Seawater desalination system and seawater desalination method

Abstract

To provide a seawater desalination system and a seawater desalination method.SOLUTION: A seawater desalination system 1000 includes a seawater desalination apparatus 70 assembled with, as one unit, a first pretreatment apparatus 1001, a second pretreatment apparatus 1002 provided in a rear flow of the first pretreatment apparatus 1001, a first ion separation apparatus 10A that penetrates cations in the seawater and blocks anions, and a second ion separation apparatus 10B that is provided in the subsequent stage side of the first ion separation apparatus 10A, penetrates anions in the penetration liquid with cations having been penetrated and blocks cations, wherein seawater with a salinity concentration of, e.g., 3.5%, is converted to a salinity concentration of 0.05% to be usable as drinking water.SELECTED DRAWING: Figure 23

Description

[Technical Field]

[0001] The present invention relates to a seawater desalination system and a seawater desalination method. [Background technology]

[0002] BACKGROUND ART Conventionally, the technology disclosed in Patent Document 1 has been proposed as an ion separation device for separating cations and anions in a solution (electrolyte).

[0003] FIG. 16 is a schematic diagram of a prior art electrolyzed water generating device. In the technology of Patent Document 1, oxidized water and reduced water that constitute electrolyzed water are produced using a three-chamber electrolyzed water production device as shown in Fig. 16. This electrolyzed water production device has an intermediate chamber 1 through which various raw waters such as pure water and tap water and supporting electrolytes such as sodium chloride (NaCl) or potassium chloride (KCl) dissolved in the raw water circulate and flow in and out, and a cation exchange membrane 4 and a cathode 5 are disposed as a partition between the intermediate chamber 1, and cations (sodium ions (NaCl) in Fig. 16) of the supporting electrolytes are separated. + 16)) dissolves in the cathode chamber 2, and an anion exchange membrane 6 and an anode 7 are disposed between the cathode chamber 2 and the intermediate chamber 1 as partitions, and an anion exchange membrane 6 and an anode 7 dissolve the anions (chlorine ions in FIG. 16) of the supporting electrolyte in the anode chamber 3.

[0004] Using this electrolyzed water generator, raw water with a supporting electrolyte dissolved therein is circulated in the intermediate chamber 1 to perform electrolysis, and the raw water is then fed into the cathode chamber 2 and the anode chamber 3, producing reduced water 8 from the cathode chamber 2 and oxidized water 9 containing chloride ions from the anode chamber 3. In this process, the physical properties of the reduced water 8 and oxidized water 9 are controlled to produce them, and electrolyzed water is obtained by mixing appropriate amounts of the reduced water 8 and the oxidized water 9. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-17405 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the electrolyzed water generator disclosed in Patent Document 1 uses ion exchange membranes to separate ions, but the ion exchange membranes (4, 6) are dedicated membranes that are permeable to cations or anions, respectively, and have the problem that they are almost impermeable to water. Therefore, as a fluid to receive the permeated ions, purified water (H2O) must be separately supplied to the cathode chamber 2 and the anode chamber 3. By supplying this water (purified water), reduced water 8 can be discharged from the cathode chamber 2, and oxidized water 9 containing chloride ions can be discharged from the anode chamber 3.

[0007] As described above, the electrolyzed water generating device using the ion exchange membrane of the prior art has a problem in that purified water must be separately supplied as carrier water to each of the cathode chamber 2 and the anode chamber 3 in order to obtain electrolyzed water.

[0008] Therefore, there is a strong demand for a technology that separates ions by permeating water from raw water without the need for a separate supply of water, such as an electrolytic water generator.

[0009] In view of the above problems, the present invention provides an ion separation device and an ion separation and concentration system that can separate ions by directly passing water from raw water (supply liquid) through the device, without the need to separately supply water as in, for example, conventional electrolytic water generation devices. [Means for solving the problem]

[0010] A seawater desalination system according to a first aspect of the present invention comprises: a first ion separation device that allows cations in seawater to pass through and blocks anions; a second ion separation device provided downstream of the first ion separation device, which allows anions in the permeate through which cations have permeated to pass and blocks cations; The seawater desalination plant is a single unit. ,and The seawater desalination apparatus comprises: a supply chamber for supplying seawater containing cations and anions; a cathode filter plate electrode disposed on both sides of the supply chamber and equipped with a diaphragm having pores for separating cations; a flat anode filter plate electrode provided with a diaphragm having pores for separating anions; a cation chamber into which the separated cations flow together with water as a cation liquid; The cathode filter plate electrode is a cathode first electrode on the supply chamber side; a cathode second electrode disposed on the cation chamber side across the diaphragm; a first power source electrically connected to the anode electrode and the cathode first electrode of the flat plate; a second power source electrically connected to the cathode first electrode and the cathode second electrode; The anode filter plate electrode is a first anode electrode on the supply chamber side; a second anode electrode disposed on the anion chamber side across the diaphragm; a third power source electrically connected to the cathode electrode and the anode first electrode of the flat plate; The anode electrode is characterized by comprising a fourth power source electrically connected to the anode first electrode and the anode second electrode.

[0012] No. 2 The seawater desalination system of the present invention First state Like Leave As a pretreatment device for the seawater desalination device, a first pretreatment device provided with a filter for removing impurities from seawater; a second pretreatment device provided with a hydrophilic polymer adsorbent that adsorbs biopolymers in the seawater from the first pretreatment device; The present invention is characterized by comprising:

[0013] No. 3 The seawater desalination method of the embodiment is a first ion separation device that allows cations in seawater to pass through and blocks anions; a second ion separation device provided downstream of the first ion separation device, which allows anions in the permeate through which cations have permeated to pass and blocks cations; The seawater desalination device is provided as a single unit. of the first aspect Using a seawater desalination system, The salinity of the seawater is reduced.

[0015] Fourth The seawater desalination method of the embodiment includes: a first ion separation device that allows cations in seawater to pass through and blocks anions; a second ion separation device provided downstream of the first ion separation device, which allows anions in the permeate through which cations have permeated to pass and blocks cations; The seawater desalination device is provided as a single unit. of the first aspect Using a seawater desalination system, The salinity of the seawater is reduced. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a schematic diagram of an ion separation device according to a first embodiment of the present invention. [Figure 2] FIG. 1 is a schematic diagram of an ion separation device according to a second embodiment of the present invention. [Figure 3A] FIG. 10 is a schematic diagram of an ion separation device according to a third embodiment of the present invention. [Figure 3B] FIG. 10 is a schematic diagram of another form of an ion separation device according to the third embodiment of the present invention. [Figure 4] FIG. 10 is a schematic diagram of an ion separation device according to a fourth embodiment of the present invention. [Figure 5] FIG. 10 is a schematic diagram of an ion separation device according to a fifth embodiment of the present invention. [Figure 6] FIG. 10 is a schematic diagram of an ion separation device according to a sixth embodiment of the present invention. [Figure 7A] 10 is a graph showing test results of the ion separation device of the sixth embodiment according to the present invention. [Figure 7B] 10 is a graph showing test results of the ion separation device of the sixth embodiment according to the present invention. [Figure 8] FIG. 10 is a schematic diagram of an ion separation device according to a seventh embodiment of the present invention. [Figure 9]FIG. 10 is a schematic diagram of an ion separation device according to an eighth embodiment of the present invention. [Figure 10A] FIG. 10 is a schematic diagram of an ion separation device of Test Example 1 of Embodiment 8 according to the present invention. [Figure 10B] FIG. 10 is a schematic diagram of an ion separation device of Test Example 2 of Embodiment 8 according to the present invention. [Figure 11A] FIG. 10 is a schematic diagram of an ion separation device according to a ninth embodiment of the present invention. [Figure 11B] FIG. 10 is a schematic diagram of an ion separation device according to a ninth embodiment of the present invention. [Figure 12] FIG. 13 is a schematic diagram of an ion separation device according to a tenth embodiment of the present invention. [Figure 13] FIG. 16 is a schematic diagram of another ion separation device according to embodiment 10 of the present invention. [Figure 14] FIG. 14 is a schematic diagram of an ion separation and concentration system equipped with an ion separation device according to an eleventh embodiment of the present invention. [Figure 15] FIG. 1 is a schematic diagram showing the results of confirming the state of ion separation in an ion separator using a BTB reagent. [Figure 16] 1 is a schematic diagram of a prior art electrolyzed water generating device. [Figure 17] FIG. 14 is a schematic diagram of another ion separation device according to embodiment 11 of the present invention. [Figure 18] FIG. 12 is a schematic diagram of an ion separation device according to a twelfth embodiment of the present invention. [Figure 19] FIG. 13 is a schematic diagram of an ion separation device according to a thirteenth embodiment of the present invention. [Figure 20] FIG. 14 is a schematic diagram of an ion separation device according to a fourteenth embodiment of the present invention. [Figure 21] FIG. 15 is a schematic diagram of an ion separation device according to a fifteenth embodiment of the present invention. [Figure 22] FIG. 16 is a schematic diagram of an ion separation and concentration system equipped with an ion separation device according to a sixteenth embodiment of the present invention. [Figure 23] FIG. 20 is a schematic diagram of a seawater desalination system including a seawater desalination apparatus according to a seventeenth embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0017] The present disclosure will be described in detail below with reference to the drawings. Note that the present disclosure is not limited to the following modes for carrying out the invention (hereinafter referred to as embodiments). Furthermore, the components in the following embodiments include those that can be easily imagined by a person skilled in the art, those that are substantially the same, and those that are within the so-called equivalent range. Furthermore, the components disclosed in the following embodiments can be combined as appropriate. In the embodiments of this specification, the same components are denoted by the same reference numerals throughout. Note that this embodiment is merely an example that embodies the configuration of the present invention, and various design changes can be made without departing from the scope of the claims.

[0018] [Embodiment 1] FIG. 1 is a schematic diagram of an ion separation device according to a first embodiment of the present invention. The ion separation device 10A according to the first embodiment is a device that separates cations dissociated in a solvent (polar solvent; for example, water) that is an electrolyte solution (hereinafter also referred to as a "feed liquid") 11. Examples of polar solvents include, but are not limited to, water, methanol, ethanol, and propanol. Here, the electrolyte solution (electrolyte solution or electrolyzed water) that is the supply liquid is a general term for a liquid in which an electrolyte, which is a substance that dissociates (ionizes) into ions and exhibits electrical conductivity, is dissolved.

[0019] Ion dissociation is a general process by which molecules (or ionic compounds such as salts and complexes) separate or split into smaller particles such as atoms, ions, and radicals, usually reversibly. The ionic crystal lattice breaks down when dissolved in water, and dissociation refers to the separation of ions that occurs when a solid ionic compound dissolves. Taking the formula unit of sodium chloride (NaCl) as an example, sodium chloride (NaCl) dissociates in water into one sodium ion (Na ion; cation (positive) ion) and one chloride ion (Cl ion; anion (negative) ion). In other words, salt (sodium chloride) that dissolves in water (HO) dissociates into its ions and is an electrolyte. In the electrolyte solution, sodium chloride (NaCl) is completely dissociated into water and becomes a cation, sodium ion (Na + ) and the anion chloride ion (Cl - ) and exists in an ionic state.

[0020] In this embodiment, sodium chloride (NaCl) is used as an example for explanation, but the present invention is not limited to this. As shown in FIG. 1, the ion separation device 10A of the first embodiment separates cations (Na + ) and anions (Cl - Electrolyte solution supply chambers (hereinafter referred to as "supply chambers") 12 supply an electrolyte solution (NaCl+H2O: hereinafter referred to as "supply solution") 11 containing cations (Na + ) a cathode filter plate electrode 14 equipped with a diaphragm (filter material) 13 for separating the separated cations (Na + and a cation chamber 17 into which the alkaline solution 16 flows together with water as a cation solution (hereinafter also referred to as "alkaline solution"). Here, the cathode filter plate electrode 14 is composed of a cathode first electrode 14A and a cathode second electrode 14B, and further, a diaphragm (filter plate) 13, which is an insulator having pores 13a, is sandwiched between the cathode first electrode 14A and the cathode second electrode 14B. Here, the diaphragm 13 may be made of, for example, cellulose, but the present invention is not limited to this.

[0021] The ion separation device 10A further includes a first power supply 41 electrically connected to the flat anode electrode 15 and the cathode first electrode 14A, and a second power supply 42 electrically connected to the cathode first electrode 14A and the cathode second electrode 14B. Here, the electrode configuration is such that the cathode second electrode 14B is at a first potential (V1), the cathode first electrode 14A is at a second potential (V2), and the flat anode electrode 15 is at a third potential (V3).

