System Water Softener

Water Softening Plant

The treatment of water through Water Softening is the most common type of Ion Exchange process. Water with hardness minerals, such as Calcium and Magnesium, are passed through a bed of Cation Exchange media to exchange the Calcium and Magnesium Ions in the water with Sodium or Potassium Ions from the Ion Exchange resin.

This effectively removes these hardness minerals from the water, but increases the Sodium and Potassium levels of the water leaving the treatment stage. The term "hardness" was originally applied to waters that were hard to wash in because hardness minerals prevent soap from lathering and produces an insoluble "curdy" precipitate in water.

Water Softener Treatment

Dissolved Calcium and Magnesium are also responsible for most scale (coating) build-up in plumbing pipes and water heaters. Hard water in the home makes bathing and laundry cleaning more difficult, leaves visible white chalky residue on plumbing fixtures and can affect the life and efficiency of electrical appliances and water heaters.

How It Works - water being treated for Hardness flows into a tank of Ion Exchange Water Softening resin. The most common resin used for this application is insoluble beads of polystyrene bonded with divinylbenzene that are about 1/64" to 1/32" in size. This Ion Exchange resin is permanently negatively charged and attract positively charged Ions (Cations). The Ion Exchange resin holds positively charged monovalent (one+ charge) Sodium (Na+) or Potassium (K+) Ions. When positively charged divalent (two++ charge) Calcium (Ca++) and Magnesium (Mg++) Cations approach the Ion Exchange resin, a chemical reaction occurs in which the Sodium or Potassium Ions on the Ion Exchange resin are replaced by an equivalent quantity of Calcium and Magnesium Ions that were in the water. There is a stronger attraction for divalent ions over monovalent ions because of the greater positive charge, therefore the less attracted Sodium and Potassium ions are released from the Ion Exchange resin and the more attracted Calcium and Magnesium Ions are adsorbed in the Ion Exchange resin.