JP2011157580A - Electrolytic synthesis method of ozone fine bubble - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method by which electrolytic water can be electrolytically synthesized from raw material water, wherein the electrolytic water has a large amount of ozone fine bubbles having an average particle size of 10-500 nm dissolved therein. <P>SOLUTION: The electrolytic water containing ≥0.02 mM of ozone fine bubbles having an average particle size of 10-500 nm is obtained by supplying an electrolyte-containing aqueous solution to an electrolytic cell 1 in which a conductive diamond anode 5 is installed, and then conducting electrolysis and synthesizing ozone; wherein the electrolysis is carried out under a current density of 0.01-0.5 A/cm<SP>2</SP>. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method for electrolytic synthesis of electrolyzed water in which ozone fine bubbles are dissolved.

[Ozone water]
Ozone water in which ozone gas is dissolved is listed on the Food Additives List in the US FDA (Food and Drug Administration) and has been approved (2001) as a bactericide in food storage and manufacturing processes. There are already many achievements in sterilization in food factories and foods themselves. Recently, in medical fields such as dermatology, ophthalmology, and dentistry, it has been attracting attention that it can reduce the load on the living body while exhibiting the same or better effect than conventional sterilized water. As a disinfectant, a chlorine-based disinfectant is widely used in terms of price and effect. However, harmful effects occur due to the use of a large amount of the chlorine-based disinfectant. It has been regarded as a problem that it is not only deteriorating the taste of the food but also imparting danger (increased THM). In addition, long-term use of hypochlorite has resulted in resistance bacteria to this drug, raising doubts about its bactericidal effect.

With the main purpose of solving this problem, it has been eagerly studied whether electrolyzed water produced by electrolysis is useful in fields such as agriculture, food, and medicine, and alternative use is progressing mainly in Japan. Paying attention to the excellent sterilization and disinfection action of electrolyzed water, use in medical sites and homes, such as sterilization, disinfection of affected areas, incisions, percutaneous openings of indwelling catheters, etc., kitchenware, baby products, furniture, etc. It is considered to be used for sterilization and disinfection of household items, toilets, bathtubs and other residential areas. Such electrolyzed water is obtained by electrolyzing water (electrolyzed water) to which a solute that generates ions upon dissolution, such as sodium chloride, is added, and where necessary an acid for adjusting the pH is added. .

The merit of acidic water is as follows.
(1) THM is excellent in safety because it is difficult to be generated when acidic.
(2) Resistant bacteria are unlikely to occur and management is easy on-site.
(3) Can be used in combination with alkaline electrolyzed water (4) Can be used as if it were tap water, and no odor remains on the fingers (5) Use immediately before (short sterilization time).

On the other hand, the merits of ozone water are as follows.
(1) Ozone (OH radical) bactericidal effect is oxidative destruction of cell walls, and there is no resistant bacteria because of indiscriminateness.
(2) There are no harmful secondary products because it is decomposed into oxygen. (3) The absence of persistence without persistence is both a merit and a demerit. If ozone gas can be kept stable in the solution, its application and effect can be expected to expand.

[Production method of ozone water]
Conventionally, ozone water is generally produced using a discharge-type ozone gas generator, and several ppm of ozone water can be easily produced, and is used in the field of water purification and food washing. However, it was limited to the field of use for the following reasons.
(1) To generate ozone once as a gas and then require two steps to dissolve in water.
(2) Since the concentration is lower than that of the electrolysis method described later, it is necessary to inject, dissolve and manufacture in water under high pressure.
(3) Since the generated power supply is high voltage and high frequency, it is difficult to reduce the size.
(4) In the ozone water generating device by discharge, it takes time (a waiting time of several minutes) until the ozone gas generation ability is stabilized, and it is difficult to instantaneously prepare ozone water having a constant concentration.

