Soil Heavy Metal Pollution Around Iron Tailing Areas at Different UsingStatus

Abstract

Heavy metal pollution was a dynamic changing process for a long period and on large spatial scale. The heavy metal content in tailing soil varied with time changing. The distribution and cumulative characteristics of heavy metals in different time and surrounding soil caused by ore dressing and smelting activities were different. The aim of this study was to assess the geochemical characteristics and pollution status of heavy metals in soil around 2 iron tailing areas at different using status. Samples were collected around the 2 different iron tailing and sieved through nylon sieves. Metals were measured in digested solutions by a atomic emission spectrometer. The concentration of all heavy metals (Fe, Mn, V, Cu, Ni) in the soil around using M tailing area exceeded local soil background value; however, the content of all metals except Fe in soil around closed W tailing areas were lower than background value. BCR results showed that average exchangeable fraction of Mn in soil around W and M accounted for 11.87%, 11.78% of the total concentration, respectively; average exchangeable and reducible fractions of Ni accounted for 26.97% and 13.59%, respectively; average oxidizable fraction of Cu accounted for 18.6%, 31.63% in soil around W and M, respectively, which were higher than other metals; residual fraction of Fe, V accounted for more than 80% of the total concentration. The results indicate the soil was moderately contaminated by heavy metal around M and unpolluted around W. However, the risk assessment results performed that Mn showed moderate potential ecological risk and other metals showed low potential risk.