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Kang M, Kang Y, Wu H, Qin D, Dai C, Wang J. The redox reactions of U(VI)/UO 2 on Tamusu claystone: Effects of Fe 2+/Fe 3+ and organic matters. CHEMOSPHERE 2024; 348:140754. [PMID: 37995974 DOI: 10.1016/j.chemosphere.2023.140754] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Revised: 11/06/2023] [Accepted: 11/16/2023] [Indexed: 11/25/2023]
Abstract
The claystone-based Tamusu area in the Bayingebi Basin, Inner Mongolia, is preselected as a China's high-level radioactive waste (HLRW) repository site. This study investigated the redox reactions of U(VI)/UO2 on Tamusu claystone. Five Tamusu claystone samples collected from boreholes Tzk1 and Tzk2 at different depths were used for batch experiments at pH ∼5.0, ∼7.0, and ∼9.0. These claystones contain considerable amounts of organic matters and Fe2+-containing minerals such as pyrite, fluorannite, and ankerite. Results showed that aqueous U(VI) could be partially reduced to U(IV) and/or U(V)-containing precipitates (U3O8, U4O9, etc.) by these Tamusu claystones, and the reaction is more favorable under acidic condition. We proposed that leaching of the structural Fe2+ followed by surface adsorption and interface reaction, is the primary mechanism responsible for U(VI) reduction. Under alkaline condition, organic matters might dominate the partial reduction of aqueous U(VI). Besides, the phosphorus-containing spots on Tamusu claystone surfaces are the reactive sites for U aggregation, implying the possible formation of U(VI)- and/or U(IV)-phosphate minerals. It is important to note that, due to the presence of minor Fe3+ in Tamusu claystones, the high-purity UO2 could undergo partial oxidation to U4O9 and/or U3O8. Therefore, insoluble UO2+x (0 < x ≤ 0.67) is proposed to be the most thermodynamically stable form in Tamusu claystone. This study enhances our comprehension of the essential geochemical processes of uranium in claystone surroundings, but also offers crucial information for the safety evaluation of China's HLRW repository.
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Affiliation(s)
- Mingliang Kang
- Sino-French Institute of Nuclear Engineering and Technology, Sun Yat-sen University, Zhuhai, 519082, China.
| | - Yixiao Kang
- Sino-French Institute of Nuclear Engineering and Technology, Sun Yat-sen University, Zhuhai, 519082, China
| | - Hanyu Wu
- Sino-French Institute of Nuclear Engineering and Technology, Sun Yat-sen University, Zhuhai, 519082, China
| | - Danwen Qin
- Sino-French Institute of Nuclear Engineering and Technology, Sun Yat-sen University, Zhuhai, 519082, China
| | - Chaocheng Dai
- College of Earth Sciences, East China University of Technology, Nanchang, 330013, China
| | - Ju Wang
- Beijing Research Institute of Uranium Geology, Beijing, 100029, China
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Poulain A, Fernandez-Martinez A, Greneche JM, Prieur D, Scheinost AC, Menguy N, Bureau S, Magnin V, Findling N, Drnec J, Martens I, Mirolo M, Charlet L. Selenium Nanowire Formation by Reacting Selenate with Magnetite. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:14817-14827. [PMID: 36184803 DOI: 10.1021/acs.est.1c08377] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The mobility of 79Se, a fission product of 235U and long-lived radioisotope, is an important parameter in the safety assessment of radioactive nuclear waste disposal systems. Nonradioactive selenium is also an important contaminant of drainage waters from black shale mountains and coal mines. Highly mobile and soluble in its high oxidation states, selenate (Se(VI)O42-) and selenite (Se(IV)O32-) oxyanions can interact with magnetite, a mineral present in anoxic natural environments and in steel corrosion products, thereby being reduced and consequently immobilized by forming low-solubility solids. Here, we investigated the sorption and reduction capacity of synthetic nanomagnetite toward Se(VI) at neutral and acidic pH, under reducing, oxygen-free conditions. The additional presence of Fe(II)aq, released during magnetite dissolution at pH 5, has an effect on the reduction kinetics. X-ray absorption spectroscopy analyses revealed that, at pH 5, trigonal gray Se(0) formed and that sorbed Se(IV) complexes remained on the nanoparticle surface during longer reaction times. The Se(0) nanowires grew during the reaction, which points to a complex transport mechanism of reduced species or to active reduction sites at the tip of the Se(0) nanowires. The concomitant uptake of aqueous Fe(II) and Se(VI) ions is interpreted as a consequence of small pH oscillations that result from the Se(VI) reduction, leading to a re-adsorption of aqueous Fe(II) onto the magnetite, renewing its reducing capacity. This effect is not observed at pH 7, where we observed only the formation of Se(0) with slow kinetics due to the formation of an oxidized maghemite layer. This indicates that the presence of aqueous Fe(II) may be an important factor to be considered when examining the environmental reactivity of magnetite.
