JP2009101302A - Promoted oxidation process - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize a promoted oxidation process which can perform a desired promoted oxidation treatment with high efficiency without enlarging an ozone generator by obtaining high-concentration ozone-dissolved water. <P>SOLUTION: A part of treated water treated by an ultraviolet irradiation device 5 is supplied to a gas dissolving membrane module 2. Ozone gas generated from the ozone generator 1 is supplied to the gas dissolving membrane module 2 so that the ozone gas flows counter to the direction of the treated water. A gas dissolving membrane is pressurized from a gas phase side to diffuse the ozone gas into the gas dissolving membrane, thereby completely dissolving the ozone gas in the treated water to generate high-concentration ozone-dissolved water. Subsequently the ozone-dissolved water carried by an ozone-dissolved water carrier pipe 14 is injected into raw water to be supplied to the ultraviolet irradiation device. In the ultraviolet irradiation device 5, the ozone-dissolved water-containing raw water is irradiated with ultraviolet rays, thereby oxidatively decomposing hardly decomposable substances contained in the raw water to remove them. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an accelerated oxidation treatment method, and more particularly to an accelerated oxidation treatment method using ozone as an oxidizing agent.

Conventionally, in the field of water treatment technology, the strong oxidizing power of ozone (O ₃ ) is used to oxidize and decompose dyes and humic colored components contained in well water and factory wastewater, and to remove odor components. Deodorization is carried out by oxidative decomposition.

  However, such ozone-only treatment using only the oxidizing power of ozone is still insufficient in oxidizing power to remove refractory substances such as organic chlorine compounds and ammonia nitrogen.

  Therefore, in recent years, research and development of an advanced oxidation process (AOP: Advanced Oxidation Process) in which a specific oxidizing agent and ultraviolet rays are used in combination have been actively conducted.

This accelerated oxidation treatment method is more powerful than ozone by irradiating a specific oxidizing agent such as ozone (O ₃ ), hydrogen peroxide (H ₂ O ₂ ), sodium hypochlorite (NaClO) with ultraviolet rays. Hydroxyl radical (.HO) having a sufficient oxidizing power is generated, and thereby it is possible to oxidatively decompose and remove the hardly decomposable harmful substances contained in the wastewater.

  That is, ozone is known to have a higher standard oxidation-reduction potential than hydrogen peroxide and sodium hypochlorite and has a strong oxidizing power, but the standard oxidation-reduction potential of the hydroxyl radical is 2.80 V. Yes, it is higher than the standard oxidation-reduction potential (2.07 V) of ozone, and therefore has higher oxidizing power than ozone.

  Since the hydroxy radical has a strong oxidizing power in this way, a single bond (C—C, N—H, etc.) binder that strongly binds organic chlorine compounds such as trichlorethylene and trihalomethane and ammonia nitrogen is formed. It can be cleaved, and it becomes possible to oxidize and decompose a hardly decomposable harmful substance into a harmless substance.

  Among the specific oxidants mentioned above, hydrogen peroxide and sodium hypochlorite are easy to handle because they are liquid at room temperature and normal pressure, but the quantum efficiency of generating hydroxyl radicals when irradiated with ultraviolet light is higher than that of ozone. Has the disadvantage of being low. Therefore, considering quantum efficiency, it is considered preferable to use ozone as the oxidizing agent.

  In recent years, various accelerated oxidation methods using ozone as an oxidizing agent have been proposed.

  For example, in Patent Document 1, as shown in FIG. 6 attached to the present specification, a reaction tower 103 having an ultraviolet lamp 101 having a wavelength of 254 nm and an air diffuser 102, and an ozone generator 104 that generates ozone are included. The ozone generated in the ozone generator 104 can be blown into the water to be treated 105 through the air diffuser 102, and the circulation line 106 of the water to be treated 102 is connected to the reaction tower 103. There has been proposed a water treatment apparatus provided with an ultraviolet treatment tower 107 having an ultraviolet lamp with a wavelength of 185 nm.

