The Study of Cesium Behavior in the 'Radioactive Contaminated Soil - Soil Solution - Sorbent - Plant' System

This work presents a comparative study of sorption characteristics of soil and modified sorbents with respect to Cs-137 as well as the results of experiments on sorbents influence on cesium transfer from soil to vegetation. Distribution coefficients, exchange capacity, sorption kinetics and reversibility of sorption of cesium by soil and surface-modified sorbents were determined. It was suggested that slow migration of cesium from soil particles to the sorbents through the soil solution will occur in the process of rehabilitation of radioactively contaminated soils. The results of experiments with oats growing on radioactive soil showed that slow sorption of cesium by components of the soil resulted in the decrease of cesium concentration ratios by the factor of 3-4 three months after contamination; then concentration ratios remained the same during next 1.5 years of the experiment. Addition of only 1 % of a surface-modified sorbent to the soil resulted in decrease of cesium transfer from soil to vegetation by an order of magnitude.