A comparative study on kinetics of ion exchange in binary system fitted by three models

A 'three-necked flask' technique is employed for the study of the kinetics of H+-UO22+ ion exchange system with strong acidic cation exchange resin. Three kinetic models are applied to the experimental data, the diffusion coefficients are calculated, and the rate constants of chemical reactions are also obtained by Moving Boundary Model. the possible effect of chemical reaction on the rate of ion exchange is discussed, and the view that the chemical reaction can retard the diffusion is developed. By analysing the behavior of the kinetic curves and the fitting results of the computer, it is found that the Moving Boundary Model is the best one for describing the ion exchange mechanism of this system