Sewage treatment material as well as preparation method and application thereof

Abstract

The invention relates to the technical field of environmental protection, and discloses a sewage treatment material and a preparation method and application thereof.The preparation method comprises the steps that a sodium silicate solution, aluminum oxide, titanium oxide and carbon nanotubes are mixed, gelatinized and dried, and carbon nanotube reinforced aerogel is prepared; a modification material is introduced to the surface of the aerogel through a chemical vapor deposition method, and modified aerogel is obtained; depositing a metal organic framework material on the surface of the modified aerogel by using a solvothermal method to prepare composite aerogel; the polytetrafluoroethylene film and the nanoscale composite metal material film are combined through a hot pressing method to form a double-layer net-shaped filter screen; finally, the composite aerogel is combined with a double-layer net-shaped filter screen, and the sewage treatment material is formed. The sewage treatment material and the method thereof provided by the invention have multiple advantages of high efficiency, rapidness, environmental protection, economy and the like, can effectively solve the problems of low efficiency, high cost, secondary pollution and the like in the existing sewage treatment technology, and have wide application prospects and popularization values.

Description

Technical Field

[0001] The present invention relates to the field of environmental protection technologies, and more particularly, to a sewage treatment material, a preparation method thereof, and an application thereof. Background Art

[0002] With the accelerating advancement of industrialization and urbanization, the problem of water pollution has become increasingly severe. In particular, pollutants such as heavy metal ions, organic pollutants, and microplastics in industrial wastewater, domestic sewage, and agricultural runoff water pose a serious threat to the ecological environment and human health. Traditional sewage treatment technologies, such as coagulation sedimentation, activated carbon adsorption, and biodegradation, generally have defects such as limited adsorption capacity, low selectivity, unstable treatment efficiency, and non-recyclable materials.

[0003] Therefore, the research and development of high-performance, adjustable, and renewable sewage treatment materials has become the focus of current research in the field of environmental science. Summary of the Invention

[0004] In view of this, the present invention provides a sewage treatment material, a preparation method thereof, and an application thereof, aiming to provide a sewage treatment material with high adsorption capacity, high selectivity, stable treatment efficiency, and recyclability, so as to solve the problems existing in the prior art.

[0005] The present invention provides a preparation method of a sewage treatment material, comprising: Mixing a sodium silicate solution with aluminum oxide and titanium oxide, adding carbon nanotubes, and obtaining a carbon nanotube-reinforced aerogel through a gelation reaction and a drying process; introducing a surface modification material on the surface of the carbon nanotube-reinforced aerogel by chemical vapor deposition to obtain a modified aerogel; depositing a metal-organic framework material on the surface of the modified aerogel by a solvothermal method to obtain a composite aerogel; using a hot pressing method to laminate a polytetrafluoroethylene membrane and a nanoscale composite metal material membrane to form a double-layer mesh filter; combining the composite aerogel with the double-layer mesh filter to form a complete sewage treatment material.

[0006] Preferably, the gelation reaction temperature is 25 - 30 °C, and the reaction time is 4 - 5 hours; the drying temperature of the drying process is 60 - 70 °C, and the drying time is 12 - 14 hours.

[0007] Preferably, the surface modification material is chitosan or alginate; the deposition temperature of the chemical vapor deposition method is 80 - 90 °C, and the deposition time is 2 - 3 hours.

[0008] Preferably, the mass ratio of the modified aerogel to the metal-organic framework material is 60:40; the metal-organic framework material is ZIF-8 or UiO-66; the reaction temperature of the solvothermal method is 150 - 160 °C, and the reaction time is 12 - 14 hours.

[0009] Preferably, the pore size of the polytetrafluoroethylene membrane is 20 - 100 microns, and the pore size of the nanoscale composite metal material membrane is 10 - 50 nanometers; the temperature of the hot pressing method is 120 - 130 °C, the pressure is 5 - 10 MPa, and the time is 10 - 15 minutes.

