1. The bipolar membrane with high water production capacity in a single time is characterized in that: the total amount of cation exchange groups in unit area of the bipolar membrane is 0.05-2 mmol/cm²The total amount of anion exchange groups is 0.05-2 mmol/cm²。

2. The bipolar membrane with high single water production according to claim 1, wherein: the total amount of cation exchange groups in unit area of the bipolar membrane is 0.16-0.5 mmol/cm²The total amount of anion exchange groups is 0.13-0.5 mmol/cm²。

3. The bipolar membrane with high single water production according to any one of claims 1 to 2, wherein: the cation exchange membrane of the same bipolar membrane is formed by laminating a plurality of sub-cation exchange membranes.

4. The bipolar membrane with high single water production according to any one of claims 1 to 2, wherein: the anion exchange membrane of the same bipolar membrane is formed by laminating a plurality of sub-anion exchange membranes.

5. The bipolar membrane with high single water production according to any one of claims 1 to 2, wherein: the cation exchange membrane and the anion exchange membrane which form the same bipolar membrane are single membrane sheets;

the thickness of the anion exchange membrane dry film sheet is 0.1 mm-5 mm, and the thickness of the cation exchange membrane dry film sheet is 0.1 mm-5 mm.

6. The bipolar membrane with high single water production according to claim 5, wherein: the thickness of the anion exchange membrane dry film sheet is 0.2 mm-1.4 mm, and the thickness of the cation exchange membrane dry film sheet is 0.2 mm-1.4 mm.

7. The bipolar membrane with high single water production according to any one of claims 1 to 2, wherein: the anion exchange membrane or the cation exchange membrane is an out-of-phase ion exchange membrane, and the content of resin powder in the anion exchange membrane or the cation exchange membrane is more than 80 percent by mass percent.

8. A membrane stack, characterized by: at least one bipolar membrane according to any one of claims 1 to 7 having a high single-pass water yield.

9. An electrodeionization apparatus, comprising: the bipolar membrane with high single water production according to any one of claims 1 to 7.

10. A method for improving single water production of an electrodeionization device is characterized by comprising the following steps: water production is carried out using an electrodeionization device having a bipolar membrane with a high single water production capacity as claimed in any one of claims 1 to 7.

Background

Ion exchange is one of the methods for extracting or removing ions from a liquid stream using ion exchange materials. Currently, ion exchange has been widely used for water purification and softening; desalting seawater and brackish water; refining and decolorizing solution (such as sugar solution). The ion exchange material has an ion exchange membrane in addition to the ion exchange resin beads and powder. The ion exchange membrane is a membrane which contains ion exchange groups and is made of high polymer materials, wherein the membrane contains all cation exchange groups and is a cation exchange membrane, and the membrane contains all anion exchange groups and is an anion exchange membrane.

In the electrodeionization technology in the prior art, the water treatment capacity of single desalination is low, and frequent regeneration is needed, so that water production is interrupted continuously, and the use of users is influenced.

Therefore, it is necessary to provide a bipolar membrane, a membrane stack, a device and a method with high water production per time to overcome the deficiencies of the prior art.

Disclosure of Invention

One of the purposes of the invention is to provide a bipolar membrane with high single water production rate by avoiding the defects of the prior art, realize high desalination effect of the bipolar membrane by increasing the total amount of ion exchange groups under the unit area of a bipolar membrane and maintain stability for a long time, so that the total amount of single water production of an electrodeionization device formed by the bipolar membrane is greatly increased.

The above object of the present invention is achieved by the following technical measures.

Provides a bipolar membrane with high water production capacity in one time, wherein the total amount of cation exchange groups in the bipolar membrane per unit area is 0.05-2 mmol/cm²The total amount of anion exchange groups is 0.05-2 mmol/cm²。

Preferably, the total amount of cation exchange groups per unit area of the bipolar membrane is 0.16-0.5 mmol/cm²The total amount of anion exchange groups is 0.13-0.5 mmol/cm²。

Preferably, the cation exchange membrane of the same bipolar membrane is formed by laminating a plurality of cation exchange membranes.

