KR102268476B1 - Multi-channel membrane capacitive deionization with enhanced deionization performance - Google Patents

Abstract

In order to achieve the above object, the present invention provides a cation exchange membrane and an anion exchange membrane facing each other; a plurality of first electrodes disposed on one side of the cation exchange membrane; a plurality of second electrodes disposed on the other side of the anion exchange membrane; and a flow path disposed between the cation exchange membrane and the anion exchange membrane.

Description

MULTI-CHANNEL MEMBRANE CAPACITIVE DEIONIZATION WITH ENHANCED DEIONIZATION PERFORMANCE

The present invention relates to a multi-channel membrane-coupled capacitive desalting device with increased desalting performance.

In the world, the value of water as a resource is increasing due to the deepening of drought caused by global warming, the depletion of groundwater, the progress of desertification, and the increase in the use of living and industrial water due to population growth and industrialization. Recycling is emerging as a new issue. In addition, as interest in the manufacture of industrial ultrapure water increases and the demand for clean water to eat and wash in daily life increases, research on the development of high-efficiency ion removal devices is being actively conducted.

In addition, when hard water is used as industrial water and household water, detergents do not dissolve well and cause industrial and sanitary problems due to the formation of scale by divalent cations (Ca2+, Mg2+, etc.). Therefore, in order to reduce the damage caused by the use of hard water, the softening process is essential, and technological development for this is actively underway. In addition, the removal of radioactive Cs+ ions present in water and the recovery of Li+ ions are recognized as important in the environment and industrial distribution.

Currently, technologies for removing ionic substances mainly use evaporation, reverse osmosis membrane, and ion exchange resin. Evaporation and reverse osmosis membrane methods have operating costs and operational problems due to high energy consumption, and are the most widely used ions. The exchange resin method has the disadvantage of creating secondary pollutants because it uses an excessive amount of acid (Acid) or salt (NaCl) during regeneration.

Research is underway in many countries around the world to compensate for the shortcomings of existing dissolved ion removal technologies and to develop new low-energy consumption-type ion removal technologies. There is a Capacitive Deionization (CDI) technology.

CDI technology, an electro-adsorption type ion removal technology, consumes less energy than other methods, and unlike the existing ion removal technology, it does not require cleaning with chemicals, so it is an environmentally friendly new ion removal technology that does not cause secondary pollution. Due to the advantage of simplicity, research is being actively conducted as a next-generation dissolved ion removal technology.

The first CDI process research was conducted in the 1960s by researchers at the University of Oklahoma in the US using a porous activated carbon electrode to study seawater desalination, and then Johnson et al. performed CDI experiments using activated carbon. However, the development was not possible due to the continuous process difficulties due to the deterioration of the electrode, which is a key factor, but research was conducted at the LLNL (Lawrence Livermore National Laboratory) in the US to develop a CDI process using a carbon airgel electrode in the mid-1990s. In addition, research on the development of a CDI process using activated carbon fibers and carbon nanotubes as electrode active materials has been conducted.

CDI is a technology that reversibly removes ions from raw water using electrochemical adsorption/desorption. This process removes ions in the raw water by storing the ions in a double layer on the electrode surface when an electric potential is applied. However, the capacitive desalination process inevitably wastes some of the charge required for ion adsorption. This is because, when the electric double layer is formed, power is consumed to repel the charged ions (ions having the same potential as the electrode potential) existing on the electrode surface. To overcome these limitations, membrane capacitive deionization (MCDI) systems have emerged. MCDI relieves 'coin charge ion repulsion' by applying an ion exchange membrane, and dramatically improves the desalination performance and charge efficiency.

Ion-selective membranes located in front of both electrodes (cation exchange membrane on cathode and anion exchange membrane on anode) saved the charge consumed by the same charge ions. The MCDI system has been actively developed for low-concentration operation, constant current operation, and energy recovery.

The development of ion exchange materials applied to MCDI proceeded in two directions.