[0010] The present invention also provides a sewage treatment material, which is prepared according to the preparation method of the above-mentioned sewage treatment material.

[0011] The present invention also provides an application of the above-mentioned sewage treatment material, characterized in that the application is A1 or A2; A1 is the application of the sewage treatment material in treating sewage; A2 is the application of the sewage treatment material in preparing sewage treatment products.

[0012] The present invention also provides a sewage treatment method, including: Using the above-mentioned sewage treatment material to adsorb pollutants in sewage.

[0013] The present invention also provides a sewage treatment method, including: Using the above-mentioned sewage treatment material to preliminarily adsorb pollutants in sewage; Constructing an electrochemical reaction cell, fixing the sewage treatment material between the anode and the cathode as the adsorption layer of the electrochemical reaction cell; applying an external electric field to perform secondary adsorption on the pollutants in sewage.

[0014] Preferably, when applying the external electric field, the voltage range is 1 - 5 V, and the current density is 10 mA / cm 2 .

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: A novel sewage treatment material is provided. This material combines the advantages of carbon nanotube enhanced aerogel, metal-organic framework material, and double-layer reticulated filter, and has high adsorption capacity, high selectivity, stable treatment efficiency, and recyclability. Through fine preparation steps and parameter optimization, the excellent performance of the sewage treatment material is ensured. Specifically: 1. High-efficiency pollutant removal ability: The sewage treatment material provided by the present invention can efficiently remove heavy metal ions and organic pollutants in sewage through the synergistic effect of composite aerogel and double-layer mesh filter. Under the condition of no power supply, the removal rate of heavy metal ions reaches 85%-90% within 30 minutes, and the removal rate of organic pollutants reaches 75%-85%. In an electrochemically responsive system, after applying a voltage of 3-5V, the removal rate of heavy metal ions reaches over 99% within 30 minutes, and the removal rate of organic pollutants reaches over 97%.

[0016] 2. Fast treatment ability By introducing an electrocatalytic reaction, the sewage treatment time is significantly shortened. Compared with the traditional adsorption method, the treatment time is shortened from 120 minutes to 30 minutes, greatly improving the treatment efficiency.

[0017] 3. Reusability of the material The sewage treatment material has good stability and reusability. It can be reused no less than 5 times after cleaning and drying, and still maintains high pollutant removal ability after each use, reducing the operating cost.

[0018] 4. Wide applicability This material and method are applicable to the removal of various pollutants (including heavy metal ions and organic pollutants), and can be widely used in the treatment of industrial wastewater, domestic sewage and polluted water sources.

[0019] 5. Environmental friendliness The raw materials (such as chitosan, alginate) and modifiers (such as MOFs) used in the material preparation process are all environmentally friendly materials and will not cause secondary pollution to the environment. No chemical agents need to be added during the electrocatalytic reaction process, avoiding the risk of secondary pollution.

[0020] 6. Simple operation The sewage treatment method is simple to operate. The voltage and treatment time can be adjusted according to actual needs, and it is applicable to sewage treatment scenarios of different scales and types.

[0021] 7. Significant economic benefits The material preparation cost is low and it can be reused, greatly reducing the economic cost of sewage treatment. The high treatment ability reduces the equipment floor area and operating energy consumption, with significant economic benefits. Specific implementation manners

[0022] Exemplary embodiments of the present disclosure will be described in more detail below. Although the following shows exemplary embodiments of the present disclosure, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided so that the present disclosure can be more thoroughly understood and the scope of the present disclosure can be fully conveyed to those skilled in the art. It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the embodiments.

[0023] Example 1 I. Preparation of Carbon Nanotube Reinforced Aerogel 1. Dosage of Raw Materials Sodium silicate solution (0.5M): 100 mL; Aluminum oxide (Al2O3): 1.0 g; Titanium oxide (TiO2): 0.5 g; Carbon nanotubes (CNTs): 1.0 g (1 wt%); Ammonia water (25% concentration): 10 mL.

