Ultrapure water production device and ultrapure water production method

Abstract

An ultrapure water production device (100) capable of removing a trace amount of oxidizing substances such as dissolved oxygen is provided with: a primary pure water tank (110) for receiving water to be treated such as primary pure water; a pump (120) for supplying the water to be treated in the primary pure water tank (110); an ultraviolet irradiation device (140) provided on the secondary side of the pump (120); and a dissolved oxygen removal device (10) that is provided downstream of the ultraviolet irradiation device (140), removes at least dissolved oxygen, and circulates at least a portion of the produced ultrapure water to the primary pure water tank. A dissolved oxygen removal device (10) is provided with an anode (11), a cathode (12), and a dissolved oxygen removal chamber (23) disposed between the anode (11) and the cathode (12) and filled with an ion exchanger, at least a portion of the ion exchanger is an ion exchanger carrying a metal catalyst, and a direct current is applied between the anode (11) and the cathode (12).

Description

Technical Field

[0001] The present invention relates to an apparatus and method for producing ultrapure water, and in particular to an ultrapure water production apparatus and method for producing ultrapure water in which the concentration of oxidizing substances such as dissolved oxygen is reduced. Background Art

[0002] Ultrapure water with a high degree of impurities removed is widely used in applications such as cleaning of silicon wafers in semiconductor manufacturing processes. Generally speaking, ultrapure water is produced in the following manner: river water, well water, industrial water, etc. are used as raw water, and the raw water is sequentially treated by a pretreatment system and a primary pure water system to generate primary pure water, which is further treated by a subsystem. The subsystem is also called a secondary pure water system. The subsystem is constructed as follows: ultrapure water is generated by sequentially treating primary pure water as treated water and supplied to the point of use, but the ultrapure water that is not supplied to the point of use is returned to the inlet side of the subsystem, so that the water circulates in the subsystem.

[0003] Most subsystems are equipped with membrane degassing devices to remove dissolved oxygen (DO) contained in the treated water, i.e., primary pure water. In the subsystem, the membrane degassing device is, for example, disposed between the outlet of the ultraviolet irradiation device and the inlet of the non-regenerative ion exchange device, or disposed at the rear stage of the non-regenerative ion exchange device. In the membrane degassing device, it is necessary to maintain the vacuum degree on the gas phase side, and therefore it is necessary to provide a vacuum pump, etc. The gas phase side is on the opposite side of the treated water across the degassing membrane. As a method for removing dissolved oxygen without relying on membrane degassing, for example, Patent Document 1 discloses the following: after adding a reducing agent such as hydrogen to the treated water, the treated water is contacted with a metal-supported catalyst carrying a metal such as palladium, and a reaction is performed in which dissolved oxygen and hydrogen generate water as shown in the following formula (1), thereby removing dissolved oxygen from the treated water.

[0004] 2H 2 +O 2 →2H 2 O (1) Similarly, Patent Document 2 discloses the following: as a method of removing dissolved oxygen in a subsystem, a precious metal catalyst filling container is arranged at the rear stage of the ultraviolet oxidation device in the subsystem, and the precious metal catalyst filling container is filled with a precious metal catalyst that has previously absorbed hydrogen. In a method of removing dissolved oxygen in treated water by adding hydrogen to the treated water and reacting the dissolved oxygen with hydrogen on a catalyst, if the amount of hydrogen added is inappropriate, the concentration of dissolved hydrogen (DH) in the treated water may become high. Therefore, Patent Document 3 discloses an oxidizing substance removal device that removes at least one of dissolved oxygen and hydrogen peroxide from treated water, and the oxidizing substance removal device has: a catalyst reaction device having a platinum group metal-supported catalyst; a hydrogenation device that is arranged at the front stage of the catalyst reaction device and adds hydrogen to the treated water; a concentration measurement unit that measures the dissolved hydrogen concentration of the treated water passing through the catalyst reaction device; and a control unit that adjusts the amount of hydrogen added in the hydrogenation device based on the measured dissolved hydrogen concentration.

[0005] In addition, as one of the devices for generating desalted water from treated water, there is an electro-deionized water production device (EDI (Electrodeionization) device). The EDI device is a device that combines electrophoresis and electrodialysis, and at least its desalination chamber is filled with an ion exchanger such as an ion exchange resin. The EDI device has the advantage of not requiring the treatment of regenerating the ion exchange resin by a reagent. In order to reduce the dissolved oxygen concentration in the desalted water generated by the EDI device, Patent Document 4 discloses the following: anion exchange resin and cation exchange resin are mixed and filled in the desalination chamber of the EDI device, and a part of the anion exchange resin is set as a catalyst resin loaded with copper and palladium, and hydrogen is added to the treated water supplied to the desalination chamber, and the treated water is desalinated in the desalination chamber, and dissolved oxygen is removed from the treated water. Since the cathode water discharged from the cathode chamber of the EDI device usually contains hydrogen, Patent Document 4 also discloses using cathode water as a hydrogen source and adding cathode water to the treated water.

[0006] Prior art literature Patent Literature Patent Document 1: Japanese Patent Application Publication No. 2010-240642 Patent Document 2: Japanese Patent Application Publication No. 2016-112532 Patent Document 3: Japanese Patent Application Publication No. 2015-166064 Patent Document 4: Japanese Patent Application Laid-Open No. 10-272474 Summary of the invention Technical problem to be solved by the invention The techniques described in Patent Documents 1 and 3 require a hydrogenation device for removing dissolved oxygen only, and the technique described in Patent Document 2 requires the preparation of a noble metal catalyst for storing hydrogen in advance. When these techniques are applied to an ultrapure water production system, additional equipment in the ultrapure water production system increases, resulting in an increase in initial cost and an increase in installation space. In addition, the technique described in Patent Document 4, which reduces the dissolved oxygen concentration in desalted water when generating desalted water using an EDI device, aims to reduce the dissolved oxygen concentration in desalted water to several tens of %. μ g / L, and cannot be directly applied to the production of ultrapure water where the dissolved oxygen concentration needs to be further reduced.

[0007] In the ultrapure water production system, it is desirable to reduce the dissolved oxygen concentration in the ultrapure water used as the treated water as much as possible, and the dissolved hydrogen concentration in the treated water also needs to be managed to be low. If the stoichiometric method is considered, the dissolved hydrogen concentration required to remove the dissolved oxygen is 1 / 8 of the dissolved oxygen concentration on a mass basis. μ g / L of dissolved oxygen and generate a dissolved oxygen concentration of less than 1 μ In the case of ultrapure water with a concentration of 100 g / L, it is necessary to manage the dissolved hydrogen concentration in a very small amount, and it is not clear whether it is possible to manage the dissolved hydrogen concentration or control the amount of hydrogen added at such a small level. In addition, it is also desired to reduce the concentration of hydrogen peroxide that is inevitably generated during the production process of ultrapure water.

