Atmospheric chemistry and physics,
Год журнала:
2022,
Номер
22(7), С. 4951 - 4967
Опубликована: Апрель 14, 2022
Abstract.
Severe
regional
haze
events,
which
are
characterized
by
exceedingly
high
levels
of
fine
particulate
matter
(PM),
occur
frequently
in
many
developing
countries
(such
as
China
and
India),
with
profound
implications
for
human
health,
weather,
climate.
The
occurrence
the
extremes
involves
a
complex
interplay
between
primary
emissions,
secondary
formation,
conducive
meteorological
conditions,
relative
contributions
various
processes
remain
unclear.
Here
we
investigated
severe
episodes
2013
over
Northern
Plain
(NCP),
evaluating
PM
production
interactions
elevated
planetary
boundary
layer
(PBL).
Analysis
ground-based
measurements
satellite
observations
properties
shows
nearly
synchronized
temporal
variations
among
three
megacities
(Beijing,
Baoding,
Shijiazhuang)
this
region
coincidence
aerosol
optical
depth
(AOD)
hotspots
during
polluted
period.
During
clean-to-hazy
transition,
measured
oxygenated
organic
concentration
([OOA])
well
correlates
odd-oxygen
([Ox]=[O3]+[NO2]),
mean
[OOA]
/
[Ox]
ratio
Beijing
is
much
larger
than
those
other
Mexico
City
Houston),
indicating
highly
efficient
photochemical
activity.
Simulations
using
Weather
Research
Forecasting
(WRF)
model
coupled
an
explicit
radiative
module
reveal
that
strong
aerosol–PBL
interaction
period
results
suppressed
stabilized
PBL
humidity,
triggering
positive
feedback
to
amplify
severity
at
ground
level.
Model
sensitivity
study
illustrates
importance
black
carbon
(BC)
haze–PBL
climatic
effect,
contributing
more
30
%
collapse
about
half
forcing
on
top
atmosphere.
Overall,
exhibits
negative
(cooling)
−63
−88
W
m−2
surface
(warming)
57
82
atmosphere,
slightly
net
−6
Our
work
establishes
synthetic
view
dominant
features
unraveling
rapid
situ
inefficient
transport,
both
amplified
atmospheric
stagnation.
On
hand,
transport
sufficiently
disperses
gaseous
precursors
(e.g.,
sulfur
dioxide,
nitrogen
oxides,
volatile
compounds,
ammonia)
clean
period,
subsequently
result
via
photochemistry
transition
multiphase
chemistry
findings
highlight
co-benefits
reduction
BC
not
only
improve
local
air
quality
minimizing
stagnation
but
also
mitigate
global
warming
alleviating
direct
forcing.
Environmental Science & Technology,
Год журнала:
2023,
Номер
57(31), С. 11572 - 11582
Опубликована: Июль 27, 2023
Aromatic
hydrocarbons
(ArHCs)
and
oxygenated
aromatic
(ArHC–OHs)
are
emitted
from
a
variety
of
anthropogenic
activities
important
precursors
secondary
organic
aerosol
(SOA)
in
urban
areas.
Here,
we
analyzed
compared
the
composition
SOA
formed
oxidation
mixture
VOCs
by
OH
NO3
radicals.
The
VOC
was
composed
toluene
(C7H8),
p-xylene
+
ethylbenzene
(C8H10),
1,3,5-trimethylbenzene
(C9H12),
phenol
(C6H6O),
cresol
(C7H8O),
2,6-dimethylphenol
(C8H10O),
2,4,6-trimethylphenol
(C9H12O)
proportion
where
were
chosen
to
approximate
day-time
traffic-related
emissions
Delhi,
alcohols
make
up
20%
mixture.
These
prominent
other
cities
as
well,
including
those
influenced
biomass
combustion.
In
experiments,
large
contributions
CxHyOzN
dimers
(C15–C18)
observed,
corresponding
fast
formation
within
15–20
min
after
start
chemistry.
Additionally,
different
combinations
initial
VOCs,
highlighting
importance
exploring
SOAs
mixed
systems.
contrast,
experiments
with
radicals
yielded
gradual
mass
formation,
CxHyOz
monomers
(C6–C9)
being
dominant
constituents.
evolution
time
tracked
degradation
observed
concurrent
monomer
species.
rates
dimer
decomposition
∼2–3
times
higher
previously
determined
for
α-pinene
O3
SOA,
dependence
particle-phase
reactions
on
oxidants.
produced
did
not
dramatically
change
over
same
frame.
No
measurable
effects
humidity
SOA.
Environmental Science Processes & Impacts,
Год журнала:
2022,
Номер
24(3), С. 351 - 379
Опубликована: Янв. 1, 2022
This
review
summarizes
in
detail
the
current
knowledge
chemical
compositions,
formation
mechanisms,
and
physicochemical
properties
of
secondary
organic
aerosols
formed
from
monocyclic
aromatic
hydrocarbons.
Environmental Science & Technology,
Год журнала:
2023,
Номер
57(16), С. 6616 - 6625
Опубликована: Апрель 13, 2023
Vehicular
evaporative
emissions
make
an
increasing
contribution
to
anthropogenic
sources
of
volatile
organic
compounds
(VOCs),
thus
contributing
secondary
aerosol
(SOA)
formation.
