Electronic Supplementary Material (ESI) for RSC Advances.
This journal is © The Royal Society of Chemistry 2016
Supplementary Information
Performance and mechanism of hierarchically porous Ce-Zr oxide
nanospheres encapsulated calcium alginate beads for fluoride
removal from water
Liang Chen a, b, Kaisheng Zhang a, b, Junyong He a, b, Xing-Guo Cai a, b, Weihong Xu a,
b, *
a
and Jin-Huai Liu a, b, *
Nano-Materials and Environmental Detection Laboratory, Institute of Intelligent
Machines, Chinese Academy of Sciences, Hefei, Anhui 230031, PR China
b
Department of Materials Science and Engineering, University of Science and
Technology of China, Hefei, Anhui 230026, PR China
Fig. S1. (a) SEM image of the Ce-Zr oxide hollow nanospheres and (b) the size
distribution of the Ce-Zr oxide nanosphere.
Fig. S2. XRD pattern of (a) Ce-Zr oxide hollow nanospheres and (b) CZ-CABs.
Fig. S3. Effect of the Ce-Zr oxide concentrations (wet beads) on fluoride removal.
Fig. S4. Linear fitting of Pseudo-first-order kinetic model.
Fig. S5. Adsorption isotherms for fluoride removal by pure calcium alginate beads
and CZ-CABs (Adsorbent dose: 0.5 g L-1, pH: 7.0)
Fig. S5 shows the adsorption isotherms of pure calcium alginate beads and CZ-CABs
at varying initial fluoride concentrations of 2 - 200 mg L-1 under neutral conditions,
respectively. The pure calcium alginate beads showed little adsorption for fluoride
with initial fluoride concentration of 2-20 mg L-1, but increased fluoride adsorption
performance at high initial fluoride concentrations and had a adsorption capacity of
56.5 mg g-1 with initial fluoride concentrations of 200 mg L-1, which were consistent
with the results of surface analyses (section 3.6).
Fig. S6. Optical image of the column for filtration study.
Fig. S7. Adsorption and desorption cycles of the regenerated CZ-CABs (Initial
fluoride concentration: 10 mg L-1, adsorbent dose: 0.5 g L-1, pH: 7.0).
Table S1 The calculations of qcal
Model
Pseudo-first-order kinetic model
Pseudo-second-order kinetic model
Equation
qcal
ln(qe  qt )  ln qe  k1t
qt
t
1
t


2
qt k2 qe
qe
qt
qe  qm
Langmuir isotherm model
K L Ce
1  K L Ce
qe  K F Ce n
Freundlich isotherm model
qe
qe
Langmuir-Freundlich isotherm model
qe  qmax
K LF Ce aLF
1  K LF Ce aLF
qe
Tempkin isotherm model
qe  BT ln A  BT ln Ce
qe
Note: where the qcal is the calculated amount of fluoride ion adsorbed for the equation
(1) ( q%  100
 (q
exp
 qcal ) / qexp  ( N i  1) )
2
Table S2 Comparative cost of traditional adsorbent and CZ-CABs
Adsorbents
Activated carbons
Activated alumina
Bone char
Clay
CZ-CABs
qe
(mg g-1)
Cost of adsorbent
(US$ kg-1)
Cost of removal of
1mg L-1 F- (US$)
Ref.
2.25
16.3
4.5
0.8
137.6
21.1
12.1
1.6
0.21
41.5
9.38
0.74
0.35
0.26
0.30
47
51
52
53
this study
Note: (Cost of removal of 1mg L-1 F-) = (Cost of adsorbent) / qe