Without going into mechanism ...
Published by Guru Das Saha
Without going into mechanism and LSI do follow as under before or inside the tank:
1. Allow pH at around 9 don't reduce.
2. Retain calcite filter. if it is not increasing Ca add CaCl2 to increase Ca to 10 ppm.
3. Inject Sodium Hexameta Phosphate ( SHMP ) to maintain 3 to 5 ppm as PO4 in the permeate
This will control corrosion in the tank and transporting line.
1 Comment
Hi Guru Das Saha.
Thanks for your help.
The potable water tanks that are corroding are the storage for each of four sites i deliver potable water to. These tanks also have a Chlorine dosing system incorporated. I cannot allow the water to be stored at a pH of 9 due to the effect on Chlorine.
Published by Chris Riley, Water/Waste water treatment operator/Plumber at Broadspectrum
1 Comment
The pH of 9 of SWRO is not because of high alkalinity or other alkaline ions it is high because it is RO water and ionic strength is less. Acid dosing to reduce pH may make the water more corrosive if the control is proper which is likely. Chlorine will be equally effective if dosed into this water at pH 9, as pH will come down to some extent during chlorination. Try implementing my suggestions as it is which can be subsequently standardised when required.
Published by Guru Das Saha