JP4815426B2 - UV water treatment equipment - Google Patents

Description

  The present invention relates to an ultraviolet water treatment apparatus capable of obtaining a plurality of different water quality levels.

  Ultraviolet rays are a type of electromagnetic wave having a wavelength in the range of 100 to 400 nm. Mercury lamps are used as low-cost ultraviolet light sources in water and sewage treatment that requires treatment of a large amount of water. Mercury vapor is enclosed in a quartz glass tube that transmits ultraviolet light from a mercury lamp, and the generated wavelength varies depending on the vapor pressure in the quartz glass tube when the lamp is lit. A lamp having a vapor pressure of 100 Pa or less is called a low-pressure mercury lamp, and generates monochromatic ultraviolet light having a wavelength of 254 nm. A lamp having a vapor pressure of 50 to 300 kPa is called a medium pressure mercury lamp, and generates a wide range from ultraviolet rays having a main wavelength of 365 nm to 200 nm or less to visible rays.

  In water and sewage treatment, ultraviolet rays are mainly used for inactivation of microorganisms and oxidative decomposition of organic substances. Microbe inactivation refers to a state in which a microorganism has lost activity such as proliferation ability or infection ability. Microbial DNA shows a peak of absorption around a wavelength of 260 nm, and absorption of ultraviolet light having a wavelength near this wavelength causes dimerization of adjacent thymine in the DNA strand, making DNA replication impossible, and microorganisms not being used. Activate.

  In the oxidative decomposition of organic matter, the organic matter may be decomposed by irradiating only ultraviolet rays, but it is mainly photocatalytic reaction by ultraviolet rays and photocatalyst, accelerated oxidation reaction by ultraviolet rays and ozone or hydrogen peroxide solution, ultraviolet rays and photocatalyst. Decomposes using a combination of photocatalytic reactions such as ozone and aqueous hydrogen peroxide and accelerated oxidation.

  In the photocatalytic reaction, when a photocatalyst such as titanium oxide immersed in water to be treated is irradiated with ultraviolet light having a wavelength of 400 nm or less or visible light having a wavelength of 400 nm or more, water is decomposed to generate a hydroxy radical. Radicals have strong oxidizing power and oxidize and decompose surrounding organic substances. The longest wavelength that can be absorbed depends on the type of photocatalyst.

  Since ozone and hydrogen peroxide used in the accelerated oxidation reaction have an oxidizing power, organic substances in the water to be treated are oxidatively decomposed. In the accelerated oxidation reaction, added ozone and hydrogen peroxide are decomposed directly or indirectly by ultraviolet rays. In the case of direct decomposition, the water to be treated is irradiated with ultraviolet rays having a wavelength of 300 nm or less. The ultraviolet rays in this band decompose ozone and hydrogen peroxide to generate hydroxy radicals. In the case of indirect decomposition, a photocatalyst is mixed into the water to be treated. The photocatalyst absorbs not only ultraviolet rays having a wavelength of 300 nm or less, but also ultraviolet rays having a wavelength of 300 nm or more and visible light to generate hydroxy radicals. This breaks down ozone and hydrogen peroxide, generating more hydroxy radicals. Since the hydroxy radical has a stronger oxidizing power than ozone and hydrogen peroxide, the oxidation and decomposition of organic substances are promoted as compared with the case of using ozone and hydrogen peroxide alone.

  When a low-pressure mercury lamp is used to inactivate microorganisms or oxidatively decompose organic substances, the generated ultraviolet rays are well absorbed by DNA, ozone, and oxygen peroxide. Therefore, inactivation and accelerated oxidation reaction can be performed with high efficiency, and electric power required for water treatment can be reduced. On the other hand, when using a medium-pressure mercury lamp, the efficiency of inactivation and accelerated oxidation reaction is inferior, but the amount of UV output per unit lamp volume is large and the number of lamps required for water treatment can be reduced, so the apparatus can be downsized. There are advantages.

  As such a water treatment apparatus, there exists a thing described in [nonpatent literature 1], [patent literature 1], and [patent literature 2].

