1
|
Reiller PE. Predominance of the alkaline earth(II) triscarbonatoactinyl(VI) complexes in different geochemical contexts: Review of existing data and estimation of potentially unidentified species. CHEMOSPHERE 2024; 350:141049. [PMID: 38182083 DOI: 10.1016/j.chemosphere.2023.141049] [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: 10/12/2023] [Revised: 12/01/2023] [Accepted: 12/26/2023] [Indexed: 01/07/2024]
Abstract
From the available thermodynamic data in the literature, a review of the impact of the formation of complexes between triscarbonatoactinyl(VI) and alkaline earth(II) (Ae) is estimated under varying conditions. First, after analyzing the literature data and using the ascertained thermodynamic data available from the commissioned reviews from the Nuclear Energy Agency (Organization for the Economic Cooperation and Development) Thermochemical DataBank Project on actinides (An) U, Np, and Pu, and from recently determined AenUO2(CO3)3(4-2n)- thermodynamic functions, the formation of AenAnO2(CO3)3(4-2n)- complexes for Pu(VI) and Np(VI) are estimated using linear free energy relationships (LFERs). The data are in good agreement with the sole determination of AePuO2(CO3)32- from Jo et al. (Dalton Trans. 49, 11605), which gives a relative confidence in the LFERs, and allows the application to actual situations. From existing uranium data, first, the impact of the origin of the data on the calculated predominance is addressed under 0.1 M NaCl and atmospheric CO2(g); second, the influence of ionic strength and salinity on predominance is estimated; and finally, the influence of temperature up to 50 °C on the solubility of uraninite in a deep geological radioactive waste storage or disposal site is calculated. For neptunium and plutonium, the impact of the potential log10β°(AenAnO2(CO3)3(4-2n)-) on Pourbaix diagrams of Pu and Np in Mg-Ca-CO3 media are estimated from Jo et al. (Dalton Trans. 49, 11605) and LFERs. Finally, the application to the speciation of Pu and Np in seawater is proposed.
Collapse
Affiliation(s)
- Pascal E Reiller
- Université Paris-Saclay, CEA, Service de Physico-Chimie (SPC), F-91191, Gif-sur-Yvette CEDEX, France.
| |
Collapse
|
2
|
Shang C, Gaona X, Oher H, Polly R, Skerencak-Frech A, Duckworth S, Altmaier M. Experimental and computational evidence of U(VI)-OH-Si(OH) 4 complexes under alkaline conditions: Implications for cement systems. CHEMOSPHERE 2024; 350:141048. [PMID: 38182084 DOI: 10.1016/j.chemosphere.2023.141048] [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: 11/03/2023] [Revised: 12/22/2023] [Accepted: 12/26/2023] [Indexed: 01/07/2024]
Abstract
The complexation of uranyl hydroxides with orthosilicic acid was investigated by experimental and theoretical methods. Spectroluminescence titration was performed in a glovebox under argon atmosphere at pH 9.2, 10.5 and 11.5, with [U(VI)] = 10-6 and 5 × 10-6 mol kgw-1. The polymerization effects of silicic acid were minimized by ruling out samples with less than 90 % monomeric silicic acid present, identified via UV-Vis spectrometry using the molybdate blue method. Linear regression analysis based on time-resolved laser-induced fluorescence spectroscopy (TRLFS) results yielded the conditional stepwise formation constants of U(VI)-OH-Si(OH)4 complexes at 0.05 mol kgw-1 NaNO3. The main spectroscopic features - characteristic peak positions and decay-time - are reported for the first time for the UO2(OH)2SiO(OH)3- species observed at pH 9.2 and 10.5 and UO2(OH)2SiO2(OH)22- predominant at pH 11.5. Quantum chemical calculations successfully computed the theoretical luminescence spectrum of the complex UO2(OH)2SiO(OH)3- species, thus underpinning the proposed chemical model for weakly alkaline systems. The conditional stability constants were extrapolated to infinite dilution using the Davies equation, resulting in log10β°(UO2(OH)2SiO(OH)3-) and log10β°(UO2(OH)2SiO2(OH)22-). Implications for U(VI) speciation in the presence and absence of competing carbonate are discussed for silicate-rich environments expected in certain repository concepts for nuclear waste disposal.
