Record Details
Field | Value |
---|---|
Title | Low Level Quantification of 1,4-Dioxane and Investigation of 1,4-Dioxane Co-Metabolism by Mycobacterium sp. 1A. |
Names |
McKeage, Kevin J.
(creator) Dolan, Mark E. (advisor) |
Date Issued | 2015-06-05 (iso8601) |
Note | Graduation date: 2015 |
Abstract | 1,4-Dioxane (dioxane) is a probable human carcinogen and is often found comingled with chlorinated aliphatic hydrocarbon (CAH) contamination since dioxane is used as a stabilizer in CAH solutions. Dioxane is miscible in water, has a low K[subscript ow], low H[subscript cc], and is highly recalcitrant in the environment. The presence and potential transformation of dioxane at CAH sites undergoing remediation has been difficult to ascertain due to the difficulty of analysis. Typical analyses performed for CAH's, such as direct liquid injection onto a gas chromatograph equipped with a flame ionization detector, are ineffective at detecting dioxane. Methods have been developed to analyze low levels of dioxane, but they require extraction techniques involving the use of harmful solvents and expensive consumables. A method of analyzing environmentally relevant concentrations of 1,4-dioxane in the sub-μg/L range by heated purge-and-trap coupled with gas chromatography mass spectrometry is presented. This method demonstrates a method detection limit of 0.13 μg/L which is below the EPA risk assessment concentration of 0.35 μg/L. Detection at this level has allowed for the characterization of the 1,4-dioxane degradation capabilities of an Actinomycete culture, Mycobacterium sp. 1A (1A). Culture 1A was found to degrade dioxane at rates two to four times faster in the absence of propane than in the presence of propane. Although propane did inhibit dioxane transformation, dioxane was still observed to be completely transformed in the presence of propane. Culture 1A was able to utilize propane or 2-propanol for growth and concurrently transform 100 μg/L of dioxane in mineral salts growth media (MSM) and in amended and non-amended site groundwater. Although culture 1A grew efficiently on 2-propanol, it exhibited lower rates of dioxane transformation than cells grown on propane. |
Genre | Thesis/Dissertation |
Topic | Mycobacterium avium |
Identifier | http://hdl.handle.net/1957/56238 |