Describe various steps of cleaning wastewater in a wastewater treatment plant.
The following steps are followed
- Screening
First, with the help of bar Screens, the wastewater is filtered for large objects/impurities like sticks, rags, cans, plastic packets, etc.
- Grit removal
The filtered water is slowly moved into a grit settling tank where sand, grit and pebbles are allowed to settle down.
- Primary sedimentation
The water is passed to a large tank having a slope where solid waste like faeces is scraped after settling and surface impurities like oil and grease are skimmed.
- Aeration
The cleared water is aerated for aerobic bacterial growth.
- Secondary sedimentation
The water is left undisturbed for several hours till suspended microbes settle at the bottom of the tank as activated sludge.
- Chlorination
Chlorine is added to disinfect water.
The following steps are followed
- Screening
First, with the help of bar Screens, the wastewater is filtered for large objects/impurities like sticks, rags, cans, plastic packets, etc.
- Grit removal
The filtered water is slowly moved into a grit settling tank where sand, grit and pebbles are allowed to settle down.
- Primary sedimentation
The water is passed to a large tank having a slope where solid waste like faeces is scraped after settling and surface impurities like oil and grease are skimmed.
- Aeration
The cleared water is aerated for aerobic bacterial growth.
- Secondary sedimentation
The water is left undisturbed for several hours till suspended microbes settle at the bottom of the tank as activated sludge.
- Chlorination
Chlorine is added to disinfect water.