Preferably, the anion-exchange membranes of the same bipolar membrane are formed by laminating a plurality of sub-anion-exchange membranes.

Preferably, the cation exchange membrane and the anion exchange membrane which form the same bipolar membrane are both single membrane pieces;

the thickness of the anion exchange membrane dry film sheet is 0.1 mm-5 mm, and the thickness of the cation exchange membrane dry film sheet is 0.1 mm-5 mm.

Preferably, the thickness of the anion exchange membrane dry film sheet is 0.2 mm-1.4 mm, and the thickness of the cation exchange membrane dry film sheet is 0.2 mm-1.4 mm.

Preferably, the anion exchange membrane or the cation exchange membrane is a heterogeneous ion exchange membrane, and the content of the resin powder in the anion exchange membrane or the cation exchange membrane is more than 80% by mass percent.

According to the bipolar membrane with high water production capacity in one time, the total amount of cation exchange groups in unit area of the bipolar membrane is 0.05-2 mmol/cm²The total amount of anion exchange groups is 0.05-2 mmol/cm². The cation exchange group can adsorb positive salt ions in raw water and release hydrogen ions, and the anion exchange group can adsorb negative salt ions in raw water and release hydroxide ions. The hydrogen ions and hydroxyl ions displaced from the bipolar membrane enter water to react to generate water. Ion exchange group total height in this bipolar membrane can adsorb more salt ion when carrying out the desalination water purification for the electrodeionization device who has this bipolar membrane has higher single system water yield, has avoided the frequent regeneration of electrodeionization device to make the problem of system water interrupt, provides convenience for the user.

The invention also aims to avoid the defects of the prior art and provide a membrane stack with high single water production amount, which realizes high desalination effect of the membrane stack and can maintain stability for a long time by increasing the total amount of ion exchange groups per unit area of bipolar membrane membranes forming the membrane stack, so that the total amount of single water production of an electrodeionization device formed by the membrane stack is greatly increased.

The above object of the present invention is achieved by the following technical measures.

Provides a membrane stack with high single water production amount, which at least comprises a bipolar membrane with high single water production amount.

The membrane stack with high single water production amount provided by the invention at least comprises one bipolar membrane with high single water production amount. The total amount of cation exchange groups in unit area of the bipolar membrane is 0.05-2 mmol/cm²The total amount of anion exchange groups is 0.05-2 mmol/cm². The cation exchange group can adsorb positive salt ions in raw water and release hydrogen ions, and the anion exchange group can adsorb negative salt ions in raw water and release hydroxide ions. The hydrogen ions and the hydroxyl ions displaced by the bipolar membrane enter raw water to react to generate water. Ion exchange group total height in this bipolar membrane can adsorb more salt ion when carrying out the desalination water purification for bipolar membrane has higher single system water volume, has avoided the problem that the frequent regeneration makes system water interrupt when the electrodeionization device system water that has this bipolar membrane, provides convenience for the user.

Another object of the present invention is to provide an electrodeionization device having a bipolar membrane with a high single-pass water production amount, which can achieve a high desalination effect and maintain stability for a long time by increasing the total amount of ion exchange groups per unit area of the bipolar membrane, so that the total amount of single-pass water production of the electrodeionization device can be greatly increased.

The above object of the present invention is achieved by the following technical measures.

Provided is an electrodeionization device having a bipolar membrane with high water production per single pass.

The electrodeionization device provided by the invention is provided with the bipolar membrane with high single-time water production, and the total amount of cation exchange groups in the unit area of the bipolar membrane with high single-time water production is 0.05-2 mmol/cm²The total amount of anion exchange groups is 0.05-2 mmol/cm². The cation exchange group can adsorb positive salt ions in raw water and release hydrogen ions, and the anion exchange group can adsorb negative salt ions in raw water and release hydroxide ions. The hydrogen ions and the hydroxyl ions displaced by the bipolar membrane enter raw water to react to generate water. Ion exchange group total height in this bipolar membrane can adsorb more salt ion when electrodeionization device carries out the desalination water purification for electrodeionization device has higher single system water yield, has avoided the frequent regeneration of electrodeionization device to make the problem of system water interrupt, provides convenience for the user.