First, the material of the ion exchange membrane was developed. As an example of such an ion exchange membrane development, NaSS-MAA-MMA copolymer was applied as a cation exchange membrane and 4-vinylbenzylchloride/styrene/ethylmethacrylate was applied as an anion exchange membrane. In addition, cross-linked quaternised polyvinyl alcohol was suggested as AEM, and the desalting capacity was improved by about 2 times. In addition to the ion exchange membrane, studies showing performance improvement through the application of an ion exchange material for coating to the electrode have also been reported.

Second, it was developed in the direction of coating the electrode with an ion exchange material. As a development example of a method for coating such an ion exchange material on an electrode, polyvinyl alcohol/sulfosuccinic acid was coated on the negative electrode as a cation exchange resin to dramatically improve the desalting performance. In addition, by spraying bromomethylated poly(2,6-dimethyl-1,4-phenyleneoxide) (BPPO) treated with sulfuric acid and amine on the positive/negative electrodes, the coating of the ion exchange material was easily successful. Nie et al. achieved good regeneration ability (30 cycles) by directly coating the electrode with polyacrylic acid as a cation exchange resin using the electrodeposition method.

As such, when using a carbon electrode, it has a large surface area and has an excellent advantage in relatively stable capacity characteristics in aqueous solution, but there is a disadvantage in that the resistance of carbon itself is not small, and it is not friendly with water because the surface characteristic is hydrophobic. It also tends to be a bit slow in terms of speed.

Therefore, the development of a desalting process having excellent speed characteristics while efficiently desalting has been required.

Patent Document 1: Republic of Korea Patent No. 1237258 Patent Document 2: Republic of Korea Patent No. 1410642 Patent Document 3: Republic of Korea Patent Publication No. 2012-0058228

In order to solve the above problems, an object of the present invention is to provide a capacitive desalting device capable of improving the desalting capacity in the capacitive desalting process.

On the other hand, the technical problems to be achieved in the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned are clearly to those of ordinary skill in the art to which the present invention belongs from the description below. can be understood

In order to achieve the above object, the present invention provides a cation exchange membrane and an anion exchange membrane facing each other; a plurality of first electrodes disposed on one side of the cation exchange membrane; a plurality of second electrodes disposed on the other side of the anion exchange membrane; and a flow path disposed between the cation exchange membrane and the anion exchange membrane.

Also, the number of the plurality of first electrodes and the plurality of second electrodes may be the same.

Also, the number of the plurality of first electrodes and the plurality of second electrodes may be 2 to 10, respectively.

In addition, the plurality of first electrodes and the plurality of second electrodes may be in contact with the electrolyte.

In addition, the electrolyte in contact with the plurality of first electrodes and the electrolyte in contact with the plurality of second electrodes may flow with each other.

Capacitive desalination apparatus according to the present invention can improve the desalination capacity in the capacitive desalination process through a plurality of first electrodes and a plurality of second electrodes.

On the other hand, the effects obtainable in the present invention are not limited to the above-mentioned effects, and other effects not mentioned will be clearly understood by those of ordinary skill in the art to which the present invention belongs from the following description. will be able

