1
|
Kaplan DI, Boyanov MI, Losey NA, Lin P, Xu C, O’Loughlin EJ, Santschi PH, Xing W, Kuhne WW, Kemner KM. Uranium Biogeochemistry in the Rhizosphere of a Contaminated Wetland. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:6381-6390. [PMID: 38547454 PMCID: PMC11008245 DOI: 10.1021/acs.est.3c10481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Revised: 03/08/2024] [Accepted: 03/11/2024] [Indexed: 04/10/2024]
Abstract
The objective of this study was to determine if U sediment concentrations in a U-contaminated wetland located within the Savannah River Site, South Carolina, were greater in the rhizosphere than in the nonrhizosphere. U concentrations were as much as 1100% greater in the rhizosphere than in the nonrhizosphere fractions; however and importantly, not all paired samples followed this trend. Iron (but not C, N, or S) concentrations were significantly enriched in the rhizosphere. XAS analyses showed that in both sediment fractions, U existed as UO22+ coordinated with iron(III)-oxides and organic matter. A key difference between the two sediment fractions was that a larger proportion of U was adsorbed to Fe(III)-oxides, not organic matter, in the rhizosphere, where significantly greater total Fe concentrations and greater proportions of ferrihydrite and goethite existed. Based on 16S rRNA analyses, most bacterial sequences in both paired samples were heterotrophs, and population differences were consistent with the generally more oxidizing conditions in the rhizosphere. Finally, U was very strongly bound to the whole (unfractionated) sediments, with an average desorption Kd value (Usediment/Uaqueous) of 3972 ± 1370 (mg-U/kg)/(mg-U/L). Together, these results indicate that the rhizosphere can greatly enrich U especially in wetland areas, where roots promote the formation of reactive Fe(III)-oxides.
Collapse
Affiliation(s)
- Daniel I. Kaplan
- Savannah
River Ecology Laboratory, University of
Georgia, Aiken, South Carolina 29802, United States
| | - Maxim I. Boyanov
- Argonne
National Laboratory, Lemont, Illinois 60439, United States
- Chemical
Engineering, Bulgarian Academy of Sciences, Sofia 1040, Bulgaria
| | - Nathaniel A. Losey
- Savannah
River National Laboratory, Aiken, South Carolina 29808, United States
| | - Peng Lin
- Savannah
River Ecology Laboratory, University of
Georgia, Aiken, South Carolina 29802, United States
| | - Chen Xu
- Marine
& Coastal Environmental Science, Texas
A&M University − Galveston, Galveston, Texas 77553, United States
| | | | - Peter H. Santschi
- Marine
& Coastal Environmental Science, Texas
A&M University − Galveston, Galveston, Texas 77553, United States
| | - Wei Xing
- Savannah
River Ecology Laboratory, University of
Georgia, Aiken, South Carolina 29802, United States
| | - Wendy W. Kuhne
- Savannah
River National Laboratory, Aiken, South Carolina 29808, United States
| | | |
Collapse
|
2
|
Jroundi F, Povedano-Priego C, Pinel-Cabello M, Descostes M, Grizard P, Purevsan B, Merroun ML. Evidence of microbial activity in a uranium roll-front deposit: Unlocking their potential role as bioenhancers of the ore genesis. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 861:160636. [PMID: 36464038 DOI: 10.1016/j.scitotenv.2022.160636] [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: 09/23/2022] [Revised: 11/26/2022] [Accepted: 11/28/2022] [Indexed: 06/17/2023]
Abstract
Uranium (U) roll-front deposits constitute a valuable source for an economical extraction by in situ recovery (ISR) mining. Such technology may induce changes in the subsurface microbiota, raising questions about the way their activities could build a functional ecosystem in such extreme environments (i.e.: oligotrophy and high SO4 concentration and salinity). Additionally, more information is needed to dissipate the doubts about the microbial role in the genesis of such U orebodies. A U roll-front deposit hosted in an aquifer driven system (in Zoovch Ovoo, Mongolia), intended for mining by acid ISR, was previously explored and showed to be governed by a complex bacterial diversity, linked to the redox zonation and the geochemical conditions. Here for the first time, transcriptional activities of microorganisms living in such U ore deposits are determined and their metabolic capabilities allocated in the three redox-inherited compartments, naturally defined by the roll-front system. Several genes encoding for crucial metabolic pathways demonstrated a strong biological role controlling the subsurface cycling of many elements including nitrate, sulfate, metals and radionuclides (e.g.: uranium), through oxidation-reduction reactions. Interestingly, the discovered transcriptional behaviour gives important insights into the good microbial adaptation to the geochemical conditions and their active contribution to the stabilization of the U ore deposits. Overall, evidences on the importance of these microbial metabolic activities in the aquifer system are discussed that may clarify the doubts on the microbial role in the genesis of low-temperature U roll-front deposits, along the Zoovch Ovoo mine.
Collapse
Affiliation(s)
- Fadwa Jroundi
- Department of Microbiology, Faculty of Science, University of Granada, Avda. Fuentenueva s/n, 18071 Granada, Spain.
| | - Cristina Povedano-Priego
- Department of Microbiology, Faculty of Science, University of Granada, Avda. Fuentenueva s/n, 18071 Granada, Spain
| | - María Pinel-Cabello
- Department of Microbiology, Faculty of Science, University of Granada, Avda. Fuentenueva s/n, 18071 Granada, Spain
| | - Michael Descostes
- ORANO Mining, 125 Avenue de Paris, 92330 Châtillon, France; Centre de Géosciences, MINES ParisTech, PSL University, 35 rue St Honoré, 77300 Fontainebleau, France
| | - Pierre Grizard
- ORANO Mining, 125 Avenue de Paris, 92330 Châtillon, France
| | - Bayaarma Purevsan
- Badrakh Energy LLC, Jamyan Gun Avenue - 9, Sukhbaatar district, 1st khoroo, UB-14240, Mongolia
| | - Mohamed L Merroun
- Department of Microbiology, Faculty of Science, University of Granada, Avda. Fuentenueva s/n, 18071 Granada, Spain
| |
Collapse
|
3
|
Ding Y, Huang X, Zhang H, Ding D. Effects of dissolved organic matter molecules on the sequestration and stability of uranium during the transformation of Fe (oxyhydr)oxides. WATER RESEARCH 2023; 229:119387. [PMID: 36459895 DOI: 10.1016/j.watres.2022.119387] [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: 09/19/2022] [Revised: 11/17/2022] [Accepted: 11/18/2022] [Indexed: 06/17/2023]
Abstract
Amorphous ferrihydrite (Fh) is abundant in aquatic environments and sediments, and often coprecipitates with dissolved organic matter (DOM) to form mineral-organic aggregates. The Fe(II)-catalyzed transformation of Fh to crystalline Fe (oxyhydr)oxides (e.g., goethite) can result in the changes of uranium (U) species, but the effects of DOM molecules on the sequestration and stability of U during Fe (oxyhydr)oxides transformation are poorly understood. In this study, the associations of DOM molecules with U during the coprecipitation of DOM with Fh were evaluated, and the effects of DOM molecules on the kinetics of U release during Fe (oxyhydr)oxides transformation were investigated using a combination of Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS), X-ray photoelectron spectroscopy (XPS), and kinetic experiments. FT-ICR-MS results indicated that, in addition to phenolic and polyphenolic compounds with higher O/C ratios, portions of phenolic compounds with lower O/C ratios and aliphatic compounds were also contributed to UO22+ binding when Fh coprecipitated with DOM. In comparison, phenolic and polyphenolic compounds with higher O/C ratios and condensed aromatics were preferentially retained on Fe (oxyhydr)oxides during the transformation. XPS results further suggested that the coprecipitated DOM molecules facilitated the reduction of U(VI) to U(IV) during the transformation, possibly through providing electrons or acting as electron shuttles. The kinetic experiment results indicated that the transformation processes accelerated U release from Fe (oxyhydr)oxides, but the coprecipitated DOM molecules slowed down U release. Our results contribute to understanding the behaviors of U and predicting the sequestration of U in the environment.
Collapse
Affiliation(s)
- Yang Ding
- Key Discipline Laboratory for National Defense for Biotechnology in Uranium Mining and Hydrometallurgy, University of South China, Hengyang 421001, China; School of Resource & Environment and Safety Engineering, University of South China, Hengyang, Hunan 421001, China
| | - Xixian Huang
- School of Resource & Environment and Safety Engineering, University of South China, Hengyang, Hunan 421001, China.
| | - Hui Zhang
- Key Discipline Laboratory for National Defense for Biotechnology in Uranium Mining and Hydrometallurgy, University of South China, Hengyang 421001, China; School of Resource & Environment and Safety Engineering, University of South China, Hengyang, Hunan 421001, China
| | - Dexin Ding
- Key Discipline Laboratory for National Defense for Biotechnology in Uranium Mining and Hydrometallurgy, University of South China, Hengyang 421001, China; School of Resource & Environment and Safety Engineering, University of South China, Hengyang, Hunan 421001, China.
| |
Collapse
|
4
|
Ding Y, Huang X, Zhang H, Ma J, Li F, Zeng Q, Hu N, Wang Y, Dai Z, Ding D. Coupled variations of dissolved organic matter distribution and iron (oxyhydr)oxides transformation: Effects on the kinetics of uranium adsorption and desorption. JOURNAL OF HAZARDOUS MATERIALS 2022; 436:129298. [PMID: 35739799 DOI: 10.1016/j.jhazmat.2022.129298] [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: 04/04/2022] [Revised: 05/25/2022] [Accepted: 06/02/2022] [Indexed: 06/15/2023]
Abstract
The interactions between dissolved organic matter (DOM) molecules and minerals play significant roles in affecting the fate of carbon and contaminants in soil environment. However, the mechanisms controlling the variations of DOM molecules distribution during the transformation of Fe (oxyhydr)oxides, and the effects of these variations on contaminant behaviors are still largely unknown. In this study, the dynamic variations of DOM properties and distributions, and the kinetics of uranium adsorption on and desorption from Fe (oxyhydr)oxides during the transformation were investigated, employing a combination of Orbitrap mass spectrometry (MS), high-resolution transmission electron microscopy (HR-TEM), and kinetic experiments. Orbitrap MS results indicated that aliphatic molecules and phenolic and polyphenolic molecules with lower O/C values were preferentially released to solution. HR-TEM results indicated that the coprecipitated DOM molecules by ferrihydrite were mainly released to solution rather than sorbed on the newly formed lepidocrocite or goethite during the transformation. Furthermore, the stirred-flow experiment results suggested that soil DOM significantly reduced the adsorption of uranium on, and accelerated the release of uranium from Fe (oxyhydr)oxides, which was ascribed to the changed distribution of DOM molecules and the structure and composition of Fe (oxyhydr)oxides. Our results contribute to predicting contaminant behaviors in soils.
