TW201315533A - Desalination system and method - Google Patents

Abstract

A desalination system comprises a silica removal apparatus configured to receive a first feed stream for silica removal. The silica removal apparatus comprises first and second electrodes, and a plurality of paired ion exchange membranes disposed between the first and second electrodes to form a plurality of alternating first and second channels. The silica removal apparatus further comprises a plurality of spacers disposed between each pair of the adjacent ion exchange membranes and between the first and second electrodes and the respective ion exchange membranes. Wherein a first member of each pair of the ion exchange membranes is an anion exchange membrane and a second member of each pair of the ion exchange membranes is an anion exchange membranes, a monovalent cation exchange membrane or a bipolar ion exchange membrane, and wherein the first members and the second members are disposed alternately within the plurality of the paired ion exchange membranes.

Description

Desalination system and method

SUMMARY OF THE INVENTION The present invention relates to desalination systems and methods for water recovery. More specifically, the present invention relates to desalination systems and methods for the use of ion exchange membranes for cerium dioxide removal and water recovery.

In an industrial process, a large amount of wastewater such as an aqueous brine solution is produced. Typically, this wastewater is not suitable for direct consumption in residential or industrial applications. In view of the limited qualified water source, it is desirable to recover qualified water from wastewater.

Attempts have been made to remove cerium oxide from wastewater containing cerium oxide or other water sources. For example, introducing a stream containing cerium oxide into a desalination apparatus such as a reverse osmosis apparatus while increasing the pH of the streams for removal of cerium oxide, because the higher the pH of the stream, the more ionized the cerium oxide high. However, in current applications, such processes have complex and rigorous pre-processing requirements and higher costs. In general, fluctuations and inefficiencies in pretreatment can cause scaling or precipitation of slightly soluble salts such as calcium sulphate or calcium carbonate sometimes in the cerium oxide removal unit, which is detrimental to cerium dioxide removal and cerium oxide. Remove the device.

Accordingly, there is a need for a novel and improved desalination apparatus, system and method for cerium oxide removal and water recovery.

One embodiment of the invention provides a desalination system. The desalination system includes a cerium oxide removal device configured to receive a first feed stream for cerium oxide removal. The cerium oxide removing device includes first and second electrodes and a plurality of first and second electrodes disposed between the first and second electrodes to form a plurality of alternating first A pair of ion exchange membranes of the second channel. The cerium oxide removal apparatus further includes a plurality of spacers disposed between each pair of adjacent ion exchange membranes and between the first and second electrodes and the respective ion exchange membranes. The first member of each pair of ion exchange membranes is an anion exchange membrane and the second component of each pair of ion exchange membranes is an anion exchange membrane, a monovalent cation exchange membrane or a bipolar ion exchange membrane, and wherein the first component and the second component The components are alternately disposed within a plurality of pairs of ion exchange membranes.

Another embodiment of the invention provides a desalination system. The desalination system includes a cerium oxide removal device. The cerium oxide removal device includes first and second electrodes, and a plurality of pairs of anion exchange membranes disposed between the first and second electrodes to form a plurality of alternating first and second channels. The cerium oxide removal apparatus further includes a plurality of spacers disposed between each pair of adjacent anion exchange membranes and between the first and second electrodes and the respective anion exchange membranes.

Embodiments of the present invention further provide a desalination process for removing cerium oxide from an aqueous stream. The desalination method comprises: passing a first feed stream through a first channel defined by a pair of ion exchange membranes for a cerium oxide removal device for cerium dioxide removal, and passing the second feed stream through The second channel defined by the pair of ion exchange membranes of the cerium oxide removal device carries away the cerium oxide removed from the first feed stream. The first member of each pair of ion exchange membranes is an anion exchange membrane and the second component of each pair of ion exchange membranes is an anion exchange membrane, a monovalent cation exchange membrane or a bipolar ion exchange membrane, and wherein the first component and the second component The components are alternately arranged within the pair of ion exchange membranes.

