Migration of radionuclides 137Cs and 90Sr in the soil – Plant system and modeling of these processes

International Conference on Nuclear Chemistry

December 08-09, 2016 San Antonio, USA

Leonid Maskalchuk

National Academy of Sciences of Belarus, Belarus

Posters & Accepted Abstracts: J Nucl Med Radiat Ther

Abstract :

The models of 137Cs and 90Sr migration in the soil��?plant system were developed. The models are based on the general mechanisms of physicochemical and biological processes in the soil-plant system, the couple of which determines migration of 137Cs and 90Sr from contaminated soils into plants. The following conclusions can be drawn from a number of laboratory experiments aimed at verification of the developed models: The parameters of 137Cs and 90Sr migration from soil into plant, calculated on the basis of parameters of soil solution, are linearly related with the coefficients of 137Cs and 90Sr accumulation in the soil��?plant system. It is a correlation between migration of 137Cs and concentration of K+ in the soil��?plant system. The cation �?+ is a concurring ion to 137Cs+ and is able to prevent it��?s fixation on soil. The migration of 90Sr in the soil��?plant system can be reduced by liming of acidic soils. This process is limited by the cation-exchange capacity (CEC) of the soil. Concentration of exchangeable forms of Ca2+ is the main factor having influence on the migration of 90Sr in the soil��?plant system. Liming leads to reduction of exchangeable forms of 90Sr and increasing of exchangeable forms of Ca2+. The maximum effect of liming is observed when the initial concentration of Ca2+ in the soil solution is less than 1/2 of CEC of the soil. Taking into account the economically acceptable level for sorbent insertion into soil (1��?4 wt %), migration of 90Sr from soils into plants is efficiently reduced (up 2 times). There is a necessary condition: the ratio of sorption potentials of the sorbent and the soil should be >25. An expression for the parameter of 137Cs and 90Sr migration in soil was received: it is a combination of parameters of soil solutions, such as concentrations of radionuclides and exchangeable cations. This parameter allows to predict coefficients of 137Cs and 90Sr accumulation in plants and to estimate the efficiency of different methods of reduction of 137Cs and 90Sr migration from soils to plants. The developed models of 137Cs and 90Sr migration in the soil��?plant system are in a good agreement with the obtained experimental data.

Biography :

Email: leonmosk@tut.by