Wastewater story · अपशिष्ट जल की कहानी
A free Chemistry lesson for Class 7 children.
Dirty water from homes, factories and farms is called wastewater or sewage.
Sewage flows through sewers to a wastewater treatment plant.
First, bar screens remove large objects like rags, sticks and plastic.
Next, sand and grit settle in a grit tank.
In the clarifier, solids settle at the bottom as sludge.
Air is pumped into the water so that bacteria can eat up the remaining waste.
Finally the water is disinfected with chlorine before it is released.
The sludge is broken down by bacteria to make biogas.