Some industries need biologically pure water, at various degrees of chemical purity, for their processes.
Other industries require water with low level of dissolved solids to minimized scale formation using it as boiler feed or free of
impurities using it as rinsing water.
By careful selection of membrane type and operational conditions, a membrane system can be designed and combined with an ion exchange unit, if necessary, to give water of the desired purity: sterile, demineralized, ultrapure or simply with reduced salinity.