[0008] The object of the present invention is to provide an ultrapure water production device and an ultrapure water production method, which can efficiently remove trace amounts of oxidizing substances such as dissolved oxygen contained in the treated water, and further, can easily manage the dissolved hydrogen concentration, so as to stably obtain good treated water quality.

[0009] Technical solutions for solving technical problems An ultrapure water production device according to one embodiment of the present invention is an ultrapure water production device for producing ultrapure water by sequentially treating treated water, and the ultrapure water production device comprises: a receiving part, which receives the treated water; a first pump, which is connected to the outlet of the receiving part and supplies the treated water; an ultraviolet irradiation device, which is arranged on the secondary side of the first pump, irradiates the treated water with ultraviolet rays and performs ultraviolet oxidation treatment; an oxidizing substance removal device, which is arranged at the rear stage of the ultraviolet irradiation device, and at least removes the oxidizing substances contained in the treated water; and a second pump, which is arranged at the rear stage of the oxidizing substance removal device and supplies the outlet water of the oxidizing substance removal device, and at least a part of the produced ultrapure water is circulated to the receiving part. Here, the oxidizing substance removal device comprises: an anode and a cathode; a dissolved oxygen removal chamber, which is arranged between the anode and the cathode and filled with an ion exchanger, and the treated water is passed therein; and a power supply device, which applies a direct current between the anode and the cathode, and at least a part of the ion exchanger filled in the dissolved oxygen removal chamber is an ion exchanger carrying a metal catalyst.

[0010] An ultrapure water production method according to one embodiment of the present invention is an ultrapure water production method for producing ultrapure water by sequentially treating treated water, and the ultrapure water production method includes: a first pressurizing step, pressurizing and supplying the treated water; an ultraviolet irradiation step, irradiating the treated water supplied by the first pressurizing step with ultraviolet rays to perform ultraviolet oxidation treatment; an oxidizing substance removal step, removing at least the oxidizing substances contained in the outlet water of the ultraviolet irradiation step; a second pressurizing step, pressurizing and supplying the outlet water of the oxidizing substance removal step; and a step of circulating at least a portion of the produced ultrapure water to the previous stage of the ultraviolet irradiation step. Here, the oxidizing substance removal step includes: a step of applying a direct current between an anode and a cathode; and a step of passing the treated water into a dissolved oxygen removal chamber arranged between the anode and the cathode and filled with an ion exchanger, wherein at least a portion of the ion exchanger filled in the dissolved oxygen removal chamber is an ion exchanger carrying a metal catalyst.

[0011] In an ultrapure water manufacturing device of one mode, dissolved oxygen in the treated water is removed in the dissolved oxygen removal chamber of the oxidizing substance removal device. The dissolved oxygen can be removed in the dissolved oxygen removal chamber because dissolved oxygen reacts with hydrogen to become water in the presence of a metal catalyst. Therefore, except for the case where the treated water introduced into the dissolved oxygen removal chamber originally contains hydrogen, it is necessary to generate hydrogen in the dissolved oxygen removal chamber, or to add hydrogen to the treated water on the upstream side of the dissolved oxygen removal chamber. However, the oxidizing substance removal device is basically the same structure as a conventional EDI device except that it is configured to remove oxidizing substances such as dissolved oxygen. In the cathode chamber of the EDI device, hydrogen is generated by the cathode reaction on the cathode surface, so that a part of the treated water supplied to the oxidizing substance removal device is branched and supplied to the cathode chamber, so that the outlet water of the cathode chamber merges with the treated water introduced into the dissolved oxygen removal chamber, thereby being able to supply the treated water containing hydrogen to the dissolved oxygen removal chamber. Alternatively, the cathode chamber itself can be used as a dissolved oxygen removal chamber. The dissolved oxygen removal chamber can also be used to remove oxidizing substances other than dissolved oxygen. Depending on the type of oxidizing substance, hydrogen is not required for the removal of the oxidizing substance. Therefore, there is a case where the water to be treated introduced into the dissolved oxygen removal chamber does not need to contain hydrogen.

[0012] It can be considered that the reaction rate of the reaction of dissolved oxygen and hydrogen in the presence of a metal catalyst is large, and in the dissolved oxygen removal chamber, the dissolved oxygen equivalent to the amount of hydrogen contained in the treated water is removed. Therefore, the dissolved hydrogen concentration of the treated water flowing out of the dissolved oxygen removal chamber is measured, and the amount of hydrogen added to the treated water is increased within the range where the dissolved hydrogen concentration of the treated water does not rise, thereby reducing the dissolved oxygen concentration in the treated water to the limit, and at the same time, the dissolved hydrogen concentration in the treated water can be managed. In the case where hydrogen is generated in the cathode chamber and the treated water that merges with the outlet water of the cathode chamber is introduced into the dissolved oxygen removal chamber, the DC current applied between the anode and the cathode of the oxidizing substance removal device is controlled according to the dissolved hydrogen concentration of the treated water, so that the dissolved oxygen concentration in the treated water can be reduced to the limit, and at the same time, the dissolved hydrogen concentration in the treated water can be managed.

[0013] In the present invention, as the metal catalyst carried by the ion exchanger filled in the dissolved oxygen removal chamber, any catalyst can be used as long as it is a catalyst that promotes the reaction of generating water from hydrogen and oxygen. As examples of such metal catalysts, iron, copper, manganese, palladium, platinum, etc. can be cited. Among them, platinum group metal catalysts not only promote the reduction reaction of oxygen, but also have high catalytic activity for the decomposition of hydrogen peroxide, and therefore can be suitable for use in the case where hydrogen peroxide is contained in the treated water. Platinum group metal catalysts refer to catalysts containing one or more metals selected from ruthenium, rhodium, palladium, osmium, iridium and platinum. Platinum group metal catalysts can contain any one of these metal elements alone, or two or more of them can be combined. Among them, platinum, palladium, and platinum / palladium alloys have high catalytic activity and are preferably used as platinum group metal catalysts.

[0014] The oxidizing substance removal device is typically also capable of removing oxidizing substances such as dissolved oxygen in the desalination chamber of the EDI device. As described later, hydrogen peroxide as an oxidizing substance can also be removed by the oxidizing substance removal device. Therefore, it is preferred that the dissolved oxygen removal chamber is divided by an ion exchange membrane, and by dividing by the ion exchange membrane, the desalination treatment of the treated water can also be efficiently performed in the dissolved oxygen removal chamber. Alternatively, the anode chamber or the cathode chamber in the EDI device can be used as a dissolved oxygen removal chamber, in which case the dissolved oxygen removal chamber is divided by an electrode plate serving as an anode or an electrode plate serving as a cathode.

