Humification
of
exogenous
soil
organic
matter
(ESOM)
remodels
the
compositions
and
microbial
communities
soil,
thus
exerting
potential
impacts
on
biogeochemical
transformation
iron
(hydr)oxides
associated
trace
metals.
Here,
we
conducted
a
70-day
incubation
experiment
to
investigate
how
aerobic
straw
humification
influenced
repartitioning
arsenic
(As)
with
ferrihydrite
in
paddy
soil.
Results
showed
that
was
characterized
by
rapid
OM
degradation
(1-14
days)
subsequent
slow
maturation
(14-70
days).
During
stage,
considerable
As
(13.1
mg·L-1)
released
into
aqueous
phase,
which
reimmobilized
solid
phase
stage.
Meanwhile,
low-crystalline
structural
As/Fe
converted
more
stable
species,
subtle
crystalline
transformation.
The
generated
highly
unsaturated
phenolic
compounds
enriched
Enterobacter
Sphingomonas
induced
(∼3.1%)
As(V)
reduction,
leading
release
during
In
carboxylic-rich
alicyclic
molecules
facilitated
reimmobilization.
Throughout
process,
organo-mineral
complexes
formed
between
via
C-O-Fe
bond
contributed
solid-phase
stabilization.
Collectively,
this
work
highlighted
ESOM
humification-driven
(hydr)oxide
redistribution,
advancing
our
understanding
coupled
behaviors
C,
Fe,
Environmental Science & Technology,
Journal Year:
2024,
Volume and Issue:
58(22), P. 9840 - 9849
Published: May 22, 2024
The
biogeochemical
processes
of
iodine
are
typically
coupled
with
organic
matter
(OM)
and
the
dynamic
transformation
iron
(Fe)
minerals
in
aquifer
systems,
which
further
regulated
by
association
OM
Fe
minerals.
However,
roles
mobility
on
Fe-OM
associations
remain
poorly
understood.
Based
batch
adsorption
experiments
subsequent
solid-phase
characterization,
we
delved
into
immobilization
iodate
iodide
different
C/Fe
ratios
under
anaerobic
conditions.
results
indicated
that
a
higher
ratio
(=1)
exhibited
greater
capacity
for
immobilizing
(∼60–80%
iodate),
was
attributed
to
affinity
significantly
decreased
extent
Fe(II)-catalyzed
caused
associated
OM.
compounds
abundant
oxygen
high
unsaturation
were
more
preferentially
ferrihydrite
than
those
poor
low
unsaturation;
thus,
capable
binding
28.1–45.4%
reactive
iodine.
At
comparable
ratios,
mobilization
aromatic
susceptible
complexes
compared
coprecipitates.
These
new
findings
contribute
deeper
understanding
cycling
is
controlled
environments.
Eco-Environment & Health,
Journal Year:
2023,
Volume and Issue:
2(4), P. 227 - 234
Published: Aug. 30, 2023
Both
biotic
and
abiotic
mechanisms
play
a
role
in
soil
CO2
emission
processes.
However,
abiotically
mediated
the
of
reactive
oxygen
species
are
still
poorly
understood
paddy
soil.
This
study
revealed
that
•OH
promoted
slurries
during
short-term
oxidation
(4
h).
generation
was
highly
hinged
on
active
Fe(II)
content,
contribution
to
efflux
10%–33%
topsoil
40%–77%
deep-soil
slurries.
Net
higher
slurries,
which
contained
more
dissolved
organic
carbon
(DOC).
correlated
well
with
DOC
contents,
suggesting
critical
DOC.
Microbial
contributed
9%–45%
production,
as
estimated
by
γ-ray
sterilization
experiments
reoxidation
process.
Solid-aqueous
separation
showed
significant
reduction
net
across
all
after
removal
original
aqueous
phase,
indicating
water
phase
main
source
(>50%).
Besides,
C
greatly
affected
pH
fluctuation
acidic
but
not
neutral/alkaline
soils.
Fourier
transform
ion
cyclotron
resonance
mass
spectrometry
excitation-emission
matrix
results
indicated
recalcitrant
macromolecular
matter
(DOM)
components
were
easily
removed
or
attacked
•OH.
The
decrease
DOM
content
combined
result
oxidation,
co-precipitation,
release.
emphasizes
significance
generally
overlooked
nonmicrobial
promoting
global
cycle,
influence
loss
environments.
Land,
Journal Year:
2024,
Volume and Issue:
13(2), P. 210 - 210
Published: Feb. 8, 2024
This
in-depth
floristic
study,
conducted
from
2019
to
2023
in
nine
temporary
wetlands
the
Guelma
and
Souk
Ahras
provinces,
northeastern
Algeria,
aims
highlight
natural
heritage
of
region
by
analyzing
composition
relation
environmental
conditions.
To
achieve
this
goal,
comprehensive
inventories
were
conducted,
revealing
presence
317
species
belonging
64
botanical
families
distributed
across
204
genera.
The
plant
diversity
at
each
site
was
assessed
using
various
biological
indices,
with
a
particular
focus
on
Taxonomic
Distinctiveness
Index
(TDI)
determine
influence
factors
such
as
fires,
altitude,
overgrazing
agropastoral
activities
biodiversity.
results
highlighted
dominance
therophytes
(43.22%)
prevalence
Mediterranean
assemblage
(66.25%).
