Abstract.
Secondary
organic
aerosols
(SOA)
from
highly
volatile
compounds
(VOCs)
are
currently
not
well
represented
in
numerical
models
as
their
heterogeneous
formation
mechanisms
the
atmosphere
remain
unclear.
Based
on
smog
chamber
experiments,
here
we
investigated
yield
and
pathway
of
SOA
acetone
photooxidation
presence
preexisting
haze
particles
((NH4)2SO4,
NH4HSO4)
mineral
dusts
(Na2SO4)under
ammonia-rich
conditions.
Our
results
showed
that
acetone-derived
can
be
remarkably
enhanced
via
multiphase
reactions
these
seeds
especially
for
dusts,
suggesting
VOCs
is
an
important
source
atmospheric
SOA.
We
found
aerosol
acidity
a
key
factor
controlling
pathways
SOA,
which
carbonyls
produced
dissolve
into
aqueous
phase
oligomerize
consist
larger
molecules
acidic
but
smaller
neutral
aerosols.
Moreover,
light
absorption
ability
formed
(NH4)2SO4
stronger
than
Na2SO4
mineral
ammonia.
yields
obtained,
estimated
importance
global
atmosphere,
9.5–18.4
Tg
yr-1,
equivalent
to
8.5–16.4
%
budget,
such
should
accounted
future
model
studies.
PNAS Nexus,
Journal Year:
2025,
Volume and Issue:
4(3)
Published: Feb. 24, 2025
Heterogeneous
oxidation
of
SO2
by
NO2
on
aerosols
has
recently
been
found
to
be
one
the
major
formation
pathways
sulfate
in
polluted
troposphere,
but
chemical
mechanisms
and
kinetics
remain
uncertain.
By
combining
lab
experiments,
theoretical
chemistry
calculations,
field
measurements,
here
we
show
that
is
critically
dependent
anions
at
air-aerosol
aqueous
interface.
The
reaction
rate
with
HSO3-
(1.1
×
108-1.6
109
M-1
s-1)
more
than
four
orders
magnitude
larger
traditionally
held
value
for
bulk
phase
due
abundant
occurrence
chloride,
nitrate,
carboxylic
air-aqueous
interface,
which
remarkably
accelerates
during
China
haze
periods
enhancing
uptake
through
interfacial
electrostatic
attraction.
Atmospheric
models
not
accounting
this
aerosol
process
likely
produce
misrepresentations
tropospheric
under
conditions.
Atmospheric chemistry and physics,
Journal Year:
2025,
Volume and Issue:
25(1), P. 425 - 439
Published: Jan. 13, 2025
Abstract.
Discrepancies
persist
between
modeled
simulations
and
measured
sulfate
concentrations
in
the
marine
boundary
layer,
especially
when
air
is
influenced
by
biomass
burning
plumes.
However,
there
has
been
a
notable
dearth
of
research
conducted
on
interactions
sea-salt
aerosol
plumes,
impeding
comprehensive
understanding
formation.
This
work
studied
formation
mixing
real
(BB)
extracts
NaCl,
mimicking
internal
mixtures
BB
particles.
BB–NaCl
particles
had
significantly
higher
rate
than
incense
(IS)–NaCl
For
fresh
particles,
followed
trend
corn
straw
(CS)–NaCl
>
rice
(RS)–NaCl
wheat
(WS)–NaCl
IS–NaCl.
The
filter
sample
aging
was
achieved
exposure
to
OH•
generated
from
UV
irradiation.
After
aging,
RS–NaCl
exhibited
highest
enhancement
rates
among
all
due
RS
NaCl.
Bulk
aqueous
experiments
spiked
with
NaCl
using
model
photosensitizers
(PSs)
nitrogen-containing
organic
compounds
(NOCs),
pyrazine
(CHN),
4-nitrocatechol
(CHON)
revealed
positive
effects
chloride
PS–CHON
system
negative
PS–CHN
Our
suggests
that
reaching
or
near
coastal
areas
can
affect
via
photosensitizer-mediated
reactions,
potentially
exacerbating
pollution.
Atmosphere,
Journal Year:
2024,
Volume and Issue:
15(8), P. 1004 - 1004
Published: Aug. 20, 2024
Aerosol
acidity
is
a
critical
factor
affecting
atmospheric
chemistry.
Here,
we
present
study
on
annual,
monthly,
and
daily
variations
in
PM2.5
pH
Shanghai
during
2010–2020.
With
the
effective
control
of
SO2
emissions,
NO2/SO2
ratio
increased
from
1.26
2010
to
5.07
2020
NO3−/SO42−
0.68
1.49.
decreased
3.27
2.93
2020,
regardless
great
achievement
reducing
industrial
NOx
emissions.
These
findings
suggest
that
aerosol
might
not
be
significantly
reduced
response
The
monthly
variation
values
exhibited
V-shape
trend,
mainly
attributable
compositions
temperature.
Atmospheric
NH3
plays
decisive
role
buffering
particle
acidity,
whereas
Ca2+
K+
are
important
buffers,
distinct
decline
2010–2016
was
associated
with
reduction
while
both
temperature
SO42−
were
drivers
winter.
Sensitivity
tests
show
increases
increasing
relative
humidity
summer
it
sensitive
winter
due
proportional
Hair+
liquid
water
content
(ALWC).
Our
results
emissions
will
affect
Atmosphere,
Journal Year:
2024,
Volume and Issue:
15(11), P. 1312 - 1312
Published: Oct. 31, 2024
Sulfate
and
nitrate
are
important
components
of
atmospheric
PM2.5,
which
is
the
main
contributor
haze.
Therefore,
studying
sources
formation
mechanisms
sulfate
very
for
prevention
control
haze
formation.
Stable
isotopes
nitrate,
including
isotopic
compositions
sulfur,
oxygen,
nitrogen,
can
be
comprehensively
used
to
study
pathways
in
evaluate
contribution
each
source
pathway.
This
paper
briefly
reviews
determination
methods
oxygen
nitrogen
focuses
on
application
above
identifying
puts
forward
research
prospects.
Atmospheric chemistry and physics,
Journal Year:
2024,
Volume and Issue:
24(24), P. 14177 - 14190
Published: Dec. 19, 2024
Abstract.
Secondary
organic
aerosols
(SOAs)
from
highly
volatile
compounds
(VOCs)
are
currently
not
well
represented
in
numerical
models
as
their
heterogeneous
formation
mechanisms
the
atmosphere
remain
unclear.
Based
on
smog
chamber
experiments,
here
we
investigated
yield
and
pathway
of
SOA
acetone
photochemical
reactions
under
low-NOx
conditions
presence
preexisting
haze
particles
((NH4)2SO4
NH4HSO4)
saline
mineral
(Na2SO4)
ammonia-rich
conditions.
Our
results
showed
that
acetone-derived
is
remarkably
enhanced
via
multiphase
these
seeds,
especially
for
particles.
We
found
aerosol
acidity
a
key
factor
controlling
pathways
SOA,
which
acids,
alcohol,
carbonyls
produced
dissolve
into
aqueous
phase
seeds
subsequently
esterify
and/or
oligomerize
SOAs
consist
larger
molecules
acidic
but
smaller
neutral
aerosols.
Moreover,
light
absorption
ability
formed
(NH4)2SO4
stronger
than
Na2SO4
particles,
ammonia,
due
to
N-containing
organics.
Through
comparison
with
methylglyoxal
(MGly),
total
2.8–8.2
times
irreversible
uptake
MGly,
suggesting
only
considering
MGly
precursor
will
probably
underestimate
role
global
production
since
abundantly
exists
troposphere.