Related Experiment Video
Updated: Apr 26, 2026
09:23
Removal of Trace Elements by Cupric Oxide Nanoparticles from Uranium In Situ Recovery Bleed Water and Its Effect on Cell Viability
Published on: June 21, 2015
9.2K
Geochemical control on uranium(IV) mobility in a mining-impacted wetland
Yuheng Wang1, Alexandre Bagnoud, Elena Suvorova
1Ecole Polytechnique Fédérale de Lausanne (EPFL) - Environmental Microbiology Laboratory (EML) EPFL-ENAC-IIE-EML, Station 6, CH-1015 Lausanne, Switzerland.
Environmental Science & Technology
|July 23, 2014
Summary
Wetlands can immobilize uranium (U). In clay-poor areas, U binds to soil organic matter, limiting its mobility. This contrasts with clay-rich zones where U mobility is higher due to associations with iron and organic colloids.
Area of Science:
- Environmental Science
- Geochemistry
- Environmental Chemistry
Background:
- Wetlands act as natural sinks for uranium (U) and trace elements.
- Previous studies identified labile noncrystalline U(IV) species bound to Al-P-Fe-Si aggregates in clay-rich wetland soils.
- Uranium mobility in porewater was linked to its association with Fe(II) and organic matter colloids.
Purpose of the Study:
- To investigate uranium speciation and mobility in a clay-poor wetland location.
- To compare uranium behavior in clay-poor versus clay-rich wetland environments.
- To elucidate factors controlling uranium immobilization in wetlands.
Main Methods:
- Field sampling in a mining-impacted wetland in France.
- Analysis of uranium speciation in soil and porewater.
- Assessment of microbial sulfate reduction and iron speciation.
Main Results:
- A different noncrystalline U(IV) species, bound to soil organic matter, dominates in clay-poor locations.
- Clay-poor areas exhibit abundant sulfate and microbial sulfate reduction, leading to pyrite precipitation.
- Lower Fe(II) concentrations in porewater of clay-poor zones result in significantly reduced uranium porewater concentrations and mobility.
- Soil-associated uranium constitutes over 99% of total uranium in both studied locations.
Conclusions:
- Low uranium mobility in clay-poor wetland locations is attributed to limited Fe(II) association with organic matter colloids in porewater.
- Alternatively, higher stability of the noncrystalline U(IV) species bound to soil organic matter contributes to uranium immobilization.
- Wetland characteristics, particularly clay content and microbial activity, significantly influence uranium speciation and mobility.
Related Concept Videos
01:25Microbial Bioremediation of Uranium
95
Microorganisms play a critical role in the transformation and immobilization of uranium in contaminated environments through four main pathways: bioreduction, biosorption, bioaccumulation, and biomineralization. These mechanisms reduce uranium’s toxicity and prevent its migration through groundwater systems, offering sustainable approaches for in situ bioremediation.Bioreduction of UraniumBioreduction is driven by anaerobic bacteria such as certain strains of Geobacter and Shewanella,...
95
01:27Microbial Leaching
218
Microbial leaching, also known as bioleaching, is an environmentally favorable method for extracting metals from low-grade ores using specific microorganisms. This biotechnological approach is particularly valuable for mining operations targeting copper, gold, and uranium, where traditional extraction methods may be economically or environmentally impractical.Copper Leaching and Microbial CatalysisIn copper bioleaching, crushed ore is arranged into heaps and irrigated with a dilute sulfuric...
218
01:19Acid Mine Drainage
108
Mining activities that disturb sulfide-rich rocks, particularly those containing pyrite (FeS₂), initiate a cascade of geochemical and microbiological processes with serious environmental implications. When exposed to air and water, pyrite undergoes oxidation, releasing sulfate, ultimately forming sulfuric acid and mobilizing heavy metals into surrounding water systems. This phenomenon, known as acid mine drainage (AMD), results in low pH waters laden with toxic elements that threaten...
108
01:24Microbes and Other Elemental Cycles
81
Microbial activity plays a pivotal role in the biogeochemical cycling of iron and manganese, especially at the redox gradients characteristic of stratified aquatic environments. These cycles are driven by microbial transformations between oxidized and reduced forms of the metals, allowing organisms to exploit them for metabolic energy and structural purposes.Iron Cycling Across Redox GradientsIn neutral, oxygen-rich surface waters, iron is predominantly found in its oxidized, insoluble ferric...
81
04:01Factors Affecting Solubility
32.1K
Compared with pure water, the solubility of an ionic compound is less in aqueous solutions containing a common ion (one also produced by dissolution of the ionic compound). This is an example of a phenomenon known as the common ion effect, which is a consequence of the law of mass action that may be explained using Le Chȃtelier’s principle. Consider the dissolution of silver iodide:
32.1K
01:26Microbial Bioremediation of Hydrocarbons
138
Bioremediation is an environmentally sustainable process that employs living organisms—primarily microorganisms—to degrade or neutralize pollutants from contaminated environments. In oil spills and hydrocarbon pollution, bioremediation involves the use of hydrocarbon-degrading bacteria to transform toxic compounds into less harmful substances. This approach leverages natural microbial metabolic processes and is considered both cost-effective and ecologically favorable compared to...
138