[0022] In this embodiment, the first power supply 41 and the second power supply 42 are set so that V1=-20V, V2=-15V, and V3=+15V. The potentials supplied from the first power source 41 and the second power source 42 are set to V3>V2>V1, and the absolute value of the potential of the cathode electrode increases as it moves away from the supply chamber 12 (|V1|>|V2|).

[0023] The electrode configuration is not limited to the configuration shown in FIG. 1. Alternatively, the cathode first electrode 14A may be earthed, the cathode first electrode 14A may be used as a reference electrode, the potential (V2) of the cathode first electrode 14A may be set to 0 V, the potential (V1) of the cathode second electrode 14B may be set to -10 V, and the potential (V3) of the flat anode electrode 15 may be set to +10 V, and the absolute value of the voltages may be changed while the potential difference between them remains unchanged.

[0024] Here, a cathode electric field Ec is generated between the cathode first electrode 14A and the cathode second electrode 14B. The cathode electric field Ec is generated by the negatively charged ions (Cl - ) from the supply chamber 12 to the cation chamber 17.

[0025] The cathode electric field Ec generated between the cathode first electrode 14A and the cathode second electrode 14B is a positive ion (Na + ) and positively charged water molecules from the supply chamber 12 toward the cation chamber 17. + ) and positively charged water molecules are drawn toward the cation chamber 17, generating an electroosmotic flow (see arrows F1 and F2 in FIG. 1). As a result, the water in the supply chamber 12 moves faster than when it moves to the cation chamber 17 simply under the filtration pressure of a pump or the like. Therefore, the amount of water moving from the supply chamber 12 to the cation chamber 17 per unit time increases.

[0026] The cation liquid 16 that has moved to the cation chamber 17 is then discharged to the outside from an outlet (not shown) of the cation chamber 17 due to filtration pressure. First supply / discharge liquid 11A from which cations have been separated in supply chamber 12 has a reduced cation concentration, and is discharged to the outside from an outlet (not shown) of supply chamber 12 due to filtration pressure.

[0027] Here, the filtration pressure by the supply pump (not shown) is preferably set so that the pressure (gauge pressure) in the supply chamber 12, which is an enclosed space, is slightly higher than atmospheric pressure, for example, 0.005 MPa or more and 0.5 MPa or less, preferably 0.02 MPa or more and 0.1 MPa or less.

[0028] Here, the cathode filter plate electrodes 14 (cathode first electrode 14A, cathode second electrode 14B) are provided with a plurality of holes 14a penetrating in the left-right direction in the figure. Water in the supply liquid 11 moves through the holes 14a of the electrodes 14.

[0029] Additionally, a galvanic corrosion prevention layer (not shown) is provided on the surfaces of the cathode filter plate electrode 14 (cathode first electrode 14A, cathode second electrode 14B) and the flat anode electrode 15. Examples of the galvanic corrosion prevention layer include an insulating coating layer and a conductive precious metal layer. Examples of materials for the galvanic corrosion prevention layer include, but are not limited to, titanium, aluminum, magnesium, and tantalum. Examples of materials for the conductive precious metal layer include, but are not limited to, platinum, gold, and palladium. In the case of an insulating coating layer, the thickness of the galvanic corrosion prevention layer is preferably, for example, about 5 μm to 30 μm, more preferably about 5 μm to 10 μm. Furthermore, the thickness of the conductive precious metal layer, such as platinum, gold, or palladium, is preferably, for example, about 0.5 μm to 10 μm, more preferably about 1 μm to 5 μm. This galvanic corrosion prevention layer inhibits corrosion of the surfaces of the cathode filter plate electrode 14 and the flat anode electrode 15. Furthermore, the cathode filter plate electrode 14 and the flat anode electrode 15 have an insulating coating layer and are therefore not in contact with the liquid that constitutes the feed liquid 11. As a result, even if a potential is applied to the cathode filter plate electrode 14 and the flat anode electrode 15, electrolysis is unlikely to occur between the liquid and the surfaces of the cathode filter plate electrode 14 and the flat anode electrode 15.

[0030] Cathode first electrode 14A faces flat-plate anode electrode 15 across supply chamber 12. Distance D1 between cathode first electrode 14A and flat-plate anode first electrode 15 is, for example, 0.1 mm or more and 100 mm or less, more preferably 0.1 mm or more and 40 mm or less.

[0031] The distance D2 between the first cathode electrode 14A and the second cathode electrode 14B is not particularly limited, but is, for example, 0.1 mm to 20 mm, more preferably 0.1 mm to 2 mm. Note that the smaller the distance D2 between the first cathode electrode 14A and the second cathode electrode 14B, the stronger the strength of the cathode electric field Ec generated between the first cathode electrode 14A and the second cathode electrode 14B.

[0032] Examples of diaphragm 13 include cellulose such as filter paper (membrane) and nanofiber, but the present invention is not limited to these. Taking filter paper as an example, the pore size is approximately 1 micron (pore diameter 1000 times 1 nanometer). Therefore, since water molecules are sub-nanometers, water can easily pass through diaphragm 13. As a result, the pump that sends supply liquid 11 into supply chamber 12 allows water to freely pass through diaphragm 13.

[0033] On the other hand, negative ions of chloride ions (Cl - ) approaching, the negative electrode and the negative ions repel each other due to the Coulomb repulsion, and therefore the negative ions cannot pass through the cathode first electrode 14A. Conversely, when positive ions (Na + ) approaches, the positive electrode and the positive ions repel each other due to Coulomb's repulsive force.

[0034] As mentioned above, filter paper can be used as the diaphragm 13, but it is more preferable to use a diaphragm having a dielectric effect. The diaphragm having a dielectric effect is made of an insulating material, and for example, a nonwoven fabric using fibers such as PP (polypropylene), PE (polyethylene), NY (nylon), or cellulose may be used. Here, by placing the diaphragm 13 having a dielectric effect between the first cathode electrode 14A and the second cathode electrode 14B, the strength of the cathode electric field Ec acting between the first cathode electrode 14A and the second cathode electrode 14B increases. The diameter of the pores 13a is preferably, for example, 0.2 mm or less. The diaphragm 13 disposed between the cathode first electrode 14A and the cathode second electrode 14B may or may not be in contact with each other. Here, the cathode filter plate electrode 14 equipped with this diaphragm 13 functions as an "ion separation membrane."

[0035] Next, an example of separating cations by supplying a sodium chloride solution as the supply liquid 11 into the supply chamber 12 will be described with reference to FIG.

[0036] As described above, the ion state in the supply chamber 12 is positive ions (sodium ions: Na + ) and anions (chlorine ions: Cl - ) and dissociated into A negative cathode first electrode 14A disposed in the supply chamber 12 is charged with a positive ion, sodium ion (Na + ) is attracted to the positive ion, sodium ion (Na + ) is drawn in, and as a result, water (H2O) also passes through, while sodium ions (Na + ) is transparent.

[0037] In contrast, chloride ions (Cl - ) is an anion, and is blocked by the cathode first electrode 14A on the cathode side, and cannot pass through the cathode first electrode 14A. - ) bounces back. - As a result, the first supply / discharge liquid 11A discharged from the supply chamber 12 contains cations (Na + ) decreases, and chloride ions (Cl - ) is concentrated.

[0038] In the present invention, the cation (Na + ), water also permeates through the diaphragm 13 that constitutes the cathode filter plate electrode 14. As a result, the permeated water contains cations (Na + ) and does not require the separate supply of purified water or other water. The cation exchange membranes and anion exchange membranes of the prior art are only able to selectively separate ions, allowing little or no water to pass through, and therefore require the separate supply of purified water or other water as carrier water.

[0039] As a result, according to the ion separation device 10A, the cation chamber 17 contains cation Na + A cation liquid (alkaline liquid) 16 in which the cations have been transferred can be obtained.

[0040] The above-described cathode filter plate electrode 14 may be configured as an integrated member including the cathode first electrode 14A, the cathode second electrode 14B, and the diaphragm 13, or the diaphragm 13 may be configured as a separate member.

[0041] [Embodiment 2] FIG. 2 is a schematic diagram of an ion separation device according to the second embodiment. The same components as those in the first embodiment are denoted by the same reference numerals and the description thereof will be omitted. In this embodiment, sodium chloride (NaCl) is also used as an example, but the present invention is not limited to this. As shown in FIG. 2, the ion separation device 10B of this embodiment is a device that separates anions dissociated in a solvent (polar solvent; for example, water).

[0042] As shown in FIG. 2, the ion separation device 10B separates cations (Na + ) and anions (Cl - A supply chamber 12 supplies a supply solution 11 containing anions (Cl), and two supply chambers 12 are disposed on both sides of the supply chamber 12. -An anode filter plate electrode 24 provided with a diaphragm 13 for separating - ), and a cathode chamber 27 into which the separated anions (Cl

[0043] Here, the anode filter plate electrode 24 is composed of an anode first electrode 24A and an anode second electrode 24B, and further, a diaphragm 13 which is an insulator having pores is sandwiched between the anode first electrode 24A and the anode second electrode 24B. This diaphragm 13 is made of an insulating material, and for example, a non-woven fabric using fibers such as PP (polypropylene), PE (polyethylene), NY (nylon), and cellulose may be used.

[0044] The ion separation device 10B further has a third power source 43 electrically connected to the flat cathode electrode 25 and the anode first electrode 24A, and a fourth power source 44 electrically connected to the anode first electrode 24A and the anode electrode second electrode 24B.

[0045] Here, the electrode configuration is such that the anode second electrode 24B is at the first potential (V11), the anode first electrode 24A is at the second potential (V12), and the flat cathode electrode 25 is at the fourth potential (V4). In this embodiment, the third power source 43 and the fourth power source 44 are set so that V11 = +20V, V12 = +15V, and V4 = -15V. Note that the potentials supplied from the third power source 43 and the fourth power source 44 are set such that V4 < V12 < V11, and the absolute value of the potential of the anode electrode increases as it is separated from the supply chamber 12 (|V11| > |V12|).

[0046] An example of supplying a sodium chloride solution (NaCl + H2O) into the supply chamber 12 as the supply liquid 11 will be described. [[ID=**24**]]As described above, the ionic state in the supply chamber 12 is such that the cations (sodium ions: Na + ) and anions (chloride ions: Cl -) and an anion, chloride ion (Cl ). - ) is attracted to the negative ion, chloride ion (Cl - ) is drawn in, resulting in chloride ions passing through while water (H2O) also passes through.

[0047] In contrast, sodium ions (Na + ) is a positive ion, and is blocked by the anode first electrode 24A (in FIG. 2, sodium ions (Na + ) bounces back), and cannot pass through the anode first electrode 24A. + As a result, the second supply / discharge liquid 11B discharged from the supply chamber 12 contains chloride ions (Cl - ) decreases, and cations (Na + ) is concentrated.

[0048] The distance D3 between the first anode electrode 24A and the second anode electrode 24B is not particularly limited, but is, for example, 0.1 mm to 20 mm, more preferably 0.1 mm to 2 mm. Furthermore, the smaller the distance D3 between the first anode electrode 24A and the second anode electrode 24B, the stronger the anode electric field Ea generated between the first anode electrode 24A and the second anode electrode 24B.

[0049] The holes 24a in the anode first electrode 24A and the anode second electrode 24B communicate with the supply chamber 12 and the anion chamber 27. The diameters of the holes 24a in the anode first electrode 24A and the anode second electrode 24B are, for example, 0.1 μm or more and 5000 μm or less, and more preferably 100 μm or more and 1000 μm or less. The diameters of the holes 24a in the anode first electrode 24A and the anode second electrode 24B do not have to be the same.

[0050] In the present invention, as described in the first embodiment, anions (Cl - ) and water permeates. As a result, the permeated water contains anions (Cl -) and does not require the separate supply of purified water. As a result, the anions (Cl - ) There is no need to separately supply purified water or other water as carrier water. The cation exchange membranes and anion exchange membranes according to the prior art are only capable of selectively permeating and separating ions, and are almost or only slightly permeable to water.

[0051] As a result, the anion chamber 27 is filled with anions such as Cl - An anion liquid (acidic liquid) 26 in which the anions have been transferred can be obtained. In addition, a diaphragm 13 having a dielectric effect may be placed between the anode first electrode 24A and the anode second electrode 24B to increase the strength of the anode electric field Ea acting between the anode first electrode 24A and the anode second electrode 24B. The above-described anode filter plate electrode 24 may be configured as an integrated member including the first anode electrode 24A, the second anode electrode 24B, and the diaphragm 23, or the diaphragm 23 may be configured as a separate member.