These and other advantages and features will be better understood from the following detailed description of the preferred embodiments of the invention.

Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. In the following description, well-known functions or constructions are not described in detail to avoid obscuring the invention in unnecessary detail.

1 is a schematic illustration of a desalination system 10 in accordance with one embodiment of the present invention. As illustrated in Figure 1, the desalination system 10 includes a desalination device 11 configured to receive a first feed stream 12 having a salt or other impurity from a first liquid source (not shown) for desalination, and A second feed stream 13 is received from a second liquid source (not shown) during or after desalination of a feed stream 12 to carry the charged species removed from the first feed stream 12 exiting the desalination unit 11.

In a non-limiting example, the salt in the first feed stream 12 can comprise charged ions such as magnesium ions (Mg ²⁺ ), calcium ions (Ca ²⁺ ), cerium oxide, sodium ions (Na ⁺ ), chlorine. Ions (Cl ^- ) and / or other ions. In a non-limiting example, the charged ions in the first feed stream 12 contain at least a portion of the target ions (such as ionized ceria) such that the desalination device 11 can be used as a ceria removal device. In some applications, the first output stream 14 can be circulated into the desalination unit 11 or other suitable desalination unit such as an inverted electrodialysis (EDR) unit for further desalination.

Generally, cerium oxide can be ionized in a rare or partial manner in the first feed stream 12. Increasing the pH of the first feed stream 12 causes ionization of the cerium oxide and facilitates its removal. Thus, as depicted in Figure 1, the desalination system 10 further includes a pH adjustment unit 16 in fluid communication with the desalination device 11 and the adjustment unit is configured to increase the pH of the first feed stream 12 to promote the first feed stream Ionization of cerium oxide in 12.

In some examples, pH adjustment unit 16 can adjust the pH of first feed stream 12 to greater than about 7, such as between about 8 and about 11. In other examples, the pH of the first feed stream 12 can be adjusted to between about 9.5 to about 11. After ionization, at least a portion of the ceria in the first feed stream 12 can be ionized into, for example, HSiO ₃ ^- and/or SiO ₃ ^2- form or other charged species. Ionized cerium oxide is illustrated, for example, in the form of HSiO ₃ ^- for ease of explanation.

For some configurations, the pH adjustment unit 16 can include a pH adjustment source (not shown) to introduce an additive into the first feed stream 12 to adjust its pH. In a non-limiting example, the pH adjustment unit 16 can introduce a basic additive into the first feed stream 12. Non-limiting examples of alkaline additives include sodium hydroxide, potassium hydroxide, and ammonium hydroxide. The alkaline additive can be introduced into the first feed stream 12 automatically or manually. In certain applications, the pH adjustment unit 16 may not be employed in the desalination system 10 and the pH of the first feed stream 12 may be pre-conditioned.

Figure 2 illustrates a schematic diagram of a desalination apparatus 11 in accordance with one embodiment of the present invention. As illustrated in FIG. 2, the desalination apparatus 11 includes a first electrode 17, a second electrode 18, a plurality of pairs of ion exchange membranes 19, 20, 21, 22 and a plurality of spacers 23. In the illustrated example, the first and second electrodes 17, 18 are connected to the positive and negative terminals (not shown) of the power source for use as the anode and cathode, respectively. Alternatively, the polarity of the first and second electrodes 17, 18 can be reversed.

In some examples, the first and second electrodes 17, 18 may comprise a metallic material, such as a titanium plate or a titanium plate coated with platinum. In other examples, the first and second electrodes 17, 18 may comprise a conductive material that may or may not conduct heat. It is hot and can have particles of smaller size and large surface area. In some examples, the electrically conductive material can comprise one or more carbon materials. Non-limiting examples of carbon materials include activated carbon particles, porous carbon particles, carbon fibers, carbon aerogels, porous mesocarbon microbeads, or combinations thereof. In other examples, the electrically conductive material can comprise a conductive composite such as manganese or iron or an oxide of both or a carbide of titanium, zirconium, vanadium, tungsten, or combinations thereof.