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Affiliation(s)
- Agnieszka Poulain
- Univ. Grenoble Alpes, Univ. Savoie Mont Blanc, CNRS, IRD, IFSTTAR, ISTerre, 38000Grenoble, France
| | | | - Jean-Marc Greneche
- Institut des Molécules et Matériaux du Mans, CNRS UMR-6283, Le Mans Université, F-72085Le Mans, France
| | - Damien Prieur
- The Rossendorf Beamline at ESRF, 71 avenue des Martyrs, 38043 Grenoble, France and HZDR Institute of Resource Ecology, Bautzener Landstrasse 400, 01328Dresden, Germany
| | - Andreas C Scheinost
- The Rossendorf Beamline at ESRF, 71 avenue des Martyrs, 38043 Grenoble, France and HZDR Institute of Resource Ecology, Bautzener Landstrasse 400, 01328Dresden, Germany
| | - Nicolas Menguy
- Sorbonne Université, Muséum National d'Histoire Naturelle, UMR CNRS 7590, IRD. Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie (IMPMC), 4 Place Jussieu, 75005Paris, France
| | - Sarah Bureau
- Univ. Grenoble Alpes, Univ. Savoie Mont Blanc, CNRS, IRD, IFSTTAR, ISTerre, 38000Grenoble, France
| | - Valérie Magnin
- Univ. Grenoble Alpes, Univ. Savoie Mont Blanc, CNRS, IRD, IFSTTAR, ISTerre, 38000Grenoble, France
| | - Nathaniel Findling
- Univ. Grenoble Alpes, Univ. Savoie Mont Blanc, CNRS, IRD, IFSTTAR, ISTerre, 38000Grenoble, France
| | - Jakub Drnec
- ESRF, 71 avenue des Martyrs, 38043Grenoble, France
| | | | - Marta Mirolo
- ESRF, 71 avenue des Martyrs, 38043Grenoble, France
| | - Laurent Charlet
- Univ. Grenoble Alpes, Univ. Savoie Mont Blanc, CNRS, IRD, IFSTTAR, ISTerre, 38000Grenoble, France
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Zhao Z, Peng S, Ma C, Yu C, Wu D. Redox Behavior of Secondary Solid Iron Species and the Corresponding Effects on Hydroxyl Radical Generation during the Pyrite Oxidation Process. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:12635-12644. [PMID: 35976700 DOI: 10.1021/acs.est.2c04624] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
During the pyrite oxidation process, aqueous ferrous/ferric ions (Fe2+/Fe3+), as well as surface-adsorbed Fe2+/Fe3+, have been widely recognized to dominate hydroxyl radical (•OH) generation, while this study reveals that the secondary solid iron species also play non-negligible roles. Based on the different forms and the presence of sites, the secondary solid iron species were classified as Fecoat (iron-containing coating on the pyrite surface) and Fedep (ex situ-deposited iron (oxyhydr)oxide that is not in contact with pyrite). Instead of participating in building a stubborn passivation layer on the pyrite surface, Fecoat is easy to fall off from the pyrite surface as the oxidation of pyrite deepens, while large fractions of Fedep and Fecoat are found to be extractable with nitrilotriacetic acid (NTA). Achieved by cyclically oxidizing pyrite within different NTA levels (0/0.1/10 mM), Fecoat and Fedep were proved to have distinct redox behavior during the pyrite oxidation process. Amorphous Fedep, originated from the hydrolyzation of dissolved Fe3+, accelerates the nonradical decay of hydrogen peroxide (H2O2); as a result, the accumulation of Fedep always decreases the •OH production during the pyrite oxidation process. However, part of Fedep adsorbs on the pyrite surface through electrostatic attraction and converts into Fecoat. The electron conduction between Fecoat and pyrite was verified, which accelerates the oxidative dissolution of pyrite, produces reactive Fe(II), and therefore favors •OH generation. This study improves our understanding of the redox behavior of pyrite in complex media such as natural processes and practical engineering systems.
