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Updated: Jul 2, 2026
20:28
A Toolkit to Enable Hydrocarbon Conversion in Aqueous Environments
Published on: October 2, 2012
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Single-well push-pull tests evaluating isobutane as a primary substrate for promoting in situ cometabolic
Hannah Rolston1, Michael Hyman2, Lewis Semprini3
1Oregon State University, Corvallis, OR, USA.
Biodegradation
|May 13, 2022
Summary
Isobutane effectively stimulates native microorganisms for in situ cometabolic degradation of groundwater contaminants. Isobutene served as a surrogate to demonstrate this enhanced microbial activity and transformation capabilities.
Area of Science:
- Environmental Microbiology
- Bioremediation
- Geochemistry
Background:
- Groundwater contamination by chlorinated aliphatic hydrocarbons and 1,4-dioxane is a significant environmental challenge.
- In situ biostimulation offers a promising approach for remediating contaminated aquifers.
- Identifying effective primary substrates for stimulating microbial cometabolism is crucial for bioremediation success.
Purpose of the Study:
- To evaluate isobutane (2-methylpropane) as a primary substrate for stimulating in situ microbial cometabolism.
- To investigate the development of an isobutane-utilizing microbial community in the aquifer.
- To demonstrate cometabolic activity using isobutene (2-methylpropene) as a surrogate for common groundwater contaminants.
Main Methods:
- Single-well push-pull tests (SWPPTs) were conducted to assess isobutane consumption and microbial community development.
- Natural drift tests were performed to determine first-order rates of isobutane consumption.
- Groundwater microcosms were used to model microbial biomass and evaluate cometabolic transformation of surrogates and contaminants.
Main Results:
- The disappearance of isobutane indicated rapid development of an isobutane-utilizing microbial community.
- Isobutene was transformed to isobutene epoxide in the presence of isobutane, demonstrating cometabolic epoxidation.
- Stimulated bacteria in microcosms transformed a mixture of contaminants, including chlorinated ethenes and 1,4-dioxane, with preferences similar to Rhodococcus rhodochrous.
Conclusions:
- Isobutane is an effective primary substrate for stimulating in situ cometabolic activity in aquifers.
- Isobutene serves as a suitable surrogate for investigating in situ cometabolic reactions.
- This approach holds potential for the bioremediation of diverse groundwater contaminants.
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