In the illustrated example, the first and second electrodes 17, 18 are in the form of plates arranged in parallel with each other to form a stacked structure. In other examples, the first and second electrodes 17, 18 can have varying shapes, such as sheets, blocks, or cylinders. Furthermore, the first and second electrodes 17, 18 can be configured in different configurations. For example, the first and second electrodes 17, 18 may be arranged concentrically with a spiral and continuous space therebetween.

The pair of ion exchange membranes 19-22 are configured to pass ions and are disposed between the first and second electrodes 17, 18 to form a plurality of alternating first and second passages 24, 25, respectively. For some configurations, the first channel 24 can be referred to as a dilution channel and the second channel 25 can be referred to as a concentration channel under operating conditions. In the illustrated example, four ion exchange membranes 19-22 are employed to form one first passage 24 and two second passages 25 that are alternately arranged. Alternatively, at least three ion exchange membranes can be employed to form one or more first channels and one or more second channels between the first and second electrodes 17, 18.

For the configuration illustrated in Figure 2, each of the first members 20, 22 and the respective second members 19, 21 of each pair of ion exchange membranes comprises an anion exchange membrane. In some embodiments, each anion exchange membrane can One of a monovalent anion exchange membrane and a normal anion exchange membrane is included. The monovalent anion exchange membrane is configured to pass only monovalent anions. Normal anion exchange membranes are configured to pass not only monovalent anions but also polyvalent anions. In a non-limiting example, suitable materials for the monovalent anion exchange membrane may comprise vinylbenzyl chloride (VBC), dibutylamine (DBA), tributylamine (TBA), and divinylbenzene ( Crosslinked copolymer of DVB).

A spacer 23 is disposed between each pair of adjacent ion exchange membranes 19-22 and between the first and second electrodes 17, 18 and the respective adjacent membranes 19, 22. In some embodiments, the spacer 23 can comprise any ion permeable, non-conductive material comprising a film and a porous and non-porous material.

Therefore, during operation, when the desalination device 11 is in a normal polarity state and a current is applied to the desalination device 11, liquids such as the first and second feed streams 12, 13 are introduced into the first channel 24 and the second channel, respectively. 25 in. In some applications, the first and second feed streams 12, 13 may or may not be introduced simultaneously into the desalination unit 11.

Due to the use of the anion exchange membranes 19-22, at least a portion of the ionized ruthenium dioxide (e.g., HSiO ₃ ^- ) and other anions (e.g., OH ^- and Cl ^- ) in the first feed stream 12 in the dilution passage 24 pass through The anion exchange membrane 20 migrates toward the anode 17 to enter the concentration passage 25. The cations such as Ca ²⁺ and Mg ²⁺ in the first feed stream 12 cannot pass through the anion exchange membrane 20 and remain in the dilution channel 24.

In the concentration channel 25, although the electric field exerts a force on the cations toward the respective electrodes (e.g., directing the cations to the cathode), cations such as Na ⁺ in the second feed stream 13 cannot migrate through the anion exchange membrane 19 and remain In the concentration channel 25. In the desalination apparatus 11, the dilution passage 24 and the concentration passage 25 are alternately arranged such that anions such as Cl ^- and OH ^- in the second feed stream 13 in the concentration passage 25 can migrate through the respective anion exchange membranes 19, 21 (for example) to enter the dilution channel 24 adjacent to the respective concentration channel 25.

In a non-limiting example, second feed stream 13 can include a soluble salt comprising an anion such as chloride ion (Cl ^- , referred to as a Cl ^- rich stream) that is active or strongly ionized. Thus, after the target ions, such as cerium oxide, migrate from the respective dilution channels 24 to the concentration channel 25, the active anions in the second feed stream 13 in the concentration channel 25 continue to migrate from the concentration channel 25 to the respective dilutions during operation. At channel 24, the anions can carry a greater portion of the ionic current than at least the target ions removed in the concentration channel 25. In other examples, the living anion comprises a sulfate ion (SO ₄ ^2- ) or a hydroxide ion (OH ^- ).

