A flow electrode capacitive deionization device with variable instantaneous wastewater treatment capacity

Abstract

This invention belongs to the field of heavy metal recovery technology and discloses a flow electrode capacitive deionization device with variable instantaneous wastewater treatment capacity. The device comprises a positive flow electrode, a positive peristaltic pump, a negative flow electrode, a negative peristaltic pump, a conductivity meter, a level gauge, a computer, a DC power supply, and an FCDI module. The FCDI module includes a cathode plate, an anode plate, and a wastewater treatment tank. The cathode plate consists of a cathode graphite plate, a cathode gasket, a cation exchange membrane, a cathode support plate, and a float plate. The cathode support plate is equipped with cathode fixing holes, conductivity detection holes, and level detection holes. This invention changes the liquid level by controlling the wastewater flow rate. The controller adjusts the input current or voltage of the device based on the liquid level signal to match the device's instantaneous wastewater treatment capacity.

Description

Technical Field

[0001] This invention belongs to the field of heavy metal recycling technology, specifically a flow electrode capacitor deionization device with variable instantaneous wastewater treatment capacity. Background Technology

[0002] Industrial wastewater contains a large amount of high-value-added recyclable metal elements, such as copper, lithium, nickel, silver, and palladium. These metal elements usually exist in wastewater in ionic form and at low concentrations. Although existing methods such as distillation, nanofiltration, reverse osmosis, and electrodialysis have been widely used, they still suffer from problems such as high energy consumption and easy damage to equipment, and it is difficult to recover high-value-added metal elements at low concentrations from wastewater.

[0003] As a novel ion adsorption technology, capacitive deionization has attracted increasing attention from researchers. During operation, ions in the wastewater gradually migrate to the surface of the electrode material under the influence of an electric field and are adsorbed by the electrode, thereby removing impurities. However, it suffers from problems such as limited processing capacity and the need for frequent electrode replacement.

[0004] The capacitive deionization method, which replaces the fixed electrode with a flowing electrode, can extend the working time, slow down and suppress the electrolysis reaction and co-ion effect of water, and can directly adsorb high-value-added metal ions in industrial wastewater. However, the water treatment chamber of the flowing electrode capacitive deionization (FCDI) technology is of a fixed size. Regardless of the working mode, the water treatment capacity is limited by the fixed chamber volume. At the same time, the energy consumption ratio in the inner chamber of the device using a fixed working voltage is not ideal, and the technology still needs to be optimized. Summary of the Invention

[0005] To address the problems mentioned in the background section, this invention provides a flow electrode capacitor deionization device with variable instantaneous wastewater treatment capacity, which can rapidly change the treatment volume during use and improve the operating efficiency of the device.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a flow electrode capacitive deionization device with variable instantaneous wastewater treatment capacity, the device comprising a positive flow electrode, a positive peristaltic pump, a negative flow electrode, a negative peristaltic pump, a conductivity meter, a level gauge, a computer, a DC power supply, and an FCDI module, wherein the FCDI module comprises a cathode plate, an anode plate, and a wastewater treatment tank, and the cathode plate comprises a cathode graphite plate, a cathode gasket, a cation exchange membrane, a cathode support plate, and a float plate;

[0007] The cathode graphite plate is equipped with a graphite tab, a cathode fixing hole, a conductivity detection hole, a liquid level detection hole, and an electrode flow channel. The cathode gasket is provided with a cathode fixing hole, a conductivity detection hole, and a liquid level detection hole. The cathode support plate is equipped with a cathode fixing hole, a conductivity detection hole, and a liquid level detection hole.

[0008] The anode plate is composed of an anode graphite plate, an anode gasket, an anion exchange membrane, and an anode support plate; the cathode graphite plate has a tab made of graphite, an anode fixing hole, and an electrode flow channel; the anode gasket has an anode fixing hole; and the anode support plate has an anode fixing hole.

