JP2005274386A - Hydrogen peroxide analyzer, and hydrogen peroxide analytical method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hydrogen peroxide analyzer and a hydrogen peroxide analytical method capable of analyzing easily and high sensitively a micro amount of hydrogen peroxide in water. <P>SOLUTION: A water specimen serving as an analytical object is introduced into the analyzer from a prescribed position A in a water treatment process by a sample collecting tube 12, the water specimen is supplied to a main analytical line including a hydrogen peroxide decomposing part 16 constituted of a column packed with a material having hydrogen peroxide decomposing ability, and a dissolved oxygen concentration measuring part 18, and is supplied to a sub-analytical line including the dissolved oxygen concentration measuring part 18, and measured values of dissolved oxygen concentration measured in the respective lines are input into a computing part 20 to calculate a hydrogen peroxide concentration in the water specimen. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an improved apparatus and method for measuring traces of hydrogen peroxide in water.

  Conventionally, as a method for analyzing the concentration of hydrogen peroxide, a method using a test paper or a test reagent, a redox titration method, a colorimetric method and the like are generally known. Such a concentration analysis of hydrogen peroxide is used for various purposes. For example, it can be used in a wastewater treatment facility for wastewater containing hydrogen peroxide. In addition, it is known that hydrogen peroxide is generated in an ultraviolet irradiation facility or the like in a production facility of pure water or ultrapure water, and the necessity of analyzing the concentration of hydrogen peroxide is being recognized. In order to analyze the concentration of hydrogen peroxide at a production facility of pure water or ultrapure water, a trace analysis with an analytical value of the order of μg / L is required. Among the various analysis methods described above, it is difficult to measure the analysis value at the μg / L level using the test paper or the test reagent method.

Patent Document 1 below discloses a method for measuring the hydrogen peroxide concentration by the oxidation-reduction titration method, and Patent Document 2 discloses a method for measuring the hydrogen peroxide concentration by the colorimetric method.
JP 2003-313012 A JP-A-8-145879

  However, in the above-mentioned conventional technology, the operation of colorimetric analysis and titration is complicated, and in-line automatic analysis is difficult. Especially for pure water or ultrapure water production equipment that wants to eliminate human intervention as much as possible. There was a problem of being unsuitable. Furthermore, since a reagent is required, there is a problem that the cost is increased due to chemical costs, maintenance, and waste liquid treatment after analysis.

  The present invention has been made in view of the above-described conventional problems, and an object of the present invention is to provide a hydrogen peroxide analyzer and a hydrogen peroxide analysis method that can easily and highly sensitively analyze a small amount of hydrogen peroxide in water. There is.

  In order to achieve the above object, the present invention provides a hydrogen peroxide analyzer for analyzing a hydrogen peroxide concentration in a sample water sampled from a predetermined position of a water treatment process. Hydrogen peroxide decomposition means for decomposing hydrogen peroxide in the sample water introduced by the sample water introduction means, and the hydrogen peroxide decomposition treatment was performed by the sample water and the hydrogen peroxide decomposition means And a dissolved oxygen concentration measuring means for measuring the dissolved oxygen concentration of the treated water.

  The present invention also provides a hydrogen peroxide analyzer for analyzing a hydrogen peroxide concentration in sample water collected from a predetermined position of a water treatment process, the sample water introducing means for introducing the sample water, and the sample water Hydrogen peroxide decomposing means for decomposing hydrogen peroxide in the sample water introduced by the introducing means, and dissolved oxygen concentration of the sample water and the treated water in which hydrogen peroxide is decomposed by the hydrogen peroxide decomposing means And a calculation means for calculating the hydrogen peroxide concentration in the sample water based on the measurement result of the dissolved oxygen concentration in the sample water and the treated water by the dissolved oxygen concentration measurement means. It is characterized by that.

  The hydrogen peroxide analyzer is preferably degassed before supplying the sample water to the hydrogen peroxide decomposition means. In this case, it is preferable to use a membrane type deaerator for the deaeration process.

  In the hydrogen peroxide analyzer, it is preferable that the hydrogen peroxide decomposition means includes at least one of activated carbon, a synthetic carbon-based adsorbent, an ion exchange resin, and a metal catalyst.

  The present invention also provides a hydrogen peroxide analysis method for analyzing a hydrogen peroxide concentration in sample water collected from a predetermined position of a water treatment process, the step of collecting the sample water, and the collected sample water And the step of measuring the dissolved oxygen concentration of the sample water and the treated water subjected to the decomposition treatment of the hydrogen peroxide.

