The desorption mechanism of dissolved organic matter on pollutants and the change of biodiversity during sediment dredging

Xing Wan; Zhicheng Liao; Huan He; Min Shi; Guoxi Yu; Fenqing Zhao; Chaochao Lai; Yan Wang; Bin Huang; Xuejun Pan

doi:10.1016/j.envres.2022.113574

The desorption mechanism of dissolved organic matter on pollutants and the change of biodiversity during sediment dredging

Environ Res. 2022 Sep;212(Pt E):113574. doi: 10.1016/j.envres.2022.113574. Epub 2022 May 27.

Authors

Xing Wan¹, Zhicheng Liao¹, Huan He², Min Shi¹, Guoxi Yu¹, Fenqing Zhao¹, Chaochao Lai¹, Yan Wang³, Bin Huang⁴, Xuejun Pan⁵

Affiliations

¹ Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming, 650500, China.
² Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming, 650500, China. Electronic address: huanhe08@kust.edu.cn.
³ Key Laboratory of Ecological Environment Evolution and Pollution Control in Mountainous and Rural Areas of Yunnan Province, Kunming, 650224, China.
⁴ Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming, 650500, China; Yunnan Provincial Key Laboratory of Carbon Sequestration and Pollution Control in Soils, Kunming, 650500, China. Electronic address: huangbin@kust.edu.cn.
⁵ Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming, 650500, China; Yunnan Provincial Key Laboratory of Carbon Sequestration and Pollution Control in Soils, Kunming, 650500, China.

PMID: 35636464
DOI: 10.1016/j.envres.2022.113574

Abstract

Sediment dredging is an effective means to control the endogenous pollution of lakes, which could significantly change the concentration and composition of organic matter, especially dissolved organic matter (DOM) in the lake. DOM is particularly important for the release of endogenous pollutants, which will inevitably bring an impact on aquatic biodiversity. Nevertheless, in recent research little attention has been paid to the desorption mechanism of DOM on pollutants and the change of biodiversity during dredging. This study investigated the physicochemical properties of DOM in the sediment by taking a sediment dredging project in Dianchi Lake in China for example. The correlations of DOM properties with the desorption behavior of nitrogen (N), phosphorus (P), cadmium (Cd), lead (Pb) and the biodiversity of aquatic organisms were analyzed. The results show that the aromaticity and humification of DOM were improved after dredging, and the high molecular weight DOM was degraded into low molecular weight substance. The desorption amount of N, P and heavy metals (Cd, Pb) were decreased as the pH values increased. Moreover, NH₄⁺-N promoted the release of Pb²⁺ from DOM, while the release of PO₄^3--P was inhibited. Correlation analysis shows that the physicochemical properties of DOM exactly affected the release of N, P, Cd and Pb. It was easier to desorb pollutants with low aromaticity and humification of DOM, leading to a decrease in the diversity of aquatic organisms. This study identified the desorption mechanism of endogenous pollutants in DOM and the ecological risk to aquatic organisms, providing a theoretical basis for the prevention and control of water pollution.

Keywords: Biodiversity; Correlation analysis; DOM; Desorption; Sediment dredging.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Biodiversity
Cadmium / analysis
China
Dissolved Organic Matter
Environmental Pollutants* / analysis
Geologic Sediments / analysis
Lakes / chemistry
Lead / analysis
Water Pollutants, Chemical* / analysis

Substances

Dissolved Organic Matter
Environmental Pollutants
Water Pollutants, Chemical
Cadmium
Lead