JP6439777B2 - Ultrapure water production apparatus and operation method of ultrapure water production apparatus - Google Patents

Description

  The present invention relates to an ultrapure water production apparatus provided with a primary pure water apparatus and a subsystem, and an operation method of the ultrapure water production apparatus, and more particularly to an ultrapure water having an ultraviolet oxidation apparatus and a platinum group metal catalyst resin tower in the subsystem. The present invention relates to a water production apparatus and a method for operating the ultrapure water production apparatus.

  Conventionally, ultrapure water used in the field of electronic industries such as semiconductors is to treat raw water with an ultrapure water production system composed of a pretreatment system, a primary pure water device, and a subsystem for processing primary pure water. It is manufactured by.

  As shown in FIG. 2, the conventional ultrapure water production apparatus 21 is generally composed of three-stage apparatuses such as a pretreatment apparatus 22, a primary pure water production apparatus 23, and a secondary pure water production apparatus (subsystem) 24. Yes. In such a pretreatment device 22 of the ultrapure water production device 21, the raw water W is subjected to pretreatment such as filtration, coagulation sedimentation, and a microfiltration membrane, and mainly suspended substances are removed.

  The primary pure water production apparatus 23 includes a tank 25 for pretreatment water W1, an ultraviolet (UV) oxidation apparatus 26, a regenerative ion exchange apparatus (such as a mixed bed type or a 4-bed 5-to-column type) 27, a membrane type deaerator 28, In addition, an RO membrane separation device, an electrodeionization device, or the like may be provided as necessary. Here, most of the electrolyte, fine particles, viable bacteria, etc. in the pretreated water W1 are removed and the organic matter is decomposed.

  The sub system 24 includes a sub tank 31 that stores the primary pure water W2 produced by the primary pure water production apparatus 23 described above, and an ultraviolet oxidation that processes the primary pure water W2 fed from the sub tank 31 via a pump (not shown). It comprises an apparatus 32, a platinum group metal catalyst resin tower 33, a membrane deaerator 34, a non-regenerative mixed bed ion exchanger 35, and an ultrafiltration (UF) membrane 36 as a membrane filtration device. Depending on the case, an RO membrane separation device or the like may be provided. In this subsystem 24, a trace amount of organic matter (TOC component) contained in the primary pure water W2 is oxidized and decomposed by ultraviolet rays in the ultraviolet oxidizer 32, and the hydrogen peroxide generated by the irradiation of the ultraviolet rays is converted into a platinum group metal catalyst resin tower. It decomposes | disassembles by 33 and removes dissolved gas, such as DO (dissolved oxygen) which is mixed in the film | membrane type deaerator 34 of the subsequent stage. Subsequently, the remaining carbonate ions, organic acids, anionic substances, as well as metal ions and cationic substances are removed by ion exchange by processing in the non-regenerative mixed bed ion exchange apparatus 35. Fine particles are removed by an ultrafiltration (UF) membrane 36 to obtain ultrapure water W 3, which is supplied to a use point 37, and unused ultrapure water returns to the sub tank 31.

  In the conventional ultrapure water production apparatus 21 as described above, the oxidative decomposition mechanism of the TOC component in the ultraviolet oxidizer 32 oxidizes and decomposes water to generate OH radicals, and oxidizes and decomposes the TOC components by the OH radicals. In general, the ultraviolet rays in the ultraviolet oxidizer 32 are irradiated with an excessive amount capable of sufficiently oxidizing and decomposing TOC in water. As described above, when the ultraviolet ray irradiation amount of the ultraviolet oxidizer 32 is large, OH radicals generated by the decomposition of water become excessive, so that excessive OH radicals associate to become hydrogen peroxide. The generated hydrogen peroxide is decomposed by contacting with the platinum group metal catalyst resin tower 33 in the subsequent stage.

  However, as a result of the study by the present inventors, it has been found that when the ultraviolet oxidizer 32 of the subsystem 24 decomposes hydrogen peroxide for a long period of time, the ability to remove hydrogen peroxide may decrease. As a result, hydrogen peroxide remaining in the ultrapure water W3 not only causes deterioration of water quality, but also may deteriorate the non-regenerative mixed bed ion exchange device 35 and the subsequent ultrafiltration (UF) membrane 36. There is. Furthermore, when hydrogen peroxide decomposes, oxygen is generated, which causes an increase in DO in water.

