by Nancy Trautmann
TNT is not the kind of substance that most people think of composting, but it can be done! At several U.S. Army depots, the water used in processing explosives was disposed of through evaporation from unlined lagoons. This has resulted in sediments and soils that are contaminated with TNT (2,4,6- trinitrotoluene) and its derivatives RDX (hexahydro-1,3,5-trinitro-1,3,5-triazine) and HMX (octahydro-1,3,5,7-tetranitro-1,3,5,7-tetraazocine).
One way of cleaning up these sediments is by incinerating them. A less expensive and more environmentally friendly method is "bioremediation," or use of natural biological and chemical processes to degrade the contaminants. That's where composting comes in. TNT, RDX, and HMX are complex organic compounds made up of carbon, nitrogen, oxygen, and hydrogen. When combined with more conventional compost ingredients such as manures, sawdust, straw, and fruit and vegetable processing wastes, the explosives become broken down into harmless chemical forms.
The Army is using composting to clean up munitions processing wastes at several of its ammunition plants, including ones in Louisiana, Wisconsin, and Oregon. At the Oregon site, composting is projected to save 2.6 million dollars compared with incinerating the contaminated soils. In addition to saving money, composting will also avoid the need for burning fossil fuels and will produce an end product usable for backfilling, landscaping, or erosion control.
For more information, take a look at these articles:
Williams, R.T. and C.A. Myler. 1990. Bioremediation using composting. Biocycle 31(11): 78-83.
Ziegenfuss, P.S. and R.T. Williams. 1991. Hazardous materials composting. Journal of Hazardous Materials 28: 91-99.
Biocycle staff. 1996. Clean Up at Munitions Sites. Biocycle 37(3): 49-50.
More Tales of Weird and Unusual Composting
Cornell Waste Management Institute ©1996
Department of Crop and Soil Sciences
Bradfield Hall, Cornell University
Ithaca, NY 14853