Sorption-Desorption and Transport of TNT and RDX in Soils
COLD REGIONS RESEARCH AND ENGINEERING LAB HANOVER NH
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Batch and miscible-displacement experiments were conducted to determine the extent of adsorption-desorption and transport of 2,4,6- trinitrotoluene TNT and 2,3,5-trinitro-1,3,5-triazine RDX in soils. A reference bentonite clay, contaminated Kolin soil from the Louisiana Army Ammunition Plant, and two uncontaminated soils were used. The TNT isotherm for bentonite clay was described equally well using linear, Freundlich, Langmuir and modified Langmuir models. TNT adsorption and desorption isotherms showed a lack of hysteric behavior, with TNT retention as a fully reversible mechanism. Transport results from bentonite clay columns indicated that TNT was a highly mobile contaminant and fully conservative in the presence of methanol as the background solution. Mobility of TNT was strongly retarded, with some 50 of the applied TNT retained in the bentonite clay column when 0.005-M CaNO32 was the background solution. Transport results in Norwood fine silty soil columns revealed that TNT was strongly retained in this low-organic-matter and low-clay- content soil. The use of a transport model with either Freundlich or linear retention and an irreversible mechanism predicted the TNT transport data well.
- Inorganic Chemistry
- Organic Chemistry
- Soil Mechanics
- Ammunition and Explosives