土壤粒级中重金属元素的形态分析与环境风险评价

Morphologic analysis and environmental risk assessment of heavy metal elements in sized-fractionational soils

研究评价不同粒级组分中重金属的活性和潜在环境风险,对3个地区土壤颗粒的分析表明,重金属在土壤中分布并不均匀,随着颗粒粒径的减小,重金属Cu、Cd元素及有机质的浓度有不断增高的趋势。线性分析显示,Cu、Cd元素浓度与有机质的浓度显著相关。形态分析表明,Cd主要以环境高活性的形态存在,其次以低活性的形态存在,环境惰性的形态仅占极小部分;Cu主要以低环境活性和环境惰性的形态存在,高环境活性的形态只占小量,Cu在土壤中的存在形态可能与土壤性质有关。

Activity and environmental risk assessments of heavy metals in soil fractions were helpful to understand and control the behaviors, chemical transformation and rules of heavy metal in environment. Chemical analysis of Cu, Cd and organic carbon in each solid fraction of soils samples from three areas showed that the concentration of these components increased as particle size decreased, and the concentration of Cu or Cd was positively co-related with organic carbon,indicating colloids and nano-colloidal particles played an impor- tant role in retaining heavy metals. Chemical fractionation by morphologic method showed that Cd mainly existed in high active form,indicating a higher risk in soil environment while Cu mainly in lower active and inert forms, minor in higher environmental activity, indicating a lower environmental risk. The existed form of Cu in soils was probably related with the quality of the soils.