Sewage treatment membrane and preparation method thereof

Abstract

The invention discloses a sewage treatment membrane and a preparation method thereof, and relates to the field of sewage treatment. When the sewage treatment membrane is prepared, porous nano titanium dioxide, 3, 5-diaminopyrazole and benzo [1, 2-B: 3, 4-B ': 5, 6-B'] trithiophene-2, 5, 8-trialdehyde are uniformly mixed to prepare modified nano titanium dioxide; the preparation method comprises the following steps: reacting 1, 3, 5, 7-tetramethylcyclotetrasiloxane, 1, 3-bis (3-aminopropyl) tetramethyldisiloxane, 2-vinyl imidazole and 1-allylhydantoin to prepare functionalized amino siloxane; and uniformly mixing p-phenylenediamine, functionalized amino siloxane, pyromellitic dianhydride, modified nano titanium dioxide and zinc nitrate hexahydrate, and treating with a sodium hypochlorite solution to obtain the sewage treatment membrane. The sewage treatment membrane prepared by the invention has excellent heavy metal ion complexing property, antibacterial property and photocatalytic degradability.

Description

Technical Field

[0001] The present invention relates to the field of sewage treatment, in particular to a sewage treatment membrane and a preparation method thereof. Background Art

[0002] There is an urgent need for the recycling of water resources and sewage treatment. Traditional sewage treatment methods mainly include physical, chemical and biological treatment technologies. However, these technologies often have problems such as poor treatment effect, high energy consumption, and large floor space. In order to improve the sewage treatment effect and reduce treatment costs, it is imperative to research and develop new sewage treatment technologies. Membrane separation technology is a technology that uses membrane materials with specific pore sizes to separate components in a solution. This technology has the advantages of simple operation, good treatment effect, and small floor space, and has gradually been widely used in the field of water treatment. However, the membrane material is easily contaminated during use, and it is difficult to restore the filtration performance after cleaning. Therefore, the present invention prepares a sewage treatment membrane with excellent photocatalytic degradation properties. Summary of the Invention

[0003] The purpose of the present invention is to provide a sewage treatment membrane and a preparation method thereof to solve the problems existing in the prior art.

[0004] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0005] A sewage treatment membrane is prepared by uniformly mixing p-phenylenediamine, functionalized aminosiloxane, pyromellitic anhydride, modified nano titanium dioxide and zinc nitrate hexahydrate, followed by treatment with a sodium hypochlorite solution.

[0006] As an optimization, the functionalized aminosiloxane is prepared by reacting 1,3,5,7-tetramethylcyclotetrasiloxane, 1,3-bis(3-aminopropyl)tetramethyldisiloxane, 2-vinylimidazole and 1-allylhydantoin.

[0007] As an optimization, the modified nano-titanium dioxide is prepared by mixing porous nano-titanium dioxide, 3,5-diaminopyrazole and benzo[1,2-B:3,4-B':5,6-B']terthiophene-2,5,8-trialdehyde.

[0008] As an optimization, the porous nano-titanium dioxide model is 260 nm and is from Nanjing Jike Biotechnology Co., Ltd.

[0009] A method for preparing a sewage treatment membrane comprises the following steps:

[0010] (1) Porous nano-titanium dioxide, 3,5-diaminopyrazole, benzo[1,2-B:3,4-B':5,6-B']terthiophene-2,5,8-trialdehyde and anhydrous ethanol were mixed in a mass ratio of 1:(1.6-1.8):(0.7-0.8):(19-21), stirred in a nitrogen atmosphere at 45-55°C and 100-300 rpm for 4-6 hours, naturally cooled to room temperature and filtered, washed with deionized water 3-5 times, and dried at 55-65°C for 11-13 hours to obtain modified nano-titanium dioxide;

[0011] (2) 1,3,5,7-tetramethylcyclotetrasiloxane and 1,3-bis(3-aminopropyl)tetramethyldisiloxane are mixed in a mass ratio of 1:(0.3-0.4), stirred at 65-75°C and 100-200 rpm for 10-20 min, trifluoromethylsulfonic acid (0.01-0.02 times the mass of 1,3,5,7-tetramethylcyclotetrasiloxane) is added, stirring is continued for 5-7 h, anhydrous sodium carbonate is added to adjust the pH to 6-7, and then filtered, and distilled at 105-115°C and 0.1-0.3 MPa for 1-2 h to obtain aminosiloxane;

