Distribution Characteristics And Risk Assessment Of Heavy Metals In Soils On Both Sides Of Nanjing Road In 2017

In this paper,the surface soil(0-20cm)on both sides of Nanjing road in 2017 was taken as the research object.The physical and chemical properties of soil,such as conductivity,salinity,pH,ammonium nitrogen,available phosphorus,available potassium,organic matter,cation exchange capacity and particle size,were systematically studied.ICP-OES inductively coupled plasma emission spectrometer was used to detect soil.The contents of Cd,Cr,Cu,Ni,Pb and Zn in surface soil of Nanjing Road area were analyzed.Soil samples were assessed by modified single pollution index method,Nemerow comprehensive pollution index and land accumulation index.The potential ecological risk index method was used to analyze the pollution status and potential risk of heavy metals in soil.SPSS 1 8.0 statistical software was used to analyze the correlation of elements,stepwise regression analysis,correlation analysis of elements and physical and chemical properties and significant difference test.The relationship between heavy metal content and traffic volume,the relationship between heavy metals,and the correlation between heavy metal content and physical and chemical properties were analyzed by correlation analysis.The main conclusions are as follows:1.Except for Ni,the remaining five heavy metals in the soil on both sides of Nanjing road exceeded the background values of Jiangsu Province.It shows that the soil on both sides of Nanjing road has been polluted by heavy metals to a certain extent.2.The correlation between Zn and Cd,Cu and Pb in road soil of Nanjing city is significant,and the correlation between Cu and Zn is significant at the same time(p<0.05 or 0.01).Except for Cr and Ni,the other four heavy metal elements in soil are positively and significantly correlated with organic matter,conductivity and salinity,indicating the adsorption of Cd,Cu,Pb and Zn in soil.Organic matter,conductivity,salinity and other environmental factors affect storage.3.Using the revised single factor index as the basis for evaluating Merlot and land accumulation index,it is concluded that the soil is heavily polluted by Cd and is basically not polluted by Ni.According to the potential ecological risk assessment,the order of the potential ecological risk level of heavy metals in the soil of Nanjing Urban Road area is:Cd>Pb>Cu>Ni>Zn>Cr.The totally potential ecological risk level is from medium to high.The order of comprehensive potential ecological risk of different functional road areas is fast Second Ring Road>fast trunk line>fast auxiliary line.4.The results of correlation analysis and principal component analysis show that the heavy metals Cd,Cu,Pb and Zn in the soil on both sides of Nanjing road mainly come from vehicle traffic pollution,while Cr and Ni mainly come from vehicle traffic pollution and industrial pollution.