The electrolysis method is inferior in terms of electric power unit as compared with the discharge method, but is widely used in special fields such as electronic component cleaning due to the feature of easily obtaining high-concentration ozone gas and water. Since a DC low-voltage power supply is used in principle, it has excellent instantaneous response and safety, and is expected to be used as a small ozone gas and ozone water generator.

  In order to efficiently generate ozone gas, it is essential to select an appropriate catalyst and electrolyte. Known electrode materials include noble metals such as platinum, α-lead dioxide, β-lead dioxide, glassy carbon impregnated with fluorocarbon, and diamond. As an electrolyte, an aqueous solution containing sulfuric acid, phosphoric acid, fluorine group and the like has been used, but it is inconvenient to handle and has not spread. A water electrolysis cell using a solid polymer electrolyte as a diaphragm and using pure water as a raw material is easy to manage in that respect and is widely used (Non-Patent Document 1). With lead dioxide, which is a conventional catalyst, ozone gas having a high concentration of 12% by weight or more can be obtained.

Patent Document 1 discloses that conductive diamond is useful as an electrode for functional water (including ozone). In a system called a direct synthesis method, a sufficient flow rate is given to a solution in the vicinity of an electrode so as to be taken out as ozone water before gasification (Patent Document 2). In patent document 3, the spraying apparatus of the electrolyzed water which melt | dissolves ozone, especially the small spray apparatus which sprays the obtained electrolyzed water in mist form are devised.

[Nano Bubble / Micro Bubble]
In recent years, basic research and practical application of fine bubbles called nanobubbles and microbubbles have been studied. Recent developments are described in the latest technology for fine bubbles, NTS (2006). Bubbles having a diameter of several to several tens of microns generated by rapidly mixing water and air float stably in water, and can store gas components over a long period of time. These bubbles gradually decrease to nano size as the gas component dissolves in the solution, but the inside becomes high pressure and high temperature as the bubble shrinkage process progresses. It has also been reported that when bubbles eventually disappear, surrounding water molecules are crushed to generate radicals.

Initially, the effects of nano- and micro-bubbles mainly composed of gas such as oxygen were reported, and it is known that ozone-containing bubbles that have become micro-bubbles have a cleaning effect. The following technologies and patents will be described.

Patent Document 4 discloses oxygen nanobubble water characterized in that the diameter of the bubbles is 50 to 500 nm, and the bubbles are made of an aqueous solution containing oxygen nanobubbles containing oxygen.

Patent Document 5 discloses ozone water having a bubble diameter of 50 to 500 nm, and comprising an aqueous solution containing ozone nanobubbles containing ozone in the bubble.

  In Patent Literature 6, ozone is present in water as ozone nanobubbles having a diameter of 200 nm or less, and the ozone concentration is 0.1 to 5 mg / L. It is disclosed that an electrolyte ion such as sodium contained in an aqueous solution is necessary to make it into an aqueous solution. This is because the presence of specific electrolyte ions around the ozone nanobubbles suppresses the dissolution of the gas inside the bubbles due to a phenomenon in which the solubility of water in the gas decreases due to an increase in electrolyte ion concentration (a salting out phenomenon).

In Patent Document 7, two microbubble generators for generating microbubbles in a liquid are formed of a conductive material having a porous property and electrolyze a liquid by applying a voltage between both electrodes. Although the microbubble generator provided with the electrode is disclosed, there is no description about ozone gas, and the electrode material is also limited.

  There are many reports on manufacturing methods. In Patent Document 8, a liquid containing microbubbles is supplied to a storage tank, and ultrasonic vibration is applied to the supplied liquid containing microbubbles to crush the microbubbles in the liquid, Discloses a method of generating nanobubbles. In addition to this, there are methods using underwater discharge, generation by ultrasonic waves, and a special glass membrane filter. In a swirl type generator, the gas of an ozone generator is mixed with circulating water to produce microbubbles. In the microbubble generator, high-pressure water is flowed and gas is absorbed under vacuum pressure through an orifice. Methods such as bubble jet (registered trademark) and fine droplet spraying have also been developed.

