JP4920019B2 - Hydrogen peroxide reduction method, hydrogen peroxide reduction device, ultrapure water production device, and cleaning method - Google Patents

Description

  The present invention relates to a method and apparatus for reducing hydrogen peroxide in water to be treated, and an ultrapure water production apparatus including the apparatus and a cleaning method.

  Conventionally, as a method for reducing hydrogen peroxide in water to be treated, there are a method of adding a reducing agent, a method of contacting with activated carbon, a method of contacting with a metal-supported resin, and the like. In the method of adding a reducing agent, a reducing agent such as sodium sulfite, sodium hydrogen sulfite, or sodium thiosulfate is added to the water to be treated containing hydrogen peroxide. Although the reaction rate between the reducing agent and hydrogen peroxide is very fast, it is possible to reliably decompose and remove hydrogen peroxide. However, it is difficult to control the amount of reducing agent added, and hydrogen peroxide is reliably removed. In order to remove it, it is necessary to add an excessive amount, so that the remaining reducing agent becomes a problem. Moreover, the method of adding a reducing agent is not preferable for the production of ultrapure water because the reducing agent increases the amount of ions in the liquid and may cause deterioration of water quality.

In the method of contacting with activated carbon, the activated carbon filling tank is usually installed and water is passed. However, since the reaction rate is slow, the water passing space velocity SV is only about 20 hr ^{-1 at the} maximum, and the apparatus is enlarged. There's a problem. In addition, activated carbon is not preferable for the production of ultrapure water because it decomposes hydrogen peroxide and itself is oxidized to cause particle collapse and outflow into the treated water.

As a method for supporting a metal on a resin, for example, a method in which water to be treated containing hydrogen peroxide is brought into contact with a catalyst resin in which a palladium catalyst metal is supported on an OH-type or Cl-type anion exchange resin ( For example, see Patent Document 1). According to this method, hydrogen peroxide is decomposed by a reaction of 2H ₂ O ₂ → 2H ₂ O + O ₂ . However, since the method of Patent Document 1 relates to wastewater treatment, the amount of palladium supported is high, the cost is increased, and the water passing space velocity SV is low, so that hydrogen peroxide in the water to be treated can be reliably treated. However, there is a problem that the apparatus becomes large.

JP-A-60-71085 JP-A-8-168756 Japanese Patent Laid-Open No. 2002-210494 JP 2006-192352 A JP 2007-185587 A

  The present invention relates to a hydrogen peroxide reduction method and apparatus capable of quickly and reliably treating hydrogen peroxide in water to be treated with a catalyst resin carrying a small amount of catalyst metal, and an ultrapure water production apparatus equipped with the apparatus. The purpose is to provide.

  The present invention relates to hydrogen peroxide for reducing hydrogen peroxide in water to be treated by bringing the water to be treated into contact with a catalyst resin in which a catalyst metal having hydrogen peroxide decomposition ability is supported on an anion exchange resin. In the reduction method, 70% or more of the total exchange capacity of the anion exchange resin is in the OH form.

  In the hydrogen peroxide reduction method, the anion exchange resin is preferably in a gel form.

  In the hydrogen peroxide reduction method, the catalyst metal is a platinum group, and the amount of the catalyst metal supported on the anion exchange resin is 10 mg-catalyst / LR to 500 mg-catalyst / LR or less. It is preferable.

Moreover, in the said hydrogen peroxide reduction method, it is preferable to make the said to-be-processed water contact the said catalyst resin in the range of the water space velocity SV30-2000hr- ¹ .

  In the hydrogen peroxide reduction method, the water to be treated is preferably treated water obtained by oxidizing and decomposing organic matter by irradiating ultraviolet rays.

  In the hydrogen peroxide reduction method, the hydrogen peroxide concentration in the treated water after contacting the catalyst resin is preferably 5 ppb or less.

  In the hydrogen peroxide reduction method, it is preferable to add hydrogen to the water to be treated.

  In the hydrogen peroxide reduction method, it is preferable that at least one of a degassing treatment and an ion exchange treatment is performed on the treated water after contacting the catalyst resin.

