Demineralization of Water Process

Demineralization of Water:

Ion-Exchange Process: Various synthetic ion-exchange resins are nowadays available for softening hard water. They are of two types:

Cation Exchange Resins represented by RH:

Hard water is first passed through cation exchange resins (RH) which removes all the cations like Ca+2, Mg+2, etc. An equivalent amount of H+ ions are released into water.

Anion Exchange Resins represented by NR4OH:

The effluent water contains acids like HCL, H2SO4 etc. Hard water is then passed through a bed of anion exchange resins (NR4OH) which removes all the anions like Cl, SO42-, etc.

The removal of all the cations and anions of the dissolved electrolyte in water is known as Deionisation or Demineralization of Water.