Influence of humic acids on the actinide migration in the environment: suitable humic acid model substances and their application in studies with uranium—a review

Sachs, Susanne; Bernhard, Gert

doi:10.1007/s10967-011-1084-0

Cited by 46 publications

(26 citation statements)

References 76 publications

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“…This bioreduction processes immobilizes the U radionuclide within the sediment column through direct microbially mediated electron transfer to form U(IV) (Reguera et al 2005), or indirect reduction catabolized by other microbially reduced species such as mackinawite (FeS) . Most notably, the presence and form of natural organic matter (NOM) has a confounding influence on U stability (Sachs and Bernhard 2011), acting to either enhance U reduction rates (and U immobilization) in the presence of certain microorganisms, or facilitate its re-release and transport through sorption or microbial metabolite production. However, if the bioreduced U has not sufficiently "aged" within the aquifer, it may be remobilized via oxidation by dissolved oxygen or nitrate (Moon et al 2007;Wu et al 2007).…”

Section: Introductionmentioning

confidence: 99%

“…Abiotically, certain mobile humic fractions complex with U(VI) (Czerwinski et al 1994;Lenhart et al 2000) affecting its mobility in oxygenated sediments (McCarthy et al 1998;Sachs and Bernhard 2011). Abiotically, certain mobile humic fractions complex with U(VI) (Czerwinski et al 1994;Lenhart et al 2000) affecting its mobility in oxygenated sediments (McCarthy et al 1998;Sachs and Bernhard 2011).…”

Section: Introductionmentioning

confidence: 99%

“…While this body of research suggests that U(VI) bioremediation strategies can be successful at the field scale with widely varying U concentrations and in the presence of co-contaminants, certain geochemical conditions and site heterogeneities impact U(VI) reduction efficiency and stewardship (Elias et al 2003;Vrionis et al 2005;N'Guessan et al 2008;Mouser et al 2009;Schloss 2009;Williams et al 2011). Most notably, the presence and form of natural organic matter (NOM) has a confounding influence on U stability (Sachs and Bernhard 2011), acting to either enhance U reduction rates (and U immobilization) in the presence of certain microorganisms, or facilitate its re-release and transport through sorption or microbial metabolite production.…”

Section: Introductionmentioning

confidence: 99%

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Influence of Carbon and Microbial Community Priming on the Attenuation of Uranium in a Contaminated Floodplain Aquifer

Mouser¹,

N'guessan

Qafoku

et al. 2014

Groundwater

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The capacity for subsurface sediments to sequester radionuclide contaminants, such as uranium (U), and retain them after bioremediation efforts are completed is critical to the long-term stewardship of re-mediated sites. In U bioremediation strategies, carbon amendment stimulates bioreduction of U(VI) to U(IV), immobilizing it within the sediments. Sediments enriched in natural organic matter are naturally capable of sequestering significant U, but may serve as sources to the aquifer, contributing to plume persistence. Two types of organic-rich sediments were compared to better understand U release mechanisms. Sediments that were artificially primed for U removal were retrieved from an area previously biostimulated while detrital-rich sediments were collected from a location never subject to amendment. Batch incubations demonstrated that primed sediments rapidly removed uranium from the groundwater, whereas naturally reduced sediments released a sizeable portion of U before U(VI)-reduction commenced. Column experiments confirmed that U release persisted for 65 pore volumes in naturally reduced sediments, demonstrating their sink-source behavior. Acetate addition to primed sediments shifted the microbial community from sulfate-reducing bacteria within Desulfobacteraceae to the iron-reducing Geobacteraceae and Firmicutes, associated with efficient U(VI) removal and retention, respectively. In contrast, Geobacteraceae communities in naturally reduced sediments were replaced by sequences with similarity to Pseudomonas spp. during U release, while U(VI) removal only occurred with enrichment of Firmicutes. These investigations stress the importance of characterizing zones with heterogeneous carbon pools at U-contaminated sites prior to the determination of a remedial strategy to identify areas, which may contribute to long-term sourcing of the contaminants.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Influence of Carbon and Microbial Community Priming on the Attenuation of Uranium in a Contaminated Floodplain Aquifer

Mouser¹,

N'guessan

Qafoku

et al. 2014

Groundwater

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“…Special attention has been recently paid to understand the influence of natural organic matter on radionuclide migration . Among others, acetic acid is the simplest organic substance that can act as a building block for humic acids and simulate their structure and functionality .…”

Section: Defining Chemical Equilibriamentioning

confidence: 99%

Affinity capillary electrophoresis in studying the complex formation equilibria of radionuclides in aqueous solutions

Sladkov

2016

Electrophoresis

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Interaction of radionuclides with inorganic and organic species present in natural environment plays an important role in their eventual dispersion. The complex equilibria established in the aqueous phase cause significant changes in the migration properties of radionuclides. Affinity capillary electrophoresis (ACE) can be fruitful in studying these equilibria. This paper reviews the recent methodological advances of the use of ACE in studying the complex equilibria of radionuclides in aqueous solutions. Special attention is paid to the determination of a number of species involved in equilibrium, species constituents (number of ligands, protonated, deprotonated), the influence of ionic strength and temperature on stability constants of complex species formed. Use of ACE for the determination of the main thermodynamic parameters (the molar Gibbs energy (Δ G ), the molar enthalpy (Δ H ) and the molar entropy (Δ S )) of complex formation reactions is also discussed. These data are essential to predict dispersion of radionuclides in the natural environment.

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“…The presence of HA reduces Co(II) adsorption at pH<8, but no obvious differences are detected when pH>8. For most materials (such as clay minerals, oxides, and carbon nanotubes), HA enhances metal ion adsorption on solid phase at low pH values, and reduces metal ion adsorption at high pH values [39,43]. The increase of metal ion adsorption at low pH values is generally attributed to the strong complexation of metal ions with HA adsorbed on solid particles, whereas the decrease of metal ion adsorption is interpreted by the formation of soluble metal-HA complexes in aqueous solution.…”

Section: Effect Of Humic Acidmentioning

confidence: 99%

Adsorption of Co(II) on Graphene Oxides from Aqueous Solution

Zhu

Zhong

2016

Pol. J. Environ. Stud.

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Influence of humic acids on the actinide migration in the environment: suitable humic acid model substances and their application in studies with uranium—a review

Cited by 46 publications

References 76 publications

Influence of Carbon and Microbial Community Priming on the Attenuation of Uranium in a Contaminated Floodplain Aquifer

Influence of Carbon and Microbial Community Priming on the Attenuation of Uranium in a Contaminated Floodplain Aquifer

Affinity capillary electrophoresis in studying the complex formation equilibria of radionuclides in aqueous solutions

Adsorption of Co(II) on Graphene Oxides from Aqueous Solution

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