Distribution and ecological risk assessment of heavy metals in sediments of Dajiuhu Lake Wetland in Shennongjia, China
Distribution and ecological risk assessment of heavy metals in sediments of Dajiuhu Lake Wetland in Shennongjia, China
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DOI：
10.1007/s11356-022-23952-3
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发表时间：
2022-11
影响因子：
5.8
通讯作者：
Jiumei Wang;Jiwen Ge;Xiaojing Yang;Dandan Cheng;Chenhao Yuan;Ziwei Liu;Shiyun Yang;Yanbiao Guo-Yanbi
中科院分区：
文献类型：
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作者：
Jiumei Wang;Jiwen Ge;Xiaojing Yang;Dandan Cheng;Chenhao Yuan;Ziwei Liu;Shiyun Yang;Yanbiao Guo-Yanbi
现代社会的快速发展导致大量的重金属排放到湿地，并不断积累，造成严重的污染。大九湖位于中国湖北省神农架林区，是国际上具有重要价值的湿地，是具有较高科学研究价值的湿地生态系统典范。本次研究于2020年8月采集了大九湖9个子湖的27个表层沉积物样品。测定了沉积物中Cd、Cr、Cu、Ni、Pb和Zn的含量。采用改进的BCR（European Community Bureau of Reference）提取方法分析了重金属的赋存形态特征。采用4种方法对重金属污染程度和生态风险进行评价。通过相关分析和主成分分析，推测了重金属的可能来源。大九湖湿地沉积物中重金属含量由高到低依次为：ZnCrNiPbCuCd。Cd的平均含量超过了国家级自然保护区的阈值，而其他重金属的含量均低于各自的阈值。但由于Pb、Cd以不同形态存在，仍对湖泊湿地造成一定的污染和生态风险。Zn、Cr、Ni、Cu对大九湖湿地湖泊的生态风险不明显。各子湖重金属含量的空间分布差异较大。湖泊沉积物中重金属元素的来源以自然因素为主，Ni、Cr、Cu主要来源于自然因素，Cd、Pb主要来源于人为因素。相反，锌有自然和人为来源。该研究为湖泊湿地重金属污染研究提供了新的思路。为大九湖湿地重金属污染的治理提供了框架和方向。
The rapid development of modern society has resulted in discharge of large, heavy metal quantities into wetlands that have been continuously accumulating, causing severe pollution. Dajiuhu, located in the Shennongjia Forest District of Hubei Province in China, is a wetland of significant value internationally, serving as a model wetland ecosystem with heightened scientific research value. In this study, 27 surface sediment samples from nine sub-lakes in Dajiuhu were collected in August 2020. The concentrations of Cd, Cr, Cu, Ni, Pb, and Zn in the sediments were determined. The heavy metal occurrence and speciation characteristics were analyzed by an improved BCR (European Community Bureau of Reference) extraction method. Four methods were used to evaluate heavy metals’ pollution degree and ecological risk. The possible source of heavy metals was inferred using correlation analysis and principal component analysis. The heavy metal content in the lake sediments of Dajiuhu wetland was from the highest to the lowest concentration as follows: ZnCrNiPbCuCd. The average Cd content exceeded the national nature reserve threshold values, while the other heavy metals measured were below their respective threshold values. However, due to the occurrence of Pb and Cd in different forms, they still pose certain pollution and ecological risk to the lake wetlands. On the other hand, Zn, Cr, Ni, and Cu do not pose an ecological risk in the lakes of the Dajiuhu wetland. The spatial distribution of heavy metal content in the nine sub-lakes did vary significantly. Regarding the heavy metal sources in the lake sediments, Ni, Cr, and Cu originate from natural factors, and Cd and Pb have mainly anthropogenic origins. In contrast, Zn has both natural and anthropogenic origins. This study provides further insights into the study of heavy metal pollution in lake wetlands. It provides a framework and a direction for managing heavy metal pollution in the Dajiuhu wetland.