  The present invention also provides a hydrogen peroxide analysis method for analyzing a hydrogen peroxide concentration in sample water collected from a predetermined position of a water treatment process, the step of collecting the sample water, and the collected sample water A step of decomposing hydrogen peroxide of the sample, a step of measuring the dissolved oxygen concentration of the sample water and the treated water subjected to the decomposition treatment of the hydrogen peroxide, and a measurement result of the dissolved oxygen concentration of the sample water and the treated water. And a step of calculating a hydrogen peroxide concentration in the specimen water.

  According to the present invention, hydrogen peroxide in water can be easily detected and / or quantified, and in particular, a small amount of hydrogen peroxide in pure water or ultrapure water can be easily detected and / or sensitively. It can be quantified.

  Hereinafter, the best mode for carrying out the present invention (hereinafter referred to as an embodiment) will be described with reference to the drawings. However, the present invention is not limited to this embodiment.

  FIG. 1 is a block diagram showing the configuration of an embodiment of the hydrogen peroxide analyzer according to the present invention. In FIG. 1, a hydrogen peroxide analyzer 10 is configured to supply sample water to be analyzed by a sampling pipe 12 from a predetermined position A of a water treatment process such as pure water or ultrapure water production equipment or wastewater treatment equipment. Introduce and collect. In this embodiment, the sample collection pipe 12 introduces sample water from two points at a predetermined position A of the water treatment process, one of which includes a hydrogen peroxide decomposition unit 16 and a dissolved oxygen concentration measurement unit 18. Sample water is introduced into the line, and the other is introduced into the blank measurement sub-analysis line including the dissolved oxygen concentration measurement unit 18. Here, the sample collecting pipe 12 corresponds to the sample water introducing means of the present invention.

  The sample water introduced into the apparatus by the sample collection pipe 12 may be freed of dissolved oxygen by a degassing apparatus (not shown) in the stage preceding the hydrogen peroxide decomposition unit 16 in the main analysis line. In the sub-analysis line, it is preferable to install a deaeration device equivalent to that installed in the main analysis line before the dissolved oxygen concentration measurement unit 18.

  As the deaerator, for example, a membrane deaerator is used. The membrane type deaerator flows the water to be treated into one chamber partitioned by a gas separation membrane and depressurizes the other chamber, thereby allowing the gas contained in the water to be treated to flow into the other chamber through the gas separation membrane. It is a device that moves and removes. As the gas separation membrane, a membrane in which a hydrophobic polymer membrane such as tetrafluoroethylene or silicone rubber is formed into an appropriate shape such as a hollow fiber membrane is usually used.

  Such a deaeration device is effective for measuring the hydrogen peroxide concentration with high accuracy when the dissolved oxygen concentration in the specimen water is high or fluctuates greatly. Depending on the hydrogen peroxide concentration (measurement range) in the sample water, for example, the hydrogen peroxide concentration of pure water or ultrapure water is several tens of μg / L or less. Deaeration (deoxygenation) is preferably performed to 10 μg / L or less. In addition, the method of deaeration (deoxygenation) is not particularly limited, but the above-mentioned membrane type deaerator is preferable in that a high-grade deaeration process can be performed in a compact manner. If the hydrogen peroxide concentration in the sample water is high or analysis with high accuracy is not required, or if the dissolved oxygen concentration in the sample water is originally low, it is not always necessary to install a deaeration device.

The sample water introduced into the main analysis line is decomposed by the hydrogen peroxide decomposition unit 16 as follows. The generated oxygen dissolves in water and becomes dissolved oxygen.
()
2H ₂ O ₂ → 2H ₂ O + O ₂ (1)

  Here, the hydrogen peroxide decomposition unit 16 may be configured by a container or a column filled with a material having hydrogen peroxide decomposition ability. The material having the ability to decompose hydrogen peroxide is not particularly limited as long as it has the ability to decompose hydrogen peroxide in water into water and oxygen, but is not dissolved in water and is difficult to denature. Is preferred. Further, in order to increase the contact efficiency with hydrogen peroxide, those having a large surface area such as granular, fibrous or porous are preferable. Examples of such materials include activated carbon, synthetic carbon-based adsorbent, ion exchange resin, metal catalyst (Pt, etc.) and the like. Of these, activated carbon and synthetic carbon-based adsorbent are particularly suitable because of their high hydrogen peroxide decomposition ability, excellent durability, and low cost. Metal catalysts also have high hydrogen peroxide decomposing ability and excellent durability, but are expensive. Furthermore, ion exchange resins are not suitable for long-term use because their ability to decompose hydrogen peroxide tends to decrease with use time.