  In Patent Document 1, accelerated oxidation treatment is performed by blowing ozone into the water to be treated 105 supplied to the reaction tower 103 by a method called an aeration method. Furthermore, in Patent Document 1, the water to be treated that passes through the circulation line 106 is irradiated with an ultraviolet lamp of the ultraviolet treatment tower 107 to convert dissolved oxygen into ozone, and ozone is supplied to the reaction tower 103 via the pump 108. ing. This ozone can also generate hydroxy radicals, thereby increasing the amount of hydroxy radicals generated and improving the efficiency of the accelerated oxidation treatment. Residual ozone that has not reacted to ultraviolet rays in the reaction tower 103 is decomposed by the ozone killer 109 and released into the atmosphere as oxygen.

  Further, in Patent Document 2, as shown in FIG. 7 attached to the present specification, a storage tank 111, an ejector 113 that sucks ozone from the ozone generator 112, and an ultraviolet irradiation tank 114 are provided in this order. A circulation channel 115 is provided, and the storage tank 111 is treated water containing a hardly decomposable organic substance from the raw water supply line 116 and treated water drawn from the storage tank 111 to the circulation channel 115 and returned to the storage tank 111 again. An accelerated oxidation treatment apparatus having a circulating water storage unit 117 for storing and a treated water storage unit 118 for storing surplus treated water from the circulating water storage unit 117 has been proposed.

  In this patent document 2, an ozone gas from the ozone generator 112 is added to the water to be treated by a method called an ejector method, and the accelerated oxidation treatment is performed by irradiating the ozone-added water with ultraviolet rays.

Japanese Patent Laying-Open No. 2002-210479 (FIG. 2) Japanese Patent Laying-Open No. 2003-340472 (FIG. 1)

  However, in Patent Document 1, ozone gas from the ozone generator 104 is diffused into the water to be treated via the air diffuser 102. However, in such a method, ozone gas is efficiently introduced into the water to be treated. It cannot be dissolved, and most ozone is dispersed in the form of large bubbles in water. Therefore, even when ultraviolet rays are irradiated from the ultraviolet lamp 101, the transmittance of ultraviolet rays is low, and thus the generation efficiency of hydroxy radicals is also low. As a result, in order to perform the desired accelerated oxidation treatment, a large amount of ozone is required, which may cause an increase in the size of the ozone generator. Moreover, in patent document 1, although the to-be-processed water which passes the circulation line 106 is irradiated with an ultraviolet lamp, and dissolved oxygen is converted into ozone, since the dissolution efficiency in the water of ozone itself is low in the first place, it is simple. An efficient accelerated oxidation treatment cannot be performed.

  In addition, since Patent Document 2 adds ozone gas from the ozone generator 112 to the water to be treated by the ejector 113, similarly to Patent Document 1, the ozone gas cannot be dissolved in the water to be treated with high efficiency. Most ozone is dispersed in water in the form of large bubbles. That is, as in Patent Document 1, even when ultraviolet rays are irradiated from the ultraviolet lamp 101, the transmittance of the ultraviolet rays is low. Therefore, a large amount of ozone is required to perform the desired accelerated oxidation treatment, and the accelerated oxidation treatment is efficient. There was a problem that it could not be done well.

  As another method of mixing ozone and water, a pump agitation method in which ozone is agitated in water using a pump is also known, but ozone gas is treated in the water to be treated in substantially the same manner as the air diffusion method and the ejector method. In other words, a large amount of ozone is required to perform the desired accelerated oxidation treatment, which may increase the size of the ozone generator.

  The present invention has been made in view of such circumstances. By obtaining high-concentration ozone-dissolved water, it is possible to perform a desired accelerated oxidation treatment with high efficiency without increasing the size of the ozone generator. It is an object to provide an accelerated oxidation treatment method that can be used.

  In order to achieve the above object, the accelerated oxidation treatment method according to the present invention treats ozone gas with a gas-dissolved film in water to dissolve the ozone gas, thereby generating high-concentration ozone-dissolved water. After being injected into the water to be treated, ultraviolet rays are irradiated to oxidize and decompose the hardly decomposable substance contained in the water to be treated.

  The accelerated oxidation treatment method of the present invention is characterized in that the gas-dissolved film has a non-porous shape through which ozone molecules diffuse and permeate.

