24 How does the purpose of secondary clarification following

24 How does the purpose of secondary clarification following activated sludge differ from that following bioflm processes? (A) (B) (C) (D) There is no difference: the purpose in either application is the same Following activated sludge requires the clarifier to thicken the settled solids. Following activated sludge requires the clarifier to concentrate the solids for recirculation. Following biofilm processes requires the clarifier to skim noating biomass. O O o

Solution

(24)Answer:- ( c ) following activated sludge requires the clarifier to concentrate the solids for recirculation.

(25) Answer:- (B) to allow the formed floc to begin settling as it approaches the outlet.

(26) Answer:- (A) 0.50 m/s

Solution:-

V = 1/n * R^(2/3) * S^(1/2)

V = 1/(0.015) * ( 0.5/4)^(2/3) * (0.001)^(1/2)

V = 0.527 m/s

Velocity = 0.94* 0.527= 0.50 m/s Answer