JP2000169988A - Water storage tank provided with water purifier - Google Patents

Abstract

PROBLEM TO BE SOLVED: To completely decompose organic matters of low molecular weight, to achieve the sterilization and deodorization, and to prevent the pollution by introducing ozone generated in a water electrolysis cell in a water to be treated in a container, and achieving the strong oxidation through the stirring circulation by a mixing pump and an oxidation promoting catalyst. SOLUTION: A water 7 to be treated which is stored in a container 3 of a water storage tank 1 is circulated in a stirring manner by a mixing pump 9 through a water suction side 11, a water discharge side 12 and a high level container 13, ozone to be supplied from a water purifier 2 to the suction side 11 through an inlet pipe 27 is mixed, and organic matters are oxidized through decomposition and sterilization through an oxidation promoting catalyst 15 such as platinum. In the purifier 2, wet ozone which is pure and easy to dissolve is efficiently and safely generated at a low cost by electrolyzing deionized water obtained by passing a part of the water 7 to be treated through an ion exchange resin tower 18 by an electrolytic cell 20 provided with a solid electrolytic film and a gas diffusion electrode. The oxidation promoting catalyst 15 generates hydro-radicals to increase the oxidizing power.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the decomposition of organic matter dissolved in water in a drinking water tank of a cup-type beverage vending machine, a goldfish water tank, a food cooling water tank, etc. using ozone generated by electrolysis of water. The present invention relates to a water storage tank provided with a water purification device for sterilization, deodorization, and prevention of pollution.

[0002]

2. Description of the Related Art Conventionally, a chlorine generator has been generally used for preventing pollution of a water storage tank installed as a drinking water tank of a cup-type beverage vending machine. The method of purifying the water tank by this chlorine generator is to immerse a pair of cathode and anode electrodes in the water tank and electrolyze the water to oxidize chlorine ions contained as impurities in the purified water on the anode surface. In this method, chlorine is generated, and the chlorine and hypochlorous acid generated by dissolving the chlorine in water are used for sterilization.

[0003] Chlorine has been used mainly as a disinfectant that can be used with peace of mind, mainly for disinfecting tap water. It is said that chlorine having a residual chlorine concentration of 0.1 ppm or more has bactericidal activity. Therefore, this chlorine generator is also set so that chlorine ions are oxidized on the anode surface and chlorine is generated so that the residual chlorine concentration becomes about 0.5 ppm. The reason for the sterilization of tap water is that chlorine is excellent in persistence, and treatment with residual chlorine is preferred to maintain the sterilization effect from tap water to each household like tap water. It is.

[0004] Disinfection and sterilization of chlorine poses a major problem in preventing contamination of a water storage tank installed as a drinking water tank of the cup-type beverage vending machine. In other words, the generated chlorine remains to emit a smell peculiar to chlorine, and chlorine or hypochlorous acid reacts with various soft drink components to form chlorine compounds, alter the taste and smell, and supply a delicious beverage. There was a fatal problem that it was not possible.

In addition, the amount of chlorine generated varies depending on the quality of the supplied tap water, and is greatly affected by the concentration of anions such as cations and chlorine ions contained in the water. It is necessary to perform preliminary experiments and set the electrolysis time. Further, the amount of generation is unstable due to the influence of deposits on the electrodes and the like, and it is difficult to set the concentration at a constant level.

Further, in recent years, it has been often pointed out that chlorine reacts with a trace amount of organic matter contained in tap water to form carcinogenic trihalomethane, and it is necessary to review chlorine sterilization. Has become.

Therefore, in recent years, Japanese Patent Application Laid-Open No. 61-14739 has been proposed.
As shown in Japanese Patent Publication No. 3 (2003), an ozonizer is attached to a water reservoir for storing drinking water of a cup-type beverage vending machine, and the ozone gas generated by the ozonizer is supplied to and dissolved in the stored water in the water reservoir. In addition, there has been proposed an apparatus which sterilizes and disinfects water to thereby maintain the quality of drinking water.

[0008] Ozone is less persistent than chlorine and decomposes into safe oxygen relatively quickly, so that it does not alter the taste of food and does not give off odors. It is suitable for disinfecting and disinfecting water tanks installed as drinking water tanks in cup-type beverage vending machines.

As a method for producing ozone, Japanese Patent Application Laid-Open No.
No. 47393, a method in which oxygen in the air is oxidized to ozone by a discharge type ozonizer, and a method in which water is electrolyzed to generate hydrogen and oxygen, and ozone is generated as a by-product when the oxygen is generated. There is a way to get.

In the method of producing ozone from oxygen in air, about 80% of nitrogen in air is oxidized at the same time, so that nitrogen oxides such as nitrogen dioxide and nitric oxide are also produced.
When ozone water is produced by blowing and dissolving the processing gas into water, nitrogen oxides are also dissolved in water at the same time, so that nitric acid is formed, resulting in a problem of strongly acidic ozone water.

The fact that 80% of nitrogen gas is contained and the oxygen concentration is as low as 20% means that the partial pressure of ozone gas in the generated processing gas is low, the amount of dissolved ozone in water is small, and Not only can water be produced, but excess ozone that is not completely soluble in water is likely to be generated. JP-A-61-14
Although it is conceivable to use surplus ozone to prevent contamination of another aquarium as shown in US Pat. No. 7,393, there is a problem that an effective sterilizing effect cannot be secured because the concentration is further reduced.

Therefore, in order to efficiently dissolve ozone in water and to generate neutral and clean ozone water, a water electrolysis type ozone generation method capable of obtaining pure and high-concentration ozone is recommended.

When the water to be treated is used for drinking,
There is a problem of harmful by-products of aldehydes formed by ozone decomposing organic substances contained in the water to be treated. As a method for accelerating the decomposition of this by-product, Japanese Patent Laid-Open No.
As disclosed in Japanese Patent No. 3597, it is known that an air diffusion tube is formed by selecting from an ozone decomposition catalyst such as platinum, manganese dioxide, copper oxide, nickel peroxide, zinc, titanium oxide, silicon dioxide and the like. .