[0015] Effects of the Invention According to the present invention, in the production of ultrapure water, a trace amount of oxidizing substances such as dissolved oxygen contained in water to be treated can be efficiently removed, and further, the dissolved hydrogen concentration can be easily managed, so that good treated water quality can be stably obtained. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a flowchart showing an example of the configuration of an ultrapure water production system.

[0017] Figure 2 This is a diagram showing an example of the structure of a dissolved oxygen removal device.

[0018] Figure 3 1 is a flowchart showing another example of the configuration of the ultrapure water production system.

[0019] Figure 4 It is a diagram showing another example of the structure of the dissolved oxygen removal device.

[0020] Figure 5 It is a diagram showing another example of the structure of the dissolved oxygen removal device.

[0021] Figure 6 It is a diagram showing another example of the structure of the dissolved oxygen removal device.

[0022] Figure 7 It is a diagram showing another example of the structure of the dissolved oxygen removal device.

[0023] Figure 8 It is a diagram showing another example of the structure of the dissolved oxygen removal device.

[0024] Fig. 9 It is a diagram showing another example of the structure of the dissolved oxygen removal device.

[0025] Fig.10 It is a diagram showing another example of the structure of the dissolved oxygen removal device.

[0026] Fig.11 It is a diagram showing another example of the structure of the dissolved oxygen removal device.

[0027] Fig.12 This is a diagram showing the structure of the dissolved oxygen removal device used in Example 1.

[0028] Fig.13 This is a graph showing the results obtained in Example 1.

[0029] Fig.14 This is a diagram showing the structure of the dissolved oxygen removal device used in Example 2. DETAILED DESCRIPTION

[0030] Next, an embodiment for implementing the present invention will be described. In an ultrapure water production system for producing ultrapure water from raw water such as industrial water, well water, and river water, an ultrapure water production apparatus according to the present invention is used as a subsystem. Figure 1 The structure of an ultrapure water production system incorporating the ultrapure water production apparatus 100 according to one embodiment is shown.

[0031] Figure 1The ultrapure water production system shown includes: a pretreatment system 200 that receives raw water and performs pretreatment; a primary pure water system 300 that treats the pretreated raw water and generates primary pure water; and an ultrapure water production device 100 of this embodiment as a subsystem that receives the primary pure water generated by the primary pure water system 300 and generates ultrapure water. The pretreatment system 200 includes a filter 210 and an activated carbon device (AC) 220, and the raw water is treated in this order. The primary pure water system 300 includes a reverse osmosis membrane device (RO) 310, which is supplied with raw water discharged from the activated carbon device 220 of the pretreatment system 200, and an ion exchange device 320, which is supplied with permeated water (RO permeated water) of the reverse osmosis membrane device 310, and obtains primary pure water from the ion exchange device 320. In addition to discharging permeated water, the reverse osmosis membrane device 310 also discharges concentrated water (RO concentrated water). The configurations of the pretreatment system 200 and the primary pure water system 300 described here are examples, and in the present embodiment, any known configuration for producing primary pure water can be used.

[0032] The ultrapure water production device 100 includes a primary pure water tank 110, which serves as a receiving part of the primary pure water supplied from the primary pure water system. The water in the primary pure water tank 110 is used as the treated water, and the treated water is sequentially treated to generate ultrapure water. A pump 120 is provided at the outlet of the primary pure water tank 110, which pressurizes and supplies the water in the primary pure water tank, i.e., the treated water. A heat exchanger (HE) 130, an ultraviolet irradiation device (UV) 140, a dissolved oxygen removal device 10 configured as an oxidizing substance removal device based on the present invention, a non-regenerative ion exchange device (CP) 160 also called a filter polisher, and an ultrafiltration membrane device (UF) 170 are sequentially provided on the secondary side of the pump 120. The ultraviolet irradiation device 140 irradiates the treated water with ultraviolet rays to perform ultraviolet oxidation treatment. The dissolved oxygen removal device 10 removes at least oxidizing substances contained in the treated water after the ultraviolet oxidation treatment. A representative substance of the oxidizing substances to be removed is dissolved oxygen. The dissolved oxygen removal device 10 will be described later.

[0033] The non-regenerative ion exchange device (CP) 160 removes ionic impurities contained in the treated water of the dissolved oxygen removal device 10, and the ultrafiltration membrane device 170 removes particulates contained in the outlet water of the non-regenerative ion exchange device (CP) 160. The outlet water, which is the permeated water of the ultrafiltration membrane device 170, is ultrapure water, and a pipe 172 for supplying the ultrapure water to the point of use is connected to the permeated water outlet of the ultrafiltration membrane device 170. Furthermore, a circulation pipe 175 for returning the ultrapure water to the primary pure water tank 110 is branched from the pipe 172. It should be noted that since the ultrafiltration membrane device 170 is a cross-flow type filtration device, the concentrated water (UF concentrated water) is also discharged from the ultrafiltration membrane device 170.

[0034] Figure 1 The ultrapure water production device 100 shown has the same structure as a general subsystem for producing ultrapure water from primary pure water, except that no membrane degassing device is provided and a dissolved oxygen removal device 10 is provided. Therefore, by supplying primary pure water to the primary pure water tank 110 and operating the pump 120, the primary pure water as the treated water is sequentially passed through the heat exchanger 130, the ultraviolet irradiation device 140, the dissolved oxygen removal device 10, the non-regenerative ion exchange device 160 and the ultrafiltration membrane device 170 and is sequentially treated, and as a result, ultrapure water is obtained as the permeate water of the ultrafiltration membrane device 170. Then, at least a part of the produced ultrapure water is returned to the primary pure water tank 110 via the circulation pipe 175. In this way, the treated water circulates inside the ultrapure water production device 100, and the purity of the ultrapure water is further improved as it circulates. It should be noted that, as described later, the dissolved oxygen removal device 10 also has a desalination function, so in Figure 1 In the ultrapure water production apparatus 10 shown, the non-regeneration type ion exchange device 160 may not be provided.

