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Abstract:
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The term ‘water pollution’ broadly refers to the contamination of
water and water bodies (e.g. lakes, rivers, oceans, groundwater etc).
Water pollution occurs when pollutants are discharged directly or
indirectly into water bodies without adequate treatment to remove the
harmful contaminants. This affects not only the plants and organisms
living in these bodies of water but also the entire natural biological
communities and the biodiversity.Advanced Oxidation Processes (AOPs) have been tested as
environment-friendly techniques for the treatment of contaminated water,
in view of their ability to convert pollutants into harmless end products.
These techniques refer to a set of treatment procedures designed to
remove organic or inorganic contaminants in wastewater by oxidation.
The contaminants are oxidized by different reagents such as air, oxygen,
ozone, and hydrogen peroxide which are introduced in precise, preprogrammed
dosages, sequences and combinations under appropriate
conditions. The procedure when combined with light in presence of
catalyst is known as photocatalysis. When ultrasound (US) is used as the
energy source, the process is referred as sonication. Sonication in
presence of catalyst is referred as sonocatalysis. Of late, combination of
light and sound as energy sources has been tested for the decontamination
of wastewater in the presence of suitable catalyst. In this case, the process
is referred as sonophotocatalysis. These AOPs are specially advantageous
in pollution control and waste water treatment because unlike many other
technologies, they do not just transfer the pollutant from one phase to another but completely degrade them into innocuous substances such as
CO2 and H2O. |