Nuclear Techniques ›› 2018, Vol. 41 ›› Issue (7): 70302-070302.doi: 10.11889/j.0253-3219.2018.hjs.41.070302

• NUCLEAR CHEMISTRY, RADIOCHEMISTRY, RADIOPHARMACEUTICALS AND NUCLEAR MEDICINE • Previous Articles     Next Articles

Effect of temperature on adsorption of U(Ⅵ) onto kaolin

ZHANG Hong1, LENG Yangchun1, WANG Yanhui1, LIU Jian1, TUO Xianguo1,2   

  1. 1. School of National Defense of Science and Technology, Southwest University of Science and Technology, Mianyang 621010, China;
    2. College of Chemistry and Environmental Engineering, Sichuan University of Science & Engineering, Zigong 643000, China
  • Received:2018-01-29 Revised:2018-03-30 Online:2018-07-10 Published:2018-07-07
  • Supported by:
    Supported by National Natural Science Foundation of China (No.41630646), Youth Fund of National Natural Science Foundation of China (No.41603124)

Abstract: [Background] The research on the disposal of clay rock in high-level waste is still in the initial stage, furthermore the research on the migration mechanism of nuclide in clay rock treatment system is weak. [Purpose] This study aims at the adsorption behavior of U(Ⅵ) onto kaolin, and provides reference for the safety evaluation system of high level waste disposal storehouse. [Methods] The effects of initial concentration of U(VI), pH and coexisting ions on the adsorption of U(VI) onto kaolin are investigated at the temperatures of 298.15 K, 308.15 K, 318.15 K and 328.15 K. [Results] The results show that the adsorption of U(VI) onto kaolin is increasing with the increase of initial concentration of U(VI). At the same concentration of U(VI), the adsorption of U(VI) onto kaolin is increasing with the increase of temperature. When the pH was 7, the adsorption of U (VI) onto kaolin is best. At the same pH, the adsorption of U(VI) onto kaolin is increasing with the increase of temperature. The coexistent ions Ca2+, CO32- and SO42- have a greater inhibitory effect on the adsorption, at the same time the adsorption of U(VI) onto kaolin is increasing with the increase of temperature. [Conclusion] with the increase of temperature, the adsorption capacity of kaolin on U(VI) is enhanced. The adsorption thermodynamic analysis proves that the adsorption of U(VI) onto kaolin is a spontaneous endothermic process. Through comparison of fourier transform infrared spectrometer (FT-IR), it is found that the absorption peaks have shifted and the intensity changes and appears a new peak, which proves that the adsorption of U(VI) onto kaolin is not only physical adsorption, there is also chemical adsorption.

Key words: U (Ⅵ), Kaolin, Temperature, Adsorption thermodynamics

CLC Number: 

  • TL941