A lime-soda softening plant treats a flow of 150 MGD, and the water has 86mg/l Ca2+, 35 mg/L Mg2+, 299 mg/L HCO3- and 6mg/l CO2. The commercial grade of quicklime has a purity of 85% and the soda ash has a purity of 95%. Determine:
a. The pounds of quicklime and soda ash required per million gallons
b. The tons of quicklime and soda ash required per month if a month is considered to be 30 days.
The solution contains 4 pages of details explaining how one would go about solving this type of problem. Every step is written out. The actual multiplication calculations are left to the reader. The generality of the procedure helps to allow the reader the understanding of how one would apply this same scenario given different starting values. A useful Table of Equivalent Common Substances is included. The procedure for writing as CaCO3 is shown, along with how to calculate the Lime and Soda Dosages required. The purity content of Quicklime and Soda Ash are taken into account during calculation. Finally, a conversion process is shown for converting values from one type of concentration units/flow units to another.