  The water treatment apparatus described in [Non-Patent Document 1] is an apparatus for inactivating microorganisms, and has a structure in which an ultraviolet lamp is immersed in a cylindrical tank. The water treatment apparatus described in [Patent Document 1] is an apparatus that oxidizes and decomposes organic matter, and immerses an ultraviolet lamp in a cylindrical tank and injects ozone bubbles into the tank. The water treatment apparatus described in [Patent Document 2] stores a required amount of liquid to be treated in a treatment tank having an ultraviolet lamp disposed therein, and a mixed gas of ozone and air from the bottom side in the treatment tank. Are sequentially aerated and supplied, and the liquid to be treated is brought into contact with stirring to oxidize, reduce, and sterilize the impurities.

  Each apparatus has one outlet for treated water, and the quality of the treated water is controlled by changing the irradiation intensity of the ultraviolet light source, the treatment flow rate, and the like. That is, only one type of treated water can be obtained from one apparatus.

JP 2003-266088 A JP 2004-329988 A Water Technology Research Center Foundation, “E-Water Guidelines Collection”, p.285 (2005)

  However, for example, in sewage treatment plants, treatments with different required water quality, such as sewage discharge water and reclaimed water, may be required.

  For reclaimed water, it may be required to inactivate microorganisms or to reduce organic substances such as odorous substances and chromaticity components. Even if inactivation of microorganisms is sufficient, the standard of reclaimed water is stricter than that of sewage effluent. For example, the reclaimed water is E. coli not detected / 100 mL, and the sewage effluent is 3000 E. coli groups / mL.

  Therefore, when the water treated on the basis of the reclaimed water is discharged into the sewage, the quality of the discharged water becomes good, but the sewage discharged water is excessively treated, and there is a problem that the operation cost of the treatment plant increases. In order to make the water treatment more efficient using the conventional technique, a plurality of different apparatuses for sewage effluent water and reclaimed water are required, and there is a problem that the installation area is increased and the cost is also increased.

  Moreover, regarding the reclaimed water required to reduce the organic matter, the difference in water quality from the sewage discharge water is even greater. This is because, in general, in order to reduce organic matter, a larger amount of UV irradiation is required than inactivating microorganisms. Recycled water irradiated with ultraviolet light until organic matter is reduced can sufficiently achieve the standard for inactivation of microorganisms. In this way, when the reclaimed water that has been treated to reduce organic matter is discharged into sewage, the water quality at the discharge destination is further improved, but the sewage effluent is excessively treated, increasing the operating cost of the treatment plant. is there. In this case as well, in order to make the water treatment more efficient using the conventional technology, a plurality of different apparatuses for sewage effluent and reclaimed water are required, which increases the installation area and increases the cost. there were.

  An object of the present invention is to provide an ultraviolet water treatment apparatus capable of obtaining a plurality of different water quality levels.

  In order to achieve the above object, an ultraviolet water treatment apparatus of the present invention has an inflow channel and an outflow channel, an ultraviolet irradiation tank through which the treated water flowing from the inflow channel flows, and the treated water. An ultraviolet ray source for irradiating ultraviolet rays, a protective material that prevents direct contact between the water to be treated and the ultraviolet ray source and transmits ultraviolet rays, and an ultraviolet ray irradiation tank provided between the inflow channel and the outflow channel. One or more branch flow paths for extracting treated water are provided, and the water to be treated in the ultraviolet irradiation tank between the branch flow path and the outflow flow path is irradiated with ultraviolet rays for different times.

  In addition, an oxidation decomposition channel communicating with the branch channel is provided inside the ultraviolet irradiation tank. In addition, an oxidant generating unit that generates ozone or hydrogen peroxide and an oxidant injection channel that injects the ozone or hydrogen peroxide connected to the oxidative decomposition channel are provided.

  According to the present invention, it is possible to obtain treated water having a plurality of different water quality levels with one apparatus by installing a branch channel in the ultraviolet irradiation tank. Therefore, compared with the case where a plurality of devices are used to obtain a plurality of treated waters having different water quality levels, the installation area of the device can be reduced.

