JPH10263535A - Water purifying device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To maintain stable high water purifying performance over a long period. SOLUTION: This water purifying device is provided with a light source 4 for emitting light containing ultraviolet ray, a light transmissive member 5 formed so as to cover the light source 4 and transmitting light from the light source 4 and a light excitation thin film 6, which is formed on the outer surface of the light transmitting member 5 in contact with a water-bearing liquid to be purified and is excited by the light from the light source 4 to purify the water-bearing liquid to be purified by a chemical reaction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a water purification device using a photocatalyst.

[0002]

2. Description of the Related Art Heretofore, water has generally been purified by activated carbon and a filter. However, recently, a technology for purifying by chemically decomposing harmful substances in water using a catalyst has been developed. Usually, the catalyst does not exert its effect unless activated. Thermal energy is the most common means of activating this catalyst. However, heating may not be possible depending on the portion to be mounted, and the catalyst activated by heat has many restrictions. However, photocatalysts, such as fluorescent lamps, that can be activated by weak light have been developed, and the effect can be exerted wherever light is irradiated. The photocatalyst is a semiconductor and generates holes when irradiated with ultraviolet light. These holes react with water to form OH
Water is purified by generating radicals and decomposing organic substances in water. That is, ultraviolet rays are indispensable. FIG. 8 shows a conventional water purification device using such a photocatalyst. UV lamp 21 is a light transmitting member 22
A ceramic honeycomb 23 carrying a photocatalyst is provided at an appropriate distance from the light transmitting member 22. Reference numeral 24 denotes an inlet for the processing liquid, and reference numeral 25 denotes an outlet. The treatment liquid is purified from the part in contact with the photocatalyst supported on the ceramic honeycomb 23. In the field of water purification, technology applied to decomposition and sterilization of organic substances by ultraviolet rays has been studied for a long time.

On the other hand, diversification of daily life and growing desire for cleanliness have increased the need to take a bath several times a day or to take a bath at any time. Furthermore, a circulating bath water purifier (generally referred to as a 24-hour bath) has become widespread because of the convenience of not having to clean the bath. The circulating bath water purifier is formed by a filter for removing relatively large dust, a purifying tank for decomposing other dirt by microorganisms, a heater for keeping heat, and a pump, and circulates and purifies hot water constantly.

[0004]

However, in the conventional water purifier, when the processing liquid comes into contact with the light-transmitting member covering the ultraviolet lamp, dirt in the water gradually adheres. If used for a long period of time, bacteria may adhere to the dirt, and furthermore, the transmission of ultraviolet light is hindered, so that the ultraviolet energy is not sufficiently distributed to the photocatalyst supported on the ceramic honeycomb. As a result, there was a problem that the water purification capacity gradually decreased.

[0005] In the purification method of the conventional circulating bath water purification apparatus, purification by microorganisms depends on circulation conditions, so that the purification ability tends to be unstable, and bacteria such as purification bacteria are liable to bathtub. May be leaked. As a countermeasure, there is one provided with a purification function using a photocatalyst, and one provided with a sterilization function using ozone or ultraviolet rays.
However, when the ultraviolet lamp is used for a long time in water as described above, dirt in the water adheres to the ultraviolet lamp and the protection tube, and the ultraviolet output decreases. As a result, there is a problem that it becomes impossible to sufficiently purify and sterilize water.

[0006] The present invention has been made in view of the above,
An object of the present invention is to provide a water purification device that can maintain a stable and high water purification capacity for a long period of time.

[0007]

According to a first aspect of the present invention, there is provided a light source for emitting light including ultraviolet light, and a light source formed to cover the light source and transmitting light from the light source. A light-transmitting member, and a light-excited thin film formed on an outer surface of the light-transmitting member, which is in contact with the water-containing liquid to be purified, and excited by light from the light source to purify the water-containing liquid to be purified by a chemical reaction. It is the gist to have. With this configuration, the dirt on the outer surface of the light-transmitting member is decomposed and the adhesion is prevented at the same time as the water-containing liquid to be purified is contacted by the chemical reaction of the photoexcited thin film.

