A high-efficiency, energy-saving, and anti-clogging nanobubble aeration process based on silicon carbide ceramic membranes

Abstract

This invention relates to the field of wastewater treatment technology, specifically to a high-efficiency, energy-saving, and anti-clogging nanobubble aeration process based on silicon carbide ceramic membranes. The process involves the installation and commissioning of a micro / nanobubble aeration device, which includes an oxygen generator, a filter, a gas flow control device, an ozone generator, a concentration detection device, a micro / nanobubble generating device, a backwashing device, a pressure detection device, a controller, a reaction device, and an ozone tail gas treatment device. This invention's nanobubble aeration process ensures stable and efficient generation of nanobubbles, improves oxygen transfer efficiency, enhances treatment effectiveness, and effectively reduces wastewater treatment costs. By combining micro / nano ozone bubbles with nano-flocculators, it effectively removes suspended particles, colloidal substances, and other impurities from wastewater. Furthermore, through the comprehensive application of multiple anti-clogging measures, it effectively solves the problem of membrane material clogging in traditional aeration processes.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment technology, specifically to a high-efficiency, energy-saving, anti-clogging nanobubble aeration process based on silicon carbide ceramic membranes. Background Technology

[0002] Aeration is a key step in wastewater treatment, aiming to provide sufficient dissolved oxygen to meet the needs of microorganisms in decomposing organic matter. Nanobubble aeration technology has attracted widespread attention because it can generate microbubbles, increase the gas-liquid contact area, and improve oxygen transfer efficiency.

[0003] In traditional nanobubble aeration processes, when using nanobubble generators to treat wastewater, pollutants such as suspended particles and colloidal substances in the wastewater enter the nanobubble generator and adhere to the surface of the membrane material, causing membrane clogging. This makes it impossible to guarantee the stable and efficient generation of nanobubbles, reducing the oxygen transfer efficiency of the aeration process. Therefore, traditional nanobubble aeration processes still face problems such as easy clogging of membrane materials, low wastewater treatment efficiency, and short service life when treating wastewater, which limits their large-scale promotion and application.

[0004] In conclusion, developing a high-efficiency, energy-saving, and anti-clogging nanobubble aeration process based on silicon carbide ceramic membranes remains a critical issue that urgently needs to be addressed in the field of wastewater treatment technology. Summary of the Invention

[0005] In view of the problems existing in the prior art, the purpose of this invention is to provide a high-efficiency, energy-saving, anti-clogging nanobubble aeration process based on silicon carbide ceramic membrane.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A high-efficiency, energy-saving, and anti-clogging nanobubble aeration process based on silicon carbide ceramic membranes includes the following steps:

[0008] S1. Complete the installation and commissioning of the micro-nano bubble aeration device, and the devices used during installation include oxygen generator, filter, gas flow control device, ozone generator, concentration detection device, micro-nano bubble generating equipment, backwashing device, pressure detection device, controller, reaction device and ozone tail gas treatment device.

[0009] S2. Take a certain amount of wastewater and put it into the reaction device. Aerate the wastewater continuously for 3-6 hours using a micro-nano bubble aeration device.

[0010] S3. According to the wastewater volume, add a certain amount of nano-flocculator and polymeric flocculant PAM to the reaction device, stir with a magnetic stirrer at 200-300 r / min for 30-60s, and let stand for 10-30min after mixing evenly.

[0011] S4. The solution in the reaction device precipitates and separates into layers. Take the supernatant and analyze it on a multi-parameter colorimeter. Determine the COD of the wastewater and supernatant according to the corresponding procedure and calculate the COD removal rate.

[0012] S5. When the micro-nano bubble generating device runs for 3 hours or the pressure difference across the silicon carbide ceramic membrane exceeds 0.2 MPa, the backwashing device automatically backwashes the micro-nano bubble generating device. At the same time, a certain amount of chemical agent is added to the reaction device periodically to prevent contaminants from depositing on the surface of the silicon carbide ceramic membrane in the micro-nano bubble generating device.

[0013] The present invention is further configured such that, in step S1, the installation and debugging of the micro / nano bubble aeration device includes the following steps:

[0014] S11. Install pressure detection devices on both sides of the silicon carbide ceramic membrane in the micro-nano bubble generating device, and install the backwashing device with the micro-nano bubble generating device.

[0015] S12. Install the micro-nano bubble generating device in the reaction device according to the design requirements, and then connect the ozone tail gas treatment device to the reaction device. Connect the pipes between the oxygen generating device, filter device, gas flow control device, ozone generating device, concentration detection device and micro-nano bubble generating device, and check whether the pipe connections are tight and whether there is any leakage.

[0016] S13. Connect the controller to the above devices to obtain the micro-nano bubble aeration device, and debug the micro-nano bubble aeration device. Adjust the gas flow rate through the gas flow control device to meet the design requirements. At the same time, check whether the micro-nano bubble generating device is working properly and observe whether bubbles are released uniformly from the membrane surface.

[0017] The present invention is further configured such that, in step S2, the wastewater is continuously circulated and aerated using a micro-nano bubble aeration device, comprising the following steps:

[0018] S21. Start the micro-nano bubble aeration device. The filter device filters the oxygen in the oxygen generator. The filtered oxygen enters the ozone generator through the gas flow control device to generate ozone.

