Preparation method of flow electrode material, flow electrode and water treatment device

Abstract

The application relates to the technical field of flow electrode capacitive deionization, and discloses a preparation method of flow electrode material, a flow electrode and a water treatment device, wherein the preparation method of the flow electrode material is embedding hydrophilic nitric acid treated carbon black particles in the interlayer structure of conventional LDH flow electrode material to form NCB-LDH flow electrode material; the flow electrode is prepared by mixing the NCB-LDH flow electrode material and suitable electrolyte to form slurry, and the flow electrode has good charge utilization efficiency, energy efficiency and desalination rate; the water treatment device comprises a water treatment module, a first cation membrane, an anion membrane and a second cation membrane are sequentially arranged in the shell of the water treatment module and are parallel to each other, the water treatment device can realize efficient water purification under the dispersed conditions in remote areas, has the advantages of zero energy consumption, compatibility with people and livestock, internal regeneration of the flow electrode, miniaturization, economization and the like.

Description

Technical Field

[0001] This invention relates to the field of flow electrode capacitive deionization technology, specifically to a method for preparing flow electrode materials, a flow electrode, and a water treatment device. Background Technology

[0002] Groundwater is one of the most important freshwater resources on Earth. Its quality is influenced by numerous factors, including meteorological and hydrological conditions, lithology, underground water supply and drainage, geological structure, and geomorphology. Located in an ancient lacustrine sedimentary zone, this area's groundwater is rich in salt minerals (such as mirabilite and gypsum) and fluoride-containing rocks (fluorite). The groundwater generally has excessive fluoride levels and significantly high levels of sulfate and total hardness. This type of high-fluoride, high-salt groundwater not only tastes terrible but can also cause health problems such as diarrhea, bone deformities, kidney and cardiovascular diseases when consumed as drinking water. Therefore, it is necessary to treat this type of groundwater before consumption.

[0003] Currently, the main technologies for purifying groundwater include membrane separation, coagulation sedimentation, electrodialysis, and electroadsorption. Membrane separation technology offers high purification efficiency and wide applicability, but suffers from drawbacks such as difficult membrane module cleaning and non-renewal, high operating costs, and high wastewater rates. While coagulation sedimentation is simple to operate and inexpensive, the treated water quality rarely meets drinking water standards, and it generates secondary pollution such as sludge. Electrodialysis utilizes ion exchange membranes and electric fields to drive ion separation and concentration, making it suitable for purifying high-concentration ion pollution. Although it boasts high removal efficiency and can operate continuously, it suffers from high energy consumption (2–5 kWh / m³) and demanding operating conditions. The above-mentioned purification technologies are difficult to apply to decentralized drinking water treatment in agricultural and pastoral areas. Electroadsorption technology, on the other hand, is a novel water treatment technology based on the electrochemical double-layer theory. It mainly removes and purifies harmful ions in water by adsorbing ions on the electrode surface through electrostatic adsorption. Electroadsorption technology has the characteristics of low energy consumption (water production energy consumption of 0.5-2.0 kWh / m³), high resistance to pollution, environmental friendliness, and convenient operation. It has unique advantages for the purification of high-fluoride and high-salinity groundwater in decentralized agricultural and pastoral areas in Northwest China.

[0004] Traditional electroadsorption technology uses fixed electrodes, whose adsorption capacity is limited by the electrode surface area and charge storage capacity. Furthermore, fixed electrodes require regeneration after adsorption saturation, resulting in discontinuous processing and low efficiency. Flow electrode capacitive deionization technology, a new form of electroadsorption, uses flowing electrodes instead of fixed electrodes. This allows for off-site regeneration of the flowing electrodes and enables continuous operation and near-unlimited adsorption capacity through electrode fluidity.

[0005] Although the flow electrode capacitive deionization technology performs well in ion removal, improving the ion removal rate, ion storage capacity, and scaling up water treatment capacity remain key to achieving efficient water purification applications under decentralized conditions. The design of the device also presents corresponding design requirements and challenges.

[0006] In the field of flow electrode materials, achieving immediate use of water for treatment under dispersed conditions places high demands on the efficiency of deionization. Traditional flow electrode materials often utilize carbon-based materials such as activated carbon. While activated carbon possesses abundant pore structure and high capacitance, its conductivity is low and its surface functional groups lack stability, requiring modification through oxidation and nitriding to improve performance. With further research, transition metal LDH Faraday materials have emerged. Compared to carbon-based materials, these generally exhibit higher ion storage capacity, lower polarization effects, and superior stability. The development of LDH flow electrode materials has become a key research focus in the field of capacitive deionization using flow electrodes. Further improving the charge utilization efficiency, energy efficiency, and desalination rate of LDH flow electrode materials has also become an important research objective in this field.

[0007] In terms of device design, since it needs to be suitable for efficient water purification in remote and dispersed areas, it can be understood as similar to a household appliance. The design must fully consider local practical issues: First, existing flowing electrode capacitive deionization devices are mostly for industrial applications. During use, the flowing electrode needs to be regenerated outside the device via a regeneration unit. This design is not conducive to miniaturization and cost-effectiveness. Second, water use in pastoral areas is divided into drinking water for humans and water for livestock. The requirements for these two are different. Drinking water has higher quality requirements but lower water consumption, while livestock water has relatively lower quality requirements but higher water consumption. The device design must consider both. Third, remote areas often experience power shortages or insufficient power supply. In addition, pastoral areas are large and water sources are relatively dispersed. The device design must fully consider their power needs. Summary of the Invention

[0008] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method for preparing a flow electrode material, a flow electrode, and a water treatment device. The NCB-LDH flow electrode material prepared by this method has a higher desalination rate in the application of flow electrode capacitive deionization technology compared with the existing conventional LDH flow electrode material. The water treatment device can achieve efficient water purification under decentralized conditions in remote areas and has advantages such as internal regeneration of the flow electrode, zero energy consumption, compatibility with humans and animals, miniaturization, and economy.

[0009] The objective of this invention is achieved through the following technical solution:

[0010] A method for preparing a flow electrode material includes the following steps:

[0011] S1. Disperse carbon black in a 2% nitric acid solution and then stir at 80°C to form a suspension, wherein the ratio of carbon black to nitric acid solution is 1g:100mL.

[0012] S2. Cool the suspension to room temperature, then centrifuge the suspension to obtain the solid phase product of the suspension, and then wash the solid phase product of the suspension repeatedly with deionized water until the pH value is basically neutral.

[0013] S3. The solid product of the suspension after washing in step S2 is dried at 60°C for 12 hours to obtain NCB;

[0014] S4. Disperse nickel chloride hexahydrate, cobalt chloride hexahydrate, hexamethylenetetramine and the NCB in a deionized water substrate and form a uniform slurry by magnetic stirring, wherein the ratio of nickel chloride hexahydrate, cobalt chloride hexahydrate, hexamethylenetetramine, NCB and deionized water substrate is 15 mmol: 10 mmol: 15.625 mmol: 0.5 g: 200 mL;

[0015] S5. The uniform slurry is transferred to a high-pressure reactor lined with polytetrafluoroethylene and subjected to a hydrothermal reaction at 100°C for 10 hours to obtain the hydrothermal reactant.

