Degradation performance and mechanisms of UV254/O3 against multi-component emerging contaminants at trace levels in water

Abstract

UV and O3 synergistic processes can effectively remove low concentrations of new pollutants in water, but the deep degradation of low concentrations of new pollutants needs further study. It was found that UV254/O3 treatment of phenol, SMX, and TC at low concentration (0.2 mmol·L-1) for 2 min resulted in a degradation rate of more than 90%, which was significantly higher than ATZ and CIP. There was a significant linear relationship between electronegativity (χ) and degradation rate constant (kobs) (Y = 6.086X - 20.339; R2 = 0.946). ROS quantitative experiments demonstrated that the electronic structures of these new pollutants could regulate the production of different reactive oxygen species (ROS) in the UV254/O3 system, and Phenol, SMX, and TC were positively correlated with the contents of superoxide anion (·O2-) and singlet oxygen (1O2). The toxicity test of Escherichia coli and the treatment experiment of municipal wastewater show that the UV254/O3 system has a good treatment effect on low-concentration new pollutants. This study reveals the treatment potential of UV254/O3 for new pollutants in practical water and provides a theoretical basis for the influence of different new pollutant structure characteristics on degradation rate.