[0024] 2. Steps Mix 100 mL of sodium silicate solution with 1.0 g of aluminum oxide and 0.5 g of titanium oxide, and stir for 30 minutes until homogeneous. Add 1.0 g of carbon nanotubes to the mixed solution, and ultrasonically disperse for 30 minutes to ensure uniform dispersion of CNTs. Slowly add 10 mL of ammonia water, stir for 10 minutes, control the reaction temperature at 25 °C, and the reaction time at 4 hours to carry out the gelation reaction. Place the gel in an oven at 60 °C and dry for 12 hours to obtain carbon nanotube-reinforced aerogel. Using the chemical vapor deposition (CVD) method, introduce chitosan (0.5 g) or alginate (0.5 g) on the surface of the aerogel, with a deposition temperature of 80 °C and a time of 2 hours.

[0025] II. Functional Modification of Marine Biological Polysaccharides 1. Dosage of Raw Materials Chitosan (extracted from shrimp shells): 0.5 g; EDC / NHS crosslinking agent: EDC 0.2 g, NHS 0.1 g; Deionized water: 50 mL.

[0026] 2. Steps Dissolve 0.5 g of chitosan in 50 mL of deionized water and stir until completely dissolved. Add 0.2 g of EDC and 0.1 g of NHS, and stir for 10 minutes to activate the carboxyl group. Immerse the aerogel in the above solution and react at 25 °C for 6 hours to make chitosan covalently bond to the surface of the aerogel. Take out the aerogel, rinse it 3 times with deionized water to remove unreacted reagents, and dry it at room temperature.

[0027] 3. Optimization of the ratio of composite aerogel and MOFs materials 1. Raw material dosage Aerogel: 6.0g; ZIF-8 (MOFs material): 4.0 g; Methanol (solvent): 100mL.

[0028] 2. Steps 6.0 g of aerogel was mixed with 4.0 g of ZIF-8, and 100 mL of methanol was added for ultrasonic dispersion for 30 minutes. The mixture was transferred to a high-pressure reactor and reacted at 150 ° C for 12 hours to allow ZIF-8 to be uniformly deposited on the surface of the aerogel. After the reaction, the composite aerogel was taken out, rinsed with methanol three times, and dried at 60 ° C for 6 hours.

[0029] 4. Preparation of double-layer mesh filter 1. Raw material dosage PTFE membrane: thickness 100 μm, pore size 20 μm; Nano-scale ZnO / TiO2 composite film: thickness 50μm, pore size 10nm; Polyvinyl alcohol (PVA) solution: 5wt%, 50mL. 2. Steps The PTFE membrane (outer layer) and the nano-ZnO / TiO2 composite membrane (inner layer) were pressed together using a hot pressing method at a temperature of 120°C, a pressure of 5 MPa, and a time of 10 minutes. A 5wt% PVA solution was sprayed on the surface of the outer PTFE membrane at a spraying volume of 0.1 mL / cm 2 , and dried at room temperature for 2 hours. The prepared double-layer mesh filter was assembled with the composite aerogel to form a complete sewage treatment material.

[0030] Example 2 1. Preparation of carbon nanotube-reinforced aerogel 1. Raw material dosage Sodium silicate solution (0.5M): 100mL; Aluminum oxide (Al2O3): 1.5g; Titanium oxide (TiO2): 1.0g; Carbon nanotubes (CNTs): 2.0 g (2 wt%); Ammonia water (25% concentration): 15mL.

[0031] 2. Steps Mix 100 mL of sodium silicate solution with 1.5 g of aluminum oxide and 1.0 g of titanium oxide, and stir for 30 minutes until homogeneous. Add 2.0 g of carbon nanotubes to the mixed solution and ultrasonically disperse for 30 minutes to ensure uniform dispersion of CNTs. Slowly add 15 mL of ammonia water, stir for 10 minutes, control the reaction temperature at 30 °C, and react for 5 hours to carry out the gelation reaction. Place the gel in an oven at 70 °C and dry for 14 hours to obtain a carbon nanotube-reinforced aerogel. Using the chemical vapor deposition (CVD) method, introduce alginate (1.0 g) onto the surface of the aerogel, with a deposition temperature of 90 °C and a time of 3 hours.

