10.1021/acs.est.7b03699.s001
Christopher
I. Olivares
Christopher
I.
Olivares
Camila L. Madeira
Camila L.
Madeira
Reyes Sierra-Alvarez
Reyes
Sierra-Alvarez
Warren Kadoya
Warren
Kadoya
Leif Abrell
Leif
Abrell
Jon Chorover
Jon
Chorover
Jim A. Field
Jim A.
Field
Environmental
Fate of <sup>14</sup>C Radiolabeled
2,4-Dinitroanisole in Soil Microcosms
American Chemical Society
2017
nonextractable soil humus fraction
electron donor amendments
Irreversible humin incorporation
extracellular oxidoreductase enzyme horseradish peroxidase
humin fraction
14 C-DNAN incorporation
HRP
remediation strategy
OC
DNAN biotransformation products
14 C-DNAN
2017-10-26 00:00:00
Journal contribution
https://acs.figshare.com/articles/journal_contribution/Environmental_Fate_of_sup_14_sup_C_Radiolabeled_2_4-Dinitroanisole_in_Soil_Microcosms/5571712
2,4-Dinitrosanisole
(DNAN) is an insensitive munitions component
replacing conventional explosives. While DNAN is known to biotransform
in soils to aromatic amines and azo-dimers, it is seldom mineralized
by indigenous soil bacteria. Incorporation of DNAN biotransformation
products into soil as humus-bound material could serve as a plausible
remediation strategy. The present work studied biotransformation of
DNAN in soil and sludge microcosms supplemented with uniformly ring-labeled <sup>14</sup>C-DNAN to quantify the distribution of label in soil, aqueous,
and gaseous phases. Electron donor amendments, different redox conditions
(anaerobic, aerobic, sequential anaerobic–aerobic), and the
extracellular oxidoreductase enzyme horseradish peroxidase (HRP) were
evaluated to maximize incorporation of DNAN biotransformation products
into the nonextractable soil humus fraction, humin. Irreversible humin
incorporation of <sup>14</sup>C-DNAN occurred at higher rates in anaerobic
conditions, with a moderate increase when pyruvate was added. Additionally,
a single dose of HRP resulted in an instantaneous increased incorporation
of <sup>14</sup>C-DNAN into the humin fraction. <sup>14</sup>C-DNAN
incorporation to the humin fraction was strongly correlated (<i>R</i><sup>2</sup> = 0.93) by the soil organic carbon (OC) amount
present (either intrinsic or amended). Globally, our results suggest
that DNAN biotransformation products can be irreversibly bound to
humin in soils as a remediation strategy, which can be enhanced by
adding soil OC.