Wastewater treatment system and method using electrolysis of water coupled with biological technology

Abstract

The present application relates to a kind of wastewater treatment system and processing method of electrolytic water anode oxygen coupling biological technology, belong to sewage treatment technical field, solve the technical problems such as the micro-aerobic sewage biological treatment technology needs accurate dissolved oxygen, organic matter remains, total nitrogen removal efficiency needs to be improved, including electrolytic water device, including polymer membrane electrolytic cell, proton exchange membrane is arranged in polymer membrane electrolytic cell, proton exchange membrane is used to divide polymer membrane electrolytic cell into cathode chamber and anode chamber, pure water is used to be introduced in cathode chamber, and the wastewater to be treated is used to be introduced in anode chamber;The wastewater inlet of anode chamber is connected with bioreactor, and the wastewater outlet of anode chamber is connected with bioreactor.In electrolysis process, oxygen evolution reaction occurs in anode, and the dissolved oxygen generated is immediately mixed with wastewater, enters bioreactor, improves the degradation efficiency of organic matter, ammonia nitrogen and other pollutants, while avoiding the disadvantages such as high energy consumption and low oxygen utilization rate caused by traditional air blowing aeration of bioreactor.

Description

Technical Field

[0001] This invention belongs to the field of wastewater treatment technology, specifically relating to a wastewater treatment system and method using electrolytic water anode oxygen generation coupled with biological technology. Background Technology

[0002] In recent decades, hydrogen has been hailed as the best and most promising alternative energy source due to its high calorific value, environmental friendliness, and lack of pollutants during combustion. Meanwhile, hydrogen's energy density is approximately 33.5 kWh / kg, compared to diesel's 13 kWh / kg; one kilogram of hydrogen used to power the electric motor in a fuel cell has the energy equivalent of one gallon of diesel. Green hydrogen, also known as renewable hydrogen, is hydrogen produced using only renewable energy sources, typically through water electrolysis. Water electrolysis is a relatively mature hydrogen production technology. Under the application of a direct current voltage, water undergoes a decomposition reaction, producing hydrogen at the cathode and oxygen at the anode, making it one of the most promising hydrogen production routes.

[0003] Hydrogen production technologies through water electrolysis mainly include alkaline water electrolysis and proton exchange membrane (PEM) water electrolysis. Alkaline electrolyzers use 20%–30% KOH as the electrolyte; PEM electrolyzers are based on PEM fuel cell technology, with the anode and cathode separated by a proton exchange membrane, and the electrolyte is deionized water. These technologies' high dependence on freshwater resources poses a threat to sustainable development, thus limiting their application, especially in regions where freshwater resources are already extremely scarce, where competition with domestic, industrial, and agricultural water use is even more significant.

[0004] Hydrogen production through water electrolysis utilizes the cathode, and the oxygen evolution reaction at the anode is often replaced by electrochemical oxidation reactions such as glucose oxidation and alcohol oxidation. However, electrochemical wastewater treatment technologies typically employ anodic oxidation and single-chamber structures when degrading organic matter and ammonia nitrogen, neglecting the cathodic reduction performance.

[0005] Microaerobic biological wastewater treatment technology removes pollutants from wastewater by controlling the dissolved oxygen concentration at a low level, creating a microaerobic environment, and utilizing the metabolic activity of microorganisms. Its advantages include high efficiency, energy saving, strong resistance to shock loads, and low sludge production. However, this technology also has some drawbacks, such as the need for precise control of dissolved oxygen concentration to maintain a microaerobic environment, which places high demands on operation and management. Furthermore, this technology leaves organic matter residues in the treated wastewater, and the total nitrogen removal efficiency needs further improvement. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide a wastewater treatment system and method using electrolytic water anode oxygen generation coupled with biological technology, which solves the technical problems of micro-oxygen wastewater biological treatment technology, such as the need for precise dissolved oxygen, organic matter residue, and the need to improve total nitrogen removal efficiency.

