摘要
The present paper deals with the retention of U(IV) and U(VI) species, both individually and in 1 :1 mixtures, on some ion-exchange resins of the normal DGA (N,N’,N’-tetra-n-octyldiglycolamide), TEVA- [trialkyl methyl-ammonium nitrate (or chloride)] and UTEVA-type (dipentyl pentylphosphonate), in different experimental conditions. The degree of retention, distribution constant, as well as enthalpy and entropy values which characterize the adsorption of uranium ions on these resins were calculated. By means of Langmuir relation, taking into account the experimental data, the maximum adsorption capacity, Langmuir constant and Gibbs free energy values for the studied processes are established.