About softening
Softening is a process of partial removal of solids solved into e solution, to reduce its hardness.
This process could be considered a particular kind of demineralization (for more information see the related page).
Having stated that most part of incrustations of surfaces in contact with water containing salts are due to bivalent metallic ions salts, and in particular Calcium and Magnesium, it is possible, in some cases to limit the process of demineralization to the removal of those ions, employing ionic exchange resins.
In this case are used cationic resins to obtain the following reaction:
- CaSO4 + Rm ------> RmSO4 + Ca++
If, for example, the metallic Ion Rm is constituted by Sodium Na, we'll obtain Sodium Sulfate, soluble, instead of Calcium Sulfate, almost insoluble.
Regeneration is carried out, instead of using strong acid, using a sodic salt of strong acid, generally NaCl (Sodium Chloride), in saturate solution, and the eluate will be constituted of CaCl2, relatively inert.
Softening, differently from demineralization, doesn't remove solids solved into water, but modify them chemically
Having stated that most part of incrustations of surfaces in contact with water containing salts are due to bivalent metallic ions salts, and in particular Calcium and Magnesium, it is possible, in some cases to limit the process of demineralization to the removal of those ions, employing ionic exchange resins.
In this case are used cationic resins to obtain the following reaction:
- CaSO4 + Rm ------> RmSO4 + Ca++
If, for example, the metallic Ion Rm is constituted by Sodium Na, we'll obtain Sodium Sulfate, soluble, instead of Calcium Sulfate, almost insoluble.
Regeneration is carried out, instead of using strong acid, using a sodic salt of strong acid, generally NaCl (Sodium Chloride), in saturate solution, and the eluate will be constituted of CaCl2, relatively inert.
Softening, differently from demineralization, doesn't remove solids solved into water, but modify them chemically