Distribution of Heavy Metals in Reclamation Soils of Mining Area

DONG Ji-hong; BIAN Zheng-fu; YU Min; DI Chun-lei

Abstract：To keep the ecological safety of reclaimed lands by filling mining wastes and fly ash into subsided lands used as agricultural purpose, we took Liuxin mining area, Xuzhou in Chi- na, as the research area, and the contents of heavy metals As, Hg, Pb, Cu, Cd, Cr and Zn in different soils, including reclaimed soils and control soil with different depths, were tested and compared with control soil. Based on that the serious Cd pollution was mainly studied. The results show that: relative to the Xuzhou soil background value, the variation degree of Hg, Cu, Cd, Pb is great; the variation degree of Zn in gangue is also great. The variation degree of As, Cr as well as fly ash site, control soil is little. Refer to the China soil quality standard, all Cd. Samples surpass the standard; with the exception of few samples of As, Zn and Cu, others do not exceed the standard. Taking Cd distribution in fly ash site as an example, the polynomial fitting model was used to describe its change regularity with depth and the fitting equation is feasible. Besides, the Kriging Model was applied to investigate the Cd distribution regulation. The built models show high fitting precision and the research results above will provide foundations for rehabilitating the polluted land in mining area and then setting corresponding measures.