[0019] S22. Adjust the ozone gas flow rate to 0.3-0.6 L / min, and use a concentration detection device to detect that the ozone concentration reaches 150-180 mg / L;

[0020] S23. After the ozone gas concentration stabilizes, start the micro-nano bubble generating device. The ozone gas enters the micro-nano bubble generating device through the pipe. The ozone gas is dispersed into ozone micro-nano bubbles by the uniform and controllable micropores of the silicon carbide ceramic membrane. After the ozone micro-nano bubbles are released from the membrane surface, they enter the wastewater of the reaction device and undergo an oxidation reaction with the organic matter in the wastewater.

[0021] S24. Simultaneously with the reaction, the ozone exhaust gas treatment device is turned on to treat the exhaust gas generated by the reaction.

[0022] The present invention is further configured such that, in step S3, the dosage of the nano-flocculator is 2-4 g / L and the dosage of the polymeric flocculant PAM is 1-3 g / L, depending on the amount of wastewater.

[0023] The present invention is further configured such that, in step S3, the preparation method of the nano-flocculator includes the following steps:

[0024] S31. Prepare nano-nickel oxide and modify it to obtain vinyl-modified nano-nickel oxide;

[0025] S32. Add 2-5 parts by weight of vinyl-modified nano nickel oxide, 5-11 parts by weight of acrylamide, 10-16 parts by weight of dimethyl diallyl ammonium chloride, 5-7 parts by weight of activated carbon, and 1-4 parts by weight of cerium nitrate to 20-37 parts by weight of deionized water. After stirring and dissolving thoroughly, prepare a monomer mixed solution of a certain concentration and lower the temperature of the monomer mixed solution to 0-3℃.

[0026] S33. Weigh out 1-3 parts by weight of ammonium persulfate and 2-5 parts by weight of sodium bisulfite, and dissolve them in 5-12 parts by weight of deionized water to prepare an initiator solution of a certain concentration.

[0027] S34. Pour nitrogen gas into the polymerization reactor for 20-30 minutes to remove oxygen from the system;

[0028] S35. Transfer the prepared monomer solution into the polymerization reactor and spray at 65m 3 After passing nitrogen gas through the gas at a flow rate of 1 / h for 1 to 1.5 hours, an initiator solution is added to initiate the polymerization reaction, which lasts for 4 to 5 hours.

[0029] S36. After the reaction is complete, pour the reaction solution into a large amount of anhydrous ethanol to precipitate the polymer. The volume ratio of anhydrous ethanol to the reaction solution is 2 to 3:1. Stir to make the precipitation more complete and let it stand for 10 to 25 minutes.

[0030] S37. Filter out the precipitate and wash it repeatedly with anhydrous ethanol to remove unreacted impurities. After each wash, perform vacuum filtration until no impurities can be detected in the washing liquid.

[0031] S38. Place the washed product in a vacuum drying oven and dry it at 30-40℃ for 2-3 hours to obtain a dried nano-flocculator.

[0032] The present invention is further configured such that, in step S31, nano-nickel oxide is prepared and modified to obtain vinyl-modified nano-nickel oxide, including the following steps:

[0033] S311. Dissolve 2-3 parts by weight of nickel acetate tetrahydrate in 110-130 parts of deionized water, and add ammonia dropwise while stirring to adjust the pH to 9.7-10. Continue stirring until nickel hydroxide sol is formed.

[0034] S312. The nickel hydroxide sol was transferred into a reaction vessel and kept in a furnace at 400°C for 4-6 hours. The product was then filtered and washed with deionized water and anhydrous ethanol until neutral. After vacuum drying at 60°C for 24 hours, nano nickel oxide was obtained.

[0035] S313. Add vinyl silane coupling agent dropwise to the surface of nano nickel oxide, stir evenly, and then add acrylic acid. The mass ratio of vinyl silane coupling agent, nano nickel oxide, and acrylic acid is 2-4:25:3-5. Stir and react for 1-2 hours to obtain vinyl-modified nano nickel oxide.

[0036] The present invention is further configured such that: in step S5, the backwashing device automatically backwashes the micro / nano bubble generating device, including the following steps:

[0037] S51. When the micro-nano bubble generating device runs for 3 hours or the pressure difference across the silicon carbide ceramic membrane exceeds 0.2 MPa, the controller automatically shuts down the oxygen generating device and issues a warning sound through the indicator.

[0038] S52. The controller automatically opens the valve of the backwashing device, allowing high-pressure gas or liquid to pass through the silicon carbide ceramic membrane of the micro-nano bubble generator in reverse at a specific pressure and flow rate, thus automatically backwashing the micro-nano bubble generator.

[0039] S53. Continuous backwashing for 15-30 minutes. During the process, observe the water quality of the backwash drainage to judge the backwashing effect. When the drainage is clear and there are no obvious impurities, turn off the backwashing device through the controller.

[0040] The present invention is further configured such that, in step S5, the chemical agent is a dispersant and a cleaning agent, wherein the amount of dispersant added is 10-20 mg / L and the amount of cleaning agent added is 4-10 mg / L.

