and Si, Fe are used to modify the titanium dioxide nanomaterial that enhances its use
as waste water decontaminating agent. For example, removal of 2–chlorophenol in
aqueous phase was achieved by Co-doped titanium dioxide nanomaterial catalyst
(Barakat et al. 2005). Rare earth Pr-doped titanium dioxide nanomaterials shows
good photocatalytic activity to degrade the phenol (Chiou and Juang 2007) Shah
et al. (2002) investigated the metalloorganic chemical vapor deposition method to
synthesize pure titanium dioxide and Pd
2+ ,Nd
3+ , Pt
4+ and Fe
3+ -doped titanium
dioxide nanoparticles and their photocatalytic activity to degrade-chlorophenol in
UV light suggesting the position of dopants in the nanomaterials.
The photo degrading properties of titanium dioxide nanomaterials are used to
remove various microorganism like bacteria (Gram-negative and Gram-positive),
fungi, algae, protozoa, and viruses (Foster et al. 2011). Disinfection of wastewater
can be achieved when titanium dioxide nanoparticles is used as dopant. For example,
sulphur-doped titanium dioxide exhibits visible -light-induced antibacterial effect
(Yu et al. 2005), while Fe- doped titanium dioxide sol-gel electrode is shown to
exhibit higher photo electrocatalytic disinfection of E. coli compared to the disinfection by the corresponding undoped electrode (Egerton et al. 2006). Different
adsorbents using titanium dioxide for the removal of different contaminants are
listed in Table 3.3.
3.3.2 Iron Oxide (Fe 2 O 3 ) Nanomaterials
Another important metal oxide nanomaterial for the decontamination of water is iron
oxide nanomaterial due to good sorption capacity, low cost, high removal capability
and easy isolation (Li et al. 2003; Oliveira et al. 2004). Recent investigation on ironbased nanomaterials clearly showed its excellent adsorption capacity for decontamination of metals, inorganic and organic pollutants (Hai and Chen 2001; Onyango
et al. 2003; Oliveira et al. 2004; Herrera et al. 2001; Wu et al. 2004, 2005) Fe 2 O 3 and
Fe 3 O 4 is the most common iron nanomaterial used as an adsorbent for the decontamination of water (Takafuji et al. 2004; Wu et al. 2005). Various parameters have
been dealt with iron oxide nanomaterial for the decontamination of metal ions
(Takafuji et al. 2004; Cornell and Schwertmann 2003). For example, Shen et al.
(2009) reported the adsorption efficiency of Ni
2+ , Cu
2+ , Cd
2+ and Cr
6+ ions by Fe 3 O 4
nanoparticles and shows strong dependency of different parameters like pH, temperature, the adsorbent species and the incubation time.
As far as removal mechanism is concerned for the decontamination of pollutants
different mechanism is used because of variable oxidation state of these
nanomaterials (Tang and Lo 2013). For instance, phosphate isolation in aqueous
phase has been investigated using iron oxide nanomaterial (Yoon et al. 2014).
E. Petala et al. (2017) report the mechanism for the isolation of arsenic using
nanocomposite of magnetic carbon nanocages (iron oxide based). Another study
by Cao et al. (2012) explained the mechanism for the decontamination of As(V) and
3 Metal and Metal Oxide Nanomaterials for Wastewater Decontamination
71
as waste water decontaminating agent. For example, removal of 2–chlorophenol in
aqueous phase was achieved by Co-doped titanium dioxide nanomaterial catalyst
(Barakat et al. 2005). Rare earth Pr-doped titanium dioxide nanomaterials shows
good photocatalytic activity to degrade the phenol (Chiou and Juang 2007) Shah
et al. (2002) investigated the metalloorganic chemical vapor deposition method to
synthesize pure titanium dioxide and Pd
2+ ,Nd
3+ , Pt
4+ and Fe
3+ -doped titanium
dioxide nanoparticles and their photocatalytic activity to degrade-chlorophenol in
UV light suggesting the position of dopants in the nanomaterials.
The photo degrading properties of titanium dioxide nanomaterials are used to
remove various microorganism like bacteria (Gram-negative and Gram-positive),
fungi, algae, protozoa, and viruses (Foster et al. 2011). Disinfection of wastewater
can be achieved when titanium dioxide nanoparticles is used as dopant. For example,
sulphur-doped titanium dioxide exhibits visible -light-induced antibacterial effect
(Yu et al. 2005), while Fe- doped titanium dioxide sol-gel electrode is shown to
exhibit higher photo electrocatalytic disinfection of E. coli compared to the disinfection by the corresponding undoped electrode (Egerton et al. 2006). Different
adsorbents using titanium dioxide for the removal of different contaminants are
listed in Table 3.3.
3.3.2 Iron Oxide (Fe 2 O 3 ) Nanomaterials
Another important metal oxide nanomaterial for the decontamination of water is iron
oxide nanomaterial due to good sorption capacity, low cost, high removal capability
and easy isolation (Li et al. 2003; Oliveira et al. 2004). Recent investigation on ironbased nanomaterials clearly showed its excellent adsorption capacity for decontamination of metals, inorganic and organic pollutants (Hai and Chen 2001; Onyango
et al. 2003; Oliveira et al. 2004; Herrera et al. 2001; Wu et al. 2004, 2005) Fe 2 O 3 and
Fe 3 O 4 is the most common iron nanomaterial used as an adsorbent for the decontamination of water (Takafuji et al. 2004; Wu et al. 2005). Various parameters have
been dealt with iron oxide nanomaterial for the decontamination of metal ions
(Takafuji et al. 2004; Cornell and Schwertmann 2003). For example, Shen et al.
(2009) reported the adsorption efficiency of Ni
2+ , Cu
2+ , Cd
2+ and Cr
6+ ions by Fe 3 O 4
nanoparticles and shows strong dependency of different parameters like pH, temperature, the adsorbent species and the incubation time.
As far as removal mechanism is concerned for the decontamination of pollutants
different mechanism is used because of variable oxidation state of these
nanomaterials (Tang and Lo 2013). For instance, phosphate isolation in aqueous
phase has been investigated using iron oxide nanomaterial (Yoon et al. 2014).
E. Petala et al. (2017) report the mechanism for the isolation of arsenic using
nanocomposite of magnetic carbon nanocages (iron oxide based). Another study
by Cao et al. (2012) explained the mechanism for the decontamination of As(V) and
3 Metal and Metal Oxide Nanomaterials for Wastewater Decontamination
71