However,
few
studies
have
been
conducted
on
SOA
formation
from
vehicle
VOCs
under
complex
pollution
conditions
with
the
coexistence
NOx,
SO2,
and
NH3.
In
this
study,
synergistic
effects
SO2
NH3
gasoline
NOx
were
examined
using
a
30
m3
smog
chamber
aid
series
mass
spectrometers.
Compared
systems
involving
or
alone,
had
greater
promotion
effect
formation,
which
was
larger
than
cumulative
two
promotions
alone.
Meanwhile,
contrasting
oxidation
state
(OSc)
in
presence
absence
observed,
could
further
increase
OSc
The
latter
attributed
wherein
N–S–O
adducts
can
be
formed
reaction
N-heterocycles
generated
Our
study
contributes
understanding
highly
its
atmospheric
implications.
Scientific Reports,
Год журнала:
2024,
Номер
14(1)
Опубликована: Март 26, 2024
Abstract
Toluene
treatment
has
received
extensive
attention,
and
ozone
synergistic
catalytic
oxidation
was
thought
to
be
a
potential
method
degrade
VOCs
(violate
organic
compounds)
due
its
low
reaction
temperature
high
efficiency.
A
series
of
bimetal/Cord
monolithic
catalysts
were
prepared
by
impregnation
with
cordierite,
including
Mn
x
Cu
5−x
/Cord,
Co
/Cord
(x
=
1,
2,
3,
4).
Analysis
textural
properties,
structures
morphology
characteristics
on
the
conducted
evaluate
their
performance
toluene
conversion.
Effects
active
component
ratio,
addition
space
velocity
investigated.
Results
showed
that
best
among
three
bimetal
catalysts,
conversion
mineralization
rates
reached
100
96%
under
condition
2
3
3.0
g/m
O
at
12,000
h
−1
.
Ozone
in
could
efficiently
avoid
40%
reduction
specific
surface
area
because
it
lower
optimal
from
300
°C.
(Co/Mn)(Co/Mn)
4
diffraction
peaks
XRD
spectra
indicated
all
four
1−x
had
spinel
structure,
peak
intensity
largest
ratio
Mn:Co
2:3.
rate
increased
rising
concentration
intermediate
products
generated
degradation
might
react
excess
generate
free
radicals
like
·OH,
which
would
improve
catalyst.
This
study
provide
theoretical
support
for
industrial
application.
Environmental Science & Technology,
Год журнала:
2025,
Номер
unknown
Опубликована: Март 25, 2025
Electrophilic
compounds
belong
to
a
group
of
critical
components
fine
particulate
matter
(PM2.5)
with
significant
health
risk,
but
little
is
known
regarding
their
occurrence
and
sources
in
the
atmosphere.
In
this
study,
we
developed
nontargeted
approach
analyze
electrophilic
urban
Beijing
identified
147
ones
diurnal
variation,
among
which
oxygenated
aromatic
(OACs)
are
predominant
species.
The
discrepancy
hierarchical
clustering
analysis
atmospheric
transformation
markers,
e.g.,
9-nitroanthracene
(9NANT)
citraconic
anhydride
(CA),
PAHs,
fluoranthene
(FLT),
suggested
potential
secondary
formation
pathway
isomeric
ratio
acephenanthrylene
(ACP)
FLT,
product-to-precursor
11H-benzo[a]fluorene-11-one
(BaFO)
further
demonstrated
prevailing
existence
oxidation.
relationship
between
night-to-day
variation
molecular
characteristics,
particularly
negative
correlation
oxygen-related
features
such
as
carbon
oxidation
state,
confirmed
that
multigenerational
processes
during
daytime
predominantly
drive
diurnal/nocturnal
differences.
This
study
achieved
systematic
identification
atmosphere,
revealing
pivotal
role
on
fate
organic
chemicals
resulted
variation.
Toxics,
Год журнала:
2025,
Номер
13(4), С. 272 - 272
Опубликована: Апрель 2, 2025
Oligomerization
of
glyoxal
(GL)
and
methylglyoxal
(MG)
plays
a
vital
role
in
secondary
organic
aerosol
(SOA)
formation
aqueous
aerosols.
However,
the
influence
emerging
contaminants
on
oligomerization
GL
MG
remains
unclear.
Therefore,
using
quantum
chemical
kinetic
calculations,
we
investigated
presence
phthalate
esters
(PAEs),
including
dimethyl
(DMP),
diethyl
(DEP),
dipropyl
(DPP),
dibutyl
(DBP),
PAEs
oligomerization.
Our
findings
indicate
that
direct
PAE-mediated
is
hindered
due
to
lack
reactive
sites.
readily
mediated
by
hydrolysates
PAEs,
which
are
preferred
forms
weakly
acidic
aerosols,
attributable
additional
-OH
groups.
The
mechanisms
show
indirect
proceeds
via
three-step
reactions,
nucleophilic
attack
carbenium
ions,
hydration,
deprotonation,
thermodynamically
kinetically
favorable.
results
reveal
GL/MG
needs
be
emphasized,
particularly
conditions
with
pH
value
approaching
neutrality.
