2 replies to this topic

[Cwsrt]

Good morning.

 

Can someone explain why pH of desalinated water can drop to a pH value of ~5.0-6.0?

 

Is this possibly due to carbon dioxide or other contaminants (as in condensate systems)?

 

Please note that we are employing a thermal desalination technology with chemical injections for antiscale, antifoam and dechlorination (no chemical for pH adjustment).

 

Appreciate your feedbacks.

 

Thank you.

 

regards,

Cwsrt

[Bobby Strain]

Obvioulsy, there is a slight excess of H⁺ ion. This is water's natural state when there are no minerals present. You can probably Google the subject and get a more scientific explanation.

 

Bobby

[aroon]

hi Cwsrt,

 

Yes, presence of dissolved CO2 is one of the main reason of decreasing pH. this is due to acidification reaction.

 

CO_2 (aq) + H₂O  H₂CO₃  HCO₃⁻ + H⁺  CO₃²⁻ + 2 H⁺

 

However, there some more components such as H2S, NH3, some organic,etc., which also causes to decrease the pH. Refer document in below link, which may be useful for you.

 

https://www.google.c....63808443,d.bmk

 

 

Regards,

Aroon