Collapse
Affiliation(s)
- Chengming Shang
- Institute for Nuclear Waste Disposal (INE), Karlsruhe Institute of Technology (KIT), 76344 Eggenstein-Leopoldshafen, Germany.
| | - Xavier Gaona
- Institute for Nuclear Waste Disposal (INE), Karlsruhe Institute of Technology (KIT), 76344 Eggenstein-Leopoldshafen, Germany.
| | - Hanna Oher
- Laboratoire de Physique des 2 Infinis Irène Juliot-Curie (IJCLab), CNRS/IN2P3, Université Paris-Saclay, 91405 Orsay, France
| | - Robert Polly
- Institute for Nuclear Waste Disposal (INE), Karlsruhe Institute of Technology (KIT), 76344 Eggenstein-Leopoldshafen, Germany
| | - Andrej Skerencak-Frech
- Institute for Nuclear Waste Disposal (INE), Karlsruhe Institute of Technology (KIT), 76344 Eggenstein-Leopoldshafen, Germany
| | - Sarah Duckworth
- Institute for Nuclear Waste Disposal (INE), Karlsruhe Institute of Technology (KIT), 76344 Eggenstein-Leopoldshafen, Germany
| | - Marcus Altmaier
- Institute for Nuclear Waste Disposal (INE), Karlsruhe Institute of Technology (KIT), 76344 Eggenstein-Leopoldshafen, Germany
| |
Collapse
|
3
|
Boussouga YA, Joseph J, Stryhanyuk H, Richnow HH, Schäfer AI. Adsorption of uranium (VI) complexes with polymer-based spherical activated carbon. WATER RESEARCH 2024; 249:120825. [PMID: 38118222 DOI: 10.1016/j.watres.2023.120825] [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: 08/11/2023] [Revised: 10/11/2023] [Accepted: 11/02/2023] [Indexed: 12/22/2023]
Abstract
Adsorption processes with carbon-based adsorbents have received substantial attention as a solution to remove uranium from drinking water. This study investigated uranium adsorption by a polymer-based spherical activated carbon (PBSAC) characterised by a uniformly smooth exterior and an extended surface of internal cavities accessible via mesopores. The static adsorption of uranium was investigated applying varying PBSAC properties and relevant solution chemistry. Spatial time-of-flight secondary ion mass spectrometry (ToF-SIMS) was employed to visualise the distribution of the different uranium species in the PBSAC. The isotherms and thermodynamics calculations revealed monolayer adsorption capacities of 28-667 mg/g and physical adsorption energies of 13-21 kJ/mol. Increasing the surface oxygen content of the PBSAC to 10 % enhanced the adsorption and reduced the equilibrium time to 2 h, while the WHO drinking water guideline of 30 µgU/L could be achieved for an initial concentration of 250 µgU/L. Uranium adsorption with PBSAC was favourable at the pH 6-8. At this pH range, uranyl carbonate complexes (UO2CO3(aq), UO2(CO3)22-, (UO2)2CO3(OH)3-) predominated in the solution, and the ToF-SIMS analysis revealed that the adsorption of these complexes occurred on the surface and inside the PBSAC due to intra-particle diffusion. For the uranyl cations (UO22+, UO2OH+) at pH 2-4, only shallow adsorption in the outermost PBSAC layers was observed. The work demonstrated the effective removal of uranium from contaminated natural water (67 µgU/L) and meeting both German (10 µgU/L) and WHO guideline concentrations. These findings also open opportunities to consider PBSAC in hybrid treatment technologies for uranium removal, for instance, from high-level radioactive waste.
Collapse
Affiliation(s)
- Youssef-Amine Boussouga
- Institute for Advanced Membrane Technology (IAMT), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, Eggenstein-Leopoldshafen 76344, Germany.
