Adsorption of UO2 2+ on natural composite materials

Jung, Jin-Woo; Hyun, Sung Pil; Lee, J. K.; Cho, Y. H.; Hahn, Pil-Soo

doi:10.1007/bf02345570

Cited by 32 publications

(22 citation statements)

References 12 publications

(8 reference statements)

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“…The adsorption of U (VI) to ferrihydrite (amorphous iron hydroxide) and goethite (crystalline Fe oxyhydroxide) is well known (McKinley et al, 1995; Turner et al, 1996; Prikryl et al, 2001). Also, goethite is reported to adsorb more U (VI) compared with phyllosilicate minerals (Jong et al, 1999). More research is needed to determine the adsorption of U on different Fe oxides at the study site.…”

Section: Discussionmentioning

confidence: 99%

Distribution of Uranium Contamination in Weathered Fractured Saprolite/Shale and Ground Water

et al. 2006

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The objective of this study was to determine how structure, stratigraphy, and weathering influence fate and transport of contaminants (particularly U) in the ground water and geologic material at the Department of Energy (DOE) Environmental Remediation Sciences Department (ERSD) Field Research Center (FRC). Several cores were collected near four former unlined adjoining waste disposal ponds. The cores were collected, described, analyzed for U, and compared with ground water geochemistry from surrounding multilevel wells. At some locations, acidic U-contaminated ground water was found to preferentially flow in small remnant fractures weathering the surrounding shale (nitric acid extractable U [U(NA)] usually < 50 mg kg(-1)) into thin (<25 cm) Fe oxide-rich clayey seams that retain U (U(NA) 239 to 375 mg kg(-1)). However, greatest contaminant transport occurs in a 2 to 3 m thick more permeable stratigraphic transition zone located between two less permeable, and generally less contaminated zones consisting of (i) overlying unconsolidated saprolite (U(NA) < 0.01 to 200 mg kg(-1)) and (ii) underlying less-weathered bedrock (U(NA) generally < 0.01 to 7 mg kg(-1)). In this transition zone, acidic (pH < 4) U-enriched ground water (U of 38 mg L(-1)) has weathered away calcite veins resulting in greater porosity, higher hydraulic conductivity, and higher U contamination (U(NA) 106 to 745 mg kg(-1)) of the weathered interbedded shale and sandstone. These characteristics of the transition zone produce an interval with a high flux of contaminants that could be targeted for remediation.

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Section: Discussionmentioning

confidence: 99%

Distribution of Uranium Contamination in Weathered Fractured Saprolite/Shale and Ground Water

et al. 2006

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“…These values were obtained by fitting the experimental data of dextran production over time. The half-saturations K M;sucrose in equation 7 for reactions in equations 5 and 6 are 7.3E-3 and 7.3E-4 (mol∕l), respectively, which are among the typical values in literature (Jung et al, 1999;Liu et al, 2001). The molar volume of the biomass was assumed to be 336 cm 3 ∕mol, a number in the middle range of those reported in the literature (Loferer-Krossbacher et al, 1998).…”

Section: Reaction Network and Kineticsmentioning

confidence: 67%

Geophysical monitoring and reactive transport simulations of bioclogging processes induced by Leuconostoc mesenteroides

Surasani

et al. 2014

GEOPHYSICS

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Although bioclogging has been used for various applications, its performance has been unpredictable. We carried out a bioclogging experiment and developed a reactive transport model to understand and quantify geophysical responses to the production of a biopolymer (dextran) in a silica sand porous medium. The developed model was used to predict effectiveness of bioclogging and the associated geophysical signature under different treatment conditions. The porosity reduction calculated from the reactive transport modeling matched the concurrent increase in electrical resistivity and confirmed the dominant contribution of pore fluid conductivity to the bulk electrical conductivity. Correlations between measured electrical phase signals and predicted mineral surface area reduction indicated the controlling effect of mineral surface area on polarization. The joint use of the two methods quantitatively estimated the extent of decrease in porosity as well as effective mineral surface area, both of which are challenging to measure nondestructively in biological systems. The joint use of the geophysical methods and reactive transport modeling provided a better understanding of the dominant processes that govern dextran-based bioclogging and the associated geophysical responses. This opens new opportunities for quantifying changes associated with bioclogging processes and can potentially lead to new conceptual models that relate hydraulic property changes to the porosity and mineral surface area, which will enhance prediction, monitoring, and control of applications that use bioclogging.

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“…Possible explanations are membrane rejection due to the rather strong negative charge of uranyl complexes (Guo et al 2001), the molecular weight of the U carbonate complexes (around 0.4 kDa; i.e. close to that of raffinose), and/ or adsorption on iron oxides (Jung et al 1999). The retention of U on the PXL 3 kDa is 6-10% higher than on the PpS despite good recoveries (97-100%).…”

Section: Retention Of Natural Watersmentioning

confidence: 96%

Comparison of Small- and Large-scale Ultrafiltration Systems for Organic Carbon and Metals in Freshwater at Low Concentration Factor

Kottelat

Vignati

Chanudet

et al. 2007

Water Air Soil Pollut

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Interdisciplinary studies on aquatic environments and cross-validation of laboratory vs. field results will likely increase the need for simultaneous use of large-and small-scale ultrafiltration systems. In this study, a comparison of two ultrafiltration systems differing in scale (PrepScale and PelliconXL, Millipore; membrane areas 0.54 m 2 and 0.005 m 2 , respectively), was made for the cut-offs 3 and 300 kDa. Large systems are useful for their high permeate throughput, while small systems are necessary when the amount of sample is limited. The ability of PrepScale and PelliconXL systems to provide comparable results for organic carbon fractionation was studied for polysaccharide solutions and natural freshwaters. In the latter, the colloidal proportions of different trace metals (V, Cr, Mn, Co, Ni, Cu, Sb, and U) were also determined. Although the colloidal proportions obtained with PelliconXL 3 kDa were sometimes slightly higher than with PrepScale 3 kDa (principally for DOC and U in natural waters), Mann-Whitney statistical test showed no significant difference in the overall fractionation properties of the two systems. Our observations show that reaching high concentration factors lead to a strong modification of colloids size distribution in the range 50-2,000 nm and thus low concentration factors are preferable to preserve the colloid integrity.

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Adsorption of UO2 2+ on natural composite materials

Cited by 32 publications

References 12 publications

Distribution of Uranium Contamination in Weathered Fractured Saprolite/Shale and Ground Water

Distribution of Uranium Contamination in Weathered Fractured Saprolite/Shale and Ground Water

Geophysical monitoring and reactive transport simulations of bioclogging processes induced by Leuconostoc mesenteroides

Comparison of Small- and Large-scale Ultrafiltration Systems for Organic Carbon and Metals in Freshwater at Low Concentration Factor

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