[0016] S6. Centrifuge the hydrothermal reactants after step S5 to obtain the hydrothermal reaction solid product, and then repeatedly wash the hydrothermal reaction solid product with deionized water until the pH value reaches 6 to 7.

[0017] S7. The hydrothermal reaction solid product washed in step S6 is vacuum dried at 60°C for 12 hours to obtain NCB-LDH flow electrode material.

[0018] A flow electrode includes an electrolyte and an NCB-LDH flow electrode material prepared by the above method. The electrolyte is adapted to the salt solution to be treated. The flow electrode is made by mixing the NCB-LDH flow electrode material with the electrolyte. The flow electrode has good charge utilization efficiency, energy efficiency and desalination rate in the application of flow electrode capacitive deionization technology.

[0019] A water treatment device includes a water treatment module. The water treatment module includes a housing. A first cation exchange membrane, an anion exchange membrane, and a second cation exchange membrane are arranged in parallel within the housing. The first cation exchange membrane, anion exchange membrane, and second cation exchange membrane are arranged sequentially. A deionization chamber is formed between the first cation exchange membrane and the anion exchange membrane. A negative electrode chamber is formed on the side of the first cation exchange membrane away from the anion exchange membrane. A concentration chamber is formed between the second cation exchange membrane and the anion exchange membrane. A positive electrode chamber is formed on the side of the second cation exchange membrane away from the anion exchange membrane. A first flow electrode port is provided at one end of the positive electrode chamber. The other end of the positive electrode chamber is connected to one end of the negative electrode chamber. A second flow electrode port is provided at the other end of the negative electrode chamber. Liquid inlets are provided at both ends of the deionization chamber. Concentrate inlets are provided at both ends of the concentration chamber.

[0020] Furthermore, the positive and negative electrode chambers are filled with the aforementioned flowing electrode, and the device also includes an electrode circulation pump, a concentrate circulation pump, an inlet pipe, and an outlet pipe. The suction end and discharge end of the electrode circulation pump are respectively connected to the first and second flowing electrode ports. The electrode circulation pump allows the flowing electrode to circulate within the positive and negative electrode chambers. The suction end and discharge end of the concentrate circulation pump are respectively connected to the two concentrate ports. The concentrate circulation pump allows the concentrate to circulate through the concentration chamber. One end of the inlet pipe is connected to one of the liquid outlets, and one end of the outlet pipe is connected to the other liquid outlet. The water treatment device can effectively desalinate water, its flowing electrode can achieve internal regeneration through circulation, and its concentration chamber can obtain a high-concentration, salt-rich concentrated product.

[0021] Furthermore, it also includes a circulation pool, a collection pool, and a collection pipe. The discharge end of the concentrated liquid circulation pump is connected to one of the concentrated liquid ports, and the other concentrated liquid port and the suction end of the concentrated liquid circulation pump are both connected to the circulation pool. The collection pool is located below the circulation pool, and the bottom of the circulation pool is connected to the upper part of the collection pool through the collection pipe.

[0022] Furthermore, the system also includes a water supply pipe, a controller, a digital electrode, a water supply valve, and a drain valve. One end of the water supply pipe is connected to the inlet pipe, and the other end is connected to the upper part of the circulation tank. The water supply valve is installed on the water supply pipe and is used to control the on / off state of the water supply pipe. The drain valve is installed on the collection pipe and is used to control the on / off state of the collection pipe. The digital electrode is installed inside the circulation tank and is used to monitor the ion concentration of the liquid in the circulation tank. The digital electrode, water supply valve, and drain valve are all electrically connected to the controller. The water treatment device can automatically change the water in the circulation tank to prevent the concentration of the concentrate in the concentration chamber from being too high and affecting the water treatment process, while also ensuring that the concentrate collected in the collection tank reaches the set concentration.

[0023] Furthermore, it also includes a mixing tank, wherein the discharge end of the electrode circulation pump is connected to the second flow electrode port, and both the first flow electrode port and the suction end of the electrode circulation pump are connected to the mixing tank.

[0024] Specifically, there are several water treatment modules. One outlet of each water treatment module is connected to the inlet pipe via a first branch pipe, and the other outlet of each module is connected to the outlet pipe via a second branch pipe. One end of the inlet pipe is open, and the other end is closed. A first on / off valve is installed on the inlet pipe section between two adjacent first branch pipes, and a second on / off valve is installed on the outlet pipe section between two adjacent second branch pipes. Third on / off valves are installed at both ends of the outlet pipe. In this water treatment device, the topology of multiple water treatment modules ensures water treatment quality and allows for switching between series and parallel connections. This allows for high-quality, low-volume water treatment and supply via series connection, and low-quality, high-volume water treatment and supply via parallel connection, achieving compatibility with both humans and livestock.

[0025] Furthermore, it also includes photovoltaic panels and batteries. The photovoltaic panels are used to convert light energy into electrical energy and store it in the batteries. The batteries are used to power the electrode circulation pump, the concentrate circulation pump, and the water treatment module. It can directly use solar energy to convert into electrical energy to power the water treatment device, realizing zero-energy use for users.

[0026] Furthermore, it also includes a frame, on which the water treatment module, electrode circulation pump, concentrate circulation pump, inlet pipe, and outlet pipe are all fixedly installed. A photovoltaic bracket is installed on the frame, and the tilt angle of the photovoltaic bracket is adjustable. The photovoltaic panel is fixedly installed on the photovoltaic bracket. Several casters are provided at the bottom of the frame, making the water treatment device easy to move and allowing the orientation and tilt angle of the photovoltaic panel to be adjusted at different water source locations and in different seasons.

[0027] The beneficial effects of this invention are:

[0028] The method for preparing the flow electrode material in this invention involves embedding NCB (hydrophilic nitric acid-treated carbon black) particles into the interlayer structure of a conventional LDH flow electrode material to form an NCB-LDH flow electrode material. The prepared NCB-LDH flow electrode material is then mixed with an electrolyte compatible with the salt solution to be treated to form a slurry, thus producing the flow electrode of this invention. In applications of flow electrode capacitive deionization technology, this flow electrode exhibits higher charge utilization efficiency, energy efficiency, and desalination rate compared to flow electrodes prepared from conventional LDH flow electrode materials. Under the same water treatment requirements, it can achieve a smaller membrane area or fewer water treatment modules, which facilitates the miniaturization and economical design of water treatment devices, meeting the needs of decentralized applications.

[0029] The present invention provides a water treatment device, including a water treatment module. The water treatment module includes a housing, and a first cation membrane, an anion membrane, and a second cation membrane are arranged in parallel within the housing. A deionization chamber is formed between the first cation membrane and the anion membrane. A negative electrode chamber is formed on the side of the first cation membrane away from the anion membrane. A concentration chamber is formed between the second cation membrane and the anion membrane. A positive electrode chamber is formed on the side of the second cation membrane away from the anion membrane. A corresponding electric field is applied to the positive and negative electrode chambers, causing the water to be treated to flow through the deionization chamber, the flow electrode to circulate between the positive and negative electrode chambers, and the concentrate to circulate through the concentration chamber. In the deionization chamber, anions and cations in the water are adsorbed and removed by the electric field, thus achieving water desalination and purification. In the negative electrode chamber, the flow electrode receives cations removed from the deionization chamber, and as these flow electrodes flow through the positive electrode chamber, these cations are adsorbed and removed back to the concentration chamber. Thus, the flow electrode can be regenerated within the water treatment module through circulation. In the concentration chamber, the concentrate receives anions from the deionization chamber and cations from the positive electrode chamber, thus achieving salt enrichment and concentration of the concentrate. This water treatment module can simultaneously achieve water purification, internal regeneration of the flowing electrode, and salt enrichment of the concentrate. Its water purification process can effectively desalinate water to obtain drinking water that meets water quality requirements. The internal regeneration process of the flowing electrode does not require a separate regeneration device, which is conducive to making the design of the water treatment device more compact and economical. The salt enrichment process of the concentrate can also provide high-quality raw materials for downstream extraction plants.

