Investigation and evaluation of typical heavy metal elements in soil around mining subsidence area

In order to find out the contents and pollution levels of heavy metal elements (Cu,Zn,Ni,Cd,Cr and Pb) in farmland soils around coal mining subsidence areas in Maoji experimental area,three typical coal mining subsidence areas(A,B,C)around Xinji No.1 Mine were selected as research objects,23 soil samples were systematically collected,the contents of six kinds of elements were determined by flame atomic absorption spectrophotometry,and the single pollution index method and comprehensive pollution index method were used to carry out heavy metal pollution evaluation.The results show that based on the spatial distribution of element content,Cu and Zn,Pb and Cd,Ni and Cr have similar pollution sources;the two-level exceeding rate of soil metal elements shows that Cu,Pb,Ni and Cr do not exceed the standard,while Cd and Zn generally exceed the standard;the results of single pollution index of elements showed that Ni content reach the warning line,Zn reached slight pollution,and Cd reach severe pollution;the order of comprehensive pollution index of farmland soil around A,B and C is A>C>B.The results of this study will be beneficial to the prevention and remediation of heavy metal pollution in agricultural land in the region.