Roles of dissolved organic matter (DOM) in shaping the distribution pattern of heavy metal in the Yangtze River

Enhang Liang; Jiarui Li; Bin Li; Shufeng Liu; Ruoqi Ma; Shanqing Yang; Hetong Cai; Zehuan Xue; Ting Wang

doi:10.1016/j.jhazmat.2023.132410

Roles of dissolved organic matter (DOM) in shaping the distribution pattern of heavy metal in the Yangtze River

J Hazard Mater. 2023 Oct 15:460:132410. doi: 10.1016/j.jhazmat.2023.132410. Epub 2023 Aug 26.

Authors

Enhang Liang¹, Jiarui Li¹, Bin Li¹, Shufeng Liu¹, Ruoqi Ma², Shanqing Yang¹, Hetong Cai¹, Zehuan Xue¹, Ting Wang³

Affiliations

¹ College of Environmental Sciences and Engineering, Peking University, The Key Laboratory of Water and Sediment Sciences, Ministry of Education, Beijing 100871, PR China.
² College of Environmental Sciences and Engineering, Peking University, The Key Laboratory of Water and Sediment Sciences, Ministry of Education, Beijing 100871, PR China; General Institute of Water Resources and Hydropower Planning and Design, Ministry of Water Resources, Beijing 100120, PR China.
³ College of Environmental Sciences and Engineering, Peking University, The Key Laboratory of Water and Sediment Sciences, Ministry of Education, Beijing 100871, PR China. Electronic address: wang_ting@pku.edu.cn.

PMID: 37647662
DOI: 10.1016/j.jhazmat.2023.132410

Abstract

Dissolved organic matter (DOM) strongly influences the solid-liquid partitioning and migration characteristics of heavy metals, yet little is known about the metal distribution and risk with the participation of DOM in large riverine systems. This study investigated the spatiotemporal distribution of 14 heavy metals and DOM along the entire Yangtze River (over 6000 km), and highlighted the critical roles of DOM in regulating the environmental behaviors of heavy metals. Significant spatial variations of metal contents were observed, with the river source and lower reach remarkably different from the upper-middle reaches. Heavy metals in the Yangtze River were mainly from the natural sources with minor anthropogenic disturbance. We found DOM could promote the conversion of metals from solid to liquid phase and DOM with higher aromaticity showed higher metal affinities. Although low ecological risks were observed in the Yangtze River, potential risks of metal leaching warrant attention, especially for As, Cd and Sb in the middle-lower reaches with higher DOM content and aromaticity. This study established a source-to-sea investigative approach to evaluate the influences of DOM features on metal partitioning, which is crucial for the risk control and sustainable management of large rivers.

Keywords: Dissolved organic matter; Distribution pattern; Ecological risk; Heavy metal; Metal partitioning.