Mineralization of 2,4- and 2,6-dinitrotoluene in soil slurries
- Air Force Research Lab., Tyndall AFB, FL (United States)
- Fraunhofer Institut fuer Grenzflaechen- und Bioverfahrenstechnik, Stuttgart (Germany)
DNT-degrading bacteria can completely degrade mixtures of DNT in liquid cultures without the production of aminonitrotoluenes. The authors determined whether specific DNT-degrading isolates could also degrade DNT from contaminated soil in the presence of indigenous microbial communities. When 2,4-DNT- and 2,6-DNT-degrading strains were added to a mixture of 2,4-DNT and 2,6-DNT in a soil slurry, disappearance of DNT was accompanied by {sup 14}CO{sub 2} release and stoichiometric appearance of nitrite. When soil historically contaminated with mixed DNT isomers was used in slurries, the combination of DNT-degrading strains removed all of the DNT from the aqueous phase and over 99% of the initial DNT. Traces of extractable DNT remained associated with the soil; however, the toxicity of the treated soil was low. After an extended acclimation period, the 2,4-DNT, and, much later, the 2,6-DNT, was degraded in the uninoculated control. The results show that aged DNT contamination can be removed effectively from soil. The addition of specific DNT-mineralizing bacteria dramatically enhances the mineralization of DNT in soil slurries. Native bacteria do not convert DNT to aminonitrotoluenes during the short incubation times required for mineralization of DNT.
- OSTI ID:
- 345136
- Journal Information:
- Environmental Science and Technology, Journal Name: Environmental Science and Technology Journal Issue: 7 Vol. 33; ISSN 0013-936X; ISSN ESTHAG
- Country of Publication:
- United States
- Language:
- English
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