Immobilization of 2,4- and 2,6-Dinitrotoluenes in Soils and Compost
Abstract
Covalent bonding of amino transformation products of trinitrotoluene (TNT) to functional groups on humic acid results in immobilized products that are not hydrolyzable, microbially degradable, or leachable. However, the extent to which these reactions occur with dinitrotoluenes (DNTs) was unknown. Since DNTs are considered toxic and many explosives-contaminated sites exhibit DNTs as well as TNT, the fate of DNTs is relevant to remediation and risk assessment. The broad objectives of this study were to demonstrate the potential for immobilization reactions of DNTs in soils and to determine the mechanisms of bonding of amino transformation products of DNTs to humic acid and humin in soils and compost treatment systems. DNTs were partitioned to soils having different physical characteristics to define adsorption and desorption kinetics and partitioning coefficients. Radiolabeled 14C dnts were used to amend soils prior to composting so that mass balance of the organic fractions of the compost could be determined and any volatile products indicated. Finally, 15N-labeled DNTs were used to amend soils prior to composting so that organic fractions could be analyzed by nuclear magnetic resonance (NMR) spectrometry. The fulvic acid, humic acid, humin, and lignocellulose fractions isolated from the 2,4-DNT compost were also analyzed by 15N NMR. Aniline, nitrobenzene, and ammonium nitrate, all labeled with 15N, were also subjected to the aerobic composting. Steady-state partitioning was not achieved in high organic carbon soils, an indication that the compounds continue to be removed from the solution phase, perhaps due to transformation and subsequent partitioning/reaction of the transformation products with the organic carbon fractions of the soil. Mass balance of 14C radioactivity during composting indicated that no volatile organic compounds (VOCs) and barely detectable levels of CO2, were generated. Most of the radioactivity was associated with the cellulose fraction7
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 2003
- Accession Number
- ADA410821
Entities
People
- Beth E. Porter
- Charolett A. Hayes
- Judith C. Pennington
- K. R. Kennedy
- Kevin A. Thorn
Organizations
- Engineer Research and Development Center