| 摘要: |
| 【目的】全面了解三峡库区干流沉积物重金属质量分数及污染情况，更好地为库区重金属污染的预防与治理提供依据。【方法】于2015年6月在三峡库区干流采集表层沉积物，总数为37个，使用电感耦合等离子体质谱仪（ICP-MS）测定了重金属元素的质量分数，采用地积累指数法和潜在生态风险评价方法评价了重金属的污染情况。【结果】三峡库区干流沉积物中重金属元素Cr、Ni、Cu、Zn、As、Cd、Pb、Hg的平均质量分数分别为106.14、42.44、60.54、151.21、12.15、0.92、54.39、0.12 mg/kg，相对于长江沉积物背景值，各元素质量分数的平均值均偏高。Ni、Cu、Pb、As元素质量分数整体呈沿程增加趋势；Zn、Cd、Hg元素质量分数源头较高，沿程呈先减小后增加趋势；Cr元素质量分数整体呈不明显增加趋势，在某些特殊位置有极值出现。Cd元素在库区干流上、下游段已达到中等污染水平；Pb元素整体处于轻度污染水平；Cu和Zn元素容易通过积累在下游产生轻度污染；Cr、As、Ni元素只有极个别断面产生污染。【结论】总体而言，Cd元素污染应该引起重视。 |
| 关键词: 三峡库区； 重金属； 污染评价 |
| DOI：10.13522/j.cnki.ggps.2017.0252 |
| 分类号: |
| 基金项目: |
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| Assessing Contents and Pollution of Heavy Metals within the Sediment Deposits in the Main Streams of the Three Gorges Reservoir |
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ZHANG Weijie, XU Jianxin
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North China Institute of Water Conservancy and Hydroelectric Power, Zhengzhou 450045, China
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| Abstract: |
| 【Objective】 Heavy metals in sediment deposits is a concern in study of ecology and environment of river and reservoir, and the purpose of this paper is to present the results of an experimental study on the mass fraction and potential contamination of heavy metals in the sediments in the main streams of the Three Gorges Reservoir. 【Method】 Samples in surface sediment deposits were taken from 37 locations in the region of the Three Gorges Reservoir in June 2015. Inductively coupled plasma source mass spectrometer (ICP-MS) was used to analyse the mass fraction of the heavy metals in the samples. Their contamination potential was evaluated using the geo-accumulation index and the potential ecological risk assessment method. 【Result】 The average mass fraction of Cr, Ni, Cu, Zn, As, Cd and Pb in the sediments of the main streams was 106.14 mg/kg, 42.44 mg/kg, 60.54 mg/kg, 151.21 mg/kg, 12.15 mg/kg, 0.92 mg/kg, 54.39 mg/kg, 0.12 mg/kg, respectively, higher than the background values in the sediments of the Yangtze River. The mass fraction of Ni, Cu, Pb and As showed an increasing trend from the upstream to the downstream; the content of Zn, Cd and Hg was higher at their sources and then decreased before increasing again along the stream. The distribution of Cr was relatively uniform except at several specific locations. There was a moderate Cd pollution in the upstream and midstream, while the pollution caused by Pb was minor. The accumulation of Cu and Zn could lead to a pollution to the downstream, and Cr, As and Ni resulted in pollution only at some specific locations. 【Conclusion】 Overall, Cd pollution is a concern and should be paid an attention. |
| Key words: Three Gorges Reservoir; heavy metals; pollution assessment |