  Regarding the applied technology, in Patent Document 9, a nanobubble-utilized polluted water purification method that purifies polluted water using nanobubbles and microbubbles is disclosed in Patent Document 10, which is a hydroponic cultivation apparatus and hydroponics method that can be sterilized. A cooling water reforming method in which ozone micro-nano bubbles are contained in the cooling water in the cooling tower is disclosed. In addition, reduction of ship operation resistance, inactivation of viruses, food field, agriculture field, water purification in aquaculture and livestock farming, contrast medium, treatment (drug delivery), etc. are being studied in the medical field.

  Regarding the manufacturing method, there was a point to be improved. That is, the method of dissolving ozone and oxygen gas in water has a large ratio of being released without being dissolved in large bubbles, which is inconvenient because it is necessary to add a device for excluding ozone gas. Therefore, the development of a method that allows ozone to be easily synthesized as nanobubbles is significant.

  As described above, the presence of hydrogen, oxygen nanobubbles and microbubbles has been reported in water electrolysis, but it is not known whether ozone nanobubbles or microbubbles can be synthesized by electrolysis. In addition, no appropriate electrode material has been reported so far.

JP-A-9-268395 JP-A-8-134777 JP 2006-346203 A JP 2005-246294 A JP 2005-246293 A JP 2007-275089 A JP 2007-38149 A JP 2006-280183 A JP 2007-10572 A JP 2008-206448 A JP 2007-326031 A

J. Electrochem. Soc., 132, 367 (1985)

  As described above, various methods for synthesizing fine bubbles have been reported, but it has not been confirmed that ozone fine bubbles can be synthesized by electrolysis. Diamond electrodes are suitable for generating ozone gas, but there has been no report on whether or not a large amount of fine bubbles can be synthesized, and it is possible to store ozone water synthesized by this method for a long period of time, and applications using fine bubbles. It was never proposed.

  An object of the present invention is to provide an electrolytic production method capable of electrolyzing an aqueous solution and synthesizing a large amount of ozone fine bubbles in the aqueous solution.

The present invention supplies electrolytic solution containing an electrolyte to an electrolysis cell in which a conductive diamond anode is installed, and performs electrolysis to produce electrolyzed water in which ozone fine bubbles (sometimes referred to as nanobubbles) are dissolved. In the method, electrolysis is carried out at a current density of 0.01 A / cm ^{2 to} 0.5 A / cm ² to produce electrolyzed water containing 0.02 mM or more of ozone fine bubbles having an average particle size of 10 nm to 500 nm. The electrolyte solution as a raw material is a method comprising at least one of carbonate ion, bicarbonate ion, nitrate ion, sulfate ion, chloride ion, perchlorate ion, hydroxide ion, sodium ion and potassium ion. It is preferable that electrolytes are contained and the concentration range thereof is 0.1 to 1000 mM.

Furthermore, it is possible to synthesize electrolyzed water containing hydrogen fine bubbles in the cathode chamber simultaneously with the synthesis of electrolyzed water in which ozone fine bubbles are dissolved in the anode chamber.

  Hereinafter, each element used in the method of the present invention will be described.

[Electrode reaction]
The anodic reaction in the electrolytic cell is
2H ₂ O = O ₂ + 4H ⁺ + 4e ⁻
Oxygen evolution proceeds, but depending on the catalyst and electrolysis conditions,
3H ₂ O = O ₃ + 6H ⁺ + 6e ⁻
Ozone is generated, and ozone water in which it is dissolved can be synthesized.

[Current density]
In general, as the current density increases, the current efficiency of ozone increases, but decomposition due to heat generation is also promoted.

The present inventors have intensively studied the influence of the current density to produce ozone micro-bubbles, the current density is in 0.01A / cm ² ~0.5A / cm ^2, an average particle diameter 10nm~500nm It has been found that electrolyzed water containing 0.02 mM or more of ozone fine bubbles can be produced. Whether the current density is smaller or larger than the above range, the generation efficiency of ozone fine bubbles is extremely reduced.

