A supported ozone catalyst and treatment process for treating dyeing and printing wastewater

Abstract

This invention discloses a supported ozone catalyst and treatment process for treating dyeing and printing wastewater, relating to the field of wastewater treatment technology. The supported ozone catalyst includes an environmentally responsive porous medium, active centers, and a bio-enzyme modified layer. The environmentally responsive porous medium is based on mesoporous alumina grafted with poly(N-isopropylacrylamide) and modified with poly(N-isopropylacrylamide) at an initial pore size of 10–15 nm. The grafting rate of poly(N-isopropylacrylamide) is 12–20%. The active centers consist of transition metal active centers and quantum dots modified thereon. The bio-enzyme modified layer is obtained by deep bio-modification of the catalyst surface with laccase, which has redox activity. This invention solves the problems of low mass transfer efficiency and poor adaptability to operating conditions of traditional fixed-pore-size catalysts by constructing an environmentally responsive porous medium grafted with poly(N-isopropylacrylamide) mesoporous alumina, making it difficult to effectively improve pollutant release efficiency under different temperature and pH conditions.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment technology, specifically to a supported ozone catalyst and treatment process for treating dyeing and printing wastewater. Background Technology

[0002] Traditional ozone catalysts cannot dynamically adjust their pore size according to environmental conditions. They cannot change their pore size to adapt to mass transfer requirements based on different temperatures and pH environments, resulting in low mass transfer efficiency in practical applications and poor adaptability to complex operating conditions. They are also unable to effectively improve pollutant release efficiency under different temperature and pH conditions, thus limiting their pollutant treatment effect. The ozone catalyst of this application can solve the problems of low mass transfer efficiency and poor adaptability to operating conditions of traditional fixed-pore-size catalysts, and the inability to effectively improve pollutant release efficiency under different temperature and pH conditions.

[0003] The shortcomings of existing ozone catalysts are:

[0004] 1. Patent document CN105080565B discloses a method for preparing a supported ozone oxidation catalyst. This document mainly considers how to provide a method for preparing a supported ozone oxidation catalyst that makes the preparation process simple, reduces the cost of catalytic oxidation, has good catalytic activity, and strong anti-poisoning ability. However, it does not consider how to solve the problems of low mass transfer efficiency and poor adaptability to working conditions of traditional fixed-pore catalysts, which make it difficult to effectively improve the pollutant release efficiency under different temperature and pH conditions.

[0005] 2. Patent document CN117960173B discloses a method for preparing a supported-blended ozone catalyst. This document mainly considers how to solve the problems of low catalytic performance, high raw material cost, and high-temperature calcination during the preparation process of existing ozone catalysts, which leads to a decrease in aggregate activity and specific surface area. However, it does not consider how to solve the problems of traditional ozone catalysts relying on ultraviolet light or high-temperature conditions, low photocatalytic efficiency, and high reaction activation energy, which make it difficult to efficiently activate ozone decomposition at room temperature.

[0006] 3. Patent document CN103240115B discloses a supported ozone catalytic oxidation catalyst and its preparation method. This document mainly considers how to find suitable support molecular sieves and metal oxide loading methods to prepare new supported ozone catalytic oxidation catalysts, thereby improving the treatment effect of organic wastewater. However, it does not consider how to solve the problems of existing biofilms being easy to deactivate, requiring offline regeneration, having long regeneration cycles and high operating costs, and being difficult to effectively suppress side reactions, having unstable adsorption capacity of cationic dyes, and having short continuous operating life of catalysts.

[0007] 4. Patent document CN101664681B discloses a supported catalyst for heterogeneous catalytic ozonation and its preparation method. This document mainly considers the problems of catalyst recovery, high reagent costs, secondary pollution caused by the introduction of impurities, low ozone utilization rate, and poor treatment efficiency when the catalyst is used. However, it does not consider how to solve the problems of low COD removal rate and decolorization rate, low treatment efficiency and high energy consumption, difficulty in efficient catalyst recovery, and shortcomings in the treatment of macromolecular pollutants when traditional single-process wastewater treatment is used. Summary of the Invention

[0008] The purpose of this invention is to provide a supported ozone catalyst and treatment process for treating dyeing and printing wastewater, so as to solve the problems mentioned in the background art.

[0009] To achieve the above objectives, the present invention provides the following technical solution: a supported ozone catalyst for treating dyeing and printing wastewater, the supported ozone catalyst comprising an environmentally responsive porous medium, an active center, and a bio-enzyme modified layer;

[0010] The environmentally responsive porous media is based on mesoporous alumina grafted with poly-N-isopropylacrylamide. The initial pore size of the mesoporous alumina is 10-15 nm, the grafting rate of poly-N-isopropylacrylamide is 12-20%, and it has temperature response characteristics in the range of 25-40 °C.

[0011] The active center consists of a transition metal active center and quantum dots modified on it;

[0012] The bio-enzyme modified layer is obtained by deep bio-modification of the catalyst surface by laccase with redox activity.

[0013] Preferably, a method for preparing a supported ozone catalyst for treating dyeing and printing wastewater is provided, wherein the method for preparing the supported ozone catalyst is as follows:

[0014] S1. Mesoporous alumina support was prepared by template method, and then poly-N-isopropylacrylamide was grafted onto mesoporous alumina by surface-initiated atom transfer radical polymerization technology to obtain environmentally responsive porous media.

[0015] S2. Prepare a transition metal active center precursor solution, impregnate an environmentally responsive porous medium in it to load the active center onto the medium, and then prepare a cadmium sulfide quantum dot solution by hydrothermal synthesis. Impregnate the environmentally responsive porous medium in the quantum dot solution to obtain a quantum dot-modified active center supported medium.

[0016] S3. Supported ozone catalyst was prepared by surface modification with bio-enzyme assistance.

[0017] Preferably, S1 also includes the following:

[0018] S11. The template agent adopts a block copolymer F127 and cetyltrimethylammonium bromide compound system with a mass ratio of 3:1.

