Chemosphere,
Journal Year:
2024,
Volume and Issue:
362, P. 142657 - 142657
Published: June 18, 2024
The
processes
leading
to
high
levels
of
arsenic
(As),
iron
(Fe),
and
manganese
(Mn)
in
groundwater,
a
naturally
reducing
aquifer
at
controlled
municipal
landfill
site,
are
investigated.
challenge
is
distinguish
the
natural
water-rock
interaction
processes,
that
allow
these
substances
dissolve
from
direct
pollution
or
enhanced
dissolution
hydroxides
as
undesired
consequences
anthropic
activities
above.
Ordinary
groundwater
monitoring
physical-chemical
parameters
inorganic
compounds
(major
trace
elements)
was
complemented
by
environmental
isotopes
(tritium,
deuterium,
oxygen-18
carbon-13)
dissolved
gases
(carbon-13
methane
carbon
dioxide
carbon-14
methane).
Pearson/Spearman
correlation
indices,
well
Principal
Component
Analysis
(PCA),
were
used
determine
main
correlations
among
variables.
concurrent
presence
As,
Fe
CH
Chemical Geology,
Journal Year:
2023,
Volume and Issue:
619, P. 121322 - 121322
Published: Jan. 18, 2023
The
contamination
of
groundwater
by
geogenic
arsenic
affects
the
health
tens
millions
people,
especially
in
South
and
Southeast
Asia.
primary
cause
highly
reducing
alluvial
deltaic
aquifers
Asia,
is
thought
to
be
microbial
reduction
Fe(III)
As(V)
(more
mobile)
Fe(II)
As(III),
respectively.
Key
understanding
Fe(III)/As(V)
process
aquifers,
identity
source
electron
donors
driving
system
–
this
has
been
a
key
area
research
within
biogeochemistry
last
two
decades.
Studies
can
broadly
divided
into
three
approaches:
1)
field-based,
which
include
organic
geochemical
analysis
aquifer
samples
deduce
composition
potential
sources
(by
variety
techniques
proxies),
and/or
multiple
biogeochemical
parameters
(microbes,
genes,
inorganic
geochemistry)
combined
with
multivariate
statistical
analysis;
2)
microcosm-based,
where
reductive
dissolution
mechanism
studied
laboratory-scale
incubation
experiments,
(including
donor
type
availability)
manipulated,
effects
monitored;
3)
in-situ
experiments
using
mineral
phases
deployed
aquifers.
Here
we
review
studies
aforementioned
approaches
address
questions:
(i)
What
are
present
aquifers?
(ii)
environmental
donors?
(iii)
Which
have
directly
implicated
release
We
find
that
available
(and
utilised),
depend
on
number
site-specific
factors,
including
geomorphological
setting,
sediment
lithology,
metabolic
communities
present.
A
wide
range
implicated,
dissolved
labile
matter,
methane
ammonium.
In
conclusion,
highlight
need
for
further
multidisciplinary
investigations
combine
state-of-the-art
analyses,
mineralogical
analyses
future
studies,
ideally
conducted
in-situ.
Environmental Science & Technology,
Journal Year:
2024,
Volume and Issue:
58(18), P. 8032 - 8042
Published: April 26, 2024
Accumulation
of
geogenic
phosphorus
(P)
in
groundwater
is
an
emerging
environmental
concern,
which
closely
linked
to
coupled
processes
involving
FeOOH
and
organic
matter
under
methanogenic
conditions.
However,
it
remains
unclear
how
P
enrichment
associated
with
methane
cycling,
particularly
the
anaerobic
oxidation
(AMO).
This
study
conducted
a
comprehensive
investigation
carbon
isotopes
dissolved
inorganic
(DIC),
CO2,
CH4,
alongside
Fe
isotopes,
microbial
communities,
functions
quaternary
aquifers
central
Yangtze
River
plain.
The
found
that
concentrations
tended
increase
Fe(II)
concentrations,
δ56Fe,
δ13C-DIC,
suggesting
accumulation
due
reductive
dissolution
positive
correlations
pmoA
gene
abundance
versus
δ13C–CH4
δ13C–CH4,
prevalent
presence
Candidatus_Methanoperedens,
jointly
demonstrated
potential
significance
Fe(III)-mediated
AMO
process
(Fe-AMO)
traditional
methanogenesis.
concentration
value,
abundance,
suggested
Fe-AMO
facilitated
groundwater.
Redundancy
analysis
confirmed
this
assertion,
identifying
as
primary
determinant
cooperative
influence
microorganisms
such
Candidatus_Methanoperedens
Geobacter
on
enrichment.
Our
work
provided
new
insights
into
dynamics
subsurface
environments.
Environmental Science & Technology Letters,
Journal Year:
2021,
Volume and Issue:
8(9), P. 832 - 837
Published: July 29, 2021
Although
arsenic
(As)
groundwater
contamination
in
South
and
Southeast
Asia
is
a
threat
to
human
health,
mechanisms
of
its
release
from
sediment
are
still
not
fully
understood.
In
many
aquifers,
Fe(III)
minerals
often
the
main
hosting
phases
for
As
their
stability
crucial
mobility.
Recently,
new
mechanism
mobilization
into
was
proposed
with
methane
(CH4)
serving
as
an
electron
donor
microbially
mediated
reductive
dissolution
As-bearing
minerals.
To
provide
unequivocal
evidence
occurrence
Fe(III)-coupled
methanotrophy,
we
incubated
sediments
As-contaminated
aquifer
Hanoi
(Vietnam)
anoxically
isotopically
labeled
13CH4.
Up
35%
available
reduced
within
232
days
simultaneous
production
13CO2
demonstrating
anaerobic
oxidation
13CH4
acceptor.
The
microbial
community
at
end
incubation
dominated
by
archaea
affiliating
Candidatus
Methanoperedens,
implying
involvement
Fe(III)-dependent
CH4
oxidation.
These
results
suggest
that
methanotrophs
can
contribute
minerals,
which
eventually
leads
As-release
groundwater.
International Journal of Environmental Research and Public Health,
Journal Year:
2022,
Volume and Issue:
19(15), P. 9606 - 9606
Published: Aug. 4, 2022
Arsenic
(As)
mobilization
in
groundwater
involves
biogeochemical
cycles
of
carbon,
iron,
and
sulfur.
However,
few
studies
have
focused
on
the
role
nitrogen-metabolizing
bacteria
As
mobilization,
as
well
transformation
between
inorganic
organic
groundwater.
In
this
study,
nitrogen
metabolisms
Citrobacter
sp.
G-C1
Paraclostridium
G-11,
isolated
from
high
Hetao
Plain,
China,
were
characterized
by
culture
experiments
genome
sequencing.
The
results
showed
was
a
dissimilatory
nitrate-reducing
bacterium.
nitrate
reduction
to
ammonia
(DNRA)
As-detoxifying
pathways
identified
enabled
simultaneously
reduce
As(V)
during
DNRA.
G-11
nitrogen-fixing
bacterium
its
activity
constrained
As.
Nitrogen
fixation
conferred
capability
fixation.
Under
anaerobic
conditions,
able
demethylate
performed
As(III)
methylation
with
arsM
gene.
Collectively,
these
not
only
evidenced
that
ammonium-generating
ars
operon
transform
more
mobile
processes,
but
also
involved