| | - James Joseph
- Institute for Advanced Membrane Technology (IAMT), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, Eggenstein-Leopoldshafen 76344, Germany
| | - Hryhoriy Stryhanyuk
- Department of Isotope Biogeochemistry, ProVIS-Centre for Chemical Microscopy, Helmholtz, Center for Environmental Research (UFZ), Leipzig, Germany
| | - Hans H Richnow
- Department of Isotope Biogeochemistry, ProVIS-Centre for Chemical Microscopy, Helmholtz, Center for Environmental Research (UFZ), Leipzig, Germany
| | - Andrea I Schäfer
- Institute for Advanced Membrane Technology (IAMT), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, Eggenstein-Leopoldshafen 76344, Germany
| |
Collapse
|
4
|
Shang C, Coreau N, Macé N, Descostes M, Reiller PE. Implications of recently derived thermodynamic data and specific ionic interaction theory parameters for (Mg/Ca) nUO 2(CO 3) 3(4-2n)- complexes on the predominance of the Mg 2+-Ca 2+-UO 22+-OH --CO 32- systems, and application to natural and legacy-mine waters. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 858:159927. [PMID: 36343816 DOI: 10.1016/j.scitotenv.2022.159927] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Revised: 10/24/2022] [Accepted: 10/30/2022] [Indexed: 06/16/2023]
Abstract
The formation of alkaline earth(II)triscarbonatouranyl(VI) (AenUO2(CO3)3(4-2n)-) species that have been evidenced both in laboratory and in-field studies, is important from slightly acidic pH up to near degraded cementitious in carbonated waters. They are also showing distinctive luminescence properties with a hypsochromic shift relative to UO22+. The conditions of pH, activities of alkaline earth(II) free ions (mostly Mg2+ and Ca2+) and carbonate ions (HCO3-) can be predicted from the thermodynamic functions and constants. The predictive validity of the activity of major alkaline ions (mostly Na+) is determined from the models used to describe the ionic strength comportment of these species, particularly using coefficients from the specific ion interaction theory (SIT). The stability domains of these species are better defined as a function of the activity of the constituents, and applied to natural waters. In this work, using recently obtained complete thermodynamic data and SIT coefficients, we will draw the stability domains of the AenUO2(CO3)3(4-2n)- species in combinations of activities of H+, HCO3-, Mg2+, Ca2+, and Na+ for a wide selection of water compositions from the literature. Water samples were collected near a French mining legacy-site (Site du Bosc, Lodève, France). After determining the major ion compositions, we will verify that the luminescence signal of uranium is in agreement with the predicted speciation in the stability domains.
Collapse
Affiliation(s)
- Chengming Shang
- Université Paris-Saclay, CEA, Service d'Études Analytiques et de Réactivité des Surfaces (SEARS), F-91191 Gif-sur-Yvette CEDEX, France
| | - Nathalie Coreau
- Université Paris-Saclay, CEA, Service d'Études du Comportement des Radionucléïdes (SECR), F-91191 Gif-sur-Yvette CEDEX, France
| | - Nathalie Macé
- Université Paris-Saclay, CEA, Service d'Études du Comportement des Radionucléïdes (SECR), F-91191 Gif-sur-Yvette CEDEX, France
| | - Michael Descostes
- ORANO Mining, Environmental R&D Department, 125 Avenue de Paris, 92330 Châtillon, France; PSL University/Mines ParisTech, Centre de Géosciences, 35 rue Saint-Honoré, 77305 Fontainebleau, France
| | - Pascal E Reiller
- Université Paris-Saclay, CEA, Service d'Études Analytiques et de Réactivité des Surfaces (SEARS), F-91191 Gif-sur-Yvette CEDEX, France.
| |
Collapse
|
5
|
Shu J, Liu J, Shi S, Wang J, Wu P, Cheng Z, Liu N, Lan T. Highly Efficient Sorption of U(VI) on TiO2 Nanosheets Supported by Amidoxime Polyacrylonitrile in A Variety of Multi-carbonate Solutions. Sep Purif Technol 2023. [DOI: 10.1016/j.seppur.2023.123491] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/02/2023]
|
6
|
Chemical thermodynamics of ternary M-An(VI)-CO 3 system (M = Mg, Ca, Sr, and Ba). RADIOCHIM ACTA 2022. [DOI: 10.1515/ract-2021-1133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
This review provides an overview of the chemical thermodynamics on ternary earth-alkaline metal-actinyl-tricarbonate systems (i.e., M-AnO2-CO3, M = Mg, Ca, Sr, and Ba) and discusses the aqueous complexation and dissolution/precipitation equilibrium for these ternary aqueous systems. The aqueous ternary U(VI) carbonate species are remarkably predominant in the U(VI) speciation under natural environmental conditions at ambient temperature and moderate ionic strength condition, while the omnipresence, according to recent studies, would be hindered by an increase in temperature and ionic strength. With respect to the ternary solid U(VI) carbonate phases, most of the previously reported data have been focused on physical properties and thus a notable lack of available data on chemical thermodynamic properties, i.e., solubility product constant, has been identified. Nevertheless, substantial influences of these ternary M-AnO2-CO3 systems on the aqueous speciation and the solubility limiting phase under the natural environmental condition are taken into account according to the thermodynamic calculation. The authors point out that the completeness of the chemical thermodynamic model for predicting the chemical behavior of actinides in nature can be further improved on the basis of a sufficient understanding of ternary M-AnO2-CO3 systems.
