estion 13 The lime requirement mgh it 20 mL of alkalinity is

estion 13 The lime requirement (mg/h it 20 mL of alkalinity is to be supplied as liquid lime Ca(OH)2 to a 10 MGD water treatment plant is closest to

Solution

Answer:- (c ) 15 mg/l

We know that

CaO + H₂O      =    Ca(OH)₂

(40 +16)                 (40 + 34)

56mg/l                       74 mg/l

Then 1mg/l Ca(OH)₂     = (56/74 )mg/l   CaO

Then 20 mg/l Ca(OH)₂    = (56/74) * 20 mg/l CaO

Then 20 mg/l Ca(OH)₂    needed 15.135 mg/l   CaO(Lime)