[0041] Beneficial effects

[0042] Compared with known public technologies, the technical solution provided by this invention has the following advantages:

[0043] Beneficial effects:

[0044] (1) In this invention, by adding nano-flocculators to wastewater, the nano-bubble aeration process combines micro-nano ozone bubbles with nano-flocculators. The nano-flocculators can effectively remove suspended particles, colloidal substances and other impurities in wastewater during wastewater treatment. When the wastewater after good flocculation and sedimentation treatment enters the aeration process of silicon carbide ceramic membrane, it can reduce the probability of pollutant adhesion on the membrane surface and reduce the risk of membrane blockage, thereby ensuring that nano-bubbles can be generated stably and efficiently, maintaining the oxygen transfer efficiency of the aeration process. At the same time, the nano-bubbles generated by the silicon carbide ceramic membrane in the micro-nano bubble generating device can greatly increase the gas-liquid contact area and improve the oxygen transfer efficiency, thereby accelerating the wastewater treatment speed and improving the treatment effect. Compared with the traditional aeration process, the aeration process of this invention has reduced energy consumption and can effectively reduce the cost of wastewater treatment.

[0045] (2) In this invention, by adding a filter device after the oxygen generator, the gas passing through the micro-nano bubble generator can be filtered to reduce impurities in the gas. At the same time, the micro-nano bubble generator is improved by adding a pressure detection device and a backwashing device. When the micro-nano bubble generator runs for 3 hours or the pressure difference across the silicon carbide ceramic membrane exceeds 0.2 MPa, the backwashing device automatically backwashes the micro-nano bubble generator. In addition, a certain amount of chemical agent is added to the reaction device periodically to prevent pollutants from depositing on the surface of the silicon carbide ceramic membrane in the micro-nano bubble generator. The nano-bubble aeration process of this invention effectively solves the problem of easy clogging of membrane materials in traditional aeration processes through the comprehensive application of various anti-clogging measures, extends the service life of membrane modules, and reduces equipment maintenance costs. Attached Figure Description

[0046] Figure 1 This is a process flow diagram of a high-efficiency, energy-saving, and anti-clogging nanobubble aeration process based on silicon carbide ceramic membranes. Detailed Implementation

[0047] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0048] The present invention will be further described below with reference to embodiments.

[0049] Example 1: Please refer to Figure 1As shown, a high-efficiency, energy-saving, and anti-clogging nanobubble aeration process based on silicon carbide ceramic membranes includes the following steps:

[0050] S1. Complete the installation and commissioning of the micro-nano bubble aeration device;

[0051] S2. Take a certain amount of wastewater and put it into the reaction device. Aerate the wastewater continuously for 3 hours using a micro-nano bubble aeration device. This includes the following steps:

[0052] S21. Start the micro-nano bubble aeration device. The filter device filters the oxygen in the oxygen generator. The filtered oxygen enters the ozone generator through the gas flow control device to generate ozone.

[0053] S22. Adjust the ozone gas flow rate to 0.3L / min, and use a concentration detection device to detect that the ozone concentration reaches 150mg / L;

[0054] S23. After the ozone gas concentration stabilizes, start the micro-nano bubble generating device. The ozone gas enters the micro-nano bubble generating device through the pipe. The ozone gas is dispersed into ozone micro-nano bubbles by the uniform and controllable micropores of the silicon carbide ceramic membrane. After the ozone micro-nano bubbles are released from the membrane surface, they enter the wastewater of the reaction device and undergo an oxidation reaction with the organic matter in the wastewater.

[0055] S24. Simultaneously with the reaction, turn on the ozone exhaust gas treatment device to treat the exhaust gas generated by the reaction.

[0056] S3. According to the wastewater volume, add a certain amount of nano-flocculator and polymeric flocculant PAM to the reaction device, stir for 30 seconds at 200r / min using a magnetic stirrer, and let stand for 10 minutes after mixing evenly.

[0057] The dosage of nano-flocculant is 2 g / L, and the dosage of polymeric flocculant PAM is 1 g / L.

[0058] The preparation method of the nano-flocculator includes the following steps:

[0059] S31. Preparation and modification of nano-nickel oxide to obtain vinyl-modified nano-nickel oxide, including the following steps:

[0060] S311. Dissolve 2 parts by weight of nickel acetate tetrahydrate in 110 parts of deionized water, and add ammonia dropwise while stirring to adjust the pH to 9.7. Continue stirring until nickel hydroxide sol is formed.

[0061] S312. The nickel hydroxide sol was transferred into a reaction vessel and kept in a furnace at 400°C for 4 hours. The product was then filtered and washed with deionized water and anhydrous ethanol until neutral. After vacuum drying at 60°C for 24 hours, nano nickel oxide was obtained.

[0062] S313. Add vinyl silane coupling agent dropwise to the surface of nano nickel oxide, stir evenly, and then add acrylic acid. The mass ratio of vinyl silane coupling agent, nano nickel oxide and acrylic acid is 2:25:3. Stir and react for 1 hour to obtain vinyl modified nano nickel oxide.

