JP4968628B2 - Equipment for simultaneous production of ozone water and hydrogen peroxide water - Google Patents

Description

  The present invention relates to an apparatus for simultaneous production of ozone water and hydrogen peroxide water by electrolysis, which is used in wastewater / sewage treatment, paper industry, semiconductor industry and the like.

  In today's environment, where environmental issues are a major issue, how efficient wastewater treatment is for the industry is a very important issue. For example, wastewater containing organic matter, such as microbial dead bodies and toilet paper pulp, is purified by a decomposition process using microorganisms in a wastewater treatment plant, but microbial dead bodies and toilet paper pulp are difficult to decompose, As a result, a large amount of sludge remains. In order to treat this sludge, it is necessary to burn it with heavy oil to fill the ash, and the work is complicated and the environmental load is large. There are similar problems with industrial wastewater in the paper industry, and efficient wastewater treatment is required.

  As a more efficient sludge treatment method, use of accelerated oxidation treated water, which is a mixture of ozone water and hydrogen peroxide water having a strong oxidizing action, is expected. Oxidative decomposition ability of ozone is strong next to fluorine, and has the advantage of no persistence. Furthermore, by adding hydrogen peroxide, the oxidizing power can be increased, so sludge can be decomposed efficiently. it can. Further, not only in wastewater treatment, but also in the semiconductor industry, high-purity accelerated oxidatively treated water that can be used for cleaning has attracted attention.

  In order to obtain accelerated oxidation treated water that is a mixture of ozone water and hydrogen peroxide water, there is a method of carefully mixing ozone water and hydrogen peroxide water produced in advance, but both compounds are highly active, It is unstable and it is essential to add a stabilizer to ozone water and hydrogen peroxide water. Since this stabilizer has a function of suppressing activity, it does not meet the purpose of the present invention to obtain accelerated oxidized water having a strong oxidizing action. Further, since the stabilizer becomes an impurity, there is a problem that it is not suitable for precision cleaning, waste water treatment, and the like.

  For this reason, in order to obtain accelerated oxidation treated water suitable for precision cleaning, wastewater treatment, etc., it is necessary to simultaneously generate ozone water and hydrogen peroxide water with high efficiency using the reaction at the anode and cathode. Become. However, there is no known technique for simultaneously oxidizing water and reducing oxygen at the anode and the cathode.

  Patent Document 1 discloses a method for simultaneously producing hydrogen peroxide and ozone using a diamond electrode as an anode. However, in this method, hydrogen peroxide is generated as a byproduct of ozone generation at the anode, and the reaction at the cathode is not intended to actively produce hydrogen peroxide.

Patent Document 2 discloses a technique for producing oxidizing water containing ozone and hydrogen peroxide using a hydrogen storage alloy such as a palladium alloy as a cathode. In this method, a mixed solution in which oxygen is added to separately produced ozone water is prepared in advance, and atomic hydrogen in the cathode generated by electrolysis is brought into contact therewith to reduce oxygen to hydrogen peroxide and coexist with ozone. Technology. In this method, since ozone needs to be generated in a separate process, a separate apparatus must be prepared, and the apparatus becomes complicated. Moreover, since expensive palladium was required for the electrode, there was also a problem that it was not practical.
JP-A-11-269686 Japanese Patent Laid-Open No. 10-324988

  Therefore, in view of the above problems, the present invention simultaneously produces high-concentration hydrogen peroxide water and high-concentration ozone water not containing impurities by electrolytic reduction of oxygen at the cathode and electrolytic oxidation of water at the anode. It is an object of the present invention to provide a device that performs the above-described process.

