Résumé:
This work aims at
valorizing olive stones as an agricultural waste into an
efficient
granular activated carbon
for the removal of Methylene blue
in
batch
and fixed bed
modes
from
aqueous solutions. The adsorption capacity of the
prepared activated carbon was evaluated using these two
modes
. The
activated
carbon
preparation was carried out in two steps: an impregnat
ion with 50%
phosphoric acid at 170 °C for 2.5 hours followed by physical activation using
steam at 750 °C. Nitrogen adsorption studies at 77
K on
the prepared and
commercial (Organosorb 10)
activated carbon
s
resulted in specific surface areas
of
1031.5 and 1029.2 m
2
.g
-
1
, respectively. The Langmuir model
was found to
describe correctly
the isothermal adsorption of
Methylene blue
for both
adsorbents and resulted in adsorption capacities for the olive stone
activated
carbon
of 107
mg.g
-
1
and
121 mg.
g
-
1
for the commercial one. This study shows
that olive stones as a waste can be valorized into a value added adsorbent that can
replace effectivel
y costly commercial materials.
