Microwave electrodeless UV light source combine ozone generation with photocatalytic simultaneous degradation of norfloxacin

Abstract

This work designed a microwave electrodeless UV light source device integrating ozone generation and photocatalysis (O3 + UV254/TiO2), norfloxacin was selected to evaluate the degradation performance of the device. The degradation and mineralization efficiencies obtained for norfloxacin (10 mg/L, 5 L) treated by the O3 + UV254/TiO2 system for 30 min and 60 min were 82.12% ± 2.84%, 97.00% ± 2.55% and 67.93 ± 0.46%, 75.77 ± 0.26%, respectively, and the highest energy yield obtained at 5 min was 465.53 ± 67.99 mg/kWh. The experiments compared the degradation effects of O3, O3 + UV254 and O3+ UV254/TiO2 treatment of NOR solutions, and the degradation efficiencies obtained at 40 min were 74.51± 2.61%, 77.09 ± 2.12% and 91.63 ± 2.62%, respectively, which showed that O3+ UV254/TiO2 exhibited the best degradation effect. In addition, the effect of coexisting inorganic salts on the degradation efficiency of norfloxacin was investigated. The identification of intermediates by HPLC-Q-TOF-MS proposed four possible degradation pathways. The ring opening of the quinolone group represents a decrease in the antibacterial activity of the norfloxacin drug, indicating that the microwave electrodeless UV light device is a promising alternative strategy for treating effluent containing norfloxacin.