Abstract: A process is described for treating water, in particular for obtaining ultrapure water, in which a decationized water stream is passed at least through a first strong base anion exchange bed and a second strong base anion exchange bed, which is arranged downstream, in particular directly downstream, of the first strong base anion exchange bed. Furthermore, a water treatment system and a counter-current ion exchange unit for carrying out such a process are described.

Abstract: A process is described for treating water, in particular for obtaining ultrapure water, in which a decationized water stream is passed at least through a first strong base anion exchange bed and a second strong base anion exchange bed, which is arranged downstream, in particular directly downstream, of the first strong base anion exchange bed. Furthermore, a water treatment system and a counter-current ion exchange unit for carrying out such a process are described.

Abstract: The hydrophilic organic contaminants and hydrogen peroxide present in semiconductor fabrication reclaims are removed by means of adsorption of a pyrolysate of a macroreticular sulphonated vinyl-aromatic polymer having a carbon content of at least 85% by weight and a carbon/hydrogen atomic ratio of from 1.5:1 to 20:1. In spite of their hydrophobic surface, the pyrolysates have a comparatively high adsorptivity for these contaminants and provide for distinctively higher removal rates than customary activated carbons.

Abstract: An apparatus for the continuous electrochemical desalination of aqueous solutions includes a wound module having a central electrode, around which are wound an anion exchanger membrane and a cation exchanger membrane, and an outer counterelectrode. Each membrane is sealed at an inner edge thereof and at a outer edge by a respective clamping device, or are anchored in a synthetic resin block, in such a way that a dilution chamber and a concentrate chamber are defined. The dilution chamber and/or the concentrate chamber may contain an ion exchanger resin. The central electrode and the outer counterelectrode each may have a constriction over at least a part of the circumference thereof. The central electrode may furthermore have a recess for receiving the inner clamping device or the inner synthetic resin block in order to achieve a winding having as spiral a cross section as possible.