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Peng D, Lyu J, Song Z, Huang S, Zhang P, Gao J, Zhang Y. Mercury budgets in the suspended particulate matters of the Yangtze River. Water Res 2023; 243:120390. [PMID: 37516080 DOI: 10.1016/j.watres.2023.120390] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 07/16/2023] [Accepted: 07/19/2023] [Indexed: 07/31/2023]
Abstract
Riverine processes are crucial for the biogeochemical cycle of mercury (Hg). The Yangtze River, the largest river in East Asia, discharges a substantial amount of Hg into the East China Sea. However, the influencing factors of the Hg budget and its recent trends remain unclear. This study quantitatively analyzed the total Hg concentration (THg) in suspended particulate matter (SPM) in the Yangtze River and calculated the Hg budget in 2018 and 2021. The results showed that the total Hg concentrations varied substantially along the river, with concentrations ranging from 23 to 883 μg/kg in 2018 and 47 to 146 μg/kg in 2021. The average Hg flux to China Sea in 2018 and 2021 were approximately 10 Mg/yr, lower than in 2016 (48 Mg/yr). Over 70% of the SPM was trapped in the Three Gorges Dam (TGD), and 22 Mg/yr of Hg settled in the TGD in 2018 and 10 Mg/yr in 2021. Hg fluxes in the Yangtze River watershed were driven by various factors, including decreased industrial emissions, increased agriculture emissions, and decreased soil erosion flux. We found that in the upper reach of the Yangtze River changed from sink to source of Hg possibly due to the resuspension of sediments, which implies that the settled sediments could be a potential source of Hg for downstream. Overall, emission control policies may have had a positive impact on reducing Hg flux to the East China Sea from 2016 to 2021, but more efforts are needed to further reduce Hg emissions.
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Affiliation(s)
- Dong Peng
- Nanjing University, School of Atmospheric Sciences, 163 Xianlin Road, Qixia Distinct, Nanjing 210023, China; Nanjing University, School of Geography and Ocean Science, Ministry of Education Key Laboratory for Coast and Island Development, 163 Xianlin Road, Qixia Distinct, Nanjing 210023, China
| | - Jixuan Lyu
- Nanjing University, School of Geography and Ocean Science, Ministry of Education Key Laboratory for Coast and Island Development, 163 Xianlin Road, Qixia Distinct, Nanjing 210023, China
| | - Zhengcheng Song
- Nanjing University, School of Atmospheric Sciences, 163 Xianlin Road, Qixia Distinct, Nanjing 210023, China
| | - Shaojian Huang
- Nanjing University, School of Atmospheric Sciences, 163 Xianlin Road, Qixia Distinct, Nanjing 210023, China
| | - Peng Zhang
- Nanjing University, School of Atmospheric Sciences, 163 Xianlin Road, Qixia Distinct, Nanjing 210023, China
| | - Jianhua Gao
- Nanjing University, School of Geography and Ocean Science, Ministry of Education Key Laboratory for Coast and Island Development, 163 Xianlin Road, Qixia Distinct, Nanjing 210023, China.
| | - Yanxu Zhang
- Nanjing University, School of Atmospheric Sciences, 163 Xianlin Road, Qixia Distinct, Nanjing 210023, China; Frontiers Science Center for Critical Earth Material Cycling, Nanjing University, Nanjing 210023, China.
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