  Since oxygen is hardly soluble in water, when electrolysis is performed at a high current density, it is reduced to water and hydrogen peroxide water cannot be obtained. Therefore, a highly efficient oxygen reduction electrode is required in order to simultaneously proceed with the ozone generation reaction and the oxygen reduction reaction that require a high current density. The present inventor has developed an oxygen reduction electrode comprising a group of particles having hydrophobic fine particles dispersed and fixed on the surface, which is optimal for a cathode and has a gas diffusion function as well as a gas concentration function and a gas holding function. By using this oxygen reduction electrode at the cathode, it has been found that even at a high current density required for ozone generation, the oxygen electrolytic reduction proceeds at an appropriate current density, and hydrogen peroxide can be obtained. did.

That is, the simultaneous hydrogen peroxide water and ozone water production apparatus of the present invention includes a cathode chamber provided with an oxygen reducing electrode, and an anode chamber that is partitioned by the cathode chamber and an ion exchange membrane and provided with an ozone generating electrode. The oxygen reduction electrode comprises a group of particles in which polytetrafluoroethylene particles obtained by dispersing polytetrafluoroethylene fine particles in a silver plating solution and performing composite plating are dispersed and fixed on the electrode particle surfaces. The ozone generating electrode is a lead dioxide mesh, and is characterized in that hydrogen peroxide is generated by reduction of oxygen at the cathode and ozone is generated by oxidation of water at the anode .

Also, the oxygen supply port and the pure water supply port and the hydrogen peroxide water taking port disposed in the cathode chamber, characterized in that a pure water supply port and the ozone water taking port to the anode chamber.

Furthermore, the simultaneous manufacturing method of the hydrogen peroxide solution and the ozone water of the present invention uses the hydrogen peroxide solution and the ozone water simultaneous manufacturing apparatus according to claim 1 or 2, and oxygen and pure water in the cathode chamber, the anode While supplying pure water to the chamber, current is passed between the electrodes, hydrogen peroxide is generated by reduction of oxygen at the cathode, and ozone is generated by oxidation of water at the anode.

  According to the apparatus for simultaneously producing hydrogen peroxide and ozone water of the present invention, high-concentration hydrogen peroxide and high-concentration ozone water containing no impurities are simultaneously produced using only oxygen and pure water as starting materials. An accelerated oxidation-treated water having an oxidizing action can be produced. In addition, since the oxygen reduction electrode is a group of particles in which hydrophobic fine particles are dispersed and fixed on the surface, the oxygen concentration in the vicinity of the surface can be increased and the oxygen can be efficiently reduced by the hydrophobic interaction. Thereby, even at a high current density required for ozone generation, reduction of oxygen proceeds at an appropriate current density, and hydrogen peroxide is obtained.

  In addition, since the hydrophobic fine particles can be uniformly dispersed and fixed on the surface of the electrode by dispersing and fixing the hydrophobic fine particles on the surface by the composite plating method, the oxygen reducing electrode has the maximum hydrophobic function. The oxygen can be reduced efficiently.

  Further, the hydrophobic fine particles are polytetrafluoroethylene, and the surface of the electrode can be reliably hydrophobized to efficiently reduce oxygen.

  According to the simultaneous production method of hydrogen peroxide solution and ozone water of the present invention, a high concentration hydrogen peroxide solution and high concentration ozone water not containing impurities are produced simultaneously using only oxygen and pure water as starting materials, An accelerated oxidation-treated water having an oxidizing action can be produced.

  Hereinafter, an embodiment of a simultaneous hydrogen peroxide solution and ozone water production apparatus of the present invention will be described with reference to the accompanying drawings.

  In FIG. 1, reference numeral 1 denotes an ion exchange membrane, which is partitioned into a cathode chamber 2 and an anode chamber 3 by the ion exchange membrane 1.

