Method and Apparatus for Scale and Biofilm Control

Abstract

Method and apparatus for electrolytically controlling the formation of scale and biofilm in water purification and other systems. An anode is deposited on or disposed on or adjacent to a surface, such as that of a quartz UV tube, providing a low pH environment which inhibits the formation of carbonate scale and biofilm.

1 . An apparatus for reducing carbonate scale formation on a surface, the apparatus comprising:
 an object in contact with a fluid;   a contaminated fluid;   a cathode; and   an anode disposed essentially contiguous to a surface of said object;   wherein said anode produces a low pH environment in the fluid at said surface.   
     
     
         2 . The apparatus of  claim 1  wherein said object comprises a UV tube. 
     
     
         3 . The apparatus of  claim 1  wherein said object comprises a sensor. 
     
     
         4 . The apparatus of  claim 1  wherein said anode is wrapped around said object. 
     
     
         5 . The apparatus of  claim 4  wherein said anode comprises a spirally wrapped wire. 
     
     
         6 . The apparatus of  claim 1  wherein said cathode comprises a housing. 
     
     
         7 . The apparatus of  claim 1  wherein said anode comprises a conductive material deposited on said surface. 
     
     
         8 . The apparatus of  claim 7  wherein said conductive material is UV-transparent. 
     
     
         9 . The apparatus of  claim 8  wherein said conductive material comprises diamond. 
     
     
         10 . The apparatus of  claim 1  wherein the fluid comprises an aqueous solution. 
     
     
         11 . The apparatus of  claim 1  further comprising a second cathode at a voltage different than a voltage of said anode and a voltage of said cathode. 
     
     
         12 . A method for reducing carbonate scale formation on a surface, the method comprising the steps of:
 providing a cathode;   disposing an anode essentially contiguous to a surface of an object;   contacting the anode and the surface with a contaminated fluid; and   electrolyzing the fluid with the anode and the cathode, thereby producing a low pH environment in the fluid in the vicinity of the anode.   
     
     
         13 . The method of  claim 12  further comprising the step of inhibiting formation of carbonate scale or a biofilm on the surface. 
     
     
         14 . The method of  claim 12  further comprising the step of removing carbonate scale or a biofilm from the surface. 
     
     
         15 . The method of  claim 12  wherein the fluid comprises an aqueous solution. 
     
     
         16 . The method of  claim 12  further comprising the step of treating the fluid with UV radiation. 
     
     
         17 . The method of  claim 12  wherein the disposing step comprises wrapping a wire anode on the surface. 
     
     
         18 . The method of  claim 12  wherein the disposing step comprises depositing the anode directly on the surface. 
     
     
         19 . The method of  claim 18  wherein the anode comprises a conductive UV-transparent material. 
     
     
         20 . The method of  claim 19  wherein the material comprises diamond. 
     
     
         21 . The method of  claim 12  further comprising the step of reversing the polarity of the anode and the cathode, thereby removing scale or biofilm from the cathode. 
     
     
         22 . The method of  claim 12  wherein the object comprises a UV tube. 
     
     
         23 . The method of  claim 12  further comprising the step of orienting the object transverse to a flow direction of the fluid. 
     
     
         24 . The apparatus of  claim 23  further comprising the step of disposing the anode parallel to and upstream of the object. 
     
     
         25 . The method of  claim 24  further comprising the step of washing an acidic solution produced at the anode around the object.