下寒武统黑色页岩土壤放射性元素的赋存形态和环境活性研究∗

摘要

下寒武统黑色页岩分布区生态环境问题日益突出，其中，土壤的放射性污染已引起关注。目前已广泛认识到，放射性核素在土壤等环境介质中的分布、迁移转化以及环境生态毒性等并不决定于它们的总含量，而主要取决于在介质中的化学形态。通过连续化学提取技术并结合每一步骤提取的残余物精细物相分析和U的微区测定对黑色页岩土壤U赋存形态进行研究并定量分析其环境活性和对环境的释放潜力，可以更好的了解其在风化成土过程中的迁移/富集机制，同时为区域放射性环境风险评价和环境治理提供科学依据。%The ecological environment problems are increasingly protruding in the Lower Cambrian black shale distribution area, wherein the radioactive pollution of the soil has aroused concern. It is now widely recognized that the distribution, mi-gration and environmental ecological toxicity of the radionuclide in soil environmental medium is not decided by their total content, but mainly by the chemical form in the medium. Through sequential chemical extraction technique and careful phase analysis of the extracted residue in each step along with micro area determination of uranium to study occurrence mode of uranium in black shale soil and to quantitatively analyze its environmental activity and its release potential, better understanding of its the migration and accumulation mechanism in the process of weathering to soil can be realized, at the same time a scientific basis for risk assessment of radioactive environment and environmental governance can be provided.