Investigation of heavy metals pollution in the Huashan´s gold mine tailing area

In order to identify the content of various heavy metals, soils of the farmland surrounding the Huashan´s gold tailing mine are studied. Surrounding soil samples are collected in new and old tailing mines. Flame atomic absorption spectrometry is taken to measure the content of Pb, Zn, Cd, Cr, and Cu. In addition, the method of combining the Geo-accumulation index and the potential ecological risk index is applied to evaluation the pollution in soils. It is able to provide the technical basis to the environmental management and recovery in this mine region. The results show that: (1) the pollution of Cu in soil samples is most important, others are arrayed in decreasing order: Cu>;Pb>;Zn>;Cd>;Cr. It should be noted that the coefficient of variation of Cu, Cd and Zn are larger, indicating that the strong impact of activities by the human; (2) the relationship between various heavy metals in old mine and the distance of sampling is not clear. However, a negative relationship is given between new mine and the distance of sampling; (3) some correlations are existed in the content of heavy metals. More closely relationships are shown in Cd and Cu, Cd and Cr, Pb and Zn. It demonstrates that these heavy metals have some homologous characteristic; (4) the results of Geo-accumulate index show that: Cu pollution levels are high, but Pb, Zn, Cd and Cr are slightly polluted. Otherwise, the two tailing mines are 2 levels pollution, a big accumulate index are presented surrounding old tailing mine; (5) From the method of potential ecological risk, we can get that: Cu is the first one for ecological harm, Cd is second, and Zn, Pb and Cr have slight harm. All results show that the two tailing mines are medium harm. According to the results, the protective system should be established, and the crops should be planted far from the tailing mines.