Promotion of peroxydisulfate activation over Cu0.84Bi2.08O4 for visible light induced photodegradation of ciprofloxacin in water matrix

A novel Cu0.84Bi2.08O4/PDS/visible-light system was developed for efficient ciprofloxacin (CIP) degradation, which displayed excellent persulfate activation performance, high CIP degradation ability and total organic carbon (TOC) removal efficiency. [GRAPHICS] A novel Cu0.84Bi2.08O4/PDS/visible-light (VL) system has been developed for efficient ciprofloxacin (CIP) degradation, which displayed much higher degradation activity and total organic carbon (TOC) removal efficiency than those of many bismuth-based and copper-based materials under visible light irradiation. More than 90% CIP could be removed over Cu0.84Bi2.08O4/PDS/VL system within 400 min. More importantly, the CIP degradation products completely lost the antibacterial activity towards Staphylococcus aureus, lowering the risk for the emergence of the drug resistance. Electron paramagnetic resonance (EPR) and trapping experiments demonstrated that sulfate radicals were the dominated reactive species and responsible for CIP degradation. Moreover, the Cu0.84Bi2.08O4/PDS/VL system maintained its high degradation capability and original composition after several recycles and easily recovered to its original activity after regeneration. The pH value, anions and ion strength had slightly influence on the CIP degradation over this reaction system. Moreover, Cu0.84Bi2.08O4/PDS/VL system also exhibited high activity for CIP degradation in actual river water. The results provided a new insight into the PDS activation for degradation of organic pollutants, which indicated a huge potential in practical wastewater treatment.