Large quantities of sewage is generated every day in cities and towns, which is treated in Sewage Treatment Plants (STPs) to make it less polluted. Given below is the flow diagram of one of the stages of STP.Observe the given flow diagram and answer the questions accordingly.

The significance of the above sediment formed is that:

Options

A. It acts as inoculum
B. It serves in formation of flocs
C. It helps in formation of natural water bodies
D. It helps in anerobic sludge digestion

Answer

A

Explanation

The activated sludge is pumped back into the aeration tank to serve as the inoculum(starter)