JPH0568975A - Electrolytic type water purifier - Google Patents

Abstract

PURPOSE:To enhance electrolytic efficiency of an ion exchange resin by removing a buffer ion having buffer action to a pH change in water by the ion exchange resin. CONSTITUTION:A water purifier contains the cation and anion exchange resins 30, 40 provided to the water introducing passages 20A, 20B to an electrolytic cell 10, the storage tanks 71, 81 provided to water discharge passages 70, 80 and alkali and acidic ion water return means 90, 100 returning the ion waters Wa, Wb in the storage tanks 71, 81 to the ion exchange resins 30, 40 through the electrolytic cell 10. Water from which a buffer ion is removed by ion exchange is electrolyzed and the ion exchange resins 30, 40 lowered in capacity can be regenerated by returning ion waters Wa, Wb.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrolytic water purifier for obtaining acidic ionized water and alkaline ionized water useful for health and medical purposes.

[0002]

2. Description of the Related Art Conventionally, by electrolyzing water, its pH is changed, that is, water is oxidized on the anode side to generate acidic ionized water, and water is reduced on the cathode side to generate alkaline ionized water. Electrolytic water purifiers are known. However, in the case of obtaining acidic ionized water, for example, if carbonate ions or hydrogen carbonate ions are present in the water to be electrolyzed, there is a problem that the electrolytic efficiency of the conventional electrolytic water purifier decreases.

That is, in H ₂ CO ₃ carbonate, unionized molecules and ions generated by dissociation are in the next dissociation (ionization) equilibrium state in an aqueous solution. H ₂ CO ₃ ⇔ 2H ⁺ + CO ₃ ² -... Also, the equilibrium constant (ionization constant) K at this time is K = [H ⁺ ] ² [CO ₃ ^2- ] / [H ₂ CO ₃ ]. ...

[0004] To this solution, the addition of sodium bicarbonate to completely dissociated, sodium bicarbonate NaHCO ₃ Since the dissociation as ^{_{NaHCO 3 → Na + + H +}} + CO 3 2- ···, CO 3 2 ^- increases the concentration of ions [CO ₃ ^2-] is the concentration of H ₂ CO ₃ equilibrium of the above formula tilted left [H
₂ CO ₃ ] also rises, the equilibrium constant K becomes a constant value, and dissociation is suppressed. Therefore, [H ₂ CO ₃ ] becomes equal to the initial carbon dioxide concentration C _1, and [CO ₃ ²⁻ ] becomes equal to the concentration C ₂ of the added sodium hydrogen carbonate NaHCO ₃ , so that the hydrogen ion concentration [H ⁺ ] ²
Becomes [H ⁺ ] ² = K · C ₁ / C ₂ ... That is, when a common ion (CO ₃ ^{2− in the} above case) is present in the aqueous solution, the concentration of hydrogen ion H ⁺ depends on the concentration of the salt that was initially in the dissociation equilibrium state and that of the added salt Ratio. Even if a small amount of acid (hydrogen ion H ⁺ ) is added to such an aqueous solution, the pH of the aqueous solution does not change because the H ⁺ ions are combined with CO ₃ ²⁻ present in a large amount in the aqueous solution. Moreover, alkali (hydroxide ion OH ^-) is added, and the OH ^- ions is combine with H ⁺ ions, H
₂ CO ₃ dissociates and releases H ⁺ , so the pH does not change.

[0005]

Therefore, in the conventional electrolytic water purifier according to the constant current method or the constant voltage method, when carbonate ions or hydrogen carbonate ions are present in the water, the anodic electrolytic reaction is caused by the buffering action as described above. The change in pH was suppressed, and the presence of cations such as Fe ³⁺ , Al ³⁺ or organic acid in water also had a buffering effect on the pH change due to the cathodic electrolysis reaction, so the electrolysis efficiency was low. .. Moreover, since the concentration of carbonate ions, hydrogen carbonate ions, etc. in water varies depending on the water intake location (region), it has been difficult to obtain electrolyzed water with the same current value and the same pH. Further, although such buffering ions can be removed by using an ion exchange resin, there is a problem that the effectiveness of the ion exchange resin deteriorates with time.

The present invention has been made in view of the above problems, and an object of the present invention is to remove a buffer ion in water having a buffering action against a pH change by an ion exchange resin to perform electrolysis. It is to improve the efficiency and to easily regenerate the effect of the ion exchange resin.

