J.C. Pennington Kay R. Kennedy Larry G. Cox C.A. Hayes B.E. Porter Kevin A. Thorn 2008 <p><span>Large-scale aerobic windrow composting has been used to bioremediate washout lagoon soils contaminated with the explosives TNT (2,4,6-trinitrotoluene) and RDX (hexahydro-1,3,5-trinitro-1,3,5-triazine) at several sites within the United States. We previously used&nbsp;</span>¹⁵<span>N NMR to investigate the reduction and binding of T</span>¹⁵<span>NT in aerobic bench -scale reactors simulating the conditions of windrow composting. These studies have been extended to 2,4-dinitrotoluene (2,4DNT) and 2,6-dinitrotoluene (2,6DNT), which, as impurities in TNT, are usually present wherever soils have been contaminated with TNT. Liquid-state&nbsp;</span>¹⁵<span>N NMR analyses of laboratory reactions between 4-methyl-3-nitroaniline-</span>¹⁵<i>N</i><span>, the major monoamine reduction product of 2,4DNT, and the Elliot soil humic acid, both in the presence and absence of horseradish peroxidase, indicated that the amine underwent covalent binding with quinone and other carbonyl groups in the soil humic acid to form both heterocyclic and non-heterocyclic condensation products. Liquid-state&nbsp;</span>¹⁵<span>N NMR analyses of the methanol extracts of 20 day aerobic bench-scale composts of 2,4-di-</span>¹⁵<i>N</i><span>-nitrotoluene and 2,6-di-</span>¹⁵<i>N</i><span>-nitrotoluene revealed the presence of nitrite and monoamine, but not diamine, reduction products, indicating the occurrence of both dioxygenase enzyme and reductive degradation pathways. Solid-state CP/MAS&nbsp;</span>¹⁵<span>N NMR analyses of the whole composts, however, suggested that reduction to monoamines followed by covalent binding of the amines to organic matter was the predominant pathway.</span></p> application/pdf 10.1021/es0720659 en ACS N-15 NMR study of the immobilization of 2,4- and 2,6-dinitrotoluene in aerobic compost article