According to a second aspect of the present invention, there is provided a light source which emits light including ultraviolet light, the light transmitting member which is formed to cover the light source and transmits light from the light source, and the light which is in contact with domestic tap water. The optical water purification unit, which is formed on the outer surface of the transparent member and is provided with a photo-excitation thin film that is excited by light from the light source and purifies the household water by a chemical reaction, temporarily stores the household water. The point is to attach to the tank. With this configuration, a large amount of domestic water is properly purified.

According to a third aspect of the present invention, in the water purification apparatus according to the second aspect, the domestic tap water is bathtub water,
The gist is that the water purified by the light water purification section is configured to be circulated and used. With this configuration, the bathtub water to be circulated is purified accurately and stably.

According to a fourth aspect of the present invention, there is provided the water purification device according to the second aspect, further comprising a microorganism water purification unit for purifying the domestic water by supporting microorganisms on a carrier such as ceramics. The gist is that it is arranged downstream of the microorganism purification section. With this configuration, it is possible to purify substances that cannot be biologically treated in domestic water, and since the optical water purification section also has a bactericidal effect, it is possible to sterilize purified bacteria flowing out of the microorganism water purification section.

According to a fifth aspect of the present invention, there is provided the water purification apparatus according to the second or third aspect, further comprising a physical filtration unit including a filter, wherein the optical water purification unit is disposed downstream of the physical filtration unit. That is the gist. With this configuration, the ultraviolet light transmittance in the light water purification unit is increased by the action of removing fine particles of the physical filtration unit, and the water purification power is improved.

According to a sixth aspect of the present invention, in the water purification apparatus according to the third aspect, a driving unit for constantly circulating the domestic water supply between the optical water purification unit and the tank; The gist of the present invention is to have a heating section for maintaining water at an optimum purification temperature and a pipe for connecting these. With this configuration, domestic tap water is maintained at an optimum temperature for microbial treatment and the like, and efficient water purification becomes possible.

[0013] The invention according to claim 7 is the invention according to claim 2,
7. The water purifier according to 3, 4, 5 or 6, wherein the domestic water to be treated contains air bubbles. With this configuration, the amount of dissolved oxygen increases, and the chemical reaction of the photoexcited thin film is promoted, thereby improving the purification effect.

[0014] The invention described in claim 8 is the second invention.
The gist of the water purifier according to any one of 3, 4, 5, 6 and 7, wherein the discharge portion to the tank has a function of containing bubbles. According to this configuration, in addition to the same effect as the above-described seventh aspect of the invention, when the domestic tap water is bathtub water, a massage effect for the bather can be obtained.

According to a ninth aspect of the present invention, in the water purifier according to any one of the first to eighth aspects, a gas or a vacuum is provided between the light source and the light transmitting member. I do. With this configuration, the ultraviolet ray transmittance increases, and the water purification efficiency improves.

According to a tenth aspect of the present invention, in the water purifier according to any one of the first to eighth aspects, the light-transmitting member is water-permeable. With this configuration, the liquid to be purified is in direct contact with the light source, and the action such as sterilization by ultraviolet rays is enhanced.

The invention according to claim 11 is the invention according to claim 10.
In the water purification apparatus described above, the gist is that the light excitation thin film is formed on an inner surface of the light transmitting member and a wall surface of the light source. According to this configuration, in addition to the same function as the above-described function of the tenth aspect, the contact area between the liquid to be purified and the photoexcitation thin film is further increased, so that a higher water purification effect can be obtained.

According to a twelfth aspect of the present invention, in the water purifier according to any one of the first to eleventh aspects, the light transmitting member is formed of quartz glass.
With this configuration, the ultraviolet transmittance is increased, and the water purification efficiency is improved.

