Table 1.3
A comparative summary of the different metal oxides that have been used in water treatment applications
Metal oxide used
Pollutant removed
Removal
efficiency (%)
Adsorption isotherm
model followed
Adsorption
capacity (mgg
À1
)
Reaction
kinetics
followed
Reference
MnO
2 nanostructures
Methylene blue
dye
85
–
68.4
–
Chen and He
(2008)
α-FeOOH hierarchical
nanostructures
Congo red
–
Langmuir
239
–
Fei et al. (2011)
Fe
3 O
4 hollow nanospheres
Neutral red
90
Langmuir
105
Pseudo second
order
Iram et al.
(2010)
Tungsten oxide nanostructures
Methylene blue
99.4
Langmuir
139
–
Jeon and Yong
(2010)
Iron and manganese oxides
As(III) and As(V)
85 and 100
Langmuir
132 and 77
Pseudo second
order
Ociński et al.
(2016)
Flower-like MgO nanostructures Pb(II) and Cd(II)
–
Langmuir
1980 and 1500
–
Cao et al.
(2012)
Magnetite/reduced graphene
oxide
As(III) and As(V)
99.9
Langmuir and
Freundlich
13.10 and 5.83
Pseudo second
order
Chandra et al.
(2010)
EDTA-functionalized Fe
3 O
4 /
graphene oxide
Pb(II), Hg(II) and
Cu(II)
96.2, 95.1 and
96.5
Langmuir
508.4, 268.4 and
301.2
Pseudo second
order
Cui et al. (2015)
Mesoporous iron/iron oxide
nanocomposites
Cr(VI)
–
Langmuir
34.1
Pseudo
first
order
Kim et al.
(2012)
MnO
2 -coated Fe
3 O
4 /MnO
2
Cd(II)
~97
Langmuir
53.2
Pseudo second
order
Kim et al.
(2013)
Graphene oxide/MnFe
2 O
4
Pb(II), As(III) and
As(V)
100, 96 and
99.5
Langmuir
673, 146 and 207 Pseudo second
order
Kumar et al.
(2014)
Fe
2 O
3 nanofibers
Cr(VI)
–
Langmuir
90.9
Pseudo second
order
Nalbandian
et al. (2016)
Iron oxide-coated sewage sludge Cu(II), Cd(II), Ni
(II) and Pb(II)
41.8, 25.4,
14.2 and 59.7
Langmuir
17.3, 14.7, 7.8
and 42.4
Pseudo second
order
Phuengprasop
et al. (2011)
20
K. Dutta