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Hinz K, Fellhauer D, Gaona X, Vespa M, Dardenne K, Schild D, Yokosawa T, Silver MA, Reed DT, Albrecht-Schmitt TE, Altmaier M, Geckeis H. Interaction of Np( v) with borate in alkaline, dilute-to-concentrated, NaCl and MgCl 2 solutions. Dalton Trans 2020; 49:1570-1581. [DOI: 10.1039/c9dt04430b] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The formation of sparingly soluble ternary Na/Mg–Np(v)–borate(s) solid phases in alkaline, dilute-to-concentrated, NaCl and MgCl2 solutions is confirmed by a multimethod experimental approach.
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Affiliation(s)
- K. Hinz
- Institute for Nuclear Waste Disposal
- Karlsruhe Institute of Technology
- Germany
| | - D. Fellhauer
- Institute for Nuclear Waste Disposal
- Karlsruhe Institute of Technology
- Germany
| | - X. Gaona
- Institute for Nuclear Waste Disposal
- Karlsruhe Institute of Technology
- Germany
| | - M. Vespa
- Institute for Nuclear Waste Disposal
- Karlsruhe Institute of Technology
- Germany
| | - K. Dardenne
- Institute for Nuclear Waste Disposal
- Karlsruhe Institute of Technology
- Germany
| | - D. Schild
- Institute for Nuclear Waste Disposal
- Karlsruhe Institute of Technology
- Germany
| | - T. Yokosawa
- Institute for Nuclear Waste Disposal
- Karlsruhe Institute of Technology
- Germany
| | - M. A. Silver
- Department of Chemistry and Biochemistry
- Florida State University
- USA
| | | | | | - M. Altmaier
- Institute for Nuclear Waste Disposal
- Karlsruhe Institute of Technology
- Germany
| | - H. Geckeis
- Institute for Nuclear Waste Disposal
- Karlsruhe Institute of Technology
- Germany
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Emerson HP, Zengotita F, Richmann M, Katsenovich Y, Reed DT, Dittrich TM. Retention of neodymium by dolomite at variable ionic strength as probed by batch and column experiments. J Environ Radioact 2018; 190-191:89-96. [PMID: 29775842 DOI: 10.1016/j.jenvrad.2018.05.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [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: 03/13/2018] [Revised: 04/21/2018] [Accepted: 05/06/2018] [Indexed: 06/08/2023]
Abstract
The results presented in this paper highlight the complexity of adsorption and incorporation processes of Nd with dolomite and significantly improve upon previous work investigating trivalent actinide and lanthanide interactions with dolomite. Both batch and mini column experiments were conducted at variable ionic strength. These data highlight the strong chemisorption of Nd to the dolomite surface (equilibrium Kd's > 3000 mL/g) and suggest that equilibrium adsorption processes may not be affected by ionic strength based on similar results at 0.1 and 5.0 M ionic strength in column breakthrough and equilibrium batch (>5 days) results. Mini column experiments conducted over approximately one year also represent a significant development in measurement of sorption of Nd in the presence of flow as previous large-scale column experiments did not achieve breakthrough likely due to the high loading capacity of dolomite for Nd (up to 240 μg/g). Batch experiments in the absence of flow show that the rate of Nd removal increases with increasing ionic strength (up to 5.0 M) with greater removal at greater ionic strength for a 24 h sampling point. We suggest that the increasing ionic strength induces increased mineral dissolution and re-precipitation caused by changes in activity with ionic strength that lead to increased removal of Nd through co-precipitation processes.
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Affiliation(s)
- H P Emerson
- Applied Research Center, Florida International University, 10555 W Flagler St, Miami, FL, 33174, United States.
| | - F Zengotita
- Applied Research Center, Florida International University, 10555 W Flagler St, Miami, FL, 33174, United States
| | - M Richmann
- Repository Science and Operations, Los Alamos National Laboratory, 1400 University Drive, Carlsbad, NM, 88220, United States
| | - Y Katsenovich
- Applied Research Center, Florida International University, 10555 W Flagler St, Miami, FL, 33174, United States
| | - D T Reed
- Repository Science and Operations, Los Alamos National Laboratory, 1400 University Drive, Carlsbad, NM, 88220, United States
| | - T M Dittrich
- Repository Science and Operations, Los Alamos National Laboratory, 1400 University Drive, Carlsbad, NM, 88220, United States; Department of Civil and Environmental Engineering, Wayne State University, 5050 Anthony Wayne Drive, Detroit, MI, 48202, United States
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Affiliation(s)
- D. T. Reed
- Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, Illinois 60439-4837, USA
| | - D. G. Wygmans
- Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, Illinois 60439-4837, USA
| | - S. B. Aase
- Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, Illinois 60439-4837, USA
| | - J. E. Banaszak
- Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, Illinois 60439-4837, USA
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Banaszak JE, VanBriesen JM, Rittmann ΒE, Reed DT. Mathematical Modelling of the Effects of Aerobic and Anaerobic Chelate Biodegradation on Actinide Speciation. RADIOCHIM ACTA 2013. [DOI: 10.1524/ract.1998.82.special-issue.445] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
- J. E. Banaszak
- Northwestern University, Evanston, Illinois 60208-3109, USA
| | | | - Β. E. Rittmann
- Northwestern University, Evanston, Illinois 60208-3109, USA
| | - D. T. Reed
- Argonne National Laboratory, Argonne, Illinois 60439, USA
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Abstract
ABSTRACTAn assessment of the fundamental research needs in understanding and predicting the migration of radionuclides in the subsurface is provided. Emphasis is on the following three technical areas: (1) aqueous speciation of radionuclides, (2) the interaction of radionuclides with substrates, and (3) intermediate-scale interaction studies. This research relates to important issues associated with environmental restoration and remediation of DOE sites contaminated with mixed radionuclide-organic wastes.
