Response mechanism of soil leachate and disinfection by-product formation to extreme precipitation events under continuous drought scenario

Yujin Yuan; Qingsong Li; Jing Deng; Xiaoyan Ma; Xiaobin Liao; Jing Zou; Jie Liao; Huahan Huang; Huilin Dai

doi:10.1016/j.scitotenv.2024.170123

Response mechanism of soil leachate and disinfection by-product formation to extreme precipitation events under continuous drought scenario

Sci Total Environ. 2024 Mar 15:916:170123. doi: 10.1016/j.scitotenv.2024.170123. Epub 2024 Jan 15.

Authors

Yujin Yuan¹, Qingsong Li², Jing Deng³, Xiaoyan Ma³, Xiaobin Liao⁴, Jing Zou⁵, Jie Liao⁶, Huahan Huang¹, Huilin Dai⁷

Affiliations

¹ Water Resources and Environmental Institute, Xiamen University of Technology, Xiamen 361005, China; Key Laboratory of Water Resources Utilization and Protection, Xiamen City, Xiamen 361005, China.
² Water Resources and Environmental Institute, Xiamen University of Technology, Xiamen 361005, China; Key Laboratory of Water Resources Utilization and Protection, Xiamen City, Xiamen 361005, China. Electronic address: leetsingsong@sina.com.
³ College of Civil Engineering, Zhejiang University of Technology, Hangzhou 310014, China.
⁴ College of Civil Engineering, Huaqiao University, Xiamen 361021, China. Electronic address: liaoxb@hqu.edu.cn.
⁵ College of Civil Engineering, Huaqiao University, Xiamen 361021, China. Electronic address: zoujing@hqu.edu.cn.
⁶ Water Resources and Environmental Institute, Xiamen University of Technology, Xiamen 361005, China. Electronic address: liaoj@xmut.edu.cn.
⁷ Water Resources and Environmental Institute, Xiamen University of Technology, Xiamen 361005, China.

PMID: 38232842
DOI: 10.1016/j.scitotenv.2024.170123

Abstract

In this study, a rainfall simulation device was employed to investigate the response mechanism of soil leachate and disinfection by-products formation potential (DBPsFP) to extreme precipitation events. The results revealed that the aromaticity of dissolved organic matter (DOM) and the concentration of hydrophobic DOM containing aromatic carbon groups in leachate decreased with rising temperature. The humification degree of DOM decreased at 25 °C (99 mm/h), while the humification degree and protein-like level of DOM increased under high temperatures droughts (45 °C and 65 °C). Higher temperatures resulted in the leach of more microbial-derived humus and low molecular phenolic compounds from soil and broadened the range of molecular weight distribution. Increasing temperature increased DBPsFP and DBPs species and caused the precursors of haloacetic acids (HAAs) in leachate to become more hydrophobic, while the precursors of trihalomethanes (THMs) became more hydrophilic. Most importantly, the increased temperature attenuated the rainfall-mediated dilution of organic pollutant concentration, and temperature has a more significant effect than extreme rainfall in DOM abundance and the formation potential (or species) of DBPs. The results help to better understand the impact of climate change on the physicochemical processes of water quality.

Keywords: Climate change; Disinfection by-products; Extreme heavy rainfall; Soil leaching; Water supply quality.