JP2006158986A - Water treatment method and device using ultraviolet light with ozone - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a water treatment device using ultraviolet light with ozone which enables the compactification of a system and can decompose hardly decomposable organic substances and the like while suppressing a water treatment cost. <P>SOLUTION: The water treatment device using ultraviolet light with ozone comprises an outer vessel 2 for water treatment, an inner vessel 3 disposed in the outer vessel 2, an ultraviolet lamp 6 disposed in the inner vessel 3, a suction pipe 7 of which one end communicates with and is connected to a space 4 for ozone generation between the inner vessel and the ultraviolet lamp, and of which the other end communicates with and is connected to a space 5 for passing water between the outer and inner vessels, and an air feeder 8 for supplying a gas in the suction pipe 7 toward the space 5 side for passing water from the space 4 side for ozone generation. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a water treatment method and a water treatment apparatus for decomposing organic substances contained in water such as domestic wastewater and industrial wastewater using ultraviolet light and ozone.

  In recent years, with the advancement of products in the chemical manufacturing industry, etc., the number of persistent organic substances that cannot be completely removed by conventional biological treatment or coagulation sedimentation treatment has increased, and factory wastewater has not been sufficiently purified. It is increasingly being discharged into the environment. While the demand for advanced treatment of wastewater is rapidly increasing against this situation, technological development of water treatment methods using ultraviolet light, ozone, and substances with strong oxidizing power (titanium oxide, hydrogen peroxide, etc.) Among them, an advanced oxidation process combining ultraviolet treatment and ozone treatment (Advanced Oxidation Process) is attracting attention.

For example, after ozone is dissolved in the water to be treated, the water to be treated is irradiated with ultraviolet rays to generate radical species (hydroxy radicals, etc.) that have stronger oxidizing power than ozone, thereby decomposing refractory organic substances. Various processing methods have been proposed (see Patent Documents 1 to 4). In any of these methods, although there is a difference in effect, it is possible to perform the decomposition treatment of the hardly decomposable organic substance in the water to be treated.
JP 2004-275969 A JP 2003-266088 A JP 2002-153891 A JP 2000-51875 A

  However, in each of the water treatment devices described in Patent Documents 1 to 4, ozone is generated using an ozone generator (ozonizer), but this ozone generator is a large-sized device. Since it is expensive, the water treatment devices of Patent Documents 1 to 4 have difficulty in achieving downsizing, and there is a problem that the cost of water treatment increases due to high equipment costs.

  This invention has been made in view of such a technical background, and it is possible to decompose a hardly decomposable organic substance or the like while reducing the cost of water treatment while reducing the size of equipment. Provided are a water treatment method and a water treatment apparatus using both ultraviolet light and ozone.

  In order to achieve the above object, the present invention provides the following means.

[1] In a water treatment method for decomposing an organic substance or the like contained in water to be treated by irradiating the water to be treated with ozone with ultraviolet light from an ultraviolet lamp,
A water treatment method using ultraviolet light and ozone in combination, wherein as the added ozone, ozone generated by irradiating oxygen present around the ultraviolet lamp with ultraviolet light from the lamp is used.

  [2] A water treatment outer tub, an inner tub disposed inside the outer tub, an ultraviolet lamp disposed in the inner tub, and one end for generating ozone between the inner tub and the ultraviolet lamp An intake pipe connected to the space and having the other end connected to a water passage space between the outer tank and the inner tank, and a gas in the intake pipe from the ozone generation space side to the water passage side A water treatment device using ultraviolet light and ozone in combination, comprising an air supply device for supplying air.

  [3] An outer tub for water treatment, an inner tub disposed in the outer tub, an ultraviolet lamp disposed in the inner tub, and one end for ozone generation between the inner tub and the ultraviolet lamp An intake pipe connected to the space and having the other end connected to a water passing space between the outer tub and the inner tub, and an aspirator attached to an intermediate position of the intake pipe. Water treatment equipment that uses both ultraviolet light and ozone.

  [4] The water treatment apparatus using both ultraviolet light and ozone according to item 3 above, wherein at least a part of the position from the aspirator to the water passage space in the intake pipe is formed in a spiral shape.

