How Much Concentrate Can You Squeeze With Closed Circuit Desalination and What to Consider

A traditional two-stage RO system was coupled with a 3rd-stage, semi-batch RO process to increase overall recovery above 92%. The CCD process was integrated as a 3rd-stage as it could achieve higher recoveries due to its cyclical operation pattern, ability to achieve higher cross-flow velocities through recirculation of the concentrate stream, and providing varying feed water salinity and flushing, which all contribute to minimize fouling and scaling of the membranes.