According to a thirteenth aspect of the present invention, in the water purifier according to any one of the first to twelfth aspects, the photoexcited thin film is formed by a sol-gel method containing titanium oxide as a main component. I do. With this configuration, the light-exciting thin film having high light transmittance is appropriately formed on the inner and outer surfaces of the light-transmitting member and the wall surface of the light source.

According to a fourteenth aspect of the present invention, there is provided the water purification apparatus according to any one of the first to thirteenth aspects, wherein the light source from the light source is located at a position facing the light-excited thin film-formed transparent member. The gist of the invention is to form at least a reflection surface that reflects ultraviolet light. With this configuration, the ultraviolet light is effectively used, and the water purification efficiency is improved.

According to a fifteenth aspect of the present invention, the above-mentioned fourteenth aspect
In the water purification device described above, the light excitation thin film is formed on the reflection surface. With this configuration, it is possible to prevent dirt from adhering to the reflection surface, and to always obtain a high reflection action.

According to a sixteenth aspect of the present invention, in the water purification apparatus according to any one of the first to fifteenth aspects, a turbulent flow is caused in the flow of the water-containing liquid to be purified on the surface on which the photoexcitation thin film is formed. The gist is to form an obstacle member. With this configuration, the frequency of contact between the photoexcitation thin film and the liquid to be purified increases, and a higher water purification effect can be obtained.

The invention according to claim 17 is the invention according to claim 16.
In the water purification device described above, the obstacle is that the surface on which the photoexcitation thin film is formed has irregularities. With this configuration, it is possible to easily form the obstacle member in the apparatus.

[0024]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing a first embodiment of the present invention. First, the configuration of the light purification unit 10A will be described. The ultraviolet lamp 4 as a light source is completely covered with the light transmitting member 5. A gas may be present between the ultraviolet lamp 4 and the light transmitting member 5, but a vacuum state having a high ultraviolet transmittance is preferable. The light transmissive member 5 is formed of quartz glass having a high ultraviolet transmittance, and a light excitation thin film 6 is formed on an outer surface in contact with the treated liquid. The opposite inner wall surface of the optical water purification unit main body with the light transmitting member 5 interposed therebetween has irregularities as an obstacle member that reflects at least ultraviolet rays and causes turbulence in the flow of the water-containing liquid to be purified. The light-excitation thin film 6 is also formed on the uneven reflection surface 7. Reference numeral 2 denotes an entrance of the light purification unit, and reference numeral 3 denotes an exit of the light purification unit. The photoexcitation thin film 6 is formed by applying and drying a titanium oxide sol containing titanium oxide as a main component several times,
It is manufactured by a method of firing and fixing, that is, a sol-gel method, and has a thickness of about 0.1 μm. Thereby, unlike the conventional method of applying a suspension of titanium oxide fine particles, a catalyst layer having high light transmittance is obtained and can be directly formed on an ultraviolet lamp, a protective tube, a wall surface, or the like.

The operation of the optical water purification unit 10A configured as described above will be described. The treatment liquid, which is the water-containing liquid to be purified, enters through the light purification unit inlet 2, is purified in the light purification unit 10 </ b> A, and is discharged from the light purification unit outlet 3. In the light purification unit 10A, the light from the ultraviolet lamp 4 activates the photoexcited thin film 6, and the treatment liquid is purified by a chemical reaction. At this time,
Since the inner wall surface of the optical water purification unit main body is formed of a reflection surface, ultraviolet rays are reflected in the optical water purification unit 10A and are effectively used.
In addition, since the photoexcitation thin film 6 is formed on the inner wall surface and has irregularities, turbulence occurs inside, and the number of contacts between the treatment liquid and the photoexcitation thin film 6 increases, and the water purification effect increases. As described above, since the organic matter in the processing liquid is decomposed by the chemical reaction on the surface on which the photoexcitation thin film 6 is formed, dirt on the surface in contact with the processing liquid is decomposed at the same time as water purification to prevent adhesion.
As a result, there is a hygienic effect of preventing transmission of ultraviolet energy. Therefore, even when used for a long period of time, ultraviolet energy is always sufficiently distributed to the photoexcited thin film 6, and a high purification effect of the photoexcited thin film 6 is obtained.