[0007]

In order to solve the above-mentioned problems, an electrolytic water purifier according to the first aspect of the present invention electrolyzes water to produce acidic ionized water on the anode side and alkaline ionized water on the cathode side. An electrolytic cell for generating a cation exchange resin provided in a water inlet to the anode chamber of the electrolytic cell, a reservoir provided in a water outlet extending from the anode chamber, and acidic ionized water in the reservoir to the anode chamber. It is configured to include acidic ion water reflux means for refluxing to the cation exchange resin via. Further, the electrolytic water purifier according to the second claim of the present invention, the same principle as in the first claim is applied to the cathode side, that is, the shade provided in the water inlet to the cathode chamber of the electrolytic cell. A configuration including an ion exchange resin, a storage tank provided in a water outlet extending from the cathode chamber, and an alkali ion water reflux means for refluxing alkali ion water in the storage tank to the anion exchange resin via the cathode chamber. It is what

[0008]

According to the structure of the present invention, the cation component of the water supplied from the water inlet to the anode chamber of the electrolytic cell is exchanged with the H ⁺ ion of the cation exchange resin. The H ⁺ ions combine with anions that have a buffering effect on pH changes, such as hydrogen carbonate ions in water, and neutralize the anions to form salts that do not have a buffering effect on pH changes. Similarly, in the water supplied from the water inlet to the cathode chamber of the electrolytic cell, the anion component thereof is exchanged with the OH ⁻ ion of the anion exchange resin. This OH ⁻ ion ^combines with a cation having a buffering effect on pH change, such as Fe ³⁺ ion in water, and neutralizes it to form a salt having no buffering effect on pH change. Therefore, it is possible to reduce the concentration of the ionic substance that inhibits the pH change. The acidic ionized water and the alkaline ionized water generated in the electrolytic cell are temporarily stored in the storage tanks provided in the water discharge paths on the anode chamber side and the cathode chamber side, respectively, and the water is selectively taken from these storage tanks.

The cation exchange resin continues to undergo the above H ⁺ ion exchange reaction, and the anion exchange resin continues to undergo the above OH ⁻ ion exchange reaction. .. However, according to the configuration of the present invention, by driving the acidic ionized water reflux means or the alkaline ionized water reflux means, for example, when the water intake is completed, the acidic ionized water stored in the storage chamber on the anode chamber side is stored in the anode chamber. The cation exchange resin is refluxed via the anodic electrolysis resin, or the alkaline ionized water stored in the storage chamber on the cathode chamber side is refluxed to the anion exchange resin via the cathodic chamber while further cathodic electrolyzing. For example, since the reverse reaction of the above ion exchange is performed,
The potency of the cation exchange resin and the anion exchange resin can be easily regenerated.

[0010]

EXAMPLE Next, an electrolytic water purifier of the present invention will be described with reference to an example shown in FIG. 1. Reference numeral 10 denotes an electrolytic cell in which the inside is divided into an anode chamber 10A and a cathode chamber 10B by a diaphragm 11. Is. An anode plate 12 is provided in the anode chamber 10A, and a cathode plate 13 is provided in the cathode chamber 10B. The anode plate 12 and the cathode plate 13 are connected via a rectifier (DC power supply) 14. A porous membrane having innumerable micropores of about 0.1 to 0.5 μm is used for the diaphragm 11, and
The anode plate 12 and the cathode plate 13 are made of stainless steel, titanium,
Platinum, ferrite, carbon or the like is used.

Reference numeral 20 is a water inlet to the electrolytic cell 10, which is a valve 2
1, which has an anode chamber-side inlet 2 connected to the anode chamber 10A
0A and cathode chamber 10B, cathode chamber side water inlet 20B
Has branched to. The anode chamber side water inlet 20A is provided with an H ⁺ type cation exchange resin 30 and the cathode chamber side water inlet 20B is provided with a filling portion of an OH ⁻ type anion exchange resin 40. Further, from the anode chamber side water inlet 20A and the cathode chamber side water inlet 20B, the drainage channel 5 is provided in front of the cation exchange resin 30 filling portion and the anion exchange resin 40 filling portion, respectively.
0 and 60 branch and extend, and these drainage channels 50 and 6
0 are provided with valves 51 and 61, respectively.