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

  A first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a longitudinal sectional view of the ultraviolet water treatment apparatus of the present embodiment, and FIG. 2 is a sectional view taken along line AA in FIG. 3 is a longitudinal sectional view of the ultraviolet water treatment apparatus of this embodiment, and FIG. 4 is a sectional view taken along the line BB in FIG.

  As shown in FIGS. 1 and 2, the cylindrical ultraviolet irradiation tank 1 has a sealed structure in which flat plates are fixed at both ends, and is a cylindrical protective material formed of quartz between the central portions of the flat plates. A protective tube 3 is attached. An ultraviolet lamp 2 that is an ultraviolet light source is installed in the axial direction in the protective tube 3, and the ultraviolet lamp 2 is connected to a lamp control device 4 that is an ultraviolet light source control device by wiring.

  The ultraviolet irradiation tank 1 is provided with an inflow channel 5, an outflow channel 7, and an outflow channel 6 that is a branch channel, and two or more outflow channels 6 are provided. The inflow channel 5 is provided at one end of the ultraviolet irradiation tank 1, the outflow channel 6 is provided at the center of the ultraviolet irradiation tank 1, and the outflow channel 7 is provided at the other end of the ultraviolet irradiation tank 1. . The outflow channel 7 is provided with an on-off valve 10. Each outflow channel 6 is provided with an open / close valve 9, and the outflow channel 6 joins the outflow channel 8. The on-off valve 9 and the on-off valve 10 are connected to the valve control device 11 by wiring and are controlled to be opened and closed by the valve control device 11.

  The arrows in FIG. 1 indicate the flow direction of the water to be treated. The water to be treated 12 flows from the inflow passage 5, and the inflowing water 12 to be treated is passed by the ultraviolet lamp 2 while passing through the ultraviolet irradiation tank 1. The treated water 13 and treated water 14 are irradiated with ultraviolet rays, and the treated water 13 and treated water 14 flow out of the ultraviolet irradiation tank 1 from the outflow channel 8 and the outflow channel 7. Comparing the amount of ultraviolet energy irradiated to the treated water 13 and the treated water 14, that is, the amount of ultraviolet irradiation, the amount of ultraviolet irradiation to the treated water 14 flowing along the entire length of the ultraviolet lamp 2 flows out in the middle of the ultraviolet lamp 2. The amount of ultraviolet rays irradiated to the treated water 13 flowing out from the passage 6 is larger than that of the treated water 14, and more microorganisms are inactivated. Here, the UV irradiation amount is UV irradiation amount = UV irradiation intensity × irradiation time.

  In the sewage treatment plant, the required inactivation level differs between sewage effluent water and reclaimed water, but by applying the ultraviolet water treatment apparatus of this embodiment, treated water 13 as sewage effluent water and treated water 14 as reclaimed water. These two treated waters can be generated more efficiently with one apparatus.

  In order to control the respective flow rates and inactivation levels of the treated water 13 and the treated water 14, the lamp controller 4 controls the irradiation intensity of the ultraviolet lamp 2, and the valve controller 11 controls each valve of the on-off valve 9. The opening degree and the opening degree of the on-off valve 10 are controlled.

  In the present embodiment, the ultraviolet water treatment apparatus using one ultraviolet lamp 2 has been described, but a plurality of ultraviolet lamps 15 may be used as shown in FIGS. In the infrared water treatment apparatus shown in FIGS. 3 and 4, the cylindrical ultraviolet irradiation tank 1 has a sealed structure in which flat plates are fixed at both ends, and a plurality of cylinders are included in the cylindrical ultraviolet irradiation tank 1. A protective tube 3 having a shape is attached so that its central axis is orthogonal to the central axis of the ultraviolet irradiation tank 1. Each of the protection tubes 3 is provided with an ultraviolet lamp 15, and each of the ultraviolet lamps 15 is connected to the lamp control device 4 by wiring. The lamp control device 4 can control each ultraviolet lamp individually.

  In this case, in order to control the inactivation level of the treated water 13 and the treated water 14, the lamp controller 4 controls the irradiation intensity of each of the ultraviolet lamps 15, or controls the turn-off and lighting time of each of the ultraviolet lamps 15. is doing.