[0052] [Embodiment 3] Fig. 3A is a schematic diagram of an ion separation device of embodiment 3. Fig. 3B is a schematic diagram of an ion separation device of another form of embodiment 3. Note that the same components as those in embodiments 1 and 2 are denoted by the same reference numerals and descriptions thereof will be omitted. As shown in FIG. 3A, the ion separation device 10C-1 of this embodiment is a combination of the ion separation device 10A of embodiment 1 and the ion separation device 10B of embodiment 2, and separates cations and anions from a supply liquid containing both ions (cations and anions) to obtain an alkaline liquid 16 and an acidic liquid 26. As shown in FIG. 3A, the ion separation device 10C-1 of the third embodiment includes an electrolyte solution supply chamber (hereinafter referred to as "supply chamber") 12 that supplies a supply liquid 11 of an electrolyte solution (e.g., NaCl solution) containing cations and anions, and two electrolyte solution supply chambers (hereinafter referred to as "supply chambers") 12 that are arranged on both sides of the supply chamber 12 and supply cations (Na + ) and a cathode filter plate electrode 14 equipped with a diaphragm (filter paper) 13 for separating anions (Cl -) and a diaphragm 13 for separating the separated cations (Na + ) flows into the cation chamber 17 together with water as a cation solution (alkaline solution) 16, and the separated anions (Cl - and an anion chamber 27 into which the acidic solution 26 flows together with water as an anion solution (acidic solution).

[0053] The ion separation device 10C-1 also has a first power supply 41 electrically connected to the cathode first electrode 14A and the anode first electrode 24A, a second power supply 42 electrically connected to the cathode first electrode 14A and the cathode second electrode 14B, and a third power supply 43 electrically connected to the anode first electrode 24A and the anode second electrode 24B. In this embodiment, the diaphragm 13 in the cathode filter plate electrode 14 is made of an insulating material, and may be, for example, a nonwoven fabric made of fibers such as PP (polypropylene), PE (polyethylene), NY (nylon), cellulose, etc.

[0054] Next, an example of separating cations and anions by supplying a sodium chloride solution as supply liquid 11 into supply chamber 12 will be described with reference to FIG. 3A.

[0055] As described above, the ion state in the supply chamber 12 is positive ions (sodium ions: Na + ) and anions (chlorine ions: Cl - ) and dissociated into A negative cathode first electrode 14A disposed in the supply chamber 12 is charged with a positive ion, sodium ion (Na + ) is attracted to the positive ion, sodium ion (Na + ) is drawn in, and as a result, water (H2O) also passes through, while sodium ions (Na + ) is transparent.

[0056] In contrast, chloride ions (Cl - ) are anions, and are therefore blocked by the negative cathode first electrode 14A and cannot pass through the cathode first electrode 14A.

[0057] In the present invention, the cation (Na + ) permeates through the diaphragm 13 that constitutes the cathode filter plate electrode 14. As a result, the cations (Na + ) There is no need to separately supply water such as purified water to the cation chamber 17 as carrier water.

[0058] In addition, in the supply chamber 12, an anode filter plate electrode (anode first electrode 24A, anode second electrode 24B) 24 disposed opposite the cathode filter plate electrode 14 is supplied with an anion, chlorine ion (Cl - ) is drawn in. The anion, chloride ion (Cl - ) is drawn in, resulting in chloride ions passing through while water (H2O) also passes through.

[0059] In contrast, sodium ions (Na + ) is a positive ion, and is therefore blocked by the anode first electrode 24A and cannot pass through the anode first electrode 24A.

[0060] As a result, sodium ions (Na + ) is concentrated in the anion chamber 27. - ) is concentrated. As a result, the third supply / discharge liquid 11C discharged from the supply chamber 12 contains sodium ions (Na + ) decreases, and chloride ions (Cl - ) also decreases.

[0061] Here, anions (Cl - ) permeates, and water also permeates. As a result, the permeated water contains anions (Cl - ) and therefore there is no need to supply purified water or other water separately.

[0062] In contrast to the ion exchange membranes used in conventional ion separation technology, which are barely permeable to water and only function to separate ions, when producing alkaline solution 16 and acidic solution 26 using the ion separation device 10C of the present embodiment, there is no need to supply purified water as carrier water.

[0063] As described above, according to the ion separation device 10C-1 of this embodiment, the ion state (sodium ion (Na + ) and chloride ions (Cl - ) mixed state: pH = 7.0), sodium ions (Na + ) permeates and sodium ions (Na + At the same time, chloride ions (Cl - ) permeates and chloride ions (Cl) enter the anion chamber 27. - ) is concentrated.

[0064] The separation of cations and anions in this ion separator 10C-1 was confirmed using pH and BTB reagent. Here, a 0.05% aqueous solution of sodium chloride (NaCl) was used as the feed solution 11, and the pH was adjusted with a carbonate buffer to a pH of 7.0. At the same time, the pH status in each chamber was visualized by coloring using BTB (bromothymol blue; BTB) reagent.

[0065] As a result of this confirmation, it was found that the ion state (sodium ion (Na + ) and chloride ions (Cl - ) (a mixed state with alkaline solution 16: pH = 7.0) was subjected to ion separation, and the pH of the alkaline solution 16 discharged from the cation chamber 17 became 11.8, and the pH of the acidic solution 26 discharged from the anion chamber 27 became 2.4.

[0066] Furthermore, when tested with the BTB reagent, the feed solution 11 (pH = 7.0) supplied to the feed chamber 12 was green, but the alkaline solution 16 (pH = 11.8) in the cation chamber 17 turned blue, and the acidic solution 26 (pH = 2.4) in the anion chamber 27 turned yellow. Furthermore, in a flame color reaction test using a copper wire, the alkaline solution 16 turned orange due to sodium ions, and the acidic solution 26 turned green due to copper chloride (CuCl2). It was also confirmed that ion separation was achieved reliably in each flame color reaction test.

[0067] As a result, the circulating liquid, which is the third supply / discharge liquid 11C discharged from the supply chamber 12, contains sodium ions (Na + ) decreases, and chloride ions (Cl - ) also decreases (pH = 4.5).

[0068] A schematic diagram of the results confirmed using this BTB reagent is shown in FIG. Figure 15 is a schematic diagram showing the results of confirming the state of ion separation in the ion separator using a BTB reagent. In Figure 15, "A" in the upper row shows the color tone of the BTB reagent. "B" in the middle row shows the state of color tone change in the supply chamber 12, which has a cation chamber 17 and an anion chamber 27 on both sides. "C" in the lower row shows the state of color tone of the supply liquid 11.

[0069] According to this embodiment, cations and anions are separated at the cathode filter plate electrode 14 and the anode filter plate electrode 24 by applying a predetermined voltage, and the separated water also permeates the cathode filter plate electrode 14 and the anode filter plate electrode 24 as ion carrier water, so there is no need to separately add water (purified water, etc.) as ion carrier water as in the conventional method.

[0070] During ion separation, a voltage is applied to the electrodes (cathode filter plate electrode 14, anode filter plate electrode 24), which generates heat and heats the feed solution 11. Furthermore, electrolysis of water generates gas around the electrodes (hydrogen gas in the cation chamber 17, and chlorine gas and oxygen gas in the anion chamber 27). The gas moves to the upper part of the sealed space of the feed chamber 12 due to buoyancy. Therefore, gas venting means such as a gas vent valve is appropriately installed in the feed chamber 12, the cation chamber 17, the anion chamber 27, or the discharge line.

[0071] 3B, the ion separation device 10C-2 has piezoelectric vibrators (vibrating members) 80, which are piezoelectric members, installed in the supply chamber 12, the cation chamber 17, and the anion chamber 27. By installing these piezoelectric vibrators (vibrating members) 80, adhesion of particles suspended in the supply liquid 11 can be prevented even when such particles are present. This allows the voltage applied to the first anode electrode 24A and the second anode electrode 24B to be lower overall than when the piezoelectric vibrators (vibrating members) 80 are not installed.

[0072] That is, in order to improve particle separation, for example, if 20 V is applied to the anode first electrode 24A and the anode second electrode 24B, by installing a piezoelectric vibrator (vibration member) 80, the applied voltage can be halved to 5 V to the anode first electrode 24A and 10 V to the anode second electrode 24B, thereby reducing the overall applied voltage. As a result, the power consumption of the ion separation device can be significantly reduced, and electrolysis and heat generation can also be suppressed. In particular, when separating heat-sensitive particles or biological matter as the separation target, the heat reduction effect is significant. Note that it is sufficient that the piezoelectric vibrator (vibration member) 80 is provided in at least one location.

[0073] [Embodiment 4] FIG. 4 is a schematic diagram of an ion separation device according to the fourth embodiment. The same components as those in the first to third embodiments are denoted by the same reference numerals and the description thereof will be omitted. The ion separator 10D of the fourth embodiment has two sets of electrodes (cathode filter plate electrodes, anode filter plate electrodes) (14-1, 14-2, 24-1, 24-2), and two sets of cation chambers 17 and anion chambers 27 (17-1, 17-2, 27-1, 27-2).

[0074] The potentials of cathode electrodes 14A-1, 14B-1, 14A-2, and 14B-2 are set to −15 V, −20 V, −30 V, and −35 V, respectively, by a power supply (not shown). The potentials of anode electrodes 24A-1, 24B-1, 24A-2, and 24B-2 are set to +15 V, +20 V, +30 V, and +35 V, respectively. The absolute values ​​of the potentials of the cathode electrodes (14A-1, 14B-1, 14A-2, 14B-2) and anode electrodes (24A-1, 24B-1, 24A-2, 24B-2) increase with increasing distance from supply chamber 12.

[0075] As shown in FIG. 4, the ion separation device 10D of the fourth embodiment includes a supply chamber 12 for supplying a supply liquid 11 of an electrolyte solution (for example, a NaCl solution: pH 7.0) containing cations and anions, cathode filter plate electrodes 14-1 and 14-2 provided on both sides of the supply chamber 12 and equipped with a diaphragm (filter material) 13 for separating cations, anode filter plate electrodes 24-1 and 24-2 provided with a diaphragm (filter material) 13 for separating anions, and a filter plate electrode 24-2 provided with a diaphragm (filter material) 13 for separating the separated cations (Na + ) flows into the cation chamber 17 (17-1, 17-2) together with water as a cation solution (alkaline solution) 16, and the separated anions (Cl - )) flows into the anion chamber 27 (27-1, 27-2) together with water as an anion liquid (acid liquid) 26.

[0076] In this embodiment, the second cation chamber 17-2 and the second anion chamber 27-2 also serve as discharge chambers for discharging the alkaline solution 16 and the acidic solution 26, respectively, and are provided with discharge holes 17a and 27a, respectively. The supply chamber 12 also has a supply hole 12a and a discharge hole 12c. The discharged liquid is a circulating liquid.

[0077] As a result, the alkaline solution 16 with an increased cation concentration and an increased pH is discharged from the discharge hole 17a of the second cation chamber 17-2. On the other hand, the acidic solution 26 with an increased anion concentration and a decreased pH is discharged from the discharge hole 27a of the second anion chamber 27-2.

[0078] In this embodiment, the ion separation device 10D has two sets of electrodes (cathode filter plate electrode, anode filter plate electrode) (14-1, 14-2, 24-1, 24-2), and two sets of cation chambers 17 and anion chambers 27 (17-1, 17-2, 27-1, 27-2), thereby increasing the ion separation efficiency. In addition, in the present invention, the installation of each cation chamber 17 and anion chamber 27 is not limited to two sets, but may be three sets (17-1, 17-2, 17-3, 27-1, 27-2, 27-3) or four sets (17-1, 17-2, 17-3, 17-4, 27-1, 27-2, 27-3, 27-4) as needed.

[0079] The ion separation devices 10A to 10D described above can be applied to any technical field where ions in an electrolyte are separated, such as in seawater desalination (desalination) devices, in addition to replacing ion exchange membranes and ion exchange resins.

[0080] [Embodiment 5] FIG. 5 is a schematic diagram of an ion separation device according to a fifth embodiment. As shown in FIG. 5, the ion separation device 10E of the fifth embodiment includes the ion separation device 10A of the first embodiment, a supply tank 55 that supplies an electrolyte solution (supply liquid 11) containing cations, a supply line L1 that supplies the supply liquid 11 from the supply tank 55 to the supply chamber 12 via a supply pump P, a circulation line L2 that circulates the first supply / discharge liquid 11A from the supply chamber 12 to the supply tank 55, and an alkaline line L3 that discharges the alkaline liquid 16 from the cation chamber 17 to the alkaline tank 56.