[0030] This water treatment device also includes a circulation tank and a collection tank. Digital electrodes monitor the concentration of the concentrated solution in the circulation tank, and a controller automates the water exchange process in the circulation tank and the collection process in the collection tank. This prevents excessively high concentrations of the concentrated solution in the concentration chamber from affecting the water treatment process, while ensuring that the concentration of the concentrated solution collected in the collection tank reaches the set value, facilitating the recovery of the collected concentrated solution. The device comprises several water treatment modules, and a piping system allows for switching between series and parallel connections. This allows for high-quality, low-volume water treatment and supply via series connection, and low-quality, high-volume water treatment and supply via parallel connection, thus achieving compatibility with humans and livestock. The device also includes photovoltaic panels and batteries, enabling zero-energy operation for users. Attached Figure Description

[0031] Figure 1 The images show a comparison of the morphological characteristics of conventional LDH flow electrode materials and the NCB-LDH flow electrode material prepared in this invention. Figure 1 Image a is a SEM image of a conventional LDH flow electrode material. Figure 1 b is a SEM image of the NCB-LDH flow electrode material prepared in this invention. Figure 1 c is a TEM image of a conventional LDH flow electrode material at a scale of 100 nm. Figure 1 d is a TEM image of the NCB-LDH flow electrode material prepared in this invention at a scale of 100 nm. Figure 1 e is a TEM image of the NCB-LDH flow electrode material prepared in this invention at a scale of 200 nm. Figure 1 f is the Ni distribution diagram in the EDS elements of the NCB-LDH flow electrode material prepared in this invention. Figure 1 g is the distribution diagram of Co in the EDS elements of the NCB-LDH flow electrode material prepared in this invention. Figure 1 h is the C distribution diagram in the EDS elements of the NCB-LDH flow electrode material prepared in this invention. Figure 1 i is the distribution diagram of O in the EDS elements of the NCB-LDH flow electrode material prepared in this invention;

[0032] Figure 2 The figures show material composition characterization data for conventional LDH flow electrode materials and the NCB-LDH flow electrode material prepared in this invention. Figure 2 a represents the XRD patterns of conventional LDH flow electrode materials and the NCB-LDH flow electrode material prepared in this invention. Figure 2 b represents the FTIR spectra of conventional LDH flow electrode materials and the NCB-LDH flow electrode materials prepared in this invention;

[0033] Figure 3 The graph shows the hydrophobicity test results for conventional LDH flow electrode materials and the NCB-LDH flow electrode material prepared in this invention. Figure 3 Figure a shows the contact angle test results for a conventional LDH flow electrode material. Figure 3 b is a contact angle test diagram of the NCB-LDH flow electrode material prepared in this invention;

[0034] Figure 4 This is a comparison chart of the electrochemical performance of conventional LDH flow electrode materials and the NCB-LDH flow electrode material prepared in this invention. Figure 4 a represents the cyclic voltammetry curve of a conventional LDH flow electrode material. Figure 4 b is the cyclic voltammetry curve of the NCB-LDH flow electrode material prepared in this invention. Figure 4 c represents the constant current charge-discharge curve of a conventional LDH flowing electrode material. Figure 4 d represents the constant current charge-discharge curve of the NCB-LDH flowing electrode material prepared in this invention. Figure 4 e represents the specific capacity of conventional LDH flow electrode materials and the NCB-LDH flow electrode material prepared in this invention at different current densities. Figure 4f is the Nyquist plot of conventional LDH flow electrode materials and NCB-LDH flow electrode materials prepared in this invention;

[0035] Figure 5 A comparison of the adsorption performance of conventional LDH slurry and the NCB-LDH slurry prepared according to this invention as electrodes in a flow electrode capacitive deionization unit for desalination. Figure 5 a is an adsorption kinetic model diagram of conventional LDH slurry and the NCB-LDH slurry of the present invention as electrodes for desalination in a flow electrode capacitor deionization unit. Figure 5 b represents the adsorption isotherm model of conventional LDH slurry and the NCB-LDH slurry of the present invention as electrodes for desalination in a flow electrode capacitor deionization unit.

[0036] Figure 6 A comprehensive analysis of the electrochemical desalination performance of conventional LDH slurry and the NCB-LDH slurry prepared in this invention as electrodes in a flow electrode capacitor deionization unit is presented. Figure 6 a is a graph showing the relationship between charge efficiency and normalized desalination energy consumption for conventional LDH slurry and the NCB-LDH slurry of this invention. Figure 6 b is a graph showing the average desalination efficiency of conventional LDH slurry and the NCB-LDH slurry of the present invention when used as electrodes for desalination in a flow electrode capacitor deionization unit.

[0037] Figure 7 This is a schematic diagram of the structure of a water treatment device according to the present invention. Figure 1 ;

[0038] Figure 8 This is a schematic diagram of the structure of a water treatment device according to the present invention. Figure 2 ;

[0039] Figure 9 This is a schematic diagram of the structure of a water treatment module in a water treatment device according to the present invention;

[0040] Figure 10 for Figure 9 Cross-sectional view of the water treatment module shown Figure 1 ;

[0041] Figure 11 for Figure 9 Cross-sectional view of the water treatment module shown Figure 2 ;

[0042] Figure 12 This is a schematic diagram illustrating the working principle of a water treatment device of the present invention in a single water treatment module;

[0043] Figure 13 This is a general schematic diagram of the working principle of a water treatment device according to the present invention;

[0044] In the diagram, 1-frame, 2-photovoltaic panel, 3-photovoltaic support, 4-caster wheel, 10-shell, 11-first cation exchange membrane, 12-anion exchange membrane, 13-second cation exchange membrane, 21-electrode circulation pump, 22-concentrate circulation pump, 23-inlet pipe, 24-outlet pipe, 25-circulation tank, 26-collection tank, 27-collection pipe, 28-make-up water pipe, 29-make-up water valve, 30-drain valve, 31-mixing tank, 32-first branch pipe, 33-second branch pipe, 34-first on / off valve, 35-second on / off valve, 36-third on / off valve. Detailed Implementation

[0045] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings, but the scope of protection of the present invention is not limited to the following description.

[0046] A method for preparing a flow electrode material includes the following steps:

[0047] S1. Disperse carbon black in a 2% (w / w) nitric acid solution and stir at 80°C for about 3 hours to form a suspension. In this step, the ratio of carbon black to nitric acid solution is 1g:100mL. The stirring process can introduce oxygen-containing functional groups on the surface of carbon black, thereby enhancing the hydrophilicity and surface activity of the carbon substrate through oxidation treatment.

