JP2007313421A - Pure water circulating feed system, pure water recycling method, and method for treating substrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pure water circulating feed system capable of enhancing a recovery rate of pure water efficiently using drainage having high cleanness. <P>SOLUTION: The pure water circulating feed system comprises a pure water production apparatus 530 including a primary pure water generation part 510 for generating the pure water and a secondary pure water generation part 520 for generating ultrapure water from the pure water, an ultrapure water path 550 for feeding the ultrapure water generated by the secondary pure water generation part 520 of the pure water production apparatus 530 to demand equipment 540, an electrodialyser 560 for generating treated water whose target ion concentration is reduced, and a treated water path 570 for feeding the treated water whose target ion concentration is reduced by the electrodialyser 560 to the secondary pure water generation part 520 of the pure water production apparatus 530. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a pure water circulation supply system, and more particularly to a pure water circulation supply system that circulates and supplies ultrapure water to a cleaning device or the like in a semiconductor device manufacturing factory or a manufacturing factory of electronic parts such as liquid crystal. The present invention also relates to a method for reusing pure water, and more particularly to a method for reusing ultrapure water supplied to a cleaning device or the like in a semiconductor device manufacturing factory or a manufacturing factory for electronic components such as liquid crystals. Furthermore, the present invention relates to a substrate processing method for processing a substrate using such ultrapure water.

  In a semiconductor device manufacturing factory and a manufacturing factory of electronic parts such as liquid crystal, ultrapure water is used for cleaning silicon wafers and liquid crystals. Ultrapure water is water purified to a high purity used for removing contamination on the surface of silicon wafers and the like, and is usually a pretreatment device using city water, industrial water, well water, etc. as raw water. It is produced through a pure water production apparatus having a secondary pure water production apparatus and a secondary pure water production apparatus (subsystem).

  In the pretreatment apparatus described above, in order to effectively produce pure water in the primary pure water generating apparatus, the turbid components of the raw water are removed by combining filtration and coagulation sedimentation. In the primary pure water generator, ionic components, fine particles, organic components, dissolved gas, and the like are removed to produce pure water. The water quality required for the pure water produced varies depending on the purpose of use, and the equipment configuration of the primary pure water generator is determined according to the quality of pure water and the amount of water produced. In general, a primary pure water generator is constituted by a filter, activated carbon, RO membrane, electric desalting, ion exchange, and the like.

  Further, in the secondary pure water generator, impurities contained in the pure water generated by the primary pure water generator are further removed, and highly purified water is supplied to the place of use and circulates. The quality of ultrapure water is maintained. In general, a secondary pure water generating device is configured by ultraviolet irradiation, ion exchange, ultrafiltration, and the like, and organic components, silica, ionic components, and fine particles in pure water are removed.

  Thus, in order to manufacture ultrapure water, impurities in raw water are removed step by step through a plurality of treatment steps by a plurality of apparatuses. For this reason, the amount of ultrapure water obtained after treatment is usually reduced with respect to raw water. Further, in such a pure water production apparatus, it is often the case that an apparatus for removing impurities is maintained in an optimum operating state using ultrapure water obtained after the treatment. Therefore, the ratio (recovery rate) between the total outlet water and the inlet water of the pure water production apparatus is not 100%. In the case of the primary pure water generator, the recovery rate is generally about 60 to 90%, and in the case of the secondary pure water generator, the recovery rate exceeds 90%.

  On the other hand, ultrapure water used for wafer cleaning and the like contains impurities on the surface of the wafer and chemicals used for cleaning, but is discharged in a relatively clean state. It is important to collect and reuse the waste water in order to improve the water usage rate and reduce the amount of waste discharged to the external environment. Although it is possible to use the collected wastewater for other purposes, many factories adopt a method of reusing it after performing some kind of treatment.

As described above, pure water is produced at a recovery rate (raw water utilization rate) of about 60 to 90% in the primary pure water generator. When ultrapure water is produced from pure water, the recovery rate further decreases. In addition, energy is required for producing pure water. Therefore, it can be said that reuse of the wastewater generated at the place of use (use point) as the raw water of ultrapure water is more effective than the reuse of the raw water as pure water. If the ionic components are removed from the wastewater generated at the place of use and the water quality is equivalent to that of pure water, it can be used as raw water for ultra pure water. For example, if you are located in a city where water charges are high, if the price of tap water is about 500 yen / m ³ , the production cost of pure water produced by the primary pure water system is about 1,000 yen / m ³ . Yes, the production cost of ultrapure water generated by the secondary pure water generator is about 1,400 yen / m ³ . Further, assuming that the amount of ultrapure water finally produced by the pure water production apparatus is 100, about 150 raw water (tap water, city water) is required.

  As described above, ion removal in the primary pure water generator has been performed using an RO membrane or an ion exchange resin. However, in recent years, electrical regeneration that does not require drug regeneration and enables continuous water flow is possible. Desalination equipment is often used. Therefore, it is sufficient that the electric desalination apparatus can be used for the treatment of the wastewater generated at the place of use, but conventionally, this method cannot be employed due to the influence of fluorine contained in the wastewater.

  That is, the electric desalting apparatus uses an electrodialysis technique in which a direct current is passed from both ends of a plurality of chambers separated by a cation exchange membrane and an anion exchange membrane. If an attempt is made to remove ions from wastewater containing fluorine using fluorine, fluorine will corrode the anode, and stable treatment operation cannot be continued.

  Even when an RO membrane was used, efficient separation was not possible due to the high membrane permeability of fluorine. Therefore, when the wastewater from the place of use is reused, it is often separated and collected according to the properties of the wastewater and reused as raw water for the primary pure water production apparatus.

  In addition, wastewater discharged from the place of use may contain substances that oxidize. Such oxidizing substances may cause deterioration of the components of the primary pure water production equipment, and may affect the processing performance. It will have an effect. For this reason, in the treatment system of recovered water, the oxidizing substance is removed with activated carbon or the like, and then supplied to the primary pure water production apparatus.

JP 2002-96068 A Japanese Patent Application Laid-Open No. 2004-8882

  The present invention has been made in view of such problems of the prior art, and provides a pure water circulation and supply system that can use wastewater with high cleanliness more efficiently and improve the recovery rate of pure water. The first purpose is to provide it.

  Moreover, this invention makes it the 2nd objective to provide the pure water reuse method which can recycle the waste_water | drain with high cleanliness more efficiently.

  Furthermore, a third object of the present invention is to provide a substrate processing method capable of processing a substrate using ultrapure water circulated efficiently.

  According to the first aspect of the present invention, there is provided a pure water circulation and supply system that can more efficiently use waste water with high cleanliness and improve the recovery rate of pure water. This pure water circulation supply system includes a pure water production apparatus having a primary pure water production section for producing pure water and a secondary pure water production section for producing ultrapure water from pure water, and the pure water production apparatus. And an ultrapure water path for supplying ultrapure water generated by the secondary pure water generator to a demand device. Further, the pure water circulation supply system includes an anode chamber having an anode, a cathode chamber having a cathode, and treated water in which the concentration of the target ions is reduced by removing the target ions from the waste water discharged from the demand equipment. A demineralization chamber for generating water, a concentration chamber for concentrating target ions in the wastewater moved from the desalination chamber to generate concentrated water having an increased concentration of the target ions, and pure water in the anode chamber. And an electrodialysis apparatus having a supply path. Furthermore, this pure water circulation supply system has a treated water path for supplying treated water whose concentration of the target ions has been reduced by the electrodialyzer to a secondary pure water generating unit of the pure water producing apparatus. .

