Question

Sewage treatment process includes all of these features, except

• A. A small part of the activate sludge is pumped back into the aeration tank to serve as incoculum
• B. Activated sludge cannot be used in anaerobic digestion process
• C. Anaerobic bacteria digest aerobic bacteria in sludge digesters
• D. Transfer of primary effluent in aeration tanks

Answer 1

Answer: (C)

Anaerobic bacteria digest aerobic bacteria in sludge digesters

The process of removal and digestion of inorganic and organic waste present in the sewage water is called sewage treatment.

A. The flocs of bacteria obtained after treatment of the sewage water is called activated sludge. A small part of it is pumped back into the aeration tank which will act as inoculum and will multiply to start the digestion of organic compounds again.

B. Activated sludge can be anaerobic bacterium as well.

C. In sludge digesters, the digestion of organic compounds occurs.

D. Primary effluent is transferred to the aeration tanks for the purpose of digestion through aerobic bacteria.

Hence, the correct answer is 'Anaerobic bacteria digest aerobic bacteria in sludge digesters'.