JP2012206048A - Drainage treatment device and drainage treatment method using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a drainage treatment device capable of effectively decomposing an organic substance present in drainage water with low energy and to provide a drainage treatment method using the same.SOLUTION: An ultraviolet oxidation device includes: a flowing tank 12 for causing treatment water to flow in one direction; a photocatalyst fiber 14 arranged in the flowing tank 12 so that the treatment water can pass therethrough; an ultraviolet irradiation part 16 capable of irradiating ultraviolet rays; and an ultraviolet irradiation part-storage part 18 which is provided in the fluid tank 12, and stores the ultraviolet irradiation part 16 so as to irradiate the ultraviolet rays to the photocatalyst fiber 14. In the drainage treatment device, the ultraviolet irradiation part-storage part 18 is constituted so that the treatment water can flow in the ultraviolet irradiation part-storage part 18. The treatment water is constituted to be introduced into the fluid tank 12 after flowing in the ultraviolet irradiation part-storage part 18.

Description

  The present invention relates to a wastewater treatment apparatus for decomposing organic matter contained in wastewater and a wastewater treatment method using the same.

  In recent years, recycling of wastewater has been promoted, and in order to recycle, organic substances contained in wastewater by biological treatment have been decomposed. However, the wastewater treatment by the above-described organisms cannot deny the enlargement of the treatment facility and the long treatment time. Therefore, there is a need for a wastewater treatment apparatus that can effectively decompose and purify organic substances contained in wastewater.

  As a method for treating wastewater containing organic matter, for example, Patent Document 1 discloses a water purification device that oxidizes and decomposes unnecessary organic matter existing in water by irradiating water with ultraviolet rays. Usually, in order to decompose organic substances in water by ultraviolet irradiation, a large amount of energy is required by using a high-power ultraviolet lamp or using many ultraviolet lamps. In Patent Document 1, in order to save energy required for decomposition, the organic substance concentration in the treated water is monitored, and the output of the ultraviolet lamp is varied according to this concentration. However, it still has a problem that a great deal of energy is required for oxidative decomposition by ultraviolet irradiation.

  Patent Document 2 discloses an apparatus for decomposing unnecessary organic substances in water using a photocatalyst. This apparatus irradiates the flat nonwoven fabric with ultraviolet light having peak wavelengths of 180 to 190 nm and 250 to 260 nm from an ultraviolet lamp installed so as to be parallel to the flat nonwoven fabric made of fibers having a photocatalytic function. This decomposes the organic substances contained in the waste water.

JP-A-6-198279 WO2009 / 063737 A1

  However, depending on the type of organic matter contained in the wastewater, since the organic matter absorbs ultraviolet rays having the above wavelength, the photocatalyst is not sufficiently irradiated with ultraviolet rays radiated from the ultraviolet lamp, and the decomposition efficiency deteriorates. is there. In other words, in order for the photocatalyst to function sufficiently, it is necessary to irradiate the photocatalyst with sufficient ultraviolet light. Irradiation is required.

  The present invention has been made in view of the above problems, and provides a wastewater treatment apparatus capable of effectively decomposing organic matter present in wastewater with low energy and a wastewater treatment method using the same. The purpose is to do.

  In order to achieve the above object, the present inventors have conducted extensive research. As a result, the wastewater treatment apparatus is provided with two reaction steps. First, the ultraviolet irradiation in the ultraviolet decomposition reaction step prevents the ultraviolet irradiation of the photocatalyst. By reducing the concentration of organic matter to the extent that there is no problem in the photocatalyst function expression, and then decomposing the remaining organic matter using the photocatalyst in the photocatalytic decomposition reaction step, wastewater treatment can be efficiently performed with low energy. I found out. At this time, by shortening the liquid phase length irradiated with ultraviolet rays in the ultraviolet decomposition reaction step, the ultraviolet rays that function the photocatalyst are transmitted, and the same ultraviolet irradiation means is used in the photocatalytic decomposition reaction step to further reduce energy. This enables efficient wastewater treatment.

  That is, the present invention is a flow tank for flowing the water to be treated in one direction, a photocatalyst fiber disposed in the flow tank so that the water to be treated can pass therethrough, and an ultraviolet irradiation unit capable of irradiating ultraviolet rays. An ultraviolet ray irradiation portion accommodating portion for accommodating the ultraviolet ray irradiation portion provided in the fluidized tank and capable of irradiating the photocatalyst fiber with ultraviolet rays; The waste water treatment apparatus is configured to be flowable in the section, and the treated water is configured to be introduced into the fluid tank after flowing in the ultraviolet irradiation section accommodating section.