[0007] To solve the above problems, the technical solution of the present invention is: a wastewater treatment system using electrolytic water anode oxygen generation coupled with biotechnology, comprising:

[0008] An electrolysis device includes a polymer thin-film electrolyzer, in which a proton exchange membrane is installed to divide the polymer thin-film electrolyzer into a cathode chamber and an anode chamber. Pure water is introduced into the cathode chamber, and wastewater to be treated is introduced into the anode chamber. The anode material in the anode chamber is nickel cobalt oxide or ruthenium oxide, and the cathode material in the cathode chamber is platinum.

[0009] A bioreactor is used to treat wastewater. The bioreactor contains activated sludge with a concentration of 3000 mg / L - 20000 mg / L and a dissolved oxygen concentration of 0.1 mg / L - 2 mg / L. The wastewater inlet and outlet of the anode chamber are connected to the bioreactor. The anode chamber is used to generate dissolved oxygen required for wastewater treatment, replacing the oxygen supply from the aeration device.

[0010] Preferably, it also includes a water storage tank, the inlet of which is connected to the bioreactor via a first pipeline, and the water storage tank is used to store wastewater entering from the bioreactor; part or all of the outlet of the water storage tank is connected to the anode chamber via a second pipeline.

[0011] Preferably, the bioreactor is an upflow sludge bed.

[0012] Preferably, the current density used in the water electrolysis device is 100 mA / cm². 2 The ratio of wastewater flow velocity to electrode area in the anode chamber is 40 cm². 3 / cm 2 / min.

[0013] Preferably, the wastewater contains organic matter and nitrogen pollutants.

[0014] Preferably, the bioreactor is a static type.

[0015] Preferably, the wastewater inlet of the bioreactor is connected to an inlet peristaltic pump, which is used to transport external wastewater into the bioreactor; the wastewater outlet of the anode chamber is connected to a reflux peristaltic pump, which is used to transport wastewater from the anode chamber into the bioreactor, and the flow rate ratio of the reflux peristaltic pump to the inlet peristaltic pump is 20:1.

[0016] Another objective of this invention is to provide a wastewater treatment method using electrolytic water anode oxygen generation coupled with biotechnology. The wastewater treatment system using the above-mentioned electrolytic water anode oxygen generation coupled with biotechnology includes the following steps: wastewater is introduced into a bioreactor, the effluent from the bioreactor enters a storage tank, a portion of the water in the storage tank is discharged, and the other portion of the water enters the anode chamber of the water electrolysis device. The oxygen generated in the anode chamber dissolves into the wastewater, and the wastewater with dissolved oxygen is returned to the bioreactor to participate in the wastewater treatment reaction.

[0017] Preferably, the synthesis process of the nickel-cobalt oxide is as follows:

[0018] S1. Pretreatment: The nickel foam is ultrasonically cleaned in acetone, anhydrous ethanol and pure water for 20-30 min in sequence, and then dried at 50-60℃ for 10-15 h.

[0019] S2. Preparation of precursor solution: Dissolve nickel nitrate hexahydrate, cobalt nitrate hexahydrate, urea and ammonium fluoride in pure water in a mass ratio of 1:1.637:0.743:1.145, and stir for 20-30 minutes to obtain a mixed solution;

[0020] S3. Hydrothermal reaction: The foamed nickel treated in step S1 and the mixed solution obtained in step S2 are transferred together to a high-pressure reactor and reacted at 130°C for 6-8 hours.

[0021] S4. Cleaning: After the reaction is complete, the material obtained in S3 is ultrasonically washed for 20-30 minutes at a power of 40-50W.

[0022] S5. Drying: After rinsing the surface of the material obtained in S4, dry it.

[0023] S6. Calcination and activation: The material obtained in S5 is placed in a muffle furnace and heated to 400℃ at a heating rate of 2℃ / min-4℃ / min, and reacted for 2 hours to obtain nickel-cobalt oxide.