Collapse
Affiliation(s)
- Yang Ding
- Key Discipline Laboratory for National Defense for Biotechnology in Uranium Mining and Hydrometallurgy, University of South China, Hengyang 421001, PR China; School of Resource & Environment and Safety Engineering, University of South China, Hengyang, Hunan 421001, PR China
| | - Xixian Huang
- School of Resource & Environment and Safety Engineering, University of South China, Hengyang, Hunan 421001, PR China; Guangdong Provincial Key Laboratory of Solid Wastes Pollution Control and Recycling, South China University of Technology, Guangzhou, Guangdong 510006, PR China.
| | - Hui Zhang
- Key Discipline Laboratory for National Defense for Biotechnology in Uranium Mining and Hydrometallurgy, University of South China, Hengyang 421001, PR China; School of Resource & Environment and Safety Engineering, University of South China, Hengyang, Hunan 421001, PR China
| | - Jianhong Ma
- Key Discipline Laboratory for National Defense for Biotechnology in Uranium Mining and Hydrometallurgy, University of South China, Hengyang 421001, PR China; School of Resource & Environment and Safety Engineering, University of South China, Hengyang, Hunan 421001, PR China
| | - Feng Li
- Key Discipline Laboratory for National Defense for Biotechnology in Uranium Mining and Hydrometallurgy, University of South China, Hengyang 421001, PR China; School of Resource & Environment and Safety Engineering, University of South China, Hengyang, Hunan 421001, PR China
| | - Qingyi Zeng
- School of Resource & Environment and Safety Engineering, University of South China, Hengyang, Hunan 421001, PR China
| | - Nan Hu
- Key Discipline Laboratory for National Defense for Biotechnology in Uranium Mining and Hydrometallurgy, University of South China, Hengyang 421001, PR China; School of Resource & Environment and Safety Engineering, University of South China, Hengyang, Hunan 421001, PR China
| | - Yongdong Wang
- Key Discipline Laboratory for National Defense for Biotechnology in Uranium Mining and Hydrometallurgy, University of South China, Hengyang 421001, PR China; School of Resource & Environment and Safety Engineering, University of South China, Hengyang, Hunan 421001, PR China
| | - Zhongran Dai
- Key Discipline Laboratory for National Defense for Biotechnology in Uranium Mining and Hydrometallurgy, University of South China, Hengyang 421001, PR China; School of Resource & Environment and Safety Engineering, University of South China, Hengyang, Hunan 421001, PR China
| | - Dexin Ding
- Key Discipline Laboratory for National Defense for Biotechnology in Uranium Mining and Hydrometallurgy, University of South China, Hengyang 421001, PR China; School of Resource & Environment and Safety Engineering, University of South China, Hengyang, Hunan 421001, PR China.
| |
Collapse
|
5
|
Velasco CA, Brearley AJ, Gonzalez-Estrella J, Ali AMS, Meza MI, Cabaniss SE, Thomson BM, Forbes TZ, Lezama Pacheco JS, Cerrato JM. From Adsorption to Precipitation of U(VI): What is the Role of pH and Natural Organic Matter? ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:16246-16256. [PMID: 34797046 PMCID: PMC8680647 DOI: 10.1021/acs.est.1c05429] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
We investigated interfacial reactions of U(VI) in the presence of Suwannee River natural organic matter (NOM) at acidic and neutral pH. Laboratory batch experiments show that the adsorption and precipitation of U(VI) in the presence of NOM occur at pH 2 and pH 4, while the aqueous complexation of U by dissolved organic matter is favored at pH 7, preventing its precipitation. Spectroscopic analyses indicate that U(VI) is mainly adsorbed to the particulate organic matter at pH 4. However, U(VI)-bearing ultrafine to nanocrystalline solids were identified at pH 4 by electron microscopy. This study shows the promotion of U(VI) precipitation by NOM at low pH which may be relevant to the formation of mineralized deposits, radioactive waste repositories, wetlands, and other U- and organic-rich environmental systems.
Collapse
Affiliation(s)
- Carmen A Velasco
- Department of Civil, Construction and Environmental Engineering, MSC01 1070, University of New Mexico, Albuquerque, New Mexico 87131, United States
| | - Adrian J Brearley
- Department of Earth and Planetary Sciences, MSC03 2040, University of New Mexico, Albuquerque, New Mexico 87131, United States
| | - Jorge Gonzalez-Estrella
- School of Civil and Environmental Engineering, Oklahoma State University, Stillwater, Oklahoma 74078, United States
| | - Abdul-Mehdi S Ali
- Department of Earth and Planetary Sciences, MSC03 2040, University of New Mexico, Albuquerque, New Mexico 87131, United States
| | - María Isabel Meza
- Department of Civil, Construction and Environmental Engineering, MSC01 1070, University of New Mexico, Albuquerque, New Mexico 87131, United States
| | - Stephen E Cabaniss
- Department of Chemistry and Chemical Biology, University of New Mexico, Albuquerque, New Mexico 87131, United States
| | - Bruce M Thomson
- Department of Civil, Construction and Environmental Engineering, MSC01 1070, University of New Mexico, Albuquerque, New Mexico 87131, United States
| | - Tori Z Forbes
- Department of Chemistry, University of Iowa, Iowa City, Iowa 52242, United States
| | - Juan S Lezama Pacheco
- Department of Earth System Science, Stanford University, Stanford, California 94305, United States
| | - José M Cerrato
- Department of Civil, Construction and Environmental Engineering, MSC01 1070, University of New Mexico, Albuquerque, New Mexico 87131, United States
| |
Collapse
|
6
|
Fast and Efficient Removal of Uranium onto a Magnetic Hydroxyapatite Composite: Mechanism and Process Evaluation. Processes (Basel) 2021. [DOI: 10.3390/pr9111927] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The exploration and rational design of easily separable and highly efficient sorbents with satisfactory capability of extracting radioactive uranium (U)-containing compound(s) are of paramount significance. In this study, a novel magnetic hydroxyapatite (HAP) composite (HAP@ CoFe2O4), which was coupled with cobalt ferrite (CoFe2O4), was rationally designed for uranium(VI) removal through a facile hydrothermal process. The U(VI) ions were rapidly removed using HAP@ CoFe2O4 within a short time (i.e., 10 min), and a maximum U(VI) removal efficiency of 93.7% was achieved. The maximum adsorption capacity (Qmax) of the HAP@CoFe2O4 was 338 mg/g, which demonstrated the potential of as-prepared HAP@CoFe2O4 in the purification of U(VI) ions from nuclear effluents. Autunite [Ca(UO2)2(PO4)2(H2O)6] was the main crystalline phase to retain uranium, wherein U(VI) was effectively extracted and immobilized in terms of a relatively stable mineral. Furthermore, the reacted HAP@CoFe2O4 can be magnetically recycled. The results of this study reveal that the suggested process using HAP@CoFe2O4 is a promising approach for the removal and immobilization of U(VI) released from nuclear effluents.
Collapse
|
7
|
Wu W, Chen Z, Huang Y, Li J, Chen D, Chen N, Su M. Red mud for the efficient adsorption of U(VI) from aqueous solution: Influence of calcination on performance and mechanism. JOURNAL OF HAZARDOUS MATERIALS 2021; 409:124925. [PMID: 33421876 DOI: 10.1016/j.jhazmat.2020.124925] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 12/18/2020] [Accepted: 12/19/2020] [Indexed: 06/12/2023]
Abstract
Iron-rich red mud is a potent radioactive drainage treatment material. However, the calcite in red mud attenuates its U adsorption capacity by restricting U adsorption onto adsorbent; it captures U as a dissociative complex in aqueous systems. This study produced macroporous iron and carbon combined calcined red mud (ICRM) and carbon calcined red mud (CRM) through calcination in the range of 500-800 °C. XRD results revealed that both series generated advantageous magnetite and calcite were fully decomposed. SEM and batch experiments highlighted ICRM calcined at 600 °C has more stable and favorable performance. The components of post-adsorption ICRM remained active, as demonstrated by FT-IR results. Additionally, ICRM@600 displayed superior U adsorption capacity (59.45 mg/g) than did all red mud adsorbents from our previous research. Zeta-potential results revealed ICRM has positive potential charges in acidic conditions, indicating it adsorbs U(VI) ions via electrostatic attraction. The main adsorption mechanisms of ICRM are surface electrostatic attraction, physical adsorption by porous structure, and chemical adsorption by active Al and Fe components. In application, ICRM@600 obtained a 82.20% U adsorption ratio in uranium mine pit drainage. Overall, this study offers theoretical guidances to radioactive drainage management and red mud reuse.
Collapse
Affiliation(s)
- Wanying Wu
- Guangdong Provincial Key Laboratory of Radionuclides Pollution Control and Resources, School of Environmental Science and Engineering, Guangzhou University, Guangzhou 510006, China; School of Environmental Science and Engineering, Guangzhou University, Guangzhou 510006, China; School for Environment and Sustainability, University of Michigan, Ann Arbor 48109, USA
| | - Zheng Chen
- Guangdong Provincial Key Laboratory of Radionuclides Pollution Control and Resources, School of Environmental Science and Engineering, Guangzhou University, Guangzhou 510006, China; School of Environmental Science and Engineering, Guangzhou University, Guangzhou 510006, China
| | - Ying Huang
- Guangdong Provincial Key Laboratory of Radionuclides Pollution Control and Resources, School of Environmental Science and Engineering, Guangzhou University, Guangzhou 510006, China; School of Environmental Science and Engineering, Guangzhou University, Guangzhou 510006, China
| | - Jinwen Li
- Guangdong Provincial Key Laboratory of Radionuclides Pollution Control and Resources, School of Environmental Science and Engineering, 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, School of Environmental Science and Engineering, Guangzhou University, Guangzhou 510006, China; School of Environmental Science and Engineering, Guangzhou University, Guangzhou 510006, China
| | - Nan Chen
- Guangdong Provincial Key Laboratory of Radionuclides Pollution Control and Resources, School of Environmental Science and Engineering, 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, School of Environmental Science and Engineering, Guangzhou University, Guangzhou 510006, China; School of Environmental Science and Engineering, Guangzhou University, Guangzhou 510006, China.
| |
Collapse
|
8
|
Rodriguez-Freire L, DeVore CL, El Hayek E, Berti D, Ali AMS, Lezama Pacheco JS, Blake JM, Spilde MN, Brearley AJ, Artyushkova K, Cerrato JM. Emerging investigator series: entrapment of uranium-phosphorus nanocrystals inside root cells of Tamarix plants from a mine waste site. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2021; 23:73-85. [PMID: 33325952 PMCID: PMC8479813 DOI: 10.1039/d0em00306a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
We investigated the mechanisms of uranium (U) uptake by Tamarix (salt cedars) growing along the Rio Paguate, which flows throughout the Jackpile mine near Pueblo de Laguna, New Mexico. Tamarix were selected for this study due to the detection of U in the roots and shoots of field collected plants (0.6-58.9 mg kg-1), presenting an average bioconcentration factor greater than 1. Synchrotron-based micro X-ray fluorescence analyses of plant roots collected from the field indicate that the accumulation of U occurs in the cortex of the root. The mechanisms for U accumulation in the roots of Tamarix were further investigated in controlled-laboratory experiments where living roots of field plants were macerated for 24 h or 2 weeks in a solution containing 100 μM U. The U concentration in the solution decreased 36-59% after 24 h, and 49-65% in two weeks. Microscopic and spectroscopic analyses detected U precipitation in the root cell walls near the xylems of the roots, confirming the initial results from the field samples. High-resolution TEM was used to study the U fate inside the root cells, and needle-like U-P nanocrystals, with diameter <7 nm, were found entrapped inside vacuoles in cells. EXAFS shell-by-shell fitting suggest that U is associated with carbon functional groups. The preferable binding of U to the root cell walls may explain the U retention in the roots of Tamarix, followed by U-P crystal precipitation, and pinocytotic active transport and cellular entrapment. This process resulted in a limited translocation of U to the shoots in Tamarix plants. This study contributes to better understanding of the physicochemical mechanisms affecting the U uptake and accumulation by plants growing near contaminated sites.