[0063] S32. Add 2 parts by weight of vinyl-modified nano nickel oxide, 5 parts by weight of acrylamide, 10 parts by weight of dimethyl diallyl ammonium chloride, 5 parts by weight of activated carbon and 1 part by weight of cerium nitrate to 20 parts by weight of deionized water. After stirring and dissolving thoroughly, prepare a monomer mixed solution of a certain concentration and lower the temperature of the monomer mixed solution to 0℃.

[0064] S33. Weigh out 1 part ammonium persulfate and 2 parts sodium bisulfite by mass, and dissolve them in 5 parts deionized water to prepare an initiator solution of a certain concentration.

[0065] S34. Pour nitrogen gas into the polymerization reactor for 20 minutes to remove oxygen from the system;

[0066] S35. Transfer the prepared monomer solution into the polymerization reactor and spray at 65m 3 After nitrogen gas was introduced at a flow rate of / h for 1h, an initiator solution was added to initiate the polymerization reaction, which lasted for 4h.

[0067] S36. After the reaction is complete, pour the reaction solution into a large amount of anhydrous ethanol to precipitate the polymer. The volume ratio of anhydrous ethanol to the reaction solution is 2:1. Stir to make the precipitation more complete and let it stand for 10 minutes.

[0068] S37. Filter out the precipitate and wash it repeatedly with anhydrous ethanol to remove unreacted impurities. After each wash, perform vacuum filtration until no impurities can be detected in the washing liquid.

[0069] S38. Place the washed product in a vacuum drying oven and dry it at 30°C for 2 hours to obtain a dried nano-flocculator.

[0070] S4. After the solution in the reaction apparatus precipitates and separates into layers, take the supernatant.

[0071] S5. When the micro-nano bubble generating device runs for 3 hours or the pressure difference across the silicon carbide ceramic membrane exceeds 0.2 MPa, the backwashing device automatically backwashes the micro-nano bubble generating device for 15 minutes. At the same time, a certain amount of chemical agent is added to the reaction device periodically to prevent pollutants from depositing on the surface of the silicon carbide ceramic membrane in the micro-nano bubble generating device.

[0072] The chemical agents used are dispersants and cleaning agents, with the dispersant added at a rate of 10 mg / L and the cleaning agent added at a rate of 4 mg / L.

[0073] Example 2: Please refer to Figure 1 As shown, a high-efficiency, energy-saving, and anti-clogging nanobubble aeration process based on silicon carbide ceramic membranes includes the following steps:

[0074] S1. Complete the installation and commissioning of the micro-nano bubble aeration device;

[0075] S2. Take a certain amount of wastewater and put it into the reaction device. Aerate the wastewater continuously for 5 hours using a micro-nano bubble aeration device. This includes the following steps:

[0076] S21. Start the micro-nano bubble aeration device. The filter device filters the oxygen in the oxygen generator. The filtered oxygen enters the ozone generator through the gas flow control device to generate ozone.

[0077] S22. Adjust the ozone gas flow rate to 0.4 L / min, and use a concentration detection device to detect that the ozone concentration reaches 165 mg / L;

[0078] S23. After the ozone gas concentration stabilizes, start the micro-nano bubble generating device. The ozone gas enters the micro-nano bubble generating device through the pipe. The ozone gas is dispersed into ozone micro-nano bubbles by the uniform and controllable micropores of the silicon carbide ceramic membrane. After the ozone micro-nano bubbles are released from the membrane surface, they enter the wastewater of the reaction device and undergo an oxidation reaction with the organic matter in the wastewater.

[0079] S24. Simultaneously with the reaction, turn on the ozone exhaust gas treatment device to treat the exhaust gas generated by the reaction.

[0080] S3. According to the wastewater volume, add a certain amount of nano-flocculator and polymeric flocculant PAM to the reaction device, stir for 50 seconds at 250 r / min using a magnetic stirrer, and let stand for 20 minutes after mixing evenly.

[0081] The dosage of nano-flocculant is 3 g / L, and the dosage of polymeric flocculant PAM is 2 g / L.

[0082] The preparation method of the nano-flocculator includes the following steps:

[0083] S31. Preparation and modification of nano-nickel oxide to obtain vinyl-modified nano-nickel oxide, including the following steps:

[0084] S311. Dissolve 3 parts by weight of nickel acetate tetrahydrate in 120 parts by weight of deionized water, and add ammonia dropwise while stirring to adjust the pH to 9.8. Continue stirring until nickel hydroxide sol is formed.

[0085] S312. The nickel hydroxide sol was transferred into a reaction vessel and kept in a furnace at 400°C for 5 hours. The product was then filtered and washed with deionized water and anhydrous ethanol until neutral. After vacuum drying at 60°C for 24 hours, nano nickel oxide was obtained.

[0086] S313. Add vinyl silane coupling agent dropwise to the surface of nano nickel oxide, stir evenly, and then add acrylic acid. The mass ratio of vinyl silane coupling agent, nano nickel oxide and acrylic acid is 3:25:4. Stir and react for 1.5 hours to obtain vinyl modified nano nickel oxide.