[0009] The bottom of the waste liquid treatment tank is provided with treatment slot holes, and the treatment slot holes correspond one-to-one with the anode fixing holes. Wastewater inlet and outlet are provided at both ends of the waste liquid treatment tank.

[0010] Preferably, both the positive and negative flow electrodes are made of carbon-based materials with a solid content between 5%wt and 15%wt.

[0011] The flow rates of the positive and negative peristaltic pumps are set between 30 ml / min and 150 ml / min.

[0012] Preferably, the electrode channel has a depth of 2 mm and a width between 2 mm and 6 mm.

[0013] Preferably, the cathode gasket and anode gasket are made of materials such as silicone or rubber, and the cathode support plate and anode support plate are made of insulating materials.

[0014] Preferably, the waste liquid treatment tank is made of insulating material.

[0015] Preferably, the probes of the conductivity meter and the level gauge can be inserted into the cathode plate of the FCDI device;

[0016] The positive electrode flows into the FCDI module via a positive peristaltic pump, and the negative electrode flows into the FCDI module via a negative peristaltic pump.

[0017] The information from the conductivity meter and level gauge is transmitted to the computer in real time.

[0018] Preferably, different amounts of wastewater are added to the FCDI module according to usage requirements, and the computer controls the current of the DC power supply through software based on real-time liquid level and conductivity data.

[0019] Wastewater entering the FCDI unit undergoes directional migration under the driving force of an electric field. Anions pass through the anion exchange membrane and are adsorbed onto the positive flow electrode, while cations pass through the cation exchange membrane and are adsorbed onto the negative flow electrode, thus completing the recovery of high-value-added ions and obtaining purified water.

[0020] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0021] This invention changes the liquid level by controlling the flow rate of wastewater. The controller adjusts the input current or voltage of the device according to the liquid level signal to match the instantaneous wastewater treatment capacity of the device; and changes the residence time of a unit volume of wastewater in the device at the same flow rate.

[0022] This invention couples the ion content in wastewater with instantaneous treatment capacity, and adjusts the input current and voltage benchmarks according to different wastewater and electrolyte concentrations to match the limiting decomposition voltage of wastewater with different concentrations, thereby improving treatment capacity. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the overall invention;

[0024] Figure 2 This is a schematic diagram of the FCDI module of the present invention;

[0025] Figure 3 This is a schematic diagram of the cathode graphite plate of the present invention;

[0026] Figure 4 This is a schematic diagram of the structure of the cathode gasket, cation exchange membrane, float plate and cathode support plate of the present invention;

[0027] Figure 5 This is a schematic diagram of the structure of the anode graphite plate of the present invention;

[0028] Figure 6 This is a schematic diagram of the structure of the anode gasket, anion exchange membrane, and anode support plate of the present invention;

[0029] Figure 7 This is a schematic diagram of the wastewater treatment tank of the present invention;

[0030] Figure 8 This is an assembly diagram of the FCDI module of the present invention;

[0031] Figure 9 This is an overall schematic diagram showing the changes in the conductivity of the solution over time, the salt content in the solution over time, the current magnitude over time, and the charge efficiency of the device over time.

[0032] Figure 10This is an overall schematic diagram showing the changes in the conductivity of the solution over time, the salt content in the solution over time, the current magnitude over time, and the charge efficiency of the device over time.

[0033] Figure 11 This is a graph showing the change in the conductivity of the solution over time during the implementation of this invention.

[0034] In the diagram: 1. Negative electrode peristaltic pump; 2. Negative electrode flowing electrode; 3. Positive electrode peristaltic pump; 4. Positive electrode flowing electrode; 5. Conductivity meter; 6. Level gauge; 7. Computer; 8. DC power supply; 9. FCDI module; 10. Purified water; 11. Wastewater; 12. Cathode plate; 13. Anode plate; 14. Wastewater treatment tank; 15. Cathode graphite plate; 16. Electrode tab; 17. Cathode fixing hole; 18. Conductivity detection hole; 19. Level detection hole; 20. Electrode flow channel; 21. Cathode gasket; 22. Cation exchange membrane; 23. Cathode support plate; 24. Float plate; 25. Anode graphite plate; 26. Anode fixing hole; 27. Anode gasket; 28. Anion exchange membrane; 29. ​​Anode support plate; 30. Treatment tank hole; 31. Wastewater inlet / outlet. Detailed Implementation

