燃煤电厂周边河流中重金属污染特征及其风险评价研究

Pollution Characteristics and Risk Assessment of Heavy Metals in Rivers Surrounding Coal-fired Power Plants

为探究燃煤电厂周边河流重金属污染特征及生态风险水平,在宝鸡市大唐电厂周边千河中采集10个样点,采用电感耦合等离子体质谱仪(ICP-MS)测定河水中10种重金属As、Cd、Cr、Mn、Cu、Zn、Ni、Co、Hg、Pb含量,运用空间插值法分析重金属污染分布特征,用污染指数法(HPI)进行风险评价。结果表明千河Mn、Hg浓度均值分别为36.67和0.13μg/L^(-1),超过《地表水环境质量标准(GB 3838-2002)》Ⅲ类标准;研究区河流上段高浓度元素有Hg、Pb、Cr,中段高浓度元素有As、Mn、Ni、Co,下段高浓度元素为Cu;千河重金属污染区域主要集中在距电厂较远的河流上段,HPI值大于30,污染程度高。

In order to explore the pollution characteristics and ecological risk level of heavy metals in rivers surrounding coal-fired power plants,10 samples were collected from Qianhe river surrounding Datang Power Plant in Baoji City.The contents of 10 heavy metals As,Cd,Cr,Mn,Cu,Zn,Ni,Co,Hg and Pb in river water were determined by ICP-MS.The spatial interpolation method was used to analyze the distribution characteristics of heavy metal pollution,and the pollution index method(HPI)was used to evaluate the risk.The results showed that the average concentrations of Mn and Hg in Qianhe river were 36.67 and 0.13μg/L^(-1),respectively,which exceeded the classⅢstandard of Environmental Quality Standard for Surface Water(GB 3838-2002).The high concentration elements in the upper reaches of the river in the study area are Hg,Pb,Cr,As,Mn,Ni,Co,and Cu in the lower reaches.The heavy metal pollution area of Qianhe River is mainly concentrated in the upper part of the river far from the power plant,and the HPI value is greater than 30,indicating high pollution degree.