SORPTION-DESORPTION CHARACTERISTICS OF URANIUM, CESIUM AND STRONTIUM IN TYPICAL PODZOL SOILS FROM UKRAINE

摘要

Sorption-desorption behaviour of uranium (U), cesium (Cs) and strontium (Sr) was examined by quantification of the solid-liquid distribution coefficients (K_d) using batch method in typical podzol soils from Ukraine. The effect of different physico-chemical parameters of soil on K_d values has been discussed. Sorption reversibility has been tested by single extraction test. U shows reversible sorption and there was no isotopic fractionation observed with a known isotopic U composition using as tracer. Cs sorption mostly occurred in an irreversible manner. The clay content and exchangeable potassium in soil play an important role in Cs fixation. Sr adsorption is observed to be reversible and mainly controlled by cation exchange and shows highest mobility in the soil-water system. The K_d values are found in the decreasing order U (log K_d ≈ 2-3) > Cs (log K_d ≈ 2) > Sr (log K_d ≈ 1).