Collapse
|
7
|
Stockmann M, Fritsch K, Bok F, Fernandes MM, Baeyens B, Steudtner R, Müller K, Nebelung C, Brendler V, Stumpf T, Schmeide K. New insights into U(VI) sorption onto montmorillonite from batch sorption and spectroscopic studies at increased ionic strength. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 806:150653. [PMID: 34597569 DOI: 10.1016/j.scitotenv.2021.150653] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Revised: 09/06/2021] [Accepted: 09/24/2021] [Indexed: 06/13/2023]
Abstract
The influence of ionic strength up to 3 mol kg-1 (background electrolytes NaCl or CaCl2) on U(VI) sorption onto montmorillonite was investigated as function of pHc in absence and presence of CO2. A multi-method approach combined batch sorption experiments with spectroscopic methods (time-resolved laser-induced fluorescence spectroscopy (TRLFS) and in situ attenuated total reflection Fourier-transform infrared spectroscopy (ATR FT-IR)). In the absence of atmospheric carbonate, U(VI) sorption was nearly 99% above pHc 6 in both NaCl and CaCl2 and no significant effect of ionic strength was found. At lower pH, cation exchange was strongly reduced with increasing ionic strength. In the presence of carbonate, U(VI) sorption was reduced above pHc 7.5 in NaCl and pHc 6 in CaCl2 system due to formation of aqueous UO2(CO3)x(2-2x) and Ca2UO2(CO3)3 complexes, respectively, as verified by TRLFS. A significant ionic strength effect was observed due to the formation of Ca2UO2(CO3)3(aq), which strongly decreases U(VI) sorption with increasing ionic strength. The joint analysis of determined sorption data together with literature data (giving a total of 213 experimental data points) allowed to derive a consistent set of surface complexation reactions and constants based on the 2SPNE SC/CE approach, yielding log K°≡SSOUO2+ = 2.42 ± 0.04, log K°≡SSOUO2OH = -4.49 ± 0.7, and log K°≡SSOUO2(OH)32- = -20.5 ± 0.4. Ternary uranyl carbonate surface complexes were not required to describe the data. With this reduced set of surface complexes, an improved robust sorption model was obtained covering a broad variety of geochemical settings over wide ranges of ionic strengths and groundwater compositions, which subsequently was validated by an independent original dataset. This model improves the understanding of U(VI) retention by clay minerals and enables now predictive modeling of U(VI) sorption processes in complex clay rich natural environments.
Collapse
Affiliation(s)
- M Stockmann
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Resource Ecology, Bautzner Landstr. 400, 01328 Dresden, Germany.
| | - K Fritsch
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Resource Ecology, Bautzner Landstr. 400, 01328 Dresden, Germany
| | - F Bok
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Resource Ecology, Bautzner Landstr. 400, 01328 Dresden, Germany
| | - M Marques Fernandes
- Paul Scherrer Institute, Laboratory for Waste Management, 5232 Villigen PSI, Switzerland
| | - B Baeyens
- Paul Scherrer Institute, Laboratory for Waste Management, 5232 Villigen PSI, Switzerland
| | - R Steudtner
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Resource Ecology, Bautzner Landstr. 400, 01328 Dresden, Germany
| | - K Müller
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Resource Ecology, Bautzner Landstr. 400, 01328 Dresden, Germany
| | - C Nebelung
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Resource Ecology, Bautzner Landstr. 400, 01328 Dresden, Germany
| | - V Brendler
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Resource Ecology, Bautzner Landstr. 400, 01328 Dresden, Germany
| | - T Stumpf
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Resource Ecology, Bautzner Landstr. 400, 01328 Dresden, Germany
| | - K Schmeide
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Resource Ecology, Bautzner Landstr. 400, 01328 Dresden, Germany.
| |
Collapse
|
8
|
Huclier-Markai S, Alliot C, Mazza M, Reiller PE. Complexation of europium(III) with exopolysaccharides from a marine bacterium envisaged as luminescent probe in a theranostic approach. Dalton Trans 2021; 50:17215-17227. [PMID: 34783812 DOI: 10.1039/d1dt03288g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Exopolysaccharide (EPS) derivatives, produced by Alteromonas infernus bacterium, showed anti-metastatic properties in osteosarcoma (bone tumor). These EPSs could be employed as new drug delivery systems for therapeutic uses. They may represent a new class of ligands to be combined in a theranostic approach with fluorescent metals, such as Eu(III), to serve as imaging probe. The goal of this work was to investigate the feasibility of such coupling by time-resolved laser-induced fluorescence spectroscopy (TRLFS). Since these EPSs are polyelectrolytes their conformation could affect the complexation properties. Thus, viscosimetric measurements were performed as a function of their concentration as well as the background electrolyte concentration. Polysaccharides conformation exhibited a lower hydrodynamic volume for the highest ionic strengths. The resulting random-coiled conformation could affect the complexation with metal for high concentration but no change was evidenced when increasing europium concentration. Two sites of complexation of Eu(III) were evidenced by TRLFS in heparin, whereas only one site was evidenced in two modified EPSs produced from Alteromonas infernus.