  Furthermore, the accelerated oxidation treatment method of the present invention is characterized in that the gas-dissolved film has a porous shape capable of generating microbubbles.

  The accelerated oxidation treatment method of the present invention is characterized in that in addition to the ozone-dissolved water, at least one of sodium hypochlorite and hydrogen peroxide is injected into the treated water and irradiated with ultraviolet rays. .

  Moreover, the accelerated oxidation treatment method of the present invention is characterized in that an excess ozone gas that has not been treated with the gas-dissolved film is decomposed with the ultraviolet rays.

  According to the above accelerated oxidation treatment method, when the gas-dissolved film has a non-porous shape, ozone molecules pass through the gas-dissolved film while diffusing. Concentrated ozone-dissolved water can be generated. Therefore, when this ozone-dissolved water is poured into the water to be treated and irradiated with ultraviolet rays, hydroxy radicals (.OH) having a strong oxidizing power can be generated with high efficiency. Thus, it is possible to efficiently promote oxidative decomposition of the hardly decomposable substance contained in the water to be treated without requiring a large amount of ozone.

  In addition, when the gas-dissolved film has a porous shape, microbubbles may be generated, but in this case as well, ozone gas does not disperse in the form of large bubbles in water, and ozone molecules Can pass through the pores of the gas-dissolving membrane to produce high concentration ozone-dissolved water. And like this, when this ozone-dissolved water is poured into the water to be treated and irradiated with ultraviolet rays, hydroxy radicals (.OH) having a strong oxidizing power can be generated with high efficiency. Thus, it is possible to efficiently promote oxidative decomposition of the hardly decomposable substance contained in the water to be treated without requiring a large amount of ozone.

  As described above, according to the accelerated oxidation treatment method of the present invention, a high-concentration ozone-dissolved water can be obtained, so that the generation efficiency of hydroxy radicals is high, and even an ozone generator having a relatively small processing capacity is desired. An accelerated oxidation treatment can be performed.

  In addition to the ozone-dissolved water, at least one of sodium hypochlorite and hydrogen peroxide is injected into the water to be treated and irradiated with ultraviolet rays, so that the hardly decomposable substance is oxidized more effectively. It becomes possible to disassemble and remove. That is, in addition to ozone-dissolved water, sodium hypochlorite and hydrogen peroxide are used in combination with ultraviolet rays, so that the concentration of organic carbon (TOC) is high or the concentration of refractory substances such as trichlorethylene and ammonia nitrogen is high. Even in the case where it is high, it is possible to construct a system capable of executing the accelerated oxidation treatment without increasing the size of the apparatus.

  Moreover, since the surplus ozone gas that has not been treated with the gas-dissolved film is decomposed with the ultraviolet rays, it is not necessary to separately provide waste ozone treatment, and it is possible to avoid as much as possible the increase in scale of the treatment system. .

  Next, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a schematic system configuration diagram showing an embodiment (first embodiment) of an accelerated oxidation treatment system using the accelerated oxidation treatment method according to the present invention.

  This accelerated oxidation treatment system includes an ozone generator 1 that generates ozone gas by silent discharge or the like, an ozone gas dissolving device 3 in which a gas dissolving film module 2 that dissolves ozone gas in water, and an ultraviolet lamp (absorption wavelength: 253. 7 nm) 4 is disposed as a main part.

  The ozone generator 1 and the gas dissolution membrane module 2 are connected via a gas supply pipe 6 so that the ozone gas generated by the ozone generator 1 can be supplied to the gas dissolution membrane module 2.

