Desalination of surface water to industrial water with lower impact on theenvironment - Part 3: Water desalination under alkaline conditions

By combining total water softening in the pretreatment stage with alkaline operation of the partial desalination reverse osmosis stage (LPRO), membran e fouling was prevented without using inhibitors or biocides. The retentate s of this stage can be further concentrated by medium pressure reverse osmo sis (MPRO) or electrodialysis reversal (EDR), thus gaining a higher product yield and possibilities for concentrate reuse. Due to the alkaline conditi ons under which the reverse osmosis membrane operates, scaling caused by si licates and fouling by disserved organic matter, e.g., humic substances are definitely prevented so that a raw feed water yield of up to 98% from rive r water can be obtained.