【摘要】 为了解太湖竺山湾及其主要入湾河流表层沉积物重金属污染状况,采用ICP-MS测定了13个采样点中Cr、Ni、Cu、Zn、As、Cd和Pb等7种重金属的含量,并采用地累积指数(I_geo)法和毒性单位（TU）法对其污染特征及潜在生态风险进行了研究.结果表明,7种重金属Cr、Ni、Cu、Zn、As、Cd、Pb的含量分别是相应背景值的2.02、2.18、4.69、5.25、1.62、13.6和2.37倍,均表现出了显著的累计效应.地累积指数表明Cr、Ni、As和Pb总体上处于无污染到轻污染状态,Cu和Zn处于轻污染状态,Cd处于轻污染到重污染状态.结合相关系数分析和聚类分析,可推断Cd主要来自于农业面源,Cu、Zn、Cr、Ni和As主要来自于工业污染,Pb一方面来源于橡胶合成和PVC生产等行业,另一方面来源于交通运输中含铅燃料的使用;生态风险评估结果表明,研究区域内重金属对栖息在沉积物中的动物群有中等到严重程度的毒性风险,7种重金属毒性单位均值由大到小为Ni>Cr>Cu>Zn>As>Pb>Cd.更多还原

【Abstract】 To explore the heavy metal pollution in surface sediments of Zhushan Bay and its main inflow rivers,the concentrations of heavy metals（ Cr,Ni,Cu,Zn,As,Cd and Pb） at 13 sampling locations were determined by ICP-MS. The methods of geo- accumulation index(I_geo) and toxic units（ TU） were adopted to examine the pollution characteristics and the potential ecological risks of the heavy metals in surface sediments. The results showed that the concentrations of Cr,Ni,Cu,Zn,As,Cd and Pb were 2. 02,2. 18,4. 69,5. 25,1. 62,13. 6,2. 37 times higher than their background concentrations,respectively. This indicated a significant cumulative effect. Geo-accumulation index revealed no-to-light pollution of Cr、Ni、As and Pb,while Cu and Zn were polluted with a low degree and Cd was polluted with a light-to-heavy degree. According to the correlation and cluster analyses,the pollution of Cd might mainly come from the agricultural non-point sources,while Cu,Zn,Cr,Ni and As mainly came from industrial pollution. Pb was probably attributed to the rubber synthesis and the PVC production industry. Apart from these,Pb might also come from the emission by vehicles.Ecological risk assessment results showed that there was a moderate to serious ecological risk posed by heavy metals to the biota in the study area. The average toxic units of the seven heavy metals followed the order of Ni > Cr > Cu > Zn > As > Pb > Cd.更多还原