Uranium uptake by algae: experimental and natural environments

Mann, H.; Fyfe, W. S.

doi:10.1139/e85-205

Cited by 24 publications

(9 citation statements)

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“…There has been some work published on the effects of U on algal species suspended in the water column (Charles et al, 2002;Franklin et al, 2000;Hogan et al, 2005;Mann and Fyfe, 1985) but less so on the effects of anthropogenic U contamination on densely packed and highly structured periphyton communities. Determining the effects of contaminants on whole communities ismore complicated than using single species, but the effort provides a more realistic picture of the impact of a stressor or contaminant on a complex natural system (Cairns et al, 1992).…”

Section: Discussionmentioning

confidence: 99%

Investigating freshwater periphyton community response to uranium with phospholipid fatty acid and denaturing gradient gel electrophoresis analyses

Small

Bunn

McKinstry

et al. 2008

Journal of Environmental Radioactivity

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Section: Discussionmentioning

confidence: 99%

Investigating freshwater periphyton community response to uranium with phospholipid fatty acid and denaturing gradient gel electrophoresis analyses

Small

Bunn

McKinstry

et al. 2008

Journal of Environmental Radioactivity

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“…Trenfield et al [21] studied the influence of dissolved organic carbon on uranium toxicity to Euglena gracilis at pH 6. Both groups [19,21], however, did not provide any information on the respective uranium speciation in the surrounding water and associated with Euglena cells.…”

Section: Introductionmentioning

confidence: 93%

“…with uranium are, however, so far very limited. In two studies [19,20] a significant accumulation of uranium by unspecified Euglena sp. cells thriving in tailings at the Elliot Lake (Ontario) were observed and from this it was concluded that specific algae must be important in the transfer of uranium from the hydrosphere to the sediments.…”

Section: Introductionmentioning

confidence: 99%

Speciation of bioaccumulated uranium(VI) by Euglena mutabilis cells obtained by laser fluorescence spectroscopy

Brockmann¹,

Arnold

Bernhard

2014

Radiochimica Acta

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The ability of Euglena mutabilis cells -a unicellular protozoan with a flexible pellicle, which is typically found in acid mine drainage (AMD) environments -to bioaccumulate uranium under acid conditions was studied in batch sorption experiments at pH 3 and 4 using Na 2 SO 4 and NaClO 4 as background media. It was found that axenic cultures of Euglena mutabilis Schmitz were able to bioaccumulate in 5 days 94.9 to 99.2% of uranium from a 1 × 10 −5 mol/L uranium solution in perchlorate medium and 95.1 to 95.9% in sodium sulfate medium, respectively. The speciation of uranium in solution and uranium bioaccumulated by Euglena mutabilis cells, were studied by laser induced fluorescence spectroscopy (LIFS). The LIFS investigations showed that the uranium speciation in the NaClO 4 systems was dominated by free uranyl(VI) species and that the UO 2 SO 4 species was dominating in the Na 2 SO 4 medium. Fluorescence spectra of the bioaccumulated uranium revealed that aqueous uranium binds to carboxylic and/or (organo)phosphate groups located on the euglenid pellicle or inside the Euglena mutabilis cells.Reduced uranium immobilization rates of 0.93-1.43 mg uranium per g Euglena mutabilis biomass were observed in similar experiments, using sterile filtrated AMD waters containing, 4.4 × 10 −5 mol/L uranium. These lower rates were attributed to competition with other cations for available sorption sites. Additional LIFS measurements, however, showed that the speciation of the bioaccumulated uranium by the Euglena mutabilis cells was found to be identical with the uranium speciation found in the bioaccumulation experiments carried out in Na 2 SO 4 and NaClO 4 media.The results indicate that Euglena mutabilis has the potential to immobilize aqueous uranium under acid condition and thus may be used in future as promising agent for immobilizing uranium in low pH waste water environments.

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“…Average concentrations of U were likely highest during drier periods when spring water (i.e., groundwater) contributions were proportionally greater. Dissolved U in the lake was subject to additional variability caused by the abundance of suspended algae with probable high affinity for U. Algae have been shown to concentrate U by as much as 1000-10,000X compared to coexisting water (Degens et al, 1979;Mann and Fyfe, 1984;Dienemann et al, 2002). Algal remains settled to the lake bottom and were incorporated into silt and clay lake sediments, forming gyttja.…”

Section: Uranium Uptake In Lakebed Sedimentsmentioning

confidence: 99%

Uranium delivery and uptake in a montane wetland, north-central Colorado, USA

Schumann

Zielinski

Otton

et al. 2017

Applied Geochemistry

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Comprehensive sampling of peat, underlying lakebed sediments, and coexisting waters of a naturally uraniferous montane wetland are combined with hydrologic measurements to define the important controls on uranium (U) supply and uptake. The major source of U to the wetland is groundwater flowing through locally fractured and faulted granite gneiss of Proterozoic age. Dissolved U concentrations in four springs and one seep ranged from 20 to 83 ppb (µg/l). Maximum U concentrations are ~300 ppm (mg/kg) in lakebed sediments and >3000 ppm in peat. Uranium in lakebed sediments is primarily stratabound in the more organic-rich layers, but samples of similar organic content display variable U concentrations. Post-depositional modifications include variable additions of U delivered by groundwater. Uranium distribution in peat is heterogeneous and primarily controlled by proximity to groundwater-fed springs and seeps that act as local point sources of U, and by proximity to groundwater directed along the peat/lakebeds contact. Uranium is initially sorbed on various organic components of peat as oxidized U(VI) present in groundwater. Selective extractions indicate that the majority of sorbed U remains as the oxidized species despite reducing conditions that should favor formation of U(IV). Possible explanations are kinetic hindrances related to strong complex formation between uranyl and humic substances, inhibition of anaerobic bacterial activity by low supply of dissolved iron and sulfate, and by cold temperatures.

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Uranium uptake by algae: experimental and natural environments

Cited by 24 publications

References 0 publications

Investigating freshwater periphyton community response to uranium with phospholipid fatty acid and denaturing gradient gel electrophoresis analyses

Investigating freshwater periphyton community response to uranium with phospholipid fatty acid and denaturing gradient gel electrophoresis analyses

Speciation of bioaccumulated uranium(VI) by Euglena mutabilis cells obtained by laser fluorescence spectroscopy

Uranium delivery and uptake in a montane wetland, north-central Colorado, USA

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