Method and apparatus for generating ozone by electrolysis

Abstract

There are provided an ozone producing method and apparatus capable of significantly increasing an amount of ozone produced in for-treatment water. In the ozone producing method of the present invention, a noble metal is used as a material constituting the anode, and the for-treatment water contains halogen ions or a compound containing halogen ions.

What is claimed is:  
     
         1 . A method for producing ozone in for-treatment water through electrolysis by passing current between an anode and a cathode, wherein a noble metal is used as a material constituting the anode, and the for-treatment water contains halogen ions or a compound containing halogen ions.  
     
     
         2 . The method of  claim 1 , wherein the halogen ions are chloride ions.  
     
     
         3 . The method of  claim 1  or  2 , wherein the anode is made of platinum, platinum-coated titanium, a platinum-coated titanium alloy, titanium coated with a platinum-iridium alloy, a titanium alloy coated with a platinum-iridium alloy, titanium coated with a platinum-iridium-tantalum alloy, or a titanium alloy coated with a platinum-iridium-tantalum alloy.  
     
     
         4 . The method of  claim 1 ,  2  or  3 , wherein a cation exchange film is disposed between the anode and the cathode.  
     
     
         5 . The method of  claim 1 ,  2 ,  3  or  4 , wherein the for-treatment water is cooled.  
     
     
         6 . The method of  claim 1 ,  2 ,  3 ,  4  or  5 , wherein a value of the current passed between the anode and the cathode is controlled.  
     
     
         7 . An ozone producing apparatus having an anode and a cathode which are immersed in for-treatment water in an electrolysis vessel, wherein the anode is made of a noble metal, and current is passed between the anode and the cathode so as to electrolyze the for-treatment water containing halogen ions or a compound containing halogen ions, thereby producing ozone in the for-treatment water.  
     
     
         8 . The apparatus of  claim 7 , wherein the halogen ions are chloride ions.  
     
     
         9 . The apparatus of  claim 7  or  8 , wherein the anode is made of platinum, platinum-coated titanium, a platinum-coated titanium alloy, titanium coated with a platinum-iridium alloy, a titanium alloy coated with a platinum-iridium alloy, titanium coated with a platinum-iridium-tantalum alloy, or a titanium alloy coated with a platinum-iridium-tantalum alloy.  
     
     
         10 . The apparatus of  claim 7 ,  8  or  9 , wherein a cation exchange film is disposed between the anode and the cathode.  
     
     
         11 . The apparatus of  claim 7 ,  8 ,  9  or  10 , which has cooling means for cooling the for-treatment water.  
     
     
         12 . The apparatus of  claim 7 ,  8 ,  9 ,  10  or  11 , which has a controller for controlling a value of the current passed between the anode and the cathode.