Pollution Characteristics and Sources Analysis of Soil Heavy Metal in Taoyuan Coal Mine of Suzhou City

Abstract

Soil is one of the most important resources and an important part of ecosystem in the development of human survival. The purposes of this study are to investigate concentration characteristics and sources analysis of heavy metals in Taoyuan coal mine of Suzhou City. 30 soil samples were collected and characterized for metal concentration (Cd, Cr, Cu, Pb, Zn and As), then the heavy metal pollution was evaluated by using pollution load index and geoaccumulation index and the sources of heavy metals were analyzed. The results revealed that the mean concentrations, except Cr, were considerably higher the reference values, especially Cd, Cu Pb and Zn in study area soil, than non-mining soil in Suzhou. The results of the geoaccumulation index (I_geo) showed the following sequence: Cd>Cu>Pb>Zn>As>Cr. At the same time, Cr and As of all samples were not contaminated, Zn and Pb were non-pollution to light pollution, Cd and Cu were light pollution to moderate pollution. The potential ecological ecological risk (E_i) values of Cd had a strong risk pollution and the other five metals belonged to a light ecological risk, the potential ecological risk (RI) mean implied moderate pollution for samples in the study area. The correlation analysis declared that the first principal component is dominated by Cd, Zn and Pb and marked correlation indicate that they should be related to coal mining, smelting processing, weathering, leaching and coal transportation. The second principal component was occupied by Cr, Cu and As, the source of Cu may be affected by Zn and Pb, Cr and As can be regarded as from the soil parent materials. It was believed that the heavy metals in the soil of Taoyuan Coal Mine were polluted to a certain extent and the accumulation of Cd, Zn and Pb were mainly affected by mining activities.