  The cathode chamber 2 is filled with a particulate oxygen reduction electrode 4, and this oxygen reduction electrode 4 is placed on an oxygen reduction electrode holding plate 5 provided in the lower portion of the cathode chamber 2. . The oxygen reduction electrode holding plate 5 may be any one that can hold the oxygen reduction electrode 4 and allows water and oxygen to pass therethrough and does not react with hydrogen peroxide. An oxygen supply pipe 6 is provided at the lower part of the oxygen reduction electrode holding plate 5, and an oxygen supply port 7 is provided to the outside of the cathode chamber 2 so as to be connected to the oxygen supply pipe 6. The oxygen supply pipe 6 has a structure having a plurality of holes at equal intervals in the longitudinal direction so that oxygen introduced from the oxygen supply port 7 can be further uniformly supplied from the lower part of the oxygen reduction electrode 4 into the cathode chamber. It has become. A pure water supply port 8 is provided on the upper surface of the cathode chamber 2 toward the outside, and a hydrogen peroxide water outlet 9 is provided on the bottom surface, and a pipe 10 is provided at the hydrogen peroxide water outlet 9. It is connected.

  An ozone generating electrode 11 is provided in the vicinity of the side wall of the anode chamber 3 partitioned by the ion exchange membrane 1. The ozone generation electrode 11 is not limited to a specific one as long as it is an electrode effective for the ozone generation reaction. For example, a lead dioxide mesh can be used. By being mesh-shaped, water can be oxidized efficiently. A pure water supply port 12 is provided on the upper surface of the anode chamber 3 and the ozone water outlet 13 is provided on the bottom surface of the anode chamber 3. A pipe 14 is connected to the ozone water outlet 13. . A pipe 10 for taking out hydrogen peroxide water and a pipe 14 for taking out ozone water are connected to each other and connected to a hydrogen peroxide / ozone mixed aqueous solution outlet 15.

  Next, a method for producing the oxygen reduction electrode 4 will be described with reference to FIG.

  As shown in FIG. 2, a current collector rod 18 having a silver counter electrode 17 bonded as a positive electrode is suspended in a plating tank 16 and a cup-type current collector having an insulating rod 20 bonded to one end of the current collector rod 19 as a negative electrode. Manufactured with a device with 21 suspended. The silver counter electrode 17 can be swung, and the cup-type current collector 21 has a rotatable structure. Electrode particles 22 are cast on the insulating basket 20, and the plating tank 16 is filled with the composite plating solution 23 containing hydrophobic fine particles. The composite plating solution 23 is agitated by a rotatable magnetic stirrer 24 disposed at the bottom of the plating tank 16.

  In the plating solution 23, a metal compound that coats the surface of the electrode particles is dissolved. The metal is not particularly limited as long as it has high corrosion resistance and is stable during electrolysis. For example, silver, nickel, iron, chromium, and cobalt can be used. Silver is particularly preferably used because it is easy to plate and easy to handle.

  Hydrophobic fine particles are not limited to specific ones as long as they are hydrophobic fine particles. For example, in addition to fluororesins such as polytetrafluoroethylene, fluorocarbons such as fluorinated graphite are used in an electrolytic atmosphere. Is also preferably used because it is stable for a long time and maintains its hydrophobicity. Polytetrafluoroethylene is particularly preferably used because it is relatively inexpensive and easily available.

  The particle size of the hydrophobic fine particles may be a size that can be uniformly dispersed in the plating solution so as to be uniformly fixed to the electrode particles. In the case of polytetrafluoroethylene, those having a size of 10 μm or less are preferably used.

  In order to uniformly disperse the hydrophobic fine particles in the plating solution, a cationic surfactant may be added. This cationic surfactant is not limited to a specific one. The concentration of the surfactant in the plating solution is preferably 0.1 to 10 g / l.

  The electrode particles 22 are not particularly limited as long as they are stable and inexpensive during electrolysis, but copper, nickel, iron, stainless steel and the like are preferably used.

  With such an apparatus, in the composite plating solution 23 stirred using the silver counter electrode 17 and the magnetic stirrer 24, the current collector rods 18 and 19 were energized while rotating the cup-type current collector 21, and the electrode particles 22 Composite plating is performed on the top. Thereby, hydrophobic fine particles can be uniformly dispersed and fixed on the electrode particle surfaces.

  Next, the operation of the simultaneous production apparatus for hydrogen peroxide water and ozone water will be described.

