Quantification of kinetic rate law parameters of uranium release from sodium autunite as a function of aqueous bicarbonate concentrations
Ravi Gudavalli A B , Yelena Katsenovich A D , Dawn Wellman C , Leonel Lagos A and Berrin Tansel B
+ Author Affiliations
- Author Affiliations
A Applied Research Center, Florida International University, 10555 W Flagler Street, Suite 2100, Miami, FL 33174, USA.
B Department of Civil and Environmental Engineering, Florida International University, 10555 W Flagler Street, Suite 3680, Miami, FL 33174, USA.
C US Department of Energy, Pacific Northwest National Laboratory, PO Box 999, K3-62, Richland, WA 99352, USA.
D Corresponding author. Email address: katsenov@fiu.edu
Environmental Chemistry 10(6) 475-485 https://doi.org/10.1071/EN13117
Submitted: 26 June 2013 Accepted: 17 October 2013 Published: 17 December 2013
Environmental context. Uranium is a key contaminant of concern because of its high persistence in the environment and toxicity to organisms. The bicarbonate ion is an important complexing agent for uranyl ions and one of the main variables affecting its dissolution. Results from this investigation provide rate law parameters for the dissolution kinetics of synthetic sodium autunite that can influence uranium mobility in the subsurface.
Abstract. Hydrogen carbonate (also known as bicarbonate) is one of the most significant components within the uranium geochemical cycle. In aqueous solutions, bicarbonate forms strong complexes with uranium. As such, aqueous bicarbonate may significantly increase the rate of uranium release from uranium minerals. Quantifying the relationship of aqueous bicarbonate solutions to the rate of uranium release during dissolution is critical to understanding the long-term fate of uranium within the environment. Single-pass flow-through experiments were conducted to estimate the rate of uranium release from Na meta-autunite as a function of bicarbonate solutions (0.0005–0.003 M) over the pH range of 6–11 and temperatures of 5–60 °C. Consistent with the results of previous investigations, the rate of uranium release from sodium autunite exhibited minimal dependency on temperature, but was strongly dependent on pH and increasing concentrations of bicarbonate solutions. Most notably at pH 7, the rate of uranium release exhibited a 370-fold increase relative to the rate of uranium release in the absence of bicarbonate. However, the effect of increasing concentrations of bicarbonate solutions on the release of uranium was significantly less under higher pH conditions. It is postulated that at high pH values, surface sites are saturated with carbonate, thus the addition of more bicarbonate would have less effect on uranium release. Results indicate that the activation energies were unaffected by temperature and bicarbonate concentration variations, but were strongly dependent on pH conditions. As the pH increased from 6 to 11, the activation energy values were observed to decrease from 29.94 to 13.07 kJ mol–1. The calculated activation energies suggest a surface controlled dissolution mechanism.
References
[1] R. G. Riley, J. M. Zachara, F. J. Wobber, Chemical Contaminants on DOE Lands and Selection of Contaminant Mixtures for Subsurface Science Research 1992 (US Department of Energy: Washington, DC).[2] D. Giammar, Geochemistry of Uranium at Mineral–Water Interfaces: Rates of Sorption–Desorption and Dissolution-Precipitation Reactions 2001, Ph.D. Dissertation, California Institute of Technology.
[3] A. G. Sowder, S. B. Clark, R. A. Fjeld, Dehydration of synthetic autunite hydrates. Radiochim. Acta. 2000, 88, 533.
| Dehydration of synthetic autunite hydrates.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD3MXotVyhtQ%3D%3D&md5=d94a27c59acd0974ff5920ecf4ed24ccCAS |
[4] B. Devivo, F. Ippolito, G. Capaldi, P. R. Simpson, Uranium Geochemistry, Mineralogy, Exploration and Resources 1984, p. 43 (The Institution of Mining and Metallurgy: London).
[5] D. Langmuir, Aqueous Environmental Geochemistry 1997 (Prentice Hall: Upper Saddle River NJ).