[0024] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0025] 1. Electrolysis-based hydrogen production technology often focuses on hydrogen production performance while neglecting the oxygen production capacity at the anode. This invention, while leveraging the cathode hydrogen production function of water electrolysis, combines the anode oxygen production function with wastewater biological treatment technology. It utilizes the anode oxygen production from water electrolysis as a source of dissolved oxygen for wastewater treatment in the bioreactor, improving the energy utilization value and in-situ oxygen supply capacity of the water electrolysis-based hydrogen production technology. A new system is constructed that simultaneously generates hydrogen at the cathode and generates oxygen at the anode, coupled with biological wastewater treatment technology to achieve full energy utilization. The oxygen generated by electrolysis enters the wastewater directly in dissolved form, with an oxygen mass transfer efficiency approaching 100%, and energy consumption reduced by 30%–50% compared to traditional blower aeration.

[0026] 2. In addition to producing oxygen, the anode side of the water electrolysis device also produces substances with strong oxidizing properties, such as hydroxyl radicals, a small amount of ozone, and a small amount of hydrogen peroxide. Therefore, it has the function of electrocatalytic oxidation. The combination of water electrolysis technology and biological treatment technology allows the electrocatalytic oxidation function of water electrolysis to further remove residual organic matter and nitrogen pollutants that are difficult to remove by biological treatment technology, thereby improving the removal efficiency of pollutants in wastewater.

[0027] 3. It achieves spatial independence between water electrolysis technology and biological treatment technology, reduces the adverse effects of highly oxidizing substances produced by water electrolysis technology on organisms, and only utilizes the ability of water electrolysis technology to degrade pollutants.

[0028] 4. Long electrode life: The corrosion rate of the integrated nickel-cobalt oxide anode is <1 μm·a -1 After 1000 hours of continuous operation, the activity decay was less than 5%.

[0029] 5. Controllable process: The dissolved oxygen concentration can be precisely controlled by adjusting the current, so as to achieve oxygen supply on demand and avoid energy waste and sludge bulking caused by excessive aeration.

[0030] 6. Wastewater treated by biotechnology has relatively stable water quality. Using biotechnology-treated wastewater as the anode electrolyte for water electrolysis to produce hydrogen saves water resources and is of great significance for my country to reduce carbon emissions, alleviate the energy and freshwater crisis and achieve sustainable development. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the wastewater treatment technology using electrolytic water anode oxygen generation coupled with biotechnology according to the present invention;

[0032] Figure 2 This is a schematic diagram illustrating the principle of wastewater treatment using the electrolytic water anode oxygen generation coupled with biological technology of the present invention.

[0033] Figure 3 This is an exploded view of the polymer thin-film electrolytic cell of the present invention;

[0034] Figure 4 This is a schematic diagram showing the dissolved oxygen concentration and dissolved oxygen conversion rate in the water storage tank under different current densities when the pump speed is 5 mL / min according to the present invention.

[0035] Figure 5 This is a schematic diagram showing the dissolved oxygen concentration and dissolved oxygen conversion rate in the water storage tank under different current densities when the pump speed is 12 mL / min according to the present invention.

[0036] Figure 6 This is a schematic diagram showing the dissolved oxygen concentration and dissolved oxygen conversion rate in the water storage tank under different current densities when the pump speed is 20 mL / min according to the present invention.

[0037] Figure 7 This is a schematic diagram showing the dissolved oxygen concentration and dissolved oxygen conversion rate in the water storage tank under different current densities when the pump speed is 25 mL / min according to the present invention.

[0038] Figure 8 This is a schematic diagram showing the dissolved oxygen concentration and dissolved oxygen conversion rate in the water storage tank under different current densities when the pump speed is 32 mL / min according to the present invention.

[0039] Figure 9 This is a schematic diagram showing the dissolved oxygen concentration and dissolved oxygen conversion rate in the water storage tank under different current densities when the pump speed is 40 mL / min according to the present invention.

[0040] Reference numerals: 1. Bioreactor; 2. Water storage tank; 3. Water electrolysis device; 31. Anode chamber; 32. Anode material; 33. Cathode chamber; 34. Cathode material; 35. Power supply; 36. Municipal sewage; 37. Pure water; 38. Proton exchange membrane; 4. First pipeline; 5. Second pipeline; 6. Anode conductive outer frame; 61. Anode cavity outer frame; 62. First proton exchange membrane pressure plate; 7. Cathode conductive outer frame; 71. Cathode cavity outer frame; 72. Second proton exchange membrane pressure plate. Detailed Implementation

[0041] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments.

