JP2001113279A - Electrodeionization equipment - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To obtain deionized water having good water quality at low voltage. SOLUTION: An anode chamber 11 having an anode 12 and a cathode 1 are provided.
4, a plurality of cation exchange membranes 16 and a plurality of anion exchange membranes 15 are alternately arranged between the anode chamber and the cathode chamber 13 arranged in the water flow direction in parallel with the two chambers. And a desalting chamber 18 and a concentrating chamber 17 for passing raw water between the adjacent cation exchange membrane and anion exchange membrane are formed alternately, and the desalination chamber is filled with an ion exchanger. In the electrodeionization apparatus described above, the ion exchanger filled in the desalting chamber is converted into an amphoteric ion exchanger 20 into which an anion exchange group and a cation exchange group have been introduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a semiconductor, a liquid crystal,
It relates to an electrodeionization device that produces deionized water used in various industrial fields such as pharmaceuticals, foods, electric power, and for consumer or research facilities. The purpose is to generate water positively and improve the quality of treated water.

[0002]

2. Description of the Related Art As an electrodeionization device, a plurality of electrodes are provided in parallel with both chambers between an anode chamber provided with an anode and a cathode chamber provided with a cathode and arranged in a water flow direction parallel to the anode chamber. A cation exchange membrane and a plurality of anion exchange membranes are alternately arranged, and a desalination chamber and a concentration chamber for passing raw water between adjacent cation exchange membranes and anion exchange membranes are provided. Alternately, the deionization chamber is filled with an ion exchanger, DC power is applied to the ion exchange membrane forming the outermost enrichment chamber and the ion exchange membrane forming the outermost desalination chamber, and the raw water is removed. For example, water is passed through the concentration chamber and the desalination chamber in a downward flow, H ⁺ ions and OH ⁻ ions are generated by water dissociation, and the ion exchanger filled in the desalination chamber is continuously regenerated while the water in the raw water is being regenerated. Transfers the salt to the concentrating chamber and continuously collects deionized water from the lower end of the desalting chamber. It is conventionally known that the concentrated water containing a large amount of salt is continuously discharged from the lower end of the concentration chamber.

[0003]

As an ion exchanger to be filled in a desalting chamber, Japanese Patent Application Laid-Open No. Hei 6-131120 discloses radiation graft polymerization irradiated with ionizing radiation such as α, β, γ-rays, electron beams, and ultraviolet rays. The use of an ion exchanger is disclosed. However, since the ion exchanger for radiation graft polymerization is produced by irradiating with ionizing radiation, there is a problem in terms of ease of production. Further, in order to improve the treatment water quality of the electrodeionization apparatus, the number of contacts between the anion exchange group and the cation exchange group of the ion exchanger in the deionization chamber is increased, and H ⁺ ions and OH ^- ions are efficiently generated by water dissociation. However, in the ion exchanger of the radiation graft polymerization, since the ion exchange groups are introduced in a mosaic shape as shown in FIG. 3, the contact points between the anion exchange groups and the cation exchange groups are small, and the water dissociation effect is reduced. Is not enough.

[0004]

SUMMARY OF THE INVENTION The present invention has been developed to solve the above-mentioned problems, and has an anode chamber having an anode, a cathode, and a water passage direction parallel to the anode chamber. Between the arranged cathode chamber, a plurality of cation exchange membranes and a plurality of anion exchange membranes are arranged alternately in parallel with both chambers, and the adjacent cation exchange membranes and anion exchange membranes are arranged. In an electric deionization apparatus in which a desalination chamber and an enrichment chamber are alternately formed for passing raw water therebetween and an ion exchanger is filled in the desalination chamber, the ion exchanger filled in the desalination chamber is anion-exchanged. It is a zwitterion exchanger in which an exchange group and a cation exchange group are mixed and introduced. The amphoteric ion exchanger in the desalting chamber is filled upstream of the desalting chamber with respect to the water flow direction,
Downstream thereof, an anion exchanger, a cation exchanger, or a mixed ion exchanger of an anion exchanger and a cation exchanger may be filled. The amphoteric ion exchanger filled in the desalting chamber may form a mixed bed with an anion exchanger, a cation exchanger, or a mixed ion exchanger of an anion exchanger and a cation exchanger.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 (a) is a longitudinal sectional view of a main part of an embodiment of the present invention, wherein 11 is a left anode chamber provided with an anode 12, 13 is provided with a cathode 14, and the above-mentioned anode chamber is provided. The right and left cathode chambers 11 arranged in the water flow direction in parallel with the
A plurality of cation exchange membranes (cation exchange membranes) 15... And a plurality of anion exchange membranes (anion exchange membranes) 16. A concentrating chamber 17 for passing raw water between the exchange membrane 15 and the anion exchange membrane 16, and a desalination for passing raw water similarly between the adjacent anion exchange membrane 16 and the anion exchange membrane 16. The chambers 18 are formed alternately. In the case of this embodiment, four chambers, a first concentrating chamber, a first desalting chamber, a second concentrating chamber, and a second desalting chamber, are formed from left to right, and an anion exchange group is provided inside each of the desalting chambers. And the amphoteric ion exchanger 20 which is introduced by mixing the cation exchange group with the cation exchange group. An anode of a DC power supply is applied to the left cation exchange membrane 15-1 forming the first concentration chamber, and a cathode of a DC power supply is applied to the right cation exchange membrane 15-3 forming the second desalination chamber. I do.