Collapse
Affiliation(s)
- Sandrine Huclier-Markai
- GIP ARRONAX, 1 rue Aronnax, F-44817 Nantes Cedex 3, France. .,SUBATECH, 4 rue Alfred Kastler, BP 20722, 44307 Nantes Cedex 3, France
| | - Cyrille Alliot
- GIP ARRONAX, 1 rue Aronnax, F-44817 Nantes Cedex 3, France. .,INSERM U892- 8 quai Moncousu, F-44007 Nantes Cedex 1, France
| | - Mattia Mazza
- GIP ARRONAX, 1 rue Aronnax, F-44817 Nantes Cedex 3, France. .,SUBATECH, 4 rue Alfred Kastler, BP 20722, 44307 Nantes Cedex 3, France
| | - Pascal E Reiller
- Université Paris-Saclay, CEA, Service d'Etudes Analytiques et de Réactivité des Surfaces (SEARS), F-91191, Gif sur Yvette, France
| |
Collapse
|
9
|
Shang C, Reiller PE. Effect of temperature on the complexation of triscarbonatouranyl(VI) with calcium and magnesium in NaCl aqueous solution. Dalton Trans 2021; 50:17165-17180. [PMID: 34781338 DOI: 10.1039/d1dt03204f] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The complex formation of triscarbonatouranyl(VI) UO2(CO3)34- with the alkaline earth metal ions Mg2+ and Ca2+ in 0.10 mol kgw-1 NaCl was studied at variable temperatures: 5-30 °C for Mg2+ and 10-50 °C for Ca2+. Under appropriate conditions, the ternary complexes (MnUO2(CO3)3(4-2n)- with n = 1 for Mg, n = {1; 2} for Ca) were identified by time-resolved laser-induced luminescence spectrometry. Their pure spectral components at 50 °C for CanUO2(CO3)3(4-2n)- and 30 °C for MgUO2(CO3)32- were recovered by multivariate curve resolution alternating least-squares analysis. Approximation models were tested to fit the experimental data-the equilibrium constants of complexation measured at different temperatures-and deduce the thermodynamic functions, i.e., enthalpy, entropy, and heat capacity. The weak influence of temperature on complexation constants induces large uncertainties in terms of thermodynamic functions. Assuming the enthalpy is constant with temperature using the Van't Hoff equation, the first stepwise complexation of UO2(CO3)34- by Ca2+ is estimated to be slightly endothermic, with , while the second stepwise complexation of CaUO2(CO3)32- by Ca2+ with is slightly exothermic, . In contrast to Ca2+, the complexation of UO2(CO3)34- by Mg2+ is slightly exothermic, with . These values are not significantly different from zero inasmuch as the uncertainties are important due to a weak dependence of log10 K° values. The entropic character of the complexation is verified as for the first stepwise complexation of UO2(CO3)34- by Ca2+, for the second stepwise complexation of CaUO2(CO3)32- by Ca2+, and for the complexation of UO2(CO3)34- by Mg2+. The energetics of complexation and sensitivity analysis of the model estimates with temperature are discussed. The uranium speciation in the case of the safety of nuclear waste management, using the present thermodynamic functions, provides support to the assessment of underground nuclear waste repositories.
Collapse
Affiliation(s)
- Chengming Shang
- Université Paris-Saclay, CEA, Service d'Études Analytiques et de Réactivité des Surfaces (SEARS), F-91191 Gif-sur-Yvette CEDEX, France.
| | - Pascal E Reiller
- Université Paris-Saclay, CEA, Service d'Études Analytiques et de Réactivité des Surfaces (SEARS), F-91191 Gif-sur-Yvette CEDEX, France.
