太湖表层沉积物重金属污染评价与来源分析

对太湖湖区表层沉积物中11种重金属的总量进行调查分析,借助地累积指数法和潜在生态风险指数法分析了重金属的污染程度和生态风险,并利用主成分分析-绝对主成分分数-多元线性回归受体模型对重金属来源进行解析.结果显示太湖沉积物中Cd、Sb含量平均值分别为江苏省土壤背景值的4.29倍和3.18倍,地累积指数表明Cd和Sb为偏中度...

Pollution Evaluation and Source Apportionment of Heavy Metals in Surface Sediments of the Taihu Lake

To understand the heavy metal pollution in surface sediment of the Taihu Lake, samples were collected and 11 heavy metals were determined. Geo-accumulation Index(I_geo) and the potential ecological risk index(RI) were used to assess the heavy metal pollution, and PCA-APCS-MLR were employed to identify the sources of heavy metals. The results showed that the average contents of Cd and Sb were 4.29 times and 3.18 times higher than those of soil background values in Jiangsu Province. I_geo and RI both showed that Cd and Sb were the main pollutants in surface sediments of the Taihu Lake. The sources of heavy metals are mainly human activities such as industry, agriculture, and transportation which enter the lake from inflow rivers. The heavy metal pollution in Zhushan Bay and Meiliang Bay were the most serious. Co, Cr, Cu, Mn, Ni, Pb, Sb, and Zn were significantly enriched, of which Co, Cr, Cu, Mn, Ni, Sb, Zn were affected by industrial sources; Cu, Mn, Zn were affected by agricultural activities; Cu and Pb were affected by urban traffics; Cd enrichment in west Taihu Lake was mainly affected by agricultural activities; Ba, Mo, Pb in south Taihu Lake were enriched and affected by traffics; East Taihu Lake was relatively clean. Comparative data from previous studies indicated that heavy metals in the sediment of the Taihu Lake decreased greatly after desilting since 2000, for example, concentrations of Pb, Cu, Cd reduced to 38.72%, 24.93% and 27.47% of that before desilting, respectively. However, considering the time-effectiveness of desilting, the future control of heavy metal in the Taihu Lake should involve more treatment scheme and protocols.