[0012] (3) aminosiloxane, 2-vinylimidazole, 1-allylhydantoin, chloroplatinic acid and toluene were mixed in a mass ratio of 1:(0.7-0.9):(1.1-1.2):(0.01-0.03):(3-5), stirred in a nitrogen atmosphere at 90-100°C and 200-400 rpm for 4-6 hours, and activated carbon with a mass of 0.3-0.5 times that of the aminosiloxane was added. After standing for 25-35 minutes, the mixture was filtered and rotary evaporated at 50-70°C for 1-2 hours to obtain functionalized aminosiloxane;

[0013] (4) P-phenylenediamine, functionalized aminosiloxane, pyromellitic anhydride and N-methylpyrrolidone were mixed in a mass ratio of 1:(1-2):(2-3):(27-29), stirred at 100-200 rpm in a nitrogen atmosphere at 20-30°C for 5-7 hours, and modified nano-titanium dioxide with a mass of 0.02-0.03 times that of p-phenylenediamine was added. The mixture was allowed to stand for 19-21 hours, and zinc nitrate hexahydrate with a mass of 0.01-0.02 times that of p-phenylenediamine was added. The mixture was stirred for 5-15 minutes and then scraped with a scraper to 100-200 μm. m thick, standing at 0-5°C for 7-9h, standing in deionized water at 4-6°C for 7-9h, freeze-dried, heated to 190-210°C at a rate of 7-9°C / min and standing for 1-2h, then heated to 290-310°C and standing for 0.5-1.5h, naturally cooled to room temperature, immersed in a sodium hypochlorite solution with a mass fraction of 0.2%-0.5%, ultrasonicated at 30-40°C for 55-65min, taken out, washed with deionized water for 3-5 times, and dried at 55-65°C for 11-13h to obtain a sewage treatment membrane.

[0014] As an optimization, the reaction equation for modifying nano-titanium dioxide in step (1) is:

[0015]

[0016] As an optimization, the reaction equation of the functionalized aminosiloxane in step (3) is:

[0017]

[0018] As an optimization, the reaction equation of the sewage treatment membrane in step (4) is:

[0019]

[0020] Where R is

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] When preparing a sewage treatment membrane, the present invention comprises the following steps: uniformly mixing porous nano titanium dioxide, 3,5-diaminopyrazole and benzo[1,2-B:3,4-B':5,6-B']terthiophene-2,5,8-trialdehyde to obtain modified nano titanium dioxide; reacting 1,3,5,7-tetramethylcyclotetrasiloxane, 1,3-bis(3-aminopropyl)tetramethyldisiloxane, 2-vinylimidazole and 1-allylhydantoin to obtain functionalized aminosiloxane; and uniformly mixing p-phenylenediamine, functionalized aminosiloxane, pyromellitic anhydride, modified nano titanium dioxide and zinc nitrate hexahydrate, followed by treatment with a sodium hypochlorite solution to obtain the sewage treatment membrane.

[0023] First, porous nano-titanium dioxide, 3,5-diaminopyrazole and benzo[1,2-B:3,4-B':5,6-B']terthiophene-2,5,8-trialdehyde were mixed to prepare modified nano-titanium dioxide; 3,5-diaminopyrazole and benzo[1,2-B:3,4-B':5,6-B']terthiophene-2,5,8-trialdehyde were polymerized and deposited on the surface of porous nano-titanium dioxide through Schiff base reaction, introducing an electron-rich benzoterthiophene structure with a planar star structure. The extended π-conjugation can promote effective π-π intermolecular interactions, improve interlayer π stacking, enhance visible light absorption, improve the photocatalytic degradation ability of TiO2, and enhance the repeatability of sewage treatment membranes; the nitrogen atoms in the surface pyrazole can provide lone pairs of electrons to form coordination bonds with zinc ions, construct a stable metal-organic framework, increase metal ion coordination sites, and at the same time broaden the light response range of TiO2, further improving the heavy metal ion complexation and photocatalytic degradation of sewage treatment membranes.