[0019] Aluminum nitrate nonahydrate and template agent were ultrasonically dispersed in a mixed solvent of ethanol and water for 30 minutes. The volume ratio of ethanol to water was 7:3. The mixture was then hydrothermally reacted at 80°C for 24 hours. Before calcination, the template agent was removed by gradient elution with 0.1M dilute hydrochloric acid.

[0020] S12, the initiator is 2-bromoisobutyryl bromide, which is bonded to the surface of alumina through silane coupling agent KH570, with a grafting density of 0.8 to 1.2 mmol / g;

[0021] The polymerization conditions were as follows: N-isopropylacrylamide monomer concentration 0.5M, catalyst cuprous bromide / ligand pentamethyldiethylenetriamine molar ratio 1:2, and reaction at 60°C for 6 hours under nitrogen protection.

[0022] Preferably, S2 also includes the following:

[0023] S21. Prepare solutions containing manganese, iron, and copper precursors respectively, and mix them evenly according to the molar ratio of manganese:iron:copper = 2:1:1 to obtain a transition metal active center precursor solution.

[0024] S22. The environmentally responsive porous medium is immersed in the transition metal active center precursor solution and fully adsorbed under ultrasonic assistance. The ultrasonic frequency is set to 40kHz, the ultrasonic power is 200W, and the ultrasonic time is 30 minutes. Then it is dried in a vacuum environment at 120℃ for 12 hours and then calcined in a muffle furnace at 500℃ for 4 hours to make the transition metal active centers firmly loaded onto the medium.

[0025] S23. A cadmium sulfide quantum dot solution with a particle size of 3-4 nm was prepared by hydrothermal synthesis. The medium loaded with transition metal active centers was immersed in the quantum dot solution and reacted fully under magnetic stirring. The quantum dot loading was controlled to account for 3.5-4.5% of the total mass of the catalyst. Then, it was dried in an oven at 60°C for 8 hours to obtain a supported medium with quantum dot modified active centers.

[0026] Preferably, S3 also includes the following:

[0027] S31. Prepare a laccase solution with a concentration of 0.5–1.0 mg / mL, place the loaded medium in the laccase solution, and treat it in a shaker at a temperature of 32–34℃ and a speed of 100–150 r / min for 2.5–3.5 hours.

[0028] S32. After the treatment is completed, the medium is washed multiple times with deionized water to remove unreacted laccase, and then dried in a vacuum drying oven at 40°C for 10 hours to obtain the final supported ozone catalyst.

[0029] Preferably, a treatment process using a supported ozone catalyst for treating dyeing and printing wastewater includes the following steps:

[0030] S1. Pre-treatment of dyeing and printing wastewater using ultrasonic and electrochemical technologies;

[0031] S2. Catalytic oxidation treatment of dyeing and printing wastewater is achieved through a fluidized bed reactor using ozone and microwaves.

[0032] S3. Adjust the pore size of the medium and the catalytic reaction according to the changes in conditions at each stage of the dyeing and printing wastewater treatment process;

[0033] S4. Achieve in-situ regeneration and stable performance control of catalyst biofilm through bioenzymes;

[0034] S5. Magnetic separation and membrane treatment technologies are used to perform solid-liquid separation and resource recovery on the treated dyeing and printing wastewater.

[0035] Preferably, S1 also includes the following:

[0036] S11. High-frequency ultrasonic treatment at 20kHz for 10 minutes resulted in a sound energy density of 0.8W / cm³. 3 Break up the chain of macromolecular pollutants;

[0037] S12. Introduce CO2 microbubbles with a diameter of less than 50μm to adjust the pH of the wastewater to 6.5±0.2, providing a neutral environment for the subsequent response of the responsive porous media;

[0038] S2 also includes the following:

[0039] S21. In the initial stage, ozone is introduced at a concentration of 120 mg / L, and after 15 minutes it is reduced to 80 mg / L. Combined with microwave dynamic adjustment, the active centers on the catalyst surface are alternately in a state of high concentration ozone adsorption and free radical generation.

[0040] S22 employs a 2450MHz microwave pulse mode with a duty cycle of 2:1 and an average power of 250W. At 35–40℃, it excites the poly(N-isopropylacrylamide) chain segments of the responsive porous medium to extend to a pore size of 18–20 nm, while simultaneously activating the photogenerated electron-hole pairs of quantum dots.

[0041] Preferably, S3 also includes the following:

[0042] S31. At a low temperature acidic stage of 15-20℃ and pH 4-5, the poly-N-isopropylacrylamide segments shrink to a pore size of 6-8 nm, adsorbing and enriching small molecule dyeing pollutants.

[0043] At a high temperature alkaline stage of 35–40℃ and pH 8–9, the poly(N-isopropylacrylamide) chain segments extend, the pore size of the medium increases to 18–20 nm, and the adsorbed pollutants are released to the surface of the active center, promoting a 40% increase in mass transfer efficiency.

[0044] S32. Under microwave excitation, cadmium sulfide quantum dots generate photogenerated electron-hole pairs at 3–4 nm, which enhance the absorption of visible light at 520 nm wavelength through surface plasmon resonance, resulting in a hydroxyl radical yield of 1.2 × 10⁻⁶. 18 radicals / mLmin.

[0045] Preferably, in S4, the following is also included:

[0046] S41. After every 2 hours of treatment, inject 0.1% ABTS solution as a laccase mediator and maintain at 32°C for 30 minutes to restore the adsorption capacity of the biofilm for cationic dyes through enzymatic cross-linking reaction, which exceeds 180 mg / g.

[0047] S42. Real-time monitoring of biofilm protein concentration using UV-Vis spectroscopy at a wavelength of 280nm, automatically adjusting the activator dosage to ensure the biofilm thickness remains stable at 50–80nm and suppress side reactions.

[0048] Preferably, S5 also includes the following:

[0049] S51. The effluent is treated by ceramic membrane with a 50nm pore size and nanofiltration, and the COD of the produced water is less than 50mg / L, the conductivity is less than 200μS / cm, and the reuse rate reaches 85%.

[0050] S52. The concentrated liquid is evaporated and crystallized to recover inorganic salts, and the residue is purified into precious metals through an acid dissolution-extraction process, with a recovery rate of over 98%.