[0087] S32. Add 4 parts by weight of vinyl-modified nano nickel oxide, 8 parts by weight of acrylamide, 12 parts by weight of dimethyl diallyl ammonium chloride, 6 parts by weight of activated carbon and 3 parts by weight of cerium nitrate to 30 parts by weight of deionized water. After stirring and dissolving thoroughly, prepare a monomer mixed solution of a certain concentration and lower the temperature of the monomer mixed solution to 2°C.

[0088] S33. Weigh out 2 parts ammonium persulfate and 4 parts sodium bisulfite by mass, and dissolve them in 8 parts deionized water to prepare an initiator solution of a certain concentration.

[0089] S34. Purge nitrogen gas into the polymerization reactor for 25 minutes to remove oxygen from the system;

[0090] S35. Transfer the prepared monomer solution into the polymerization reactor and spray at 65m 3 After nitrogen gas was introduced at a flow rate of / h for 1.5h, an initiator solution was added to initiate the polymerization reaction, which lasted for 5h.

[0091] S36. After the reaction is complete, pour the reaction solution into a large amount of anhydrous ethanol to precipitate the polymer. The volume ratio of anhydrous ethanol to the reaction solution is 3:1. Stir to make the precipitation more complete and let it stand for 15 minutes.

[0092] S37. Filter out the precipitate and wash it repeatedly with anhydrous ethanol to remove unreacted impurities. After each wash, perform vacuum filtration until no impurities can be detected in the washing liquid.

[0093] S38. Place the washed product in a vacuum drying oven and dry it at 35°C for 2 hours to obtain a dried nano-flocculator.

[0094] S4. After the solution in the reaction apparatus precipitates and separates into layers, take the supernatant.

[0095] S5. When the micro-nano bubble generating device runs for 3 hours or the pressure difference across the silicon carbide ceramic membrane exceeds 0.2 MPa, the backwashing device automatically backwashes the micro-nano bubble generating device for 20 minutes. At the same time, a certain amount of chemical agent is added to the reaction device periodically to prevent pollutants from depositing on the surface of the silicon carbide ceramic membrane in the micro-nano bubble generating device.

[0096] The chemical agents used are dispersants and cleaning agents, with the dispersant added at a rate of 15 mg / L and the cleaning agent added at a rate of 6 mg / L.

[0097] Example 3: Please refer to Figure 1 As shown, a high-efficiency, energy-saving, and anti-clogging nanobubble aeration process based on silicon carbide ceramic membranes includes the following steps:

[0098] S1. Complete the installation and commissioning of the micro-nano bubble aeration device;

[0099] S2. Take a certain amount of wastewater and put it into the reaction device. Aerate the wastewater continuously for 6 hours using a micro-nano bubble aeration device. This includes the following steps:

[0100] S21. Start the micro-nano bubble aeration device. The filter device filters the oxygen in the oxygen generator. The filtered oxygen enters the ozone generator through the gas flow control device to generate ozone.

[0101] S22. Adjust the ozone gas flow rate to 0.6L / min, and use the concentration detection device to detect that the ozone concentration reaches 180mg / L;

[0102] S23. After the ozone gas concentration stabilizes, start the micro-nano bubble generating device. The ozone gas enters the micro-nano bubble generating device through the pipe. The ozone gas is dispersed into ozone micro-nano bubbles by the uniform and controllable micropores of the silicon carbide ceramic membrane. After the ozone micro-nano bubbles are released from the membrane surface, they enter the wastewater of the reaction device and undergo an oxidation reaction with the organic matter in the wastewater.

[0103] S24. Simultaneously with the reaction, turn on the ozone exhaust gas treatment device to treat the exhaust gas generated by the reaction.

[0104] S3. According to the wastewater volume, add a certain amount of nano-flocculator and polymeric flocculant PAM to the reaction device, stir for 60 seconds at 300r / min using a magnetic stirrer, and let stand for 30 minutes after mixing evenly.

[0105] The dosage of nano-flocculant is 4 g / L, and the dosage of polymeric flocculant PAM is 3 g / L.

[0106] The preparation method of the nano-flocculator includes the following steps:

[0107] S31. Preparation and modification of nano-nickel oxide to obtain vinyl-modified nano-nickel oxide, including the following steps:

[0108] S311. Dissolve 3 parts by weight of nickel acetate tetrahydrate in 130 parts of deionized water, and add ammonia dropwise while stirring to adjust the pH to 10. Continue stirring until nickel hydroxide sol is formed.

[0109] S312. The nickel hydroxide sol was transferred into a reaction vessel and kept in a furnace at 400°C for 6 hours. The product was then filtered and washed with deionized water and anhydrous ethanol until neutral. After vacuum drying at 60°C for 24 hours, nano nickel oxide was obtained.

[0110] S313. Add vinyl silane coupling agent dropwise to the surface of nano nickel oxide, stir evenly, and then add acrylic acid. The mass ratio of vinyl silane coupling agent, nano nickel oxide and acrylic acid is 4:25:5. Stir and react for 2 hours to obtain vinyl modified nano nickel oxide.