  In the wastewater treatment apparatus according to the present invention, the ultraviolet irradiation unit accommodation unit includes an inner tube that accommodates the ultraviolet irradiation unit and an outer tube that covers the inner tube, and a portion to be treated is disposed between the inner tube and the outer tube. It is preferable that the water flow.

  Moreover, the waste water treatment apparatus according to the present invention is configured to be able to store the water to be treated, and is configured to be able to store the water to be treated, the first supply tank communicating with the ultraviolet irradiation unit accommodating portion, A second supply tank that communicates with the first supply tank, and the water to be treated in the first supply tank is configured to be circulated in the first supply tank and the ultraviolet irradiation unit accommodating portion, and to be treated in the second supply tank. It is preferable that the water is configured to be able to circulate in the second supply tank and the fluidized tank, and the water to be treated in the first supply tank is configured to be supplied into the second supply tank.

  Furthermore, in the wastewater treatment apparatus according to the present invention, it is preferable that at least one of the first supply tank and the second supply tank is provided with an oxidant addition means, and the oxidant addition means includes hydrogen peroxide, ozone, and hypoxia. It is preferable that at least one of sodium chlorate can be added. By providing the oxidizing agent adding means in this way, wastewater treatment can be efficiently performed with lower energy.

  Furthermore, in the wastewater treatment apparatus according to the present invention, it is preferable that the inner tube can transmit wavelengths of 180 to 190 nm and 250 to 260 nm by 90% or more, and the outer tube has wavelengths of 180 to 190 nm and 250 to 260 nm. Is preferably 90% or more, and the radial interval between the inner tube and the outer tube is preferably 1 to 10 mm.

  In the wastewater treatment apparatus according to the present invention, the ultraviolet irradiation unit preferably includes an ultraviolet lamp in the inner tube, and the ultraviolet lamp can preferably irradiate ultraviolet rays having peak wavelengths of 180 to 190 nm and 250 to 260 nm. .

  Furthermore, in the wastewater treatment apparatus according to the present invention, the photocatalytic fiber is preferably a non-woven fabric of photocatalytic fiber having titanium oxide on its surface, and the non-woven fabric of photocatalytic fiber is a flat nonwoven fabric formed in a flat plate shape. The flat nonwoven fabric is preferably arranged so that its surface intersects the flow direction of the waste water, and the photocatalytic fiber comprises an oxide phase (first phase) mainly composed of a silica component and Ti. A silica-based composite comprising a composite oxide fiber with a metal compound phase (second phase) containing, wherein the Ti content of the metal oxide constituting the second phase is increasing in a slanting manner toward the surface layer of the fiber In addition, it is preferably an oxide fiber. In addition, platinum (Pt), palladium (Pd), ruthenium (Ru), rhodium (Rh), gold (Au), silver (Ag), copper are formed on the surface of the photocatalyst fiber. (Cu It is preferable that at least one metal among iron (Fe), nickel (Ni), zinc (Zn), gallium (Ga), germanium (Ge), indium (In) and tin (Sn) is supported. .

  The present invention also includes a photocatalyst fiber through which water to be treated can pass, an ultraviolet irradiation unit capable of irradiating ultraviolet rays, and an ultraviolet irradiation unit accommodation unit that accommodates the ultraviolet irradiation units and allows the treated water to flow inside. A wastewater treatment method for oxidatively decomposing an organic substance contained in water to be treated flowing in a fluidized tank, wherein the water to be treated is irradiated with ultraviolet rays from the ultraviolet irradiation section. An ultraviolet decomposition reaction step that flows in the irradiation unit housing unit, and water to be treated that flows in the ultraviolet irradiation unit housing unit passes between the photocatalytic fibers in a state in which the photocatalyst fiber is irradiated with ultraviolet rays from the ultraviolet irradiation unit. And a photocatalytic decomposition reaction step.

  As described above, according to the present invention, it is possible to provide a wastewater treatment apparatus capable of effectively decomposing organic matter present in wastewater with low energy and a wastewater treatment method using the same.

It is a conceptual sectional view of the waste water treatment equipment concerning this embodiment. It is a conceptual sectional view of the ultraviolet reaction part and photocatalyst reaction part concerning this embodiment. It is a conceptual diagram of a photocatalyst cartridge.

