Quantifying the Light-Absorption Properties and Molecular Composition of Brown Carbon Aerosol from Sub-Saharan African Biomass Combustion
Environmental Science & Technology,
Год журнала:
2024,
Номер
unknown
Опубликована: Фев. 23, 2024
Sub-Saharan
Africa
is
a
hotspot
for
biomass
burning
(BB)-derived
carbonaceous
aerosols,
including
light-absorbing
organic
(brown)
carbon
(BrC).
However,
the
chemically
complex
nature
of
BrC
in
BB
aerosols
from
this
region
not
fully
understood.
We
generated
smoke
chamber
through
smoldering
combustion
common
sub-Saharan
African
fuels
(hardwoods,
cow
dung,
savanna
grass,
and
leaves).
quantified
aethalometer-based,
real-time
light-absorption
properties
BrC-containing
organic-rich
accounting
variations
wavelength,
fuel
type,
relative
humidity,
photochemical
aging
conditions.
In
filter
samples
collected
Botswana
winter,
we
identified
182
species,
classified
into
lignin
pyrolysis
products,
nitroaromatics,
coumarins,
stilbenes,
flavonoids.
Using
an
extensive
set
standards,
determined
species-specific
mass
emission
factors.
Our
analysis
revealed
linear
relationship
between
combined
species
contribution
to
chamber-measured
aerosol
(0.4–14%)
mass-absorption
cross-section
at
370
nm
(0.2–2.2
m2
g–1).
Hierarchical
clustering
resolved
key
molecular-level
components
matrix,
with
photochemically
aged
emissions
leaf
cow-dung
showing
fingerprints
similar
those
found
aerosols.
These
quantitative
findings
could
potentially
help
refine
climate
model
predictions,
aid
source
apportionment,
inform
effective
air
quality
management
policies
human
health
global
climate.
Язык: Английский
Molecular composition of secondary brown carbon from styrene at low-to-high oxidation degrees
Environmental Pollution,
Год журнала:
2025,
Номер
368, С. 125795 - 125795
Опубликована: Фев. 3, 2025
Язык: Английский
Low-Cost Hourly Ambient Black Carbon Measurements at Multiple Cities in Africa
Environmental Science & Technology,
Год журнала:
2024,
Номер
58(28), С. 12575 - 12584
Опубликована: Июль 2, 2024
There
is
a
notable
lack
of
continuous
monitoring
air
pollutants
in
the
Global
South,
especially
for
measuring
chemical
composition,
due
to
high
cost
regulatory
monitors.
Using
our
previously
developed
low-cost
method
quantify
black
carbon
(BC)
fine
particulate
matter
(PM2.5)
by
analyzing
reflected
red
light
from
ambient
particle
deposits
on
glass
fiber
filters,
we
estimated
hourly
BC
concentrations
with
filter
tapes
beta
attenuation
monitors
(BAMs).
measurements
obtained
through
this
were
validated
against
reference
aethalometer
between
August
2
and
23,
2023
Addis
Ababa,
Ethiopia,
demonstrating
very
strong
agreement
(R2
=
0.95
slope
0.97).
We
present
three
cities
sub-Saharan
Africa
(SSA)
one
North
America:
Abidjan
(Côte
d'Ivoire),
Accra
(Ghana),
Ababa
(Ethiopia),
Pittsburgh
(USA).
The
average
measurement
period
at
Abidjan,
Accra,
Central
summer,
winter,
Jacros
sites
3.85
μg/m3,
5.33
5.63
3.89
9.14
0.52
respectively.
made
up
14–20%
PM2.5
mass
SSA
compared
only
5.6%
Pittsburgh.
data
all
(SSA
America)
show
pronounced
diurnal
pattern
prominent
peaks
during
morning
evening
rush
hours
workdays.
A
comparison
Goddard
Earth
Observing
System
Composition
Forecast
(GEOS-CF)
estimates
shows
that
model
performs
well
predicting
most
but
struggles
predict
an
resolution.
Adding
more
ground
could
help
evaluate
improve
performance
transport
models.
Our
can
potentially
use
existing
BAM
networks,
such
as
BAMs
U.S.
Embassies
around
globe,
measure
concentrations.
composition
data,
thus
acquired,
be
crucial
identifying
emission
sources
effective
policymaking
SSA.