For example, the soluble salt comprises sodium chloride (NaCl). At least a larger portion of the ionic current may be carried by Cl ^- or other active or strongly ionized anions such as OH ^- resulting in at least a larger portion of the anions not carrying the ion current. In a non-limiting example, the concentration of active cations can be greater than the concentration of the target ions removed in each of the concentration channels 25. In other examples, when migrating from the concentration channel 25 to the respective dilution channels 24, the ion mobility of the active ions is greater than the ion mobility of the removed target ions in the respective concentration channels 25. In some applications, the amount of active ions in the second feed stream 13 during migration may be greater than the amount of HSiO ₃ ^- migrated into the concentration channel 25 to migrate from the concentration channel 25 to the respective dilution channels 24.

Thus, a portion of the active cations in the second feed stream 13 in the concentration channel 25 can migrate through the respective anion exchange membranes into the adjacent dilution channels 24. Since the active anion in the second feed stream 13 can carry a larger portion of the ion current than the removed target ion in the concentration channel 25 as it continues to migrate from the concentration channel 25 to the respective dilution channel 24 during operation, Most of the HSiO ₃ ^- cannot migrate further through the anion exchange membranes 19, 21 to enter the dilution channels 24 to remain in the respective concentration channels 25 after migrating from the respective dilution channels 24 into the concentration channels 25.

For some configurations, to increase the ion current carried by the living anion in the second feed stream 13 as it migrates from the concentration channel 25 into the dilution channel 24, as illustrated in Figure 1, the desalination system 10 further includes The ion conditioning unit 26 in fluid communication with the second feed stream 13 promotes at least more active anions in the second feed stream 13 than in the concentration channel 25 as it continues to migrate from the concentration channel 25 to the respective dilution channels 24 during operation. The removed target ions carry a larger portion of the ionic current. In a non-limiting example, ion conditioning unit 26 introduces a sodium chloride solution to increase the concentration of active ions in second feed stream 13. In some applications, the ion conditioning unit 26 may or may not be employed.

Therefore, as illustrated in FIG. 2, the second feed stream 13 passes through the concentration passage 25 to carry away the target anion such as HSiO ₃ ^{- which} migrates from the dilution passage 24, from the desalination apparatus 11 so that the dilution stream (product stream) 14 The effluent stream 15 has a lower and higher concentration of charged species, such as target ions comprising ionized cerium oxide, respectively, as compared to the first and second feed streams 12, 13.

Generally, increasing the pH of the first feed stream 12 can cause fouling or contamination of the cations including, but not limited to, Ca ²⁺ and Mg ²⁺ in the desalination unit. For the configuration illustrated in Figure 1, since the desalination device 11 is employed, the ionized ceria in the first feed stream 12 can be removed while such as Ca ²⁺ and Mg ²⁺ in the first feed stream 12 The cations may remain in the dilution channel 24 and may not concentrate in the concentration channel such that fouling or contamination propensity in the concentration channel 25 may be avoided or mitigated.

In some examples, the polarity of the first and second electrodes 17, 18 of the desalination device 11 can be reversed. In the reverse polarity state, the dilution channel from the normal polarity state can be used as a concentration channel to receive the second feed stream 13, and the concentration channel from the normal polarity state can be used as a dilution channel to receive the first feed stream 12 The first feed stream 12 is desalted (e.g., removed by the cerium oxide in the first feed stream 12) and reduces the tendency of the anions and cations in the desalination unit 11 to contaminate.