  Further, the present invention is a process for reducing hydrogen peroxide in water to be treated by bringing water to be treated containing hydrogen peroxide into contact with a catalyst resin in which a catalyst metal having hydrogen peroxide decomposition ability is supported on an anion exchange resin. In the hydrogen oxide reduction device, 70% or more of the total exchange capacity of the anion exchange resin is OH type.

  The ultrapure water production apparatus of the present invention includes an ultraviolet oxidation apparatus, the hydrogen peroxide reduction apparatus, a membrane deaeration apparatus, a non-regenerative ion exchange apparatus, and a particulate separation membrane apparatus, and the order Pass the water to be treated.

  The ultrapure water production apparatus of the present invention includes an ultraviolet oxidation apparatus, the hydrogen peroxide reduction apparatus, a non-regenerative ion exchange apparatus, a membrane deaeration apparatus, and a particulate separation membrane apparatus, and the order Pass the water to be treated.

  Moreover, the cleaning method of the present invention cleans an electronic component or an electronic component manufacturing instrument with treated water obtained by the hydrogen peroxide reduction method.

  According to the present invention, hydrogen peroxide in water to be treated can be quickly and reliably removed with a catalyst resin carrying a small amount of catalyst metal.

  Embodiments of the present invention will be described below. This embodiment is an example for carrying out the present invention, and the present invention is not limited to this embodiment.

  FIG. 1 is a schematic diagram illustrating an example of a configuration of an ultrapure water production apparatus according to the present embodiment. As shown in FIG. 1, the ultrapure water production apparatus 1 includes a pretreatment system 2, a primary pure water system 3, and a subsystem 4. The pretreatment system 2 includes, for example, agglomeration, pressurized flotation (precipitation), and a filtration device. The primary pure water system 3 includes, for example, an ion exchange device, a reverse osmosis membrane device, a vacuum deaeration device, and a regenerative ion exchange. Equipment (mixed bed type, 2 bed 3 tower type, 4 bed 5 tower type, etc.) etc. are provided.

  First, raw water such as industrial water is passed through the pretreatment system 2 to remove some suspended substances and organic substances in the raw water, and then supplied to the primary pure water system 3. In the primary pure water system 3, the treated water treated in the pretreatment system 2 is passed through an ion exchange device (not shown) to remove impurity ions in the water, and then a reverse osmosis membrane device (not shown). Water to remove inorganic ions, organic substances, fine particles, etc. in water, and then pass water through a vacuum deaerator (not shown) to remove dissolved oxygen and other gases in the water, followed by regeneration. Primary pure water can be obtained by passing water through a type ion exchanger (not shown) and removing ions remaining in the water.

  As shown in FIG. 1, the subsystem 4 includes a pure water storage tank, an ultraviolet oxidation device (UV oxidation device), a hydrogen peroxide reduction device, a membrane type deaeration device, a non-regenerative ion exchange device, and fine particles. A separation membrane device. By the subsystem 4, ultrapure water having higher purity than the primary pure water obtained by the primary pure water system 3 can be obtained. Each said apparatus is connected by piping, and primary primary water is passed in the said order.

As shown in FIG. 1, the primary pure water obtained by the primary pure water system 3 is supplied to a pure water storage tank. And the primary pure water stored in the pure water storage tank is supplied to the ultraviolet oxidizer. The ultraviolet oxidation apparatus includes an ultraviolet lamp capable of irradiating primary pure water with ultraviolet rays having a wavelength of at least about 100 to 200 nm, and oxidizes and decomposes organic substances in the primary pure water. Organic substances are oxidatively decomposed to organic acids and further to CO ₂ . For example, the ultraviolet oxidation apparatus preferably includes an ultraviolet lamp capable of irradiating ultraviolet rays having a wavelength near 185 nm. Note that an ultraviolet sterilizer mainly for the purpose of sterilizing the water to be treated may be provided in the front stage or the rear stage of the ultraviolet oxidizer. The ultraviolet sterilizer includes an ultraviolet lamp capable of irradiating ultraviolet rays having a wavelength of at least about 254 nm. Although the ultraviolet lamp used for an ultraviolet oxidation apparatus etc. is not specifically limited, For example, a low pressure mercury lamp etc. are preferable. In addition, as the ultraviolet oxidation apparatus, there are a distribution type and an immersion type, but the distribution type is preferable in terms of processing efficiency.

