Environmental Engineering Reference
In-Depth Information
5.4.1.1 Physical Characteristics of Activated Carbon After High Temperature
Removal
Table 5.4 shows the changes in the physical structure characteristics of ACs treated
by decomposing SFGs with protective inert gas at temperatures of 1200 °C. The
surface physical characteristics of ACs were determined by Autosorb/1/C, a type of
automated chemisorption/physisorption analyzer for surface area and pore size
measurements.
The specific surface area, total pore volume, and micropore volume of treated
ACs decreased. The decrease in the specific surface area of AC was about 20%
except for C-AC, which was about 10%. Based on changes in the characteristics of
total pore and micropore volumes, the influence of the decomposing process on
micropore volume was less than that on other pore volumes.
The fractal dimension also indicated that the surface roughness of treated AC
increased but the overall physical structure characteristics of treated AC did not
change a lot.
Ta b l e 5. 4
Changes in the physical structure characteristics of ACs treated by decomposing SFGs
Specific
surface area
(m
2
/g)
Total pore
volume
(cm
3
/g)
Micropore
volume (<20Å)
(cm
3
/g)
Average
pore size
(Å)
Treated by de-
composing SFGs
Fractal di-
mension (
D
)
ACs
YES
1515
0.94
0.72
24.7
2.62
A-AC
NO
1218
0.71
0.58
23.6
2.70
YES
1561
1.46
0.74
37.4
2.53
B-AC
NO
1220
1.03
0.58
33.8
2.60
YES
1091
0.59
0.51
21.7
2.86
C-AC
NO
1004
0.52
0.47
22.0
2.86
YES
1070
0.81
0.48
30.4
2.76
D-AC
NO
799
0.68
0.38
33.9
2.79
5.4.1.2 Chemical Characteristics of Activated Carbon After High Tempera-
ture Removal
The surface chemical compositions of ACs were analyzed using a JEOL JEM/2010
electron microscope with the INCA energy dispersive X-ray microanalysis.
Fig. 5.16 shows the Transmission Electron Microscopy (TEM) micrographs and
energy dispersive X-ray microanalysis of element compositions at locations 1 (0.2
m observation) and 2 (0.5 m observation) on the surface of A-AC. The atoms and
weight distribution proportion of elements at locations 1 and 2 on the surface of
A-AC are shown in Tables 5.5 and 5.6, respectively. Among the elements found on
the surface of A-AC, Cu was composed of a device for supporting the sample
during the analyzing.
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