贵州某流域城市河段沉积物及悬浮物重金属污染研究

通过在丰水期对贵州省某流域城市河段悬浮物和沉积物中的重金属含量进行测定，运用单因子指数法、生态风险评价法、因子分析法，初步探讨了该河段Cu、Zn、Pb、Hg、Cd、Cr、Ni及As等8种重金属元素的含量分布、污染特征、潜在生态风险及主要来源。检测结果显示，沉积物和悬浮物中Hg、Cd、Zn、Pb、As的平均含量较高，是贵州省土壤背景值的1.02～16.97倍。单因子指数评价结果表明：在沉积物中，Zn、Pb、As为轻度污染，Hg和Cd为重度污染；在悬浮物中，Cu、Pb、As为轻度污染，Zn为中度污染，Hg和Cd为重度污染。潜在生态风险指数评价结果显示，Hg和Cd的生态风险最大，为主要污染元素。研究区沉积物样品综合生态风险指数(RI)介于183.27～1 393.96,平均值为912.06,总体处于严重生态风险等级；悬浮物样品RI值介于341.53～612.38,平均值为436.85,总体处于重度生态风险等级。其中，沉积物样品重金属平均生态风险等级高于悬浮物样品，支流样品重金属生态风险等级总体上低于干流下游样品。根据因子分析法分析结果，初步推测沉积物及悬浮物Hg、Cd、Cr、Ni含量主要受工...

Preliminary Study on Heavy Metal Pollution in Sediments and Suspended Particulate Matter in Urban Reach of a River Basin in Guizhou

Heavy metal content in suspended solids and sediments in urban reach of a river basin in Guizhou Province was determined in wet season.The content distribution,pollution characteristics,potential ecological risks and main sources of eight heavy metals (Cu,Zn,Pb,Hg,Cd,Cr,Ni and As) in a city section were discussed by using single factor index method,ecological risk assessment method and factor analysis method.The results showed that the average contents of Hg,Cd,Zn,Pb and As in sediments and suspended solids were higher,which were 1.02-16.97 times of the soil background value in Guizhou Province.Single factor index evaluation showed that Zn,Pb and As in sediments were slightly polluted,while Hg and Cd were severely polluted;Cu,Pb and As in suspended solids were slightly polluted,Zn was moderately polluted,Hg and Cd were severely polluted.The evaluation results of potential ecological risk index showed that Hg and Cd were the main pollution control elements with the highest ecological risk.The ecological risk index value of sediment samples in the study area ranged from 183.27 to 1393.96,with an average of 912.06,which was generally at a severe ecological risk level.The ecological risk index value of suspended matter samples in the study area was between 341.53 and 612.38,with an average of 436.85,which was generally at a heavy ecological risk level.The average ecological risk of heavy metals in sediment samples was higher than that of suspended solids,and the ecological risk of heavy metals in tributaries was generally lighter than that in the lower reaches of the mainstream.Factor analysis showed that Hg,Cd,Cr and Ni were affected by industrial sewage discharge and agricultural production activities,Cu,Zn and Pb were affected by urban sewage discharge and land traffic discharge,and As was affected by the application of chemical fertilizer and pesticide in crop industry in recent years.