[0051] Compared with the prior art, the beneficial effects of the present invention are:

[0052] 1. This invention constructs an environmentally responsive porous medium by grafting poly(N-isopropylacrylamide) onto mesoporous alumina, achieving dynamic adjustment of pore size within the range of 6–20 nm with temperature (10–48 °C) and pH (4–9). Compared with traditional fixed-pore-size catalysts, this design improves mass transfer efficiency by 40%. Experimental data shows that under alkaline conditions at 35–40 °C, the pore size of the medium expands to 18–20 nm, significantly improving pollutant release efficiency. This breakthrough overcomes the technical bottleneck of poor adaptability to operating conditions of traditional catalysts, thus solving the problems of low mass transfer efficiency and poor adaptability to operating conditions of traditional fixed-pore-size catalysts, making it difficult to effectively improve pollutant release efficiency under different temperature and pH conditions.

[0053] 2. This invention utilizes cadmium sulfide quantum dots to modify the active centers of transition metals via surface plasmon resonance, achieving enhanced absorption of visible light at 520 nm and a hydroxyl radical yield of 1.32–1.58 × 10⁻⁶ under 2450 MHz microwave excitation. 18 Compared to traditional ozone catalysts that rely on ultraviolet light or high temperatures, this technology improves photocatalytic efficiency by 86-88% while lowering the activation energy to below 35°C. Experiments have verified that quantum dot modification enables the catalyst to efficiently activate ozone decomposition at room temperature. Therefore, it can solve the problems of traditional ozone catalysts that rely on ultraviolet light or high temperatures, have low photocatalytic efficiency, and have high activation energy, making it difficult to efficiently activate ozone decomposition at room temperature.

[0054] 3. This invention achieves dynamic biofilm repair through a laccase-ABTS mediator system, maintaining the cationic dye adsorption capacity stably above 180 mg / g and extending the catalyst's continuous operating life to 380–450 hours. Compared with existing technologies that are prone to biofilm deactivation and require offline regeneration, this method dynamically adjusts the activator dosage by monitoring the biofilm protein concentration in real time, shortening the regeneration cycle to 2 hours / cycle and significantly reducing operating costs. Experiments show that the biofilm thickness is stably controlled at 50–80 nm after regeneration, effectively suppressing side reactions. Therefore, it can solve the problems of existing biofilms being prone to deactivation, requiring offline regeneration, having long regeneration cycles and high operating costs, being difficult to effectively suppress side reactions, having unstable cationic dye adsorption capacity, and having short catalyst continuous operating life.

[0055] 4. This invention integrates ultrasonic disruption, microwave enhancement, ozone catalysis, and magnetic membrane separation technologies to achieve a COD removal rate of 95.2% and a decolorization rate of 99.5% under conditions of influent COD = 1000 mg / L and color intensity 6000 times, with an energy consumption of only 0.92 kWh / m³. 3Compared to traditional single processes, this system improves treatment efficiency by 30% and reduces energy consumption by 41% through ultrasonic pre-crushing of macromolecular pollutants, microwave-assisted ozone generation of hydroxyl radicals, and efficient catalyst recovery via magnetic membrane. Blank control group experiments confirmed that omitting quantum dot and microwave treatment would lead to a 17-21% decrease in pollutant removal rate, verifying the necessity of multi-field coupling. Therefore, it can solve the problems of low COD removal and decolorization rates, low treatment efficiency, high energy consumption, difficulty in efficient catalyst recovery, and shortcomings in treating macromolecular pollutants in traditional single processes for wastewater treatment. Detailed Implementation

[0056] The technical solutions in the embodiments of the present invention have been clearly and completely described. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0057] Example 1

[0058] A supported ozone catalyst for treating dyeing and printing wastewater, the supported ozone catalyst comprising an environmentally responsive porous medium, an active center, and a bio-enzyme modified layer;

[0059] The environmentally responsive porous media is based on mesoporous alumina grafted with poly-N-isopropylacrylamide. The initial pore size of the mesoporous alumina is 10-15 nm, the grafting rate of poly-N-isopropylacrylamide is 12-20%, and it has temperature response characteristics in the range of 25-40 °C.

[0060] The active center consists of a transition metal active center and quantum dots modified on it;

[0061] The bio-enzyme modified layer is obtained by deep bio-modification of the catalyst surface by laccase with redox activity.

[0062] Example 2

[0063] A method for preparing a supported ozone catalyst for treating dyeing and printing wastewater. The method for preparing the supported ozone catalyst is as follows:

[0064] S1. Mesoporous alumina support was prepared by template method, and then poly-N-isopropylacrylamide was grafted onto mesoporous alumina by surface-initiated atom transfer radical polymerization technology to obtain environmentally responsive porous media.

[0065] S2. Prepare a transition metal active center precursor solution, impregnate an environmentally responsive porous medium in it to load the active center onto the medium, and then prepare a cadmium sulfide quantum dot solution by hydrothermal synthesis. Impregnate the environmentally responsive porous medium in the quantum dot solution to obtain a quantum dot-modified active center supported medium.

[0066] S3. Supported ozone catalyst was prepared by surface modification with bio-enzyme assistance.

[0067] S1 also includes the following:

[0068] S11. The template agent adopts a block copolymer F127 and cetyltrimethylammonium bromide compound system with a mass ratio of 3:1.

[0069] Aluminum nitrate nonahydrate and template agent were ultrasonically dispersed in a mixed solvent of ethanol and water for 30 minutes. The volume ratio of ethanol to water was 7:3. The mixture was then hydrothermally reacted at 80°C for 24 hours. Before calcination, the template agent was removed by gradient elution with 0.1M dilute hydrochloric acid.

[0070] S12, the initiator is 2-bromoisobutyryl bromide, which is bonded to the surface of alumina through silane coupling agent KH570, with a grafting density of 1.0 mmol / g;

[0071] The polymerization conditions were as follows: N-isopropylacrylamide monomer concentration 0.5M, catalyst cuprous bromide / ligand pentamethyldiethylenetriamine molar ratio 1:2, and reaction at 60°C for 6 hours under nitrogen protection.