Collapse
Affiliation(s)
- Lucia Rodriguez-Freire
- Department of Civil and Environmental Engineering, New Jersey Institute of Technology, Newark, New Jersey 07102, USA.
| | - Cherie L DeVore
- Department of Civil Engineering, MSC01 1070, University of New Mexico, Albuquerque, New Mexico 87131, USA
| | - Eliane El Hayek
- Department of Chemistry, MSC03 2060, University of New Mexico, Albuquerque, New Mexico 87131, USA
| | - Debora Berti
- Oceanography Department, Texas A&M University, College Station, Texas 77845, USA
| | - Abdul-Mehdi S Ali
- Department of Earth and Planetary Sciences, MSC03 2040, University of New Mexico, Albuquerque, New Mexico 87131, USA
| | - Juan S Lezama Pacheco
- Department of Environmental Earth System Science, Stanford University, Stanford, California 94305, USA
| | - Johanna M Blake
- Department of Chemistry, MSC03 2060, University of New Mexico, Albuquerque, New Mexico 87131, USA and U.S. Geological Survey, 6700 Edith Blvd NE, Albuquerque, New Mexico 87113, USA
| | - Michael N Spilde
- Department of Earth and Planetary Sciences, MSC03 2040, University of New Mexico, Albuquerque, New Mexico 87131, USA
| | - Adrian J Brearley
- Department of Earth and Planetary Sciences, MSC03 2040, University of New Mexico, Albuquerque, New Mexico 87131, USA
| | - Kateryna Artyushkova
- Department of Chemical and Biological Engineering, MSC01 1120, University of New Mexico, Albuquerque, New Mexico 87131, USA
| | - José M Cerrato
- Department of Civil Engineering, MSC01 1070, University of New Mexico, Albuquerque, New Mexico 87131, USA
| |
Collapse
|
9
|
Denham ME, Amidon MB, Wainwright HM, Dafflon B, Ajo-Franklin J, Eddy-Dilek CA. Improving Long-term Monitoring of Contaminated Groundwater at Sites where Attenuation-based Remedies are Deployed. ENVIRONMENTAL MANAGEMENT 2020; 66:1142-1161. [PMID: 33098454 DOI: 10.1007/s00267-020-01376-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Accepted: 10/05/2020] [Indexed: 06/11/2023]
Abstract
This study presents an effective approach to tackle the challenge of long-term monitoring of contaminated groundwater sites where remediation leaves residual contamination in the subsurface. Traditional long-term monitoring of contaminated groundwater sites focuses on measuring contaminant concentrations and is applicable to sites where contaminant mass is removed or degraded to a level below the regulatory standard. The traditional approach is less effective at sites where risk from metals or radionuclides continues to exist in the subsurface after remedial goals are achieved. We propose a long-term monitoring strategy for this type of waste site that focuses on measuring the hydrological and geochemical parameters that control attenuation or remobilization of contaminants while de-emphasizing contaminant-concentration measurements. We demonstrate how this approach would be more effective than traditional long-term monitoring, using a site in South Carolina, USA, where groundwater is contaminated by several radionuclides. A comprehensive enhanced attenuation remedy has been implemented at the site to minimize discharge of contamination to surface water. The immobilization of contaminants occurs in three locations by manipulation of hydrological and geochemical parameters, as well as by natural attenuation processes. Deployment of our proposed long-term monitoring strategy will combine subsurface and surface measurements using spectroscopic tools, geophysical tools, and sensors to monitor the parameters controlling contaminant attenuation. The advantage of this approach is that it will detect the potential for contaminant remobilization from engineered and natural attenuation zones, allowing potential adverse changes to be mitigated before contaminant attenuation is reversed.
Collapse
Affiliation(s)
- Miles E Denham
- Panoramic Environmental Consulting, LLC, Aiken, SC, USA.
| | | | | | | | - Jonathan Ajo-Franklin
- Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Rice University, Houston, TX, USA
| | | |
Collapse
|
10
|
Ramírez-Guinart O, Kaplan D, Rigol A, Vidal M. Deriving probabilistic soil distribution coefficients (K d). Part 1: General approach to decreasing and describing variability and example using uranium K d values. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2020; 222:106362. [PMID: 32858445 DOI: 10.1016/j.jenvrad.2020.106362] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2020] [Revised: 07/13/2020] [Accepted: 07/18/2020] [Indexed: 06/11/2023]
Abstract
A general approach is presented to derive probabilistic radionuclide distribution coefficients (Kd) in soils from a Kd dataset. The main aim was to derive informed estimates with a low inherent uncertainty by restricting the Kd value data to subsets based on key soil factors and the experimental approach used to calculate the Kd value (e.g., sorption and desorption tests). As an example, the general approach was applied to uranium (U) Kd values that are part of a critically reviewed dataset containing more than 5000 soil Kd entries for 83 elements and an additional 2000 entries of Kd data for 75 elements gathered from a selection of other, non-soil, geological materials. The overall soil U Kd dataset included 196 values spanning a range of four orders of magnitude (1-67,000 L kg-1), with additional 50 entries for other geological materials. Whereas the effect of the experimental approach could be disregarded, major factors in decreasing U Kd variability were pH and organic matter content (OM). Limitation in the number of entries made it difficult to use texture information (sand, silt, clay) to further decrease U Kd variability. The integrated combination of pH + OM permitted some soil groups to have U Kd confidence intervals as narrow as two orders of magnitude. Specifically for U Kd, data in the Mineral (< 20% OM) and Organic (≥ 20% OM) partial datasets were significantly different. Analogue data from geological materials other than soils, such as subsoil, till and gyttja (a lacustrine mud having elevated organic matter (OM) contents), were also statistically evaluated to determine whether they could be used to fill U Kd data gaps. It was shown that U Kd from subsoils and tills, but not gyttjas, could be used to enhance soil U Kd datasets. Selection of probabilistic Kd values for risk modelling can be made more reliably and with less uncertainty by using appropriate geochemical data representative of the study site to narrow the wide range of potential Kd values.
Collapse
Affiliation(s)
- Oriol Ramírez-Guinart
- Chemical Engineering and Analytical Chemistry Department, Faculty of Chemistry, University of Barcelona, Martí i Franqués 1-11, 08028, Barcelona, Spain
| | | | - Anna Rigol
- Chemical Engineering and Analytical Chemistry Department, Faculty of Chemistry, University of Barcelona, Martí i Franqués 1-11, 08028, Barcelona, Spain.
| | - Miquel Vidal
- Chemical Engineering and Analytical Chemistry Department, Faculty of Chemistry, University of Barcelona, Martí i Franqués 1-11, 08028, Barcelona, Spain
| |
Collapse
|
11
|
Fuller AJ, Leary P, Gray ND, Davies HS, Mosselmans JFW, Cox F, Robinson CH, Pittman JK, McCann CM, Muir M, Graham MC, Utsunomiya S, Bower WR, Morris K, Shaw S, Bots P, Livens FR, Law GTW. Organic complexation of U(VI) in reducing soils at a natural analogue site: Implications for uranium transport. CHEMOSPHERE 2020; 254:126859. [PMID: 32957279 DOI: 10.1016/j.chemosphere.2020.126859] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Revised: 04/07/2020] [Accepted: 04/19/2020] [Indexed: 06/11/2023]
Abstract
Understanding the long-term fate, stability, and bioavailability of uranium (U) in the environment is important for the management of nuclear legacy sites and radioactive wastes. Analysis of U behavior at natural analogue sites permits evaluation of U biogeochemistry under conditions more representative of long-term equilibrium. Here, we have used bulk geochemical and microbial community analysis of soils, coupled with X-ray absorption spectroscopy and μ-focus X-ray fluorescence mapping, to gain a mechanistic understanding of the fate of U transported into an organic-rich soil from a pitchblende vein at the UK Needle's Eye Natural Analogue site. U is highly enriched in the Needle's Eye soils (∼1600 mg kg-1). We show that this enrichment is largely controlled by U(VI) complexation with soil organic matter and not U(VI) bioreduction. Instead, organic-associated U(VI) seems to remain stable under microbially-mediated Fe(III)-reducing conditions. U(IV) (as non-crystalline U(IV)) was only observed at greater depths at the site (>25 cm); the soil here was comparatively mineral-rich, organic-poor, and sulfate-reducing/methanogenic. Furthermore, nanocrystalline UO2, an alternative product of U(VI) reduction in soils, was not observed at the site, and U did not appear to be associated with Fe-bearing minerals. Organic-rich soils appear to have the potential to impede U groundwater transport, irrespective of ambient redox conditions.
