Adsorption behavior of Se(IV) in calcium-based (natural) bentonite and sodium-based (engineered modified) bentonite
-
Cong Huang
and
Rong Hua
Abstract
Bentonite plays a significant role as a buffer backfill material in geological disposal due to its unique properties that are crucial for the safe containment of high-level radioactive waste. In this work, the impact of various factors on the adsorption of selenite (Se(IV)) by both calcium-based and sodium-based bentonite was examined using batch experiments. As a result, both types of bentonite achieve adsorption equilibrium with Se(IV) within approximately 120 h. The adsorption capacity decreases with increasing initial concentration of Se(IV), while it is positively influenced by longer contact times and higher temperatures. The partition coefficient (K d ) exhibits a complex relationship with pH, initially decreasing, then increasing, and finally decreasing again. Additionally, ionic strength significantly affects the adsorption process. These observations suggest that Se(IV) adsorption on bentonite is pH-dependent and involves a non-spontaneous heat-absorbing process, likely a chemical reaction dominated by the ion-exchange form of chemisorption in a monomolecular layer. This process aligns well with the isothermal adsorption model and the simulated secondary kinetics of the Langmuir model. Furthermore, the adsorption of Se(IV) is notably hindered by the increased electrostatic repulsion between the negatively charged bentonite surface and the negatively charged species HSeO32− and SeO32−. The Fourier transform infrared spectra showed that the positions, intensities and shapes of the spectral characteristic peaks of the functional groups before and after adsorption did not change significantly.
-
Research ethics: The local Institutional Review Board deemed the study exempt from review. OR.
-
Informed consent: Informed consent was obtained from all individuals included in this study, or their legal guardians or wards.
-
Author contributions: All authors have accepted responsibility for the entire content of this manuscript and approved its submission.
-
Use of Large Language Models, AI and Machine Learning Tools: None declared.
-
Conflict of interest: All other authors state no conflict of interest.
-
Research funding: The China Uranium Industry Co., Ltd.- the Foundation of State Key Laboratory of Nuclear Resources and Environment Joint Innovation Fund Project (2022NRE-LH-15), Key Project of Jiangxi Natural Science Foundation (20232ACB203014) and Project of Nuclear Technology Research and Development (Proto-Nuclear Energy Development) (HNKF202311(48)).
-
Data availability: The data in this article can be made public without any restrictions.
References
1. Rose, M. N.; Boothman, C.; Shaw, S. Salinity Controls on Steel Biocorrosion Relevant to the Disposal of High-Level Radioactive Waste. Appl. Clay Sci. 2025, 267, 107723. https://doi.org/10.1016/j.clay.2025.107723.Search in Google Scholar
2. Abramova, E.; Popova, N.; Artemiev, G. Biological Factors Affecting the Evolution of Safety Barrier Materials in the Yeniseisky Deep Geological Repository. Eng. Geol. 2023, 312, 106931. https://doi.org/10.1016/j.enggeo.2022.106931.Search in Google Scholar
3. El Alam, J.; Revil, A.; Dick, P. Influence of the Water Content on the Complex Conductivity of Bentonite. Eng. Geol. 2023, 322: 107183. https://doi.org/10.1016/j.enggeo.2023.107183.Search in Google Scholar
4. Zhang, Z.; Zhang, F.; Muhammed, R. D. Effect of Air Volume Fraction on the Thermal Conductivity of Compacted Bentonite Materials. J. Eng. Geol. 2021, 284, 106045. https://doi.org/10.1016/j.enggeo.2021.106045.Search in Google Scholar
5. Fujiyama, T.; Kaku, K. Current Status of the Geological Disposal Programme and an Overview of the Safety Case at the Pre-Siting Stage in Japan. Rock Mech. Bull. 2023, 2, 100062; https://doi.org/10.1016/j.rockmb.2023.100062.Search in Google Scholar