The invention also aims to avoid the defects of the prior art and provide a method for improving the single water production of an electrodeionization device, the method prepares the membrane stack of the electrodeionization device by using a bipolar membrane with high total amount of ion exchange groups per unit area, and the bipolar membrane with high total amount of ion exchange groups can adsorb more salt ions, so that the method for improving the single water production total amount of the electrodeionization device is greatly improved.

The above object of the present invention is achieved by the following technical measures.

Provides a method for improving single water production of an electrodeionization device, which adopts the electrodeionization device with a bipolar membrane with high single water production to produce water.

The method for improving the single water production of the electrodeionization device provided by the invention adopts the electrodeionization device with the bipolar membrane with high single water production capacity to produce water. The cation exchange group can adsorb positive salt ions in raw water and release hydrogen ions, and the anion exchange group can adsorb negative salt ions in raw water and release hydroxide ions. The hydrogen ions and the hydroxyl ions displaced by the bipolar membrane enter raw water to react to generate water. The method has the advantages that the total amount of ion exchange groups in the bipolar membrane with high single-time water production is high, and more salt ions can be adsorbed when the electrodeionization device with the bipolar membrane is used for desalting and purifying water, so that the electrodeionization device has higher single-time water production, the problem that the electrodeionization device is frequently regenerated to interrupt water production is solved, and convenience is brought to users.

Drawings

The invention is further illustrated by means of the attached drawings, the content of which is not in any way limiting.

FIG. 1 is a schematic structural diagram of a bipolar membrane with high single-pass water production according to the present invention.

FIG. 2 is a schematic structural diagram of a bipolar membrane in example 2 of the present invention.

FIG. 3 is a schematic structural view of an electrodeionization apparatus of embodiment 9 of the invention.

FIG. 4 is a schematic structural diagram of an electrodeionization apparatus of embodiment 10 of the invention.

FIG. 5 is a schematic structural view of an electrodeionization apparatus of example 11 of the present invention.

In fig. 1 to 5, there are included:

a cation exchange membrane 100, an anion exchange membrane 200,

An electrode cation exchange membrane 110, an electrode anion exchange membrane 210,

A sub-cation exchange membrane 300, a sub-anion exchange membrane 400,

A cathode film electrode 500, an anode film electrode 600,

A porous material 510, a current collector 520,

A porous material 610, a current collector 620.

Detailed Description

The invention is further illustrated by the following examples.

Example 1.

The bipolar membrane has high water production per time, and the total amount of cation exchange groups in unit area of the bipolar membrane is 0.05-2 mmol/cm²The total amount of anion exchange groups is 0.05-2 mmol/cm². As shown in fig. 1, the bipolar membrane is composed of a cation-exchange membrane 100 and an anion-exchange membrane 200 laminated or heat-pressed together. The cation exchange membrane 100 contains cation exchange groups, and the anion exchange membrane 200 contains anion exchange groups. The cation exchange group can adsorb positive salt ions in raw water and release hydrogen ions in the raw water, and the anion exchange group can adsorb negative salt ions in the raw water and release hydroxide ions in the raw water. The higher the content of ion exchange groups in the bipolar membrane is, the stronger the bipolar membrane has the adsorption capacity on salt ions in raw water, so that the desalting capacity of the bipolar membrane is stronger.

The cation exchange membrane 100 of the same bipolar membrane can be formed by laminating a plurality of sub-cation exchange membranes 300. The anion exchange membrane 200 of the same bipolar membrane may be formed by laminating a plurality of sub-anion exchange membranes 400. The sub-cation exchange membrane 300 may be the conventional cation exchange membrane 100, and the sub-anion exchange membrane 400 may be the conventional anion exchange membrane 200. The bipolar membrane with high single-time water production is prepared by using the conventional ion exchange membrane, the preparation process of the bipolar membrane with high single-time water production can be simplified, the cost is reduced, and the content of ion exchange groups in the bipolar membrane can be doubled by stacking multiple layers of the bipolar membranes.

