Rapid Nighttime Darkening of Biomass Burning Brown Carbon by Nitrate Radicals Is Suppressed by Prior Daytime Photochemical Aging
ACS Earth and Space Chemistry,
Год журнала:
2025,
Номер
unknown
Опубликована: Апрель 12, 2025
Язык: Английский
Aromatic Structures Govern the Formation of Chlorinated Byproducts in Dichlorine Radical Reactions
Environmental Science & Technology,
Год журнала:
2024,
Номер
58(42), С. 19048 - 19057
Опубликована: Окт. 9, 2024
Radical-induced
disinfection
byproduct
(DBP)
formation
is
drawing
attention
with
increasing
applications
of
advanced
oxidation
processes
(AOPs).
Cl
Язык: Английский
Insight Into the Molecular Photooxidation Evolution Mechanism of Brown Carbon Released From Residential Solid Fuel Combustion
Journal of Geophysical Research Atmospheres,
Год журнала:
2024,
Номер
130(1)
Опубликована: Дек. 30, 2024
Abstract
Solid
fuels
were
one
of
the
important
emission
sources
brown
carbon
(BrC).
This
study
investigates
molecular
composition
BrC
derived
from
combustion
five
types
residential
solid
(i.e.,
firewood,
corn
cob,
bituminous
coal,
anthracite,
and
biomass
briquette)
their
photooxidation
evolution
mechanisms
using
an
oxidation
flow
reactor.
Results
show
that
nitrogen‐containing
sulfur‐containing
organic
compounds
are
main
components
methanol‐soluble
(MSOC)
emitted
these
fuels,
with
intensity
being
33%–43%
23%–56%,
respectively,
depending
on
fuel
type.
The
processes
mediated
by
NO
3
⋅
OH
significantly
altered
distribution
aged
MSOC.
formation
typical
chromophores
(e.g.,
nitro‐aromatic
compounds)
also
proves
role
in
reaction.
However,
photo‐enhancement
effect
reaction
could
not
offset
destruction
conjugation
degree
aromaticity
oxidation,
resulting
a
significant
reduction
light
absorption
capacity
BrC.
mass
coefficient
at
365
nm
for
12
days
remaining
decreased
47.0%–55.8%
compared
to
fresh
BrC,
except
which
only
5.3%.
These
findings
mechanism
generated
useful
reducing
uncertainties
climate
change
studies
involving
aerosol.
Язык: Английский
Insight Into the Environment Implication of Primary and Photochemical Aging Processes of Nitrogen‐Containing Organic Chromophores From Residential Fuel Combustion Over Qinghai‐Tibet Plateau
Journal of Geophysical Research Atmospheres,
Год журнала:
2024,
Номер
130(1)
Опубликована: Дек. 24, 2024
Abstract
The
Qinghai‐Tibet
Plateau
(TPL),
crucial
for
the
global
climate,
lacks
a
comprehensive
understanding
of
nitrogen‐containing
organic
compound
(NOCs)
emissions
and
their
impact
on
light
absorption
radiative
forcing
through
atmospheric
oxidation.
This
study
examined
NOCs
from
dung
bitumite
combustion
in
TPL
oxidation
by
hydroxyl
(·OH)
nitrate
(·NO
3
)
radicals
using
an
integrated
experimental
theoretical
approach.
Dung
produced
higher
NOC
emissions,
mainly
methyl
types,
while
emitted
more
fused‐ring
NOCs.
Exposure
to
intense
solar
radiation
resulted
substantial
photobleaching
reactions,
reducing
maximum
molar
at
300–400
nm
wavelengths
76.9%–96.4%.
Moreover,
radical
maintained
spectral
characteristics
producing
minor
decreases
48.9%–58.8%.
oxidative
aging
exhibited
structure‐dependent
responses,
wherein
both
·NO
·OH
induced
photo‐enhancement
effects
proportional
number
aromatic
rings
molecular
structure.
Oxidation
generally
reduced
but
enhanced
it
NOCs,
particularly
which
increased
simple
efficiency
43.7%.
provides
insights
into
NOCs'
regional
climate
air
quality,
emphasizing
need
source‐specific
considerations
models
TPL's
unique
high‐altitude
environment.
Язык: Английский