1 is an exemplary view schematically showing a capacitive desalination apparatus according to Embodiment 1 of the present invention;
Figure 2 is an exemplary view showing the ion removal mechanism in the capacitive desalination device according to the first embodiment of the present invention,
3 is an exemplary view schematically showing a capacitive desalination apparatus according to Example 2 of the present invention;
Figure 4 is an exemplary view showing the ion removal mechanism in the capacitive desalting device according to the second embodiment of the present invention,
5 is a graph showing a concentration change curve according to repeated adsorption and desorption according to the capacitive desalination device according to Example 1 of the present invention, showing the results according to the change in the concentration of the redox reaction material in the electrolyte;
6 is a graph showing the desalination performance according to the concentration of the redox reactant in the electrolyte in the capacitive desalting device according to Example 1 of the present invention;
7 is a graph showing the pH change of treated water during the desalting and regeneration process through the capacitive desalting device according to Example 1 of the present invention;
8 is a graph showing the cyclic voltammetry measurement results according to the capacitive desalination apparatus according to Example 1 of the present invention;
9 is a graph showing the results of observing the continuous desalination process using the redox reaction material according to Example 1 of the present invention;
10 is a graph showing a change in the concentration of effluent according to a change in the number of electrode pairs in the capacitive desalination apparatus according to Example 2 of the present invention;
11 is a graph showing a change in the pH of treated water according to a change in the number of electrode pairs in the capacitive desalination apparatus according to Example 2 of the present invention;
12 is a graph showing the desalination amount (SAC), the desalination amount per electrode weight, and the charge efficiency according to a change in the number of electrode pairs in the capacitive desalination apparatus according to Example 2 of the present invention.

Other advantages and features of the present invention, and a method of achieving them will become apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms, and only this embodiment serves to complete the disclosure of the present invention, and to obtain common knowledge in the art to which the present invention pertains. It is provided to fully inform the possessor of the scope of the invention, and the present invention is only defined by the scope of the claims.

Even if not defined, all terms (including technical or scientific terms) used herein have the same meaning as commonly accepted by common technology in the prior art to which this invention belongs. Terms defined by general dictionaries may be construed as having the same meaning as they have in the related description and/or in the text of the present application, and are conceptualized even if not expressly defined herein.

nor will it be construed as overly formal.

The terminology used herein is for the purpose of describing the embodiments and is not intended to limit the present invention. As used herein, the singular also includes the plural unless specifically stated otherwise in the phrase. As used herein, 'comprise' and/or various conjugations of this verb, eg, 'comprise', 'comprising', 'comprising', 'comprising', etc., refer to the referenced composition, ingredient, component, A step, operation and/or element does not exclude the presence or addition of one or more other compositions, components, components, steps, operations and/or elements. As used herein, the term 'and/or' refers to each of the listed components or various combinations thereof.

Meanwhile, terms such as '~ unit', '~ group', '~ block', and '~ module' used throughout this specification may mean a unit that processes at least one function or operation. For example, it can mean software, hardware components such as FPGAs or ASICs. However, '~ part', '~ group', '~ block', and '~ module' are not meant to be limited to software or hardware. '~ unit', '~ group', '~ block', and '~ module' may be configured to reside in an addressable storage medium or to regenerate one or more processors.

Accordingly, as an example, '~ part', '~ group', '~ block', and '~ module' are components such as software components, object-oriented software components, class components, and task components. fields, processes, functions, properties, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuitry, data, databases, data structures, tables, arrays and include variables. The functions provided within the components and '~part', '~gi', '~block', and '~module' are smaller than the number of components and '~bu', '~gi', '~block' ', '~modules' or may be further separated into additional components and '~parts', '~groups', '~blocks', and '~modules'.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings of the present specification.

1 is an exemplary view schematically showing a capacitive desalting apparatus according to Example 1 of the present invention, and FIG. 2 is an exemplary view showing an ion removal mechanism in the capacitive desalting apparatus according to Example 1 of the present invention .

Embodiment 1 of the present invention is characterized in that the redox reaction material is included in the electrolytic solution flowing to the electrode side in the capacitive desalination device.

In the capacitive desalination apparatus according to the first embodiment of the present invention, a central flow path 11 providing a path through which seawater, salt water or wastewater is introduced and the treated treated water 10 is discharged, and one side of the central flow path 11 . The cation exchange membrane 21 disposed in the cation exchange membrane 22 disposed on the other side of the central flow path 11, the first flow path 31 disposed on one side of the cation exchange membrane 21, the other side of the anion exchange membrane 22 A pair of electrodes 41 and 42 disposed in the second flow path 32, the first flow path 31, and the second flow path 32, respectively, and the second flow path 32 disposed in the , and an electrolyte solution 30 containing a redox reaction material.