In this embodiment, a bipolar membrane a and a bipolar membrane B are selected to form a membrane stack a and a membrane stack B to perform an experiment on the desalination rate of the membrane stack, wherein the bipolar membrane a has a membrane area of 0.2m for 1 membrane each²The cation exchange membrane 300 and the anion exchange membrane 400 were laminated, and the bipolar membrane B was composed of two sheets each having a membrane area of 0.2m²The cation exchange membrane 300 and the anion exchange membrane 400 are laminated. The experimental steps are as follows: the two membrane stacks were respectively installed in an electrodeionization device, then 750ppm NaCl solution was introduced into the membrane stack A and the membrane stack B at a flow rate of 0.5L/min, the NaCl solution was passed through the membrane stacks at one time, and the salt rejection rates of the two membrane stacks were changed with time as shown in the following table:

TABLE 1 desalination rate of Membrane Stack A and Membrane Stack B as a function of time

It should be noted that, the number of the daughter ion exchange membranes constituting the stack B is twice that of the stack a, and the ion exchange group content in the stack B is twice that of the stack a. From table 1, the desalination rate of the membrane stack B is less attenuated within 10min, the desalination performance is slower, and the total amount of water production by single desalination of the membrane stack B is favorably increased.

The bipolar membrane with high single water production amount has higher ion exchange group content, and can adsorb more salt ions when the electrodeionization device with the bipolar membrane carries out raw water desalination and purification, and the desalination performance is slow down in decay, so that the electrodeionization device has higher single water production total amount.

Example 2.

A bipolar membrane with high single water production capacity, other characteristics are the same as example 1, except that: as shown in fig. 2, the cation exchange membrane 100 of the same bipolar membrane is formed by laminating 4 sheets of cation exchange membranes 300. The anion exchange membrane 200 of the same bipolar membrane is formed by laminating 4 sheets of anion exchange membranes 400. The more the quantity of the ion exchange membranes, the more the content of the ion exchange groups in the bipolar membrane, and the more salt ions can be adsorbed when the electrodeionization device with the bipolar membrane is used for raw water desalination and purification, so that the electrodeionization device has higher single water production total amount.

Example 3.

A bipolar membrane with high single water production capacity, other characteristics are the same as example 1, except that: the cation exchange membrane 100 and the anion exchange membrane 200 which form the same bipolar membrane are single membrane pieces, the thickness of the anion exchange membrane 200 dry membrane piece is 0.1 mm-5 mm, and the thickness of the cation exchange membrane dry membrane piece 100 is 0.1 mm-5 mm. The method of increasing the ion exchange group content in the bipolar membrane in this embodiment is to increase the membrane piece thickness of the cation exchange membrane 100 and the anion exchange membrane 200 constituting the bipolar membrane.

In this embodiment, the bipolar membrane C and the bipolar membrane D are further selected to form a membrane stack C and a membrane stack D to perform an experiment on the desalination rate of the membrane stack, wherein the anion exchange membrane and the cation exchange membrane dry membrane which form the bipolar membrane D are selected from the anion exchange membrane and the cation exchange membrane of this embodiment. The membrane stack C selects a cation exchange membrane and an anion exchange membrane with common thicknesses, the thickness of the ion exchange membrane which forms the bipolar membrane D is twice that of the bipolar membrane C, and the membrane areas of the two bipolar membranes are both 0.2m². The experimental steps are as follows: the two membrane stacks were respectively installed in an electrodeionization device, then 750ppm NaCl solution was introduced into the membrane stack A and the membrane stack B at a flow rate of 0.5L/min, the NaCl solution was passed through the membrane stacks at one time, and the salt rejection rates of the two membrane stacks were changed with time as shown in the following table:

TABLE 2 desalination rate of Membrane Stack C and Membrane Stack D as a function of time

Duration (min)	Membrane stack C	Membrane stack D
			1	77.3％	66.3％
2	75.5％	66.7％
			3	71.6％	66.6％
4	65.2％	65.5％
			5	58.9％	64.8％
6	50.2％	64.6％
			7	43.1％	62.5％
8	35.4％	60.8％
			9	30.5％	60.1％
10	21.7％	55.3％

Note that, the thickness of the bipolar membrane constituting the membrane stack D is twice that of the membrane stack C, and the content of the ion exchange group in the membrane stack D is twice that of the membrane stack C. From table 2, the desalination rate of the membrane stack D is less attenuated within 10min, and the desalination performance is slower, which is beneficial to the increase of the total water production amount by single desalination of the membrane stack D.