  The ultraviolet water treatment apparatus shown in FIGS. 1 to 4 is an internally illuminated ultraviolet water treatment apparatus, but may be an externally illuminated ultraviolet water treatment apparatus.

  A second embodiment of the present invention will be described with reference to FIG. FIG. 5 is a longitudinal sectional view of the ultraviolet water treatment apparatus.

  Although this embodiment is configured in the same manner as the ultraviolet water treatment apparatus shown in FIG. 1, the cylindrical ultraviolet irradiation tank 1 of this embodiment has a sealed structure in which flat plates are fixed at both ends. A protective tube 3, which is a cylindrical protective material made of quartz, is attached between the central portions. An ultraviolet lamp 2 is installed in the protective tube 3, and the ultraviolet lamp 2 is connected to the lamp control device 4 by wiring. The ultraviolet irradiation tank 1 of the present embodiment is formed by an outer cylinder portion 32 having a large outer diameter at the center and an inner cylinder portion 31 having a small outer diameter, and has a double tube structure. The cylindrical portion 31 is partitioned by an ultraviolet transmitting wall 33 that transmits ultraviolet rays. A space 37 that is an oxidative decomposition flow path is formed on the outer cylinder part 32 side from the ultraviolet ray transmitting wall 33, and the outer cylinder part 32 and the inner cylinder part 31 communicate with each other via the outer cylinder inlet 34.

  The inflow passage 5 is provided on one end side of the inner cylinder portion 31, and the outflow passage 7 to which the on-off valve 10 is attached is provided on the other end side. A plurality of outflow passages 6 to which the on-off valves 9 are attached are provided on the side of the outer cylinder part 32 that is far from the outer cylinder inlet 34, and oxidation is provided on the side of the outer cylinder part 32 that is closer to the outer cylinder inlet 34. An agent injection channel 35 is provided, and the oxidant injection channel 35 is connected to an oxidant injection device 36.

  The arrows in FIG. 5 indicate the flow direction of the water to be treated. The water to be treated 12 flows from the inflow channel 5, and the inflowing water 12 to be treated is passed by the ultraviolet lamp 2 while passing through the ultraviolet irradiation tank 1. It becomes the treated water 14 in which microorganisms are inactivated by irradiation with ultraviolet rays, and a part flows out of the ultraviolet irradiation tank 1 as treated water 14 from the outflow channel 7.

  On the other hand, the treated water that has flowed into the outer cylinder portion 32 from the outer cylinder inlet 34 is treated as intermediate treated water 37 and flows out of the ultraviolet irradiation tank 1 from the outflow passage 8 as treated water 13. An oxidizing agent such as ozone or hydrogen peroxide is injected into the intermediate treated water 37 by the oxidizing agent injection device 36. The ultraviolet rays irradiated from the ultraviolet lamp 2 pass through the water to be treated 12 and the ultraviolet light transmitting wall 33 and irradiate the intermediate treated water 37 mixed with the oxidizing agent. The oxidizing agent in the intermediate treated water 37 absorbs ultraviolet rays to generate hydroxy radicals, and oxidizes and decomposes organic substances in the intermediate treated water 37.

  By such treatment, treated water 13 in which microorganisms are inactivated and organic matter is oxidized and decomposed, and treated water 14 in which microorganisms are inactivated are obtained. In sewage treatment plants, reclaimed water is required to have a higher inactivation level than sewage effluent, and there are cases where reduction of organic substances such as deodorization and decolorization is required. By applying the ultraviolet water treatment apparatus of the present embodiment, two kinds of treated water, that is, treated water 14 that is sewage discharge water and treated water 13 that is reclaimed water can be generated by one apparatus, and the apparatus installation area can be reduced.

  In order to control the flow rate and oxidative decomposition level of the treated water 13 and the flow rate and inactivation level of the treated water 14, the lamp control device 4 controls the irradiation intensity of the ultraviolet lamp 2, and the valve control device 11 opens and closes the open / close valve. There is a method of controlling each of the 9 valve openings and the valve opening of the on-off valve 10. Further, the amount of the oxidizing agent injected into the intermediate treated water is controlled by the oxidizing agent injection device 36. In the present embodiment, the ultraviolet water treatment apparatus using one ultraviolet lamp 2 has been described, but a plurality of ultraviolet lamps may be used as shown in FIG. 3 of the first embodiment. In that case, there is a method of controlling the amount of ultraviolet irradiation by turning off and turning on each of the ultraviolet lamp groups. The present embodiment can also be applied to an externally lit ultraviolet water treatment apparatus.

