Sorption-Desorption and Transport of TNT and RDX in Soils
Abstract
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 Ca(NO3)2 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.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1994
- Accession Number
- ADA285570
Entities
People
- H. M. Selim
- Iskandar K. Iskandar
Organizations
- Cold Regions Research and Engineering Laboratory