[0111] S32. Add 5 parts by weight of vinyl-modified nano nickel oxide, 11 parts by weight of acrylamide, 16 parts by weight of dimethyl diallyl ammonium chloride, 7 parts by weight of activated carbon and 4 parts by weight of cerium nitrate to 37 parts by weight of deionized water. After stirring and dissolving thoroughly, prepare a monomer mixed solution of a certain concentration and lower the temperature of the monomer mixed solution to 3°C.

[0112] S33. Weigh out 3 parts ammonium persulfate and 5 parts sodium bisulfite by mass, and dissolve them in 12 parts deionized water to prepare an initiator solution of a certain concentration.

[0113] S34. Purge nitrogen gas into the polymerization reactor for 30 minutes to remove oxygen from the system;

[0114] S35. Transfer the prepared monomer solution into the polymerization reactor and spray at 65m 3 After nitrogen gas was introduced at a flow rate of / h for 1.5h, an initiator solution was added to initiate the polymerization reaction, which lasted for 5h.

[0115] S36. After the reaction is complete, pour the reaction solution into a large amount of anhydrous ethanol to precipitate the polymer. The volume ratio of anhydrous ethanol to the reaction solution is 3:1. Stir to make the precipitation more complete and let it stand for 25 minutes.

[0116] S37. Filter out the precipitate and wash it repeatedly with anhydrous ethanol to remove unreacted impurities. After each wash, perform vacuum filtration until no impurities can be detected in the washing liquid.

[0117] S38. Place the washed product in a vacuum drying oven and dry it at 40°C for 3 hours to obtain a dried nano-flocculator.

[0118] S4. After the solution in the reaction apparatus precipitates and separates into layers, take the supernatant.

[0119] S5. When the micro-nano bubble generating device runs for 3 hours or the pressure difference across the silicon carbide ceramic membrane exceeds 0.2 MPa, the backwashing device automatically backwashes the micro-nano bubble generating device for 30 minutes. At the same time, a certain amount of chemical agent is added to the reaction device periodically to prevent contaminants from depositing on the surface of the silicon carbide ceramic membrane in the micro-nano bubble generating device.

[0120] The chemical agents used are dispersants and cleaning agents, with the dispersant added at a rate of 20 mg / L and the cleaning agent added at a rate of 10 mg / L.

[0121] Comparative Example 1: Please refer to Figure 1 As shown, this embodiment provides a high-efficiency, energy-saving, anti-clogging nanobubble aeration process based on silicon carbide ceramic membrane. The process is roughly the same as that in embodiment 1, except that no nano-flocculator is added in step S3.

[0122] Comparative Example 2: Please refer to Figure 1 As shown, this embodiment provides a high-efficiency, energy-saving, anti-clogging nanobubble aeration process based on silicon carbide ceramic membrane. The process is roughly the same as that in embodiment 1, except that the polymeric flocculant PAM is not added in step S3.

[0123] Comparative Example 3: Please refer to Figure 1 As shown, this embodiment provides a high-efficiency, energy-saving, and anti-clogging nanobubble aeration process based on silicon carbide ceramic membrane. The process is roughly the same as that in Embodiment 1, the main difference being that silicon carbide ceramic membrane is not used in the micro-nano bubble generating device.

[0124] Tests: Wastewater treated by the aeration processes of Examples 1-3 was designated as Example Groups 1-3, and wastewater treated by the aeration processes of Comparative Examples 1-3 was designated as Control Groups 1-3. According to GB18918-2002 standard, the COD removal rate, NH3-N removal rate, and TOC removal rate of the wastewater in the Experimental Groups 1-3 and Control Groups 1-3 were tested respectively, and the relevant data were recorded in Table 1.

[0125] Table 1: Experimental Data Recording Table

[0126]

[0127]

[0128] As shown in Table 1, compared with control groups 1-3, the wastewater treated by the aeration processes of Examples 1-3 showed significantly improved COD removal rate, NH3-N removal rate, and TOC removal rate. Furthermore, when treating wastewater using the aeration process of Example 1, the installation and commissioning of the micro-nano bubble aeration device were first completed. A certain amount of wastewater was placed in the reaction device, and the wastewater was continuously circulated and aerated for 3 hours using the micro-nano bubble aeration device. Based on the wastewater volume, a certain amount of nano-flocculator and polymeric flocculant PAM were added to the reaction device. The mixture was stirred for 30 seconds at 200 r / min using a magnetic stirrer. After thorough mixing, the mixture was allowed to stand for 10 minutes until the solution in the reaction device precipitated and separated into layers. The supernatant was then collected. When micro-nano bubbles were produced... When the operating time of the generating device reaches 3 hours or the pressure difference across the silicon carbide ceramic membrane exceeds 0.2 MPa, the backwashing device automatically backwashes the micro-nano bubble generating device for 15 minutes. At the same time, a certain amount of chemical agent is added to the reaction device periodically to prevent pollutants from depositing on the surface of the silicon carbide ceramic membrane in the micro-nano bubble generating device. The chemical agent is a dispersant and a cleaning agent. The amount of dispersant added is 10 mg / L and the amount of cleaning agent added is 4 mg / L. The COD of the wastewater and supernatant is measured and the COD removal rate is calculated. The wastewater treated by the aeration process of Example 1 has the highest COD removal rate, NH3-N removal rate and TOC removal rate, which are 88.8%, 90.2% and 75.3%, respectively.