Figure 3 illustrates a schematic diagram of a desalination apparatus 30 in accordance with another embodiment of the present invention. The configuration illustrated in Figure 3 is similar to the configuration illustrated in Figure 2. The two configurations in Figures 2-3 differ in that each of the second members 31 of the ion exchange membranes 20, 22, 31 of the cerium oxide removal device 30 of Figure 3 comprises a monovalent cation exchange membrane such that plural An alternating monovalent cation exchange membrane (second member) 31 and an anion exchange membrane (first member) 20, 22 respectively form a plurality of alternating first and second passages 24, 25, which are also referred to under operating conditions. To dilute and concentrate the channels 24, 25.

The monovalent cation exchange membrane 31 is configured to pass monovalent cations. In a non-limiting example, suitable materials for the monovalent cation exchange membrane 31 may comprise a crosslinked copolymer derived from acrylamide methyl propane sulfonic acid (AMPS) and ethylene glycol dimethacrylate (EGDMA).

Therefore, similar to the configuration of FIG. 2, during operation, when the desalination device 30 is in a normal polarity state and a current is applied to the desalination device 30, the first and second feed streams 12, 13 respectively enter the first passage 24 and In the second channel 25. Due to the removal of device 30 desalting, the first feed stream 12 of such HSiO ₃ ^- ionizing at least part of silicon dioxide and the like, or such as OH ^- and Cl ^- anion through the other anion exchange membrane 20 to migrate towards the anode 17 into the In each of the second channels 25 .

The polyvalent cations in the first feed stream 12, including but not limited to, Ca ²⁺ and/or Mg ^{2+ ,} cannot migrate through the monovalent cation exchange membrane 31 to move toward the cathode 18 and thus remain in the dilution channel 24 . In some applications, monovalent cations such as Na ⁺ in the first feed stream 12 can migrate through the monovalent cation exchange membrane 31 to move toward the cathode 18 and into the adjacent concentration channel 25.

In the concentration channel 25, an anion such as HSiO ₃ ^{- which} migrates from the dilution channel 24 cannot migrate further through the monovalent cation exchange membrane 31 to move toward the anode 17 and migrate to the adjacent dilution channel 24 due to the presence of the monovalent cation exchange membrane 31. And thus remain in the respective concentration channels 25. Due to the presence of the anion exchange membranes 20, 22, cations such as Na ⁺ in the concentration channel 25 may also remain in the concentration channel 25.

Thus, during the passage of the second feed stream 13 through the concentration channel 25, the monovalent cations and anions (e.g., HSiO ₃ ^- and/or SiO ₃ ^2- ) that migrate from the dilution channel 24 to the concentration channel 25 can be carried away from the desalination unit 30. The diluent stream (product stream) 14 and the effluent stream 15 can have lower and higher concentrations of charged species such as ionized ruthenium dioxide, respectively, as compared to the first and second feed streams 12, 13.

Thus, since a monovalent cation exchange membrane 31 is employed in the desalination unit 30, at least a portion of the ionized cerium oxide can be removed from the first feed stream 12. At the same time, cations such as Ca ²⁺ and Mg ²⁺ in the first feed stream 12 can remain in the dilution channel 24 and cannot be concentrated in the concentration channel 25 to avoid or mitigate the tendency to foul or contaminate therein.

Figure 4 illustrates a schematic diagram of a desalination apparatus 32 in accordance with yet another embodiment of the present invention. The configuration illustrated in Figure 4 is similar to the configuration of Figure 3. The two configurations in Figures 3-4 differ in that each second member 33 of the ion exchange membrane of the desalination device 32 in Figure 4 is a bipolar membrane rather than the monovalent cation exchange membrane 31 of Figure 3. Therefore, a plurality of alternating bipolar membranes (second members) 33 and anion exchange membranes (first members) 20, 22 are disposed between the first and second electrodes 17, 18 to form a plurality of alternating first and The second channel 24, 25.

In a non-limiting example, a bipolar membrane can generally include a cation exchange membrane, an anion exchange membrane, and a tie layer disposed between the cation exchange membrane and the anion exchange membrane. During operation of the bipolar membrane, a cation exchange membrane and water across the anion exchange membrane to diffuse into the bonding layer dissociates into H ⁺ and OH ^- ions. H ⁺ ions migrate through the cation exchange membrane to the cathode and OH ⁻ ions migrate through the anion exchange membrane to the anode. Other cations may be excluded from the binding layer by the cation exchange layer and other anions may be excluded from the binding layer by the anion exchange layer.