[0014]

However, according to the method disclosed in Japanese Patent Application Laid-Open No. Hei 4-243597, the amount of pure high-concentration ozone gas obtained by electrolysis of water is limited by using a diffuser. Insufficient pressure and sufficient diffusing effect cannot be obtained.Also, since the diffuser tube is composed of an ozone decomposition catalyst, the ozone reacts with water to produce hydroxyl radicals which are more oxidizing than ozone molecules. Decomposition has progressed, and there is a drawback that organic substances in water are not efficiently decomposed.

Therefore, an object of the present invention is to solve the above-mentioned problems.

[0016]

In order to achieve the above object, the present invention provides an electrolytic cell having a cathode chamber, an anode chamber, a solid electrolyte membrane separating the cathode chamber and the anode chamber, A water tank containing an oxidation-promoting catalyst for generating hydroxyl radicals upon contact with ozone in the water to be treated, and containing ozone generated by electrolysis of water in the electrolytic cell. The gas is introduced into the water to be treated in the water storage tank by an introduction pipe.

A mixing pump having a function of supplying and draining the water to be treated in the water storage tank and circulating and stirring the water to be treated is provided in the water storage tank, and a gas containing ozone is introduced into the water absorption side of the mixing pump. An oxidation-promoting catalyst is arranged on the drain side of the mixing pump.

A reaction vessel into which water to be treated is introduced from the drain side of the mixing pump is provided, and a porous oxidation-promoting catalyst is provided in the reaction vessel.

A mixing pump having a function of supplying and draining the water to be treated in the water storage tank and circulating and stirring the water to be treated is provided in the water storage tank, and a gas containing ozone is introduced into the water absorption side of the mixing pump. The surface of the rotating blades of the mixing pump is formed of an oxidation promoting catalyst.

A voltage is applied to the oxidation-promoting catalyst and the counter electrode member having electrical insulation with respect to the oxidation-promoting catalyst via the water to be treated.

Further, the voltage applied to the oxidation promoting catalyst and the counter electrode member can be varied. In addition, a DC voltage is applied by a DC voltage applying device so that the counter electrode member is used as an anode and the oxidation promoting catalyst is used as a cathode.

The oxidation-promoting catalyst is made of platinum and / or a material obtained by surface-treating platinum on titanium.

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention can be embodied by adopting the constitution described in each claim. However, the constitution and the operation by the constitution are described below so that the embodiment can be easily understood.

According to the first aspect of the present invention, there is provided an electrolytic cell having a cathode chamber, an anode chamber, a solid electrolyte membrane for partitioning the cathode chamber and the anode chamber, storing the water to be treated, and A water storage tank provided with an oxidation-promoting catalyst that generates hydroxyl radicals upon contact with ozone,
A gas containing ozone generated by electrolysis of water in the electrolytic cell is introduced into the water to be treated in the water storage tank by an introduction pipe.

Pure and high-concentration wet ozone produced by the electrolysis of water is relatively easily dissolved in the water to be treated and reacts with various bacteria and organic substances contained in the water to be treated. It produces hydroxyl radicals with high oxidizing power in the process of reacting to decompose low molecular organic substances that cannot be decomposed by ozone alone, thereby enhancing the water purification effect.

According to a second aspect of the present invention, a mixing pump having a function of supplying and discharging the water to be treated in the water storage tank and circulating and stirring the water to be treated is provided in the water storage tank, and ozone is supplied to the water absorption side of the mixing pump. A gas containing gas was introduced, and an oxidation promoting catalyst was disposed on the drain side of the mixing pump.
Therefore, since the ozone oxidation promoting catalyst is provided on the discharge side of the mixing pump, the ozone and the water to be treated are efficiently dissolved by the mixing pump, and the oxidation is promoted on the discharge side of the mixing pump having a relatively high dissolved ozone concentration. By disposing the catalyst, sterilization and water purification effects can be enhanced.

According to a third aspect of the present invention, a reaction vessel into which water to be treated is introduced from the drain side of the mixing pump is provided, and a porous oxidation-promoting catalyst is provided in the reaction vessel. The porous oxidation-promoting catalyst having a large surface area in the reaction vessel intensively and efficiently sterilizes and decomposes organic substances.

According to a fourth aspect of the present invention, a mixing pump having a function of supplying and draining water to be treated in a water storage tank and circulating and stirring the water to be treated in the water storage tank is provided in the water storage tank. A gas containing ozone is introduced into the mixing pump, and the surface of the rotating blades of the mixing pump is formed of an oxidation-promoting catalyst.Forcibly circulating and agitating the water to be treated by the rotating blades and simultaneously promoting the oxidation of ozone. Sterilization and decomposition of organic matter were performed more reliably.

According to a fifth aspect of the present invention, a voltage is applied to the oxidation-promoting catalyst and the counter electrode member having electrical insulation with respect to the oxidation-promoting catalyst via water to be treated. By applying an electric potential to the medium, the decomposition of ozone is accelerated and the generation of hydroxyl radicals is activated, so that sterilization and decomposition of organic substances are further promoted.

According to a sixth aspect of the present invention, the applied voltage can be varied, and the rate of ozonolysis is adjusted according to the degree of contamination of the water to be treated, that is, according to the amount of germs and organic substances, to reduce unnecessary ozonolysis. It is something to avoid.

According to a seventh aspect of the present invention, a DC voltage is applied by a DC voltage applying device so that the counter electrode member becomes the anode and the oxidation accelerating catalyst becomes the cathode. What to do.

The invention according to claim 8 is characterized in that the oxidation-promoting catalyst is made of platinum and / or a material obtained by surface-treating platinum on titanium, which is versatile, has appropriate ozonolysis characteristics, and has corrosion resistance. By using high platinum, useless ozone decomposition can be avoided.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. (Embodiment 1) FIG. 1 shows a configuration of a water storage tank 1 and a water purification device 2 thereof according to Embodiment 1 of the present invention.