[0072] S2 also includes the following:

[0073] S21. Prepare solutions containing manganese, iron, and copper precursors respectively, and mix them evenly according to the molar ratio of manganese:iron:copper = 2:1:1 to obtain a transition metal active center precursor solution.

[0074] S22. The environmentally responsive porous medium is immersed in the transition metal active center precursor solution and fully adsorbed under ultrasonic assistance. The ultrasonic frequency is set to 40kHz, the ultrasonic power is 200W, and the ultrasonic time is 30 minutes. Then it is dried in a vacuum environment at 120℃ for 12 hours and then calcined in a muffle furnace at 500℃ for 4 hours to make the transition metal active centers firmly loaded onto the medium.

[0075] S23. A cadmium sulfide quantum dot solution with a particle size of 3 nm was prepared by hydrothermal synthesis. The medium loaded with transition metal active centers was immersed in the quantum dot solution and reacted fully under magnetic stirring. The quantum dot loading was controlled to account for 3.8% of the total mass of the catalyst. Then, it was dried in an oven at 60°C for 8 hours to obtain a supported medium with quantum dot modified active centers.

[0076] S3 also includes the following:

[0077] S31. Prepare a laccase solution with a concentration of 0.5 mg / mL, place the loading medium in the laccase solution, and treat it in a shaker at a temperature of 32℃ and a speed of 100 r / min for 3.5 hours.

[0078] S32. After the treatment is completed, the medium is washed multiple times with deionized water to remove unreacted laccase, and then dried in a vacuum drying oven at 40°C for 10 hours to obtain the final supported ozone catalyst.

[0079] A treatment process using a supported ozone catalyst for treating dyeing and printing wastewater includes the following steps:

[0080] S1. Pre-treatment of dyeing and printing wastewater using ultrasonic and electrochemical technologies;

[0081] S2. Catalytic oxidation treatment of dyeing and printing wastewater is achieved through a fluidized bed reactor using ozone and microwaves.

[0082] S3. Adjust the pore size of the medium and the catalytic reaction according to the changes in conditions at each stage of the dyeing and printing wastewater treatment process;

[0083] S4. Achieve in-situ regeneration and stable performance control of catalyst biofilm through bioenzymes;

[0084] S5. Magnetic separation and membrane treatment technologies are used to perform solid-liquid separation and resource recovery on the treated dyeing and printing wastewater.

[0085] S1 also includes the following:

[0086] S11. High-frequency ultrasonic treatment at 20kHz for 10 minutes resulted in a sound energy density of 0.8W / cm³. 3 Break up the chain of macromolecular pollutants;

[0087] S12. Introduce CO2 microbubbles with a diameter of less than 50μm to adjust the pH of the wastewater to 6.5±0.2, providing a neutral environment for the subsequent response of the responsive porous media;

[0088] S2 also includes the following:

[0089] S21. In the initial stage, ozone is introduced at a concentration of 120 mg / L, and after 15 minutes it is reduced to 80 mg / L. Combined with microwave dynamic adjustment, the active centers on the catalyst surface are alternately in a state of high concentration ozone adsorption and free radical generation.

[0090] S22 uses a 2450MHz microwave pulse mode with a duty cycle of 2:1 and an average power of 250W to excite the poly(N-isopropylacrylamide) chain segments of the responsive porous medium to extend to a pore size of 18-20nm at 35℃, while simultaneously activating the photogenerated electron-hole pairs of quantum dots.

[0091] S3 also includes the following:

[0092] S31. At a low temperature acidic stage of 15-20℃ and pH 4-5, the poly-N-isopropylacrylamide segments shrink to a pore size of 6-8 nm, adsorbing and enriching small molecule dyeing pollutants.

[0093] At a high temperature alkaline stage of 35–40℃ and pH 8–9, the poly(N-isopropylacrylamide) chain segments extend, the pore size of the medium increases to 18–20 nm, and the adsorbed pollutants are released to the surface of the active center, promoting a 40% increase in mass transfer efficiency.

[0094] S32. Under microwave excitation, cadmium sulfide quantum dots generate photogenerated electron-hole pairs at 3–4 nm, which enhance the absorption of visible light at 520 nm wavelength through surface plasmon resonance, resulting in a hydroxyl radical yield of 1.2 × 10⁻⁶. 18 radicals / mLmin.

[0095] S4 also includes the following:

[0096] S41. After every 2 hours of treatment, inject 0.1% ABTS solution as a laccase mediator and maintain at 32°C for 30 minutes to restore the adsorption capacity of the biofilm for cationic dyes through enzymatic cross-linking reaction, which exceeds 180 mg / g.

[0097] S42. Real-time monitoring of biofilm protein concentration using UV-Vis spectroscopy at a wavelength of 280nm, automatically adjusting the activator dosage to ensure the biofilm thickness remains stable at 50–80nm and suppress side reactions.

[0098] S5 also includes the following:

[0099] S51, the effluent is treated by ceramic membrane with a 50nm pore size and nanofiltration;

[0100] S52. The concentrated liquid is evaporated and crystallized to recover inorganic salts, and the residue is purified into precious metals through an acid dissolution-extraction process.

[0101] Example 3

[0102] A method for preparing a supported ozone catalyst for treating dyeing and printing wastewater. The method for preparing the supported ozone catalyst is as follows:

[0103] S1. Mesoporous alumina support was prepared by template method, and then poly-N-isopropylacrylamide was grafted onto mesoporous alumina by surface-initiated atom transfer radical polymerization technology to obtain environmentally responsive porous media.

[0104] S2. Prepare a transition metal active center precursor solution, impregnate an environmentally responsive porous medium in it to load the active center onto the medium, and then prepare a cadmium sulfide quantum dot solution by hydrothermal synthesis. Impregnate the environmentally responsive porous medium in the quantum dot solution to obtain a quantum dot-modified active center supported medium.

[0105] S3. Supported ozone catalyst was prepared by surface modification with bio-enzyme assistance.

[0106] S1 also includes the following:

[0107] S11. The template agent adopts a block copolymer F127 and hexadecyltrimethylammonium bromide compound system with a mass ratio of 2:1.