Collapse
Affiliation(s)
- Adam J Fuller
- Centre for Radiochemistry Research, Department of Chemistry, The University of Manchester, Manchester, M13 9PL, UK
| | - Peter Leary
- School of Natural and Environmental Sciences, Newcastle University, Newcastle, NE1 7RU, UK
| | - Neil D Gray
- School of Natural and Environmental Sciences, Newcastle University, Newcastle, NE1 7RU, UK
| | - Helena S Davies
- Research Centre for Radwaste Disposal, and Williamson Centre for Molecular Environmental Science, Department of Earth and Environmental Sciences, The University of Manchester, Manchester, M13 9PL, UK
| | | | - Filipa Cox
- Research Centre for Radwaste Disposal, and Williamson Centre for Molecular Environmental Science, Department of Earth and Environmental Sciences, The University of Manchester, Manchester, M13 9PL, UK
| | - Clare H Robinson
- Research Centre for Radwaste Disposal, and Williamson Centre for Molecular Environmental Science, Department of Earth and Environmental Sciences, The University of Manchester, Manchester, M13 9PL, UK
| | - Jon K Pittman
- Research Centre for Radwaste Disposal, and Williamson Centre for Molecular Environmental Science, Department of Earth and Environmental Sciences, The University of Manchester, Manchester, M13 9PL, UK
| | - Clare M McCann
- School of Natural and Environmental Sciences, Newcastle University, Newcastle, NE1 7RU, UK
| | - Michael Muir
- School of Geoscience, University of Edinburgh, Edinburgh, EH9 3FF, UK
| | - Margaret C Graham
- School of Geoscience, University of Edinburgh, Edinburgh, EH9 3FF, UK
| | - Satoshi Utsunomiya
- School of Chemistry, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395, Japan
| | - William R Bower
- Centre for Radiochemistry Research, Department of Chemistry, The University of Manchester, Manchester, M13 9PL, UK; Radiochemistry Unit, Department of Chemistry, The University of Helsinki, 00014, Finland
| | - Katherine Morris
- Research Centre for Radwaste Disposal, and Williamson Centre for Molecular Environmental Science, Department of Earth and Environmental Sciences, The University of Manchester, Manchester, M13 9PL, UK
| | - Samuel Shaw
- Research Centre for Radwaste Disposal, and Williamson Centre for Molecular Environmental Science, Department of Earth and Environmental Sciences, The University of Manchester, Manchester, M13 9PL, UK
| | - Pieter Bots
- Research Centre for Radwaste Disposal, and Williamson Centre for Molecular Environmental Science, Department of Earth and Environmental Sciences, The University of Manchester, Manchester, M13 9PL, UK
| | - Francis R Livens
- Centre for Radiochemistry Research, Department of Chemistry, The University of Manchester, Manchester, M13 9PL, UK; Research Centre for Radwaste Disposal, and Williamson Centre for Molecular Environmental Science, Department of Earth and Environmental Sciences, The University of Manchester, Manchester, M13 9PL, UK
| | - Gareth T W Law
- Centre for Radiochemistry Research, Department of Chemistry, The University of Manchester, Manchester, M13 9PL, UK; Radiochemistry Unit, Department of Chemistry, The University of Helsinki, 00014, Finland.
| |
Collapse
|
12
|
Stetten L, Lefebvre P, Le Pape P, Mangeret A, Blanchart P, Merrot P, Brest J, Julien A, Bargar JR, Cazala C, Morin G. Experimental redox transformations of uranium phosphate minerals and mononuclear species in a contaminated wetland. JOURNAL OF HAZARDOUS MATERIALS 2020; 384:121362. [PMID: 31634806 DOI: 10.1016/j.jhazmat.2019.121362] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Revised: 09/27/2019] [Accepted: 09/29/2019] [Indexed: 06/10/2023]
Abstract
Reducing conditions and high organic carbon content make wetlands favorable to uranium (U) sequestration. However, such environments are subjected to water-table fluctuations that could impact the redox behavior of U and its mobility. Our previous study on U speciation in a contaminated wetland has suggested a major role of water-table redox fluctuations in the redistribution of U from U(IV)-phosphate minerals to organic U(VI) and U(IV) mononuclear species. Here, we investigate the mechanisms of these putative processes by mimicking drying or flooding periods via laboratory incubations of wetland samples. LCF-XANES and EXAFS analyses show the total oxidation/reduction of U(IV)/U(VI)-mononuclear species after 20 days of oxic/anoxic incubation, whereas U-phosphate minerals are partly oxidized/reduced. SEM-EDXS combined with μ-XRF and μ-XANES analyses suggest that autunite Ca(UO2)2(PO4)2⋅11H2O is reduced into lermontovite U(PO4)(OH)⋅H2O, whereas oxidized ningyoite CaU(PO4)2⋅2H2O is locally dissolved. The release of U from this latter process is observed to be limited by U(VI) adsorption to the soil matrix and further re-reduction into mononuclear U(IV) upon anoxic cycling. Analysis of incubation waters show, however, that dissolved organic carbon enhances U solubilization even under anoxic conditions. This study brings important information that help to assess the long-term stability of U in seasonally saturated organic-rich contaminated environments.
Collapse
Affiliation(s)
- Lucie Stetten
- Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie (IMPMC), UMR 7590 CNRS-Sorbonne Université-IRD-MNHN, case 115, 4 place Jussieu, 75252 Paris Cedex 5, France; Institut de Radioprotection et de Sûreté Nucléaire, IRSN, 31 avenue de la Division Leclerc, 92262 Fontenay-aux-Roses, France; University of Vienna, Centre for Microbiology and Environmental Systems Science, Department of Environmental Geosciences, Althanstraße 14, UZA II, 1090 Vienna, Austria.
| | - Pierre Lefebvre
- Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie (IMPMC), UMR 7590 CNRS-Sorbonne Université-IRD-MNHN, case 115, 4 place Jussieu, 75252 Paris Cedex 5, France
| | - Pierre Le Pape
- Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie (IMPMC), UMR 7590 CNRS-Sorbonne Université-IRD-MNHN, case 115, 4 place Jussieu, 75252 Paris Cedex 5, France
| | - Arnaud Mangeret
- Institut de Radioprotection et de Sûreté Nucléaire, IRSN, 31 avenue de la Division Leclerc, 92262 Fontenay-aux-Roses, France
| | - Pascale Blanchart
- Institut de Radioprotection et de Sûreté Nucléaire, IRSN, 31 avenue de la Division Leclerc, 92262 Fontenay-aux-Roses, France
| | - Pauline Merrot
- Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie (IMPMC), UMR 7590 CNRS-Sorbonne Université-IRD-MNHN, case 115, 4 place Jussieu, 75252 Paris Cedex 5, France
| | - Jessica Brest
- Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie (IMPMC), UMR 7590 CNRS-Sorbonne Université-IRD-MNHN, case 115, 4 place Jussieu, 75252 Paris Cedex 5, France
| | - Anthony Julien
- Institut de Radioprotection et de Sûreté Nucléaire, IRSN, 31 avenue de la Division Leclerc, 92262 Fontenay-aux-Roses, France
| | - John R Bargar
- Stanford Synchrotron Radiation Lightsource (SSRL), SLAC National Accelerator National Laboratory, MS 69, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| | - Charlotte Cazala
- Institut de Radioprotection et de Sûreté Nucléaire, IRSN, 31 avenue de la Division Leclerc, 92262 Fontenay-aux-Roses, France
| | - Guillaume Morin
- Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie (IMPMC), UMR 7590 CNRS-Sorbonne Université-IRD-MNHN, case 115, 4 place Jussieu, 75252 Paris Cedex 5, France
| |
Collapse
|
13
|
Bone SE, Cliff J, Weaver K, Takacs CJ, Roycroft S, Fendorf S, Bargar JR. Complexation by Organic Matter Controls Uranium Mobility in Anoxic Sediments. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:1493-1502. [PMID: 31886668 DOI: 10.1021/acs.est.9b04741] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Uranium contamination threatens the availability of safe and clean drinking water globally. This toxic element occurs both naturally and as a result of mining and ore-processing in alluvial sediments, where it accumulates as tetravalent U [U(IV)], a form once considered largely immobile. Changing hydrologic and geochemical conditions cause U to be released into groundwater. Knowledge of the chemical form(s) of U(IV) is essential to understand the release mechanism, yet the relevant U(IV) species are poorly characterized. There is growing belief that natural organic matter (OM) binds U(IV) and mediates its fate in the subsurface. In this work, we combined nanoscale imaging (nano secondary ion mass spectrometry and scanning transmission X-ray microscopy) with a density-based fractionation approach to physically and microscopically isolate organic and mineral matter from alluvial sediments contaminated with uranium. We identified two populations of U (dominantly +IV) in anoxic sediments. Uranium was retained on OM and adsorbed to particulate organic carbon, comprising both microbial and plant material. Surprisingly, U was also adsorbed to clay minerals and OM-coated clay minerals. The dominance of OM-associated U provides a framework to understand U mobility in the shallow subsurface, and, in particular, emphasizes roles for desorption and colloid formation in its mobilization.
Collapse
Affiliation(s)
- Sharon E Bone
- Stanford Synchrotron Radiation Lightsource , SLAC National Accelerator Laboratory , Menlo Park , California 94025 , United States
| | - John Cliff
- Environmental Molecular Sciences Laboratory , Pacific Northwest National Laboratory , Richland , Washington 99354 , United States
| | - Karrie Weaver
- Earth System Science Department , Stanford University , Stanford , California 94305 , United States
| | - Christopher J Takacs
- Stanford Synchrotron Radiation Lightsource , SLAC National Accelerator Laboratory , Menlo Park , California 94025 , United States
| | - Scott Roycroft
- Earth System Science Department , Stanford University , Stanford , California 94305 , United States
| | - Scott Fendorf
- Earth System Science Department , Stanford University , Stanford , California 94305 , United States
| | - John R Bargar
- Stanford Synchrotron Radiation Lightsource , SLAC National Accelerator Laboratory , Menlo Park , California 94025 , United States
| |
Collapse
|
14
|
Pregler A, Surbeck H, Eikenberg J, Werthmüller S, Szidat S, Türler A. Increased uranium concentrations in ground and surface waters of the Swiss Plateau: A result of uranium accumulation and leaching in the Molasse basin and (ancient) wetlands? JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2019; 208-209:106026. [PMID: 31437807 DOI: 10.1016/j.jenvrad.2019.106026] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Revised: 08/09/2019] [Accepted: 08/10/2019] [Indexed: 06/10/2023]
Abstract
Increased uranium (U) concentrations are found in certain ground and surface waters of the Swiss Plateau. Analysis of more than 100 public fountains revealed that increased 238U concentrations frequently occur close to the interface between the Lower Freshwater Molasse and the Upper Marine Molasse, cropping out in the western part of the Swiss Molasse Basin. Out of these locations, Mont Vully, situated ca. 20 km west of Berne, was studied in detail. As this hill consists of the two aforementioned stratigraphic Molasse units, it represents an ideal case study. Two springs at the northern slopes of Mont Vully exhibit the highest 238U concentrations with more than 300 mBq/L and were thus monitored for almost two years in order to screen possible seasonal variations. Further water samples were collected from spring captures, creeks and drainage pipes. The pipes drain the farmland north of Mont Vully showing 238U concentrations with more than 600 mBq/L. In order to discover the reason for the duplication in concentration, gamma dose rate measurements were accomplished on the farmland, revealing elevated dose rates of up to 160 nSv/h. These are located above ancient pathways of creeks that originated from Mont Vully. At these locations with elevated dose rates, three shallow sediment drill cores were taken and analyzed for their U content. The sediment cores can essentially be divided into three parts: (i) an upper soil with common U concentrations of about 30 Bq/kg 238U, (ii) an U-rich peat horizon with concentrations of up to 500 Bq/kg 238U, and (iii) an impermeable clay unit that acts as an aquitard with again minor 238U concentrations. Radiocarbon dating of the U-rich peat horizon reveals ages younger than 8.1 kyrs. This study suggests that a wetland was formed on top of the impermeable clay layer after the last glaciation during the Holocene. The stream waters with 238U concentrations of more than 300 mBq/L originating from Mont Vully contributed significantly to the water supply for the development of the wetland. Due to the reducing conditions that are present in wetlands, the dissolved U in the incoming streams was reduced and adsorbed onto organic matter. Accordingly, an entrapment for U was generated, persisting for at least 6 kyrs - a sufficient time to accumulate up to 500 Bq/kg. In the course of the last century, numerous wetlands in Switzerland were drained by capturing streams and installing drainage pipes to make the land suitable for agriculture. This kind of melioration was also done at the wetlands north of Mont Vully resulting in a subsequent change in redox conditions within the soil. The solubility of U depends on its oxidation state and U can be oxidized by oxygen-rich rainwater. The rainwater leached the U adsorbed on the peat yielding 238U concentrations of more than 600 mBq/L. Consequently, the duplication of 238U concentrations in the drainage water as compared to the original concentration that creeks brought into the ancient wetlands has been clarified during this study. Twenty of the analyzed public fountains in the Swiss Plateau exhibited a 238U concentration of more than 50 mBq/L. All of them could have contributed to the formation of a wetland after the last glaciation, which leads to the assumption that the situation at Mont Vully is not a singularity in the Swiss Plateau.