Язык: Английский
Low-Cost Hourly Ambient Black Carbon Measurements at Multiple Cities in Africa
Опубликована: Март 5, 2024
There
is
a
notable
lack
of
continuous
monitoring
air
pollutants
in
the
Global
South,
especially
for
measuring
chemical
composition,
due
to
high
cost
regulatory
monitors.
Using
our
previously
developed
low-cost
method
quantify
black
carbon
(BC)
fine
particulate
matter
(PM2.5)
by
analyzing
reflected
red
light
from
ambient
particle
deposits
on
glass
fiber
filters,
we
estimated
hourly
BC
concentrations
with
filter
tapes
Beta
Attenuation
Monitors
(BAMs).
measurements
obtained
through
this
were
validated
against
reference
aethalometer
Addis
Ababa,
Ethiopia,
demonstrating
very
strong
agreement
(R2
=
0.95
and
slope
0.97).
We
present
three
cities
sub-Saharan
Africa
(SSA)
one
North
America:
Abidjan
(Côte
d’Ivoire),
Accra
(Ghana),
Ababa
(Ethiopia),
Pittsburgh
(USA).
The
average
measurement
period
at
Abidjan,
Accra,
Central
summer,
winter,
Jacros
winter
sites
3.85
µg.m-3,
5.33
5.63
3.89
9.14
µg.m-3
0.52
respectively.
made
up
14
–
20%
PM2.5
mass
African
cities,
compared
only
5.6%
Pittsburgh.
data
these
show
pronounced
diurnal
pattern
prominent
peaks
during
morning
evening
rush
hours
workdays.
Comparison
between
Goddard
Earth
Observing
System
composition
forecast
(GEOS-CF)
estimates
shows
that
model
performs
well
predicting
most
but
struggles
predict
an
resolution.
Adding
more
ground
could
help
calibrate
improve
performance
transport
models.
This
can
potentially
use
existing
BAM
networks,
BAMs
US
embassies
around
globe,
measure
method.
data,
thus
acquired,
be
crucial
identifying
emission
sources
effective
policymaking
South.
Язык: Английский
Molecular Characterization of Atmospheric Organic Aerosols: Contemporary Applications of High-resolution Mass Spectrometry
TrAC Trends in Analytical Chemistry,
Год журнала:
2024,
Номер
181, С. 117986 - 117986
Опубликована: Сен. 25, 2024
Язык: Английский
Influence of relative humidity and aging on the optical properties of organic aerosols from burning African biomass fuels
Aerosol Science and Technology,
Год журнала:
2024,
Номер
unknown, С. 1 - 23
Опубликована: Окт. 11, 2024
Biomass
burning
(BB)
is
a
major
source
of
atmospheric
fine
carbonaceous
aerosols,
which
play
significant,
yet
uncertain,
role
in
modulating
the
Earth's
radiation
balance.
However,
accurately
representing
their
optical
properties
climate
models
remains
challenging
due
to
factors
such
as
particle
size,
mixing
state,
combustion
type,
chemical
composition,
aging
processes,
and
relative
humidity
(RH).
In
our
study,
we
investigated
BB
organic-rich
aerosols
generated
from
smoldering
sub-Saharan
African
biomass
fuels.
Fuel
samples
were
collected
Africa
laboratory.
We
quantified
key
parameters,
including
mass
cross-sections
for
extinction
(2.04
±
0.32
−
15.5
2.48
m2/g),
absorption
(0.04
0.01–0.3
0.1
scattering
(1.9
0.68–15.3
5.5
m2/g).
Wavelength-dependent
used
determine
Ångström
exponents.
The
single
albedo
these
ranged
0.8
0.03
1.0
0.04
observed
wavelength-dependent
behavior.
Extinction
emission
determined
at
wavelength
550
nm,
with
values
ranging
42
5
293
32
m2/kg.
Notably,
exhibited
fuel-type
dependence,
differences
between
hardwood
other
fuels,
grass
animal
dung.
Aging
increased
while
had
opposite
effect
across
all
Nitrate
radical
oxidation,
both
photo
dark
conditions,
also
influenced
properties.
findings
are
expected
close
gap
understanding
aerosol
emissions
one
least
studied
regions
world
–
providing
information
air
quality
region.