  Oxygen is supplied from the oxygen supply port 7 to the cathode chamber 2, pure water is supplied from the pure water supply port 8, and pure water is supplied from the pure water supply port 12 to the anode chamber 3. Electrolysis is performed by energizing between the electrodes 11 for use. As a result, oxygen is reduced in the cathode chamber 2 to generate hydrogen peroxide, and water is oxidized in the anode chamber 3 to generate ozone. The generated hydrogen peroxide and ozone are dissolved in pure water and then taken out from the hydrogen peroxide water outlet 9 and the ozone water outlet 13, respectively. Subsequently, hydrogen peroxide water and ozone water are mixed at the connecting portions of the pipes 10 and 14, and the hydrogen peroxide / ozone mixed aqueous solution, which is the accelerated oxidation treatment water, is taken out from the hydrogen peroxide / ozone mixed aqueous solution outlet 15. .

  As described above, the simultaneous hydrogen peroxide water and ozone water production apparatus of the present embodiment is partitioned by the cathode chamber 2 provided with the oxygen reduction electrode 4, the cathode chamber 2 and the ion exchange membrane 1, and ozone. And an anode chamber 3 having a generation electrode 11, wherein the oxygen reduction electrode 4 is composed of a group of particles in which hydrophobic fine particles are dispersed and fixed on the surface, and generates hydrogen peroxide by reducing oxygen at the cathode, By constructing the anode to generate ozone by oxidation of water, high-concentration hydrogen peroxide water and high-concentration ozone water containing no impurities are produced simultaneously using only oxygen and pure water as starting materials, and strong oxidation It is possible to produce accelerated oxidized water having an action. Further, since the oxygen reducing electrode is hydrophobic, the oxygen concentration in the vicinity of the electrode surface can be increased by the hydrophobic interaction, and oxygen can be efficiently reduced. Furthermore, since the oxygen reduction electrode is a group of hydrophobic particles, even at a high current density required for ozone generation, oxygen reduction proceeds at an appropriate current density, and hydrogen peroxide is obtained.

  Further, according to the simultaneous production apparatus for hydrogen peroxide and ozone water of the present example, the oxygen reduction electrode 4 is obtained by dispersing and fixing hydrophobic fine particles on the surface by a composite plating method. Since the fine particles can be uniformly dispersed and fixed on the electrode surface, the hydrophobic function of these hydrophobic fine particles is maximized, and oxygen can be reduced efficiently.

  Further, according to the simultaneous production apparatus for hydrogen peroxide solution and ozone water of this example, the hydrophobic fine particles are polytetrafluoroethylene, so that the electrode surface can be reliably hydrophobized and oxygen can be efficiently reduced. .

  Further, according to the apparatus for simultaneously producing hydrogen peroxide water and ozone water of the present embodiment, the cathode chamber is provided with the oxygen supply port 7, the pure water supply port 8, and the hydrogen peroxide solution outlet 9, and the anode chamber 3 is provided with a pure water supply port 12 and an ozone water outlet 13 to simultaneously produce high-concentration hydrogen peroxide water and high-concentration ozone water not containing impurities, using only oxygen and pure water as starting materials, It is possible to produce accelerated oxidation-treated water having a strong oxidizing action.

  Furthermore, according to the simultaneous manufacturing method of the hydrogen peroxide solution and the ozone water of the present embodiment, using the simultaneous manufacturing apparatus for the hydrogen peroxide solution and the ozone water according to any one of claims 1 to 4, While supplying oxygen and pure water to the anode 2 and pure water to the anode chamber 3, electricity is passed between the two electrodes to generate hydrogen peroxide by reducing oxygen at the cathode, and simultaneously generate ozone by oxidizing water at the anode. As a result, it is possible to simultaneously produce high-concentration hydrogen peroxide water and high-concentration ozone water not containing impurities using only oxygen and pure water as starting materials, thereby producing accelerated oxidation-treated water having a strong oxidizing action.