  [5] The water treatment apparatus using the ultraviolet light and ozone according to any one of the above items 2 to 4, wherein the outer tub is configured by a reflector that reflects ultraviolet light inward.

  [6] A water treatment apparatus using both ultraviolet light and ozone according to any one of items 2 to 4 above, wherein a reflector that reflects ultraviolet light is arranged on the inner side outside or inside the outer tank. .

  In the invention of [1], since ultraviolet light and ozone are used in combination to decompose organic substances contained in the water to be treated, not only easily decomposable organic substances but also hardly decomposable organic substances etc. Can also be decomposed. Furthermore, as ozone added to the water to be treated, ozone generated by irradiating ultraviolet light from the lamp to oxygen present around the ultraviolet lamp used to generate ultraviolet light is used. Since it is not necessary to provide a dedicated facility such as an ozone generator for generating ozone, the apparatus can be made compact and water treatment costs can be reduced.

  In the invention of [2], since the ultraviolet light from the ultraviolet lamp is irradiated to the water to be treated that passes through the water passage space between the outer tank and the inner tank, the organic substances and the like in the water to be treated are decomposed. . Moreover, the ozone generated by irradiating the ultraviolet light from the lamp to the oxygen in the ozone generating space between the inner tank and the ultraviolet lamp is generated between the outer tank and the inner tank by the air supply device via the intake pipe. It is sent to the space for water flow. In this water flow space, organic substances, etc. in the water to be treated are decomposed by the action of ozone, and a part of this ozone is a radical species (hydroxy radical, etc.) that has strong oxidizing power when irradiated with ultraviolet light from the lamp. Thus, the radical species also decomposes the hardly decomposable organic substance in the water to be treated. In this water treatment apparatus, it is not necessary to provide a dedicated facility such as an ozone generation apparatus separately for generating ozone, so that the apparatus can be made compact and water treatment costs can be reduced.

  In the invention of [3], since the ultraviolet light from the ultraviolet lamp is irradiated to the water to be treated that passes through the water passage space between the outer tank and the inner tank, the organic substances in the water to be treated are decomposed. . In addition, the ozone generated by irradiating the ultraviolet light from the lamp to the oxygen in the ozone generation space between the inner tank and the ultraviolet lamp is sucked by the reduced pressure generated when the water to be treated passes through the aspirator. Due to the action, the air is sent to the water passing space between the outer tank and the inner tank via the intake pipe. In this water flow space, organic substances, etc. in the water to be treated are decomposed by the action of ozone, and a part of this ozone is a radical species (hydroxy radical, etc.) that has strong oxidizing power when irradiated with ultraviolet light from the lamp. Thus, the radical species also decomposes the hardly decomposable organic substance in the water to be treated. In this water treatment apparatus, it is not necessary to provide a dedicated facility such as an ozone generation apparatus separately for generating ozone, so that the apparatus can be made compact and water treatment costs can be reduced. In addition, the ozone generated in the ozone generation space can be supplied to the water flow space by using a simple aspirator, and there is no need for a separate dedicated facility, making the entire device more compact. There are advantages you can do.

  In the invention of [4], since at least a part of the position from the aspirator to the water flow space in the intake pipe is formed in a spiral shape, when the treated water and ozone pass through the spiral portion, The treated water and ozone are sufficiently mixed, and the ozone is sufficiently dissolved in the treated water, so that there is an advantage that the decomposition action can be further improved.

  In the invention of [5], since the outer tub is composed of a reflecting plate that reflects ultraviolet light toward the inner side, the ultraviolet light that has reached the outer tub is returned to the inner side without being released to the outside for reuse. This can further improve the decomposition efficiency of organic substances and the like.

  In the invention of [6], similarly to the invention of [5], the ultraviolet light that has reached the outer tub can be returned to the inner side without being released to be reused. Efficiency can be further improved.

  One Embodiment of the water treatment apparatus (1) which used together the ultraviolet light and ozone which concern on this invention is shown to FIGS. In these drawings, (2) is an outer tank for water treatment, (3) is an inner tank, (6) is an ultraviolet lamp, (7) is an intake pipe, and (8) is an aspirator.