  Next, an embodiment of the waste water treatment apparatus according to the present invention will be described. As shown in FIGS. 1 and 2, the wastewater treatment apparatus according to the present embodiment includes a fluid tank body 10 separated into three tanks in the vertical direction and a first fluid tank 12 in the middle stage of the fluid tank body 10. A photocatalyst cartridge 14 disposed so that treated water can pass therethrough, an ultraviolet irradiation lamp 16 capable of irradiating ultraviolet rays, an ultraviolet irradiation lamp accommodating member 18 provided in the first fluid tank 12 and accommodating the ultraviolet irradiation lamp 16; A first supply tank 20 in which water to be treated such as waste water is stored; and a second supply tank 22 in which water to be treated in which the water to be treated has been subjected to an ultraviolet decomposition reaction process by the ultraviolet irradiation lamp 16 is stored. Yes.

  The fluid tank body 10 is formed in a substantially rectangular parallelepiped shape, the second fluid tank 24 disposed in the lower stage, the first fluid tank 12 disposed in the middle stage, and the third fluid tank 26 disposed in the upper stage. It has. An inflow port 28 through which water to be treated can flow is provided on the upstream side of the first fluid tank 12, and an outflow port from which the treated water subjected to the photocatalytic decomposition reaction process by the photocatalyst cartridge 14 can be discharged on the downstream side. 30 is provided. In addition, an inlet 32 through which water to be treated can flow is provided on the upstream side of the second fluid tank 24, and the water to be treated on which ultraviolet decomposition reaction treatment has been performed is located on the downstream side of the third fluid tank 26. A discharge outlet 34 is provided.

  11 photocatalyst cartridges 14 are installed in the first fluid tank 12 in a state where 11 photocatalyst cartridges 14 are juxtaposed along the flow direction over the entire area perpendicular to the flow direction of the water to be treated. As shown in FIG. 3, each photocatalyst cartridge 14 comprises a flat nonwoven fabric 14A and a pair of wire meshes 14B, 14B, and the flat nonwoven fabric 14A is sandwiched between a pair of stainless steel wire meshes 14B, 14B. Thus, by using the wire nets 14B and 14B as a support material to form a cartridge shape, the flat nonwoven fabric 14A having a deteriorated photocatalytic function can be easily replaced. Desorption can be facilitated by providing a multi-stage photocatalyst cartridge with a connecting structure using a frame or the like. In this embodiment, although 11 photocatalyst cartridges were used, the number can be arbitrarily determined according to the required water quality and the like, for example, 1 to 50. Moreover, in this embodiment, although the flat nonwoven fabric 14A was fixed to the 1st fluidized tank 12 as the photocatalyst cartridge 14, you may install by another means. Furthermore, in this embodiment, each photocatalyst cartridge 14 is installed so that its surface intersects perpendicularly to the flow direction of water. However, it is sufficient that the flowing water passes through the flat nonwoven fabric 14A efficiently, for example, in the flow direction. On the other hand, it may be installed at an angle of around 10 °, preferably around 5 °.

  The ultraviolet irradiation lamp 16 is formed in a columnar shape, and a cylindrical cover member (not shown) is provided on the outer surface thereof. The cover member is made of a material that transmits not only 250 to 260 nm but also a peak wavelength of 180 to 190 nm, for example, synthetic quartz. A general low-pressure mercury lamp originally has two wavelengths of 185 nm and 254 nm. However, since glass as a material of a normal cover member does not transmit short-wave ultraviolet light, only a wavelength of 254 nm is irradiated. In the wastewater treatment apparatus according to this embodiment, the ultraviolet irradiation lamp 16 can irradiate ultraviolet rays having peak wavelengths of 180 to 190 nm and 250 to 260 nm by making the material of the cover member special as described above. It is configured. The ultraviolet rays irradiated from the ultraviolet irradiation lamp 16 have a peak wavelength at 180 to 190 nm, preferably 185 nm, and a peak wavelength at 250 to 260 nm, preferably 254 nm.

  A total of 50 ultraviolet irradiation lamp accommodating members 18 are installed in each of five photocatalyst cartridges 14 in the first fluid tank 12 in parallel. Each ultraviolet irradiation lamp housing member 18 is composed of a double tube including a cylindrical outer tube 18A and an inner tube 18B, and is a material that transmits 90% or more of a peak wavelength of 180 to 190 nm as well as 250 to 260 nm. For example, it is made of synthetic quartz. The radial distance between the outer tube 18A and the inner tube 18B is preferably 1 to 10 mm, and particularly preferably 3 to 8 mm. The lower ends of these ultraviolet irradiation lamp housing members 18 all pass through the bottom surface of the first fluid tank 12 and reach the second fluid tank 24, and the upper ends both penetrate the upper surface of the first fluid tank 12. The water to be treated that has reached the inside of the third fluid tank 26 and has flowed into the second fluid tank 24 from the inlet 32 passes through between the outer pipe 18A and the inner pipe 18B of each ultraviolet irradiation lamp housing member 18. Three fluid tanks 26 are configured to flow. Thus, when flowing between the outer tube 18A and the inner tube 18B, the water to be treated is irradiated with ultraviolet rays from the ultraviolet irradiation lamp 16, and organic substances and the like can be decomposed to some extent. In the present embodiment, the ultraviolet irradiation lamp housing member 18 is formed in a cylindrical shape, but is not limited thereto, and may be any shape that extends in the longitudinal direction. The number of the ultraviolet irradiation lamps 16 is determined according to the required water quality, the amount of unnecessary organic matter contained in the water to be treated, and the like. In the present embodiment, the inner tube 18B is formed in a cylindrical shape, but may be any shape as long as the ultraviolet irradiation lamp 16 can be disposed at the center.