[0081] The ion separation device 10E of this embodiment 5 continuously supplies the supply liquid 11 from the supply tank 55 into the supply chamber 12, thereby separating cations into the cation chamber 17, and by circulating the liquid within the supply chamber 12, it is possible to continuously obtain a cation liquid (alkaline liquid) 16 in the alkaline tank 56. Moreover, by installing the ion separation device 10B of the second embodiment in place of the ion separation device 10A, an anion liquid (acid liquid) can be obtained.

[0082] [Embodiment 6] FIG. 6 is a schematic diagram of an ion separation device according to a sixth embodiment. As shown in FIG. 6 , the ion separation device 10F of the sixth embodiment includes the ion separation device 10D of the fourth embodiment, a supply tank 55 that supplies an electrolyte solution (supply liquid 11) containing cations, a supply line L1 that supplies the supply liquid 11 from the supply tank 55 to the supply chamber 12 via a supply pump P-1, a circulation tank 57 that temporarily stores the first supply / discharge liquid 11A from the supply chamber 12 to circulate it to the supply chamber 12, an alkali line L3 that discharges the alkaline solution 16 from the cation chamber 17 to the alkali tank 56 by the supply pump P-2, a supply line L4 that supplies the first supply / discharge liquid 11A from the supply chamber 12 to the circulation tank 57, and a supply line L5 that supplies the first supply / discharge liquid 11A from the anion chamber 27 to the circulation tank 57. and an acid line L5 that discharges the acid solution 26 via a supply pump P-3 into an acid solution tank 58. A pressure relief valve (not shown) is provided in the circulation line L4 to adjust the pressure (for example, to about 0.03 MPa).

[0083] By using the ion separation device 10F of this embodiment 6, cationic liquid (alkaline liquid) 16 can be continuously obtained in the alkaline tank 56, and anionic liquid (acidic liquid) 26 can be continuously obtained in the acidic liquid tank 58.

[0084] Here, the test results of ion separation performed using an ion separation device 10F of the sixth embodiment as shown in FIG. 6 and an aqueous solution of sodium nitrate (NaNO3) as the supply liquid 11 are shown in FIG. 7 (FIGS. 7A and 7B). The separation target was a 0.05% aqueous solution of NaNO3, and the pH was adjusted to 7.0 with a carbonate buffer. + / NO3 - The ion concentration was measured using an ion meter.

[0085] As shown in Figure 7A, the separation efficiency of the positive Na ion was 95.4% (20 min), 88.5% (40 min), and 83.1% (60 min). As shown in Figure 7B, the separation efficiency of the negative NO ion was 96.6% (20 min), 94.9% (40 min), and 94.3% (60 min). The results of FIGS. 7A and 7B reveal that the ion separation device of this embodiment can effectively separate cations and anions.

[0086] [Embodiment 7] 8 is a schematic diagram of an ion separation device according to embodiment 7. Note that the same components as those in the above-described embodiments are given the same reference numerals and their description will be omitted.

[0087] Although the ion separation devices 10A to 10F of the first to sixth embodiments have been described as techniques for separating cations or anions in an electrolyte solution, the ion separation device of the present invention is not limited to this.

[0088] The ion separator 10G of the seventh embodiment has the same configuration as the ion separator 10C of the third embodiment (see FIG. 3) described above, but the supply liquid supplied to the supply chamber 12 contains particles (Ptcl "●" in the figure). - The particle 50 is separated from the particle-containing supply liquid 51 containing the ions 50 as well as the particles 50. Since cations (e.g., Na ions) and anions (e.g., chloride ions) are separated in the same manner as described above, the ion separation device 10E of this embodiment will be described with a particular focus on the separation of particles 50.

[0089] As shown in FIG. 8, the supply chamber 12 of the ion separation device 10G is provided with an inlet 12a for introducing particle-containing supply liquid 51, a supply liquid inlet line 12b connected to the inlet 12a and equipped with a supply pump P, a third outlet 12c for discharging discharge liquid 51A from which particles 50, cations, and anions have been separated, and an outlet line 12d connected to the third outlet 12c.

[0090] The cation chamber 17 of the ion separation device 10G is provided with a first outlet 17a for discharging the cation liquid 16 and a first outlet line 17b connected to the first outlet 17a. The anion chamber 27 of the ion separation device 10G is provided with a second outlet 27a for discharging the concentrate 65 containing the anion liquid and a second outlet line 27b connected to the second outlet 27a.

[0091] Cathode first electrode 14A faces anode first electrode 24A across supply chamber 12. Distance D1 between cathode first electrode 14A and anode first electrode 24A is a distance that allows particles 50 in particle-containing supply liquid 51 to move toward anode first electrode 24A, and is, for example, 0.1 mm or more and 100 mm or less, more preferably 0.1 mm or more and 20 mm or less.

[0092] The pore diameter 13a of the diaphragm 13 is also large enough to allow the particles 50 in the particle-containing supply liquid 51 to move toward the first anode electrode 24A and the second anode electrode 24B.

[0093] In the method of operating the ion separation device 10G, first, the supply pump P is driven to supply the particle-mixed supply liquid 51 to the supply chamber 12. The supply pump P is continuously driven to continuously supply the particle-mixed supply liquid 51. The pressure by the supply pump P is set so that the pressure (gauge pressure) in the sealed space S of the supply chamber 12 is higher than atmospheric pressure, for example, 0.005 MPa or more and 0.5 MPa or less, preferably 0.02 MPa or more and 0.1 MPa or less.

[0094] The pressure downstream of the first discharge line 17b and the second discharge line 27b is adjusted to be approximately equal to atmospheric pressure by a pressure regulating valve (not shown). As a result, a pressure (hereinafter referred to as filtration pressure) from the first supply port 12a (supply chamber 12) toward the cation chamber 17 and the anion chamber 27 acts on the sealed space S.

[0095] A cathode first potential V1 supplied from the cathode first power supply 61 to the cathode first electrode 14A is set to -20 V. A cathode second potential V2 supplied from the cathode second power supply 62 to the cathode second electrode 14B is set to -30 V. In other words, the cathode power supplies to the cathode electrodes cathode potentials (V1, V2) of the same polarity as the polarity (negative) of the particles 50. Furthermore, the absolute value of the cathode potential supplied from the cathode power supply increases with increasing distance from the supply chamber 12 (|V2|>|V1|).

[0096] The anode first potential V11 supplied from the anode first power supply 63 to the anode first electrode 24A is set to +20 V. The anode second potential V12 supplied from the anode second power supply 64 to the anode second electrode 24B is set to +30 V. In other words, the anode power supply supplies to the anode electrodes anode potentials (V11, V12) of a polarity different from the polarity (negative) of the particles 50. Furthermore, the absolute value of the anode potential supplied from the anode power supply increases with increasing distance from the supply chamber 12 (|V12|>|V11|).

[0097] According to the above-described operating method, when particle-mixed supply liquid 51 is supplied to supply chamber 12, particles 50 contained in particle-mixed supply liquid 51 are subjected to a repulsive force from cathode first electrode 14A, which is charged with the same polarity (see arrow A1 in FIG. 8). Furthermore, particles 50 are subjected to an attractive force from anode first electrode 24A, which is charged with the opposite polarity (see arrow B1 in FIG. 8). As a result, particles 50 in supply chamber 12 move toward anode first electrode 24A.

[0098] Then, particle-mixed supply liquid 51 (particle-mixed supply liquid 51 with a high concentration of particles 50) near anode first electrode 24A passes through holes 24a of anode first electrode 24A and holes 24a of anode second electrode 24B due to filtration pressure, and particles 50 move to anion chamber 27 (see arrow F4 in FIG. 8). Furthermore, in the process of passing through anode first electrode 24A and anode second electrode 24B, the proportion of water in particle-mixed supply liquid 51 decreases and the proportion of particles 50 increases, resulting in a concentrate 65. Details will be described below.

[0099] As a result, the positively charged water molecules move slower than when they move to the anion chamber 27 simply due to filtration pressure. This reduces the amount of water passing between the first anode electrode 24A and the second anode electrode 24B per unit time. As a result, the proportion of water contained in the particle-mixed supply liquid 51 that has moved to the anion chamber 27 becomes smaller than that of the particle-mixed supply liquid 51 near the first anode electrode 24A.

[0100] Furthermore, the anode electric field Ea between the first anode electrode 24A and the second anode electrode 24B exerts an attractive force that draws the negatively charged particles 50 from the first anode electrode 24A toward the second anode electrode 24B (see arrow F4 in FIG. 8). That is, the particles 50 are subjected to an attractive force from the electric field when passing between the first anode electrode 24A and the second anode electrode 24B. This causes the particles 50 to move faster than they would if they were simply subjected to filtration pressure and moved to the anion chamber 27. As a result, the amount of particles 50 passing between the first anode electrode 24A and the second anode electrode 24B per unit time increases, and therefore the ratio of particles 50 per unit volume contained in the particle-mixed supply liquid 51 that has moved to the anion chamber 27 becomes higher than that of the particle-mixed supply liquid 51 in the vicinity of the first anode electrode 24A.

[0101] In this way, the particle-containing supply liquid 51 becomes concentrated with particles 50 as it passes between the first anode electrode 24A and the second anode electrode 24B, and turns into a concentrate 65 containing anionic liquid and concentrated particles. Then, this concentrate 65 passes through the second outlet 27a and is discharged from the second discharge line 27b due to filtration pressure.

[0102] Meanwhile, particle-mixed supply liquid 51 having a low concentration of particles 50 accumulates near cathode first electrode 14A in supply chamber 12. This particle-mixed supply liquid 51 passes through holes 14a in cathode first electrode 14A and holes 14a in cathode second electrode 14B due to filtration pressure, and moves to cation chamber 17 (see arrow F2 in FIG. 8).

[0103] Here, a cathode electric field Ec is generated between the cathode first electrode 14A and the cathode second electrode 14B. The cathode electric field Ec exerts a repulsive force that inhibits the movement of the negatively charged particles 50 from the supply chamber 12 to the cation chamber 17. Therefore, the particles 50 are inhibited from moving to the cation chamber 17.

[0104] Furthermore, the cathode electric field Ec generated between the cathode first electrode 14A and the cathode second electrode 14B exerts a force that draws positively charged water molecules from the supply chamber 12 toward the cation chamber 17. An electroosmotic flow occurs in which the positively charged water molecules are drawn toward the cation chamber 17 (see arrow F2 in FIG. 8). As a result, the water in the supply chamber 12 moves at a faster rate than when it moves to the cation chamber 17 simply due to filtration pressure. Therefore, the amount of water moving from the supply chamber 12 to the cation chamber 17 per unit time increases.

[0105] Then, the cation liquid 16, which is the water that has moved to the cation chamber 17 (the filtrate from which the particles 50 have been separated), is discharged from the first outlet 17a due to the filtration pressure.

[0106] As described above, most of the water contained in the particle-containing supply liquid 51 moves toward the cation chamber 17. In other words, the volume of water moving per unit time from the supply chamber 12 to the cation chamber 17 or the anion chamber 27 is larger in the cation chamber 17. Therefore, the flow rates discharged from the first outlet 17a and the second outlet 27a are set to, for example, 9:1 (e.g., 10-fold concentration) using the first valve 17c and the second valve 27c, and adjusted so that a large amount of water is discharged from the first outlet 17a. As a result, a large amount of water is continuously discharged as filtrate from the first outlet 17a. Furthermore, a concentrate 65 in which particles 50 are concentrated is continuously discharged from the second outlet 27a.

[0107] Here, in this embodiment, the flow rate is set to, for example, 9:1 (for example, 10 times concentrated), but by adjusting the flow rate of the metering pump, the flow rate can also be appropriately set to, for example, 2:1 (for example, 3 times concentrated).

[0108] Here, as described above, particle-mixed supply liquid 51 contains cations (Na ions) and anions (Cl ions), and therefore the cations and anions are separated, and alkaline solution 16 and acidic solution 26 are discharged from cation chamber 17 and anion chamber 27. At this time, particle-mixed supply liquid 51 contains particles 50, and therefore particle separation is also carried out at the same time.

[0109] [Embodiment 8] FIG. 9 is a schematic diagram of an ion separation device according to the eighth embodiment. The same components as those in the first to seventh embodiments are denoted by the same reference numerals and the description thereof will be omitted.

[0110] The ion separation device of the present invention can separate cations or anions in an electrolyte solution, and can also separate ions when charged particles are present in the electrolyte solution.

