Journal of Hazardous Materials,
Год журнала:
2024,
Номер
486, С. 136997 - 136997
Опубликована: Дек. 24, 2024
In
this
study,
a
novel
adsorbent
called
Ca@SP
was
developed
by
immobilizing
microalgae
protein
(Spirulina
platensis,
SP)
in
an
alginate
matrix
for
enhanced
Pb²⁺
removal
from
aqueous
solutions.
Synthesized
via
situ
crosslinking,
leverages
the
synergistic
effects
of
alginate's
gel-forming
ability
and
SP's
N-rich
biomass.
Characterization
revealed
green
spherical
hydrogel
with
BET
specific
surface
area
159.5
m²/g.
The
composite
exhibited
pH-dependent
highly
selective
adsorption
over
other
divalent
metal
ions,
which
can
be
explained
relatively
lower
hydrated
Gibbs
free
energy
Pb²⁺.
main
mechanisms
were
identified
as
physical
adsorption,
electrostatic
interaction,
complexation,
ion
exchange.
Column
experiments
demonstrated
Ca@SP's
effectiveness
under
various
operational
conditions,
including
flow
rate,
influent
concentration,
column
heights.
RSM
employed
to
optimize
process,
initial
pH
emerging
critical
parameter
influencing
efficiency.
Desorption
showed
that
acidic
solvents
had
higher
desorption
efficiency
than
alkaline
solvents,
potential
reusability
confirmed.
These
results
suggest
has
effective
sustainable
environments.
Minerals,
Год журнала:
2025,
Номер
15(5), С. 465 - 465
Опубликована: Апрель 30, 2025
Numerous
studies
have
been
conducted
on
the
removal
of
heavy
and
toxic
metals
using
protonated
dry
alginate
beads
(PDABs)
as
a
cation
exchanger.
However,
there
is
scarcity
research
kinetics
copper
elution
with
biosorbents,
despite
necessity
restoring
them
to
their
original
state
undiminished
biosorption
capacity
for
reuse.
This
study
analyzes
parameters
that
directly
affect
rate
ions
from
PDABs.
The
examined
include
temperature
(5–80
°C),
sulfuric
acid
concentration
(0.0005–0.0153
M),
stirring
speed
(0–500
rev
min−1),
different
acids
(HNO3,
HCl,
HClO4).
Additionally,
stability
was
assessed
over
multiple
cycles.
results
indicate
mechanism
governed
by
ion
exchange
between
protons.
significantly
influenced
H2SO4
concentration,
achieving
an
efficiency
98.6%
at
80
°C
0.0056
M.
were
adequately
described
Lagergren
pseudo-first-order
model.
dependence
found
be
order
0.4.
Furthermore,
intrinsic
constants
determined,
activation
energy
9.2
kJ
mol−1
obtained
within
studied
range.
These
findings
chemically
controlled
process.
Materials,
Год журнала:
2025,
Номер
18(3), С. 629 - 629
Опубликована: Янв. 30, 2025
This
paper
presents
the
preparation
and
study
of
properties
alginate
materials,
which
were
obtained
on
basis
sodium
alginate,
activated
carbon,
cellulose,
calcium
chloride.
Alginate–carbon
(AlgCa
+
C)
alginate–cellulose
Cel)
composites,
as
well
pure
(AlgCa)
for
comparative
purposes,
obtained.
Their
textural
(nitrogen
adsorption/desorption
isotherms),
morphological
(scanning
electron
microscopy),
thermal
(thermal
analysis),
acid–base
(pH
drift
method)
properties,
swelling
index,
investigated.
Additionally,
to
determine
adsorption
comprehensive
equilibrium
kinetic
studies
salts
ibuprofen
(IBP),
diclofenac
(D),
naproxen
(NPX)
from
aqueous
solutions
biocomposities
carried
out.
Adsorption
isotherms
fitted
using
Marczewski–Jaroniec
isotherm
equation
(R2
=
0.941–0.988).
Data
rate
analyzed
simple
equations,
best
quality
fit
was
multi-exponential
−
1
(3.9
×
10−4)–(6.9
10−4)).
The
highest
values
reached
in
systems
with
alginate–carbon
composite
1.23
mmol/g
NPX,
0.81
D,
0.43
IBP.
AlgCa
C
material
characterized
by
a
large
specific
surface
area
(1151
m2/g),
high
degree
(300%)
resistance
temperatures.