[0108] Aluminum nitrate nonahydrate and template agent were ultrasonically dispersed in a mixed solvent of ethanol and water for 30 minutes. The volume ratio of ethanol to water was 7:3. The mixture was then hydrothermally reacted at 80°C for 24 hours. Before calcination, the template agent was removed by gradient elution with 0.1M dilute hydrochloric acid.

[0109] S12, the initiator is 2-bromoisobutyryl bromide, which is bonded to the surface of alumina through silane coupling agent KH570, with a grafting density of 1.2 mmol / g;

[0110] The polymerization conditions were as follows: N-isopropylacrylamide monomer concentration 0.5M, catalyst cuprous bromide / ligand pentamethyldiethylenetriamine molar ratio 1:2, reaction at 65°C for 6 hours under nitrogen protection.

[0111] S2 also includes the following:

[0112] S21. Prepare solutions containing manganese, iron, and copper precursors respectively, and mix them evenly according to the molar ratio of manganese:iron:copper = 2:1:1 to obtain a transition metal active center precursor solution.

[0113] S22. The environmentally responsive porous medium is immersed in the transition metal active center precursor solution and fully adsorbed under ultrasonic assistance. The ultrasonic frequency is set to 40kHz, the ultrasonic power is 200W, and the ultrasonic time is 30 minutes. Then it is dried in a vacuum environment at 120℃ for 12 hours and then calcined in a muffle furnace at 500℃ for 4 hours to make the transition metal active centers firmly loaded onto the medium.

[0114] S23. A cadmium sulfide quantum dot solution with a particle size of 3 nm was prepared by hydrothermal synthesis. The medium loaded with transition metal active centers was immersed in the quantum dot solution and reacted fully under magnetic stirring. The quantum dot loading was controlled to account for 4.3% of the total mass of the catalyst. Then, it was dried in an oven at 60°C for 8 hours to obtain a supported medium with quantum dot modified active centers.

[0115] S3 also includes the following:

[0116] S31. Prepare a laccase solution with a concentration of 0.9 mg / mL, place the loading medium in the laccase solution, and treat it in a shaker at a temperature of 33℃ and a speed of 100 r / min for 3.5 hours.

[0117] S32. After the treatment is completed, the medium is washed multiple times with deionized water to remove unreacted laccase, and then dried in a vacuum drying oven at 40°C for 10 hours to obtain the final supported ozone catalyst.

[0118] A treatment process using a supported ozone catalyst for treating dyeing and printing wastewater includes the following steps:

[0119] S1. Pre-treatment of dyeing and printing wastewater using ultrasonic and electrochemical technologies;

[0120] S2. Catalytic oxidation treatment of dyeing and printing wastewater is achieved through a fluidized bed reactor using ozone and microwaves.

[0121] S3. Adjust the pore size of the medium and the catalytic reaction according to the changes in conditions at each stage of the dyeing and printing wastewater treatment process;

[0122] S4. Achieve in-situ regeneration and stable performance control of catalyst biofilm through bioenzymes;

[0123] S5. Magnetic separation and membrane treatment technologies are used to perform solid-liquid separation and resource recovery on the treated dyeing and printing wastewater.

[0124] S1 also includes the following:

[0125] S11. High-frequency ultrasonic treatment at 20kHz for 8 minutes, resulting in a sound energy density of 1.0W / cm³. 3 Break up the chain of macromolecular pollutants;

[0126] S12. Introduce CO2 microbubbles with a diameter of less than 50μm to adjust the pH of the wastewater to 6.5±0.2, providing a neutral environment for the subsequent response of the responsive porous media;

[0127] S2 also includes the following:

[0128] S21. In the initial stage, ozone is introduced at a concentration of 120 mg / L, and after 15 minutes it is reduced to 80 mg / L. Combined with microwave dynamic adjustment, the active centers on the catalyst surface are alternately in a state of high concentration ozone adsorption and free radical generation.

[0129] S22 uses a 2450MHz microwave pulse mode with a duty cycle of 2:1 and an average power of 250W to excite the poly(N-isopropylacrylamide) chain segments of the responsive porous medium to extend to a pore size of 18-20nm at 35℃, while simultaneously activating the photogenerated electron-hole pairs of quantum dots.

[0130] S3 also includes the following:

[0131] S31. At a low temperature acidic stage of 15-20℃ and pH 4-5, the poly-N-isopropylacrylamide segments shrink to a pore size of 6-8 nm, adsorbing and enriching small molecule dyeing pollutants.

[0132] At a high temperature alkaline stage of 35–40℃ and pH 8–9, the poly(N-isopropylacrylamide) chain segments extend, the pore size of the medium increases to 18–20 nm, and the adsorbed pollutants are released to the surface of the active center, promoting a 40% increase in mass transfer efficiency.

[0133] S32. Under microwave excitation, cadmium sulfide quantum dots generate photogenerated electron-hole pairs at 3–4 nm, which enhance the absorption of visible light at 520 nm wavelength through surface plasmon resonance, resulting in a hydroxyl radical yield of 1.2 × 10⁻⁶. 18 radicals / mLmin.

[0134] S4 also includes the following:

[0135] S41. After every 2 hours of treatment, inject 0.11% ABTS solution as a laccase mediator and maintain at 32°C for 25 minutes to restore the adsorption capacity of the biofilm for cationic dyes through enzymatic cross-linking reaction, which exceeds 180 mg / g.

[0136] S42. Real-time monitoring of biofilm protein concentration using UV-Vis spectroscopy at a wavelength of 280nm, automatically adjusting the activator dosage to ensure the biofilm thickness remains stable at 50–80nm and suppress side reactions.

[0137] S5 also includes the following:

[0138] S51, the effluent is treated by ceramic membrane with a 50nm pore size and nanofiltration;

[0139] S52. The concentrated liquid is evaporated and crystallized to recover inorganic salts, and the residue is purified into precious metals through an acid dissolution-extraction process.

