A carbon aerogel adsorption electrode and an electro-adsorption system based on the carbon aerogel adsorption electrode

Abstract

The application discloses a carbon aerogel adsorption electrode and an electric adsorption system based on the carbon aerogel adsorption electrode, and a method for preparing the carbon aerogel adsorption electrode. The method adopts normal pressure drying technology, greatly reduces energy consumption in the electrode preparation process while ensuring that the electrode has large porosity. Compared with the existing electric adsorption process for regenerating circulating cooling water, the electrode regeneration process needs to be suspended for adsorption, which influences the adsorption and regeneration efficiency. The application adopts ex-situ regeneration electric adsorption, improves ion adsorption capacity, and realizes electrode regeneration in ex-situ, thereby ensuring continuous operation of the electric adsorption process, improving the adsorption and regeneration efficiency, and further improving the desalination efficiency. The electric adsorption system can be used for removing anions and cations of the circulating cooling water, and the obtained regenerated water can be used as make-up water for a cooling tower.

Description

Technical Field

[0001] This invention relates to a carbon aerogel adsorption electrode, and also to an electroadsorption system based on the aforementioned carbon aerogel adsorption electrode. Background Technology

[0002] During the operation of industrial circulating cooling water systems, the cooling water temperature rises after heat exchange with the heat exchanger. This heat is then transferred to the air via cooling tower spraying and airflow, resulting in some water evaporation and CO2 release. After multiple cycles, the evaporation causes various inorganic and organic ions in the water to concentrate, and the CO2 release leads to an increase in pH. Calcium and magnesium ions, among others, easily reach supersaturation and crystallize out of the water to form scale, which deposits on the heat exchange fins, affecting heat transfer efficiency. To alleviate scaling, corrosion, and microbial growth in circulating cooling water systems, and to increase the concentration ratio of the circulating cooling water while reducing makeup water consumption, corrosion and scale inhibitors, bactericides, and slime removers are often added. These agents have played a role to some extent. However, relying solely on these agents presents challenges in accurate dosage. Too little agent has limited effectiveness, while excessive amounts not only increase operating costs but may also lead to the accumulation of other ions or the generation of foam. Therefore, constructing a circulating cooling water treatment system and reusing reclaimed water as makeup water is crucial.

[0003] Currently, desalination methods such as electrodialysis, reverse osmosis, and ion exchange have been proven effective, but they require high-level pretreatment and frequent material replacement increases operating costs. Electroadsorption, as a novel water treatment technology, is based on the double-layer theory. It utilizes the electrochemical properties of electrode surfaces to adsorb anions and cations, releasing the adsorbed ions by reversing or short-circuiting the power supply, and discharging the concentrated wastewater to achieve purification. However, existing conventional electroadsorption systems require pausing the adsorption process during regeneration, even with high-adsorption-capacity materials, which still affects adsorption and regeneration efficiency. Using two electroadsorption systems would undoubtedly increase equipment investment costs. Summary of the Invention

[0004] Purpose of the Invention: The present invention aims to provide a carbon aerogel adsorption electrode that simultaneously possesses microporous, mesoporous, and macroporous structures and has a large number of ion intercalation channels, thereby significantly increasing the electrode's ion adsorption capacity and improving the desalination rate. Another purpose of the present invention is to provide an electroadsorption system based on the above-mentioned carbon aerogel adsorption electrode, which does not require pausing the adsorption process during regeneration, thereby effectively improving the adsorption efficiency of the electroadsorption system.

[0005] Technical solution: The carbon aerogel adsorption electrode of the present invention is prepared by the following method, specifically:

[0006] (1) Mix resorcinol (R) and formaldehyde (F) aqueous solution at a molar ratio of 1:1 to 1:3, and add alkaline catalyst (NaOH) to obtain RF solution with pH of 10 to 11.