Moreover,
8.83%
endemic,
1.89%
protected
Algerian
legislation
1.26%
listed
IUCN
Red
List.
study
identified
Priority
Conservation
Zones
(PCA)
where
preservation
ponds,
particularly
MTG,
TRC,
BTH,
GZE,
is
crucial.
Additionally,
ecological
boundaries
between
ponds
identified,
highlighting
marked
similarities
certain
pairs
notable
isolations,
evident
case
BTH
significantly
high
TDI.
These
underscore
critical
importance
studied
region,
emphasizing
need
integrate
its
biodiversity
into
conservation
efforts
enhance
overall
integrity.
Environmental Science & Technology,
Journal Year:
2024,
Volume and Issue:
58(23), P. 10095 - 10107
Published: May 28, 2024
Land
use
change
from
native
vegetation
to
cropping
can
significantly
affect
the
quantity
and
quality
of
soil
organic
matter
(SOM).
However,
it
remains
unclear
how
chemical
composition
SOM
is
affected
by
such
changes.
This
study
employed
a
sequential
extraction
partition
an
Oxisol
into
several
distinct
fractions:
water-soluble
fractions
(ultrapure
water
(W)),
organometal
complexes
(sodium
pyrophosphate
(PP)),
short-range
ordered
(SRO)
oxides
(hydroxylamine-HCl
(HH)),
well-crystalline
(dithionite-HCl
(DH)).
Coupled
with
Fourier
transform
ion
cyclotron
resonance
mass
spectrometry
(FT-ICR-MS),
impact
land
on
molecular
different
OM
was
investigated.
Greater
amounts
were
observed
in
PP
HH
compared
other
fractions,
highlighting
their
importance
stabilization.
The
varied
based
extracted
phases,
lignin-like
tannin-like
compounds
being
prevalent
while
aliphatic-like
dominated
DH
fraction.
Despite
changes
concentration
each
fraction
cropping,
there
little
influence
associated
mineral
phases.
No
significant
selective
loss
or
preservation
carbon
observed,
indicating
remained
unchanged.
Environmental Science & Technology,
Journal Year:
2024,
Volume and Issue:
58(27), P. 11998 - 12007
Published: June 27, 2024
Landscape
wildfires
generate
a
substantial
amount
of
dissolved
black
carbon
(DBC)
annually,
yet
the
molecular
nitrogen
(N)
structures
in
DBC
are
poorly
understood.
Here,
we
systematically
compared
chemodiversity
N-containing
molecules
among
three
different
samples
from
rice
straw
biochar
pyrolyzed
at
300,
400,
and
500
°C,
one
leached
organic
(LDOC)
sample
composted
straw,
fire-affected
soil
matter
(SDOMFire)
using
Fourier-transform
ion
cyclotron
resonance
mass
spectrometry
(FT-ICR
MS).
N-Containing
contributed
20.0%,
36.1%,
43.7%
total
compounds
Combined
(pooling
together
DBC),
LDOC,
SDOMFire,
respectively,
with
fewer
N
atoms
had
higher
proportions
(i.e.,
N1
>
N2
N3).
The
were
dominated
by
polycyclic
aromatic
(62.2%)
(14.4%)
components,
while
those
LDOC
lignin-like
(50.4%)
(30.1%)
components.
composition
SDOMFire
more
similar
to
than
LDOC.
As
temperature
rose,
proportion
nitrogenous
component
significantly
increased
concurrent
enhanced
oxidation
unsaturation
N.
indicated
density
functional
theory
(DFT)-based
thermodynamic
calculations,
aliphatic
amide
decreased
23.2%
7.9%,
whereas
that
nitroaromatic
10.0%
39.5%
as
300
°C;
alternatively,
5/6
membered
ring
remained
relatively
stable
(∼31%)
peaked
400
°C
(32.7%).
Our
work
first
provides
comprehensive
thorough
description
DBC,
which
helps
better
understand
predict
their
fate
biogeochemical
behavior.
The
groups
from
dissolved
organic
matter
(DOM)
enhance
cadmium
(Cd)
immobilization
on
Fe
oxyhydroxide,
while
it
is
difficult
to
evaluate
the
contributions
of
different
binding
configurations
and
strength
between
Cd
oxyhydroxides
because
DOM's
complex
composition
lack
in
situ
methods.
Here,
we
selected
small
molecules
with
representative
functional
investigate
molecular
mechanisms
goethite
using
batch
experiments,
solid
characterization,
theoretical
calculations,
single-molecule
force
spectroscopy
(SMFS)
combined
K-means
analysis.
These
increase
adsorption
goethite,
carboxyl
showing
most
substantial
enhancement
(increased
by
81.7%).
Solid-state
characterization
reveals
that
primary
driver
enhanced
immobilization,
promoting
formation
new
Cd–O(C)
Cd–O(Fe/C)
bonds.
Especially,
thermodynamic
analysis
indicates
bonds
represent
75%–80%
total
presence
molecules.
Notably,
newly
developed
results
show
a
strong
correlation
capacity,
which
may
deepen
understanding
DOM-mediated
oxyhydroxides,
offering
crucial
insights
into
behavior
providing
basis
for
pollution
control
subsurface
superficial
environments.
