Environmental Engineering Reference
In-Depth Information
100
80
60
40
20
0
0.0
0.5
1.0
1.5
2.0
Surface Area (m
2
/g)
Figure 5.6
Effect of bagasse surface area on Congo red adsorption [56].
Table 5.3
Effect of impregnation ratio on the textural characteristics of bagasse-
based activated carbons [
58].
Impregnation Ratio
Langmuir SA
(
m
2
g
-1
)
Pore vol.
(
cc.g
-1
)
Av. Pore
Diameter (Å)
25
4.86
0.003
27.5
50
287
0.107
14.9
75
526
0.194
14.8
100
790
0.288
14.6
high temperature of 900 C under nitrogen atmosphere. Then the atmo-
sphere was changed to carbon dioxide for various periods of time (1-15 h)
for activation. Depending on the activation time, the surface area ranged
from 400-1400
m
2
g
-1
. More details regarding the physical and chemical
properties of the prepared activated carbons have been given in Table 5.4.
Also, as illustrated in Figure 5.7, as the surface area increased, the acid
blue uptake capacity of the activated carbon was enhanced, where the acti-
vated carbon with a surface area of 1433
mg.g
-1
had an adsorption capac-
ity of 385
mg.g
-1
. They applied two mathematical models, Langmuir and
Freundlich, to fit their experimental data and found that the Freundlich
equation was the best-fit model. By reviewing the Freundlich parameters,
it was concluded that the steric hindrance associated with the size of the
dye molecules accounts for the observed effect of pore size and surface
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