洪泽湖表层沉积物中重金属的分布特征及潜在生态危害

Distribution of Heavy Metals and Potential Ecological Risk in the Surface Sediment of Hongze Lake

采用变异系数、富集系数、潜在生态危害指数分析评价洪泽湖表层沉积物中的重金属的相关特性。评价结果表明:重金属的空间分布离散性及富集程度存在明显差异,重金属元素空间波动程度依次为Cd>Cu>Pb>As>Cr>Zn>Hg,富集程度依次为Cr>Zn>As>Cu=Pb>Hg>Cd;重金属潜在生态危害处于轻微水平,潜在生态危害系数依次为Hg>As>Cd>Cr>Cu>Zn>Pb,洪泽湖南部、东部出湖口表层沉积物重金属潜在生态危害指数较大,网围养殖区受到重金属的轻微污染;Cr,Zn,Pb,Cd污染来源基本一致,对重金属潜在生态危害综合指数影响较大。

Indexes on the variation coefficients, accumulation coefficients and potential ecological risk were analyzed to obtain the characteristics of heavy metal distribution in the surface sediment of Hongze Lake. Results showed that there was obvious discrepancy in space distribution and the accumulation of heavy metals. The order of space fluctuation extent of heavy metals was Cd^Cu ~〉Pb^As^Cr^Zn^Hg, and the order of heavy metal accumulation was Cr^Zn^As^Cu= Pb 〉Hg^Cd. The potential ecological risk of these heavy metals was very slight, and the order of potential ecological risk was Hg]〉As〉Cd〉Cr〉Cu〉Zn〉Pb; the risk indexes at the south and east exits in the lake were larger, and the enclosure culture area was slightly polluted by heavy metals. The pollution sources of Cr, Zn, Pb, Cd were basically the same, and these metals deter- mined to a large extent the potential ecological risk of heavy metals in the comprehensive index.