question_answer

Differentiate between primary sludge and activated sludge.

Answer:

The differences between primary sludge and activated sludge are as follows

Primary sludge	Activated sludge
It includes all solid substances which get settled after primary treatment.	It is the sediment formed from the effluent after secondary treatment.
It does not possess flocs of decomposer microbes.	It possesses flocs of decomposer microbes.
No aeration is required.	Formation of activated sludge requires aeration.
Little decomposition occurs during formation of primary sludge.	A lot of decomposition occurs during the formation of activated sludge.