Peroxymonosulfate activation by α-MnO2/MnFe2O4 for Norfloxacin degradation: efficiency and mechanism

Abstract Norfloxacin (NOF), as a quinolone antibiotic, is difficult to be directly degraded by conventional treatment owing to its typical stable quinolone ring structure. Advanced oxidation process (AOP) based on sulfate radical is a new technology exhibiting excellent oxidizing ability, pH stability, and activity via Fe and Mn. In this research, the Fe-Mn bimetallic catalyst (α-MnO2/MnFe2O4) was developed. Characterization tests were then performed to describe the morphology, crystal structure, and metal-binding properties of the materials. Based on the degradation analysis of NOF, the optimal conditions for NOF degradation in the ferromanganese-bimetal-activated persulfate system was explored. For mechanism studies, the change in material before and after use was examined to clarify ion circulation in the α-MnO2/MnFe2O4 catalyst and confirm the possible functions of different metals. The results could guide further research on the catalytic mechanism of α-MnO2/MnFe2O4 and the development of optimal operation strategies for practical NOF degradation.