[0024] Secondly, 1,3,5,7-tetramethylcyclotetrasiloxane, 1,3-bis(3-aminopropyl)tetramethyldisiloxane, 2-vinylimidazole and 1-allylhydantoin were reacted to prepare functionalized aminosiloxane; p-phenylenediamine, functionalized aminosiloxane, pyromellitic anhydride, modified nano-titanium dioxide and zinc nitrate hexahydrate were mixed and treated with sodium hypochlorite solution to prepare a sewage treatment membrane; 2-vinylimidazole and 1-allylhydantoin were grafted onto the long silicon-oxygen chain by hydrosilylation reaction. The nitrogen atom in imidazole can provide lone pair electrons to form a coordination bond with zinc ions, forming a stable metal-organic framework with pyrazole on the modified nano-titanium dioxide, increasing the heavy metal ionization. The zinc ions can interact with proteins and enzymes on bacterial cell membranes, destroy their functions, inhibit bacterial growth, and improve the heavy metal ion complexing, photocatalytic degradation and antibacterial properties of sewage treatment membranes. A uniform network structure is formed through low-temperature crystallization treatment, giving the sewage treatment membrane good filtration properties. In the process of hot-pressing amination to form polyimide, the reaction time is reduced, the incomplete reaction is promoted, some carboxyl structures are retained, and the heavy metal ion complexing of sewage treatment membranes is improved. Sodium hypochlorite is used to chlorinate hydantoin to form a renewable halamine structure, which improves the antibacterial and reusability of sewage treatment membranes. DETAILED DESCRIPTION

[0025] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0026] The raw materials used in the following examples and comparative examples are all commercially available:

[0027] The porous nano-titanium dioxide model is 260nm and comes from Nanjing Jike Biotechnology Co., Ltd.

[0028] Example 1:

[0029] A method for preparing a sewage treatment membrane, comprising the following steps:

[0030] (1) Porous nano-titanium dioxide, 3,5-diaminopyrazole, benzo[1,2-B:3,4-B':5,6-B']terthiophene-2,5,8-trialdehyde and anhydrous ethanol were mixed in a mass ratio of 1:1.6:0.7:19, stirred at 45°C and 100 rpm for 6 h in a nitrogen atmosphere, naturally cooled to room temperature, filtered, washed with deionized water three times, and dried at 55°C for 13 h to obtain modified nano-titanium dioxide;

[0031] (2) 1,3,5,7-tetramethylcyclotetrasiloxane and 1,3-bis(3-aminopropyl)tetramethyldisiloxane were mixed in a mass ratio of 1:0.3, stirred at 65°C and 100 rpm for 20 min, trifluoromethylsulfonic acid (0.01 times the mass of 1,3,5,7-tetramethylcyclotetrasiloxane) was added, and stirring was continued for 7 h. Anhydrous sodium carbonate was added to adjust the pH to 6, and then filtered, and distilled at 105°C and 0.1 MPa for 2 h to obtain aminosiloxane;

[0032] (3) Aminosiloxane, 2-vinylimidazole, 1-allylhydantoin, chloroplatinic acid, and toluene were mixed in a mass ratio of 1:0.7:1.1:0.01:3, stirred at 90°C and 200 rpm for 6 h in a nitrogen atmosphere, and activated carbon (0.3 times the mass of aminosiloxane) was added. After standing for 25 min, the mixture was filtered and rotary evaporated at 50°C for 2 h to obtain functionalized aminosiloxane.

[0033] (4) P-phenylenediamine, functionalized aminosiloxane, pyromellitic anhydride and N-methylpyrrolidone were mixed in a mass ratio of 1:1:2:27, stirred at 20°C and 100 rpm in a nitrogen atmosphere for 7 hours, modified nano-titanium dioxide with a mass of 0.02 times that of p-phenylenediamine was added, and the mixture was allowed to stand for 19 hours. Zinc nitrate hexahydrate with a mass of 0.01 times that of p-phenylenediamine was added and stirred for 15 minutes. The mixture was scraped with a scraper to a thickness of 100 μm, allowed to stand at 0°C for 9 hours, allowed to stand in deionized water at 4°C for 9 hours, freeze-dried, heated to 190°C at 7°C / min and allowed to stand for 2 hours, then heated to 290°C and allowed to stand for 1.5 hours, cooled naturally to room temperature, immersed in a sodium hypochlorite solution with a mass fraction of 0.2%, ultrasonicated at 30°C for 65 minutes, washed three times with deionized water after removal, and dried at 55°C for 13 hours to obtain a sewage treatment membrane.

