it depends however Single ...
Published by Engr. Mansoor Ahmed PhD. Scholar, Consultant/Advisor Water/Wastewater Treatment - Consultant
it depends however Single Pass RO will be better in the sense low CAPEX and Low OPEX . even for sich low feed TDS.. you can use the reject for any other purpose easily. in addition RO has lesser foot print and fully automation.
ion exchange reject cannot be used and even it's regeneration and other aspects require skilled operator than RO. ion exchange has bigger foot print too.
My recommendation is to go for RO you can easily get