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Brush LH, Grbic-Galic D, Reed DT, Tong X, Vreeland RH, Westerman RE. Preliminary Results of Laboratory Studies of Repository Chemistry for the Waste Isolation Pilot Plant. ACTA ACUST UNITED AC 2011. [DOI: 10.1557/proc-212-893] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
ABSTRACTThe design-basis, defense-related, transuranic (TRU) waste to be emplaced in the Waste Isolation Pilot Plant (WIPP) could, if sufficient H2O and nutrients were present, produce as much as 1,500 moles of gas per drum of waste. Gas production could pressurize the repository to lithostatic pressure (150 atm) and perhaps higher.Anoxic corrosion of Fe and Fe-base alloys and microbial degradation of cellulosics are the processes of greatest concern, but radiolysis of brine could also be important. The proposed backfill additives CaC03, CaO, CuSO4, KOH, and NaOH may remove or prevent the production of some of the expected gases. We describe these processes and present preliminary results of laboratory studies of anoxic corrosion and microbial activity.
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Abstract
AbstractNeptunium is found predominantly as Np(IV) in reducing environments, but as Np(V) in aerobic environments. Currently, it is not known how the interplay between biotic and abiotic processes affects Np redox speciation in the environment. To evaluate the effect of anaerobic microbial activity on the fate of Np in natural systems, Np(V) was added to a microcosm inoculated with anaerobic sediments from a metal-contaminated freshwater lake. The consortium included metal-reducing, sulfate-reducing, and methanogenic microorganisms, and acetate was supplied as the only exogenous substrate. Addition of more than 10−5M Np did not inhibit methane production. Total Np solubility in the active microcosm, as well as in sterilized control samples, decreased by nearly two orders of magnitude. A combination of analytical techniques, including VIS-NIR absorption spectroscopy and XANES, identified Np(IV) as the oxidation state associated with the sediments. The similar results from the active microcosm and the abiotic controls suggest that microbially produced Mn(II/III) and Fe(II) may serve as electron donors for Np reduction.
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Affiliation(s)
- D. T. Reed
- Chemical Technology Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL, 60439-4837
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Abstract
Summary
The bio-sorption of neptunyl (NpO2
+) by Pseudomonas fluorescens was investigated. The overall goals of this research are to identify key interactions between neptunium and soil bacteria and to model these effects under subsurface-related conditions. Neptunyl, which is generally thought to be non-sorptive, was significantly sorbed under all conditions studied. At initial neptunyl concentrations of 4.75 µM and pH = 7, as much as 85% of the neptunium was sorbed under aerobic conditions. Kinetic studies show that neptunyl was sorbed rapidly within the first 15 minutes. The extent of sorption also increased with pH. In all cases, the sorbed neptunium was shown to be NpO2
+ by X-ray absorption near edged spectroscopy (XANES) analysis, confirming that there was no reduction to Np(IV) under the conditions of our experiment. The sorption data were modeled using Langmuir and Freundlich isotherms. A comparison of the two approaches showed a significantly better fit for the Freundlich isotherm, and the Freundlich parameter values suggest interactions between sorbed NpO2
+ molecules. These data show that bio-sorption, even for neptunyl, has a significant role in defining the speciation of neptunium and, hence, its overall mobility in the subsurface.
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Abstract
The radiotoxicity of plutonium in NTA-degrading Chelatobacter heintzii cell suspensions was investigated as part of a more general study to establish the key interactions between actinide-organic complexes and microorganisms in the subsurface. The radiation tolerance of C. heintzii, based on 60Co gamma irradiation experiments, was 165 +/- 30 Gy. No bacteria survived irradiation doses greater than 500 Gy. In the presence of plutonium, where alpha particle decay was the primary source of ionizing radiation, the observed toxicity was predominantly radiolytic rather than chemical. This was evident by the greater effect of activity, rather than concentration, on the toxicity noted. Bioassociation of plutonium with C. heintzii was postulated to be an important and necessary step in the observed loss of cell viability since this was the best way to account for the observed death rate. The radiotoxicity of plutonium towards bacteria is a potentially important consideration in the bioremediation of sites contaminated with radionuclide-organic mixtures and the bioprocessing of nuclear waste.
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Affiliation(s)
- D T Reed
- Chemical Technology Division, Argonne National Laboratory, IL 60439, USA.
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Affiliation(s)
- D. T. Reed
- Chemical Technology Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL, 60439-4837
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Affiliation(s)
- S. Okajima
- Chemical Technology Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439-4837
| | - D. T. Reed
- Chemical Technology Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439-4837
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Abstract
ABSTRACTGas generation due to alpha particle deposition was investigated in four WIPP relevant brines; WIPP brine A, ERDA-6, DH-36 and G8-B. This was done by spiking each brine with plutonium-239 and periodically sampling the gas phase to determine the nature of the gaseous products and the rates of gas generation. The predominant gas generated radiolytically was hydrogen, with yields ranging from 0.6 to 1.5 molec/100 eV for the four brines tested. Plutonium (VI) was stable in two synthetic brines, WIPP brine A and ERDA-6 but was rapidly reduced in the underground collected brines DH-36 and G8-B, although most of the plutonium remained in solution.
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Affiliation(s)
- D. T. Reed
- Chemical Technology Division, Argonne National Laboratory, 9700 South Gass Avenue, Argonne, IL 60439-4837
| | - D. L. Bowers
- Chemical Technology Division, Argonne National Laboratory, 9700 South Gass Avenue, Argonne, IL 60439-4837
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