TY - JOUR
T1 - Covalent binding with model quinone compounds unveils the environmental fate of the insensitive munitions reduced product 2,4-diaminoanisole (DAAN) under anoxic conditions
AU - Menezes, Osmar
AU - Kadoya, Warren M.
AU - Gavazza, Savia
AU - Sierra-Alvarez, Reyes
AU - Mash, Eugene A.
AU - Abrell, Leif
AU - Field, Jim A.
N1 - Funding Information:
This work was funded by the National Science Foundation , USA [grant number NSF CBET-1510698 ] and the Strategic Environmental Research and Development Program , USA [grant number ER19-1075 ]. O.M. acknowledges the scholarships from the Science and Technology Foundation of the State of Pernambuco , Brazil [grant number IBPG-0958-3.01/16 ] and Coordination for the Improvement of Higher Education Personnel , Brazil [grant number PN 88881.189549/2018-01 ]. S.G. acknowledges the CAPES-PrInt project, Brazil [grant number 88887.311967/2018-00 ]. The authors acknowledge the experimental support from Stanley Wong and Anton Gomeniuc.
Publisher Copyright:
© 2021
Copyright:
Copyright 2021 Elsevier B.V., All rights reserved.
PY - 2021/7/5
Y1 - 2021/7/5
N2 - 2,4-Dinitroanisole (DNAN) is an insensitive munitions compound expected to replace 2,4,6-trinitrotoluene (TNT). The product of DNAN's reduction in the environment is 2,4-diaminoanisole (DAAN), a toxic and carcinogenic aromatic amine. DAAN is known to become irreversibly incorporated into soil natural organic matter (NOM) after DNAN's reduction. Herein, we investigate the reactions between DAAN and NOM under anoxic conditions, using 1,4-benzoquinone (BQ) and methoxybenzoquinone (MBQ) as model humic moieties of NOM. A new method stopped the fast reactions between DAAN and quinones, capturing the fleeting intermediates. We observed that DAAN incorporation into NOM (represented by BQ and MBQ models) is quinone-dependent and occurs via Michael addition, imine (Schiff-base) formation, and azo bond formation. After dimers are formed, incorporation reactions continue, resulting in trimers and tetramers. After 20 days, 56.4% of dissolved organic carbon from a mixture of DAAN (1 mM) and MBQ (3 mM) had precipitated, indicating an extensive polymerization, with DAAN becoming incorporated into high-molecular-weight humic-like compounds. The present work suggests a new approach for DNAN environmental remediation, in which DNAN anaerobic transformation can be coupled to the formation of non-extractable bound DAAN residues in soil organic matter. This process does not require aerobic conditions nor a specific catalyst.
AB - 2,4-Dinitroanisole (DNAN) is an insensitive munitions compound expected to replace 2,4,6-trinitrotoluene (TNT). The product of DNAN's reduction in the environment is 2,4-diaminoanisole (DAAN), a toxic and carcinogenic aromatic amine. DAAN is known to become irreversibly incorporated into soil natural organic matter (NOM) after DNAN's reduction. Herein, we investigate the reactions between DAAN and NOM under anoxic conditions, using 1,4-benzoquinone (BQ) and methoxybenzoquinone (MBQ) as model humic moieties of NOM. A new method stopped the fast reactions between DAAN and quinones, capturing the fleeting intermediates. We observed that DAAN incorporation into NOM (represented by BQ and MBQ models) is quinone-dependent and occurs via Michael addition, imine (Schiff-base) formation, and azo bond formation. After dimers are formed, incorporation reactions continue, resulting in trimers and tetramers. After 20 days, 56.4% of dissolved organic carbon from a mixture of DAAN (1 mM) and MBQ (3 mM) had precipitated, indicating an extensive polymerization, with DAAN becoming incorporated into high-molecular-weight humic-like compounds. The present work suggests a new approach for DNAN environmental remediation, in which DNAN anaerobic transformation can be coupled to the formation of non-extractable bound DAAN residues in soil organic matter. This process does not require aerobic conditions nor a specific catalyst.
KW - 2,4-Dinitroanisole (DNAN)
KW - Aromatic amine
KW - Humic material
KW - Insensitive high explosive
KW - Quinone
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U2 - 10.1016/j.jhazmat.2021.125459
DO - 10.1016/j.jhazmat.2021.125459
M3 - Article
AN - SCOPUS:85101066360
VL - 413
JO - Journal of Hazardous Materials
JF - Journal of Hazardous Materials
SN - 0304-3894
M1 - 125459
ER -