  A raw water supply pipe 7 is connected to the ultraviolet irradiation device 5, and an in-line mixer 8 is interposed in the pipe of the raw water supply pipe 7. In addition, a treated water transport pipe 9 is connected to the ultraviolet irradiation device 5, and the treated water transport pipe 9 is connected to a branch pipe 11 having a control valve 10 interposed at a point a in the pipeline. Further, the branch pipe 11 is connected to the gas dissolving membrane module 2. Thus, part or all of the treated water treated by the ultraviolet irradiation device 5 can be supplied to the gas-dissolving membrane module 2 via the treated water transport pipe 9 and the branch pipe 11. The treated water transport pipe 9 is provided with a pre-filter 12 at an appropriate position upstream from the point a, and it is possible to remove suspended substances (SS) that can be contained in the treated water from the ultraviolet irradiation device 5. ing. Further, a control valve 13 is interposed downstream of the branch point a of the treated water transport pipe 9 and a control valve is provided so that a reducing agent that reduces residual ozone in the treated water can be injected into the treated water. A reducing agent injection device 17 is disposed at an appropriate position downstream of 13.

  The reducing agent contained in the reducing agent injection device 17 is not particularly limited as long as the residual ozone contained in the treated water can be reduced to oxygen, but sodium bisulfite is preferably used. can do.

  The raw water supply pipe 7 is connected to the ozone-dissolved water transport pipe 14 connected to the gas-dissolving membrane module 2 at a point b on the upstream side of the in-line mixer 8, and the ultraviolet light of the ozone-dissolved water dissolved in the gas-dissolving membrane module 2 is used. Supply to the irradiation apparatus 5 is enabled.

  Further, the ultraviolet irradiation device 5 and the gas dissolving membrane module 2 are connected via an exhaust ozone transport pipe 15, and surplus ozone gas that has not been dissolved by the gas dissolving membrane module 2 can be supplied to the ultraviolet irradiation device 5. .

  An oxidizer injection device 16 is disposed upstream of the point b of the raw water supply pipe 7 so as to be able to inject the raw water. Here, at least one of sodium hypochlorite and hydrogen peroxide is used as the oxidant contained in the oxidant injection device 16. By using such an oxidant in combination with ozone, it is possible to generate a large amount of hydroxy radicals having a strong oxidizing action, such as when the concentration of organic carbon in the wastewater is particularly high, trichloroethylene ammonia nitrogen, etc. Even when the concentration of the hardly decomposable substance is particularly high, these hardly decomposable substances can be effectively oxidized and decomposed, and COD and the like can be reduced.

  FIG. 2 is a partially broken front view of the gas dissolution membrane module 2.

  The gas-dissolving membrane module 2 has a gas-dissolving membrane 19 built in a vessel 18 formed in a cylindrical shape, and has an ozone gas inlet 20 at its bottom surface and a larger diameter than the ozone gas inlet 20. The ozone-dissolved water discharge port 21 is provided, and the ozone gas discharge port 22 and the treated water supply port 23 are provided on the upper surface of the ozone-dissolved water discharge port 21 so as to face the ozone gas introduction port 20 and the ozone-dissolved water discharge port 21, respectively. Yes.

  The gas-dissolving film 19 is made of a fluororesin such as PTFE (polytetrafluoroethylene), has substantially no pores, and has a non-porous shape having a uniform cross section.

  In the gas dissolution membrane module 2 thus formed, the treated water from the ultraviolet irradiation device 5 is supplied from the treated water supply port 23 to the vessel 18 through the treated water transport pipe 9 and the branch pipe 11. On the other hand, ozone gas from the ozone generator 1 is supplied from the ozone gas inlet 20 to the vessel 18 through the ozone gas supply pipe 6. As the gas-dissolving membrane module 2, for example, an ozone gas permeation module such as “Infuser” manufactured by Pall Corporation can be used.

  FIG. 3 is an enlarged schematic view of a portion X in FIG.

  That is, as shown in FIG. 3, when a pressure of a predetermined pressure (for example, 0.2 MPa) is applied from the gas phase side through which ozone gas passes and the liquid phase side through which treated water passes is atmospheric pressure, 24 diffuses in the gas-dissolving film 19 and is completely dissolved in the treated water, becomes ozone-dissolved water 25, and is discharged from the ozone-dissolved water discharge port 21 to the ozone-dissolved water supply pipe 14.

  In this way, the ozone gas and the treated water are supplied to the vessel 18 so as to face each other. The ozone molecules 24 diffuse in the gas-dissolving film 19 and come into contact with the treated water, so that the ozone molecules 24 are completely dissolved in the treated water. Is generated.

