JP2017171627A - Aqueous solution and object treatment method - Google Patents

Abstract

An object of the present invention is to provide an aqueous solution that has high activity and can be easily used. The aqueous solution contains, as main components, nitrite ions, hydrogen peroxide, and a buffering component having a buffering property in a pH range of 6 to 8 and a concentration of 0.5 mM to 100 mM. and pH is 6 or more and 8 or less. [Selection drawing] Fig. 1A

Description

  The present disclosure relates to an aqueous solution and an object processing method using the aqueous solution.

  Conventionally, sterilization or decomposition of organic substances has been performed using chemicals, functional water, alcohol, or the like. As the drug, for example, glutar or sodium hypochlorite can be used. However, these drugs have a peculiar irritating odor, and are highly harmful to humans and the environment and have a high persistence. As functional water, hypochlorous acid water or ozone water can be used. Although these functional waters and alcohols are less harmful and persistent, they emit a characteristic odor such as chlorine odor, ozone odor or alcohol odor. Alcohol is weakly bactericidal against viruses.

  On the other hand, in a living body, sterilization is performed by peroxynitrous acid having no odor and strong activity. Specifically, superoxide dismutase (SOD), nitric oxide synthase (Nitric Oxide Synthase; NOS) and the like are combined with superoxide and NO radicals to bind peroxynitrite. Is generated. Various scientific studies have been conducted to examine the properties of peroxynitrite having odorless and strong activity (see, for example, Non-Patent Documents 1 and 2).

Anbar, Taube; J. American Chem. Soc., 1954, Vol. 76, No. 24, 6243-6247 Makoto Tsuboi, “Scientific study on the elimination of peroxynitrite (reactive nitrogen species) by carotenoids”, 2011

  However, Non-Patent Document 1 describes that such a reaction proceeds very rapidly under acidic conditions. Further, in the method described in Non-Patent Document 2, the generated solution needs to be stored frozen. For this reason, a utilization opportunity and utilization environment are limited and it is difficult to use for the purpose to utilize when desiring to utilize disinfection.

  Therefore, the present disclosure provides an aqueous solution that has high activity and can be easily used, and an object processing method using the aqueous solution.

  In order to solve the above problems, an aqueous solution according to one embodiment of the present disclosure has, as main components, nitrite ions, hydrogen peroxide, buffering in a pH range of 6 to 8, and a concentration of 0. A buffer component of 5 mM or more and 100 mM or less, and a pH of 6 or more and 8 or less.

  For example, the object processing method according to an aspect of the present disclosure includes preparing an aqueous solution containing nitrite ions and hydrogen peroxide as main components and having a pH of 6 or more and 8 or less, Adjusting the pH of the aqueous solution to be less than 6 or greater than 8, and bringing the aqueous solution into contact with an object.

  According to the present disclosure, it is possible to provide an aqueous solution that has high activity and can be easily used, and an object processing method using the aqueous solution.

It is a figure which shows the result of the decomposition | disassembly test of indigo carmine by the aqueous solution which concerns on the Example of Embodiment 1. FIG. It is a figure which shows the result of the decomposition | disassembly test of indigo carmine by the aqueous solution which concerns on the comparative example 1. It is a figure which shows the result of the decomposition | disassembly test of indigo carmine by the aqueous solution which concerns on the comparative example 2. Time-of-flight mass spectrometry (TOF-MS) of a substance having a mass number of 138.02 contained in a mixed solution (liquid sample D and liquid sample E) when phenol is mixed with an aqueous solution according to each of the example and comparative example 1 It is a figure which shows the result analyzed by the method. It is a figure which shows the result of having analyzed the substance with the mass number of 138.02 shown in FIG. 2A by the tandem mass spectrometry. Time-of-flight mass spectrometry (TOF-MS) for a substance having a mass number of 109.03 contained in a mixed solution (liquid sample D and liquid sample E) when phenol was mixed with the aqueous solution according to each of the example and comparative example 1 It is a figure which shows the result analyzed by the method. It is a figure which shows the result of having analyzed the substance with a mass number of 109.03 shown in FIG. 3A by the tandem mass spectrometry. It is a figure which shows the result of the decomposition | disassembly test of indigo carmine at the time of acidifying the aqueous solution which concerns on an Example. It is a figure which shows the result of the decomposition | disassembly test of indigo carmine at the time of making the aqueous solution which concerns on an Example alkaline. It is a figure which shows the relationship between pH of the aqueous solution which concerns on an Example, and the decomposition rate of indigo carmine. It is a figure for demonstrating the decomposition | disassembly rate shown to FIG. 5A. It is a figure which shows the structure of the target object processing apparatus which concerns on Embodiment 2. FIG. 10 is a flowchart showing an operation (object processing method) of the object processing apparatus according to the second embodiment. It is a figure which shows the structure of the target object processing apparatus which concerns on the modification of Embodiment 2. FIG. 10 is a flowchart showing an operation (object processing method) of an object processing apparatus according to a modification of the second embodiment.

(Knowledge that became the basis of this disclosure)
Peroxynitrite (ONOHH) is generated by mixing a solution containing nitrite ion (NO ₂ ⁻ ) with a solution containing hydrogen peroxide (H ₂ O ₂ ) to make the mixed solution acidic. To do. Specifically, the reaction shown by the following (Formula 1) has occurred.

(Formula 1) NO ₂ ⁻ + H ₂ O ₂ + H ⁺ (acidic) → ONOOH + H ₂ O

  When peroxynitrous acid is brought into contact with an object, a strong oxidization or hydroxylation reaction, or a nitrosation or nitration reaction can be performed to cause a disinfection action and an organic substance decomposition action. At this time, no odor such as irritating odor is generated. In the absence of an object under acidic conditions, peroxynitrous acid is rapidly changed to nitric acid, which is a structural isomer, and its activity is lost, so its persistence is low.

  Further, by making the liquid property of the mixed solution alkaline, hydrogen peroxide contained in the mixed solution becomes active. Hydrogen peroxide can cause a disinfection action and an organic substance decomposition action when in contact with an object. At this time, no odor such as irritating odor is generated. In the absence of an object under alkaline conditions, the decomposition of hydrogen peroxide proceeds and the activity decreases.

  Nitrite ions are unstable by themselves and are usually stable in an aqueous solution of nitrite using an alkali metal such as sodium nitrite, potassium nitrite, or lithium nitrite, or an alkaline earth metal. Since such an aqueous solution of nitrite is alkaline with a pH of about 9, the decomposition reaction of hydrogen peroxide proceeds gradually.

  From the above, the aqueous solution according to one embodiment of the present disclosure has, as main components, nitrite ions, hydrogen peroxide, and buffering in a pH range of 6 to 8, and a concentration of 0.5 mM or more. The buffer component is 100 mM or less, and the pH is 6 or more and 8 or less.

  Thereby, aqueous solution can be stably stored by keeping liquidity neutral. Moreover, peroxynitrous acid with high activity can be produced | generated or hydrogen peroxide can be activated by acidifying or alkalizing aqueous solution as needed. In this way, the aqueous solution can be easily used for sterilization or decomposition of organic substances. In addition, peroxynitrous acid does not generate odors such as irritating odors, and its activity is quickly lost, so its persistence is low. For this reason, there is little influence on an environment.

  Moreover, since the aqueous solution which concerns on this aspect contains the buffer component which has buffering property in pH 6-8, pH can be stabilized in neutral range. This facilitates pH adjustment (acidification or alkalinization) or handling during storage.