The central flow path 11 may provide a path through which seawater, salt water, or wastewater may be introduced and the treated treated water 10 may be discharged.

Here, the seawater, brine or wastewater may include desalting cations and anions.

A cation exchange membrane 21 is disposed on one side of the central flow path 11 , and an anion exchange membrane 22 is disposed on the other side, so that cations and anions in seawater, brine or wastewater can be exchanged.

Here, any of the ion exchange membranes 21 and 22 and the electrodes 41 and 42 that have been used in conventional capacitive electrodes (battery, storage battery, etc.) can be used, and a person of ordinary skill in the art It can be appropriately selected and used according to the purpose and conditions of its use.

The cation exchange membrane 21 and the anion exchange membrane 22 are micropore insulating membranes, and may be ion exchange (conductive) membranes. The cation exchange membrane 21 and the anion exchange membrane 22 are installed for electrophysical separation. The micropore insulating separator is capable of only ion movement, and the ion exchange (conductive) membrane is a cation or anion. can be selectively moved.

The electrodes 41 and 42 may include a first electrode 41 disposed adjacent to the cation exchange membrane 21 and a second electrode 42 disposed adjacent to the anion exchange membrane 22 .

Meanwhile, since the amount of ions adsorbed to the electrodes 41 and 42 is determined according to the capacitance of the used electrode, a porous carbon electrode having a large specific surface area may be used in the present invention.

The first electrode 41 is disposed in the first flow path 31 disposed on one side of the cation exchange membrane 21 , and the second electrode 42 is disposed in the second flow path 32 disposed on the other side of the anion exchange membrane 22 . can be placed within.

Here, the first electrode 41 may be disposed to be spaced apart from the cation exchange membrane 21 , and the second electrode 42 may be disposed to be spaced apart from the anion exchange membrane 22 .

Here, although not shown, the first electrode 41 may be coated with a negative electrode active material, and the second electrode 42 may be coated with a positive electrode active material.

3 is an exemplary view schematically showing a capacitive desalting apparatus according to a second embodiment of the present invention, and FIG. 4 is an exemplary view showing an ion removal mechanism in the capacitive desalting apparatus according to the second exemplary embodiment of the present invention.

3 and 4 , a plurality of first electrodes 141 are disposed in the first flow path 31 , and a plurality of second electrodes 142 are disposed in the second flow path 32 .

For example, a plurality of first electrodes 141a , 141b , 141c and 141d are disposed on one side of the cation exchange membrane 21 , and a plurality of second electrodes 142a , 142b , 142c and a plurality of second electrodes 142a , 142b , 142c and the other side of the anion exchange membrane 22 are disposed on one side of the cation exchange membrane 21 . 142d) is placed.

Meanwhile, according to FIG. 3 , although the number of the first electrode 141 and the second electrode 142 is illustrated as four, the number is not limited to four, and five or more electrodes may be provided, respectively.

In this case, the first electrodes 141a to 141d and the second electrodes 142a to 142d may be provided in the same number.

For example, when the number of the first electrodes 141a to 141d is greater than the number of the second electrodes 142a to 142d, the first electrodes 141a to 141d are adsorbed within a shorter time than the second electrodes 142a to 142d. The capacity is saturated and can no longer adsorb ions.

When the adsorption capacity is saturated, since a desorption process for dropping ions attached to the electrode must be performed, the first electrodes 141a to 141d and the second electrodes 142a to 142d are preferably saturated at a similar time. Therefore, it is preferable to provide the same number of electrodes in order to reduce the difference in saturation timing.

However, depending on the embodiment, it is also possible to make a difference in the number of both electrodes.

The electrodes 141 and 142 may include a current collector 43 . The current collector 43 recovers electrons generated by the electrochemical reaction of the active material or supplies electrons necessary for the electrochemical reaction to improve desalting performance.