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Affiliation(s)
- Zhenyu Zhao
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science & Engineering, Tongji University, Shanghai 200092, P.R. China
| | - Shuai Peng
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science & Engineering, Tongji University, Shanghai 200092, P.R. China
| | - Canming Ma
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science & Engineering, Tongji University, Shanghai 200092, P.R. China
| | - Chao Yu
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science & Engineering, Tongji University, Shanghai 200092, P.R. China
| | - Deli Wu
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science & Engineering, Tongji University, Shanghai 200092, P.R. China
- Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, P.R. China
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Ou T, Wu Y, Han W, Kong L, Song G, Chen D, Su M. Synthesis of thickness-controllable polydopamine modified halloysite nanotubes (HNTs@PDA) for uranium (VI) removal. JOURNAL OF HAZARDOUS MATERIALS 2022; 424:127208. [PMID: 34592591 DOI: 10.1016/j.jhazmat.2021.127208] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 08/19/2021] [Accepted: 09/09/2021] [Indexed: 06/13/2023]
Abstract
Halloysite nanotubes (HNTs) are considered structurally promising adsorption materials, but their application is limited due to their poor native adsorption properties. Improving the adsorption capacity of HNTs for radioactive U(VI) is of great significance. By controlling the mass ratio of HNTs and dopamine (DA), composite adsorbents (HNTs@PDA) with different polydopamine (PDA) layer thicknesses were synthesized. Characterization of HNTs@PDA demonstrated that the original structure of the HNTs was maintained. Adsorption experiments verified that the adsorption capacity of HNTs@PDA for U(VI) was significantly improved. The effects of solution pH, temperature, and coexisting ions on the adsorption process were investigated. The removal efficiency was observed to be 75% after five repeated uses. The adsorption mechanism of U(VI) by HNTs@PDA can be explained by considering electrostatic interactions and the complexation of C-O, -NH- and C-N/CN in the PDA layer. This study provides some basic information for the application of HNTs for U(VI) removal.
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Affiliation(s)
- Tao Ou
- Guangdong Provincial Key Laboratory of Radionuclides Pollution Control and Resources, Guangzhou University, Guangzhou 510006, China; School of Environmental Science and Engineering, Guangzhou University, Guangzhou 510006, China
| | - Yuhua Wu
- Guangdong Provincial Key Laboratory of Radionuclides Pollution Control and Resources, Guangzhou University, Guangzhou 510006, China; School of Environmental Science and Engineering, Guangzhou University, Guangzhou 510006, China
| | - Weixing Han
- Guangdong Provincial Key Laboratory of Radionuclides Pollution Control and Resources, Guangzhou University, Guangzhou 510006, China; School of Environmental Science and Engineering, Guangzhou University, Guangzhou 510006, China
| | - Lingjun Kong
- Guangdong Provincial Key Laboratory of Radionuclides Pollution Control and Resources, Guangzhou University, Guangzhou 510006, China; School of Environmental Science and Engineering, Guangzhou University, Guangzhou 510006, China
| | - Gang Song
- Guangdong Provincial Key Laboratory of Radionuclides Pollution Control and Resources, Guangzhou University, Guangzhou 510006, China; School of Environmental Science and Engineering, Guangzhou University, Guangzhou 510006, China
| | - Diyun Chen
- Guangdong Provincial Key Laboratory of Radionuclides Pollution Control and Resources, Guangzhou University, Guangzhou 510006, China; School of Environmental Science and Engineering, Guangzhou University, Guangzhou 510006, China
| | - Minhua Su
- Guangdong Provincial Key Laboratory of Radionuclides Pollution Control and Resources, Guangzhou University, Guangzhou 510006, China; School of Environmental Science and Engineering, Guangzhou University, Guangzhou 510006, China.
