某废弃的草酸生产场地土壤重金属污染特征与风险评价

Characteristics and Evaluation of Heavy Metal Pollution in Soil of a Chemical Site

该文以合肥市某废弃的草酸生产场地的Ni、Pb、As、Ba、Cr、Cu、Hg重金属为研究对象进行测定与分析,采用克里金插值法对其表层空间分布进行描述,采用相关性分析与主成分分析法对其来源进行分析,采用地累积指数法和潜在生态风险指数法进行评价。结果表明,七种重金属最大值均超过安徽省土壤背景值,其中Pb在各土层的最大值均超过了GB 36600-2018中的第二类用地筛选值,最大值在0~0.5m,其他六种重金属最大值均未超过筛选值。主成分分析表明,土壤中Pb主要来源于原料生产过程中的遗撒泄漏,Ba、Hg主要来自污水不达标排放。地累积指数评价表明,9.72%点位的Pb处于中度及以上污染状态,其中重污染集中在酸化车间。潜在生态风险法表明,该场地整体处于轻度风险。

This article takes Ni,Pb,As,Ba,Cr,Cu,and Hg heavy metals from an abandoned oxalic acid production site in Hefei City as the research object for measurement and analysis.The Kriging interpolation method is used to describe the surface spatial distribution,correlation analysis and principal component analysis are used to analyze their sources,and the land accumulation index method and potential ecological risk index method are used for evaluation.The results showed that the maximum values of Ni,Pb,As,Ba,Cr,Cu and Hg all exceeded the soil background values in Anhui Province.The maximum values of Principal component analysis indicates that Pb in all soil layers exceeded the second type of land use screening values in GB 36600—2018,with a maximum value of 0~0.5 m,and the maximum values of the other six heavy metals were not above the screening values.Pb in soil is mainly from the leakage of raw materials in the production process,while Ba and Hg are mainly from the substandard discharge of factory sewage.The single factor index evaluation showed that 9.72%of Pb sites were polluted,and the heavily polluted sites were concentrated in the acidizing workshop.The health risk assessment showed that Pb in the soil exceeded the acceptable risk level.