Process for preducing mixed electrolyzed water

Abstract

This invention discloses a process for preparing a mixed electrolyzed water consisting of a cathodic and an anodic electrolyzed waters comprising the step of electrolyzing an aqueous solution of an organic electrolyte containing a water-soluble inorganic salt in less than 0.1 mM and an organic electrolyte in 1 to 50 mM which is fed into a non-diaphragm electrolytic bath comprising at least a pair of inactive electrodes separated from each other by an inter-electrode distance of 2 mm or less, wherein the aqueous solution of an organic electrolyte with pH equal to that of the mixed electrolyzed water prepared by electrolysis is neutralized with a titration volume less than that for the raw aqueous solution in neutralization titration with an aqueous solution of sodium hydroxide or has a higher dismutation activity to superoxide radical per mole than the raw aqueous solution.

Description

TECHNICAL FIELD [0001] This invention relates to a process for preparing a mixed electrolyzed water consisting of an anodic and a cathodic electrolyzed waters, which is capable of dismutating superoxide radical. In particular, this invention relates to a process for preparing a mixed electrolyzed water capable of dismutating superoxide radical, comprising electrolyzing an aqueous organic electrolyte solution containing virtually only an organic water-soluble electrolyte such a ascorbic acid as an electrolyte. BACKGROUND OF THE INVENTION [0002] It has been well-known that using an electrolytic bath within which inactive electrodes made of platinum or a platinum alloy are placed via a diaphragm, aqueous dilute electrolyte solution of an alkali-metal chloride is electrolyzed, followed by removing an anodic electrolyzed water (acidic water) with a lower pH generated in the anodic side, which can be utilized for sterilization or disinfection. Examples of a diaphragm used include a charge...

AI Technical Summary

Benefits of technology

[0015] We have intensely attempted to solve the above problem, and have finally found that when mixing an anodic electrolyzed water with a cathodic electrolyzed water, oxygen generated in an anode side and hydrogen generated in a cathode side quickly react to form water so that oxidation of ascorbic acid actually fails to occur. Furthermore, it has been found that these electrolyzed waters can be effectively mixed by selecting a inter-electrode distance not more than a certain value; that thus a mixed electrolyzed water having improved ability of dismutating superoxide radical can be effectively prepared; and further that there is no need to discharge a cathodic electrolyzed water as waste.

[0017] Since a raw electrolysis water comprising an organic electrolyte as an electrolysis aid is electrolyzed and resulting an anodic and a cathodic electrolyzed waters are mixed in this invention, the mixed electrolyzed water thus obtained has a lower DO and improved ability to dismutate superoxide radical. The mixed electrolyzed water can be, therefore, conveniently used in a variety of applications such as sterilization, disinfection, granulation, health maintenance and cosmetic applications. Furthermore, since an anodic and a cathodic electrolyzed waters are prepared as a mixture in this preparation process, it requires a simpler manufacturing apparatus in comparison with a conventional process where an electrolyzed water in one electrode side is taken out. Additionally, since as an organic electrolyte, this invention employs a vitamin, ascorbic acid whose safety to a human body has been established, the cathodic electrolyzed water prepared using the vitamin as an electrolysis aid is also quite safe.

[0040] When dissolving a low-dissociating substance such as AsA in a cathodic electrolyzed water prepared by electrolysis of a dilute aqueous electrolyte solution such as a brine, the dissociation is accelerated. As a result, it has been found that a dismutation activity (SOD activity) for superoxide radical is increased in comparison with an aqueous solution of AsA with an equal pH. Specifically, dissociation of the OH group at 2-position of AsA shown in formula (8) is accelerated so that the group becomes more reactive to a radical or active oxygen. The OH group at 3-position is consumed in neutralization of the alkaline electrolyzed water. The OH, therefore, exhibits lower SOD activity and does not act as a scavenger to superoxide radical. Thus, a low-dissociating water-soluble substance can be dissolved in an electrolyzed water with improved dissociating ability, to improve dissociation of the substance, resulting in making the low-dissociating water-soluble substance more reactive.

[0042] When an anode and a cathode are closely disposed to each other and these electrodes are not separated by a diaphragm, an anodic and a cathodic electrolyzed waters may be easily mixed. As a result, dissolved oxygen generated by anodic oxidation of water reacts with dissolved hydrogen generated by cathodic reduction of water, to give water. In addition, polarity of an electrolysis voltage can be alternated to further accelerate mixing of the anodic and the cathodic electrolyzed waters. Consequently, a concentration of dissolved oxygen generated by oxidation of water in the anode becomes 1 mg / L or less because the dissolved oxygen is consumed by AsA and reducing dissolved hydrogen.

Problems solved by technology

In an alkaline range, although the OH at 2-position is dissociated into —O− and H+, its dissociation ratio is too low to allow ascorbic acid to be used as an electrolytic aid.

It is, however, well-known that ascorbic acid undergoes autoxidation in an aqueous solution, leading to deteriorated reducing power.

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