It is preferable that the first flow path 31 and the second flow path 32 communicate with each other, and the electrolyte 30 introduced into the first flow path 31 is directed toward the first electrode 41 and the second electrode 42 side. It may be discharged to the second flow path 32 side.

The electrolyte solution 30 may include a redox reaction material.

Here, the redox material of the electrolyte solution 30 may include a ferro cyanide compound.

In one example, the redox material of the electrolyte 30 may be selected as _{Na 4} Fe(CN) _{6 .}

On the other hand, the redox reaction material of the electrolyte 30 may be subjected to a redox reaction as shown in the following [reaction formula].

[reaction formula]

2 and 4 , the cation exchange membrane 21 may selectively permeate cations, and the anion exchange membrane 22 may selectively permeate anions.

In addition, when the generated potential difference supplied from the outside, for example, a potential difference in the range of 0.6 to 1.2v is applied to the first electrode 41 and the second electrode 42 , the electrode is charged with a certain amount of charge.

When brine water containing ions is passed through the charged electrodes 41 and 42, ions having an opposite charge to the charged electrode move to the respective electrodes 41 and 42 by electrostatic force to move to the electrodes 41 and 42. The water adsorbed to the surface and passing through the electrodes 41 and 42 becomes pure water (treated water) 40 from which ions are removed.

In addition, the electrolyte 30 flows in the first flow path 31 and the second flow path 32 in which the electrodes 41 and 42 are disposed, and the redox reaction material of the electrolyte 30 is a voltage applied to the electrodes. Due to the redox reaction, cations or anions are introduced into the electrolyte 30 through the cation exchange membrane 21 and the anion exchange membrane 22 to balance the charge of the electrolyte solution, and the central flow path 11 is desalted. performance can be increased.

For example, the redox reaction material in the first flow passage 31 may perform a reduction reaction due to the voltage applied to the first electrode 41 , and the redox reaction material in the second flow passage 32 is the second electrode Oxidation can be carried out due to the + voltage applied to (42)

That is, the capacitive desalination apparatus according to Example 1 of the present invention can simultaneously utilize the ion treatment mechanism according to the capacitance of the electrode and the ion treatment mechanism according to the electron transfer reaction through the Redox Couple, Demineralization performance can be improved.

On the other hand, when the desorption process is described, when the adsorption capacity of the electrodes 41 and 42 is saturated, no more ions can be adsorbed, so that the ions of the influent come out as they are in the outflow. In order to regenerate the electrodes by desorbing ions adsorbed to the electrodes 41 and 42, the electrodes 41 and 42 are shorted or a potential opposite to the adsorption potential is applied. In this case, the electrodes lose charge or have an opposite charge, so that the adsorbed ions are rapidly desorbed, and the electrode is regenerated.

<Measurement results according to Example 1 of the present invention>

Hereinafter, with reference to FIGS. 5 to 8, the desalination performance of the capacitive desalination apparatus according to Example 1 of the present invention will be described in comparison with the comparative example.

comparative example

_{In Comparative Example, Na 4} Fe(CN) ₆ was selected as the redox reactant in the electrolyte flowing through the electrode side flow path, and the concentration of the redox reactant was set to 0 mM.

Examples according to the change in the concentration of the redox reactant material

_{In Example 1, Na 4} Fe(CN) ₆ was selected as the redox reactant in the electrolyte flowing through the electrode side flow path, and the concentration of the redox reactant was set as shown in [Table 1] below.

Example 1-1

Example 1-2
Examples 1-3
Examples 1-4
density

10 mM
30 mM
50 mM
100 mM

5 is a graph showing a concentration change curve according to repeated adsorption and desorption according to the capacitive desalination apparatus according to Example 1 of the present invention, and showing the results according to the change in the concentration of the redox reactant in the electrolyte.

Referring to FIG. 5 , it can be seen that as the concentration of the redox reactant in the electrolyte flowing through the first flow passage and the second flow passage increases, the concentration of the treated water discharged through the central flow passage decreases.