[0042] Example: Figures 1-9 As shown, this embodiment provides a wastewater treatment system using electrolytic water anode oxygen generation coupled with biotechnology, including an electrolytic water device 3 and a bioreactor 1. The electrolytic water device 3 includes a polymer thin-film electrolytic cell, in which a proton exchange membrane 38 is installed. The proton exchange membrane 38 divides the polymer thin-film electrolytic cell into a cathode chamber 33 and an anode chamber 31. Pure water 37 is introduced into the cathode chamber 33, and wastewater to be treated is introduced into the anode chamber 31. The anode material 32 in the anode chamber 31 is nickel cobalt oxide or ruthenium oxide, and the cathode material 34 in the cathode chamber 33 is platinum. The bioreactor 1 is used to treat wastewater. The bioreactor 1 contains activated sludge with a sludge concentration of 3000 mg / L - 20000 mg / L, and the dissolved oxygen concentration in the bioreactor 1 is 0.1 mg / L. -2mg / L; the wastewater inlet of the anode chamber 31 is connected to the bioreactor 1, and the wastewater outlet of the anode chamber 31 is connected to the bioreactor 1. The anode chamber 31 is used to generate dissolved oxygen required by the bioreactor 1 to treat wastewater, so as to replace the oxygen supply to the bioreactor 1 by the aeration device.

[0043] With the above setup, in the polymer thin-film electrolyzer, nickel-cobalt oxide is used as the anode material 32 and platinum as the cathode material 34. The polymer thin-film electrolyzer is divided into an anode chamber 31 and a cathode chamber 33 by a proton exchange membrane 38. Wastewater first enters the bioreactor 1 for treatment. The treated wastewater then enters the anode chamber 31 of the water electrolysis device 3 through the outlet of the bioreactor 1, while pure water 37 is introduced into the cathode chamber 33. During electrolysis, an oxygen evolution reaction occurs at the anode, and the generated high-purity dissolved oxygen immediately mixes with the wastewater. The wastewater in the anode chamber 31 of the water electrolysis device 3 enters the bioreactor 1, which can provide sufficient electron acceptors for subsequent biochemical treatment, thereby significantly improving the degradation efficiency of pollutants such as organic matter and ammonia nitrogen. At the same time, it avoids the disadvantages of high energy consumption, low oxygen utilization rate, and large gas-liquid mass transfer resistance caused by the traditional aeration of the bioreactor 1. In addition to producing oxygen, the anode side of the water electrolysis device 3 also produces substances with strong oxidizing properties, thus possessing the function of electrocatalytic oxidation. The combination of water electrolysis technology and biological treatment technology allows the electrocatalytic oxidation function of water electrolysis to further remove residual organic matter and nitrogen pollutants that are difficult to remove by biological treatment technology, thereby improving the removal efficiency of pollutants in wastewater.

[0044] In this embodiment of a wastewater treatment system using electrolytic water anode oxygen generation coupled with biotechnology, a water storage tank 2 is also included. The inlet of the water storage tank 2 is connected to the bioreactor 1 via a first pipe 4, and the water storage tank 2 is used to store wastewater entering from the bioreactor 1. Part or all of the outlet of the water storage tank 2 is connected to the anode chamber 31 via a second pipe 5. With this configuration, the treated wastewater in the bioreactor 1 first enters the water storage tank 2. A portion of the water in the water storage tank 2 can be discharged, while the remaining water enters the anode chamber 31 of the water electrolysis device 3. The water storage tank 2 serves to regulate and intercept water flow.

[0045] In this embodiment of a wastewater treatment system using an electrolytic water anode oxygen generation coupled with biotechnology, the current density used in the water electrolysis device 3 is 100 mA / cm². 2 The wastewater flow rate in anode chamber 31 has an electrode area ratio of 40 cm². 3 / cm 2 / min.

[0046] In this embodiment, a wastewater treatment system using electrolytic water anode oxygen generation coupled with biotechnology contains organic matter and nitrogen pollutants.