[0140] Example 4

[0141] A method for preparing a supported ozone catalyst for treating dyeing and printing wastewater. The method for preparing the supported ozone catalyst is as follows:

[0142] S1. Mesoporous alumina support was prepared by template method, and then poly-N-isopropylacrylamide was grafted onto mesoporous alumina by surface-initiated atom transfer radical polymerization technology to obtain environmentally responsive porous media.

[0143] S2. Prepare a transition metal active center precursor solution, impregnate an environmentally responsive porous medium in it to load the active center onto the medium, and then prepare a cadmium sulfide quantum dot solution by hydrothermal synthesis. Impregnate the environmentally responsive porous medium in the quantum dot solution to obtain a quantum dot-modified active center supported medium.

[0144] S3. Supported ozone catalyst was prepared by surface modification with bio-enzyme assistance.

[0145] S1 also includes the following:

[0146] S11. The template agent adopts a block copolymer F127 and cetyltrimethylammonium bromide compound system with a mass ratio of 3:1.

[0147] Aluminum nitrate nonahydrate and template agent were ultrasonically dispersed in a mixed solvent of ethanol and water for 30 minutes. The volume ratio of ethanol to water was 7:3. The mixture was then hydrothermally reacted at 80°C for 24 hours. Before calcination, the template agent was removed by gradient elution with 0.1M dilute hydrochloric acid.

[0148] S12, the initiator is 2-bromoisobutyryl bromide, which is bonded to the surface of alumina through silane coupling agent KH570, with a grafting density of 0.8 mmol / g;

[0149] The polymerization conditions were as follows: N-isopropylacrylamide monomer concentration 0.5M, catalyst cuprous bromide / ligand pentamethyldiethylenetriamine molar ratio 1:2, and reaction at 60°C for 6 hours under nitrogen protection.

[0150] S2 also includes the following:

[0151] S21. Prepare solutions containing manganese, iron, and copper precursors respectively, and mix them evenly according to the molar ratio of manganese:iron:copper = 2:1:1 to obtain a transition metal active center precursor solution.

[0152] S22. The environmentally responsive porous medium is immersed in the transition metal active center precursor solution and fully adsorbed under ultrasonic assistance. The ultrasonic frequency is set to 40kHz, the ultrasonic power is 200W, and the ultrasonic time is 30 minutes. Then it is dried in a vacuum environment at 120℃ for 12 hours and then calcined in a muffle furnace at 500℃ for 4 hours to make the transition metal active centers firmly loaded onto the medium.

[0153] S23. A cadmium sulfide quantum dot solution with a particle size of 4 nm was prepared by hydrothermal synthesis. The medium loaded with transition metal active centers was immersed in the quantum dot solution and reacted fully under magnetic stirring. The quantum dot loading was controlled to account for 3.6% of the total mass of the catalyst. Then, it was dried in an oven at 60°C for 8 hours to obtain a supported medium with quantum dot modified active centers.

[0154] S3 also includes the following:

[0155] S31. Prepare a laccase solution with a concentration of 0.5 mg / mL, place the loading medium in the laccase solution, and treat it in a shaker at a temperature of 32℃ and a speed of 100 r / min for 3.5 hours.

[0156] S32. After the treatment is completed, the medium is washed multiple times with deionized water to remove unreacted laccase, and then dried in a vacuum drying oven at 40°C for 10 hours to obtain the final supported ozone catalyst.

[0157] A treatment process using a supported ozone catalyst for treating dyeing and printing wastewater includes the following steps:

[0158] S1. Pre-treatment of dyeing and printing wastewater using ultrasonic and electrochemical technologies;

[0159] S2. Catalytic oxidation treatment of dyeing and printing wastewater is achieved through a fluidized bed reactor using ozone and microwaves.

[0160] S3. Adjust the pore size of the medium and the catalytic reaction according to the changes in conditions at each stage of the dyeing and printing wastewater treatment process;

[0161] S4. Achieve in-situ regeneration and stable performance control of catalyst biofilm through bioenzymes;

[0162] S5. Magnetic separation and membrane treatment technologies are used to perform solid-liquid separation and resource recovery on the treated dyeing and printing wastewater.

[0163] S1 also includes the following:

[0164] S11. High-frequency ultrasonic treatment at 20kHz for 10 minutes resulted in a sound energy density of 0.8W / cm³. 3 Break up the chain of macromolecular pollutants;

[0165] S12. Introduce CO2 microbubbles with a diameter of less than 30μm to adjust the pH of the wastewater to 6.5±0.2, providing a neutral environment for the subsequent response of the responsive porous media;

[0166] S2 also includes the following:

[0167] S21. In the initial stage, ozone is introduced at a concentration of 120 mg / L, and after 15 minutes it is reduced to 80 mg / L. Combined with microwave dynamic adjustment, the active centers on the catalyst surface are alternately in a state of high concentration ozone adsorption and free radical generation.

[0168] S22 uses a 2450MHz microwave pulse mode with a duty cycle of 2:1 and an average power of 250W to excite the poly(N-isopropylacrylamide) chain segments of the responsive porous medium to extend to a pore size of 18-20nm at 35℃, while simultaneously activating the photogenerated electron-hole pairs of quantum dots.

[0169] S3 also includes the following:

[0170] S31. At a low temperature acidic stage of 15-20℃ and pH 4-5, the poly-N-isopropylacrylamide segments shrink to a pore size of 6-8 nm, adsorbing and enriching small molecule dyeing pollutants.

[0171] At a high temperature alkaline stage of 35–40℃ and pH 8–9, the poly(N-isopropylacrylamide) chain segments extend, the pore size of the medium increases to 18–20 nm, and the adsorbed pollutants are released to the surface of the active center, promoting a 40% increase in mass transfer efficiency.

[0172] S32. Under microwave excitation, cadmium sulfide quantum dots generate photogenerated electron-hole pairs at 3–4 nm, which enhance the absorption of visible light at 520 nm wavelength through surface plasmon resonance, resulting in a hydroxyl radical yield of 1.2 × 10⁻⁶. 18 radicals / mLmin.

[0173] S4 also includes the following:

[0174] S41. After every 2 hours of treatment, inject 0.1% ABTS solution as a laccase mediator and maintain at 32°C for 30 minutes to restore the adsorption capacity of the biofilm for cationic dyes through enzymatic cross-linking reaction, which exceeds 180 mg / g.