[0048] S2. Cool the suspension obtained in step S1 to room temperature, then centrifuge the suspension to obtain the solid phase product, and then wash the solid phase product repeatedly with deionized water until it reaches a basically neutral pH value.

[0049] S3. The solid phase product of the suspension after washing in step S2 is dried at 60°C for 12 hours to obtain NCB (hydrophilic nitric acid treated carbon black).

[0050] S4. Nickel chloride hexahydrate (NiCl2·6H2O), cobalt chloride hexahydrate (CoCl2·6H2O), hexamethylenetetramine (HMT), and NCB obtained in step S3 are dispersed in a deionized water substrate and a homogeneous slurry is formed by magnetic stirring. In this step, the ratio of nickel chloride hexahydrate (NiCl2·6H2O), cobalt chloride hexahydrate (CoCl2·6H2O), hexamethylenetetramine (HMT), NCB, and deionized water substrate is 15 mmol: 10 mmol: 15.625 mmol: 0.5 g: 200 mL.

[0051] S5. The uniform slurry obtained in step S4 is transferred to a high-pressure reactor lined with polytetrafluoroethylene and subjected to hydrothermal reaction at 100°C for 10 hours to obtain the hydrothermal reactant.

[0052] S6. Centrifuge the hydrothermal reactants after step S5 to obtain the hydrothermal reaction solid product. Then wash the hydrothermal reaction solid product repeatedly with deionized water until its pH value is 6 to 7.

[0053] S7. The hydrothermal reaction solid product washed in step S6 is vacuum dried at 60°C for 12 hours to obtain a black powder NCB-LDH flow electrode material.

[0054] The NCB-LDH flow electrode material prepared according to the above method is used as an example. The conventional LDH flow electrode material (the conventional LDH manufacturing process is basically the same as the preparation method of the above NCB-LDH flow electrode material, the only difference is that NCB is not prepared in steps S1 to S3 and NCB is not added in step S4) is used as a comparative example for comparative testing as follows.

[0055] Characterization tests:

[0056] Morphological images of NCB-LDH flow electrode materials and conventional LDH flow electrode materials were obtained using scanning electron microscopy, such as... Figure 1 As shown in Figure a, conventional LDH flow electrode materials exhibit an aggregated, petal-like nanosheet structure with a typical layered morphology, compared to... Figure 1 As shown in b, the NCB-LDH flow electrode material exhibits granular NCB uniformly embedded in the interlayer structure of LDH.

[0057] Further morphological images of the NCB-LDH flow electrode material and conventional LDH flow electrode material were obtained using transmission electron microscopy, such as... Figure 1 As shown in c, conventional LDH flow electrode materials consist of ultrathin plate-like layers; while... Figure 1 As shown in d, the NCB-LDH flowing electrode material exhibits a uniform dispersion of NCB between LDH sheets. This structural configuration is conducive to the formation of an interconnected conductive network and to simultaneously enhancing the material's electron transport and ion adsorption properties.

[0058] like Figure 1 e to Figure 1 As shown in Figure i, the EDS elemental distribution analysis results also show that NCB is uniformly distributed in the NCB-LDH flow electrode material, confirming that NCB has been successfully incorporated.

[0059] The crystal structures of conventional LDH flow electrode materials and NCB-LDH flow electrode materials were characterized by X-ray diffraction (XRD), and the results are as follows: Figure 2As shown in Figure a, the conventional LDH flow electrode material exhibits characteristic diffraction peaks at approximately 11.28°, 23.82°, 34.78°, and 61.14°. These characteristic diffraction peaks are also retained in the NCB-LDH flow electrode material, indicating that the introduction of NCB did not significantly disrupt the LDH nucleation process or crystal growth. Compared to the conventional LDH flow electrode material, the NCB-LDH flow electrode material shows new characteristic diffraction peaks at approximately 25.84° and 43.18°, corresponding to the (111) and (110) crystal planes of graphite carbon, confirming that NCB has been successfully incorporated into the conventional LDH flow electrode material. Compared to the conventional LDH flow electrode material, as shown by the (006) crystal plane position, the characteristic diffraction peaks of the NCB-LDH flow electrode material are slightly broadened, and a new characteristic diffraction peak is added near 43.18°, further proving that NCB has been loaded onto LDH. According to the Bragg equation, after the introduction of NCB, the interlayer spacing of the (003) crystal plane increased from 0.79 nm to 0.88 nm. This increase in interlayer spacing is attributed to the electrostatic rebalancing of the LDH layers caused by the NCB framework.

[0060] like Figure 2 As shown in b, Fourier transform infrared spectroscopy (FTIR) was used to further verify that NCB was successfully incorporated into the LDH framework: conventional LDH flow electrode materials showed up at 3640 cm⁻¹. -1 A characteristic absorption peak appears at [value missing], corresponding to the stretching vibrations of surface hydroxyl groups and interlayer water molecules (OH). After the introduction of NCB, the NCB-LDH flow electrode material exhibits a peak at 3630-3360 cm⁻¹. -1 The presence of multiple broadened absorption peaks within the range indicates the introduction of additional hydroxyl groups after NCB surface oxidation; the peaks at 1660-1590 cm⁻¹... -1 The characteristic absorption peak observed at 1470-1070 cm⁻¹ corresponds to the bending vibration of the interlayer HOH groups, further confirming the increased hydroxyl content; -1 Vibrational peaks of CO and C=O functional groups were detected in the interval, indicating that CO exists in the interlayer of both LDH and NCB-LDH composite materials. 2- In addition, 1000cm -1 The nearby peaks correspond to the stretching vibrations of Ni-O and Co-O in the LDH lattice. In summary, FTIR spectroscopy confirms that NCB has been successfully loaded and a chemically compatible NCB-LDH composite structure has been formed.

[0061] like Figure 3 a, Figure 3As shown in b, the contact angle test results indicate that the hydrophilicity of the NCB-LDH flow electrode material is significantly enhanced after the introduction of NCB, specifically, the contact angle decreases from 55.64° to 38.87°. This improved surface wettability facilitates more efficient electrolyte penetration, thereby reducing the ion diffusion resistance on the electrode surface and in the internal pores, ultimately forming faster and more continuous ion transport and adsorption channels in the material.

[0062] Electrochemical testing:

[0063] The electrochemical performance of conventional LDH flow electrode materials and NCB-LDH flow electrode materials was evaluated using cyclic voltammetry (CV), such as... Figure 4 a, Figure 4 As shown in b, both electrode materials exhibit non-rectangular and asymmetric CV curves, a typical characteristic of pseudocapacitive behavior. With increasing scan rate, the current response enhances, while the overall shape of the CV curve remains largely unchanged, indicating stable reversibility. After introducing NCB, the CV curve becomes closer to a rectangle and exhibits a higher peak current density, reflecting its enhanced capacitance and faster charge transfer rate.

[0064] The electrochemical performance of conventional LDH flow electrode materials and NCB-LDH flow electrode materials was evaluated using galvanostatic charge-discharge (GCD), such as... Figure 4 c. Figure 4 As shown in d, the NCB-LDH flow electrode material exhibits a longer discharge time and a smoother discharge plateau (especially under high current conditions), indicating that it has excellent charge storage dynamics. This improvement is attributed to the conductive NCB framework, which enhances the double-layer ion storage within the electrode and accelerates ion transport.