[0047] In this embodiment of a wastewater treatment system using electrolytic water anode oxygen generation coupled with biotechnology, the bioreactor 1 is a static type. With this configuration, the system does not employ an aeration device; instead, it provides oxygen by dissolving the oxygen generated from water electrolysis into the wastewater. Therefore, a static type micro-aerobic sludge reactor makes it easier to create a micro-aerobic environment.

[0048] In this embodiment, the wastewater is municipal sewage 36, with COD, ammonia nitrogen, and total nitrogen concentrations of 300 mg / L, 42 mg / L, and 45 mg / L, respectively. The wastewater enters bioreactor 1 via an influent peristaltic pump. Bioreactor 1 can be an upflow sludge bed with an effective volume of 1.8 L, operating at room temperature with a hydraulic retention time of 18 h. The sludge concentration is 5600 mg / L, the volatile suspended solids concentration of the sludge mixture is 2900 mg / L, and the dissolved oxygen concentration is 0.3 mg / L. The wastewater treated by the upflow sludge bed enters the anode chamber 31 of the water electrolysis device 3 as the anode electrolyte. The water electrolysis device 3 uses a proton exchange membrane electrolysis cell, which is 4 cm long, 4 cm wide, and 1.6 cm thick. Ruthenium oxide is used as the anode material 32, and a platinum mesh is used as the cathode material 34. The power supply 35 applies a voltage of 1.5 V, and deionized water is used as the cathode electrolyte. After oxygen is generated in the anode chamber 31 of the water electrolysis device 3, the effluent from the anode chamber 31, containing dissolved oxygen, is returned to the bioreactor 1 via a reflux peristaltic pump. The flow rate ratio of the reflux peristaltic pump to the influent peristaltic pump of the bioreactor 1 is 20:1. The cathode hydrogen production Faraday efficiency of the water electrolysis device 3 is 99%, and the hydrogen production rate is 4.3 mol / d. The effluent COD, ammonia nitrogen, and total nitrogen concentrations of the entire system are 18 mg / L, 0.2 mg / L, and 3 mg / L, respectively, with removal rates reaching 94%, 99.5%, and 93%, respectively. COD refers to chemical oxygen demand.

[0049] This embodiment provides an analysis of the oxygen supply capacity of a wastewater treatment system using electrolytic water anode oxygen generation coupled with biotechnology. Electrolytic reoxygenation experiments were conducted using a PEM electrolyzer. Figure 3 The diagram shows the structure of a PEM electrolyzer. Experiments were conducted at different pump speeds, applying pressures of 5, 10, 20, 50, 100, and 200 mA / cm² to the PEM electrolyzer. -2 The current density was measured to investigate the effect of wastewater flow rate on dissolved oxygen concentration and dissolved oxygen conversion rate in the designed continuous flow electrochemical reactor during the reaction process.

[0050] exist Figure 3 In this PEM electrolyzer, an anode conductive outer frame 6, an anode cavity outer frame 61, a first proton exchange membrane plate 62, an anode material 32, a proton exchange membrane 38, a cathode material 34, a second proton exchange membrane plate 72, a cathode cavity outer frame 71, a cathode conductive outer frame 7, and a power supply 35. The positive terminal of the power supply 35 is electrically connected to the anode conductive outer frame 6, and the negative terminal of the power supply 35 is electrically connected to the cathode conductive outer frame 7. An inlet and an outlet are respectively provided on the anode conductive outer frame 6 and the cathode conductive outer frame 7. The proton exchange membrane 38 is sandwiched and fixed between the first proton exchange membrane plate 62 and the second proton exchange membrane plate 72. Through openings are provided in the anode cavity outer frame 61, the first proton exchange membrane plate 62, the cathode cavity outer frame 71, and the second proton exchange membrane plate 72 to form an anode chamber 31 and a cathode chamber 33.