Have higher ion exchange group content in this bipolar membrane of single system water height, when the electrodeionization device who has this bipolar membrane carries out raw water desalination and purification, can adsorb more salt ion, and desalination performance decay slows down for electrodeionization device has higher single system water total amount.

Example 4.

A bipolar membrane with high single water production capacity, other characteristics are the same as example 1, except that: the total amount of cation exchange groups in unit area of the bipolar membrane is 0.16-0.5 mmol/cm²The total amount of anion exchange groups is 0.13-0.5 mmol/cm². The bipolar membrane with high single water production capacity has higher ion exchange group content, and when the electrodeionization device with the bipolar membrane is used for raw water desalination and purification, the desalination performance is reduced, so that the electrodeionization device has higher single water production total amount.

Example 5.

A bipolar membrane with high single water production capacity, other characteristics are the same as example 1, except that: the thickness of the anion exchange membrane dry film sheet is 0.2 mm-1.4 mm, and the thickness of the cation exchange membrane dry film sheet is 0.2 mm-1.4 mm. The bipolar membrane with high single water production capacity has higher ion exchange group content, and when the electrodeionization device with the bipolar membrane is used for raw water desalination and purification, the desalination performance is reduced, so that the electrodeionization device has higher single water production total amount.

Example 6.

A bipolar membrane with high single water production capacity, other characteristics are the same as example 1, except that: the anion exchange membrane 200 or the cation exchange membrane 100 is a heterogeneous ion exchange membrane, and the content of resin powder in the anion exchange membrane 200 or the cation exchange membrane 100 is more than 80% by mass percent. The higher the content of the resin powder in the ion exchange membrane is, the higher the content of the ion exchange groups in the ion exchange membrane is, and the stronger the salt ion adsorption capacity of the prepared bipolar membrane is.

The embodiment also selects a bipolar membrane E and a bipolar membrane F to form a membrane stack E and performs an experiment on the desalination rate of the membrane stack by the membrane stack F, wherein the bipolar membrane F selects the bipolar membrane ion exchange membrane of the embodiment to form, the content of resin powder in the bipolar membrane F is twice of that of the bipolar membrane E, and the membrane areas of the two bipolar membranes are 0.2m². The experimental steps are as follows: the two membrane stacks were installed in an electrodeionization device, and then 750ppm NaCl solution was introduced into the membrane stack E and the membrane stack F at a flow rate of 0.5L/min, respectively, and the NaCl solution was passed through the membrane stacks at once, and the salt rejection rates of the two membrane stacks were changed with time as shown in the following table:

TABLE 3 desalination Rate of Membrane Stack E and Membrane Stack F as a function of time

Note that, the content of the resin powder in the bipolar membrane constituting the membrane stack F is twice as large as that of the bipolar membrane constituting the membrane stack E, and the content of the ion exchange group in the membrane stack F is twice as large as that of the membrane stack E. From table 3, the desalination rate of the membrane stack F is less attenuated within 10min, the desalination performance is slower, and the total amount of water produced by single desalination of the membrane stack F is favorably increased.

Have higher ion exchange group content in this bipolar membrane of single system water height, when the electrodeionization device who has this bipolar membrane carries out raw water desalination and purification, can adsorb more salt ion, and desalination performance decay slows down for electrodeionization device has higher single system water total amount.

Example 7.

A membrane stack comprises a pair of electrodes and at least one bipolar membrane with high single-time water production amount, which is arranged between the electrodes. Have higher ion exchange group content in the bipolar membrane of single system water yield height, then have higher ion exchange group content in the membrane stack, when electrodeionization device carries out raw water desalination and purification, can adsorb more salt ion, and the desalination performance decay slows down for electrodeionization device has higher single system water total amount.

Example 8.

