Environmental Science & Technology Letters,
Год журнала:
2024,
Номер
11(2), С. 114 - 121
Опубликована: Янв. 22, 2024
Shale
gas
extraction
has
raised
environmental
concerns
on
regional
water
resources.
Horizontal
drilling
is
a
process
in
which
fluids
containing
complex
organic
and
inorganic
chemicals
are
intensively
applied.
Accidental
spill
improper
disposal
of
related
wastes
might
pose
risks
to
surrounding
groundwater
environment.
Given
ground
quality,
persistent,
mobile,
toxic
(PMT)
very
persistent
mobile
(vPvM)
substances
should
be
particular
attention.
However,
recent
research
rarely
focused
chemical
compositions
fluids,
the
harmful
PMT/vPvM
remain
unknown.
In
this
study,
we
utilized
nontarget
screening
strategy
detect
identify
compounds
collected
southwest
China.
Specifically,
total
number
371
were
detected
main
fraction
was
alicyclic
compounds.
Later,
an
original
machine
learning
model
developed
by
us
applied
candidate
among
Our
study
identified
29
substances,
thus
providing
list
prioritized
for
early
warning
risk
assessment
contamination.
Environmental Science & Technology Letters,
Год журнала:
2021,
Номер
9(2), С. 102 - 111
Опубликована: Дек. 30, 2021
Emissions
from
residential
biomass
burning
are
a
significant
source
of
atmospheric
brown
carbon
(BrC).
In
this
study,
we
used
liquid
chromatography-photodiode
array-high
resolution
tandem
mass
spectrometry
to
investigate
the
chromophoric
fingerprinting
BrC
emitted
burning.
total,
59
major
chromophores
were
identified,
which
accounted
for
49–85%
total
light
absorption
(averaged
between
300
and
500
nm)
different
samples.
These
include
furans,
lignin
pyrolysis
products,
coumarins,
flavonoids,
stilbenes,
N-containing
aromatic
compounds,
unsubstituted
or
oxygenated
polycyclic
hydrocarbons,
some
newly
reported
as
species
(e.g.,
stilbenes
substituted
phenyl
cyanates).
Among
seven
common
all
samples
while
specific
certain
biofuel
conditions.
For
instance,
3,3′-dimethoxyquercetin
wheat
burning,
p-hydroxybenzaldehyde
apigenin
maize
smoldering,
4-nitro-2-vinylphenol
flaming,
nodakenetin
anthanthrene
wood
flaming
fuel
type
condition.
The
identified
optical
markers
will
be
essential
understanding
chemical
processes
in
future
studies,
source-specific
chromophore
profiles
developed
study
prerequisite
apportioning
types
conditions,
is
key
estimating
radiative
forcing.
Environmental Science & Technology,
Год журнала:
2022,
Номер
56(12), С. 7578 - 7587
Опубликована: Июнь 1, 2022
Humic-like
substances
(HULIS)
are
macromolecular
complex
groups
in
water-soluble
organic
compounds
(WSOC).
pH
is
a
crucial
factor
that
influences
the
chemical
transformations
of
HULIS
atmospheric
particles,
but
this
has
been
rarely
investigated,
especially
under
varying
conditions.
This
study
attempted
to
unveil
transformation
mechanisms
range
conditions
using
optical
methods.
The
pH-dependent
light
absorption
and
fluorescence
properties
were
comprehensively
analyzed;
acidity
coefficient
(pKa)
relation
structures
was
determined,
hypothetical
with
increasing
analyzed
by
characterizations.
results
suggested
greatly
impacted
efficiencies
both
winter
summer
seasons,
pKa
an
important
inflection
point.
ranged
from
3.5
8.0
6.4
10.0
summer.
acidic/basic
identified
as
−OH
or
−NH2
substituted
quinolines,
carboxylic
aromatics,
pyridines.
pH-sensitive
species
accounted
for
about
6%
21%
HULIS-C
(carbon
concentrations
HULIS)
summer,
respectively.
spectra
might
result
charge
transfer
reactions
deprotonation.
Journal of Geophysical Research Atmospheres,
Год журнала:
2021,
Номер
126(23)
Опубликована: Ноя. 23, 2021
Abstract
The
major
fraction
of
intermediate
and
semi‐volatility
organic
compounds
(I/SVOCs)
is
still
unresolved
by
traditional
analyses,
leaving
large
complex
mixture
(UCM)
limiting
the
estimation
secondary
aerosol
(SOA).
This
study
addressed
UCM
employing
two‐dimensional
gas
chromatography−time‐of‐flight
mass
spectrometry.
ratios
in
I/SVOCs
emitted
from
household
burning
biomass
coal
were
reduced
to
1.0
±
0.3%
2.1
2.0%,
respectively,
these
levels
are
one
order
magnitude
less
than
those
reported
previous
studies.
Phenols,
polycyclic
aromatic
hydrocarbons,
ketones
made
contribution
emission
factors
(EFs)
(65.9
9.6%)
for
burning,
while
amides,
acids,
esters
constituted
majority
EFs
(56.5
45.0%)
burning.
Furthermore,
SOA
production
can
be
predicted
via
highly
identified
based
on
volatility
distributions
each
speciated
species.
These
contribute
with
76.0
12.7%
82.0
60.3%
respectively.
Underestimated
ratio
62.5
25.2%
80.9
2.8%
Bins
method
has
been
well
addressed.
obtained
results
suggest
that
nontarget
analysis
significantly
improve
accuracy
environmental
impacts
addressing
chemical
components
at
molecular
level.
Environmental Science & Technology,
Год журнала:
2022,
Номер
56(11), С. 7017 - 7028
Опубликована: Март 18, 2022
The
molecular
composition
of
atmospheric
particulate
matter
(PM)
in
the
urban
environment
is
complex,
and
it
remains
a
challenge
to
identify
its
sources
formation
pathways.
Here,
we
report
seasonal
variation
organic
aerosols
(OA),
based
on
172
PM2.5
filter
samples
collected
Beijing,
China,
from
February
2018
March
2019.
We
applied
hierarchical
cluster
analysis
(HCA)
large
nontarget-screening
data
set
found
strong
difference
OA
chemical
composition.
Molecular
fingerprints
major
compound
clusters
exhibit
unique
pattern
Van
Krevelen-space.
that
summer
Beijing
features
higher
degree
oxidation
proportion
organosulfates
(OSs)
comparison
during
wintertime,
which
exhibits
high
contribution
(nitro-)aromatic
compounds.
OSs
appeared
with
intensity
summer-haze
conditions,
indicating
importance
anthropogenic
enhancement
secondary
Beijing.
Furthermore,
quantified
four
main
total
using
surrogate
standards.
With
this
approach,
are
able
explain
small
fraction
(∼11–14%)
monitored
by
Time-of-Flight
Aerosol
Chemical
Speciation
Monitor
(ToF-ACSM).
However,
observe
correlation
between
sum
measured
ToF-ACSM,
identified
represent
variability
cycles.
This
study
highlights
potential
nontarget
screening
combination
HCA
for
gaining
better
understanding
origin
environment.