  Water is decomposed and OH radicals are generated by the ultraviolet rays irradiated by the ultraviolet oxidizer. Most of the generated OH radicals are used for decomposing organic substances in primary pure water, but surplus OH radicals are polymerized to generate hydrogen peroxide.

In the present embodiment, it is preferable that the hydrogen peroxide reducing device is installed at the subsequent stage of the ultraviolet oxidizing device, and the treated water discharged from the ultraviolet oxidizing device is supplied to the hydrogen peroxide reducing device. Thereby, the hydrogen peroxide produced | generated with the ultraviolet-ray oxidation apparatus can be removed efficiently. The hydrogen peroxide reduction device reduces the hydrogen peroxide in the treated water by bringing the treated water containing hydrogen peroxide into contact with the catalyst resin in which the catalytic metal having the ability to decompose hydrogen peroxide is supported on the anion exchange resin. It is. Hydrogen peroxide in the water to be treated is decomposed by a reaction of 2H ₂ O ₂ → 2H ₂ O + O ₂ .

  Here, as the anion exchange resin used in this embodiment, 70% or more of the total exchange capacity of the anion exchange resin is in the OH form. Thereby, since the basicity of the resin is increased, hydrogen peroxide in the water to be treated can be efficiently captured, and decomposition of hydrogen peroxide can be promoted. 90% or more of the total exchange capacity of the anion exchange resin is preferably in the OH form, and 95% or more is in the OH form in that the basicity of the resin can be further increased and the decomposition of hydrogen peroxide can be further promoted. It is more preferable that When the proportion of OH form is lower than the above range, it is necessary to increase the amount of catalytic metal supported with hydrogen peroxide decomposition capability in order to improve the decomposition efficiency of hydrogen peroxide, resulting in an increase in cost and elution of catalyst metal. Such problems arise.

  The anion exchange resin may contain a part of a weakly basic anion exchange resin, but the strong basic anion exchange resin has a higher basicity than the weakly basic anion exchange resin, and hydrogen peroxide. Since decomposition | disassembly of can be accelerated | stimulated more, it is preferable to be comprised only with strong basic anion exchange resin. In addition, among strong basic anion exchange resins, type I strong basic anions are superior to type II strong basic anion exchange resins in that elution of organic carbon (TOC) components can be suppressed. An exchange resin is more preferable.

  In addition, examples of the form of the anion exchange resin include a gel form, a porous form, and an MR form. The gel form is preferable in that elution of the organic carbon (TOC) component from the anion exchange resin can be suppressed. Furthermore, although the reason is not clear, the porous type, the MR type, and the like have a high degree of cross-linking and are difficult to diffuse into the matrix, resulting in a decrease in the reaction rate. However, the gel type has a lower degree of cross-linking than the porous type, MR type, etc., easily diffuses into the matrix, and the reaction rate is higher than that of the porous type, MR type, etc., thus improving the decomposition efficiency of hydrogen peroxide. Can be made.

  The catalyst metal used in the present embodiment is not particularly limited as long as it has hydrogen peroxide decomposition ability, but it is preferable to use a platinum group having high catalyst efficiency. Examples of the platinum group include ruthenium, rhodium, palladium, osmium, iridium and platinum. These platinum groups can be used alone, in combination of two or more, can be used as two or more alloys, or can be a naturally produced mixture of purified products. It can also be used without being separated into a single substance. Among these, platinum, palladium, platinum / palladium alloy alone or a mixture of two or more of these is preferable from the viewpoint of high catalyst efficiency, and palladium is more preferable from the viewpoint of cost.

  The method of supporting the catalytic metal on the anion exchange resin is not particularly limited. For example, after passing a solution of hexachloroplatinic acid, chloropalladic acid or the like through the anion exchange resin, a reducing agent such as formalin is passed. There is a method of watering and supporting a catalyst metal.

