Kinetic study of ultrasonic-assisted uranium adsorption by anion exchange resin

摘要

In this paper, the adsorption kinetics of uranium from the acidic leaching solution by ion exchange resin (201 x 8) in ultrasonic environment was studied by adsorption tests. The effect of sulphate concentration and ultrasonic wave on the adsorption results was investigated. The results show that the adsorption capacity of the resin decreases with the increase of sulphate concentration, while the introduction of ultrasonic wave can improve the adsorption capacity by more than 15%. The kinetic study reveals that the adsorption process could be well elucidated with Pseudo-second-order model. The adsorption capacity and reaction rate constant of the resin increase with the increase of ultrasonic power. Adsorption control mechanism analysis shows that the adsorption process was controlled by intra-particle diffusion and the particle diffusion coefficient increased with the increase of ultrasonic power. The particle diffusion coefficient was about twice as much as that without ultrasonic wave when the ultrasonic power reached 160 W. Thermodynamic study shows that the adsorption isotherms of uranium on the resin are well fitted by the Langmuir isotherm. The adsorption capacity of the resin is stable according to the cycling tests and the structure and molecule structure of the resin remain undamaged after uranium adsorption in the ultrasonic environment as proved by FTIR and SEM analysis.