Soil heavy meatl geochemical bar in high risk zone by coal mining

• 1、College of Natural Resoruces and Environment, Norhtwest A&F University, Yangling, Shaanxi 712100

Abstract：Analysis on soil heavy metal geochemical bar is very important to understand element migration, enrichment and pollution in coal mining area. In this paper, based on the sampling in cultured land on 52 sites around coal mining area in Daliuta town, heavy metal concentration, enrichment and pollution were assessed. The results indicated that coal mining has significant contribution on soil heavy metal enrichment and pollution in the past 20 years in Daliuta coal mining area. Heavy metals has accumulated in the surface layer (0-20cm), the concentration of heavy metals were 11-52% higher than sublayer except Zn, which indicated that soil heavy metal geochemical bar has formed in the surface layer. But the enrichment was not very intensive by the EF (Enrichment factor) range from 1.7 to 3.3 of heavy metals in the surface layer. The concentration of heavy metals were higher than the environmental background value, but were lower than environmental quality standard for soil (II), soil was still clean. Soil heavy metal pollution by coal mining was a slow procedure, and some of the element has near to pollution grade. Therefore, the significant enrichment of heavy metals in surface layer should be given high attention.

Keywords： Soil science Soil geochemical bar coal mining Daliuta Town