[0035] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Example

[0036] like Figure 1 As shown, the present invention provides a flow electrode capacitor deionization device for wastewater with variable instantaneous treatment capacity. The device includes a positive flow electrode 4, a positive peristaltic pump 3, a negative flow electrode 2, a negative peristaltic pump 1, a conductivity meter 5, a level gauge 6, a computer 7, a DC power supply 8, and an FCDI module 9.

[0037] like Figure 2 As shown, the FCDI module 9 includes a cathode plate 12, an anode plate 13, and a waste liquid treatment tank 14.

[0038] like Figure 3 and Figure 4As shown, the cathode plate 12 is composed of a cathode graphite plate 15, a cathode gasket 21, a cation exchange membrane 22, a cathode support plate 23, and a float plate 24. The cathode graphite plate 15 is equipped with a graphite tab 16, a cathode fixing hole 17, a conductivity detection hole 18, a liquid level detection hole 19, and an electrode flow channel 20. The cathode gasket 21 is provided with a cathode fixing hole 17, a conductivity detection hole 18, and a liquid level detection hole 19. The cathode support plate 23 is equipped with a cathode fixing hole 17, a conductivity detection hole 18, and a liquid level detection hole 19.

[0039] like Figure 5 and Figure 6 As shown, the anode plate 13 is composed of an anode graphite plate 25, an anode gasket 27, an anion exchange membrane 28, and an anode support plate 29; the cathode graphite plate 15 has a tab 16 made of graphite, an anode fixing hole 26, and an electrode flow channel 20; the anode gasket 27 has an anode fixing hole 26; and the anode support plate 29 has an anode fixing hole 26.

[0040] The electrode channel 20 has a depth of 2mm and a width between 2mm and 6mm.

[0041] like Figure 7 As shown, the bottom of the waste liquid treatment tank 14 is provided with a treatment tank hole 30 and the treatment tank hole 30 corresponds one-to-one with the anode fixing hole 26. Wastewater inlet and outlet ports 31 are provided at both ends of the waste liquid treatment tank 14.

[0042] The cathode gasket 21 and anode gasket 27 are made of materials such as silicone and rubber, and the cathode support plate 23 and anode support plate 29 are made of insulating materials; the positive electrode flow electrode 4 and the negative electrode flow electrode 2 are both made of carbon-based materials, and the solid content is between 5%wt and 15%wt.

[0043] The flow rates of the positive electrode peristaltic pump 3 and the negative electrode peristaltic pump 1 are set between 30 ml / min and 150 ml / min.

[0044] Before formal assembly, it is necessary to confirm that all components of FCDI module 9 are completely dry. After complete drying, such as... Figure 8 As shown, the cation exchange membrane 22 is placed on the electrode flow channel 20 of the cathode graphite plate 15, and then the cathode gasket 21 and cathode support plate 23 are placed on the cation exchange membrane 22 in sequence and fixed with plastic screws to ensure that the ion exchange membrane will not fall off and that the cathode gasket 21 does not cover the electrode flow channel 20.

[0045] After completion, the float plate 24 is installed below the cathode graphite plate 15 to complete the assembly of the cathode plate 12 of the FCDI device. The anion exchange membrane 28 is placed on the electrode flow channel 20 of the anode graphite plate 25. Then, the anode gasket 27 and the anode support plate 29 are placed on the cation exchange membrane 22 in sequence to ensure that the ion exchange membrane will not fall off and that the cathode gasket 21 does not cover the electrode flow channel 20, thus completing the pre-assembly of the anode plate 13 of the FCDI device.