[0034] Example 2:

[0035] A method for preparing a sewage treatment membrane, comprising the following steps:

[0036] (1) Porous nano-titanium dioxide, 3,5-diaminopyrazole, benzo[1,2-B:3,4-B':5,6-B']terthiophene-2,5,8-trialdehyde and anhydrous ethanol were mixed in a mass ratio of 1:1.7:0.75:20, stirred at 50°C and 200 rpm for 5 h in a nitrogen atmosphere, naturally cooled to room temperature and filtered, washed with deionized water 4 times, and dried at 60°C for 12 h to obtain modified nano-titanium dioxide;

[0037] (2) 1,3,5,7-tetramethylcyclotetrasiloxane and 1,3-bis(3-aminopropyl)tetramethyldisiloxane were mixed in a mass ratio of 1:0.35, stirred at 70°C and 150 rpm for 15 min, trifluoromethylsulfonic acid (0.015 times the mass of 1,3,5,7-tetramethylcyclotetrasiloxane) was added, and stirring was continued for 6 h. Anhydrous sodium carbonate was added to adjust the pH to 6.5, and then filtered, and distilled at 110°C and 0.2 MPa for 1.5 h to obtain aminosiloxane;

[0038] (3) Aminosiloxane, 2-vinylimidazole, 1-allylhydantoin, chloroplatinic acid, and toluene were mixed in a mass ratio of 1:0.8:1.15:0.02:4, stirred at 95°C and 300 rpm for 5 h in a nitrogen atmosphere, and activated carbon (0.4 times the mass of aminosiloxane) was added. After standing for 30 min, the mixture was filtered and rotary evaporated at 60°C for 1.5 h to obtain functionalized aminosiloxane.

[0039] (4) P-phenylenediamine, functionalized aminosiloxane, pyromellitic anhydride and N-methylpyrrolidone were mixed in a mass ratio of 1:1.5:2.5:28, stirred at 25°C and 150 rpm for 6 h in a nitrogen atmosphere, and modified nano-titanium dioxide with a mass of 0.025 times that of p-phenylenediamine was added, and the mixture was allowed to stand for 20 h. Zinc nitrate hexahydrate with a mass of 0.015 times that of p-phenylenediamine was added, stirred for 10 min, and coated with a scraper to a thickness of 150 μm. The mixture was allowed to stand at 3°C for 8 h, and then allowed to stand in deionized water at 5°C for 8 h. The mixture was freeze-dried, heated to 200°C at 8°C / min and allowed to stand for 1.5 h, then heated to 300°C and allowed to stand for 1 h. The mixture was naturally cooled to room temperature, immersed in a sodium hypochlorite solution with a mass fraction of 0.35%, ultrasonicated at 35°C for 60 min, washed four times with deionized water after removal, and dried at 60°C for 12 h to obtain a sewage treatment membrane.

[0040] Example 3:

[0041] A method for preparing a sewage treatment membrane, comprising the following steps:

[0042] (1) Porous nano-titanium dioxide, 3,5-diaminopyrazole, benzo[1,2-B:3,4-B':5,6-B']terthiophene-2,5,8-trialdehyde and anhydrous ethanol were mixed in a mass ratio of 1:1.8:0.8:21, stirred at 55°C and 300 rpm for 4 h in a nitrogen atmosphere, cooled naturally to room temperature, filtered, washed with deionized water 5 times, and dried at 65°C for 11 h to obtain modified nano-titanium dioxide;

[0043] (2) 1,3,5,7-tetramethylcyclotetrasiloxane and 1,3-bis(3-aminopropyl)tetramethyldisiloxane were mixed in a mass ratio of 1:0.4, stirred at 75°C and 200 rpm for 10 min, trifluoromethylsulfonic acid (0.02 times the mass of 1,3,5,7-tetramethylcyclotetrasiloxane) was added, and stirring was continued for 5 h. Anhydrous sodium carbonate was added to adjust the pH to 7, and then filtered, and distilled at 115°C and 0.3 MPa for 1 h to obtain aminosiloxane;

[0044] (3) Aminosiloxane, 2-vinylimidazole, 1-allylhydantoin, chloroplatinic acid, and toluene were mixed in a mass ratio of 1:0.9:1.2:0.03:5, stirred at 100°C and 400 rpm for 4 h in a nitrogen atmosphere, and activated carbon (0.5 times the mass of aminosiloxane) was added. After standing for 35 min, the mixture was filtered and rotary evaporated at 70°C for 1 h to obtain functionalized aminosiloxane.