[0007] (2) Dissolve hexadecyltrimethylammonium bromide (CTAB) in deionized water to form a dispersion, wherein the molar ratio of hexadecyltrimethylammonium bromide to resorcinol is 0.01 to 0.1:1; slowly add the RF solution from step (1) to the dispersion, and simultaneously add 0.3% graphene oxide dispersion at a dosage of 2000 ppm to 5000 ppm to obtain a mixture; the concentration of graphene oxide in the mixture is 2000 ppm to 5000 ppm; turn on magnetic stirring at 80℃ to 85℃, and form a sol-gel system through cross-linking polymerization reaction, and then age for 3 to 4 days;

[0008] This invention uses an atmospheric pressure drying method to prepare carbon aerogel. To avoid the collapse of the aerogel pore structure under atmospheric pressure drying, this invention uses hexadecyltrimethylammonium bromide (CTAB) as a template agent, which can directionally control the formation of gel particles and pore structure during the crosslinking polymerization reaction of phenolic monomers. It can also act as a surfactant to reduce surface tension. Graphene oxide is used as a modifying additive, which can enhance the conductivity and the carboxyl functional groups on its surface can be hydrogen-bonded with the hydroxyl groups on the surface of phenolic monomers to form a graphene-reinforced three-dimensional structure, which can ensure that the morphology is maintained during the atmospheric pressure drying process.

[0009] (3) The gel formed after aging is placed in a blower drying oven for normal pressure drying at 70℃~80℃ for 4h~5h; then it is placed in a carbonization furnace, protected by nitrogen, and heat-treated at 600℃~1000℃ for 2h~3h to obtain carbon aerogel electrode material.

[0010] (4) Mix 100 mL of KMnO4 solution with a concentration of 0.5 mol / L to 0.7 mol / L with 1 g of carbon aerogel electrode material and react in a hydrothermal reactor at 120℃ to 150℃ for 2 h to 3 h. After hydrothermal modification, the nano-sized manganese dioxide formed is uniformly dispersed on the surface of the graphene-reinforced carbon aerogel adsorption electrode. It stores charge through a rapid and reversible redox reaction, thereby improving the specific capacitance of the carbon aerogel adsorption electrode. After the reaction, the solid and liquid are separated, and the solid product is washed with deionized water and dried to obtain a graphene-reinforced carbon aerogel adsorption electrode supported on MnO2.

[0011] To further improve the electrochemical performance of carbon aerogel adsorption electrodes, this invention uses manganese dioxide (MnO2) as a transition metal oxide loaded onto the surface of carbon aerogel. The nano-state MnO2, as a transition metal oxide, can store charge through rapid and reversible redox reactions, giving the carbon aerogel adsorption electrode a higher specific capacitance, enabling it to carry more charge and enhancing the electrode adsorption effect.

[0012] This invention uses resorcinol and formaldehyde as reactants, followed by aging treatment, which polymerizes into a chain-like three-dimensional structure in a liquid environment to improve strength; then the solvent is removed by drying to obtain a low-density organic aerogel material; finally, high-temperature carbonization causes the pore structure to shrink, increasing the proportion of mesopores and micropores, resulting in a significant increase in the specific surface area of ​​the carbon aerogel electrode material.

[0013] The electroadsorption system based on the aforementioned carbon aerogel adsorption electrode includes a reaction chamber and an anode zone, a purification zone, and a cathode zone disposed within the reaction chamber. The anode zone consists of two opposing semi-cylindrical carbon aerogel adsorption electrodes and a rectangular insulating plate fixed between them. The semi-cylindrical carbon aerogel adsorption electrodes in the anode zone are covered with anion exchange membranes (allowing only anions to pass through, effectively increasing desalination performance and preventing cation adsorption to the electrodes during regeneration). The area of ​​the rectangular insulating plate is the same as the area of ​​the opposing surfaces of the two semi-cylindrical carbon aerogel adsorption electrodes. The cathode zone also consists of two opposing semi-cylindrical carbon aerogel adsorption electrodes and a rectangular insulating plate fixed between them. The semi-cylindrical carbon aerogel adsorption electrodes in the cathode zone are covered with cation exchange membranes (allowing only cations to pass through, effectively increasing desalination performance and preventing anion adsorption to the electrodes during regeneration). The area of ​​the rectangular insulating plate is the same as the area of ​​the opposing surfaces of the two semi-cylindrical carbon aerogel adsorption electrodes. The purification zone is located within the anode zone. Between the anode and cathode zones; the lower part of the purified water zone has an inlet, and the upper part has an outlet; it also includes a lifting mechanism and a rotating mechanism; the fixed end of the lifting mechanism is fixed to the bottom plate of the reaction chamber by bearings, and the anode or cathode zone is fixed to the drive end of the lifting mechanism; the rotating mechanism is fixed to the outside of the bottom plate of the reaction chamber, and the drive shaft of the rotating mechanism is fixedly connected to the lifting mechanism, and the rotating mechanism drives the lifting mechanism to rotate relative to the reaction chamber; it also includes four magnetic interfaces fixed to the top plate of the reaction chamber and connected to an external power source, and the four magnetic interfaces are respectively set to correspond one-to-one with the four semi-cylindrical carbon aerogel adsorption electrodes of the anode and cathode zones; among them, the semi-cylindrical carbon aerogel adsorption electrodes that are relatively close to the anode and cathode zones serve as anode adsorption electrodes and cathode adsorption electrodes; the semi-cylindrical carbon aerogel adsorption electrodes that are relatively far from the anode and cathode zones serve as anode regeneration electrodes and cathode regeneration electrodes; the anode adsorption electrodes and cathode adsorption electrodes are respectively connected to the positive and negative terminals of the external power source through the magnetic interfaces, and the anode regeneration electrodes and cathode regeneration electrodes are respectively connected to the negative and positive terminals of another external power source through the magnetic interfaces.

