Biodegradation of 2,4-Dinitrotoluene and 2,6-Dinitrotoluene in a Pilot-Scale Aerobic Slurry Reactor System
Final rept. 17 Feb-6 Aug 1999
RICE UNIV HOUSTON TX DEPT OF ENVIRONMENTAL SCIENCE AND ENGINEERING
Pagination or Media Count:
A pilot-scale study was conducted to evaluate the use of slurry reactors to treat 2,4-dinitrotoluene 2,4-DNT and 2,6-dinitrotoluene 2,6-DNT contaminated soils from two former Army ammunition plants, the Volunteer Army Ammunition Plant VAAP, Chattanooga, TN and the Badger Army Ammunition Plant BAAP, Baraboo, WI. Two identical 70-L Eimco bioreactors were augmented with aerobic DNT-mineralizing cultures and operated in series for a period of 3 months. The first reactor was fed soils wash after the removal of large particulates using soil washing. The effluent from the first reactor was fed to the second reactor after each feeding cycle. Stable performance and complete degradation of 2,4-DNT within 2 days was demonstrated at a loading rate of up to 20 17,000 microM for VAAP soil, and 40 11,230 microM for BAAP soil. The degradation of 2,6-DNT was minor in the first reactor, but was achieved in the second reactor in both cases. Studies indicate that the presence of high 2,4-DNT concentrations prevented sustained 2,6-DNT degradation. This effect was mitigated by the sequential mode of reactor operation. Results also demonstrated stoichiometric release of nitrite and NaOH consumption from the degradation of dinitrotoluene, implying the applications of these inexpensive measures for routine process control.
- Soil Mechanics
- Environmental Health and Safety