  For example, when there is no (or weak) buffering property, the liquidity of the aqueous solution may change unintentionally during storage or contact with an object, and the activity may be lost. On the other hand, if the buffering property is too strong, a large amount of acid or alkali is required when the aqueous solution is acidified or alkalized. In the aqueous solution which concerns on this aspect, since the density | concentration of a buffer component is 0.5 mM or more and 100 mM or less, it has suitable buffer property. Therefore, pH adjustment (acidification or alkalinization) or handling during storage becomes easier.

  For example, the aqueous solution which concerns on 1 aspect of this indication may contain a nitrate ion further.

  Thereby, the aqueous solution can be kept neutral.

  For example, the buffer component may be phosphoric acid.

  As a result, pH adjustment (acidification or alkalinization) or handling during storage becomes easier.

  For example, the concentration of the buffer component may be 1 mM or more and 10 mM or less.

  Thereby, pH adjustment (acidification or alkalinization) or handling during storage becomes extremely easy.

  For example, the object processing method according to an aspect of the present disclosure includes preparing an aqueous solution containing nitrite ions and hydrogen peroxide as main components and having a pH of 6 or more and 8 or less, Adjusting the pH of the aqueous solution to be less than 6 or greater than 8, and bringing the aqueous solution into contact with an object.

  Thereby, peroxynitrous acid which has high activity can be produced | generated, or hydrogen peroxide can be activated by acidifying or making alkaline aqueous solution. Therefore, the aqueous solution can be easily used for sterilization or decomposition of organic substances.

  For example, the adjusting step may be performed after the contacting step.

  As a result, the pH of the aqueous solution is adjusted after the aqueous solution is brought into contact with the object, so that when the activity of the aqueous solution is increased, it can act on the object immediately. Accordingly, it is possible to efficiently decompose the object.

  Further, for example, the contacting step may be performed after the adjusting step.

  Thereby, after increasing activity, since aqueous solution is made to contact a target object, reaction with aqueous solution and a target object can be controlled. For example, the reaction rate between the aqueous solution and the object can be adjusted.

  Further, for example, in the adjusting step, (i) an acid, a base or a salt, (ii) a solution containing at least one of an acid, a base or a salt, (iii) a gas or a solid which dissolves into an acid or a base, Alternatively, (iv) the pH of the aqueous solution may be adjusted by adding the gas, the liquid, or a solution containing a living organism that generates a solid to the aqueous solution.

  Thereby, pH of aqueous solution can be adjusted easily. Specifically, the material for adjusting the pH can be selected from many materials. For example, an inexpensive material can be selected, and the cost can be reduced.

  For example, in the step of adjusting, the pH of the aqueous solution may be adjusted by electrolyzing the aqueous solution.

  Thereby, pH of aqueous solution can be adjusted, without adding a chemical | medical agent etc. Thus, since it is not specifically limited to the adjustment method of pH of aqueous solution, For example, pH can be adjusted with the method suitable for a target object.

  In addition, for example, the aqueous solution may further include a buffer component having a pH in the range of 6 to 8 and a concentration of 0.5 mM to 100 mM.

  Thereby, since pH can be stabilized in the neutral range, pH adjustment (acidification or alkalinization) or handling during storage becomes easy.

  Hereinafter, embodiments will be specifically described with reference to the drawings.

  It should be noted that each of the embodiments described below shows a comprehensive or specific example. Numerical values, shapes, materials, components, arrangement positions and connection forms of components, steps, order of steps, and the like shown in the following embodiments are merely examples, and are not intended to limit the present disclosure. In addition, among the constituent elements in the following embodiments, constituent elements that are not described in the independent claims indicating the highest concept are described as optional constituent elements.

  Each figure is a mimetic diagram and is not necessarily illustrated strictly. Therefore, for example, the scales and the like do not necessarily match in each drawing. Moreover, in each figure, the same code | symbol is attached | subjected about the substantially same structure, The overlapping description is abbreviate | omitted or simplified.

  In the present specification, “neutral” means that the pH (hydrogen ion index) is 6 or more and 8 or less. “Alkaline” means that the pH is greater than 8. “Acid” means that the pH is less than 6.

  “Neutralization” means “neutralization”, that is, pH is 6 or more and 8 or less. “Alkalinization” means making it “alkaline”, that is, making the pH higher than 8. “Acidification” means making it “acidic”, that is, making the pH lower than 6.

(Embodiment 1)
[1. Aqueous solution]
First, the aqueous solution according to the present embodiment will be described.

The aqueous solution according to the present embodiment is an aqueous solution containing nitrite ions (NO ₂ ⁻ ), hydrogen peroxide (H ₂ O ₂ ), and a buffer component as main components, and has a pH of 6 or more and 8 or less. It is. Specifically, the aqueous solution is a mixed solution in which a first solution containing nitrite ions, a second solution containing hydrogen peroxide, and a third solution containing a buffer component are mixed. The main component means a component having a concentration of 10 times or more with respect to substances other than nitrite ions, hydrogen peroxide and buffer components in the aqueous solution.

The first solution containing nitrite ions is an aqueous solution containing a nitrite such as sodium nitrite (NaNO ₂ ), for example. The nitrite is, for example, a nitrite using an alkali metal or an alkaline earth metal, and specifically, potassium nitrite, lithium nitrite, or the like may be used.

  The second solution containing hydrogen peroxide is, for example, an aqueous solution containing hydrogen peroxide (hydrogen peroxide solution).

The third solution containing a buffer component is an aqueous solution containing a buffer component such as phosphoric acid (H ₃ PO ₄ ). Buffer components are not limited to phosphoric acid, but include components such as tris / hydrochloric acid, HEPES, EDTA, citric acid / sodium citrate, or acetic acid (CH ₃ COOH) and boric acid (H ₃ BO ₃ ). Or a wide range buffer.

  The buffer component has a buffering property in a pH range of 6 to 8. That is, the buffer component is neutrally buffered. Even if a small amount of acid or base is added to an aqueous solution containing a buffer component, the pH hardly changes, so that the aqueous solution can be stored neutrally and stably.

  The concentration of the buffer component is 0.5 mM or more and 100 mM or less. Preferably, the concentration of the buffer component is 1 mM or more and 10 mM or less. More preferably, the concentration of the buffer component is 5 mM or more and 10 mM or less. This eliminates the need for more acid or base than necessary when adjusting the pH of the aqueous solution (acidification or alkalinization). Therefore, the liquidity of the aqueous solution can be easily changed, and the activity of the aqueous solution can be easily exhibited.

  In this Embodiment, although the density | concentration of the nitrite ion contained in aqueous solution and the density | concentration of hydrogen peroxide are not specifically limited, For example, it is 100 mM or less. Thereby, the aqueous solution can be easily used for sterilization or decomposition of organic substances.

  For example, when the concentrations of both nitrite ions and hydrogen peroxide are too high, the reaction gradually proceeds even if the aqueous solution (mixed solution) is kept neutral. For this reason, it is not suitable for long-term storage of aqueous solution. In addition, when peroxynitrite is generated by acidifying the aqueous solution, the peroxynitrite changes to nitric acid after the reaction. For this reason, since aqueous solution becomes strong acidity, adjustment of reaction rate becomes difficult.

  Further, as shown in the above (Formula 1), equimolar peroxynitrite is generated from equimolar nitrite ions and hydrogen peroxide. For this reason, the molar concentration of nitrite ions and the molar concentration of hydrogen peroxide may be substantially the same.