  The present invention has been made in view of the above problems, and includes platinum in an ultrapure water production apparatus that includes a primary pure water apparatus and a subsystem, and includes an ultraviolet oxidation apparatus and a platinum group metal catalyst resin tower in the subsystem. It is an object of the present invention to provide an ultrapure water production apparatus and a method for operating the ultrapure water production apparatus in which a decrease in the hydrogen peroxide removal ability of the group metal catalyst resin tower is suppressed.

  First, the present invention provides a primary pure water apparatus having an ultraviolet oxidation apparatus, a regenerative mixed bed ion exchange tower or an electrodeionization apparatus and a membrane deaeration apparatus, an ultraviolet oxidation apparatus, a platinum group metal catalyst resin tower and a membrane. An ultrapure water production apparatus comprising a sub-system for treating primary pure water obtained from the primary pure water apparatus, wherein a platinum group metal is disposed after the ultraviolet oxidation apparatus of the primary pure water apparatus Provided is an ultrapure water production apparatus provided with a catalyst resin tower (Invention 1).

  According to this invention (Invention 1), by providing a platinum group metal catalyst resin tower in the subsequent stage of the ultraviolet oxidation apparatus of the primary pure water apparatus, the peroxidation of the platinum group metal catalyst resin tower in the subsequent stage of the subsystem ultraviolet oxidation apparatus A decrease in hydrogen removal capability can be suppressed. This is due to the following reasons. That is, the decrease in the hydrogen peroxide removal ability of the platinum group metal catalyst resin tower in the latter stage of the subsystem UV oxidation apparatus is that the hydrogen is less than equivalent to hydrogen peroxide in the water to be treated, and the platinum group metal catalyst is oxidized. It is thought that it is to do. Next, as a result of examination by the present inventors on the cause of the shortage of hydrogen relative to hydrogen peroxide, hydrogen peroxide and hydrogen are generated along with the decomposition of organic substances in the ultraviolet oxidation apparatus of the primary pure water apparatus. It was found that hydrogen peroxide was caused to flow into the subsystem while being removed by the deaerator. Therefore, if a platinum group metal catalyst resin tower is installed after the UV oxidizer of the primary deionizer and hydrogen peroxide generated in the UV oxidizer of the primary deionizer is decomposed, the sub-system UV oxidizer will be The amount of hydrogen peroxide in the water to be treated is reduced, the hydrogen approaches the equivalent to hydrogen peroxide, and deterioration of the platinum group metal catalyst can be prevented.

  In the said invention (invention 1), it is preferable that the said subsystem further has a non-regenerative type mixed bed type ion exchange column (invention 2).

  According to this invention (Invention 2), a trace amount of organic matter contained in the water to be treated is decomposed by the ultraviolet oxidizer, remaining carbonate ions, organic acids, anionic substances, metal ions entering from the previous stage, and cationic properties. The material can be removed by ion exchange.

  In the said invention (invention 1 and 2), the platinum group metal in the platinum group metal catalyst resin tower of the said primary pure water apparatus and the platinum group metal catalyst resin tower of the said subsystem is platinum, palladium, or a platinum / palladium alloy. Is preferred (Invention 3).

  According to this invention (Invention 3), a trace amount of hydrogen peroxide contained in the treated water can be efficiently decomposed and removed.

  In the said invention (invention 1-3), it is preferable that the said platinum group metal is a particle | grain of the platinum group metal with an average particle diameter of 1-50 nm (invention 4).

  According to this invention (invention 4), hydrogen peroxide contained in the treated water can be decomposed and removed particularly efficiently.

  The present invention secondly, an ultraviolet oxidation apparatus, a platinum group metal catalyst resin tower, a regenerative mixed bed ion exchange tower or electrodeionization apparatus, a primary pure water apparatus having a membrane degassing apparatus, an ultraviolet oxidation apparatus, A method for operating an ultrapure water production apparatus comprising a platinum group metal catalyst resin tower and a membrane deaerator, and a subsystem for treating primary pure water obtained from the primary pure water apparatus, comprising: Provided is an operation method of an ultrapure water production apparatus for producing ultrapure water by continuously passing water through the primary pure water apparatus and the subsystem (Invention 5).

