SOFTENERS

º    BY ION EXCHANGE RESINS

Softening is carried out by passing water through an ion exchange cationic resin bed of sodium cycle. The resin, whose insoluble molecules are made up by a polymeric anion and a sodium cation, presents high affinity for divalent cations, such as calcium and magnesium, that generate the hardness that is desired to reduce or eliminate. The reaction is reversible, which is why the resin can be regenerated by making it react by surface contact with a concentrated solution of sodium chloride in order to exchange the calcium and magnesium cations by sodium.

The units are manufactured in standard vertical tanks, whose sizes range from 14” to 120” in diameter and 72” to 144” of straight section.

º    LIME/SODA COLD PRECIPITATION

This process is advantageously used to treat water with moderate to high hardness between 150 and 1000 ppm CaCO3, for which the softening process by ion exchange is not economically nor technically advisable