  A third embodiment of the present invention will be described with reference to FIG. FIG. 6 is a longitudinal sectional view of the ultraviolet water treatment apparatus of this embodiment.

  The present embodiment is configured in the same manner as in the second embodiment, but in the ultraviolet water treatment apparatus of the present embodiment, a photocatalyst 38 is enclosed in the outer cylindrical portion 32, and an oxidant injection channel 35 and an oxidant injection device 36 are provided. It has the structure which removed.

  A part of the water to be treated 12 irradiated with ultraviolet rays by the ultraviolet lamp 2 flows into the outflow channel 7, and the rest flows into the outer cylinder part 32 from the outer cylinder inlet 34 as intermediate treated water 37. The inflow intermediate treated water 37 flows into the outflow channel 8 while being in contact with the photocatalyst 38. At this time, the photocatalyst 38 irradiated with ultraviolet rays generates hydroxy radicals, and oxidizes and decomposes organic substances in the intermediate treated water 37.

  In this embodiment, there is an advantage that the medium pressure mercury lamp can be effectively used. Unlike low-pressure mercury lamps, medium-pressure mercury lamps generate ultraviolet rays having a wavelength of 300 nm or more and visible rays in addition to ultraviolet rays having a wavelength of 300 nm or less. Since ultraviolet rays and visible light having a wavelength of 300 nm or more do not contribute to inactivation of microorganisms and decomposition of the oxidizing agent, in Examples 1 and 2, even if an intermediate pressure mercury lamp is used, ultraviolet rays and visible light having a wavelength of 300 nm or more are used. Not available. However, since the photocatalyst absorbs ultraviolet light having a wavelength of 300 nm or less and ultraviolet light having a wavelength of 300 nm or more and visible light to generate a hydroxy radical, the use of the photocatalyst can effectively utilize ultraviolet light having a wavelength of 300 nm or more and visible light.

  In addition, by using a medium pressure mercury lamp, microorganisms are inactivated by ultraviolet rays having a wavelength of 300 nm or less, and the oxidative decomposition of organic matter is divided into wavelength regions using ultraviolet rays having a wavelength of 300 nm or more and visible rays, It is possible to provide an ultraviolet water treatment apparatus capable of effectively utilizing wavelength characteristics.

  FIG. 7 shows the absorptance in sewage secondary treated water of ultraviolet rays and visible rays. The absorptance is expressed as a percentage absorbed in the sample water when ultraviolet rays or visible light travels straight through 1 cm of the sample water. As can be seen from FIG. 7, in the secondary treated water of sewage, ultraviolet rays having a wavelength of 300 nm or more and visible rays have a smaller absorption rate than ultraviolet rays having a wavelength of 300 nm or less and are not easily absorbed.

  Therefore, when ultraviolet light and visible light from the medium pressure mercury lamp are irradiated in the secondary treated water, a region where ultraviolet light and visible light having a wavelength of 300 nm or more are irradiated far away from the medium pressure mercury lamp. By installing the outer cylinder part 32 encapsulated with the photocatalyst 38 in this region, ultraviolet rays with a wavelength of 300 nm or less are used to inactivate microorganisms in the treated water 12 of the inner cylinder part 31, and ultraviolet rays with a wavelength of 300 nm or more are visible. The light beam can be used for oxidative decomposition of the organic matter in the intermediate treated water 37 of the outer cylinder portion 32.

  In addition, since the treated water other than the sewage secondary treated water such as drainage, purified water, and river water has the same tendency as the tendency shown in FIG. 7, the same device structure can be obtained.

