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A. Srivastava
water, and this is due to lack of protocol to dispose off or to return such drugs to the
pharmacist/concerned agency. All these have led to increased concentration of pharmaceutical compounds in water bodies and wastewater streams. Among the potential
sources of entry of pharmaceuticals and personal care products (PPCPs) in the environment, municipal sewage treatment plants (STPs) contribute a major part (Deegan
et al. 2011). These compounds have the tendency to a mass in living tissues and thus
enter the food chain. The threat lies in the fact that the environmental and human toxicology of most of these compounds have not been studied much, although now this
group of chemicals is receiving more attention. Effective treatment of wastewater is
essential for public health and sanitation, water reclamation, preventing environmental pollution, and protecting water resources from contaminants getting introduced
into the water systems. Furthermore, the treated wastewater is a potential resource,
and its reuse will partially offset supply and demand in water-stressed areas (Nancharaiah et al. 2019). It is, therefore, an urgent need not only to develop reliable and
cost-effective methods to analyze wide range of pharmaceutical compounds but also
to find techno-economically feasible options for their efficient removal from water.
17.1 Conventional Methods of Water Treatment
Mainly four common conventional methods are there to treat wastewater. These
include physical, biological, chemical, and sludge treatment.
Physical Water Treatment (PWT) The main practice involved in physical wastewater treatment is sedimentation, in which insoluble/heavy particles suspended in
wastewater get settled down due to gravity. When the insoluble material settles
down at the base, pure water can be decanted. Physical processes like screening,
sedimentation, and skimming for removing the solids are also included under PWT.
Aeration is another useful technique of PWT. The process consists of circulating
air through water to supply excessive oxygen to it. Filtration is also a widely accepted
method of PWT and is used for filtering the contaminants by the use of special filters
that can separate the contaminants and insoluble particles present in wastewaters.
Sand filters are most commonly used filters as they are readily affordable. Even the
grease found present on the surface of some wastewaters can be removed through
this method.
Biological Water Treatment (BWT) In this method of water treatment, various
biological processes are carried out to break down the organic matter like soap, human
waste, oils and food, etc., which are present in wastewater. In BWT, microorganisms
metabolize the organic matter present in wastewater. BWT can be carried out by
three ways:
• Aerobic processes: Organic matter of wastewater is decomposed by bacteria in
the presence of oxygen, whereby it is converted to carbon dioxide that can be used
by plants.
A. Srivastava
water, and this is due to lack of protocol to dispose off or to return such drugs to the
pharmacist/concerned agency. All these have led to increased concentration of pharmaceutical compounds in water bodies and wastewater streams. Among the potential
sources of entry of pharmaceuticals and personal care products (PPCPs) in the environment, municipal sewage treatment plants (STPs) contribute a major part (Deegan
et al. 2011). These compounds have the tendency to a mass in living tissues and thus
enter the food chain. The threat lies in the fact that the environmental and human toxicology of most of these compounds have not been studied much, although now this
group of chemicals is receiving more attention. Effective treatment of wastewater is
essential for public health and sanitation, water reclamation, preventing environmental pollution, and protecting water resources from contaminants getting introduced
into the water systems. Furthermore, the treated wastewater is a potential resource,
and its reuse will partially offset supply and demand in water-stressed areas (Nancharaiah et al. 2019). It is, therefore, an urgent need not only to develop reliable and
cost-effective methods to analyze wide range of pharmaceutical compounds but also
to find techno-economically feasible options for their efficient removal from water.
17.1 Conventional Methods of Water Treatment
Mainly four common conventional methods are there to treat wastewater. These
include physical, biological, chemical, and sludge treatment.
Physical Water Treatment (PWT) The main practice involved in physical wastewater treatment is sedimentation, in which insoluble/heavy particles suspended in
wastewater get settled down due to gravity. When the insoluble material settles
down at the base, pure water can be decanted. Physical processes like screening,
sedimentation, and skimming for removing the solids are also included under PWT.
Aeration is another useful technique of PWT. The process consists of circulating
air through water to supply excessive oxygen to it. Filtration is also a widely accepted
method of PWT and is used for filtering the contaminants by the use of special filters
that can separate the contaminants and insoluble particles present in wastewaters.
Sand filters are most commonly used filters as they are readily affordable. Even the
grease found present on the surface of some wastewaters can be removed through
this method.
Biological Water Treatment (BWT) In this method of water treatment, various
biological processes are carried out to break down the organic matter like soap, human
waste, oils and food, etc., which are present in wastewater. In BWT, microorganisms
metabolize the organic matter present in wastewater. BWT can be carried out by
three ways:
• Aerobic processes: Organic matter of wastewater is decomposed by bacteria in
the presence of oxygen, whereby it is converted to carbon dioxide that can be used
by plants.