[0129] Comparing Examples 1-3 with Control Group 1, when wastewater was treated using the aeration process of Control Group 1 without the addition of nano-flocculators, the COD removal rate, NH3-N removal rate, and TOC removal rate in Control Group 1 were reduced. In Example 1, when a certain amount of nano-flocculators and polymeric flocculants PAM were added to the reaction device according to the wastewater volume, with the nano-flocculator dosage being 2 g / L and the polymeric flocculant PAM dosage being 1 g / L, the COD removal rate, NH3-N removal rate, and TOC removal rate in the wastewater could be significantly improved.

[0130] In this invention, when treating wastewater using the aeration process described in Example 1, a nano-flocculator is added to the wastewater. This aeration process combines micro- and nano-ozone bubbles with the nano-flocculator. The nano-flocculator effectively removes suspended particles, colloidal substances, and other impurities from the wastewater. After proper flocculation and sedimentation, the wastewater entering the silicon carbide ceramic membrane aeration process reduces the probability of contaminant adhesion to the membrane surface, lowers the risk of membrane blockage, and ensures stable and efficient generation of nano-bubbles, maintaining the oxygen transfer efficiency of the aeration process. Simultaneously, the nano-bubbles generated by the silicon carbide ceramic membrane in the micro- and nano-bubble generating device greatly increase the gas-liquid contact area, improve oxygen transfer efficiency, thereby accelerating wastewater treatment speed and improving treatment effect. Compared with traditional aeration processes, the aeration process of this invention reduces energy consumption and effectively lowers wastewater treatment costs.

[0131] By adding a filter device after the oxygen generator, the gas passing through the micro-nano bubble generator can be filtered, reducing impurities in the gas. Simultaneously, the micro-nano bubble generator is improved by adding a pressure detection device and a backwashing device. When the micro-nano bubble generator has been running for 3 hours or the pressure difference across the silicon carbide ceramic membrane exceeds 0.2 MPa, the backwashing device automatically backwashes the micro-nano bubble generator. In addition, a certain amount of chemical agent is periodically added to the reaction device to prevent contaminants from depositing on the surface of the silicon carbide ceramic membrane in the micro-nano bubble generator. This invention's aeration process, through the comprehensive application of multiple anti-clogging measures, effectively solves the problem of membrane material clogging in traditional aeration processes, extends the service life of the membrane module, and reduces equipment maintenance costs.

[0132] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions will not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A high-efficiency, energy-saving, anti-clogging nanobubble aeration process based on silicon carbide ceramic membrane, characterized in that, Includes the following steps: S1. Complete the installation and commissioning of the micro-nano bubble aeration device, and the devices used during installation include oxygen generator, filter, gas flow control device, ozone generator, concentration detection device, micro-nano bubble generating equipment, backwashing device, pressure detection device, controller, reaction device and ozone tail gas treatment device. S2. Take a certain amount of wastewater and put it into the reaction device. Aerate the wastewater continuously for 3-6 hours using a micro-nano bubble aeration device. The process of aerating the wastewater continuously using a micro-nano bubble aeration device includes the following steps: S21. Start the micro-nano bubble aeration device. The filter device filters the oxygen in the oxygen generator. The filtered oxygen enters the ozone generator through the gas flow control device to generate ozone. S22. Adjust the ozone gas flow rate to 0.3-0.6 L / min, and use a concentration detection device to detect that the ozone concentration reaches 150-180 mg / L; S23. After the ozone gas concentration stabilizes, start the micro-nano bubble generating device. The ozone gas enters the micro-nano bubble generating device through the pipe. The ozone gas is dispersed into ozone micro-nano bubbles by the uniform and controllable micropores of the silicon carbide ceramic membrane. After the ozone micro-nano bubbles are released from the membrane surface, they enter the wastewater of the reaction device and undergo an oxidation reaction with the organic matter in the wastewater. S24. Simultaneously with the reaction, turn on the ozone exhaust gas treatment device to treat the exhaust gas generated by the reaction. S3. Based on the wastewater volume, add a certain amount of nano-flocculator and polymeric flocculant PAM to the reaction apparatus. Stir with a magnetic stirrer at 200–300 r / min for 30–60 s. After mixing evenly, let stand for 10–30 min. Based on the wastewater volume, the dosage of the nano-flocculator is 2–4 g / L, and the dosage of the polymeric flocculant PAM is 1–3 g / L. The preparation method of the nano-flocculator includes the following steps: S31. Prepare nano-nickel oxide and modify it to obtain vinyl-modified nano-nickel oxide; S32. Add 2-5 parts by weight of vinyl-modified nano nickel oxide, 5-11 parts by weight of acrylamide, 10-16 parts by weight of dimethyl diallyl ammonium chloride, 5-7 parts by weight of activated carbon, and 1-4 parts by weight of cerium nitrate to 20-37 parts by weight of deionized water. After stirring and dissolving thoroughly, prepare a monomer mixed solution of a certain concentration and lower the temperature of the monomer mixed solution to 0-3℃. S33. Weigh out 1-3 parts by weight of ammonium persulfate and 2-5 parts by weight of sodium bisulfite, and dissolve them in 5-12 parts by weight of deionized water to prepare an initiator solution of a certain concentration. S34. Pour nitrogen gas into the polymerization reactor for 20-30 minutes to remove oxygen from the system; S35. Transfer the prepared monomer solution into the polymerization reactor and spray at 65m 3 After passing nitrogen gas through the gas at a flow rate of 1 / h for 1 to 1.5 hours, an initiator solution is added to initiate the polymerization reaction, which lasts for 4 to 5 hours. S36. After the reaction is complete, pour the reaction solution into a large amount of anhydrous ethanol to precipitate the polymer. The volume ratio of anhydrous ethanol to the reaction solution is 2 to 3:

