Methane in soil gas may have undesirable consequences. The soil gas may be able to form a flammable mixture with air and present an explosion hazard. Aerobic biodegradation of the methane in soil gas may consume oxygen that would otherwise be available for biodegradation of gasoline hydrocarbons. The consumption of oxygen by methane may increase the chance of completing a vapor intrusion pathwa...

BACKGROUND Erroneous diffusing capacity of the lung for carbon monoxide (Dlco) values as measured by spectrophotometry were observed at our facility in ethanol-intoxicated subjects. An atypical methane curve tracing was noted in these subjects. STUDY OBJECTIVES We hypothesized that ethanol intoxication interferes with Dlco measurements obtained using methane and designed a study to assess the...

Fuel ethanol releases can stimulate methanogenesis in impacted aquifers, which could pose an explosion risk if methane migrates into enclosed spaces where ignitable conditions exist. To assess this potential risk, a flux chamber was emplaced on a pilot-scale aquifer exposed to continuous release (21 months) of an ethanol solution (10% v:v) that was introduced 22.5 cm below the water table. Desp...

In a field experiment at Vandenberg Air Force Base (VAFB) designed to mimic the impact of a small-volume release of E10 (10% ethanol and 90% conventional gasoline), two plumes were created by injecting extracted groundwater spiked with benzene, toluene, and o-xylene, abbreviated BToX (No-Ethanol Lane) and BToX plus ethanol (With-Ethanol Lane) for 283 days. We developed a reactive transport mode...

The increased probability of groundwater contamination by ethanol-blended fuel calls for improved understanding of how remediation efforts affect the fate and transport of constituents of concern, including the generation and fate of fermentation byproducts. A pilot-scale (8 m³) model aquifer was used to investigate changes in the concentrations of ethanol and its metabolites (methane and volat...

A minority of methanotrophs are able to utilize multicarbon compounds as growth substrates in addition to methane. The pathways utilized by these microorganisms for assimilation of multicarbon compounds, however, have not been explicitly examined. Here, we report the draft genome of the facultative methanotroph Methylocystis sp. strain SB2 and perform a detailed transcriptomic analysis of cultu...

The oxidation of ethanol to acetate by cultures of Methunobacillus omelianskii was found by Barker to be dependent upon carbon dioxide (1) ; using C140Z, Stadtman and Barker demonstrated conclusively that carbon dioxide was the precursor of methane (2). Recently Johns and Barker have reported hydrogen formation from ethanol by resting cells of M. omelianskii in the absence of carbon dioxide (3)...

The objective of this study was to assess the limonene removal efficiency of three pre-treatment methods when applied to citrus waste and to evaluate their effects on the biochemical methane potential and the methane production rate using batch anaerobic tests. The methods tested were based on removal (biological pretreatment by fungi) or recovery (steam distillation and ethanol extraction) of ...