JPH10309582A - Production method of acidic electrolytic water and acidic electrolytic water - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a sterilization effect from being lowered with time after electrolysis by electrolyzing a fixed quantity of an electrolyte having a fixed concentration to generate an acidic electrolytic water and adding an inorganic acid buffer solution therein to adjust a hydrogen ion concentration. SOLUTION: Acidic electrolytic water 2 obtained by electrolyzing in an electrolytic cell 11 is selected by a four-way valve 17 and an inorganic acid buffer solution such as an acetic acid buffer solution, a hydrochloric acid buffer solution or a phosphoric acid buffer solution is ejected thereinto to adjust a hydrogen ion concentration. The inorganic acid buffer solution having a characteristic of adjusting a hydrogen ion concentration without decomposing hydrochloric acid and changing a sterilization effect is used and the concentration is adjusted in accordance with the hydrogen ion concentration to be adjusted. As the result, the change of the hydrochloric acid concentration in the acidic electrolytic water with time is suppressed and the lowering of the sterilization effect with time is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to the sterilization of various instruments and hands of workers in laboratories handling living organisms, disinfection in hospitals, etc., disinfection in plant cultivation, etc. Acidic electrolyzed water that has a disinfecting effect such as bactericidal and antibacterial properties used as a disinfectant for veterinary and livestock industries, public places requiring sanitation, places requiring disinfection, etc.,
And a method for producing the acidic electrolyzed water.

[0002]

2. Description of the Related Art It is known that when electrolyzing distilled water or an electrolyte solution, acidic electrolyzed water is generated on the anode side and alkaline electrolyzed water is generated on the cathode side. Generally, alkaline electrolyzed water is called alkaline water, alkaline ionized water, or the like, while acidic electrolyzed water is called acidic water, strongly oxidized water, strongly acidic water, super oxidized water, or the like. Conventionally, it has been empirically known that this acidic electrolyzed water may have bactericidal or antibacterial properties.

[0003]

Conventionally, when acidic electrolyzed water is used as germicidal water, the degree of bactericidal or antibacterial bactericidal effect of the acidic electrolyzed water depends on the degree of bactericidal effect at the time of manufacturing the acidic electrolyzed water. , The bactericidal effect is reduced due to a change over time after production.

[0004] Therefore, in order to make the sterilizing effect of the acidic electrolyzed water more effective and to keep the sterilizing effect of the acidic electrolyzed water high even after a lapse of time, it is necessary to produce a high concentration of the electrolyzed water at the time of production. , It is necessary to use a large amount of acidic electrolyzed water.

[0005] However, since the influence of the acidic and other chemical properties of acidic electrolyzed water on the environment generally depends on the concentration of the acidic electrolyzed water, the use of a high concentration of the acidic electrolyzed water or a large amount of the acidic electrolyzed water causes environmental problems. May increase the effect on

Therefore, the present invention solves the conventional problems,
It is an object of the present invention to provide a method for producing acidic electrolyzed water having a reduced decrease in the hypochlorite concentration of the electrolyzed acidic electrolyzed water after the electrolysis and a decrease in the sterilizing effect, and an acidic electrolyzed water obtained by the production method. As a result, electrolyzed water having a low concentration, a high bactericidal effect, and a reduced effect on the environment is obtained.

[0007]

Means for Solving the Problems The electrolyte solution is a solution containing a halogen group element having a high electronegativity, which tends to become a monovalent anion such as chlorine, bromine or iodine. An electrolyte solution is injected into an electrolytic cell in which an anode and a cathode are opposed to each other with an ion-permeable diaphragm interposed therebetween, and a voltage is applied between the anode and the cathode to electrolyze the electrolyte solution. The alkaline electrolyzed water is produced on the cathode side.

[0008] The applicant of the present patent application has examined the sterilizing properties of acidic electrolyzed water and found that there is a correlation between the sterilizing effect of electrolyzed water and the concentration of hypochlorous acid. Has confirmed that it is mainly caused by hypochlorous acid contained in electrolyzed water, and has filed a patent application for a method of producing electrolyzed water having a bactericidal effect. Furthermore, the applicant of the present patent application has also filed a patent application for a method for quantitatively measuring the sterilizing effect of sterilizing water (Japanese Patent Application No. Hei 7-2667).
No. 7).

