Nascent
MnO2
colloids
produced
during
permanganate
oxidation
process
is
highly
oxidative
and
appealing
for
the
of
emerging
organic
contaminants
(EOCs).
However,
nascent
usually
show
dense
bulked
structure
which
blocks
availability
active
sites
further
enhancement
reactivity.
Herein,
spherical
with
mesoporous
were
synthesized
via
redox
reactions
between
colloidal
nanospheres
plant
polyphenol
(e.g.,
tannic
acid)
permanganate.
The
shows
exposure
abundant
surface-Mn
(III)
(16.2
mol%),
thus
exhibits
outstanding
performance
towards
EOCs.
Complete
removal
bis-phenol
A
(BPA,
10
mg/L)
was
obtained
1.0
mM
in
40
min
at
neutral
pH.
Mechanism
study
reveals
that
both
Mn(III)
Mn(IV)
contribute
to
BPA.
presence
surface-Mn(III)
greatly
promotes
reactivity
colloids,
leading
a
high
kinetic
0.12
min−1
initial
min.
selectivity
toward
electron
rich
EOCs
good
complicated
water
matrix,
revealing
promising
potential
application.
This
work
provides
distinct
case
engineering
novel
structured
efficient
elimination
water.
Proceedings of the National Academy of Sciences,
Journal Year:
2024,
Volume and Issue:
121(23)
Published: May 28, 2024
Peracetic
acid
(PAA)
is
emerging
as
a
versatile
agent
for
generating
long-lived
and
selectively
oxidative
organic
radicals
(R–O
•
).
Currently,
the
conventional
transition
metal–based
activation
strategies
still
suffer
from
metal
ion
leaching,
undesirable
by-products
formation,
uncontrolled
reactive
species
production.
To
address
these
challenges,
we
present
method
employing
BiOI
with
unique
electron
structure
PAA
activator,
thereby
predominantly
CH
3
C(O)O
radicals.
The
specificity
of
generation
ensured
superior
performance
BiOI/PAA
system
across
wide
pH
range
(2.0
to
11.0),
even
in
presence
complex
interfering
substances
such
humic
acids,
chloride
ions,
bicarbonate
real-world
water
matrices.
Unlike
catalytic
methods,
degrades
sulfonamides
without
producing
any
toxic
by-products.
Our
findings
demonstrate
advantages
decontamination
pave
way
development
eco-friendly
decontaminations
based
on
peroxides.
Environmental Science & Technology,
Journal Year:
2024,
Volume and Issue:
58(44), P. 19571 - 19583
Published: Oct. 23, 2024
Radical-based
advanced
oxidation
processes
(AOPs)
are
among
the
most
effective
technologies
employed
to
destroy
organic
pollutants.
Compared
common
inorganic
radicals,
such
as
Environmental Science & Technology,
Journal Year:
2024,
Volume and Issue:
58(18), P. 8065 - 8075
Published: April 10, 2024
We
report
a
previously
unrecognized
but
efficient
reductive
degradation
pathway
in
peroxydisulfate
(PDS)-driven
soil
remediation.
With
supplements
of
naturally
occurring
low-molecular-weight
organic
acids
(LMWOAs)
anaerobic
biochar-activated
PDS
systems,
rates
12
γ-hexachlorocyclohexanes
(HCH)-spiked
soils
boosted
from
40%
without
LMWOAs
to
maximum
99%
with
1
mM
malic
acid.
Structural
analysis
revealed
that
an
increase
α-hydroxyl
groups
and
diminution
pKa1
values
facilitated
the
formation
carboxyl
anion
radicals
(COO•–)
via
electrophilic
attack
by
SO4•–/•OH.
Furthermore,
kinetics
were
strongly
correlated
matter
(SOM)
contents
than
iron
minerals.
Combining
newly
developed
situ
fluorescence
detector
quenching
experiments,
we
showed
for
high,
medium,
low
SOM
contents,
dominant
reactive
species
switched
singlet
oxygen/semiquinone
SO4•–/•OH
then
COO•–
(contribution
increased
30.8
66.7%),
yielding
superior
HCH
degradation.
Validation
experiments
using
model
compounds
highlighted
critical
roles
redox-active
moieties,
such
as
phenolic
–
OH
quinones,
radical
conversion.
Our
study
provides
insights
into
environmental
behaviors
related
activation
persulfate
broader
horizon
inspiration
more
advanced
reduction
technologies.
Environmental Science & Technology,
Journal Year:
2024,
Volume and Issue:
58(19), P. 8576 - 8586
Published: May 2, 2024
Humic
acid
(HA)
is
ubiquitous
in
natural
aquatic
environments
and
effectively
accelerates
decontamination
by
permanganate
(Mn(VII)).
However,
the
detailed
mechanism
remains
uncertain.
Herein,
intrinsic
mechanisms
of
HA's
impact
on
phenolics
oxidation
Mn(VII)
its
intermediate
manganese
oxo-anions
were
systematically
studied.
Results
suggested
that
HA
facilitated
transfer
a
single
electron
from
Mn(VII),
resulting
sequential
formation
Mn(VI)
Mn(V).
