Aerobic Biodegradation of MTBE in Uncontaminated and Gasoline-Contaminated Aquifer Sediments

In this study, the biodegradation potential of MTBE in uncontaminated and previously contaminated aquifer sediments under aerobic conditions was investigated. Laboratory microcosms were constructed using aquifer samples collected from three different areas of a shallow gasoline-contaminated aquifer in eastern Fairfax Co., Va in the Atlantic Coastal Plain province. Uncontaminated aquifer samples were collected upgradient of the plume, and contaminated aquifer samples were collected in the source area and in an area downgradient of the source. Biodegradation of MTBE was observed in microcosms that contained previously contaminated aquifer sediments. More complete degradation was observed in aquifer sediments containing a low level of petroleum contamination than in heavily contaminated aquifer sediments. Biodegradation of MTBE appeared to be limited by a lack of oxygen in heavily contaminated soils. When degradation was discernible it appeared to follow a first order pattern with a rate constant (l) of between 0.037 and 0.066 d-1, following a lag period of 20 to 40 days. In microcosms containing lightly contaminated aquifer material, MTBE was respiked during active metabolism, and degradation occurred with no lag or acclimation period. Results indicated that little or no degradation occurred in the microcosms containing uncontaminated soil. The results of this research suggest that the availability and level of petroleum hydrocarbon compounds influence indigenous microorganisms capable of degrading MTBE.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Environmental Planning

Department dc:contributor.department

Environmental Engineering

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

1999

Author dc:creator

• Zoeckler, Jeff Radcliffe

Chairs dc:contributor.committeechair

• Widdowson, Mark A.
• Novak, John T.

Committee member dc:contributor.committeemember

• Love, Nancy G.

• biodegradation
• MTBE
• petroleum hydrocarbon compounds
• acclimation
• concentration
• indigenous microorganisms
• microcosm

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Dc Identifier Other

etd-072199-094735

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/43865