Further, if the current density is smaller than the lower limit value, the current efficiency is decreased, and _CNB is 1 ppm or less, which is not suitable for practical use. If the value is larger than the upper limit value, the temperature increases, resulting in a decrease in current efficiency, an increase in the electrode basic unit, and an electrode having a short life, which is not practical.

[Other electrolysis conditions]
Although electrolysis may be performed at normal pressure, it is preferable to perform electrolysis under high pressure in order to obtain a higher concentration of fine ozone bubbles.

  The lower the temperature, the higher the current efficiency of ozone at the electrode and the higher the solubility. However, the temperature of the solution is preferably 5 ° C. to 60 ° C. because it is a factor for increasing the cell voltage.

[Anode material]
The anode base material is limited to valve metals such as titanium and niobium, alloys thereof, and silicon. Diamond is considered promising as an electrode material because it can control electrical conductivity by doping. The diamond electrode is inactive against the decomposition reaction of water, and ozone and hydrogen peroxide are reported to be generated in addition to oxygen in the oxidation reaction. The catalyst only needs to be present on a part of the anode, and there is no problem even if a part of the substrate is exposed.

A typical hot filament CVD method for producing a conductive diamond electrode will be described. Using a hydrocarbon gas such as methane CH ₄ as a carbon source or an organic substance such as alcohol, it is sent together with hydrogen gas into the CVD chamber, and while maintaining a reducing atmosphere, the filament is heated to a temperature of 1800 to 2400 ° C. at which carbon radicals are generated. Heat. At this time, an electrode base material is installed in a temperature (750 to 950 ° C.) region where diamond is deposited. The hydrocarbon gas concentration with respect to hydrogen is 0.1 to 10 vol%, and the pressure is 20 hPa to 1013 hPa (1 atm).

In order for diamond to obtain good conductivity, it is indispensable to add a trace amount of elements having different valences. A preferable content of boron B or phosphorus P is 1 to 100,000 ppm, and more preferably 100 to 10,000 ppm. Trimethylboron (CH ₃ ) ₃ B is used as the raw material compound, but it is also preferable to use boron oxide B ₂ O ₃ , pentaoxide 2 phosphorus P ₂ O _5, etc., which are less toxic. The shape of the electrode substrate can be not only a plate but also particles, fibers, plates, perforated plates, bars, and the like.

  In order to produce ozone fine bubbles by electrolysis, it is preferable to quickly remove supersaturated ozone components generated by electrolysis from the electrode surface. As a result of the study, it was confirmed that the smaller the surface roughness, the smoother the finer bubbles that can be synthesized. The roughness of the electrode surface is preferably in the range of 1 to 100 microns.

[Cathode material]
The cathodic reaction is mainly hydrogen generation, and it is preferable to use an electrode catalyst that does not embrittle with hydrogen, and platinum group metals, nickel, stainless steel, titanium, zirconium, gold, silver, carbon, diamond and the like are preferable. The cathode base material is limited to stainless steel, zirconium, carbon, nickel, titanium and the like. In the apparatus used for the method of the present invention, all of them are in contact with water in which ozone or peroxide is dissolved.

[Membrane material]
In order to keep the active substance generated by the electrode reaction stable, a neutral diaphragm or an ion exchange membrane can be used. The film may be either a fluororesin or a hydrocarbon resin, but the former is preferable in terms of ozone and peroxide corrosion resistance. The ion exchange membrane has a function to prevent the substances generated at the anode and cathode from being consumed at the opposite electrode, and to rapidly proceed electrolysis even when the liquid conductivity is low. This is essential when water or the like is used as a raw material. The material is preferably a fluororesin system or a polyimide resin system.

