SORPTION OF RADIOCESIUM ON SOILS IN THE PRESENCE OF ELECTROLYTES

The influence of background electrolytes (KCl, NH4Cl, CTABr) in differ ent concentrations on the sorption ability of radiocesium by measuring the distribution coefficient has been studied. Sorption isotherms of cesium for characterization of soil sorption ability were used. Sorpti on of cesium depends on its concentration and at least three different sorption sites are active in the sorption process. In the case of low cesium concentration, two very selective sites with high distribution coefficients are responsible for the sorption. With increasing cesium concentration in the aqueous phase, distribution coefficient is decre asing. Frayed edge sites of illite in soil and exchangeable potassium are probably responsible for nonlinear isotherms at low cesium concent rations. From sorption isotherms and determination of potassium by act ivation analysis, it was found that the capacity of very selective sit es for different concentrations of background electrolyte was up to 7 mmol . kg-1.