JPH11226575A - Production of drinking water by electrolysis - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain healthy drinking water with a reduced sodium content from the cathode side of secondary electrolysis by re-electrolyzing anodic water produced by primary electrolysis. SOLUTION: In a method for producing drinking water, chlorine is removed from anodic water obtained by primary electrolysis, the anodic water, as raw water on the cathode side of secondary electrolysis, is electrolyzed again. The anodic water of the primary electrolysis is added with 0.03-1% of ethanol and/or 0.005-1% of an organic acid and electrolyzed again. Or, the anodic water is added with at least one of 0-0.02% of a potassium, 0.001-0.25% of a calcium salt, and 0.0005-0.12% of a magnesium salt to be electrolyzed again.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing low sodium drinking water by electrolysis.

[0002]

2. Description of the Related Art It has been known that electrolysis of water produces electrolytic cathode water (alkali ion water) and electrolytic anode water (acidic ion water). The electrolyzed water generator for generating electrolyzed water is configured such that the inside of an electrolyzer is divided into two regions by a diaphragm, an anode is arranged in one region, a cathode is arranged in the other region, and a current is applied to both electrodes. To generate electrolytic cathodic water from the region on the cathode side and electrolytic anodic water from the region on the anode side. In general, electrolytic cathodic water as alkaline ionized water is used as drinking water for health enhancement, and electrolytic anodic water is used as sterilizing and disinfecting water or face washing water.

[0003]

Electrolytic cathode water as drinking water contains a large amount of cations. For this reason, the sodium content in the electrolytic cathode water inevitably increases, and there is a contradiction that it contains many health-inhibitory factors due to sodium while being water for drinking that is good for health. In order to obtain electrolytic cathode water with low sodium content, it is conceivable to remove the cations by subjecting the raw water before electrolysis to reverse osmosis, ion exchange, distillation, etc., and then add an electrolyte to perform electrolysis. . However, this method has poor economic efficiency and generates cations by electrolysis,
Even if sodium could be reduced, it could not be significantly reduced.

[0004] The present invention has been made in view of this point,
Provided is a method for producing drinking water by electrolysis that can obtain healthy drinking water with low sodium content from the cathode side of secondary electrolysis by re-electrolyzing the electrolytic anode water generated in the primary electrolysis. The purpose is to:

[0005]

In order to achieve the above object, the present invention is to remove chlorine from electrolytic anodic water obtained by primary electrolysis, and to remove the chlorine-removed water from the cathode side of secondary electrolysis. The raw water is then electrolyzed again.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below.
In the water electrolyzed by the electrolyzed water generator, electrolyzed cathodic water is generated from the cathode side, and electrolyzed anode water is generated from the anode side.
The method for generating the electrolytic cathode water and the electrolytic anode water and the apparatus for generating the electrolytic water are known, and thus description thereof will be omitted. The electrolyzed water generator used in the experiment is as follows: Electrodes: double-sided platinum fired titanium plate, thickness = 0.4 mm, width = 74 mm
Height = 114mm Diaphragm: synthetic resin, 0.003 Ω / cm ² , thickness = 0.12mm, width = 95m
m, height = 125mm Electrolyzer: PP effective capacity 700ml × 2 Total capacity 1.4l Electrode distance: 8mm Electrolyte power supply: 0.8A Constant current Use tap water as raw water. Through all the experiments described below,
Electrolysis was performed for 15 minutes, and the water temperature before electrolysis was 16 ± 2 ° C. Tap water quality: pH 6.7 ± 0.6, dissolved oxygen is represented by DO and the unit is mg / L. Redox potential (Eh) 598 ± 80mv, Electric conductivity (EC) 247 ± 20μs / cm, Residual chlorine (DC) 0.6 ± 0.2ppm,

[0007] Raw water as used herein refers to general tap water, well water, and the like, and refers to neutral water that can be drunk by humans without being mixed with a special chemical agent or the like. First, primary electrolysis is performed on tap water as raw water. . Electrolysis results when tap water is used as raw water for primary electrolysis Anode water: pH 2.49 DO <25 Eh 1044 EC 1160 DC 10 Cathode water: pH 11.11 DO 4.8 Eh -856 EC 511 DC 0.6 Electrolysis voltage at the end of electrolysis is 42V Next, the following shows primary electrolysis results when a chemical agent is mixed into raw water. An example in which ethanol is added to tap water to perform electrolysis is shown below. . Ethanol in tap water as raw water for primary electrolysis 0.1
Electrolysis result after adding 4% Anode water: pH 2.45 DO <25 Eh 1040 EC 1150 DC 10 Cathode water: pH 11.35 DO 4.7 Eh -862 EC 567 DC 0.4 Electrolysis voltage at the end of electrolysis 40.4V Add organic acid to tap water An example of electrolysis is shown below. . Citric acid (organic acid) in tap water as raw water for primary electrolysis
Of 0.02% of water added Anode water: pH 2.72 DO <25 Eh 997 EC 1130 DC 5 Cathode water: pH 7.45 DO 4.0 Eh -769 EC 198 DC 0.1 Electrolysis voltage at the end of electrolysis 19.7V