  When a column packed with a material capable of decomposing hydrogen peroxide is used as the hydrogen peroxide decomposing portion 16, the column water flow rate is appropriately determined according to various conditions such as the type of packing material and the concentration of hydrogen peroxide in the sample water to be analyzed. Although it is determined, it is preferable to set SV1 to 100 with respect to the amount of filler. When the flow rate is lowered, the contact time between the hydrogen peroxide and the packing material increases, the hydrogen peroxide decomposition rate increases, and the oxygen production rate tends to increase. However, the oxygen production rate through the column and piping system tends to increase. Permeation tends to cause an increase in dissolved oxygen concentration. On the other hand, when the flow rate is increased, the effect of increased dissolved oxygen concentration due to the permeation of oxygen in the atmosphere is less likely to occur, but the contact time between hydrogen peroxide and the filler is reduced, and the oxygen generation rate is reduced, resulting in analysis accuracy May be reduced.

  The dissolved oxygen concentration of the sample water introduced into the main analysis line and the sub-analysis line is measured by the dissolved oxygen concentration measuring unit 18. The dissolved oxygen concentration measurement unit 18 can be configured by a known dissolved oxygen meter. The measurement value of the dissolved oxygen concentration measurement unit 18 is input to the calculation unit 20, and the hydrogen peroxide concentration in the sample water is calculated based on a predetermined calculation formula. In this case, the measured value of the dissolved oxygen concentration in the sub-analysis line is used as a blank value.

  In order to obtain the hydrogen peroxide concentration from the dissolved oxygen concentration, for example, a calibration curve can be used. FIG. 2 shows an example of this calibration curve. In FIG. 2, the horizontal axis represents the difference in dissolved oxygen concentration (ΔDO) between the main analysis line and the sub-analysis line (blank value), and the vertical axis represents the hydrogen peroxide concentration of the sample water, which was obtained in the examples described later. is there. When measuring the dissolved oxygen concentration in the main analysis line, it is not always necessary to decompose all the hydrogen peroxide in the sample water into water and oxygen in the hydrogen peroxide decomposition unit 16. Make a calibration curve under the same conditions with the same conditions such as the type of hydrogen peroxide-decomposable material, the filling amount, the flow rate of sample water in the hydrogen peroxide decomposition unit 16, the temperature, and the piping system. For example, hydrogen peroxide in the sample water can be detected and quantitatively analyzed.

  It is preferable to provide a flow meter 22 on the inlet side or the outlet side of the hydrogen peroxide decomposition unit 16 and on the outlet side of the dissolved oxygen concentration measurement unit 18, respectively. Thereby, the sample water can be supplied to the hydrogen peroxide decomposition unit 16 and the dissolved oxygen concentration measurement unit 18 at an appropriate flow rate. In the main analysis line, the normal hydrogen peroxide decomposition unit 16 and the dissolved oxygen concentration measurement unit 18 have different proper flow rates, and therefore it is preferable to provide a bypass pipe on the inlet side of the dissolved oxygen concentration measurement unit 18. The sample water that has flowed through the main analysis line and the sub-analysis line is drained to the drainage facility B. Since the wastewater is not added with a reagent unlike the conventional colorimetric analysis or titration wastewater, it can be easily treated and recovered and reused.

  In the above-described hydrogen peroxide analyzer 10, the configuration in which the calculation unit 20 is provided has been described. However, if the measurement value of the dissolved oxygen concentration measurement unit 18 is obtained, the measurer can calculate the approximate hydrogen peroxide from the calibration curve or the like. Since the concentration can be determined, the calculation unit 20 is not necessarily provided in the hydrogen peroxide analyzer 10 if the hydrogen peroxide concentration is simply determined. The main analysis line and the sub-analysis line may be temporarily attached to the water treatment process.

  Pipes used in the hydrogen peroxide analyzer 10 described above, in particular, a sample collecting pipe 12 for introducing the sample water, a hydrogen peroxide decomposition section 16 and its inlet / outlet pipe, a pipe to the dissolved oxygen concentration measuring section 18, etc. It is preferable to use a material such as stainless steel or nylon having low gas permeability. The reason is that if oxygen in the atmosphere permeates through the piping system and dissolves in a large amount of sample water, the concentration of dissolved oxygen increases and accurate measurement cannot be performed.