  In the present embodiment, the ratio of the molar concentration of hydrogen peroxide to nitrite ions in the aqueous solution (= hydrogen peroxide / nitrite ions) is in the range of more than 0.5 and less than 2. Preferably, the ratio is in a range greater than 0.75 and less than 1.25.

  Hydrogen peroxide contained in the aqueous solution is decomposed and reduced by long-term storage. For this reason, high activity can be realized even after long-term storage by making the molar concentration of hydrogen peroxide larger than the molar concentration of nitrite ions in advance.

  In addition, peroxynitrous acid has a short life under acidic conditions, and the time for acting on the object is short. For this reason, by making the molar concentration of nitrite ions larger than the molar concentration of hydrogen peroxide in advance, nitrite remaining after the action of peroxynitrous acid is used, and weak sterilization or preserving under acidic conditions. And so on.

  In the present embodiment, the aqueous solution is neutralized by mixing the third solution containing a neutral buffer component. However, the present invention is not limited to this. Nitrate ions may be added instead of or in addition to the buffer component. That is, the aqueous solution may contain nitrate ions. Moreover, the aqueous solution which concerns on this Embodiment does not need to contain the buffer component.

[2. Activity of aqueous solution (decomposition power)]
In order to confirm the high activity (decomposition power) of the aqueous solution according to the present embodiment, the present inventor produced several types of liquid samples (Examples and Comparative Examples), and indigo carmine using the produced liquid samples. The decomposition test was conducted.

  Indigo carmine has an absorption maximum for light having a wavelength of 610 nm. That is, when indigo carmine is present in the liquid sample, light having a wavelength of 610 nm is absorbed, and thus the absorbance of the liquid sample with respect to light having the wavelength becomes a large value. On the other hand, when the indigo carmine contained in the liquid sample is decomposed and decreased, light with a wavelength of 610 nm is not absorbed, and thus the absorbance of the liquid sample with respect to the light with the wavelength becomes a small value. Therefore, the time change of the absorbance when the liquid sample and indigo carmine are mixed can be used as an index of the activity level (decomposition power) of the liquid sample.

  Then, the time change of the light absorbency with respect to the light of a wavelength of 610 nm in the liquid sample which mixed indigo carmine was measured using the spectrometer. In each of the following tests, the initial concentration of indigo carmine is 10 mg / L.

[2-1. Example]
The liquid sample A according to the example will be described. The liquid sample A is a neutral aqueous solution (mixed solution) containing nitrite ions, hydrogen peroxide, and a buffer component (phosphoric acid).

First, a 1M phosphate buffer having a pH of 7.2 was prepared (prepared). Specifically, this phosphate buffer is a mixture of 44.0 g of sodium dihydrogen phosphate dihydrate (NaH ₂ PO ₄ .2H ₂ O) and 30.2 g of sodium hydrogen phosphate (NaHPO ₄ ). And was made up to 500 mL with ultrapure water.

  To 14.85 mL of the 7.14 mM sodium nitrite solution, 150 μL of 1 M phosphate buffer at pH 7.2 was added to form a nitrite solution. Furthermore, a hydrogen peroxide solution is produced by adding 5 μL of 30% aqueous hydrogen peroxide to 15 mL of 10 mM phosphate buffer obtained by diluting 1M phosphate buffer at pH 7.2 with ultrapure water 100 times. did. The aqueous solution (namely, liquid sample A) which concerns on an Example was produced by mixing these nitrous acid solutions and hydrogen peroxide solution by equivalent.

[2-2. Comparative Example 1]
Next, the liquid sample B according to Comparative Example 1 will be described. The liquid sample B is a neutral aqueous solution (mixed solution) containing nitrite ions and a buffer component (phosphoric acid).

  By diluting the nitrous acid solution used for the preparation of the liquid sample A according to the example with the 10 mM phosphate buffer twice, the sodium nitrite solution having a pH of 7.2 is changed to the liquid according to the comparative example 1. Sample B was prepared.

[2-3. Comparative Example 2]
Next, the liquid sample C according to Comparative Example 2 will be described. The liquid sample C is a neutral aqueous solution (mixed solution) containing hydrogen peroxide and a buffer component (phosphoric acid).

  By diluting the hydrogen peroxide solution used for the preparation of the liquid sample A according to the example with the 10 mM phosphate buffer solution twice, the hydrogen peroxide solution with a pH of 7.2 is related to the comparative example 2. A liquid sample C was prepared.

[2-4. Test results]
Each of the above liquid samples A to C was neutralized (maintained neutral), acidified, or alkalized to perform an indigo carmine decomposition test. In addition, acidification was performed by adding sulfuric acid (4.5N). Alkalinization was performed by adding an aqueous sodium hydroxide solution (4.5 N). Specific addition amounts are as shown in Table 1 below.

  1A to 1C are diagrams showing the results of indigo carmine decomposition tests using aqueous solutions according to Examples, Comparative Examples 1 and 2, respectively.

[2-4-1. neutral]
As shown in FIGS. 1A to 1C, in any of the liquid samples A to C, the absorbance hardly decreases with the passage of time in the neutral state. That is, it can be seen that the liquid sample A according to the example is neutral and stable.

[2-4-2. Acidification]
When the liquid sample A according to the example was acidified, as shown in FIG. 1A, the absorbance rapidly decreased with time. Liquid sample A is considered to generate peroxynitrous acid and decompose indigo carmine.

  When the liquid sample B which concerns on the comparative example 1 is acidified, as FIG. 1B shows, the light absorbency is falling with progress of time. However, as compared with the liquid sample A according to the example, it can be seen that the degree of decrease in absorbance (gradient of the graph) is gentle and the decomposition rate is slow. Therefore, it is considered that the liquid sample A and the liquid sample B are different in substances that contribute to the decomposition of indigo carmine. Specifically, in the liquid sample B, it is considered that not nitrous acid but nitrite ions decompose indigo carmine. The decomposition power of nitrite ions is about one-tenth that of peroxynitrite.

  When the liquid sample C which concerns on the comparative example 2 is acidified, as shown to FIG. 1C, it is hardly falling with progress of time similarly to the neutral case.

[2-4-3. Alkaline]
When each of the liquid sample A and the liquid sample C according to Example and Comparative Example 2 was made alkaline, the absorbance decreased with time as shown in FIGS. 1A and 1C. The degree of each decrease is substantially the same. That is, it can be seen that the alkalinized liquid sample A and the alkalinized liquid sample B have substantially the same decomposition power.

  In addition, when no indigo carmine was added to the liquid sample A according to the example, the concentration of hydrogen peroxide decreased when alkalized, but almost no decrease in nitrite concentration and increase in nitric acid concentration were observed. . Therefore, in the liquid sample A according to the example, it is considered that hydrogen peroxide is activated and indigo carmine is decomposed.

  When the liquid sample B according to Comparative Example 1 is made alkaline, as shown in FIG. 1B, it hardly decreases with the passage of time.

[3. Peroxynitrite confirmation test (mass spectrometry)]
As described above, in the liquid sample A according to the embodiment, when acidified, peroxynitrous acid is generated to exhibit extremely high decomposing power, and when alkalized, hydrogen peroxide is activated. By doing so, it is thought that high resolution power is demonstrated. Below, when the liquid sample A is acidified, the experimental result performed in order to confirm that peroxy nitrous acid has generate | occur | produced is demonstrated.

First, phenol (C ₆ H ₅ OH) was dissolved in ultrapure water to prepare a phenol solution having a concentration of 10,000 mg / L. Furthermore, by adding a phenol solution at a volume ratio of 100: 1 (= liquid sample A or B: phenol) to each of the liquid sample A according to the example and the liquid sample B according to comparative example 1, the concentration of phenol is increased. It was prepared to be 100 mg / L.

