In
this
study,
a
pyrite-based
autotrophic
denitrification
(PAD)
system,
polycaprolactone
(PCL)-supported
heterotrophic
(PHD)
and
pyrite/PCL-based
split-mixotrophic
(PPMD)
system
were
constructed.
The
pyrite
particle
size
was
controlled
in
1-3,
3-5,
or
5-8
mm
both
the
PAD
PPMD
systems
to
investigate
effect
of
on
performance
bioreactors.
results
showed
that
achieved
best
efficiency
with
an
average
removal
rate
98.98%
treatment
1-3
size,
whereas
it
only
19.24%
size.
At
different
phases
whole
experiment,
nitrate
rates
PHD
remained
stable
at
high
level
(>
94%).
Compared
reduced
concentrations
sulfate
chemical
oxygen
demand
final
effluent
efficiently.
Finally,
Spearman
correlation
analysis
used
construct
interconnection
network
diagram
between
water
quality
indicators,
found
explained
intrinsic
metabolic
pathways
nitrogen,
sulfur,
carbon
three
phases.
Environmental Technology,
Journal Year:
2025,
Volume and Issue:
unknown, P. 1 - 14
Published: April 5, 2025
Nitrate
pollution
in
groundwater
has
steadily
increased
globally,
posing
a
potential
threat
to
human
health.
Introduction
of
exogenous
electron
donors
can
significantly
enhance
nitrogen
removal
from
nitrate-contaminated
groundwater.
Yet,
conventional
individual
autotrophic
or
heterotrophic
denitrification
approaches
have
the
disadvantage
low
efficiency
high
cost.
This
study
investigated
performance
laboratory-scale
solid-phase
(SPD)
permeable
reactive
barrier
(PRB)
using
polyhydroxybutyrate-co-valerate
(PHBV)/pyrite
mixture
as
an
donor
for
denitrification.
Two
different
mass
ratios
(1:1
and
1:2)
were
established
experimental
setup.
The
results
showed
that
under
influent
levels
between
20
37
mg·L-1,
PHBV/pyrite
system
at
ratio
1:1
achieved
maximum
nitrate
97.03%,
with
rate
99.13
mg
NO3--N
NO3--N·L-1·d-1.
Moreover,
1:2
reached
97.65%
111.04
NO3--N·L-1·d-1
terms
optimum
rate.
Dissolved
organic
carbon
was
undetectable
effluent
both
systems.
superior
one
1:1,
implying
appropriate
addition
pyrite
mixtrophic
systems
could
Additionally,
dominant
genera
identified
respectively
Cloacibacterium
Acinetobacter
two
systems,
indicating
varying
modulate
succession
nitrogenremoving
microorganisms.
Specifically,
favoured
aerobic
microbial
growth,
thereby
enhancing
biological
removal.
findings
provided
valuable
alternative
in-situ
remediation
nitrate-polluted
Water Environment Research,
Journal Year:
2024,
Volume and Issue:
96(5)
Published: May 1, 2024
Abstract
In
this
study,
a
pyrite‐based
autotrophic
denitrification
(PAD)
system,
polycaprolactone
(PCL)‐supported
heterotrophic
(PHD)
and
pyrite+PCL‐based
split‐mixotrophic
(PPMD)
system
were
constructed.
The
pyrite
particle
size
was
controlled
in
1–3,
3–5,
or
5–8
mm
both
the
PAD
PPMD
systems
to
investigate
effect
of
on
performance
bioreactors.
It
found
that
achieved
best
efficiency
with
an
average
removal
rate
98.98%
treatment
1‐
3‐mm
size,
whereas
it
only
19.24%
5‐
8‐mm
size.
At
different
phases
whole
experiment,
nitrate
rates
PHD
remained
stable
at
high
level
(>94%).
Compared
reduced
concentrations
sulfate
chemical
oxygen
demand
final
effluent
efficiently.
interconnection
network
diagram
explained
intrinsic
metabolic
pathways
nitrogen,
sulfur,
carbon
three
phases.
addition,
microbial
community
analysis
showed
beneficial
for
enrichment
Firmicutes
.
Finally,
impact
mechanism
proposed.
Practitioner
Points
reduction
improving
process.
change
had
NO
2
−
‐N
accumulation
system.
NH
4
+
increased
decrease
production
SO
2−
systems.
correlations
among
indicators
could
be
well
explained.
