Frozen Soil Barriers for Explosives Containment
Abstract
Explosives are a major contaminant of Department of Defense sites. Many uncertainties exist with respect to the mobility and stability of explosives in soils. The specific objectives of this work are to test the efficacy of frozen barriers to restrain movement of RDX, TNT, and picric acid through soils; test the concept of leaching contaminated soils above a frozen barrier as a method for soil cleanup; and compare the mobility and stability of explosives in an aged, field-contaminated soil versus a freshly contaminated soil. Two methods of adding explosives were examined. In Treatment 1, explosives were added in aqueous solution to a clean soil. In Treatment 2, explosives from an aged, field-contaminated soil were used. In Treatment 1, where the aqueous phase explosives were added above a stable frozen barrier, there was no significant movement of explosives into the frozen barrier. There was significant movement of explosives (picric acid >> RDX TNT) into the frozen barrier in Treatment 2. However, this is believed to have occurred when the contaminated soil was added on top of the frozen soil, which caused a temporary thawing of the frozen barrier surface. A stable frozen barrier is effective in restraining the movement of RDX, TNT, and picric acid in soils. Water extractions of the field-contaminated soil recovered 44-56% of the picric acid, 11% of the TNT, and 4-5% of the RDX; only for the highly soluble picric acid would water extractions be a useful technique for cleanup of explosives in soils. About 88% of the TNT added in aqueous solution to Treatment 1 was missing at the end of the three-month experiment, demonstrating that there was a rapid transformation of TNT into unknown products or unextractable forms in soils.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 2000
- Accession Number
- ADA382716
Entities
People
- Deborah K. Pelton
- Giles M. Marion
Organizations
- Cold Regions Research and Engineering Laboratory