[0035] Next, use Figure 2 The oxidizing substance removal device according to the present invention, namely the dissolved oxygen removal device 10, is described. The dissolved oxygen removal device 10 has the function of removing oxidizing substances in the water to be treated, for example, removing dissolved oxygen in the water to be treated. Hydrogen peroxide is generated during the ultraviolet oxidation treatment, so the dissolved oxygen removal device 10 installed at the subsequent stage of the ultraviolet irradiation device 140 also removes hydrogen peroxide as an oxidizing substance. Figure 2 As shown, the dissolved oxygen removal device 10 is similar to a conventional EDI device, and includes an anode chamber 21 provided with an anode 11 and a cathode chamber 25 provided with a cathode 12, and a concentration chamber 22, a dissolved oxygen removal chamber 23, and a concentration chamber 24 are provided in sequence from the anode chamber 21 side between the anode chamber 21 and the cathode chamber 25. The anode chamber 21 and the concentration chamber 22 are divided by a cation exchange membrane 31, the concentration chamber 22 and the dissolved oxygen removal chamber 23 are divided by an anion exchange membrane 32, the dissolved oxygen removal chamber 23 and the concentration chamber 24 are divided by a cation exchange membrane 33, and the concentration chamber 24 and the cathode chamber 25 are divided by an anion exchange membrane 34. The anode chamber 21 is filled with a cation exchange resin (CER) as a cation exchanger, and the concentration chambers 22, 24, and the cathode chamber 25 are filled with an anion exchange resin (AER) as an anion exchanger. The ion exchanger having a metal catalyst supported on its surface is filled in the dissolved oxygen removal chamber 23 in a single bed manner. In Figure 2In the structure shown, an anion exchange resin with palladium (Pd) supported on the surface is filled in the dissolved oxygen removal chamber 23 in a single bed. In the following description, the anion exchange resin with palladium (Pd) supported on the surface is referred to as Pd supported anion exchange resin (Pd AER). Figure 2 In FIG. 1 , pipes for circulating liquid are indicated by solid lines, and wirings for applying direct current to the electrodes 11 and 12 and transmitting various signals are indicated by dotted lines.

[0036] The treated water, which is the outlet water of the ultraviolet irradiation device 140, is supplied to the inlet of the dissolved oxygen removal chamber 23 via the pipe 41. A pipe 42 and a pipe 43 are branched from the pipe 41, and the pipe 42 is used to supply the treated water to the cathode chamber 25, and the pipe 43 supplies the treated water to the concentration chambers 22 and 24 as the concentration chamber supply water. The outlet water of the cathode chamber 25 merges with the treated water flowing in the pipe 41 at the downstream side of the position where the pipe 42 branches from the pipe 41 via the pipe 44. Therefore, a part of the treated water introduced into the dissolved oxygen removal chamber 23 is the treated water after passing through the cathode chamber 25. The total amount of the treated water other than the part supplied to the concentration chambers 22 and 24 can also be introduced into the dissolved oxygen removal chamber 23 after passing through the cathode chamber 25. The treated water from which the dissolved oxygen has been removed is discharged from the dissolved oxygen removal chamber 23 via the pipe 46. The outlet water of the concentration chambers 22 and 24 is supplied to the anode chamber 21 via the pipe 47 , and the outlet water of the anode chamber 21 is discharged to the outside of the dissolved oxygen removal device 10 via the pipe 48 as waste water.

[0037] A dissolved hydrogen concentration meter (DH meter) 51 for measuring the dissolved hydrogen concentration of the treated water is connected to the pipe 46 through which the treated water, which is the outlet water of the dissolved oxygen removal chamber 23, flows. Furthermore, the dissolved oxygen removal device 10 includes: a power supply device 52 for applying a direct current between the anode 11 and the cathode 12; and a control device 53 for controlling the power supply device 52. The measured value of the dissolved hydrogen concentration meter 51 is sent to the control device 53, and the control device 53 controls the power supply device 52 so that the current flowing between the anode 11 and the cathode 12 changes based on the measured value of the dissolved hydrogen concentration meter 51, that is, the dissolved hydrogen concentration in the treated water.

[0038] Next, Figure 2 The removal of dissolved oxygen in the dissolved oxygen removal device 10 shown in FIG. 1 is described. A direct current is applied between the anode 11 and the cathode 12, and the treated water is supplied to the dissolved oxygen removal chamber 23 and the cathode chamber 25 while the concentration chamber supply water is supplied to the concentration chambers 22 and 24. In the cathode chamber 25, a cathode reaction is carried out on the surface of the cathode 12 by the direct current to generate hydrogen (H 2), the treated water discharged from the cathode chamber 25 as outlet water contains hydrogen. The outlet water merges with the treated water flowing in the pipe 41 from the cathode chamber 25 via the pipe 44, so hydrogen is added to the treated water introduced into the dissolved oxygen removal chamber 23. The hydrogen is not only dissolved in the treated water, but also dispersed in the treated water as tiny bubbles. If the treated water containing hydrogen in this way flows into the dissolved oxygen removal chamber 23, the dissolved oxygen in the treated water reacts with hydrogen on the surface of the Pd-loaded anion exchange resin (Pd AER) filled in the dissolved oxygen removal chamber 23 to generate water. The amount of dissolved oxygen in the treated water that reacts with hydrogen is reduced, and the dissolved hydrogen is also reduced. Since the reaction rate of hydrogen and oxygen in the presence of palladium as a metal catalyst is large, if the treated water contains a sufficient amount of hydrogen, the treated water with the dissolved oxygen fully removed is discharged from the dissolved oxygen removal chamber 23. If hydrogen exists in the dissolved oxygen removal chamber 23, the dissolved oxygen is removed, so the dissolved oxygen can be removed even if the direct current is applied intermittently between the anode 11 and the cathode 12, taking into account the retention time of the treated water in the dissolved oxygen removal chamber 23 and the cathode chamber 25. Furthermore, the treated water may be intermittently introduced into the dissolved oxygen removal chamber 23 while applying the direct current continuously or intermittently.

[0039] Since the Pd-loaded anion exchange resin is an anion exchanger, the dissolved oxygen removal chamber 23 filled with the Pd-loaded anion exchange resin functions in the same manner as a desalination chamber in a conventional EDI device, and desalination of the treated water is also performed in the dissolved oxygen removal chamber 23. For example, carbonate ions (CO 3 2- ), bicarbonate ion (HCO 3 - ) and other anions are captured by the Pd-supported anion exchange resin. Hydroxyl ions (OH) are also generated by the dissociation of water on the surface of the cation exchange membrane 33 facing the dissolved oxygen removal chamber 23. - ), the anions captured by the Pd-loaded anion exchange resin (Pd AER) are freed by ion exchange with hydroxide ions, move by the electric field between the anode 11 and the cathode 12, and move to the concentration chamber 22 through the anion exchange membrane 32. Then, the anions moved to the concentration chamber 22 are discharged to the outside of the device through the anode chamber 21 along with the flow of the supply water in the concentration chamber 22.

[0040] The Pd-loaded anion exchange resin can also decompose hydrogen peroxide, so the hydrogen peroxide in the treated water is also removed in the dissolved oxygen removal device 10. In the ultrapure water production device 100 of this embodiment, the hydrogen peroxide in the treated water can be removed. When the Pd-loaded anion exchange resin decomposes hydrogen peroxide, the decomposition products are water and oxygen. The dissolved oxygen concentration increases by generating oxygen, but the generated oxygen reacts with hydrogen in the presence of the Pd-loaded anion exchange resin to become water, so there is no significant increase in the dissolved oxygen concentration caused by the decomposition and removal of hydrogen peroxide.

