Mixed-bed water demineralisation
Mixed-bed water demineralisation
Along with undissolved contaminants (particles), most waters contain dissolved ions in different concentrations. Metals and hydrogen are present as cations (positive load), while acid residues and hydroxyl ions are found as anions (negative load).
Those dissolved (dissociated) ions are removed in water treatment units by special cation and anion exchange resins. The resins adsorb the ions dissolved in the water while donating an equivalent amount of identically loaded ions to the water.
The cations dissolved in the water (e.g. Mg++,Ca++, Na+, K+) are replaced by H+ ions through cation exchange resins, while the anions (e.g. Cl-, NO3-, SO42-) are replaced by OH- groups through anion exchange resins. Pure, totally demineralised water is produced.
If the ion exchange resins are saturated (depleted), they can be re-activated through reversal of the adsorption process by means of suitable regenerating agents.
Depleted mixed bed resin can be sent to Herco for regeneration.