[0051] Experimental results are as follows Figures 4-9 As shown, in Figure 4 In the case where the pump rate is 5 mL / min, at 5, 10, and 20 mA / cm... -2 At current densities of 50, 100, and 200 mA / cm³, the dissolved oxygen concentration in the effluent from anode chamber 31 is relatively low. -2 At high current densities, dissolved oxygen concentration increases significantly. Because the oxygen production rate is faster at high current densities, dissolved oxygen in the water becomes almost saturated under long residence time conditions, and excess oxygen escapes in gaseous form, resulting in poor dissolved oxygen conversion rate under high current density and low flow rate conditions. Figure 5 The graph shows the changes in dissolved oxygen concentration and dissolved oxygen conversion rate at different current densities when the pump speed is increased to 12 mL / min. The change in dissolved oxygen concentration at the lower current is similar to that at 5 mL / min, with a slight increase in dissolved oxygen conversion rate. Figures 6-9 In the process, as the pump speed continuously increases, i.e., the hydraulic residence time continuously decreases, at 5, 10, and 20 mAcm... -2 At low current densities, the dissolved oxygen concentration did not change significantly, but the dissolved oxygen conversion rate increased at 50, 100, and 200 mA / cm². -2 At a current density of [value missing], the dissolved oxygen conversion rate is significantly improved. This is largely due to the faster oxygen production rate caused by the high current density. Under a shorter hydraulic residence time, oxygen can be fully dissolved in the electrolyte of the anode chamber 31, which is difficult to achieve under a longer hydraulic residence time. Figure 9 As can be seen, although a short hydraulic residence time can lead to a high dissolved oxygen concentration and dissolved oxygen conversion rate, the effect of the hydraulic impact caused by the high flow velocity on electrolysis is likely due to the fact that the final result in a lower dissolved oxygen concentration and conversion rate compared to other conditions.

[0052] The wastewater treatment method of the wastewater treatment system of electrolytic water anode oxygen generation coupled with biotechnology in this embodiment includes the following steps: wastewater is introduced into bioreactor 1, the effluent of bioreactor 1 enters water storage tank 2, part of the water in water storage tank 2 is discharged, and the other part of the water enters the anode chamber 31 of water electrolysis device 3, the oxygen generated in the anode chamber 31 dissolves into the wastewater, and the wastewater with dissolved oxygen is returned to bioreactor 1 to participate in the wastewater treatment reaction.

[0053] In this embodiment of a wastewater treatment system using electrolytic water anode oxygen generation coupled with biotechnology, the synthesis process of nickel-cobalt oxide is as follows:

[0054] S1. Pretreatment: The nickel foam was ultrasonically cleaned in acetone, anhydrous ethanol and pure water for 30 min in sequence, and then dried at 60℃ for 12 h.

[0055] S2. Preparation of precursor solution: Dissolve nickel nitrate hexahydrate, cobalt nitrate hexahydrate, urea and ammonium fluoride in pure water in a mass ratio of 1:1.637:0.743:1.145, and stir for 30 min to obtain a mixed solution;

[0056] S3. Hydrothermal reaction: The foamed nickel treated in step S1 and the mixed solution obtained in step S2 are transferred together to a high-pressure reactor and reacted at 130°C for 8 hours.

[0057] S4. Cleaning: After the reaction is complete, the material obtained in S3 is ultrasonically washed for 30 minutes at 50W power.

[0058] S5. Drying: After rinsing the surface of the material obtained in S4, dry it at 60℃ for 12 hours.

[0059] S6. Calcination and activation: The material obtained in S5 is placed in a muffle furnace and heated to 400℃ at a heating rate of 2℃ / min, and reacted for 2 hours to obtain nickel-cobalt oxide.