  According to the pure water circulation and supply system according to the present invention, target ions such as fluorine can be removed from the waste water discharged from the demand equipment by the electrodialysis apparatus, and treated water having a cleanliness equivalent to that of pure water can be obtained. Can be generated. Therefore, this treated water can be reused as raw water for supplying ultrapure water by supplying it to the secondary pure water generator of the pure water production apparatus. Thus, according to the pure water circulation supply system concerning the present invention, the drainage discharged from demand equipment can be used more efficiently, and the recovery rate of pure water can be improved. In addition, by supplying pure water to the anode chamber, for example, even if fluorine is contained in the wastewater from the demand equipment, it is prevented that fluorine in the anode chamber of the electrodialyzer is mixed, and the corrosion problem of the electrode Does not occur.

  According to the 2nd aspect of this invention, the pure water circulation supply system which can use the waste_water | drain with high cleanliness more efficiently and can improve the recovery rate of pure water is provided. This pure water circulation supply system includes a pure water production apparatus having a primary pure water production section for producing pure water and a secondary pure water production section for producing ultrapure water from pure water, and the pure water production apparatus. An ultrapure water path for supplying ultrapure water generated by the secondary pure water generator to a demand device, and an oxidizing substance removing device that removes an oxidizing substance from waste water discharged from the demand device. Further, this pure water circulation supply system removes target ions from an anode chamber having an anode, a cathode chamber having a cathode, and waste water from which an oxidizing substance has been removed by the oxidizing substance removing device. A demineralization chamber for generating treated water having a reduced concentration, a concentration chamber for concentrating target ions in the wastewater moved from the demineralization chamber to generate concentrated water having an increased concentration of the target ions, and An electrodialysis apparatus having a path for supplying pure water to the anode chamber. Further, such a pure water circulation supply system has a treated water path for supplying treated water having the concentration of the target ions reduced by the electrodialyzer to a secondary pure water generating unit of the pure water producing apparatus. ing.

  According to the pure water circulation supply system according to the present invention, an oxidizing substance is removed from waste water discharged from a demand device by an oxidizing substance removing device, and fluorine or the like is removed from the waste water from which the oxidizing substance has been removed. Ions can be removed by an electrodialyzer, and treated water having a cleanliness equivalent to that of pure water can be generated. Therefore, this treated water can be reused as raw water for supplying ultrapure water by supplying it to the secondary pure water generator of the pure water production apparatus. Thus, according to the pure water circulation supply system concerning the present invention, the drainage discharged from demand equipment can be used more efficiently, and the recovery rate of pure water can be improved. In addition, by supplying pure water to the anode chamber, for example, even if fluorine is contained in the wastewater from the demand equipment, it is prevented that fluorine in the anode chamber of the electrodialyzer is mixed, and the corrosion problem of the electrode Does not occur.

  According to the third aspect of the present invention, there is provided a pure water recycling method capable of more efficiently reusing wastewater with high cleanliness. In this method, pure water is generated by the primary pure water generation unit of the pure water production apparatus, and ultrapure water is generated from the pure water by the secondary pure water generation unit of the pure water production apparatus. The ultrapure water produced | generated by the secondary pure water production | generation part of the said pure water manufacturing apparatus is supplied to a demand apparatus. Wastewater discharged from the above-mentioned demand equipment is supplied to the desalination chamber of the electrodialysis machine. While supplying pure water to the anode chamber of the electrodialysis apparatus, a voltage is applied between the anode disposed in the anode chamber and the cathode disposed in the cathode chamber to remove target ions from the waste water, Generates treated water with reduced concentration of target ions. The treated water in which the concentration of the target ions is lowered is supplied to the secondary pure water generation unit of the pure water production apparatus and reused.

  According to the 4th aspect of this invention, the pure water reuse method which can recycle the waste_water | drain with high cleanliness more efficiently is provided. In this method, pure water is generated by the primary pure water generation unit of the pure water production apparatus, and ultrapure water is generated from the pure water by the secondary pure water generation unit of the pure water production apparatus. The ultrapure water produced | generated by the secondary pure water production | generation part of the said pure water manufacturing apparatus is supplied to a demand apparatus. Waste water discharged from the demand equipment is supplied to an oxidizing substance removing device, and the oxidizing substance is removed from the waste water by the oxidizing substance removing device. The waste water from which the oxidizing substance has been removed is supplied to the desalting chamber of the electrodialyzer. While supplying pure water to the anode chamber of the electrodialysis apparatus, a voltage is applied between the anode disposed in the anode chamber and the cathode disposed in the cathode chamber to remove target ions from the waste water, Generates treated water with reduced concentration of target ions. The treated water in which the concentration of the target ions is lowered is supplied to the secondary pure water generation unit of the pure water production apparatus and reused.

  According to the 5th aspect of this invention, the substrate processing method which can process a board | substrate using the ultrapure water circulated efficiently is provided. In this method, the substrate is processed using the ultrapure water in the demand equipment.

  According to the pure water circulation supply system according to the present invention, target ions such as fluorine can be removed from the waste water discharged from the demand equipment, and treated water having a cleanliness equivalent to that of pure water can be generated. it can. Therefore, this treated water can be reused as raw water for supplying ultrapure water by supplying it to the secondary pure water generator of the pure water production apparatus. Thus, according to the pure water circulation supply system concerning the present invention, the drainage discharged from demand equipment can be used more efficiently, and the recovery rate of pure water can be improved.

  Hereinafter, an embodiment of a pure water circulation supply system according to the present invention will be described in detail with reference to FIGS. 1 to 16, the same or corresponding components are denoted by the same reference numerals, and redundant description is omitted.

  FIG. 1 is a schematic diagram showing a pure water circulation supply system 500 according to the first embodiment of the present invention. As shown in FIG. 1, a pure water circulation system 500 includes a primary pure water generation unit 510 that generates pure water from supplied tap water, and ultrapure water from pure water generated by the primary pure water generation unit 510. The ultrapure water produced by the pure water production apparatus 530 is supplied to a pure water production apparatus 530 having a secondary pure water production unit 520 that produces water and a demand device (use point) 540 that requires ultrapure water. The ultrapure water path 550, the electrodialyzer 560 that generates treated water from which, for example, fluorine ions have been removed from the wastewater discharged from the demand equipment 540, and the treated water from the electrodialyzer 560 are purified by the secondary pure water of the pure water production apparatus 530. And a treated water path 570 for supplying water to the water generator 520.

  For example, a demanding device 540 may be a cleaning device that cleans a silicon wafer, liquid crystal, or the like using ultrapure water in a semiconductor device manufacturing factory or a manufacturing factory for electronic components such as liquid crystal. Among the wastewater generated in the demand equipment 540, wastewater whose concentration in the wastewater exceeds 1% is separated, and relatively dilute wastewater is supplied to the electrodialyzer 560 through the drainage path 580. Yes. The pure water circulation supply system 500 in the present embodiment is applied when a substance having an oxidizing action is not contained in the wastewater supplied from the demand device 540. This waste water may be fluorine-containing waste water or waste water not containing fluorine.

