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 (G50) was observed for the combined system. The addition of H2O2 and K2S2O4 improved the ENRO degradation due to the generation of & BULL;OH and & BULL;SO42-. In the presence of NO3-, 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 CO32-. The trapping experiment indicated that & BULL;OH played an important part in the ENRO degradation. The addition of UV into the DBD system decreased H2O2 concentration in deionized water, and increased & BULL;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.

Automated summary

A novel technology of coupling dielectric barrier discharge and ultraviolet was investigated to efficiently degrade enrofloxacin. The addition of H2O2 and K2S2O4 improved the degradation rate. The presence of NO3-, SO(4)(2-), Cl-, and CO32- affected the degradation differently. & BULL;OH played an important part in the degradation. DFT analysis revealed the degradation mechanisms of ENRO.