  The 1st supply tank 20 is provided with the oxidizing agent addition part 36 provided in the upper direction, and the air injection part 38 provided in the 1st supply tank 20 inner surface vicinity, and it peroxidizes to to-be-processed water from each. An oxidant such as hydrogen water or sodium hypochlorite is added and air is injected. The supply amount of the oxidant is controlled by a computer (not shown). The first supply tank 20 communicates with the inlet 32 of the second fluid tank 24 via the first circulation path 40 and the outlet 34 of the third fluid tank 26 via the second circulation path 42. Communicating with The first circulation path 40 is provided with a pump 44 and an ozone supply unit 46, and the water to be treated in the first supply tank 20 is caused to flow to the inlet 32 of the second fluid tank 24 by the pump 44. The ozone supply unit 46 can inject ozone into the water to be treated. Further, a valve 48 is provided on the downstream side of the ozone supply section 46 of the first flow path 40, a third circulation path 50 branches from the valve 48, and the third circulation path 50 is connected to the second circulation path 50. It communicates with the supply tank 22.

  The second supply tank 22 includes an oxidizer addition section 52 provided above the air supply section 54 and an air injection section 54 provided in the vicinity of the inner bottom surface of the second supply tank 22. An oxidant such as hydrogen water or sodium hypochlorite is added and air is injected. The supply amount of the oxidant is controlled by a computer (not shown). The second supply tank 22 communicates with the inlet 28 of the first fluid tank 12 via the fourth circulation path 56 and the outlet 30 of the first fluid tank 12 via the fifth circulation path 58. Communicating with The fourth circulation path 56 is provided with a pump 60 and an ozone supply unit 62, and the water to be treated in the second supply tank 22 is caused to flow to the inlet 28 of the first fluid tank 12 by the pump 60. The ozone supply unit 62 can inject ozone into the water to be treated.

  The air injection units 38 and 54 are devices that can be bubbled from the lower portions of the first supply tank 20 and the second supply tank 22 by an aeration method. The air supply amount is preferably 200 to 500 L / min, more preferably 350 L / min, with respect to 200 L / min of water to be treated. The amount of dissolved oxygen in the bubbled water is preferably 50 to 100% in terms of saturation. Further, air may be supplied together with or instead of the air injection portions 38 and 54 using a microbubble generator. In general, the microbubble generation method includes a pressure dissolution method, an ejector method, a cavitation method, and a swivel method, and the microbubble generation method is preferably a pressure dissolution method and an ejector method. Since the characteristics of microbubbles depend on the diameter and amount of bubbles generated, a pressure-melting generation method that can generate relatively large amounts of fine bubbles is particularly preferable. The diameter of the generated microbubbles is preferably 30 μm or less. The amount of dissolved oxygen in the water in which the microbubbles are generated by the microbubble generator is preferably 80 to 150% in terms of saturation. Oxygen above the saturation amount of dissolved oxygen can be dissolved by the self-pressurizing effect of the microbubbles.

  In the wastewater treatment apparatus according to the present embodiment, the flat nonwoven fabric 14A of the photocatalyst cartridge 14 is a composite of an oxide phase (first phase) mainly composed of a silica component and a metal oxide phase (second phase) containing titanium. It is a silica-based composite oxide fiber composed of an oxide phase, and is composed of a photocatalyst fiber in which the abundance ratio of titanium of the metal oxide constituting the second phase increases in a gradient toward the surface layer of the fiber.

  The surface of the photocatalytic fiber is platinum (Pt), palladium (Pd), ruthenium (Ru), rhodium (Rh), gold (Au), silver (Ag), copper (Cu), iron (Fe), nickel (Ni). One or more of zinc (Zn), gallium (Ga), germanium (Ge), indium (In), and tin (Sn) may be supported. The supporting method is not particularly limited. For example, light having an energy equal to or higher than the energy corresponding to the band gap of the metal oxide constituting the second phase while contacting the liquid containing the supported metal ions and the photocatalytic fiber. Can be carried by irradiation.

