Oxidation of Aminodinitrotoluenes with Ozone:  Products and Pathways

Spanggord, Ronald J.; Yao, Chenhui; Mill, Theodore

doi:10.1021/es990190h

Cited by 19 publications

(14 citation statements)

References 13 publications

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“…The 4-amino-2-hydroxylamino-6-nitrotoluene is subsequently transformed to a compound tentatively identified as 2-amino-5-hydroxy-4-hydroxylamino-6-nitrotoluene (J. Hughes, personal communication). Ozone-mediated oxidation of ADNTs yields nitrate, nitrite, and small organic molecules, including pyruvic and glyoxylic acids (33), which could be assimilated in other biodegradative pathways.…”

Section: Transformation Of Adntmentioning

confidence: 99%

Oxidative Transformation of Aminodinitrotoluene Isomers by Multicomponent Dioxygenases

Johnson¹,

Smets

Spain³

2001

Appl Environ Microbiol

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The electron-withdrawing nitro substituents of 2,4,6-trinitrotoluene (TNT) make the aromatic ring highly resistant to oxidative transformation. The typical biological transformation of TNT involves reduction of one or more of the nitro groups of the ring to produce the corresponding amine. Reduction of a single nitro substituent of TNT to an amino substituent increases the electron density of the aromatic nucleus considerably. The comparatively electron-dense nuclei of the aminodinitrotoluene (ADNT) isomers would be expected to be more susceptible to oxygenase attack than TNT. The hypothesis was tested by evaluating three nitroarene dioxygenases for the ability to hydroxylate the ADNT isomers. The predominant reaction was dioxygenation of the ring to yield nitrite and the corresponding aminomethylnitrocatechol. A secondary reaction was benzylic monooxygenation to form aminodinitrobenzyl alcohol. The substrate preferences and catalytic specificities of the three enzymes differed considerably. The discovery that the ADNT isomers are substrates for the nitroarene dioxygenases reveals the potential for extensive bacterial transformation of TNT under aerobic conditions.

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Section: Transformation Of Adntmentioning

confidence: 99%

Oxidative Transformation of Aminodinitrotoluene Isomers by Multicomponent Dioxygenases

Johnson¹,

Smets

Spain³

2001

Appl Environ Microbiol

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“…Currently, incineration is the most effective remediation alternative, but it is expensive for use with polluted soils because of the costs of soil excavation, transport, and energy for incineration. For the treatment of TNT in liquid wastes, several technologies have been proposed, e.g., chemical reduction (5,11,12,66,137), thermal decomposition, subcritical water (104), photocatalytic degradation (197), electrohydraulic discharge (250), granular iron (59), and ozonolysis (136,216,222). Several biologically based technologies have also been developed for the remediation of TNT-contaminated soils; of these approaches, the most thoroughly investigated are soil slurry reactors, composting, and land farming.…”

Section: Applications In Tnt Bioremediationmentioning

confidence: 99%

Biological Degradation of 2,4,6-Trinitrotoluene

Esteve‐Núñez

Caballero

Ramos

2001

Microbiol Mol Biol Rev

421

287

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Nitroaromatic compounds are xenobiotics that have found multiple applications in the synthesis of foams, pharmaceuticals, pesticides, and explosives. These compounds are toxic and recalcitrant and are degraded relatively slowly in the environment by microorganisms. 2,4,6-Trinitrotoluene (TNT) is the most widely used nitroaromatic compound. Certain strains of Pseudomonas and fungi can use TNT as a nitrogen source through the removal of nitrogen as nitrite from TNT under aerobic conditions and the further reduction of the released nitrite to ammonium, which is incorporated into carbon skeletons. Phanerochaete chrysosporium and other fungi mineralize TNT under ligninolytic conditions by converting it into reduced TNT intermediates, which are excreted to the external milieu, where they are substrates for ligninolytic enzymes. Most if not all aerobic microorganisms reduce TNT to the corresponding amino derivatives via the formation of nitroso and hydroxylamine intermediates. Condensation of the latter compounds yields highly recalcitrant azoxytetranitrotoluenes. Anaerobic microorganisms can also degrade TNT through different pathways. One pathway, found in Desulfovibrio and Clostridium, involves reduction of TNT to triaminotoluene; subsequent steps are still not known. Some Clostridium species may reduce TNT to hydroxylaminodinitrotoluenes, which are then further metabolized. Another pathway has been described in Pseudomonas sp. strain JLR11 and involves nitrite release and further reduction to ammonium, with almost 85% of the N-TNT incorporated as organic N in the cells. It was recently reported that in this strain TNT can serve as a final electron acceptor in respiratory chains and that the reduction of TNT is coupled to ATP synthesis. In this review we also discuss a number of biotechnological applications of bacteria and fungi, including slurry reactors, composting, and land farming, to remove TNT from polluted soils. These treatments have been designed to achieve mineralization or reduction of TNT and immobilization of its amino derivatives on humic material. These approaches are highly efficient in removing TNT, and increasing amounts of research into the potential usefulness of phytoremediation, rhizophytoremediation, and transgenic plants with bacterial genes for TNT removal are being done

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“…Buehler et al, 1984;Gonzalez et aI., 1997;Ko et aI., 2000;Magi et aI., 1997;Mokrini et al, 1997;Munoz etal., 2000Munoz etal., , 2001Spanggord et al, 2000;Staehlin and Hoigne, 1982;Staehlin et al, 1984;Weavers et al, 1998). The complexity of aqueous phase ozonation is revealed by decomposition rate laws that vary between '/2, 1st and 2nd order in ozone depending on the initiation rate and water purity (Staehlin and Hoigne, 1985).…”

Section: Ozonementioning

confidence: 99%

Evaluation of the Salicylic Acid–Liquid Phase Scrubbing Technique to Monitor Atmospheric Hydroxyl Radicals

Salmon

Schiller

Harris

2004

Journal of Atmospheric Chemistry

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Abstract. A novel method has been examined for monitoring tropospheric hydroxyl radicals (OH), the most important oxidant in tropospheric chemistry. Aqueous phase salicylic acid reacts with atmospheric OH to produce 2,5-dihydroxy benzoic acid (2,5-DHBA) and other products. High Performance Liquid Chromatography (HPLC) is used to separate the post-reaction solution and the products are quantified using fluorescence detection. Unlike other methods, it has been reported to be inexpensive, portable and relatively simple. Although the sensitivity was sufficient to measure typical daytime OH concentrations of 0.04--0.4 ppt., the method was hindered by numerous interferences. Successive identification and elimination of these still resulted in a signal that was much larger than expected. Tests showed that this was not likely to be due to ozone, H0 2 , NOx, H 2 0 2 , aerosols, light or bacteria. Experimental and numerical studies suggest that the interference could be due to methyl peroxy radicals. The effect of many other components in the atmosphere, both individual and combined, must also be tested before the method can be used reliably in the field. The validity of previous reports of ambient hydroxyl measurements using this technique is therefore brought into question.

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Oxidation of Aminodinitrotoluenes with Ozone: Products and Pathways

Cited by 19 publications

References 13 publications

Oxidative Transformation of Aminodinitrotoluene Isomers by Multicomponent Dioxygenases

Oxidative Transformation of Aminodinitrotoluene Isomers by Multicomponent Dioxygenases

Biological Degradation of 2,4,6-Trinitrotoluene

Evaluation of the Salicylic Acid–Liquid Phase Scrubbing Technique to Monitor Atmospheric Hydroxyl Radicals

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