  Of the ozone gas supplied to the vessel 18, excess ozone gas that has not diffused through the gas dissolution film 19 is discharged from the ozone gas discharge port 22 to the exhaust ozone transport pipe 15.

  Next, an operation method of the accelerated oxidation treatment system will be described with reference to FIG.

  First, raw water into which an appropriate amount of oxidizing agent has been injected by the oxidizing agent injection device 16 is supplied to the ultraviolet irradiation device 5 through the raw water supply pipe 7. Here, as raw water, wastewater or irrigation water that has been pretreated can be used. For example, wastewater subjected to membrane separation activated sludge treatment, ultrafiltration treatment, sand filtration treatment, or treated water subjected to iron removal and manganese removal treatment can be used as raw water.

  As the oxidant, as described above, at least one of sodium hypochlorite and hydrogen peroxide that can generate hydroxy radicals (.OH) by irradiation of the ultraviolet irradiation device 5 is used.

  When the raw water containing the oxidant is supplied to the ultraviolet irradiation device 5, the ultraviolet lamp 4 is irradiated to the oxidant-containing raw water. When the oxidizing agent is sodium hypochlorite, a hydroxyl radical is generated according to chemical reaction formulas (1) and (2). When hydrogen peroxide is used, a hydroxy radical is generated according to chemical reaction formula (3).

  And the impurity in raw | natural water is oxidatively decomposed | disassembled by the oxidizing power of this hydroxyl radical, and treated water is produced | generated.

  Next, the treated water is discharged to the treated water transport pipe 9 and the suspended matter is removed by the prefilter 12. When the control valve 13 is closed and the control valve 10 is opened, the treated water passes through the branch pipe 11 and is supplied to the gas dissolution membrane module 2. In addition, the opening degree of the control valve 10 is adjusted so that the supply amount of the treated water to the gas dissolution membrane module 2 becomes a predetermined flow rate (for example, 60 L / min).

On the other hand, ozone gas having a predetermined concentration (for example, 100 g / Nm) is generated in the ozone generator 1 by means such as silent discharge. The ozone gas generated by the ozone generator 1 is supplied to the gas dissolution membrane module 2 at a predetermined flow rate (for example, 8.3 NL / min). The ozone gas is pressurized at a predetermined pressure (for example, 0.2 MPa), diffuses through the gas-dissolved film 19 and is completely dissolved in the treated water, and becomes high-concentration ozone-dissolved water 25 (for example, 8 g / m ³ ). Then, ozone-dissolved water 25 at a predetermined flow rate (for example, 3.6 m ³ / h) is injected into the raw water supply pipe 7 through the ozone-dissolved water supply pipe 14 and supplied to the ultraviolet irradiation device 5 through the in-line mixer 8. Is done.

  In the ultraviolet irradiation device 5, the ozone-dissolved water 25 undergoes a decomposition reaction of ozone as shown in the reaction formula (4) in addition to the chemical reaction formulas (1) to (3) to generate hydroxy radicals.

  On the other hand, surplus ozone gas that has not diffused into the gas-dissolved film 18 is diffused into the ultraviolet irradiation device 5 through the exhaust ozone transport pipe 15 and decomposed into oxygen by the ultraviolet rays from the ultraviolet lamp 4.

  And after that, the opening degree of the control valve 10 and the control valve 13 is adjusted, and part of the treated water oxidized and decomposed by the ultraviolet irradiation device 5 is supplied to the gas dissolution membrane module 2 to generate ozone dissolved water 25. The other treated water that has not been supplied to the gas-dissolving membrane module 2 is supplied with a reducing agent from the reducing agent injection device 17 and the residual ozone is reduced and decomposed into oxygen. Tower, boiler, etc.).

  As described above, part of the treated water discharged from the ultraviolet irradiation device 5 circulates in the gas-dissolved membrane module 2 and the ozone-dissolved water transport pipe 14 and is supplied to generate ozone-dissolved water 25. It becomes.

