化工园区内重点企业土壤重金属分布特征及风险评估研究

Studies on Pollution Characteristics and Risk Assessment of Heavy Metals in Soil of industrial Enterprises in Industrial Parks

为探明工业园区重点企业土壤重金属分布特征及潜在风险影响,本文以宁夏区内某化工园区内16家重点企业作为研究对象,采集并测定了土壤中As、Cd、Cu、Pb、Hg和Ni等重金属。采用单因子污染指数法、内梅罗综合污染指数法、地累积指标法和潜在生态风险评价法进行了污染程度评价。结果表明:土壤中As、Cd、Cu、Pb、Hg、Ni平均含量分别为10.8、0.20、24、21.1、0.072、28 mg/kg,均未超出《土壤环境质量标准》(GB 15618—2018)(pH>7.5)中土壤污染风险筛选值标准,Hg、Cd、Pb和Cu平均含量略高于背景值,Hg的平均值为背景值2.6倍。单因子污染指数和内梅罗综合污染指数评价结果表明,重金属均呈清洁(安全)水平,土壤表现为无重金属污染状态。潜在生态风险指数评价结果表明,土壤整体呈轻微生态环境风险。但地累积指数结果表明,Cd和Hg积累明显,应该予以关注。

In order to understand the characteristics of heavy metals contamination in the soils,this paper taked 16 industrial enterprises in industrial parks of Ningxia as the resaerch object.soil heavy metals(As、Cd、Cu、Pb、Hg and Ni)were investigated and tested.The pollution status was evaluated by single factor pollution index method,Nemerow comprehensive pollution index method,ground accumulation index method,potential ecological hazard index method and geological accumulation index method.The average contents of As、Cd、Cu、Pb、Hg and Ni in the soils of survey area were 10.8、0.20、24、21.1、0.072 and 28 mg/kg,respectively,which were all lower than the threshold values of the secondary standard of National Environmental Quality Standard for Soil(GB 15618-2018)(pH>7.5).But the average contents of Hg,Cd,Pb and Cu were lower than the background value of Ningxia,while the average content of Hg was 2.6 times higher than the background value.Two analysis methods results(The single factor pollution index and Nemerow comprehensive pollution index)showed that the pollution degree was clean(safe)level,and the soil in the studied area showed no heavy metal pollution.Further,the ground accumulation index revealed that the soil was in slightly potential ecological risk.Although the soils industrial parks of Ningxia had little affects from the heavy metal pollution,but the accumulation of Hg and Cd were obvious,the impact of these two heavy metals on soil environment of industrial parks should be pay attention as soon as possible.