  In order to control the flow rate and oxidative decomposition level of the treated water 13 and the flow rate and inactivation level of the treated water 14, the lamp controller 4 controls the irradiation intensity of the ultraviolet lamp 2. Further, the valve control device 11 controls the valve opening degree of the on-off valve 9 and the valve opening degree of the on-off valve 10. In the present embodiment, the ultraviolet water treatment apparatus using one ultraviolet lamp 2 has been described. However, as shown in the first embodiment, a plurality of ultraviolet lamps may be used. In that case, the amount of ultraviolet irradiation is controlled by turning off and turning on each of the ultraviolet lamp groups.

  FIG. 6 shows an internally-illuminated ultraviolet water treatment apparatus, but this embodiment can also be applied to an externally-illuminated ultraviolet water treatment apparatus.

  A fourth embodiment of the present invention will be described with reference to FIG. FIG. 8 is a longitudinal sectional view of the ultraviolet water treatment apparatus of this embodiment.

  The present embodiment is configured in the same manner as the second embodiment, but the ultraviolet water treatment apparatus of the present embodiment has a configuration in which a photocatalyst 38 is enclosed in the outer cylindrical portion 32.

  In Example 2, when the oxidizing agent mixed in the intermediate treated water 37 of the outer cylindrical portion 32 is irradiated with ultraviolet rays by the ultraviolet lamp 2 to decompose the oxidizing agent and generate a hydroxy radical, a wavelength of 300 nm or less is generated. Although ultraviolet rays are necessary, as shown in FIG. 7, ultraviolet rays having a wavelength of 300 nm or less have a large absorption rate into the water to be treated 12. Therefore, the diameter of the inner cylinder part 31 cannot be increased, and the treatment flow rate of the treated water 14 cannot be set large.

  In Example 3, since the photocatalyst 38 is enclosed in the outer cylinder part 32 and the ultraviolet-ray and visible light with a wavelength of 300 nm or more with small absorption rate to the to-be-processed water 12 can also be utilized, the diameter of the inner cylinder part 31 can be enlarged. . However, as described in [Non-Patent Document 1], the amount of oxidative decomposition of organic substances by photocatalytic reaction is generally smaller than the amount of oxidative decomposition by accelerated oxidation reaction. Therefore, in order to ensure a certain level of oxidative decomposition, it is necessary to reduce the flow rate of the intermediate treated water 37 and lengthen the ultraviolet irradiation time, and the flow rate of the treated water 13 cannot be set large.

  In the present embodiment, in order to increase the flow rates of the treated water 13 and the treated water 14, the oxidizing agent is decomposed by the hydroxy radicals generated by the photocatalyst 38 enclosed in the outer cylinder portion 32, and further the hydroxy radicals are generated. Thereby, ultraviolet rays having a wavelength of 300 nm or more and visible rays generated by the medium pressure mercury lamp can be used for the decomposition of the oxidizing agent. Therefore, the diameter of the inner cylinder part 31 can be increased, and the treatment flow rate of the treated water 14 can be set large. Moreover, since the production | generation of a hydroxyl radical can be accelerated | stimulated by increasing the injection amount of an oxidizing agent, the process flow rate of the treated water 13 can be set large.

  The lamp controller 4 controls the irradiation intensity of the ultraviolet lamp 2 in order to control the flow rate and oxidative decomposition level of the treated water 13 and the flow rate and inactivation level of the treated water 14. Further, the valve control device 11 controls the opening degree of each on-off valve 9 and the opening degree of the on-off valve 10. Further, the amount of the oxidizing agent injected into the intermediate treated water is controlled by the oxidizing agent injection device 36. In the present embodiment, the ultraviolet water treatment apparatus provided with one ultraviolet lamp 2 has been described. However, as shown in the first embodiment, a plurality of ultraviolet lamps may be used. In that case, the amount of ultraviolet irradiation is controlled by turning off and turning on each of the ultraviolet lamp groups. FIG. 8 shows the internally-illuminated ultraviolet water treatment apparatus, but this embodiment can also be applied to an externally-illuminated ultraviolet water treatment apparatus.

  A fifth embodiment of the present invention will be described with reference to FIGS. 9 is a longitudinal sectional view of the ultraviolet water treatment apparatus of this embodiment, and FIG. 10 is a sectional view taken along the line CC in FIG.