The water storage tank 1 has a water storage container 3 and a lid 4. The water 7 to be treated is maintained at a predetermined water level H by opening and closing a water supply valve 6 according to a signal from a float 5.

The water 7 to be treated in the water storage tank 1 is
The water flows through the guide pipe 10 from the water suction side 11 to the drainage side 12 by the mixing pump 9 rotating at the above, and is lifted to the hill vessel 13 at a position higher than the water level H, and is dropped from the drainage port 14 to be circulated and stirred.

The water purification device 2 includes a mixing pump 9 having a water supply / drainage function and an oxidation promoting catalyst 15 having an oxidation promoting function.
And an ozone generator 16 having a function of generating ozone gas
It is composed of

The oxidation-promoting catalyst body 15 is fixed in the water 7 to be treated in the water storage tank 1 by a holder 17 and is made of a material in which platinum is plated on the surface of an expanded titanium material.

[0038] The ozone generator 16 includes the ion exchange resin tower 1
An electrolysis cell 20 provided with a gas separation chamber 8 and a gas separation chamber 19 and a control circuit 21 are provided.

The ion exchange resin tower 18 is provided with a filter A2
The space between the filter 2 and the filter B23 is filled with the ion exchange resin 24. The lower portion of the ion exchange resin tower 18 and the guide pipe 10 on the drain side 12 of the mixing pump 9 are communicated by a communication pipe 25.

The upper part of the ion-exchange resin tower 18 and the gas separation chamber 19 can be passed through a water passage 26.
Further, at the upper part of the gas separation chamber 19, there are provided an introduction pipe 27 for guiding the gas to the water suction side 11 of the mixing pump 9 and an air hole 28 for adjusting the pressure. Between the separation chamber 19 and the ozone decomposition catalyst 2
9 are provided.

FIG. 2 is a longitudinal sectional view showing the structure of the electrolytic cell 20 for generating ozone by electrolysis of water. A cathode chamber 33 having a cathode 32 having a gas diffusion electrode 30 and a current collector 31; and an anode chamber 35 having an anode 34 serving as an ozone generating electrode.
Are separated by a solid electrolyte membrane 36 and have a zero gap.

The solid electrolyte membrane 36 is a membrane mainly composed of a fluororesin having a sulfonic acid group capable of exchanging hydrogen ions. The solid electrolyte membrane 36 has a hydrogen ion conduction type utilizing the property that hydrogen ions of the sulfonic acid group can freely enter and exit. It has been developed as a solid electrolyte membrane 36.

The solid electrolyte membrane 36 is a polymer substance having a property of transmitting only hydrogen ions, and relatively does not transmit or transmit other ions. The solid electrolyte membrane 3 of the hydrogen ion conduction type membrane used in this embodiment
No. 6 used an N117 solid polymer membrane sold by DuPont under the trade name of Nafion membrane.

The anode 34 was formed by electrodepositing β-type lead dioxide on the surface of a porous corrosion-resistant metallic titanium substrate.

The cathode 32 is made of a porous mesh having air permeability, and is formed by pressing a mixture of a carbon powder and a fluororesin powder carrying ultrafine platinum particles on the surface thereof to provide a water repellent with an appropriate water repellency. It is formed as a joined body of the conductive gas diffusion electrode 30 and the current collector 31 that transmits electric charges uniformly.

Reference numeral 37 denotes an intake / exhaust mechanism comprising an intake fan 39 attached to an intake port 38 for inhaling outside air, and an exhaust port 40, which sequentially sends outside air containing oxygen to the gas diffusion electrode 30 of the cathode chamber 33. It is.

The electrolytic cell 20 and the gas separation chamber 19 communicate with each other through the lower opening 41 and the gas transfer pipe 42. The ion exchange water that has passed through the ion exchange resin tower 18 is injected into the gas separation chamber 19 and the anode chamber. Water will also be injected into 35.

Reference numeral 43 denotes a gas transfer pipe 42 which is a mixed gas of oxygen gas and ozone gas generated by electrolysis of water in the anode chamber 35.
To the gas separation chamber 19 through the space 44
Is discharged from the outlet 43 and discharged from the outlet 43 through the inlet pipe 27 to the water suction side 11 of the mixing pump 9.
Is introduced through a fine adjustment valve 45. Gas separation chamber 19
Some of the gas in the air hole 28 through the ozone decomposition catalyst 29
Through to the atmosphere.

Here, the fixing position of the gas separation chamber 19 and the anode chamber 35 is set higher than the water level H of the water 7 to be treated in the water storage tank 1, so that the mixing pump 9 is operated and the elevated vessel 1
3 is filled with the to-be-processed water 7, so that the gas separation chamber 19 and the anode chamber 35 are also filled with ion-exchanged water at a water level balance.

The control circuit 21 also has a storage battery function,
Even if the mixing pump 9 is stopped, the electrolysis is continued for a while to dry the surface of the anode 34 and prevent the reduction reaction.

Reference numeral 46 denotes an ozone gas sensor for sensing the ozone concentration in the water storage tank 1. The ozone gas sensor 46 sends a signal to the control circuit 21 and adjusts the voltage applied to the anode 34 and the cathode 32 of the electrolytic cell 20 to adjust the ozone concentration. Control.

Here, the surface treatment step of the oxidation promoting catalyst 15 and the anode 34 used in Embodiment 1 of the present invention will be described.

First, as a pretreatment, the oxidation-promoting catalyst 15 is degreased by ultrasonic cleaning with a 5% surfactant solution of a porous corrosion-resistant metal titanium base material, and rinsed with ion-exchanged water. % Oxalic acid solution in boiling water for 5 minutes to remove the oxidized layer on the surface. Immediately before the base treatment, 1N sulfuric acid was used as an electropolishing liquid and electrolytic reduction was performed on the cathode side at 4 A / dm ² . .

