How does the activated sludge appear?

Out of the below given methods which of these produce an odour?

What is the term used for reuse of sewage sludge?

_____ devices remove materials which would damage equipment or interfere with a process.

What is the amount of solids released into wastewater by human beings?

__________ is a process which involves further removal of the nitrogen.

Tube settlers are classified as which type of treatment?

What is the size of the openings for a fine screen?