Determine the lime and soda ash dose, in mg/L as CaO and Na2CO3 , to soften the hames R...

Determine the lime and soda ash dose, in mg/L as CaO and Na₂CO₃ , to soften the hames River water to a final hardness of less than 125 mg/L as CaCO₃. Assume that all the lkalinity is bicarbonate and that the lime is 90% pure and the soda ash is 97% pure.