Meanwhile, referring to FIG. 5 , the concentration of the discharged treated water decreases as the concentration of the redox reactant in the electrolyte increases. However, when the concentration of the redox reactant exceeds 50 mM, the decrease in the concentration of the discharged treated water is It can be seen that there is no increase.

That is, in the 10 mM capacitive desalting apparatus for treated water according to Example 1 of the present invention, it is preferable that the concentration of the redox reactant in the electrolyte is greater than 0 mM and less than or equal to 50 mM, and when the concentration of the treated water increases (>10 mM) ), a higher concentration of the redox reactant may be desirable.

6 is a graph showing the desalination performance according to the concentration of the redox reactant in the electrolyte in the capacitive desalting device according to Example 1 of the present invention.

Here, salt adsorption capacity (SAC) represents the desalination performance, charge efficiency represents electric energy efficiency as charge efficiency, and capacitance represents the storage capacity of the electrode.

First, looking at the desalination performance and the storage capacity of the electrode, it can be seen that the desalination performance (SAC) of Examples 1-1 to 1-4 is significantly increased compared to the comparative example.

Here, it can be seen that the desalting performance converges similarly to the critical performance when the concentration of the redox reactant in the electrolyte is 50 mM.

On the other hand, looking at the charge efficiency, it can be confirmed that the charge efficiency does not decrease under all the conditions of Comparative Examples and Examples 1-1 to 1-4, and high efficiency is maintained.

7 is a graph showing the pH change of treated water during the desalting and regeneration process through the capacitive desalting apparatus according to Example 1 of the present invention.

Referring to FIG. 7 , ^{it is for measuring a change in pH due to H +} and OH ⁻ , and is a graph showing the measurement of the pH of treated water. In general, pH is an indicator that can confirm the adsorption/desorption reaction of ions in the solution or the oxidation/reduction reaction by a certain chemical species in the cell when an electric force is applied to the electrode. should be preferred.

Overall, it was slightly acidic, and it could be confirmed that the Examples and Comparative Examples with significantly high efficiency did not show a large change in pH. The range of change in pH was about ±0.1, and the deviation was quite low, and it can be confirmed that the force applied to the electrode was more favorable to the adsorption/desorption reaction of ions.

8 is a graph showing the measurement results of the cyclic voltammetry according to the capacitive desalination apparatus according to Example 1 of the present invention.

Here, since oxidation and reduction occur at different potentials depending on materials and electrodes, qualitative analysis is possible from the characteristic potentials shown in the cyclic voltammogram (CV), and quantitative analysis is also possible from the current magnitude at this time. .

Cyclic voltammetry shows the electrochemical redox behavior of the analyte, and the capacitance is proportional to the cyclic voltammetry area, so the capacitance at the electrode can be confirmed.

That is, referring to FIG. 8 , it can be confirmed that when the redox reaction material is included in the electrolyte, the electric capacity is increased.

9 is a graph showing the results of observing the continuous desalination process using the redox reaction material according to Example 1 of the present invention.

It can be seen that the redox reactants in the electrolyte 30 continuously enable desalting of treated water, and it can be seen that desalting is possible not only of low concentration treated water (10 mM) but also seawater (600 mM). .

In addition, the redox reactant material can continuously perform a reduction reaction due to the - voltage applied to the first electrode 41 , and continuously perform the oxidation reaction due to the + voltage applied to the second electrode 42 . Therefore, continuous desalination is possible.

<Measurement results according to Example 2 of the present invention>

Hereinafter, with reference to FIGS. 10 to 12, the desalination performance of the capacitive desalination apparatus according to Example 2 of the present invention will be described by comparing it with a comparative example.

comparative example

In the comparative example, the number of the first electrode and the second electrode was set to one each.

Example 2

In Example 2, the number of the first electrodes 141 and the second electrodes 142 was set to 2 to 4, respectively.