After the above pretreatment, chloroplatinic acid was added in an amount of 0.1% each.
It was immersed in a mixed solution of hydrochloric acid adjusted to a molar concentration, preliminarily dried at 40 ° C. for 15 minutes, and baked at 520 ° C. This baking base treatment was repeated three times to provide a conductive metal oxide base layer of about 1 μm.

Next, the surface to be treated with the underlayer is set at 4 A / dm.^TwoAt 30
After performing the electrolytic reduction treatment for 2 seconds, chloroplatinic acid was added to each of 0.1 ml.
Immersed in a hydrochloric acid mixed solution adjusted to a concentration of 1 mol, and
dm ^TwoFor 20 minutes.

Similarly, as a pretreatment, the anode 34 is degreased by ultrasonic cleaning with a 5% surfactant solution of a porous corrosion-resistant metallic titanium substrate, rinsed with ion-exchanged water, % Oxalic acid solution in boiling water for 5 minutes to remove the oxidized layer on the surface. Immediately before the base treatment, 1N sulfuric acid was used as an electropolishing liquid and electrolytic reduction was performed on the cathode side at 4 A / dm ² . .

After the above pretreatment, chloroplatinic acid was added in an amount of 0.1% each.
It was immersed in a mixed solution of hydrochloric acid adjusted to a molar concentration, preliminarily dried at 40 ° C. for 15 minutes, and baked at 520 ° C. This baking base treatment was repeated three times to provide a conductive metal oxide base layer of about 1 μm.

Next, the undertreated surface was subjected to electrolytic reduction treatment at 4 A / dm ² for 30 seconds, followed by electroplating of lead dioxide as an ozone generation selective catalyst.

In the plating of lead dioxide, first, a saturated lead oxide solution of 3.5N sodium hydroxide was used as a plating bath to prepare a plating bath.
A / dm ² treatment on the anode side for 20 minutes formed α-type lead dioxide of several microns. The bath temperature at this time was 40 ° C.

Next, in a 1N nitric acid bath of 30% by weight of lead nitrate, a catalyst layer of β-type lead dioxide as an ozone generation selective catalyst was formed at the anode under the conditions of 4 A / dm ² for 40 minutes. . The bath temperature at this time was 70 ° C.

Hereinafter, the chemical reaction in the electrolytic cell 20 having the anode 34 of the first embodiment described above, the reaction on the surface of the oxidation promoting catalyst 15, and the operation of the water storage tank 1 and the water purification device 2 will be described.

First, when the water 7 to be treated, which is the source water, is supplied to the water storage tank 1 from the water supply valve 6 and the water is filled to the water level H, the float 5 is activated and the water supply is stopped. In addition, the drain side 1 of the mixing pump 9 immersed in the water tank 1 by the water level adjusting force.
The water flows into the ion exchange resin tower 18 through the communication pipe 25 communicating with the second guide pipe 10 and is filled with the water to be treated to the H level. Filled water to be treated is filtered by filter A2
2. While passing through the ion-exchange resin 24 and the filter B23, metal ions as cations contained in the water to be treated are converted into hydrogen ions, and chloride ions and carbonate ions as anions are converted into hydroxyl ions. And ion-exchanged water having an electric conductivity of 2 μs or less.

Next, when the power of the water purification device 2 is turned on, the drive motor 8 and the control circuit 21 are in an operating state, the mixing pump 9 is operated, a DC voltage is applied to the anode 34 and the cathode 32, and the suction fan 39 is operated. .

When the mixing pump 9 is operated, the circulation and agitation of the water 7 to be treated is started, and a flow is drawn from the water suction side 11 into the mixing pump 9 and discharged to the drain side 12. The momentum of the flow starts circulation of the water 7 to be treated, which is pumped up to the hill 13 using the guide pipe 10 and falls from the drain 14 into the water reservoir 3.

Incidentally, as the water level rises to the hill vessel 13, the water level in the ion exchange resin tower 18 also rises,
Ion-exchanged water enters the gas separation chamber 19 through the water passage 26, and also enters the anode chamber 35 through the lower opening 41. Further, since the ion-exchanged water works as an electrolytic solution, the solid electrolyte membrane 3 is passed through an air-permeable anode 34.
Fill the surface of No. 6.

When the interface between the anode 34 and the solid electrolyte membrane 36 is filled with an electrolyte solution which is ion-exchanged water, the solid electrolyte membrane 3
6 absorbs water and activates the hydrogen ion of the sulfonic acid group,
The conduction between the cathode 32 and the anode 34 is improved, and the electrolysis reaction of the electrolytic solution, which is ion-exchanged water, starts at the interface between the anode 34 and the solid electrolyte membrane 36.

The material of the surface of the anode 34 is β-type lead dioxide, which has a high corrosion potential and functions as an ozone generation selective catalyst containing reactive oxygen. Almost no electrode material is dissolved. The water molecules in the electrolytic solution are oxidized, and the reactions of Chemical Formulas 1 to 4 occur. Oxygen gas and ozone gas are generated from the surface of the anode 34 mainly from chemical formulas 1 and 4 from the equilibrium potential of the reaction formula.

Here, if the surface of the plating is made of platinum or the like, the oxygen overvoltage is low, and only the reaction of Formula 1 is performed, and the generation of ozone is small, but the oxygen overvoltage is high, and β-type lead dioxide containing reactive oxygen has the following problems. Since the reaction oxygen intervenes as a catalyst in the reaction formula 1, the reaction of the formula 4 is positively caused,
Ozone is efficiently generated, and the ozone concentration in the generated gas increases. In the first embodiment, when a DC voltage of 3.5 V is applied and a current of 2 A flows, about 50 mg /
hr ozone generation was obtained.