[0065] like Figure 4 As shown in e, the NCB-LDH flow electrode material achieves a higher specific capacitance (in 1 A·g). -1 The current density is 406 C·g -1 ), and maintained excellent rate performance (at 10 A·g). -1 With a capacity retention of 88.4% at current density, its performance is significantly better than that of conventional LDH flow electrode materials (at 10 A·g). -1 Below is 18C·g -1 (Capacity retention was 19.5%). These results confirm that the introduction of NCB significantly improves electron and ion transport pathways by forming a well-integrated conductive network rich in surface hydroxyl groups.

[0066] To further elucidate the mechanisms of charge transfer and ion diffusion, EIS tests were performed, such as... Figure 4As shown in f, the Nyquist plot displays a near-semi-circular arc in the high-frequency region and a sloping line in the low-frequency region, corresponding to the charge transfer resistance (Rct), equivalent series resistance (Rs), and Warburg diffusion impedance (W), respectively. After introducing NCB, the Rct value decreased by approximately 67.1%, highlighting the role of NCB in reducing internal resistance and enhancing interfacial charge transport. These improvements collectively contribute to the excellent desalination and electrochemical performance of the NCB-LDH flow electrode material in flow electrode capacitive deionization systems.

[0067] Deionization performance test:

[0068] The experimental setup consists of a flow electrode capacitor deionization unit, a conductivity meter, a peristaltic pump, and a DC power supply. The flow electrode capacitor deionization unit has a conventional structure, comprising a shell, an anion exchange membrane, and a cation exchange membrane. The anion and cation exchange membranes are arranged parallel to each other within the shell, forming a liquid flow chamber between them. The side of the anion exchange membrane furthest from the liquid flow chamber forms the positive electrode flow chamber, and the side of the cation exchange membrane furthest from the liquid flow chamber forms the negative electrode flow chamber. The structure of this flow electrode capacitor deionization unit can be found in the invention patent "Cathode Flow Electrode Liquid, Flow Electrode Capacitor Deionization Device and Its Application" (CN202110405356.3). During the experiment, the flow electrode capacitor deionization unit was operated in closed-loop mode in short-circuit mode under an applied voltage of 1.2V using a DC power supply, forming positive and negative electrodes at the positive and negative flow electrode chambers, respectively. Flow electrode slurry (prepared by mixing and stirring the flow electrode material with an electrolyte of the same type as the salt solution to be removed; in the experiment, the example used NCB-LDH flow electrode material mixed with 1000 mg / L NaCl solution to prepare the NCB-LDH slurry, while the comparative example used conventional LDH flow electrode material mixed with 1000 mg / L NaCl solution to prepare the LDH slurry) was pumped using a peristaltic pump. 250 mL of NaCl solution was pumped into the flow electrode chamber using a peristaltic pump. The flow rate continuously circulates through the liquid flow chamber, and the conductivity of the NaCl solution is monitored in real time by a conductivity meter to determine the ion concentration. The principle of this flow electrode capacitive deionization unit is as follows: under the electroadsorption effect of the positive electrode flow chamber, anions in the NaCl solution flowing through the liquid flow chamber are adsorbed outwards. These anions pass through the anion exchange membrane and enter the flow electrode slurry in the positive electrode flow chamber. Under the electroadsorption effect of the negative electrode flow chamber, cations in the NaCl solution flowing through the liquid flow chamber are adsorbed outwards. These cations pass through the cation exchange membrane and enter the flow electrode slurry in the negative electrode flow chamber. Thus, both anions and cations in the NaCl solution flowing through the liquid flow chamber can be effectively removed. The ion removal effect, i.e., the desalination performance, of different flow electrode slurries can be detected by real-time monitoring with a conductivity meter.

[0069] Desalination performance is evaluated using four key parameters: salt adsorption capacity (SAC, unit: mg·g). -1 Average desalination rate (ASRR, unit μmol·cm) -2 ・min -1 ), charge efficiency (CE, in %) and energy normalized desalination capacity (ENRS, in μmol·J) -1 The calculation formula is as follows:

[0070] ,

[0071] ,

[0072] ,

[0073] ,

[0074] Where: C0 (unit: mg·L) -1 The initial concentration of the Cl⁻ solution is Ct (unit: mg·L⁻). -1 Let t be the concentration of Cl⁻ solution at time t, V (in L) be the volume of Cl⁻ solution, m (in g) be the electrode mass, and M be the molar mass of NaCl (58.4 g·mol⁻¹). -1 A (in cm²) is the effective contact area between the ion exchange membrane and the flow channel, t (in seconds) is the adsorption time, and F is the Faraday constant (96485 C·mol⁻¹). -1 I (unit: A) is the instantaneous current at the adsorption moment, and U (unit: V) is the applied voltage.

[0075] like Figure 5 a, Figure 5 As shown in b, the adsorption capacities of both electrodes (NCB-LDH slurry and LDH slurry) gradually increased over time until equilibrium was reached. Notably, the equilibrium adsorption capacity of the NCB-LDH slurry was significantly higher than that of the LDH slurry, indicating that the introduction of NCB can significantly improve desalination performance. This observation is consistent with the kinetic fitting results (Table 1): under both pseudo-first-order and pseudo-second-order kinetic models, the NCB-LDH slurry exhibited superior adsorption capacity. The steeper adsorption curve of the NCB-LDH slurry further confirms that NCB not only accelerates the adsorption rate but also improves the equilibrium adsorption capacity. Both electrodes showed high correlation coefficients under both kinetic models, indicating that the overall adsorption process is the result of the combined effects of diffusion-controlled physisorption and reaction-controlled chemisorption.

[0076]

[0077] The adsorption capacity of both electrodes increased with increasing equilibrium salt concentration until saturation was reached. This phenomenon can be attributed to the gradual occupancy of active sites. Throughout the concentration range, the adsorption performance of the NCB-LDH slurry was consistently superior to that of the LDH slurry, especially under high salinity conditions (>2000 mg·L⁻¹). -1 This highlights its stronger desalination capability in the concentration system. Table 2 shows the maximum adsorption capacity of NCB-LDH slurry (57.08 mg·g⁻¹). -1 The concentration was significantly higher than that of LDH slurry (39.12 mg·g⁻¹). -1 This further confirms its superior ion storage capacity at high concentrations. Furthermore, the adsorption data of the NCB-LDH slurry showed a better fit to the Langmuir model than the Freundlich model, indicating that the adsorption process is dominated by monolayer adsorption on uniform active sites. This result demonstrates that the introduction of NCB promotes a more uniform distribution and higher activity of adsorption sites, thereby enhancing the adsorption capacity.