  In this embodiment, since 70% or more of the total exchange capacity of the anion exchange resin is in the OH form, hydrogen peroxide can be effectively decomposed even if the amount of catalyst metal supported is small. As a result, it has effects such as cost reduction and catalytic metal elution reduction. In this embodiment, the amount of the platinum group catalyst metal supported on the anion exchange resin is not particularly limited, but is 10 mg-catalyst / LR (R is an anion exchange resin based on the OH form) to A range of 500 mg-catalyst / LR is preferable, and a range of 10 mg-catalyst / LR to 50 mg-catalyst / LR is more preferable. If the supported amount of the catalyst metal is less than 10 mg-catalyst / LR, the decomposition efficiency of hydrogen peroxide may be reduced, and if it exceeds 500 mg-catalyst / LR, the cost increases, Problems such as elution may occur.

Since the catalyst resin of the present embodiment has a high hydrogen peroxide decomposition efficiency, even if the water passing space velocity SV of the water to be treated to the catalyst resin is increased, a high hydrogen peroxide removal performance is exhibited. A preferable range of the water passing space velocity SV in the present embodiment is a range of 30 to 2000 hr ⁻¹ . Usually, when the water passing space velocity SV is less than 30 hr ⁻¹ , it is not preferable in the production of ultrapure water because the elution of impurities from the resin may increase. Moreover, when the water flow space velocity SV exceeds 2000 hr ⁻¹ , the pressure loss of water flow becomes excessive.

  The hydrogen peroxide reduction method of the present embodiment uses treated water obtained by oxidatively decomposing organic substances by irradiating ultraviolet rays in a subsystem, that is, a small amount of hydrogen peroxide (for example, 10 ppb to 50 ppb) generated by the treatment of the ultraviolet oxidation apparatus. It can be suitably applied to the treated water.

  The hydrogen peroxide concentration in the treated water obtained by the hydrogen peroxide reduction method of the present embodiment is preferably 5 ppb or less, and more preferably 1 ppb or less. If the concentration of hydrogen peroxide contained in the treated water is 5 ppb or less, it can be suitably used for washing electronic components, medical water, etc. in the semiconductor manufacturing industry.

  Moreover, in this embodiment, it is preferable to provide hydrogen supply means in the hydrogen peroxide reducing device to supply hydrogen into the water to be treated containing hydrogen peroxide. Accordingly, it is possible to perform a deaeration process for removing a gas such as oxygen generated by the decomposition of hydrogen peroxide together with the decomposition of hydrogen peroxide.

  In the present embodiment, at least one of a membrane deaeration device and a non-regenerative ion exchange device is installed at the subsequent stage of the hydrogen peroxide reduction device, and the treated water obtained by the hydrogen peroxide reduction method of the present embodiment is used. It is preferable to perform at least one of a deaeration process and an ion exchange process. Thereby, the gas and impurities in treated water can be removed effectively.

  Membrane type deaerators contain treated water discharged from the hydrogen peroxide reducing device in one chamber partitioned by a gas separation membrane and are decompressed in the other chamber so that they are contained in the treated water through the gas separation membrane. It is a device that removes the generated gas by transferring it to the other chamber. As the gas separation membrane, for example, a membrane formed by forming a hydrophobic polymer membrane such as tetrafluoroethylene or polyolefin into a hollow fiber membrane or the like is used. The device for removing the gas contained in the treated water discharged from the hydrogen peroxide reduction device is not limited to the membrane type deaeration device. For example, a vacuum deaeration device, a heating deaeration device, etc. Good. However, when using a vacuum deaeration device, a heating deaeration device, or the like, impurities may be mixed into water from these devices, or impurities may be eluted into water from the filling of the device. On the other hand, if a membrane type deaerator is used, such a problem does not occur.

  The non-regenerative ion exchange device (cartridge polisher) is not particularly limited as long as it can remove impurities such as cations and anions in the treated water discharged from the hydrogen peroxide reduction device. Ion exchange apparatus (single-bed type) with a mixed bed of basic cation exchange resin and strong base anion exchange resin, ion exchange apparatus (single-bed type with one tower) using a single bed of strong basic anion exchange resin, strong base Multi-layer type ion exchange device (single-layer type with one tower) and a strong bed provided with a single bed layer of functional anion exchange resin on the inlet side and a mixed bed layer of strong acid cation exchange resin and strongly basic anion exchange resin on the outlet side An ion exchange apparatus (two-column type) in which a resin tower with a single bed of basic anion exchange resin is provided on the front side, and a resin tower with a mixed bed of strongly acidic cation exchange resin and strong base anion exchange resin is provided on the rear stage. It is below. Among these, it is preferable to use a mixed-bed single-column ion exchange apparatus in that the pH of the treated water is small at any position in the apparatus and ion exchange can be performed efficiently.

