梁子湖沉积物中重金属及营养盐分布特征研究

Distribution Characteristic of Heavy Metals and Nutrient in Sediments of Liangzi Lake

以梁子湖沉积物为研究对象,调查了沉积物p H、粒径、氮、磷含量及烧失量等理化指标,分析了沉积物中铜(Cu)、铬(Cr)、铅(Pb)、汞(Hg)、砷(As)等5种重金属的垂直分布情况。通过背景值法和美国国家海洋与大气管理局(NOAA)的效应范围法定量评价梁子湖沉积物重金属污染状况,结果表明,汞和砷是梁子湖沉积物的主要污染物。内梅罗污染指数法和潜在生态危害指数法评估结果表明,当以长江干流Ⅰ级和Ⅱ级背景值作为基准时,梁子湖沉积物重金属潜在生态危害指数分别为364.0和182.3,分别对应着重度和中度生态风险程度。

Vertical distribution features of physical and chemical iiadicators such as pH, particle size, nitrogen content, phosphorus content and loss on ignition, and five species of heavy metals such as Cu, Cr, Pb, Hg, As were studied to assess the degree of pollution of sediments from Liangzi Lake. It was found that Hg and As were the main pollutants of sediments from the Lake by way of background value method and the U.S. National Oceanic and Atmospheric Administration （NOAA） quantitative evaluation of the effect of the range. Nemerow pollution power and potential ecological risk index assessment results showed that when Level Ⅰ and Level Ⅱ background values of Yangtze River were used as benchmarks, the index of potential ecological risk of heavy metals in sediments from the Lake were 364.0 and 182.3 respectively, corresponding to the degree of emphasis and a moderate degree of ecological risks.