  The method for separating the diluted wastewater from the wastewater generated by the demand equipment 540 described above is not particularly limited. When the demand equipment 540 can switch the discharge pipe according to the property of the wastewater, the wastewater drain 580 is connected to the outlet of the lean wastewater, and the lean wastewater is collected separately. When dilute wastewater and rich wastewater are discharged from the demand equipment 540 through a common pipe, a branch line and an automatic valve are provided in the common pipe, and automatic based on the electrical signal generated from the demand equipment 540 or the time of the operation process. It is possible to control the opening and closing of the valve to guide the diluted wastewater to the drainage path 580. Alternatively, an instrument such as a densitometer or a conductivity meter may be provided in the common pipe, and the automatic valve may be controlled to open and close based on the measured value of the instrument to guide the diluted wastewater to the drainage path 580.

  In this way, the diluted waste water from the demand device 540 is supplied to the electrodialysis device 560, and the electrodialysis device 560 generates treated water from which fluorine ions have been removed from the diluted waste water, and the waste water supplied to the electrodialysis device 560 is The electrodialysis technique described later separates, for example, into clean treated water from which fluorine ions have been removed and concentrated water whose volume has been reduced. The separated treated water is supplied to the secondary pure water generation unit 520 of the pure water production apparatus 530 through the treated water path 570 as raw water for ultra pure water and reused. The method for discharging the separated concentrated water is not particularly limited. For example, substances contained in the concentrated water can be recovered and reused, or discarded as waste or treated at a general wastewater treatment facility in the factory. You may do it.

  Thus, according to the pure water circulation supply system of the present embodiment, target ions such as fluorine can be removed from the waste water discharged from the demand equipment 540 by the electrodialysis apparatus 560, and the same cleanness as pure water is obtained. Treated water can be produced. Therefore, this treated water can be supplied to the secondary pure water generation unit 520 of the pure water production apparatus 530 and reused as raw water for generating ultrapure water. Thus, according to the pure water circulation supply system of this embodiment, the drainage discharged | emitted from the demand apparatus 540 can be used more efficiently, and the recovery rate of pure water can be improved.

  Next, various configuration examples of the electrodialysis apparatus 560 will be described. FIG. 2 is a schematic diagram illustrating a first configuration example of the electrodialysis apparatus 560. As shown in FIG. 2, the electrodialysis apparatus includes an electrodialysis tank 1 having an anode chamber 10, a buffer chamber 20, a concentration chamber 30, a desalting chamber 40, a concentration chamber 21, and a cathode chamber 50. The electrodialysis apparatus also includes an polar liquid tank 71 that supplies pure water to the anode chamber 10 and the cathode chamber 50 via a pump 70, and a buffer that supplies buffer water to the buffer chamber 20 and the concentration chamber 21 via a pump 72. A water tank 73 and a concentrated water tank 75 for supplying concentrated water to the concentration chamber 30 via a pump 74 are provided.

  The anode 2 is disposed inside the anode chamber 10, and the cathode 3 is disposed inside the cathode chamber 50. A voltage is applied between the anode 2 and the cathode 3 to perform electrodialysis described below. The desalination chamber 40 is supplied with the diluted waste water from the above-mentioned demand device 540, and the desalination chamber 40 removes the fluorine ions from the diluted waste water (hereinafter referred to as raw water) to obtain treated water having a reduced fluorine concentration. Generate. Further, the buffer chamber 20 blocks fluorine ions (target ions) in the raw water from flowing directly from the concentration chamber 30 into the anode chamber 10. Further, the concentration chamber 30 concentrates the fluorine ions in the raw water moved from the desalting chamber 40 to generate concentrated water having an increased fluorine ion concentration.

  FIG. 3 is a schematic diagram showing the electrodialysis tank 1 of FIG. As shown in FIG. 3, the anode chamber 10 and the buffer chamber 20 are partitioned by a cation exchange membrane CM1 that is a kind of ion exchange membrane, and the buffer chamber 20 and the concentration chamber 30 are cations that are a kind of ion exchange membrane. Partitioned with an exchange membrane CM2. The concentration chamber 30 and the desalting chamber 40 are partitioned by an anion exchange membrane AM1, which is a kind of ion exchange membrane, and the concentration chamber 21 and the desalting chamber 40 are a cation exchange membrane CM3, which is a kind of ion exchange membrane. It is partitioned by. The cathode chamber 50 and the concentration chamber 21 are partitioned by an anion exchange membrane AM2, which is a kind of ion exchange membrane. In FIG. 3, the packings located on both sides of the ion exchange membrane are not shown.

  The anode chamber 10 is filled with a cation exchange nonwoven fabric CF1, which is a kind of ion exchanger. The buffer chamber 20 is filled with a cation exchange nonwoven fabric CF2 which is a kind of ion exchanger, a cation exchange spacer CS1 which is a kind of ion exchanger, and a cation exchange nonwoven cloth CF3 which is a kind of ion exchanger. Since the ion exchange nonwoven fabric is a nonwoven fabric ion exchanger that is densely composed of thin fibers with a large surface area, it has a high ability to capture and conduct ions, but the pressure loss increases when filled in an electrodialysis tank. There's a problem. On the other hand, the ion exchange spacer is an ion exchange function introduced on the surface of a reticulated spacer usually used in conventional electrodialysis tanks. It has excellent water dispersibility, low pressure loss, but low ion trapping ability. There is a problem. In the electrodialysis tank 1 in this configuration example, by filling the ion exchange nonwoven fabric and the ion exchange spacer in combination, the pressure loss can be reduced while maintaining the ion capturing ability and the conducting ability high.

  The concentration chamber 30 is filled with a cation exchange nonwoven fabric CF4 which is a kind of ion exchanger, a cation exchange spacer CS2 which is a kind of ion exchanger, and an anion exchange nonwoven fabric AF1 which is a kind of ion exchanger. The desalting chamber 40 is filled with an anion exchange nonwoven fabric AF2 which is a kind of ion exchanger, an anion exchange spacer AS1 which is a kind of ion exchanger, and a cation exchange nonwoven fabric CF5 which is a kind of ion exchanger.

  The concentration chamber 21 is filled with a cation exchange nonwoven fabric CF6 which is a kind of ion exchanger, a cation exchange spacer CS3 which is a kind of ion exchanger, and an anion exchange nonwoven fabric AF3 which is a kind of ion exchanger. The cathode chamber 50 is filled with an anion exchange nonwoven fabric AF4 which is a kind of ion exchanger.

  From the polar liquid tank 71, pure water as the polar liquid is supplied to the anode chamber 10 and the cathode chamber 50. Since the effluent from the anode chamber 10 has a higher fluorine ion concentration than that of pure water, the entire amount is supplied to the buffer water tank 73 without being circulated to the polar liquid tank 71 in this configuration example. . Since the outflow water from the cathode chamber 50 is usually extremely dilute in fluorine ion concentration and has been experimentally confirmed to be almost the same concentration level as pure water, in this configuration example, replenishment of polar solution is performed. In order to do so, it circulates in the polar liquid tank 71. Note that a part or all of the effluent water from the anode chamber 10 may be circulated to the polar liquid tank 71. Alternatively, the effluent water from the anode chamber 10 may be supplied to the concentrated water tank 75.