The applicant of the present application examined the relationship between the hydrogen ion concentration of the acidic electrolyzed water, the hypochlorous acid concentration and the sterilizing effect, and the adjustment of the hydrogen ion concentration delayed the decrease in the hypochlorous acid concentration. I found something.

Therefore, the method for producing acidic electrolyzed water of the present invention produces an acidic electrolyzed water by electrolyzing a fixed amount of an electrolyte solution and generates a hydrogen ion concentration by adding a buffer of an inorganic acid to the acidic electrolyzed water. Adjust to stabilize the concentration of hypochlorous acid in the acidic electrolyzed water and reduce the change over time.

The decrease in the decrease in hypochlorous acid concentration due to the adjustment of the hydrogen ion concentration is effective when the pH value is adjusted to 3.5 to 5.5, and preferably the hydrogen ion concentration is adjusted to a pH value of 4.5. By adjusting to, the decrease in the concentration of hypochlorous acid can be delayed and the bactericidal effect can be maintained.

The inorganic acid buffer used for adjusting the hydrogen ion concentration may be acetic acid, a solution of acetic acid, a solution of a basic salt of acetic acid or a solution of a basic salt of acetic acid, or a solution of hydrochloric acid, a solution of hydrochloric acid, or a basic solution of hydrochloric acid. A salt or a solution of a basic salt of hydrochloric acid, or a solution of phosphoric acid, a solution of phosphoric acid, a solution of a basic salt of phosphoric acid, or a solution of a basic salt of phosphoric acid can be used.

Further, the acidic electrolyzed water of the present invention can be made into an acidic electrolyzed water capable of delaying a decrease in hypochlorous acid concentration and maintaining a bactericidal effect by being produced by the above-described production method. .

[0014]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a schematic configuration diagram for producing the acidic electrolyzed water of the present invention. In FIG. 1, an electrolytic cell 11 includes two chambers separated by a selective ion exchange membrane 15, and an electrode 13 and an electrode 14 are provided in each chamber. The DC voltage source 12 is connected to the electrodes 13 and 14, and a positive voltage is applied to the electrode 13 to form an anode, and a negative voltage is applied to the electrode 14 to form a cathode.
Note that it is not necessary to fix the electrode 13 to the anode and the electrode 14 to the cathode, and by switching the polarity, deterioration of the electrodes can be suppressed. The electrolytic solution 1 is injected into the electrolytic cell 11 through a valve 16, and the acidic electrolytic water 2 obtained by electrolysis is extracted from the anode side, and the alkaline electrolytic water 3 is extracted.
Is extracted from the cathode side.

The four-way valve 17 selects and extracts one of the acidic electrolyzed water 2 and the alkaline electrolyzed water 3 from the electrolytic cell 11. The valve 18 is configured to add the inorganic acid buffer 5 to the electrolyzed water extracted from the four-way valve 17, thereby adjusting the hydrogen ion concentration of the acidic electrolyzed water 2. The acidic electrolyzed water 6 to which the inorganic acid buffer 5 has been added can be stored in an acidic electrolyzed water container 7. The pH meter 8 measures the hydrogen ion concentration of the produced acidic electrolyzed water 6. In the configuration shown in FIG. 1, the four-way valve 17 and the valve 1
Through 9, it is also possible to extract the acidic electrolyzed water 2 or the alkaline electrolyzed water 3 without adjusting the hydrogen ion concentration.

In the production of the acidic electrolyzed water of the present invention, an electrolyte solution 1 containing a halogen element having a high electronegativity, which is apt to become a monovalent anion such as chlorine, bromine or iodine, is injected into the electrolytic cell 11. A voltage is applied between the anode 13 and the cathode 14 which are arranged facing each other in the electrolytic cell 11 to electrolyze the electrolyte solution 1. By this electrolysis, acidic electrolyzed water is generated on the anode 13 side, and alkaline electrolyzed water is generated on the cathode 14 side.

The acidic electrolyzed water 6 of the present invention is obtained by adding an inorganic acid buffer 5 to the acidic electrolyzed water 2 obtained by electrolysis to adjust the hydrogen ion concentration to obtain an acidic electrolyzed water.

