The softening of hard water requires an ion exchange method. Its purpose is to use a cation exchange resin to exchange calcium and magnesium ions in hard water with sodium ions to reduce the concentration of calcium and magnesium ions in the water source. The softening reaction formula is as follows:
Ca2 ++ 2Na-EX → Ca-EX2 + 2Na + 1
Mg2 ++ 2Na-EX → Mg-EX2 + 2Na + 1
EX in the formula represents an ion exchange resin. After these ion exchange resins combine Ca2 + and Mg2 +, Na + ions originally contained therein are released.
The resin matrix contains sodium chloride. During the softening of hard water, sodium ions will be gradually used up and the softening effect of the exchange resin will gradually decrease. At this time, regeneration work is needed. That is, a specific concentration of saline is added at regular intervals, usually 10%. The reaction method is as follows:
Ca-EX2 + 2Na + (concentrated saline) → 2Na-EX + Ca2 +
Mg-EX2 + 2Na + (concentrated saline) → 2Na-EX + Mg2 +
If there is no softening of cations in the water treatment process, not only the calcium and magnesium bodies will be deposited on the reverse osmosis membrane, which will reduce the efficiency or even destroy the reverse osmosis membrane. It will also be easy to get hard water syndrome after long-term drinking. Hard water softeners can also cause bacterial reproduction problems, so the device needs to have a backflush function. After a period of time, backflush once to prevent too much impurities from adsorbing on it.
The fully automatic sodium ion exchanger uses the principle of ion exchange to remove calcium and magnesium scaling ions in water. When raw water containing hardness ions passes through the resin layer in the exchanger, the calcium and magnesium ions in the water are replaced with sodium ions adsorbed by the resin. The resin adsorbs calcium and magnesium ions and the sodium ions enter the water. Water is softened water with its hardness removed.