  The water treatment outer tub (2) is formed of a transparent cylindrical body made of quartz glass, and an inner tub (3) is disposed inside the outer tub (2). It is formed of a transparent cylindrical body made of quartz glass. The inner diameter of the outer tub (2) is designed to be larger than the outer diameter of the inner tub (3), whereby a water passage space (5) is provided between the outer tub (2) and the inner tub (3). Is secured (see FIGS. 2 and 3). An upper lid (13) is joined to the upper ends of the outer tub (2) and the inner tub (3), while a bottom lid (14) is joined to the lower ends of the outer tub (2) and the inner tub (3). ) Is joined. A treated water delivery pipe (11) for delivering treated water is connected and fixed to the delivery port (22) of the upper lid (13). In the present embodiment, a cylindrical specular ultraviolet light reflector (not shown) that reflects ultraviolet light inward is laminated and integrated on the outer peripheral surface of the outer tub (2).

  An ultraviolet lamp (6) is disposed inside the inner tank (3), and an ozone generation space (4) is formed between the ultraviolet lamp (6) and the inner tank (3). (See FIGS. 2 and 3). In this embodiment, a low-pressure mercury lamp is used as the ultraviolet lamp (6). In FIG. 1, reference numeral (10) denotes a power supply unit of the ultraviolet lamp.

  One end of an intake pipe (7) is disposed in the ozone generation space (4). In the present embodiment, the one end of the intake pipe (7) is disposed so as to be lower than the bisected position of the height of the ozone generation space (4) (see FIGS. 1 and 3). The other end of the intake pipe (7) is connected and connected to the water flow space (5) by being connected and fixed to the introduction port (21) of the bottom cover part (14).

  Further, an aspirator (water flow pump) (8) is attached to a midway position of the intake pipe (7). And most of the position from the aspirator (8) to the water flow space (5) in the intake pipe (7) is spirally wound to constitute the intake spiral pipe part (7X). As shown in FIG. 1, the intake pipe (7) is connected to one of the three-way connection ports (upper connection port) of the aspirator (8), and the intake spiral tube (7X) is connected to the left end connection port. ) Is connected, and the water pipe (12) is connected to the remaining right end connection port. A water feeder (9) is attached to the water pipe (12), and the water to be treated is driven by the water feeder (9) into the water pipe (12), the aspirator (8), and the spiral pipe for intake air ( 7X), and sequentially passes through the inlet (21) of the bottom cover portion and is sent into the water passage space (5). Then, when the water to be treated passes through the aspirator (8), a reduced pressure is generated in the aspirator (8), and the gas in the pipe (7) from the intake pipe (7) is reduced by this pressure reduction. 7X), that is, ozone generated in the ozone generation space (4) is taken into the intake spiral tube portion (7X) via the intake pipe (7), and ozone is supplied to the water flow space (7X). 5) It will be sent in. In this embodiment, a pump is used as the water feeder (9). In FIG. 3, reference numeral (15) denotes an oxygen introduction opening. In this embodiment, the atmosphere (air) is taken into the ozone generation space (4) through the oxygen introduction opening (15). It is.

  Then, when the power supply unit (10) is turned on to turn on the ultraviolet lamp (6) and the water feeder (9) is driven to bring the water treatment device (1) into operation, the water to be treated is fed. The water pipe (12), the aspirator (8), the intake spiral pipe part (7X), and the inlet (21) of the bottom cover part (14) are passed through in this order to be sent into the water flow space (5). Further, the ozone generated in the ozone generating space (4) is reduced by the pressure reduction in the aspirator (8) generated when the water to be treated passes through the aspirator (8), that is, by the suction action, and the intake pipe (7). And is then taken into the aspirator (8) through which the ozone passes through the inlet spiral tube (7X) and the inlet (21) of the bottom lid (14) in order while being mixed with the water to be treated. And is sent into the water flow space (5). At this time, since the water to be treated and ozone are sufficiently mixed by passing through the intake spiral pipe portion (7X), the ozone is sufficiently dissolved in the water to be treated. In this way, the water to be treated in which ozone is sufficiently dissolved is sent into the water flow space (5).