[0014] The water purification area is equipped with an inlet rectifier plate at the bottom and an outlet rectifier plate at the top. The opening on the inlet rectifier plate is connected to the external water inlet pipe, and the opening on the outlet rectifier plate is connected to the external water outlet pipe.

[0015] Among them, the cylindrical carbon aerogel adsorption electrodes in the anode and cathode regions are slidably connected to the rectifier plate.

[0016] The vertical height between the inlet rectifier plate and the outlet rectifier plate shall not exceed the height of the anode and cathode areas; the distance between the outlet rectifier plate and the top plate of the reaction tank shall not be less than the distance between the electrode and the magnetic suction interface before lifting; and the distance between the inlet rectifier plate and the bottom plate of the reaction tank shall not be less than the distance between the fixed end of the lifting mechanism and the anode or cathode area after lifting.

[0017] The diameters of the cylindrical anode and cathode regions are consistent with the width of the reaction chamber. The anode and cathode regions divide the reaction chamber into a clean water zone and a regeneration zone. The regeneration zone has an inlet at the bottom and an outlet at the top, through which raw water is introduced during electrode regeneration. The area where the regeneration electrode is located is the regeneration zone, and the area where the adsorption electrode is located is the clean water zone. When the rotating mechanism rotates 180°, the semi-cylindrical carbon aerogel adsorption electrode, which was originally used as an adsorption electrode, becomes a regeneration electrode. Due to the reverse connection of the electrodes, the adsorbed ions are released, and concentrated water is discharged from the top of the regeneration zone.

[0018] The lifting mechanism is a lifting cylinder. Before the lifting cylinder lifts, the sum of the heights of the lifting cylinder and the anode or cathode area is less than the height of the reaction chamber (the height difference is no more than 1 cm). Before the lifting cylinder lifts, the distance between the electrode and the magnetic interface is no more than 1 cm. Therefore, the lifting cylinder lifts the cathode and anode areas to a height of no more than 1 cm.

[0019] The rotating mechanism is a motor.

[0020] Before the adsorption process begins, circulating water is drawn from the raw water tank using a magnetic pump. Simultaneously, a cylinder pressurizes and lifts the electrode, connecting it to the magnetic interface. An external electric field voltage of 0.5V–1.5V is applied. Due to the electric field, anions and cations in the solution gradually migrate towards their opposite polarity plates, causing dissolved salts and other substances in the water to accumulate and concentrate on the electrode surface, where they are then adsorbed onto the micropores inside the electrode. The conductivity of the effluent is monitored concurrently with the reaction; a fluctuating increase in conductivity indicates that the electrode has reached saturation. Subsequently, the cylinder depressurizes, causing the electrode to descend and disconnect from the magnetic interface. Simultaneously, the motor is activated, and the cylinder rotates 180° to exchange positions between the regeneration and adsorption electrodes. The cylinder then pressurizes again, raising the electrode height and connecting it to the magnetic interface. This electrode exchange process lasts approximately 0.5s–1s. At this point, raw water from the raw water tank is introduced into the regeneration zone. Due to the reverse polarity of the electrodes, the adsorbed ions in the regeneration zone are released, and the concentrated water is discharged from the top of the regeneration zone and enters the concentrated water tank. Regeneration is complete when the conductivity of the effluent returns to that of the raw water. Simultaneously, the purification zone can continuously achieve ion adsorption. After adsorption, the water flows out through the effluent rectifier plate and then into the effluent pipe.