Collapse
Affiliation(s)
- Anja Pregler
- Paul Scherrer Institute, Department for Radiation Safety and Security, 5232 Villigen PSI, Switzerland; University of Bern, Department of Chemistry and Biochemistry, Freiestrasse 3, 3012 Bern, Switzerland.
| | | | - Jost Eikenberg
- Paul Scherrer Institute, Department for Radiation Safety and Security, 5232 Villigen PSI, Switzerland
| | - Simon Werthmüller
- Schenker Korner Richter AG, Büttenenhalde 42, 6006 Luzern, Switzerland
| | - Sönke Szidat
- University of Bern, Department of Chemistry and Biochemistry, Freiestrasse 3, 3012 Bern, Switzerland; University of Bern, Oeschger Centre for Climate Change, 3012 Bern, Switzerland
| | - Andreas Türler
- University of Bern, Department of Chemistry and Biochemistry, Freiestrasse 3, 3012 Bern, Switzerland
| |
Collapse
|
15
|
Bower WR, Morris K, Livens FR, Mosselmans JFW, Fallon CM, Fuller AJ, Natrajan L, Boothman C, Lloyd JR, Utsunomiya S, Grolimund D, Ferreira Sanchez D, Jilbert T, Parker J, Neill TS, Law GTW. Metaschoepite Dissolution in Sediment Column Systems-Implications for Uranium Speciation and Transport. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:9915-9925. [PMID: 31317743 DOI: 10.1021/acs.est.9b02292] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Metaschoepite is commonly found in U-contaminated environments and metaschoepite-bearing wastes may be managed via shallow or deep disposal. Understanding metaschoepite dissolution and tracking the fate of any liberated U is thus important. Here, discrete horizons of metaschoepite (UO3·nH2O) particles were emplaced in flowing sediment/groundwater columns representative of the UK Sellafield Ltd. site. The column systems either remained oxic or became anoxic due to electron donor additions, and the columns were sacrificed after 6- and 12-months for analysis. Solution chemistry, extractions, and bulk and micro/nano-focus X-ray spectroscopies were used to track changes in U distribution and behavior. In the oxic columns, U migration was extensive, with UO22+ identified in effluents after 6-months of reaction using fluorescence spectroscopy. Unusually, in the electron-donor amended columns, during microbially mediated sulfate reduction, significant amounts of UO2-like colloids (>60% of the added U) were found in the effluents using TEM. XAS analysis of the U remaining associated with the reduced sediments confirmed the presence of trace U(VI), noncrystalline U(IV), and biogenic UO2, with UO2 becoming more dominant with time. This study highlights the potential for U(IV) colloid production from U(VI) solids under reducing conditions and the complexity of U biogeochemistry in dynamic systems.
Collapse
Affiliation(s)
- William R Bower
- Centre for Radiochemistry Research, School of Chemistry , The University of Manchester , Manchester , U.K. , M13 9PL
- Research Centre for Radwaste Disposal and Williamson Research Centre, School of Earth and Environmental Sciences , The University of Manchester , Manchester , U.K. , M13 9PL
- Radiochemistry Unit, Department of Chemistry , The University of Helsinki , Helsinki , Finland , 00014
| | - Katherine Morris
- Research Centre for Radwaste Disposal and Williamson Research Centre, School of Earth and Environmental Sciences , The University of Manchester , Manchester , U.K. , M13 9PL
| | - Francis R Livens
- Centre for Radiochemistry Research, School of Chemistry , The University of Manchester , Manchester , U.K. , M13 9PL
- Research Centre for Radwaste Disposal and Williamson Research Centre, School of Earth and Environmental Sciences , The University of Manchester , Manchester , U.K. , M13 9PL
| | | | - Connaugh M Fallon
- Centre for Radiochemistry Research, School of Chemistry , The University of Manchester , Manchester , U.K. , M13 9PL
- Research Centre for Radwaste Disposal and Williamson Research Centre, School of Earth and Environmental Sciences , The University of Manchester , Manchester , U.K. , M13 9PL
- Radiochemistry Unit, Department of Chemistry , The University of Helsinki , Helsinki , Finland , 00014
| | - Adam J Fuller
- Centre for Radiochemistry Research, School of Chemistry , The University of Manchester , Manchester , U.K. , M13 9PL
| | - Louise Natrajan
- Centre for Radiochemistry Research, School of Chemistry , The University of Manchester , Manchester , U.K. , M13 9PL
| | - Christopher Boothman
- Research Centre for Radwaste Disposal and Williamson Research Centre, School of Earth and Environmental Sciences , The University of Manchester , Manchester , U.K. , M13 9PL
| | - Jonathan R Lloyd
- Research Centre for Radwaste Disposal and Williamson Research Centre, School of Earth and Environmental Sciences , The University of Manchester , Manchester , U.K. , M13 9PL
| | - Satoshi Utsunomiya
- Kyushu University , Department of Chemistry , 744 Motooka , Nishi-ku , Fukuoka Japan , 819-0395
| | - Daniel Grolimund
- Swiss Light Source , Paul Scherrer Institute , Villigen , Switzerland , 5232
| | | | - Tom Jilbert
- Ecosystems and Environmental Research Programme, Faculty of Biological and Environmental Sciences , The University of Helsinki , Helsinki , Finland , 00014
| | - Julia Parker
- Diamond Light Source , Harwell Science and Innovation Campus , Didcot , U.K. , OX11 0DE
| | - Thomas S Neill
- Research Centre for Radwaste Disposal and Williamson Research Centre, School of Earth and Environmental Sciences , The University of Manchester , Manchester , U.K. , M13 9PL
| | - Gareth T W Law
- Centre for Radiochemistry Research, School of Chemistry , The University of Manchester , Manchester , U.K. , M13 9PL
- Radiochemistry Unit, Department of Chemistry , The University of Helsinki , Helsinki , Finland , 00014
| |
Collapse
|
16
|
Velasco CA, Artyushkova K, Ali AMS, Osburn CL, Gonzalez-Estrella J, Lezama-Pacheco JS, Cabaniss SE, Cerrato JM. Organic Functional Group Chemistry in Mineralized Deposits Containing U(IV) and U(VI) from the Jackpile Mine in New Mexico. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:5758-5767. [PMID: 30998849 PMCID: PMC6557721 DOI: 10.1021/acs.est.9b00407] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
We investigated the functional group chemistry of natural organic matter (NOM) associated with both U(IV) and U(VI) in solids from mineralized deposits exposed to oxidizing conditions from the Jackpile Mine, Laguna Pueblo, NM. The uranium (U) content in unreacted samples was 0.44-2.6% by weight determined by X-ray fluorescence. In spite of prolonged exposure to ambient oxidizing conditions, ≈49% of U(IV) and ≈51% of U(VI) were identified on U LIII edge extended X-ray absorption fine structure spectra. Loss on ignition and thermogravimetric analyses identified from 13% to 44% of NOM in the samples. Carbonyl, phenolic, and carboxylic functional groups in the unreacted samples were identified by fitting of high-resolution X-ray photoelectron spectroscopy (XPS) C 1s and O 1s spectra. Peaks corresponding to phenolic and carbonyl functional groups had intensities higher than those corresponding to carboxylic groups in samples from the supernatant from batch extractions conducted at pH 13, 7, and 2. U(IV) and U(VI) species were detected in the supernatant after batch extractions conducted under oxidizing conditions by fitting of high-resolution XPS U 4f spectra. The outcomes from this study highlight the importance of the influence of pH on the organic functional group chemistry and U speciation in mineralized deposits.