  As shown in FIGS. 9 and 10, the cylindrical ultraviolet irradiation tank 1 has a sealed structure in which flat plates are fixed at both ends, and is a cylindrical protective material formed of quartz between the central portions of the flat plates. A protective tube 3 is attached. An ultraviolet lamp 2 is installed in the protective tube 3, and the ultraviolet lamp 2 is connected to the lamp control device 4 by wiring.

  The ultraviolet irradiation tank 1 is provided with an inflow channel 5 and an outflow channel 7. The inflow channel 5 is provided at one end of the ultraviolet irradiation tank 1, and the outflow channel 7 is provided at the other end of the ultraviolet irradiation tank 1. The outflow channel 7 is provided with an on-off valve 10. At least one oxidation decomposition channel 41 is provided in the central portion of the ultraviolet irradiation tank 1, and the oxidation decomposition channel 41 communicates with the ultraviolet irradiation tank 1 through an inlet 42. An oxidant injection device 36 is connected to the oxidative decomposition channel 41 by a channel 35 for injecting an oxidant, and an outflow channel 8 having an on-off valve 43 is connected. The on-off valve 9, the on-off valve 10, and the on-off valve 43 are connected to the valve control device 11 by wiring and are controlled to be opened and closed by the valve control device 11. A plurality of oxidative decomposition channels 41 and on-off valves 43 may be provided.

  In the ultraviolet treatment apparatus of this embodiment, an oxidation decomposition channel 41, an inlet 42, an outlet channel 8, an on-off valve 43, a channel 35, and an oxidant injection device 36 are added to the cylindrical ultraviolet irradiation tank 1. Therefore, it can be realized by a simple additional work for making a through hole.

  The arrows in FIG. 9 indicate the flow direction, and the treated water 12 flows into the ultraviolet irradiation tank 1 from the inflow channel 5 and flows out as treated water 14 from the outflow channel 7. On the other hand, the intermediate treated water 37 flowing into the oxidative decomposition channel 41 from the inlet 42 flows out as treated water 13 from the outflow channel 8.

  When the oxidative decomposition channel 41 is made of an ultraviolet light transmitting material, the intermediate treated water 37 in the oxidative decomposition channel 41 can be irradiated with ultraviolet rays, and the treated water 13 that is the sewage discharge water and the recycled water can be used as in the first embodiment. Two treated waters of a certain treated water 14 can be generated more efficiently with one apparatus.

  When the photocatalyst holding body in which a photocatalyst is sintered in a member having a gap such as a wire mesh is used as the oxidation decomposition channel 41, the water 12 to be treated can flow into the oxidation decomposition channel from the gap between the sintered photocatalysts. When encapsulating the photocatalyst 38 inside the oxidative decomposition channel 41, the intermediate treated water 37 flows out in contact with the photocatalyst 38 in the same manner as in the third embodiment without using an ultraviolet transmitting material in the oxidative decomposition channel 41. When flowing into the path 8, the photocatalyst 38 irradiated with ultraviolet rays generates hydroxy radicals and oxidatively decomposes organic substances in the intermediate treated water 37.

  When the oxidative decomposition channel 41 is made of an ultraviolet transmitting material, the photocatalyst 38 is sealed inside the oxidative decomposition channel 41, and the oxidant is injected, it is mixed into the intermediate treated water 37 as in the fourth embodiment. The oxidant is irradiated with ultraviolet rays from the ultraviolet lamp 2 to decompose the oxidant to generate a hydroxy radical, and the oxidant is decomposed by the hydroxy radical generated by the photocatalyst 38 enclosed in the oxidative decomposition channel 41. Hydroxy radicals can be generated.

  The amount of UV irradiation is controlled by turning off and turning on each UV lamp group. FIG. 9 shows an internally-illuminated ultraviolet water treatment apparatus, but this embodiment can also be applied to an externally-illuminated ultraviolet water treatment apparatus.