[0111] In this embodiment, a sodium hydroxide (NaOH) aqueous solution is used as the supply liquid, and the explanation will be given using an example of a particle-mixed supply liquid 51 in which particles (marked with "●" in the figure) 50 are mixed in this sodium hydroxide aqueous solution, but the present invention is not limited to this. As shown in FIG. 9, the ion separation device 10H of the eighth embodiment separates cations (Na + ) and anions (OH - ), a supply chamber 12 that supplies a particle-mixed supply solution 51 containing particles 50, and two supply chambers 12 that are disposed on both sides of the supply chamber 12 and supply positive ions (Na + ) a cathode filter plate electrode 14 equipped with a diaphragm (filter material) 13 for separating the separated cations (Na + and a cation chamber 17 into which the alkaline solution 16 flows together with water as a cation solution (hereinafter also referred to as "alkaline solution").

[0112] In addition, the ion separation device 10H of embodiment 8 further includes a supply tank 55 that supplies particle-mixed supply liquid 51 to the supply chamber 12, an alkaline tank 56 that receives alkaline liquid 16, a supply line L1 that supplies the particle-mixed supply liquid 51 from the supply tank 55 to the supply chamber 12 via a supply pump P, a circulation line L2 that circulates the discharge liquid 51B from the supply chamber 12 to the supply tank 55, and an alkaline line L3 that discharges alkaline liquid 16 from the cation chamber 17 to the alkaline tank 56. Here, the cathode filter plate electrode 14 is composed of a cathode first electrode 14A and a cathode second electrode 14B, each having pores 14a, and further, a diaphragm 13, which is an insulator having pores 13a, is sandwiched between the cathode first electrode 14A and the cathode second electrode 14B.

[0113] Next, using Figure 9, we used cations (Na + ) and anions (OH - ), negatively charged particles (●(Ptcl - An example will be described in which particle-containing supply liquid 51 containing cations 50 is supplied into supply chamber 12 to separate cations from particles 50.

[0114] As described above, the ion state in the supply chamber 12 is positive ions (sodium ions: Na + ) and anions (hydroxyl ions: OH - ) and dissociated into A negative cathode first electrode 14A disposed in the supply chamber 12 is charged with a positive ion, sodium ion (Na + ) is attracted to the positive ion, sodium ion (Na + ) is drawn in, and as a result, water (H2O) also passes through, while sodium ions (Na + ) is transparent.

[0115] In contrast, hydroxide ions (OH - ) and negatively charged particles (●(Ptcl - )) 50 are anions, and are blocked by the negative cathode first electrode 14A, and are unable to pass through the cathode first electrode 14A. FIG. 9 illustrates the behavior of the negatively charged particles 50 bouncing back within the supply chamber 12. Therefore, the negatively charged particles 50 are concentrated within the supply chamber 12. As a result, the discharge liquid 51B discharged from the supply chamber 12 contains cations (Na + ) decreases, and the negatively charged particles 50 become concentrated.

[0116] As a result, the cation chamber 17 is filled with Na + A cationic liquid (alkaline liquid as filtrate) 16 in which the negatively charged particles 50 have been moved can be obtained, and an effluent liquid 51B in which the negatively charged particles 50 have been concentrated can be obtained from the supply chamber 12 side.

[0117] As a result, according to this embodiment, the particles (●(Ptcl - )) 50 is a valuable material, the cations (e.g., Na) that are impurities contained in the valuable material + etc.) can be easily removed.

[0118] Here, conventionally, in order to remove cations (e.g., Na ions) present in an aqueous solution containing valuable substances, it has been necessary to use so-called diafiltration, in which a dilution operation and a separation operation are repeated multiple times using a large amount of water, which requires time and effort.

[0119] <Test Example 1> FIG. 10A is a schematic diagram of Test Example 1 of the ion separation device of the eighth embodiment. Next, using FIG. 10A, a cation (Na + ) and anions (OH - ), an example of a test will be described in which particle-mixed supply liquid 51 containing negatively charged particles 50 is supplied into supply chamber 12 to separate cations, anions, and particles 50. Colloidal silica (particle size: 100 nm) was used as particles 50.

[0120] As shown in FIG. 10A, the ion separator 10I of the first embodiment is the ion separator 10H shown in FIG. 9, further comprising a receiving tank 59 for receiving the supply / discharge liquid 51B from the supply chamber 12, and an alkali line L2 for discharging the liquid to the receiving tank 59. + is separated and Na + The discharged liquid (particles (●(Ptcl)) discharged from the supply chamber 12 with a reduced concentration - ))51B including ))50 is stored in receiving tank 59.

[0121] When the pH of particle-containing supply liquid 51 is set to 7.0, particles 50 are negatively charged and are therefore blocked by negative cathode first electrode 14A, preventing them from passing through cathode first electrode 14A. Therefore, in FIG. 10A, particles 50 are concentrated in supply chamber 12. As a result, discharge liquid 51B discharged from supply chamber 12 contains cations (Na + ) decreases and the particles 50 become concentrated. The results of this test are shown in Table 1.

[0122] [Table 1]

[0123] As shown in Table 1, when the supply time of the feed liquid was 0 minutes, TS (total evaporation residue; colloidal silica concentration, sodium concentration) was 1.006 wt%, pH was 7.0, and the Na ion concentration was 21 ppm. The properties of the discharged liquid 51B were measured, and after a supply time of 40 minutes, the TS (total evaporation residue; colloidal silica concentration, sodium concentration) was 2.277 wt%, the colloidal silica concentration ratio was 2.3 times, the pH was 4.3, the Na ion concentration was 12 ppm, and the Na ion separation efficiency was 42.9%. After a supply time of 60 minutes, the TS (total evaporation residue; colloidal silica concentration, sodium concentration) was 2.405 wt%, the colloidal silica concentration ratio was 2.4 times, the pH was 3.9, the Na ion concentration was 12 ppm, and the Na ion separation efficiency was 42.9%. After a supply time of 180 minutes, the TS (total evaporation residue; colloidal silica concentration, sodium concentration) was 2.405 wt%, the colloidal silica concentration ratio was 2.4 times, the pH was 3.9, the Na ion concentration was 12 ppm, and the Na ion separation efficiency was 42.9%. The thorium concentration was 2.274 wt%, the colloidal silica concentration ratio was 2.3 times, the pH was 3.6, the Na ion concentration was 10 ppm, and the Na ion separation efficiency was 52.4%.

[0124] Furthermore, when the properties of the cationic liquid 16 were measured, after a 40-minute supply time, the TS (total evaporation residue; colloidal silica concentration, sodium concentration) was 0.016 wt%, the colloidal silica concentration was 98.4 times, the pH was 9.1, the Na ion concentration was 29 ppm, and the Na ion concentration was 1.4%. After a 60-minute supply time, the TS (total evaporation residue; colloidal silica concentration, sodium concentration) was 0.017 wt%, the colloidal silica concentration was 98.3 times, the pH was 9.2, the Na ion concentration was 31 ppm, and the Na ion concentration was 1.5%. After a 180-minute supply time, the TS (total evaporation residue; colloidal silica concentration, sodium concentration) was 0.027 wt%, the colloidal silica concentration was 97.4 times, the pH was 9.1, the Na ion concentration was 30 ppm, and the Na ion concentration was 1.4%.

[0125] As is clear from the results in [Table 1], Na ions, which are cations, were separated from the particle-containing supply liquid 51, and colloidal silica, which is particles 50 in the discharge liquid, was concentrated, demonstrating good separation efficiency of colloidal silica.

[0126] <Test Example 2> FIG. 10B is a schematic diagram of Test Example 2 of the ion separation device of the eighth embodiment. Next, an ion separator 10J shown in FIG. 10B is the same as the ion separator 10H of FIG. 9, except that a distilled water supply tank 55B that supplies distilled water (DW) to 55A is installed. The test was carried out in the same manner as in Test Example 1, and colloidal silica (particle size: 100 nm) was used as the particles 50.

[0127] The ion separation device 10J of Test Example 2 is provided with a distilled water supply tank 55B that supplies distilled water DW to the supply tank 55A. By providing this distilled water supply tank 55B, when performing ion separation, the distilled water DW is supplied to the slurry (particles+Na ions) in the supply tank 55A in an amount equal to the amount of discharged alkaline solution 16, which is the filtrate.

[0128] By supplying this distilled water DW, the silica concentration in the supply tank 55A and the silica concentration in the discharged liquid 51B, which is the circulating liquid returning to the supply tank 55A, are kept constant (1 wt%), and Na ions are discharged together with the filtrate, which is the alkaline liquid 16.

[0129] Here, the supply flow rate of particle-containing supply liquid 51 from supply tank 55A to supply chamber 12 was F11=10 ml / min, and the return flow rate of the circulating liquid, which is discharged liquid 51B, was F12=4 ml / min. The supply flow rate of distilled water DW was set to F14=6 ml / min, and the discharge flow rate of alkaline solution 16, which was the filtrate, was set to 6 ml / min, so that the amounts were equal. It was verified that the Na ion concentration in the circulating fluid had decreased from an initial concentration of 20 ppm in the supply tank 55A to 0 ppm as measured by an ion meter.

[0130] The results of this test are shown in Table 2.

[0131] [Table 2]

[0132] As shown in Table 2, when the supply time of the supply liquid was 0 minutes, the TS (total evaporation residue; colloidal silica concentration, sodium concentration) in the raw liquid that was the supply liquid was 1.021 wt%, the pH was 9.0, and the Na ion concentration was 29 ppm.

[0133] First, the properties of the raw solution in supply tank 55A were measured. After a 40-minute supply time, the TS (total evaporation residue; colloidal silica concentration, sodium concentration) was 0.818 wt%, the pH was 6.5, the Na ion concentration was 10 ppm, and the Na ion separation efficiency was 50%. After an 80-minute supply time, the TS (total evaporation residue; colloidal silica concentration, sodium concentration) was 0.802 wt%, the pH was 4.0, the Na ion concentration was 5 ppm, and the Na ion separation efficiency was 75.0%. After a 120-minute supply time, the TS (total evaporation residue; colloidal silica concentration, sodium concentration) was 0.764 wt%, the pH was 3.7, the Na ion concentration was 3 ppm, and the Na ion separation efficiency was 85.0%. When the supply time was 150 minutes, TS (total evaporation residue; colloidal silica concentration, sodium concentration) was 0.717 wt%, pH was 3.7, Na ion concentration was 2 ppm, and Na ion separation efficiency was 90.0%.

[0134] Next, the properties of the discharged liquid (circulating liquid) 51B were measured. After a 40-minute supply time, the TS (total evaporation residue; colloidal silica concentration, sodium concentration) was 1.845 wt%, the colloidal silica concentration was 1.9 times, the pH was 3.2, the Na ion concentration was 5 ppm, and the Na ion separation efficiency was 75%. After an 80-minute supply time, the TS (total evaporation residue; colloidal silica concentration, sodium concentration) was 2.058 wt%, the colloidal silica concentration was 2.0 times, the pH was 3.2, the Na ion concentration was 3 ppm, and the Na ion separation efficiency was 85%. After a 120-minute supply time, the TS (total evaporation residue; colloidal silica concentration, sodium concentration) was 1.704 wt%, the colloidal silica concentration was 1.7 times, the pH was 3.2, the Na ion concentration was 2 ppm, and the Na ion separation efficiency was 90%. When the supply time was 150 minutes, TS (total evaporation residue; colloidal silica concentration, sodium concentration) was 1.516 wt%, the colloidal silica concentration ratio was 1.5 times, pH was 3.2, the Na ion concentration was 0 ppm, and the Na ion separation efficiency was 100%.

[0135] Furthermore, when the properties of the cationic liquid 16 were measured, after a 40-minute supply time, the TS (total evaporation residue; colloidal silica concentration, sodium concentration) was 0.013 wt%, the colloidal silica concentration was 98.7 times, the pH was 10.5, the Na ion concentration was 20 ppm, and the Na ion concentration was 1.0%. After an 80-minute supply time, the TS (total evaporation residue; colloidal silica concentration, sodium concentration) was 0.009 wt%, the colloidal silica concentration was 99.1 times, the pH was 10.4, the Na ion concentration was 11 ppm, and the Na ion concentration was 0.6%. After a 120-minute supply time, the TS (total evaporation residue; colloidal silica concentration, sodium concentration) was 0.000 wt%, the colloidal silica concentration was 100.0 times, the pH was 9.9, the Na ion concentration was 5 ppm, and the Na ion concentration was 0.3%. From the above results, it was found that the separation efficiency of 100% was achieved when the concentration of Na ions in the circulating fluid was 0 ppm, and the separation efficiency of particles was also 100%. -))50) 100% separation efficiency was achieved, and Na ion removal (0 ppm) was also achieved.