6. Lee, J.; Kim, K.; Kim, I.; Ju, H.; Jeong, J.; Lee, C.; Cho, D. High-Efficiency Deep Geological Repository System for Spent Nuclear Fuel in Korea with Optimized Decay Heat in a Disposal Canister and Increased Thermal Limit of Bentonite. Nucl. Eng. Technol. 2023, 55(4), 1540–1554. https://doi.org/10.1016/j.net.2023.02.031.Search in Google Scholar
7. Ren, G. L.; Huang, W. H.; Lin, Z. H.; Chung, C. C. Laboratory Assessment of Real-Time Water Infiltration Measurement in SPV200 Bentonite Using TDR for High-Level Radioactive Waste Disposal Design. Measurement 2025, 242, 116077. https://doi.org/10.1016/j.measurement.2024.116077.Search in Google Scholar
8. Wang, Z. F.; Wu, T.; Ren, P.; Hua, R.; Wu, H.; Xu, M. H.; Tong, Y. H. Through-diffusion Study of Se(IV) in γ-Irradiated Bentonite and Bentonite-Magnetite. Radioanal. Nucl. Chem. 2019, 322, 801–808. https://doi.org/10.1007/s10967-019-06802-4.Search in Google Scholar
9. Wang, H.; Wu, T.; Chen, J.; Zheng, Q.; He, CH.; Zhao, Y. L. Sorption of Se(IV) on Fe- and Al-Modified Bentonite. Radioanal. Nucl. Chem. 2015, 303, 107–113. https://doi.org/10.1007/s10967-014-3422-5.Search in Google Scholar
10. Tang, X.; Zhou, S.; Liu, X.; Hu, B. Evidence of Nuclide Migration from High-Level Radioactive Waste Glass via Geogas. Appl. Radiat. Isot. 2024, 211, 111399. https://doi.org/10.1016/j.apradiso.2024.111399.Search in Google Scholar PubMed
11. Li, Y.; Shi, Y. L.; He, J. G. Effects of Cu on the Sorption of Selenite in Gaomiaozi Bentonite. Environ. Chem. 2020, 39 (02), 334–342; https://doi.org/10.7524/j.issn.0254-6108.2019031503.Search in Google Scholar
12. He, J. G.; Shi, Y. L.; Yang, X. Y.; Zhou, W. Q.; Li, Y.; Liu, C. L. Influence of Fe(II) on the Se(IV) Sorption under Oxic/Anoxic Conditions Using Bentonite. Chemosphere 2018, 193, 367–384. https://doi.org/10.1016/j.chemosphere.2017.10.143.Search in Google Scholar PubMed
13. Jiang, Q. F.; Liu, W. G.; Liao, Y. X. Study on the Regularity of Se(IV) Adsorption by Bentonite from Different Regions. Kerntechnik 2023, 88(5), 556–565. https://doi.org/10.1515/kern-2023-0025.Search in Google Scholar
14. Zhang, H. Diffusion and Adsorption of Re(VII) and Se(IV) Tamusu Clay Rock [D]; East China University Of Technology: Nanchang, Jiangxi, 2020.Search in Google Scholar
15. Sun, Y. Z.; Liu, Z. X.; Tang, R. J. Investigating Diffusion Mechanism for HTO and Se(IV)/Se(VI) in Compacted Tamusu Clay Rock with Different Column Lengths. Radiochim. Acta. 2022, 110(12), 979–993. https://doi.org/10.1515/ract-2022-0070.Search in Google Scholar
16. Ullah, H.; Liu, G.; Yousaf, B. A Comprehensive Review on Environmental Transformation of Selenium: Recent Advances and Research Perspectives. Environ. Geochem. Health 2019, 41, 1003–1035. https://doi.org/10.1007/s10653-018-0195-8.Search in Google Scholar PubMed
17. Wang, H.; Huang, Li; Guo, J. Study on Sodium-modified Suspensoid Process of Bentonite. Gold Sci. Technol. 2012, 20 (01), 89–93; https://doi.org/1005-2518(2012)01-0089-05.Search in Google Scholar
18. Holtzer, M.; Bobrowski, A.; Grabowska, B. Montmorillonite: A Comparison of Methods for Its Determination in Foundry Bentonites. Metalurgija 2011, 50 (2), 119–122; https://doi.org/10.1007/s11661-010-0490-1.Search in Google Scholar
19. Montavon, G.; Guo, Z.; Lützenkirchen, J.; Alhajji, E.; Kedziorek, M.; Bourg, A.; Grambow, B. Interaction of Selenite with MX-80 Bentonite: Effect of Minor Phases, pH, Selenite Loading, Solution Composition and Compaction. Colloids Surf. A Physicochem. Eng. Asp. 2009, 332(2–3), 71–77. https://doi.org/10.1016/j.colsurfa.2008.09.014.Search in Google Scholar
20. Kumar, A.; Lingfa, P. Sodium Bentonite and Kaolin Clays: Comparative Study on Their FT-IR, XRF, and XRD. Mater. Today Proc. 2020, 22, 737–742. https://doi.org/10.1016/j.matpr.2019.10.037.Search in Google Scholar
21. Şenol, Z. M.; Şimşek, S. Insights into Effective Adsorption of Lead Ions from Aqueous Solutions by Using Chitosan-Bentonite Composite Beads. J. Polym. Environ. 2022, 30(9), 3677–3687. https://doi.org/10.1007/s10924-022-02464-8.Search in Google Scholar
