Process for desalting salt water and sterilisation using an electrodialyser

摘要

The novel electrodialyser serves for electrodialysis, but has an additional membrane upstream of the porous anode and porous cathode. Thus separate anode and cathode compartments and prechambers are formed through which the salt water passes through the overflow channels into dilution chambers, where the desalting process takes place by membranes which form the concentration chambers in which the salt brine which is discharged collects. At salt concentrations of < 1 g/l, salt brine is fed from the concentration chambers to the intake stream, from which salt brine, the water hardness salts have been previously been precipitated by addition of alkali from the cathode chamber, slow passing through from behind the porous cathode comprising sintered metal in order to prevent metal deposits on its surface from the dissolved salts. A part-stream of the desalted water exiting from the cathode prechamber is fed from the rear to the front to the anode chamber through the porous electrode which comprises sintered metal, where it absorbs hydrogen ions and then is admixed again with the end product, by which means its pH can be adjusted.