[0041] The ultrapure water production device 100 of this embodiment is configured as a subsystem in the ultrapure water production system 100. If a membrane degassing device is provided on the primary pure water system side, the dissolved oxygen concentration of the treated water at the inlet of the dissolved oxygen removal device 10 is several μ g / L~tens μ g / L. As can be seen from the examples described later, in the dissolved oxygen removal device 10 of this embodiment, as long as the treated water contains hydrogen equivalent to the dissolved oxygen, the dissolved oxygen can be fully removed. Therefore, if the dissolved hydrogen concentration of the treated water is monitored by the dissolved hydrogen concentration meter 51 and the current value flowing between the anode 11 and the cathode 12 is controlled, the dissolved hydrogen concentration in the treated water can be managed and the dissolved oxygen concentration can be less than 1. μ g / L, the dissolved hydrogen concentration in the treated water can be less than 1 μ g / L. The amount of hydrogen to be generated to remove dissolved oxygen can be small, so the value of the direct current flowing between the anode 11 and the cathode 12 can also be reduced. Since the dissolved oxygen concentration and dissolved hydrogen concentration in the treated water are low, in the ultrapure water production device 100, there is no need to set a membrane degassing device for removing dissolved oxygen, etc.

[0042] use Figure 3 Another example of the ultrapure water production apparatus 100 will be described. Figure 1 In the ultrapure water production device 100 shown, the ultrapure water is circulated in the ultrapure water production device 100 by a pump 120 provided at the outlet of the primary pure water tank 110, and the ultrapure water is supplied to the point of use via the pipe 172. In the case where the pressure loss between the ultrapure water production device 100 and the point of use is large, including the pressure loss caused by the height of the position of the point of use, it is necessary to increase the discharge pressure of the pump 120. However, when the discharge pressure is increased, the anion exchange membranes 32, 34 and the cation exchange membranes 31, 33 in the dissolved oxygen removal device 10 may be damaged. Therefore, in Figure 3 In the ultrapure water production device 10 shown in FIG. Figure 1In the ultrapure water production device 100 shown, a booster pump 150 is provided at the front stage of the non-regeneration type ion exchange device 160, and the booster pump 150 pressurizes and supplies the treated water from the dissolved oxygen removal device 10. By providing the booster pump 150, it is possible to prevent the anion exchange membranes 32, 34 and the cation exchange membranes 31, 33 in the dissolved oxygen removal device 10 from being damaged, and at the same time, the supply capacity of ultrapure water to the use point can be improved.

[0043] exist Figure 1 and Figure 3 In the ultrapure water production apparatus 100 shown in the figure, the structure of the dissolved oxygen removal device 10 is not Figure 2 The structure shown in FIG. 1 can be various structures. Figures 4 to 11 An example of the structure of the dissolved oxygen removal device 10 is described. Figure 5 The dissolved oxygen removal device 10 shown in the following figures is Figure 2 Compared with the dissolved oxygen removal device 10 shown in FIG. 1 , only the structure of the dissolved oxygen removal chamber 23 and the arrangement of the dissolved oxygen removal chamber 23 and the concentration chambers 22 and 24 are different. Figures 5 to 11 In the figure, the description of the dissolved oxygen concentration meter 51, the power supply 52 and the control device 53 is omitted.

[0044] exist Figure 2 In the dissolved oxygen removal device 10 shown, a part of the treated water is branched and supplied to the concentration chambers 22 and 24 as concentration chamber supply water, but water other than the treated water may be used as the concentration chamber supply water. Figure 4 In the dissolved oxygen removal device 10 shown, UF concentrated water produced in the ultrafiltration membrane device 170 in the ultrapure water production device 100 is supplied to the pipe 43, and the UF concentrated water is supplied to the concentration chambers 22 and 24 as concentration chamber supply water.

[0045] Figure 5 The dissolved oxygen removal device 10 shown is a device as follows: Figure 2 In the dissolved oxygen removal device 10 shown, Pd-loaded anion exchange resin (Pd-AER) and anion exchange resin (AER) not loaded with a metal catalyst are mixed, that is, a mixed bed is filled in the dissolved oxygen removal chamber 23. In this structure, the amount of expensive palladium catalyst used can be reduced, thereby reducing costs.

[0046] Figure 6 The dissolved oxygen removal device 10 shown is Figure 2 The dissolved oxygen removal device 10 shown is the same as that shown in FIG. Figure 2The difference of the dissolved oxygen removal device 10 shown is that the dissolved oxygen removal chamber 23 has a multi-bed structure and the Pd-loaded anion exchange resin is provided only on the upstream side of the flow in the dissolved oxygen removal chamber 23. In the dissolved oxygen removal chamber 23, an anion exchange resin (AER) not loaded with a metal catalyst is filled on the downstream side of the flow. Since the reaction rate of hydrogen and oxygen in the presence of the Pd-loaded anion exchange resin is sufficiently high, even if the Pd-loaded anion exchange resin is filled in a multi-bed manner arranged in a part of the dissolved oxygen removal chamber 23, the dissolved oxygen in the water to be treated can be sufficiently removed. When the Pd-loaded anion exchange resin is arranged in the dissolved oxygen removal chamber 23 in a multi-bed manner, as long as there is no ion exchanger other than the Pd-loaded anion exchange resin in the area where the Pd-loaded anion exchange resin is arranged, that is, as long as the Pd-loaded anion exchange resin is arranged in a single bed manner limited to the area, the layer of the Pd-loaded anion exchange resin can be filled in any position in the dissolved oxygen removal chamber 23. In this case, it is necessary to prevent the generation of treated water that does not pass through the layer of the Pd-loaded anion exchange resin but flows in the dissolved oxygen removal chamber 23. In order to suppress the deterioration of the anion exchange resin that does not load the metal catalyst due to hydrogen peroxide, when the Pd-loaded anion exchange resin is arranged in the dissolved oxygen removal chamber 23 in a double bed manner, it is preferable to arrange the Pd-loaded anion exchange resin in the dissolved oxygen removal chamber 23 on the upstream side of the flow of the treated water. Figure 6 In the structure shown, the amount of expensive palladium catalyst used can be reduced, so the cost can be reduced.

[0047] Figure 7 The dissolved oxygen removal device 10 shown is Figure 6 The dissolved oxygen removal device 10 shown is the same as that shown in FIG. Figure 6 The dissolved oxygen removal device 10 shown is different in that the ion exchanger filled in the downstream area of ​​the dissolved oxygen removal chamber 23 of the multi-bed type is not an anion exchange resin without a metal catalyst but a cation exchange resin (CER) without a metal catalyst.