[0032] II. Functional Modification of Marine Biological Polysaccharides 1. Dosage of Raw Materials Alginate (extracted from seaweed): 1.0 g; EDC / NHS cross-linking agent: 0.3 g of EDC and 0.15 g of NHS; Deionized water: 50 mL.

[0033] 2. Procedures Dissolve 1.0 g of alginate in 50 mL of deionized water and stir until completely dissolved. Add 0.3 g of EDC and 0.15 g of NHS, and stir for 10 minutes to activate the carboxyl groups. Immerse the aerogel in the above solution and react at 30 °C for 8 hours to allow the alginate to bind to the surface of the aerogel through covalent bonds. Take out the aerogel, rinse it 3 times with deionized water to remove the unreacted reagents, and dry it at room temperature.

[0034] III. Ratio Optimization of Composite Aerogel and MOFs Materials 1. Dosage of Raw Materials Aerogel: 6.0 g; UiO-66 (MOFs material): 4.0 g; Ethanol (solvent): 100 mL.

[0035] 2. Procedures Mix 6.0 g of aerogel with 4.0 g of UiO-66, add 100 mL of ethanol, and ultrasonically disperse for 30 minutes. Transfer the mixture to a high-pressure reactor and react at 160 °C for 14 hours to allow UiO-66 to be uniformly deposited on the surface of the aerogel. After the reaction, take out the composite aerogel, rinse it 3 times with ethanol, and dry it at 70 °C for 8 hours.

[0036] IV. Preparation of Double-Layer Mesh Filter 1. Dosage of Raw Materials PTFE membrane: thickness 150 μm, pore size 100 μm Nanoscale ZnO / TiO2 composite membrane: thickness 100 μm, pore size 50 nm Polyurethane (PU) solution: 10 wt%, 50 mL 2. Steps Use the hot pressing method to press the PTFE membrane (outer layer) and the nano-scale ZnO / TiO2 composite membrane (inner layer) together. The hot pressing temperature is 130 °C, the pressure is 10 MPa, and the time is 15 minutes. Spray 10 wt% PU solution on the surface of the outer PTFE membrane, and the spraying amount is 0.2 mL / cm 2 , and dry at room temperature for 3 hours. Assemble the prepared double-layer mesh filter and the composite aerogel to form a complete sewage treatment material.

[0037] Test Example 1 I. Test Materials Sewage treatment material prepared in Example 1 Sewage treatment material prepared in Example 2 II. Test Pollutants Heavy metal ions: Pb 2+ (lead ions), Cd 2+ (cadmium ions).

[0038] Organic pollutants: phenol (phenolic pollutants), methyl orange (dye pollutants).

[0039] III. Test Steps 1. Prepare simulated sewage: Heavy metal ion solutions: Prepare Pb solutions with a concentration of 50 mg / L respectively 2+ and Cd 2+ solutions.

[0040] Organic pollutant solutions: Prepare phenol and methyl orange solutions with a concentration of 50 mg / L respectively.

[0041] 2. Adsorption test: Take 100 mL of simulated sewage and add 0.1 g of sewage treatment material.

[0042] Oscillate and adsorb at 150 rpm at 25 °C, and take samples at different time points (10 minutes, 30 minutes, 60 minutes, 120 minutes).

[0043] 3. Measure the pollutant concentration: Use an atomic absorption spectrometer (AAS) to measure the heavy metal ion concentration.

[0044] Use a UV-visible spectrophotometer (UV-Vis) to measure the organic pollutant concentration.

[0045] 4. Calculate the removal rate: Removal rate (%) = (Initial concentration - Remaining concentration) / Initial concentration × 100% IV. Test Results 1. The removal effect of heavy metal ions is shown in Table 1.

