^137Cs的土壤地球化学及其侵蚀示踪意义

13 7Cs是环境中一种重要的放射性同位素 ,它是由大气核试验和核事故产生并在环境中赋存和蓄积 ,在环境地球化学的研究中有着广泛的用途。目前 ,对于高含量 1 3 7Cs的环境行为研究较多 ,但是对环境背景水平的 1 3 7Cs(多为几千个 Bq/ m2 )的地球化学行为的研究 ,由于研究方法和实验设计上的困难却相对研究较少 ,极不利于 1 3 7Cs在更大的范围内为人类服务。基于此 ,从土壤中 1 3 7Cs的来源和时间分布、1 3 7Cs在土壤中的吸附固定、土壤中 1 3 7Cs的迁移运动 3个方面论述 1 3 7Cs的地球化学 ,对1 3 7Cs的侵蚀示踪原理与技术路线进行综述。最后对1 3 7Cs相对其它核素在土壤侵蚀示踪上的比较优势进行归纳总结

Soil Geochemistry Characteristics of 137 Cs and Its Theory of Tracing Soil Erosion

Cs is an important radionuclide in the environment. It is produced by nuclear test in the atmosphere and nuclear accidents, then existed and accumulated. 137 Cs are used in many fields of environmental geochemistry. The behavior of 137 Cs at high content has researched much more. But pay little attention to the geochemistry behavior of 137 Cs at environmental background level because of the difficulties of research methods and experiment design. For the extensive usage of 137 Cs at several thousand becquerels as a tracer in the soil erosion and lake and reservoir sediment research, these use need detailed understanding of the environmental behavior of 137 Cs. The results showed that: (1) the source and fallout of 137 Cs with time in soil body. (2) the adsorption and fixation in soil composition. (3) input and output of 137 Cs in soil. In the end, the theory of tracing soil erosion and technical path of quantifying erosion using 137 Cs are discussed, the advantages of 137 Cs as a tracer compared to the other radionuclide are concluded.