Reference numeral 70 is a water ion outlet for acidic ionized water extending from the anode chamber 10A, and 80 is a water outlet for alkaline ionized water extending from the cathode chamber 10B. A storage tank 71 and a valve 72 on the intake side are provided in the outlet 70 of the acidic ionized water.
Similarly, a reservoir 81 is provided in the outlet 80 of the alkaline ionized water.
And a valve 82 on the intake side. Further, between the acidic ionized water storage tank 71 and the anode chamber 10A, there is a reflux water channel 91 which is different from the water discharge channel 70, and in this reflux water channel 91 there is a valve 92 and from the storage tank 71 to the anode chamber 10A. A pump 93 for supplying water is provided, and these constitute the acidic ion water reflux means 90. Similarly, between the alkaline ionized water storage tank 81 and the cathode chamber 10B, there is a reflux water channel 101 which is different from the water discharge channel 80, and in this reflux water channel 101 is a valve 102 and from the storage tank 81 to the cathode chamber 10B. A pump 103 for supplying water to the alkaline ionized water reflux means 100 is provided.

In the above structure, the untreated water W from the water supply source (not shown) opens the valve 21 of the water inlet 20,
By closing the valves 51 and 61 of the drainage channels 50 and 60, the water is branched from the water inlet channel 20 to 20A and 20B and supplied to the anode chamber 10A and the cathode chamber 10B of the electrolytic cell 10, respectively. At this time, when the rectifier 14 which is a DC power supply is turned on, water is oxidized by the anode plate 12 in the anode chamber 10A, that is, the following reaction occurs due to + electrolysis. H ₂ O → 2H ⁺ + 2e ⁻ + 1 / 2O ₂ ····· In the cathode chamber 10B, water is reduced by the cathode plate 13, that is, by −electrolysis, The following reactions occur. ^{_{H 2 O + e - → OH}} - + 1 / 2H 2 ····················

The hydrogen ions H ⁺ generated in the anode chamber 10A and the hydroxide ion OH ⁻ generated in the cathode chamber 10B by this reaction are associated with water molecules having a strong polarity.
The diaphragm 11 has a size that does not easily pass through the diaphragm 11 and is retained in the anode chamber 10A and the cathode chamber 10B, respectively, and water molecules freely pass through the diaphragm 11 to enable continuous electrolysis. Therefore, the concentration of hydrogen ions H ⁺ increases in the anode chamber 10A, the pH decreases, and acidic ion water Wa is generated, while the concentration of hydroxide ions OH ⁻ increases in the cathode chamber 10B. The pH rises and the alkaline water Wb is produced.

Acidic ion water W produced in the anode chamber 10A
a is temporarily stocked in the storage tank 71, and the cathode chamber 10
The alkaline ionized water Wb generated in B is temporarily stocked in the storage tank 81, and is selectively taken from the water discharge passage 70 or 80 by opening / closing the valves 72 and 82.

Here, the untreated water W passing through the anode chamber side water inlet 20A passes through the cation exchange resin 30 before flowing into the anode chamber 10A, whereby the following ion exchange is carried out. RH ⁺ + M ⁺ → RM ⁺ + H ⁺ ... (RM ⁺ is H ⁺ type ion exchange resin, M ⁺ is cation in water) Therefore, the hydrogen carbonate ions contained in the water W are neutralized by the subsequent reaction with the H ⁺ ions as described above. _{^{H + + HCO 3 - → H}} 2 CO 3 ······················ Therefore, pH decreased combines with H ⁺ ions generated in the anode chamber 10A Since the hydrogen carbonate ion that inhibits the above is removed, the above anodic electrolysis reaction can be promoted.

Further, the untreated water W passing through the cathode chamber side water inlet 20B passes through the anion exchange resin 40 before flowing into the cathode chamber 10B, whereby the following ion exchange is carried out. ^{ROH - + A - → RA -} + OH - ···················· (ROH - is OH ^- type ion exchange resin, A ^- in water anions) for this , Fe ³⁺ ions contained in the water W are neutralized by the following reaction with OH ⁻ ions according to the above. 3OH ⁻ + Fe ³⁺ → Fe (OH ⁻ ) ₃ ······· Therefore, the pH rises by combining with OH ⁻ ions generated in the cathode chamber 10B. Since the cation components such as Fe ³⁺ , Al ³⁺ , and organic acid, which hinder the above, are removed, the above-mentioned cathodic electrolysis reaction can be promoted.

