The conventional approach to desalting brackish waters is to use reverse osmosis (RO) with a blend stream to achieve a desired target water quality. Sulfuric acid is typically dosed in the feed along with an antiscalant to prevent fouling from sulfate salts, calcium phosphate, calcium carbonate and silica. Caustic or lime is added to the blended product to produce stable, nonaggressive water. This paper describes an alternate approach using a two pass system with NF and RO. The two pass approach offers a means of removing predominantly sodium chloride (NACl) while reducing chemical addition requirements for pH adjustment. A pilot study was conducted through the summer of 2014 to demonstrate the viability of this approach.
This presentation is available to AMTA Members only.
- Robert McCandless, P.E.
- Brown and Caldwell
- AMTA/AWWA Membrane Technology Conference, Orlando, FL
- AMTA/AWWA Membrane Technology Conference
- Optimizing salinity, Reclaimed water, pH adjustment