Field Demonstration of Acetone Pretreatment and Composting of Particulate-TNT-Contaminated Soil

• Published in: Bioremediation journal 2002-06, Vol.6 (2), p.191-204
• Main Authors: Radtke, Corey W., Smith, Dan M., Owen, G. Scott, Roberto, Francisco F.
• Format: Article
• Language: English
• Subjects: acetone; Biodegradation of pollutants; Biological and medical sciences; bioremediation; Biotechnology; compost; Environment and pollution; fragment; Fundamental and applied biological sciences. Psychology; Industrial applications and implications. Economical aspects; particulate; solvent; TNT
• ISSN: 1088-9868; 1547-6529
• DOI: 10.1080/10588330208951213

Solid fragments of explosives in soil are common in explosives testing and training areas. In this study we initially sieved the upper 6 in of contaminated soil through a 3-mm mesh, and found 2,4,6-trinitrotoluene (TNT) fragments. These contributed to an estimated concentration of 1.7 kg per cubic yard soil, or for 2000 ppm TNT in the soil. Most of the fragments ranged 4 mm to 10 mm diameter in size, but explosives particles weighing up to 56 g (about 4 cm diameter) were frequently observed. An acetone pretreatment/composting system was then demonstrated at field scale. The amount of acetone required for a TNT-dissolving slurry process was controlled by the viscosity of the soil/acetone mix rather than the TNT dissolution rate. The amount needed was estimated at about 55 gallons acetone per cubic yard soil. Smaller, 5- to 10-mm-diameter fragments went into solution in less than 15 min at a mixer speed of 36 rpm, with a minimum of 2 g TNT going into solution per 30 min for the larger chunks. The slurries were then mixed with compost starting materials and composted in a vented 1 yd 3 container. After 34 days incubation time TNT was below the site-specific regulatory threshold of 44 ppm. TNT metabolites and acetone were also below their regulatory thresholds established for the site.