Collapse
Affiliation(s)
- Carmen A. Velasco
- Department of Civil, Construction & Environmental Engineering, MSC01 1070, University of New Mexico, Albuquerque, New Mexico 87131, United States
| | - Kateryna Artyushkova
- Department of Chemical and Biological Engineering, MSC01 1120, University of New Mexico, Albuquerque, New Mexico 87131, United States
| | - Abdul-Mehdi S. Ali
- Department of Earth and Planetary Sciences, MSC03 2040, University of New Mexico, Albuquerque, New Mexico 87131, United States
| | - Christopher L. Osburn
- Department of Marine, Earth, and Atmospheric Sciences, North Carolina State University, Raleigh, North Carolina 27607, United States
| | - Jorge Gonzalez-Estrella
- Department of Civil, Construction & Environmental Engineering, MSC01 1070, University of New Mexico, Albuquerque, New Mexico 87131, United States
| | - Juan S. Lezama-Pacheco
- Department of Environmental Earth System Science, Stanford University, Stanford, California 94305, United States
| | - Stephen E. Cabaniss
- Department of Chemistry and Chemical Biology, University of New Mexico, Albuquerque, New Mexico 87131, United States
| | - José M. Cerrato
- Department of Civil, Construction & Environmental Engineering, MSC01 1070, University of New Mexico, Albuquerque, New Mexico 87131, United States
- Corresponding Author. Telephone: (001) (505) 277-0870. Fax: (001) (505) 277-1918
| |
Collapse
|
17
|
Noël V, Boye K, Kukkadapu RK, Li Q, Bargar JR. Uranium storage mechanisms in wet-dry redox cycled sediments. WATER RESEARCH 2019; 152:251-263. [PMID: 30682569 DOI: 10.1016/j.watres.2018.12.040] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Revised: 11/30/2018] [Accepted: 12/01/2018] [Indexed: 06/09/2023]
Abstract
Biogeochemical redox processes that govern radionuclide mobility in sediments are highly sensitive to forcing by the water cycle. For example, episodic draining and intrusion of oxidants into reduced zones during dry seasons can create biogeochemical seasonal hotspots of enhanced and changed microbial activity, affect the redox status of minerals, initiate changes in sediment gas and water transport, and stimulate the release of organic carbon, iron, and sulfur by oxidation of solid reduced species to aqueous oxic species. In the Upper Colorado River Basin, water-saturation of organic-enriched sediments locally promotes reducing conditions, denoted 'Naturally Reduced Zones' (NRZs), that accumulate strongly U(IV)sol. Subsequently, fluctuating hydrological conditions introduce oxidants, which may reach internal portions of these sediments and reverse their role to become secondary sources of Uaq. Knowledge of the impact of hydrological variability on the alternating import and export of contaminants, including U, is required to predict contaminant mobility and short- and long-term impacts on water quality. In this study, we tracked U, Fe, and S oxidation states and speciation to characterize the variability in redox processes and related Usol solubility within shallow fine-grained NRZs at the legacy U ore processing site at Shiprock, NM. Previous studies have reported U speciation and behavior in permanently saturated fine-grained NRZ sediments. This is the first report of U behavior in fine-grained NRZ-like sediments that experience repeated redox cycling due to seasonal fluctuations in moisture content. Our results support previous observations that reducing conditions are needed to accumulate Usol in sediments, but they counter the expectation that Usol predominantly accumulates as U(IV)sol; our data reveal that Usol may accumulate as U(VI)sol in roughly equal proportion to U(IV)sol. Surprisingly high abundances of U(VI)sol confined in transiently saturated fine-grained NRZ-like sediments suggest that redox cycling is needed to promote its accumulation. We propose a new process model, where redox oscillations driven by annual water table fluctuations, accompanied by strong evapotranspiration in low-permeability sediments, promote conversion of U(IV)sol to relatively immobile U(VI)sol, which suggests that Usol is accumulating in a form that is resistant to redox perturbations. This observation contradicts the common idea that U(IV)sol accumulated in reducing conditions is systematically re-oxidized, solubilized and transported away in groundwater.
Collapse
Affiliation(s)
- Vincent Noël
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, United States
| | - Kristin Boye
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, United States
| | - Ravi K Kukkadapu
- Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, WA, 99354, United States
| | - Qingyun Li
- Department of Environmental Earth System Science, Stanford University, Stanford, CA, 94305, United States
| | - John R Bargar
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, United States.
| |
Collapse
|
18
|
Mangeret A, Blanchart P, Alcalde G, Amet X, Cazala C, Gallerand MO. An evidence of chemically and physically mediated migration of 238U and its daughter isotopes in the vicinity of a former uranium mine. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2018; 195:67-71. [PMID: 30292908 DOI: 10.1016/j.jenvrad.2018.08.018] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Revised: 07/08/2018] [Accepted: 08/29/2018] [Indexed: 06/08/2023]
Abstract
The present study reports the evidence of a radioactive contamination in a wetland located downstream from a former French U mine in Brittany. This situation is demonstrated according to the measurements of gamma dose rates and activity ratios of 238U and 232Th-decay series nuclides, which give the justification regarding the accumulation of significant amounts of 238U, 230Th and 226Ra in this wetland. The dose rate map highlights an increase of radiation level along the former mine water pathway compared to the background value, with a maximum value of 1500 nSv.h-1 reached in the wetland. Activities of 238U, 230Th and 226Ra and 232Th/238U ratios measured in surface wetland soils are significantly higher than the geochemical background. 230Th/238U ratios less than unity suggest a preferential accumulation of U in the wetland, compared to its daughter isotopes. Moreover, the loss of 226Ra compared to 230Th raises its higher mobility compared to its parent isotope. In far-field sediments, 226Ra/238U ratio of 1.76 implies a different geochemical behavior of U, which could be explained by the occurrence of mobile U species. The results suggest that contamination of wetland soils and far-field sediments could result from discharges of underground mine waters.
Collapse
Affiliation(s)
- Arnaud Mangeret
- Institut de Radioprotection et de Sureté Nucléaire (IRSN), PSE-ENV. BP 17, Fontenay-aux-Roses, 92262, France.
| | - Pascale Blanchart
- Institut de Radioprotection et de Sureté Nucléaire (IRSN), PSE-ENV. BP 17, Fontenay-aux-Roses, 92262, France
| | - Gilles Alcalde
- Institut de Radioprotection et de Sureté Nucléaire (IRSN), PSE-ENV. BP 17, Fontenay-aux-Roses, 92262, France
| | - Xavier Amet
- Institut de Radioprotection et de Sureté Nucléaire (IRSN), PSE-ENV. BP 17, Fontenay-aux-Roses, 92262, France
| | - Charlotte Cazala
- Institut de Radioprotection et de Sureté Nucléaire (IRSN), PSE-ENV. BP 17, Fontenay-aux-Roses, 92262, France
| | - Marie-Odile Gallerand
- Institut de Radioprotection et de Sureté Nucléaire (IRSN), PSE-ENV. BP 17, Fontenay-aux-Roses, 92262, France
| |
Collapse
|
19
|
Hayek EE, Torres C, Rodriguez-Freire L, Blake JM, De Vore CL, Brearley AJ, Spilde MN, Cabaniss S, Ali AMS, Cerrato J. Effect of Calcium on the Bioavailability of Dissolved Uranium(VI) in Plant Roots under Circumneutral pH. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:13089-13098. [PMID: 30412391 PMCID: PMC6341987 DOI: 10.1021/acs.est.8b02724] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
We integrated field measurements, hydroponic experiments, microscopy, and spectroscopy to investigate the effect of Ca(II) on dissolved U(VI) uptake by plants in 1 mM HCO3- solutions at circumneutral pH. The accumulation of U in plants (3.1-21.3 mg kg-1) from the stream bank of the Rio Paguate, Jackpile Mine, New Mexico served as a motivation for this study. Brassica juncea was the model plant used for the laboratory experiments conducted over a range of U (30-700 μg L-1) and Ca (0-240 mg L-1) concentrations. The initial U uptake followed pseudo-second-order kinetics. The initial U uptake rate ( V0) ranged from 4.4 to 62 μg g-1 h-1 in experiments with no added Ca and from 0.73 to 2.07 μg g-1 h-1 in experiments with 12 mg L-1 Ca. No measurable U uptake over time was detected for experiments with 240 mg L-1 Ca. Ternary Ca-U-CO3 complexes may affect the decrease in U bioavailability observed in this study. Elemental X-ray mapping using scanning transmission electron microscopy-energy-dispersive spectrometry detected U-P-bearing precipitates within root cell walls in water free of Ca. These results suggest that root interactions with Ca and carbonate in solution affect the bioavailability of U in plants. This study contributes relevant information to applications related to U transport and remediation of contaminated sites.
Collapse
Affiliation(s)
- Eliane El Hayek
- Department of Chemistry and Chemical Biology, MSC03 2060, University of New Mexico, Albuquerque, New Mexico 87131, United States
- Phone: (001) (505) 582-1362,
| | - Chris Torres
- Department of Chemical and Biological Engineering, MSC01 1120, University of New Mexico, Albuquerque, New Mexico 87131, United States
| | - Lucia Rodriguez-Freire
- Department of Civil and Environmental Engineering, New Jersey Institute of Technology, Newark, New Jersey 07102, United States
| | - Johanna M. Blake
- U.S. Geological Survey, 6700 Edith Blvd. NE, Albuquerque, New Mexico 87113, United States
| | - Cherie L. De Vore
- Department of Civil Engineering, MSC01 1070, University of New Mexico, Albuquerque, New Mexico 87131, United States
| | - Adrian J. Brearley
- Department of Earth and Planetary Sciences, MSC03 2040, University of New Mexico, Albuquerque, New Mexico 87131, United States
| | - Michael N. Spilde
- Department of Earth and Planetary Sciences, MSC03 2040, University of New Mexico, Albuquerque, New Mexico 87131, United States
| | - Stephen Cabaniss
- Department of Chemistry and Chemical Biology, MSC03 2060, University of New Mexico, Albuquerque, New Mexico 87131, United States
| | - Abdul-Mehdi S. Ali
- Department of Earth and Planetary Sciences, MSC03 2040, University of New Mexico, Albuquerque, New Mexico 87131, United States
| | - JoséM. Cerrato
- Department of Civil Engineering, MSC01 1070, University of New Mexico, Albuquerque, New Mexico 87131, United States
- Corresponding Authors Phone: (001) (505) 277-0870; fax: (001) (505) 277-1918;
| |
Collapse
|
20
|
Stetten L, Blanchart P, Mangeret A, Lefebvre P, Le Pape P, Brest J, Merrot P, Julien A, Proux O, Webb SM, Bargar JR, Cazala C, Morin G. Redox Fluctuations and Organic Complexation Govern Uranium Redistribution from U(IV)-Phosphate Minerals in a Mining-Polluted Wetland Soil, Brittany, France. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:13099-13109. [PMID: 30339761 DOI: 10.1021/acs.est.8b03031] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Wetlands have been proposed to naturally attenuate U transfers in the environment via U complexation by organic matter and potential U reduction. However, U mobility may depend on the identity of particulate/dissolved uranium source materials and their redox sensitivity. Here, we examined the fate of uranium in a highly contaminated wetland (up to 4500 mg·kg-1 U) impacted by former mine water discharges. Bulk U LIII-EXAFS and (micro-)XANES combined with SEM-EDXS analyses of undisturbed soil cores show a sharp U redox boundary at the water table, together with a major U redistribution from U(IV)-minerals to U(VI)-organic matter complexes. Above the water table, U is fully oxidized into mono- and bidentate U(VI)-carboxyl and monodentate U(VI)-phosphoryl complexes. Minute amounts of U(VI)-phosphate minerals are also observed. Below the water table, U is fully reduced and is partitioned between U(IV)-phosphate minerals (i.e., ningyoite and a lermontovite-like phase), and bidentate U(IV)-phosphoryl and monodentate U(IV)-carboxyl complexes. Such a U redistribution from U-minerals inherited from mine water discharge deposits could result from redox cycling nearby the water table fluctuation zone. Oxidative dissolution of U(IV)-phosphate minerals could have led to U(VI)-organic matter complexation, followed by subsequent reduction into U(IV)-organic complexes. However, uranium(IV) minerals could have been preserved in permanently waterlogged soil.