[Electrolysis cell]
A one-chamber cell composed of an anode, a cathode and an electrolyte solution, and a two-chamber cell further including a diaphragm can be used as an electrolysis cell. FIG. 1 shows a two-chamber cell. The distance between the electrodes is preferably 0.1 mm to 50 mm, more preferably about 0.1 mm to 2 mm. If it is closer than this, a short circuit is likely to occur due to contact, and if it is farther than this, the cell voltage increases. Each chamber is provided with an electrolyte supply port and discharge port, and a generated gas discharge port. The produced electrolyzed water can be stored in the cell chamber, but is preferably stored in a separate container. As the tank material, a material that is not affected by electrolyzed water is selected. If there is no particular problem, PE resin or the like may be used. In a two-chamber cell in which an anode chamber and a cathode chamber are partitioned by a diaphragm, electrolyzed water containing ozone fine bubbles from the anode chamber and electrolyzed water containing hydrogen fine bubbles from the cathode chamber can be synthesized simultaneously. Is an excellent electrolyzer.

[Raw material water]
Electrolyzed water (raw water) with the addition of a solute that generates ions upon dissolution, such as sodium chloride, and the addition of an acid for pH adjustment (raw water) is obtained by dissolving the ozone fine bubbles. It is done.

The raw water contains at least one electrolyte of carbonate ion, bicarbonate ion, nitrate ion, sulfate ion, chloride ion, hydroxide ion, sodium ion, potassium ion, and the concentration range thereof. It is preferable that it is 0.1-1000 mM. These ions are known to have an effect of suppressing coalescence of bubbles, and are preferably included in the degree of synthesis of fine bubbles. If it is smaller than this range, the inhibitory effect cannot be expected, and if it is larger than this range, it will simply be a useless additive, and the practicality of the synthesized solution will be poor.

  Tap water, well water, etc. can also be used as raw water. However, since the conductivity is small and the resistance loss in the cell voltage cannot be ignored, it is preferable to add the above electrolyte. Moreover, in the processing object containing many metal ions, such as tap water, well water, seawater, there exists a possibility that a hydroxide or a carbonate may precipitate on the cathode surface and reaction may be inhibited. In addition, an oxide such as silica is deposited on the surface of the anode. In order to prevent this, by applying a reverse current every appropriate time (1 minute to 1 hour), it is acidified at the cathode and alkalized at the anode. The separation reaction proceeds easily.

  If the concentration is higher than the above, an increase in nanobubble concentration can be expected. However, when the generated electrolyzed water is put to practical use, a process such as dilution or removal of the added electrolyte is required, which is inconvenient.

[Generated electrolyzed water]
As reported previously, potassium, sodium, lithium ions as cations as electrolytes that suppress the coalescence of bubbles, and hydroxide ions, chloride ions, nitrate ions, bromide ions, sulfate ions, etc. as anions. Are known. By selecting these electrolytes and remaining in the synthesized electrolyzed water, it is possible to synthesize long-lived nano and micro bubbles (ozone fine bubbles). Microbubbles can be synthesized even without selecting an electrolyte that suppresses coalescence of these bubbles. However, it is preferable to avoid ions that easily oxidize by electrolysis of chloride ions or the like and generate hypochlorous acid or the like because the ozone generation efficiency is reduced. On the other hand, when synthesizing a solution in which an ozone component that is fine bubbles and hypochlorous acid coexist, raw material water in which chloride ions are dissolved at a low concentration can be used. These salts have a function of generating peroxides by electrolysis and responsible for the persistence of the bactericidal effect.

  The synthesized electrolyte can be stored and can be used depending on the application. Since the fine bubbles are charged in the solution and the zeta potential has pH dependence, it is possible to control the ozone sterilizing power by controlling the pH. That is, when the target substance or organism is positively charged, the fine bubbles are negatively charged. When the target is negatively charged, the fine bubbles are positively charged.