The
formed
Mn(V)
was
further
reduced
to
Mn(III)
through
double
process
HA.
responsible
for
HA-boosted
as
active
species
attacking
pollutants,
while
tended
act
due
their
own
instability.
In
addition,
could
serve
stabilizer
form
complex
with
produced
retard
disproportionation
Mn(III).
Notably,
did
not
mineralize
but
essentially
changed
composition.
According
results
Fourier-transform
ion
cyclotron
resonance
mass
spectrometry
second
derivative
analysis
infrared
spectroscopy,
we
found
triggered
decomposition
C–H
bonds
subsequently
oxygen-containing
functional
groups
(i.e.,
C–O).
This
study
might
shed
new
light
HA/manganese
oxo-anion
process.
Environmental Science & Technology,
Journal Year:
2024,
Volume and Issue:
58(42), P. 19080 - 19089
Published: Sept. 14, 2024
Organic
contaminants
with
lower
Hammett
constants
are
typically
more
prone
to
being
attacked
by
reactive
oxygen
species
(ROS)
in
advanced
oxidation
processes
(AOPs).
However,
the
interactions
of
an
organic
contaminant
catalytic
centers
and
participating
ROS
complex
lack
in-depth
understanding.
In
this
work,
we
observed
abnormal
phenomenon
AOPs
that
degradation
electron-rich
phenolics,
such
as
4-methoxyphenol,
acetaminophen,
4-presol,
was
unexpectedly
slower
than
electron-deficient
phenolics
a
Mn(II)/nitrilotriacetic
acid/peroxymonosulfate
(Mn(II)/NTA/PMS)
system.
The
established
quantitative
structure-activity
relationship
revealed
volcano-type
dependence
rates
on
pollutants.
Leveraging
substantial
analytical
techniques
modeling
analysis,
concluded
would
inhibit
generation
both
primary
(Mn(III)NTA)
secondary
(Mn(V)NTA)
high-valent
manganese
through
complexation
competition
effects.
Specifically,
form
hydrogen
bond
Mn(II)/NTA/PMS
outer-sphere
interactions,
thereby
reducing
electrophilic
reactivity
PMS
accept
electron
transfer
from
Mn(II)NTA,
slowing
down
Mn(III)NTA.
Furthermore,
generated
Mn(III)NTA
is
inclined
react
due
their
higher
reaction
rate
(8314
±
440,
6372
146,
6919
31
M
Triplet-state
dissolved
organic
matter
(3DOM*)
plays
a
crucial
role
in
environmental
aquatic
photochemistry,
with
2,4,6-trimethylphenol
(TMP)
frequently
used
as
chemical
probe
or
quencher
due
to
its
high
reactivity
3DOM*.
However,
the
influence
of
TMP-derived
oxidation
intermediates
on
target
photochemical
reactions
has
not
been
comprehensively
examined.
This
study
investigated
TMP's
effect
photolysis
sulfamethoxazole
(SMX),
common
antibiotic
found
natural
waters,
presence
different
DOM
sources
model
photosensitizer.
Contrary
expectation,
TMP
significantly
accelerated
SMX
photolysis,
extent
enhancement
depending
and
concentrations.
Laser
flash
kinetic
modeling
suggested
long-lived
reactive
species
(TMP-RS),
including
phenoxyl
radicals,
semiquinone
quinones,
key
factors
this
process.
Unlike
3DOM*,
TMP-RS
may
react
formation
non-SMX•+
intermediates.
process
prevents
reduction
SMX•+
subsequent
regeneration
SMX.
The
successfully
predicts
dynamic
contributions
various
during
reaction,
highlighting
critical
TMP-RS.
advances
our
understanding
involvement
triplet-state
photochemistry
suggests
reconsideration
RSs
play
transformation
micropollutants.
Environmental Science & Technology,
Journal Year:
2024,
Volume and Issue:
58(35), P. 15681 - 15690
Published: April 26, 2024
Pharmaceutically
active
compounds
are
an
important
category
of
emerging
pollutants,
and
their
biological
transformation
processes
in
the
environment
crucial
for
understanding
evaluating
migration,
transformation,
environmental
fate
pollutants.
The
cytochrome
P450
105
enzyme
family
has
been
proven
to
play
role
degradation
exogenous
However,
its
thermostability
catalytic
activity
still
need
be
improved
better
adapt
complex
conditions.
This
work
elucidates
key
mechanisms
residues
reaction
through
multiple
computational
strategies,
establishes
a
mutation
library,
obtains
21
single-point
designs.
Experimental
verification
showed
that
16
single
mutants
had
enhanced
thermostability,
with
R89F
L197Y
showing
highest
increases
at
135
119%
relative
wild-type
enzyme,
respectively.
Additionally,
as
result
higher
specific
D390Q,
it
was
selected
combination
mutagenesis,
ultimately
resulting
three
(R89F/L197Y,
R89F/D390Q,
R89F/L197Y/D390Q)
activity.
study
provides
modification
approach
constructing
efficient
variants
semirational
design
can
contribute
development
control
technologies