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.
Chemical Society Reviews,
Год журнала:
2025,
Номер
unknown
Опубликована: Янв. 1, 2025
The
light-absorbing
chemical
components
of
atmospheric
organic
aerosols
are
commonly
referred
to
as
Brown
Carbon
(BrC),
reflecting
the
characteristic
yellowish
brown
appearance
aerosol.
Environmental Science & Technology,
Год журнала:
2024,
Номер
58(15), С. 6736 - 6743
Опубликована: Апрель 2, 2024
Acidity
is
an
important
property
of
particulate
matter
(PM)
in
the
atmosphere,
but
its
association
with
PM
toxicity
remains
unclear.
Here,
this
study
quantitively
reports
effect
acidity
level
on
via
pH-control
experiments
and
cellular
analysis.
Oxidative
stress
cytotoxicity
potencies
acidified
samples
at
pH
1–2
were
up
to
2.8–5.2
2.1–13.2
times
higher
than
those
8–11,
respectively.
The
toxic
from
real-world
smoke
plumes
2.3
9.1–18.2
greater
5.6,
demonstrating
a
trend
similar
that
samples.
Furthermore,
impact
was
manifested
by
promoting
metal
dissolution.
dramatic
increase
2–3
orders
magnitude
water-soluble
content
dominated
variation
toxicity.
significant
correlation
between
sulfate,
value,
Fe,
IC20,
EC1.5
(p
<
0.05)
suggested
acidic
sulfate
could
enhance
dissolving
insoluble
metals.
findings
uncover
superficial
adverse
health
outcomes
epidemiological
research
highlight
control
wet
plume
emissions
mitigate
effects
acidity.
Atmospheric chemistry and physics,
Год журнала:
2025,
Номер
25(5), С. 2763 - 2780
Опубликована: Март 4, 2025
Abstract.
Nitrogen-containing
organic
compounds
(NOCs)
impact
air
quality
and
human
health.
Here,
the
abundance,
potential
precursors,
main
formation
mechanisms
of
NOCs
in
PM2.5
during
winter
were
compared
for
first
time
among
Haerbin
(dependent
on
coal
heating),
Beijing
(natural
gas
as
heating
energy),
Hangzhou
(no
centralized
policy).
The
total
signal
intensity
CHON+,
CHN+,
CHON−
was
highest
lowest
Hangzhou.
Anthropogenic
aromatics
accounted
73
%–93
%
all
identified
precursors
Haerbin.
Although
abundance
aromatic-derived
lower
than
Haerbin,
also
contributors
to
NOC
Beijing.
exhibited
levels
aromatic
precursors.
Furthermore,
non-metric
multidimensional
scaling
analysis
indicated
an
overall
reduction
fossil
fuel
combustion
pollution
along
route
from
We
found
that
aqueous-phase
processes
(mainly
condensation,
hydrolysis,
or
dehydration
reduced
mainly
oxidization
hydrolysis
oxidized
NOCs)
can
promote
transformation
produce
NOCs,
leading
most
significant
increase
(particularly
haze
days).
Reduced
precursor
emissions
(the
lowest)
constrained
NOCs.
results
suggest
aerosol
coal-dependent
cities
is
controlled
by
anthropogenic
processes.
Thus,
without
effective
emission
controls,
through
may
still
pose
a
large
threat
quality.
Atmospheric chemistry and physics,
Год журнала:
2024,
Номер
24(12), С. 6987 - 6999
Опубликована: Июнь 18, 2024
Abstract.
While
aqueous-phase
processing
is
known
to
contribute
the
formation
of
nitrogen-containing
organic
compounds
(NOCs),
specific
pathways
involved
remain
poorly
understood.
In
this
study,
we
aimed
characterize
NOCs
present
in
both
pre-fog
aerosols
and
fog
water
collected
at
a
suburban
site
northern
China.
Fourier-transform
ion
cyclotron
resonance
mass
spectrometry
was
utilized
analyze
molecular
composition
negative
positive
modes
electrospray
ionization
(ESI−
ESI+).
samples,
constituted
significant
portion,
accounting
for
over
60
%
all
assigned
formulas
ESI−
more
than
80
ESI+.
By
comparing
originating
from
biomass
burning,
coal
combustion,
vehicle
emissions,
identified
that
72.3
were
attributed
primary
anthropogenic
sources
(pNOCs),
while
remaining
categorized
as
secondary
formed
within
(saNOCs).
