What happens to activated sludge?

Options

A. It is generally released into natural water bodies like rivers and streams
B. It is completely pumped back into aeration tank to serve as inoculum
C. The major part of the sludge is pumped into large tanks called anaerobic sludge digesters
D. It undergoes sequential filtration

Answer

C

Explanation

A small part of the activated sludge is pumped back into aeration tank called anaerobic sludge is pumped into large tank called anaerobic sludge digesters.