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uranium tailings speciation

Geoscience, Remote Sensing and GIS: Environmental ...

May 27, 2019· 6 Speciation and Solubility Modeling 106 6.1 Introduction 106 6.2 A Uranium Mill Tailings Impoundment 107 6.2.1 The Site 107 6.2.2 The Purpose of Geochemical Modeling 108 6.2.3 Site Geology and Data 111 6.2.4 Selection of Modeling …

Uranium Mill Tailings Radiation Control Act - Wikipedia

The Uranium Mill Tailings Radiation Control Act (1978) is a United States environmental law that amended the Atomic Energy Act of 1954 and authorized the Environmental Protection Agency to establish health and environmental standards for the stabilization, restoration, and disposal of uranium …

(PDF) Study on Occurrence Speciation and Activity of ...

Study on Occurrence Speciation and Activity of Uranium Tailing Contaminants in the Presence of S . oneidensis MR-1 under Anaerobic Conditions ... Taked a uranium tailings pond in Hunan province as ...

Health and Environmental Protection Standards for Uranium ...

The U.S. Environmental Protection Agency (EPA) is proposing new health and environmental protection standards under the Uranium Mill Tailings Radiation Control Act (UMTRCA) of 1978. The standards proposed in this action would be applicable to byproduct materials produced by uranium in-situ...

Biogeochemical aspects of uranium mineralization, mining ...

ronment. Uranium is mined by three basic methods: surface (open pit), underground, and solution mining (in situ leaching or in situ recovery), depending on the deposit grade, size, location, geology and economic considerations (Abdelouas, 2006). Solid wastes at U mill tailings (UMT) sites can include both standard tailings

Microbes affect the speciation of various uranium ...

Microbes affect the speciation of various uranium compounds . 3 cates, phosphates, carbonates, and vanadates. The concentration of uranium can vary between 0.5 and 20%, with the highest amount occurring in Canadian ores. Mill tailings, a by-product of the mineral extraction process, contain up to 2% uranium.

XAFS of Synthetic Iron(III)-Arsenate Co-Precipitates and ...

XAFS studies were carried out for chemical speciation of arsenic species in uranium mill neutralized raffinate solids. To aid the structural characterization, synthetic iron(III)-arsenate co-precipitates were prepared to mimic the actual uranium mill tailings neutralization products. The principle components analysis method was used to validate

Determination and modelling of geochemical speciation of ...

as a result of acid mine drainage arising from oxidation of pyrite (FeS2) in the tailings dumps. The research is aimed at the quantitative assessment of the distribution of uranium and the modelling of its geochemical speciation in gold mine polluted land. Uranium in the form of uraninite (UO2) and brannerite (UTi2O6) is normally associated with

Bioremediation of Uranium Contaminated Soils and Wastes

BIOREMEDIATION OF URANIUM CONTAMINATED SOILS AND WASTES A. J. FRANCIS Department of Applied Science Brookhaven National Laboratory Upton, New York 11973 USA Abstract Contamination of soils, water, and sediments by radionuclides and toxic metals from uranium mill tailings, nuclear fuel manufacturing and nuclear weapons production is a major concern.

In situ Chemical Speciation of Uranium in Soils and ...

Uptake and speciation of uranium in synthetic gypsum (CaSO 4 •2H 2 O): Applications to radioactive mine tailings. Journal of Environmental Radioactivity 2018, 181, 8-17. DOI: 10.1016/j.jenvrad.2017.10.010.

ExxonMobil Use Only Highland Uranium Mill Site

- 11e.(2) seepage from tailings - Supporting Hydrologic Data - Site Chloride and Sulfate Mass Balance - Site Transport of Uranium + Uranium Speciation * Uranium Isotope Activity Ratio" Site Visit. 4 . E*onMobil. Environmental Services

Real Time Speciation of Uranium during Active ...

understanding uranium speciation during bioremediation, it is also necessary to examine biogenic U IV oxidation under field ... ing site at Old Rifle, Colo., which is a Uranium Mill Tailings Remedial Action UMTRA site, part of the U.S. Department of Energy's DOE's …

NUREG/CR-3404, 'Predictive Geochemical Modeling of ...

permeability cells packed with geologic materials and percolated with uranium mill tailings solutions. Initial calculations of ion speciation and mineral solubility and our understanding of the chemical processes occurring in the modeled system were used to select solid phases for inclusion in the conceptual model.

Chemical Speciation of Arsenic in Uranium Raffinates

knowledge of the arsenic speciation in these mine tailings and its stability in the environment is of paramount importance. In order to study the speciation of arsenic within the mine tailings, neutralization of the natural raffinates was simulated via a series of laboratory experiments that used synthetic raffinate solutions at different pH's.

Molybdenum Speciation in Uranium Mine Tailings Using X-Ray ...

Uranium (U) mill tailings in northern Saskatchewan, Canada, contain elevated concentrations of molybdenum (Mo). The potential for long-term (>10 000 years) mobilization of Mo from the tailings management facilities to regional groundwater systems is an environmental concern. To assist in characterizing long-term stability, X-ray absorption spectroscopy was used to define the chemical …

Speciation Dynamics of Arsenic in Tailing Heap Leachates ...