  According to this invention (invention 5), by disposing a platinum group metal catalyst resin tower after the ultraviolet oxidation device of the primary pure water device, hydrogen peroxide generated in the ultraviolet oxidation device of the primary pure water device is decomposed. Therefore, the amount of hydrogen peroxide in the water to be treated in the latter stage of the UV oxidizer of the subsystem is reduced, and hydrogen approaches the equivalent of hydrogen peroxide. Water can be produced.

  In the said invention (invention 5), it is preferable that the platinum group metal in the platinum group metal catalyst resin tower of the said primary pure water apparatus and the platinum group metal catalyst resin tower of the said subsystem is platinum, palladium, or a platinum / palladium alloy. (Invention 6).

  According to this invention (invention 6), a trace amount of hydrogen peroxide contained in the treated water can be efficiently decomposed and removed.

  In the said invention (invention 5 or 6), it is preferable that the said platinum group metal is a platinum group metal particle | grain with an average particle diameter of 1-50 nm (invention 7).

  According to this invention (invention 7), hydrogen peroxide contained in the treated water can be decomposed and removed particularly efficiently.

In the above invention (invention 5~7), H ₂ O ₂ concentration in the treated water of the ultraviolet oxidation device of the subsystem is 10-100 [mu] g / L, of the subsystems of the treated water of a platinum group metal catalyst resin column The H ₂ O ₂ concentration is preferably 0.1 to 10 μg / L (Invention 8).

According to this invention (Invention 8), the ultraviolet oxidation apparatus and the platinum group metal catalyst resin tower so that the H ₂ O ₂ concentration of the treated water in the subsystem ultraviolet oxidation apparatus and the platinum group metal catalyst resin tower is within the above range. By controlling the treatment conditions in the above, the adverse effect of the platinum group metal catalyst resin tower on the membrane deaerator in the subsequent stage is suppressed to a minimum, and the hydrogen peroxide concentration and dissolved oxygen of the obtained ultrapure water are reduced. The concentration can be very low.

  According to the present invention, the primary pure water obtained by decomposing hydrogen peroxide generated in the ultraviolet oxidizer is supplied to the subsystem, and the accompanying hydrogen peroxide is small. Since the concentration of hydrogen peroxide in the treated water decreases and hydrogen is relatively close to the equivalent to hydrogen peroxide, it is possible to produce ultrapure water while preventing deterioration of the platinum group metal catalyst.

It is a flowchart which shows the ultrapure water manufacturing apparatus by one Embodiment of this invention. It is a flowchart which shows the conventional ultrapure water manufacturing apparatus.

  Hereinafter, an ultrapure water production apparatus according to an embodiment of the present invention and a method for operating the apparatus will be described in detail with reference to FIG.

  FIG. 1 is a flowchart showing an ultrapure water production apparatus according to an embodiment of the present invention. In FIG. 1, an ultrapure water production apparatus 1 includes a pretreatment device 2, a primary pure water production device 3, and secondary pure water. The pretreatment device 2 is constituted by filtration of raw water W such as industrial water, well water, city water, coagulation sedimentation, a microfiltration membrane, and the like. ing.

  The primary pure water production apparatus 3 includes a tank 5 of pretreated water W1 as water to be treated, an ultraviolet (UV) oxidizer 6, a platinum group metal catalyst resin tower 7, a regenerative ion exchanger (mixed bed type or four beds 5). A tower type or the like) 8 and a membrane type deaerator 9.

  The sub-system 4 includes a sub-tank 11 for storing the primary pure water W2 produced by the primary pure water production apparatus 3 described above, an ultraviolet oxidizer 12 for treating the primary pure water supplied from the sub-tank 11, and a platinum group metal catalyst. A resin tower 13, a membrane deaerator 14, a non-regenerative mixed bed ion exchanger 15, and an ultrafiltration (UF) membrane 16 as a membrane filtration device are provided. After the passed ultrapure water W3 is supplied to the use point 17, the unused ultrapure water W3 is returned to the sub tank 11.

  In the ultrapure water production apparatus 1 as described above, the platinum group metal catalyst resin charged in the platinum group metal catalyst resin tower 7 and the platinum group metal catalyst resin tower 13 is obtained by supporting a platinum group metal on a carrier resin. .

