Experiences in laboratory studies of the effects of bioclogging of porous media

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Authors:Bertetti, F. P.; Hill, M. E.; Bagtzoglou, A. C.; Birnbaum, S. J.; McAllister, L. P.
Author Affiliations:Primary:
Southwest Research Institute, CNWRA, San Antonio, TX, United States
Columbia University, United States
University of Texas at San Antonio, United States
CH2M Hill, United States
Volume Title:Geological Society of America, 2000 annual meeting
Source:Abstracts with Programs - Geological Society of America, 32(7), p.354; Geological Society of America, 2000 annual meeting, Reno, NV, Nov. 9-18, 2000. Publisher: Geological Society of America (GSA), Boulder, CO, United States. ISSN: 0016-7592
Publication Date:2000
Note:In English
Summary:Problems caused by bioclogging of hydrologic systems are not new, and subsurface bioremediation efforts have recently stimulated renewed attention to this phenomenon. Oil-field researchers have long been aware of the reduction in porosity and permeability associated with enhanced microbial growth, and investigators have examined the potential for selective plugging of portions of geologic formations to enhance the secondary recovery of oil. A similar selective plugging approach might be utilized at contaminated sites to create, in effect, a containment wall or bio-barrier that would slow the migration of subsurface contaminants while also providing contaminant remediation. To investigate the feasibility of this approach and characterize the effects of bioclogging of sediments, a series of bench-scale laboratory studies have been conducted to evaluate the potential for native microflora to inhibit groundwater flow through a reduction in hydraulic conductivity (K). These experiments used indigenous microflora that were isolated from both contaminated and pristine locations. The flow system was modeled using columns packed with natural and simulated sediments and operated over a range of time, flow rates, saturation, and carbon (nutrient) concentrations. Various techniques were employed to measure K and characterize the nature of the clogging within the column materials. Results indicate that: (i) growth enhancement of both a single strain or collection of organisms effectively reduces K, (ii) the reduction in K is caused by pore throat clogging with cell aggregates and bridging of the pore throat by microbial exopolymers, and (iii) the reduction in K over time can be correlated to flow rate and nutrient concentration. A coupled microbe-hydrologic model was developed from the results of the laboratory investigations and used to produce simulations that estimate effects on K and changes in the flow field of a porous medium resulting from microbial activity stimulation. Results of these studies suggest that the effects of bioclogging can be used to enhance bioremediation efforts.
Subjects:Bioremediation; Carbon; Characterization; Effects; Enhanced recovery; Experimental studies; Ground water; Hydraulic conductivity; Laboratory studies; Models; Movement; Nutrients; Permeability; Petroleum engineering; Pollution; Porosity; Porous materials; Remediation; Saturation; Secondary recovery; Simulation; Bioclogging
Record ID:2003076976
Copyright Information:GeoRef, Copyright 2018 American Geosciences Institute. Reference includes data supplied by the Geological Society of America, Boulder, CO, United States
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