The cation exchange resin 30 and the anion exchange resin 40 are required to be regenerated because the effectiveness of ion exchange decreases with time by continuing the above treatment. Therefore, for example, when the water intake is completed, the valve 21 of the water inlet 20 and the water outlet 70,
The valves 72 and 82 of 80 are closed, the valves 51 and 61 of the drainage channels 50 and 60, the valves 92 and 102 of the acidic ion water reflux means 90 and the alkaline ion water reflux means 100 are opened, and the pumps 93 and 103 are turned on. Drive and rectifier 14
Turn on. As a result, the acidic ionized water Wa stored in the storage tank 71 is further subjected to anodic electrolysis in the anode chamber 10A, becomes sufficiently acidic, and is refluxed to the cation exchange resin 30, and the alkaline ions stored in the storage tank 81 are also stored. Water w
Since b is further subjected to cathodic electrolysis in the cathode chamber 10B and becomes sufficiently alkaline and is refluxed to the anion exchange resin 40, the reverse reactions of the above and and, respectively, occur, whereby the ion exchange resins 30 and 40 are regenerated.

FIG. 2 shows the change in pH in the anode chamber when the ion-exchanged water is electrolyzed using the electrolytic water purifier and when the non-ion-exchanged water is electrolyzed using the conventional electrolytic water purifier. It is the experimental value shown. As a result, it was confirmed that the water purifier of the present invention which electrolyzes water after ion exchange has a more remarkable decrease in pH at each current value and is more effective as acidic ionized water.

The present invention is not limited to the above embodiment. For example, in order to reduce the concentration of carbonate ions and hydrogen carbonate ions in the water W from the water supply source, it is effective to add an acid into water, for example, to add lactic acid, and the aeration method is also effective. The water inlet 20 may be provided with an acid addition device or an aeration device. In addition, according to the above-described embodiment, the ion-exchange resin 3 is made to flow back from the storage tanks 71 and 81.
The water used for regenerating 0, 40 is discharged from the drainage channels 50, 60, but this water is temporarily stocked by a storage means (not shown), and is treated together with the untreated water W from the inlet channel 20 in the electrolytic cell 1
It may be supplied to 0 for reuse.

[0021]

As is apparent from the above description, according to the electrolytic water purifier of the present invention, since the water in which the buffer ions in the water are neutralized by the ion exchange is electrolyzed, the pH of the electrolyzed It is possible to make the change remarkable and improve the electrolysis efficiency. Further, since the concentration of the above-mentioned buffer ions can be reduced to a constant value, it is possible to obtain ionic water having the same current value and the same pH even under different water qualities. In addition, the ion exchange resin with reduced potency has an excellent effect that it can be easily regenerated by refluxing the ionized water stocked in the storage tank, further electrolyzing it, and performing an ion exchange reverse reaction with this ionized water. Play.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a schematic configuration of an embodiment of the present invention.

FIG. 2 is a graph showing a change in pH in the anode chamber when electrolyzing decarboxylated water and non-decarboxylated water.

[Explanation of symbols]

 10 Electrolyzer 10A Anode Chamber 10B Cathode Chamber 20,20A, 20B Water Inlet 30 Cation Exchange Resin 40 Anion Exchange Resin 50,60 Drainage 70,80 Water Outlet 71,81 Storage Tank 90 Acid Ion Water Reflux Means 100 Alkaline Ion Water reflux means W Untreated water Wa Acid ionized water Wb Alkaline ionized water

Claims (2)

[Claims] 1. An electrolytic cell for electrolyzing water to produce acidic ionized water on the anode side and alkaline ionized water on the cathode side, and a cation exchange resin provided in a water inlet to the anode chamber of the electrolytic cell,
Electrolysis comprising a storage tank provided in a water outlet extending from the anode chamber, and acidic ion water reflux means for refluxing the acidic ion water in the reservoir to the cation exchange resin via the anode chamber. Water purifier. 2. An electrolytic cell for electrolyzing water to produce acidic ionized water on the anode side and alkaline ionized water on the cathode side, and an anion exchange resin provided in a water inlet to the cathode chamber of the electrolytic cell,
Electrolysis characterized by including a storage tank provided in a water outlet extending from the cathode chamber, and alkali ion water reflux means for refluxing the alkali ion water in the storage chamber to the anion exchange resin via the cathode chamber. Water purifier.