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Water Softening |
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Softening process
Removal of hardness from water is called softening. The
softening is done by ion exchange process. The ion
exchange process works on the replacement of the calcium
and magnesium ions in the water by an equivalent number
of sodium ions.
This eliminates the unwanted charasteristic of hard
water because the sodium salt neither form scale nor a
scum with soap but only lather.The resin will take up
the calcium ion to the extent of what sodium ions resin
will have with it.
Therefore, to give new sodium ions to the resins, the
cheapest and the easiest mean would be to pass the
solution of sodium-chloride (common-salt) through the
resin. The same resin can be used over and over again to
produce soft water a - periodic dossage of sodium
chloride (common-salt) solution. So, recurring cost in
such process is only the cost of common salt.
PURIC systems use the basic ion exchange
principle. With this principle, ions in solution,
including metallic cations such as calcium (Ca ++) and
anions such as chloride (Cl -) are exchanged for other
ions such as hydrogen ie. (H +) and hydrdxyl (OH-) that
are contained inside synthetic ion exchange resins. By
passing the solution through columns of cation and anion
exchange resin, all the ions can be exchanged, leaving
only hydrogen and hydroxyl, which combine, leaving pure
water. Alternatively, by suitable choice of ion exchange
resin, only a portion of the ions can be selectively
removed.
When their exchange capacity has been exhausted,ion
exchange resins can be regenerated.
Today, although the use of ion exchange for water
deioniser is wide spread, its potential in other
application such as chemical processing, material
recovery and pollution abatement remains virtually
untapped. On request write-ups on the above matter can
be submitted.
Portable water deioniser
Water deionisation plant (TWO BED UNIT)
The water free from all minerals is called deionised
water.
Regular water has various salts in dilute form which are
called dissolved solids. Demineralised water is obtained
after passing the raw water through DM Plant.
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