An electrodeionization apparatus having at least one bipolar membrane and electrode pair with high water production per single pass. The electrode pair may be a metal electrode, a carbon electrode, a graphite electrode, or the like, or may be a porous electrode. In this embodiment, a deionization apparatus having a porous electrode is exemplified, and as shown in fig. 3, an electrode pair comprising a pair of porous electrodes is provided, and a flow path is formed between the electrode and the bipolar membrane, and between the bipolar membrane and the bipolar membrane. In this embodiment, the anion exchange membrane 200 and the cation exchange membrane 100 that constitute bipolar membrane are single-layer membranes, and the dry film thickness is 0.7mm, and the bipolar membrane thickness that this embodiment chose for use is great, has more ion exchange groups, and bipolar membrane can adsorb more salt ion, and electrodeionization device single system water height. In the present embodiment, one bipolar membrane with high water production per time may be included, or another number of bipolar membranes, such as 2, 3, 4, etc., may be included, and generally 1 to 50 bipolar membranes are included, or more bipolar membranes may be included.

In this embodiment, the porous electrode is provided with a collector 520, and the collector 520, the porous material 510, and the ion exchange membrane are laminated in this order to constitute the porous electrode. The current collector 520 is made of one or more of metal, metal alloy, graphite, graphene, carbon nanotube, and conductive plastic. The current collector 520 may have a sheet or plate structure, which provides both support and electrical conductivity for the porous material 510 and the ion exchange membrane. The way in which the current collector 520, the porous material 510, and the ion exchange membrane are sequentially stacked may be physical clamping, thermal bonding, or adhesive bonding, but is not limited to these three ways.

In this embodiment, the porous material 510 has a porous structure with a pore size of 0.5-50 nm. The porous material 510 is an electrical conductor prepared from one or more of activated carbon, carbon black, carbon nanotubes, graphite, carbon fibers, carbon cloth, carbon aerogel, metal powder, metal oxides, and conductive polymers. It should be noted that the porous material 510 can also be made of other conductive materials with large specific surface, and is not limited to the conductive materials listed in this embodiment, but the specific surface is preferably larger than 100m²A hydrophobic conductive material.

The ion exchange membrane in the porous electrode is adjacent to the membrane stack, and the ion exchange membrane in the porous electrode can be either the anion exchange membrane 210 or the cation exchange membrane 110. Since the ion exchange resin in the porous electrode is close to the membrane stack, a flow channel is formed between the bipolar membrane and the porous electrode, and pure water is generated when the electrodeionization device carries out desalination. The ion exchange membrane in the porous electrode of this example is a single-layer structure, and has only one ion exchange membrane, and the membrane thickness is 0.7 mm. It should be noted that the type and thickness of the ion exchange membrane in the porous electrode can be flexibly selected according to actual needs, and are not limited to the ion exchange membrane in this embodiment.

It should be noted that the types or thicknesses of the anion exchange membrane 200 or the cation exchange membrane 100 constituting the bipolar membrane and the anion exchange membrane 210 or the cation exchange membrane 110 on the porous electrode may be the same or different, and in this embodiment, the ion exchange membrane constituting the membrane stack and the ion exchange membrane of the porous electrode are different.

In this embodiment, the porous material 510 has a porous structure with a pore size of 0.5-50 nm. The porous material 510 is activated carbon, carbon black, carbon nanotubes, graphite, carbon fibers, carbon cloth, carbon aerogel, metal powder,An electrical conductor made from one or more of a metal oxide and a conductive polymer. It should be noted that the porous material 510 can also be made of other conductive materials with large specific surface, and is not limited to the conductive materials listed in this embodiment, but the specific surface is preferably larger than 100m²A hydrophobic conductive material.

In this embodiment, a plurality of bipolar membranes arranged at intervals are arranged between the electrode pair, and the arrangement modes of the plurality of bipolar membranes are the same. The number of bipolar membranes between the electrode pairs may be set to 1 to 50. The number of the bipolar membranes can be specifically selected according to the water quality to be purified. This embodiment exemplifies a case where the bipolar membrane between the pair of electrodes is set to 2 sheets.