The configuration shown in FIG. 1 is an example of the configuration, and does not limit the method for producing acidic electrolyzed water of the present invention.
The present invention can be implemented by other configurations.

Next, the method for producing acidic electrolyzed water according to the present invention will be described for the case where the hydrogen ion concentration is adjusted using a buffer solution and the case where the hydrogen ion concentration is adjusted using a basic solution.

In the apparatus for producing acidic electrolyzed water shown in FIG.
When the hydrogen ion concentration is adjusted using a buffer solution, the acidic electrolyzed water 2 obtained by electrolysis in the electrolytic cell 11 is supplied to the four-way valve 17.
Then, an inorganic acid buffer 5 such as an acetate buffer, a hydrochloric acid buffer, or a phosphate buffer is injected into the acidic electrolyzed water 2 via a valve 18 to adjust the hydrogen ion concentration. The inorganic acid buffer is a buffer having a property of adjusting the hydrogen ion concentration without decomposing the hypochlorous acid contained in the solution and without changing the sterilizing effect. The concentration of the inorganic acid buffer 5 is as follows. The one adjusted according to the hydrogen ion concentration to be adjusted is used. Thus, only the hydrogen ion concentration can be adjusted without considering the decomposition of hypochlorous acid in the acidic electrolyzed water due to the addition of the inorganic acid buffer. Further, the change with time of the concentration of hypochlorous acid in the acidic electrolyzed water can be reduced.

FIGS. 2 and 3 are Raman spectra of the aqueous sodium hypochlorite solution at each pH. The Raman spectrum in FIG. 2 shows the case where the pH was adjusted by adding acetic acid (CH ₃ COOH), and the Raman spectrum in FIG. 3 shows the case where the pH was adjusted by adding hydrochloric acid (HCl).

In this Raman spectrum, SO ₄ ^2-
Is around 980 (cm ^-1 ), and ClO ₃ ^- is 930 (cm ^-1 ).
Near, HClO is 714 (cm ^-1) near, ClO ^- 7
Cl ₂ has a peak near 28 (cm ⁻¹ ), and Cl ₂ has a peak near 540 (cm ⁻¹ ).

In a solution in which hypochlorous acid is dissolved, HClO
The ClO ^- is in or Cl ₂ and chemical equilibrium, the concentration of p
It becomes a value according to H. When this solution is allowed to stand in an open container that is not completely closed, Cl ₂ is released into the atmosphere little by little. HClO, ClO ^-, and chemical equilibrium between Cl ₂ moves along with the release of Cl _2, further Cl ₂
Is released. As the release of Cl ₂ progresses, the chemical equilibrium promotes the movement from HClO to ClO ₂ ⁻ and Cl ₂ , and the concentration of HClO decreases.

According to the Raman spectra of FIGS.
The peak intensity of l ₂ is strongly detected at low pH conditions.
Under conditions of low pH, Cl ₂ is present in high concentrations in the solution. Therefore, as shown in the chemical equilibrium, the release of Cl _{2 into} the atmosphere proceeds and hypochlorous acid is lost from the solution. Therefore, when the pH is low, Cl ₂
Hypochlorous acid is reduced with the release of, and the bactericidal effect is reduced.

The acidic electrolyzed water of the present invention adjusts the pH (hydrogen ion concentration) to stabilize the concentration of hypochlorous acid in the acidic electrolyzed water, thereby maintaining the sterilizing effect. The Raman spectrum of FIG. 2 shows that acetic acid (CH
₃ COOH) to adjust the pH. In the Raman spectrum of FIG. 2, a change in the Cl ₂ peak appearing at around 540 (cm ⁻¹ ) due to the pH is slightly detected at pHs of 3.9 and 4.4, but is slightly changed at pHs of 3.9 and 4.4. It is not detected at all under two or more conditions. The Raman spectrum of FIG. 3 shows that the solution contains hydrochloric acid (HCl).
Was added to adjust the pH. In the Raman spectrum of FIG. 3, Cl appearing around 540 (cm ^-1 )
_The change due to the pH of the peak No. ₂ is not detected at all when the pH is 7.9 or more.

Thus, under conditions of high pH, Cl ₂
Is scarcely present in the solution and hypochlorous acid is not reduced by the release of Cl ₂ .

