ION EXCHANGE

The substitution of one Ion for another in certain substances. Either Anion Exchange or Cation Exchange is possible. The most common cation exchange involves the conversion of Hard Water to Soft Water by means of a Water Softening process. Hard water contains the divalent ions of calcium (Ca+2) and magnesium (Mg+2), which cause soap and detergents to form precipitates in water. A Water Softener consists of a resin that is saturated with sodium ions (Na+). As hard water percolates through the resin, the ions of calcium or magnesium are removed as they attach to the resin, thus releasing (being exchanged for) sodium ions.