[6] I. Casas, J. De Pablo, J. Gimenez, M. E. Torrero, J. Bruno, E. Cera, R. J. Finch, R. C. Ewing, The role of pe, pH, and carbonate on the solubility of UO2 and uraninite under nominally reducing conditions. Geochim. Cosmochim. Acta 1998, 62, 2223.
| The role of pe, pH, and carbonate on the solubility of UO2 and uraninite under nominally reducing conditions.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK1cXlvFWkurg%3D&md5=06d6e276b255912560062fdab9c80ab2CAS |
[7] M. Sutton, P. Warwick, A. Halla, C. Jones, Carbonate induced dissolution of uranium containing precipitates under cement leachate conditions. J. Environ. Monit. 1999, 1, 177.
| Carbonate induced dissolution of uranium containing precipitates under cement leachate conditions.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK1MXitVKksL8%3D&md5=797c41f7fe6e01aea17bfa12a5e378bdCAS | 11529097PubMed |
[8] I. Pérez, I. Casas, M. Martín, J. Bruno, The thermodynamics and kinetics of uranophane dissolution in bicarbonate test solutions. Geochim. Cosmochim. Acta 2000, 64, 603.
| The thermodynamics and kinetics of uranophane dissolution in bicarbonate test solutions.Crossref | GoogleScholarGoogle Scholar |
[9] E. S. Ilton, C. Liu, W. Yantasee, Z. Wang, D. A. Moore, A. R. Felmy, J. M. Zachara, The dissolution of synthetic Na-boltwoodite in sodium carbonate solutions. Geochim. Cosmochim. Acta 2006, 70, 4836.
| The dissolution of synthetic Na-boltwoodite in sodium carbonate solutions.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD28XpvVOks7c%3D&md5=fe9a29cd7ed5fdb8afad0153f65cf213CAS |
[10] I. Pérez, I. Casas, M. E. Torrero, E. Cera, L. Duro, J. Bruno, Dissolution studies of soddyite as a long-term analogue of the oxidative alteration of the spent nuclear fuel matrix. Proc. MRS 1996, 465, 565.
| Dissolution studies of soddyite as a long-term analogue of the oxidative alteration of the spent nuclear fuel matrix.Crossref | GoogleScholarGoogle Scholar |
[11] D. M. Wellman, J. P. Icenhower, A. P. Gamerdinger, S. W. Forrester, Effects of pH, temperature, and aqueous organic material on the dissolution kinetics of meta-autunite minerals, (Na, Ca)2–1[(UO2)(PO4)]2·3H2O. Am. Mineral. 2006, 91, 143.
| Effects of pH, temperature, and aqueous organic material on the dissolution kinetics of meta-autunite minerals, (Na, Ca)2–1[(UO2)(PO4)]2·3H2O.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD28XlvVSjsA%3D%3D&md5=a3d9c47bd7eb54f02a9a2889e808b910CAS |
[12] D. M. Wellman, K. M. Gunderson, J. P. Icenhower, S. W. Forrester, Dissolution kinetics of synthetic and natural meta-autunite minerals, X3–n (n)+[(UO2)(PO4)]2·xH2O, under acidic conditions. Geochem. Geophys. Geosyst. 2007, 8, Q11001.
| Dissolution kinetics of synthetic and natural meta-autunite minerals, X3–n (n)+[(UO2)(PO4)]2·xH2O, under acidic conditions.Crossref | GoogleScholarGoogle Scholar |
[13] R. Vochten, M. Deliens, Transformation of curite into metaautunite paragenesis and electrokinetic properties. Phys. Chem. Miner. 1980, 6, 129.
| Transformation of curite into metaautunite paragenesis and electrokinetic properties.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaL3cXmtVOmtLw%3D&md5=e80a3e7bd60961fb8f26226d31badaadCAS |
[14] D. M. Wellman, J. G. Catalano, J. P. Icenhower, A. P. Gamerdinger, Synthesis and characterization of sodium meta-autunite, Na[UO2PO4]·3H2O. Radiochim. Acta 2005, 93, 393.