[0078]

[0079] like Figure 6 As shown in Figure a, the overall desalination performance of the electrode was comprehensively evaluated by assessing the charge utilization efficiency and normalized energy consumption during the ion adsorption process. The NCB-LDH slurry exhibited a charge transfer efficiency of 46.72%, significantly higher than the 36.58% of the LDH slurry. This indicates that the introduction of NCB greatly improved the effective utilization of charge in adsorbing salt ions. Normalized desalination energy consumption, defined as the amount of desalination achievable per unit of energy input, is a key indicator of the process's energy efficiency; a higher value indicates better energy performance. The NCB-LDH slurry achieved 1.62 μmol·J. -1 The ENRS value was improved by 26.6% compared to LDH slurry. This improvement is attributed to the formation of a conductive carbon network, which promotes faster electron transport and more efficient energy utilization.

[0080] Figure 6 b shows that the average desalination rate of the NCB-LDH slurry reached 0.7839, an improvement of 27.5% compared to the LDH slurry. Overall, the introduction of NCB brings significant advantages to the NiCo-LDH electrode in terms of charge utilization efficiency, energy efficiency, and desalination rate. These performance improvements stem from the synergistic effect of improved electronic conductivity and increased accessibility to electroactive sites, ultimately optimizing the capacitive deionization process and making it suitable for high-performance desalination applications.

[0081] The structure of a water treatment device is as follows Figure 7 , Figure 8 As shown, it includes, Figures 9 to 11The water treatment module shown includes a housing 10. A first cation exchange membrane 11, an anion exchange membrane 12, and a second cation exchange membrane 13 are arranged in parallel within the housing 10. These membranes are sequentially arranged. A deionization chamber is formed between the first cation exchange membrane 11 and the anion exchange membrane 12. A negative electrode chamber is formed on the side of the first cation exchange membrane 11 away from the anion exchange membrane 12. A concentration chamber is formed between the second cation exchange membrane 13 and the anion exchange membrane 12. A positive electrode chamber is formed on the side of the second cation exchange membrane 13 away from the anion exchange membrane 12. A first flow electrode port is provided at one end of the positive electrode chamber, and the other end of the positive electrode chamber is connected to one end of the negative electrode chamber. A second flow electrode port is provided at the other end of the negative electrode chamber. Liquid inlets are provided at both ends of the deionization chamber, and concentrated liquid inlets are provided at both ends of the concentration chamber.

[0082] The positive and negative electrode chambers are filled with flowing electrodes, such as Figure 12 As shown, an electrode circulation pump 21, a concentrate circulation pump 22, an inlet pipe 23, and an outlet pipe 24 are also provided. The electrode circulation pump 21 and the concentrate circulation pump 22 are peristaltic pumps. The suction end and the discharge end of the electrode circulation pump 21 are connected to the first flow electrode port and the second flow electrode port, respectively. The suction end and the discharge end of the concentrate circulation pump 22 are connected to two concentrate ports, respectively. One end of the inlet pipe 23 is connected to one liquid outlet, and one end of the outlet pipe 24 is connected to another liquid outlet.

[0083] The water treatment device operates as follows when it has only a single water treatment module: Figure 12As shown, during operation, corresponding electric fields are applied to the positive and negative electrode chambers. The electrode circulation pump 21 pumps the flowing electrode to circulate along the second flowing electrode port, the negative electrode chamber, the positive electrode chamber, and the first flowing electrode port. The concentrate circulation pump 22 pumps the concentrate to circulate in the concentration chamber. The pressurized water to be treated (the inlet pressure can be directly provided by the water pumping equipment at the water source) enters from the inlet pipe 23, enters the deionization chamber through the liquid outlet at one end of the deionization chamber, flows to the liquid outlet at the other end of the deionization chamber, and is finally discharged through the outlet pipe 24. In the above process, the water treatment device simultaneously completes three processes: water purification, flow electrode regeneration, and concentrate concentration. The water purification process refers to the process where, as the pressurized water flows through the deionization chamber, it is influenced by the electric field adsorption. Cations in the pressurized water pass through the first cation membrane 11 and enter the flow electrode in the negative electrode chamber, while anions in the pressurized water pass through the anion membrane 12 and enter the concentrate in the concentration chamber. Thus, the pressurized water effectively removes anions and cations as it flows through the deionization chamber, completing the desalination process. The flow electrode regeneration process refers to the process where, during the circulation of the flow electrode by the electrode circulation pump 21, the flow electrode receives water from the deionization chamber as it flows through the negative electrode chamber. The cations in the positive electrode chamber are absorbed by the electric field, and the flow electrode that receives these cations then flows through the positive electrode chamber. The electric field adsorption causes these cations to pass through the second cation membrane 13 and enter the concentration chamber. Thus, the flow electrode is regenerated through circulation within the water treatment module. The concentration process of the concentrate occurs in the concentration chamber. The second cation membrane 13 can block and retain anions absorbed from the pressurized water in the concentration chamber, and the anion membrane 12 can block and retain cations that are regenerated and released from the flow electrode in the positive electrode chamber in the concentration chamber. Thus, a salt-rich concentrate can be formed in the concentration chamber. It should be understood that circulating the concentrate is beneficial for the uniform distribution of anions and cations received in the concentration chamber.

[0084] To achieve on-demand water treatment—that is, to obtain drinking water meeting standards directly from the outlet pipe 24 after groundwater is introduced into the inlet pipe 23—it is usually necessary to increase the membrane area within the water treatment module or to use multiple water treatment modules in a series topology. In specific implementation, the flowing electrode in this water treatment device is made by mixing an electrolyte with the aforementioned NCB-LDH flowing electrode material. This electrolyte is compatible with the salt solution to be treated (e.g., for fluoride removal, the electrolyte uses a sodium fluoride solution of approximately the same concentration). During mixing, the NCB-LDH flowing electrode material and the electrolyte are thoroughly mixed and stirred into a slurry. As mentioned above, the NCB-LDH slurry has significant advantages in charge utilization efficiency, energy efficiency, and desalination rate. Under the same water treatment requirements, compared to existing flowing electrode materials, it can achieve a smaller membrane area or fewer water treatment modules. This translates to a more compact and economical design for the overall water treatment device, meeting the needs of decentralized applications.

[0085] Furthermore, such as Figure 12 As shown, the water treatment device also includes a circulation tank 25, a collection tank 26, and a collection pipe 27. The discharge end of the concentrate circulation pump 22 is connected to one concentrate port, and the other concentrate port and the suction end of the concentrate circulation pump 22 are both connected to the circulation tank 25. The collection tank 26 is located below the circulation tank 25, and the bottom of the circulation tank 25 and the upper part of the collection tank 26 are connected through the collection pipe 27. In practical applications, the concentration of the concentrate in the concentration chamber will continuously increase. When the concentration of the concentrate is too high, an excessively high concentration difference will be formed between the concentration chamber and the deionization chamber, which is not conducive to the working process of the water treatment module. Therefore, the circulation tank 25 and the collection tank 26 are designed. During normal operation, the circulation tank 25 provides the concentrate, and the concentrate circulation pump 22 draws the concentrate from the circulation tank 25 and pumps it into the concentration chamber, eventually flowing back to the circulation tank 25 to complete the circulation of the concentrate. When the concentration of the concentrate in the circulation tank 25 is too high, the concentrate in the circulation tank 25 can be discharged into the collection tank 26 for collection. It should be understood that, based on the flow electrode capacitive deionization technology, the water treatment module allows for a wide range of concentrate concentrations, meaning that the collected concentrate has a high concentration. This high-concentration, salt-rich concentrate is a high-quality raw material for downstream extraction plants. Although the single-unit output of concentrate is low under dispersed conditions, if this water treatment device can be widely adopted, achieve economies of scale, and overcome transportation barriers, it can facilitate recycling by downstream extraction plants and bring certain economic benefits to users.