  Furthermore, sulfuric acid was added to each solution under the same conditions as the acidification in the above-described decomposition test of indigo carmine. Each solution was neutralized by adding the same amount of sodium hydroxide 200 seconds after the addition of sulfuric acid. Thus, the liquid sample A and the liquid sample B which were mixed with the phenol solution and neutralized after acidification are referred to as a liquid sample D and a liquid sample E, respectively.

  Below, the product contained in each of liquid sample D and liquid sample E was analyzed by mass spectrometry. The analysis results are shown in FIGS. 2A to 3B.

  When peroxynitrous acid is generated, phenol and peroxynitrous acid react with each other, and —O—N═O or —OH of peroxynitrous acid (ONOOH) is added to the meta position or para position of phenol. Therefore, when it was confirmed that both a substance in which —O—N═O was added to the meta or para position of phenol and a substance in which —OH was added to the meta or para position of phenol were generated. It can be seen that peroxynitrite is generated.

FIG. 2A shows a time of flight mass spectrometry (TOF-MS) method for substances having a mass number of 138.02 (C ₆ H ₄ NO ₃ ) contained in each of liquid sample D and liquid sample E. It is a figure which shows the result of having analyzed. FIG. 2B is a diagram showing an analysis result obtained by analyzing the substance with a mass number of 138.02 shown in FIG. 2A by tandem mass spectrometry.

FIG. 3A is a diagram illustrating a result of analyzing a substance having a mass number of 109.03 (C ₆ H ₅ O ₂ ) contained in each of the liquid sample D and the liquid sample E by a time-of-flight mass spectrometry (TOF-MS) method. It is. FIG. 3B is a diagram showing an analysis result obtained by analyzing the substance having a mass number of 109.03 shown in FIG. 3A by tandem mass spectrometry.

  Tandem mass spectrometry was performed under the following conditions.

<Liquid chromatograph> UPLC H-Class
Analytical column: ACQUITY UPLC (registered trademark) BEH C18 1.7μm (2.1mmID × 100mm)
Eluent A: Pure water Eluent B: Acetonitrile Column oven temperature: 40 ° C
<Mass spectrometer> SYNAPT G2-Si
Measurement mode: ESI (Electrospray Ionization)
Polarity: Negative Measurement mass range: m / z = 50-1000
MSMS voltage: 15-30V

  As shown in (a) of FIG. 2A and (a) of FIG. 3A, production of a characteristic substance with mass numbers of 138.02 and 109.03 was confirmed from the liquid sample D. Specifically, a first substance corresponding to a peak at a time of 2.78 having a mass number of 138.02 shown in FIG. 2A (a), and a mass number of 109.02 shown in FIG. It was confirmed that the 2nd substance corresponding to the peak of time 1.76 was generated.

  FIG. 2B shows the result of analyzing the first substance by tandem mass spectrometry. As shown in FIG. 2B, substances having mass numbers of 108.2 and 92.03 are detected as fragments of substances having a mass number (mass-to-charge ratio (m / z)) of 138.02. Each difference from 138.02 is about 30 and about 36, which correspond to molecular weights of -N = O and -O-N = O, respectively. Therefore, it was confirmed that the first substance was a substance in which —O—N═O was added to the carbon atom at the para or meta position of phenol.

  FIG. 3B shows the result of analyzing the second substance by tandem mass spectrometry. As shown in FIG. 3B, a substance with a mass number of 91.02 is detected as a fragment with a mass number of 109.03. The difference from 109.03 is about 18, which roughly corresponds to the molecular weight of -OH. Therefore, it was confirmed that the second substance was an added substance that was a substance in which —OH was added to a carbon atom at the para or meta position of phenol.

  From the above, from the liquid sample D, a substance in which —O—N═O was added to a carbon atom at the para or meta position of phenol, and —OH was added to a carbon atom in the para or meta position of phenol. Since it was confirmed that both substances were produced, it was confirmed that peroxynitrite was generated in the liquid sample D.

  As shown in FIG. 2A (b), the liquid sample E did not show a peak at time 2.78. In other words, it was confirmed that the liquid sample E does not contain a substance in which —O—N═O is added to the para-position or meta-position carbon atom of phenol.

  Further, as shown in FIG. 3A (b), the liquid sample E did not show a peak with a retention time of 1.76. That is, it was confirmed that the liquid sample E does not contain a substance in which —OH is added to the carbon atom at the para or meta position of phenol.

  From the above, it was confirmed that no peroxynitrite was generated in the liquid sample E.

  When acidification was performed without adding phenol to a mixed solution of nitrous acid and hydrogen peroxide (liquid sample A), the concentrations of nitrous acid and hydrogen peroxide decreased, and the concentration of nitric acid increased.

[4. Change in activity (degradability) against pH]
Next, several types of liquid samples (Examples) were prepared and manufactured in order to investigate changes in the decomposition power of the aqueous solution when the pH of the aqueous solution (mixed solution) containing nitrite ions and hydrogen peroxide was changed. A decomposition test of indigo carmine was performed using a liquid sample.

[4-1. Liquid sample]
Below, 16 types of produced liquid samples I-XVI are demonstrated.

(I) NaNO ₂ + H ₂ O ₂ + Nitric acid, pH = 7.02
The liquid sample I is an aqueous solution having a pH of 7.02 in which a 200 mM sodium nitrite aqueous solution (NaNO ₂ aqueous solution) and a 200 mM hydrogen peroxide aqueous solution (H ₂ O ₂ aqueous solution) are mixed. Specifically, 62.5 μL of 200 mM NaNO ₂ aqueous solution and 62.5 μL of 200 mM H ₂ O ₂ aqueous solution are mixed with 2.375 mL of ultrapure water, and 1 μL of 1 mM nitric acid aqueous solution is further added. Thus, a liquid sample I was prepared.

(II) NaNO ₂ + H ₂ O ₂ + phosphate buffer, pH = 7.25
The liquid sample II is an aqueous solution having a pH of 7.25 in which a 200 mM NaNO ₂ aqueous solution, a 200 mM H ₂ O ₂ aqueous solution, and a 100 mM phosphate buffer are mixed. Specifically, first, using NaH ₂ PO ₄ .2H ₂ O and NaHPO ₄ , 5 mL of a 100 mM phosphate buffer solution having a pH of 7.25 was adjusted. By adding 42.5 mL of ultrapure water to the phosphate buffer and mixing 1.25 mL of the 200 mM NaNO ₂ aqueous solution and 1.25 mL of the 200 mM H ₂ O ₂ aqueous solution, Sample II was made.

(III) NaNO ₂ + H ₂ O ₂ + phosphate buffer, pH = 2
Liquid sample III is a pH 2 aqueous solution in which liquid sample II is acidified. Specifically, 12.5 μL of 2000 mg / L indigo carmine aqueous solution is mixed with 2.5 mL of liquid sample II, and liquid sample III is prepared by mixing 10 μL of 4.5 N H ₂ SO ₄ liquid. did.

(IV) NaNO ₂ + H ₂ O ₂ + phosphate buffer, pH = 2.5
The liquid sample IV is an aqueous solution having a pH of 2.5 obtained by acidifying the liquid sample II. A liquid sample IV was prepared in the same manner as the liquid sample III except that the amount of the H ₂ SO ₄ solution added was ₆ μL.