[0046] Table 1

[0047] 2. The removal effect of organic pollutants is shown in Table 2 Table 2

[0048] 3. Result analysis (1) Removal effect of heavy metal ions The removal rates of both materials for Pb 2+ and Cd 2+ increase with time, and the removal rates reach over 97% after 120 minutes.

[0049] The removal rate of Example 2 is slightly higher than that of Example 1, probably due to the higher carbon nanotube concentration and the excellent adsorption performance of the MOFs material (UiO-66).

[0050] (2) Removal effect of organic pollutants The removal rates of both materials for phenol and methyl orange increase with time, and the removal rates reach over 94% after 120 minutes.

[0051] The removal rate of Example 2 is slightly higher than that of Example 1, probably due to the alginate modification and the larger membrane pore size, which improve the adsorption ability of organic pollutants.

[0052] (3) Overall performance Example 2 is superior to Example 1 in the removal of both heavy metal ions and organic pollutants, indicating that the higher carbon nanotube concentration, alginate modification and the combination of UiO-66 optimize the material performance.

[0053] (4) Conclusion The sewage treatment materials prepared in Example 1 and Example 2 both show excellent pollutant removal ability and are applicable to the sewage treatment of heavy metal ions and organic pollutants. Due to parameter optimization (such as higher carbon nanotube concentration, alginate modification and the use of UiO-66), Example 2 is slightly superior to Example 1 in adsorption performance.

[0054] (5) Principle analysis ① Raw material selection Ⅰ Carbon nanotube reinforced aerogel (CNT@Aerogel) Structure of aerogel: Aerogel is a material with low density and high specific surface area, mainly composed of gas and having a very large porosity. This structure endows it with excellent thermal insulation, low thermal conductivity and good adsorption properties.

[0055] Carbon nanotube reinforcement: Carbon nanotubes (CNTs) have high conductivity and strength. Adding CNTs can enhance the mechanical properties and conductivity of aerogels. At the same time, due to their nanoscale size, CNTs can effectively increase the specific surface area of aerogels, thereby improving their adsorption capacity, especially in the adsorption application of environmental pollutants.

[0056] Surface modification (chitosan and alginate): Chitosan and alginate can increase the surface hydrophilicity of aerogels through interactions such as forming hydrogen bonds or covalent bonds with the aerogel surface, thereby improving their adsorption performance for water-soluble pollutants.

[0057] Ⅱ Marine biopolymer modifiers Crosslinking reaction of chitosan: Chitosan, as a natural polysaccharide, has good biocompatibility and degradability. Through N-acetylation reaction or crosslinking reaction, the molecular structure of chitosan is modified, enhancing the stability of its binding to the aerogel surface and improving its adsorption performance for pollutants. The amino and hydroxyl groups of chitosan can form electrostatic or hydrogen bond interactions with pollutants, improving hydrophilicity and adsorption capacity.

[0058] Crosslinking reaction of alginate: Alginate can form a stable network structure with metal ions through crosslinking reaction, thereby improving its surface hydrophilicity and adsorption capacity and enhancing the pollutant removal ability of aerogels.

[0059] Ⅲ Metal-organic frameworks (MOFs) Structural characteristics of MOFs: Metal-organic frameworks (MOFs) are a class of three-dimensional porous materials composed of metal ions or metal clusters connected by coordination bonds with organic ligands. MOFs have extremely high specific surface area and porosity, which makes them have important applications in gas storage, separation, catalysis, adsorption, etc.

[0060] Selective adsorption: Through selective pore size and surface functional groups, MOFs can be combined with aerogels to enhance the selective adsorption performance of aerogels for specific pollutants (such as organic substances, heavy metal ions, etc.).

[0061] Ⅳ Double-layer reticulated filter materials Function of the outer PTFE membrane: Polytetrafluoroethylene (PTFE) membrane has excellent chemical stability and hydrophobicity, which can effectively block pollutants with larger particles in water, while maintaining good mechanical strength and corrosion resistance. Its pore size design (20 - 100 microns) enables it to filter out larger particles.