  FIG. 3 is a block diagram showing the configuration of another embodiment of the hydrogen peroxide analyzer according to the present invention. The same elements as those in FIG.

  A characteristic point in FIG. 3 is that the sample collecting pipe 12 introduces the sample water into the main analysis line and the sub-analysis line from one point at a predetermined position A in the water treatment process. According to such a configuration, the sample water collection port provided in the water treatment process may be one place, and sample water collection from the water treatment process that is actually in operation can be facilitated.

  FIG. 4 is a block diagram showing the configuration of still another embodiment of the hydrogen peroxide analyzer according to the present invention. The same components as those in FIG. In the embodiment shown in FIG. 4, a deaeration device 14 is further added to the embodiment shown in FIG. This deaeration device 14 is arranged before the sample collection pipe 12 branches into a main analysis line and a sub-analysis line, and the deaeration conditions can be equalized in both lines.

  5 and 6 are block diagrams showing the configuration of still another embodiment of the hydrogen peroxide analyzer according to the present invention. The same elements as those in FIG.

  A characteristic point in FIG. 5 is that the dissolved oxygen concentration measuring unit 18 is used as one unit, and the dissolved oxygen concentration is measured by switching the main analysis line and the sub-analysis line by a valve. According to such a configuration, the number of expensive dissolved oxygen concentration measuring units 18 can be reduced, and the cost of the hydrogen peroxide analyzer 10 can be reduced.

  6 is characterized in that sample water is further introduced into the main analysis line and the sub-analysis line from one point at a predetermined position A in the water treatment process in the embodiment of FIG. . This can reduce the cost of the apparatus and facilitate the collection of the sample water.

  In each of the embodiments described above, when a material having excellent durability such as activated carbon or synthetic carbon-based adsorbent is used as a material having hydrogen peroxide decomposition ability, it can be used for a long time, thus facilitating maintenance. it can. Further, since it is not necessary to use a reagent for analysis as in the conventional colorimetric or titration method, the hydrogen peroxide concentration can be easily measured.

  Further, according to the present invention, since the measurement of the hydrogen peroxide concentration in the sample water can be automated, the hydrogen peroxide analyzer and the peroxidation particularly suitable for pure water or ultrapure water production equipment that should avoid human intervention as much as possible. Hydrogen analysis method can be realized.

  Hereinafter, specific examples of the present invention will be described as examples.

  The calibration curve shown in FIG. 2 was created by the following procedure.

First, ultrapure water was produced from primary pure water obtained by pretreatment and primary pure water treatment of industrial water using the ultrapure water production system shown in FIG. The specifications of the ultrapure water production system shown in FIG. 7 are as follows.
・ Membrane deaerator (MD): Dainippon Ink & Chemicals Module SEPAREL EF-040P
・ Low-pressure ultraviolet irradiation oxidizer (UVox): ADF20 manufactured by Chiyoda Corporation
・ Ion exchange (cartridge polisher CP) equipment: CP resin ESG-1 made by Organo
・ Ultrafiltration membrane device (UF): Module OLT-5026 manufactured by Asahi Kasei Corporation
・ Water temperature: 23 ± 1 ℃

  When producing ultrapure water with the ultrapure water production system shown in FIG. 7, the ultraviolet irradiation amount in the low-pressure ultraviolet irradiation oxidizer was changed to change the hydrogen peroxide concentration in the ultrapure water. Thereafter, a part of the outlet water of the low-pressure ultraviolet irradiation oxidizer was introduced as sample water into the hydrogen peroxide analyzer 10 shown in FIG. 1, and the dissolved oxygen concentration measurement unit 18 analyzed the dissolved oxygen concentration.

  Further, the hydrogen peroxide concentration in the sample water was analyzed by a phenolphthalein colorimetric method.

  From the above measurement results, the relationship between the dissolved oxygen concentration difference (ΔDO) of the specimen water and the hydrogen peroxide concentration was plotted, and the calibration curve shown in FIG. 2 was obtained.