Collapse
Affiliation(s)
- Lucie Stetten
- Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie (IMPMC) , UMR 7590 CNRS-Sorbonne Université-IRD-MNHN , case 115, 4 place Jussieu , 75252 Paris Cedex 5, France
- Institut de Radioprotection et de Sûreté Nucléaire, IRSN , 31 Avenue de la Division Leclerc , 92262 Fontenay-aux-Roses , France
| | - Pascale Blanchart
- Institut de Radioprotection et de Sûreté Nucléaire, IRSN , 31 Avenue de la Division Leclerc , 92262 Fontenay-aux-Roses , France
| | - Arnaud Mangeret
- Institut de Radioprotection et de Sûreté Nucléaire, IRSN , 31 Avenue de la Division Leclerc , 92262 Fontenay-aux-Roses , France
| | - Pierre Lefebvre
- Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie (IMPMC) , UMR 7590 CNRS-Sorbonne Université-IRD-MNHN , case 115, 4 place Jussieu , 75252 Paris Cedex 5, France
| | - Pierre Le Pape
- Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie (IMPMC) , UMR 7590 CNRS-Sorbonne Université-IRD-MNHN , case 115, 4 place Jussieu , 75252 Paris Cedex 5, France
| | - Jessica Brest
- Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie (IMPMC) , UMR 7590 CNRS-Sorbonne Université-IRD-MNHN , case 115, 4 place Jussieu , 75252 Paris Cedex 5, France
| | - Pauline Merrot
- Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie (IMPMC) , UMR 7590 CNRS-Sorbonne Université-IRD-MNHN , case 115, 4 place Jussieu , 75252 Paris Cedex 5, France
| | - Anthony Julien
- Institut de Radioprotection et de Sûreté Nucléaire, IRSN , 31 Avenue de la Division Leclerc , 92262 Fontenay-aux-Roses , France
| | - Olivier Proux
- Université Grenoble Alpes, CNRS, IRD Irstea Météo, OSUG, FAME , 38000 Grenoble , France
- BM30B/CRG-FAME, ESRF , Polygone Scientifique Louis Néel , 71 avenue des Martyrs , 38000 Grenoble , France
| | - Samuel M Webb
- Stanford Synchrotron Radiation Lightsource (SSRL) , SLAC National Accelerator National Laboratory , MS 69, 2575 Sand Hill Road , Menlo Park , California 94025 , United States
| | - John R Bargar
- Stanford Synchrotron Radiation Lightsource (SSRL) , SLAC National Accelerator National Laboratory , MS 69, 2575 Sand Hill Road , Menlo Park , California 94025 , United States
| | - Charlotte Cazala
- Institut de Radioprotection et de Sûreté Nucléaire, IRSN , 31 Avenue de la Division Leclerc , 92262 Fontenay-aux-Roses , France
| | - Guillaume Morin
- Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie (IMPMC) , UMR 7590 CNRS-Sorbonne Université-IRD-MNHN , case 115, 4 place Jussieu , 75252 Paris Cedex 5, France
| |
Collapse
|
21
|
Xu R, Wu K, Han H, Ling Z, Chen Z, Liu P, Xiong J, Tian F, Zafar Y, Malik K, Li X. Co-expression of YieF and PhoN in Deinococcus radiodurans R1 improves uranium bioprecipitation by reducing chromium interference. CHEMOSPHERE 2018; 211:1156-1165. [PMID: 30223331 DOI: 10.1016/j.chemosphere.2018.08.061] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2017] [Revised: 08/03/2018] [Accepted: 08/13/2018] [Indexed: 06/08/2023]
Abstract
Overexpression of the enzyme phosphatase (PhoN/PhoK) in the radiation-resistant bacterium Deinococcus radiodurans could be an efficient strategy for uranium remediation. However, the presence of other metals in nuclear wastes often interferes with uranium bioprecipitation. In our study, the uranium-precipitating ability of the PhoN-expressing D. radiodurans strain (Deino-phoN) significantly decreased by 45.4% in 13 h in the presence of chromium (VI); however, it was partially recovered after supplementation with chromium (III). Therefore, the reduction of chromium (VI) to chromium (III) was obtained by the co-expression of the YieF protein and PhoN in D. radiodurans (Deino-phoN-yieF). As a result, an increase in the chromium (VI) reduction (25.1%) rate was observed in 24 h. Furthermore, uranium precipitation also increased by 28.0%. For the decontamination of groundwater, we immobilized Deino-phoN-yieF cells using Polyvinyl alcohol (PVA)-sodium alginate (SA) beads, followed by incubation in a bioreactor. Approximately 99% of chromium (VI) and uranium (VI) was removed after 4 continuous cycles operated for a period of over 20 days at room temperature (25 °C). Therefore, Deino-phoN-yieF could be used as a potential biological agent for mixed radioactive nuclear waste remediation.
Collapse
Affiliation(s)
- Rong Xu
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Tianshui South Road #222, Lanzhou, Gansu 730000, PR China
| | - Kejia Wu
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Tianshui South Road #222, Lanzhou, Gansu 730000, PR China
| | - Huawen Han
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Tianshui South Road #222, Lanzhou, Gansu 730000, PR China
| | - Zhenmin Ling
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Tianshui South Road #222, Lanzhou, Gansu 730000, PR China
| | - Zhengjun Chen
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Tianshui South Road #222, Lanzhou, Gansu 730000, PR China
| | - Pu Liu
- Department of Development Biology Sciences, School of Life Sciences, Lanzhou University, Tianshui South Road #222, Lanzhou, Gansu 730000, PR China
| | - Jian Xiong
- Wuhan Optics Valley Bluefire New Energy Co., Ltd, Fozulingsanlu Wuhan East Lake Development Zone #29, Wuhan, Hubei 430205, PR China
| | - Fake Tian
- Wuhan Optics Valley Bluefire New Energy Co., Ltd, Fozulingsanlu Wuhan East Lake Development Zone #29, Wuhan, Hubei 430205, PR China
| | - Yusuf Zafar
- Agricultural Research Council, 20-Attaturk Avenue, Sector G-5/1, Islamabad, Pakistan
| | - Kamaran Malik
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Tianshui South Road #222, Lanzhou, Gansu 730000, PR China
| | - Xiangkai Li
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Tianshui South Road #222, Lanzhou, Gansu 730000, PR China.
| |
Collapse
|
22
|
Bordelet G, Beaucaire C, Phrommavanh V, Descostes M. Chemical reactivity of natural peat towards U and Ra. CHEMOSPHERE 2018; 202:651-660. [PMID: 29602097 DOI: 10.1016/j.chemosphere.2018.03.140] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2017] [Revised: 03/15/2018] [Accepted: 03/20/2018] [Indexed: 06/08/2023]
Abstract
Peat is a complex material with several organic constituents that contribute to its high capacity to retain metals. In the context of uranium mining, peat can accumulate high concentrations of uranium and its decay products such as radium. Hence, interaction with peat appears to be a key factor in the understanding of the geochemical mechanisms controlling the fate of these products. This study aims to determine the sorption properties of two trace elements, U(VI) and 226Ra, on natural organic matter from peat. The presented method was applied to both natural peat samples originating from a mining context, with various contents of organic matter (from 40 to 70%) and detrital loads, and wetland peat with a more than 98% composition of organic matter. In the present study, considering peat material as a sorbent, its reactivity towards metals and other contaminants can be described as that of an ion-exchanger. A relatively simple model of ion-exchange based on the sorption properties of carboxylic sites has been applied with success to describe the sorption of uranium and radium. In the general overview of the different mechanisms able to control the mobility of these radionuclides in a uranium mining context, organic matter is likely one of the main contributors to radionuclide scavenging even under oxic conditions.
Collapse
Affiliation(s)
- G Bordelet
- CEA Saclay, DEN/DANS/DPC/SECR/L3MR, Bât: 450, F-91191 Gif-sur-Yvette, France
| | - C Beaucaire
- CEA Saclay, DEN/DANS/DPC/SECR/L3MR, Bât: 450, F-91191 Gif-sur-Yvette, France
| | - V Phrommavanh
- ORANO Mining, R&D Dpt, BAL 4246D-3, Tour AREVA - 1, Place Jean Millier 92084 Paris la Defense Cedex, France
| | - M Descostes
- ORANO Mining, R&D Dpt, BAL 4246D-3, Tour AREVA - 1, Place Jean Millier 92084 Paris la Defense Cedex, France.
| |
Collapse
|
23
|
Bhattacharyya A, Campbell KM, Kelly SD, Roebbert Y, Weyer S, Bernier-Latmani R, Borch T. Biogenic non-crystalline U (IV) revealed as major component in uranium ore deposits. Nat Commun 2017; 8:15538. [PMID: 28569759 PMCID: PMC5461479 DOI: 10.1038/ncomms15538] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Accepted: 04/06/2017] [Indexed: 11/09/2022] Open
Abstract
Historically, it is believed that crystalline uraninite, produced via the abiotic reduction of hexavalent uranium (U(VI)) is the dominant reduced U species formed in low-temperature uranium roll-front ore deposits. Here we show that non-crystalline U(IV) generated through biologically mediated U(VI) reduction is the predominant U(IV) species in an undisturbed U roll-front ore deposit in Wyoming, USA. Characterization of U species revealed that the majority (∼58-89%) of U is bound as U(IV) to C-containing organic functional groups or inorganic carbonate, while uraninite and U(VI) represent only minor components. The uranium deposit exhibited mostly 238U-enriched isotope signatures, consistent with largely biotic reduction of U(VI) to U(IV). This finding implies that biogenic processes are more important to uranium ore genesis than previously understood. The predominance of a relatively labile form of U(IV) also provides an opportunity for a more economical and environmentally benign mining process, as well as the design of more effective post-mining restoration strategies and human health-risk assessment. Crystalline uraninite is believed to be the dominant form in uranium deposits. Here, the authors find that non-crystalline U(IV) generated through biologically mediated U(VI) reduction is the predominant U(IV) species in ore deposits, implying that biogenic processes are more important than previously thought.