[0069]

Embedded image

[0070]

Embedded image

[0071]

Embedded image

[0072]

Embedded image

Since the electrolytic solution is ion-exchanged water and there is almost no counter ion for hydrogen ions, excess hydrogen ions move to the cathode chamber 33 through the solid electrolyte membrane 36 which is a hydrogen ion conductive membrane. Therefore, no increase in the hydrogen ion concentration is observed in the anode chamber 35, the pH is maintained at the same pH as the source water or the ion-exchanged water, and the treated water 7 uses purified water,
If it is neutral, it will maintain neutrality.

The cathode 32 of the cathode chamber 33 is the gas diffusion electrode 30
And the oxygen contained in the outside air sent by the suction fan 39, the electrons flowing as a negative potential from the cathode 32, and the electrons generated in the anode chamber 35 and passing through the solid electrolyte membrane 36. There are three components with the coming hydrogen ions, and a water molecule is generated by causing the reaction of Chemical Formula 5. The generated water molecules are adsorbed on the solid electrolyte membrane 36 or are vaporized and discharged from the exhaust port 40.

[0075]

Embedded image

Further, by being closely attached to the solid electrolyte membrane 36, oxygen contained in the outside air, electrons carried through the cathode 32, and hydrogen ions passing through the solid electrolyte membrane 36 are converted to platinum When the gas diffusion electrode 30 of the cathode 32 and the solid electrolyte membrane 36 are isolated from each other, the movement of hydrogen ions is hindered by the nonconductive gas layer, and the reaction can be smoothly performed by the catalytic action of the fine particles. Without going
If the cathode 32 has no through-hole, the cathode 32 itself blocks the movement of oxygen from the surface in contact with the outside air to the solid electrolyte membrane 36, so that the three components cannot react smoothly.

As described above, a porous mesh-like material having through holes such as the porous gas diffusion electrode 30 is used as the cathode 32, and is attached to the solid electrolyte membrane 36 in close contact with the cathode 32, so that a suction / exhaust mechanism is provided. The generation of water by the oxygen fed by the 37, the hydrogen ions passing from the anode chamber 35 through the solid electrolyte membrane 36, and the electrons carried through the cathode 32 is the generation of hydrogen gas from the surface of the cathode 32. Can be eliminated, and the danger of fire or explosion due to hydrogen gas can be eliminated. In addition, since the cathode chamber 33 does not require an electrolytic solution, purified water, ion-exchanged water, distilled water, pure water, or the like, it is not necessary to manage the treatment of the electrolytic water and control the concentration, and the structure of the electrolytic cell 20 is very simple. And the cost of components can be reduced.

In the anode chamber 35, oxygen and ozone mainly generated by the reaction of Chemical Formulas 1 and 4 are generated. The mixed gas of oxygen and ozone is supplied from the gas transfer pipe 42 of the electrolytic cell 20 to the gas separation chamber 1.
9 and moves to the space portion 44 on the water surface by buoyancy. Since the space portion 44 on the water surface communicates with the water suction side 11 of the mixing pump 9 by the introduction pipe 27 of a thin tube, the space portion 4 on the water surface
It is led to the water suction side 11 of the mixing pump 9 which is slightly reduced in pressure from 4. If a large amount of gas is generated, the surplus gas is released to the atmosphere through the air holes 28. At this time, since it is released to the atmosphere via the ozone decomposition catalyst 29, there is no danger due to ozone leakage.

That is, since the water 7 to be treated is circulated and agitated by the mixing pump 9, the mixed gas containing ozone is mixed with the water 7 to be treated in the water storage tank 1, and the water to be treated 7 in the water storage tank 1 is sterilized. The amount of mixed gas to be mixed is
The fineness is adjusted by the fine adjustment valve 45 and the concentration is set.

Here, if there is no air hole 28, the fine adjustment valve 4
Due to the opening / closing degree of 5, the balance between the slightly reduced pressure amount of the mixing pump 9 and the mixed gas amount generated by the electrolysis is not balanced, and the pressure of the space portion 44 on the water surface in the gas separation chamber 19 changes, and the water surface moves up and down. In the worst case, the water in the gas separation chamber 19 may be exhausted, or the space 44 on the water surface may be lost, and the electrolyzed water may flow into the water storage tank 1 through the introduction pipe 27. However, when the air hole 28 is provided, if the amount of the mixed gas generated by the electrolysis is large, a part of the mixed gas will
When a large amount is discharged from the air hole 28 to the atmosphere through the air hole and is drawn by a slight decompression, air enters through the air hole 28 to maintain the water level of the gas separation chamber 19 at the same level as the water level of the elevated container 13. Can be.

As described above, the ion-exchange water is directly produced from the source water to be treated 7 by the ion-exchange resin tower 18, so that it is pure, high-concentration and moisturized regardless of the quality of the water 7 to be treated. Water electrolysis ozone can be obtained, even when dissolved in water, it is almost neutral, there is little effect on the human body, and the treated water that has been ozone sterilized has no peculiar smell like chlorine,
Reacting with the extract of the soft drink to lessen the taste and odor is lessened, so that a delicious drink can be provided, and the drainage does not adversely affect the environment.

When the amount of ozone contained in the water 7 to be treated in the water storage tank 1 increases and surplus ozone is generated,
3, the ozone gas concentration in the upper space increases. This ozone gas concentration is sensed by an ozone gas sensor 46 and the DC voltage of the
The ozone concentration in can be controlled.

The water electrolysis type ozone has a feature that the humidity of the mixed gas itself is high in addition to a feature of being pure and having a high concentration. This feature suggests that oxygen molecules and ozone molecules are attracted to water vapor molecules by intermolecular attraction, making it easier to be familiar with.
Electrolytic ozone is easier to dissolve than the difference in solubility in water due to the partial pressure difference according to Henry's law.

