METHOD OF WATER DEMINERALIZATION OR DEIONIZATION

摘要

In full water desalination with simultaneous neutralisation of water from ion exchange regeneration, the water is freed from Ca- and Mg-ions, before actual full desalination, in a water-softening step. A weakly acidic cation exchanger having -COOH functional gps. in Na form is used, opt. combined with a strongly acidic cation exchanger having -SO3H functional gps. in Na form. When exhausted, the softening step exchangers are regenerated in 2 steps; first with acid waste waters from the full desalination plant cation exchange step regeneration, and then with alkaline waste waters from the full desalination plant anion exchanger step regeneration. The process is used in feed water conditioning for high-pressure tanks. Useful cation exchanger vol. capacity is increased. Investment costs for neutralisation are reduced because the capacious neutralisation vessels are replaced by a cation softening step functioning in the full desalination plant.