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Updated: May 14, 2026
10:11
Microdialysis of Ethanol During Operant Ethanol Self-administration and Ethanol Determination by Gas Chromatography
Published on: September 5, 2012
Denatured ethanol release into gasoline residuals, Part 1: source behaviour
Juliana G Freitas1, James F Barker
1Departamento de Ciências Biológicas, Universidade Federal de São Paulo, Rua São Nicolau, 210, Diadema, São Paulo 09913-030, Brazil. jgfreitas@unifesp.br
Journal of Contaminant Hydrology
|February 5, 2013
Summary
Ethanol fuel spills can increase gasoline mobility in groundwater. However, water table fluctuations cause separation between ethanol and hydrocarbons, limiting long-term impacts on contamination.
Area of Science:
- Environmental Science
- Hydrogeology
- Petroleum Engineering
Background:
- Ethanol is increasingly used in fuels, raising concerns about its environmental fate, particularly its interaction with gasoline hydrocarbons in groundwater.
- Spills of denatured ethanol (E95), containing hydrocarbon denaturants, may affect pre-existing gasoline contamination by altering hydrocarbon mobility.
Purpose of the Study:
- To evaluate the behavior of E95 ethanol and its impact on gasoline contamination in a field setting.
- To understand how ethanol affects the mobility and distribution of Non-Aqueous Phase Liquids (NAPLs) in groundwater.
Main Methods:
- A field test was conducted at the CFB-Borden aquifer, involving initial gasoline (E10) contamination followed by an E95 release.
- Monitoring utilized soil cores, multilevel wells, and a glass access tube to track contaminant movement.
- Excavation of the source zone at the end of the test allowed for quantification of remaining compounds.
Main Results:
- E95 ethanol persisted in the capillary fringe and unsaturated zone for over 200 days, despite water table fluctuations.
- Gasoline NAPL saturation in the soil doubled, indicating increased mobility and redistribution within the source zone.
- Water table oscillations led to the separation of ethanol from NAPL and denaturants, with NAPL moving deeper and ethanol rising.
Conclusions:
- Ethanol's presence initially increases gasoline mobility and NAPL saturation.
- Water table fluctuations cause phase separation, limiting the duration of ethanol's impact on hydrocarbon residuals.
- The environmental impact of ethanol on existing gasoline contamination is likely significant only in the early stages post-spill.
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