[0086] Furthermore, a water supply pipe 28, a controller (not shown in the diagram), a digital electrode (not shown in the diagram), a water supply valve 29, and a drain valve 30 are also provided. One end of the water supply pipe 28 is connected to the inlet pipe 23, and the other end of the water supply pipe 28 is connected to the upper part of the circulation tank 25. Both the water supply valve 29 and the drain valve 30 are electrically controlled valves. The water supply valve 29 is installed on the water supply pipe 28 and is used to control the opening and closing of the water supply pipe 28. The drain valve 30 is installed on the collection pipe 27 and is used to control the opening and closing of the collection pipe 27. The digital electrode can be a TDS-8002 large-range digital electrode, which is installed in the circulation tank 25 and is used to monitor the ion concentration of the liquid in the circulation tank 25. The digital electrode, water supply valve, and drain valve are all electrically connected to the controller. During application, a concentration threshold is set. When the digital electrode detects that the liquid concentration in the circulation tank 25 reaches this threshold, the controller controls the drain valve 30 to open, allowing the liquid in the circulation tank 25 to drain into the collection tank 26 through the collection pipe 27 under its own weight. After a set delay, the liquid in the circulation tank 25 is completely drained. Then, the controller controls the drain valve 30 to close and controls the water supply valve 29 to open, introducing water from the inlet pipe 23 into the circulation tank 25 to replenish the water. After a set delay, the controller again controls the water supply valve 29 to close. Thus, this water treatment device can achieve online monitoring of the liquid concentration in the circulation tank 25 and automatic water replacement, ensuring the normal operation of the water treatment device and also ensuring that the collected concentrate has a high concentration for easy recovery.

[0087] Furthermore, a mixing tank 31 is also provided. The discharge end of the electrode circulation pump 21 is connected to the second flow electrode port. The first flow electrode port and the suction end of the electrode circulation pump 21 are both connected to the mixing tank 31. The mixing tank 31 is used to prepare or hold the flow electrode slurry according to the water to be treated. After the electrode circulation pump 21 draws the flow electrode slurry from the mixing tank 31, it is injected into the negative electrode chamber through the second flow electrode port. Then the flow electrode slurry flows through the positive electrode chamber and flows back to the mixing tank 31 through the first flow electrode port.

[0088] In specific implementation, such as Figure 7 , Figure 8 , Figure 13 As shown, several water treatment modules are configured. One outlet of each module is connected to the inlet pipe 23 via a first branch pipe 32, and the other outlet of each module is connected to the outlet pipe 24 via a second branch pipe 33. The inlet pipe 23 is open at one end and closed at the other, with the open end serving as the inlet and connecting to the water pumping equipment. A first on / off valve 34 is installed on each section of the inlet pipe 23 between two adjacent first branch pipes 32, and a second on / off valve 35 is installed on each section of the outlet pipe 24 between two adjacent second branch pipes 33. A third on / off valve 36 is installed at both ends of the outlet pipe 24. This configuration forms a series-parallel switching structure, capable of meeting different water needs in pastoral areas and achieving compatibility between humans and livestock.

[0089] Specifically, with Figure 13 Taking the example of the embodiment with eight water treatment modules shown, when all first on / off valves 34 are open, all second on / off valves 35 are open, one third on / off valve 36 is open and the other third on / off valve 36 is closed, the eight water treatment modules are in parallel mode. At this time, the pressurized water entering from the inlet end of the inlet pipe 23 flows through the deion chambers of the eight water treatment modules and is discharged from one end of the outlet pipe 24. In this parallel mode, the water purification effect is relatively low but the allowable water flow is large, which is suitable for application scenarios such as livestock water use where the water quality requirements are relatively low but the water consumption is large; when Figure 13 As shown, the first, third, and fifth first opening / closing valves 34 from the left are all closed; the second, fourth, and sixth first opening / closing valves 34 from the left are all open; the first, third, fifth, and seventh second opening / closing valves 35 from the left are all open; the second, fourth, and sixth second opening / closing valves 35 from the left are all closed; and the third opening / closing valve 36 at the left end is closed while the third opening / closing valve 36 at the right end is open. Figure 13 The six water treatment modules on the left are in series. Pressurized water entering through the inlet of inlet pipe 23 flows sequentially through the deionization chambers of these six modules. If the seventh valve 34 (from the left) is open, the water treated by the first six modules in series can simultaneously flow through the deionization chambers of the seventh and eighth modules and then exit from the right end of outlet pipe 24. If the seventh valve 34 is closed, the seventh module is added to the series connection, and the water treated by the first six modules flows through its deionization chamber and exits from the right end of outlet pipe 24. This series connection mode ensures water purification but allows for a smaller flow rate, making it suitable for applications with high water quality requirements but low water consumption, such as drinking water. Besides the series and parallel connection modes, this water treatment device allows for flexible selection of the number and series / parallel connection of water treatment modules based on water quality requirements and water consumption. For example, it can use… Figure 13 As shown, the second and sixth first-opening / closing valves 34 from the left are both closed, while the other first-opening / closing valves 34 are all open. The fourth second-opening / closing valve 35 from the left is closed, while the other second-opening valves 35 are all open. When the third-opening / closing valve 36 at the left end is closed and the third-opening / closing valve 36 at the right end is open, each pair of the first six water treatment modules from the left is connected in parallel. These three parallel groups of water treatment modules are then connected in series. Regarding the water accumulation at the right end of the inlet pipe 23 during the water treatment process, as... Figure 7 , Figure 8 As shown, during implementation, the inlet pipe 23 is positioned above the outlet pipe 24. When the inlet water head is lost, the accumulated water can be discharged into the outlet pipe 24 under its own weight.

[0090] It should be understood that the aforementioned first on / off valve 34, second on / off valve 35, and third on / off valve 36 can be selected as manual valves controlled by the user in a series-parallel connection mode, or they can be selected as electric valves electrically connected to the aforementioned controller to automatically adjust the mode when the user inputs water usage parameters; each water treatment module can be configured according to... Figure 12 The illustrated configuration is equipped with a separate electrode circulation pump 21 and a concentrate circulation pump 22. During implementation, it can also be configured as follows: Figure 7 , Figure 8 , Figure 13 As shown, the concentration chambers of each water treatment module are connected in series, and the first and second flow electrode ports of two adjacent water treatment modules are connected. This allows each water treatment module to share a set of electrode circulation pump 21 and concentrate circulation pump 22, making the entire water treatment device more compact and economical, and meeting the needs of use under decentralized conditions.

[0091] Furthermore, such as Figure 7 , Figure 8 As shown, the water treatment device also includes a photovoltaic panel 2 and a storage battery (not shown in the diagram). The photovoltaic panel 2 converts solar energy into electrical energy and stores it in the storage battery. The storage battery powers the electrode circulation pump 21, the concentrate circulation pump 22, and the water treatment module. Therefore, this water treatment device can directly convert solar energy into electrical energy to power its operation, achieving zero-energy use for users. It is suitable for applications in large pastoral areas with dispersed water sources.