(V) NaNO ₂ + H ₂ O ₂ + phosphate buffer, pH = 3
The liquid sample V is an aqueous solution having a pH of 3 obtained by acidifying the liquid sample II. A liquid sample V was prepared in the same manner as the liquid sample III except that the amount of the H ₂ SO ₄ liquid added was 5 μL.

(VI) NaNO ₂ + H ₂ O ₂ + phosphate buffer, pH = 6
The liquid sample VI is an aqueous solution having a pH of 6 obtained by acidifying the liquid sample II. A liquid sample VI was prepared in the same manner as the liquid sample III except that the amount of the H ₂ SO ₄ liquid added was 2.5 μL.

(VII) NaNO ₂ + H ₂ O ₂ + phosphate buffer, pH = 8
The liquid sample VII is an aqueous solution having a pH of 8 in which the liquid sample II is neutralized. Instead of H ₂ SO ₄ , liquid sample VII was prepared by mixing 1.5 μL of 4.5 N NaOH.

(VIII) NaNO ₂ + H ₂ O ₂ + phosphate buffer, pH = 8.5
The liquid sample VIII is an aqueous solution having a pH of 8.5 obtained by alkalizing the liquid sample II. Instead of H ₂ SO ₄ , liquid sample VIII was prepared by mixing 2 μL of 4.5 N NaOH.

(IX) NaNO ₂ + H ₂ O ₂ + phosphate buffer, pH = 11
The liquid sample IX is an aqueous solution having a pH of 11 obtained by alkalizing the liquid sample II. Instead of H ₂ SO ₄ , liquid sample IX was prepared by mixing 4 μL of 4.5 N NaOH.

(X) NaNO ₂ + H ₂ O ₂ + phosphate buffer, pH = 11.5
The liquid sample X is an aqueous solution having a pH of 11.5 obtained by alkalizing the liquid sample II. Instead of H ₂ SO ₄ , liquid sample X was prepared by mixing 7.5 μL of 4.5 N NaOH.

(XI) NaNO ₂ + H ₂ O ₂ + phosphate buffer, pH = 12
The liquid sample XI is an aqueous solution having a pH of 12 obtained by alkalizing the liquid sample II. A liquid sample XI was prepared by mixing 14 μL of 4.5 N NaOH instead of H ₂ SO ₄ .

(XII) NaNO ₂ + H ₂ O ₂ + acetic acid buffer, pH = 4
The liquid sample XII is an aqueous solution having a pH of 4 in which the liquid sample I and an acetate buffer are mixed. Specifically, first, acetic acid (CH ₃ COOH) and ultrapure water are mixed to prepare a 2M acetic acid aqueous solution, and by mixing 4.5 N NaOH at 60 μL per 1 mL of the acetic acid aqueous solution, A pH 4 acetate buffer was prepared. Liquid sample XII was prepared by mixing 11 μL of indigo carmine aqueous solution and 11 μL of acetate buffer in 2.2 mL of liquid sample I.

(XIII) NaNO ₂ + H ₂ O ₂ + acetic acid buffer, pH = 5
The liquid sample XIII is an aqueous solution having a pH of 5 in which the liquid sample I and an acetate buffer are mixed. A liquid sample XIII was prepared in the same manner as the liquid sample XII except that the amount of NaOH added was 280 μL per mL.

(XIV) NaNO ₂ + H ₂ O ₂ + acetic acid buffer, pH = 5.5
The liquid sample XIV is an aqueous solution having a pH of 5.5, in which the liquid sample I and an acetate buffer are mixed. A liquid sample XIV was produced in the same manner as the liquid sample XII except that the amount of NaOH added was 380 μL per mL.

(XV) NaNO ₂ + H ₂ O ₂ + borate buffer, pH = 9
The liquid sample XV is an aqueous solution having a pH of 9 in which the liquid sample I and a borate buffer are mixed. Specifically, first, boric acid (H ₃ BO ₃ ) and ultrapure water are mixed to prepare a 0.5 M boric acid aqueous solution, and a ratio of 40 μL with respect to 1 mL of the boric acid aqueous solution. A borate buffer with a pH of 9 was made by mixing 5N NaOH. Liquid sample XV was prepared by mixing 11 μL of indigo carmine aqueous solution and 44 μL of borate buffer solution with 2.2 mL of liquid sample I.

(XVI) NaNO ₂ + H ₂ O ₂ + borate buffer, pH = 10
The liquid sample XVI is an aqueous solution having a pH of 10 in which the liquid sample I and a borate buffer are mixed. A liquid sample XVI was prepared in the same manner as the liquid sample XV, except that the amount of NaOH added was 90 μL per mL.

[4-2. Test results]
The results of the indigo carmine degradation test using the above 16 types of liquid samples I to XVI are shown in FIGS. 4A and 4B. FIG. 4: A is a figure which shows the result of the decomposition | disassembly test of indigo carmine at the time of acidifying the aqueous solution which concerns on an Example. FIG. 4B is a diagram illustrating a result of an indigo carmine decomposition test when the aqueous solution according to the example is alkalized. 4A and 4B, the horizontal axis represents the decomposition time, and the vertical axis represents the absorbance. The decomposition time on the horizontal axis is the time from when indigo carmine is added to the solution for I, II, and XII to XVI, and from the time when the pH of the liquid is changed for III to XI.

  In FIG. 4A, the time change of each light absorbency of neutral liquid samples I and VI and acidic liquid samples III-V and XII-XIV is shown. As can be seen from FIG. 4A, in the neutral liquid samples I and VI, the absorbance is substantially constant with respect to the decomposition time, and it can be seen that indigo carmine is hardly decomposed.

  On the other hand, in the acidic liquid samples III to V and XII to XIV, the absorbance decreases as the decomposition time elapses. Specifically, it can be seen that the smaller the pH, the greater the rate of decrease in absorbance and the faster the decomposition rate of indigo carmine. In particular, in the liquid samples XII and III to V having a pH of 4 or less, it can be seen that the decomposition of indigo carmine progressed rapidly because the absorbance decreased rapidly.

  From the above, it was confirmed that the aqueous solution exhibits high decomposing power by acidifying an aqueous solution in which nitrite ions and hydrogen peroxide are mixed. At this time, the buffer component may be either phosphoric acid or acetic acid, and it can be confirmed that there is no particular limitation.

  FIG. 4B shows changes in absorbance of the neutral liquid samples I, II and VII and the alkaline liquid samples VII to XI, XV and XVI over time. As can be seen from FIG. 4B, in the neutral liquid samples I, II, and VII, it can be seen that the absorbance is substantially constant with respect to the decomposition time, and indigo carmine is not decomposed. In the liquid sample VII having a pH of 8, the absorbance was slightly decreased, and it was confirmed that the decomposition of indigo carmine was slowly progressing.

  On the other hand, in the alkaline liquid samples VII to XI, XV, and XVI, the absorbance decreases as the decomposition time elapses. Specifically, it can be seen that the greater the pH, the greater the rate of decrease in absorbance and the faster the decomposition rate of indigo carmine. In particular, in the liquid samples IX to XI having a pH of 11 or more, it can be seen that the decomposition of indigo carmine progressed rapidly since the absorbance decreased rapidly.

  From the above, it was confirmed that the aqueous solution exhibits high decomposing power by making the aqueous solution obtained by mixing nitrite ions and hydrogen peroxide alkaline. At this time, the buffer component may be either phosphoric acid or boric acid, and it can be confirmed that there is no particular limitation.

  FIG. 5A is a graph showing the relationship between the pH of the aqueous solution according to the example and the decomposition rate (decomposition rate) of indigo carmine. FIG. 5B is a diagram for explaining the decomposition rate shown in FIG. 5A.