  Further, buffer water is supplied from the buffer water tank 73 to the buffer chamber 20 and the concentration chamber 21. The effluent water from the buffer chamber 20 and the concentration chamber 21 is supplied to the buffer water tank 73 and the concentrated water tank 75. In the configuration example described above, a part of the effluent water from the buffer chamber 20 and the concentration chamber 21 is supplied to the concentrated water tank 75. However, the whole amount of the effluent water is supplied to the concentrated water tank 75. It is good.

  Further, the concentrated water is supplied from the concentrated water tank 75 to the concentration chamber 30. The effluent from the concentration chamber 30 is taken out as concentrated water, and a part thereof is supplied to the concentrated water tank 75.

  With such a configuration, hydrogen ions generated by the water electrolysis reaction in the anode chamber 10 are ion-conducted on the cation exchangers CF1, CM1, CF2, CS1, CF3, CM2, CF4, and CS2, and the buffer chamber 20 is It is possible to reach the concentration chamber 30 via the route. Therefore, the voltage applied to the anode chamber 10 and the buffer chamber 20 does not depend on the ion concentration of the anolyte and buffer water, and can be kept low.

  When water containing anions is electrodialyzed, the anions in the raw water are concentrated in the concentrated water. Normally, the concentrated anion hardly passes through the cation exchange membranes CM2 and CM1 on the anode 2 side and leaks to the buffer chamber 20 or the anode chamber 10, for example. There is a phenomenon in which a part of the fluorine ions in the water permeates through the cation exchange membrane CM2 separating the concentration chamber 30 and the buffer chamber 20, and reaches the buffer chamber 20 and thus the anode chamber 10 located on the anode 2 side of the concentration chamber 30. It may happen.

  In this example, pure water is always replenished to the anode chamber 10 by the above-described configuration, and fluorine ions leaking from the buffer chamber 20 to the anode chamber 10 are discharged out of the anode chamber 10 and the anode chamber 10 is discharged. Can be maintained at a very low value. Moreover, electrode corrosion due to fluorine can be suppressed.

  Further, with respect to the fluorine concentration in the buffer chamber 20, the outflow water from the anode chamber 10 is replenished to the buffer water in the buffer water tank 73, so that the fluorine ions leaking from the concentration chamber 30 to the buffer chamber 20 are removed. 20 can be discharged to the outside. Thereby, although the concentration is slightly higher than that of the anode chamber 10, the fluorine concentration in the buffer chamber 20 can be maintained at a low value. Further, since the concentrated water is replenished by the outflow water from the buffer chamber 20 and the concentrating chamber 21, the amount of replenished pure water added to the concentrated water tank 75 can be reduced.

  Moreover, since pure water is used as the replenishing water for the polar liquid, the fluorine concentration in the replenishing water does not fluctuate or increase depending on the operating conditions. For this reason, the fluorine concentration in the anode chamber 10 can always be maintained at an extremely low value regardless of the operating conditions. Moreover, the corrosion prevention of the anode 2 can be made more reliable. Here, when the treated water can be used instead of pure water, such as when the quality of the treated water of the electrodialyzer is equal to that of pure water, the treated water may be used instead of pure water.

  In addition, since the buffer water is replenished by the outflow water from the anode chamber 10, the amount of water discharged from the anode chamber 10 to the outside of the apparatus and the amount of replenished pure water added to the buffer water can be reduced. . In particular, if the total amount of the outflow water from the anode chamber 10 is supplied to the buffer water tank 73, the amount of water discharged from the anode chamber 10 to the outside of the apparatus and the amount of makeup pure water added to the buffer water are made zero. be able to.

  Further, since the concentrated water is replenished by the outflow water from the buffer chamber 20 and the concentrating chamber 21, the amount of pure water to be added to the concentrated water and the water discharged from the buffer chamber 20 and the concentrating chamber 21 to the outside of the apparatus. The amount of can be reduced. In particular, when the total amount of concentrated water is covered by the outflow water from the buffer chamber 20 and the concentration chamber 21, the amount of pure water added to the concentrated water and the water discharged from the buffer chamber 20 and the concentration chamber 21 to the outside of the apparatus. The amount of can be zero.

  As the kind of drainage discharged from the electrodialysis tank 1, the amount of water discharged from the anode chamber 10 to the outside of the device and the amount of water discharged from the buffer chamber 20 and the concentration chamber 21 to the outside of the device are zero. In this case, there are only two systems of treated water and concentrated water, and the piping system does not become complicated. The equilibrium fluorine concentration in the anode chamber 10, the buffer chamber 20, and the concentration chamber 21 adjusts the amount of polar liquid supplied to the anode chamber 10 and the cathode chamber 50 and the amount of buffer water supplied to the buffer chamber 20 and the concentration chamber 21. Can be adjusted arbitrarily. In the configuration example shown in FIG. 2, at least a part of the polar liquid and / or buffer water may be mixed with raw water or treated water.

  FIG. 4 is a schematic diagram illustrating a second configuration example of the electrodialysis apparatus 560. The electrodialysis apparatus in this example has basically the same configuration as the electrodialysis apparatus in the first configuration example described above, but differs from the electrodialysis apparatus in the first configuration example in the following points. .

  Buffer water is supplied from the buffer water tank 73 only to the buffer chamber 20, and is not supplied to the concentration chamber 21. Instead, the outflow water from the cathode chamber 50 is supplied to the concentration chamber 21. Further, the effluent water from the concentration chamber 21 is supplied to the polar liquid tank 71 to replenish the polar liquid.

  The cations present in the raw water are concentrated in the concentration chamber 21 adjacent to the cathode chamber 50. When it is determined that the concentrated cations do not adversely affect the processing performance of the electrodialysis apparatus, the cations are shown in FIG. Such a configuration can be used. Needless to say, the effluent from the concentration chamber 21 may be supplied to the buffer water tank 73. Even with such a configuration, the effects of the present invention can be achieved.

  FIG. 5 is a schematic diagram illustrating a third configuration example of the electrodialysis apparatus 560. The electrodialysis apparatus in this example has basically the same configuration as the electrodialysis apparatus in the first configuration example described above, but differs from the electrodialysis apparatus in the first configuration example in the following points. .

  Buffer water is supplied from the buffer water tank 73 only to the buffer chamber 20, and is not supplied to the concentration chamber 21. Instead, pure water as the polar liquid is supplied from the polar liquid tank 71 to the anode chamber 10 and the concentration chamber 21. Further, the effluent water from the concentration chamber 21 is supplied to the cathode chamber 50 adjacent to the concentration chamber 21. Even with such a configuration, the effects of the present invention can be achieved.

  FIG. 6 is a schematic diagram illustrating a fourth configuration example of the electrodialysis apparatus 560, and FIG. 7 is a schematic diagram illustrating the electrodialysis tank 101a of FIG. The electrodialysis apparatus in this example has basically the same configuration as the electrodialysis apparatus in the first configuration example described above, but is adjacent to the cathode chamber 50, and includes buffer water (FIG. 2), polar liquid ( 4) or the concentrating chamber 21 to which pure water (FIG. 5) was supplied is used as the concentrating chamber 31 to which concentrated water is supplied in FIG. Yes. Even with such a configuration, the effects of the present invention can be achieved.