| Synthesis and characterization of sodium meta-autunite, Na[UO2PO4]·3H2O.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2MXpslOhsLY%3D&md5=98788638c0c5e420c283940b9d5f9824CAS |
[15] S. Brunauer, P. H. Emmett, E. Teller, Adsorption of gases in multimolecular layers. J. Am. Chem. Soc. 1938, 60, 309.
| Adsorption of gases in multimolecular layers.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaA1cXivFaruw%3D%3D&md5=5650fabcd8f93d1a74bb7aec0f52bffdCAS |
[16] K. L. Nagy, Dissolution and precipitation kinetics of sheet silicates, in Chemical Weathering Rates of Silicate Minerals (Eds A. F. White, S. L. Brantley) 1995, pp. 173–233 (Mineralogical Society of America: Washington, DC).
[17] P. Aagaard, H. C. Helgeson, Thermodynamic and kinetic constraints on reaction rates among minerals and aqueous solutions. I. Theoretical considerations. Am. J. Sci. 1982, 282, 237.
| Thermodynamic and kinetic constraints on reaction rates among minerals and aqueous solutions. I. Theoretical considerations.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaL38XksFyksbg%3D&md5=b04626baa3a814fbc0ca1393fd915721CAS |
[18] A. C. Lasaga, Chemical kinetics of water-rock interactions. J. Geophys. Res. 1984, 89, 4009.
| Chemical kinetics of water-rock interactions.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaL2cXksFyjtLw%3D&md5=1bbb64f33ff7c55270657d2c2ed4f77fCAS |
[19] B. P. McGrail, W. L. Ebert, J. Bakel, D. K. Peeler, Measurement of kinetic rate law parameters on a Na–Ca–Al borosilicate glass for low-activity waste. J. Nucl. Mater. 1997, 249, 175.
| Measurement of kinetic rate law parameters on a Na–Ca–Al borosilicate glass for low-activity waste.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK2sXmsVKkurs%3D&md5=9f39982dec68d88026cb6c6fa572b27aCAS |
[20] E. M. Pierce, J. P. Icenhower, R. J. Serne, J. G. Catalano, Experimental determination of UO2(cr) dissolution kinetics: Effects of solution saturation state and pH. J. Nucl. Mater. 2005, 345, 206.
| Experimental determination of UO2(cr) dissolution kinetics: Effects of solution saturation state and pH.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2MXpsF2msrs%3D&md5=60530917d68e0ad0cf95f8b75ec0f632CAS |
[21] J. P. Icenhower, D. M. Strachan, B. P. McGrail, R. D. Scheele, E. A. Rodriguez, J. L. Steele, V. L. Legore, Dissolution kinetics of pyrochlore ceramics for the disposition of plutonium. Am. Mineral. 2006, 91, 39.
| Dissolution kinetics of pyrochlore ceramics for the disposition of plutonium.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD28Xlsl2ruw%3D%3D&md5=ddc9d45f7e58e45891fe1d012c16feb7CAS |
[22] E. M. Pierce, E. A. Rodriguez, L. J. Calligan, W. J. Shaw, B. P. McGrail, An experimental study of the dissolution rates of simulated aluminoborosilicate waste glasses as a function of pH and temperature under dilute conditions. Appl. Geochem. 2008, 23, 2559.
| An experimental study of the dissolution rates of simulated aluminoborosilicate waste glasses as a function of pH and temperature under dilute conditions.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1cXhtVGnsLrE&md5=49c2547c0736589244e753db6924f7c0CAS |
[23] I. Grenthe, J. Fuger, R. Konings, R. Lemire, A. Muller, C. Nguyen-Trung, Chemical Thermodynamics of Uranium 1992 (OECD Nuclear Energy Agency: Amsterdam).
[24] R. Guillaumont, T. Fanghänel, J. Fuger, I. Grenthe, V. Neck, D. A. Palmer, M. H. Rand, Update on the Chemical Thermodynamics of Uranium, Neptunium, Plutonium, Americium and Technetium 2003, Vol. 5 (Elsevier: Amsterdam).