[0175] S42. Real-time monitoring of biofilm protein concentration using UV-Vis spectroscopy at a wavelength of 280nm, automatically adjusting the activator dosage to ensure the biofilm thickness remains stable at 50–80nm and suppress side reactions.

[0176] S5 also includes the following:

[0177] S51, the effluent is treated by ceramic membrane with a 50nm pore size and nanofiltration;

[0178] S52. The concentrated liquid is evaporated and crystallized to recover inorganic salts, and the residue is purified into precious metals through an acid dissolution-extraction process.

[0179] Example 5

[0180] A blank control group was set up. S23 was omitted in the preparation method of the supported ozone catalyst. The grafting density was 0.9 mmol / g, the laccase concentration was 0.6 mg / mL, and the remaining steps were the same as in Example 2.

[0181] In the supported ozone catalyst treatment process, S22 is omitted, the ozone concentration is kept constant at 100 mg / L, and the remaining steps are the same as in Example 2.

[0182] Example 6

[0183] The performance testing and processing results of Examples 2, 3, 4, and the blank control group Example 5 are as follows:

[0184] The catalyst characterization and detection results are as follows:

[0185]

[0186] The test results for the dyeing and printing wastewater treatment data (influent COD = 1000 mg / L, color = 6000 times) are as follows:

[0187] index Example 2 Example 3 Example 4 Example 5 COD removal rate (%) 93.7 95.2 91.8 75.3 Decolorization rate (%) 99.1 99.5 98.3 82.1 <![CDATA[Effluent BOD5 / COD]]> 0.42 0.45 0.38 0.25 <![CDATA[Energy consumption (kWh / m 3 )]]> 0.85 0.92 0.78 1.2

[0188] The dynamic response performance test results are as follows:

[0189]

[0190] Performance testing and processing results show that:

[0191] This supported ozone catalyst achieves efficient synergy between intelligent pore size regulation and multi-field coupled catalysis through a ternary synergistic design of "environmentally responsive medium - quantum dot modification - bioenzyme modification".

[0192] The environmentally responsive porous media is based on mesoporous alumina grafted with poly-N-isopropylacrylamide. Its pore size can intelligently shrink / expand in the range of 6 to 20 nm with temperature of 10 to 48 °C and pH of 4 to 9, which significantly improves the mass transfer efficiency by up to 40%.

[0193] Quantum dot-modified transition metal active centers enhance the absorption of 520 nm visible light through surface plasmon resonance, resulting in a hydroxyl radical yield of 1.32–1.58 × 10⁻⁶. 18 The radicals / mLmin were increased by 86-88% compared to the control group.

[0194] The bio-enzyme modified layer achieves in-situ regeneration of the biofilm through laccase mediator, maintaining the adsorption capacity above 180 mg / g and extending the catalyst stability to 380–450 hours.

[0195] The treatment process employs an integrated technology of ultrasonic crushing, microwave enhancement, ozone catalysis, and magnetic membrane separation. Under conditions of influent COD = 1000 mg / L and color intensity of 6000 times, Example 3 achieved a COD removal rate of 95.2% and a decolorization rate of 99.5%, with the effluent BOD / COD ratio increased to 0.45 and energy consumption of only 0.92 kWh / m³. 3 .

[0196] The blank control group, which omitted quantum dot and microwave treatments, experienced a 21-17% decrease in pollutant removal rate and a 41% increase in energy consumption, verifying the necessity of multi-technology synergy.

[0197] Process parameter optimization shows that the optimal overall performance is achieved when the mass ratio of template agent F127 to CTAB is 2:1, the quantum dot loading is 4.3%, and the grafting density is 1.2 mmol / g. The response time is shortened to 38-55 seconds, providing an efficient solution for the deep treatment of dyeing and printing wastewater.

[0198] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

Claims

1. A supported ozone catalyst for treating dyeing and printing wastewater, characterized in that, Supported ozone catalysts include an environmentally responsive porous medium, active centers, and a bio-enzyme modified layer; The environmentally responsive porous media is based on mesoporous alumina grafted with poly-N-isopropylacrylamide. The initial pore size of the mesoporous alumina is 10-15 nm, the grafting rate of poly-N-isopropylacrylamide is 12-20%, and it has temperature response characteristics in the range of 25-40 °C. The active center consists of a transition metal active center and quantum dots modified on it; The bio-enzyme modified layer is obtained by deep bio-modification of the catalyst surface by laccase with redox activity.

2. A method for preparing a supported ozone catalyst for treating dyeing and printing wastewater, applicable to the supported ozone catalyst for treating dyeing and printing wastewater as described in claim 1, characterized in that, The preparation method of supported ozone catalyst is as follows: S1. Mesoporous alumina support was prepared by template method, and then poly-N-isopropylacrylamide was grafted onto mesoporous alumina by surface-initiated atom transfer radical polymerization technology to obtain environmentally responsive porous media. S2. Prepare a transition metal active center precursor solution, impregnate an environmentally responsive porous medium in it to load the active center onto the medium, and then prepare a cadmium sulfide quantum dot solution by hydrothermal synthesis. Impregnate the environmentally responsive porous medium in the quantum dot solution to obtain a quantum dot-modified active center supported medium. S3. Supported ozone catalyst was prepared by surface modification with bio-enzyme assistance.

3. The method for preparing a supported ozone catalyst for treating dyeing and printing wastewater according to claim 2, characterized in that, S1 also includes the following: S11. The template agent adopts a block copolymer F127 and cetyltrimethylammonium bromide compound system with a mass ratio of 3:

1. Aluminum nitrate nonahydrate and template agent were ultrasonically dispersed in a mixed solvent of ethanol and water for 30 minutes. The volume ratio of ethanol to water was 7:

3. The mixture was then hydrothermally reacted at 80°C for 24 hours. Before calcination, the template agent was removed by gradient elution with 0.1M dilute hydrochloric acid. S12, the initiator is 2-bromoisobutyryl bromide, which is bonded to the surface of alumina through silane coupling agent KH570, with a grafting density of 0.8 to 1.2 mmol / g; The polymerization conditions were as follows: N-isopropylacrylamide monomer concentration 0.5M, catalyst cuprous bromide / ligand pentamethyldiethylenetriamine molar ratio 1:2, and reaction at 60°C for 6 hours under nitrogen protection.

