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.
(b) The centre of flocs will become anoxic, which would cause death of bacteria and eventually breakage of flocs.
Explanation:
In the secondary treatment of sewage, if oxygen availability to activated sludge flocs (masses of bacteria associated with fungal filaments to form mesh like structure) is reduced; the centre of flocs will becomes anoxic, which would cause death of bacteria and eventually breakage of flocs.