  As the carrier resin for supporting the platinum group metal, an ion exchange resin can be used, and an anion exchange resin can be particularly preferably used. The anion exchange resin used in the present embodiment is preferably a strongly basic anion exchange resin based on a styrene-divinylbenzene copolymer, and particularly preferably a gel type resin. Since the platinum group metal is negatively charged, it is stably supported on the anion exchange resin and hardly peels off. The exchange group of the anion exchange resin is preferably in the OH form. In the OH-type anion exchange resin, the resin surface becomes alkaline and promotes decomposition of hydrogen peroxide.

  The supported platinum group metal has low elution to ultrapure water and high catalytic activity, so it can be passed at a high water flow rate, so even if any elution occurs, the eluate concentration is suppressed and early water quality is reduced. This is preferable in that deterioration is suppressed. Examples of the platinum group metal include ruthenium, rhodium, palladium, osmium, iridium, and platinum. These platinum group metals can be used individually by 1 type, can be used in combination of 2 or more types, can also be used as an alloy of 2 or more types, or the refined product of the naturally produced mixture Can also be used without separating them into single bodies. Among these, platinum, palladium, a platinum / palladium alloy alone or a mixture of two or more thereof can be used particularly suitably because of their high catalytic activity.

  In particular, as the platinum group metal catalyst resin, the above-described carrier resin in which particles of a platinum group metal having a nano-order particle size are supported can be suitably used.

  There is no restriction | limiting in particular in the method of manufacturing a platinum group metal nanoparticle, For example, a metal salt reduction reaction method, a combustion method, etc. can be mentioned. Among these, the metal salt reduction reaction method can be suitably used because it is easy to produce and stable metal nanoparticles can be obtained. In the case of a metal salt reduction reaction method, for example, 0.1 to 0.4 mmol / L aqueous solution of chloride such as platinum, nitrate, sulfate, metal complex, etc., alcohol, citric acid or a salt thereof, formic acid, acetone Metal nanoparticles can be produced by adding 4 to 20 equivalents of a reducing agent such as acetaldehyde and boiling for 1 to 3 hours. Further, for example, by dissolving 1-2 mmol / L of hexachloroplatinic acid, potassium hexachloroplatinate, etc. in an aqueous polyvinylpyrrolidone solution, adding a reducing agent such as ethanol, and heating and refluxing in a nitrogen atmosphere for 2 to 3 hours, platinum is obtained. Nano colloidal particles can also be produced.

  The average particle diameter of the platinum group metal nanoparticles is preferably 1 to 50 nm, more preferably 1.2 to 20 nm, and still more preferably 1.4 to 5 nm. When the average particle diameter of the metal nanoparticles exceeds 50 nm, the specific surface area of the nanoparticles becomes small, and the catalytic activity for the decomposition and removal of hydrogen peroxide may be reduced. On the other hand, if the average particle size of the metal nanoparticles is less than 1 nm, the catalytic activity for the decomposition and removal of hydrogen peroxide may be lowered.

  The amount of platinum group metal nanoparticles supported on the anion exchange resin as described above is preferably 0.01 to 0.2% by weight, more preferably 0.04 to 0.1% by weight. . If the supported amount of metal nanoparticles is less than 0.01% by weight, the catalytic activity for the decomposition and removal of hydrogen peroxide may be insufficient. The amount of metal nanoparticles supported is less than 0.2% by weight, and sufficient catalytic activity is exhibited for the decomposition and removal of hydrogen peroxide. Usually, it is not necessary to support more than 0.2% by weight of metal nanoparticles. It is not economical. Moreover, when the loading amount of metal nanoparticles increases, the risk of metal elution into water also increases.

  Next, an operation method of the ultrapure water production apparatus 1 according to this embodiment having the above-described configuration will be described.

  First, the turbidity in the raw water W is mainly removed by processing the raw water W by operations such as coagulation sedimentation, coagulation filtration, and coagulation pressure levitation. The pretreated water W1 is temporarily stored in the tank 5 and is supplied to the primary pure water device 3 by a pump (not shown).

