洞庭湖表层沉积物重金属污染状况评估

发布时间：2019-01-02 07:36

【摘要】：基于2010—2015年连续对洞庭湖3个主要湖区10个采样点的表层沉积物中Cd、Hg、As、Cu、Pb和Cr等重金属含量分析,对洞庭湖湖区表层沉积物中重金属的时空分布特征进行了探讨,并采用地积累指数法、潜在生态风险指数法和对数衰减模型评价洞庭湖沉积物重金属的污染状况.结果表明,洞庭湖沉积物中重金属平均含量大小顺序为CrPbCuAsCdHg,Cd、Cr和Pb的含量年际变化变幅较大,Hg、Cu和As则较小.地积累指数值(I_(geo))和单因子生态风险值(E_i~r)表明Cd和Hg是洞庭湖沉积物重金属主要污染物;从产生可以观察到毒性效果的最大可能性(P_(max))来看,Cd是洞庭湖沉积物重金属首要潜在水生生物风险毒性因子.综合地累积指数值(I_(tot))、总潜在生态风险值(RI)和预测的水生生物毒性比率(Y)的评价结果表明,在2010—2015年期间全湖重金属呈重度污染,面临重度潜在生态风险并可能具有产生水生生物毒性的风险,其各子湖区重金属的污染程度、潜在生态风险水平及潜在水生生物毒性水平排序为南洞庭湖东洞庭湖西洞庭湖;从随时间的变化趋势来看,在2014—2015年期间全湖及其东洞庭湖和南洞庭湖两个湖区的重金属污染程度、潜在生态风险水平及潜在水生生物毒性水平都要比2010—2013年降低,西洞庭湖区的重金属潜在生态风险水平及潜在水生生物毒性水平没有变化.
[Abstract]:Based on the analysis of heavy metals such as Cd,Hg,As,Cu,Pb and Cr in the surface sediments of 10 sampling sites in three main lakes of Dongting Lake from 2010 to 2015, The spatial and temporal distribution characteristics of heavy metals in the surface sediments of Dongting Lake were discussed. The pollution status of heavy metals in sediments of Dongting Lake was evaluated by the method of land accumulation index, potential ecological risk index and logarithmic attenuation model. The results show that the order of the average contents of heavy metals in sediments of Dongting Lake is that the contents of CrPbCuAsCdHg,Cd,Cr and Pb vary more annually than those of Hg,Cu and As. Soil accumulation index (I _ (geo) and single-factor ecological risk value (E_i~r) indicated that Cd and Hg were the main pollutants of heavy metals in Dongting Lake sediments. According to the maximum possibility of producing toxic effects (P _ (max), Cd is the primary potential risk factor for heavy metals in sediments of Dongting Lake. The combined cumulative index value (I _ (tot), total potential ecological risk value, (RI) and predicted aquatic toxicity ratio (Y) showed that heavy metals were heavily polluted throughout the lake between 2010 and 2015, Faced with severe potential ecological risk and may have the risk of aquatic biological toxicity, the pollution degree of heavy metals, the potential ecological risk level and the potential aquatic biological toxicity level of each sub-lake are ranked as East Dongting Lake and West Dongting Lake in South Dongting Lake. From the trend of change over time, the levels of heavy metal pollution, potential ecological risk and potential aquatic toxicity in the whole lake and its two lakes, East Dongting Lake and South Dongting Lake, are lower in 2014-2015 than in 2010-2013. The level of potential ecological risk of heavy metals and the potential toxicity of aquatic organisms in the West Dongting Lake region were not changed.
【作者单位】：湖南省洞庭湖生态环境监测中心;
【基金】：2015年湖南省环境保护科技计划项目(2015015)资助~~
【分类号】：X824

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