11 Nanotechnology: An Efficient Technique of Contaminated …
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combined with sensing devices, they can selectively assist in the detection of trace
pollutants (Li et al. 2008).
11.2.1 Nanomaterials Applied in Water Treatment
11.2.1.1 Zeolites
These are defined as crystalline, inorganic porous material bearing highly ordered
structure and generally comprises of oxygen, aluminium and silicon according to
(Camblor et al. 1998). The unique characteristics of zeolites which make it suitable
for various applications like ion exchange, separation and catalysis are high surface
area, chemical and mechanical resistance as reported by Song et al. (2005). These
characteristics are the reason behind its application in the treatment of wastewater.
The traditional method of synthesis of zeolites of the range from 1 to 10 micrometre,
while nanoscaled zeolites consist of five-to-hundred nanometre with uniform and
discrete crystals as reported by Ding and Zheng (2007), Camblor et al. (1998), Xu
et al. (2004).
11.2.2 Carbon-Based Nanomaterials
11.2.2.1 Graphene Nanomaterials
Graphene is defined as consisting of single layer of graphite structure having the
structure similar to honeycomb. It has unique electrical and thermal conductivity.
One of the oxidative forms of graphene which consists of oxygen-based functional
moieties like epoxy, carbonyl, hydroxyl is graphene oxide. Its attractive properties
have captured the attention for application related to various environmental problems.
Graphene possesses excellent number of pi-bonds. Graphene and graphene oxide
bear large surface area. According to Sun et al. (2010), generally in the adsorption
process induced by graphene-based nanomaterials, there are five interactions which
are possible and they are electrostatic and covalent interaction, hydrogen bonding,
pi–pi interaction and hydrophilic effect. These materials are identified to be suitable
for treatments of wastewater using adsorption process to eliminate the contaminants
from the water. Graphene oxide and reduced graphene oxide, which is the modified
form of graphene oxide, are reported to be capable of eliminating heavy metals from
the contaminated water like arsenic (trivalent and pentavalent), mercury (divalent),
cadmium (divalent), copper (divalent), lead (divalent). The graphene-based nanomaterial is also capable of adsorbing anionic contaminants. Li et al. (2011) reported
that graphene is capable of adsorbing fluoride very efficiently with a load capacity of
around thirty-five milligram per gram at 25 °C at pH seven (Li et al. 2011). In Vasudevan and Lakshmi (2012) reported their research on the adsorption of phosphate using
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combined with sensing devices, they can selectively assist in the detection of trace
pollutants (Li et al. 2008).
11.2.1 Nanomaterials Applied in Water Treatment
11.2.1.1 Zeolites
These are defined as crystalline, inorganic porous material bearing highly ordered
structure and generally comprises of oxygen, aluminium and silicon according to
(Camblor et al. 1998). The unique characteristics of zeolites which make it suitable
for various applications like ion exchange, separation and catalysis are high surface
area, chemical and mechanical resistance as reported by Song et al. (2005). These
characteristics are the reason behind its application in the treatment of wastewater.
The traditional method of synthesis of zeolites of the range from 1 to 10 micrometre,
while nanoscaled zeolites consist of five-to-hundred nanometre with uniform and
discrete crystals as reported by Ding and Zheng (2007), Camblor et al. (1998), Xu
et al. (2004).
11.2.2 Carbon-Based Nanomaterials
11.2.2.1 Graphene Nanomaterials
Graphene is defined as consisting of single layer of graphite structure having the
structure similar to honeycomb. It has unique electrical and thermal conductivity.
One of the oxidative forms of graphene which consists of oxygen-based functional
moieties like epoxy, carbonyl, hydroxyl is graphene oxide. Its attractive properties
have captured the attention for application related to various environmental problems.
Graphene possesses excellent number of pi-bonds. Graphene and graphene oxide
bear large surface area. According to Sun et al. (2010), generally in the adsorption
process induced by graphene-based nanomaterials, there are five interactions which
are possible and they are electrostatic and covalent interaction, hydrogen bonding,
pi–pi interaction and hydrophilic effect. These materials are identified to be suitable
for treatments of wastewater using adsorption process to eliminate the contaminants
from the water. Graphene oxide and reduced graphene oxide, which is the modified
form of graphene oxide, are reported to be capable of eliminating heavy metals from
the contaminated water like arsenic (trivalent and pentavalent), mercury (divalent),
cadmium (divalent), copper (divalent), lead (divalent). The graphene-based nanomaterial is also capable of adsorbing anionic contaminants. Li et al. (2011) reported
that graphene is capable of adsorbing fluoride very efficiently with a load capacity of
around thirty-five milligram per gram at 25 °C at pH seven (Li et al. 2011). In Vasudevan and Lakshmi (2012) reported their research on the adsorption of phosphate using