[25] J. W. Ejnik, M. M. Hamilton, P. R. Adams, A. J. Carmichael, Optimal sample preparation conditions for the determination of uranium in biological samples by kinetic phosphorescence analysis (KPA). J. Pharm. Biomed. Anal. 2000, 24, 227.
| Optimal sample preparation conditions for the determination of uranium in biological samples by kinetic phosphorescence analysis (KPA).Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD3cXoslGgsb8%3D&md5=92d6e4d3f2923a3b396208ac5082b2a6CAS | 11130202PubMed |
[26] W. Stumm, J. Morgan, Aquatic Chemistry: Chemical Equilibria and Rates in Natural Waters, 3rd edn 1996 (Wiley: New York).
[27] Y. Zhang, K. P. Hart, W. L. Bourcier, R. A. Day, M. Colella, B. Thomas, Z. Aly, A. Jostsons, Kinetics of uranium release from Synroc phases. J. Nucl. Mater. 2001, 289, 254.
| Kinetics of uranium release from Synroc phases.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD3MXisFCns74%3D&md5=d92d3de2d9181d732974ba26bb223ec3CAS |
[28] R. A. Berner, Rate control of mineral dissolution under earth surface conditions. Am. J. Sci. 1978, 278, 1235.
| Rate control of mineral dissolution under earth surface conditions.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaE1MXktFeqtQ%3D%3D&md5=f3ceb058d44448b3b004a908d7a5af30CAS |
[29] G. Jordan, W. Rammensee, Dissolution rates and activation energy for dissolution of brucite (001): a new method based on the microtopography of crystal surfaces. Geochim. Cosmochim. Acta 1996, 60, 5055.
| Dissolution rates and activation energy for dissolution of brucite (001): a new method based on the microtopography of crystal surfaces.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK2sXhtVagsL4%3D&md5=50d4e05cc054f53c5bb3aa1e70940321CAS |
[30] J. D. Pablo, I. Casas, J. Gimenez, M. Molera, M. Rovira, L. Duro, The oxidative dissolution mechanism of uranium dioxide. I. The effect of temperature in hydrogen carbonate medium. Geochim. Cosmochim. Acta 1999, 63, 3097.
| The oxidative dissolution mechanism of uranium dioxide. I. The effect of temperature in hydrogen carbonate medium.Crossref | GoogleScholarGoogle Scholar |
[31] P. D. Scott, D. Glasser, M. J. Nico, Kinetics of dissolution of β-uranium trioxide in acid and carbonate solutions. J. Chem. Soc., Dalton Trans. 1977, 20, 1939.
| Kinetics of dissolution of β-uranium trioxide in acid and carbonate solutions.Crossref | GoogleScholarGoogle Scholar |
[32] G. Heisbourg, S. Hubert, N. Dacheux, J. Ritt, The kinetics of dissolution of Th1–xUxO2 solid solutions in nitric media. J. Nucl. Mater. 2003, 321, 141.
| The kinetics of dissolution of Th1–xUxO2 solid solutions in nitric media.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD3sXmvValurY%3D&md5=8900cae6da485ee73b8af92f1d464183CAS |
[33] A. G. Sowder, S. B. Clark, R. A. Fjeld, The impact of mineralogy in the UVI–Ca–PO4 system on the environmental availability of uranium. J. Radioanal. Nucl. Chem. 2001, 248, 517.
| The impact of mineralogy in the UVI–Ca–PO4 system on the environmental availability of uranium.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD3MXkvVagur4%3D&md5=adbd1773e614a7643c839993c99c3368CAS |
[34] W. Stumm, Chemistry of the Solid–Water Interface 1992 (Wiley: New York).
[35] S. M. Kraemer, J. G. Hering, Influence of solution saturation state on the kinetics of ligand-controlled dissolution of aluminum oxide. Geochim. Cosmochim. Acta 1997, 61, 2855.
| Influence of solution saturation state on the kinetics of ligand-controlled dissolution of aluminum oxide.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK2sXlsFKhur0%3D&md5=d325eccac79e1855fda8cb9dbc8e42b9CAS |
