Water treatment process, and membrane separation process and water treatment plant suitable therefor

摘要

A description is given of a multistage process for treating water, wherein a water stream is purified in a membrane separation stage and a downstream deionization unit having at least one concentrate chamber and at least one diluate chamber, wherein the water stream is separated in the membrane separation device into a concentrate stream and at least two permeate streams of different electrical conductivity, and wherein at least the permeate stream having the highest electrical conductivity is fed at least partially into the at least one concentrate chamber and at least the permeate stream having the lowest electrical conductivity is fed at least partially into the at least one diluate chamber of the downstream deionization unit. In addition, a membrane separation device is described which is constructed in such a manner that at least two permeate streams having different electrical conductivity can be generated therein, and also a water treatment plant, comprising at least one such membrane separation device and at least one deionization unit having at least one concentrate chamber and at least one diluate chamber.