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Chen Z, Wang S, Hou H, Chen K, Gao P, Zhang Z, Jin Q, Pan D, Guo Z, Wu W. China's progress in radionuclide migration study over the past decade (2010-2021): Sorption, transport and radioactive colloid. CHINESE CHEM LETT 2022. [DOI: 10.1016/j.cclet.2022.02.054] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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Effect of natural pyrite oxidation on the U(VI) adsorption under the acidic and neutral conditions. J Radioanal Nucl Chem 2021. [DOI: 10.1007/s10967-021-07857-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Yao W, Min X, Li Q, Li K, Qu S, Dong Z. Formation and in-situ dissociation of particulate arsenic in the zinc-containing flue gas from nonferrous metallurgy. Sep Purif Technol 2021. [DOI: 10.1016/j.seppur.2021.118575] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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Hua Y, Li D, Gu T, Wang W, Li R, Yang J, Zhang WX. Enrichment of Uranium from Aqueous Solutions with Nanoscale Zero-valent Iron: Surface Chemistry and Application Prospect. ACTA CHIMICA SINICA 2021. [DOI: 10.6023/a21040160] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Wang J, Fang F, Zhou Y, Yin M, Liu J, Wang J, Wu Y, Beiyuan J, Chen D. Facile modification of graphene oxide and its application for the aqueous uranyl ion sequestration: Insights on the mechanism. CHEMOSPHERE 2020; 258:127152. [PMID: 32544809 DOI: 10.1016/j.chemosphere.2020.127152] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 05/17/2020] [Accepted: 05/19/2020] [Indexed: 06/11/2023]
Abstract
Graphene oxide (GO) has been proved with favorable affinity to U(VI), while some drawbacks such as poor dispersity and low adsorption performance limit its application. Herein, cetyltrimethylammonium bromide (CTAB) modified graphene oxide (MGO) composites were successfully fabricated, characterized and compared with graphene oxide (GO) in the sequestration of U(VI) in aqueous solutions. The results showed that maximum adsorption rate of MGO (99.21%) was obviously higher than that of GO (66.51%) under the same initial condition. Simultaneous introduction of C-H and NO coupled with the enhanced dispersity of GO after modification were mainly responsible for the updated performance verified with multiple characterization techniques. Based on the results of kinetics and isotherms investigations, the experimental data were best described by Pseudo-first-order kinetic model and Redlich-Peterson isotherm model. The results of ΔH, ΔS and ΔG show that adsorptive behaviors of uranyl ion on MGO are endothermic and spontaneous. The study provides a feasible alternative to the chemical modification of GO and enhancing the performance towards uranyl ion removal from solution.
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Affiliation(s)
- Jin Wang
- School of Environmental Science and Engineering, Guangzhou University, Guangzhou, 510006, China; Guangdong Provincial Key Laboratory of Radionuclides Pollution Control and Resources, Guangzhou, 510006, China
| | - Fa Fang
- School of Environmental Science and Engineering, Guangzhou University, Guangzhou, 510006, China
| | - Yuchen Zhou
- School of Environmental Science and Engineering, Guangzhou University, Guangzhou, 510006, China
| | - Meiling Yin
- School of Environmental Science and Engineering, Guangzhou University, Guangzhou, 510006, China
| | - Juan Liu
- School of Environmental Science and Engineering, Guangzhou University, Guangzhou, 510006, China.
| | - Jinwen Wang
- School of Environmental Science and Engineering, Guangzhou University, Guangzhou, 510006, China
| | - Yang Wu
- School of Environmental Science and Engineering, Guangzhou University, Guangzhou, 510006, China
| | - Jingzi Beiyuan
- School of Environment and Chemical Engineering, Foshan University, Foshan 528000, Guangdong, China.
| | - Diyun Chen
- School of Environmental Science and Engineering, Guangzhou University, Guangzhou, 510006, China; Guangdong Provincial Key Laboratory of Radionuclides Pollution Control and Resources, Guangzhou, 510006, China
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