  FIG. 2 is a schematic diagram showing an example of the configuration of an ultrapure water production apparatus according to another embodiment of the present invention. As shown in FIG. 2, the subsystem 4 includes a pure water storage tank, an ultraviolet oxidation device (UV oxidation device), a hydrogen peroxide reduction device, a non-regenerative ion exchange device, a membrane deaeration device, and fine particles. A separation membrane device. And each said apparatus is connected by piping, and passes primary pure water in the said order. Here, when the SV of the hydrogen peroxide reducing device is high and there is a slight amount of hydrogen peroxide leakage, if there is a non-regenerative ion exchange device immediately after the hydrogen peroxide reducing device, the decomposition of hydrogen peroxide Since oxygen is generated by the reaction, it is preferable to install a membrane type deaerator at the subsequent stage of the non-regenerative ion exchanger as shown in FIG. When there is no leakage of hydrogen peroxide, when a small amount of impurities are eluted from the membrane deaerator, it can be removed by a non-regenerative ion exchange device. Therefore, as shown in FIG. It is preferable to install a non-regenerative ion exchange device after the deaeration device.

  Next, the treated water discharged from the non-regenerative ion exchange device (or membrane deaeration device) is supplied to the particulate separation membrane device. As the fine particle separation membrane, an ultrafiltration membrane or the like can be used. The fine particle separation membrane device can remove fine particles flowing out from a non-regenerative ion exchange device or the like. With the above structure, high-purity ultrapure water from which organic substances, hydrogen peroxide, dissolved gas (oxygen, etc.), carbon dioxide, ionic substances (impurities), and fine particles are removed can be obtained. The ultrapure water thus obtained is fed to the use point 5. In addition, it is preferable to supply a part of the obtained ultrapure water from the circulation path 6 to the pure water storage tank and circulate it constantly, regardless of whether ultrapure water is used or not. Thereby, highly pure ultrapure water can be obtained stably.

And it is preferable to use the process water obtained by such a method of this embodiment for washing | cleaning of the electronic component and the manufacture tool of an electronic component. In the manufacture of electronic components, for example, semiconductor manufacturing processes, cleaning is performed after various material surfaces such as silicon, SiO ₂ , Al, and Cu are formed and processed. However, depending on the material, it easily reacts with an oxidizing substance, and unexpected oxidation (change / degeneration) occurs. With the recent miniaturization and sophistication of devices, even a slight amount of oxidation has a great effect, resulting in a decrease in yield. For example, in the presence of hydrogen peroxide as an oxidizing substance, unexpected oxidation occurs on the surface of a material that is easily oxidized, such as Si → SiO ₂ , Al → Al ₂ O ₃ , Cu → CuO, and the cause of yield reduction It may become. Therefore, by the method of the present embodiment, washing with treated water from which hydrogen peroxide has been reduced and removed in advance can prevent such unexpected oxidation and increase the yield. This treated water may be used for washing as water for functional water production such as hydrogen water or water for chemical solution dilution, in addition to being used as ultrapure water rinsing water.

  Here, examples of the electronic component to be cleaned with the treated water obtained by the method of the present embodiment include a silicon substrate, a semiconductor substrate such as a semiconductor wafer, a substrate material such as a glass substrate for liquid crystal, a memory element, a CPU, a sensor element, Examples include, but are not limited to, finished products and semi-finished products such as solar cells, electrical contacts made of copper and silver. In addition, examples of the electronic device manufacturing tool include, but are not limited to, a quartz tube, a cleaning tank, and a substrate carrier.

  Hereinafter, although an example and a comparative example are given and the present invention is explained more concretely in detail, the present invention is not limited to the following examples.