  The first phase is an oxide phase mainly composed of a silica component, and may be amorphous or crystalline, and may be a metal element or metal oxide capable of forming a solid solution or a eutectic compound with silica. It may contain. Examples of the metal element (A) that can form a solid solution with silica include titanium. Examples of the metal element (B) of the metal oxide that can form a solid solution with silica include aluminum, zirconium, yttrium, lithium, sodium, barium, calcium, boron, zinc, nickel, manganese, magnesium, and iron. It is done.

  The first phase forms the internal phase of the silica-based composite oxide fiber and plays an important role in bearing the mechanical properties. The ratio of the first phase to the entire silica-based composite oxide fiber is preferably 40 to 98% by weight, and the desired function of the second phase is sufficiently expressed, and high mechanical properties are also expressed. For this purpose, it is more preferable to control the ratio of the first phase within the range of 50 to 95% by weight.

  On the other hand, the second phase is a metal oxide phase containing titanium and plays an important role in developing the photocatalytic function. An example of the metal constituting the metal oxide is titanium. The metal oxide may be a simple substance, or may be a co-melting compound or a substance in which a substitutional solid solution is formed by a specific element, but is preferably titania. The second phase forms the surface layer phase of the silica-based composite oxide fiber, and the proportion of the second phase of the silica-based composite oxide fiber varies depending on the type of metal oxide, but is 2 to 60% by weight. Preferably, it is more preferably controlled within a range of 5 to 50% by weight in order to sufficiently exhibit its function and to simultaneously exhibit high strength. The crystal grain size of the metal oxide containing titanium in the second phase is preferably 15 nm or less, and particularly preferably 10 nm or less.

  The proportion of titanium in the metal oxide contained in the second phase increases in a gradient toward the surface of the silica-based composite oxide fiber, and the thickness of the region where the composition gradient is clearly recognized is the surface layer. From 5 to 500 nm, but may be about 1/3 of the fiber diameter. The “existence ratio” of the first phase and the second phase refers to the first phase with respect to the metal oxide constituting the first phase and the entire metal oxide constituting the second phase, that is, the entire silica-based composite oxide fiber. % By weight and the second phase metal oxide.

In wastewater treatment device according to the present embodiment, the average UV intensity on flat nonwoven 14A is preferably is preferably 1~10mW / cm ^2, a further range of 2~8mW / cm ^2. When the ultraviolet intensity on the surface of the flat nonwoven fabric 14A is 1 to 10 mW / cm ² , water treatment with two ultraviolet components can be performed with high efficiency. In order to make such a range, the distance between the ultraviolet irradiation lamp 16 and the flat nonwoven fabric 14A may be set to an appropriate range. Here, the average ultraviolet intensity can be obtained by measuring the ultraviolet intensity at a plurality of locations from the center to the end of the nonwoven fabric surface, and averaging these values.

  The photocatalyst fiber having the inclined structure as described above can be produced by a known method, for example, based on the method described in WO2009 / 63737.

  Next, the operation of the waste water treatment apparatus according to this embodiment will be described. First, the water to be treated in the first supply tank 20 is supplied into the second fluid tank 24 through the first circulation path 40 by operating the pump 44. The treated water supplied into the second fluid tank 24 flows between the outer tube 18A and the inner tube 18B of the ultraviolet irradiation lamp housing member 18 and flows to the third fluid tank 26. At that time, the ultraviolet irradiation lamp 16 UV decomposition reaction treatment is performed. Next, the water to be treated in the third fluid tank 26 flows to the first supply tank 20 via the second circulation path 42, and the first fluid tank 20 → second fluid tank 24 → third fluid tank 26 → third. Circulate with one supply tank 20. During this circulation, an oxidant is appropriately added from the oxidant addition unit 36 to the water to be treated in the first supply tank 20, and air is injected from the air injection unit 38 to flow through the first circulation path 40. Ozone is supplied to the treated water from the ozone supply unit 46. Then, after being circulated for a predetermined time, the valve 48 is operated, and the water to be treated flows into the second supply tank 22 through the third circulation path 50.

