The formation of microbial barriers in saturated porous media
- National Hydrology Research Inst., Saskatoon, Saskatchewan (Canada)
Control of contaminant migration in the subsurface to prevent off-site migration and facilitate treatment is an essential component of any remediation scheme. In situ plugging of pore spaces by introduced bacteria has been suggested as a mechanism to seal permeable zones and to enhance bioremediation. This procedure involves the injection of bacteria which adsorb to the geologic media, are stimulated with a nutrient solution and grow producing an exopolysaccharide plug. The objective of the current research was to evaluate the feasibility of in situ placement of biological barriers for containment of contaminants in subsurface environments. Transport of bacteria through sands at a groundwater velocity of 0.3 m/day and the impact of growth and exopolymer production during nutrient stimulation were studied over time using confocal laser microscopy and viable fluorescence exclusion techniques. The inoculum rapidly colonized the sand matrix and dominated surface sites while forming extensive biofilms. After three to four days the native ground-water flora invaded the established biofilm, creating a mixed species biofilm which reduced the effective porosity of the geologic medium. The resulting biobarrier reduced the hydraulic conductivity of the porous media by two orders of magnitude, and exhibited self-sealing properties in response to changes in hydraulic head.
- OSTI ID:
- 6060851
- Report Number(s):
- CONF-9310166-; CODEN: JEVHAH
- Journal Information:
- Journal of Environmental Health; (United States), Vol. 56:3; Conference: Association of Ground Water Scientists and Engineers (AGWSE) educational seminar on chlorinated volatile organic compounds in ground water, Kansas City, MO (United States), 17-20 Oct 1993; ISSN 0022-0892
- Country of Publication:
- United States
- Language:
- English
Similar Records
Permeable Reactive Biobarriers for In Situ Cr(VI) Reduction: Bench Scale Tests Using Cellulomonas sp. Strain ES6
Effect of bacterial extracellular polymers on the saturated hydraulic conductivity of sand columns
Related Subjects
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
POLLUTANTS
BIODEGRADATION
BACTERIA
ENVIRONMENTAL TRANSPORT
GROUND WATER
HYDRAULIC CONDUCTIVITY
UNDERGROUND
WATER POLLUTION CONTROL
CHEMICAL REACTIONS
CONTROL
DECOMPOSITION
HYDROGEN COMPOUNDS
LEVELS
MASS TRANSFER
MICROORGANISMS
OXYGEN COMPOUNDS
POLLUTION CONTROL
WATER
540220* - Environment
Terrestrial- Chemicals Monitoring & Transport- (1990-)
560300 - Chemicals Metabolism & Toxicology