[0008] By the first electrolysis, cations such as sodium, potassium, calcium and magnesium contained in the raw water move to the cathode side. Therefore, the anode water obtained as a result of the primary electrolysis contains these sodium, potassium,
Water with less cations such as calcium and magnesium can be obtained. However, the residual chlorine content (DC) of raw water is 0.6 ± 0.2p
pm, the residual chlorine amount of the electrolytic anode water obtained by the primary electrolysis is 10% in the case of only tap water (raw water).
ppm,. 10 ppm when ethanol is added to tap water,
5 ppm when citric acid (organic acid) is added, and 7 ppm when acetic acid (organic acid) is added, and the residual chlorine amount increases. The present invention reduces the residual chlorine content of the electrolytic anode water obtained in the primary electrolysis. For this purpose, a method of removing chlorine by filtering the primary electrolyzed anode water by activated carbon filtration or heating boiling, or a method of leaving chlorine in an open system for about two days to diffuse chlorine is effective.

[0009] The electrolyzed anolyte obtained by the primary electrolysis and having a reduced amount of residual chlorine is used again as raw water on the cathode side of the secondary electrolysis and electrolyzed again. At this time, 0.03% to 1% (weight volume percent, that is, 0.03 to 1 g is added to 100 cc raw water) of ethanol to the raw water on the cathode side of the secondary electrolysis, or 0.005% to 1% (Weight volume percent, 0.00 in raw water of 100cc)
(Addition of 5 to 1 g) may be added. The following percentages are all weight volume percentages. . The water obtained by reducing the residual chlorine concentration of the anodic water obtained in the primary electrolysis to, for example, 3 ppm with activated carbon is used as raw water on the cathode side of the secondary electrolysis,
0.14 ethanol was added only to the raw water on the cathode side of the secondary electrolysis.
% Anode water: pH 2.45 DO 24.7 Eh 1022 EC 1095 DC 6 Cathode water: pH 10.61 DO 3.5 Eh 845 EC 281 DC 0.6 Electrolysis voltage at the end of electrolysis 17.2V Secondary obtained by this secondary electrolysis Electrolytic cathode water pH 10.6
1 has a lower pH value than the primary electrolytic cathode water pH of 11.35. The pH difference of 0.74 during this time indicates that the number of hydroxyl group ions in the secondary electrolytic cathode water obtained in is about one-fifth of that in the primary electrolytic cathode water obtained in This indicates that the amount of sodium ion forming the counter ion is sufficiently small.

In the raw water on the cathode side of the secondary electrolysis, 0.03% to
The addition of at least one of 1% ethanol or 0.005% to 1% of an organic acid is for removing active oxygen generated in the cathode water. 0.03% to 1% of ethanol is added, but below the lower limit, there is no effect of removing active oxygen, and above the upper limit of ethanol, alcohol odor remains in the produced water. In addition, the measurement accuracy at the time of addition and 0.05%, assuming that the user has a constitution that is sensitive to ethanol when consumed as a daily beverage,
It is desirable to add in the range of 0.5%. 0.005
% To 1% of the organic acid is added, the effect is lost below the lower limit, and the sourness is felt above the upper limit. The accuracy of measurement at the time of addition and 0.01 when not intended to obtain sourness when consumed as a daily drink.
% To 0.05%.

In addition, re-electrolysis may be performed by adding compounds such as potassium salts, calcium salts, and magnesium salts to the raw water on the cathode side of the secondary electrolysis (primary electrolysis anode water). Further, an organic acid such as ascorbic acid may be added as needed. . The anode water generated by the primary electrolysis was used as the raw water on the cathode side of the secondary electrolysis, and the electrolysis was performed by adding 0.01% each of calcium hydroxide and ascorbic acid to only the raw water on the cathode side of the secondary electrolysis. Anode water: pH 2.53 DO <25 Eh 1110 EC 1340 DC 20 Cathode water: pH 10.30 DO 3.0 Eh 834 EC 388 DC ND Electrolysis voltage at the end of electrolysis 12.2V In the primary electrolysis, sodium, potassium, calcium, magnesium, etc. are 1 as cations. Since they are contained in the secondary electrolytic cathode water, they are reduced in the primary electrolytic anode water. The purpose is to obtain drinking water (secondary cathodic water) with reduced sodium, but the required potassium, calcium and magnesium are also reduced at the same time. For this reason,
In order to obtain necessary amounts of potassium, calcium, and magnesium, chemical substances such as potassium salts, calcium salts, and magnesium salts are added to the raw water on the cathode side of the secondary electrolysis (primary electrolysis anode water).

