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Yin X, Wu P, Shi S, Zhao Y, Li H, Li F, Liao J, Liu N, Yang Y, Lan T. Sorption behavior and mechanism of U(VI) on Tamusu clay in the presence of U(VI)-CO 3 complexes. J Environ Radioact 2023; 270:107286. [PMID: 37633243 DOI: 10.1016/j.jenvrad.2023.107286] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Revised: 08/17/2023] [Accepted: 08/20/2023] [Indexed: 08/28/2023]
Abstract
The sorption behavior of U(VI) on Tamusu clay sampled from a pre-selected high-level radioactive waste (HLW) disposal site in Inner Mongolia (China) was studied systematically in the U(VI)-CO3 solution at pH 7.8 by batch experiments. The results demonstrated that the distribution coefficients (Kd) decreased with the increasing values of pHinitial, [U(VI)]initial, and ionic strength, but increased with the extended time and the rising temperature. The sorption was a pH-dependent, heterogeneous, spontaneous, and endothermic chemical process, which could be better described by Freundlich isothermal model and pseudo-second-order kinetic model. The presence of humic acid (HA) or fulvic acid (FA) significantly inhibited the U(VI) sorption, due to the enhanced electrostatic repulsion between the negatively charged HA/FA adsorbed on the clay surface and the negative U(VI) species, as well as the well dispersed HA/FA aggregates in solution wrapping the U(VI) species. The FTIR and XPS spectra indicated that the HCO3- groups on the surface of Tamusu clay after hydroxylation and the ‒OH groups in HA/FA were involved in the U(VI) sorption. The results reported here provide valuable insights into the further understanding of U(VI) migration in geological media.
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Affiliation(s)
- Xiaoyu Yin
- Key Laboratory of Radiation Physics and Technology of the Ministry of Education, Institute of Nuclear Science and Technology, Sichuan University, Chengdu, 610064, PR China
| | - Peng Wu
- Key Laboratory of Radiation Physics and Technology of the Ministry of Education, Institute of Nuclear Science and Technology, Sichuan University, Chengdu, 610064, PR China
| | - Shilong Shi
- Key Laboratory of Radiation Physics and Technology of the Ministry of Education, Institute of Nuclear Science and Technology, Sichuan University, Chengdu, 610064, PR China
| | - Yufan Zhao
- Key Laboratory of Radiation Physics and Technology of the Ministry of Education, Institute of Nuclear Science and Technology, Sichuan University, Chengdu, 610064, PR China
| | - Honghui Li
- China Institute for Radiation Protection, Taiyuan, 030006, PR China
| | - Feize Li
- Key Laboratory of Radiation Physics and Technology of the Ministry of Education, Institute of Nuclear Science and Technology, Sichuan University, Chengdu, 610064, PR China
| | - Jiali Liao
- Key Laboratory of Radiation Physics and Technology of the Ministry of Education, Institute of Nuclear Science and Technology, Sichuan University, Chengdu, 610064, PR China
| | - Ning Liu
- Key Laboratory of Radiation Physics and Technology of the Ministry of Education, Institute of Nuclear Science and Technology, Sichuan University, Chengdu, 610064, PR China
| | - Yuanyou Yang
- Key Laboratory of Radiation Physics and Technology of the Ministry of Education, Institute of Nuclear Science and Technology, Sichuan University, Chengdu, 610064, PR China.
| | - Tu Lan
- Key Laboratory of Radiation Physics and Technology of the Ministry of Education, Institute of Nuclear Science and Technology, Sichuan University, Chengdu, 610064, PR China.
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He H, Liu J, Dong Y, Li H, Zhao S, Wang J, Jia M, Zhang H, Liao J, Yang J, Yang Y, Liu N. Sorption of selenite on Tamusu clay in simulated groundwater with high salinity under aerobic/anaerobic conditions. J Environ Radioact 2019; 203:210-219. [PMID: 30927564 DOI: 10.1016/j.jenvrad.2019.03.020] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2018] [Revised: 03/12/2019] [Accepted: 03/16/2019] [Indexed: 06/09/2023]
Abstract
The sorption behavior of selenite onto the Tamusu clay from a preselected high-level radioactive waste disposal site in Inner Mongolia, China, was first investigated in simulated groundwater with high salinity by batch sorption experiments under aerobic/anaerobic conditions. The results demonstrated that the Kd values rapidly decreased and then remained steady in the pH range of 2.0-8.0. However, selenite sorption was promoted when pH exceeded 8.0, which might be attributed to the coprecipitation between Ca2+ and SeO32-. Besides, the change trend of the Kd values as functions of various parameters was not affected by oxygen. The sorption kinetics and isotherms could be well fitted by the pseudo-second-order kinetic model and the Freundlich model for both aerobic and anaerobic conditions, and the calculated thermodynamic parameters (△G and △H) suggested that the selenite sorption process was a spontaneous and endothermic process. Additionally, the XPS results revealed that Se(IV) could be reduced to Se (0) only in anaerobic conditions and that the different amounts of Fe on the clay surface led to the discrepancy of the Se(IV) Kd values under aerobic and anaerobic conditions even in high-salt simulated groundwater. Overall, our findings in this study are significant in regards to the retardation of selenite on the host rock under high salinity conditions.
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Affiliation(s)
- Hanyi He
- Key Laboratory of Radiation Physics and Technology (Sichuan University), Ministry of Education, Institute of Nuclear Science and Technology, Sichuan University, Chengdu, 610064, PR China
| | - Jun Liu
- Key Laboratory of Radiation Physics and Technology (Sichuan University), Ministry of Education, Institute of Nuclear Science and Technology, Sichuan University, Chengdu, 610064, PR China
| | - Yang Dong
- Key Laboratory of Radiation Physics and Technology (Sichuan University), Ministry of Education, Institute of Nuclear Science and Technology, Sichuan University, Chengdu, 610064, PR China
| | - Honghui Li
- China Institute for Radiation Protection, Taiyuan, 030006, PR China
| | - Shuaiwei Zhao
- China Institute for Radiation Protection, Taiyuan, 030006, PR China
| | - Jing Wang
- Key Laboratory of Radiation Physics and Technology (Sichuan University), Ministry of Education, Institute of Nuclear Science and Technology, Sichuan University, Chengdu, 610064, PR China
| | - Meilan Jia
- China Institute for Radiation Protection, Taiyuan, 030006, PR China
| | - Han Zhang
- Key Laboratory of Radiation Physics and Technology (Sichuan University), Ministry of Education, Institute of Nuclear Science and Technology, Sichuan University, Chengdu, 610064, PR China
| | - Jiali Liao
- Key Laboratory of Radiation Physics and Technology (Sichuan University), Ministry of Education, Institute of Nuclear Science and Technology, Sichuan University, Chengdu, 610064, PR China.
| | - Jijun Yang
- Key Laboratory of Radiation Physics and Technology (Sichuan University), Ministry of Education, Institute of Nuclear Science and Technology, Sichuan University, Chengdu, 610064, PR China
| | - Yuanyou Yang
- Key Laboratory of Radiation Physics and Technology (Sichuan University), Ministry of Education, Institute of Nuclear Science and Technology, Sichuan University, Chengdu, 610064, PR China
| | - Ning Liu
- Key Laboratory of Radiation Physics and Technology (Sichuan University), Ministry of Education, Institute of Nuclear Science and Technology, Sichuan University, Chengdu, 610064, PR China.
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