Water Research X,
Journal Year:
2023,
Volume and Issue:
19, P. 100166 - 100166
Published: Jan. 10, 2023
Mainstream
nitrogen
removal
via
anammox
is
widely
recognized
as
a
promising
wastewater
treatment
process.
However,
its
application
challenging
at
large
scale
due
to
unstable
suppression
of
nitrite-oxidizing
bacteria
(NOB).
In
this
study,
pilot-scale
mainstream
process
was
implemented
in
an
Integrated
Fixed-film
Activated
Sludge
(IFAS)
configuration.
Stable
operation
with
robust
NOB
maintained
for
over
one
year.
This
achieved
through
integration
three
key
control
strategies:
i)
low
dissolved
oxygen
(DO
=
0.4
±
0.2
mg
O2/L),
ii)
regular
free
nitrous
acid
(FNA)-based
sludge
treatment,
and
iii)
residual
ammonium
concentration
(NH4+
setpoint
∼8
N/L).
Activity
tests
FISH
demonstrated
that
barely
survived
flocs
were
inhibited
biofilms.
Despite
receiving
organic-deficient
from
High-Rate
(HRAS)
system
the
feed,
stable
effluent
total
mostly
below
10
N/L,
which
attributed
successful
retention
bacteria.
study
successfully
large-scale
long-term
generated
new
practical
knowledge
retention.
Environmental Science & Technology,
Journal Year:
2023,
Volume and Issue:
57(11), P. 4522 - 4532
Published: March 10, 2023
Chemically
enhanced
primary
treatment
(CEPT)
followed
by
partial
nitritation
and
anammox
(PN/A)
anaerobic
digestion
(AD)
is
a
promising
roadmap
to
achieve
energy-neutral
wastewater
treatment.
However,
the
acidification
of
caused
ferric
hydrolysis
in
CEPT
how
stable
suppression
nitrite-oxidizing
bacteria
(NOB)
PN/A
challenge
this
paradigm
practice.
This
study
proposes
novel
scheme
overcome
these
challenges.
Results
showed
that,
dosing
FeCl3
at
50
mg
Fe/L,
process
removed
61.8%
COD
90.1%
phosphate
reduced
alkalinity
as
well.
Feeding
low
wastewater,
nitrite
accumulation
was
achieved
an
aerobic
reactor
operated
pH
4.35
aided
acid-tolerant
ammonium-oxidizing
(AOB),
namely,
Candidatus
Nitrosoglobus.
After
polishing
following
anoxic
(anammox),
satisfactory
effluent,
containing
41.9
±
11.2
mg/L,
total
nitrogen
5.1
1.8
N/L,
0.3
0.2
P/L,
achieved.
Moreover,
performances
integration
were
well
maintained
operating
temperature
12
°C,
10
investigated
micropollutants
from
wastewater.
An
energy
balance
assessment
indicated
that
integrated
system
could
self-sufficiency
domestic