  FIG. 8 is a schematic diagram showing a fifth configuration example of the electrodialysis apparatus 560, and FIG. 9 is a schematic diagram showing the electrodialysis tank 101b of FIG. The electrodialysis apparatus in this example has basically the same configuration as the electrodialysis apparatus in the first configuration example described above, but the concentration chamber is located between the desalting chamber 40 and the concentration chamber 30 in FIG. 30 and the desalting chamber 40 are further different from the electrodialysis apparatus in the first configuration example in that they are further added. Even with such a configuration, the effects of the present invention can be achieved. As in the case of FIG. 6, the concentrating chamber 21 adjacent to the cathode chamber 50 may be used as the concentrating chamber 31 and the concentrated water may be supplied to the concentrating chamber 31.

  FIG. 10 is a schematic diagram illustrating a sixth configuration example of the electrodialysis apparatus 560. Similar to the electrodialysis apparatus shown in FIG. 2, this electrodialysis apparatus has the effect of preventing the corrosion of the anode, and even when hydrofluoric acid wastewater containing metal ions is targeted, hydrofluoric acid and metal ions are removed. It can be concentrated separately. Moreover, since the metal ions are separated and concentrated as soluble chlorides, not as precipitated hydroxides, troubles such as precipitation in the electrodialysis tank can be avoided.

  As shown in FIG. 10, the electrodialysis apparatus includes an anode chamber 210, a buffer chamber 220, an acid concentration chamber 230, a desalting chamber 240, an alkali concentration chamber 231, an acid supply chamber 260, a bipolar chamber 261, a buffer chamber 220, an acid. An electrodialysis tank 201 having a concentration chamber (first concentration chamber) 230, a desalting chamber 240, an alkali concentration chamber (second concentration chamber) 231, an acid supply chamber (ion supply chamber) 260, and a cathode chamber 250 is provided. Yes. Thus, in this example, the buffer chamber 220, the acid concentration chamber 230, the desalting chamber 240, the alkali concentration chamber 231 and the acid supply chamber 260 are provided on both sides of the bipolar chamber 261, respectively.

  Further, as shown in FIG. 10, the electrodialysis apparatus includes a polar liquid tank 271 that supplies pure water to the anode chamber 210 and the cathode chamber 250 via a pump 270, and buffer water to the buffer chamber 220 via a pump 272. Buffer water tank 273 to be supplied, acid concentrated water tank 275 for supplying acid concentrated water to the acid concentration chamber 230 via a pump 274, and alkali concentrated water for supplying alkali concentrated water to the alkali concentration chamber 231 via a pump 276 A tank 277 and an acid supply water tank 279 for supplying acid supply water to the acid supply chamber 260 via a pump 278 are provided.

  In addition, the electrodialysis apparatus includes an acid stock solution tank 281 that supplies an acid stock solution such as HCl to the acid supply water tank 279 via a pump 280, and a pH monitor 282 that measures the pH of the acid supply water tank 279. . Further, the electrodialysis apparatus includes a raw water tank 284 that supplies raw water to the desalting chamber 240 via a pump 283, and a raw water tank that supplies detoxification wastewater (treated water containing fluorine) via activated carbon 285 and a cartridge filter 286. And a pump 287 for supplying to 284.

  An anode 202 is disposed inside the anode chamber 210, and a cathode 203 is disposed inside the cathode chamber 250. In addition, an electrode 204 is disposed inside the bipolar chamber 261. The desalination chamber 240 is supplied with the diluted waste water from the above-mentioned demand device 540, and the desalination chamber 240 receives fluorine ions (first target ions) and calcium ions (second target ions) from the diluted waste water (raw water). ) Is removed to produce treated water with reduced fluorine and calcium ion concentrations. Further, the buffer chamber 220 blocks fluorine ions in the raw water from flowing directly from the acid concentrating chamber 230 into the anode chamber 210. Further, the acid concentrating chamber 230 concentrates the fluorine ions in the raw water moved from the desalting chamber 240 to generate (first) concentrated water having an increased fluorine ion concentration. Further, the alkali concentration chamber 231 generates (second) concentrated water having a calcium ion concentration increased by concentrating calcium ions in the raw water moved from the desalting chamber 240. The acid supply chamber 260 supplies ions having a polarity opposite to the calcium ions in the wastewater to the alkali concentration chamber 231.

  FIG. 11 is a schematic diagram showing the electrodialysis tank 201 of FIG. As shown in FIG. 11, the anode chamber 210 and the buffer chamber 220 are partitioned by a cation exchange membrane CM11 which is a kind of ion exchange membrane, and the buffer chamber 220 and the acid concentration chamber 230 are a kind of ion exchange membrane. It is partitioned by a cation exchange membrane CM12. The acid concentrating chamber 230 and the desalting chamber 240 are partitioned by an anion exchange membrane AM11 which is a kind of ion exchange membrane, and the desalting chamber 240 and the alkali concentrating chamber 231 are a cation exchange membrane CM13 which is a kind of ion exchange membrane. It is partitioned by. The alkali concentrating chamber 231 and the acid supply chamber 260 are partitioned by an anion exchange membrane AM12 which is a kind of ion exchange membrane, and the acid supply chamber 260 and the bipolar chamber 261 are a kind of ion exchange membrane. Partitioned by an anion exchange membrane AM13. In addition, in FIG. 11, illustration of the packing located in the both sides of an ion exchange membrane is abbreviate | omitted.

  The anode chamber 210 is filled with a cation exchange nonwoven fabric CF11 which is a kind of ion exchanger. The buffer chamber 220 is filled with a cation exchange nonwoven fabric CF12 which is a kind of ion exchanger, a cation exchange spacer CS11 which is a kind of ion exchanger, and a cation exchange nonwoven cloth CF13 which is a kind of ion exchanger.

  The acid concentrating chamber 230 is filled with a cation exchange nonwoven fabric CF14 which is a kind of ion exchanger, a cation exchange spacer CS12 which is a kind of ion exchanger, and an anion exchange nonwoven fabric AF11 which is a kind of ion exchanger. The desalting chamber 240 is filled with an anion exchange nonwoven fabric AF12 which is a kind of ion exchanger, an anion exchange spacer AS11 which is a kind of ion exchanger, and a cation exchange nonwoven cloth CF15 which is a kind of ion exchanger.

  The alkali concentrating chamber 231 is filled with a cation exchange nonwoven fabric CF16 which is a kind of ion exchanger, a cation exchange spacer CS13 which is a kind of ion exchanger, and an anion exchange nonwoven fabric AF13 which is a kind of ion exchanger. The acid supply chamber 260 is filled with an anion exchange nonwoven fabric AF14 which is a kind of ion exchanger, an anion exchange spacer AS12 which is a kind of ion exchanger, and an anion exchange nonwoven fabric AF15 which is a kind of ion exchanger.

  The bipolar chamber 261 is filled with anion exchange nonwoven fabric AF16 and cation exchange nonwoven fabric CF11 which are a kind of ion exchanger. Since the structure from the electrode 204 of the bipolar chamber 261 to the cathode 203 of the cathode chamber 250 is the same as the structure from the cation exchange nonwoven fabric CF11 to the anion exchange nonwoven fabric AF16 described above, description thereof is omitted here.

  From the polar liquid tank 271, pure water as the polar liquid is supplied to the anode chamber 210, the bipolar chamber 261, and the cathode chamber 250. Outflow water from the anode chamber 210, the bipolar chamber 261, and the cathode chamber 250 is circulated to the polar liquid tank 271 to replenish the polar liquid.

