Kinetics Of Absorption Of Cesium In Red Soil In Southwest Area

Developing nuclear power is one of the main methods to solve the short of energy sources. With the rapid development of nuclear technique especially nuclear power station, large of radial waste has been produced inevitably. Meantime, with the long-term running of the nuclear military fair, some nuclear establishments have been retired. If the radial wastes be released into the environment, they would become to be the potential pollution resource.Cs is the 55 element in the Periodic Table, belongs to the alkali metal of IA. ¹³⁴Cs, ¹³⁷Cs are the major components of the nuclear fission. It can enter into the environment by atmosphere sedimentation or by underground water. It is one of the important factors for the environmental evaluation.In this paper, according to the red soil characteristics in some place of Southwest, the characteristics of kinetics absorption of Cs in soil were studied by static and dynamic experiment methods. According to the experimental results, the characteristics of migration and adsorption mechanism of Cs in soil can be determined, and also the place for storing up the radial waste containing Cs can be selected. The research results are showed following.1. The Cs isothermal adsorption in red soil is determined by static method and the isothermal adsorption process can be fitted by Freundilich equation. The absorption of Cs in soil is affected by the pH value of soil. The saturation absorption capacities of Cs in soil were 26.38 mg/g, 28.62 mg/g, 31.57 mg/g, and 34.85 mg/g respectively with the value ofpH of 4, 6, 8, and 10.2. The absorption of Cs in red soil under different condition is studied by dynamic experiment methods. The results indicated that the dynamic absorption capacities of Cs in soil increased with the increase of pH value of cesium adsorption solution and the initial concentration of cesium adsorption solution, decreased with the increase of sample soil granularity and K⁺ concentration. There is no obvious linearly connection with the flux on the cesium absorption solution.3. The Elovich equation, parabola equation, double constant equation and first-order equation were used to simulate Cs adsorption in red soil. The results indicated that Elovich equation was the best dynamic model to describe Cs adsorption in red soil; the next was the first-order equation.4. The regression equation is simulated between dynamic absorption capacities and pH value, initial concentration, soil granularity. The linearity is very good.5. The main components of the red soil are montmorillonite, illite, quartz and feldspar. The percentage content for them in the research red soil is 40 %, 19 %, 28 % and 13 % respectively. Quartz has no adsorption ability to Cs, so the minerals adsorbing Cs are montmorillonite, illite and feldspar.