LAUSR

The paper presents the investigation on the estimated efficiency of iron (III) chloride solutions in the decontamination process of radioactive soils with 90Sr, according to kinetic and thermodynamic characteristics of the desorption process. The specific 90Sr radioactivity of soil samples was (3.9±0.3)·104 Bq·g. The adsorption isotherms of Sr2+ and Fe3+ are described with the Langmuir equation. The values of Gibbs energy G298 = -4.65 kJ·mol -1 and equilibrium ion exchange constant Keq = 6.5 confirm the hypothesis of strontium removal from soils with iron (III) cations. The effectiveness of the method is substantiated by experimental and calculated results of this study samples of radioactive soils are deactivated in 90% after 9.5 hours, whereas the kinetic constant is 6.77·10 s-1. The suggested method of soil cleanup with 0.2 M Fe3+ solutions is optimal and complies with the environmental requirements.