[0021] Beneficial effects: Compared with the prior art, the present invention has the following significant effects: (1) The carbon aerogel carbon material prepared by the present invention has good chemical stability and high conductivity, and the pore size is less than 20nm, which has a larger specific surface area than the adsorption electrode of the same volume; the MnO2 loaded on the carbon aerogel matrix makes the electrode have a higher specific capacitance, which is conducive to the rapid storage and release of charge, thereby enhancing the adsorption capacity of the electrode for ions, and thus having a high desalination rate; (2) The method of preparing carbon aerogel electrode in the present invention adopts atmospheric pressure drying technology, which greatly reduces the energy consumption of the electrode preparation process while ensuring that the electrode has a large porosity; (3) Compared with the existing electro-adsorption process of circulating cooling water regeneration, which requires pausing adsorption to complete the electrode regeneration process, affecting the adsorption and regeneration efficiency, the present invention adopts ex-situ regeneration electro-adsorption, which increases the ion adsorption amount and can realize electrode regeneration in an ex-situ, thereby ensuring the continuous operation of the electro-adsorption process, improving the adsorption and regeneration efficiency, and thus improving the desalination efficiency; the electro-adsorption system of the present invention can be used for the removal of anions and cations of circulating cooling water, and the regenerated water obtained can be used as makeup water for reuse in the cooling tower. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the electroadsorption system.

[0023] Figure 2 A top view showing the connection between the electrodes and the magnetic interface;

[0024] Figure 3 This is a side view showing the connection between the electrode and the magnetic interface. Detailed Implementation

[0025] Example 1

[0026] The preparation method of the semi-cylindrical carbon aerogel adsorption electrode of the present invention includes the following steps:

[0027] (1) Resorcinol and formaldehyde were selected as raw materials for RF gel. The aqueous solution of resorcinol (R) and formaldehyde (F) was added to the beaker to the 200mL mark (200mL RF solution) according to the molar ratio of resorcinol (R) to formaldehyde (F) of 1:2. NaOH was added to control the pH of the RF solution to 10. At the same time, CTAB solution was prepared according to the molar ratio of CTAB / R = 0.1.

[0028] (2) Slowly add the RF solution in the beaker to the CTAB solution, and at the same time slowly add 1 mL of graphene oxide dispersion (the mass concentration of graphene oxide dispersion is 0.3%). Turn on the magnetic stirring at 1000 r / min at 80℃. After the sol-gel system is formed, quickly transfer it to the semi-cylindrical prefabricated template tank, and then continue aging for 3 days.

[0029] (3) The formed gel was placed in a forced-air drying oven and dried at 75°C for 5 hours under normal pressure.

[0030] (4) Then it was placed in a carbonization furnace, protected by nitrogen, and heat-treated at 800℃ for 2 hours to obtain a carbon aerogel adsorption electrode.

[0031] (5) Dissolve 0.05 mol of KMnO4 in 100 mL of deionized water and mix it with 1 g of carbon aerogel electrode material prepared in step (4); then transfer the mixture to a hydrothermal reactor and react at 120 °C for 2 h.

[0032] (6) After natural cooling, the reactants are removed, washed repeatedly with deionized water and dried to obtain a carbon aerogel adsorption electrode supported on MnO2 and reinforced with graphene.

[0033] The N2 adsorption-desorption isotherms and pore structure of the carbon aerogel prepared in Example 1 were tested. The average pore size was 2.79 nm, and the specific surface area was 287.3 m². 2 The numerous microporous structures provide channels for the migration of ions and electrons. Cyclic voltammetry (CV) tests were conducted on the sample, and the specific capacitance was measured to be 319.7 F / g at a current density of 0.5 A / g, which enhances the amount of stored and released charge and strengthens the electrode's ability to adsorb ions.

