1. The distribution and enrichment of trace elements in surface and core sediments from the Changjiang River Estuary, China: Evidence for anthropogenic inputs and enhanced availability of rare earth elements (REE).
- Author
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Zhang, Xiaoyu, Du, Wen, Xu, Zhijie, Cundy, Andrew B., Croudace, Ian W., Zhang, Weiyan, Jin, Haiyan, and Chen, Jianfang
- Subjects
RARE earth metals ,TRACE elements ,RIVER sediments ,TRACE metals ,SEDIMENTS ,ESTUARIES - Abstract
Huge amount of trace metals emitted through manmade activities are carried by the Changjiang River into the East China Sea. Most of them deposit in the Changjiang River Estuary and threaten the regional aquatic environment. In this study, major and trace elements of 34 archive surface sediments and two cores are examined. Sequential extraction procedures were also performed on surface sediments from 12 sites. We found that Tl, Tm, Er show distinct accumulation in surface sediments in the order of Tm > Tl > Er. Particularly, abnormally elevated HREE are observed mainly in those sites near the mouth of the estuary. Most elements exhibit an obvious reduction in the upper 30 cm of core B8, reflecting a decrease of sediment discharge from Changjiang River runoff. The increase of some trace elements recorded in the upper 20 cm of core C3 demonstrates a distinct local anthropogenic input in recent years. • Most trace elements are sourced from land except Sr and Ba, related closely with their geochemical behavior. • Distribution characteristics of elements are dominantly controlled by complicated hydrodynamic and grain sorting procession. • HREE particularly Tm and Er combining with Tl are anthropogenic, indicating ecological risk. • The decrease of riverine sediments induces the decrease of metals in top core sediments of the Changjiang River. • Some metals show accumulation in the top of core sediment from mouth of Hangzhou Bay, indicating local anthropogenic input. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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