PREDICTION OF SOLID LIQUID DISTRIBUTION COEFFICIENTS OF RADIOCESIUM IN SOILS AND SEDIMENTS .2. A NEW PROCEDURE FOR SOLID-PHASE SPECIATION OF RADIOCESIUM/

A new procedure is developed for assessing the speciation of radiocaes ium in soils and freshwater sediments. The method relies on the differ ence in the variation of K-D(137Cs) with NH4 concentration when Cs is present in the regular ion exchange complex or the micaceous frayed ed ge sites. The theoretical basis for the method is presented. The exper imental procedure is based on the measurement of K-D(137Cs) as a funct ion of NH4 concentration in a mixed K-Ca solution of constant composit ion. It is demonstrated that in most sediments and some soils, even so me peat soils of 80% organic matter content, K-D(137Cs) response to NH 4 concentration coincides with the one obtained for a reference illite clay. thus showing quantitative adsorption of radiocaesium in the fra yed edge sites of the micaceous clays. Copyright (C) 1996 Elsevier Sci ence Ltd