水库型与河流型水源地保护区土壤重金属污染评价与研究——以广安市为例

为摸清广安市城市集中式饮用水水源地一、二级保护区周边土壤环境状况,采用单项污染指数评价法和内梅罗综合污染指数法,对广安市河流型、水库型两种典型饮用水水源地保护区土壤污染状况进行评估,并简要分析周边环境敏感点。结果表明:水库型水源地29个、河流型水源地44个土壤检测样品均未检出镉,铜、锌、铅、镍、总铬、汞、砷均检出,变异系数分别在16.6%~62.1%和15.3%~56.6%之间,说明水源地周边土壤环境受到外界的干扰显著;水库型、河流型水源地土壤中铜、锌、铅、镍、总铬、汞、砷污染指数均小于1,表明两处水源地均未受到已检重金属污染;水库型、河流型水源地内梅罗综合污染指数范围分别为0.16~0.68、0.14~0.44,全部点位内梅罗综合污指数评价等级均为Ⅰ级,表明这两处的饮用水水源地周边土壤是清洁安全的。

Assessment and Study on the Heavy Metal Pollution of Soil in the Reservoir-type Water Source and River-type Water Source Protection Area--Taking Guang'an City as an Example

In order to find out the soil environmental conditions around the first and second level protection zones of centralized drinking water sources in Guang’an City,the single pollution index evaluation method and the Nemero comprehensive pollution index method were used to evaluate the soil pollution conditions of the two typical drinking water sources in Guang’an City,i.e.river type and reservoir type,and briefly analyzed the surrounding environmental sensitive points.The results showed that Cd was not detected in 29 samples of reservoir type water source and 44 samples of river type water source,Cu,Zn,Pb,Ni,total Cr,Hg and as were all detected,and the coefficient of variation was 16.6%~62.1% and 15.3%~56.6% respectively,indicating that the soil environment around the water source was significantly disturbed by the outside world.The pollution indexes of Cu,Zn,Pb,Ni,total Cr,Hg,and As in the soil of reservoir and river water sources were all less than 1,indicating that the two water sources were not polluted by the detected heavy metals.The comprehensive pollution index range of the reservoir type and river type water sources was 0.16~0.68 and 0.14~0.44 respectively,and the comprehensive pollution index evaluation grade of all points was level I,indicating that the surrounding soil of these two drinking water sources is clean and safe.