  In the following examples, the simultaneous production method of hydrogen peroxide solution and ozone water of the present invention will be described more specifically. The present invention is not limited to the following examples, and various modifications can be made.

  Using the apparatus shown in FIG. 2, an oxygen reduction electrode 4 as a particle group in which hydrophobic fine particles were dispersed and fixed on the surface was produced. A polytetrafluoroethylene fine particle having a particle diameter of 0.2 μm was dispersed in a thiocyanate silver plating solution using a cationic surfactant to obtain a composite plating solution 23. A copper particle 22 having a particle diameter of 2 mm is cast on a cup-shaped current collector 21, and composite plating is performed on the copper particle 22 while stirring with a silver counter electrode 17 in this liquid, and an electrode for hydrophobic silver particle group oxygen reduction 4 was obtained.

  Further, α-lead dioxide and then β-lead dioxide were electrodeposited on a 10 mesh titanium mesh to obtain an electrode 11 for generating ozone.

  The obtained oxygen reduction electrode 4 and ozone generation electrode 11 are arranged together with the ion exchange membrane 1 as shown in FIG. 1, while supplying pure water from the pure water supply ports 8 and 12 and supplying oxygen from the oxygen supply port 7. Electrolysis was performed, oxygen was reduced in the cathode chamber 2, and water was oxidized in the anode chamber 3.

Oxygen reduction electrode 4 which is a group of hydrophobic silver particles having a total area of 105 cm ² as a cathode, and a lead dioxide mesh plate ozone generation electrode 11 having an effective area of 1.26 cm ² as an anode, both sides of 25 cm ² of ion exchange membrane 1 Arranged. When energization was performed for 60 minutes at an oxygen flow rate of 4 ml / min, a pure water flow rate of 4 ml / min, and a current density of 100 mA / cm ² , hydrogen peroxide having a concentration of 6.3 ppm in the cathode chamber 2 had a concentration of 7 in the anode chamber 3. It was confirmed that 2 ppm of ozone was generated.

It is a schematic diagram which shows the structure of the simultaneous manufacturing apparatus of the hydrogen peroxide solution of this invention, and ozone water. It is a schematic diagram which shows the structure of the formation apparatus of the electrode for oxygen reduction.

1 Ion Exchange Membrane 2 Cathode Chamber 3 Anode Chamber 4 Oxygen Reduction Electrode (Cathode)
7 Oxygen supply port 8 Pure water supply port 9 Hydrogen peroxide water outlet
11 Ozone generating electrode (anode)
12 Pure water supply port
13 Ozone water outlet

Claims (3)

And a cathode chamber with an oxygen reduction electrode comprises an anode chamber having an ozone generating electrode with partitioned by the cathode chamber and an ion exchange membrane, the oxygen reduction electrode, a silver plating solution, polytetra It consists of a group of particles in which polytetrafluoroethylene obtained by dispersing fluoroethylene fine particles and performing composite plating is dispersed and fixed on the surface of the electrode particles. The ozone generating electrode is a lead dioxide mesh, and oxygen is reduced at the cathode. The apparatus for simultaneously producing hydrogen peroxide and ozone water is characterized in that hydrogen peroxide is generated by means of, and simultaneously ozone is generated by oxidation of water at the anode. According to claim 1, characterized in that the cathode chamber oxygen supply port and the pure water supply port and the hydrogen peroxide water taking port disposed on, provided the pure water supply port and the ozone water taking port to the anode chamber Equipment for simultaneous production of hydrogen peroxide water and ozone water.   Using the hydrogen peroxide water and ozone water simultaneous production apparatus according to claim 1 or 2, while supplying oxygen and pure water to the cathode chamber and pure water to the anode chamber, a current is passed between the electrodes, A method for simultaneously producing hydrogen peroxide water and ozone water, wherein hydrogen peroxide is generated by reduction of oxygen in the atmosphere and ozone is simultaneously generated by oxidation of water at the anode.

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