Subsurface cobalt-60 migration from a low-level waste disposal site

Killey, R.W.D.; McHugh, Joe; Champ, D. R.; Cooper, E.L.; Young, J.L.

doi:10.1021/es00121a004

Cited by 115 publications

(65 citation statements)

References 7 publications

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“…However, these methods may be hampered by membrane clogging [49,61,62], by possible concentration polarization effects [34], and by adsorption [32,62], The other methods from above are seldom applicable for a direct analysis of speciation of radionuclides at environmental concentrations, as they enable only a treatment of small volumes of water (as e.g., interstitial waters or pore waters in sediments or unsaturated soils). Examples of the application of paper electrophoresis (after pre-concentration of contaminated groundwaters by evaporation), size exclusion chromatography, or small-volume ultra-filtration can be found [63,64], Ultra-filtration and ultracentrifugation can be used to distinguish between dissolved and colloidal species. Since colloids represent a delicate metastable state of matter, even these simple operations may affect the system due to changes in ionic strength, pH, and Eh.…”

Section: Methods For Direct Speciation Analysis Of Aerosolsmentioning

confidence: 99%

“…Among these methods are high performance liquid chromatography (HPLC, with pre-concentration, [64]), batch arrangements for adsorption [67], ion exchange [64,70], and solvent extraction [70], These methods are very useful in model experiments (see below), and can be used for an analysis of contaminated or waste waters [64,76].…”

Section: Methods For Direct Speciation Analysis Of Aerosolsmentioning

confidence: 99%

“…The procedures differ in significance and/ or order of individual extraction steps, but most often the following forms are distinguished: free-bound or exchangeable, bound in carbonates, associated with Fe and Mn (hydr)oxidic coatings, associated with organic matter and residual forms in crystal lattices of minerals. Some authors [64,103] included isotope exchange with stable isotopes as an extraction step for radionuclides to determine exchangeable forms.…”

Section: Methods For Direct Speciation Analysis In the Lithospherementioning

confidence: 99%

“…For instance, grinding or drying of sediments may change the leachability of radionuclides [115]. On the other hand, a fractionation of the sample according to grain size or mineralogie composition, prior to the extraction, may ease the interpretation of the results [64]. The biggest problem with leaching procedures is low selectivity of the extractions for several reasons :…”

Section: Methods For Direct Speciation Analysis In the Lithospherementioning

confidence: 99%

“…These techniques aim at the study of the association of radionuclides with individual mineral grains, or of spatial distributions of radionuclides in the solid phase. The analysis can be performed by simple means, like microscopic picking, or other separations of well characterized components [64,94,129], as well as by sophisticated experimental procedures, like fission track autoradiography in mica detectors [130], fission track mapping and delayedneutron counting [131], or dispersed-grain nuclear emulsion techniques [132], Demchuk et al [133] used contact autoradiography, in combination with microscopy, for characterization of hot particles from the fallout of Chernobyl.…”

Section: Methods For Direct Speciation Analysis In the Lithospherementioning

confidence: 99%

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Speciation of Radionuclides in the Environment

Gunten

Beneš

1995

Radiochimica Acta

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Methods for the determination of the speciation of radionuclides in aerosols, in aquatic solutions, in sediments, soils and rocks are reviewed. At present, most of the results about speciation are deduced from model calculations, model experiments, and separation of species (forms) of radionuclides, e.g., by sequential extraction procedures. Methods of direct determination of speciation of radionuclides (e.g., by laser induced spectroscopy) are in general not yet sensitive enough for a measurement of the very low concentrations of radionuclides in the environment. The methodological part of this paper is followed by a review of the very abundant literature about speciation of important radionuclides in the environment, i.e., in the atmosphere, hydrosphere and lithosphère. The review does not include the biosphere. Literature up to spring 1993 is included (with a few more recent additions).

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Section: Methods For Direct Speciation Analysis Of Aerosolsmentioning

confidence: 99%

Section: Methods For Direct Speciation Analysis Of Aerosolsmentioning

confidence: 99%

Section: Methods For Direct Speciation Analysis In the Lithospherementioning

confidence: 99%

Section: Methods For Direct Speciation Analysis In the Lithospherementioning

confidence: 99%

Section: Methods For Direct Speciation Analysis In the Lithospherementioning

confidence: 99%

See 3 more Smart Citations

Speciation of Radionuclides in the Environment

Gunten

Beneš

1995

Radiochimica Acta

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References

2016

Hydrogeochemistry Fundamentals and Advances

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Kinetic evaluation of the effects of bioavailability of organic ligands on biodegradation in the presence of common sesquioxide grain coatings

Brooks

Mills

Herman

et al. 1997

Enviro Toxic and Chemistry

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Radionuclides and metals can be mobilized by chelating agents typically present in low‐level radioactive liquid wastes that are disposed of in shallow land trenches; persistence of the organic chelating agent in the subsurface environment is a critical control on solubilization and transport of the complexed nuclide. Low‐molecular‐weight organic compounds are susceptible to uptake by bacteria, yet the biodegradation rates of nuclide‐ligand complexes in a mixture of solids (soil minerals) and liquids (ground water) are poorly known. We investigated the rate of citrate uptake in the presence of cobalt by a mixed bacterial community under experimental conditions designed to explore the impacts of citrate concentration, temperature, and chemistry of mineral surfaces. Dilute solutions with a typical sandy‐aquifer groundwater composition and equimolar amounts of cobalt and citrate ranging from 4 to 320 μM were combined with four different sand treatments: uncoated quartz sand, Fe‐coated quartz sand, Mn‐coated quartz sand, and no sand. Mineralization (net 14CO2 produced) and assimilation (14C retained on a 0.2‐μm filter) were quantified. Initial rates of citrate mineralization and of assimilation were independent of temperature in the presence of Fe‐ and Mn‐coated sands but were lower at lower temperatures (15°C versus 25°C) for the no‐sand and the uncoated sand, but the fraction of total carbon taken up (respiration plus assimilation) that the cells assimilated was greater at 15°C than at 25°C. In the presence of Fe‐coated sand, the mixed culture assimilated a greater fraction of carbon at both temperatures. The van Slyke equation, based on a model of sequential irreversible reactions, was fit to the results of the heterotrophic uptake experiments. The estimated value of the van Slyke constant indicated that mass‐transfer constraints limited the overall rate of citrate uptake, and that biokinetic limitations became more important at the lower temperature for the no‐sand and uncoated sand treatments. The sorption of citrate to the sand surface did not limit the rate of uptake. Further, complexation with cobalt did not alter the rate of citrate degradation or the rate of bacterial growth. The results suggest that transmembrane citrate transport limited the rate of uptake. The benefit that the bacteria derived from being associated with the solid sand surface was not directly related to the extent of citrate sorption, but might have resulted from a local elevation in the concentration of nutrients (e.g., P or N) available to the adsorbed bacteria, which may have allowed a more efficient processing of carbon into biomass. Sesquioxide coatings enhance the sorptive properties of the mineral grains, and in these experiments, the bacteria derived benefit from being associated with the solid sand surface.

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Subsurface cobalt-60 migration from a low-level waste disposal site

Cited by 115 publications

References 7 publications

Speciation of Radionuclides in the Environment

Speciation of Radionuclides in the Environment

References

Kinetic evaluation of the effects of bioavailability of organic ligands on biodegradation in the presence of common sesquioxide grain coatings

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