  The degradation rate (degradation rate) of indigo carmine is indicated by the change over time in the concentration of indigo carmine. Specifically, as shown in FIG. 5B, the slope of the absorbance curve (that is, the rate of change in absorbance) at the point of 15 seconds after the start of degradation was converted to the time change in the concentration of indigo carmine (ie, the rate of degradation). . More specifically, the change with time in concentration was calculated by multiplying the slope of the absorbance curve by a coefficient (2.72 ppm / abs) calculated from a calibration curve of absorbance with respect to the concentration of indigo carmine. In addition, in the range where pH is less than 2 or more than 12, accurate measurement was not possible because the decomposition rate was too high.

  As shown in FIG. 5A, the degradation rate is larger than 0 in the liquid sample whose pH is smaller than 6 or larger than 9. In particular, a liquid sample having a pH of less than 4 or greater than 10 has a high decomposition rate, and it can be seen that the liquid sample has a sufficiently high decomposition ability.

  Further, as shown in FIGS. 4A and 4B, it was confirmed that indigo carmine was decomposed even when the pH was 5, 5.5, 8, and 8.5. In addition, even when the pH is 6, as shown in FIG. 4A, the decomposition of indigo carmine is proceeding, albeit slightly. From the above, by adjusting the pH of the aqueous solution according to the present embodiment to be smaller than 6 or larger than 8, the aqueous solution can exhibit high activity (decomposition power).

[5. Storage possibility]
Then, the storage possibility of the aqueous solution which concerns on this Embodiment is demonstrated.

  In order to confirm the storage possibility of the aqueous solution according to the present embodiment, the present inventor prepared several types of liquid samples and left them at room temperature for 10 days. The concentration of nitrite ion immediately after the preparation of the liquid sample and after standing for 10 days was measured by ion chromatography, and the change in the concentration of hydrogen peroxide was measured by a colorimetric method. Table 2 shows the measurement results.

First, a mixed solution (a) of a 100 mM NaNO ₂ aqueous solution and a 100 mM H ₂ O ₂ aqueous solution was prepared by mixing a 200 mM NaNO ₂ aqueous solution, a 200 mM H ₂ O ₂ aqueous solution, and ultrapure water. By diluting the mixed solution 10 times or 100 times with ultrapure water, a mixed solution (b) of 10 mM NaNO ₂ aqueous solution and 10 mM H ₂ O ₂ aqueous solution, 1 mM NaNO ₂ aqueous solution and 1 mM H H _{2 respectively.} A mixed solution (c) with ₂ O ₂ aqueous solution was prepared.

Furthermore, 1M phosphate buffer having a pH of 7.2 is added to each of the mixed solutions (a) to (c) at a volume ratio of 100: 1 (= mixed solution (a) to (c): phosphate buffer). Were mixed to prepare mixed solutions (d) to (e). That is, the mixed solution (d) is a mixed solution of a 100 mM NaNO ₂ aqueous solution, a 100 mM H ₂ O ₂ aqueous solution, and a phosphate buffer. The mixed solution (e) is a mixed solution of a 10 mM NaNO ₂ aqueous solution, a 10 mM H ₂ O ₂ aqueous solution, and a phosphate buffer. The mixed solution (f) is a mixed solution of a 1 mM NaNO ₂ aqueous solution, a 1 mM H ₂ O ₂ aqueous solution, and a phosphate buffer.

In Table 2, the pH is the pH immediately after preparation of the mixed solution. NO ₂ ^- initial value ratio, NO ₂ after standing for 10 days for immediately after the production of the mixed solution ^- represents the ratio of the concentrations. The same applies to the H ₂ O ₂ initial value ratio.

  As shown in Table 2, it can be seen that in the mixed solutions (a) to (c) in which the phosphate buffer was not mixed, nitrite ions increased and hydrogen peroxide decreased to 75% or less. As described above, since equimolar peroxynitrite is produced from equimolar nitrite ions and hydrogen peroxide, decreasing the concentration of hydrogen peroxide also reduces the amount of peroxynitrite produced. For this reason, compared with immediately after preparation, the activity of the mixed solution when acidified or alkalized is lowered.

  On the other hand, in the mixed solutions (d) to (f) neutralized by mixing the phosphate buffer, the concentration of 85% or more is maintained although the hydrogen peroxide is slightly decreased. Moreover, although the increase or decrease is seen also about nitrite ion, the density | concentration of 90% or more is maintained. Thus, it turns out that the reduction | decrease of nitrite ion can fully be suppressed compared with the case where a phosphate buffer solution is not added.

  From the above, a mixed solution containing nitrite ions and hydrogen peroxide can be stored for a long period of time by adding a buffer component such as a phosphate buffer to neutralize it. When the stored aqueous solution is used for the purpose of sterilization or the like, the oxidizing power can be exhibited by adjusting the pH of the aqueous solution.

[6. Disinfection test]
Hereinafter, a sterilization test performed by the inventor using the aqueous solution according to the present embodiment will be described. Table 3 shows the test results. The sterilization test was performed using the liquid samples A to C described above.

The sterilization test will be described. First, a predetermined amount of Escherichia coli was mixed with sample water to produce a bacterial solution adjusted to 10 ⁴ cfu. The sample water is as shown in Table 3.

  After spraying 1 mL of the bacterial solution on the standard agar medium using a spiral plater, the reaction was stopped every predetermined time. Specifically, the reaction stop process was performed every 10 seconds, 30 seconds, 60 seconds, 120 seconds, 300 seconds, 600 seconds, 30 minutes, and 1 hour. When the sample water was acidic or alkaline, the reaction stop treatment was neutralized (added 2.33 μL of base or acid).

  After the reaction termination treatment, the cells were cultured for 16 hours using a thermostatic bath (30 ° C.). Thereafter, the number of bacteria was counted using a colony counter.

  As shown in Table 3, when the mixed buffer solution (liquid sample A) of nitrous acid and hydrogen peroxide was acidified, the sterilization time was about 10 seconds. On the other hand, when the buffer solution (liquid sample B) containing only nitrous acid was acidified, the sterilization time was about 2.5 minutes. Therefore, it can be seen that the liquid sample A has a higher sterilization effect. The sterilization time was measured as the time until the viable cell rate reached 1% after contact with the bacterial solution.

  Further, when the mixed buffer solution of nitrous acid and hydrogen peroxide (liquid sample A) was made alkaline, the sterilization time was about 5 minutes. On the other hand, when the buffer solution containing only hydrogen peroxide (liquid sample C) was made alkaline, the sterilization time was about 8 minutes. Therefore, it can be seen that when the liquid sample A and the liquid sample C are made alkaline, the sterilization time is 10 minutes or less, and they have substantially the same sterilization power. In addition, although E. coli has a sterilizing effect even if the pH becomes acidic or alkaline, it can be sterilized in a shorter time by using the above-described configuration.

  On the other hand, all of the neutral liquid samples A to C did not reach 1% after 1 hour, and could not be sterilized.

  As described above, it can be seen that the aqueous solution containing nitrite ions, hydrogen peroxide, and a buffer component according to the present embodiment can be used for sterilization when acidified or alkalinized. In addition, this result suggests that liquid samples produced in other experiments can be used for sterilization as well.

(Embodiment 2)
Below, the target object processing apparatus which concerns on Embodiment 2, and its operation | movement (namely, target object processing method) are demonstrated.