[0136] [Embodiment 9] 11A is a schematic diagram of an ion separation device according to embodiment 9. Note that the same components as those in the first to eighth embodiments are denoted by the same reference numerals and their description will be omitted. As shown in FIG. 11A, the ion separation device of the ninth embodiment is a seawater desalination device 70 formed by connecting the ion separation device 10A of the first embodiment and the ion separation device 10B of the second embodiment in series.

[0137] As shown in FIG. 11A, the ion separation device of the ninth embodiment is a modified example of the ion separation device described above, and the lower side in the figure is the ion separation device 10A of the first embodiment, and the upper side is the ion separation device 10B of the second embodiment.

[0138] The ion separation device 10A of embodiment 1 on the lower side and the ion separation device 10B of embodiment 2 on the upper side constitute a unit, and by connecting multiple such units, the ion separation efficiency of cations and anions is significantly improved.

[0139] In this embodiment, salt water (NaCl) is used as the supply liquid 71. As shown in Fig. 11A, the lower ion separation device 10A allows cations to pass through but blocks anions, while the upper ion separation device 10B allows anions to pass through but blocks cations. That is, the ion separation device of the fifth embodiment separates cations and anions from saltwater, and therefore can function as a so-called seawater desalination device.

[0140] As shown in FIG. 11A, a seawater desalination apparatus 70, which is an ion separation apparatus of the ninth embodiment, has a first ion separation device 10A disposed in the lower stage, and supplies a sodium chloride aqueous solution (brine) 71 into the supply chamber 12 of the first ion separation device 10A.

[0141] Sodium ions in the supplied sodium chloride aqueous solution 71 permeate the cathode filter plate electrode 14 together with water. In this first ion separation device 10A, Na ions permeate the cathode filter plate electrodes 14 (14A, 14B), while chloride ions are blocked by the cathode filter plate electrode 14, resulting in the chloride ions being concentrated and discharged from the supply chamber 12. The alkaline liquid 16 through which the sodium ions have permeated is discharged from the cation chamber 17 as the first cation liquid 16-1. The separation efficiency of Na ions in this first stage is 95%, and Na ions are reduced by about 95%.

[0142] Next, the first cationic liquid 16-1 is supplied into the supply chamber 22 of the second ion separation device 10B on the upper side. The first cationic liquid 16-1, which is a cationic permeate liquid in which sodium ions have been concentrated in the first ion separation device 10A on the lower side, is converted into sodium ions (Na + ) are blocked by the anode filter plate electrodes 24 (24A, 24B), only water passes through, and desalinated water 72 is discharged from the anion chamber 27. The first ion separation device 10A and the second ion separation device 10B are combined to form a module, and by installing multiple stages of this module, it is possible to + The ion concentration can be reduced to a desired concentration.

[0143] In order to reduce the salt content of seawater from 3.5%, it is generally considered that a salt concentration of 0.05% is required for it to be used as a drink.

[0144] FIG. 11B is a schematic diagram of a seawater desalination facility including a plurality of units of the seawater desalination apparatus, which is the ion separation apparatus of the ninth embodiment. As shown in FIG. 11B, the seawater desalination plant 70 is configured as a plurality of units, forming an n-stage module, thereby making it possible to reduce the salinity concentration to a desired level. As a result, by configuring the seawater desalination apparatus 70 from a plurality of units, it is possible to reduce the salinity of seawater (salinity: approximately 3.5%) to that of domestic water.

[0145] In this way, the reverse osmosis membrane method, which uses reverse osmosis membranes that are commonly used in seawater desalination systems, can desalinate seawater with a salt concentration of 3.5% to a salt concentration of 0.05%, making it suitable for drinking water.However, this method can desalinate seawater to a sodium ion concentration of the same or higher.

[0146] In addition, particles (such as plankton and other living organisms, organic matter, inorganic matter, etc.) in seawater - Even when the charged particles 50 are present, as described above, the charged particles 50 can also be separated, so that seawater can be desalinated. Particles can be separated if they are charged to one side or the other.

[0147] In addition, conventional seawater desalination using reverse osmosis membrane equipment involves the removal of particles (e.g., organisms such as plankton, organic matter, inorganic matter, etc.): - ))50 causes clogging of the reverse osmosis membrane, so it was treated in the upstream stage of the reverse osmosis membrane device.

[0148] In other words, in the prior art seawater desalination using the reverse osmosis membrane method, seawater is purified to the utmost extent in pretreatment to prevent clogging of the sub-nanometer pores of the reverse osmosis membrane.

[0149] In contrast, in the seawater desalination plant 70 using the ion separation device of the present invention, the charged particles (●(Ptcl - ))50 can be separated, so even if there is some plankton, etc., separation processing is possible as long as it is electrically charged.

[0150] That is, negatively charged particles can be blocked by the lower stage first treatment ion separator 10A, and positively charged particles can be blocked by the upper stage second treatment ion separator 10B.

[0151] A common technique for desalinating seawater is the "reverse osmosis membrane method," which uses the "reverse osmosis phenomenon" to apply an artificial high pressure greater than the osmotic pressure to the saltwater, forcing only the water molecules in the saltwater across a semipermeable membrane and into the freshwater.

[0152] This conventional reverse osmosis seawater desalination method poses a problem, for example, in that it generates brine water with concentrated salt content from the desalination plant. In most cases, untreated brine is simply dumped into the sea, posing a serious risk that harmful chemicals such as anti-scalant and anti-fouling agents contained in the waste will contaminate the ocean and adversely affect marine life and ecosystems. Furthermore, because brine contains a large amount of salt, its salinity is higher than that of the receiving water, resulting in the problem of consuming dissolved oxygen (DO) in the receiving water.

[0153] The seawater desalination plant 70 that employs the ion separation device of the present invention does not have this problem of brine. While the reverse osmosis membrane method requires a pretreatment process for the seawater supplied to the reverse osmosis membrane, the seawater desalination plant of the present invention is efficient because it only requires the installation of a simple pretreatment facility consisting of a sand filter to remove impurities from the seawater.

[0154] [Embodiment 10] 12 and 13 are schematic diagrams of an ion separation device according to a tenth embodiment. The same components as those in the above-described embodiment are denoted by the same reference numerals and the description thereof will be omitted. The ion separator in FIG. 12 has an active electrode arrangement, while the ion separator in FIG. 13 has a passive electrode arrangement.

[0155] The ion separator 10K in FIG. 12 is configured such that power is supplied to all eight electrodes by connecting them to a power source. The ion separator 10D of the fourth embodiment has two sets of electrodes (cathode filter plate electrodes, anode filter plate electrodes) (14-1, 14-2, 24-1, 24-2), and two sets of cation chambers 17 and anion chambers 27 (17-1, 17-2, 27-1, 27-2).

[0156] The power supplies (ES1, ES2, IS1, IS2, IS3, IS4, IS5, IS6) set the potentials of cathode electrodes 14A-1, 14B-1, 14A-2, and 14B-2 to −15 V, −20 V, −30 V, and −35 V, respectively. Also, the potentials of anode electrodes 24A-1, 24B-1, 24A-2, and 24B-2 are set to +15 V, +20 V, +30 V, and +35 V, respectively. The absolute values ​​of the potentials of the cathode electrodes (14A-1, 14B-1, 14A-2, 14B-2) and anode electrodes (24A-1, 24B-1, 24A-2, 24B-2) are set to increase with increasing distance from supply chamber 12. In contrast, the ion separator 10L in FIG. 13 has power supplies connected only to the two electrodes at both ends to supply potentials of −35V and +35V. 12 and 13, the ion separation chamber is indicated by a dashed line. Note that a piezoelectric vibrator 80 is disposed in the ion separation devices 10K and 10L of the present embodiment.

[0157] [Embodiment 11] FIG. 14 is a schematic diagram of an ion separation and concentration system including the ion separation device of the eleventh embodiment.

[0158] As shown in Fig. 14, an ion separation and concentration system 100 of the eleventh embodiment includes a valuable resource concentrator 102 that concentrates a dilute solution 101 containing particles 50, which are valuable resources, together with the particles 50, into concentrated valuable resources 103. The dilute solution (cations, valuable resources) contains at least one of cations and anions, and the valuable resources 103, and an ion separator 104 (for example, any one of the ion separators 10A, 10B, 10C, and 10H of the above-described embodiments) that removes either cations or anions or both from the concentrated valuable resources 103. Note that Fig. 14 illustrates cations as ions.

[0159] The valuable resource concentrator may be, for example, a filter such as a rotary ceramic membrane filter (Dynafilter; registered trademark), but the present invention is not limited to this. There is no.

[0160] According to the ion separation and concentration system 100 of this embodiment, a diluted solution with a low concentration of valuable materials is concentrated once in the concentrator 102, and then cations (Na ions) that are impurities can be separated from the concentrated valuable materials 103.

[0161] As a result, the valuable materials are concentrated, the ion concentration in the valuable materials is reduced, and the purity of the valuable materials is improved.

[0162] That is, as explained in the ion separation device 10H of embodiment 8 using Figure 9, by separating cations (Na ions) while circulating the particles (●(Ptcl-)) 50 as they are, if the particles (●(Ptcl-)) 50 are valuable materials, it is possible to easily remove cations (e.g., Na+, etc.) that are impurities contained in the valuable materials, thereby improving the purity of the product.

[0163] [Embodiment 11] FIG. 17 is a schematic diagram of another ion separation device according to the eleventh embodiment. The same components as those in the above-described embodiment are denoted by the same reference numerals and the description thereof will be omitted.

[0164] The ion separator 10M in FIG. 17 is a conventional ion separator equipped with a so-called ion exchange membrane function.

[0165] In this embodiment, sodium chloride (NaCl) will be used as an example. As shown in FIG. 17, the ion separation device 10M of the eleventh embodiment separates cations (Na + ) and anions (Cl - Electrolyte solution supply chambers (hereinafter referred to as "supply chambers") 12 supply an electrolyte solution (NaCl+H2O: hereinafter referred to as "supply solution") 11 containing cations (Na + ) a cathode filter plate electrode 14 equipped with a diaphragm (filter material) 13 for separating the separated cations (Na +The cation chamber 17 is provided with a cationic liquid (hereinafter also referred to as "alkaline liquid") 110 into which the alkaline liquid flows together with water, and further with a flat cathode electrode (negative electrode) 25 provided in a position facing the cathode filter plate electrode 14 in the cation chamber 17. Supply chamber 12 is provided with a supply port and a discharge port (not shown), and supply chamber 12 is supplied with supply liquid 11, which is an electrolyte.

[0166] The cation chamber 17 is provided with a substitution liquid supply port and a substitution liquid discharge port (not shown) for supplying a substitution liquid for replacing the migrated cations, and a substitution liquid 110 is supplied into the cation chamber 17. This substitution liquid 110 is used to replace the cations (Na + ) is replaced with alkaline solution 110A.

[0167] Here, the cathode filter plate electrode 14 is composed of a cathode first electrode 14A and a cathode second electrode 14B, and further, a diaphragm (filter plate) 13, which is an insulator having pores 13a, is sandwiched between the cathode first electrode 14A and the cathode second electrode 14B. Here, the diaphragm 13 can be made of, for example, cellulose, but the present invention is not limited to this.

[0168] The ion separation device 10M further includes a first power supply 41 electrically connected to the flat-plate anode electrode 15 and the cathode first electrode 14A, a second power supply 42 electrically connected to the cathode first electrode 14A and the cathode second electrode 14B, and a fifth power supply 45 electrically connected to the flat-plate cathode electrode 25 and the cathode first electrode 14A. Here, the electrode configuration is such that the cathode second electrode 14B is at a first potential (V1), the cathode first electrode 14A is at a second potential (V2), the flat anode electrode 15 is at a third potential (V3), and the flat cathode electrode 25 is at a fourth potential (V4). The power supplies (first power supply 41, second power supply 42, fifth power supply 45) are set so that the potentials are V3>V2>V1>V4.

[0169] The absolute value of the potential of the cathode electrode increases as it is farther away from supply chamber 12 (|V4|(40V)>|V1|(20V)>|V2|(10V)).

[0170] In the ion separator 10A shown in the first embodiment of FIG. 1, water is allowed to pass through the cathode filter plate electrode . However, in the eleventh embodiment, the structure is such that only a small amount of water passes through. This is because the supply liquid 11 and the replacement liquid 110 are supplied in a balanced manner. As a result, at the cathode filter plate electrode 14, the Na ions are attracted to the cathode first electrode 14A on the cathode side and move into the cation chamber 17. At this time, there is almost no movement of water, so that as a result, only ions move from the supply liquid (NaCl) 11 to the replacement liquid (distilled water) 110, and the replacement liquid 110 is replaced.