  When the water to be treated is stored in the second supply tank 22, the pump 60 is operated to supply the water to be treated in the second supply tank 22 into the first fluid tank 12 through the fourth circulation path 56. The inside of the first fluid tank 12 is caused to flow. At this time, a photocatalytic decomposition reaction process is performed by the photocatalyst cartridge 14 in which the water to be treated is irradiated with ultraviolet rays from the ultraviolet irradiation lamp 16. Next, the water to be treated in the first fluid tank 12 flows to the second supply tank 22 via the fifth circulation path 58 and circulates between the second supply tank 22 → the first fluid tank 12 → the second supply tank 22. To do. During this circulation, the water to be treated in the second supply tank 22 is appropriately added with an oxidizing agent from the oxidizing agent adding section 52, and air is injected from the air injecting section 54 to flow through the fourth circulation path 56. Ozone is supplied to the treated water from the ozone supply unit 62. Simultaneously with the circulation of the second supply tank 22 → the first fluid tank 12 → the second fluid tank 22, the circulation of the first supply tank 20 → the second fluid tank 24 → the third fluid tank 26 → the first supply tank 20 is performed. You can do it.

  Hereinafter, examples of the waste water treatment apparatus according to the present invention will be described.

(Production Example 1)
A 5-liter three-necked flask was charged with 2.5 liters of anhydrous toluene and 400 g of metallic sodium, heated to the boiling point of toluene under a nitrogen gas stream, and 1 liter of dimethyldichlorosilane was added dropwise over 1 hour. After completion of the dropwise addition, the mixture was heated to reflux for 10 hours to form a precipitate. The precipitate was filtered, washed with methanol and then with water to obtain 420 g of white powder of polydimethylsilane. 250 g of this polydimethylsilane was charged into a three-necked flask equipped with a water-cooled reflux and heated and reacted at 420 ° C. for 30 hours under a nitrogen stream to obtain polycarbosilane having a number average molecular weight of 1200.

  To 16 g of polycarbosilane synthesized by the above method, 100 g of toluene and 64 g of tetrabutoxytitanium are added, preheated at 100 ° C. for 1 hour, then slowly heated to 150 ° C. and allowed to react for 5 hours to obtain modified polycarbosilane. Synthesized. In order to intentionally allow the low molecular weight organometallic compound to coexist with the modified polycarbosilane, 5 g of tetrabutoxytitanium was added to obtain a mixture of the modified polycarbosilane and the low molecular weight organometallic compound.

  After the mixture of the modified polycarbosilane and the low molecular weight organometallic compound was dissolved in toluene, the mixture was charged into a melt blow spinning apparatus, the interior was sufficiently purged with nitrogen, and the temperature was raised to distill off the toluene. Spinning was performed. The spun nonwoven fabric was heated to 150 ° C stepwise in air and infusible, and then fired in air at 1200 ° C for 1 hour to obtain titania / silica fibers as photocatalyst fibers.

  In the photocatalyst fiber obtained in Production Example 1, the proportion of the first phase was 80% by weight and the proportion of the second phase was 20% by weight. The abundance ratio was determined by fluorescent X-ray analysis. The particle diameter of titania crystal particles contained in the second phase was 8 nm. The particle diameter was determined by TEM (transmission electron microscope observation). From the surface of the photocatalyst fiber, the existing ratio of titanium metal oxide was inclined at a depth of 300 nm. The inclination depth was determined by Auger electron spectroscopy.

(Production Example 2)
The titanium oxide / silica fiber nonwoven fabric obtained in Production Example 1 was immersed in a palladium plating solution (Paradex: made by Tanaka Kikinzoku Co., Ltd.) with a palladium concentration of 2.5 ppm, and ultraviolet light having a wavelength of 351 nm was 4 mW / cm ² . Irradiated with intensity for 4 hours. After the irradiation, the fiber was taken out, washed with water, and further dried to obtain a palladium-supported titanium oxide / silica fiber nonwoven fabric according to Production Example 2. From the results of the weight measurement, the amount of palladium supported was 0.05% by weight.

Example 1
Using the nonwoven fabric made of titanium oxide / silica fiber obtained in Production Example 1, a photocatalyst cartridge 14 including a flat nonwoven fabric 14A shown in FIG. 3 was prepared, and the waste water treatment apparatus shown in FIG. 1 was prepared. However, the oxidizing agent addition parts 36 and 52 and the ozone supply parts 46 and 62 were not provided. The ultraviolet irradiation lamp 16 used is NIQ201 / 107XL manufactured by Heraeus, and synthetic quartz is used as the inner tube 18B. The output was 200 W, and 50 ultraviolet irradiation lamps 16 were used. The wavelengths emitted from the ultraviolet irradiation lamp 16 are both 254 nm and 185 nm. The distance between the ultraviolet irradiation lamp 16 was 50 mm, and the distance between the ultraviolet irradiation lamp 16 and the photocatalyst cartridge 14 was 25 mm. The average ultraviolet intensity on the surface of the flat nonwoven fabric 14A was 10 mW / cm ² . The ultraviolet intensity was measured using a UV POWER METER manufactured by Hamamatsu Photonics.