Example 1
An acrylic column having an inner diameter of 25 mm and a height of 30 cm was filled with 40 mL of catalyst resin (layer height: 8 cm), and pure water containing about 30 ppb of hydrogen peroxide was passed under conditions of SV200 to 1000 hr ⁻¹ . As the catalyst resin of Example 1, the moisture retention ability is 60 to 70% on the basis of OH form, and palladium is added to a strong base anion exchange resin (form I) in a gel form, 5,30,970 mg-Pd / LR. The supported one was used. Further, 95% or more of the total exchange capacity of the gel-type anion exchange resin was prepared to be in the OH form. Moreover, the water quality of the pure water during the water flow period had a resistivity of 18 MΩcm or more and a TOC concentration of 1 ppb or less. The results of the hydrogen peroxide removal rate at the acrylic column outlet in Example 1 are summarized in Table 1. FIG. 3 shows the relationship between the removal rate of hydrogen peroxide and the amount of palladium supported in SV400hr ⁻¹ of Example 1. In Table 1 and FIG. 3, when the removal rate of the treated water at the outlet of the acrylic column was less than the lower limit of hydrogen peroxide analysis quantitative determination (<1 ppb), the removal rate was indicated as> 97%.

  It can be seen from Table 1 and FIG. 3 that the higher the amount of palladium supported, the higher the removal rate of hydrogen peroxide. Further, as can be seen from FIG. 3, the removal efficiency of hydrogen peroxide did not change when the amount of palladium supported was 30 mg-Pd / LR or more. Further, in order to reduce the hydrogen peroxide concentration in pure water from about 30 ppb to 5 ppb or less (hydrogen peroxide removal rate of 83% or more), it is sufficient that the supported amount of palladium is 10 mg-Pd / LR or more. I found out that

(Examples 2 to 4)
An acrylic column having an inner diameter of 25 mm and a height of 30 cm was packed with 40 mL of catalyst resin (layer height: 8 cm), and pure water containing about 30 ppb of hydrogen peroxide was passed under conditions of SV1000 to 2500 hr ⁻¹ . As the catalyst resin of Example 2, a water-holding capacity of 60 to 70% on the basis of OH type, and a strong base anion exchange resin (type I) in a gel form carrying 170 mg-Pd / LR of palladium. Using. As the catalyst resin of Example 3, a strong base anion exchange resin (type I) having a water retention capacity of 60 to 70% on the basis of OH type and palladium supported on 970 mg-Pd / LR Using. In Examples 2 and 3, 95% or more of the total exchange capacity of the gel-type anion exchange resin was prepared to be in the OH form. As the catalyst resin of Example 4, the water retention capacity is 60 to 70% on the basis of the OH form, and 970 mg-Pd / LR (palladium) is added to the strong base anion exchange resin (form I) in the gel form. ) A supported one was used. Further, in Example 4, 70% of the total exchange capacity of the gel-type anion exchange resin was prepared in the OH form and 30% in the Cl form. Moreover, the water quality of the pure water during the water flow period had a resistivity of 18 MΩcm or more and a TOC concentration of 1 ppb or less. Table 2 summarizes the concentration results of hydrogen peroxide at the acrylic column outlets of Examples 2 to 4.

(Comparative example)
As a catalyst resin of a comparative example, the water retention capacity is 60 to 70% on the basis of the OH form, and 970 mg-Pd / LR (on the basis of the OH form) of palladium is added to the strong base anion exchange resin (form I) in the gel form The supported one was used. In the comparative example, 99% or more of the total exchange capacity of the gel-type anion exchange resin was prepared to be in the Cl form. Otherwise, the test was performed under the same conditions as in Examples 2-4. Table 2 summarizes the hydrogen peroxide concentration results at the outlet of the acrylic column of the comparative example.

  From Table 2, it can be seen that the hydrogen peroxide removal efficiency increases as the proportion of the OH form of the anion exchange resin increases as the palladium loading is the same. Thus, hydrogen peroxide can be removed with higher efficiency as the proportion of the OH form is higher, so that even when the amount of catalyst metal supported is low, processing at a high flow rate is possible. That is, even if the amount of catalyst metal supported is small, hydrogen peroxide can be effectively decomposed, so that cost reduction and elution of catalyst metal can be reduced.

