(60) Co + ~ (95) Zr In The Ecological Environment In The Behavior Dynamics

Nuclear electron will be quickly developed in near future in our country, and 60Co> 95Zr is one of the main activated products and fission products of nuclear reactor. Cobalt is an important trace neutron element to animals and plants. Considering the sudden occurring and the seriousness of injury of the nuclear polluting accidence, it needs to have a systematical study on the behavior in environment, animals and plants of 60Co and 95Zr. The isotope tracer techniques were applied to study the adsorption, transportation, accumulation and distribution of 60Co and 95Zr in different ecosystems, different plants and animals. Based on the principle of tracer dynamic compartment models, the mathematical formulae were established via computer simulation to describe the behavior of 60Co and 95Zr in ecosystems and thus provided some basic information for the behavior of 60Co and 95Zr in the environment. Five sections as follows:Section one: The energy spectrum curve of 60Co and 95Zr's solid samples and water samples were measured by using BH 1224 multichannel energy spectromenter, and the influence of its metrical repeatability, the weight of samples and radioactivity on the results were determined and analyzed, then concluded the corresponding calibration curve.Section two: The adsorption and desorption of 60Co and 95Zr were studied in paddy soil on powdery loam, yellow-red earth, paddy soil on blue purple clay and sea clay, the results showed that after 60Co and 95Zr entered into the flood soil, it was quickly adsorbed by soil and reached the adsorption equilibrum, and desorped difficultly. The order of the saturated adsorption rate and Redistribution coefficient) of 60Co and 95Zr at the balance value was: sea clay, puddy soil on blue purple clay, paddy soil on powdery loam, yellow-red earth. The order of Df(desorption factor) value was: yellow-red earth, paddy soil on powdery loam, puddy soil on blue purple clay, sea clay. The dynamic behavior of 60Co and 95Zr in the soils could be described by a closed two-compartment model.Section three: The leaching and vertical transport of ^Co and 95Zr in two representational soils (paddy soil, yellow-red earth) were studied with soil-pole installation. The results showed that: (1) the content of ^Co and 95Zr in collected leaching water was low after passing through soil column. (2) most of 60Co and 95Zr remained in surface soils. (3) the content of ^Co and 95Zr were attenuated by the law of index with the depth of the soils.Section four: The dynamics of transportation, accumulation, disappearance and distribution of 60Co and 95Zr in the wheat-soil system and broadbean-soil system were studied, and the mathematical model of the behaviour law was built. It was shown that (1) 60Co and 95Zr were transported rapidly in the system after they were lead into the surface layer of soil. The uptake of 60Co and95Zr by wheat and broadbean was mainly via root, and redistribution to other parts of wheat and broadbean. Concentration then in root was much higher than in other parts of wheat and broadbean plant. The specific activity of 60Co and 95Zr in wheat plant rapidly increased to a maximum value, then decreased. The specific activity of 60Co and 95Zr in each part of wheat plant was found to be arranged in order of root > straw > husk > seed. The specific activity of ^Co and 95Zr in each part of broadbean plant was as follows root > straw > husk > seed. (2) 60Co and 95Zr were mainly detained in 6 cm of surface soil, and specific activity of 60Co and 95Zr in soil presented a individual exponential declining with depth of soil.(3)The dynamic law can be described as multinomial exponential function of concentration in the wheat-soil system.(4)The wheat and broadbean plant had some ability to accumulate 60Co and95Zr in soil.Section five: Study on the distribution and accumulation of 60Co and95Zr in the aquatic system. When 60Co and 95Zr was introduced into aquatic system, it was transported and transformed via deposit, complex with other ions, adsorb and absorb in the systems an...