10 is a graph showing a change in the concentration of treated water according to a change in the number of pairs of electrodes 141a to 141d and 142a to 142d in the capacitive desalination apparatus according to Example 2 of the present invention.

Referring to FIG. 10 , it can be seen that as the number of pairs of electrodes 141a to 141d and 142a to 142d increases, the concentration of the treated water 10 discharged through the central flow path 11 decreases. Therefore, it can be seen that as the number of electrodes 141 and 142 is increased, the desalination performance of the capacitive desalination device is improved.

11 is a graph showing the pH change of the treated water 10 according to the change in the number of pairs of electrodes 141a to 141d and 142a to 142d in the capacitive desalination apparatus according to Example 2 of the present invention.

Referring to FIG. 11 , the treated water 10 exhibited weak acidity as a whole, but even if the number of pairs of electrodes 141a to 141d and 142a to 142d increased, the range of change in pH was about ±0.3, indicating that the deviation was quite small. can Accordingly, it can be seen that charge efficiency is high and side reactions are small even when the number of pairs of electrodes 141a to 141d and 142a to 142d is increased.

12 shows the desalination amount (SAC), the desalination amount per electrode weight and the charge efficiency according to the change in the number of pairs of electrodes 141a to 141d and 142a to 142d in the capacitive desalination device according to Example 2 of the present invention; It is a graph.

Salt adsorption capacity (SAC) represents the amount of desalination, charge efficiency represents electrical energy efficiency as charge efficiency, and specific SAC represents the amount of desalination per electrode weight.

Referring to FIG. 12 , as the number of pairs of electrodes 141a to 141d and 142a to 142d increases, a total salt adsorption capacity (SAC) increases. However, the desalination amount per electrode weight (Specific SAC) appears to decrease.

That is, considering the increase in the manufacturing cost of the desalting device due to the increase in the number of pairs of electrodes 141a to 141d, 142a to 142d, it is preferable to appropriately control the number of electrodes used in the desalting device of the present invention, and the electrode ( 141, 142) the number of pairs is most preferably from 2 to 10 pairs.

However, depending on the embodiment, it is also possible to provide 11 or more pairs.

In this case, when the first electrode and the second electrode are not provided in the same number, the number of each electrode is preferably 2 to 10.

However, depending on the embodiment, it is also possible to provide 11 or more.

On the other hand, in the case of charge efficiency, it can be seen that even if the number of pairs of electrodes 141a to 141d and 142a to 142d is increased, charge efficiency does not decrease and high efficiency is maintained. Through this, it is thought that the efficiency will be maintained even if the number of electrode pairs is increased, and more desalination is possible per hour.

The present invention described above is not limited by the above-described embodiments and the accompanying drawings, and it is common in the technical field to which the present invention pertains that various substitutions, modifications and changes are possible within the scope without departing from the technical spirit of the present invention. It will be clear to those who have the knowledge of

10: treated water 11: central flow path
21: cation exchange membrane 22: anion exchange membrane
30: electrolyte 31: first euro
32: second flow passage 41: first electrode
42: second electrode 43: current collector
141 a, b, c, d: first electrode 142 a, b, c, d: second electrode

Claims (5)

a cation exchange membrane and an anion exchange membrane facing each other;
a plurality of first electrodes disposed on one side of the cation exchange membrane;
a plurality of second electrodes disposed on the other side of the anion exchange membrane; and
Capacitive desalination apparatus comprising a; flow path disposed between the cation exchange membrane and the anion exchange membrane.
The method of claim 1,
The number of the plurality of first electrodes and the number of the plurality of second electrodes is the same.
The method of claim 1,
The number of the plurality of first electrodes and the plurality of second electrodes is 2 to 10, respectively.
The method of claim 1,
The plurality of first electrodes and the plurality of second electrodes are in contact with the electrolytic solution.
5. The method of claim 4,
The electrolytic solution in contact with the plurality of first electrodes and the electrolyte in contact with the plurality of second electrodes flow with each other.

Images