  Further, buffer water is supplied from the buffer water tank 273 to the buffer chamber 220. The effluent water from the buffer chamber 220 is supplied to the buffer water tank 273 and the raw water tank 284. Part of the effluent water that has exited from the anode chamber 210, the bipolar chamber 261, and the cathode chamber 250 is mixed with the effluent water that has exited from the buffer chamber 220.

  Further, acid concentrated water is supplied from the acid concentrated water tank 275 to the acid concentrating chamber 230. The effluent from the acid concentrating chamber 230 is taken out as concentrated water, and a part thereof is supplied to the acid concentrated water tank 275. Further, the alkali concentrated water is supplied from the alkali concentrated water tank 277 to the alkali concentrating chamber 231. The effluent water from the alkali concentrating chamber 231 is supplied to the alkali concentrated water tank 277.

  Since there is a concern that fluorine may flow into the bipolar chamber 261 from the buffer chamber 220 adjacent to the cathode chamber 250 side of the bipolar chamber 261, in this example, the bipolar chamber 261 has pure water as in the anode chamber 210. Water is supplied. Further, the effluent water exiting the bipolar chamber 261 is also used as makeup water for the buffer water tank 273 in the same manner as the effluent water exiting the anode chamber 210.

  With such a configuration, the acid and the metal ion can be separately concentrated. Further, the metal ions form a soluble salt with the anion derived from the mineral acid supplied by electrophoresis from the acid supply chamber 260, thereby preventing the metal hydroxide and the like from being precipitated. For example, when hydrochloric acid is used as the mineral acid, calcium ions contained in the raw water can be concentrated as calcium chloride having high solubility.

  12 is a schematic diagram illustrating a seventh configuration example of the electrodialysis apparatus 560, and FIG. 13 is a schematic diagram illustrating the electrodialysis tank 301 of FIG. The electrodialysis tank 301 is obtained by omitting the acid supply chamber 260 provided on the cathode 203 side of the alkali concentration chamber 231 in the electrodialysis tank of the sixth configuration example described above. Such a structure can be used when concentrating cations (cations) that do not precipitate even when alkaline, such as ammonium ions.

  FIG. 14 is a schematic diagram illustrating an eighth configuration example of the electrodialysis apparatus 560. As shown in FIG. 14, the electrodialysis tank 401 of this electrodialysis apparatus includes an anode chamber 210, a buffer chamber 220, an acid concentration chamber 230, a desalting chamber 240, an alkali concentration chamber 231, an acid supply chamber 260, and a cathode chamber 250. In the electrodialysis tank 201 of the sixth configuration example described above, the bipolar chamber 261 is eliminated and each chamber is only one. Even with such a configuration, the effects of the present invention can be achieved.

In each configuration example described above, the electrodialysis apparatus preferably performs constant current operation or constant voltage operation, and the current density is preferably 10 A / dm ² or less, particularly preferably 3 A / dm ² or less. The thickness of the desalting chamber and the concentration chamber is 1 to 10 mm, preferably 2 to 4 mm. When a sheet-like material such as a nonwoven fabric or a spacer is used as the ion exchanger, the number and type of filling in each chamber can be arbitrarily set. Preferably, the liquid is supplied to each chamber so that the fluorine concentration in the anode chamber is less than 1 mg / L and the fluorine concentration in the buffer chamber is less than 10 mg / L.

  As the electrode material, platinum, tantalum, niobium, diamond, SUS, or the like can be used. In addition, a material obtained by plating platinum, gold, iridium oxide, or the like on a base material such as titanium, nickel, monel, hastelloy, or inconel can be used as an electrode.

  The shape of the electrode may be a flat plate shape or a lath net shape having water permeability and gas permeability. Although there is no restriction | limiting in particular in the ion concentration in concentrated water, It is preferable that the density | concentration of a cation or an anion exists in the range of 100-100,000 mg / L. Although there is no restriction | limiting in particular in the density | concentration of raw | natural water, It is preferable that the density | concentration of a cation or an anion exists in the range of 5-500 mg / L. The concentration of treated water obtained in this case can be adjusted to a desired value by setting operating conditions such as a current value. For example, treated water having a cation or anion concentration in the range of 0.01 to 10 mg / L is obtained.

  There is no restriction | limiting in particular as a pure water supplied to an anode chamber, a cathode chamber, and a bipolar chamber, All the pure water manufactured by the pure water manufacturing method normally used by those skilled in the art can be used. For example, using pure water produced by a known technique such as RO (reverse osmosis membrane), ion exchange method, distillation method, electric desalting method or a combination thereof, or ultrapure water whose purity is further enhanced Can do. The amount of pure water supplied to the anode chamber is most preferably set so that the fluorine concentration in the anode chamber is less than 1 mg / L.

  As an ion exchanger filled in the anode chamber, cathode chamber, bipolar chamber, buffer chamber, desalting chamber, and concentration chamber of the electrodialysis apparatus described above, an ion exchange group is formed on a polymer fiber substrate by graft polymerization. It is preferable to use the introduced one. The grafted substrate made of polymer fibers may be a polyolefin-based polymer, for example, a kind of single fiber such as polyethylene or polypropylene, or a composite fiber composed of a polymer having a different core and sheath. It may be. Examples of the composite fibers that can be used include core-sheath composite fibers having a polyolefin-based polymer, for example, polyethylene as a sheath component, and polymers other than those used as the sheath component, for example, polypropylene as a core component. . A material in which an ion exchange group is introduced into such a composite fiber material using a radiation graft polymerization method is excellent as an ion exchange capacity and can be produced in a uniform thickness. Therefore, it is preferable as an ion exchange fiber material used for the above-mentioned purpose. . Examples of the form of the ion exchange fiber material include woven fabric and non-woven fabric.

  In addition, as an ion exchanger in the form of a spacer member such as an oblique network, a polyolefin polymer resin, for example, a polyethylene oblique network (net) widely used in an electrodialysis tank, A material imparted with an ion exchange function using a radiation graft polymerization method is preferable because of its excellent ion exchange ability and excellent dispersibility of raw water.

  The radiation graft polymerization method is a technique in which a monomer is introduced into a substrate by irradiating a polymer substrate with radiation to form radicals and reacting the monomer with this. Examples of radiation that can be used in the radiation graft polymerization method include α rays, β rays, γ rays, electron beams, ultraviolet rays, and the like, and it is preferable to use gamma rays and electron beams. The radiation graft polymerization method includes pre-irradiation graft polymerization method in which a graft substrate is irradiated with radiation in advance and then brought into contact with the graft monomer and reacted, and simultaneous irradiation graft polymerization method in which radiation is irradiated in the presence of the substrate and the monomer. However, either method can be used.

  In addition, by the contact method of the monomer and the base material, a liquid phase graft polymerization method for performing polymerization while the base material is immersed in the monomer solution, a vapor phase graft polymerization method for performing the polymerization by bringing the base material into contact with the vapor of the monomer, Examples of the method include an impregnation gas phase graft polymerization method in which the substrate is immersed in the monomer solution and then taken out from the monomer solution and reacted in the gas phase, and any method can be used.

  The ion exchange group introduced into the fiber base material such as a nonwoven fabric or the spacer base material is not particularly limited, and various cation exchange groups or anion exchange groups can be used. For example, as the cation exchange group, a strong acid cation exchange group such as a sulfone group, a neutral acid cation exchange group such as a phosphate group, a weak acid cation exchange group such as a carboxyl group, and an anion exchange group include primary to first-order cation exchange groups. Weakly basic anion exchange groups such as tertiary amino groups and strong basic anion exchange groups such as quaternary ammonium groups can be used. Or the ion exchanger which has both the said cation exchange group and anion exchange group can also be used.

