Biofilm treatment of soil for waste containment and remediation
- Univ. of Wyoming, Laramie, WY (United States)
This paper examines the potential for creating low-permeability reactive barriers for waste treatment and containment by treating soils with Beijerinckia indica, a bacterium which produces an exopolysaccharide film. The biofilm adheres to soil particles and causes a decrease in soil hydraulic conductivity. In addition, B. Indica biodegrades a variety of polycyclic aromatic hydrocarbons and chemical carcinogens. The combination of low soil hydraulic conductivity and biodegradation capabilities creates the potential for constructing reactive biofilm barriers from soil and bacteria. A laboratory study was conducted to evaluate the effects of B. Indica on the hydraulic conductivity of a silty sand. Soil specimens were molded with a bacterial and nutrient solution, compacted at optimum moisture content, permeated with a nutrient solution, and tested for k{sub sat} using a flexible-wall permeameter. Saturated hydraulic conductivity (k{sub sat}) was reduced from 1 x 10{sup -5} cm/sec to 2 x 10{sup -8} cm/sec: by biofilm treatment. Permeation with saline, acidic, and basic solutions following formation of a biofilm was found to have negligible effect on the reduced k{sub sat}, for up to three pore volumes of flow. Applications of biofilm treatment for creating low-permeability reactive barriers are discussed, including compacted liners for bottom barriers and caps and creation of vertical barriers by in situ treatment.
- Research Organization:
- US Department of Energy (USDOE), Washington DC (United States)
- OSTI ID:
- 576628
- Report Number(s):
- CONF-970208-Proc.; ON: DE98001967; TRN: 98:005202
- Resource Relation:
- Conference: International containment technology conference and exhibition, St. Petersburg, FL (United States), 9-12 Feb 1997; Other Information: PBD: [1997]; Related Information: Is Part Of International Containment Technology Conference: Proceedings; PB: 1140 p.
- Country of Publication:
- United States
- Language:
- English
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