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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
Changes in microbial community composition and geochemistry during uranium and technetium bioimmobilization
Mandy M Michalsen1, Aaron D Peacock, Anne M Spain
1Department of Civil Engineering, Oregon State University, Corvallis, OR 97331, USA. mandy.michalsen@gmail.com
Applied and Environmental Microbiology
|July 17, 2007
Summary
Ethanol additions enhanced uranium and technetium removal in groundwater by stimulating microbial activity. Microbial community analysis revealed shifts in bacterial populations, indicating adaptation to changing geochemical conditions and electron donor availability.
Area of Science:
- Environmental Science
- Geomicrobiology
- Environmental Chemistry
Background:
- Previous studies showed ethanol additions enhance uranium (U) and technetium (Tc) removal in groundwater.
- Ethanol stimulated iron- and sulfate-reducing conditions, improving contaminant removal compared to controls.
Purpose of the Study:
- To characterize microbial communities in ethanol-stimulated and control groundwater columns.
- To link microbial community shifts to geochemical changes and contaminant mobility.
Main Methods:
- Combined signature lipid (phospholipid fatty acid analysis) and nucleic acid-based (PCR-DGGE, quantitative PCR, 16S rRNA gene clone libraries) microbial characterization.
- Analysis of geochemical variables and redundancy analysis to correlate community composition with environmental factors.
Main Results:
- Microbial biomass increased significantly (approx. 2 orders of magnitude) in the ethanol-stimulated column.
- Distinct spatial shifts in microbial community composition were observed, with Geobacteraceae increasing near the outlet.
- Proteobacteria dominated the inlet, while candidate division OP11 dominated the outlet in the stimulated column.
- Geochemical variables explained 68% of the variance in microbial community composition.
Conclusions:
- Ethanol addition significantly alters groundwater microbial community structure and function.
- Microbial community shifts are strongly correlated with geochemical gradients and enhanced U and Tc removal.
- Geobacteraceae and candidate division OP11 play key roles in contaminant remediation under stimulated conditions.
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