Compositions, devices and methods for stabilizing and increasing the efficacy of halogen dioxide

Abstract

Compositions and methods for increasing the stability and/or efficacy of chlorine dioxide, and particularly chlorine dioxide generated via electrolysis of chlorite. The present invention further relates to electrolysis devices for producing chlorine dioxide, comprising the stabilizing and efficacy-increasing compositions of the present invention, as well as methods of using both the chlorine dioxide-stabilizing and efficacy-increasing compositions and devices disclosed herein.

What is claimed is:  
     
         1 . A hydroxide ion scavenging system for stabilizing a halogen dioxide solution, said system comprising 
 (a) from about 0.001% to about 10% by weight of the total of a hydroxide ion scavenger-comprising halogen dioxide precursor solution, a hydroxide ion scavenging system; and    (b) from about 0.000001% to about 50% by weight of the total of a hydroxide ion scavenging-comprising halogen dioxide precursor solution, one or more halogen salt precursors;    wherein agents for use in said hydroxide ion scavenging system are selected from the group consisting of: organic acids, salts of organic acids, inorganic acids, salts of inorganic acids, and mixtures thereof;    further wherein said hydroxide ion scavenging system is adapted to increase the concentration of a halogen dioxide solution by at least about 5% in comparison to the concentration of a corresponding halogen dioxide solution that does not comprise said hydroxide ion-scavenging system, when both solutions are measured at 25° C., three hours following halogen dioxide generation.    
     
     
         2 . The hydroxide ion scavenging system of  claim 1 , wherein halogen dioxide is pre-generated.  
     
     
         3 . The hydroxide ion scavenging system of  claim 1 , wherein halogen dioxide is generated on demand.  
     
     
         4 . A hydroxide ion scavenging system for stabilizing a halogen dioxide solution, said system comprising 
 (a) from about 0.001% to about 10% by weight of the total of a hydroxide ion scavenging-comprising halogen dioxide solution, a hydroxide ion scavenging system; and    (b) from about 0.000001% to about 1% by weight of the total of a hydroxide ion scavenging-comprising halogen dioxide solution, halogen dioxide;    wherein said hydroxide ion scavenging agents are selected from the group consisting of: organic acids, salts of organic acids, inorganic acids, salts of inorganic acids, and mixtures thereof;    further wherein said hydroxide ion scavenging system is adapted to increase the concentration of a halogen dioxide solution by at least about 5% in comparison to the concentration of a corresponding halogen dioxide solution that does not comprise said hydroxide ion-scavenging system, when both solutions are measured at 25° C., three hours following generation.    
     
     
         5 . The hydroxide ion scavenging system of  claim 4 , wherein said hydroxide ion scavenging system is used to stabilize a chlorine dioxide solution.  
     
     
         6 . An Interfacial Tension (IFT)-Lowering system for increasing the stability and/or efficacy of a halogen dioxide solution, said system comprising: 
 (a) from about 0.00001% to about 10%, by weight of the total of an IFT-lowering system-comprising halogen dioxide precursor solution, an IFT-lowering system    (b) from about 0.000001% to about 50%, by weight of the total of an IFT-lowering system-comprising halogen dioxide precursor solution, one or more halogen salt precursors;    wherein agents for use in said IFT-lowering system are selected from the group consisting of: IFT-lowering polymers, IFT-lowering solvents, IFT-lowering surfactants and mixtures thereof; further wherein said IFT-lowering system is adapted to convey at least about 5% greater reduction in the number of microbes to the IFT-lowering system-comprising halogen dioxide solution, in comparison to a corresponding halogen dioxide solution that does not comprise the said IFT-lowering system.    
     
     
         7 . An Interfacial Tension (IFT)-Lowering system for increasing the stability and/or efficacy of a halogen dioxide solution, said system comprising: 
 (c) from about 0.00001% to about 10%, by weight of the total of an IFT-lowering system-comprising halogen dioxide solution, an IFT-lowering system    (d) from about 0.000001% to about 1%, by weight of the total of an IFT-lowering system-comprising halogen dioxide solution, halogen dioxide;    wherein agents for use in said IFT-lowering system are selected from the group consisting of: IFT-lowering polymers, IFT-lowering solvents, IFT-lowering surfactants and mixtures thereof; further wherein said IFT-lowering system is adapted to convey at least about 5% greater reduction in the number of microbes to the IFT-lowering system-comprising halogen dioxide solution, in comparison to a corresponding halogen dioxide solution that does not comprise the said IFT-lowering system.    
     
     
         8 . The IFT-lowering system of  claim 7 , wherein said IFT-lowering system is used to increase the efficacy of a chlorine dioxide solution.  
     
     
         9 . A halogen dioxide stabilizing and efficacy-increasing system, said system comprising the hydroxide ion-scavenging system in accordance with  claim 1  and the IFT-lowering system in accordance with  claim 6;   
       wherein said halogen dioxide stabilizing and efficacy-increasing system is characterized by a concentration of halogen dioxide of at least about 5% greater the concentration of a corresponding halogen dioxide that does not comprise said halogen dioxide stabilizing and efficacy-increasing system at 25° C., three hours following generation;  
       further wherein said halogen dioxide stabilizing and efficacy-increasing system is adapted to convey at least about 5% greater reduction in the number of microbes than a corresponding halogen dioxide solution that does not comprise said halogen dioxide stabilizing and efficacy-increasing system.  
     
