Biodegradation of 2,4-Dinitrotoluene in the Waste Streams of a Munitions Plant

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dc.contributor.authorChristopher, Heidi Jandellen
dc.contributor.committeechairBoardman, Gregory D.en
dc.contributor.committeememberFreedman, David L.en
dc.contributor.committeememberLove, Nancy G.en
dc.contributor.committeememberNovak, John T.en
dc.contributor.departmentEnvironmental Engineeringen
dc.date.accessioned2014-03-14T20:31:15Zen
dc.date.adate2000-11-02en
dc.date.available2014-03-14T20:31:15Zen
dc.date.issued1998-09-15en
dc.date.rdate2000-11-02en
dc.date.sdate1999-02-01en
dc.description.abstractWastewater from the manufacture of propellants typically contains 2,4-dinitrotoluene (DNT), a suspected animal carcinogen. Previous studies have indicated that DNT is aerobically biodegradable. However, inconsistent removal of DNT during aerobic treatment has been observed at a munitions wastewater treatment plant, necessitating the use of activated carbon pre-treatment. The objective of this study was to evaluate the effect of nutrient and cosubstrate amendments on the rate and extent of DNT removal. Addition of ethanol (100-500 mg/l) and phosphate (0.8-3.3 mg/l) significantly accelerated the rate of aerobic DNT (0.3-5.6 mg/l) biodegradation. Addition of phosphate alone also increased the rate of DNT degradation, but to a lesser degree. The presence of ethyl ether, another substrate commonly found in munitions plant wastewater, had comparatively little effect on the rate of DNT removal. Interruptions in the DNT manufacturing process can result in DNT being absent from the munitions plant wastewater for extended periods. The effect of such interruptions was evaluated in semi-continuously operated reactors, fed daily with phosphate-amended wastewater, at a hydraulic residence time of 3 days. DNT removal resumed without a lag even after it was absent from the feed for periods up to 15 days. During aerobic biodegradation of DNT, reduction to 4-amino-2-nitrotoluene and 2-amino-4-nitrotoluene was consistently observed, with reduction at the para position predominating. The highest level of aminonitrotoluene formation was 23% of the total DNT degraded. Aminonitrotoluene isomers were consumed shortly after they formed in the semi-continuously operated reactors, confirming the potential for degradation of these metabolites. Although the aminonitrotoluene isomers are not currently regulated, their presence in treated munitions wastewater is a concern due to possible toxicity.en
dc.description.degreeMaster of Scienceen
dc.identifier.otheretd-020199-165526en
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-020199-165526/en
dc.identifier.urihttp://hdl.handle.net/10919/31106en
dc.publisherVirginia Techen
dc.relation.haspartfig5.pdfen
dc.relation.haspartetd.pdfen
dc.relation.haspartfigs1234.pdfen
dc.relation.hasparttables.pdfen
dc.rightsIn Copyrighten
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/en
dc.subject2-amino-4-nitrotolueneen
dc.subjectPhosphorusen
dc.subjectaerobic biodegradationen
dc.subjectdinitrotolueneen
dc.subject4-amino-2-nitrotolueneen
dc.subjectmunitions wastewateren
dc.titleBiodegradation of 2,4-Dinitrotoluene in the Waste Streams of a Munitions Planten
dc.typeThesisen
thesis.degree.disciplineEnvironmental Planningen
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen
thesis.degree.levelmastersen
thesis.degree.nameMaster of Scienceen

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