  In the water flow space (5), since the ultraviolet light from the ultraviolet lamp (6) is irradiated to the water to be treated in which ozone is sufficiently dissolved, the organic substances in the water to be treated are decomposed. . In addition, organic substances in the water to be treated are decomposed by the action of ozone, and a part of the ozone is converted into radical species (hydroxy radicals, etc.) having strong oxidizing power by ultraviolet light irradiation from the ultraviolet lamp (6). The hardly decomposable organic substance in the water to be treated is also decomposed by the radical species. The treated water thus decomposed moves upward and is sent to the treated water delivery pipe (11) through the delivery port (22) of the upper lid part (13). The treated water sent out is not only easily decomposable organic substances, but also sufficiently degradable organic substances due to the action of ultraviolet light, the oxidizing action of ozone, and the oxidizing action of radical species generated by irradiation of ozone with ultraviolet light. It has been decomposed.

  According to the water treatment device (1), since it is not necessary to provide a dedicated facility such as an ozone generation device separately for generating ozone, the device (1) can be made compact and the water treatment cost can be reduced. can do.

  In addition, in the said embodiment, the structure which laminated | stacked and integrated the reflecting plate which reflects an ultraviolet light on the inner side is employ | adopted on the outer peripheral surface of the said outer tank (2), but such an ultraviolet light reflecting plate is used. You may employ | adopt the structure which does not provide. Further, when adopting a configuration in which an ultraviolet light reflection plate is provided, for example, a configuration in which a reflection plate that reflects ultraviolet light on the inner side is laminated and integrated on the inner peripheral surface of the outer tub (2) is adopted. Alternatively, the outer tub (2) itself may be composed of a reflector that reflects ultraviolet light inward.

  Moreover, in the said embodiment, the spiral pipe part (7X) for intake in which a part of position from the aspirator (8) in the intake pipe (7) to the water flow space (5) was formed in a spiral shape is provided. However, a configuration in which such a spiral tube portion is not particularly provided may be employed. However, at least a part of the position from the aspirator (8) to the water flow space (5) in the intake pipe (7) is spiral from the viewpoint of further dissolving ozone in the water to be treated and further improving the decomposition action. It is preferable to adopt the configuration formed in the above.

  Moreover, in the said embodiment, although the inner tank (3) is comprised with quartz glass, it is not specifically limited to such a material, It is a material (ultraviolet light transmissive material) which can permeate | transmit an ultraviolet light. Anything is acceptable. Moreover, the inner tank (3) may be made of a reflective material that partially reflects ultraviolet light inward. In this case, the ozone generation efficiency in the ozone generation space (4) is further improved. There are advantages that can be made. Alternatively, the inner tank (3) may be made of a material that transmits, for example, 50% of ultraviolet light and reflects the remaining 50% to the inner side.

  Further, in the embodiment, by attaching the aspirator (8) to the intake pipe (7), the water to be treated and ozone are sufficiently mixed in the intake spiral pipe section (7X), and this intake spiral pipe section ( 7X), both treated water and ozone (that is, treated water in which ozone is sufficiently dissolved) are sent to the water space (5). It is not limited to the configuration in which both ozone are supplied from the same pipe to the water passage space. For example, as shown in FIG. 6, an intake pipe having one end connected to the ozone generation space (4) ( 7) The other end of 7) is connected to the water flow space (5) through the air inlet (23) of the bottom cover (14), while the water pipe (12) to which the water feeder (9) is attached is connected to the bottom. Connected to the water flow space (5) through the water inlet (24) of the lid (14) , The intake pipe (7) to the insufflation device (8) may be adopted fitted with. In the configuration of FIG. 6, the water to be treated is fed from the water inlet (24) of the bottom lid (14) into the water flow space (5), while ozone is sucked into the bottom lid (14). Air is fed into the water passage space (5) from the mouth (23).

