Mountain wetlands: Efficient uranium filters — potential impacts

Owen, Douglass E.; Otton, James K.

doi:10.1016/0925-8574(95)00013-9

Cited by 57 publications

(51 citation statements)

References 18 publications

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“…Several authors have outlined the relevance of biological processes for the development of stable biogenic ore deposits. In a study of 145 minerotrophic wetlands in the mountainous sub-alpine zone of the Rockies, Owen and Otton (1995) documented the vegetation type, and hydrological and topographical conditions of bogs and fens which accumulate U in sediments. Of the 145 bogs investigated, 67 showed U enrichment.…”

Section: Stage 3: Reduction/transformation/biomineralizationmentioning

confidence: 99%

The removal of uranium from mining waste water using algal/microbial biomass

Kalin¹,

Wheeler²,

Meinrath³

2005

Journal of Environmental Radioactivity

303

134

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We describe a three step process for the removal of uranium (U) from dilute waste waters.Step one involves the sequestration of U on, in, and around aquatic plants such as algae. Cell wall ligands efficiently remove U(VI) from waste water. Growing algae continuously renew the cellular surface area.Step 2 is the removal of U-algal particulates from the water column to the sediments.Step 3 involves reducing U(VI) to U(IV) and transforming the ions into stable precipitates in the sediments. The algal cells provide organic carbon and other nutrients to heterotrophic microbial consortia to maintain the low E H , within which the U is transformed.Among the microorganisms, algae are of predominant interest for the ecological engineer because of their ability to sequester U and because some algae can live under many extreme environments, often in abundance. Algae grow in a wide spectrum of water qualities, from alkaline environments (Chara, Nitella) to acidic mine drainage waste waters (Mougeotia, Ulothrix). If they could be induced to grow in waste waters, they would provide a simple, longterm means to remove U and other radionuclides from U mining effluents. This paper reviews the literature on algal and microbial adsorption, reduction, and transformation of U in waste streams, wetlands, lakes and oceans.

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Section: Stage 3: Reduction/transformation/biomineralizationmentioning

confidence: 99%

The removal of uranium from mining waste water using algal/microbial biomass

Kalin¹,

Wheeler²,

Meinrath³

2005

Journal of Environmental Radioactivity

303

134

View full text Add to dashboard Cite

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“…In the majority of the cases, U mines or mine tailings (Pfeifer et al, 1994;Owen and Otton, 1995;Schö ner et al, 2008;Sobolewski, 1999), or phosphate fertilizers (Zielinski et al, 2006) were main sources for U input. However, another study considers a similar situation by which high U enrichment (up to 1000 ppm) occurs in a peat bog (which is located close to a natural U mineralization), where it is accumulated due to complexation and retention by carboxyl functional groups (Read et al, 1993).…”

Section: U Binding To Dischma Soilsmentioning

confidence: 99%

“…At neutral to alkaline pH conditions, U(VI) can be retained in soil by adsorption to soil minerals or precipitation as U(VI) minerals such as uranyl hydroxide, or calcium uranyl phosphate (e.g., uranophane). Further, uranyl is known to complex readily with organic molecules such as acetate, oxalate or humic acid (Haas and Northup, 2004), which might explain why high U concentrations have been reported in humic-rich environments such as peats and bogs (e.g., Read et al, 1993;Owen and Otton, 1995;Gonzalez et al, 2006). This correlation results from the fact that the humic and fulvic acids, which are the main components of aqueous organic matter (OM), are efficient at exchanging protons with metals thereby forming aqueous complexes (Stumm and Morgan, 1996).…”

Section: Introductionmentioning

confidence: 99%

“…Naturally-occurring high U concentrations in ground and surface water are documented in alpine regions (Owen and Otton, 1995;Deflorin, 2004) where the surrounding bedrock consists mainly of crystalline rocks that commonly contain trace amounts of U (Bernhard, 2005). Weathering processes mobilize U from the rock and transport it to the pedosphere where it accumulates in the soil.…”

Section: Introductionmentioning

confidence: 99%

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Speciation of naturally-accumulated uranium in an organic-rich soil of an alpine region (Switzerland)

Regenspurg

Margot-Roquier

Harfouche

et al. 2010

Geochimica et Cosmochimica Acta

104

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Very high concentrations of uranium (up to 4000 ppm) were found in a natural soil in the Dischma valley, an alpine region in the Grisons canton in Switzerland. The goal of this study was to examine the redox state and the nature of uranium binding in the soil matrix in order to understand the accumulation mechanism. Pore water profiles collected from Dischma soil revealed the establishment of anoxic conditions with increasing soil depth.

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“…1 They also found a maximum U level of 10,000 ppm detected in woody peat and organic rich sediments at the Flodelle Creek natural wetland (Washington State, United States). 2 Regenspurg et al discovered concentrations of uranium up to 4,000 ppm in a natural organic-rich soil in the Dischma valley, 3 an alpine region in Switzerland. All of the areas in which these types of natural U accumulation were identified are in mountainous regions and underlain by granites or rhyolitic volcanic rocks that are commonly uraniferous.…”

Section: ■ Introductionmentioning

confidence: 99%

Geochemical Control on Uranium(IV) Mobility in a Mining-Impacted Wetland

Wang

Bagnoud

Suvorova

et al. 2014

Environ. Sci. Technol.

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Wetlands often act as sinks for uranium and other trace elements. Our previous work at a mining-impacted wetland in France showed that a labile noncrystalline U(IV) species consisting of U(IV) bound to Al−P−Fe−Si aggregates was predominant in the soil at locations exhibiting a Ucontaining clay-rich layer within the top 30 cm. Additionally, in the porewater, the association of U(IV) with Fe(II) and organic matter colloids significantly increased U(IV) mobility in the wetland. In the present study, within the same wetland, we further demonstrate that the speciation of U at a location not impacted by the clay-rich layer is a different noncrystalline U(IV) species, consisting of U(IV) bound to organic matter in soil. We also show that the clay-poor location includes an abundant sulfate supply and active microbial sulfate reduction that induce substantial pyrite (FeS 2 ) precipitation. As a result, Fe(II) concentrations in the porewater are much lower than those at clay-impacted zones. U porewater concentrations (0.02−0.26 μM) are also considerably lower than those at the clay-impacted locations (0.21−3.4 μM) resulting in minimal U mobility. In both cases, soil-associated U represents more than 99% of U in the wetland. We conclude that the low U mobility reported at clay-poor locations is due to the limited association of Fe(II) with organic matter colloids in porewater and/or higher stability of the noncrystalline U(IV) species in soil at those locations.

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Mountain wetlands: Efficient uranium filters — potential impacts

Cited by 57 publications

References 18 publications

The removal of uranium from mining waste water using algal/microbial biomass

The removal of uranium from mining waste water using algal/microbial biomass

Speciation of naturally-accumulated uranium in an organic-rich soil of an alpine region (Switzerland)

Geochemical Control on Uranium(IV) Mobility in a Mining-Impacted Wetland

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