Degradation products of 2,4,6-Trinitrotoluene by a microbial consortia
- Clark Atlanta Univ., Atlanta, GA (United States); and others
Remediation of contaminated soils can be accomplished using microbial species. Of particular interest is the remediation of explosive contaminated soils. A microbial consortia has been developed which removes TNT by an unexplained mechanism. Our goal is to understand the degradation of TNT by this microbial mat. Constructed mats have been generated in our laboratory by enriching water with ensiled grass and adding specific microbial components for organic degradation. Microbial mats are natural mixed microbial communities dominated by cyanobacterias (blue-green algae). In this research, degradation products of TNT have been identified using GC/MS. Ninety-seven percent of TNT (1000 mg/L), was removed in < 1 day by floating mats placed over TNT-contaminated water in quiescent ponds. Metabolites of TNT, 2, 4-Dinitro-6 amminotoluene and 2-Nitro-4,6 diaminotoluene has been observed after 1 day of mat treatment. A mechanism is postulated for this degradation showing that two of the nitro groups of the TNT molecule are being reduced to amino groups systematically. Anoxic zones in the mat, containing sulfur-reducing bacteria, may account for the reduction of TNT. GC/MS shows significant decreases in metabolite concentrations in 4-7 days, indicating continued degradation of TNT. It has been found by toxicity assays that these metabolites appeared to be nontoxic and nonmutagenic. These results suggest that floating microbial mats may be useful for the decontamination of sites in the environment contaminated with TNT. Further studies using {sup 13}C TNT will focus on the fate of the carbon, to determine the intermediates products prior to transformations into hydrocarbons or utilization by the bacteria consortia.
- Research Organization:
- National Association of Environmental Professionals, Washington, DC (United States)
- OSTI ID:
- 126014
- Report Number(s):
- CONF-9506115-; TRN: 95:006735-0109
- Resource Relation:
- Conference: 20. National Association of Environmental Professionals annual conference and exposition: environmental challenges - the next twenty years, Washington, DC (United States), 10-13 Jun 1995; Other Information: PBD: 1995; Related Information: Is Part Of Environmental challenges: The next 20 years. Proceedings; PB: 932 p.
- Country of Publication:
- United States
- Language:
- English
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