In addition, the specification of the hydrogen peroxide analyzer 10 of FIG. 1 is as follows.
・ Sample collection pipe and dissolved oxygen concentration measurement part introduction pipe: Nylon tube ・ Hydrogen peroxide decomposition part column: Acrylic column ・ Filling material: Mitsubishi Chemical Calgon granular activated carbon (Diahope 006) 100 mL
・ Dissolved oxygen meter of dissolved oxygen concentration measurement part: 3600 made by Orbis Fair
・ Column flow rate 50mL / min (SV30)
・ Water temperature 23 ± 1 ℃
-Inlet dissolved oxygen concentration (specimen water-soluble oxygen concentration) 10 μg / L or less

  As can be seen from the results shown in FIG. 2, there is a high correlation between the dissolved oxygen concentration difference (ΔDO) of the sample water and the hydrogen peroxide concentration, and by measuring the dissolved oxygen concentration difference (ΔDO) of the sample water. Highly sensitive detection or quantification of hydrogen peroxide concentration

It is a block diagram showing the structure of one Embodiment of the hydrogen peroxide analyzer concerning this invention. It is a figure which shows the example of the calibration curve for calculating | requiring a hydrogen peroxide concentration. It is a block diagram showing the structure of other embodiment of the hydrogen peroxide analyzer concerning this invention. It is a block diagram showing the structure of further another embodiment of the hydrogen peroxide analyzer concerning this invention. It is a block diagram showing the structure of further another embodiment of the hydrogen peroxide analyzer concerning this invention. It is a block diagram showing the structure of further another embodiment of the hydrogen peroxide analyzer concerning this invention. It is a figure which shows the structural example of an ultrapure water manufacturing system.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Hydrogen peroxide analyzer, 12 Sample collection piping, 14 Deaeration apparatus, 16 Hydrogen peroxide decomposition | disassembly part, 18 Dissolved oxygen concentration measurement part, 20 Calculation part, 22 Flowmeter.

Claims (7)

A hydrogen peroxide analyzer for analyzing the concentration of hydrogen peroxide in sample water collected from a predetermined position of a water treatment process,
A sample water introduction means for introducing the sample water;
Hydrogen peroxide decomposing means for decomposing hydrogen peroxide in the sample water introduced by the sample water introducing means,
Dissolved oxygen concentration measuring means for measuring the dissolved oxygen concentration of the sample water and treated water that has been subjected to hydrogen peroxide decomposition treatment by the hydrogen peroxide decomposing means;
A hydrogen peroxide analyzer characterized by comprising: A hydrogen peroxide analyzer for analyzing the concentration of hydrogen peroxide in sample water collected from a predetermined position of a water treatment process,
A sample water introduction means for introducing the sample water;
Hydrogen peroxide decomposing means for decomposing hydrogen peroxide in the sample water introduced by the sample water introducing means,
Dissolved oxygen concentration measuring means for measuring the dissolved oxygen concentration of the sample water and treated water that has been subjected to hydrogen peroxide decomposition treatment by the hydrogen peroxide decomposing means;
Calculation means for calculating the hydrogen peroxide concentration in the sample water based on the measurement result of the dissolved oxygen concentration in the sample water and treated water by the dissolved oxygen concentration measurement means;
A hydrogen peroxide analyzer characterized by comprising:   3. The hydrogen peroxide analyzer according to claim 1, wherein the sample water is deaerated before being supplied to the hydrogen peroxide decomposition means.   The hydrogen peroxide analyzer according to claim 3, wherein a membrane type deaerator is used for the deaeration process.   5. The process according to claim 1, wherein the hydrogen peroxide decomposition means includes at least one of activated carbon, a synthetic carbon-based adsorbent, an ion exchange resin, and a metal catalyst. Hydrogen oxide analyzer. A hydrogen peroxide analysis method for analyzing the concentration of hydrogen peroxide in sample water collected from a predetermined position of a water treatment process,
Collecting the sample water;
Decomposing hydrogen peroxide in the collected sample water;
Measuring the dissolved oxygen concentration of the sample water and the treated water subjected to the decomposition treatment of the hydrogen peroxide;
A hydrogen peroxide analysis method comprising: A hydrogen peroxide analysis method for analyzing the concentration of hydrogen peroxide in sample water collected from a predetermined position of a water treatment process,
Collecting the sample water;
Decomposing hydrogen peroxide in the collected sample water;
Measuring the dissolved oxygen concentration of the sample water and the treated water subjected to the decomposition treatment of the hydrogen peroxide;
Calculating the hydrogen peroxide concentration in the sample water based on the measurement result of the dissolved oxygen concentration in the sample water and the treated water;
A hydrogen peroxide analysis method comprising:

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