[0045] (4) P-phenylenediamine, functionalized aminosiloxane, pyromellitic anhydride and N-methylpyrrolidone were mixed in a mass ratio of 1:2:3:29, stirred at 30°C and 200 rpm in a nitrogen atmosphere for 5 h, modified nano-titanium dioxide with a mass of 0.03 times that of p-phenylenediamine was added, and the mixture was allowed to stand for 19 h. Zinc nitrate hexahydrate with a mass of 0.02 times that of p-phenylenediamine was added and stirred for 5 min. The mixture was scraped with a scraper to a thickness of 200 μm, allowed to stand at 5°C for 7 h, allowed to stand in deionized water at 6°C for 7 h, freeze-dried, heated to 210°C at 9°C / min and allowed to stand for 1 h, then heated to 310°C and allowed to stand for 0.5 h, cooled naturally to room temperature, immersed in a sodium hypochlorite solution with a mass fraction of 0.5%, ultrasonicated at 40°C for 55 min, washed 5 times with deionized water after removal, and dried at 65°C for 11 h to obtain a sewage treatment membrane.

[0046] Comparative Example 1:

[0047] The preparation method of the sewage treatment membrane in Comparative Example 1 differs from that in Example 2 only in step (1), and step (1) is deleted. Step (4) is modified as follows: p-phenylenediamine, functionalized aminosiloxane, pyromellitic anhydride and N-methylpyrrolidone are mixed in a mass ratio of 1:1.5:2.5:28, stirred at 25°C and 150 rpm for 6 h in a nitrogen atmosphere, porous nano-titanium dioxide with a mass of 0.025 times that of p-phenylenediamine is added, and the mixture is allowed to stand for 20 h. Zinc nitrate hexahydrate with a mass of 0.015 times that of p-phenylenediamine is added and stirred for 10 min. The mixture is scraped with a scraper to a thickness of 150 μm, allowed to stand at 3°C for 8 h, allowed to stand in deionized water at 5°C for 8 h, freeze-dried, heated to 200°C at 8°C / min and allowed to stand for 1.5 h, then heated to 300°C and allowed to stand for 1 h, cooled naturally to room temperature, immersed in a sodium hypochlorite solution with a mass fraction of 0.35%, ultrasonicated at 35°C for 60 min, washed four times with deionized water after removal, and dried at 60°C for 12 h to obtain a sewage treatment membrane. The remaining steps are the same as in Example 2.

[0048] Comparative Example 2:

[0049] The preparation method of the sewage treatment membrane of Comparative Example 2 differs from that of Example 2 only in step (3). Step (3) is modified as follows: aminosiloxane, 1-allylhydantoin, chloroplatinic acid, and toluene are mixed in a mass ratio of 1:1.15:0.02:4, stirred at 95°C and 300 rpm for 5 h in a nitrogen atmosphere, activated carbon (0.4 times the mass of the aminosiloxane) is added, the mixture is allowed to stand for 30 min, filtered, and rotary evaporated at 60°C for 1.5 h to obtain the functionalized aminosiloxane. The remaining steps are the same as those of Example 2.

[0050] Comparative Example 3:

[0051] The preparation method of the sewage treatment membrane of Comparative Example 3 differs from that of Example 2 only in step (4). Step (4) is modified as follows: p-phenylenediamine, functionalized aminosiloxane, pyromellitic anhydride and N-methylpyrrolidone are mixed in a mass ratio of 1:1.5:2.5:28, stirred at 25°C and 150rpm for 6h in a nitrogen atmosphere, modified nano-titanium dioxide with a mass of 0.025 times that of p-phenylenediamine is added, and the mixture is allowed to stand for 20h. Zinc nitrate hexahydrate with a mass of 0.015 times that of p-phenylenediamine is added and stirred for 10min. The mixture is scraped with a scraper to a thickness of 150μm, allowed to stand at 3°C for 8h, allowed to stand in deionized water at 5°C for 8h, freeze-dried, heated to 200°C at 8°C / min and allowed to stand for 1.5h, then heated to 300°C and allowed to stand for 1h, naturally cooled to room temperature, washed 4 times with deionized water, and dried at 60°C for 12h to obtain a sewage treatment membrane. The remaining steps are the same as in Example 2.