Collapse
Affiliation(s)
- Amrita Bhattacharyya
- Department of Soil and Crop Sciences, Colorado State University, Fort Collins, Colorado 80523-1170, USA
| | | | | | - Yvonne Roebbert
- Institut für Mineralogie, Leibniz Universitat Hannover, Hannover D-30167, Germany
| | - Stefan Weyer
- Institut für Mineralogie, Leibniz Universitat Hannover, Hannover D-30167, Germany
| | - Rizlan Bernier-Latmani
- Environmental Microbiology Laboratory, École Polytechnique Fédérale de Lausanne, Lausanne CH-1015, Switzerland
| | - Thomas Borch
- Department of Soil and Crop Sciences, Colorado State University, Fort Collins, Colorado 80523-1170, USA.,Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523-1872, USA
| |
Collapse
|
24
|
Blake JM, De Vore CL, Avasarala S, Ali AM, Roldan C, Bowers F, Spilde MN, Artyushkova K, Kirk MF, Peterson E, Rodriguez-Freire L, Cerrato JM. Uranium mobility and accumulation along the Rio Paguate, Jackpile Mine in Laguna Pueblo, NM. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2017; 19:605-621. [PMID: 28352908 DOI: 10.1039/c6em00612d] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The mobility and accumulation of uranium (U) along the Rio Paguate, adjacent to the Jackpile Mine, in Laguna Pueblo, New Mexico was investigated using aqueous chemistry, electron microprobe, X-ray diffraction and spectroscopy analyses. Given that it is not common to identify elevated concentrations of U in surface water sources, the Rio Paguate is a unique site that concerns the Laguna Pueblo community. This study aims to better understand the solid chemistry of abandoned mine waste sediments from the Jackpile Mine and identify key hydrogeological and geochemical processes that affect the fate of U along the Rio Paguate. Solid analyses using X-ray fluorescence determined that sediments located in the Jackpile Mine contain ranges of 320 to 9200 mg kg-1 U. The presence of coffinite, a U(iv)-bearing mineral, was identified by X-ray diffraction analyses in abandoned mine waste solids exposed to several decades of weathering and oxidation. The dissolution of these U-bearing minerals from abandoned mine wastes could contribute to U mobility during rain events. The U concentration in surface waters sampled closest to mine wastes are highest during the southwestern monsoon season. Samples collected from September 2014 to August 2016 showed higher U concentrations in surface water adjacent to the Jackpile Mine (35.3 to 772 μg L-1) compared with those at a wetland 4.5 kilometers downstream of the mine (5.77 to 110 μg L-1). Sediments co-located in the stream bed and bank along the reach between the mine and wetland had low U concentrations (range 1-5 mg kg-1) compared to concentrations in wetland sediments with higher organic matter (14-15%) and U concentrations (2-21 mg kg-1). Approximately 10% of the total U in wetland sediments was amenable to complexation with 1 mM sodium bicarbonate in batch experiments; a decrease of U concentration in solution was observed over time in these experiments likely due to re-association with sediments in the reactor. The findings from this study provide new insights about how hydrologic events may affect the reactivity of U present in mine waste solids exposed to surface oxidizing conditions, and the influence of organic-rich sediments on U accumulation in the Rio Paguate.
Collapse
Affiliation(s)
- Johanna M Blake
- Department of Chemistry, MSC03 2060, University of New Mexico, Albuquerque, New Mexico 87131, USA.
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
25
|
Chen A, Shang C, Shao J, Zhang J, Huang H. The application of iron-based technologies in uranium remediation: A review. THE SCIENCE OF THE TOTAL ENVIRONMENT 2017; 575:1291-1306. [PMID: 27720254 DOI: 10.1016/j.scitotenv.2016.09.211] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Revised: 09/25/2016] [Accepted: 09/26/2016] [Indexed: 06/06/2023]
Abstract
Remediating uranium contamination is of worldwide interest because of the increasing release of uranium from mining and processing, nuclear power leaks, depleted uranium components in weapons production and disposal, and phosphate fertilizer in agriculture activities. Iron-based technologies are attractive because they are highly efficient, inexpensive, and readily available. This paper provides an overview of the current literature that addresses the application of iron-based technologies in the remediation of sites with elevated uranium levels. The application of iron-based materials, the current remediation technologies and mechanisms, and the effectiveness and environmental safety considerations of these approaches were discussed. Because uranium can be reduced and reoxidized in the environment, the review also proposes strategies for long-term in situ remediation of uranium. Unfortunately, iron-based materials (nanoscale zerovalent iron and iron oxides) can be toxic to microorganisms. As such, further studies exploring the links among the fates, ecological impacts, and other environmentally relevant factors are needed to better understand the constraints on using iron-based technologies for remediation.
Collapse
Affiliation(s)
- Anwei Chen
- College of Resources and Environment, Hunan Agricultural University, Changsha 410128, PR China
| | - Cui Shang
- College of Resources and Environment, Hunan Agricultural University, Changsha 410128, PR China
| | - Jihai Shao
- College of Resources and Environment, Hunan Agricultural University, Changsha 410128, PR China.
| | - Jiachao Zhang
- College of Resources and Environment, Hunan Agricultural University, Changsha 410128, PR China
| | - Hongli Huang
- College of Resources and Environment, Hunan Agricultural University, Changsha 410128, PR China
| |
Collapse
|
26
|
Koster van Groos PG, Kaplan DI, Chang HS, Seaman JC, Li D, Peacock AD, Scheckel KG, Jaffé PR. Uranium fate in wetland mesocosms: Effects of plants at two iron loadings with different pH values. CHEMOSPHERE 2016; 163:116-124. [PMID: 27522183 PMCID: PMC7307573 DOI: 10.1016/j.chemosphere.2016.08.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Revised: 07/31/2016] [Accepted: 08/01/2016] [Indexed: 06/06/2023]
Abstract
Small-scale continuous flow wetland mesocosms (∼0.8 L) were used to evaluate how plant roots under different iron loadings affect uranium (U) mobility. When significant concentrations of ferrous iron (Fe) were present at circumneutral pH values, U concentrations in root exposed sediments were an order of magnitude greater than concentrations in root excluded sediments. Micro X-ray absorption near-edge structure (μ-XANES) spectroscopy indicated that U was associated with the plant roots primarily as U(VI) or U(V), with limited evidence of U(IV). Micro X-ray fluorescence (μ-XRF) of plant roots suggested that for high iron loading at circumneutral pH, U was co-located with Fe, perhaps co-precipitated with root Fe plaques, while for low iron loading at a pH of ∼4 the correlation between U and Fe was not significant, consistent with previous observations of U associated with organic matter. Quantitative PCR analyses indicated that the root exposed sediments also contained elevated numbers of Geobacter spp., which are likely associated with enhanced iron cycling, but may also reduce mobile U(VI) to less mobile U(IV) species.
Collapse
Affiliation(s)
| | | | - Hyun-Shik Chang
- Savannah River Ecology Laboratory, University of Georgia, Aiken, SC 29802, USA
| | - John C Seaman
- Savannah River Ecology Laboratory, University of Georgia, Aiken, SC 29802, USA
| | - Dien Li
- Savannah River National Laboratory, Aiken, SC 29808, USA
| | | | | | | |
Collapse
|
27
|
Mikutta C, Langner P, Bargar JR, Kretzschmar R. Tetra- and Hexavalent Uranium Forms Bidentate-Mononuclear Complexes with Particulate Organic Matter in a Naturally Uranium-Enriched Peatland. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2016; 50:10465-10475. [PMID: 27635434 DOI: 10.1021/acs.est.6b03688] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Peatlands frequently serve as efficient biogeochemical traps for U. Mechanisms of U immobilization in these organic matter-dominated environments may encompass the precipitation of U-bearing mineral(oid)s and the complexation of U by a vast range of (in)organic surfaces. The objective of this work was to investigate the spatial distribution and molecular binding mechanisms of U in soils of an alpine minerotrophic peatland (pH 4.7-6.6, Eh = -127 to 463 mV) using microfocused X-ray fluorescence spectrometry and bulk and microfocused U L3-edge X-ray absorption spectroscopy. The soils contained 2.3-47.4 wt % organic C, 4.1-58.6 g/kg Fe, and up to 335 mg/kg geogenic U. Uranium was found to be heterogeneously distributed at the micrometer scale and enriched as both U(IV) and U(VI) on fibrous and woody plant debris (48 ± 10% U(IV), x̅ ± σ, n = 22). Bulk U X-ray absorption near edge structure (XANES) spectroscopy revealed that in all samples U(IV) comprised 35-68% of total U (x̅ = 50%, n = 15). Shell-fit analyses of bulk U L3-edge extended X-ray absorption fine structure (EXAFS) spectra showed that U was coordinated to 1.3 ± 0.2 C atoms at a distance of 2.91 ± 0.01 Å (x̅ ± σ), which implies the formation of bidentate-mononuclear U(IV/VI) complexes with carboxyl groups. We neither found evidence for U shells at ∼3.9 Å, indicative of mineral-associated U or multinuclear U(IV) species, nor for a substantial P/Fe coordination of U. Our data indicates that U(IV/VI) complexation by natural organic matter prevents the precipitation of U minerals as well as U complexation by Fe/Mn phases at our field site, and suggests that organically complexed U(IV) is formed via reduction of organic matter-bound U(VI).
Collapse
Affiliation(s)
- Christian Mikutta
- Soil Chemistry Group, Institute of Biogeochemistry and Pollutant Dynamics, Department of Environmental Systems Science, CHN, ETH Zurich , 8092 Zurich, Switzerland
- Section for Environmental Chemistry and Physics, Department of Plant and Environmental Sciences, University of Copenhagen , DK-1871 Frederiksberg C, Denmark
| | - Peggy Langner
- Soil Chemistry Group, Institute of Biogeochemistry and Pollutant Dynamics, Department of Environmental Systems Science, CHN, ETH Zurich , 8092 Zurich, Switzerland
| | - John R Bargar
- Stanford Synchrotron Radiation Lightsource Directorate, SLAC National Accelerator Laboratory , Menlo Park, California 94025, United States
| | - Ruben Kretzschmar
- Soil Chemistry Group, Institute of Biogeochemistry and Pollutant Dynamics, Department of Environmental Systems Science, CHN, ETH Zurich , 8092 Zurich, Switzerland
| |
Collapse
|
28
|
Drobot B, Bauer A, Steudtner R, Tsushima S, Bok F, Patzschke M, Raff J, Brendler V. Speciation Studies of Metals in Trace Concentrations: The Mononuclear Uranyl(VI) Hydroxo Complexes. Anal Chem 2016; 88:3548-55. [DOI: 10.1021/acs.analchem.5b03958] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
- Björn Drobot
- Institute of Resource Ecology, and ‡Helmholtz Institute
Freiberg for Resource
Technology, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, 01328 Saxony, Germany
| | - Anne Bauer
- Institute of Resource Ecology, and ‡Helmholtz Institute
Freiberg for Resource
Technology, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, 01328 Saxony, Germany
| | - Robin Steudtner
- Institute of Resource Ecology, and ‡Helmholtz Institute
Freiberg for Resource
Technology, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, 01328 Saxony, Germany
| | - Satoru Tsushima
- Institute of Resource Ecology, and ‡Helmholtz Institute
Freiberg for Resource
Technology, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, 01328 Saxony, Germany
| | - Frank Bok
- Institute of Resource Ecology, and ‡Helmholtz Institute
Freiberg for Resource
Technology, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, 01328 Saxony, Germany
| | - Michael Patzschke
- Institute of Resource Ecology, and ‡Helmholtz Institute
Freiberg for Resource
Technology, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, 01328 Saxony, Germany
| | - Johannes Raff
- Institute of Resource Ecology, and ‡Helmholtz Institute
Freiberg for Resource
Technology, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, 01328 Saxony, Germany
| | - Vinzenz Brendler
- Institute of Resource Ecology, and ‡Helmholtz Institute
Freiberg for Resource
Technology, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, 01328 Saxony, Germany
| |
Collapse
|