That is, in the water purifier 2 of the water storage tank 1 using the water electrolysis type ozone, it is possible to estimate the underwater ozone concentration by sensing the ozone gas concentration in the space above the water surface of the water storage tank 1, and control with the inexpensive ozone gas sensor 46. Can be easily done.

In the first embodiment of the present invention, 0.1 p
By using a tin-doped indium oxide thin film ozone gas sensor 46 with an ozone gas concentration of pm and a large resistance change, the resistance change is captured as a signal, and the voltage applied to the electrolytic cell 20 is controlled to thereby control the water storage tank 1. The ozone concentration in the water in the inside could be stabilized to 50 μg / liter or less.

Although the ozone gas is mixed only with the water 7 to be treated, it has a bactericidal effect, but there is a problem of by-products after decomposing organic substances. That is, a small amount of organic substances such as humic acid contained in the purified water is decomposed, and low-molecular-weight organic acids such as oxalic acid and formic acid are generated, and the pH changes. It is also said that drinking alcohol produces formaldehyde, which is harmful to human health.

However, in the first embodiment described above, in the water 7 to be treated in the water storage container 3, the oxidation-promoting catalyst 15 obtained by surface-treating a porous titanium material with platinum is disposed. It is said that when ozone in water comes into contact with a platinum catalyst, the reaction of chemical formulas (6) to (9) proceeds to generate hydroxyl radicals. These hydroxyl radicals have a higher oxidizing power than ozone and also decompose low molecular weight organic substances that cannot be decomposed by ozone alone. .

[0088]

Embedded image

[0089]

Embedded image

[0090]

Embedded image

[0091]

Embedded image

Thus, the to-be-treated water 7 containing ozone circulated in the water storage container 3 by the mixing pump 9 generates hydroxyl radicals on the surface of the oxidation-promoting catalyst 15 to promote oxidative decomposition of organic substances. Therefore, oxalic acid, formic acid, and formaldehyde, which are said to be harmful, are efficiently decomposed into safe carbon dioxide and water. FIG. 3 plots the change in the concentration of organic matter depending on the presence or absence of the oxidation-promoting catalyst, with the consumption of potassium permanganate as an index. Oxalic acid was added to the organic substances subjected to the test such that the consumption of potassium permanganate was about 10 mg / liter.

As shown by the curve A in FIG. 3, oxalic acid could be decomposed only by about 30% in the oxidation using only ozone, whereas when the catalyst was coexisted with the ozone in the curve B, about 30% was decomposed. 100% decomposition has been achieved. In other words, the fact that the decomposition reaction of organic substances, which was insufficient only by the oxidizing power of ozone, was promoted only by the coexistence of the oxidation-promoting catalyst, suggesting that hydroxyl radicals having a stronger oxidizing power than ozone were generated.

(Embodiment 2) FIG. 4 shows a configuration of a water storage tank and a water purification device thereof according to Embodiment 2 of the present invention. The same components as those in the first embodiment are denoted by the same reference numerals, and detailed description is omitted.

The structures of the water storage tank 1 and the water purification device 2 are the same as those of the first embodiment.
3 is installed at the outlet of the drain port 14 so that the water to be treated is introduced into the reaction vessel 47 from the drain side of the mixing pump 9. The same porous titanium material as in the first embodiment, which was subjected to a platinum treatment, was used.

Hereinafter, the operation of the second embodiment described above will be described, but the chemical reactions and the like in the electrolytic cell 20 are the same as those of the first embodiment, and a description thereof will be omitted.

When the mixing pump 9 is operated, the circulation and stirring of the water to be treated is started, and a flow is drawn from the water suction side 11 into the mixing pump 9 and discharged to the drain side 12. The momentum of this flow is pumped up to the hill vessel 13 using the guide pipe 10 as a guide, and flows out from the drain port 14. At this time, since the reaction vessel 47 containing the oxidation promoting catalyst is fixed to the drain port 14, all of the circulating water to be treated enters the reaction vessel 47 without being dispersed and comes into contact with the oxidation promoting catalyst body 15. Become. That is, the ozone contained in the water to be treated 7 surely touches the oxidation promoting catalyst 15 to efficiently generate hydroxyl radicals and further promote the decomposition of organic substances.

(Embodiment 3) FIG. 5 shows a configuration of a water storage tank and a water purification device thereof according to Embodiment 3 of the present invention. The same components as those in the first embodiment are denoted by the same reference numerals, and detailed description is omitted.

The structures of the water storage tank 1 and the water purification device 2 are the same as those of the first embodiment. The oxidation promoting catalyst 15 is filled in the guide pipe 10 on the mixing pump 9 and is fixed to the inner wall of the guide pipe 10. Things. As the material of the oxidation-promoting catalyst body 15, the same porous titanium material as in the first embodiment, which was subjected to a platinum treatment, was used.

Hereinafter, the operation of the third embodiment described above will be described, but the chemical reaction and the like in the electrolytic cell 20 are the same as in the first embodiment, and a description thereof will be omitted.

When the mixing pump 9 is operated, the circulation and agitation of the water 7 to be treated is started, and a flow is drawn from the water suction side 11 into the mixing pump 9 and discharged to the drain side 12. The momentum of this flow is pumped up to the hill vessel 13 using the guide pipe 10 as a guide, and flows out from the drain port 14. At this time, the oxidation promoting catalyst 15 is fixed in the guide pipe 10 above the mixing pump 9. As a result, the circulating water 7 comes into contact with the oxidation-promoting catalyst 15 without being dispersed. In addition, contacting the oxidation-promoting catalyst 15 at a time when ozone is sufficiently contained in the water-to-be-treated 7 means that hydroxyl radicals are efficiently generated before the ozone is self-decomposed, thereby further promoting the decomposition of organic substances. Become.

(Embodiment 4) FIG. 6 shows a configuration of a water storage tank and a water purification device thereof according to Embodiment 4 of the present invention. The same components as those in the first embodiment are denoted by the same reference numerals, and detailed description is omitted.

