Environmental Science & Technology,
Год журнала:
2025,
Номер
unknown
Опубликована: Апрель 16, 2025
Sulfate
formation
in
the
aerosol
aqueous
phase
represents
a
pH-sensitive
atmospheric
chemical
process,
with
pathways
significantly
influenced
by
fluctuations
acidity.
Buffer
capacity,
stemming
from
conjugate
acid-base
pairs,
can
resist
pH
changes
multiphase
systems
under
external
perturbations.
However,
regulating
role
of
buffering
pH-dependent
sulfate
mechanisms
remains
unexplored.
Here,
we
propose
that
stabilize
and
further
regulate
dominant
pathways.
In
this
work,
delve
into
instantaneous
buffer
capacity
β
based
on
field
observation
theoretical
calculation
introduce
total
α
system
to
quantify
buffer-constrained
change
after
acid/base
variation
during
entire
process.
The
NH4+/NH3
agent
(average
30.8
mol
kg-1)
shows
superior
effect
stabilizing
pathway
transition
compared
HNO3/NO3-
15.1
kg-1).
Geos-Chem
simulation
machine
learning
results
also
validate
as
pivotal
factor
formation.
addition
reactants,
agents
be
factors
concern
for
mechanism.
diverse
sensitivities
region-specific
responses
provide
insight
acid
base
emission
measures,
modulating
regional
acidity,
understanding
pH-related
processes.
Toxics,
Год журнала:
2024,
Номер
12(2), С. 105 - 105
Опубликована: Янв. 26, 2024
Sulfate
(SO42−)
is
an
essential
chemical
species
in
atmospheric
aerosols
and
plays
influential
role
their
physical–chemical
characteristics.
The
mechanisms
of
secondary
SO42−
aerosol
have
been
intensively
studied
air-polluted
cities.
However,
few
studies
focused
on
cities
with
good
air
quality.
One-year
PM2.5
samples
were
collected
the
tropical
island
city
Haikou,
water-soluble
inorganic
ions,
as
well
Fe
Mn,
analyzed.
results
showed
that
non-sea-salt
(nss-SO42−)
was
dominant
accounting
for
40–57%
total
ions
Haikou.
S(IV)+H2O2
pathway
main
formation
wintertime
contributing
to
57%
formation.
By
contrast,
54%
produced
by
S(IV)+Fe×Mn
summer.
In
spring
autumn,
S(IV)+H2O2,
S(IV)+Fe×Mn,
S(IV)+NO2
pathways
contributed
equally
ionic
strength
controlling
parameter
pathway,
while
pH
identified
a
key
factor
mediates
produce
SO42−.
This
study
contributes
our
understanding
production
under
low
concentrations
but
high
percentages.
Journal of Geophysical Research Atmospheres,
Год журнала:
2024,
Номер
129(3)
Опубликована: Янв. 31, 2024
Abstract
Carbonate
radical
anion
()
is
generally
overlooked
in
atmospheric
chemistry.
Our
recent
work
emphasizes
the
important
role
of
carbonate
radicals
produced
on
mineral
dust
surfaces
fast
sulfate
production
under
solar
irradiation
presence
CO
2
at
specifically
low
RH
and
light
intensity.
Yet
so
far
how
involves
affects
secondary
diverse
RH,
intensity,
complex
constituent
matrix
remains
unknown,
which
essentially
limits
our
comprehensive
knowledge
initiated
SO
oxidation
scheme
atmosphere.
Herein,
we
explored
heterogeneous
over
both
model
authentic
clays
relevant
RHs
intensities.
Interestingly,
observe
that
promotes
yield
atmospheric‐relevant
This
observation
relates
to
favorable
kinetic
between
while
auto‐quenching
these
ions
largely
minimized
due
sufficient
sites
crustal
constituents.
Furthermore,
employing
a
suite
machine
learning
strategies,
evaluated
relative
importance
each
within
airborne
minerals
or
as
well
environmental
conditions
including
humidity,
concentration
affecting
uptake
capability.
On
this
basis,
formation
mediated
by
dust‐driven
pathway,
accounting
for
nearly
∼20.9%
overall
contribution
end
century
during
some
pollution
episodes,
even
higher
than
gas‐phase
(∼16.9%),
will
be
increased
163%
if
‐initiated
incorporated.
Environmental Science & Technology,
Год журнала:
2024,
Номер
58(25), С. 11096 - 11104
Опубликована: Июнь 12, 2024
Hydrogen
peroxide
(H2O2)
plays
a
crucial
role
as
an
oxidizing
agent
within
the
tropospheric
environment,
making
substantial
contribution
to
sulfate
formation
in
hydrated
aerosols
and
cloud
fog
droplets.
Field
observations
show
that
high
levels
of
H2O2
are
often
observed
heavy
haze
events
polluted
air.
However,
source
remains
unclear.
Here,
using
droplets
formed
situ
by
deliquescence
hygroscopic
compounds
under
relative
humidity
(RH),
photochemistry
imidazole-2-carbaldehyde
(2-IC)
ultraviolet
irradiation
was
explored.
The
results
indicate
2-IC
produces
IM–C•–OH
IM–C•═O
radicals
via
H
transfer
itself
its
excited
triplet
state
generates
organic
peroxides
presence
O2,
which
has
evident
effect
on
SO2,
suggesting
potential
involvement
this
pathway
atmospheric
sulfate.
is
limited
acidic
or
containing
ammonium
ions,
no
detected
nitrate,
whereas
citric
acid
have
obvious
promotion
formation.
These
findings
provide
valuable
insights
into
behaviors
photosensitizers,
H2O2,