22. Wang, R.; Xu, H.; Wei, S.; Wu, D. The Characteristics and Mechanisms of Selenite Adsorption by MOF-Fe. Acta Sci. Circumst. 2018, 38, 3127–3137; https://doi.org/10.13671/j.hjkxxb.2018.0210.Search in Google Scholar
23. Goldberg, S. Macroscopic Experimental and Modeling Evaluation of Selenite and Selenate Adsorption Mechanisms on Gibbsite. Soil Sci. Soc. Am. J. 2014, 78(2), 473–479. https://doi.org/10.2136/sssaj2013.06.0249.Search in Google Scholar
24. Jeon, H. G.; Choi, S.; Kim, J. S. Mechanistic Insights into Selenite and Selenate Immobilization Using Brucite-Rich Magnesium Precipitate Derived from Seawater Electrochlorination Facility. J. Environ. Chem. Eng. 2024, 12(5), 114081. https://doi.org/10.1016/j.jece.2024.114081.Search in Google Scholar
25. Li, Z.; Liang, D.; Peng, Q. Interaction between Selenium and Soil Organic Matter and its Impact on Soil Selenium Bioavailability: A Review. Geoderma 2017, 295, 69–79. https://doi.org/10.1016/j.geoderma.2017.02.019.Search in Google Scholar
26. Jang, M.; Pak, S.; Kim, M. J. Comparison of Adsorption Characteristics of Se (IV) and Se (VI) onto Hematite: Effects of Reaction Time, Initial Concentration, pH, and Ionic Strength. Environ. Earth Sci. 2015, 74, 1169–1173.23. https://doi.org/10.1007/s12665-015-4103-6.Search in Google Scholar
27. Xie, F.; Zhang, M. Bimetallic Water Oxidation: One-Site Catalysis with Two-Sites Oxidation. J. Energy Chem. 2021, 63(12), 1–7. https://doi.org/10.1016/j.jechem.2021.08.047.Search in Google Scholar
28. Meher, A. K.; Jadhav, A.; Labhsetwar, N. Simultaneous Removal of Selenite and Selenite from Drinking Water Using Mesoporous Activated Alumina. Appl. Water Sci. 2019, 10, 1–12; https://doi.org/10.1007/s13201-019-1090-x.Search in Google Scholar
© 2025 Walter de Gruyter GmbH, Berlin/Boston
Articles in the same Issue
- Frontmatter
- Original Papers
- Highly efficient separation of Np(IV) with three Benzene-centered tripodal diglycolamides: solvent extraction and supported liquid membrane transport studies
- Mechanistic insights into La(III) extraction using HDEHP: toward effective rare earth recovery from radioactive waste
- Influence of carbon dioxide and water concentration on terbium thin films produced by Molecular Plating
- Adsorption behavior of Se(IV) in calcium-based (natural) bentonite and sodium-based (engineered modified) bentonite
- Assessing the protective properties of Anti-inflammatory and antioxidant compounds against gamma radiation
- Electromagnetic radiation shielding of NBR rubber composites loaded with magnetite and manganese dioxide
- Beyond conventional barriers: gamma radiation protection innovations with BaO–PbO2–B2O3–Pr6O11 glass systems
- Study of the influence of micro-and nano-scale ZnO particles on the radiation shielding capability of B2O3–PbO–BaO–ZnO glass system
Articles in the same Issue
- Frontmatter
- Original Papers
- Highly efficient separation of Np(IV) with three Benzene-centered tripodal diglycolamides: solvent extraction and supported liquid membrane transport studies
- Mechanistic insights into La(III) extraction using HDEHP: toward effective rare earth recovery from radioactive waste
- Influence of carbon dioxide and water concentration on terbium thin films produced by Molecular Plating
- Adsorption behavior of Se(IV) in calcium-based (natural) bentonite and sodium-based (engineered modified) bentonite
- Assessing the protective properties of Anti-inflammatory and antioxidant compounds against gamma radiation
- Electromagnetic radiation shielding of NBR rubber composites loaded with magnetite and manganese dioxide
- Beyond conventional barriers: gamma radiation protection innovations with BaO–PbO2–B2O3–Pr6O11 glass systems
- Study of the influence of micro-and nano-scale ZnO particles on the radiation shielding capability of B2O3–PbO–BaO–ZnO glass system