[0048] Figure 8 The dissolved oxygen removal device 10 shown is Figure 6 The dissolved oxygen removal device 10 shown is the same as that shown in FIG. Figure 6 The dissolved oxygen removal device 10 shown is different in that a downstream region in a dissolved oxygen removal chamber 23 of a multi-bed type is filled with an anion exchange resin not supporting a metal catalyst and a cation exchange resin not supporting a metal catalyst in a mixed bed system (MB).

[0049] exist Figure 2 , Figures 4 to 8In the dissolved oxygen removal device 10 shown, between the anode 11 and the cathode 12, a desalination chamber can be provided on the cathode side or the anode side of the dissolved oxygen removal chamber 23 in a manner adjacent to the dissolved oxygen removal chamber 23 via an intermediate ion exchange membrane. In this case, the outlet water from the dissolved oxygen removal chamber 23 can be passed into the desalination chamber, or the treated water can be passed into the desalination chamber and then supplied to the dissolved oxygen removal chamber 23. The desalination chamber is filled with an ion exchanger. The intermediate ion exchange membrane can be an anion exchange membrane, a cation exchange membrane, or a composite membrane such as a bipolar membrane. By configuring in this way, the desalination performance of the dissolved oxygen removal device 10 can be improved.

[0050] Fig. 9 An example of the dissolved oxygen removal apparatus 10 in which a desalination chamber is provided adjacent to the dissolved oxygen removal chamber 23 is shown. Fig. 9 The dissolved oxygen removal device 10 shown is a device as follows: Figure 2 In the dissolved oxygen removal device 10 shown, a desalination chamber 26 is arranged between the dissolved oxygen removal chamber 23 and the concentration chamber 24. The dissolved oxygen removal chamber 23 and the desalination chamber 26 are separated by a cation exchange membrane 35 as an intermediate ion exchange membrane, and the desalination chamber 26 and the concentration chamber 24 are separated by the cation exchange membrane 33. The desalination chamber 26 is filled with a cation exchange resin. The treated water that merges with the outlet water of the cathode chamber 25 is introduced into the dissolved oxygen removal chamber 23 via the pipe 41, and the outlet water of the dissolved oxygen removal chamber 23 is supplied to the desalination chamber 26 via the pipe 49, and the treated water from which the dissolved oxygen is removed and the desalination treatment is performed flows out of the desalination chamber 26 via the pipe 46. Fig. 9 In the example shown, the desalination chamber 26 is filled with a cation exchange resin in a single bed manner, but the filling manner of the ion exchange resin in the desalination chamber 26 is not limited thereto. For example, the desalination chamber 26 may be filled with an anion exchange resin and a cation exchange resin in a mixed bed manner, or the desalination chamber 26 may be filled with an anion exchange resin and a cation exchange resin in a multiple bed manner so that the upstream side is a layer of the cation exchange resin. It should be noted that when the desalination chamber 26 is filled with an anion exchange resin and a cation exchange resin in a mixed bed manner or a multiple bed manner, an anion exchange membrane is used in the intermediate ion exchange membrane that divides the dissolved oxygen removal chamber 23 and the desalination chamber 26.

[0051] Figure 2 , Figures 4 to 9 The dissolved oxygen removal device 10 shown has the same structure as a conventional EDI device except that the desalination chamber in the EDI device is used as the dissolved oxygen removal chamber 23 and dissolved oxygen is also removed in the dissolved oxygen removal chamber 23. In a conventional EDI device, a plurality of desalination chambers can be provided between the anode and the cathode. Figure 2 , Figures 4 to 9In the dissolved oxygen removal device 10 shown, the structure including the anion exchange membrane 32, the dissolved oxygen removal chamber 23, the cation exchange membrane 33 and the concentration chamber 24 is also used as a repeating unit. By arranging multiple such repeating units between the concentration chamber 22 adjacent to the anode chamber 21 and the anion exchange membrane 34 dividing the cathode chamber 25, multiple dissolved oxygen removal chambers 23 can be arranged between the anode 11 and the cathode 12. Fig.10 The dissolved oxygen removal device 10 shown is Figure 2 The dissolved oxygen removal device 10 shown is provided with a plurality of dissolved oxygen removal chambers 23, and the treated water added with the outlet water of the cathode chamber 25 is distributed in parallel and passed into the plurality of dissolved oxygen removal chambers 23 via the pipe 41. The treated water from which the dissolved oxygen has been removed is discharged from each dissolved oxygen removal chamber 23.

[0052] Furthermore, in the ultrapure water production apparatus according to the present invention, the cathode chamber 25 itself can function as the dissolved oxygen removal chamber 13 in the dissolved oxygen removal device 10. In this case, it is not necessary to provide a dissolved oxygen removal chamber separately from the cathode chamber. Fig.11 The figure shows a dissolved oxygen removal device 10 in which the cathode chamber itself serves as a dissolved oxygen removal chamber. Fig.11 The dissolved oxygen removal device shown is provided with an anode chamber 21 provided with an anode 11, a concentration chamber 24 divided from the anode chamber 21 by a cation exchange membrane 31, and a cathode chamber 25 provided with a cathode 12 and divided from the concentration chamber 24 by an anion exchange membrane 34. The anode chamber 21 is filled with a cation exchange resin, and the concentration chamber 24 is filled with an anion exchange resin. The cathode chamber 25 is filled with a Pd-loaded anion exchange resin in a single bed. The treated water containing dissolved oxygen is supplied to the cathode chamber 25 via a pipe 41, and the treated water passes through the cathode chamber 25. The treated water is supplied to the concentration chamber 24 via a pipe 43 branched from the pipe 41, and the outlet water of the concentration chamber 24 is directly supplied to the anode chamber 21 via a pipe 47. The outlet water of the anode chamber 21 is discharged to the outside via a pipe 48 as drainage.

[0053] exist Fig.11In the dissolved oxygen removal device 10 shown, a direct current is applied between the anode 11 and the cathode 12, and the treated water is supplied to the concentration chamber 24 and the cathode chamber 25. In the cathode chamber 25, a cathode reaction is carried out on the surface of the cathode 12 by utilizing the direct current to generate hydrogen. The hydrogen reacts with the dissolved oxygen in the treated water on the surface of the Pd-supported anion exchange resin to generate water. The amount of dissolved oxygen in the treated water that reacts with hydrogen is reduced. As a result, treated water with dissolved oxygen fully removed is discharged from the cathode chamber 25. If hydrogen exists in the cathode chamber 25, the dissolved oxygen is removed, so considering the residence time of the treated water in the cathode chamber 25, a direct current can also be applied intermittently between the anode 11 and the cathode 12. Furthermore, it is also possible to intermittently pass the treated water into the dissolved oxygen removal chamber 23 while applying a direct current continuously or intermittently.

