The Pollution Evaluation and Spatial Distribution of Soil Heavy Metals Surrounding Chemical Industrial Park

Abstract

On the basis of collecting 39 surface soil samples in Nanjing Liuhe Chemical Industrial Park as well as its surrounding area, and determining the total contents of Cu, As, Pb, Hg, Cd, this article evaluated the pollution index of soil heavy metals with the application of single factor index method and Nemero pollution index method. Meanwhile, the authors used Ordinary Kriging Method to draw the spatial distribution map of heavy metals pollution and then analyzed the influence of chemical industry park on the soil with the difference in distance and wind direction. The result shows that the soil heavy metals pollution produces large harm, and the average composite pollution index which is 1.13 reaches the pollution level. The degree of heavy metal pollution is correlated with the distance from chemical industrial park, which is demonstrated that, the closer the site is to the industrial park, the higher the pollution index is. The influence radii of the different elements rank as Hg>Pb>Cd>Cu>As. Furthermore, the diffusion characteristic of the heavy metals in different directions is consistent with the wind direction, and the pollution index is higher in the downwind southwest and northwest direction.