| |
Collapse
|
10
|
Shang C, Reiller PE. The determination of the thermodynamic constants of MgUO 2(CO 3) 32- complex in NaClO 4 and NaCl media by time-resolved luminescence spectroscopy, and applications in different geochemical contexts. Dalton Trans 2021; 50:4363-4379. [PMID: 33693449 DOI: 10.1039/d0dt04124f] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The formation constants and specific ion interaction coefficients of MgUO2(CO3)32- complex were determined in 0.1 to 1.0 mol kgw-1 NaCl and 0.10 to 2.21 mol kgw-1 NaClO4 media in the framework of the specific ion interaction theory (SIT), by time-resolved laser-induced luminescence spectroscopy. The upper limits of ionic strength were chosen in order to limit luminescence quenching effects generated by high concentrations of Cl- and ClO4- already observed during our earlier studies on CanUO2(CO3)3(4-2n)- complexes (Shang & Reiller, Dalton Trans., 49, 466; Shang et al., Dalton Trans., 49, 15443). The cumulative formation constant determined is , and the specific ion interaction coefficients are ε(MgUO2(CO3)32-, Na+) = 0.19 ± 0.11 kgw mol-1 in NaClO4 and ε(MgUO2(CO3)32-, Na+) = 0.09 ± 0.16 kgw mol-1 in NaCl. Two gratings of 300 and 1800 lines per mm were used to acquire MgUO2(CO3)32- luminescence spectra, where the high-resolution 1800 lines per mm grating detected slight spectral shifts for the principal luminescent bands relative to CanUO2(CO3)3(4-2n)-. The applications of the consistent set of thermodynamic constants and ε values for MnUO2(CO3)3(4-2n)- (M = Mg and Ca) were examined in different geochemical contexts, where Mg over Ca concentration ratio varies to help defining the relative importance of these species.
Collapse
Affiliation(s)
- Chengming Shang
- Université Paris-Saclay, CEA, Service d'Études Analytiques et de Réactivité des Surfaces (SEARS), F-91191 Gif-sur-Yvette CEDEX, France.
| | | |
Collapse
|
11
|
Shang C, Reiller PE, Vercouter T. Spectroluminescence measurements of the stability constants of Ca nUO 2(CO 3) 3(4-2n)- complexes in NaClO 4 medium and the investigation of interaction effects. Dalton Trans 2020; 49:15443-15460. [PMID: 33140787 DOI: 10.1039/d0dt03164j] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The stability constants of ternary calcium uranyl tricarbonate complexes, CaUO2(CO3)32- and Ca2UO2(CO3)3(aq), were determined in NaClO4 medium at various ionic strengths using time-resolved laser-induced luminescence spectroscopy (TRLS) - also known as time-resolved laser-induced fluorescence spectroscopy (TRLFS). As in a previous study, the potential precipitation of schoepite (UO3·2H2O) and calcite (CaCO3) was avoided via titration of the triscarbonatouranyl complex with Ca2+ at varying pH values. The Ringböm coefficients relative to UO2(CO3)34- were individually evaluated under test sample conditions. Steadily enhanced luminescence intensity and increased decay-times were representative of complexation processes. The stoichiometry of calcium was quantified by slope analysis, and its measured intensity was corrected by using the corresponding Ringböm coefficient. The conditional formation constants, i.e. log10 Kn.1.3, were then assessed after rounding off the slope values to their nearest integers. Cumulative formation constants at infinite dilution log10 β°n.1.3, and specific ion interaction parameters ε were determined based on the experimental origin and slope values, respectively, over the range of 0.1-2.46 mol kgw-1 NaClO4 using the specific ion interaction theory (SIT) approach. The cumulative stability constants are log10 β°(CaUO2(CO3)32-) = 27.26 ± 0.04 and log10 β°(Ca2UO2(CO3)3(aq)) = 30.53 ± 0.06. The specific ion interaction coefficients are estimated to be ε(CaUO2(CO3)32-,Na+) = (0.02 ± 0.04) kgw mol-1 and ε(Ca2UO2(CO3)3(aq),NaClO4) = (0.18 ± 0.07) kgw mol-1. These latter values are different from the ones that were previously obtained in NaCl, and underlying causes are discussed from different aspects. This work provides valuable information to address the interaction effects between Ca-UO2-CO3 species and 1 : 1 type electrolytes. It is suggested that the affinity of the cation in a background electrolyte with CanUO2(CO3)3(4-2n)- (n = {1;2}) has to be taken into consideration at high ionic strengths, especially for globally non-charged species.