[0034] An electroadsorption system was constructed based on the carbon aerogel adsorption electrode prepared in Example 1, such as... Figures 1-3As shown, the electroadsorption system includes a reaction chamber and an anode zone, a purified water zone, and a cathode zone disposed within the reaction chamber. The anode zone consists of two opposing semi-cylindrical carbon aerogel adsorption electrodes and a rectangular insulating plate fixed between the two semi-cylindrical carbon aerogel adsorption electrodes (the three are fixedly connected). The semi-cylindrical carbon aerogel adsorption electrodes in the anode zone are covered with anion exchange membranes (allowing only anions to pass through, effectively increasing desalination performance, and preventing cations from being adsorbed onto the electrodes during regeneration). The area of ​​the rectangular insulating plate is equal to the area of ​​the opposing surfaces of the two semi-cylindrical carbon aerogel adsorption electrodes. The cathode region consists of two opposing semi-cylindrical carbon aerogel adsorption electrodes and a rectangular insulating plate fixed between them. The semi-cylindrical carbon aerogel adsorption electrodes in the cathode region are covered with a cation exchange membrane (allowing only cations to pass through, effectively increasing desalination performance and preventing anions from adsorbing onto the electrodes during regeneration). The area of ​​the rectangular insulating plate is the same as the area of ​​the opposing surfaces of the two semi-cylindrical carbon aerogel adsorption electrodes. The purified water region is located between the anode and cathode regions. The lower part of the purified water region has an inlet rectifier plate, and the upper part has an outlet rectifier plate. The system includes a flow plate, with openings on the inlet flow plate connected to an external inlet pipe and openings on the outlet flow plate connected to an external outlet pipe. The electro-adsorption system also includes a lifting cylinder and a rotating motor. The fixed end of the lifting cylinder is fixed to the bottom plate of the reaction chamber via bearings, and the anode or cathode area is fixed to the drive end of the lifting cylinder. The rotating motor is fixed to the outside of the bottom plate of the reaction chamber, and its drive shaft is fixedly connected to the lifting cylinder, driving the lifting cylinder to rotate relative to the reaction chamber. The electro-adsorption system also includes four magnetic interfaces fixed to the top plate of the reaction chamber and connected to an external power source. Each magnetic interface is correspondingly set to one of the four semi-cylindrical carbon aerogel adsorption electrodes in the anode and cathode regions. The semi-cylindrical carbon aerogel adsorption electrodes that are relatively close to each other in the anode and cathode regions serve as the anode adsorption electrode and the cathode adsorption electrode, respectively. The semi-cylindrical carbon aerogel adsorption electrodes that are relatively far apart in the anode and cathode regions serve as the anode regeneration electrode and the cathode regeneration electrode, respectively. The anode adsorption electrode and the cathode adsorption electrode are connected to the positive and negative terminals of an external power source through the magnetic interface, respectively. The anode regeneration electrode and the cathode regeneration electrode are connected to the negative and positive terminals of another external power source through the magnetic interface, respectively.

[0035] Among them, the cylindrical carbon aerogel adsorption electrodes in the anode and cathode regions are slidably connected to the rectifier plate.

[0036] The vertical height between the inlet rectifier plate and the outlet rectifier plate shall not exceed the height of the anode and cathode areas; the distance between the outlet rectifier plate and the top plate of the reaction tank shall not be less than the distance between the electrode and the magnetic suction interface before lifting; and the distance between the inlet rectifier plate and the bottom plate of the reaction tank shall not be less than the distance between the fixed end of the lifting mechanism and the anode or cathode area after lifting.

[0037] The diameters of the cylindrical anode and cathode regions are consistent with the width of the reaction chamber. The anode and cathode regions divide the reaction chamber into a clean water zone and a regeneration zone. The regeneration zone has an inlet at the bottom and an outlet at the top, through which raw water from the raw water tank is introduced during electrode regeneration. The area where the regeneration electrode is located is the regeneration zone, and the area where the adsorption electrode is located is the clean water zone. When the rotating mechanism rotates 180°, the semi-cylindrical carbon aerogel adsorption electrode, which was originally used as an adsorption electrode, becomes a regeneration electrode. Due to the reverse connection of the electrode, the adsorbed ions are released, and concentrated water is discharged from the top of the regeneration zone.

[0038] Before the lifting cylinder lifts, the sum of the heights of the lifting cylinder and the anode or cathode area is less than the height of the reaction chamber (the height difference is no more than 1cm); before the lifting cylinder lifts, the distance between the electrode and the magnetic interface is no more than 1cm. Therefore, the lifting cylinder lifts the cathode and anode areas to a height of no more than 1cm.