  As the water to be treated, phenol was dissolved in ion-exchanged water to obtain a 100 ppm phenol aqueous solution. The ultraviolet absorptivity (254 nm) of this aqueous phenol solution was 50%. Hereinafter, the ultraviolet absorptance was measured using an ultraviolet-visible light spectrophotometer (UV-2450) manufactured by Shimadzu Corporation and using a quartz cell with an optical path length of 10 mm. In the first supply tank 20, a total of 350 L / min of air aeration was generated from the air injection section 38, while in the second supply tank 22, a total of 200 L / min of air aeration was generated from the air injection section 54. Furthermore, in the 1st supply tank 20, the microbubble was generated at 60 L / min from the microbubble generator which is not shown in figure. The average dissolved oxygen saturation in the treatment solution in each supply tank was 110% in the first supply tank 20 and 80% in the second supply tank 22. The dissolved oxygen amount was measured using a HORIBA D-50 dissolved oxygen meter, and the saturated dissolved oxygen amount was calculated from the temperature and the dissolved oxygen amount in water.

  The phenol aqueous solution 1000 L was supplied to the waste water treatment apparatus at a speed of 167 L / min to perform a circulation treatment. The UV decomposition reaction treatment was performed for 10 passes, the processed liquid was opened from the first supply tank 20 to the second supply tank 22 with the valve opened, and the photocatalytic decomposition reaction treatment was performed for 10 passes. In the waste water treatment apparatus, 1000 L of phenol aqueous solution is circulated at 167 L / min, and the processing time for processing 1000 L of the entire solution in 6.0 minutes is defined as one pass for convenience. In Example 1, first, UV decomposition reaction treatment is performed for 10 passes (treatment time is 60 minutes), then photocatalytic decomposition reaction treatment is performed for 10 passes (treatment time is 60 minutes), and the entire wastewater treatment apparatus is treated for 120 minutes. Went.

(Example 2)
The examination was performed under the same conditions as in Example 1 except that the nonwoven fabric made of palladium-supported titanium oxide / silica fiber obtained by the method described in Production Example 2 was used.

(Example 3)
Examination was performed under the same conditions as in Example 2 except that the oxidizer addition units 36 and 52 were respectively installed in the first supply tank 20 and the second supply tank 22 and hydrogen peroxide was added to each supply tank. Hydrogen peroxide was an aqueous solution having a concentration of 10%, and the addition amount was 67.5 ml / min in the first supply tank 20 and 7.5 ml / min in the second supply tank 22.

Example 4
Examination was performed under the same conditions as in Example 2 except that the oxidizer addition units 36 and 52 were respectively installed in the first supply tank 20 and the second supply tank 22 and sodium hypochlorite was added to each supply tank. It was. Sodium hypochlorite was an aqueous solution having a concentration of 10%, and the addition amount was 45 ml / min in the first supply tank 20 and 5 ml / min in the second supply tank 22.

(Example 5)
Except that ozone supply units 46 and 62 are installed in the first circulation path 40 and the fourth circulation path 56, respectively, and ozone is added during the ultraviolet decomposition reaction process and the photocatalytic decomposition reaction process, the same as in Example 2. The examination was conducted under conditions. The ozone generation capacities of the used ozone supply units 46 and 62 are 1500 mg / h in the first circulation path 40 and 250 mg / h in the fourth circulation path 56.

(Comparative Example 1)
The examination was performed under the same conditions as in Example 1 except that the nonwoven fabric made of titanium oxide / silica fiber obtained by the method of Production Example 1 shown in FIG.

(Comparative Example 2)
The same examination as in Example 1 was performed except that the outer tube 18A shown in FIG. 1 was not provided and the ultraviolet decomposition reaction treatment was not performed.

  The results are shown in Table 1. In Table 1, the number of passes is the total number of passes.

  It can be seen that the wastewater treatment apparatus according to the present invention exhibits excellent organic matter decomposition performance, and further exhibits extremely efficient decomposition performance by adding an oxidizing agent.