Therefore, by storing the produced electrolyzed water at a somewhat high pH, a decrease in hypochlorous acid due to the release of Cl ₂ can be prevented.

The solution in which hypochlorous acid is dissolved has a pH of
Is known to exhibit the highest bactericidal activity near 4.5. When this pH is around 4.5, it coincides with the pH region where the percentage of hypochlorous acid is highest in the chemical equilibrium.

Therefore, when the pH of the produced electrolyzed water is adjusted to about 4.5 with acetic acid and stored, the decrease in the concentration of hypochlorous acid can be prevented quite effectively. When the pH of water is adjusted to about 4.5 with hydrochloric acid and stored, it is possible to prevent a decrease in the concentration of hypochlorous acid to some extent.

When the produced electrolyzed water is stored under conditions where the pH is considerably higher than 4.5 and used for sterilization, the
Can be lowered to around 4.5 for use. In this case, the reagent for adjusting the pH to a high condition is not limited to acetic acid and hydrochloric acid, and other pH adjusting reagents can be used.

When acetic acid is used as a reagent for adjusting the pH to a high condition, by keeping the pH at around 4.5, the solution can be stored and used at the same pH, and hypochlorous acid is used. Both effects of preventing the concentration from decreasing and a high bactericidal effect can be obtained at the same time.

In the above description, hydrochloric acid and acetic acid are shown as buffers, but similar effects can be obtained with phosphoric acid.

[0033]

As described above, according to the present invention,
The decrease in the concentration of hypochlorous acid in the acidic electrolyzed water after the electrolysis can be delayed, and the bactericidal effect can be maintained.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram for producing acidic electrolyzed water of the present invention.

FIG. 2 is a Raman spectrum of a sodium hypochlorite solution when pH is adjusted with acetic acid.

FIG. 3 is a Raman spectrum of a sodium hypochlorite solution when pH is adjusted with hydrochloric acid.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electrolyte solution 2 Acidic electrolysis water 3 Alkaline electrolysis water 4 Basic solution 5 Inorganic acid buffer 6 Acid electrolysis water which adjusted hydrogen ion concentration 7 Acid electrolysis water container 8 pH meter 11 Electrolysis tank 12 DC voltage source 13 Anode electrode 14 Cathode Electrode 15 Selective ion exchange membrane 16, 18, 19 Valve 17 Four-way valve 21 Pump

Claims (6)

[Claims] An acidic electrolytic water is produced by electrolyzing a constant amount of an electrolytic solution having a constant concentration, and a buffer solution of an inorganic acid is added to the acidic electrolytic water to adjust a hydrogen ion concentration. A method for producing acidic electrolyzed water, characterized by stabilizing an acid concentration. 2. The method for producing acidic electrolyzed water according to claim 1, wherein the pH value is adjusted to a hydrogen ion concentration of 3.5 to 5.5. 3. The inorganic acid buffer comprises acetic acid, acetic acid solution, acetic acid basic salt, acetic acid basic salt solution, hydrochloric acid, hydrochloric acid solution, hydrochloric acid basic salt, hydrochloric acid basic salt. 3. The method for producing acidic electrolyzed water according to claim 1, wherein the solution is a solution, phosphoric acid, a solution of phosphoric acid, a solution of a basic salt of phosphoric acid, or a solution of a basic salt of phosphoric acid. 4. An acidic electrolyzed water characterized in that a buffer for reducing a decrease in hypochlorous acid concentration is added to an acidic electrolyzed water generated by electrolyzing a predetermined amount of an electrolyte solution having a predetermined concentration. 5. The acidic electrolyzed water according to claim 5, wherein the pH value is a hydrogen ion concentration of 3.5 to 5.5. 6. The inorganic acid buffer comprises acetic acid, acetic acid solution, acetic acid basic salt, acetic acid basic salt solution, hydrochloric acid, hydrochloric acid solution, hydrochloric acid basic salt, hydrochloric acid basic salt. The acidic electrolyzed water according to claim 4 or 5, which is a solution, a solution of phosphoric acid, a solution of phosphoric acid, a solution of a basic salt of phosphoric acid, or a solution of a basic salt of phosphoric acid.