[0046] according to Figure 3 As shown, the unfixed anode plate 13 is fixed to the bottom of the waste liquid treatment tank 14 with plastic screws, and then the cathode plate 12 is placed in the waste liquid treatment tank 14 to complete the assembly of the FCDI module 9.

[0047] according to Figure 1 Connect the components as shown, and then insert the probes of the conductivity meter 5 and the level gauge 6 into the conductivity detection hole 18 and the level detection hole 19 of the cathode plate 12 in the FCDI module 9, respectively. Connect the positive and negative terminals of the DC power supply 8 to the anode plate 13 and the cathode plate 12 of the FCDI module 9, respectively.

[0048] Turn on the positive peristaltic pump 3 and the negative peristaltic pump 1, and simultaneously inject 300ml of wastewater 11 with a Li1+ ion content of approximately 1.6g / L into one end of the wastewater inlet / outlet 31 of the wastewater treatment tank 14. After the system stabilizes for 10 minutes, turn on the conductivity meter 5, the level meter, and the DC power supply 8 to start the corresponding program on the computer to begin treating the wastewater 11. At this time, the cathode plate 12 floats up, and the floating height and conductivity are displayed on the computer. The floating height is approximately 32mm, and the conductivity is 3046μS / cm. The program controls the DC power supply 8 to input a voltage of 1.32V to the FCDI.

[0049] Implementation results are as follows Figure 9 As shown, after 60 minutes, the solution conductivity decreased to 160 μS / cm, and the current also decreased with time. The charge efficiency finally reached 91%. After the ion adsorption was completed, wastewater 11 was released from the other end of the FCDI module 9, with an ion removal rate of approximately 94.7%.

[0050] in, Figure 9 Specifically:

[0051] (a) Graph showing the change in the conductivity of the solution over time;

[0052] (b) Graph showing the change in salt content in the solution over time;

[0053] (c) shows the change in current magnitude over time;

[0054] (d) Graph showing the change of device charge efficiency over time. Example

[0055] According to Embodiment 1, after connecting the FCDI module 9 to the various components, 500ml of wastewater 11 with a Cu2+ ion content of approximately 1.6g / L is injected from one end of the wastewater inlet / outlet 31 of the wastewater treatment tank 14. After the system stabilizes for 10 minutes, the conductivity meter 5, level meter, and DC power supply 8 are turned on to start the corresponding program on the computer to begin treating the wastewater 11. At this time, the cathode plate 12 floats up, and the floating height and conductivity are displayed on the computer. The floating height is approximately 53mm, and the conductivity is 6148μS / cm. The program controls the DC power supply 8 to input a voltage of 2.58V to the FCDI.

[0056] Implementation results are as follows Figure 10 As shown, after 60 minutes, the solution conductivity decreased to 378 μS / cm, and the current also decreased with time. The charge efficiency finally reached 90%. After the ion adsorption was completed, wastewater 11 was released from the other end of the FCDI module 9, with an ion removal rate of approximately 93.9%.

[0057] in, Figure 10 Specifically:

[0058] (a) Graph showing the change in the conductivity of the solution over time;

[0059] (b) Graph showing the change in salt content in the solution over time;

[0060] (c) shows the change in current magnitude over time;

[0061] (d) Graph showing the change of device charge efficiency over time. Example

[0062] According to Example 1, after connecting the FCDI module 9 to the various components, 300ml of wastewater 11 with a Li1+ ion content of approximately 1.6g / L is simultaneously injected into one end of the wastewater inlet / outlet 31 of the wastewater treatment tank 14. After the system stabilizes for 10 minutes, the conductivity meter 5, level meter, and DC power supply 8 are turned on to start the corresponding program on the computer to begin treating the wastewater 11. The above process is repeated six times, and the adsorption capacity of the device is recorded for each of the six consecutive times. The results are as follows: Figure 11 As shown, the device remained stable throughout the process, and the final ion removal rate was 93.5%.