  Further, in the embodiment, as the ozone generated in the ozone generation space (4) is sucked into the intake pipe (7), air is introduced into the atmosphere from the oxygen introduction opening (15) of the upper lid (13). (Air) is taken into the ozone generation space (4). For example, as shown in FIG. 4, an oxygen supply pipe (31) extended from an oxygen supply (31) such as an oxygen cylinder ( By adopting a configuration in which 32) is disposed in the ozone generation space (4), the ozone generated in the ozone generation space (4) is taken into the intake pipe (7). Oxygen may be newly introduced (supplied) into the ozone generation space (4).

  Moreover, the structure which connected the some of the water treatment apparatus (1) of this invention in series is also employable. For example, as shown in FIG. 5, the structure which connected the treated water delivery pipe | tube (11) of one water treatment apparatus (1A) to the aspirator (8) of the other water treatment apparatus (1B) is also employable.

  The water treatment method and water treatment apparatus using ultraviolet light and ozone according to the present invention are not particularly limited. For example, the waste water containing a hard-to-decompose organic substance is decomposed, the colored waste water is decolorized, and BOD is used. It is used for (biochemical oxygen demand) reduction, COD (chemical oxygen demand) reduction and the like, and can be applied to various other fields. Examples of the hardly decomposable organic substance include phenol, p-cresol, and p-chlorophenol.

  Next, specific examples of the present invention will be described.

<Example 1>
The water treatment apparatus (1) having the structure shown in FIGS. 1 to 3 was used to decompose the water to be treated containing trace amounts of phenol, p-cresol, and p-chlorophenol. That is, water to be treated containing phenol 153 mg / dm ³ , p-cresol 156 mg / dm ³ , and p-chlorophenol 112 mg / dm ³ is placed in a 1 L tank, and a water pipe is placed near the bottom of the internal space of the tank. While the tip of (12) is placed, the tip of the treated water delivery pipe (11) is placed near the upper part of the internal space of the tank, and in this state, the power supply unit (10) is turned on and the ultraviolet lamp (6) Is turned on and the water supply device (9) is driven to bring the water treatment device (1) into an operation state for 150 minutes, whereby the water to be treated is circulated through the tank and the water treatment device (1) in order at a constant flow rate. It was.

In addition, an aluminum foil was used as the ultraviolet light reflection plate laminated on the outer peripheral surface of the outer tub (2). The volume of the water passage space (5) between the outer tank (2) and the inner tank (3) is 230 cm ³ , and the ozone supply amount to the water passage space (5) is 8.4 mg / h. there were. The main wavelengths of the low-pressure mercury lamp used as the ultraviolet lamp (6) were 185 nm and 254 nm. After operating the water treatment device (1) for 150 minutes, water in the tank is collected and quantitative analysis is performed using a capillary gas chromatograph (GC-17A, manufactured by Shimadzu Corporation). From the material balance before and after the water treatment, phenol is obtained. , P-cresol and p-chlorophenol were calculated.

<Example 2>
Example 1 except that the water treatment apparatus (1) is a water treatment apparatus having the configuration shown in FIGS. In the same manner, the water to be treated was decomposed.

<Example 3>
As the water treatment device (1), a water treatment device having the configuration shown in FIGS. 1 to 3 and having a configuration in which the spiral pipe portion for intake (7X) is replaced with a straight pipe (configuration without the spiral pipe portion) was used. Except for the above, the water to be treated was decomposed in the same manner as in Example 1.

<Example 4>
As the water treatment device (1), the water treatment device having the configuration shown in FIGS. 1 to 3, the ultraviolet light reflection plate is omitted (there is no ultraviolet light reflection plate), and the intake spiral tube portion (7X) is omitted ( The water to be treated was decomposed in the same manner as in Example 1 except that a straight pipe was used.

<Comparative Example 1>
The water treatment apparatus (1) is the same as that of the first embodiment except that the water treatment apparatus having the configuration shown in FIGS. 1 to 3 and having a configuration in which the intake pipe is omitted (a configuration having no intake pipe) is used. The water to be treated was decomposed (only ultraviolet light irradiation, not using ozone).