  In addition, as a functional group, a functional group derived from iminodiacetic acid and its sodium salt, various amino acids such as phenylalanine, lysine, leucine, valine and proline and a functional group derived from its sodium salt, derived from iminodiethanol An ion exchanger having a functional group or the like may be used.

  Examples of the monomer having an ion exchange group that can be used for the above-described purpose include acrylic acid (AAc), methacrylic acid, sodium styrenesulfonate (SSS), sodium methallylsulfonate, sodium allylsulfonate, sodium vinylsulfonate, Examples thereof include vinylbenzyltrimethylammonium chloride (VBTAC), diethylaminoethyl methacrylate, dimethylaminopropylacrylamide and the like.

  For example, by conducting radiation graft polymerization using sodium styrenesulfonate as a monomer, a sulfone group that is a strongly acidic cation exchange group can be introduced directly into the substrate, and vinylbenzyltrimethylammonium chloride is used as a monomer. By using the radiation graft polymerization, a quaternary ammonium group which is a strongly basic anion exchange group can be directly introduced into the substrate.

  Examples of the monomer having a group that can be converted into an ion exchange group include acrylonitrile, acrolein, vinylpyridine, styrene, chloromethylstyrene, and glycidyl methacrylate (GMA). For example, glycidyl methacrylate is introduced into the substrate by radiation graft polymerization, and then a sulfone group, which is a strongly acidic cation exchange group, is introduced into the substrate by reacting with a sulfonating agent such as sodium sulfite, or chloromethyl After graft polymerization of styrene, a quaternary ammonium group that is a strongly basic anion exchange group can be introduced into the substrate by immersing the substrate in an aqueous trimethylamine solution to perform quaternary ammonium formation.

  In addition, after graft polymerization of chloromethylstyrene on a base material, a sulfide is reacted to form a sulfonium salt, and then sodium iminodiacetate is reacted to introduce a sodium iminodiacetate group as a functional group into the base material. . Alternatively, after first graft-polymerizing chloromethylstyrene to the substrate, the chloro group is replaced with iodine, then reacted with iminodiacetic acid diethyl ester to replace iodine with the iminodiacetic acid diethyl ester group, and then sodium hydroxide is added. By converting the ester group to a sodium salt by reaction, a sodium iminodiacetate group can be introduced as a functional group into the substrate.

  Among the various types of ion exchangers described above, an ion exchange fiber material in the form of a nonwoven fabric or a woven fabric is particularly preferable. Fiber materials such as woven fabric and non-woven fabric have a very large surface area compared to materials in the form of resin beads and diagonal meshes, so the amount of ion-exchange groups introduced is large, and micropores inside the beads like resin beads. Or, there are no ion exchange groups in the macropores, and all ion exchange groups are arranged on the surface of the fiber, so that metal ions in the treated water are easily diffused in the vicinity of the ion exchange groups, and ion exchange Is adsorbed by. Therefore, when an ion exchange fiber material is used, the removal / recovery efficiency of metal ions can be further improved.

  In addition to the above ion exchange fiber material, known ion exchanger resin beads can be used. For example, by using beads such as polystyrene cross-linked with divinylbenzene as a base resin, this is treated with a sulfonating agent such as sulfuric acid or chlorosulfonic acid to perform sulfonation and introduce sulfone groups into the base material. The strongly acidic cation exchange resin beads that can be used in the above-described configuration examples can be obtained.

  Such a production method is well known, and examples of the cation exchange resin beads produced by such a method include those marketed under various trade names. Also, functional groups derived from iminodiacetic acid and its sodium salt as functional groups, various amino acids such as phenylalanine, lysine, leucine, valine and proline and functional groups derived from their sodium salts, functionalities derived from iminodiethanol Resin beads having groups and the like may be used.

  If the electrodialyzer in the above-described configuration example is used to treat wastewater containing at least ammonium ions and fluorine, the ammonium ions and fluorine are removed from the wastewater to produce treated water with reduced concentrations of ammonium ions and fluorine. The first concentrated water having an increased fluorine concentration and the second concentrated water having an increased ammonium ion concentration can be produced. Alternatively, by treating at least the metal ions that form metal hydroxide sludge and the fluorine-containing wastewater by the electrodialysis apparatus in each configuration example described above, the metal ions and fluorine are removed from the wastewater by removing the metal ions and fluorine. As a result, the first concentrated water having a higher fluorine concentration and the second concentrated water having a higher metal ion concentration can be generated.

  In the case of wastewater containing hydrogen peroxide and fluorine, the wastewater may be supplied to the electrodialysis apparatus after being subjected to hydrogen peroxide decomposition treatment. Moreover, it is preferable that the fluorine concentration of waste water exceeds 1 mg / L and is 10,000 mg / L or less, and the fluorine concentration of treated water is preferably less than 1 mg / L.

  According to the electrodialysis apparatus described in each of the above-described configuration examples, it is possible to treat concentrated wastewater in which the concentration of contained substances in the wastewater exceeds 1%, but the concentrated wastewater discharged from the demand device 540 If the amount is small, it is not reasonable to re-concentrate after mixing dilute waste water and rich waste water. In such a case, as described above, it is preferable to separate and collect the lean waste water and the thick waste water from the waste water discharged from the demand device 540.

  FIG. 15 is a schematic diagram showing a configuration of a pure water circulation system according to the second embodiment of the present invention. The pure water circulation system in the first embodiment described above is applied when the substance having an oxidizing action is not included in the waste water from the demand equipment 540, but the pure water circulation in the present embodiment. The system is applied when a substance having an oxidizing action (oxidizing substance) is contained in waste water from the demand equipment 540.

  That is, since each component of the pure water circulation system is easily affected by substances having an oxidizing action, as shown in FIG. 15, an oxidizing substance is introduced from the waste water from the demand equipment 540 before the electrodialyzer 560. The oxidizing substance removing device 600 to be removed is provided, and the oxidizing substance removing device 600 removes the oxidizing substance from the waste water before supplying it to the electrodialyzer 560. The substance having oxidizing action (oxidizing substance) here does not indicate a specific substance but means a substance such as ozone or hydrogen peroxide. Note that a method for removing the oxidizing substance in the oxidizing substance removing apparatus 600 is not particularly limited, and various methods can be used. For example, a method using a catalyst such as activated carbon or platinum, a method using ultraviolet irradiation, a method of injecting a substance having a reducing action, or the like can be used.

  The diluted waste water from which the oxidizing substances have been removed is supplied to the electrodialysis apparatus 560 described above, and is separated into clean treated water and concentrated water from which ionic components in the waste water have been removed. The treated water is supplied to the secondary pure water generation unit 520 of the pure water production apparatus 530 as raw water for ultra pure water and reused. The method for discharging the separated concentrated water is not particularly limited. For example, substances contained in the concentrated water can be recovered and reused, or discarded as waste or treated at a general wastewater treatment facility in the factory. You may do it.