(Examples 5 to 8)
An acrylic column having an inner diameter of 25 mm and a height of 30 cm was filled with 40 mL of catalyst resin (layer height: 8 cm), and pure water containing about 30 ppb of hydrogen peroxide was passed under conditions of SV250 to 2000 hr ⁻¹ . As a catalyst resin of Example 5, a water-holding capacity of 60 to 70% in terms of OH type, and a strong base anion exchange resin (type I) in a gel form carrying 60 mg-Pd / LR of palladium. Using. As the catalyst resin of Example 6, MR type anion exchange resin (Rohm and Haas, IRA900) carrying 60 mg-Pd / LR of palladium was used. As the catalyst resin of Example 7, MR type anion exchange resin (Rohm and Haas, IRA900) carrying 120 mg-Pd / LR of palladium was used. As the catalyst resin of Example 8, MR type anion exchange resin (Rohm and Haas, IRA900) carrying palladium on 550 mg-Pd / LR was used. In Examples 5 to 8, 95% or more of the total exchange capacity of the gel-type or MR-type anion exchange resin was prepared to be in the OH form. Moreover, the water quality of the pure water during the water flow period had a resistivity of 18 MΩcm or more and a TOC concentration of 1 ppb or less. Table 3 summarizes the hydrogen peroxide concentration results at the acrylic column outlets of Examples 5 to 8.

  From Table 3, it can be seen that if the amount of palladium supported is the same, the gel-type anion exchange resin has higher hydrogen peroxide removal efficiency than the MR-type anion exchange resin. That is, when the gel is used, the amount of catalyst metal supported can be further reduced. As described above, the gel form can also reduce the elution of organic carbon components and fine particles from the ion exchange resin as compared with the MR form.

It is a schematic diagram which shows an example of a structure of the ultrapure water manufacturing apparatus which concerns on this embodiment. It is a schematic diagram which shows an example of a structure of the ultrapure water manufacturing apparatus which concerns on other embodiment of this invention. It is a figure which shows the relationship between the removal rate of hydrogen peroxide in SV400hr ^-1 of Example 1, and a palladium load.

Explanation of symbols

  1 ultrapure water production equipment, 2 pretreatment system, 3 primary pure water system, 4 subsystems, 5 points of use, 6 circuit.

Claims (7)

Reduction of hydrogen peroxide by reducing the hydrogen peroxide in the treated water by bringing the treated water containing hydrogen peroxide into contact with the catalyst resin in which the catalytic metal having the ability to decompose hydrogen peroxide is supported on a strongly basic anion exchange resin A method,
The catalytic metal is a platinum group;
Wherein more than 95% of the total exchange capacity of the strongly basic anion exchange resin Ri OH Katachidea,
The method for reducing hydrogen peroxide , wherein the amount of the catalytic metal supported on the strongly basic anion exchange resin is in the range of 10 mg-catalyst / LR to 170 mg-catalyst / LR . The method for reducing hydrogen peroxide according to claim 1, wherein the strongly basic anion exchange resin is in a gel form. The catalyst resin is obtained by passing a platinum group ion solution through the strong base anion exchange resin, and then passing a reducing agent and supporting the platinum group as a catalyst metal on the strong base anion exchange resin. The method for reducing hydrogen peroxide according to claim 1 or 2, wherein: The method for reducing hydrogen peroxide according to any one of claims 1 to 3, wherein the water to be treated is brought into contact with the catalyst resin at a water space velocity of SV 200 to 2000 hr ^-1 .   The method for reducing hydrogen peroxide according to any one of claims 1 to 4, wherein the water to be treated is treated water obtained by irradiating ultraviolet rays to oxidatively decompose organic substances. Reduction of hydrogen peroxide by reducing the hydrogen peroxide in the treated water by bringing the treated water containing hydrogen peroxide into contact with the catalyst resin in which the catalytic metal having the ability to decompose hydrogen peroxide is supported on a strongly basic anion exchange resin A device,
The catalytic metal is a platinum group;
Wherein more than 95% of the total exchange capacity of the strongly basic anion exchange resin Ri OH Katachidea,
The hydrogen peroxide reducing apparatus , wherein the amount of the catalyst metal supported on the strongly basic anion exchange resin is in the range of 10 mg-catalyst / LR to 170 mg-catalyst / LR . The catalyst resin is obtained by passing a platinum group ion solution through the strong base anion exchange resin and then passing a reducing agent to carry the platinum group as a catalyst metal on the strong base anion exchange resin. The hydrogen peroxide reducing device according to claim 6, wherein

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