[0039] Example 2

[0040] The electroadsorption system of Example 1 is used to remove anions and cations from the solution. The specific process is as follows:

[0041] Step 1: The experimental water samples were taken from the circulating water of three cooling towers in an integrated circuit manufacturing plant in East China. The original water conductivity was measured to be 1317 μs / cm, 1582 μs / cm, and 1643 μs / cm, respectively. The applied adsorption voltage was 1.5 V, and the flow rate was 40 mL / min.

[0042] Step 2: During adsorption, the cylinder pressurizes the electrode, causing it to rise and connect to the magnetic interface. The anode and cathode adsorption electrodes are connected to the positive and negative terminals of an external power source via the magnetic interface, respectively. Due to electrostatic adsorption, the cations and anions in the purified water zone are adsorbed onto the anode and cathode adsorption electrodes, respectively. The conductivity of all three sample solutions decreases sharply at the beginning, then the decrease slows down, and eventually stabilizes. Among them, the group with 1643 μs / cm shows the largest gradient of decrease, and the conductivity reaches a stable value of 53 μs / cm after 150s, with a desalination rate of 97%. After 800s, the conductivity of the effluent shows an upward trend, indicating that the adsorption electrodes are saturated.

[0043] Step 3: Subsequently, the cylinder depressurizes, causing the electrode to descend and disconnect from the magnetic interface. At the same time, the motor rotates and rotates 180° to exchange the positions of the regeneration electrode and the adsorption electrode. Then, the cylinder pressurizes, causing the electrode height to rise again and reconnect to the magnetic interface.

[0044] Step 4: The electrode conversion process lasts for 1 second. At the same time, raw water from the raw water tank is introduced into the bottom of the regeneration zone. Since the anode regeneration electrode and the cathode regeneration electrode are connected to the negative and positive terminals of another power source, the adsorbed ions are released in the regeneration zone under the application of reverse voltage and discharged as concentrated water.

[0045] Step 5: The adsorption electrode continues to adsorb, achieving continuous electro-adsorption and avoiding the need for intermittent adsorption processes due to regeneration in traditional electro-adsorption technology, thus improving adsorption efficiency (by avoiding intermittent adsorption processes, continuous operation can improve the adsorption efficiency of the entire system); after the regeneration electrode completes regeneration, this cycle ends, and the next regeneration cycle begins after the adsorption electrode is saturated.

Claims

1. An electroadsorption system based on a carbon aerogel adsorption electrode, characterized in that: The reaction chamber includes an anode zone, a purified water zone, and a cathode zone. The anode zone consists of two opposing semi-cylindrical carbon aerogel adsorption electrodes and a rectangular insulating plate fixed between them. The semi-cylindrical carbon aerogel adsorption electrodes in the anode zone are covered with anion exchange membranes. The cathode zone also consists of two opposing semi-cylindrical carbon aerogel adsorption electrodes and a rectangular insulating plate fixed between them. The semi-cylindrical carbon aerogel adsorption electrodes in the cathode zone are covered with cation exchange membranes. The purified water zone is located between the anode and cathode zones. The purified water zone has an inlet at the bottom and an outlet at the top. The reaction chamber also includes a lifting mechanism and a rotating mechanism. The fixed end of the lifting mechanism is fixed to the bottom plate of the reaction chamber via bearings, and the anode and cathode zones are respectively fixed to their corresponding... The lifting mechanism is located on the drive end of the reaction chamber; the rotating mechanism is fixed to the outside of the bottom plate of the reaction chamber, and the drive shaft of the rotating mechanism is fixedly connected to the lifting mechanism. The rotating mechanism drives the lifting mechanism to rotate relative to the reaction chamber; it also includes four magnetic interfaces fixed on the top plate of the reaction chamber and connected to an external power source. The four magnetic interfaces are respectively set to correspond one-to-one with the four semi-cylindrical carbon aerogel adsorption electrodes in the anode and cathode regions; among them, the semi-cylindrical carbon aerogel adsorption electrodes that are relatively close to each other in the anode and cathode regions serve as anode adsorption electrodes and cathode adsorption electrodes; the semi-cylindrical carbon aerogel adsorption electrodes that are relatively far apart in the anode and cathode regions serve as anode regeneration electrodes and cathode regeneration electrodes; the anode adsorption electrodes and cathode adsorption electrodes are respectively connected to the positive and negative terminals of the external power source through the magnetic interfaces, and the anode regeneration electrodes and cathode regeneration electrodes are respectively connected to the negative and positive terminals of another external power source through the magnetic interfaces.