[0054] Since the Pd-loaded anion exchange resin is an anion exchanger, anions in the treated water are captured by the Pd-loaded anion exchange resin. Hydroxyl ions (OH) are also generated by the cathode reaction at the cathode 12. - ), the anions captured by the Pd-supported anion exchange resin are freed by ion exchange with hydroxide ions, move through the electric field between the anode 11 and the cathode 12, and move to the concentration chamber 24 through the anion exchange membrane 34. Then, the anions moved to the concentration chamber 24 are discharged to the outside of the device through the anode chamber 21 along with the flow of the supply water in the concentration chamber 24. That is, in Fig.11 In the dissolved oxygen removal device 10 shown in FIG. 1 , anions are also desalted in the cathode chamber 25. In addition, the Pd-loaded anion exchange resin can also decompose hydrogen peroxide, so Fig.11 The dissolved oxygen removal device 10 shown can also remove hydrogen peroxide in the water to be treated, similarly to the dissolved oxygen removal device 10 described above.

[0055] Above, use Figure 2 , Figures 4 to 11 The dissolved oxygen removal device 10 as an oxidizing substance removal device is described. As described above, the dissolved oxygen removal device 10 has a structure as an EDI device, and therefore, as in the case of a general EDI device, the flow direction of water in each chamber (i.e., the anode chamber 21, the concentration chambers 22 and 24, the dissolved oxygen removal chamber 23, the cathode chamber 25, and the desalination chamber 26) is not limited to Figure 2 , Figures 4 to 11 For example, the flow of water in the dissolved oxygen removal chamber 23 and the concentrating chambers 22 and 24 adjacent thereto may be in a parallel flow relationship. In addition, instead of supplying the outlet water of the concentrating chambers 22 and 24 to the anode chamber 21, the outlet water of the concentrating chambers 22 and 24 may be supplied to the anode chamber 21 in parallel.

[0056] Furthermore, in each of the above-mentioned dissolved oxygen removal devices 10, the ion exchange resin filled in the concentration chambers 22 and 24 is not limited to the anion exchange resin. In at least one of the concentration chambers 22 and 24 constituting the dissolved oxygen removal device 10, the anion exchange resin and the cation exchange resin may be filled in a mixed bed or a multiple bed. It is also possible to configure such that the ion exchange membrane 31 that divides the anode chamber 21 and the concentration chamber 22 adjacent thereto is removed, and the concentration chamber 22 itself functions as the anode chamber 21. Similarly, it is also possible to configure such that the anion exchange membrane 34 that divides the cathode chamber 25 and the concentration chamber 24 adjacent thereto is removed, and the concentration chamber 24 itself functions as the cathode chamber 25.

[0057] Example Hereinafter, the present invention will be described in further detail based on examples.

[0058] [Example 1] Assembly Fig.12 The dissolved oxygen removal device shown. Fig.12 The dissolved oxygen removal device shown is the following device: Figure 2 In the dissolved oxygen removal device 10 shown, the dissolved hydrogen concentration meter 51 for measuring the dissolved hydrogen concentration of the treated water is removed, and instead, a dissolved hydrogen concentration meter (DH meter) 56 connected to the piping 44 and measuring the dissolved hydrogen concentration of the outlet water of the cathode chamber 25 is provided. Ultrapure water is used as the treated water, and the ultrapure water is supplied to the dissolved oxygen removal device via the piping 41 at a flow rate of 105 L / h. The supplied treated water is branched and flows into the cathode chamber 25 at a flow rate of 5 L / h, and flows into the concentration chambers 22 and 24 at a total flow rate of 5 L / h. The outlet water of the cathode chamber 25 merges with the treated water flowing in the piping 41, so the flow rate of the treated water flowing out of the dissolved oxygen removal chamber 23 is 100 L / h.

[0059] The power supply device 52 is controlled by the control device 53 to gradually increase the DC current value applied between the anode 11 and the cathode 12, and the dissolved hydrogen concentration in the outlet water of the cathode chamber 25 is measured by the dissolved hydrogen concentration meter (DH meter) 56. The results are shown in Fig.13 . Fig.13 The horizontal axis of is the applied current value per unit flow rate of the treated water flowing out of the dissolved oxygen removal chamber 23. In addition, the amount of hydrogen generated by the dissociation reaction of water generated in the cathode chamber 25 is theoretically calculated based on the applied current value, and the calculated value is shown as a theoretical value. Fig.13 .Depend on Fig.13 It can be seen that the measured dissolved hydrogen concentration is very consistent with the theoretical value, especially at the low current side. Therefore, by controlling the DC current value applied between the anode 11 and the cathode 12, even at a current value less than 10 μg / L, the dissolved hydrogen concentration in the treated water supplied to the dissolved oxygen removal chamber 23 can be managed. This means that it is possible to add only the amount of hydrogen required to remove the dissolved oxygen contained in the treated water, and it is also possible to manage the dissolved hydrogen concentration in the treated water flowing out of the dissolved oxygen removal chamber 23.

[0060] [Example 2] Assembly Fig.14 The dissolved oxygen removal device shown. Fig.14 The dissolved oxygen removal device shown is the following device: Figure 2 In the dissolved oxygen removal device 10 shown in the figure, instead of the dissolved hydrogen concentration meter 51 for measuring the dissolved hydrogen concentration of the treated water, a meter connected to the pipe 46 for measuring the dissolved hydrogen concentration, dissolved oxygen (DO) concentration and hydrogen peroxide (H 2 O 2 ) concentration measuring device 57, and further, a measuring device 58 connected to the piping 41 and measuring the dissolved hydrogen concentration, dissolved oxygen concentration and hydrogen peroxide concentration in the treated water supplied to the dissolved oxygen removal device is set. The treated water is supplied to the dissolved oxygen removal device at a flow rate of 105L / h via the piping 41. At this time, a part of the supplied treated water is branched and flows into the cathode chamber 25 at a flow rate of 5L / h, and another part flows into the concentration chambers 22 and 24 at a total flow rate of 5L / h. The outlet water of the cathode chamber 25 merges with the treated water flowing in the piping 41, so the flow rate of the treated water flowing out of the dissolved oxygen removal chamber 23 is 100L / h.

