Microbial transformations of TNT and DNT in contaminated soils and aquifer materials at Weldon Spring, Missouri

Conference · Sat Dec 31 04:00:00 EST 1994

OSTI ID:37573

Bradley, P M; Chapelle, F H; Landmeyer, J E ^[1]

---

1. Geological Survey-WRD, Columbia, SC (United States)

Microorganisms, indigenous to surface soils and aquifer materials collected at a munition-contaminated site (Weldon Spring, Missouri), transformed 2,4,6-trinitrotoluene (TNT) and 2,4-dinitrotoluene (DNT) to aminonitro-intermediates within 20 to 70 days. Carbon mineralization studies using both unlabeled (TNT and DNT) and radiolabeled ({sup 14}C-TNT) substrates indicated that a significant fraction of these source compounds was degraded to CO{sub 2}. These results indicate that in situ bioremediation may be a viable alternative for cleanup of nitroaromatics-contaminated sites. The effects of TNT and SNT concentrations on microbial activity (net CO{sub 2} production) at the site were also evaluated. TNT and DNT concentrations as low as 1 and 0.1 {mu}M, respectively, significantly inhibited activity in microcosms containing surface soil from an uncontaminated location. TNT and DNT concentrations in the range of 1 to 100 {mu}M stimulated CO{sub 2} production by contaminated surface soil and aquifer material, but exposure to a concentration of 1,000 {mu}M completely inhibited microbial activity. The apparent toxicity of high concentrations of TNT and DNT may explain the persistence of TNT at the munitions site in spite of the presence of microbial communities capable of degrading nitroaromatic compounds.

• OSTI ID: 37573
• Report Number(s): CONF-9403190--; ISBN 1-882132-28-9
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
BIODEGRADATION
CARBON 14 COMPOUNDS
DECONTAMINATION
GROUND WATER
IN-SITU PROCESSING
LAND RECLAMATION
MISSOURI
NITRO COMPOUNDS
REMEDIAL ACTION
SOILS
TRACER TECHNIQUES
WATER RECLAMATION