Environmental Engineering Reference
In-Depth Information
Flow
restri
c
tor
3-way
valve
Hg input
measurement
Thermometer
Thermometer
MFC
N
2
Bubble
ow
meter
Mercury
source
Oil bath
Oven
Hg output
measurement
figure 7.16
Fixed-bed apparatus for the determination of mercuric chloride capture characteristics. reproduced with permission from
ref. [43]. © elsevier Science.
Flue gas
HgCl
2
(vapor)
Solvent
≈ 2 nm
Hg
2+
Hg
2+
Hg
2+
Hg
2+
Chelating ligand
Bonding chain
Silica substrate
figure 7.17
Schematic representation of chelating adsorbent for vapor-phase mercury. reproduced with permission from ref. [43].
© elsevier Science.
O
H
N
OH
NH
2
HN
figure 7.18
histidine.
protein, cyanobacterium metallothionein (SmtA) [45]. The formed SmtA-gO composites were found to exhibit ultrahigh
selectivity toward the adsorption of Cd and were then assembled onto the surface of cytopore microbeads and used for highly
selective adsorption and preconcentration of ultratrace Cd. In comparison with bare gO (carboxyl-rich gO)-loaded cytopore
(gO@cytopore), SmtA-gO-loaded cytopore (SmtA-gO@cytopore) shows a 3.3-fold improvement over the binding
capacity of Cd, that is, 7.70 mg/g for SmtA-gO@cytopore compared to 2.34 mg/g for that by gO@cytopore. Another
example is the functionalization of MWCNTs with histidine (Fig. 7.18), which was shown as a simple, rapid, and reliable
approach for improving the selectivity and adsorption capacity of MWCNTs toward Cd
2+
[46]. An additional advantage is