In the primary pure water device 3, the organic matter (TOC) in the pretreated water W <b> 1 is oxidized by the ultraviolet (UV) oxidation device 6 to become an organic acid, and further to carbon dioxide. Moreover, OH radicals and hydrogen are generated by the decomposition of the water in the pretreatment water W1 due to the ultraviolet rays excessively irradiated by the ultraviolet oxidation treatment apparatus 6, and the excess OH radicals associate to become hydrogen peroxide. As a result, the H ₂ O ₂ concentration of the treated water of the ultraviolet oxidizer 6 is 10 to 100 μg / L. Further, hydrogen is removed by a membrane deaerator 9 described later. As a result, conventionally, treated water having a high hydrogen peroxide concentration and reduced hydrogen is supplied to the subsystem 4 as primary pure water, which causes a deterioration in the function of the platinum group metal catalyst resin tower 13 on the subsystem side. It was.

Therefore, in the present embodiment, the generated hydrogen peroxide is decomposed by providing a platinum group metal catalyst resin tower 7 in the subsequent stage of the ultraviolet oxidizer 6. Accordingly, the H ₂ O ₂ concentration is about 0.1 to 10 μg / L, and particularly when platinum group metal nanoparticles are used, the H ₂ O ₂ concentration is about 0.1 to 1 μg / L. 6 treated water. Then, most of the electrolyte (ionic components) in the pretreated water W1 is removed by a regenerative ion exchange device (mixed bed type or 4 bed 5 tower type) 8 and further dissolved oxygen etc. by a membrane type deaerator 9 dissolved gas to remove the organic matter (TOC) 2 ppb or _less, to obtain a concentration of H 2 _{O 2} 0.1-10 / L of primary pure water W2. The primary pure water W2 is once stored in the sub tank 11, and then sent to the subsystem 4 by a pump (not shown).

Next, in the subsystem 4, a trace amount of organic matter remaining in the primary pure water W2 is oxidized in the ultraviolet (UV) oxidizer 12 to become an organic acid, and further to carbon dioxide. At this time, in order to remove the organic matter to the utmost limit, the ultraviolet oxidation treatment device 12 is irradiated with excessive ultraviolet rays, so that the OH radicals generated by the decomposition of the water in the primary pure water W2 become excessive, so that the excess OH radicals associate By doing so, hydrogen peroxide is generated. As a result, the H ₂ O ₂ concentration in the primary pure water W2 is about 0.1 to 10 μg / L to about 10 to 100 μg / L, which is higher than that of the primary pure water W2.

Then, the generated hydrogen peroxide is decomposed at a later stage of the platinum group metal catalyst resin tower 13, when the concentration of H ₂ O ₂ is using 10 [mu] g / L degrees or less, especially platinum group metal nanoparticles, H ₂ O _The concentration of ₂ is 5 μg / L or less, particularly 1 μg / L or less, which is lower than the treated water of the ultraviolet oxidation treatment apparatus 12.

  On the other hand, oxygen is also generated by the decomposition of hydrogen peroxide, and the dissolved oxygen increases due to this, so the dissolved oxygen is removed by the membrane type deaerator 14 provided in the subsequent stage. Then, trace amounts of carbonate ions, organic acids, anionic substances, metal ions and cationic substances flowing in from the previous stage are removed by the non-regenerative mixed bed ion exchanger 15 and ultrafiltration (UF) is performed. It is possible to produce ultrapure water W3 by removing fine particles with the film 16. This ultrapure water W3 is supplied to the use point 17, and the unused ultrapure water W3 is returned to the sub tank 11.

  The ultrapure water W3 in the present embodiment is, for example, resistivity: 18.1 MΩ · cm or more, fine particles: particle size of 50 nm or more and 1000 / L or less, viable bacteria: 1 / L or less, TOC (Total Organic) Carbon): 1 μg / L or less, Total silica: 0.1 μg / L or less, Metals: 1 ng / L or less, Ions: 10 ng / L or less.

  In particular, when the platinum group metal catalyst resin of the platinum group metal catalyst resin tower 13 is used in which platinum group metal nanoparticles are supported on an anion exchange resin, the anion exchange resin supporting the platinum group metal nanoparticles is: Since the specific surface area is large, the reaction rate of hydrogen peroxide decomposition is very fast, and the water passing space velocity can be increased. Since the amount of water flow is larger than the amount of the catalyst, the influence of the metal eluted from the catalyst into the treated water can be greatly reduced. Furthermore, hydrogen peroxide in water decomposes rapidly upon contact with the platinum group metal nanocolloid particles supported on the anion exchange resin and does not act on the anion exchange resin. There is no risk that organic carbon (TOC) will be eluted.