     
         10 . A halogen dioxide stabilizing and efficacy-increasing system, said system comprising the hydroxide ion-scavenging system in accordance with  claim 4  and the IFT-lowering system in accordance with  claim 7;   
       wherein said halogen dioxide stabilizing and efficacy-increasing system is characterized by a concentration of halogen dioxide of at least about 5% greater the concentration of a corresponding halogen dioxide that does not comprise said halogen dioxide stabilizing and efficacy-increasing system at 25° C., three hours following generation;  
       further wherein said halogen dioxide stabilizing and efficacy-increasing system is adapted to convey at least about 5% greater reduction in the number of microbes than a corresponding halogen dioxide solution that does not comprise said halogen dioxide stabilizing and efficacy-increasing system.  
     
     
         11 . A halogen dioxide generating system, comprising: 
 a) a source of an aqueous feed solution comprising a halogen dioxide salt;    b) a non-membrane electrolysis cell comprising an anode and a cathode, and having a cell chamber with an inlet and an outlet;    c) a means for passing the aqueous feed solution into the chamber and along a passage adjacent to the anode, and out of the outlet;    d) an electric current supply to flow a current through the aqueous feed solution in the passage, to convert a portion of the halogen dioxide salt to halogen dioxide, and thereby form an aqueous effluent comprising halogen dioxide; and    e) a chamber comprising a system selected from the group consisting of: a hydroxide ion scavenging system for stabilizing said halogen dioxide solution; an IFT-lowering system for increasing the stability and/or efficacy of said halogen dioxide solution and combinations thereof.    
     
     
         12 . The halogen dioxide generating system of  claim 11  wherein the anode and the cathode are confronting and co-extensive, with a chamber gap of 1.0 mm or less.  
     
     
         13 . The halogen dioxide generating system of  claim 11  wherein the anode and the cathode are confronting and co-extensive, with a chamber gap of 0.5 mm or less.  
     
     
         14 . The halogen dioxide generating system of  claim 11  wherein the anode and the cathode are confronting and co-extensive, with a chamber gap of 0.2 mm or less.  
     
     
         15 . The halogen dioxide generating system of  claim 11  wherein the anode is a conductive porous anode.  
     
     
         16 . A halogen dioxide generating system, comprising: 
 a) a source of an aqueous feed solution comprising a halogen dioxide salt;    b) a non-membrane electrolysis cell comprising an anode and a cathode, and having a cell chamber with an inlet and an outlet;    c) a means for passing the aqueous feed solution into the chamber and along a passage adjacent to the anode, and out of the outlet;    d) an electric current supply to flow a current through the aqueous feed solution in the passage, to convert a portion of the halogen dioxide salt to halogen dioxide, and thereby form an aqueous effluent comprising halogen dioxide; and    e) a chamber comprising both a hydroxide ion scavenging system and an IFT-lowering system for increasing the stability and efficacy of the halogen dioxide solution.    
     
     
         17 . The halogen dioxide generating system of  claim 16  wherein the anode and the cathode are confronting and co-extensive, with a chamber gap of 1.0 mm or less.  
     
     
         18 . The halogen dioxide generating system of  claim 16  wherein the anode and the cathode are confronting and co-extensive, with a chamber gap of 0.5 mm or less.  
     
     
         19 . The halogen dioxide generating system of  claim 16  wherein the anode and the cathode are confronting and co-extensive, with a chamber gap of 0.2 mm or less.  
     
     
         20 . The halogen dioxide generating system of  claim 16  wherein the anode is a conductive porous anode.  
     
     
         21 . A halogen dioxide generating and re-circulating system, comprising: 
 a) a source of an aqueous feed solution comprising a halogen dioxide salt;    b) a non-membrane electrolysis cell comprising an anode and a cathode, and having a cell chamber with an inlet and an outlet;    c) a means for passing the aqueous feed solution into the chamber, and along a passage adjacent to the anode, and out of the outlet;    d) an electric current supply to flow a current through the aqueous solution between the anode and the cathode, to convert at least a portion of the halogen dioxide salt in the passage to halogen dioxide, and thereby form an aqueous effluent comprising halogen dioxide;    e) a means for delivering the aqueous effluent into contact with a halogen dioxide depletion target, whereby a portion of the halogen dioxide in the aqueous effluent oxidizes the depletion target and reverts back to a halogen dioxide salt;    f) a means for returning the depleted effluent comprising the reverted halogen dioxide salt back to the source; and    g) a means for delivering a hydroxide ion scavenging system for stabilizing said halogen dioxide solution.    
     
