Environmental Science Processes & Impacts,
Journal Year:
2024,
Volume and Issue:
26(12), P. 2297 - 2308
Published: Jan. 1, 2024
Compost-derived
dissolved
organic
matter
(DOMC)
is
a
heterogeneous
assemblage
of
different
redox-active
molecules.
We
hypothesize
that
DOMC
can
interact
with
Cr(VI)
and
reduce
it
to
Cr(III),
thereby
influencing
the
dynamics
in
soil
aquatic
environments.
Here,
DOMC,
along
humic
substances
isolated
from
red
black
soil,
were
fractionated
into
acid
fractions
(i.e.,
HAC,
HAB,
HAR)
fulvic
FAC,
FAB,
FAR),
respectively.
The
reduction
interaction
between
six
investigated.
results
showed
total
capacity
(TRC)
was
26.77-49.34
μM
per
mg
OM.
TRC
HA
35.54-49.34
OM,
which
exceeded
FA
(26.77-31.29
OM).
had
HA/FA
ratio
0.64,
higher
than
substance
(0.59)
(0.20).
sum
35.57
larger
(32.87
OM)
(33.01
positively
correlated
TOC,
TN,
phenol
C,
alkyl
aromatic
C
contents
negatively
E2/E3,
O-alkyl
carboxyl
contents.
at
pH
6
negligible,
whereas
32-67%
reduced
2.
capacities
(RC2,
RC2,
RC6)
2-6
(R2
>
0.71)
C.
Spectral
analysis
there
no
obvious
complexation
6,
thus
but
solution
could
affect
accessibility
molecules
influence
reduction.
Peatlands
store
one-third
of
the
world's
soil
organic
carbon.
Globally
increased
fires
altered
peat
matter
chemistry,
yet
redox
property
and
molecular
dynamics
peat-dissolved
(PDOM)
during
remain
poorly
characterized,
limiting
our
understanding
postfire
biogeochemical
processes.
Clarifying
these
dynamic
changes
is
essential
for
effective
peatland
fire
management.
This
study
demonstrates
temperature-dependent
in
electron
exchange
capacity
(EEC)
PDOM
by
simulating
burning,
significantly
affecting
microbial
iron
reduction.
At
low
temperatures
(200-250
°C),
EEC
remains
constant
releasing
more
phenolic
moieties
to
enhance
electron-donating
(EDC).
Higher
(500
°C)
diminish
90%
consuming
phenolic-quinone
moieties.
Pyrolytic
(pyPDOM)
contributes
40%
soil,
with
this
contribution
declining
at
higher
temperatures.
Phenolic-quinone
primary
redox-active
pyPDOM.
Fourier
transform
ion
cyclotron
resonance
mass
spectrometry
analysis
shows
that
EDC
depends
on
types
than
abundance,
monophenol-like
molecules
(
Environmental Science & Technology,
Journal Year:
2024,
Volume and Issue:
58(21), P. 9040 - 9050
Published: May 14, 2024
Despite
the
widespread
use
of
photochemical
and
optical
properties
to
characterize
dissolved
organic
matter
(DOM),
a
significant
gap
persists
in
our
understanding
relationship
among
these
properties.
This
study
infers
molecular
basis
for
DOM
using
comprehensive
framework
known
structural
moieties
within
DOM.
Utilizing
Suwannee
River
Fulvic
Acid
(SRFA)
as
model
DOM,
carboxylated
aromatics,
phenols,
quinones
were
identified
dominant
contributors
absorbance
spectra,
quinones,
aldehydes,
ketones
major
radiative
energy
pathways.
It
was
estimated
that
chromophores
constitute
∼63%
w/w
carbon
SRFA
∼47%
overall
SRFA.
Notably,
estimations
indicate
pool
fluorescent
compounds
photosensitizing
are
likely
distinct
from
each
other
at
wavelengths
below
400
nm.
perspective
offers
practical
tool
aid
identification
probable
chemical
groups
when
interpreting
data
challenges
current
"black
box"
thinking.
Instead,
can
be
closely
by
assuming
is
composed
mixture
individual
compounds.
The
priming
effect
(PE)
is
recognized
as
an
important
mechanism
influencing
organic
matter
transformation
in
aquatic
systems.
land-ocean
continuum
(LOAC)
has
received
large
quantities
of
dissolved
(DOM)
from
various
sources,
which
ideal
interface
for
PE
research.
Here,
we
investigated
the
process
by
utilizing
such
a
coastal
environment
to
explore
turnover
DOM
LOAC
system.
Suwannee
River
natural
was
selected
background,
and
external
environmental
samples
were
introduced
track
changes
carbon.
together
with
variations
compositions,
structures
characterized.
Generally,
river
estuary
environments
exhibited
positive
PE,
while
offshore
zone
showed
negative
effect.
Additionally,
nutrients,
salinity,
composition
all
contributed
PE.
After
incubation,
feature
carbon
sources
transferred
terrestrial
autochthonous.
carbonyl
alcohol
functional
groups
significantly
decomposed,
methyl
methylene
increased
heteroatoms
further
accelerated
process.
data
also
shows
that
special
parameters
molecular
markers
can
be
utilized
response
This
research
indicates
change
flux
imbalance
its
budget
systems
could
partially
explained
perspective