[1. Constitution]
FIG. 6 is a diagram showing a configuration of the object processing apparatus 10 according to the present embodiment. The target object processing apparatus according to the present embodiment processes the target object 11 such as a bacterium using the aqueous solution (mixed solution of nitrite ions, hydrogen peroxide, and a buffer component) according to the first embodiment. Device.

  The object 11 is a substance that is decomposed (or killed) by the first embodiment. Specifically, the object 11 is an organic substance, a microorganism, or a bacterium.

  As illustrated in FIG. 6, the object processing apparatus 10 includes a container 20, a supply unit 30, a control circuit 40, and a contact unit 50. Below, each component which comprises the target object processing apparatus 10 is demonstrated in detail.

[1-1. container]
The container 20 is a container for containing a liquid. The container 20 is provided with a supply port 21 for supplying a liquid and a discharge port 22 for discharging the liquid.

  The container 20 is formed from a material having resistance to acid or alkali, for example. For example, the container 20 is formed of a resin material such as polyvinyl chloride or tetrafluoroethylene (PFA), a metal material such as stainless steel, or a ceramic. The size and shape of the container 20 are not particularly limited.

  The discharge port 22 is provided with a valve 23 that can be freely opened and closed. In the present embodiment, opening and closing of the valve 23 is controlled by the control circuit 40. The valve 23 may be manually opened and closed by the user. The supply port 21 may be provided with a similar valve.

  In the present embodiment, the neutral mixed solution 12 according to the first embodiment is put into the container 20 through the supply port 21. The neutral mixed solution 12 is an aqueous solution having a pH of 6 or more and 8 or less, containing nitrite ions, hydrogen peroxide and a buffer component as main components. The buffer component is a substance having a buffering property in a pH range of 6 to 8, for example, phosphoric acid.

  As described in Embodiment 1, since the neutral mixed solution 12 can be stored, it can also be stored in the container 20 for a certain period. That is, the container 20 may be used as a storage container for the mixed solution 12.

[1-2. Supply section]
The supply unit 30 supplies a pH adjusting substance for adjusting the pH of the liquid in the container 20 into the container 20. For example, the supply unit 30 supplies a predetermined amount of the pH adjusting substance into the container 20 at a predetermined timing based on an instruction from the control circuit 40. The supply unit 30 adjusts the pH of the mixed solution 12 stored in the container 20 by supplying, for example, a solution containing an acid, a base, or a salt as a pH adjusting substance into the container 20.

  The supply unit 30 includes, for example, a container for containing a pH adjusting substance, and a pump and / or a valve connected to the container and supplying the pH adjusting substance to the container 20. For example, the control circuit 40 controls the pump to adjust the pressure difference between the container in which the pH adjusting substance is stored and the container 20 in which the neutral mixed solution 12 is stored. Further, the control circuit 40 controls the opening / closing operation of the valve, whereby the supply unit 30 supplies the pH adjusting substance into the container 20 at a predetermined timing.

In the present embodiment, the pH adjusting substance is (i) an acid, a base or a salt, (ii) a solution containing at least one of an acid, a base or a salt, (iii) a gas or a solid which dissolves into an acid or a base Or (iv) a solution containing an organism that generates the gas or the liquid or solid. Specifically, the pH adjusting substance may be an acid such as sulfuric acid (H ₂ SO ₄ ) or nitric acid (HNO ₃ ), a base such as an aqueous solution of sodium hydroxide (NaOH) or ammonia (NH ₃ ), or aluminum sulfate (Al ₂ (SO ₄ ) ₃ ) and magnesium chloride (MgCl ₂ ).

[1-3. Control circuit]
The control circuit 40 controls the supply unit 30. Specifically, the control circuit 40 controls the supply amount and supply timing of the pH adjusting substance supplied from the supply unit 30 to the container 20.

  In the present embodiment, the control circuit 40 causes the supply unit 30 to supply the pH adjusting substance into the container 20 when the neutral mixed solution 12 is placed in the container 20. Thereby, for example, the neutral mixed solution 12 and the pH adjusting substance are mixed in the container 20, and the pH of the mixed solution 12 is adjusted. For example, the mixed solution 13 whose pH is adjusted to be smaller than 6 or larger than 8 is discharged to the outside through the discharge port 22 and comes into contact with the object 11. As shown in Embodiment 1 above, the acidified or alkalinized mixed solution 13 has high activity (decomposition power), and thus can decompose the object 11.

  In the present embodiment, the control circuit 40 further controls opening and closing of the valve 23 provided in the discharge port 22. Specifically, after the neutral mixed solution 12 is acidified or alkalinized in the container 20, the control circuit 40 opens the valve 23 so that the acidified or alkalinized mixed solution 13 is brought into contact with the contact portion. 50.

  The control circuit 40 includes, for example, a non-volatile memory that stores a program and a processor that executes the program. The control circuit 40 may further include a volatile memory that is a temporary storage area for executing a program, and an input / output port. The control circuit 40 is, for example, a microcomputer (a microcontroller or a microcomputer).

[1-4. Contact part]
The contact part 50 is a part for bringing the mixed solution 13 whose pH is adjusted in the container 20 into contact with the object 11. In the present embodiment, the contact portion 50 is connected to the discharge port 22 of the container 20 via the valve 23.

  The contact part 50 is a container which puts the target object 11, for example. The mixed solution 13 can be brought into contact with the object 11 by the mixed solution 13 being put into the contact portion 50 through the discharge port 22. The contact portion 50 may be an ejector such as a spray. In this case, the contact part 50 can make the mixed solution 13 contact the target object 11 by ejecting the mixed solution 13 toward the target object 11.

  The contact part 50 makes the mixed solution 13 contact the object containing the target object 11, for example. The object including the object 11 is, for example, a household item such as tableware, a medical device, or a building material such as a bathroom floor or window glass. Alternatively, the object including the target object 11 is a human oral cavity including caries bacteria or periodontal disease bacteria as the target object 11, or food or animals and plants including the spoilage bacteria as the target object 11.

[2. Operation (object processing method)]
Subsequently, the operation (that is, the object processing method) of the object processing apparatus 10 according to the present embodiment will be described with reference to FIG. FIG. 7 is a flowchart showing the operation of the object processing apparatus 10 according to the present embodiment.

  First, a neutral aqueous solution containing nitrite ions and hydrogen peroxide is prepared (S10). Specifically, a mixed solution 12 shown in FIG. 6 is prepared. Here, the preparation of the mixed solution 12 includes not only the generation of the mixed solution 12 but also the meaning of procuring the mixed solution 12. In the present embodiment, as a preparation of the mixed solution 12, the mixed solution 12 is put into the container 20 through the supply port 21.

  Next, the pH of the prepared aqueous solution is adjusted to be smaller than 6 or larger than 8 (S12). Specifically, the control circuit 40 controls the supply unit 30 to supply the pH adjusting substance into the container 20. Thereby, by mixing the mixed solution 12 and the pH adjusting substance in the container 20, the pH of the mixed solution 12 is adjusted to be smaller than 6 (acidification) or larger than 8 (alkalization).

  In addition, the grade which adjusts the pH of the mixed solution 12 is determined according to the oxidizing power requested | required of the mixed solution 13 after adjustment, for example. For example, when a stronger oxidizing power is required, a large amount of acid may be supplied from the supply unit 30 so that the pH becomes smaller. Or when weak oxidizing power is required, you may supply a small amount of acids or bases from the supply part 30 so that pH may become a value close | similar to neutrality. The type and supply amount of the pH adjusting substance may be determined according to the type of the object 11, for example.