     
         22 . A halogen dioxide generating and re-circulating system, comprising: 
 a) a source of an aqueous feed solution comprising a halogen dioxide salt;    b) a non-membrane electrolysis cell comprising an anode and a cathode, and having a cell chamber with an inlet and an outlet;    c) a means for passing the aqueous feed solution into the chamber, and along a passage adjacent to the anode, and out of the outlet;    d) an electric current supply to flow a current through the aqueous solution between the anode and the cathode, to convert at least a portion of the halogen dioxide salt in the passage to halogen dioxide, and thereby form an aqueous effluent comprising halogen dioxide;    e) a means for delivering the aqueous effluent into contact with a halogen dioxide depletion target, whereby a portion of the halogen dioxide in the aqueous effluent oxidizes the depletion target and reverts back to a halogen dioxide salt;    f) a means for returning the depleted effluent comprising the reverted halogen dioxide salt back to the source; and    g) a means for delivering an IFT-lowering system for increasing the stability and/or efficacy of said halogen dioxide solution.    
     
     
         23 . A battery-powered electrolysis device for use to make on demand an aqueous solution comprising chlorine dioxide, comprising: 
 a) an electrolysis cell comprising an anode and a cathode, and having a cell chamber;    b) a means for pumping an aqueous feed solution comprising a halogen dioxide salt into the cell chamber and along a passage adjacent to the anode;    c) a battery for flowing electrical current between the anode and the cathode when the aqueous feed solution flows within the chamber and along the passage, whereby a portion of the halogen dioxide salt is converted to halogen dioxide; and    d) a means for delivering a hydroxide ion scavenging system for stabilizing said halogen dioxide solution.    
     
     
         24 . The battery-powered electrolysis device according to  claim 23 , wherein the device is a solution spray bottle, wherein the pumping means comprises a electrically-driven pump that pumps solution from the bottle to the electrolysis cell, and wherein the electrolysis cell comprises an anode and a confronting, co-extensive cathode, having a cell chamber gap of 1.0 mm or less.  
     
     
         25 . The battery-powered electrolysis device according to  claim 23 , wherein the device is a solution spray bottle, wherein the pumping means comprises a electrically-driven pump that pumps solution from the bottle to the electrolysis cell, and wherein the electrolysis cell comprises an anode and a confronting, co-extensive cathode, having a cell chamber gap of 0.5 mm or less.  
     
     
         26 . The battery-powered electrolysis device according to  claim 23 , wherein the device is a solution spray bottle, wherein the pumping means comprises a electrically-driven pump that pumps solution from the bottle to the electrolysis cell, and wherein the electrolysis cell comprises an anode and a confronting, co-extensive cathode, having a cell chamber gap of 0.2 mm or less.  
     
     
         27 . A battery-powered electrolysis device for use to make on demand an aqueous solution comprising chlorine dioxide, comprising: 
 a) an electrolysis cell comprising an anode and a cathode, and having a cell chamber;    b) a means for pumping an aqueous feed solution comprising a halogen dioxide salt into the cell chamber and along a passage adjacent to the anode;    c) a battery for flowing electrical current between the anode and the cathode when the aqueous feed solution flows within the chamber and along the passage, whereby a portion of the halogen dioxide salt is converted to halogen dioxide; and    d) a means for delivering an IFF-lowering system for increasing the stability and/or efficacy of said halogen dioxide solution.    
     
     
         28 . The battery-powered electrolysis device according to  claim 27 , wherein the device is a solution spray bottle, wherein the pumping means comprises a electrically-driven pump that pumps solution from the bottle to the electrolysis cell, and wherein the electrolysis cell comprises an anode and a confronting, co-extensive cathode, having a cell chamber gap of 1.0 mm or less.  
     
     
         29 . The battery-powered electrolysis device according to  claim 27 , wherein the device is a solution spray bottle, wherein the pumping means comprises a electrically-driven pump that pumps solution from the bottle to the electrolysis cell, and wherein the electrolysis cell comprises an anode and a confronting, co-extensive cathode, having a cell chamber gap of 0.5 mm or less.  
     
     
         30 . The battery-powered electrolysis device according to  claim 27 , wherein the device is a solution spray bottle, wherein the pumping means comprises a electrically-driven pump that pumps solution from the bottle to the electrolysis cell, and wherein the electrolysis cell comprises an anode and a confronting, co-extensive cathode, having a cell chamber gap of 0.2 mm or less.  
     
     
         31 . A method of stabilizing halogen dioxide, said method comprising the step of delivering a hydroxide ion scavenging system to a halogen dioxide solution for which increased stability is desired;  
       wherein said method is adapted to increase the concentration of a halogen dioxide solution by at least about 5% in comparison to the concentration of a corresponding halogen dioxide solution that does not contain said hydroxide ion scavenging system, when both solutions are measured at 25° C., three hours following generation; and  
       wherein said method is adapted to increase the efficacy of a chlorine dioxide solution.  
     
     
         32 . A method of increasing the efficacy of halogen dioxide, said method comprising the step of delivering an Interfacial Tension (IFT)-lowering system to a halogen dioxide solution for which increased efficacy is desired;  
       wherein said method is adapted to increase the efficacy of a chlorine dioxide solution.  
     
     
         33 . A method of increasing the stability and efficacy of a halogen dioxide solution, said method comprising the step of delivering a hydroxide ion scavenging system and an Interfacial Tension (IFT)-lowering system to a halogen dioxide solution for which increased stability and efficacy is desired.