1.1 Introduction
Since, water is the most essential compound for survival of majority of lives on
earth; therefore, its contamination in any form is going to cause an irreversible,
irreparable and detrimental effect on lifeforms on our planet. As humans, we use
water on a daily basis for various purposes – the most important of which is its
consumption. Therefore, owing to the ever-increasing levels of pollution of water
bodies around the world at an alarming rate, we are forced to consume harmful and
toxic substances that are present in water. Apart from consumption, owing to the
various daily activities like washing, cleaning, etc., we regularly come in contact
with water along with the contaminants that are present in it. The pollutant particles
present in water are harmful, most often toxic and in certain cases carcinogenic
and/or mutagenic as well (Sciacca and Conti 2009; Saxena et al. 2016; Naushad et al.
2018; Lu and Astruc 2018). Regular intake and contact with these substances can
lead to severe health issues, even leading to death in the extreme cases (Landrigan
et al. 2018; Saha et al. 2017). With already high level of pollution, followed by
continuous addition of pollutants each passing moment, the concentration of the
different categories of polluting materials are often present in excess of the prescribed safety limit.
It is a general perception that underground water is probably one of the least
contaminated sources of water due to the fact that it has the least possibility of
getting exposed to pollutants, as it is considered to be protected within the natural
underground reservoirs and also getting naturally filtered out of pollutants while
passing through different layers of rocks present underground. However, various
human activities have led to slow leaching and percolation of chemicals, in the forms
of fertilizers, pesticides, arsenic, etc., to these underground water reservoirs and, in
the process, contaminating the underground water. Moreover, the underground
water reserves are in grave danger and facing near total exhaustion in most parts
of the world, including India and parts of west and southeast Asia as well as parts of
Africa, Central, North and South America, Europe and Australia. The future prediction on the underground fresh water scarcity issue is threatening enough to immediately start taking remedial steps with extremely high intensity and rapid pace.
Now, alternatives to underground water are water available in waterbodies, such as
oceans, seas, rivers, lakes, ponds, etc. However, these are the most contaminated
source of water, and is most often not fit for consumption or other daily usages.
These water bodies keep on getting increased level of pollutants mainly from
industrial, municipal, domestic, agricultural and animal wastewater effluents. On
the other hand, the largest water reservoirs in the world are the oceans and seas.
However, we have still not been able to utilize, to a satisfactory extent, the water
contained in these bodies mainly because of their inherently high salt content, apart
from the presence of pollutants. Therefore, the present fresh water crisis scenario can
be summarized as arising due to three following reasons: (a) rapid depletion and near
extinction of underground water, (b) huge level of polluting contamination of water
bodies and (c) inherent salinity of water present in seas and oceans.
2
K. Dutta
Since, water is the most essential compound for survival of majority of lives on
earth; therefore, its contamination in any form is going to cause an irreversible,
irreparable and detrimental effect on lifeforms on our planet. As humans, we use
water on a daily basis for various purposes – the most important of which is its
consumption. Therefore, owing to the ever-increasing levels of pollution of water
bodies around the world at an alarming rate, we are forced to consume harmful and
toxic substances that are present in water. Apart from consumption, owing to the
various daily activities like washing, cleaning, etc., we regularly come in contact
with water along with the contaminants that are present in it. The pollutant particles
present in water are harmful, most often toxic and in certain cases carcinogenic
and/or mutagenic as well (Sciacca and Conti 2009; Saxena et al. 2016; Naushad et al.
2018; Lu and Astruc 2018). Regular intake and contact with these substances can
lead to severe health issues, even leading to death in the extreme cases (Landrigan
et al. 2018; Saha et al. 2017). With already high level of pollution, followed by
continuous addition of pollutants each passing moment, the concentration of the
different categories of polluting materials are often present in excess of the prescribed safety limit.
It is a general perception that underground water is probably one of the least
contaminated sources of water due to the fact that it has the least possibility of
getting exposed to pollutants, as it is considered to be protected within the natural
underground reservoirs and also getting naturally filtered out of pollutants while
passing through different layers of rocks present underground. However, various
human activities have led to slow leaching and percolation of chemicals, in the forms
of fertilizers, pesticides, arsenic, etc., to these underground water reservoirs and, in
the process, contaminating the underground water. Moreover, the underground
water reserves are in grave danger and facing near total exhaustion in most parts
of the world, including India and parts of west and southeast Asia as well as parts of
Africa, Central, North and South America, Europe and Australia. The future prediction on the underground fresh water scarcity issue is threatening enough to immediately start taking remedial steps with extremely high intensity and rapid pace.
Now, alternatives to underground water are water available in waterbodies, such as
oceans, seas, rivers, lakes, ponds, etc. However, these are the most contaminated
source of water, and is most often not fit for consumption or other daily usages.
These water bodies keep on getting increased level of pollutants mainly from
industrial, municipal, domestic, agricultural and animal wastewater effluents. On
the other hand, the largest water reservoirs in the world are the oceans and seas.
However, we have still not been able to utilize, to a satisfactory extent, the water
contained in these bodies mainly because of their inherently high salt content, apart
from the presence of pollutants. Therefore, the present fresh water crisis scenario can
be summarized as arising due to three following reasons: (a) rapid depletion and near
extinction of underground water, (b) huge level of polluting contamination of water
bodies and (c) inherent salinity of water present in seas and oceans.
2
K. Dutta