BRIEF DESCRIPTION OF THE DRAWINGS The longitudinal cross-sectional view of the ultraviolet-ray water processing apparatus which is Example 1 of this invention. FIG. 2 is a cross-sectional view taken along line AA in FIG. 1. The longitudinal cross-sectional view of the ultraviolet-ray water processing apparatus of a present Example. FIG. 4 is a cross-sectional view taken along the line BB in FIG. 3. The longitudinal cross-sectional view of the ultraviolet-ray water processing apparatus which is Example 2 of this invention. The longitudinal cross-sectional view of the ultraviolet-ray water processing apparatus which is Example 3 of this invention. The figure which shows the absorption factor of the ultraviolet-ray and visible light with respect to sewage secondary treatment water. The longitudinal cross-sectional view of the ultraviolet-ray water processing apparatus which is Example 4 of this invention. The longitudinal cross-sectional view of the ultraviolet-ray water processing apparatus which is Example 5 of this invention. FIG. 10 is a sectional view taken along the line CC in FIG. 9.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Ultraviolet irradiation tank 2 Ultraviolet lamp 3 Protection tube 4 Lamp control device 5 Inflow flow path 6, 7, 8 Outflow flow path 9,10,43 On-off valve 11 Valve control apparatus 15 Ultraviolet lamp 31 Inner cylinder part 32 Outer cylinder part 33 Ultraviolet light Permeation wall 34 Inlet 35 Flow path 36 Oxidant injection device 38 Photocatalyst 41 Oxidation decomposition flow path

Claims (7)

  A protective material that transmits ultraviolet light, disposed in the ultraviolet irradiation tank, an ultraviolet light source that radiates ultraviolet light disposed in the protective material, an ultraviolet light source control device connected to the ultraviolet light source, and the ultraviolet irradiation tank An inflow channel of water to be treated provided on one end side of both ends, and a first outflow channel of treated water having a first on-off valve provided on the other end side of both ends of the ultraviolet irradiation tank A second outflow passage of treated water having a second on-off valve provided in the central portion of the ultraviolet tank, and a valve control device for controlling the opening degree of the first on-off valve and the second on-off valve UV water treatment equipment with. An ultraviolet ray irradiation tank having an inflow channel at one end and an outflow channel at the other end, in which treated water flowing from the inflow channel flows, an ultraviolet ray source for irradiating ultraviolet rays to the treated water, and the treated material One or more branch flows that extract treated water from a UV irradiation tank provided between the inflow channel and the outflow channel, and a protective material that prevents direct contact between the water and the UV source and transmits ultraviolet rays And an ultraviolet water treatment apparatus for performing ultraviolet irradiation for a time in which the ultraviolet irradiation time to the water to be treated flowing out from the branch flow path is different from the ultraviolet irradiation time to the water to be treated flowing out from the outflow flow path .   A protective material that transmits ultraviolet light, disposed in the ultraviolet irradiation tank, an ultraviolet light source that radiates ultraviolet light installed in the protective material, an ultraviolet light source control device connected to the ultraviolet light source, and both ends of the ultraviolet light tank An inflow channel of water to be treated provided on one end side, a first outflow channel of treated water having a first on-off valve provided on the other end side of both ends of the ultraviolet irradiation tank, An oxidative decomposition flow path, which is a flow path for injecting an oxidant provided at a central portion in the ultraviolet irradiation tank and having an inlet communicating with the ultraviolet irradiation tank, and connected to the oxidative decomposition flow path An ultraviolet water treatment apparatus comprising a second outflow passage for treated water having a second on-off valve, and a valve control device for controlling the opening degree of the first on-off valve and the second on-off valve.   The ultraviolet water treatment apparatus according to claim 3, wherein the oxidative decomposition channel is an ultraviolet light transmitting material.   4. The ultraviolet water treatment according to claim 3, further comprising an oxidant generating unit that generates ozone or hydrogen peroxide, and an oxidant injection channel that injects the ozone or hydrogen peroxide connected to the oxidative decomposition channel. apparatus.   The ultraviolet water treatment apparatus according to claim 4 or 5, wherein a photocatalyst is enclosed in the oxidative decomposition channel.   The ultraviolet water treatment apparatus according to claim 6, wherein the oxidative decomposition channel is formed of a photocatalyst holding body holding a photocatalyst.

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