Environmental Science & Technology,
Год журнала:
2025,
Номер
unknown
Опубликована: Апрель 24, 2025
Microaeration
has
been
reported
to
improve
anaerobic
digestion,
which
is
generally
attributed
increased
microbial
diversity,
but
a
thorough
explanation
lacking.
In
this
study,
it
was
found
that
intermittent
microaeration
(IMA)
supplied
an
digester
could
oxidize
Fe(II)
produced
by
dissimilatory
iron
reduction
(DIR)
form
Fe(III)/Fe(II)
cycle
and
generate
extracellular
reactive
oxygen
species
(ROS)
treatment
of
phenol-containing
wastewater.
The
results
showed
compared
the
control
group
without
IMA,
removal
rates
COD
phenol
29.54
49.68
percentage
points,
respectively,
daily
average
methane
production
85.44%.
slowed
down
loss
(13.97%)
released
from
sludge
due
lower
solubility
Fe(III)
facilitated
•OH
generation
(1.22
±
0.04
μM)
via
Fenton-like
reactions.
DIR
accelerated
degradation.
Metagenomic
analysis
revealed
abundance
methanogens
antioxidant
enzymes-encoding
genes
in
response
oxidative
stress
significantly
IMA
control,
enabling
methanogenesis
proceed
smoothly
under
microaeration.
This
study
investigated
ROS
induced
during
digestion
their
roles
promoting
performance,
thereby
providing
new
perspective
for
optimizing
systems
with
ACS ES&T Engineering,
Год журнала:
2024,
Номер
4(8), С. 1990 - 2001
Опубликована: Июнь 28, 2024
Ammonia
inhibition
often
occurs
during
anaerobic
digestion
(AD)
of
the
protein-rich
substrate.
Iron-containing
substances
were
proved
to
be
efficient
in
alleviating
ammonia
stress.
However,
mechanisms
behind,
especially
distinct
impacts
different
forms
iron
materials,
are
not
fully
revealed.
Here,
performances
FeCl3
and
Fe3O4
on
AD
systems
under
stress
investigated.
Moreover,
behind
these
revealed
compared
at
transcriptional
level.
Results
showed
that
additions
with
an
equal
amount
element
content
(1.29
mM)
led
increased
cumulative
biogas
methane
yields
concentration
3
g/L.
Furthermore,
addition
iron-containing
alleviated
accumulation
volatile
fatty
acids
(VFAs)
extracellular
polymeric
(soluble
carbohydrates
protein)
caused
by
stress,
which
also
had
obvious
positive
effect
electron
transfer
capability.
Microbial
analysis
demonstrated
microbes
(e.g.,
orders
Methanosarcinales,
Clostridiales,
Syntrophobacterales)
associated
direct
interspecies
(DIET),
syntrophic
acetate
oxidization,
degradation
organic
compounds
enriched.
Metatranscriptomic
inhibited
process
disrupting
cellular
redox
homeostasis,
infecting
ATPase
activity,
affecting
energy
supply,
inhibiting
methane-producing
enzyme
suppressing
expression
cell
conductive
structure
genes.
Meanwhile,
enhanced
basal
metabolism
as
well
microbial
enzymic
activities
methanogenesis.
indicated
free
species
(FeCl3)
can
relieve
propionate
oxidizing
bacteria,
enhance
DIET
stimulating
synthesis
c-type
cytochrome,
thus
promote
production.
may
production
related
genes
facilitating
system
a
capacitor.
Overall,
results
ferric
chloride
magnetite
alleviate
high-nitrogen
waste
through
mechanisms.