FIG. 2 shows a second embodiment of the present invention. In the light water purification section 10B of the present embodiment, the light transmissive member 5a made of quartz glass has water permeability, and has a structure in which the ultraviolet lamp 4 and the treatment liquid are in direct contact. And
The photoexcitation thin film 6 is formed not only on the outer surface of the water-permeable light-transmitting member 5a but also on the inner surface and the ultraviolet lamp 4 itself. According to this structure, the water-permeable light-transmitting member 5a
The treatment liquid purified by the photoexcitation thin film 6 on the outer surface is further purified by the photoexcitation thin film 6 on the inner surface of the light transmitting member 5a and the surface of the ultraviolet lamp 4, so that the water purification effect is further improved. In addition, since the area of the photoexcitation thin film 6 of the entire apparatus increases, a higher water purification effect can be expected.

FIG. 3 shows a third embodiment of the present invention. In the water purification section 10C of the present embodiment, the ultraviolet lamp 4 has a structure in direct contact with the treatment liquid, and the photoexcitation thin film 6 is formed on the surface of the ultraviolet lamp 4. In this case, the U-shaped tube of the ultraviolet lamp 4 is preferable because the area of the photoexcitation thin film 6 is larger in the U-shaped tube than in the straight tube.

Using the optical water purifiers 10A, 10B, and 10C of the first to third embodiments described above, water purification performance was examined using the conventional optical water purifier of FIG. 8 as a comparative example. A treatment liquid containing 10 mg / L of an organic substance is supplied to each light purification section at a flow rate of 20 L / m.
Water was passed in, and the amount of remaining organic matter was measured. FIG. 4 shows the results. As a result, the following can be understood. In the conventional light purifying section, since the photoexcitation thin film is carried on the ceramic honeycomb, the farther from the ultraviolet lamp, ultraviolet rays do not spread, and the purification effect of the photoexcitation thin film is poor. For it,
In the optical water purifiers 10A, 10B, and 10C of the present embodiment, the photoexcitation thin film 6 is irradiated with sufficient ultraviolet rays, so that the purification effect is enhanced. Among them, the optical water purification unit 10B of the second embodiment
Since the light excitation thin film 6 is formed on the inner and outer surfaces of the light transmitting member 5a and the surface of the ultraviolet lamp 4, the cleaning area is the largest and the effect is high. Next, since the area of the photoexcitation thin film 6 becomes smaller in the order of the optical water purification unit 10A of the first embodiment and the optical water purification unit 10C of the third embodiment, the purification ability also decreases gradually.