[0062] Function of the inner - layer nano - metal oxide film: Nano - metal oxides (such as ZnO, TiO2) have functions such as photocatalysis and antibacterial properties. They can degrade harmful substances in water using ultraviolet light or other external stimuli during the filtration process. The nano - scale pore size (10 - 50 nanometers) enables the inner - layer film to effectively intercept tiny particles and dissolved pollutants in water.

[0063] Function of the hydrophilic coating: Coating a hydrophilic coating (such as polyvinyl alcohol, polyurethane) on the outer - layer PTFE membrane can improve the water flow - through property of the membrane, thereby enhancing the filtration efficiency and strengthening the membrane's ability to intercept pollutants.

[0064] ② Preparation steps Ⅰ Preparation of carbon nanotube - reinforced aerogel Sol - gel method: The sol - gel method is a commonly used method for low - temperature synthesis of aerogels, which generates a gel structure through reactions in solution. Aluminum oxide (Al2O3) and titanium oxide (TiO2) can form a network structure in solution, while sodium silicate (Na2SiO3) provides a silicon - oxygen framework for the matrix of the aerogel. After adding carbon nanotubes, the high conductivity and high strength of CNTs can enhance the mechanical properties of the aerogel.

[0065] CVD surface treatment: Chemical vapor deposition (CVD) is a technique that deposits modifiers (such as chitosan or alginate) onto the surface of the aerogel using gas - phase reactions. Through the CVD process, a polysaccharide modification layer can be formed on the surface of the aerogel, enhancing its hydrophilicity and adsorption ability for organic substances in water.

[0066] Ⅱ Functional modification of marine biological polysaccharides EDC / NHS cross - linking reaction: EDC (1 - ethyl - 3 - (3 - dimethylaminopropyl) carbodiimide) and NHS (N - hydroxysuccinimide) are commonly used cross - linkers that form stable amide bonds through chemical reactions in aqueous solution. Cross - linking and modifying the polysaccharide with the surface of the aerogel ensures a stable connection between the polysaccharide and the aerogel surface, improving the functionality of the material.

[0067] Ⅲ Ratio optimization of composite aerogel and MOFs materials Solvothermal deposition: The solvothermal method is a method of depositing MOFs materials onto the surface of the aerogel under high - temperature and high - pressure conditions. The deposition of MOFs materials increases the specific surface area of the aerogel and, through interactions with the aerogel surface, improves its adsorption performance for pollutants.

[0068] Ⅳ Preparation of double - layer reticulated filter Hot - pressing film formation: The hot - pressing method uses high temperature and high pressure to form a polymer material in a mold. The different pore - size designs of the outer - layer PTFE membrane and the inner - layer nano - composite metal membrane enable the filter to efficiently filter pollutants with different particle sizes.

[0069] Nanofiber membrane synthesis technology: Through electrospinning or other nanofiber preparation technologies, a membrane structure with nanoscale pore sizes can be obtained, further enhancing the efficiency of filtration materials.

[0070] Hydrophilic coating: The hydrophilic coating can reduce the contact angle of the membrane, improve water flowability, and enhance the filtration efficiency of the membrane, especially in a humid environment.

[0071] Test Example 2 In this test example, a sewage treatment material was combined with an electrode material to construct an electrochemical reaction cell, and the electronic state of the adsorption sites on the surface of the sewage treatment material was adjusted by applying an external electric field (voltage range: 1 - 5V). The electrochemical catalytic reaction was used to further improve the removal efficiency of pollutants.

[0072] I. Test Process 1. Test Materials The sewage treatment material prepared in Example 2.

[0073] Electrode Materials: Anode: Carbon cloth modified with conductive polymer polyaniline (PANI).

[0074] Cathode: Carbon-based material (graphene-coated carbon cloth).

[0075] Simulated Sewage: Heavy Metal Ions: Pb 2+ , Cd 2+ (Concentration: 50 mg / L).