  As mentioned above, although one embodiment of the present invention has been described with reference to the accompanying drawings, the present invention is not limited to the above embodiment, and a platinum group metal is disposed downstream of the ultraviolet (UV) oxidizer 6 of the primary pure water apparatus 3. A catalyst resin tower 7 may be provided, and various modifications can be made. For example, as the platinum group metal catalyst resin of the platinum group metal catalyst resin tower 13 of the subsystem 4, it is preferable to use an anion exchange resin carrying platinum group metal nanoparticles. In this case, the ultraviolet light of the primary pure water device 3 is used. As the platinum group metal catalyst resin tower 7 in the latter stage of the (UV) oxidizer 6, an anion exchange resin supporting platinum group metal nanoparticles may be used, or a general platinum group metal catalyst resin may be used. It may be used to make them different. In addition, the primary pure water device 3 and the sub-system 4 may be provided with desalting means such as an RO membrane separation device and an electrodeionization device and other various elements as necessary. Further, a pure water production apparatus may be provided to have a three-stage configuration.

  EXAMPLES Hereinafter, although an Example and a comparative example are given and this invention is demonstrated more concretely, this invention is not limited to the following Example.

[Example 1]
Platinum nano colloidal particles having an average particle diameter of 3.5 nm were supported on a strongly basic gel type anion exchange resin at a supported amount of 0.07% by weight, and platinum group metal nanoparticles were supported as a platinum group metal catalyst resin. An anion exchange resin was prepared.

  In the ultrapure water production apparatus 1 having the apparatus configuration shown in FIG. 1, the platinum group metal catalyst resin towers 7 and 13 are constructed using the platinum group metal catalyst resin described above to produce ultrapure water W3. The hydrogen peroxide concentration (initial) of the inlet water and outlet water of the platinum group metal catalyst resin tower 13 was measured. The results are shown in Table 1. In addition, the hydrogen peroxide concentration (end stage) of the outlet water of the platinum group metal catalyst resin tower 13 after the operation of the ultrapure water production apparatus 1 was continued for a long period of time was measured. The results are shown in Table 1. The hydrogen peroxide concentration is adjusted to 10 g by adding sodium sulfate (anhydrous) to 4.8 mg of phenolphthalein, 8 mg of copper sulfate (anhydrous) and 48 mg of sodium hydroxide to prepare a reagent for quantitative determination of the hydrogen peroxide concentration. . 0.5 g of the reagent was added to 10 mL of test water, dissolved, and allowed to stand at room temperature for 10 minutes, and then calculated based on the measured absorbance at 552 nm.

[Comparative Example 1]
In Example 1, the ultrapure water production apparatus was constructed in the same manner except that the platinum group metal catalyst resin tower 7 was not provided after the ultraviolet oxidation apparatus 6 of the primary pure water apparatus 3 to produce ultrapure water W3. Table 1 shows the results of measuring the hydrogen peroxide concentration (initial stage) of the inlet water and outlet water of the platinum group metal catalyst resin tower 13 of the subsystem 4. In addition, the hydrogen peroxide concentration (end stage) of the outlet water of the platinum group metal catalyst resin tower 13 after the operation of the ultrapure water production apparatus 1 was continued for a long period of time was measured. The results are shown in Table 1.

  As is apparent from Table 1, in Comparative Example 1 having no platinum group metal catalyst resin tower 7 in the subsequent stage of the ultraviolet oxidation device 6 of the primary pure water device 3, the hydrogen peroxide concentration of the ultrapure water W3 after long-term operation is increased. However, in Example 1, there was almost no change.

[Comparative Examples 2 and 3 and Reference Example]
In Comparative Example 1, the resin of the platinum group metal catalyst resin tower 13 after long-term operation is separated and taken out into three regions of a surface layer portion, a middle portion, and a lower portion, and the resin for the surface layer portion and the middle portion are packed in respective test columns. A platinum group metal catalyst resin tower for testing was used. As a reference example, a new resin was similarly packed in a test column to obtain a platinum group metal catalyst resin tower.

