(A) study on the concentration of seawater uranium by ion exchange

Abstract

Adsorption of uranium contained in natural seawater was studied in a fluidized bed, and dilute uranium solution was concentrated by ion exchange column. The model for solid diffusion control case was obtained. In adsorption experiment in natural seawater, there was poor adsorption because a large quantity of mosses and shells accumulated on stainless steel screen, which led to bad contact with seawater. In case of exclusion by ion exchange column, the equilibrium distribution coefficient was not significantly affected by flow rate or particle size. In elution experiment, there was no adsorption in the solution of eluent concentration. For the irreversible case, because of the dilution effect of solution in intraparticle and interparticle void space, experimental result did not match well with theory during early time, but after peak time was reached, model matched well. Diffusivity obtained from experimental data was of the order of $10^{-6}cm^2/\sec$, and was a function of Reynolds number. As Reynolds number increased, diffusivity increased. However, in the range of high Reynolds number, diffusivity became constant. It may be explained by the fact that mass transport by film diffusion was quite slow at low Reynolds number.