Bioremediation of highly energetic compounds: a search for remediation technologies

When TNT (N-source) was treated with anaerobic sludge ii biotransformed int o triaminotoluene (TAT) in high yield (80%). Results of experiments using C -13-labeling indicate that denitrated or deaminated products such as p-cres ol and toluene were not formed, Whereas C-14-labeling showed negligible min eralization (<0.1% (CO2)-C-14) despite the complete disappearance of TNT. O n the other hand, when TNT (175 <mu>M) was treated with the fungus Phaneroc haete chrysosporium it disappeared completely in less than two weeks, but m ineralization (liberated (CO2)-C-14) did not exceed 1 %. Several intermedia tes, marked with the initial formation of the two monohydroxylamino-dinitro toluene (HADNT) followed by their transformation to monoamino-dinitrotoluen es (ADNT), diamines (DANT), acetylated TNT products, and azo and hydrate de rivatives were detected. In contrast, high concentrations (ca 20,000 ppm) o f RDX and HMX were effectively degraded (ca 70%) in soil slurries using mun icipal anaerobic sludge. RDX and HMX disappearance was accompanied by the e limination of toxicity associated with RDX and HMX as determined by the Mic rotox test.