【摘要】 为了解升金湖湿地生态系统环境状况,采集表层沉积物样品,分析其中重金属Cd、Cu、Pb、Zn和Hg以及粒度、TOC和TN的含量和分布特征,运用地质累积指数法和潜在生态风险指数法进行污染程度和潜在生态风险评价。结果表明,沉积物中Cd、Cu、Pb、Zn和Hg的平均含量分别为0.91 mg·kg^-1±1.00 mg·kg^-1, 37.51 mg·kg^-1±7.69 mg·kg^-1,50.11mg·kg^-1±12.34mg·kg^-1,147.98mg·kg^-1±20.97mg·kg^-1和118.7μg·kg^-1±45.6μg·kg^-1,均高于区域水系沉积物元素背景值。相关分析显示,Cu、Pb和Zn显著正相关,指示它们具有同源性。地质累积指数法计算结果表明升金湖重金属污染水平较低,重金属累积程度排序为Hg>Cd>Cu>Pb>Zn;而潜在生态风险指数法结果表明升金湖整体处于中高度生态风险状态,排序为Hg>Cd>Cu=Pb=Zn,Hg和Cd是主要的风险贡献因子。重金属污染程度与潜在生态风险指数有时候取决于环境背景值的选取。更多还原

【Abstract】 In order to understand the environmental status of the wetland systems, we collected the surface sediments from Shengjin Lake, analyzed the heavy metals including Cd, Cu, Pb, Zn and Hg, grain size, total organic carbon（TOC） and total nitrogen（TN） in sediments, and evaluated the pollution degree of heavy metals by using the geoaccumulation index and potential ecological risk index. The results showed that the concentrations of Cd, Cu, Pb, Zn and Hg in the sediments were 0.91 mg·kg^-1±1.00 mg·kg^-1, 37.51 mg·kg^-1±7.69 mg·kg^-1, 50.11 mg·kg^-1±12.34 mg·kg^-1, 147.98 mg·kg^-1±20.97 mg·kg^-1 and118.7 μg·kg^-1±45.6 μg·kg^-1, respectively, and all of them were higher than each of their regional environmental baseline. Cu,Pb and Zn correlated very well with each other, indicating likely common sources. The results of geoaccumulation index of metals indicated a low pollution level at Shengjin Lake, following the order of Hg>Cd>Cu>Pb>Zn. While the potential ecological risk index of heavy metals indicated a moderate to high ecological risk, following the order of Hg>Cd>Cu=Pb=Zn.Hg and Cd were the main contributing factors for the potential ecological risk of heavy metals. Sometimes, the level of heavy metals contamination in lakes or rivers depends on the selection of the environmental baseline.更多还原