Environmental Engineering Reference
In-Depth Information
(a)
(b)
Mag = 100 X
Mag = 59 X
WD = 9 mm
200 µm
100 nm
WD = 9 mm
Signal A = In lens
Signal A = SE2
EHT = 10.00 kV
EHT = 10.00 kV
Spectrum35
Cl
(d)
C
(c)
O
Fe
Fe
Cl
Fe
0
2
4
6
8
10
keV
100 µm
Mag = 350 X
WD = 10 mm
Full scale 371 cts Cursor: 0.000
EHT = 10.00 kV
Signal A = In lens
Spectrum13
(e)
Cl
C
(f)
As
Fe
Na
O
Fe
Cl
Fe
As
0
2
4
6
8
10
100 nm
Mag = 100 KX
WD = 3 mm
Full scale 393 cts Cursor: 15.477 (2cts)
keV
Signal A = In lens
EHT = 10.00 kV
FIGURE 36.6
(a) SEM image of Fe-doped phenolic spherical beads; (b) SEM image of the surface of polymeric beads dispersed
with heterogeneous phase; (c) EDX spectra of Fe/As on the surface; (d) SEM image of Fe-doped activated beads;
(e) SEM image of the surface of arsenic-treated Fe-doped activated beads; and (f) EDX spectra of Fe/As on the
surface. (From A.K. Sharma et al., Chem. Eng. Sci ., 65, 3591, 2010.)
(Figure 36.6b) at large magniication shows the absence of pores on the external surface
of the beads. The SEM image also shows the dispersion of a heterogeneous phase on the
external surface of beads. Porosity develops in the beads after carbonization and subse-
quent activation. Figure 36.6c is the representative EDX spectrum. The concentrations of
Fe obtained from the spectra ranged between 0.6% and 2.5% (w/w). Figure 36.6d shows an
SEM image of the activated beads. A distinct change in the surface morphology because of
the activation is evident from the images. The surface morphology also changed following
adsorption with arsenic, as observed in the corresponding SEM image (Figure 36.6e) of the
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