[0092] Furthermore, a frame 1 is also provided, on which the aforementioned water treatment module, electrode circulation pump 21, concentrate circulation pump 22, inlet pipe 23, outlet pipe 24, as well as circulation tank 25, collection tank 26, and mixing tank 31 are all integrated and fixedly installed. A photovoltaic bracket 3 is installed on the frame 1, and the photovoltaic panel 2 is fixedly installed on the photovoltaic bracket 3. The tilt angle of the photovoltaic bracket 3 is adjustable, allowing the tilt angle of the photovoltaic panel 2 to be adjusted in different seasons. Several casters 4 are provided at the bottom of the frame 1 to facilitate the movement of the entire water treatment device and to facilitate the adjustment of the orientation of the photovoltaic panel 2 towards the direction of sunlight at different water intake points.

[0093] The above description is merely a preferred embodiment of the present invention. It should be understood that the present invention is not limited to the forms disclosed herein and should not be construed as excluding other embodiments. It can be used in various other combinations, modifications, and environments, and can be altered within the scope of the concept described herein through the above teachings or related technologies or knowledge. Modifications and variations made by those skilled in the art that do not depart from the spirit and scope of the present invention should be within the protection scope of the appended claims.

Claims

1. A method for preparing a flow electrode material, characterized in that, Includes the following steps: S1. Disperse carbon black in a 2% nitric acid solution and then stir at 80°C to form a suspension, wherein the ratio of carbon black to nitric acid solution is 1g:100mL. S2. Cool the suspension to room temperature, then centrifuge the suspension to obtain the solid phase product of the suspension, and then wash the solid phase product of the suspension repeatedly with deionized water until the pH value is basically neutral. S3. The solid product of the suspension after washing in step S2 is dried at 60°C for 12 hours to obtain NCB; S4. Disperse nickel chloride hexahydrate, cobalt chloride hexahydrate, hexamethylenetetramine and the NCB in a deionized water substrate and form a uniform slurry by magnetic stirring, wherein the ratio of nickel chloride hexahydrate, cobalt chloride hexahydrate, hexamethylenetetramine, NCB and deionized water substrate is 15 mmol: 10 mmol: 15.625 mmol: 0.5 g: 200 mL; S5. The uniform slurry is transferred to a high-pressure reactor lined with polytetrafluoroethylene and subjected to a hydrothermal reaction at 100°C for 10 hours to obtain the hydrothermal reactant. S6. Centrifuge the hydrothermal reactants after step S5 to obtain the hydrothermal reaction solid product, and then repeatedly wash the hydrothermal reaction solid product with deionized water until the pH value reaches 6 to 7. S7. The hydrothermal reaction solid product washed in step S6 is vacuum dried at 60°C for 12 hours to obtain NCB-LDH flow electrode material.

2. A flow electrode, characterized in that, The method for preparing the NCB-LDH flow electrode material includes an electrolyte and a flow electrode material as described in claim 1, wherein the electrolyte is adapted to the salt solution to be treated, and the flow electrode is prepared by mixing the NCB-LDH flow electrode material with the electrolyte.

3. A water treatment device, characterized in that, The device includes a water treatment module, which includes a housing. A first cation exchange membrane, an anion exchange membrane, and a second cation exchange membrane are arranged in parallel inside the housing. The first cation exchange membrane, anion exchange membrane, and second cation exchange membrane are arranged sequentially. A deionization chamber is formed between the first cation exchange membrane and the anion exchange membrane. A negative electrode chamber is formed on the side of the first cation exchange membrane away from the anion exchange membrane. A concentration chamber is formed between the second cation exchange membrane and the anion exchange membrane. A positive electrode chamber is formed on the side of the second cation exchange membrane away from the anion exchange membrane. The positive electrode chamber has a first flow electrode port at one end, the other end of the positive electrode chamber is connected to one end of the negative electrode chamber, and the other end of the negative electrode chamber has a second flow electrode port. The deionization chamber has liquid inlets at both ends, and the concentration chamber has concentrated liquid inlets at both ends. The positive and negative electrode chambers are filled with a flow electrode as described in claim 2.

4. A water treatment device according to claim 3, characterized in that, It also includes an electrode circulation pump, a concentrate circulation pump, an inlet pipe, and an outlet pipe. The suction end and discharge end of the electrode circulation pump are respectively connected to the first flow electrode port and the second flow electrode port. The suction end and discharge end of the concentrate circulation pump are respectively connected to the two concentrate ports. One end of the inlet pipe is connected to one of the liquid flow ports, and one end of the outlet pipe is connected to the other liquid flow port.

5. A water treatment device according to claim 4, characterized in that, It also includes a circulation pool, a collection pool, and a collection pipe. The discharge end of the concentrated liquid circulation pump is connected to one of the concentrated liquid ports, and the other concentrated liquid port and the suction end of the concentrated liquid circulation pump are both connected to the circulation pool. The collection pool is located below the circulation pool, and the bottom of the circulation pool is connected to the top of the collection pool through the collection pipe.

6. A water treatment device according to claim 5, characterized in that, It also includes a water supply pipe, a controller, a digital electrode, a water supply valve, and a drain valve. One end of the water supply pipe is connected to the water inlet pipe, and the other end of the water supply pipe is connected to the upper part of the circulation tank. The water supply valve is installed on the water supply pipe and is used to control the opening and closing of the water supply pipe. The drain valve is installed on the collection pipe and is used to control the opening and closing of the collection pipe. The digital electrode is installed in the circulation tank and is used to monitor the ion concentration of the liquid in the circulation tank. The digital electrode, the water supply valve, and the drain valve are all electrically connected to the controller.

7. A water treatment device according to claim 4, characterized in that, It also includes a mixing tank, the discharge end of the electrode circulation pump is connected to the second flow electrode port, and both the first flow electrode port and the suction end of the electrode circulation pump are connected to the mixing tank.

8. A water treatment apparatus according to any one of claims 4 to 7, characterized in that, The water treatment modules are multiple, and one liquid outlet of each of the multiple water treatment modules is connected to the inlet pipe through a first branch pipe, and another liquid outlet of each of the multiple water treatment modules is connected to the outlet pipe through a second branch pipe. One end of the inlet pipe is open and the other end is closed. A first on / off valve is provided on the inlet pipe section between two adjacent first branch pipes. A second on / off valve is provided on the outlet pipe section between two adjacent second branch pipes. A third on / off valve is provided at both ends of the outlet pipe.

9. A water treatment device according to claim 8, characterized in that, It also includes a photovoltaic panel and a storage battery. The photovoltaic panel is used to convert light energy into electrical energy and store it in the storage battery. The storage battery is used to power the electrode circulation pump, the concentrate circulation pump, and the water treatment module.

10. A water treatment device according to claim 9, characterized in that, It also includes a frame, on which the water treatment module, electrode circulation pump, concentrate circulation pump, inlet pipe, and outlet pipe are all fixedly installed. A photovoltaic bracket is installed on the frame, the tilt angle of the photovoltaic bracket is adjustable, the photovoltaic panel is fixedly installed on the photovoltaic bracket, and several casters are provided at the bottom of the frame.

Images