[0076] Organic Pollutants: Phenol, Methyl Orange (Concentration: 50 mg / L).

[0077] 2. Construction of Electrochemical Reaction Cell The sewage treatment material was fixed between the anode and the cathode as the adsorption layer of the electrochemical reaction cell. 100 mL of simulated sewage was added to the reaction cell. An external power supply was connected, and the voltage range was set to 1 - 5V, and the current density was 10 mA / cm 2 .

[0078] 3. Test Steps (1) Initial Adsorption Under the condition of no power supply, the sewage treatment material was immersed in the simulated sewage for 30 minutes for adsorption.

[0079] (2) Electrochemical Catalytic Reaction The external power supply was turned on, and the voltages were set to 1V, 3V, and 5V respectively, and the reaction time was 30 minutes.

[0080] (3) Sampling and Analysis Sampling was carried out at 10 minutes, 20 minutes, and 30 minutes under different voltage conditions.

[0081] The concentration of heavy metal ions was determined using an atomic absorption spectrometer (AAS).

[0082] The concentration of organic pollutants was determined using a UV-Vis spectrophotometer (UV-Vis).

[0083] 4. Calculate the removal rate: Removal rate (%) = (Initial concentration - Residual concentration) / Initial concentration × 100% II. Test results 1. The removal effect of heavy metal ions is shown in Table 3 Table 3

[0084] 2. The removal effect of organic pollutants is shown in Table 4 Table 4

[0085] III. Result analysis 1. Influence of voltage on the removal efficiency: As the voltage increased, the removal efficiency of pollutants increased significantly. At a voltage of 5V, after 30 minutes, the removal rates of Pb 2+ and Cd 2+ reached 99.8% and 99.5% respectively, and the removal rates of phenol and methyl orange reached 98.7% and 97.9% respectively.

[0086] The introduction of the electric field enhanced the electron transfer ability on the surface of the composite aerogel material, promoted the electrochemical catalytic reaction, and improved the adsorption and degradation efficiency of pollutants.

[0087] 2. Influence of time on the removal efficiency At the same voltage, as the reaction time increased, the removal efficiency gradually increased. After 30 minutes, the removal rates of all pollutants reached over 95%.

[0088] 3. Comparison with Test Example 1 Under the condition of no power supply (Test Example 1), after 120 minutes, the removal rates of Pb 2+ and Cd 2+ were 99.3% and 98.8% respectively, and the removal rates of phenol and methyl orange were 97.2% and 96.5% respectively.

[0089] In the electrochemically responsive system, it only takes 30 minutes to achieve similar or even higher removal efficiency, indicating that the electrochemical catalytic reaction significantly improves the sewage treatment efficiency.

[0090] 4. Conclusion The electrochemically responsive sewage treatment system significantly improves the pollutant removal efficiency of composite aerogel materials by applying an external electric field. At a voltage of 5V, high-efficiency removal of heavy metal ions and organic pollutants can be achieved within 30 minutes (removal rate > 97%). The treatment efficiency of this system is significantly better than that of traditional adsorption methods (Test Example 1), and it is suitable for efficient and rapid sewage treatment applications.

[0091] IV. Principle Analysis 1. Electric Field Regulation of Adsorption Capacity Under the action of an external electric field (1 - 5V), the electron distribution on the surface of the composite aerogel changes, affecting the adsorption capacity of pollutants: Heavy metal ions: Strengthen the electrostatic attraction through charge regulation and improve the ion capture efficiency.

[0092] Organic pollutants: Change the π-π interaction between molecules, making it easier for pollutants to be adsorbed by the MOF structure or carbon nanotubes.

[0093] 2. Electrochemical Catalytic Degradation Redox reaction: The composite aerogel material combines with electrodes (such as carbon-based materials, conductive polymers) to form an electrode interface, which can catalyze the degradation of pollutants at an appropriate potential: Anodic oxidation: Generate hydroxyl radicals (•OH) to non-selectively degrade organic pollutants (such as phenol, dyes, etc.) and directly oxidize heavy metals to improve their removability.