The mixing pump 9 has a function of supplying and draining the water 7 to be treated in the water storage tank 1 and circulates and agitates the water 7 to be treated in the water storage tank 1. Other configurations are the same as those of the first embodiment.

Hereinafter, the operation of the above-described fourth embodiment will be described. When the mixing pump 9 operates, the circulation and agitation of the water 7 to be treated is started, and a flow is drawn from the water suction side 11 into the mixing pump 9 and discharged to the drain side 12. The momentum of this flow is pumped up to the hill vessel 13 using the guide pipe 10 as a guide, and flows out from the drain port 14. At this time, the oxidation promoting catalyst 15 is formed on the rotating blades 48 of the mixing pump 9 to circulate. The water to be treated comes into contact with the oxidation-promoting catalyst body 15 without being dispersed. That is, the ozone contained in the water to be treated touches the oxidation promoting catalyst 15 to efficiently generate hydroxyl radicals and further promote the decomposition of organic substances. Further, the reaction can be performed in the vicinity of the dissolution of ozone in the water 7 to be treated, and the organic substance can be decomposed more efficiently by reacting the ozone at the time of high concentration dissolution without self-decomposition.

(Embodiment 5) FIG. 7 shows a configuration of a water storage tank and a water purification device thereof according to Embodiment 5 of the present invention. The same components as those in the first embodiment are denoted by the same reference numerals, and detailed description is omitted.

This water purification device 2 has a DC voltage application device 49.
And the oxidation-promoting catalyst 1 fixed to the induction pipe 10
Reference numeral 5 denotes a cathode 50, which has an electrical insulation property with respect to the oxidation promoting
A direct current voltage is applied via the water to be treated 7 so that the counter electrode member 51 fixed in 0 becomes the anode 52, and other configurations are the same as those in the first embodiment.

The material of the oxidation accelerating catalyst 15 and the counter electrode member 51 is a material obtained by subjecting titanium to platinum treatment. The voltage applied by the DC voltage applying device 49 can be varied, and the organic matter is 5 mg in terms of potassium permanganate consumption. A potential of 5 V was applied at a rate of 5 V / liter or more, and a potential of 3 V was applied at a rate of 5 mg / liter or less.

The operation of the fifth embodiment described above will be described below. When the mixing pump 9 is operated, the circulation and stirring of the water to be treated 7 is started, and the water to be treated 7 containing ozone generated in the electrolytic cell 20 is sucked into the mixing pump 9 from the water suction side 11 and discharged to the drain side 12. Occurs. The momentum of this flow is pumped up to the hill vessel 13 using the guide pipe 10 as a guide, and flows out from the drain port 14. At this time, the oxidation promoting catalyst 15 is
When immobilized inside, the reaction of Chemical formula 6 to Chemical formula 9 occurs on the surface of the oxidation-promoting catalyst, and a hydroxyl radical having a stronger oxidizing power than ozone is generated, thereby promoting decomposition with organic substances.
Further, when a negative potential is applied, the decomposition of ozone is accelerated by the reaction of ozone with hydrogen ions (other cations and the like) and electrons by the reaction of Chemical Formula 10. The acceleration of the ozonolysis also accelerates the reactions of Chemical formulas 6 to 9 to increase the production of hydroxyl radicals and promote the decomposition with organic substances.

[0109]

Embedded image

The acceleration of the decomposition is proportional to the applied voltage, and the higher the applied voltage, the faster the decomposition. If the applied voltage is excessively increased in a state where the amount of organic substances is small, only meaningless ozonolysis is accelerated, and the hydroxyl radical generated during the reaction cannot be effectively used. Therefore, the DC voltage applying device 49 is made variable so that an appropriate decomposition rate can be selected.

Further, in this embodiment, the counter electrode member 51 is required to have corrosion resistance as the anode 52, and an electrode obtained by subjecting titanium to platinum surface treatment is used. By doing the same, the same effect can be obtained even if an AC voltage is applied.

In this example, platinum and a surface-treated titanium with platinum were used as the oxidation-promoting catalyst 15 because platinum had an appropriate ozone decomposition rate and abrasion with ozone by the catalyst. This is to reduce the number. Activated carbon and manganese dioxide, copper oxide, silicon dioxide, alumina, iron oxide, etc. are available as ozonolysis catalysts. Activated carbon and manganese dioxide have too large an ozone decomposition performance, and powdering and attrition are slow, including other catalysts. The combination of platinum and titanium is the best for sterilization of drinking water.

The porous body refers to a sintered body of expanded metal or titanium fiber, but it is effective even if it is not porous. However, it is effective to use a porous body to increase the surface area.

In this embodiment, the electrolytic cell 20 and the gas separation chamber 19 are installed higher than the water level H of the water storage tank 1, and when the mixing pump 9 is stopped, the anode chamber 3 of the electrolytic cell 20 is stopped.
5, the ion-exchanged water is automatically drained from the electrolysis cell 2 by the storage battery function even after the mixing pump 9 is stopped.
Although the configuration in which deterioration of the electrodes is prevented as much as possible by continuing application of the potential to 0, the configuration of the water tank and the purification device is not specified.

[0115]

As described above, the present invention relates to an electrolytic cell having a cathode compartment, an anode compartment, a solid electrolyte membrane for partitioning the cathode compartment and the anode compartment, storing water to be treated, and A water tank provided with an oxidation-promoting catalyst for generating hydroxyl radicals in contact with ozone, wherein a gas containing ozone generated by electrolysis of water in the electrolytic cell is treated in the water to be treated in the water tank. Pure and high-concentration wet ozone generated by the electrolysis of water dissolves relatively easily in the water to be treated and reacts with various bacteria and organic substances contained in the water to be treated. Oxygen is generated, and hydroxyl radicals with high oxidizing power are generated in the process of reaction between the oxidation promoting catalyst and ozone, thereby decomposing low molecular organic substances that cannot be decomposed by ozone alone and improving the water purification effect. That.