Thus, similar to the configuration of FIG. 3, an anion such as HSiO ₃ ^- in the first feed stream 12 in the dilution channel enters the adjacent concentration channel 25 during operation. The cations such as Ca ²⁺ and Mg ²⁺ in the first feed stream 12 cannot migrate through the bipolar membrane 33 and remain in the respective dilution channels 24. In the concentration passage 25, since the bipolar membrane 33 is not contained, an anion such as HSiO ₃ ^{- which} migrates from the dilution passage remains in the respective concentration passages 25 and cannot enter the adjacent dilution passage 24.

Thus, during the passage of the second feed stream 13 through the concentration channel 25, anions such as HSiO ₃ ^{- which} migrate from the dilution channel 24 can be carried away from the desalination unit 32 and separated from cations such as Ca ²⁺ and Mg ²⁺ to avoid Scale or contamination in each concentration channel.

In certain applications, in order to avoid and/or reduce the tendency of fouling of cations such as Ca ²⁺ and Mg ²⁺ in the desalination apparatus 11, 30 or 32 (this tendency may be caused by the use of the pH adjusting unit 16), Prior to introducing the first feed stream 12 into the cerium oxide removal unit, a pretreatment unit can be employed to pretreat the liquid to at least partially remove the polyvalent cations therein to produce a total dissolved solids (TDS) content and A first feed stream 12 of a concentration value such as Ca ²⁺ and Mg ²⁺ .

Figure 5 illustrates a schematic of a desalination system 10 in accordance with another embodiment of the present invention. The configuration illustrated in Figure 5 is similar to the configuration of Figure 1. The two configurations of Figures 1 and 5 differ in that the pretreatment unit 34 is disposed upstream of the desalination device 11 and in fluid communication with the desalination device 11 to pretreat the input liquid 35 to remove therein such as calcium and magnesium. At least a portion of the ions, such as ions, strongly ionize the ions, thereby producing a first feed stream 12 having a suitable TDS content and a suitable cation concentration value.

For the illustrated configuration, the pre-processing unit 34 includes an inverted electrodialysis (EDR) device. Alternatively, the pre-processing unit 34 may also include an electrodialysis (ED) device, a supercapacitor desalination (SCD) device, or a softening device to pre-treat the input liquid 35.

Thus, during operation, the input liquid 35 is introduced into the EDR device 34 for processing such that at least a portion of the anions and/or cations (e.g., Ca2 ⁺ and ^Mg2+ ) can be removed from the input liquid 35, thereby producing a suitable TDS. The first feed stream 12 of the desired and cation concentration values is for introduction into the desalination unit 11. At the same time, second input liquid 36 is also introduced into EDR unit 34 to carry ions removed from input liquid 35 away from EDR unit 34, thereby producing an effluent stream 37 that can have a higher concentration of charged species than second input liquid 36. .

In certain applications, the desalination system 10 can further include a precipitation unit 38 in fluid communication with the EDR device 34. The precipitation unit 38 can provide a second input liquid 36 that circulates into the EDR device 34. As the second input liquid 36 continues to circulate, the concentration of salt or other impurities continues to increase, and some salts having low solubility, such as calcium sulfate, reach saturation or supersaturation in the second input liquid 36. Therefore, the degree of saturation or supersaturation can reach the point at which precipitation begins to occur in the precipitation unit 38. In some examples, at least a portion of the second input liquid 36 can be discharged from the passage 39 from the precipitation unit 38. Fluid 40 may be introduced to supplement second input liquid 36. In a non-limiting example, fluid 40 can have a water source similar to liquid 35.