4. The method for preparing a supported ozone catalyst for treating dyeing and printing wastewater according to claim 2, characterized in that, S2 also includes the following: S21. Prepare solutions containing manganese, iron, and copper precursors respectively, and mix them evenly according to the molar ratio of manganese:iron:copper = 2:1:1 to obtain a transition metal active center precursor solution. S22. The environmentally responsive porous medium is immersed in the transition metal active center precursor solution and fully adsorbed under ultrasonic assistance. The ultrasonic frequency is set to 40kHz, the ultrasonic power is 200W, and the ultrasonic time is 30 minutes. Then it is dried in a vacuum environment at 120℃ for 12 hours and then calcined in a muffle furnace at 500℃ for 4 hours to make the transition metal active centers firmly loaded onto the medium. S23. A cadmium sulfide quantum dot solution with a particle size of 3-4 nm was prepared by hydrothermal synthesis. The medium loaded with transition metal active centers was immersed in the quantum dot solution and reacted fully under magnetic stirring. The quantum dot loading was controlled to account for 3.5-4.5% of the total mass of the catalyst. Then, it was dried in an oven at 60°C for 8 hours to obtain a supported medium with quantum dot modified active centers.

5. The method for preparing a supported ozone catalyst for treating dyeing and printing wastewater according to claim 2, characterized in that, S3 also includes the following: S31. Prepare a laccase solution with a concentration of 0.5–1.0 mg / mL, place the loaded medium in the laccase solution, and treat it in a shaker at a temperature of 32–34℃ and a speed of 100–150 r / min for 2.5–3.5 hours. S32. After the treatment is completed, the medium is washed multiple times with deionized water to remove unreacted laccase, and then dried in a vacuum drying oven at 40°C for 10 hours to obtain the final supported ozone catalyst.

6. A treatment process for a supported ozone catalyst for treating dyeing and printing wastewater, employing the supported ozone catalyst for treating dyeing and printing wastewater as described in claim 1, characterized in that, The supported ozone catalyst treatment process includes the following: S1. Pre-treatment of dyeing and printing wastewater using ultrasonic and electrochemical technologies; S2. Catalytic oxidation treatment of dyeing and printing wastewater is achieved through a fluidized bed reactor using ozone and microwaves. S3. Adjust the pore size of the medium and the catalytic reaction according to the changes in conditions at each stage of the dyeing and printing wastewater treatment process; S4. Achieve in-situ regeneration and stable performance control of catalyst biofilm through bioenzymes; S5. Magnetic separation and membrane treatment technologies are used to perform solid-liquid separation and resource recovery on the treated dyeing and printing wastewater.

7. The treatment process for a supported ozone catalyst for treating dyeing and printing wastewater according to claim 6, characterized in that, S1 also includes the following: S11. High-frequency ultrasonic treatment at 20kHz for 10 minutes resulted in a sound energy density of 0.8W / cm³. 3 Break up the chain of macromolecular pollutants; S12. Introduce CO2 microbubbles with a diameter of less than 50μm to adjust the pH of the wastewater to 6.5±0.2, providing a neutral environment for the subsequent response of the responsive porous media; S2 also includes the following: S21. In the initial stage, ozone is introduced at a concentration of 120 mg / L, and after 15 minutes it is reduced to 80 mg / L. Combined with microwave dynamic adjustment, the active centers on the catalyst surface are alternately in a state of high concentration ozone adsorption and free radical generation. S22 employs a 2450MHz microwave pulse mode with a duty cycle of 2:1 and an average power of 250W. At 35–40℃, it excites the poly(N-isopropylacrylamide) chain segments of the responsive porous medium to extend to a pore size of 18–20 nm, while simultaneously activating the photogenerated electron-hole pairs of quantum dots.

8. The treatment process for a supported ozone catalyst for treating dyeing and printing wastewater according to claim 6, characterized in that, S3 also includes the following: S31. At a low temperature acidic stage of 15-20℃ and pH 4-5, the poly-N-isopropylacrylamide segments shrink to a pore size of 6-8 nm, adsorbing and enriching small molecule dyeing pollutants. At a high temperature alkaline stage of 35–40℃ and pH 8–9, the poly(N-isopropylacrylamide) chain segments extend, the pore size of the medium increases to 18–20 nm, and the adsorbed pollutants are released to the surface of the active center, promoting a 40% increase in mass transfer efficiency. S32. Under microwave excitation, 3–4 nm cadmium sulfide quantum dots generate photogenerated electron-hole pairs, which enhance the absorption of visible light at a wavelength of 520 nm through surface plasmon resonance, resulting in a hydroxyl radical yield of 1.2 × 10⁻⁶. 18 radicals / mL·min.

9. The treatment process for a supported ozone catalyst for treating dyeing and printing wastewater according to claim 6, characterized in that, S4 also includes the following: S41. After every 2 hours of treatment, inject 0.1% ABTS solution as a laccase mediator and maintain at 32°C for 30 minutes to restore the adsorption capacity of the biofilm for cationic dyes through enzymatic cross-linking reaction, which exceeds 180 mg / g. S42. Real-time monitoring of biofilm protein concentration using UV-Vis spectroscopy at a wavelength of 280nm, automatically adjusting the activator dosage to ensure the biofilm thickness remains stable at 50–80nm and suppress side reactions.

10. The treatment process for a supported ozone catalyst for treating dyeing and printing wastewater according to claim 6, characterized in that, S5 also includes the following: S51. The effluent is treated by ceramic membrane with a 50nm pore size and nanofiltration, and the COD of the produced water is less than 50mg / L, the conductivity is less than 200μS / cm, and the reuse rate reaches 85%. S52. The concentrated liquid is evaporated and crystallized to recover inorganic salts, and the residue is purified into precious metals through an acid dissolution-extraction process, with a recovery rate of over 98%.

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