  FIG. 16 is a schematic diagram showing a configuration of a pure water circulation system according to the third embodiment of the present invention. As shown in FIG. 16, in this embodiment, a plurality of electrodialyzers 560 (two in FIG. 16) in the first embodiment described above are connected in series, and the secondary pure water of the pure water production apparatus 530 is connected. The quality of the treated water supplied to the water generator 520 is further improved. FIG. 16 shows an example in which two electrodialyzers 560 are connected in series. However, the number of electrodialyzers 560 that are directly connected is not limited to two. Also good. In addition, an oxidizing substance removing device 600 as in the second embodiment may be provided in front of a plurality of electrodialyzers 560.

  The preferred embodiments of the present invention have been described above, but the present invention is not limited to the above-described embodiments, and it goes without saying that the present invention may be implemented in various forms within the scope of the technical idea.

It is a schematic diagram which shows the structure of the pure water circulation system in the 1st Embodiment of this invention. It is a schematic diagram which shows the 1st structural example of the electrodialysis apparatus used in the pure water circulation system which concerns on this invention. It is a schematic diagram which shows the electrodialysis tank of FIG. It is a schematic diagram which shows the 2nd structural example of the electrodialysis apparatus used in the pure water circulation system which concerns on this invention. It is a schematic diagram which shows the 3rd structural example of the electrodialysis apparatus used in the pure water circulation system which concerns on this invention. It is a schematic diagram which shows the 4th structural example of the electrodialysis apparatus used in the pure water circulation system which concerns on this invention. It is a schematic diagram which shows the electrodialysis tank of FIG. It is a schematic diagram which shows the 5th structural example of the electrodialysis apparatus used in the pure water circulation system which concerns on this invention. It is a schematic diagram which shows the electrodialysis tank of FIG. It is a schematic diagram which shows the 6th structural example of the electrodialysis apparatus used in the pure water circulation system which concerns on this invention. It is a schematic diagram which shows the electrodialysis tank of FIG. It is a schematic diagram which shows the 7th structural example of the electrodialysis apparatus used in the pure water circulation system which concerns on this invention. It is a schematic diagram which shows the electrodialysis tank of FIG. It is a schematic diagram which shows the 8th structural example of the electrodialysis apparatus used in the pure water circulation system which concerns on this invention. It is a schematic diagram which shows the structure of the pure water circulation system in the 2nd Embodiment of this invention. It is a schematic diagram which shows the structure of the pure water circulation system in the 3rd Embodiment of this invention.

Explanation of symbols

1, 101a, 101b, 201, 301, 401 Electrodialysis tank 2 Anode 3 Cathode 10, 210 Anode chamber 20, 220 Buffer chamber 21, 30, 31 Concentration chamber 40, 240 Desalination chamber 50, 250 Cathode chamber 70, 72, 74, 270, 272, 274, 276, 278, 280, 287 Pump 71, 271 Polar liquid tank 73, 273 Buffer water tank 75 Concentrated water tank 230 Acid concentrating chamber 231 Alkaline concentrating chamber 260 Acid supply chamber 261 Bipolar chamber 275 Acid Concentrated water tank 277 Alkaline concentrated water tank 279 Acid supply water tank 281 Acid stock solution tank 282 pH monitor 284 Raw water tank 285 Activated carbon 286 Cartridge filter 500 Pure water circulation supply system 510 Primary pure water generation unit 520 Secondary pure water generation unit 530 Pure Water production equipment 540 Demand equipment (use point)
550 Ultrapure water path 560 Electrodialysis apparatus 570 Treated water path 580 Drainage path 600 Oxidizing substance removing apparatus AF1 to AF4, AF11 to AF16 Anion exchange nonwoven fabric AM1, AM2, AM11 to AM13 Anion exchange membrane AS1, AS11, AS12 Anion exchange spacer CF1-CF6, CF11-CF16 Cation exchange nonwoven fabric CM1-CM3, CM11-CM13 Cation exchange membrane CS1-CS3, CS11-CS13 Cation exchange spacer

Claims (6)

A pure water production apparatus having a primary pure water generation unit that generates pure water and a secondary pure water generation unit that generates ultrapure water from pure water;
An ultrapure water path for supplying ultrapure water generated by a secondary pure water generator of the pure water production apparatus to a demand device;
An anode chamber having an anode; a cathode chamber having a cathode; a desalination chamber that removes target ions from waste water discharged from the demand equipment to generate treated water in which the concentration of the target ions is reduced; An electrodialyzer having a concentration chamber for concentrating target ions in the wastewater moved from the salt chamber to generate concentrated water in which the concentration of the target ions is increased, and a path for supplying pure water to the anode chamber; ,
A treated water path for supplying treated water in which the concentration of the target ions is reduced by the electrodialyzer to a secondary pure water generating unit of the pure water producing apparatus;
A pure water circulation supply system. A pure water production apparatus having a primary pure water generation unit that generates pure water and a secondary pure water generation unit that generates ultrapure water from pure water;
An ultrapure water path for supplying ultrapure water generated by a secondary pure water generator of the pure water production apparatus to a demand device;
An oxidizing substance removing device for removing the oxidizing substance from the waste water discharged from the demand equipment;
An anode chamber having an anode, a cathode chamber having a cathode, and treated water in which the concentration of the target ions is reduced by removing the target ions from the waste water from which the oxidizing substances have been removed by the oxidizing substance removing device. A desalination chamber, a concentration chamber for concentrating the target ions in the wastewater moved from the desalination chamber to generate concentrated water in which the concentration of the target ions is increased, and a path for supplying pure water to the anode chamber An electrodialyzer having
A treated water path for supplying treated water in which the concentration of the target ions is reduced by the electrodialyzer to a secondary pure water generating unit of the pure water producing apparatus;
A pure water circulation supply system.   The pure water circulation supply system according to claim 1 or 2, wherein a plurality of the electrodialyzers are connected in series. Pure water is generated by the primary pure water generation unit of the pure water production device,
Ultra pure water is produced from pure water by the secondary pure water production unit of the pure water production apparatus,
Supplying ultrapure water generated by the secondary pure water generation unit of the pure water production apparatus to the demand equipment;
Supply the waste water discharged from the demand equipment to the desalination chamber of the electrodialysis machine,
While supplying pure water to the anode chamber of the electrodialysis apparatus, a voltage is applied between the anode disposed in the anode chamber and the cathode disposed in the cathode chamber to remove target ions from the waste water, Generate treated water with reduced concentration of target ions,
A pure water reuse method, characterized in that treated water having a reduced concentration of the target ions is supplied to a secondary pure water generation unit of the pure water production apparatus and reused. Pure water is generated by the primary pure water generation unit of the pure water production device,
Ultra pure water is produced from pure water by the secondary pure water production unit of the pure water production apparatus,
Supplying ultrapure water generated by the secondary pure water generation unit of the pure water production apparatus to the demand equipment;
Supplying wastewater discharged from the demand equipment to the oxidizing substance removing device;
Removing the oxidizing substance from the waste water by the oxidizing substance removing device;
Supplying the waste water from which the oxidizing substance has been removed to the desalting chamber of the electrodialysis machine,
While supplying pure water to the anode chamber of the electrodialysis apparatus, a voltage is applied between the anode disposed in the anode chamber and the cathode disposed in the cathode chamber to remove target ions from the waste water, Generate treated water with reduced concentration of target ions,
A pure water reuse method, characterized in that treated water having a reduced concentration of the target ions is supplied to a secondary pure water generation unit of the pure water production apparatus and reused.   6. The substrate processing method according to claim 4, wherein the substrate is processed using the ultrapure water.

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