[0171] Therefore, at the beginning of operation, only Na ions pass through, so the Na ion concentration in the replacement liquid (distilled water) 110 is low, but as operation continues, only Na ions gradually pass through, so the Na ion concentration in the replacement liquid (distilled water) 110 increases and it becomes an alkaline liquid.

[0172] Here, the reasons for the lack of water movement include the following: 1) The diaphragm 13 acts as a filtration resistance, and water hardly passes through. 2) There is almost no pressure difference between the two chambers (supply chamber 12 / cation chamber 17). 3) The supply tank (not shown) and the replacement liquid supply tank (not shown) that supply the supply liquid 11 are supplied from approximately the same position (that is, at the same flow rate as the pump).

[0173] As described above, according to the ion separation device 10M of this embodiment, cations (Na ions) in the supply liquid 11 supplied into the supply chamber 12 are attracted to the cathode first electrode 14A on the cathode side and move (permeate) within the cation chamber 17.

[0174] According to this embodiment, the migrated (permeated) cations (Na ions) are replaced with a substitution fluid 110 separately supplied into the cation chamber 17, thereby providing a so-called ion dialysis function.

[0175] On the other hand, anions (Cl ions) are repelled by cathode first electrode 14A and cannot move, and remain within supply chamber 12. As a result, as operation continues, the amount of cations (Na ions) in supply chamber 12 decreases, and the amount of anions (Cl ions) increases. As the operation time passes, the substitution liquid 110 changes from distilled water (pH 7.0) to an alkaline solution of sodium hydroxide solution (pH=11.8).

[0176] The replacement fluid 110 may or may not be circulated. The feed liquid side may or may not be circulated.

[0177] That is, by implementing the following three patterns as necessary, it is possible to provide an ion separation device that exhibits ion dialysis function. Pattern 1) Do not circulate either the supply liquid or the replacement liquid. Pattern 2) Circulate only either the supply solution or the replacement solution. Pattern 3) Circulate both the supply liquid and the replacement liquid.

[0178] [Embodiment 12] FIG. 18 is a schematic diagram of an ion separation device according to the twelfth embodiment. The same components as those in the ion separation device of embodiment 11 are denoted by the same reference numerals and will not be described again. In this embodiment, sodium chloride (NaCl) will also be used as an example. As shown in FIG. 18, an ion separation device 10N of this embodiment is a device that separates anions dissociated in a solvent (polar solvent; for example, water).

[0179] As shown in FIG. 18, the ion separator 10N separates cations (Na + ) and anions (Cl -A supply chamber 12 supplies a supply solution 11 containing anions (Cl), and two supply chambers 12 are disposed on both sides of the supply chamber 12. - ) and a flat cathode electrode 25. - The anion chamber 27 is provided with an anion solution (hereinafter also referred to as "acid solution") 26 into which the anion solution flows together with water, and further includes a flat anode electrode (positive electrode) 15 disposed in a position facing the anode filter plate electrode 24 in the anion chamber 27. Supply chamber 22 is provided with a supply port and a discharge port (not shown), and supply chamber 22 is supplied with supply liquid 11, which is an electrolyte. The anion chamber 27 is provided with a substitution fluid supply port and a substitution fluid discharge port for supplying a substitution fluid 110 for replacing the migrated anions, and the substitution fluid 110 is supplied into the anion chamber 27 . This replacement liquid 110 contains anions (Cl) that have been transferred into the anion chamber 27 by ion exchange using the anode filter plate electrode 24. - ) is replaced with acidic solution 110B.

[0180] Here, the anode filter plate electrode 24 is composed of a first anode electrode 24A and a second anode electrode 24B, and further, a diaphragm 23, which is an insulator having fine holes, is sandwiched between the first anode electrode 24A and the second anode electrode 24B. The diaphragm 23 is made of an insulating material, and may be, for example, a nonwoven fabric made of fibers such as PP (polypropylene), PE (polyethylene), NY (nylon), or cellulose.

[0181] The ion separation device 10N has a third power supply 43 electrically connected to the flat-plate cathode electrode 25 and the anode first electrode 24A, a fourth power supply 44 electrically connected to the anode first electrode 24A and the anode second electrode 24B, and a sixth power supply 46 electrically connected to the flat-plate anode electrode 15 and the anode second electrode 24B.

[0182] Here, the electrode configuration is such that the anode second electrode 24B has a first potential (V11), the anode first electrode 24A has a second potential (V12), the flat cathode electrode 25 has a fifth potential (V5), and the flat anode electrode 15 has a sixth potential (V6). The power supplies (the third power supply 43, the fourth power supply 44, and the sixth power supply 46) are set so that V5 < V12 < V11 < V6.

[0183] Note that as the distance from the supply chamber 12 increases, the absolute value of the potential of the anode electrode becomes larger (|V6| (40 V) > |V11| (20 V) > |V12| (10 V)).

[0184] An example of supplying a sodium chloride solution (NaCl + H2O) as the supply liquid 11 into the supply chamber 22 will be described. As described above, the ionic state in the supply chamber 22 is dissociated into cations (sodium ions: Na + ) and anions (chloride ions: Cl - ). Chloride ions (Cl - ), which are anions, are drawn into the anode first electrode 24A disposed in the supply chamber 12.

[0185] In the ion separation device 10B of Embodiment 2 shown in FIG. 2 described above, water was permeated through the anode filter electrode 24. However, in the ion separation device 10N of this Embodiment 12, a configuration is adopted in which only a little water is allowed to pass through. This is because the supply liquid 11 and the replacement liquid 110 are supplied in a balanced manner. As a result, anions (chloride ions: Cl - ) are drawn into the anode first electrode 24A on the anode side and move (permeate) into the anion chamber 27. At this time, since there is almost no movement of water, as a result, only chloride ions (Cl - ) move (permeate) from the supply liquid (NaCl) 11 in the supply chamber 22 to the replacement liquid (distilled water) 110 in the anion chamber 27, and the supply liquid is replaced with the replacement liquid 110, resulting in an acidic solution.

[0186] As described above, according to the ion separation device 10N of this embodiment, anions (chlorine ions) in the supply liquid 11 are attracted to the anode first electrode 24A on the anode side and move (permeate) into the anion chamber 27. The anions (chlorine ions) that have migrated (permeated) are replaced by a replacement fluid 110 that is separately supplied into the anion chamber 27, thereby achieving the so-called ion dialysis function.

[0187] On the other hand, positive ions (Na ions) are repelled by anode first electrode 24A and cannot move, and remain within supply chamber 12. As a result, as operation continues, the amount of cations (Na ions) in supply chamber 12 increases, and the amount of anions (Cl ions) decreases. As the operation time passes, the substitution liquid 110 changes from distilled water (pH 7.0) to an acidic liquid (pH = 2.4).

[0188] [Embodiment 13] 19 is a schematic diagram of an ion separation device according to embodiment 13. Note that the same components as those in embodiments 11 and 12 are denoted by the same reference numerals and their description will be omitted. As shown in Figure 19, the ion separation device 10P of this embodiment is a combination of the ion separation device 10M of embodiment 11 and the ion separation device 10N of embodiment 12, and separates cations and anions and replaces them with replacement liquid 110 to obtain an alkaline liquid 16 and an acidic liquid 26.

[0189] As shown in FIG. 19, the ion separation device 10P of the thirteenth embodiment includes a supply chamber 12 for supplying a supply liquid 11 of an electrolyte solution (e.g., NaCl solution) containing cations and anions, and two ions (NaCl solution) disposed on both sides of the supply chamber 12 for supplying the cations (Na + ) and a cathode filter plate electrode 14 equipped with a diaphragm (filter paper) 13 for separating anions (Cl - The anode filter plate electrode 24 is provided with a diaphragm 23 for separating the separated cations (Na+), the cation chamber 17 into which the separated cations (Na+) flow together with water as a cation solution (alkaline solution) 16, and the separated anions (Cl - and an anion chamber 27 into which the acidic solution 26 flows together with water as an anion solution (acidic solution). Furthermore, it is provided with a flat cathode electrode (negative electrode) 25 provided in a position facing the cathode filter plate electrode 14 in the cation chamber 17, and a flat anode electrode (positive electrode) 15 provided in a position facing the anode filter plate electrode 24 in the anion chamber 27.

[0190] The ion separation device 10P has a first power supply 41 electrically connected to the cathode first electrode 14A and the anode first electrode 24A, a second power supply 42 electrically connected to the cathode first electrode 14A and the cathode second electrode 14B, a fourth power supply 44 electrically connected to the anode first electrode 24A and the anode second electrode 24B, a fifth power supply 45 electrically connected to the flat-plate cathode electrode 25 and the cathode second electrode 14B, and a sixth power supply 46 electrically connected to the flat-plate anode electrode 15 and the anode second electrode 24B.

[0191] The cation chamber 17 is provided with a substitution liquid inlet and a substitution liquid outlet for supplying a substitution liquid to replace the migrated cations, and a substitution liquid 110 is supplied into the cation chamber 17. This substitution liquid 110 is used to replace the cations (Na ions) that have been migrated into the cation chamber 17 by ion exchange using the cathode filter plate electrode 14. + ) is replaced with the replacement liquid 110 to form the alkaline liquid 110A.

[0192] The anion chamber 27 is provided with a substitution fluid supply port and a substitution fluid discharge port for supplying a substitution fluid 110 for replacing the migrated anions, and the substitution fluid 110 is supplied into the anion chamber 27 . This replacement liquid 110 contains anions (Cl) that have been transferred into the anion chamber 27 by ion exchange using the anode filter plate electrode 24. - ) is replaced with the replacement liquid 110 to form the acidic liquid 110B.

[0193] In this embodiment, the diaphragm 13 in the cathode filter plate electrode 14 is made of an insulating material, and may be, for example, a nonwoven fabric made of fibers such as PP (polypropylene), PE (polyethylene), NY (nylon), cellulose, etc.

[0194] Next, an example of dialysis separation of cations and anions by supplying a sodium chloride solution as the supply liquid 11 into the supply chamber 12 will be described with reference to FIG.

[0195] As described above, the ion state in the supply chamber 12 is positive ions (sodium ions: Na + ) and anions (chlorine ions: Cl - ) and dissociated into A negative cathode first electrode 14A disposed in the supply chamber 12 is charged with a positive ion, sodium ion (Na + ) is drawn in.

[0196] In contrast, chloride ions (Cl - ) are anions, and are therefore blocked by the negative cathode first electrode 14A and cannot pass through the cathode first electrode 14A.

[0197] As a result, at the cathode filter plate electrode 14, Na ions are attracted to the cathode first electrode 14A on the cathode side and move into the cation chamber 17. At this time, there is almost no movement of water, so that as a result, only ions move from the supply liquid (NaCl) 11 to the replacement liquid (distilled water) 110, and are replaced by the replacement liquid 110, becoming alkaline liquid 110A.

[0198] In addition, in the supply chamber 12, an anode filter plate electrode (anode first electrode 24A, anode second electrode 24B) 24 disposed opposite the cathode filter plate electrode 14 is supplied with an anion, chlorine ion (Cl - ) is drawn in. The anion, chloride ion (Cl - ) is drawn in, chloride ions will pass through. As a result, the permeated chlorine ions replace the replacement water 110 to form an acidic solution 110B.

[0199] In contrast, sodium ions (Na + ) is a positive ion, and is therefore blocked by the anode first electrode 24A and cannot pass through the anode first electrode 24A.

[0200] As a result, sodium ions (Na + ) is concentrated by dialysis. - ) is dialyzed and concentrated. As a result, the third supply discharge liquid 11C discharged from the supply chamber 12 contains sodium ions (Na + ) decreases, and chloride ions (Cl - ) also decreases.

[0201] As described above, according to the ion separation device 10P of this embodiment, the ion state (sodium ion (Na + ) and chloride ions (Cl - ) mixed state: pH = 7.0), sodium ions (Na + ) permeates and sodium ions (Na + ) is concentrated. At the same time, chloride ions (Cl - ) permeates and chloride ions (Cl) enter the anion chamber 27. - ) is concentrated.

[0202] The separation of cations and anions in this ion separator 10P was confirmed using pH and BTB reagent. Here, a 0.05% aqueous solution of sodium chloride (NaCl) was used as the feed liquid 11, and the pH was adjusted with a carbonate buffer to a pH of 7.0. At the same time, the pH status in each chamber was visualized by coloring using BTB (bromothymol blue; BTB) reagent.