Hydrogen peroxide was added to ultrapure water (less than 1 μg / L hydrogen peroxide) at 300 μg / L and 1000 μg / L, respectively, to prepare test inlet water, and this test inlet water was passed through the test column described above. Velocity (SV) The hydrogen peroxide concentration in the outlet water after downward flowing water at 300 hr ⁻¹ was measured. The results are shown in Table 2.

  As is clear from Table 2, the treated water in Comparative Example 2 in which the column was filled with the resin of the surface layer portion of the platinum group metal catalyst resin tower 13 after long-term operation was more effective than Comparative Example 3 in which the middle resin was packed in the column. The concentration of hydrogen peroxide was low. As a result, it can be seen that the middle resin has a greater reduction in hydrogen peroxide resolution. When water flows downward through the platinum group metal catalyst resin tower 13, the hydrogen peroxide concentration decreases as it goes downward from the surface layer, while the dissolved hydrogen concentration decreases. The decrease in resolution is presumed to be due to oxidative degradation due to hydrogen shortage.

1 Ultrapure water production equipment 3 Primary pure water production equipment 4 Subsystem (secondary pure water production equipment)
6 UV Oxidation Device 7 Platinum Group Metal Catalyst Resin Tower 8 Regenerative Ion Exchange Device 9 Membrane Deaerator 12 UV Oxidizer 13 Platinum Group Metal Catalyst Resin Tower 14 Membrane Deaerator 15 Non-regenerative Mixed Bed Ion Exchange Device W Raw water W1 Pretreatment water W2 Primary pure water W3 Ultrapure water (secondary pure water)

Claims (8)

Ultraviolet oxidation device, have a regenerative mixed bed ion exchange column or electrodeionization apparatus and membrane type degassing apparatus, for removing impurities of ionic components and TOC components or the like contained in the water to be treated (pre-treated water) A primary pure water device,
An ultraviolet oxidation device, a platinum group metal catalyst resin tower, and a membrane type deaeration device, for removing impurities such as trace amounts of fine particles and trace ions contained in the primary pure water obtained from the primary pure water device In an ultrapure water production apparatus equipped with a subsystem,
An ultrapure water production apparatus in which a platinum group metal catalyst resin tower is provided after the ultraviolet oxidation apparatus of the primary pure water apparatus.   The ultrapure water production apparatus according to claim 1, wherein the subsystem further includes a non-regenerative mixed bed ion exchange tower.   The ultrapure water according to claim 1 or 2, wherein the platinum group metal in the platinum group metal catalyst resin tower of the primary pure water device and the platinum group metal catalyst resin tower of the subsystem is platinum, palladium, or a platinum / palladium alloy. manufacturing device.   The ultrapure water manufacturing apparatus according to any one of claims 1 to 3, wherein the platinum group metal is a platinum group metal particle having an average particle diameter of 1 to 50 nm. Ultraviolet oxidation device, the platinum group metal catalyst resin column, have a regenerative mixed bed ion exchange column or electrodeionization apparatus, and a film-type deaerator, ionic components and TOC contained in the water to be treated (pre-treated water) A primary pure water device for removing impurities such as components ;
An ultraviolet oxidation device, a platinum group metal catalyst resin tower, and a membrane type deaeration device, for removing impurities such as trace amounts of fine particles and trace ions contained in the primary pure water obtained from the primary pure water device A method of operating an ultrapure water production apparatus comprising a subsystem,
A method for operating an ultrapure water production apparatus, wherein ultrapure water is produced by continuously passing water to be treated through the primary pure water apparatus and the subsystem.   The ultrapure water production apparatus according to claim 5, wherein the platinum group metal in the platinum group metal catalyst resin tower of the primary pure water apparatus and the platinum group metal catalyst resin tower of the subsystem is platinum, palladium, or a platinum / palladium alloy. Driving method.   The operation method of the ultrapure water manufacturing apparatus according to claim 5 or 6, wherein the platinum group metal is a platinum group metal particle having an average particle diameter of 1 to 50 nm. The H ₂ O ₂ concentration of the treated water of the ultraviolet oxidizer of the subsystem is 10 to 100 μg / L, and the H ₂ O ₂ concentration of the treated water of the platinum group metal catalyst resin tower of the subsystem is 0.1 to 10 μg. The operation method of the ultrapure water production apparatus according to claim 5, which is / L.

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