[0052] Test Case

[0053] 1. Heavy metal ion complexation

[0054] Test method: The wastewater treatment membranes obtained in each embodiment and comparative example were subjected to a nanofiltration device model Sterlitech HP4750 to measure the wastewater copper ion concentration C0 and the permeate side copper ion concentration C1, and the retention rate was calculated as (C0-C1) / C0*100%.

[0055] 2. Antibacterial properties

[0056] Test method: Take 2×2cm test samples of the wastewater treatment membranes obtained in each embodiment and comparative example according to GB / T37206, sterilize them under high pressure and place them in 10mL of a 10% 6 CFU / mL of Escherichia coli culture was cultured at 37℃ for 12h under shaking conditions. The culture was diluted 10 5 Then use an "L"-shaped stick to evenly spread it on the surface of the solid culture medium, record the number of colonies N1 in the culture medium after 12 hours (the blank group N0 is the group without sample), and calculate the inhibition rate = (N0-N1) / N0*100%.

[0057] 3. Photocatalytic degradation

[0058] Test method: Take 5 g of samples of the sewage treatment membranes obtained in each embodiment and comparative example, add the samples and 20 mL of a 100 mg / L methylene blue solution into a reactor, darken for 6 hours, and irradiate with a 500 W xenon lamp for 4 hours at a distance of 10 cm from the light source to the reactor. Test the degradation rate with a UV-visible spectrophotometer; desorb the sample after adsorption and degradation in ethanol, dry it at 60°C for 8 hours, remove the ethanol, take 10 mg, and degrade it by adsorption with a methylene blue solution with a concentration of 10 mg / L. Repeat the adsorption, degradation and desorption steps 5 times to test the persistent degradation rate.

[0059] Table 1 below shows the analysis results of the heavy metal ion complexing properties, antibacterial properties and photocatalytic degradation properties of the sewage treatment membranes of Examples 1 to 3 of the present invention and Comparative Examples 1 to 3.

[0060] Table 1

[0061] Retention rate (%) Antibacterial rate% Degradation rate% Persistent degradation rate% Example 1 92.4 98.7 93.5 90.9 Example 2 93.5 99.1 93.8 91.2 Example 3 93.1 97.3 92.9 91.1 Comparative Example 1 90.6 95.8 65.1 60.2 Comparative Example 2 64.8 89.4 72.4 71.6 Comparative Example 3 92.3 32.5 92.7 89.7

[0062] From the comparison of the experimental data of Examples 1 to 3 and Comparative Examples 1 to 3 in Table 1, it can be found that the sewage treatment membrane prepared by the present invention has good heavy metal ion complexation, antibacterial and photocatalytic degradation properties.

[0063] Comparative Example 1 is unmodified porous nano-titanium dioxide; by comparison, the retention rate, degradation rate and persistent degradation rate of Examples 1, 2 and 3 are higher than those of Comparative Example 1, which shows that 3,5-diaminopyrazole and benzo[1,2-B:3,4-B':5,6-B']terthiophene-2,5,8-trialdehyde are polymerized and deposited on the surface of porous nano-titanium dioxide through the Schiff base reaction, and an electron-rich benzoterthiophene structure is introduced. Its planar star structure and extended π-conjugation can promote effective π-π intermolecular interactions, improve interlayer π stacking, enhance visible light absorption, improve the photocatalytic degradation ability of TiO2, and enhance the repeatability of sewage treatment membranes; the nitrogen atoms in the surface pyrazole can provide lone pairs of electrons to form coordination bonds with zinc ions, construct a stable metal organic framework, increase metal ion coordination sites, and at the same time broaden the light response range of TiO2, further improving the heavy metal ion complexation and photocatalytic degradation of the sewage treatment membrane.

