Ion Exchange resin Regeneration steps
The general regeneration procedure for ion echange vessels is as follows:
Backwash resin bed (co-flow regeneration only) to remove suspended solids and decompact the bed.
Inject regenerant diluted in appropriate water quality. The injection is at a low flow rate, so that the contact time is 20 to 40 minutes.
Displace the regenerant with dilution water at the same flow rate.
Rinse the bed at service flow rate with feed water until the desired treated water quality is obtained.
The above is valid for most ion exchange columns, e.g. softening, nitrate removal, de-alkalisation. For demineralisation, the cation column is regenerated first with acid, then the anion column with caustic soda; alternatively, both are regenerated at the same time.