What would happen if oxygen availability to activated sludge flocs is reduced ?
(A) It will slow down the rate of degradation of organic matter.
(B) The centre of flocs will become anoxic, which would cause death of bacteria and eventually breakage of flocs.
(C) Flocs would increase in size as anaerobic bacteria would grow around flocs.
(D) Protozoa would grow in large numbers.

Options

A. It will slow down the rate of degradation of organic matter.
B. The centre of flocs will become anoxic, which would cause death of bacteria and eventually breakage of flocs.
C. Flocs would increase in size as anaerobic bacteria would grow around flocs.
D. Protozoa would grow in large numbers.

Answer

B

Explanation

If oxygen availability to activated sludge floes is reduced the centre of flocks will become anoxic, which would cause death of bacteria as they require oxygen and eventually breakage of flocks. As a result foul smelling products are produced in anaerobic decomposition.