Figure 6 illustrates an experimental diagram illustrating the cerium oxide removal efficiency of the experimental desalination apparatus 11 of one embodiment of the present invention. The desalination device 11 of Fig. 2 is used as an example for the purpose of ease of illustration. In this exemplary experiment, the first feed stream 12 has a total dissolved solids (TDS) content of about 350 ppm, which contains 40 ppm of cerium oxide. The pH of the first feed stream 12 is adjusted to 11 prior to introduction of the desalination unit 11. As illustrated in Figure 6, the cerium oxide removal efficiency of the desalination device 11 during about 5 days of continuous processing It is about 50% and relatively stable, which indicates that the cerium oxide in the first feed stream 12 can be effectively removed and the fouling in the second feed stream 13 can be correspondingly reduced.

It should be noted that the configurations in Figures 1-5 are merely illustrative. For some configurations, the configuration of Figures 1-5 can be employed for the removal of cerium oxide from aqueous streams or liquids. In other examples, the configurations in Figures 1-5 can be used to remove any other suitable ions, such as dianions in a liquid. In an embodiment of the invention, the first component of each pair of ion exchange membranes of the desalination apparatus 11, 30 or 32 is an anion exchange membrane and the second component of each pair of ion exchange membranes is, for example, used for dioxide oxidation. An anion exchange membrane, a monovalent cation exchange membrane or a bipolar ion exchange membrane removed by hydrazine. Therefore, ions such as cerium oxide in the first feed stream 12 can be efficiently and stably removed. Additionally, a pretreatment unit can be employed to further avoid fouling or contamination propensity during desalting of the first feed stream 12.

While the invention has been illustrated and described with respect to the exemplary embodiments of the invention, it is not intended to Therefore, other modifications and equivalents of the inventions disclosed herein will be apparent to those skilled in the <RTIgt; The spirit and scope of the definition.

10‧‧‧Desalting system

11‧‧‧Desalting device

12‧‧‧First feed stream

13‧‧‧Second feed stream

14‧‧‧First output stream

15‧‧‧Outflow

16‧‧‧pH adjustment unit

17‧‧‧First electrode (anode)

18‧‧‧Second electrode (cathode)

19‧‧‧Ion exchange membrane

20‧‧‧Ion exchange membrane

21‧‧‧Ion exchange membrane

22‧‧‧Ion exchange membrane

23‧‧‧ spacers

24‧‧‧First channel (dilution channel)

25‧‧‧Second channel (concentrated channel)

26‧‧‧Ion conditioning unit

30‧‧‧Desalting device

31‧‧‧Price cation exchange membrane

32‧‧‧Desalting device

33‧‧‧ Bipolar membrane

34‧‧‧Pretreatment unit

35‧‧‧Input liquid

36‧‧‧Second input liquid

37‧‧‧ outflow

38‧‧‧Precipitation unit

39‧‧‧ channel

40‧‧‧ fluid

1 is a schematic view of a desalination system according to an embodiment of the present invention; FIGS. 2-4 are schematic views of a ceria removal device according to various embodiments of the present invention; and FIG. 5 is a desalination system according to another embodiment of the present invention. Schematic; and Figure 6 is an experimental diagram illustrating the cerium oxide removal efficiency of the cerium oxide removal apparatus of one embodiment of the present invention.

10‧‧‧Desalting system

11‧‧‧Desalting device

12‧‧‧First feed stream

13‧‧‧Second feed stream

14‧‧‧First output stream

15‧‧‧Outflow

16‧‧‧pH adjustment unit

26‧‧‧Ion conditioning unit

Claims (20)