[0094] Cathodic reduction: Reduce heavy metal ions to promote precipitation removal. Change the surface activity through charge transfer to improve the pollutant decomposition efficiency.

[0095] 3. Electrochemical Regeneration and Self-Cleaning Under the action of an external electric field, the adsorption-saturated composite aerogel can release the adsorbed pollutants to achieve material regeneration and extend its service life: Organic pollutants: Are decomposed into harmless small molecules through electrochemical oxidation under the action of the electric field.

[0096] Heavy metal ions: Are enriched in the cathode region and removed by precipitation, electrophoresis, electrodeposition, etc.

[0097] Finally, it should be noted that: The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that: Modifications or equivalent replacements can still be made to the specific implementation manners of the present invention, and any modifications or equivalent replacements that do not depart from the spirit and scope of the present invention should be covered within the protection scope of the claims of the present invention.

Claims

1. A preparation method of a sewage treatment material, characterized in that, Comprising: Mix sodium silicate solution with aluminum oxide and titanium oxide, add carbon nanotubes, and obtain carbon nanotube-reinforced aerogel through gelation reaction and drying treatment; Introduce surface modification material on the surface of the carbon nanotube-reinforced aerogel by chemical vapor deposition method to obtain modified aerogel; Deposit metal-organic framework material on the surface of the modified aerogel by solvothermal method to obtain composite aerogel; Use hot pressing method to laminate polytetrafluoroethylene membrane and nanoscale composite metal material membrane to form a double-layer mesh filter; Combine the composite aerogel with the double-layer mesh filter to form a complete sewage treatment material.

2. The preparation method of the sewage treatment material according to claim 1, characterized in that The gelation reaction temperature is 25 - 30 °C, and the reaction time is 4 - 5 hours; The drying temperature of the drying treatment is 60 - 70 °C, and the drying time is 12 - 14 hours.

3. The preparation method of the sewage treatment material according to claim 1, characterized in that The surface modification material is chitosan or alginate; The deposition temperature of the chemical vapor deposition method is 80 - 90 °C, and the deposition time is 2 - 3 hours.

4. The preparation method of the sewage treatment material according to claim 1, characterized in that, The mass ratio of the modified aerogel to the metal-organic framework material is 60:40; The metal-organic framework material is ZIF-8 or UiO-66; The reaction temperature of the solvothermal method is 150 - 160 °C, and the reaction time is 12 - 14 hours.

5. The preparation method of the sewage treatment material according to claim 1, characterized in that, The pore size of the polytetrafluoroethylene membrane is 20 - 100 microns, and the pore size of the nanoscale composite metal material membrane is 10 - 50 nanometers; The temperature of the hot pressing method is 120 - 130 °C, the pressure is 5 - 10 MPa, and the time is 10 - 15 minutes.

6. A sewage treatment material, characterized in that The sewage treatment material is obtained by the preparation method of the sewage treatment material according to any one of claims 1 - 5.

7. The application of the sewage treatment material according to claim 6, characterized in that, The application is A1 or A2; The A1 is the application of the sewage treatment material in treating sewage; The A2 is the application of the sewage treatment material in preparing sewage treatment products.

8. A sewage treatment method, characterized in that, Comprising: Adsorb pollutants in sewage with the sewage treatment material according to claim 6.

9. A sewage treatment method, characterized in that, Comprising: Preliminarily adsorb pollutants in sewage with the sewage treatment material according to claim 6; Construct an electrochemical reaction cell, fix the sewage treatment material between the anode and the cathode as the adsorption layer of the electrochemical reaction cell; Apply an external electric field to perform secondary adsorption on pollutants in sewage.

10. The sewage treatment method according to claim 9, characterized in that, When an external electric field is applied, the voltage range is 1 - 5 V and the current density is 10 mA / cm 2 .

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