Degradation of enrofloxacin in aqueous by DBD plasma and UV: Degradation performance, mechanism and toxicity assessment

Enrofloxacin (ENRO) as a highly toxic antibiotic poses great threats to human health and environmental safety. In this study, a novel technology of coupling dielectric barrier discharge (DBD) and ultraviolet (UV) was investigated to efficiently degrade ENRO in aqueous, and had a higher degradation rate. The ENRO degradation rate achieved approximately 93.9% at 30 min, and approximately 1.20 g kWh −1 of energy yield (G 50 ) was observed for the combined system. The addition of H 2 O 2 and K 2 S 2 O 4 improved the ENRO degradation due to the generation of ·OH and ·SO 4 2- . In the presence of NO 3 – , the ENRO degradation played a tendency to promote first and then decrease, and the presence of SO 4 2- resulted in the positive effect, while the negative effect was shown in the presence of Cl - and CO 3 2– . The trapping experiment indicated that ·OH played an important part in the ENRO degradation. The addition of UV into the DBD system decreased H 2 O 2 concentration in deionized water, and increased ·OH concentration. The DFT analysis showed the degradation mechanisms of ENRO at a molecular level. The degradation of ENRO mainly involved the oxidation of the piperazine group, the removal of ethyl acetate and the substitution of the F atom. The toxicity of ENRO and its degradation intermediates was evaluated.