In view of this, we investigated the migration and speciation of inorganic arsenic in mine water discharged from a spring of leachates from a uranium-tailing heap to a wetland pond in Zobes-Mechelgrün in south-west Saxony in Germany.

6 Potential Environmental Effects of Uranium Mining ...

• Significant potential environmental risks are associated with extreme natural events and failures in management practices. Extreme natural events (e.g., hurricanes, earthquakes, intense rainfall events, drought) have the potential to lead to the release of contaminants if facilities are not designed and constructed to withstand such events, or fail to perform as designed.

Leak detection systems for uranium mill tailings ...

Uranium mill tailings impoundments require long-term (200 to 1000 years) stabilization. This report reviews currently available methodologies for evaluating factors that can have a significant influence on tailings stabilization and develops methodologies in technical areas where none presently exist.

Uranium speciation in two Freital mine tailing samples ...

We investigated the uranium speciation in a former WISMUT mine tailing, which was buried for 30 years under mine and construction debris. Chemical extractions, EXAFS, µ-XRD, and µ-XRF reveal two...

Capacity of Lemna gibba L. (Duckweed) for Uranium and ...

Uranium content of the ore is often only between 0.1% and 0.2%, which resulted in excavating large amounts of ore to get a reasonable amount of uranium. Consequently, apart from the radioactive constituents, tailings also contain other contaminants, e.g., arsenic (Diehl, 2003). High arsenic solubility leads to its leaching from the dump and ...

Evolution of uranium distribution and speciation in mill ...

Mar 01, 2016· Uranium distribution in the tailings pile of COMINAK, from the surface crust down to the base clay layer. The dark gray area indicates the range of uranium content that is expected in tailings given the ore grade and process efficiency. Uranium content was measured by ICP-MS and ICP-AES (squares) and HPGe (triangles).

MIGRATION OF METALS INTO GROUNDWATER FROM …

biological matrices, speciation analysis, risk assessment and use of sorbents for removal of contaminants. Currently she is involved in characterization and speciation of metals in uranium mill tailings and determination of distribution coefficient for natural radionuclides in geological matrices, to study the migration of radionuclides.

Tracking Tailings - AREVA and Canadian Light Source study ...

The uranium mine tailings research conducted on behalf of AREVA is an excellent example of the Canadian Light Source and its scientists collaborating with industries, says Jeff Cutler, chief strategic relations officer at the CLS.

Uranium(VI) Sorption Complexes on Montmorillonite as a ...

Uranium mill tailings have also pro- ... transport and facilitate restoration, information concerning the speciation of uranium in soils and groundwaters is needed. Un-der oxidizing conditions, dissolved uranium is predominantly in ... (VI) SORPTION COMPLEXES ON MONTMORILLONITE 39 amphoteric surface sites and the surface complexation reac-

Chemical Speciation of Arsenic in Uranium Mine Tailings by ...

Chemical Speciation of Arsenic in Uranium Mine Tailings by XAFS J. N. Cutler,1,2 D. T. Jiang,1,3 G. Remple4 1 Canadian Light Source, Saskatoon, SK, Canada 2 Department of Chemistry, University of Saskatchewan, Saskatoon, Saskatchewan, Canada 3 Department of Physics, University of Saskatchewan, Saskatoon, Saskatchewan, Canada

Geochemical Modeling of the Speciation of Uranium in an ...

This study was aimed at the quantitative assessment of the distribution of uranium and the modeling of its geochemical speciation. Geochemical analyses of tailings, water and sediment in areas of previous mining were performed.

THE EFFECT OF URANIUM MILL TAILINGS MINERALOGICAL ...

Therefore, the investigation of the effect of uranium tailings mineralogy on solid-state speciation of 226 210 natural occurring radionuclides, particularly Ra and Pb, is of great important in predictive modeling of the radiological situation in immediate areas of uranium tailings repositories.

Evaluation and application of anion exchange resins to ...

Evaluation and application of anion exchange resins to measure groundwater uranium flux at a former uranium mill site Valerie Stuckera, James Ranvillea,*, Mark Newmanb, Peacockd, Jaehyun Choc, Kirk Hatfieldb aDepartment of Chemistry and Geochemistry, Colorado School of Mines, Golden, CO, USA bDepartment of Civil and Coastal Engineering, University of Florida, Gainesville, FL, USA

Chemical speciation of arsenic in uranium mine tailings by ...

Request PDF on ResearchGate | Chemical speciation of arsenic in uranium mine tailings by X-ray absorption spectroscopy | In order to understand the evolving world of environmental issues, the ...

Mend | Panel Wetlands – A Case History of Partially ...

containing partially submerged pyritic uranium tailings. It had a total area of 14.5 ha, and contained approximately 236,000 tonnes of tailings spread over an area of 12.9 ha. Approximately 88% of the tailings area was underwater, leaving an area of 1.6 ha in the western part of the basin where the tailings were exposed.