A desalination system comprising: a cerium oxide removal device configured to receive a first feed stream for cerium oxide removal and comprising: first and second electrodes; a plurality of pairs of ion exchange membranes Arranging between the first and second electrodes to form a plurality of alternating first and second channels; a plurality of spacers disposed between each of the adjacent ion exchange membranes and the Between the first and second electrodes and the respective ion exchange membranes; and wherein each of the first members of the plasma exchange membrane is an anion exchange membrane and each of the second component of the plasma exchange membrane is an anion exchange membrane, a monovalent cation exchange membrane or a bipolar ion exchange membrane, and wherein the first members and the second members are alternately disposed within the plurality of the pair of ion exchange membranes. The desalination system of claim 1, wherein each of the plurality of paired ion exchange membranes of the cerium oxide removal device comprises the anion exchange membrane. The desalination system of claim 2, wherein each of the anion exchange membranes comprises a monovalent anion exchange membrane or a normal anion exchange membrane. The desalination system of claim 1, further comprising a pH adjustment unit in fluid communication with the ceria removal unit and configured to adjust the pH of the first feed stream. The desalination system of claim 1, wherein the cerium oxide removal device is further The step is configured to receive a second feed stream to carry away ions removed from the first feed stream. The desalination system of claim 1, further comprising an ion conditioning unit in fluid communication with the ceria removal unit and configured to adjust an anion concentration in the second feed stream. The desalination system of claim 1, further comprising a pretreatment unit in fluid communication with the ceria removal device, and the unit is configured to at least partially remove polyvalent cations in the liquid to The first feed stream is produced prior to introduction of the feed stream into the cerium oxide removal unit. A desalination system according to claim 1, wherein the second member of the plasma exchange membrane comprises the bipolar membrane. A desalination system comprising: a cerium oxide removal device comprising: first and second electrodes; a plurality of pairs of anion exchange membranes disposed between the first and second electrodes to form a plurality of alternating First and second channels; and a plurality of spacers disposed between each of the adjacent anion exchange membranes and between the first and second electrodes and the respective anion exchange membranes. The desalination system of claim 9, wherein the cerium oxide removal device is configured to receive a first feed stream and a second feed stream for cerium dioxide removal to shift from the first feed stream In addition to the cerium oxide, it is carried away via the first and second passages that are alternated. The desalination system of claim 9, further comprising moving with the cerium oxide A pH adjustment unit other than the device being in fluid communication and configured to adjust the pH of the first feed stream. The desalination system of claim 9, further comprising an ion conditioning unit in fluid communication with the ceria removal device and configured to increase an anion concentration in the second feed stream. A desalination method for removing cerium oxide from an aqueous stream, comprising: defining a first feed stream through a pair of ion exchange membranes defined by a cerium oxide removal device for cerium dioxide removal a passage; passing the second feed stream through a second passage defined by the pair of ion exchange membranes of the cerium oxide removal unit to carry away the cerium oxide removed from the first feed stream; The first member of the plasma exchange membrane is an anion exchange membrane and each of the second member of the plasma exchange membrane is an anion exchange membrane, a monovalent cation exchange membrane or a bipolar ion exchange membrane, and wherein the first The member and the second members are alternately disposed within the pair of ion exchange membranes. The desalination method of claim 13, wherein the cerium oxide removing device comprises: first and second electrodes; a plurality of the pair of ion exchange membranes disposed between the first and second electrodes to form Arranging the first and second channels alternately; and a plurality of spacers disposed between each of the adjacent ion exchange membranes and the first and second electrodes and the respective ion exchange membranes between. The desalination method of claim 13, wherein each of the pair of ion exchange membranes of the cerium oxide removal device comprises the anion exchange membrane. The desalination process of claim 13, further comprising adjusting the pH of the first feed stream prior to introducing the first feed stream to the ceria removal unit. The desalination process of claim 16, wherein the pH of the first feed stream is adjusted to be between about 9.5 and about 11. The desalination process of claim 13, further comprising increasing the concentration of the anion of the second feed stream prior to introducing the second feed stream to the ceria removal unit. The desalination process of claim 18, wherein the anions in the second feed stream comprise living anions, and wherein the living anions comprise one or more of chloride ions, sulfate ions, and hydroxide ions. The desalination process of claim 13, further comprising at least partially removing the multivalent cations in the liquid to produce the first feed stream prior to introducing the first feed stream to the ceria removal unit.