Question

Explain primary process of waste water treatment plant .

》No wrong answer !

Answer 1

1 Primary treatment consists of temporarily holding the sewage in a quiescent basin where heavy solids can settle to the bottom while oil, grease and lighter solids float to the surface. The settled and floating materials are removed and the remaining liquid may be discharged or subjected to secondary treatment. Some sewage treatment plants that are connected to a combined sewer system have a bypass arrangement after the primary treatment unit. This means that during very heavy rainfall events, the secondary and tertiary treatment systems can be bypassed to protect them from hydraulic overloading, and the mixture of sewage and stormwater only receives primary treatment.
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Answer 2

wwtp consists of following steps
1. primary treatment:
a) screening_ bar screens remove the large particals.
b) grit and sand removal tank_
grit and sand are allowed to settle down.
c) primary sedimentation_ water is allowed to settle down and decantation takes place.
2. secondary treatment;
a) aeration_ compressed air is provided to allow aerobic bacteria to grow.
b) secondary sedimentation_ again small impurities are allowed to settle down.
3_ tertiary treatment_ water us treated with ozone and chlorine...