Unique
found
classified
(sfNOCs).
Through
comprehensive
“precursor–product
pair”
screening
involving
39
reaction
pathways,
observed
nitration
reaction,
amine
pathway,
intramolecular
N-heterocycle
pathway
NH3
addition
reactions
contributed
43.6
%,
22.1
11.6
saNOCs,
respectively.
contrast,
these
26.8
28.4
29.7
sfNOCs,
This
disparity
likely
influenced
by
diverse
precursors,
aqueous
acidity,
gas-phase
species
partitioning.
Correspondingly,
saNOCs
contain
higher
abundance
carbohydrate-like
highly
oxygenated
with
two
nitrogen
atoms
compared
pNOCs.
Conversely,
sfNOCs
exhibited
content
lipid-like
fewer
oxygen
atoms.
These
results
underscore
distinct
processes
contributing
diversity
water,
which
may
lead
their
different
climate
effects.
Environmental Science & Technology,
Год журнала:
2024,
Номер
58(46), С. 20588 - 20597
Опубликована: Ноя. 7, 2024
The
linkages
between
BrC
optical
properties
and
chemical
composition
remain
inadequately
understood,
with
quantified
chromophores
explaining
less
than
25%
of
ambient
aerosol
light
absorption.
This
study
characterized
38
typical
in
aerosols
collected
Xi'an,
absorption
contributions
to
ranging
from
1.6
±
0.3
5.8
2.6%
at
365
nm.
Based
on
these
chromophores,
an
interpretable
machine
learning
model
the
Shapley
Additive
Explanation
(SHAP)
method
were
employed
explore
relationships
composition.
attained
high
accuracy
Pearson
correlation
coefficients
(
ACS Earth and Space Chemistry,
Год журнала:
2025,
Номер
unknown
Опубликована: Янв. 3, 2025
Secondary
brown
carbon
is
an
important
component
of
the
atmosphere.
The
contribution
secondary
atmospheric
from
reaction
methylglyoxal
(MG)
with
ammonium
sulfate
(AS)
has
been
demonstrated
in
laboratory.
However,
mechanism
still
unclear,
especially
influenced
by
other
factors,
for
example,
inorganic
salt.
In
this
study,
effect
soluble
iron
salt
on
between
MG
and
AS
was
investigated
through
chemical
analysis
methods,
including
optical
molecular
probes.
results
indicate
that
ferrous
may
promote
MG–AS
accelerate
formation
carbon.
Ferrous
exhibits
a
higher
catalytic
activity
than
ferric
does.
Moreover,
indicates
Fe(II)
true
catalyst,
rate
constant
13
times
uncatalyzed
reaction,
while
Fe(III)
due
to
its
reduction
MG.
addition,
complex
aqueous
phase
identified.
Environmental Science & Technology,
Год журнала:
2024,
Номер
unknown
Опубликована: Дек. 13, 2024
The
removal
capacity
of
aftertreatment
technologies
equipped
on
diesel
exhaust
in
intermediate
and
semivolatile
organic
compounds
(I/SVOCs)
remains
unclear.
This
study
quantified
the
effect
typical
(China
VI)
engine-emitted
I/SVOCs,
related
secondary
aerosol
(SOA),
toxic
effects.
devices
could
mitigate
emission
factors
(EFs)
by
70.8
±
3.4
to
82.5
20.9%
for
72.7
18.6
77.5
4.2%
SOA
production,
75.7
9.3
82.4
9.2%
equivalent
quantity
(TEQ).
Aftertreatment
units
are
better
removing
alkanes,
benzenes,
ketones.
TEQ
from
cold-start
cycle
is
1.3-
5.7-fold
higher
than
that
hot-start
cycle.
In
contrast,
EFs
ship-emitted
I/SVOCs
3.7-
5.3-fold
those
vehicles
with
an
system
when
burning
same
fuel,
leading
2.1-
3.0-fold
production
3.1-
6.7-fold
TEQ.
Implementation
control
marine
engines
reduce
I/SVOC
EFs,
eye
irritation
ships
76.7
12.2,
75.1
79.1
9.6%,
respectively.
These
results
indicate
it
vital
equip
improve
air
quality
protect
human
health.
