安庆市区湖泊表层沉积物中砷、汞含量分布研究及生态风险评价

Distribution and ecological risk assessment of arsenic,mercury in the surface sediments from urban lakes of Anqing City

为调查安庆市区湖泊重金属污染状况,采集了安庆市区7个湖泊共22点的表层沉积物样品,分析了两种重金属As和Hg的含量分布。结果表明,As,Hg的含量范围分别为13.97~48.21 mg/kg和0.15~1.76mg/kg,均值含量分别为26.84mg/kg,0.58mg/kg。各市区湖泊不同程度的受到重金属As和Hg的污染。地累积指数法评价表明,市区湖泊普遍受到了Hg的轻度污染,而As的地累积指数普遍较低。生态风险评价表明,安庆市区湖泊潜在生态风险主要来自于Hg,东大湖、莲湖及菱湖处于中等的潜在生态风险状态,其他湖泊的潜在生态风险状态较低。

To investigate the heavy metals pollution,twenty-two surface sediment samples from urban lakes of Anqing City are collected,and two heavy metals,arsenic（As） and mercury（Hg） are analyzed.The results show that the range concentration of As and Hg in urban lakes are 13.97~48.21mg/kg and 0.15-1.76 mg/kg,while the average concentration are26.84 mg/kg and 0.58 mg/kg,which means the urban lakes are generally polluted by Hg and As.Furthermore,the ecological risk assessment is evaluated by geo-accumulation index（/geo） and potential ecological risk index（RI）./geo showes that urban lakes are generally polluted by Hg slightly,while the/geo value of As is lower.RI showes that the potential ecological risk of urban lakes is dominated by Hg.Dongda lake,Lian lake and Ling lake are in middle potential ecological risk,while other lakes are in lower ecological risk.