吕梁市土壤重金属污染特征及评价

Characteristic and Evaluation of Soil Pollution by Heavy Metal of Luliang

通过采集吕梁市采暖期和非采暖期不同功能区的土壤样品,用原子吸收光谱仪测定土壤中镍、铜、铅、锌、镉的含量,并评价其污染程度。Cu、Ni、Zn的浓度均低于山西土壤元素背景值,Pb、Cd的浓度高于山西土壤元素背景值,其中采暖期分别超标3.56、25.47倍,非采暖期分别超标3.66、19.75倍。单因子污染指数法显示土壤受到Pb、Cd的人为污染。内梅罗综合污染指数采暖期和非采暖期分别为18.54、14.42,表明土壤受到重金属重度污染,浓度超标可能与吕梁市周边煤矿较多,矿区污染严重、分散式燃煤、化肥使用及机动车尾气排放有关。

Collecting the samples of soil from different functional areas of Lvliang city during the non- heating period and heating period. Soil samples were obtained and analyzed for Ni,Cu,Pb,Zn and Cd by atomic absorption spectrometry. the pollution levels of heavy metals were assessed with single factor pollution index and Nemerow integrated pollution index.The concentrations of Cu,Zn,Ni were lower than the corresponding background values in Shanxi,but the contents of Cd,Pb exceeded the corresponding background values,the mean contents of Pb and Cd were 3. 56 and 25. 47 times in the heating period respectively; which were 3. 66 and 19. 75 times in the non- heating period respectively,as high as the soil background values of Shanxi. Single factor pollution index showed that the urban soil in Luliang has been polluted by Cd and Pb. Nemerow pollution index in heating period and non- heating period were 18. 54,14. 42,respectively. Heavy metal pollution were severe in soil. The excess of these elements in soils primarily results from decentralized coal combustion,fertilization,and emission of motor vehicles.