12 First fluid tank (fluid tank)
14 Photocatalyst cartridge (photocatalyst fiber)
16 UV irradiation lamp (UV irradiation section)
18 Ultraviolet irradiation lamp accommodation part (ultraviolet irradiation part accommodation part)

Claims (15)

A fluid tank for flowing the water to be treated in one direction;
A photocatalyst fiber disposed in the fluidized tank so that water to be treated can pass therethrough,
An ultraviolet irradiation unit capable of irradiating ultraviolet rays; and
Provided in the fluidized tank, and capable of irradiating the photocatalyst fiber with ultraviolet rays, and equipped with an ultraviolet ray irradiation portion accommodating portion for accommodating the ultraviolet ray irradiation portion,
The ultraviolet irradiation unit storage unit is configured such that water to be treated can flow in the ultraviolet irradiation unit storage unit,
The waste water treatment apparatus is characterized in that the water to be treated is configured to be introduced into the fluidized tank after flowing in the ultraviolet irradiation part accommodating part.   The ultraviolet irradiating unit accommodating unit includes an inner tube that accommodates the ultraviolet irradiating unit and an outer tube that covers the inner tube, and is configured such that water to be treated flows between the inner tube and the outer tube. The waste water treatment apparatus according to claim 1. A first supply tank configured to be able to store the water to be treated and communicated with the ultraviolet irradiation unit housing part, and a second supply tank configured to be able to store the water to be treated and communicated with the fluid tank. ,
The water to be treated in the first supply tank is configured to be able to circulate in the first supply tank and the ultraviolet irradiation unit accommodating part,
The treated water in the second supply tank is configured to be able to circulate in the second supply tank and the fluidized tank, and is configured to be able to supply the treated water in the first supply tank into the second supply tank. The waste water treatment apparatus according to claim 1 or 2.   4. The waste water treatment apparatus according to claim 3, wherein at least one of the first supply tank and the second supply tank is provided with an oxidant addition means.   The wastewater treatment apparatus according to claim 4, wherein the oxidizing agent adding means can add at least one of hydrogen peroxide, ozone, and sodium hypochlorite.   The waste water treatment apparatus according to any one of claims 2 to 5, wherein the inner tube is capable of transmitting wavelengths of 180 to 190 nm and 250 to 260 nm by 90% or more.   The waste water treatment apparatus according to any one of claims 2 to 6, wherein the outer tube can transmit wavelengths of 180 to 190 nm and 250 to 260 nm by 90% or more.   The wastewater treatment apparatus according to any one of claims 2 to 7, wherein the ultraviolet irradiation unit includes an ultraviolet irradiation lamp in the inner tube.   The wastewater treatment apparatus according to claim 8, wherein the ultraviolet irradiation lamp can irradiate ultraviolet rays having peak wavelengths of 180 to 190 nm and 250 to 260 nm.   The waste water treatment apparatus according to any one of claims 2 to 9, wherein the radial interval between the inner pipe and the outer pipe is 1 to 10 mm.   The wastewater treatment apparatus according to any one of claims 1 to 10, wherein the photocatalyst fiber is a non-woven fabric of photocatalyst fiber having titanium oxide on its surface.   The nonwoven fabric of photocatalyst fibers is a flat nonwoven fabric formed in a flat plate shape, and the flat nonwoven fabric is arranged so that its surface intersects the flow direction of drainage. Wastewater treatment equipment.   The photocatalyst fiber is composed of a composite oxide fiber of an oxide phase (first phase) mainly composed of a silica component and a metal compound phase (second phase) containing Ti, and is a metal oxide constituting the second phase. The waste water treatment apparatus according to any one of claims 1 to 12, wherein the waste water treatment apparatus is a silica-based composite oxide fiber in which an existing ratio of Ti increases in a slope toward the surface layer of the fiber.   On the surface of the photocatalytic fiber, platinum (Pt), palladium (Pd), ruthenium (Ru), rhodium (Rh), gold (Au), silver (Ag), copper (Cu), iron (Fe), nickel (Ni) 14. At least one metal among zinc, zinc (Zn), gallium (Ga), germanium (Ge), indium (In), and tin (Sn) is supported. Wastewater treatment equipment. In a fluidized tank having a photocatalyst fiber through which treated water can pass, an ultraviolet irradiation unit capable of irradiating ultraviolet rays, and an ultraviolet irradiation unit accommodating unit that accommodates the ultraviolet irradiation unit and allows the treated water to flow inside A wastewater treatment method for oxidizing and decomposing organic substances contained in the water to be treated,
An ultraviolet decomposition reaction step in which the water to be treated flows through the ultraviolet irradiation unit accommodating portion in a state where the ultraviolet rays are irradiated from the ultraviolet irradiation unit to the water to be treated;
A photocatalytic decomposition reaction step in which water to be treated that has flowed in the ultraviolet irradiation unit housing portion passes between the photocatalytic fibers in a state in which the photocatalytic fiber is irradiated with ultraviolet rays from the ultraviolet irradiation unit. Wastewater treatment method.

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