Hg
2+ (Mahapatra et al. 2013). Activated Al 2 O 3 loaded with alum at pH: 6.5 (Tripathy
et al. 2006) and nano-AlO(OH) at pH: 7 ha been used for the removal of fluoride ion
from water (Wang et al. 2009a, b). Further study by Bhatnagara et al. (2010) showed
the decontamination of nitrate from waters using alumina nanomaterials with the
sorption capacity 4.0 mg/g at optimum pH: 4.4.
Recently, functionalized Al 2 O 3 membranes have been reported for water filtration
processes. For example, DeFriend et al. studied the fabrication of alumina ultrafilter
(UF) membranes which is showing high selectivity toward dyes. Removal of methyl
violet and malachite green from water is achieved by nano aluminium hydroxide
(Kerebo et al. 2016) and nano Al 2 O 3 particle (Pathania et al. 2016). Few aluminium
oxide nanomaterials as adsorbents have been listed along with polluted species in
Table 3.6.
3.3.5 Cerium Oxide (CeO 2 ) Nanomaterials
Rare earth oxides emerge as other adsorbents for the decontamination of arsenate,
fluoride and phosphate anions as well as for removal of arsenate, fluoride and
phosphate anions (Hideaki et al. 1987; Tokunaga et al. 1995). Ceria among them
is considered to be important due to its unique properties like ease in conduction of
oxygen ion and increase in capacity to store oxygen (Trovarelli 1996; Inaba and
Tagawa 1996). However, use of cerium oxide nanomaterials in water treatment is
rare, due to their costs involved. Although few adsorbents are used to remove
Table 3.5 Different types of zinc oxide-based nanomaterial adsorbents and pollutants
S. No. Adsorbents
Polluted species
References
1
ZnO Nano-assembly
Cu
2+ , Pb
2+ , Co
2+ , Hg
2+ , Cd
2+ ,
As
3+ , Ni
2+
Singh et al. (2011a, b)
2
Mesoporous ZnO
nanorods
Pb
2+ , Cd
2+
Kumar et al. (2013)
3
ZnO Nanorods
Methyl Orange, Rh6G
Ma et al. (2011), Kim and
Huh (2011)
5
Flower like ZnO
Phenol
Xu et al. (2009)
6
ZnO (Nano-disks)
Methyl Orange
Zhai et al. (2012)
7
ZnO (porous
octahedron)
Methyl Orange
Zheng et al. (2009)
8
ZnO (flower like
assembly)
MB, RhB
Singh et al. (2013a, b, c)
9
1% Ag-doped ZnO
Methyl Orange
Yildirim et al. (2013)
10
Cu-doped ZnO
Resazurin
Mohan et al. (2012)
11
Mn doped ZnO Nanoassembly
MB
Barick et al. (2010)
12
Co doped ZnO
RhB
Qiu et al. (2008)
3 Metal and Metal Oxide Nanomaterials for Wastewater Decontamination
75
2+ (Mahapatra et al. 2013). Activated Al 2 O 3 loaded with alum at pH: 6.5 (Tripathy
et al. 2006) and nano-AlO(OH) at pH: 7 ha been used for the removal of fluoride ion
from water (Wang et al. 2009a, b). Further study by Bhatnagara et al. (2010) showed
the decontamination of nitrate from waters using alumina nanomaterials with the
sorption capacity 4.0 mg/g at optimum pH: 4.4.
Recently, functionalized Al 2 O 3 membranes have been reported for water filtration
processes. For example, DeFriend et al. studied the fabrication of alumina ultrafilter
(UF) membranes which is showing high selectivity toward dyes. Removal of methyl
violet and malachite green from water is achieved by nano aluminium hydroxide
(Kerebo et al. 2016) and nano Al 2 O 3 particle (Pathania et al. 2016). Few aluminium
oxide nanomaterials as adsorbents have been listed along with polluted species in
Table 3.6.
3.3.5 Cerium Oxide (CeO 2 ) Nanomaterials
Rare earth oxides emerge as other adsorbents for the decontamination of arsenate,
fluoride and phosphate anions as well as for removal of arsenate, fluoride and
phosphate anions (Hideaki et al. 1987; Tokunaga et al. 1995). Ceria among them
is considered to be important due to its unique properties like ease in conduction of
oxygen ion and increase in capacity to store oxygen (Trovarelli 1996; Inaba and
Tagawa 1996). However, use of cerium oxide nanomaterials in water treatment is
rare, due to their costs involved. Although few adsorbents are used to remove
Table 3.5 Different types of zinc oxide-based nanomaterial adsorbents and pollutants
S. No. Adsorbents
Polluted species
References
1
ZnO Nano-assembly
Cu
2+ , Pb
2+ , Co
2+ , Hg
2+ , Cd
2+ ,
As
3+ , Ni
2+
Singh et al. (2011a, b)
2
Mesoporous ZnO
nanorods
Pb
2+ , Cd
2+
Kumar et al. (2013)
3
ZnO Nanorods
Methyl Orange, Rh6G
Ma et al. (2011), Kim and
Huh (2011)
5
Flower like ZnO
Phenol
Xu et al. (2009)
6
ZnO (Nano-disks)
Methyl Orange
Zhai et al. (2012)
7
ZnO (porous
octahedron)
Methyl Orange
Zheng et al. (2009)
8
ZnO (flower like
assembly)
MB, RhB
Singh et al. (2013a, b, c)
9
1% Ag-doped ZnO
Methyl Orange
Yildirim et al. (2013)
10
Cu-doped ZnO
Resazurin
Mohan et al. (2012)
11
Mn doped ZnO Nanoassembly
MB
Barick et al. (2010)
12
Co doped ZnO
RhB
Qiu et al. (2008)
3 Metal and Metal Oxide Nanomaterials for Wastewater Decontamination
75