[0061] As the treated water, two types of treated water were used: ultrapure water without hydrogen peroxide added and ultrapure water with hydrogen peroxide added. For each treated water, the treated water was supplied to the dissolved oxygen removal device while the DC current value applied between the anode 11 and the cathode 12 was gradually increased to measure the dissolved hydrogen concentration, dissolved oxygen concentration and hydrogen peroxide concentration in the treated water. When ultrapure water without hydrogen peroxide was used as the treated water, the dissolved hydrogen concentration, dissolved oxygen concentration and hydrogen peroxide concentration of the treated water were as shown in Table 1, and the dissolved hydrogen concentration, dissolved oxygen concentration and hydrogen peroxide concentration in the treated water at this time were as shown in Table 2 according to the applied current value per unit flow rate of the treated water.

[0062] [Table 1] [Table 2] When ultrapure water to which hydrogen peroxide was added was used as the treated water, the dissolved hydrogen concentration, dissolved oxygen concentration, and hydrogen peroxide concentration of the treated water were shown in Table 3. The dissolved hydrogen concentration, dissolved oxygen concentration, and hydrogen peroxide concentration in the treated water at this time were shown in Table 4 at the applied current value per unit flow rate of the treated water.

[0063] [Table 3] [Table 4] From the results shown in Tables 1 to 4, it can be seen that, regardless of whether hydrogen peroxide is added or not, by increasing the current value of the direct current applied between the anode 11 and the cathode 12, the dissolved oxygen concentration of the treated water is reduced, and the dissolved oxygen concentration can be reduced to less than 1. μ g / L. In addition, it can be seen that if the dissolved oxygen concentration is less than 1 μ g / L, and then the current value is further increased, the dissolved hydrogen concentration is 1 μ That is, the dissolved oxygen removal device used in the ultrapure water production device according to the present invention, for example Figure 2 In the dissolved oxygen removal device 10 shown in Table 2, the current value is 85 mA·h / m 3 The current value in Table 4 is 380mA·h / m 3 As shown in the case of μ By increasing the current value applied between the anode 11 and the cathode 12 within a range of 1.5 g / L or more, the dissolved oxygen concentration in the treated water and the dissolved oxygen concentration can be maintained at less than 1. μ g / L. In addition, it can be seen that the hydrogen peroxide concentration can also be less than 1 μ g / L. About making the dissolved oxygen concentration less than 1 μ The current value required for removing hydrogen peroxide is greater in Table 4 than in Table 2. This is because hydrogen is also required to remove hydrogen peroxide.

[0064] Description of Reference Numerals 10 Dissolved oxygen removal device 11 Anode 12 Cathode 21 Anode chamber 22, 24 Concentration Room 23 Dissolved Oxygen Removal Chamber 25 Cathode Chamber 26 Desalination Chamber 31, 33, 35 Cation exchange membrane 32, 34 Anion exchange membrane 100 Ultrapure water production equipment 110 Primary pure water tank 130 Pumps 140 Ultraviolet irradiation device 150 Booster Pump 160 Non-regenerative ion exchange device 170 Ultrafiltration membrane device.

Claims

1. An ultrapure water production device, which produces ultrapure water by sequentially treating water to be treated, The ultrapure water production device comprises: A receiving part, which receives the treated water; a first pump connected to the outlet of the receiving part and supplying the treated water; An ultraviolet irradiation device is arranged on the secondary side of the first pump, and irradiates the water to be treated with ultraviolet rays to perform ultraviolet oxidation treatment; An oxidizing substance removing device, which is arranged at a later stage of the ultraviolet irradiation device and removes at least oxidizing substances contained in the treated water; as well as a second pump, which is disposed at the rear stage of the oxidizing substance removal device and supplies outlet water of the oxidizing substance removal device, At least a portion of the produced ultrapure water is circulated to the receiving portion, The oxidizing substance removal device comprises: Anode and cathode; a dissolved oxygen removal chamber, which is disposed between the anode and the cathode and filled with an ion exchanger and into which the treated water flows; as well as a power supply device for applying a direct current between the anode and the cathode, At least a portion of the ion exchanger filled in the dissolved oxygen removal chamber is an ion exchanger carrying a metal catalyst.

2. The ultrapure water production device according to claim 1, wherein: The ultrapure water production device also has: a measuring unit that measures a dissolved hydrogen concentration of treated water discharged from the dissolved oxygen removal chamber; and A control device controls the hydrogen concentration in the water to be treated introduced into the dissolved oxygen removal chamber based on the measurement value of the measurement unit.

3. The ultrapure water production device according to claim 2, wherein: The control device controls the power supply device to change a value of a current applied between the anode and the cathode.

4. The ultrapure water production device according to claim 3, wherein: The oxidizing material removal device has a cathode chamber in which the cathode is arranged. At least a portion of the treated water introduced into the oxidizing substance removal device is treated water after passing through the cathode chamber.

5. The ultrapure water production device according to claim 4, wherein: The ultrapure water production device further comprises an ultrafiltration membrane device, wherein the ultrafiltration membrane device is arranged at a subsequent stage of the oxidizing substance removal device. The oxidizing substance removing device comprises at least one concentrating chamber provided adjacent to the dissolved oxygen removing chamber, and an anode chamber provided with the anode. The concentrated water discharged from the ultrafiltration membrane device is supplied to the concentrating chamber and the anode chamber.

6. The ultrapure water production device according to claim 5, wherein: The dissolved oxygen removal chamber is partitioned by at least one of an electrode plate serving as the anode, an electrode plate serving as the cathode, and an ion exchange membrane.

7. A method for producing ultrapure water, which is a method for producing ultrapure water by sequentially treating water to be treated, The ultrapure water production method comprises: A first pressurizing step, pressurizing and supplying the treated water; an ultraviolet irradiation step of irradiating the water to be treated supplied in the first pressurizing step with ultraviolet rays to perform ultraviolet oxidation treatment; an oxidizing substance removing step, at least removing the oxidizing substances contained in the outlet water of the ultraviolet irradiation step; a second pressurizing step of pressurizing and supplying the outlet water of the oxidizing substance removing step; as well as a step of circulating at least a portion of the produced ultrapure water to a stage preceding the ultraviolet irradiation step, The oxidative substance removal process comprises: The process of applying a direct current between the anode and cathode; as well as The step of introducing the water to be treated into a dissolved oxygen removal chamber which is arranged between the anode and the cathode and filled with an ion exchanger, At least a portion of the ion exchanger filled in the dissolved oxygen removal chamber is an ion exchanger carrying a metal catalyst.

8. The method for producing ultrapure water according to claim 7, wherein: The dissolved hydrogen concentration of the treated water flowing out of the dissolved oxygen removal chamber is measured, and the value of the current applied between the anode and the cathode is controlled according to the measured dissolved hydrogen concentration.

9. The method for producing ultrapure water according to claim 7 or 8, wherein: At least a portion of the water to be treated introduced into the dissolved oxygen removal chamber is water to be treated that has passed through a cathode chamber in which the cathode is provided.

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