| 三峡库区及上游表层沉积物重金属形态特征及其生态风险 |
| Fraction Characteristics and Ecological Risk of Heavy Metals in Surface Sediments of Three Gorges Reservoir and the Upper Reaches |
| 投稿时间：2021-09-15 修订日期：2021-11-03 |
| DOI：10.15928/j.1674-3075.202109150324 |
| 中文关键词:重金属 形态 生态风险 表层沉积物 三峡水库 |
| 英文关键词:heavy metal fraction ecological risk surface sediment Three Gorges Reservoir |
| 基金项目:国家自然科学基金（51779158） |
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| 中文摘要: |
| 研究三峡库区表层沉积物中重金属形态特征及其潜在生态风险，为制定库区重金属污染防治措施提供基础资料。2020年11月，在三峡库区上游合江江段和江津江段以及库区巴南江段和长寿江段采集21个沉积物样品，通过连续提取法对重金属Cu、Pb、Cr、Cd、As、Hg总量及形态特征进行分析。结果显示：三峡库区及上游江段研究江段沉积物重金属平均含量Cr > Pb > Cu >As > Cd > Hg，其中Cu、Pb和Cd的含量高于长江流域沉积物重金属背景值，库区长寿江段重金属含量最高；重金属形态占比具有明显差异，研究江段Pb的铁锰结合态占比高达34.99%~43.17%，Cd的离子交换态含量最高，其在合江、江津、巴南和长寿江段沉积物重金属形态总和中的占比分别为17.41%、16.65%、20.56%和18.88%，而As、Hg、Cu和Cr的残渣态含量较高，其中Hg和Cr的残渣态占比分别超过了80%和88%；研究江段沉积物中重金属污染负荷指数PLI值和潜在生态风险指数RI值分别为0.90~1.61和112.49~245.03，其中库区长寿和巴南江段指数值较高。综合结果表明，库区长寿和巴南江段沉积物重金属污染较严重，总体处于中等污染水平，Cd和Pb是主要贡献者，其中Cd具有较大的生物可利用性和潜在生态风险。 |
| 英文摘要: |
| The characteristics and potential ecological risk of heavy metals in surface sediments from the Three Gorges Reservoir area and the upper reaches were studied, aiming to provide basic data for the prevention and control of heavy metal pollution in the reservoir area. In November 2020, 21 sediment samples were collected from the Hejiang and Jiangjin sections in the upper reaches, Banan and Changshou sections in the Three Gorges Reservoir area. The total concentrations and fractions of Cu, Pb, Cr, Cd, As and Hg were analyzed by using continuous extraction method. Results show that the average concentration of heavy metals in sediments were in the order of Cr > Pb > Cu >As > Cd > Hg, and the levels of Cu, Pb and Cd were higher than the background values of the Yangtze River basin. Heavy metals presented obvious spatial distribution differences, and were higher in Changshou section compared with other sections. The fraction of each form varied significantly among the heavy metals. The fraction of Fe-Mn oxide fraction of Pb was as high as 34.99%-43.17%. Cd had the highest percentage of the exchangeable fraction, accounting for 17.41%, 16.65%, 20.56% and 18.88% in the sediments of Hejiang, Jiangjin, Banan and Changshou sections, respectively. The residual fractions of As, Hg, Cu and Cr were relatively high and the residual fraction percentages of Hg and Cr exceeded 80% and 88%, respectively. The ecological risk assessment results show that the pollution load index (PLI) and the potential ecological risk index (RI) values were 0.90-1.61 and 112.49-245.03, respectively, and the index value in theBanan and Changshou sections was higher. The comprehensive evaluation show that the heavy metal pollution was serious in the sediment of Changshou and Banan sections in the Three Georges Reservoir and at a moderate pollution level. Cd and Pb were the primary heavy metal pollutants, and Cd was more bioavailable and posed larger potential ecological risk. |
| 董 纯,杨 志,朱其广,唐会元,李嗣新,陈小娟.2022.三峡库区及上游表层沉积物重金属形态特征及其生态风险[J].水生态学杂志,43(1):16-23. |
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