Morphological distribution and pollution evaluation of heavy metals in soil of Ganzhou city

Taking the heavy metals of soil in the six functional areas of Ganzhou city as the study objects, surface soils(0~20 cm) were collected at 50 sites. The contents and origin of of heavy metals (Pb, Zn, Cu, Cd, Cr) were determined and analyzed using the modified Community Bureau of Reference (BCR) sequential extraction procedure. The risks of the heavy metals were evaluated using the ratio of secondary phase and primary phase method and single factor index. The results show that the coefficient of variation of Pb and Cu in the soil of heavy metals in the study area is large, and the correlation between heavy metals Zn, Cu and Pb is significant. The results from the single factor index indicate that soils in six functional areas are affected severely by the pollution of heavy metal Cd; residential and industrial areas are slightly contaminated by heavy metals Cr; traffic areas are slightly contaminated by heavy metals Pb and Zn. The heavy metal speciation in the study area (Cd、Cr、Cu、Pb、Zn) is mainly in the residual state. The soil is not polluted by heavy metals in the study area with the secondary and primary phase value less than 1.