1. Environmental Decay Pathways of the Chemicals of Concern (COCs)

2. Soil Concentrations of Contaminants Contaminant Average Concentration of Detections (  g/kg) No. Detects/No. Total Samples Maximum Concentration (  g/kg) Clean-up Goal (  g/kg) RDX4,00037/12340,000120 HMX1,00030/1238,000250 TNT1701/123170250 2,4-DNT791/879700 2A-DNT20712/1235501,240 4A-DNT1804/123260330 Nitroglyce rin (NG) 3,2001/1233,2002,500

3. Characteristics of COCs  RDX-Royal Demolition Explosive (1,3,5-trinitro-1,3,5-triazacyclohexane) –Military explosive –Toxic to humans & mammals-carcinogen  HMX-High Melting Explosive (1,3,5,7-tetranitro-1,3,5,7-tetrazacyclooctane) –Impurity resulting from RDX production –Associated systemic poisoning (marrow & liver)

4. Fate and Transport:  Biological Decay –Aerobic/Anaerobic  Abiotic Decay –UV  Adsorption –Reversible/Irreversible  Transport –How do pH/Temperature affect solubility

5. Degradation of RDX  Mineralized by White Rot Fungus –Uses RDX as main source of nitrogen –Produces CO 2 and N 2 0  Subcritical Water –RDX starts degrading with 100 o C H 2 0 –>99.9% destruction with 275 o C H 2 0  Anaerobic Co-metabolism –Converted to Acetate

6. Degradation of HMX  UV Radiation Oxidizes HMX – H 2 O 2 as catalyst  Sunlight breaks down HMX in H 2 0  Subcritical Water –HMX starts degrading with 125 o C H 2 0 –>98% destruction with 275 o C H 2 0  Anaerobic Degradation via Reduction –Converted to methanol and chloroform

7. Transport  RDX solubility- 60mg/L –Low affinity for soil particles –However, sorption is nearly irreversible  HMX- nearly insoluble in H 2 O –Likely to move into groundwater

8. Nitroglycerin

9.  Metabolization –P. chrysosporium  Produces di and mono nitrates –G. candidum  Produce glycerol –Transgenic Plants  Metabolize more slowly than microbes