What kind of process is secondary treatment?

Select the correct sequence with respect to sewage treatment.
$i$. Removal of suspended solid particles by primary treatment.
$ii$. Wastewater screening
$iii$. Anaerobic bacteria digest activated sludge.
$iv$. Treatment by flocs in aeration tank.
$v$. Grit settling

Physical removal of large and small stable solid particles from the sewage through filtration and sedimentation is called

Before discharging municipal wastewater into natural water bodies like rivers and streams,it is passed through which of the following?

How is primary sludge formed?

Sewage water is purified by ..........