Problem:
A well water with a total hardness of 10.76 ppm is to be used for a pharmaceutical industry, which requires finished water hardness to be 3 ppm. An ion exchange resin is selected requiring 0.3 pounds of salt per kilo-grain of hardness removed to regenerate.
Required:
Question 1: What is the salt usage for the each regeneration if the system regenerated every 10 days?
Question 2: What size resin tanks (diameter, height) would be required for a duplex system with no redundancy?
Note: Provide support for your underlying principle.