In this embodiment, one porous electrode has a cation exchange membrane 110, defined as an anode membrane electrode 600, and the other porous electrode has an anion exchange membrane 210, defined as a cathode membrane electrode 500; the anion-exchange membrane 200 in the bipolar membrane closest to the anode electrode 600 faces the anode electrode 600; the cation-exchange membrane 100 in the bipolar membrane closest to the cathode electrode 500 faces the cathode electrode 500.

According to the electrodeionization device, when water is produced, all single channels simultaneously produce water, and no concentrated water is produced. During regeneration, the regeneration can be realized by reversing the poles, and the regeneration process is also carried out in a single channel. Therefore, the bipolar membrane electrodeionization device has a simple water path structure.

The electrodeionization device repeatedly utilizes the membrane area of the bipolar membrane, and the electrolytic ion exchange mode greatly improves the speed and efficiency of ion exchange. The bipolar membrane electrodeionization device does not generate gas in polar water and scale formation.

So this electrodeionization device adopts the structure of porous electrode and bipolar membrane, can avoid among the prior art problem that the utmost point water hydrolysis produced gas and scale deposit, and the diaphragm that the ion exchange membrane of bipolar membrane and porous electrode department chose for use is thicker, has more ion exchange group, can adsorb more salt ion for electrodeionization device has higher single system water yield.

Example 9.

An electrodeionization apparatus having the same other features as in example 9 except that: as shown in fig. 4, the porous electrode is formed by laminating a current collector and a porous material, and does not have an electrode ion exchange membrane.

According to the electrodeionization device, when water is produced, all single channels simultaneously produce water, and no concentrated water is produced. During regeneration, the regeneration can be realized by reversing the poles, and the regeneration process is also carried out in a single channel. Therefore, the bipolar membrane electrodeionization device has a simple water path structure.

The electrodeionization device repeatedly utilizes the membrane area of the bipolar membrane, and the electrolytic ion exchange mode greatly improves the speed and efficiency of ion exchange. The bipolar membrane electrodeionization device does not generate gas in polar water and scale formation.

So this electrodeionization device adopts the structure of porous electrode and bipolar membrane, can avoid among the prior art problem that the utmost point water hydrolysis produced gas and scale deposit, and the diaphragm that the ion exchange membrane of bipolar membrane and porous electrode department chose for use is thicker, has more ion exchange group, can adsorb more salt ion for electrodeionization device has higher single system water yield.

Example 10.

An electrodeionization apparatus having the same other features as in example 9 except that: as shown in fig. 5, the cation exchange membrane 100 of the same bipolar membrane and the cation exchange membrane 100 of the porous electrode are each formed by laminating 3 sheets of cation exchange membranes 300. The anion exchange membrane 200 and the cation exchange membrane 100 of the porous electrode of the same bipolar membrane are respectively formed by laminating 3 pieces of anion exchange membranes 400. The present example shows that the daughter ion exchange membranes forming the stack are identical to the daughter ion exchange membranes on the porous electrodes. The bipolar membranes between the electrode pairs were set to 2 sheets. The ion exchange membrane is composed of a plurality of ion exchange membranes, so that more ion exchange groups are arranged in the ion exchange membrane, the salt absorption capacity of the bipolar membrane is enhanced, and the single-time water production of the electrodeionization device with the bipolar membrane is high.

Example 11.

A method for improving single water production of an electrodeionization device adopts the electrodeionization device with a bipolar membrane with high single water production to produce water. The total amount of ion exchange groups in the bipolar membrane of the prepared electrodeionization device used by the method is high, and more salt ions can be adsorbed when the electrodeionization device is used for desalting and purifying water, so that the electrodeionization device has higher single water production amount, the problems of frequent regeneration and water production interruption of the electrodeionization device are avoided, convenience is provided for users, meanwhile, the method does not increase the number of flow channels, the increase degree of the volume of the system is small, and the cost of the flow channels is saved.

Finally, it should be noted that the above embodiments are only used for illustrating the technical solutions of the present invention and not for limiting the protection scope of the present invention, and although the present invention is described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions can be made on the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.