[Quantification of nano / micro bubbles in electrolyzed water]
Potassium iodide is added to the electrolytic solution taken out from the anode chamber, and oxidation-reduction titration with sodium thiosulfate is performed to calculate the concentration of dissolved ozone and the current efficiency. The ozone concentration at this time is C ₁ (mM). Further, after the collected electrolyte solution is diluted five times with pure water, the concentration and current efficiency are calculated by the same measurement method. When the latter concentration is C ₅ (mM), the nanobubble concentration C _NB can be estimated by the following equation.

C ₅ × 5 − C ₁ = C _NB

The ozone concentration was measured by the KI method. It can also be quantified by UV method, indigo method and the like. The concentration C _NB of the entire ozone water including ozone fine bubbles in the method of the present invention is 0.02 mM (1 ppm) or more. If the concentration is less than this, a practical effect cannot be expected.

  The method of the present invention is expected to contribute to the expansion of the use of electrolyzed water devices in fields such as sterilization, disinfection, and decolorization. By performing ozone generation and nanobubble generation in a single process, the device can be reduced in size, weight, and cost, which can greatly contribute to practical use.

The schematic longitudinal cross-sectional view which shows the two-chamber cell which can be used for this invention method.

  Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings and examples.

FIG. 1 is a schematic longitudinal sectional view showing a two-chamber cell that can be used in the method of the present invention.
The two-chamber cell 1 is divided into an anode chamber 3 and a cathode chamber 4 by a perfluorosulfonic acid cation exchange membrane 2. On the side of the anode chamber 3 of the cation exchange membrane 2, a diamond anode 5 in which a conductive diamond layer doped with impurities is coated on a plate-like substrate made of valve metal or the like is disposed at an interval. A plate-like cathode 6 is provided on the cathode chamber side of the membrane 2 with a space therebetween.

  A raw material anode water supply port 7 and a synthesized ozone fine bubble dissolved water outlet 8 are respectively formed laterally at the lower and upper portions of the anode chamber 3, and laterally at the lower and upper portions of the cathode chamber 4. The raw material cathode water supply port 9 and the synthesized hydrogen gas outlet 10 are formed respectively.

A current density of 0.01 A / cm ^{2 to} 0 is supplied to the anode chamber 3 and the cathode chamber 4 of the cell 1 while supplying the raw water containing the electrolyte from the raw anode water supply port 7 and the raw cathode water supply port 9. Current is supplied so as to be 5 A / cm ² . Thereby, ozone fine bubbles having an average particle diameter of 10 nm to 500 nm are synthesized in the anode chamber at a concentration of 0.02 mM or more, and at the same time, hydrogen gas is generated in the cathode chamber by normal water electrolysis. The obtained electrolyzed water for dissolving the ozone fine bubbles is taken out from the ozone fine bubble-dissolved water outlet 8 and used for a predetermined use.

[Examples and Comparative Examples]

"Example 1"
A niobium plate electrode (5 cm × 5 cm) having a conductive diamond catalyst (boron doping concentration of 1300 ppm) layer formed on the surface was used as the anode. An ion exchange membrane (Dafon Nafion 117, thickness 0.2 mm) is used as a diaphragm, and a plate electrode (5 cm × 5 cm) formed by plating with 0.2 μm platinum is used as a cathode. An electrolysis cell having two chambers was constructed. Gas and liquid flow paths were provided in each chamber of the electrolysis cell. A 0.5 M sodium nitrate aqueous solution adjusted to pH 12 with NaOH was used as a raw material and supplied at a rate of 35 mL / min from the lower part of the anode chamber and the cathode chamber. The current density was 0.1 A / cm ² and the temperature was controlled at 25 ° C. at the outlet. The hydrated dissolved component concentration C ₁ of ozone gas was 0.25 mM, and the concentration C ₅ in the 5-fold dilution method was 1.8 mM. From this difference, the concentration of ozone water as nanobubbles was 1.55 mM. The current efficiency for the nanobubbles was 21%.