[0203] As a result of this confirmation, it was found that the ion state (sodium ion (Na + ) and chloride ions (Cl -) (a mixture of alkaline solution 110B and anion solution 110B: pH = 7.0) was subjected to ion separation, and the pH of the alkaline solution 110B discharged from the cation chamber 17 became 11.8, and the pH of the acidic solution 110B6 discharged from the anion chamber 27 became 2.4.

[0204] Furthermore, when tested with a BTB reagent, the feed solution (pH = 7.0) 11 supplied to the feed chamber 12 was green, but the alkaline solution (pH = 11.8) 16 in the cation chamber 17 changed to blue, and the acidic solution (pH = 2.4) 26 in the anion chamber 27 changed to yellow. Furthermore, in a flame color reaction test using a copper wire, the alkaline solution 16 turned orange due to sodium ions, and the acidic solution 26 turned green due to copper chloride (CuCl2), confirming that ion separation was achieved reliably in each flame color reaction test.

[0205] As a result, the circulating liquid, which is the third supply / discharge liquid 11C discharged from the supply chamber 12, contains sodium ions (Na + ) decreases, and chloride ions (Cl - ) also decreases (pH = 4.5).

[0206] 3B, a piezoelectric vibrator (vibration member) 80, which is a piezoelectric member, may be installed in the supply chamber 12, the cation chamber 17, and the anion chamber 27. This prevents adhesion of particles 42, and therefore the voltage applied to the anode first electrode 24A and the anode second electrode 24B can be reduced overall.

[0207] [Embodiment 14] 20 is a schematic diagram of an ion separation device according to embodiment 14. Note that the same components as those in the above-described embodiments are given the same reference numerals and their description will be omitted.

[0208] Although the ion separation devices 10M to 10P of the eleventh to thirteenth embodiments have been described as techniques for separating cations or anions in an electrolyte solution by dialysis, the ion separation device of the present invention is not limited to this. The ion separator 10Q of the fourteenth embodiment has the same configuration as the ion separator 10P of the nineteenth embodiment (see FIG. 19) described above, but the supply liquid supplied to the supply chamber 12 contains particles (Ptcl "●" in the drawing). - The dialysis separation of ions is also continuously carried out in the particle-mixed feed solution 51 containing the particles 50. That is, in the electrodialysis apparatus of the prior art, when particles are mixed in the material to be separated, the particles adhere to the dialysis membrane, preventing the electrodialysis from proceeding.

[0209] In contrast, the ion separation device 10 of this embodiment can continue to perform dialysis separation even when particles are mixed in. Particles (negatively charged) 50, like anions (chlorine ions), repel cathode first electrode 14A and do not move to cation chamber 17. On the other hand, there is no movement of water in anion chamber 27, so the particles that would have moved with the movement of water hardly move at all. This is because there is no pressure difference between the supply chamber 12 and the anion chamber 27 between the supply liquid 11 and the replacement liquid 110, so there is almost no movement of water. As a result, particles 50 remain in supply chamber 12, but only both ions (cations and anions) permeate both chambers (cation chamber 17 and anion chamber 27), where they are replaced with the replacement liquid, becoming alkaline liquid 110A and acidic liquid 110B, respectively.

[0210] [Embodiment 15] FIG. 21 is a schematic diagram of an ion separation device according to the fifteenth embodiment. As shown in FIG. 21, the ion separation device 10R of the fifteenth embodiment includes the ion separation device 10P of the thirteenth embodiment (see FIG. 19), a supply tank 55 for supplying an electrolyte solution (supply liquid 11) containing cations, and a supply line L for supplying the supply liquid 11 from the supply tank 55 to the supply chamber 12 via a supply pump P-1. 1-1a circulation line L1-2 for circulating the first supply / discharge liquid 11C from the supply chamber 12 to the supply chamber 12; an alkali line L3-1 for discharging the alkaline solution 110A from the cation chamber 17 to the alkali tank 56; and an alkali line L4-2 for circulating the alkaline solution 110A from the alkali tank 56 to the cation chamber 17 as replacement water by a pump P-2. 3-2 and an acid line L for discharging the acid solution 110B from the anion chamber 27 to the acid solution tank 58. 5-1 The acidic solution 110B is circulated from the acidic solution tank 58 to the anion chamber 27 as replacement water by the pump P-3 through the acidic solution line L. 5-2 It is equipped with the following.

[0211] By using the ion separation device 10R of this embodiment 15, alkaline liquid 110A, which is a cationic liquid that has been replaced with the replacement liquid 110, can be continuously obtained in the alkaline tank 56, and acidic liquid 110B, which is an anionic liquid that has been replaced with the replacement liquid 110, can be continuously obtained in the acidic liquid tank 58.

[0212] [Embodiment 16] FIG. 22 is a schematic diagram of an ion separation and concentration system including the ion separation device of the eleventh embodiment.

[0213] As shown in FIG. 22, the ion separation and concentration system 200 of the 16th embodiment includes a valuables concentration device 102 that concentrates a dilute solution 101 containing particles 50, which are valuables, together with the particles 50, into a concentrated valuables 103, the dilute solution (cations, valuables) containing at least one of cations and anions, and an ion separation device 204 (for example, any one of ion separation device 10M, ion separation device 10N, ion separation device 10C, and ion separation device 10P) that removes either or both of the cations and anions in the concentrated valuables 103.

[0214] An example of a valuable resource concentrator is a filtration device such as a rotary ceramic membrane filter (Dynafilter; registered trademark), but the present invention is not limited to this.

[0215] According to the ion separation and concentration system 200 of this embodiment, a diluted solution with a low concentration of valuable materials is concentrated once in the concentrator 102, and then impurities such as cations and anions can be separated from the concentrated valuable materials 103.

[0216] As a result, the valuable materials are concentrated, the ion concentration in the valuable materials is reduced, and the purity of the valuable materials is improved.

[0217] That is, as explained in the ion separation device 10Q of the fourteenth embodiment with reference to FIG. 20, the particles (●(Ptcl - )) 50 is circulated as it is, and the cations (Na ions) are separated to separate the particles (●(Ptcl - ))50 is a valuable material, it is possible to easily remove cations (e.g., Na ions, etc.) that are impurities contained in the valuable material, thereby improving the purity of the product.

[0218] Furthermore, even when the diluted solution contains only anions or a mixture of cations and anions rather than cations, the ions can be easily removed, thereby improving the purity of the product.

[0219] The electrode configuration of the ion separator having the ion dialysis separation function described above may also be the active electrode arrangement shown in FIG. 12 or the passive electrode arrangement shown in FIG.

[0220] [Embodiment 17] FIG. 23 is a schematic diagram of a seawater desalination system including the seawater desalination apparatus 70 of the ninth embodiment described above. 23, a seawater desalination system 1000 according to the seventeenth embodiment of the present invention includes a first pretreatment device 1001, a second pretreatment device 1002 provided downstream of the first pretreatment device 1001, and a seawater desalination device 70 provided downstream of the second pretreatment device 1002. The devices are connected by piping.

[0221] The first pretreatment device 1001 is, for example, a sand filter device, and is equipped with a pretreatment container into which seawater 1010A taken from the sea is introduced, and a filter material made of filter sand or the like filled in the pretreatment container. The seawater 1010A supplied into the first pretreatment container 1001 passes through the filter material, and contaminants such as turbid components and impurities contained in the seawater 1010A are removed.

[0222] The second pretreatment device 1002 includes an adsorption vessel (e.g., a column) (not shown) to which seawater 1010A from the first pretreatment device 1001 is supplied, and a hydrophilic polymer adsorbent, for example, placed in the adsorption vessel. The hydrophilic polymer adsorbent is a material that can efficiently adsorb biopolymers, which are the main cause of biofouling among fouling-causing substances.

[0223] 23, a seawater desalination system 1000 takes in seawater 1010 from the ocean and supplies the seawater 1010 to a first pretreatment device 1001 through piping. The seawater 1010 supplied to the first pretreatment device 1001 is pretreated by the first pretreatment device 1001, and impurities contained in the seawater 1010 are removed. Pretreated seawater 1010A pretreated in first pretreatment device 1001 is supplied as first treated water to second pretreatment device 1002. Fouling-causing substances contained in the first treated water are adsorbed and removed by this second pretreatment device 1002. The second treated seawater 1010B from which fouling-causing substances have been adsorbed and removed in the second pretreatment device 1002 is supplied to the seawater desalination device 70, where it is separated into concentrated water 1011 and fresh water 1012.

[0224] As mentioned above, the reverse osmosis membrane method, which uses a reverse osmosis membrane and is generally used in seawater desalination systems, reduces seawater with a salinity of 3.5% to a salinity of 0.05% so that it can be used as drinking water. However, it is possible to desalinate seawater to a sodium ion concentration similar to or higher than this. Furthermore, seawater can be desalinated even when it contains particles (for example, living organisms such as plankton, organic matter, inorganic matter, etc.). In other words, particles contained in seawater can be separated if they are charged to one of two things. Therefore, depending on the particles to be removed, it may be possible to omit the installation of the second pre-treatment device 1002. This allows the system configuration to be simplified. [Industrial Applicability]

[0225] The present invention can be applied to seawater desalination systems and seawater desalination methods in general. [Explanation of symbols]

[0226] 10A~10R Ion Separator 11 Electrolyte solution (supply solution) 11A 1st supply and discharge liquid 11B 2nd supply and discharge liquid 11C 3rd supply and discharge liquid 12 Supply room 12a entrance 12b Supply liquid introduction line 12c 3rd outlet 13 Diaphragm (filter material) 14 Cathode filter plate electrode 14A Cathode 1st electrode 14B Cathode second electrode 15 Flat anode electrode 16 Cationic liquid (alkaline liquid) 17 Cation Chamber 17a 1st outlet 22 Supply room 24 Anode filter plate electrode 24A Anode 1 24B Anode second electrode 25 Flat cathode electrode 26 Anionic liquid (acidic liquid) 27 Anion Chamber 27a 2nd outlet 50 particles 51 Particle mixed feed liquid 51A Drainage fluid 70 Seawater desalination equipment 71 Sodium chloride solution (seawater) 80 Piezoelectric vibrator 100 Ion Separation and Concentration System 110 Substitution liquid 110A Alkaline solution 110B Acidic liquid 1000 Seawater Desalination System DW Distilled water P supply pump

Claims

1. a first ion separation device that allows cations in seawater to pass through and blocks anions; a second ion separation device provided downstream of the first ion separation device, which allows anions in the permeate through which cations have permeated to pass and blocks cations; The seawater desalination plant is provided with a unit including the above. The seawater desalination apparatus comprises: a supply chamber for supplying seawater containing cations and anions; a cathode filter plate electrode disposed on both sides of the supply chamber and equipped with a diaphragm having pores for separating cations; a flat anode filter plate electrode provided with a diaphragm having pores for separating anions; a cation chamber into which the separated cations flow together with water as a cation liquid; The cathode filter plate electrode is a cathode first electrode on the supply chamber side; a cathode second electrode disposed on the cation chamber side across the diaphragm; a first power source electrically connected to the anode electrode and the cathode first electrode of the flat plate; a second power source electrically connected to the cathode first electrode and the cathode second electrode; The anode filter plate electrode is an anode first electrode on the supply chamber side; a second anode electrode disposed on the anion chamber side across the diaphragm; a third power source electrically connected to the cathode electrode and the anode first electrode of the flat plate; a fourth power source electrically connected to the anode first electrode and the anode second electrode.

2. As a pretreatment device for the seawater desalination device, a first pretreatment device provided with a filter for removing impurities from seawater; a second pretreatment device provided with a hydrophilic polymer adsorbent for adsorbing biopolymers in the seawater from the first pretreatment device; 2. The seawater desalination system according to claim 1, further comprising:

3. a first ion separation device that allows cations in seawater to pass through and blocks anions; a second ion separation device provided downstream of the first ion separation device, which allows anions in the permeate through which cations have permeated to pass and blocks cations; The seawater desalination system of claim 1 is provided with a seawater desalination apparatus comprising the above as a single unit, A seawater desalination method comprising reducing the salt concentration in the seawater.

4. As a pretreatment device for the seawater desalination device, a first pretreatment device provided with a filter for removing impurities from seawater; a second pretreatment device provided with a hydrophilic polymer adsorbent for adsorbing biopolymers in the seawater from the first pretreatment device; 4. The method for desalination of seawater according to claim 3, further comprising:

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