兰州市农田土壤重金属污染评价与研究

通过测定兰州市三县五区主要农田土壤中的重金属砷、铅、铜、锌含量,利用单因子污染指数法和内梅罗综合污染指数法,结合兰州土壤背景值及国家标准(GB15618-1995),进行重金属污染评价.结果表明:以国家标准为标准的评价体系中,兰州市农田土壤总体综合污染指数为0.81,污染水平为警戒级,单因子污染程度为砷＞铅＞铜＞锌;西...

Investigation and evaluation on heavy metals pollution in farmland soil in Lanzhou City

The heavy metals(As,Pb,Cu and Zn) contaminations were evaluated in farmland soil of Lanzhou City according to background values and national standard(GB15618-1995),applying the single factor pollution index and Nemerow integrated index.Based on the national standard.The results showed that,the general integrated pollution index was 0.81,which demonstrated a warning level of contamination,and the single factor index was taking the order of As>Pb>Cu>Zn in the whole study area;the single factor index was in order of As>Pb>Cu>Zn in Xigu and Honggu District,and Gaolan County;while the single factor index was in order of As>Cu>Pb>Zn in urban district,Yongdeng and Yuzhong County;there was a light pollution of As in urban and Xigu District;the integrated pollution index was Xigu District>urban district>Gaolan County>Yongdeng County>Honggu District>Yuzhong County,and the pollution ranking was light in Xigu District and urban district,warning in Gaolan County,and safety in others.Referred to the Lanzhou background values,the results showed that the general integrated pollution index was 2.20 with a moderate level of contamination,and the single factor index was Cu>Pb>As>Zn in the whole study area;the order of the single factor index in different counties or districts was the same with the results evaluated by national standard;the integrated pollution index in different counties or districts was Xigu District>urban district>Gaolan County>Yongdeng County>Honggu District>Yuzhong County.Heavy level of contamination was found in Xigu District,the urban district and Gaolan County were moderate pollution,while others light pollution;in general,the ranking of contamination was safety in farming area,whereas light in non-farming area.