Photo-transformation of wastewater effluent organic matter reduces the formation potential and toxicity of chlorinated disinfection byproducts

Du, Penghui1,2; Chen, Guoping1,2,3; Zhang, Peng1,2; Yang, Biwei1,2; Wang, Junjian1,2

2023-10-15

10.1016/j.ecoenv.2023.115515

ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY   Impact Factor & Quartile

0147-6513

1090-2414

Sunlight exposure can degrade and transform discharged wastewater effluent organic matter (EfOM) in aquatic systems, potentially enhancing the feasibility of reusing wastewater for drinking purposes. However, there remains a lack of comprehensive understanding regarding the sunlight-induced changes in the molecular-level composition, characteristics, and chlorine reactivity of EfOM. Herein, we investigated the impact of sunlight on the optical properties, chemical composition, and formation of disinfection byproducts of EfOM using multiple spectroscopic analyses, high-resolution mass spectrometry, chlorination experiments, and in vitro bioassays. Upon natural sunlight exposure, we observed significant decreases in ultraviolet-visible absorbance and fluorescence intensity of EfOM, indicating the destruction of chromophores and fluorophores. Photolysis generally yields products with lower molecular weight and aromaticity, and with higher saturation and oxidation levels. Moreover, a shift within the EfOM from condensed aromatic-like compounds to tannin-like components was observed. Furthermore, sunlight exposure reduced the reactivity of EfOM toward the formation of trihalomethanes and haloacetonitriles during chlorination, while there was a slight increase in the specific formation potential of haloketones. Importantly, the disinfection byproducts resulting from chlorination of the irradiated EfOM exhibited reduced microtoxicity. Overall, this study provides new insights into alterations in EfOM under sunlight exposure and aids in predicting the health risks of effluent discharge in water environments.

Effluent organic matter Sunlight Fourier transform ion cyclotron resonance mass spectrometry Disinfection byproducts Toxicity

SCI

English

First ; Corresponding

National Natural Science Foundation of China["22206070","42122054","42192513"] ; Shenzhen Science and Technology Innovation Commission["JCYJ20220818100403007","JCYJ20190809142611503"] ; Guangdong Basic and Applied Basic Research Foundation["2021A1515110153","2021B1515020082"] ; Key Platform and Scientific Research Projects of Guangdong Provincial Education Department[2020KCXTD006]

Environmental Sciences & Ecology ; Toxicology

Environmental Sciences ; Toxicology

WOS:001088606700001

ACADEMIC PRESS INC ELSEVIER SCIENCE

ENVIRONMENT/ECOLOGY

Web of Science

1.Southern Univ Sci & Technol, Sch Environm Sci & Engn, Guangdong Key Lab Soil & Groundwater Pollut Contro, Shenzhen 518055, Guangdong, Peoples R China
2.Southern Univ Sci & Technol, Sch Environm Sci & Engn, State Environm Protect Key Lab Integrated Surface, Shenzhen 518055, Guangdong, Peoples R China
3.Peking Univ, Sch Urban Planning & Design, Shenzhen 518055, Guangdong, Peoples R China

Du, Penghui,Chen, Guoping,Zhang, Peng,et al. Photo-transformation of wastewater effluent organic matter reduces the formation potential and toxicity of chlorinated disinfection byproducts[J]. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY,2023,265.

Du, Penghui,Chen, Guoping,Zhang, Peng,Yang, Biwei,&Wang, Junjian.(2023).Photo-transformation of wastewater effluent organic matter reduces the formation potential and toxicity of chlorinated disinfection byproducts.ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY,265.

Du, Penghui,et al."Photo-transformation of wastewater effluent organic matter reduces the formation potential and toxicity of chlorinated disinfection byproducts".ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 265(2023).