FIG. 4 shows a fourth embodiment of the present invention. In the present embodiment, a water purification system is systemized. The light water purification section is intended to treat domestic tap water for treatment, and is installed in a temporary storage tank or the like. The tank for storing is a dedicated water tank or a bathtub 14 or the like. When the processing liquid 1 is stored in the bath 14, particles of the processing liquid 1 are first removed by the physical filtration unit 8 including a filter by the power of the circulation pump 9. As a result, the light transmittance of the light purification section 10 is improved, and sufficient ultraviolet energy is given to the photoexcitation thin film. Therefore, the physical filtration unit 8 needs to be installed at a stage before the optical water purification unit 10. Next, the treatment liquid 1 is treated in the microorganism purification section 12 while being kept at an appropriate temperature in the heating section 11. In the microbial treatment, there is an optimum temperature at which the microorganisms are actively activated. However, since this temperature is about 40 ° C., the heating unit 11 holds the treatment liquid 1 at this temperature. Therefore, it is necessary that the heating unit 11 be located before the microorganism purification unit 12. Further, the treatment liquid 1 is purified in the optical water purification section 10 and discharged together with fine bubbles from the discharge port 13. Bacteria effective for purification are breeding in the microbial water purification unit 12, but there is a possibility that these bacteria may flow out, albeit slightly. On the other hand, since the light purification unit 10 also has a sterilizing effect,
The spilled purification bacteria can be sterilized. In addition, in order to effectively treat a surfactant or the like that microorganisms are not good at, it is desirable that the light water purification unit 10 be located downstream of the microorganism water purification unit 12. In addition, the treatment liquid 1 containing bubbles not only has a massage effect for bathers, but also has high dissolved oxygen, and thus is effective against microorganisms. In addition, the photoexcited thin film forms holes and electrons by the energy of ultraviolet rays, and the radical reaction by the holes has the effect of decomposing and sterilizing organic substances. Dissolved oxygen in water has an effect of consuming electrons and preventing recombination of electrons and holes, and a radical reaction is efficiently performed.

The water purification performance was examined using the above-mentioned water purification system. The optical water purification unit 10B of the second embodiment and the conventional optical water purification unit of FIG. 8 as a comparative example are incorporated in the water purification system of FIG. 5, and a treatment liquid containing 10 mg / L of organic matter is passed at a flow rate of 20 L / min. Water was added, and the amount of organic matter for one hour after the start was measured. After the measurement was completed, the operation of the apparatus was continued. On the next day, the operation of the apparatus was stopped, and after adding 10 mg / L of an organic substance, the operation was restarted and measured. This operation was continuously performed for one month. FIG. 6 shows the amount of organic matter one hour after the start of purification.
As a result, the water purification device provided with the optical water purification unit 10B of the present embodiment not only has a high initial water purification effect, but also does not cause dirt to adhere to the portion in contact with the treatment liquid. And organic matter is effectively decomposed. On the other hand, in the conventional optical water purification section, dirt adheres to the glass tube covering the ultraviolet lamp, and the ultraviolet transmittance is reduced, so that the effect of the photoexcited thin film is also reduced. FIG. 7 shows the change over time in the amount of organic matter in the initial stage and one hour after the start of purification 30 days later. From this result, the water purification device provided with the optical water purification unit 10B of the present embodiment is sufficiently purified in one hour even after 30 days. On the other hand, in the conventional light water purification section, since the organic matter of the previous day remains without being purified,
Initially, it contained 12 mg / L of organic matter. Further, even when the purification was started, the effect of the light purification section was poor, so that the purification was not sufficient in one hour.

As described above, according to the optical water purification section of the present embodiment, it is possible to effectively purify the water using the photoexcited thin film in the water and to maintain the stable ability for a long time.

[0033]

As described above, according to the first aspect of the present invention, a light source that emits light including ultraviolet light, and a light transmissive member that is formed to cover the light source and transmits light from the light source. And a light-excited thin film formed on the outer surface of the light-transmissive member that is to be contacted by the water-containing liquid to be purified and excited by light from the light source to purify the water-containing liquid to be purified by a chemical reaction. Dirt on the outer surface of the light-transmitting member is decomposed by the chemical reaction of the light-excited thin film and adhesion is prevented, so that stable water purification ability can be maintained for a long time.

According to the second aspect of the present invention, the light source that emits light including ultraviolet light, the light-transmitting member formed so as to cover the light source and transmitting the light from the light source, and household water are in contact with each other. An optical water purification section having a light excitation thin film formed on the outer surface of the light transmitting member and being excited by light from the light source and purifying the household water by a chemical reaction, temporarily cleans the household water. Since it is attached to the storage tank, a large amount of domestic water can always be purified accurately.

According to the third aspect of the present invention, the domestic tap water is bathtub water, and the water purified by the light purification section is circulated and used. The purification treatment can be performed quickly and stably.

