青海西宁蚂蚁沟水库沉积物的重金属分布与生态风险评价研究

Distribution and Ecological Risk of Heavy Metals in Sediments of the Mayigou Reservoir in Xining City，Qinghai Province

中文关键词:  重金属  生态风险  沉积物  水库  青藏高原

英文关键词:Heavymetals  Ecologicalrisk  Sediment  Reservoir  Qinghai-XizangPlateau

中文摘要:

      水库对保障人们的生产生活发挥着重要的作用。目前对青藏高原上水库沉积物中重金属的研究仍比较缺乏。位于青藏高原最大城市的蚂蚁沟水库( MR)是研究人类活动对水库环境影响的一个典型案例。文章研究了重金属(As、Cd、Co、Cr、Cu、Mo、Ni、Pb、Sb和 Zn)在水库沉积物和表土中的分布、污染程度和生态风险。所有重金属的平均浓度都超过了其相应的背景值。 I(地积累指数)和 EF(富集系数)表明，在 22%的采样点中， Cd表现出中等程度的富集。 mCd(修正后的污染程度)表明， 90geo%的采样点为中度污染水平。 RI(潜在生态风险指数)显示，近一半的采样点表现出中度的生态风险。 Cd的来源与 MR周围的城市地区和工业区的人类活动有一定联系。我们的研究结果表明， MR沉积物的重金属污染并不严重，但 MR周围的人类活动应该在未来得到更多的关注。该研究结果将为青藏高原上水库的生态环境保护提供一定参考价值。

英文摘要:

      The reservoir is avital safeguardfor living andproduction in the world. Research on heavy met-als in sediments of reservoirs on the Qinghai-XizangPlateau(QTP)is very scarce.The Mayigou Reservoir(MR)，locatedinthelargestcityoftheQTP，isagreatcaseforstudyingimpactcausedbyhumanactivities on environment of the reservoir. Here the distribution，pollution level，and ecological risk of heavy metals(As，Cd，Co，Cr，Cu，Mo，Ni，Pb，Sb，andZn)in sediments and topsoils of the MR were studied. The average concentrations of all heavy metals exceeded their corresponding background values. The Igeo(geo-accumulation index)and EF(enrichment factor)values indicated that Cd exhibited moderately severe en-richment in 22% of sampling sites. The mCd(modified degree of contamination)values demonstrated that 90% of sampling sites were moderate pollution level. The RI(potential ecological risk index) values showed that nearly half of sampling sites exhibited moderate ecological risk. The sources of Cd was cer-tainly correlated with anthropogenic activities in urban area and industrial zone around the MR. These re-sults indicated that pollution of the MRis not serious，yet human activities around the MR shouldbe given more attentions in the future. The results of the study will provide some reference for ecologicalprotection ofreservoirsontheQinghai-XizangPlateau.