  Next, the aqueous solution after adjusting the pH is brought into contact with the object 11 (S14). Specifically, the control circuit 40 opens the valve 23 to supply the contact solution 50 with the acidified or alkalinized mixed solution 13. Thereby, the mixed solution 13 and the target object 11 contact in the contact part 50, and the target object 11 is decomposed | disassembled.

  As mentioned above, in this Embodiment, step S14 made to contact the target object 11 is performed after step S12 which adjusts pH. Thereby, since the mixed solution 13 after raising activity is made to contact the target object 11, reaction of the mixed solution 13 and the target object 11 can be controlled. For example, the reaction rate between the mixed solution 13 and the object 11 can be adjusted.

  In the present embodiment, an example in which the pH of a neutral mixed solution is adjusted by supplying a pH adjusting substance has been described, but the present invention is not limited thereto. For example, the pH of the aqueous solution may be adjusted by electrolyzing a neutral mixed solution. For example, the object processing apparatus 10 shown in FIG. 6 may include a pair of electrode pairs arranged in the container 20 and a power source for applying a voltage between the electrode pairs.

  Moreover, in this Embodiment, although the mixed solution 12 was supplied in the container 20 from the supply port 21, you may produce | generate the mixed solution 12 in the container 20. FIG. Specifically, a first solution containing nitrite ions, a second solution containing hydrogen peroxide, and a third solution containing a buffer component are supplied into the container 20 from the supply port 21 and the like. The mixed solution 12 may be generated by mixing.

(Modification)
Below, the modification of said Embodiment 2 is demonstrated.

  FIG. 8 is a diagram showing the configuration of the object processing apparatus 10a according to this modification. As shown in FIG. 8, the object processing apparatus 10 a according to this modification is different in that the object 11 is placed in the container 20. That is, the object processing apparatus 10a may not include the discharge port 22 and the contact unit 50. Below, it demonstrates centering around difference with said Embodiment 2, and abbreviate | omits or simplifies description about the same point.

  In the present modification, the object 11 is placed in the container 20. Therefore, before the pH of the neutral mixed solution 12 is adjusted, the mixed solution 12 and the object 11 come into contact with each other. In addition, the target object 11 is mixed with the mixed solution 12 and put into the container 20 from the supply port 21, for example. Alternatively, the supply unit 30 may put the object 11 in the container 20.

  FIG. 9 is a flowchart showing the operation (object processing method) of the object processing apparatus 10a according to this modification. As shown in FIG. 9, the step of preparing a neutral aqueous solution (specifically, the mixed solution 12) is the same as that in the second embodiment.

  In this modification, the prepared aqueous solution is brought into contact with the object 11 (S22). Specifically, the mixed solution 12 and the object 11 are brought into contact within the container 20.

  Next, the pH of the aqueous solution after contact is adjusted to be smaller than 6 or larger than 8 (S24). Specifically, the control circuit 40 controls the supply unit 30 to supply the pH adjusting substance into the container 20. Thereby, in the container 20, by mixing the mixed solution 12 and the pH adjusting substance that are in contact with the object 11, the pH of the mixed solution 12 is smaller than 6 (acidified) or larger than 8 (alkalineized). )adjust.

  As mentioned above, in this Embodiment, step S24 which adjusts pH of the mixed solution 12 is performed after step S22 made to contact the target object 11. FIG. Thereby, since the pH of the mixed solution 12 is adjusted after making the mixed solution 12 contact the target object 11, if the activity of the mixed solution 12 is raised, it can act on the target object 11 immediately. Therefore, the decomposition | disassembly of the target object 11 etc. can be performed efficiently.

(Other embodiments)
As mentioned above, although the aqueous solution and the target object processing method which concern on one or some aspect were demonstrated based on embodiment, this indication is not limited to these embodiment. Unless it deviates from the main point of this indication, the form which carried out various deformation | transformation which those skilled in the art thought to this embodiment, and the structure constructed | assembled combining the component in different embodiment is also included in the scope of this indication. It is.

  For example, in Embodiment 2 described above, the pH of the mixed solution 12 containing nitrite ions, hydrogen peroxide, and a buffer component is adjusted to be smaller than 6 or larger than 8, but the present invention is not limited to this. The pH of the mixed solution 12 may be adjusted to be smaller than 5 or larger than 9. Moreover, the mixed solution 12 does not need to contain the buffer component. For example, in the case where the mixed solution 12 is not stored for a long period of time, the activity when the mixed solution 12 is acidified or alkalinized is increased by acidifying or alkalizing the mixed solution 12 that does not contain a buffer component. 11 can be disassembled. When the buffer component is not included, the pH of the mixed solution 12 can be largely adjusted by adding a small amount of acid or base.

  Further, for example, in the above-described embodiment, an aqueous solution containing nitrite ions, hydrogen peroxide, and a buffer component is generated by mixing a solution containing a drug. However, the present invention is not limited to this. For example, a liquid in which hydrogen peroxide or nitrite ions are generated by plasma treatment of a liquid such as tap water may be used. Alternatively, a liquid obtained by adding nitrite to a solution in which hydrogen peroxide is generated by electrolysis using a diamond electrode may be used. Alternatively, a liquid in which hydrogen peroxide is added after nitrous acid is generated by nitrate-reducing bacteria from a solution containing nitric acid may be used. That is, there are no particular limitations on the method (preparation method) for generating each of the first solution containing nitrite ions, the second solution containing hydrogen peroxide, and the third solution containing a buffer component.

  Each of the above-described embodiments can be variously changed, replaced, added, omitted, etc. within the scope of the claims or an equivalent scope thereof.

  The present disclosure can be used as an aqueous solution that has high activity and can be easily used, and a method for treating an object using the aqueous solution. For example, it can be used for organic substance decomposition treatment, sterilization of microorganisms, bacteria, and the like. be able to.

10, 10a Object processing device 11 Object 12, 13 Mixed solution 20 Container 21 Supply port 22 Discharge port 23 Valve 30 Supply unit 40 Control circuit 50 Contact unit

Claims (10)

The main components include nitrite ions, hydrogen peroxide, and buffer components having a pH in the range of 6 to 8 and a concentration of 0.5 mM to 100 mM.
An aqueous solution having a pH of 6 or more and 8 or less. The aqueous solution according to claim 1, further comprising nitrate ions. The aqueous solution according to claim 1 or 2, wherein the buffer component is phosphoric acid. The aqueous solution according to claim 1, wherein a concentration of the buffer component is 1 mM or more and 10 mM or less. Preparing an aqueous solution containing nitrite ions and hydrogen peroxide as main components and having a pH of 6 or more and 8 or less;
Adjusting the pH of the aqueous solution to be less than 6 or greater than 8.
Contacting the object with the aqueous solution. The object processing method according to claim 5, wherein the adjusting step is performed after the contacting step. The object processing method according to claim 5, wherein the contacting step is performed after the adjusting step. In the adjusting step, (i) an acid, a base or a salt, (ii) a solution containing at least one of an acid, a base or a salt, (iii) a gas or a solid which dissolves into an acid or a base, or (iv) The object processing method according to any one of claims 5 to 7, wherein the pH of the aqueous solution is adjusted by adding a solution containing a living organism that generates the gas or the liquid or a solid to the aqueous solution. The object processing method according to any one of claims 5 to 7, wherein in the adjusting step, the pH of the aqueous solution is adjusted by electrolyzing the aqueous solution. The object according to any one of claims 5 to 9, wherein the aqueous solution further has a buffering property in a pH range of 6 to 8, and contains a buffer component having a concentration of 0.5 mM to 100 mM. Processing method.

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