The diverse roles of halide ions in the degradation of bisphenol A via UV/peracetic acid process at different pH values: Radical chemistry, and transformation pathways

Yanan Shao; Shuai Li; Xue Wei; Yanlan Zhao; Jie Liang; Xiaodong Li

doi:10.1016/j.jhazmat.2023.133053

The diverse roles of halide ions in the degradation of bisphenol A via UV/peracetic acid process at different pH values: Radical chemistry, and transformation pathways

J Hazard Mater. 2024 Mar 5:465:133053. doi: 10.1016/j.jhazmat.2023.133053. Epub 2023 Dec 8.

Authors

Yanan Shao¹, Shuai Li¹, Xue Wei¹, Yanlan Zhao¹, Jie Liang¹, Xiaodong Li²

Affiliations

¹ College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China.
² College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China. Electronic address: lxdfox@hnu.edu.cn.

PMID: 38113739
DOI: 10.1016/j.jhazmat.2023.133053

Abstract

UV/Peracetic Acid (UV/PAA), as an innovative advanced oxidation process (AOP), is employed to treat bisphenol A (BPA) in water through the generation of hydroxyl radicals (•OH) and carbon-centered radicals (R-C•). The impact of halide ions (Cl^-; Br^-; I^-) on the efficiency of UV/PAA was investigated for the first time under varying pH levels. The presence of halide ions exerted an influence on the reactivity of •OH and R-C•, exhibiting varying degrees of impact across different pH conditions. It was discovered that pH exerts a significant influence on its efficiency, with optimal removal performance observed at a pH 9. The degradation of BPA was inhibited by Cl^- through the generation of reactive chlorine species (RCS), which triggers the interconversion between •OH and R-C•. Reactive bromine species (RBS) were produced in the presence of Br^-, facilitating BPA degradation and generating HOBr as a supplementary source of •OH radicals. I^- primarily generate reactive iodine species (RIS) through photolysis, which facilitates the degradation of BPA. The transformation of BPA involves hydroxylation, demethylation, halogenation, and cleavage reactions to form various products and pathways. The toxicity test demonstrates that the UV/PAA treatment of BPA exhibits lower toxicity, thereby indicating its environmentally friendly.

Keywords: BPA; Reactive halogen species; Toxicity assessment; Transformation pathway; UV/PAA process.