Adsorption of radioelements on mixtures of minerals - experimental study

An experimental study has been undertaken concerning the adsorption of radioelements on mixtures of minerals. The question is whether the adsorption of trace elements by rocks and soils can be easily predicted from the properties of the constituent minerals. The goal of these experiments was the comparison between the measurements of distribution coefficients of some radioelements for pure minerals and for binary mixtures according to the Doehlert's uniform shell designs and to test an additive law of combination of Kd. The results showed that when one of the constituents acts as a dilutant in the mixture, i.e. it presents a very low adsorption capacity with respect to some trace element, then the relations of additivity of Kd are fulfilled. Otherwise, these relations are not satisfied and this is probably caused, in the present cases, by interactions from solubilized species. (C) 2000 Elsevier Science Ltd. All rights reserved.