土壤生态地球化学风险评价——以乐陵-河口地区为例

The Soil Ecological Geochemistry Risk Assessment——A Case Study in Leling-Estuary Area

以全国土地污染防治项目取得的地球化学数据为基础,对乐陵-河口地区土壤重金属含量水平、污染现状、主要来源进行系统研究,并在研究区内开展土壤生态地球化学风险评价,结果表明:表层土壤中元素Cd、Hg、Pb富集系数较大,其平均含量分别为0.16mg/kg、0.030 mg/kg、21.8 mg/kg,表现出明显的表层富集特征。区内土壤重金属元素潜在生态危害轻微级达到90.07%,中等的占9.58%,强的占0.35%,没有很强和极强级别,土壤潜在生态危害不很严重。Hg、Cd、As 3种元素对土壤危害的贡献率之和达到86.55%,Hg是调查区土壤污染最严重和危害最大的重金属元素,其生态危害贡献率就达到了48.03%;Cd次之,强和很强生态危害等级以上的土壤样品占总数的0.32%;土壤重金属元素危害程度从大到小的排序为Hg>Cd>Pb>As>Cu>Ni>Cr>Zn。该研究在制定重金属污染防治对策、进行土壤环境质量保护等方面具有重要的指导作用。

Based on the geochemical data obtained from the national project about the prevention and control of soil contamination,through studying on the pollution investigation and the temporal and spatial variation of soil heavy metal,this study analyzed the pollution status and dynamic changes of soil heavy metals profoundly and systematically,carried out ecological geochemical assessment of risk in the study area.The results showed that：potential ecological risk of heavy metals in the soil was in slight level.The contribution the elements Hg,Cd,As in soil damage reached 86.55％.The contribution of the ecological hazards of the element Hg reached 48.03％.The samples that the degree of ecological hazard of Hg are very serious and extremely serious accounted for 9.69％ of the total,The contribution of Hg in ecological hazard only reach 44.64％ among the three elements ; The samples of Cd above the level of serious ecological hazards accounted for 0.32％.The elements sorted in descending in ecological hazard is Hg ＞ Cd ＞ Pb ＞ As ＞ Cu ＞ Ni ＞ Cr ＞ Zn.This study will provide technical support for heavy metal pollution prevention and soil environmental quality protection.