典型石油场地周边土壤重金属形态特征及源解析

为研究荆门市某石油场地周边表层土壤重金属形态特征和来源，对研究区土壤中Cr、As、Cd、Sb、Hg、Pb、Ni、Cu和Pb这9种重金属总量和赋存形态进行了调查分析，对土壤中重金属的生态风险和生物有效性进行评价，并且用多元分析方法对重金属的来源进行辨析.结果表明，Cd在土壤中主要是以酸溶态和可还原态为主，含量平均值为0.19 mg·kg^-1，占到4种形态总和的79.86%；Cr、Cu、Zn、As、Sb和Pb主要以残渣态为主，Hg主要以残渣态和可氧化态为主，在土壤中稳定性较好.Cr处于无风险状态，Sb、Pb、Ni和Cu的风险评价结果为低风险.Cd、Hg、Zn和As的风险指数均达到中等风险水平，尤其Cd接近高风险标准，需要引起相关重视.土壤重金属总量和赋存形态的相关性和主成分分析结果表明，As、Cr、Ni、Sb、Hg和Pb等重金属主要来源受自然输入影响较大，重金属Cd受工业生产人为活动的外源性因素影响较为明显.

Species Distribution and Source Analysis of Heavy Metals in Surrounding Soil Around Typical Petroleum Sites

In order to understand the speciation characteristics and sources of heavy metals in the surface soil around a petroleum site in Jingmen City, the total amount and occurrence form of nine heavy metals including Cr, As, Cd, Sb, Hg, Pb, Ni, Cu, and Pb in the soil of the study area were determined, and the ecological risk and bioavailability of heavy metals in the soil were evaluated. The sources of heavy metals were analyzed using multivariate analysis. The results showed that Cd was mainly in acid-soluble and reducible forms in the soil, with an average content of 0.19 mg·kg^-1, accounting for 79.86% of the total of the four forms; Cr, Cu, Zn, As, Sb, and Pb were mainly in the residual form. Hg was mainly in the residue state and oxidizable state and had good stability in the soil. Cr was in a risk-free state, and the risk assessment results of Sb, Pb, Ni, and Cu indicated low risk. The risk indexes of Cd, Hg, Zn, and As all reached the medium risk level, especially Cd, which was close to the high risk standard, thus requiring particular attention. The correlation and principal component analysis of the total amount of heavy metals in the soil and their existing forms showed that the main sources of heavy metals such as As, Cr, Ni, Sb, Hg, and Pb were greatly affected by natural input, and the heavy metal Cd was more obviously affected by exogenous factors caused by human activities in industrial production.