咸阳城市道路绿化带土壤重金属含量特征及污染评价

Heavy Metal Content Characteristics and Pollution Evaluation of Soil in Green Belt of Urban Roads in Xianyang City

对咸阳市两条交通干道的绿化带表层土壤进行取样测定,对其中6种重金属元素锌(Zn)、铅(Pb)、铬(Cr)、铜(Cu)、镍(Ni)、镉(Cd)的含量等特征及污染情况进行分析,运用地积累指数法和潜在生态风险指数法对绿化带土壤重金属的污染程度进行评价,再结合多元统计方法,对数据进行相关性分析和主成分分析,以此来推测判断其污染来源。分析得出2/3的重金属元素的平均含量超过当地和国家土壤元素背景值,元素受外界影响因素显著,空间分析性大。其中Cd和Pb的污染程度较高,其余4种的污染程度及潜在风险均较轻微,但Cd元素超标率较低,两条道路平均超标率只有33.5%。由多元统计分析可知,该研究区土壤重金属污染是多种因素共同影响的结果,推测交通运输相关活动对土壤重金属污染具有主要贡献。

This paper samples and measures the topsoil of the green belts of two traffic trunks in Xianyang City,and analyzes the characteristics and pollution of six heavy metal elements such as zinc,lead,chromium,copper,nickel and cadmium.The potential ecological risk index method evaluates the pollution degree of heavy metals in the green belt soil.Finally,the multivariate statistical method is combined with the previous research to analyze the correlation and principal component analysis of the data to estimate the source of pollution.The analysis found that the average content of 2/3 heavy metal elements exceeds the background values of local and national soil elements,and the elemental elements are significantly affected by external influences,and the spatial analysis is large.Among them,Cd and Pb have higher pollution degree,and the other four kinds of pollution degree and potential risk are relatively mild,but the Cd element exceeding the standard rate is low,and the average rate of the two roads exceeding the standard rate is only 33.5%.According to the multivariate statistical analysis,the heavy metal pollution of soil elements in this study area is the result of multiple factors.It is speculated that transportation-related activities have a major contribution to soil heavy metal pollution.