A potassium salt (as potassium chloride) is added in an amount of 0 to 0.02% for controlling electric conductivity. If the upper limit is exceeded, the pH of the generated cathode water becomes too high (the alkali becomes strong). Preferably, the addition amount of potassium is 0 to 0.01%. This 0.01% is a sufficient amount as long as there is no electrolytic inhibition factor (such as a very large amount of carbonate ions) in the raw water. Calcium salt (including calcium chloride) is added in an amount of 0.001% to 0.25%. Above this, the amount of calcium ions in the generated cathodic water becomes too large, which may cause diarrhea. Further, precipitates are easily formed in the water passage of the electrolytic device, which affects the electrolytic efficiency. Preferably, the amount of calcium added is 0.002% or more.
0.1%. Below this range, the concentration cannot be said to be calcium-additive. Above this range, more acid is added to the cathode water to prevent precipitation, and the acidity of the produced water becomes stronger. Magnesium salt (including magnesium chloride) is added in an amount of 0.0005% to 0.12%. It is desirable that the amount of added magnesium is, as a rule, 1/2 of calcium. If the content is 0.12% or more, the amount of magnesium ions in the generated cathode water becomes too large, which may cause diarrhea. Further, precipitates are easily formed in the water passage of the electrolytic device, which affects the electrolytic efficiency. Preferably, the amount of magnesium added is 0.002% to 0.1%. Below that range, the concentration cannot be said to be substantial addition of magnesium, and above that range, more acid is added to the cathode water to prevent precipitation, and not only the acidity of the generated water becomes stronger, but also You can feel the taste.

[0013] If necessary, 0.005% to 1%, together with chemical compounds such as potassium salt, calcium salt, and magnesium salt.
Of organic acid is added. When an organic acid is added together with a compound such as a potassium salt, a calcium salt, and a magnesium salt, various effects are obtained. For example, when only a calcium salt such as calcium hydroxide is added, the generated secondary electrolytic cathode water goes too far to the alkali side, so that the organic acid functions to adjust the pH. In the case of other than potassium salts, they serve to prevent their precipitation. Furthermore,
As described above, it has the function of reducing the amount of dissolved active oxygen.

[0014]

As described above, according to the method for producing drinking water by electrolysis according to the present invention, activated carbon filtration, heating boiling and the like are performed from primary electrolytic anode water having a reduced amount of sodium and a large residual chlorine amount. The amount of residual chlorine is removed, and the electrolysis is performed again using the primary electrolytic anode water as the cathode raw water for secondary electrolysis. This makes it possible to obtain good drinking water having a low sodium content and a small residual chlorine amount on the secondary electrolytic cathode side. By adding a mineral other than sodium to the primary electrolytic anode water and performing electrolysis, water containing a mineral amount other than sodium reduced by the primary electrolytic anode water can be obtained. Thus, by re-electrolyzing the primary electrolyzed anode water, it is possible to obtain electrolyzed drinking water in which cations are controlled more than usual electrolyzed cathodic water without special pretreatment.

Claims (9)

[Claims] 1. An electrolysis method comprising removing chlorine from electrolytic anode water obtained by primary electrolysis, and electrolyzing the water from which chlorine has been removed again as raw water on the cathode side of secondary electrolysis. Method for producing drinking water. 2. The method of adding 0.1% to the electrolytic anode water obtained by primary electrolysis.
The method for producing drinking water by electrolysis according to claim 1, wherein at least one of 03% to 1% of ethanol or 0.005% to 1% of organic acid is added and electrolyzed again. 3. The amount of the ethanol to be added is 0.05% to
3. The method for producing drinking water by electrolysis according to claim 2, wherein the amount is set to 0.5%. 4. The organic acid to be added is 0.01% to 0.1%.
3. The method for producing drinking water by electrolysis according to claim 2, wherein the concentration is set to 0.05%. 5. The method according to claim 1, wherein the primary electrolysis anode water contains 0% to 0.02%.
% Of a potassium salt, 0.001% to 0.25% of a calcium salt, or 0.0005% to 0.12% of a magnesium salt, followed by re-electrolysis. A method for producing drinking water by electrolysis according to claim 1. 6. The amount of the potassium salt to be added is 0% to 0.0%.
The method for producing drinking water by electrolysis according to claim 5, wherein the concentration is 1%. 7. The calcium salt to be added is 0.002
The method for producing drinking water by electrolysis according to claim 5, characterized in that the amount is from 0.1% to 0.1%. 8. The magnesium salt to be added is 0.00
The method for producing drinking water by electrolysis according to claim 5, wherein the concentration is 2% to 0.1%. 9. The method according to claim 1, wherein the primary electrolytic anode water contains 0.005% to
9. The method for producing drinking water by electrolysis according to claim 5, wherein 1% of an organic acid is added.