Related Experiment Video
Updated: Jul 5, 2026
10:30
Soil Lysimeter Excavation for Coupled Hydrological, Geochemical, and Microbiological Investigations
Published on: September 11, 2016
Microbial activity and distribution during enhanced contaminant dissolution from a NAPL source zone.
Benjamin K Amos1, Eric J Suchomel, Kurt D Pennell
1School of Civil and Environmental Engineering, Georgia Institute of Technology, 311 Ferst Drive, 3228 ES&T Building, Atlanta, GA 30332-0512, USA.
Water Research
|May 9, 2008
Summary
Microbial reductive dechlorination of tetrachloroethene (PCE) enhanced NAPL dissolution in sand columns. Sulfurospirillum multivorans grew in NAPL source zones, promoting contaminant breakdown when concentrations were not toxic.
Area of Science:
- Environmental microbiology
- Bioremediation
- Geochemistry
Background:
- Tetrachloroethene (PCE) is a common groundwater contaminant.
- Understanding microbial reductive dechlorination is crucial for effective remediation.
- Nonaqueous phase liquid (NAPL) source zones pose challenges for bioremediation.
Purpose of the Study:
- To investigate microbial reductive dechlorination of PCE by Sulfurospirillum multivorans.
- To evaluate the impact of NAPL composition on microbial activity and PCE dechlorination.
- To assess the potential for microbial growth within PCE NAPL source zones.
Main Methods:
- Laboratory experiments using one-dimensional sand columns.
- Simulated PCE nonaqueous phase liquid (NAPL) source zones (mixed or pure PCE).
- Quantitative real-time PCR targeting the pceA gene to track S. multivorans populations.
Main Results:
- Significant PCE to cis-DCE dechlorination occurred in mixed-NAPL columns.
- PCE-NAPL dissolution was enhanced up to 13.6-fold in the presence of S. multivorans.
- Microbial growth and activity were observed within the NAPL source zone under non-toxic conditions.
- Minimal dechlorination and growth occurred in pure PCE-NAPL columns due to toxic concentrations.
Conclusions:
- Microbial growth within NAPL source zones is feasible if contaminant concentrations are below toxic levels.
- Microbial activity can significantly enhance NAPL dissolution and bioremediation.
- The composition of NAPL influences the effectiveness of microbial reductive dechlorination.
Related Concept Videos
01:30Microbial Wastewater Treatment
Microbial communities in aquatic ecosystems play a key role in the natural breakdown of contaminants introduced through domestic and industrial effluents. Acting as biological catalysts, these microbes change and mineralize a wide range of organic and inorganic pollutants under different redox conditions.In oxygen-rich surface waters, aerobic heterotrophs lead organic matter breakdown, using oxygen as the terminal electron acceptor to efficiently oxidize substrates to carbon dioxide and water.
01:25Microbial Mats
Microbial communities forming biofilms and mats represent complex, spatially structured ecosystems where metabolic processes are stratified according to light, oxygen, and nutrient gradients. Biofilms are initial colonization stages, only a few millimeters thick, while mature microbial mats can reach centimeter-scale thickness and display intricate vertical organization. Their structural and functional heterogeneity allows microorganisms to occupy distinct ecological niches within a few...
01:24Freshwater Microbial Ecology
Freshwater systems such as streams, rivers, and lakes exhibit distinct physical and biological characteristics that influence their microbial communities. These environments are broadly categorized into lotic systems—those with flowing waters like streams and most rivers—and lentic systems, which include still or slow-moving waters such as lakes, ponds, and marshes.In lentic systems, phytoplankton drive primary production, generating autochthonous organic carbon. In contrast, lotic systems...
01:30Marine Microbial Ecology
Marine microbial ecosystems are shaped by distinct physicochemical limits, including high salinity, low nutrient availability, and fluctuating oxygen levels. These conditions favor smaller microbial cell sizes, which maximize their surface-to-volume ratio for efficient nutrient uptake.Microbial activity and community composition are closely linked to biogeochemical cycles, particularly in dynamic environments like estuaries, where halotolerant microbes thrive in response to variable salinity...
01:26Microbial Bioremediation of Hydrocarbons
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 physical or...
01:22Microenvironments
Microorganisms inhabit highly localized spaces known as microenvironments, which are defined by distinct physical and chemical characteristics. These include oxygen concentration, pH, temperature, light availability, and nutrient levels. The conditions within a microenvironment can differ markedly from those in the surrounding area and significantly influence microbial growth, metabolism, and community structure.Microenvironments often display sharp physicochemical gradients over small spatial...