  As described above, in the present embodiment, the above-described hydroxy radical generated by irradiating sodium hypochlorite and / or hydrogen peroxide with ultraviolet rays and the hydroxy radical generated by irradiating ozone with ultraviolet rays are used in combination. As a result, a strong oxidizing action is promoted, whereby the raw water, that is, an organic chlorine compound contained in the water to be treated and a hardly decomposable substance such as ammonia nitrogen are oxidatively decomposed.

  That is, according to the present embodiment, not only decolorization, deodorization, and inactivation of microorganisms, but also persistent decomposition of ammonia nitrogen, organic chlorine compounds such as trichloroethylene, tetrachloroethylene, 1,2-cis-dichloroethylene, and trihalomethane. The oxidative decomposition of the active substance can be performed, and COD and the like can be suppressed.

  Moreover, the ozone gas is completely dissolved without generating bubbles by the non-porous gas-dissolving film 19 to generate the high-concentration ozone-dissolved water 25, so that the ultraviolet light transmittance is high and the hydroxyl radical is highly efficient. Thus, the ozone generator 1 can be downsized.

  Further, excess ozone gas that has not diffused into the gas dissolution film 19 due to exceeding the solubility of ozone in water passes through the exhaust ozone transport pipe 15 and is collected in the ultraviolet irradiation device 5 and decomposed into oxygen by ultraviolet irradiation. In addition, it is not necessary to separately provide an exhaust ozone treatment device, and the system can be simplified.

  FIG. 4 is a schematic system configuration diagram showing a second embodiment of an accelerated oxidation treatment system using the accelerated oxidation treatment method of the present invention. In the second embodiment, ozone gas is completely dissolved in raw water. I am letting.

  That is, in the second embodiment, the raw water supply pipe 7 is connected to the raw water branch pipe 26 at the point c, and the raw water branch pipe 26 is connected to the gas module 2. In addition, a control valve 27 and a pre-filter 28 are sequentially interposed in the raw water branch pipe 26.

  Further, the treated water transport pipe 30 is connected to the ultraviolet irradiation device 5 and an activated carbon adsorbing device 29 is provided instead of the reducing agent injection device of the first embodiment.

  In the second embodiment, when the control valve 27 is opened, a part of the raw water into which an appropriate amount of oxidant has been injected by the oxidant injection device 16 is removed after the suspended matter is removed by the prefilter 28. It is supplied to the gas-dissolving membrane module 2 at a flow rate (for example, 60 L / min). Here, as the raw water, wastewater and effluent pretreated in advance can be used as in the first embodiment. For example, membrane separation activated sludge treatment, ultrafiltration treatment, sand filtration treatment, and the like can be used. The treated water that has been subjected to the drainage and the iron removal and manganese removal treatment can be used as raw water.

  In the gas-dissolving membrane module 2, as in the first embodiment, ozone gas is dissolved in the gas-dissolving membrane using the ozone gas from the ozone generator 1 and the raw water as counterflows to generate ozone-dissolved water 25, and the point b The ozone-dissolved water 25 is injected into the raw water.

  The raw water into which the oxidizing agent and ozone-dissolved water 25 from the oxidizing agent injection device 16 are injected is supplied to the ultraviolet irradiation device 5 through the in-line mixer 8. In the ultraviolet irradiation device 5, sodium hypochlorite, hydrogen peroxide, and ozone-dissolved water contained in the raw water are irradiated with ultraviolet rays to generate hydroxy radicals as shown in the chemical reaction formulas (1) to (4). .

  As a result, raw water, that is, a hardly decomposable substance such as an organic chlorine compound and ammonia nitrogen contained in the water to be treated is oxidatively decomposed to produce treated water.

  Then, the treated water treated by the ultraviolet irradiation device 5 is transported by the treated water transport pipe 30, the residual ozone is adsorbed and removed by the activated carbon of the activated carbon adsorbing device 29, and supplied to an external device such as a cooling tower or a boiler. The

  The excess ozone gas that has not diffused into the gas-dissolved film 19 is diffused into the ultraviolet irradiation device 5 through the exhausted ozone transport pipe 15 as in the first embodiment, and is absorbed by the ultraviolet rays from the ultraviolet lamp 4. Decomposed into oxygen. As a result, it is not necessary to separately provide an exhaust ozone treatment device.