According to the fourth aspect of the present invention, there is provided a microorganism purifying section for purifying the domestic water by supporting microorganisms on a carrier such as ceramics, and the light purifying section is located downstream of the microorganism purifying section. The water purification unit can stably purify substances that can not be treated in living water for a long period of time, and the light purification unit also has a bactericidal effect. Can be performed accurately.

According to the fifth aspect of the present invention, there is provided a physical purification unit including a filter, and the optical water purification unit is disposed downstream of the physical filtration unit. In this case, the ultraviolet transmittance is increased, and high water purification power can be maintained for a long period of time.

According to the invention of claim 6, a drive section for constantly circulating the domestic water supply between the light purification section and the tank, and maintaining the household water at an optimum purification temperature. Since the heating unit and the piping connecting these are provided, domestic water can be maintained at an optimum temperature for microbial treatment and the like, and more efficient water purification can be maintained for a long time.

According to the seventh aspect of the present invention, since the household water to be treated contains bubbles, the amount of dissolved oxygen is increased, the chemical reaction of the photoexcited thin film is promoted, and a higher water purification power is obtained for a long time. Can be maintained over time.

According to the eighth aspect of the present invention, since the function of containing air bubbles is imparted to the discharge section to the tank,
In addition to the effect similar to the effect of the invention described in claim 7, when the domestic tap water is bathtub water, a massage effect for a bather can be obtained.

According to the ninth aspect of the present invention, since the space between the light source and the light-transmitting member is in a gas or vacuum state, the transmittance of ultraviolet rays is increased, and high water purification efficiency can be maintained for a long time. it can.

According to the tenth aspect of the present invention, since the light-transmitting member is made of water-permeable material, the liquid to be purified comes into direct contact with the light source, and the action of sterilization by ultraviolet rays is enhanced, and a high water-purifying power is obtained for a long time. Can be maintained over time.

According to the eleventh aspect of the present invention, since the photoexcitation thin film is formed on the inner surface of the light transmissive member and the wall surface of the light source, the contact area between the liquid to be purified and the photoexcitation thin film increases. High water purification power can be maintained stably for a long time.

According to the twelfth aspect of the present invention, since the light-transmitting member is formed of quartz glass, the transmittance of ultraviolet rays is increased, and high water purification efficiency can be maintained for a long time.

According to the thirteenth aspect of the present invention, since the photoexcitation thin film is formed by a sol-gel method containing titanium oxide as a main component, the photoexcitation thin film having high light transmittance is formed on the inner and outer surfaces of the light transmission member and the wall surface of the light source. It can be formed properly and can maintain high water purification power stably for a long time.

According to the fourteenth aspect of the present invention, a reflecting surface for reflecting at least ultraviolet light from the light source is formed at a position facing the light-exciting thin film formed transmissive member therebetween, so that ultraviolet light is effective. High water purification efficiency can be maintained over a long period of time.

According to the fifteenth aspect of the present invention, since the photoexcitation thin film is formed on the reflection surface, adhesion of dirt to the reflection surface is prevented, a high reflection action is always obtained, and a high water purification efficiency is further improved. Can be maintained for a long time.

According to the sixteenth aspect of the present invention, since the obstruction member that causes turbulence in the flow of the water-containing liquid to be purified is formed on the surface on which the light-excited thin film is formed. The frequency of contact increases, and higher water purification efficiency can be maintained for a long time.

According to the seventeenth aspect of the present invention, since the obstacle member is formed by forming irregularities on the surface on which the photoexcited thin film is formed, it is possible to easily form the obstacle member in the apparatus. The same effect as the effect of the invention described in claim 16 can be easily obtained.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a first embodiment of a water purification device according to the present invention.

FIG. 2 is a configuration diagram showing a second embodiment of the present invention.

FIG. 3 is a configuration diagram showing a third embodiment of the present invention.

