Environmental Engineering Reference
In-Depth Information
Table 5.7
Comparison of adsorption capacities of peat.
Modification
Surface
Area
(
m
2
g
-1
)
Dye Type
pH
Adsorption
Capacity
(
mg.g
-1
)
Ref.
N/A
…
Acid Blue 25
…
12.7
[65]
Basic Blue 69
195
N/A
0.7
Reactive Black 5
7
7.0
[66]
N/A
…
Methylene Blue
3
303
[67]
H
2
SO
4
- Polyvinylalcohol
and formaldehyde
9-11
Basic Magenta
…
67.6
[124]
Basic Green 4
69.0
N/A
32.5
Basic Blue 3
…
512.9
[68]
Basic Red 22
270.9
Basic Yellow 21
655.8
Table 5.8
Effect
of temperature on textural characteristics of bamboo chars [72].
Temperature
(K)
Yield (%)
BET SA
(
m
2
g
-1
)
Pore vol.
(
cc.g
-1
)
Micropore
vol.
(
cc.g
-1
)
Mesopore
vol.
(
cc.g
-1
)
673
30.8
110
0.044
0.018
0.026
773
25.3
126
0.103
0.025
0.078
873
25.1
156
0.079
0.065
0.014
973
24.0
194
0.102
0.083
0.019
1073
23.0
263
0.145
0.097
0.048
1173
22.6
327
0.185
0.140
0.045
the pyrolysis temperature increased from 673 to 1173 K, the surface area
also increased from 110 to 327
mg.g
-1
, according to Table 5.8. This was
attributed to the pore development with the removal of volatiles at higher
temperatures, which also accounts for the reduction in the production
yield of activated carbon. The very rapid increase of surface area at tem-
peratures of higher than 1073 K was related to the decomposition of the
lignin, whereas cellulose and hemicellulose decompositions occurred at a
much lower temperature (673 K). Very prolonged furnace holding time
decreased the surface area due to the realignment of carbon atoms and
consequent contraction of char. Also, by changing the heating rate differ-
ent surface areas revealed the temperature gradient inside the particles. It
is worth noting that the highest surface area was obtained at a heating rate
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