Collapse
Affiliation(s)
- Chengming Shang
- Université Paris-Saclay, CEA, Service d'Études Analytiques et de Réactivité des Surfaces (SEARS), F-91191 Gif-sur-Yvette CEDEX, France.
| | - Pascal E Reiller
- Université Paris-Saclay, CEA, Service d'Études Analytiques et de Réactivité des Surfaces (SEARS), F-91191 Gif-sur-Yvette CEDEX, France.
| | - Thomas Vercouter
- Université Paris-Saclay, CEA, Service d'Études Analytiques et de Réactivité des Surfaces (SEARS), F-91191 Gif-sur-Yvette CEDEX, France.
| |
Collapse
|
12
|
Oher H, Vercouter T, Réal F, Shang C, Reiller PE, Vallet V. Influence of Alkaline Earth Metal Ions on Structures and Luminescent Properties of Na mM nUO 2(CO 3) 3(4-m-2n)- (M = Mg, Ca; m, n = 0-2): Time-Resolved Fluorescence Spectroscopy and Ab Initio Studies. Inorg Chem 2020; 59:15036-15049. [PMID: 33000939 DOI: 10.1021/acs.inorgchem.0c01986] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The luminescence spectra of triscarbonatouranyl complexes were determined by experimental and theoretical methods. Time-resolved laser-induced fluorescence spectroscopy was used to monitor spectra of uranyl and bicarbonate solutions at 0.1 mol kgw-1 ionic strength and pH ca. 8. The concentrations of Mg2+ and Ca2+ in the samples were chosen in order to vary the proportions of the alkaline earth ternary uranyl complexes MgUO2(CO3)32-, CaUO2(CO3)32-, and Ca2UO2(CO3)3. The luminescence spectrum of each complex was determined by decomposition in order to compare it with the simulated spectra of model structures NamMnUO2(CO3)3(4-m-2n)- (M = Mg, Ca; m, n = 0-2) obtained by quantum chemical methods. The density functional theory (DFT) and time-dependent (TD)-DFT methods were used with the PBE0 functional to optimize the structures in the ground and excited states, respectively, including relativistic effects at the spin-free level, and water solvent effects using a continuum polarizable conductor model. The changes in the structural parameters were quantified with respect to the nature and the amount of alkaline earth counterions to explain the luminescence spectra behavior. The first low-lying excited state was successfully computed, together with the vibrational harmonic frequencies. The DFT calculations confirmed that uranyl luminescence originates from electronic transitions from one of the four nonbonding 5f orbitals of uranium to an orbital that has a uranyl-σ (5f, 6d) character mixed with the 2p atomic orbitals of the carbonate oxygens. Additional single-point calculations using the more accurate TD-DFT/CAM-B3LYP allow one to determine the position of the luminescence "hot band" for each structure in the range 467-476 nm and compared fairly well with experimental reports at around 465 nm. The complete luminescence spectra were built from theoretical results with the corresponding assignment of the electronic transitions and vibronic modes involved, mainly the U-Oax stretching mode. The resulting calculated spectra showed a very good agreement with experimental band positions and band spacing attributed to MgUO2(CO3)32-, CaUO2(CO3)32-, and Ca2UO2(CO3)3. The evolution of luminescence intensities with the number of alkaline earth metal ions in the structure was also correctly reproduced.
Collapse
Affiliation(s)
- Hanna Oher
- Service d'Études Analytiques et de Réactivité des Surfaces, Université Paris-Saclay, CEA, 91191 Gif-sur-Yvette, France.,UMR 8523-PhLAM-Physique des Lasers Atomes et Molécules, Université de Lille, CNRS, 59000 Lille, France
| | - Thomas Vercouter
- Service d'Études Analytiques et de Réactivité des Surfaces, Université Paris-Saclay, CEA, 91191 Gif-sur-Yvette, France
| | - Florent Réal
- UMR 8523-PhLAM-Physique des Lasers Atomes et Molécules, Université de Lille, CNRS, 59000 Lille, France
| | - Chengming Shang
- Service d'Études Analytiques et de Réactivité des Surfaces, Université Paris-Saclay, CEA, 91191 Gif-sur-Yvette, France
| | - Pascal E Reiller
- Service d'Études Analytiques et de Réactivité des Surfaces, Université Paris-Saclay, CEA, 91191 Gif-sur-Yvette, France
| | - Valérie Vallet
- UMR 8523-PhLAM-Physique des Lasers Atomes et Molécules, Université de Lille, CNRS, 59000 Lille, France
| |
Collapse
|
13
|