Claims

1. A wastewater treatment system using electrolytic water anode oxygen generation coupled with biological technology, characterized in that, include: The water electrolysis device (3) includes a polymer thin-film electrolyzer, in which a proton exchange membrane (38) is installed. The proton exchange membrane (38) is used to divide the polymer thin-film electrolyzer into a cathode chamber (33) and an anode chamber (31). Pure water (37) is introduced into the cathode chamber (33), and wastewater to be treated is introduced into the anode chamber (31). The anode material (32) in the anode chamber (31) is nickel cobalt oxide or ruthenium oxide, and the cathode material (34) in the cathode chamber (33) is platinum. Bioreactor (1) is used to treat wastewater. The bioreactor (1) is filled with activated sludge with a sludge concentration of 3000 mg / L - 20000 mg / L and a dissolved oxygen concentration of 0.1 mg / L - 2 mg / L. The wastewater inlet of the anode chamber (31) is connected to the bioreactor (1), and the wastewater outlet of the anode chamber (31) is connected to the bioreactor (1). The anode chamber (31) is used to generate dissolved oxygen required for the bioreactor (1) to treat wastewater, so as to replace the oxygen supply to the bioreactor (1) by the aeration device. It also includes a water storage tank (2), the inlet of which is connected to the bioreactor (1) through a first pipeline (4), and the water storage tank (2) is used to store the sewage coming in from the bioreactor (1); part or all of the outlet of the water storage tank (2) is connected to the anode chamber (31) through a second pipeline (5); The effluent from the bioreactor (1) enters the water storage tank (2), a portion of the water in the water storage tank (2) is discharged, and the other portion of the water enters the anode chamber (31) of the water electrolysis device (3).

2. The wastewater treatment system according to claim 1, characterized in that, The bioreactor (1) is an upflow sludge bed.

3. The wastewater treatment system according to claim 1, characterized in that, In the water electrolysis device (3), the current density used is 100 mA / cm². 2 The ratio of sewage flow velocity to electrode area in the anode chamber (31) is 40 cm². 3 / cm 2 / min.

4. The wastewater treatment system according to claim 1, characterized in that, Wastewater contains organic matter and nitrogen pollutants.

5. A wastewater treatment system using electrolytic water anode oxygen generation coupled with biotechnology according to claim 1, characterized in that, The bioreactor (1) is a static type.

6. A wastewater treatment system using electrolytic water anode oxygen generation coupled with biotechnology according to claim 1, characterized in that, The wastewater inlet of the bioreactor (1) is connected to an inlet peristaltic pump, which is used to transport external wastewater into the bioreactor (1); the wastewater outlet of the anode chamber (31) is connected to a return peristaltic pump, which is used to transport wastewater from the anode chamber (31) into the bioreactor (1), and the flow rate ratio of the return peristaltic pump to the inlet peristaltic pump is 20:

1.

7. A wastewater treatment method using electrolytic water anode oxygen generation coupled with biological technology, characterized in that, The wastewater treatment system using the electrolytic water anode oxygen generation coupled with biotechnology as described in claim 1 includes the following steps: wastewater is fed into a bioreactor (1), the effluent from the bioreactor (1) enters a water storage tank (2), a portion of the water in the water storage tank (2) is discharged, and the other portion of the water enters the anode chamber (31) of the water electrolysis device (3), the oxygen generated in the anode chamber (31) dissolves into the wastewater, and the wastewater with dissolved oxygen is returned to the bioreactor (1) to participate in the wastewater treatment reaction.

8. A wastewater treatment method according to claim 7, characterized in that, The synthesis process of the nickel-cobalt oxide is as follows: S1. Pretreatment: The nickel foam is ultrasonically cleaned in acetone, anhydrous ethanol and pure water for 20-30 min in sequence, and then dried at 50-60℃ for 10-15 h. S2. Preparation of precursor solution: Dissolve nickel nitrate hexahydrate, cobalt nitrate hexahydrate, urea and ammonium fluoride in pure water in a mass ratio of 1:1.637:0.743:1.145, and stir for 20-30 minutes to obtain a mixed solution; S3. Hydrothermal reaction: The foamed nickel treated in step S1 and the mixed solution obtained in step S2 are transferred together to a high-pressure reactor and reacted at 130°C for 6-8 hours. S4. Cleaning: After the reaction is complete, the material obtained in S3 is ultrasonically washed for 20-30 minutes at a power of 40-50W. S5. Drying: After rinsing the surface of the material obtained in S4, dry it. S6. Calcination and activation: The material obtained in S5 is placed in a muffle furnace and heated to 400℃ at a heating rate of 2℃ / min-4℃ / min, and reacted for 2 hours to obtain nickel-cobalt oxide.

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