Correction (adjustment) of
pH.
Principle.
The pH adjustment of water is to inject reactants in order to
decrease the pH (per acidification) or raise the pH (per
alkalinization or basifying) to a pH desired value.
The chemical action of the products thus give, as a function of pH of
the water present and the desired pH :
- a decrease or increase of pH
- a decrease or an increase in the alkalinity
(TAC)
- a decrease or increase in free CO2
- adding water to some elements such as sulphates SO4
² - or chlorides Cl-, for example.
Note: Calcium (calcium hardness) does not change.
To do this, six reagents are provided:
Notes alkalinization.
Two cases may occur:
- water is in equilibrium or scale-forming : basification can
lead to a softening of water only (the figurative point on
the Hallopeau carbon graphic goes to the right
balance of CaCO3).
As the objective is not to obtain decarbonate water, the
calculation is not performed.
- water is aggressive: the basification is a water
neutralization, stopping at a desired pH (ie, without necessarily
reach equilibrium)
See thus possibly neutralizing
topic.
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