2. The electroadsorption system according to claim 1, characterized in that: The carbon aerogel adsorption electrode is prepared by the following method, specifically including the following steps: (1) Mix resorcinol and formaldehyde aqueous solution at a molar ratio of 1:1 to 1:3, add alkaline catalyst to obtain RF solution with pH of 10 to 11; (2) Prepare a CTAB dispersion with a molar ratio of hexadecyltrimethylammonium bromide to resorcinol of 0.01~0.1:1; slowly add the RF solution from step (1) to the CTAB dispersion, and at the same time add a graphene oxide dispersion with a mass fraction of 0.3~0.4% to obtain a mixture; turn on magnetic stirring at 80℃~85℃, and form a sol-gel system through cross-linking polymerization reaction, and then age for 3d~4d; (3) The gel formed after aging is placed in a blower drying oven for normal pressure drying. After drying, it is placed in a carbonization furnace, protected by nitrogen, and heat-treated at 600℃~1000℃ for 2h~3h to obtain carbon aerogel electrode material. (4) Mix 100 mL of KMnO4 solution with a concentration of 0.5 mol / L to 0.7 mol / L with 1 g of carbon aerogel electrode material and react in a hydrothermal reactor at 120℃ to 150℃ for 2 h to 3 h. After hydrothermal modification, the nano-sized manganese dioxide formed is uniformly dispersed on the surface of the graphene-reinforced carbon aerogel adsorption electrode to obtain a graphene-reinforced carbon aerogel adsorption electrode supported on MnO2.

3. The electroadsorption system according to claim 2, characterized in that: In step (2), the concentration of graphene oxide in the mixture is 2000ppm~5000ppm.

4. The electroadsorption system according to claim 2, characterized in that: In step (3), the product is dried at a temperature of 70℃~80℃ for 4h~5h.

5. The electroadsorption system according to claim 1, characterized in that: The lower part of the water purification area is equipped with an inlet rectifier plate, and the upper part is equipped with an outlet rectifier plate. The opening on the inlet rectifier plate is connected to the external water inlet pipe, and the opening on the outlet rectifier plate is connected to the external water outlet pipe.

6. The electroadsorption system according to claim 1, characterized in that: The cylindrical carbon aerogel adsorption electrodes in the anode and cathode regions are slidably connected to the rectifier plate.

7. The electroadsorption system according to claim 1, characterized in that: The vertical height between the inlet rectifier plate and the outlet rectifier plate shall not exceed the height of the anode or cathode area; the distance between the outlet rectifier plate and the top plate of the reaction chamber shall not be less than the distance between the electrode and the magnetic suction interface before lifting; the distance between the inlet rectifier plate and the bottom plate of the reaction chamber shall not be less than the distance between the fixed end of the lifting mechanism and the anode or cathode area after lifting.

8. The electroadsorption system according to claim 1, characterized in that: The diameters of the cylindrical anode and cathode regions are consistent with the width of the reaction chamber. The anode and cathode regions divide the reaction chamber into a clean water zone and a regeneration zone. The regeneration zone has an inlet at the bottom and an outlet at the top, and raw water is introduced during electrode regeneration. The area where the regeneration electrode is located is the regeneration zone, and the area where the adsorption electrode is located is the clean water zone. When the rotating mechanism rotates 180°, the semi-cylindrical carbon aerogel adsorption electrode that was originally used as an adsorption electrode becomes the regeneration electrode. The electrode is reversed and the adsorbed ions are released, and the concentrated water is discharged from the top of the regeneration zone.

9. The electroadsorption system according to claim 1, characterized in that: The lifting mechanism is a lifting cylinder. Before the lifting cylinder lifts, the sum of the heights of the lifting cylinder and the anode or cathode area is less than the height of the reaction chamber. Before the lifting cylinder lifts, the distance between the electrode and the magnetic interface is no more than 1 cm. Therefore, the lifting cylinder lifts the cathode and anode areas to a height of no more than 1 cm.

10. The electroadsorption system according to claim 1, characterized in that: The rotating mechanism is an electric motor.

Images