A mixing pump having a function of supplying and draining the water to be treated in the water storage tank and circulating and stirring the water to be treated is provided in the water storage tank, and a gas containing ozone is introduced into the water absorption side of the mixing pump. The mixing pump has an oxidation-promoting catalyst on the drain side. The mixing pump efficiently dissolves ozone and the water to be treated, and the oxidation-promoting catalyst is placed on the drain side of the dissolved high-concentration ozone mixing pump. By disposing the medium, the sterilizing and purifying effects can be enhanced.

A reaction vessel into which water to be treated is introduced from the drain side of the mixing pump is provided, and a porous oxidation-promoting catalyst is provided in the reaction vessel, and the reaction vessel has a large surface area. Sterilization and decomposition of organic substances are intensively and efficiently performed by the porous oxidation-promoting catalyst.

A mixing pump having a function of supplying and draining the water to be treated in the water storage tank and circulating and stirring the water to be treated is provided in the water storage tank, and a gas containing ozone is introduced into the water absorption side of the mixing pump. The surface of the mixing pump's rotating blades is made of an oxidation-promoting catalyst.Forcibly circulating and agitating the water to be treated with the rotating blades, and at the same time promoting the oxidation of ozone, sterilization and decomposition of organic substances are more reliably achieved. Done.

Further, a voltage is applied to the oxidation-promoting catalyst and the counter electrode member having electrical insulation properties with respect to the oxidation-promoting catalyst via water to be treated, and a potential is applied to the oxidation-promoting catalyst. In addition, the decomposition of ozone is accelerated and the generation of hydroxyl radicals is activated, so that sterilization and decomposition of organic substances are further promoted.

Further, the applied voltage can be varied, and the rate of ozonolysis is adjusted according to the degree of contamination of the water to be treated, that is, according to the amount of various bacteria and organic substances, so that useless ozonolysis is avoided. is there.

Further, by applying a DC voltage by using a DC voltage applying device so that the counter electrode member becomes the anode and the oxidation promoting catalyst becomes the cathode, the oxidation can be efficiently promoted by the cathode having a reducing action.

Further, since the oxidation promoting catalyst is made of platinum and / or a material obtained by surface-treating titanium to titanium, platinum or titanium having general versatility, appropriate ozonolysis characteristics and high corrosion resistance is used. This can avoid unnecessary ozonolysis.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a water storage tank and a water purification device thereof according to Embodiment 1 of the present invention.

FIG. 2 is a longitudinal sectional view of the electrolytic cell according to Embodiment 1 of the present invention.

FIG. 3 is a graph showing a decomposition rate of an organic substance depending on the presence or absence of an oxidation-promoting catalyst in Embodiment 1 of the present invention, and showing a correlation between potassium permanganate consumption and treatment time.

FIG. 4 is a schematic diagram of a water storage tank and a water purification device thereof according to Embodiment 2 of the present invention.

FIG. 5 is a schematic diagram of a water storage tank and a water purification device thereof according to Embodiment 3 of the present invention.

FIG. 6 is a schematic diagram of a water storage tank and a water purification device thereof according to Embodiment 4 of the present invention.

FIG. 7 is a schematic diagram of a water storage tank and a water purification device thereof according to Embodiment 5 of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Water storage tank 2 Water purifier 7 Treated water 9 Mixing pump 11 Water absorption side 12 Drainage side 15 Oxidation promotion catalyst 19 Gas separation chamber 20 Electrolysis cell 27 Introducing pipe 32 Cathode 33 Cathode chamber 34 Anode 35 Anode chamber 36 Solid electrolyte membrane 47 Reaction Container 48 Rotating blade 49 DC voltage application device 50 Cathode 51 Counter electrode member 52 Anode

Claims (8)

[Claims] 1. An electrolytic cell having a cathode chamber, an anode chamber, and a solid electrolyte membrane separating the cathode chamber and the anode chamber; a water to be treated; And a water tank provided with an oxidation-promoting catalyst body for generating water, and a gas containing ozone generated by electrolysis of water in the electrolytic cell is introduced into the water to be treated in the water tank by an introduction pipe. A water tank provided with a water purification device, characterized in that: 2. A mixing pump having a function of supplying and discharging water to be treated in a water storage tank and circulating and stirring the water to be treated is provided in the water storage tank, and a gas containing ozone is introduced into a water absorption side of the mixing pump; The water tank provided with the water purification device according to claim 1, wherein an oxidation promoting catalyst is disposed on a drain side of the mixing pump. 3. The reaction vessel according to claim 2, wherein a reaction vessel into which water to be treated is introduced from a drain side of the mixing pump is provided, and a porous oxidation promoting catalyst is provided in the reaction vessel. Water tank with water purification device. 4. A mixing pump having a function of supplying and draining water to be treated in a water storage tank and circulating and stirring the water to be treated is provided in the water storage tank, and a gas containing ozone is introduced into a water absorption side of the mixing pump. The water tank provided with the water purifier according to claim 1, wherein the surface of the rotary blade of the mixing pump is formed of an oxidation promoting catalyst. 5. The apparatus according to claim 1, wherein a voltage is applied to the oxidation-promoting catalyst and a counter electrode member having electrical insulation with respect to the oxidation-promoting catalyst via water to be treated. A water storage tank provided with the water purification device according to any one of Items 1 to 4. 6. A water storage tank provided with a water purification device according to claim 5, wherein the voltage applied to the oxidation promoting catalyst and the counter electrode member can be varied. 7. A water storage provided with a water purification device according to claim 5, wherein a DC voltage is applied by a DC voltage application device such that the counter electrode member serves as an anode and the oxidation promoting catalyst serves as a cathode. Tank. 8. The water storage provided with a water purification device according to claim 1, wherein the oxidation-promoting catalyst is made of platinum and / or a material obtained by surface-treating platinum on titanium. Tank.