Язык: Английский
Molecular Characterization and Photoreactivity of Organic Aerosols Formed from Pyrolysis of Urban Materials during Fires at the Wildland–Urban Interface
ACS ES&T Air,
Год журнала:
2024,
Номер
1(11), С. 1495 - 1506
Опубликована: Окт. 17, 2024
Fires
at
the
wildland-urban
interface
(WUI)
are
increasing
in
magnitude
and
frequency,
emitting
organic
aerosol
(OA)
with
unknown
composition
atmospheric
impacts.
In
this
study,
we
investigated
chemical
of
OA
produced
through
600
°C
pyrolysis
ten
urban
materials
nitrogen,
which
were
subsequently
aged
under
UV
light
for
2
h.
The
analysis
utilized
ultrahigh-performance
liquid
chromatography
(UHPLC)
separation,
coupled
a
photodiode
array
(PDA)
detector
high-resolution
mass
spectrometer
(HRMS)
molecular
characterization.
Hierarchical
clustering
demonstrated
that
lumber-derived
was
most
diverse
distinct
composition.
Unaged
(for
each
material)
did
not
significantly
differ
identities.
Potential
aromatic
brown
carbon
(BrC)
chromophores
(based
on
their
degree
unsaturation)
constituted
13-42%
all
assigned
compounds.
PDA
chromatograms
revealed
multiple
BrC
chromophoric
species
either
enhanced
or
degraded
as
result
aging,
providing
insights
into
specific
responsible
photobleaching
photoenhancement
overall
absorption
coefficient.
Thirty-six
identified
across
types,
structures
confirmed
using
reference
standards.
Components
plasticizers
resins,
such
phthalic
terephthalic
acids,
structurally
samples.
We
present
potential
WUI
fires
components
epoxies,
dyes,
adhesives
commonly
used
manufacturing
materials.
Photolysis
impact
emitted
from
burning
Язык: Английский
Chemical Characterization of Organic Aerosol Tracers Derived from Burning Biomass Indigenous to Sub-Saharan Africa: Fresh Emissions versus Photochemical Aging
ACS ES&T Air,
Год журнала:
2024,
Номер
1(11), С. 1463 - 1482
Опубликована: Окт. 22, 2024
Wildfires
are
increasingly
frequent
and
intense,
leading
to
substantial
production
of
biomass
burning
(BB)-derived
organic
aerosol
(BBOA).
BBOA
adversely
affects
public
health
perturbs
the
climate.
Although
African
fires
account
for
over
50%
worldwide
BB-derived
emissions,
few
studies
have
systematically
analyzed
molecular
tracers
in
fresh
versus
photochemically
aged
BB
emissions
representative
fires.
Therefore,
by
using
gas
chromatography
interfaced
electron
ionization
quadrupole
mass
spectrometry
(GC/EI-MS),
we
chemically
characterized
filter
samples
collected
from
both
six
fuels
found
Sub-Saharan
Africa
(Cordia
africana,
Baikiaea
plurijuga,
Acacia
erioloba,
Colophospermum
mopane,
cow
dung,
a
fuel
mixture).
were
generated
furnace
mimicking
smoldering
combustion
subsequently
injected
into
humidified
laboratory
chamber
(70%
±
3%
RH).
Seventeen
known
tracer
compounds
(e.g.,
levoglucosan,
mannosan,
coniferyl
alcohol,
catechol,
palmitic
acid)
targeted,
quantified,
compared
between
emissions.
Furthermore,
total-suspended
atmospheric
particulate
matter
(PM)
Botswana
during
fire
season
also
GC/EI-MS.
We
identified
laboratory-generated
constituents
that
PM
could
plausibly
serve
as
unique
D-pinitol)
future
field
studies.
Язык: Английский
Real-time chemical characterization of primary and aged biomass burning aerosols derived from Sub-Saharan African biomass fuels in smoldering fires
Environmental Science Atmospheres,
Год журнала:
2024,
Номер
unknown
Опубликована: Янв. 1, 2024
The
influence
of
biomass
burning
(BB)-derived
organic
aerosol
(OA)
emissions
on
solar
radiation
Язык: Английский