As shown in FIG. 1 (b), an amphoteric ion exchanger 20 in which an anion exchange group and a cation exchange group are mixed and introduced is a mixture of an anion exchange group and a cation exchange group in a styrene base or the like. The anion exchange group is a quaternary ammonium group such as a trimethylammonium group or a diethylethanolammonium group,
It has a primary to tertiary amino group, and the cation exchange group has a sulfonic acid group, a phosphoric acid group and a carboxyl group. The ion exchanger refers to a fibrous or bead-shaped ion exchange resin or a graft exchanger in which an exchange group is introduced into a fiber or nonwoven fabric by using graft polymerization.

The desalting chamber 18 may be filled with only the amphoteric ion exchanger 20 as shown in FIG. 1A, or may be filled with water as shown in FIG. 2A in order to improve the water dissociation effect. An amphoteric ion exchanger 20 is filled upstream with respect to the water flow direction in the salt chamber, and an anion exchanger 21 or a cation exchanger 22 is packed downstream.
Or a mixed ion exchanger obtained by mixing an anion exchanger and a cation exchanger. A mixture of the amphoteric ion exchanger 20 and the anion exchanger 21 (FIG. 2B), a mixture of the amphoteric ion exchanger 20 and the cation exchanger 22 (FIG. 2C), The mixture of the body 20 and the anion exchanger 21 and the cation exchanger 22 (FIG. 2d) may be filled.

When an anion or a cation exchanger is used in combination with the amphoteric ion exchanger as shown in FIG. 2, the ratio of the amphoteric ion exchanger 20 is 3 to 80 with respect to the whole volume of the desalting chamber.
% Showed good results, but particularly preferably 5 to 30%.

The city water is treated with an activated carbon device (Kurita KW10-30 manufactured by Kurita Kogyo Co., Ltd.) and then with an RO membrane device (Mac Ace KN200 manufactured by Kurita Kogyo Co., Ltd.), and then charged into the desalting chamber 18 of FIG. The ion exchanger is replaced with the above paragraph 0.
As described in 007, an electric deionization test apparatus of Pure Ace PA-200 (100 liters / hour) manufactured by Kurita Kogyo Co., Ltd. was used, and a desalination test was performed by passing water downward. The result of the example, and a cation exchange resin (SK1B manufactured by Mitsubishi Chemical Corporation) and an anion exchange resin (SA10A manufactured by Mitsubishi Chemical Corporation) were mixed in the desalting chamber at a volume mixing ratio of cation and anion exchange resin of 4: 4. Comparative Example 1 filled with the mixture mixed in Step 6,
The same electrodeionization test apparatus according to Comparative Example 2 was used in which the ion exchange group described in the conventional example was introduced into the desalination chamber in a mosaic state with the ion exchange groups being introduced in a mosaic manner, and water was passed in a downward flow. The results are shown in Table 1.

[0010] The anion exchange membrane of the electrodeionization test apparatus used was Amplex A501 manufactured by Asahi Kasei Corporation.
The SB and the cation exchange membrane were Amplex K501 SB manufactured by Asahi Kasei Corporation.

In each embodiment, the amphoteric ion exchanger packed in the desalting chamber was manufactured by Mitsubishi Chemical Co., Ltd.
1 was used. 2 (a), (b), (c),
In each example of (d), the filling ratio of the amphoteric ion exchange resin was set to 20% with respect to the volume of the desalting chamber.

[0012]

[Table 1]

As is clear from Table 1, when the amphoteric ion exchanger was filled in the desalting chamber, deionized water of good quality could be obtained despite the low voltage operation.

[0014]

According to the present invention, the water dissociation at the contact point between the anion exchange group and the cation exchange group of the amphoteric ion exchanger packed in the desalting chamber is efficiently increased. Improved deionized water can be obtained.

[Brief description of the drawings]

FIG. 1A is a cross-sectional view schematically showing a main part of an electrodeionization apparatus according to the present invention, and FIG. 1B is a schematic view showing a contact state between an anion exchange group and a cation exchange group of an amphoteric ion exchanger.

FIGS. 2 (a), (b), (c) and (d) are cross-sectional views of four desalting chambers usable in the present invention.

FIG. 3 is a schematic diagram showing a mosaic contact state between an anion exchange group and a cation exchange group of an ion exchanger by radiation graft polymerization.

[Explanation of symbols]

 REFERENCE SIGNS LIST 11 anode compartment 12 anode compartment anode 13 cathode compartment 14 cathode compartment cathode 15 anion (anion) exchange membrane 16 cation (cation) exchange membrane 17 enrichment compartment 18 desalination compartment 20 amphoteric ion exchanger 21 anion exchanger 22 cation Exchanger

Claims (3)

[Claims] 1. A plurality of cation exchange membranes, parallel to both chambers, between an anode chamber having an anode and a cathode chamber having a cathode and arranged in a water flow direction parallel to the anode chamber. A plurality of anion exchange membranes are alternately arranged, and a desalination chamber and a concentration chamber for passing raw water between adjacent cation exchange membranes and anion exchange membranes are alternately formed, and the water is removed. In an electrodeionization apparatus in which a salt chamber is filled with an ion exchanger, the ion exchanger filled in the deionization chamber is an amphoteric ion exchanger in which anion exchange groups and cation exchange groups are mixed and introduced. Electrodeionization equipment. 2. The electrodeionization apparatus according to claim 1, wherein the amphoteric ion exchanger in the deionization chamber is filled upstream of the deionization chamber with respect to the direction of water flow, and an anion exchanger and a cation are provided downstream of the deionization chamber. An electrodeionization apparatus characterized by being filled with an exchanger or a mixed ion exchanger of an anion exchanger and a cation exchanger. 3. The electrodeionization apparatus according to claim 1, wherein the amphoteric ion exchanger packed in the desalting chamber is an anion exchanger, a cation exchanger, or a mixed ion of an anion exchanger and a cation exchanger. An electrodeionization device comprising a mixed bed with an exchanger.