[0063] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0064] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A wastewater flow electrode capacitive deionization device with variable instantaneous treatment capacity, the device is composed of a positive electrode flow electrode (4), a positive electrode peristaltic pump (3), a negative electrode flow electrode (2), a negative electrode peristaltic pump (1), a conductivity meter (5), a liquid level meter (6), a computer (7), a direct current power supply (8) and an FCDI module (9), characterized in that, The FCDI module (9) comprises a cathode plate (12), an anode plate (13) and a waste liquid treatment tank (14), the cathode plate (12) is composed of a cathode graphite plate (15), a cathode gasket (21), a cation exchange membrane (22), a cathode support plate (23) and a floating plate (24); The cathode graphite plate (15) is provided with a cathode fixed hole (17), an electrical conductivity detection hole (18) and a liquid level detection hole (19) and an electrode flow channel (20) made of graphite, the cathode gasket (21) is provided with the cathode fixed hole (17), the electrical conductivity detection hole (18) and the liquid level detection hole (19), and the cathode support plate (23) is provided with the cathode fixed hole (17), the electrical conductivity detection hole (18) and the liquid level detection hole (19); The anode plate (13) is composed of an anode graphite plate (25), an anode gasket (27), an anion exchange membrane (28) and an anode support plate (29), the anode graphite plate (25) is provided with an anode fixed hole (26) and an electrode flow channel (20) made of graphite, the anode gasket (27) is provided with the anode fixed hole (26), and the anode support plate (29) is provided with the anode fixed hole (26); The waste liquid treatment tank (14) is provided with a treatment tank hole (30) at the bottom, and the treatment tank hole (30) corresponds to the anode fixed hole (26) one by one, and the waste liquid treatment tank (14) is provided with a wastewater inlet and outlet (31) at two ends.

2. The flow-electrode capacitive deionization device for variable instantaneous treatment of wastewater of claim 1, wherein: The positive flow electrode (4) and the negative flow electrode (2) are both made of carbon-based materials, and the solid content is between 5%wt-15%wt. The flow rate of the positive peristaltic pump (3) and the negative peristaltic pump (1) is set to be between 30ml / min-150ml / min.

3. The flow-electrode capacitive deionization device for variable instantaneous wastewater treatment capacity of claim 1, wherein: The depth of the electrode flow channel (20) is 2mm, and the width is between 2mm-6mm.

4. The flow-electrode capacitive deionization device for variable instantaneous wastewater treatment capacity of claim 1, wherein: The cathode gasket (21) and the anode gasket (27) are made of silica gel and rubber materials, and the cathode support plate (23) and the anode support plate (29) are made of insulating materials.

5. The flow-electrode capacitive deionization device for variable instantaneous wastewater treatment capacity of claim 1, wherein: The waste liquid treatment tank (14) is made of insulating materials.

6. The flow-electrode capacitive deionization device for variable instantaneous wastewater treatment capacity of claim 1, wherein: The probes of the conductivity meter (5) and the liquid level meter (6) can be inserted into the cathode plate (12) of the FCDI module (9); The positive flow electrode (4) enters the FCDI module (9) through the positive peristaltic pump (3), and the negative flow electrode (2) can enter the FCDI module (9) through the negative peristaltic pump (1); The information of the conductivity meter (5) and the liquid level meter (6) is transmitted to the computer (7) in real time.

7. The flow-electrode capacitive deionization device for variable instantaneous wastewater treatment capacity of claim 1, wherein: Different amounts of wastewater (11) are added to the FCDI module (9) according to the use requirements, and the computer (7) controls the current size of the direct current power supply (8) through software according to the real-time liquid level and conductivity data results. The wastewater (11) entering the FCDI module (9) migrates directionally under the action of electric field driving force, anions are adsorbed on the positive flow electrode (4) after passing through the anion exchange membrane (28) respectively, and cations are adsorbed on the negative flow electrode (2) after passing through the cation exchange membrane (22) respectively, to complete the recovery of high-value-added ions, and obtain purified water (10).

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