Jo Y, Cho HR, Yun JI. Visible-NIR absorption spectroscopy study of the formation of ternary plutonyl(VI) carbonate complexes. Dalton Trans 2020; 49:11605-11612. [PMID: 32780063 DOI: 10.1039/d0dt01982h] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We present the first experimental evidence for the ternary complexation of calcium and magnesium ions with plutonyl(vi)tricarbonate species in carbonate-containing aqueous solutions using visible-NIR spectrophotometric titration. Prior to studying the ternary plutonyl(vi) carbonate complexation, visible-NIR absorption spectral information of PuO2(CO3)22- and PuO2(CO3)34- was successfully obtained. PuO2(CO3)22- has a prominent peak at 853 nm and its molar absorptivity was determined to be ε853, PuO2(CO3)22- = 49.0 ± 4.2 M-1·cm-1. The spectrophotometric titration results by adding calcium or magnesium to the plutonyl(vi) carbonate system consisting of PuO2(CO3)22- and PuO2(CO3)34- indicate the formation of CaPuO2(CO3)32- and MgPuO2(CO3)32- complexes and provide the formation constants at 0.1 M H/NaClO4 for MPuO2(CO3)32- from PuO2(CO3)34-, log K = 4.33 ± 0.50 and 2.58 ± 0.18 for M = Ca2+ and Mg2+, respectively. In addition, the formation constants of CaPuO2(CO3)32- and MgPuO2(CO3)32- from PuO2(CO3)34- at infinite dilution (log K°) were proposed to be 6.05 ± 0.50 and 4.29 ± 0.18, respectively, based on the correction of ionic strength using the Davies equation. The absorption spectrum of the ternary plutonyl(vi) complexes of CaPuO2(CO3)32- is similar to that of PuO2(CO3)34- with the exception of a characteristic absorption peak at 808 nm (ε808, CaPuO2(CO3)32- = 42.9 ± 1.6 M-1·cm-1). According to the calculated aqueous plutonyl(vi) speciation including the ternary plutonyl(vi) complexes, CaPuO2(CO3)32- is considered the dominant Pu(vi) species under environmental conditions, and plutonyl(vi) may be more mobile than expected in previous assessments.
Collapse
Affiliation(s)
- Yongheum Jo
- Department of Nuclear and Quantum Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea.
| | - Hye-Ryun Cho
- Nuclear Chemistry Research Team, Korea Atomic Energy Research Institute, 111 Daedeok-daero 989 beon-gil, Yuseong-gu, Daejeon 34057, Republic of Korea
| | - Jong-Il Yun
- Department of Nuclear and Quantum Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea.
| |
Collapse
|
14
|
Reiller PE, Descostes M. Development and application of the thermodynamic database PRODATA dedicated to the monitoring of mining activities from exploration to remediation. CHEMOSPHERE 2020; 251:126301. [PMID: 32145577 DOI: 10.1016/j.chemosphere.2020.126301] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Revised: 11/19/2019] [Accepted: 02/20/2020] [Indexed: 06/10/2023]
Abstract
A growing demand exists on the monitoring of both uranium mining activities and their environmental impacts. In order to help understanding and modelling both these aspects, a thermodynamic database dedicated to uranium mining activities is developed: the PRODATA database. Relevant species and phases for uranium and radium are chosen from existing compilations of data, complemented with important missing data for the application to mining activities and environmental monitoring. Important major anions and cations chemistry are included, as well as secondary pollutants such as arsenic, lead, or nickel. Applications of the PRODATA extracted database file for PhreeqC to theoretical speciation calculations of uranium and radium for actual water compositions - either linked to uranium mining activities, or under monitoring for environmental survey - are presented. Wider applications to other available water compositions from different geochemical concepts are also tested. For the tested cases, the major radium and uranium species obtained using PRODATA are compared with other available thermodynamic database (Thermochimie, LLNL, Wateq4f, Minteq, PSI/NAGRA). The choice of the database file - and of the ionic strength correction - can strongly impact the final speciation results. Sulphate complexes of radium and uranium are of particular importance in mining exploitation context, and carbonate uranium complexes - particularly [Formula: see text] complexes - are crucial for environmental monitoring. The latter complexes are key species for the aqueous speciation of uranium, even in reducing environment where U(IV) low solubility usually governs uranium mobility.
Collapse
Affiliation(s)
- Pascal E Reiller
- Den - Service D'Études Analytiques et de Réactivité des Surfaces (SEARS), CEA, Université Paris-Saclay, F-91191, Gif-sur-Yvette, France.
| | - Michaël Descostes
- ORANO Group Mining R&D Dpt, 125 Avenue de Paris, F-92320, Châtillon, France
| |
Collapse
|