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5.2.2 Wastewater Treatment
Conventionally wastewater is the used water. The use of water adds additional
constituents making it useless for same purpose.
Polluted water is abandoned in surface water bodies such as ponds, wastewater
tanks, ditches and so on stabilize the wastewater, but supply of oxygen limits the
biodegradation process (Saito et al. 2002).
Effluents discharged from wastewater treatment plants are probable sources of
pathogenic bacteria in the freshwater environment (Frigon et al. 2013). Environmental
protection requires the use of suitable purification systems (Aghalari et al. 2020). As
it is not possible for the composition of wastewater treatment plant effluent to match
the water quality of the receiving system, effluent is likely to significantly impact the
biological and chemical characteristics of the receiving ecosystem (Drury et al. 2013).
Hospitals are important sources of pollutants, which include residues of pharmaceuticals, active component of drugs and metabolite, iodinated contrast media, chemicals,
radioactive markers, etc. The discharge of hospital wastewater, without appropriate
treatment would expose the public in danger of infection (Wang et al. 2020).
Sources of wastewater include the following:
• Human excreta often mixed with toilet paper
• Washing water (clothes, dishes, vehicle, etc.)
• Discarding surplus liquids (cool drinks, cleaning liquid, cooking oil, etc.)
• Industrial process
• Industrial cooling
The constituents picked by water to wastewater depend on the use it has been put
to. Letting the wastewater without treating would result in pollution of water bodies,
soil, and air and contamination of food, which has historically happened in many
instances and discussed in Vol I. That means humans are left with three options:
1. To treat water before use
2. To treat wastewater
3. To treat water and wastewater
Historically, civilization started adopting first choice, which is treating before
use. But later onwards humans started adopting second option also. Furthermore,
currently there is no alternative to the third option even though many developing
countries do not treat wastewater generated by local bodies and are yet to strictly
enforce the laws against private polluters.
It is uneconomical for a country to let a polluter to allow contaminants and build
the contamination in food, air, natural water resources and treat the water by user
every time it is required.
The reasons are many that include the following:
1. Country has to bear the cost of treatment of humans who have gone sick due to
consumption of polluted water and contaminated food.
2. Country will also lose a good proportion of working hours due to sick people.
5.2 Engineering Control
5.2.2 Wastewater Treatment
Conventionally wastewater is the used water. The use of water adds additional
constituents making it useless for same purpose.
Polluted water is abandoned in surface water bodies such as ponds, wastewater
tanks, ditches and so on stabilize the wastewater, but supply of oxygen limits the
biodegradation process (Saito et al. 2002).
Effluents discharged from wastewater treatment plants are probable sources of
pathogenic bacteria in the freshwater environment (Frigon et al. 2013). Environmental
protection requires the use of suitable purification systems (Aghalari et al. 2020). As
it is not possible for the composition of wastewater treatment plant effluent to match
the water quality of the receiving system, effluent is likely to significantly impact the
biological and chemical characteristics of the receiving ecosystem (Drury et al. 2013).
Hospitals are important sources of pollutants, which include residues of pharmaceuticals, active component of drugs and metabolite, iodinated contrast media, chemicals,
radioactive markers, etc. The discharge of hospital wastewater, without appropriate
treatment would expose the public in danger of infection (Wang et al. 2020).
Sources of wastewater include the following:
• Human excreta often mixed with toilet paper
• Washing water (clothes, dishes, vehicle, etc.)
• Discarding surplus liquids (cool drinks, cleaning liquid, cooking oil, etc.)
• Industrial process
• Industrial cooling
The constituents picked by water to wastewater depend on the use it has been put
to. Letting the wastewater without treating would result in pollution of water bodies,
soil, and air and contamination of food, which has historically happened in many
instances and discussed in Vol I. That means humans are left with three options:
1. To treat water before use
2. To treat wastewater
3. To treat water and wastewater
Historically, civilization started adopting first choice, which is treating before
use. But later onwards humans started adopting second option also. Furthermore,
currently there is no alternative to the third option even though many developing
countries do not treat wastewater generated by local bodies and are yet to strictly
enforce the laws against private polluters.
It is uneconomical for a country to let a polluter to allow contaminants and build
the contamination in food, air, natural water resources and treat the water by user
every time it is required.
The reasons are many that include the following:
1. Country has to bear the cost of treatment of humans who have gone sick due to
consumption of polluted water and contaminated food.
2. Country will also lose a good proportion of working hours due to sick people.
5.2 Engineering Control