Environmental Investigation and Risk Assessment of an Abandoned Mining Area

In order to provide basic information for soil remediation and land use planning of an abandoned mining area in Tieshan District, Huangshi City, pollution status of soil, groundwater and surface water were investigated, the biological toxicity of soil and water were analyzed and the ecological risk of heavy metals in soil were assessed in the present study. The results show that certain heavy metal pollution occurred in the production site, mainly as As, Cr, Cu, Ni, Cd and Pb; The concentrations of heavy metals in surface water and groundwater were low, which met the quality standard of Class Ⅲ in Surface Water Environmental Quality Standards (GB 3838-2002) and Class Ⅴ in Groundwater Quality Standards (GB/T 14848-2017), respectively. Toxicological results show that 13.8% of soil sampling sites were toxic to plant seed germination, and the rest had low toxicity level. All of the water samples had no toxic effects on the growth of luminescent bacteria. Risk assessment results indicate that the area exceeding the risk screening were 2 307m² under Class II land (non-sensitive site). The area corresponding to the Class Ⅲ or higher risk of effective heavy metals and strong or higher ecological risk were 48 642 and 49 135 m², respectively. The results of this study can provide a basis for the risk control scheme and remediation measures for the mining area to ensure that the soil quality meets the requirements of the planned land use.