  As described above, in the second embodiment as well, as in the first embodiment, ozone gas is completely dissolved in the non-porous gas-dissolving film 19 without generating bubbles. Water 25 can be obtained, and therefore, the transmittance of ultraviolet rays is high, and the ozone generator 1 can be downsized.

  And by using together the hydroxy radical produced | generated by irradiating sodium hypochlorite and / or hydrogen peroxide with ultraviolet rays, and the hydroxy radical produced | generated by irradiating ozone with ultraviolet rays, 1st Embodiment and Similarly, strong oxidative action is promoted, thereby not only decolorization, deodorization and inactivation of microorganisms, but also ammonia nitrogen, organochlorine compounds such as trichloroethylene, tetrachloroethylene, 1,2-cis-dichloroethylene, trihalomethane, etc. It is possible to oxidize and decompose hardly decomposable substances, and to suppress COD and the like.

  The present invention is not limited to the above embodiment. In the first and second embodiments, a gas-dissolving film having a non-porous shape as shown in FIG. 3 is used, but a porous gas-dissolving film 31 as shown in FIG. 5 is used. May be.

  That is, by setting the atmospheric pressure on the liquid phase side through which water passes and pressurizing a predetermined pressure (for example, about 0.2 MPa) from the gas phase side through which ozone gas passes, The ozone-dissolved water 32 is obtained by passing through and dissolving in water with generation of microbubbles.

  Even when the porous gas-dissolving film 31 is used in this way, ozone gas and water come into contact with each other through the gas-dissolving film 31, and the ozone gas is dissolved in water. Unlike the aeration method or the pump agitation method, high-concentration ozone-dissolved water 32 that reacts with ultraviolet irradiation with high efficiency can be obtained without being dispersed in the form of large bubbles in water.

  In each of the above embodiments, sodium hypochlorite or / and hydrogen peroxide are used in combination with ozone-dissolved water. Depending on the quality of the raw water, sodium hypochlorite or / and hydrogen peroxide is injected. Can be omitted. In the present invention, since hydroxyl radicals can be generated from ozone gas with high efficiency, for example, when the concentration of organic carbon is low, the concentration of a specific chlorine compound such as trichloroethylene is low, the concentration of ammonia is low, etc. It is possible to perform a desired accelerated oxidation treatment only by the combination of the above.

1 is a schematic system configuration diagram showing an embodiment (first embodiment) of an accelerated oxidation treatment system using an accelerated oxidation treatment method according to the present invention. 3 is a partially cutaway front view of the gas-dissolving membrane module 2. FIG. It is the schematic diagram which expanded the X section of FIG. It is a schematic system block diagram which shows 2nd Embodiment of the promotion oxidation processing system using the promotion oxidation processing method which concerns on this invention. It is the expanded sectional view showing typically other embodiments of a gas dissolution film. It is a schematic diagram of the prior art described in patent document 1. FIG. It is a schematic diagram of the prior art described in patent document 2. FIG.

Explanation of symbols

4 UV Lamp 19 Gas Dissolved Film 25 Ozone Dissolved Water 31 Gas Dissolved Film 32 Ozone Dissolved Water

Claims (5)

  Ozone gas is treated with a gas-dissolving film in water to dissolve the ozone gas, producing high-concentration ozone-dissolved water, injecting the ozone-dissolved water into the treated water, irradiating with ultraviolet rays, An accelerated oxidation method characterized by oxidatively decomposing a hardly decomposable substance contained therein.   The accelerated oxidation treatment method according to claim 1, wherein the gas-dissolved film has a non-porous shape through which ozone molecules diffuse and permeate.   The accelerated oxidation treatment method according to claim 1, wherein the gas-dissolved film has a porous shape capable of generating microbubbles.   4. In addition to the ozone-dissolved water, at least one of sodium hypochlorite and hydrogen peroxide is injected into the water to be treated and irradiated with ultraviolet rays. The accelerated oxidation treatment method according to crab.   The accelerated oxidation treatment method according to any one of claims 1 to 4, wherein an excess ozone gas that has not been treated with the gas-dissolved film is decomposed with the ultraviolet rays.

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