FIG. 4 is a diagram showing the water purification performance of the first to third embodiments together with a comparative example.

FIG. 5 is a block diagram showing a fourth embodiment of the present invention.

FIG. 6 is a diagram showing water purification performance (1) of the fourth embodiment together with a comparative example.

FIG. 7 is a diagram showing water purification performance (2) of the fourth embodiment together with a comparative example.

FIG. 8 is a configuration diagram of a conventional water purification device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 treatment liquid (purified water-containing liquid) 4 ultraviolet lamp (light source) 5, 5a light-transmitting member 6 light-exciting thin film 7 reflection surface with irregularities 8 physical filtration unit 9 circulation pump 10, 10A, 10B, 10C light purification unit 11 Heating section 12 Microbial water purification section 13 Outlet

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI C02F 3/06 ZAB F24H 9/00 W F24H 9/00 B01D 35/02 J (72) Inventor Tohru Yamaguchi 3 Shimbashi, Minato-ku, Tokyo Chome 3-9 Toshiba Ebu E Co., Ltd.

Claims (17)

[Claims] 1. A light source that emits light including ultraviolet light, a light-transmitting member formed so as to cover the light source and transmitting light from the light source, and a light-transmitting member that is in contact with the water-containing liquid to be purified. A water-excited thin film formed on an outer surface and excited by light from the light source to purify the water-containing liquid to be purified by a chemical reaction. 2. A light source that emits light including ultraviolet light, an outer surface of the light transmissive member formed so as to cover the light source, and a light transmissive member that transmits the light from the light source and a household water supply. A water purification section provided with a photo-excitation thin film that is formed in the water and is excited by light from the light source to purify the household water by a chemical reaction, attached to a tank that temporarily stores the household water. A water purification device characterized by the following. 3. The water purification device according to claim 2, wherein the domestic tap water is bathtub water, and the purified water in the optical water purification unit is circulated and used. 4. A microbial water purification unit for purifying the domestic water by supporting microorganisms on a carrier such as ceramics, and wherein the light water purification unit is disposed downstream of the microorganism water purification unit. The water purification device according to claim 2, wherein 5. The water purification device according to claim 2, further comprising a physical filtration unit including a filter, wherein the optical water purification unit is disposed downstream of the physical filtration unit. 6. A drive section for constantly circulating the domestic tap water, a heating section for maintaining the domestic tap water at an optimum purification temperature, and a connection between the light purifying section and the tank. The water purification device according to claim 3, further comprising a pipe. 7. The domestic tap water to be treated contains air bubbles.
The described water purification device. 8. The discharge section to the tank is provided with a function of containing air bubbles.
The water purifier according to 3, 4, 5, 6 or 7. 9. Between the light source and the light transmitting member,
2. A gas or vacuum state.
9. The water purification device according to any one of claims 1 to 8. 10. The water purification device according to claim 1, wherein the light-transmitting member is water-permeable. 11. The water purification device according to claim 10, wherein the light excitation thin film is formed on an inner surface of the light transmitting member and a wall surface of the light source. 12. The water purification device according to claim 1, wherein the light transmitting member is formed of quartz glass. 13. The water purification device according to claim 1, wherein the photoexcited thin film is formed by a sol-gel method containing titanium oxide as a main component. 14. A reflection surface for reflecting at least ultraviolet light from the light source is formed at a position facing the light-exciting thin film-formed transmissive member therebetween. The water purification device according to any one of the above. 15. The water purification apparatus according to claim 14, wherein the light excitation thin film is formed on the reflection surface. 16. The method according to claim 1, wherein an obstruction member that causes a turbulent flow in the flow of the water-containing liquid to be purified is formed on the surface on which the photoexcitation thin film is formed. Water purification equipment. 17. The water purification apparatus according to claim 16, wherein the obstacle member has a surface on which the light-excited thin film is formed with irregularities.