<Comparative example 2>
The water treatment apparatus (1) is the same as in Example 1 except that the water treatment apparatus having the configuration shown in FIGS. 1 to 3 and having an aluminum tank attached to the inner surface of the inner tank is used. Treated water was decomposed (only use of ozone produced by irradiation of ultraviolet light into the ozone generation space, no irradiation of ultraviolet light into the water passage space).

  As is apparent from the table, the treated water of Examples 1 to 4 treated by the treatment method using the treatment apparatus of the present invention is sufficiently decomposed for phenol, p-cresol, and p-chlorophenol. It was. Moreover, the decomposition rate in Examples 1-4 is the comparative example processed only by the decomposition rate and ozone in the comparative example 1 processed only by ultraviolet light in any of phenol, p-cresol, and p-chlorophenol. 2 was higher than the sum of the decomposition rate in 2. It is considered that this is because ozone was irradiated with ultraviolet light to generate hydroxy radicals, and the decomposition reaction was further promoted by the hydroxy radicals.

  Moreover, the decomposition rate of Example 3 which laminated | stacked the ultraviolet light reflecting plate on the outer peripheral surface of an outer tank was a numerical value higher than the decomposition rate of Example 4 which does not provide the ultraviolet light reflecting plate. Moreover, the decomposition rate of Example 2 in which the spiral tube portion was provided was higher than that in Example 4 in which the spiral tube portion was not provided. Furthermore, the decomposition rate of Example 1 in which the ultraviolet light reflector is laminated on the outer peripheral surface of the outer tub and the spiral tube portion is provided is higher than the decomposition rate of Example 4 in which the ultraviolet light reflector and the spiral tube portion are not provided. It was a remarkably high number.

It is a perspective view which shows one Embodiment of the water treatment apparatus of this invention. It is a cross-sectional view of the water treatment apparatus of FIG. It is a longitudinal cross-sectional view of the water treatment apparatus of FIG. It is a perspective view which shows other embodiment of the water treatment apparatus of this invention. It is a perspective view which shows other embodiment of the water treatment apparatus of this invention. It is a perspective view which shows other embodiment of the water treatment apparatus of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Water treatment apparatus 2 ... Outer tank 3 ... Inner tank 4 ... Space for ozone generation 5 ... Space for water flow 6 ... Ultraviolet lamp 7 ... Intake pipe 7A ... Spiral pipe part for intake 8 ... Aspirator (air supply device)
9 ... Water feeder

Claims (6)

In the water treatment method for decomposing organic substances contained in the water to be treated by irradiating the water to be treated with ozone with ultraviolet light from an ultraviolet lamp,
A water treatment method using ultraviolet light and ozone in combination, wherein as the added ozone, ozone generated by irradiating oxygen present around the ultraviolet lamp with ultraviolet light from the lamp is used. An outer tank for water treatment,
An inner tank disposed inside the outer tank;
An ultraviolet lamp disposed in the inner tank;
An intake pipe having one end connected in communication with the ozone generating space between the inner tank and the ultraviolet lamp, and the other end connected in communication with the water passing space between the outer tank and the inner tank;
A water treatment device using ultraviolet light and ozone in combination, comprising: an air supply device for supplying the gas in the intake pipe from the ozone generation space side to the water flow space side. An outer tank for water treatment,
An inner tank disposed inside the outer tank;
An ultraviolet lamp disposed in the inner tank;
An intake pipe having one end connected in communication with the ozone generating space between the inner tank and the ultraviolet lamp, and the other end connected in communication with the water passing space between the outer tank and the inner tank;
A water treatment apparatus using ultraviolet light and ozone in combination, comprising: an aspirator attached to an intermediate position of the intake pipe.   The water treatment apparatus using both ultraviolet light and ozone according to claim 3, wherein at least a part of a position from the aspirator to the water passage space in the intake pipe is formed in a spiral shape.   The water treatment apparatus which used together the ultraviolet light and ozone of any one of Claims 2-4 by which the said outer tank is comprised with the reflecting plate which reflects an ultraviolet light inward.   The water treatment apparatus using ultraviolet light and ozone according to any one of claims 2 to 4, wherein a reflection plate that reflects ultraviolet light is disposed on the inner side of the outer tank or the inner side thereof.

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