Manganese oxides activated peroxymonosulfate for ciprofloxacin removal: Effect of oxygen vacancies and chemical states

Ciprofloxacin (CIP) as an anti-inflammatory drug is frequently detected in various water resources. Recently, Sulfate Radical-based advanced oxidation processes with manganese oxides have been recognized as a highly effective method for CIP degradation. Herein, ε-MnO 2 was obtained through a convenient drying process. After different atmospheric treatments, MnO and Mn 2 O 3 were fabricated for subsequent degradation experiments. The results show that MnO exhibits better catalytic activity than Mn 2 O 3 , with high removal efficiency of almost 84.3% for CIP. Quenching test and electron paramagnetic resonance spectra confirm that 1 O 2 is the dominant species during reaction, while ·OH and SO 4 ·- play a supporting role. A related discussion about the role of valence states of Mn and oxygen vacancies is presented, which can provide a theoretical basis for further development of Mn/peroxymonosulfate system.