Environmental Science & Technology,
Journal Year:
2022,
Volume and Issue:
56(16), P. 11578 - 11588
Published: July 25, 2022
Acidic
nitrification
is
attracting
wide
attention
because
it
can
enable
robust
suppression
of
nitrite-oxidizing
bacteria
(NOB)
in
wastewater
treatment.
This
study
reports
a
comprehensive
assessment
the
novel
acidic
process
to
identify
key
factors
that
govern
stable
nitrite
accumulation.
A
laboratory-scale
moving-bed
biofilm
reactor
receiving
low-alkalinity
was
continuously
operated
under
conditions
(pH
<
6)
for
around
two
years,
including
nine
stages
varying
influent
and
operational
conditions.
The
results
revealed
accumulation
related
three
factors,
i.e.,
ammonium
concentration,
operating
pH,
ammonia-oxidizing
microbial
community.
These
impact
by
altering
situ
concentration
free
nitrous
acid
(FNA),
which
potent
inhibitor
NOB.
critical
FNA
approximately
one
part
per
million
(ppm,
∼1
mg
HNO2-N/L),
above
stably
maintained
an
nitrifying
system.
findings
this
suggest
via
ammonia
oxidation
be
range
conditions,
as
long
ppm-level
established.
Taking
low-strength
mainstream
(40–50
NH4+-N/L)
with
limited
alkalinity
example,
experimentally
demonstrated
at
pH
4.35,
2.3
±
0.6
HNO2-N/L
attained.
Under
these
Candidatus
Nitrosoglobus
became
only
oxidizer
detectable
16S
rRNA
gene
sequencing.
deepen
our
understanding
systems,
informing
further
development
treatment
technologies.
Environmental Science & Technology,
Journal Year:
2023,
Volume and Issue:
57(51), P. 21503 - 21526
Published: Dec. 14, 2023
Innovation
in
decarbonizing
wastewater
treatment
is
urgent
response
to
global
climate
change.
The
practical
implementation
of
anaerobic
ammonium
oxidation
(anammox)
treating
domestic
the
key
reconciling
carbon-neutral
management
with
sustainable
development.
Nitrite
availability
prerequisite
anammox
reaction,
but
how
achieve
robust
nitrite
supply
and
accumulation
for
mainstream
systems
remains
elusive.
This
work
presents
a
state-of-the-art
review
on
recent
advances
anammox,
paying
special
attention
available
pathways
(forward-going
(from
nitrite)
backward-going
nitrate
nitrite)),
controlling
strategies,
physiological
ecological
characteristics
functional
microorganisms
involved
supply.
First,
we
comprehensively
assessed
nitrite-oxidizing
bacteria
control
methods,
outlining
that
these
technologies
are
transitioning
possessing
multiple
selective
pressures
(such
as
intermittent
aeration
membrane-aerated
biological
reactor),
integrating
side
stream
free
ammonia/free
nitrous
acid
suppression
recirculated
sludge
treatment),
maintaining
high
activity
ammonia-oxidizing
competing
oxygen
bacteria.
We
then
highlight
emerging
strategies
supply,
including
production
driven
by
novel
microbes
(ammonia-oxidizing
archaea
complete
ammonia
bacteria)
reduction
(partial
denitrification
nitrate-dependent
methane
oxidation).
resources
requirement
different
analyzed,
hybrid
pathway
combining
partial
nitrification
encouraged.
Moreover,
data-driven
modeling
process
well
proactive
microbiome
proposed
hope
achieving
application.
Finally,
existing
challenges
further
perspectives
highlighted,
i.e.,
investigation
nitrite-supplying
bacteria,
scaling-up
from
laboratory
under
real
conditions,
stable
performance
fundamental
insights
this
aim
inspire
advance
our
understanding
about
provide
robustly
shed
light
important
obstacles
warranting
settlement.