1. Stir to make the precipitation more complete and let it stand for 10 to 25 minutes. S37. Filter out the precipitate and wash it repeatedly with anhydrous ethanol to remove unreacted impurities. After each wash, perform vacuum filtration until no impurities can be detected in the washing liquid. S38. Place the washed product in a vacuum drying oven and dry it at 30-40℃ for 2-3 hours to obtain a dried nano-flocculator. S4. The solution in the reaction device precipitates and separates into layers. Take the supernatant and analyze it on a multi-parameter colorimeter. Determine the COD of the wastewater and supernatant according to the corresponding procedure and calculate the COD removal rate. S5. When the micro-nano bubble generating device runs for 3 hours or the pressure difference across the silicon carbide ceramic membrane exceeds 0.2 MPa, the backwashing device automatically backwashes the micro-nano bubble generating device. At the same time, a certain amount of chemical agent is added to the reaction device periodically to prevent contaminants from depositing on the surface of the silicon carbide ceramic membrane in the micro-nano bubble generating device.

2. The high-efficiency, energy-saving, anti-clogging nanobubble aeration process based on silicon carbide ceramic membrane according to claim 1, characterized in that, In step S1, the installation and commissioning of the micro / nano bubble aeration device includes the following steps: S11. Install pressure detection devices on both sides of the silicon carbide ceramic membrane in the micro-nano bubble generating device, and install the backwashing device with the micro-nano bubble generating device. S12. Install the micro-nano bubble generating device in the reaction device according to the design requirements, and then connect the ozone tail gas treatment device to the reaction device. Connect the pipes between the oxygen generating device, filter device, gas flow control device, ozone generating device, concentration detection device and micro-nano bubble generating device, and check whether the pipe connections are tight and whether there is any leakage. S13. Connect the controller to the above devices to obtain the micro-nano bubble aeration device, and debug the micro-nano bubble aeration device. Adjust the gas flow rate through the gas flow control device to meet the design requirements. At the same time, check whether the micro-nano bubble generating device is working properly and observe whether bubbles are released uniformly from the membrane surface.

3. The high-efficiency, energy-saving, anti-clogging nanobubble aeration process based on silicon carbide ceramic membrane according to claim 2, characterized in that, In step S31, nano-nickel oxide is prepared and modified to obtain vinyl-modified nano-nickel oxide, including the following steps: S311. Dissolve 2-3 parts by weight of nickel acetate tetrahydrate in 110-130 parts of deionized water, and add ammonia dropwise while stirring to adjust the pH to 9.7-10. Continue stirring until nickel hydroxide sol is formed. S312. The nickel hydroxide sol was transferred into a reaction vessel and kept in a furnace at 400°C for 4-6 hours. The product was then filtered and washed with deionized water and anhydrous ethanol until neutral. After vacuum drying at 60°C for 24 hours, nano nickel oxide was obtained. S313. Add vinyl silane coupling agent dropwise to the surface of nano nickel oxide, stir evenly, and then add acrylic acid. The mass ratio of vinyl silane coupling agent, nano nickel oxide, and acrylic acid is 2-4:25:3-5. Stir and react for 1-2 hours to obtain vinyl-modified nano nickel oxide.

4. The high-efficiency, energy-saving, anti-clogging nanobubble aeration process based on silicon carbide ceramic membrane according to claim 1, characterized in that, In step S5, the backwashing device automatically backwashes the micro / nano bubble generating device, including the following steps: S51. When the micro-nano bubble generating device runs for 3 hours or the pressure difference across the silicon carbide ceramic membrane exceeds 0.2 MPa, the controller automatically shuts down the oxygen generating device and issues a warning sound through the indicator. S52. The controller automatically opens the valve of the backwashing device, allowing high-pressure gas or liquid to pass through the silicon carbide ceramic membrane of the micro-nano bubble generator in reverse at a specific pressure and flow rate, thus automatically backwashing the micro-nano bubble generator. S53. Continuous backwashing for 15-30 minutes. During the process, observe the water quality of the backwash drainage to judge the backwashing effect. When the drainage is clear and there are no obvious impurities, turn off the backwashing device through the controller.

5. The high-efficiency, energy-saving, anti-clogging nanobubble aeration process based on silicon carbide ceramic membrane according to claim 1, characterized in that, In step S5, the chemical agent is a dispersant and a cleaning agent, wherein the amount of dispersant added is 10-20 mg / L and the amount of cleaning agent added is 4-10 mg / L.

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