[Example 2]
When electrolysis was performed in the same manner as in Example 1 except that the current density was 0.4 A / cm ² , the ozone gas dissolved component concentration C ₁ was 0.2 mM, and the concentration C ₅ in the 5-fold dilution method was 1. From this difference, the ozone water concentration as nanobubbles was 1.7 mM. The current efficiency for the nanobubbles was 5.5%.

[Example 3]
When electrolysis was performed in the same manner as in Example 1 except that the current density was 0.08 A / cm ² , the concentration C ₅ in the 5-fold dilution method was 0.8 mM, and the current efficiency with respect to nanobubbles was 1.4%. Met.

[Example 4]
When electrolysis was performed in the same manner as in Example 1 except that the current density was 0.01 A / cm ² , the concentration C ₅ in the 5-fold dilution method was 0.02 mM, and the current efficiency related to nanobubbles was 2.7%. Met.

[Comparative Example 1]
When electrolysis was performed in the same manner as in Example 1 except that the current density was 0.005 A / cm ² , the concentration C ₅ in the 5-fold dilution method was below the measurement limit.

[Comparative Example 2]
When electrolysis was conducted in the same manner as in Example 1 except that the current density was 0.55 A / cm ² , the concentration C ₅ in the 5-fold dilution method was 0.01 mM.

[Example 5]
Except for using 0.5 M sodium perchlorate adjusted to pH 12 with NaOH, the same electrolysis as in Example 1 was performed. As a result, the ozone gas dissolved component concentration C ₁ was 0.1 mM, and the 5-fold dilution method was used. the concentration C ₅ of a 0.3 mM, the concentration of ozone water as nanobubbles from this difference was 0.2 mM. The current efficiency for nanobubbles was 3.5%.

  Also, hydrogen water was obtained from the cathode chamber, and as hydrogen nanobubbles, a hydrogen gas dissolution concentration of 1 mM and a concentration of 3 mM by a 5-fold dilution method were obtained.

"Example 6"
A silicon plate electrode (3.5 cm × 3.5 cm) on which a conductive diamond catalyst (boron doping concentration 1300 ppm) was formed was used as the anode. When the same measurement as in Example 1 was performed using 0.01 M sodium carbonate, the dissolved ozone concentration C ₁ was 0.3 mMM at a current density of 0.1 A / cm ² , and the concentration C ₅ in the 5-fold dilution method was Was 0.9 mM and the current efficiency for nanobubbles was 8%.

[Comparative Example 3]
When a cell similar to that of Example 1 was assembled and tested except that a platinum plate was used as the anode, the hydrated dissolved component concentration C ₁ of ozone gas was 0.01 mM, and the concentration C ₅ in the 5-fold dilution method was Was an amount that could not be measured. From this, it was speculated that the presence of fine bubbles could not be confirmed.

1 2 chamber cell 2 cation exchange membrane 3 anode chamber 4 cathode chamber 5 diamond anode 6 plate cathode

Claims (3)

In a method for producing electrolyzed water in which ozone fine bubbles are dissolved by supplying an aqueous solution containing an electrolyte to an electrolysis cell in which a conductive diamond anode is installed, and performing electrolysis, the current density is 0.01 A / cm ^2. A method comprising producing electrolyzed water containing 0.02 mM or more of ozone fine bubbles having an average particle diameter of 10 nm to 500 nm by performing electrolysis at ˜0.5 A / cm ² .   The electrolyte is at least one selected from the group consisting of carbonate ion, bicarbonate ion, nitrate ion, sulfate ion, chloride ion, perchlorate ion, hydroxide ion, sodium ion and potassium ion, and its concentration range The method according to claim 1, wherein is 0.1 mM to 1000 mM.   The method according to claim 1, wherein electrolyzed water containing hydrogen fine bubbles is synthesized in the cathode chamber simultaneously with synthesis of electrolyzed water containing ozone fine bubbles in the anode chamber.

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