Method of treating water with chlorine dioxide

Abstract

A method of treating water with chlorine dioxide (ClO 2 ), by: surrounding a reaction chamber, in which the ClO 2 is generated, with water, wherein the water surrounding the reaction chamber is simultaneously the water to be treated; and passing a reaction solution comprising the ClO 2 formed in the reaction chamber out of the reaction chamber through an outlet directly into the water, thus treating the water.

1 . A method of treating water with chlorine dioxide (ClO 2 ), comprising:
 surrounding a reaction chamber, in which the ClO 2  is generated, with water, wherein the water surrounding the reaction chamber is simultaneously the water to be treated; and   passing a reaction solution comprising the ClO 2  formed in the reaction chamber out of the reaction chamber through an outlet directly into the water, thus treating the water.   
     
     
         2 . The method according to  claim 1 , wherein the reaction chamber is a reactor. 
     
     
         3 . The method according to  claim 2 , wherein the reactor is a tubular reactor. 
     
     
         4 . The method according to  claim 1 , wherein reactants used to generate the ClO 2 , and optionally dilution water, are mixed in the reaction chamber. 
     
     
         5 . The method according to  claim 1 , wherein the reaction time for the generation of ClO 2  in the reaction chamber is from 4 to 60 minutes. 
     
     
         6 . The method according to  claim 5 , wherein the reaction time is from 4 to 6 minutes. 
     
     
         7 . The method according to  claim 6 , wherein the reaction time is from 0.1 to 1.5 minutes. 
     
     
         8 . The method according to  claim 7 , wherein the reaction time is from 0.3 minutes to 0.6 minutes. 
     
     
         9 . The method according to  claim 1 , wherein the ClO 2  is generated from an alkali metal chlorite salt and hydrochloric acid as reactants. 
     
     
         10 . The method according to  claim 1 , wherein the ClO 2  is generated from sodium chlorite and hydrochloric acid as reactants. 
     
     
         11 . The method according to  claim 1 , wherein the ClO 2  is generated from sodium chlorite in an aqueous solution of from 3.5% to 40%. 
     
     
         12 . The method according to  claim 1 , wherein the ClO 2  is generated from hydrochloric acid in a concentration of from 3.5% to 42%. 
     
     
         13 . The method according to  claim 1 , wherein the ClO 2  is generated from sodium chlorite and chlorine as reactants. 
     
     
         14 . The method according to  claim 1 , wherein dilution water is used in the generation of ClO 2 . 
     
     
         15 . The method according to  claim 1 , wherein a conductivity value of the reaction solution is measured in the reaction solution leaving the reaction chamber. 
     
     
         16 . The method according to  claim 1 , wherein the reaction chamber is situated in a pipe, the water which is to be treated flowing through the pipe. 
     
     
         17 . The method according to  claim 1 , wherein no dilution water is used in the generation of ClO 2 . 
     
     
         18 . The method according to  claim 1 , wherein the reaction chamber is operated without a pressure control appliance. 
     
     
         19 . The method according to  claim 1 , wherein the reactor has a free outlet at the reactor outlet, in such a manner that the pressure in the reaction chamber can only increase to the value which is exerted on the reaction chamber by the surrounding water. 
     
     
         20 . The method according to  claim 1 , wherein the reaction solution leaving the reaction chamber through an outlet is diluted in such a manner that the renewal rate at the outlet of the water which is to be treated is from about 0.1 m 3 /h to 20 m 3 /h per gram and hour of ClO 2  generated. 
     
     
         21 . The method according to  claim 1 , wherein concentrations of reactants used in generating ClO 2  are selected in such a manner that a concentration of ClO 2  at the outlet is greater than 3 g/l of solution. 
     
     
         22 . The method according to  claim 21 , wherein concentrations of reactants used in generating ClO 2  are selected in such a manner that a concentration of ClO 2  at the outlet is greater than 26 g/l of solution. 
     
     
         23 . The method according to  claim 22 , wherein concentrations of reactants used in generating ClO 2  are selected in such a manner that a concentration of ClO 2  at the outlet is greater than 80 g/l of solution. 
     
     
         24 . The method according to  claim 21 , wherein the reaction chamber in which the ClO 2  is generated is a reactor without a pressure control appliance and equipped with a free outlet. 
     
     
         25 . The method according to  claim 24 , wherein the water surrounding the reaction chamber exerts a pressure on the ClO 2 -containing reaction solution in the reaction chamber of a magnitude that the solubility limit of ClO 2  in water at a given temperature is not exceeded. 
     
     
         26 . The method according to  claim 10 , wherein the concentration of the hydrochloric acid is 33-42% and that of the sodium chlorite solution is 25-40%. 
     
     
         27 . A method of treating water with chlorine dioxide (ClO 2 ), comprising:
 surrounding a reaction chamber, in which the ClO 2  is generated, with water; and   passing a reaction solution comprising the ClO 2  formed in the reaction chamber out of the reaction chamber through an offtake situated at one end of the reaction chamber to one or more other sites, directly into the water at the one or more other sites, thus treating the water.