnO2 process reached 97.0% under the conditions: Fe3O4-MnO2 = 100 mg/L, O-3 flow rate = 100 mL/min, initial solution pH = 7.0. In addition, the effects of catalyst dosage, O-3 flow rate and initial solution pH on the degradation of BPA were studied respectively. Moreover, the recyclability and stability of Fe3O4-MnO2 magnetic composites were also investigated. The results showed that Fe3O4-MnO2 magnetic composites have high catalytic activity, stability and recyclability for BPA degradation. Furthermore, the degradation intermediates of BPA were detected and the degradation pathways of BPA were proposed comprehensively. Finally, the possible reaction mechanism of Fe3O4-MnO2/O-3 process was proposed. In brief, all the results confirmed that the Fe3O4-MnO2/O-3 process was a simple, nonhazardous, efficient and promising technology for the degradation of BPA in aqueous solution.