2013; Gehrke et al. 2015). Carbon nanotubes (CNTs) on account of generation of
oxidative stress in microbes causes rupturing of cell membranes, thus disinfecting
the air carrying tonnes of harmful bacteria and viruses (Brady-Estévez et al. 2008;
Nepal et al. 2008; Mostafavi et al. 2009). CNTs show competence for elimination of
even trace concentrations of toxic constituents of air (Long and Yang 2001). CNTs
have also been explored to be used as chemical sensors for the sensing of carbon
monoxide, carbon dioxide (Varghese et al. 2001), ammonia and nitrogen dioxide
(Kong et al. 2000). Adsorption of vapours of organic compounds like hexane,
toluene and cyclohexane fits them in the category of heterogeneous adsorbents
(Agnihotri et al. 2005).
Treatment of noxious gases and pathogens is successfully carried out with the
help of nano-photocatalysts, which have more potential than their macro-sized
counterparts. Many efforts have been made by researchers to develop catalysts
driven by sunlight for the detoxification of the air. TiO 2 working in conjunction
with other metals have the potential of escalating the prevailing standards of cleanup. When it gets doped with nitrogen, the resultant material TiO 2-X N X showed
enhanced photocatalytic activity even in the visible region of sunlight by increasing
the absorption capacity (Asahi et al. 2001). In addition to it, various other nonmetallic doping elements such as bromide, chloride (Luo et al. 2004), fluorine (Ho et al.
2006) and carbon (Sakthivel and Kisch 2003) have been tested and showed a greater
plunge in the energy levels of TiO 2 , thus enhancing the photocatalytic edges of the
concerned naturally occurring oxide of metal. The resultant shifting of energy bands
to lower levels has been exploited for the degradation of carbon monoxide, benzene,
acetaldehyde and other related organic vapours in air. Combustion involving processes results into the release of harmful elements containing vapours like mercury.
Silica Nps have been incorporated in titania to form nanocomposites of silica-titania
for oxidizing adsorbed mercury into mercuric oxide with less volatile nature
(Pitoniak et al. 2005). Nanomaterials of silica offers the application of heavy metal
removal like that of cadmium and lead from the combustion gases (Biswas and
Zachariah 1997; Lee et al. 2005). Nano-catalysts derived from oxides of metal have
been installed in thermal power plants to remove nitrogen oxides from effluents
(Rickerby and Morrison 2007). Formaldehyde pollution of air is photocatalytically
degraded by Zhang et al. using 3-D macroporous Au-CeO 2 Nps (Zhang et al. 2009).
Successful efforts have been made to degrade benzene and acetone using Ag/AgBr/
TiO 2 nanocomposites (Zhang et al. 2011).
3.4.3 Nanotechnology in Lithosphere
Soil is considered as a sink for pharmaceutical products with concentrations ranging
in units of μg/kg (Gottschall et al. 2012). Ziari et al. had postulated the positive
impact of Nps on the strength of soil. Zycosoil, modified version of glasphalt stands
at higher strength profile with resistance to rutting and stiffness modulus than its
conventional counterpart – asphalt (Ziari et al. 2015). Nanotechniques have made
successful contribution in improving soil quality which have pushed the agriculture
3 Environmental Nanotechnology: Its Applications, Effects and Management
53
oxidative stress in microbes causes rupturing of cell membranes, thus disinfecting
the air carrying tonnes of harmful bacteria and viruses (Brady-Estévez et al. 2008;
Nepal et al. 2008; Mostafavi et al. 2009). CNTs show competence for elimination of
even trace concentrations of toxic constituents of air (Long and Yang 2001). CNTs
have also been explored to be used as chemical sensors for the sensing of carbon
monoxide, carbon dioxide (Varghese et al. 2001), ammonia and nitrogen dioxide
(Kong et al. 2000). Adsorption of vapours of organic compounds like hexane,
toluene and cyclohexane fits them in the category of heterogeneous adsorbents
(Agnihotri et al. 2005).
Treatment of noxious gases and pathogens is successfully carried out with the
help of nano-photocatalysts, which have more potential than their macro-sized
counterparts. Many efforts have been made by researchers to develop catalysts
driven by sunlight for the detoxification of the air. TiO 2 working in conjunction
with other metals have the potential of escalating the prevailing standards of cleanup. When it gets doped with nitrogen, the resultant material TiO 2-X N X showed
enhanced photocatalytic activity even in the visible region of sunlight by increasing
the absorption capacity (Asahi et al. 2001). In addition to it, various other nonmetallic doping elements such as bromide, chloride (Luo et al. 2004), fluorine (Ho et al.
2006) and carbon (Sakthivel and Kisch 2003) have been tested and showed a greater
plunge in the energy levels of TiO 2 , thus enhancing the photocatalytic edges of the
concerned naturally occurring oxide of metal. The resultant shifting of energy bands
to lower levels has been exploited for the degradation of carbon monoxide, benzene,
acetaldehyde and other related organic vapours in air. Combustion involving processes results into the release of harmful elements containing vapours like mercury.
Silica Nps have been incorporated in titania to form nanocomposites of silica-titania
for oxidizing adsorbed mercury into mercuric oxide with less volatile nature
(Pitoniak et al. 2005). Nanomaterials of silica offers the application of heavy metal
removal like that of cadmium and lead from the combustion gases (Biswas and
Zachariah 1997; Lee et al. 2005). Nano-catalysts derived from oxides of metal have
been installed in thermal power plants to remove nitrogen oxides from effluents
(Rickerby and Morrison 2007). Formaldehyde pollution of air is photocatalytically
degraded by Zhang et al. using 3-D macroporous Au-CeO 2 Nps (Zhang et al. 2009).
Successful efforts have been made to degrade benzene and acetone using Ag/AgBr/
TiO 2 nanocomposites (Zhang et al. 2011).
3.4.3 Nanotechnology in Lithosphere
Soil is considered as a sink for pharmaceutical products with concentrations ranging
in units of μg/kg (Gottschall et al. 2012). Ziari et al. had postulated the positive
impact of Nps on the strength of soil. Zycosoil, modified version of glasphalt stands
at higher strength profile with resistance to rutting and stiffness modulus than its
conventional counterpart – asphalt (Ziari et al. 2015). Nanotechniques have made
successful contribution in improving soil quality which have pushed the agriculture
3 Environmental Nanotechnology: Its Applications, Effects and Management
53