11 Nanotechnology: An Efficient Technique of Contaminated …
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that seawater due to its salinity is very corrosive and hence requires the utilization of stainless steel and austenitic, and as a result, excessive energy consumption,
high cost and maintenance are required. To ease this problem, various nanofiltration
membranes are present as an alternative to ultrafiltration and osmosis. The advantage
of using nanofiltration over existing conventional reverse osmosis processes is that
there is less energy consumption and less pressure (Van der Bruggen and Vandecasteele 2003). There are wide range of application of nanofiltration membranes like
the elimination of viruses, microbes, heavy metals and pesticides and also seawater
desalination (Van der Bruggen et al. 2001). From the literature survey, it is reported
that the technical of viral nanofiltration is very effective and efficient in separating
all the biological contaminants. Nanomaterials like alumina fibres and nanotubes
are used for building materials which possess controlled dimensions, density and
shape in order to filter specific components (Mera et al. 2010). Ceramics and polymer are the main categories of membrane materials which exhibit unique benefits
for the fabrication of membrane with multifunctionalities (Mera et al. 2009). The
unique thermal and chemical stability of ceramic membranes adds extra benefits like
enabling it to perform even in extreme condition of temperature and pH and also in the
presence of oxidizing surrounding (Rossi et al. 2014). Ozone oxidizes carbon–carbon
double bonds of organic molecules and electron-rich species. Some polymeric materials like sulfonated polyethersulfone, cross-linked poly(furfuryl alcohol), thin-film
composite, cellulose acetates are reported to be used for desalination.
11.4.2 Magnetic Nanocomposites
Magnetic nanomaterial and nanocatalyst are capable of purifying different types
of inorganic and organic contaminants dispersed in water (Shipley et al. 2009). In
general, metals and enzymes are applied as catalyst but their catalytic performance
enhances by modifying it into nanoscale. At nanoscale, the materials are longer lasting, more reactive and also display better selectivity. Investigation is performed on
magnetic nanoparticles because of their application in the removal of many chemical owing to their high surface area and property of binding with chemical even in
the absence of auxiliary adsorbent material. Magnetite (Fe 3 O 4 ) nanoparticles displayed efficient adsorption behaviour for removing arsenic. These nanoparticles can
be later easily being removed from treated water at lower magnetic field (Fuhrer et al.
2011). The smaller size of these nanoparticles causes enhancement in surface area,
surface energy and fraction of atoms on the surface. By using microwave synthesis
method using sodium hydroxide and ferrous sulphate in the presence of solvent mixture containing water and ethylene glycol, magnetite magnetic microsphere can be
synthesized. Other iron-containing minerals which are applied in wastewater treatment by the adsorption process are maghemite, lepidocrocite, hematite, goethite,
ferrihydrite, feroxyhyte and akaganeite. On surface modification, magnetic nanomaterials display selectivity towards different contaminants and effectively remove
heavy metals like As and other pollutants from water.
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that seawater due to its salinity is very corrosive and hence requires the utilization of stainless steel and austenitic, and as a result, excessive energy consumption,
high cost and maintenance are required. To ease this problem, various nanofiltration
membranes are present as an alternative to ultrafiltration and osmosis. The advantage
of using nanofiltration over existing conventional reverse osmosis processes is that
there is less energy consumption and less pressure (Van der Bruggen and Vandecasteele 2003). There are wide range of application of nanofiltration membranes like
the elimination of viruses, microbes, heavy metals and pesticides and also seawater
desalination (Van der Bruggen et al. 2001). From the literature survey, it is reported
that the technical of viral nanofiltration is very effective and efficient in separating
all the biological contaminants. Nanomaterials like alumina fibres and nanotubes
are used for building materials which possess controlled dimensions, density and
shape in order to filter specific components (Mera et al. 2010). Ceramics and polymer are the main categories of membrane materials which exhibit unique benefits
for the fabrication of membrane with multifunctionalities (Mera et al. 2009). The
unique thermal and chemical stability of ceramic membranes adds extra benefits like
enabling it to perform even in extreme condition of temperature and pH and also in the
presence of oxidizing surrounding (Rossi et al. 2014). Ozone oxidizes carbon–carbon
double bonds of organic molecules and electron-rich species. Some polymeric materials like sulfonated polyethersulfone, cross-linked poly(furfuryl alcohol), thin-film
composite, cellulose acetates are reported to be used for desalination.
11.4.2 Magnetic Nanocomposites
Magnetic nanomaterial and nanocatalyst are capable of purifying different types
of inorganic and organic contaminants dispersed in water (Shipley et al. 2009). In
general, metals and enzymes are applied as catalyst but their catalytic performance
enhances by modifying it into nanoscale. At nanoscale, the materials are longer lasting, more reactive and also display better selectivity. Investigation is performed on
magnetic nanoparticles because of their application in the removal of many chemical owing to their high surface area and property of binding with chemical even in
the absence of auxiliary adsorbent material. Magnetite (Fe 3 O 4 ) nanoparticles displayed efficient adsorption behaviour for removing arsenic. These nanoparticles can
be later easily being removed from treated water at lower magnetic field (Fuhrer et al.
2011). The smaller size of these nanoparticles causes enhancement in surface area,
surface energy and fraction of atoms on the surface. By using microwave synthesis
method using sodium hydroxide and ferrous sulphate in the presence of solvent mixture containing water and ethylene glycol, magnetite magnetic microsphere can be
synthesized. Other iron-containing minerals which are applied in wastewater treatment by the adsorption process are maghemite, lepidocrocite, hematite, goethite,
ferrihydrite, feroxyhyte and akaganeite. On surface modification, magnetic nanomaterials display selectivity towards different contaminants and effectively remove
heavy metals like As and other pollutants from water.