Short-cut
biological
nitrogen
removal
(sBNR)
favors
the
paradigm
shift
toward
energy-positive
and
carbon-neutral
wastewater
treatment
processes.
Partial
nitrification
(PN)
is
a
key
approach
to
provide
nitrite
for
anammox
or
denitritation
during
sBNR,
its
stability
precondition
achieving
robust
performance.
However,
maintaining
stable
mainstream
PN
process
has
been
long-standing
challenge.
This
review
analyzes
from
microbial
ecology
perspective,
focusing
on
niche
differentiation
among
nitrifiers.
First,
we
propose
that
systems
are
ecologically
unstable,
failure
of
due
reactivation
nitrite-oxidizing
bacteria
(NOB)
can
be
regarded
as
behavior
restore
system
stabilization.
Thus,
primarily
relies
enhancing
between
ammonia-oxidizing
(AOB)
NOB.
We
then
summarize
realized
niches
indigenous
nitrifiers
within
discuss
their
ecophysiological
characteristics
(e.g.,
cell
structure
substrate
affinity)
define
specific
ecological
niches.
By
comparing
breadths
AOB
NOB
various
axes,
further
identify
different
responses
(resistance)
(resilience)
exogenous
perturbations.
Finally,
outlook
through
an
lens.
provides
insights
into
instability
process,
which
intended
guide
derivation
optimized
strategies
single-factor
integrated
solutions.
This
case
study
explored
the
mechanisms
influencing
anoxic/oxic
processes
in
100
ton/h
treatment
system
of
coal
gasification
gray
water
(CGGW).
It
was
experiencing
"spiked"
and
COD,
unstable
operation.
To
identify
issues
find
solution,
sideline
simulation
experiments
were
commenced
by
installing
600
times
miniaturized
bioreactor
14
m3
with
70
L/h
inlet
flow
rate.
Data
during
start-up
revealed
that
period
sludge
acclimation
(24
days)
stabilization
(10
days),
30%
reflux
from
oxic-
to
anoxic-pond,
0.8-1.2
mg
L‒1
DO
oxic-pond
favored
nitrification.
However,
it
could
not
sustain
denitrification
without
adding
organic
carbon
anoxic-pond.
Therefore,
two
co-substrates
(glucose
methanol)
supplemented
separately
metabolic
response
aerobic/anaerobic
ammonia-oxidizing
bacteria
(AerAOB/AnAOB),
denitrifying
(DNB).
Glucose
increased
both
ponds
reflecting
hampered
partial
anammox
anoxic-pond
heterotrophic
non-function
over
DNB,
intolerance
AOB
carbon.
also
declined
depriving
AerAOB
AnAOB.
Methanol
addition
quickly
enhanced
denitrification;
however,
later
declined,
spiked.
By
reducing
methanol,
effluent
COD
met
standards
again.
indicated
overdosed
methanol
exceeded
DNB
usage,
carried
oxic-pond,
where
restricted
AOB's
growth
On
this
basis,
dosage
main
plant
reduced
2400
1540
kg/day,
which
meet
standards,
achieved
plant's
operational
stability.
These
findings
conceptualized
CGGW
model
"synergistic
anammox-nitrification
denitrification-anammox
(SPANDA)"
regulated
lower
dosage.
