The photoactivity of complexation of DOM and copper in aquatic system: Implication on the photodegradation of TBBPA

Zhansheng Li; Baocheng Qu; Jingqiu Jiang; Tadiyose Girma Bekele; Hongxia Zhao

doi:10.1016/j.scitotenv.2023.163620

The photoactivity of complexation of DOM and copper in aquatic system: Implication on the photodegradation of TBBPA

Sci Total Environ. 2023 Jul 20:883:163620. doi: 10.1016/j.scitotenv.2023.163620. Epub 2023 Apr 25.

Authors

Zhansheng Li¹, Baocheng Qu², Jingqiu Jiang³, Tadiyose Girma Bekele¹, Hongxia Zhao⁴

Affiliations

¹ Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology, Dalian University of Technology, Linggong Road 2, Dalian 116023, China.
² College of Marine Technology and Environment, Dalian Ocean University, Heishijiao Street 52, Dalian 116024, China.
³ Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, No.12 South Zhongguancun Ave., Haidian District, Beijing 100081, China.
⁴ Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology, Dalian University of Technology, Linggong Road 2, Dalian 116023, China. Electronic address: hxzhao@dlut.edu.cn.

PMID: 37100127
DOI: 10.1016/j.scitotenv.2023.163620

Abstract

The photoactivity of dissolved organic matter (DOM) has a great impact on the photodegradation of organic pollutants in natural waters. In this study, the photodegradation of TBBPA was investigated under simulated sunlight irradiation in the presence of copper ion (Cu²⁺), dissolved organic matter (DOM) and Cu-DOM complexation (Cu-DOM) to illustrate the effect of Cu²⁺ on photoactivity of DOM. The rate of photodegradation of TBBPA in the presence of Cu-DOM complex was 3.2 times higher than that in pure water. The effects of Cu²⁺, DOM and Cu-DOM on the photodegradation of TBBPA were highly pH dependent and hydroxyl radical(·OH) responded for the acceleration effect. Spectral and radical experiments indicated that Cu²⁺ had high affinity to fluorescence components of DOM, and acted as both the cation bridge and electron shuttle, resulting the aggregation of DOM and increasing of steady-state concentration of ·OH (·OH_ss). Simultaneously, Cu²⁺ also inhibited intramolecular energy transfer leading to the decrease of steady-state concentration singlet oxygen (¹O_2ss) and triplet of DOM (³DOM^⁎_ss). The interaction between Cu²⁺ and DOM followed the order of conjugated carbonyl CO, COO^- or CO stretching in phenolic groups and carbohydrate or alcoholic CO groups. With these results, a comprehensive investigation on the photodegradation of TBBPA in the presence of Cu-DOM was conducted, and the effect of Cu²⁺ on the photoactivity of DOM was illustrated. These findings helped to understanding the potential mechanism of interaction among metal cation, DOM and organic pollutants in sunlit surface water, especially for the DOM-induced photodegradation of organic pollutants.

Keywords: Cu-DOM complexation; DOM; Photodegradation; TBBPA.