[0064] Comparative Example 2 does not graft 2-vinylimidazole onto aminosiloxane; by comparison, Examples 1, 2, and 3 have higher retention rates, antibacterial rates, degradation rates, and sustained degradation rates than Comparative Example 2, indicating that 2-vinylimidazole and 1-allylhydantoin are grafted onto the long silicon chain using a hydrosilylation reaction, and the nitrogen atom in imidazole can provide lone pairs of electrons to form coordination bonds with zinc ions, forming a stable metal-organic framework with the pyrazole on the modified nano-titanium dioxide, increasing the heavy metal ion coordination sites, and broadening the light response range of TiO2. At the same time, zinc ions can interact with proteins and enzymes on bacterial cell membranes, destroy their functions, inhibit bacterial growth, and improve the heavy metal ion complexation, photocatalytic degradation, and antibacterial properties of the sewage treatment membrane.

[0065] Comparative Example 3 did not perform halogen amination modification on 1-allylhydantoin; by comparison, Examples 1, 2, and 3 had higher antibacterial rates than Comparative Example 3, indicating that the use of sodium hypochlorite to chlorinate hydantoin formed a renewable halogenamine structure, thereby improving the antibacterial properties of the sewage treatment membrane.

[0066] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A sewage treatment membrane, characterized in that: The sewage treatment membrane is prepared by mixing p-phenylenediamine, functionalized aminosiloxane, pyromellitic anhydride, modified nano-titanium dioxide and zinc nitrate hexahydrate and then treating with a sodium hypochlorite solution; The functionalized aminosiloxane is prepared by reacting 1,3,5,7-tetramethylcyclotetrasiloxane, 1,3-bis(3-aminopropyl)tetramethyldisiloxane, 2-vinylimidazole and 1-allylhydantoin; The modified nano titanium dioxide is prepared by uniformly mixing porous nano titanium dioxide, 3,5-diaminopyrazole and benzo[1,2-B:3,4-B':5,6-B']terthiophene-2,5,8-trialdehyde.

2. A method for preparing a sewage treatment membrane, characterized in that: The method comprises the following preparation steps: (1) porous nano-titanium dioxide, 3,5-diaminopyrazole, benzo[1,2-B:3,4-B':5,6-B']terthiophene-2,5,8-trialdehyde and anhydrous ethanol were mixed, stirred in a nitrogen atmosphere, cooled to room temperature, filtered, washed and dried to obtain modified nano-titanium dioxide; (2) 1,3,5,7-tetramethylcyclotetrasiloxane and 1,3-bis(3-aminopropyl)tetramethyldisiloxane were mixed and stirred, trifluoromethanesulfonic acid was added, and the stirring was continued. Anhydrous sodium carbonate was added, and the mixture was filtered and distilled to obtain aminosiloxane; (3) aminosiloxane, 2-vinylimidazole, 1-allylhydantoin, chloroplatinic acid, and toluene were mixed, stirred under a nitrogen atmosphere, activated carbon was added, the mixture was allowed to stand, filtered, and rotary evaporated to obtain functionalized aminosiloxane; (4) P-phenylenediamine, functionalized aminosiloxane, pyromellitic anhydride and N-methylpyrrolidone were mixed and stirred in a nitrogen atmosphere, modified nano-titanium dioxide was added, and the mixture was allowed to stand. Zinc nitrate hexahydrate was added and stirred, and the mixture was scraped with a spatula and allowed to stand. The mixture was allowed to stand in deionized water, freeze-dried, heated and allowed to stand, heated and allowed to stand again, cooled to room temperature, immersed in a sodium hypochlorite solution, sonicated, washed and dried to obtain a wastewater treatment membrane.

3. The method for preparing a sewage treatment membrane according to claim 2, characterized in that: The preparation process of the modified nano-titanium dioxide in step (1) is as follows: porous nano-titanium dioxide, 3,5-diaminopyrazole, benzo[1,2-B:3,4-B':5,6-B']terthiophene-2,5,8-trialdehyde and anhydrous ethanol are mixed in a mass ratio of 1:(1.6-1.8):(0.7-0.8):(19-21), stirred in a nitrogen atmosphere at 45-55°C and 100-300rpm for 4-6h, naturally cooled to room temperature and then filtered, washed with deionized water 3-5 times, and dried at 55-65°C for 11-13h to obtain modified nano-titanium dioxide.

4. The method for preparing a sewage treatment membrane according to claim 2, wherein: The preparation process of the aminosiloxane in step (2) is as follows: 1,3,5,7-tetramethylcyclotetrasiloxane and 1,3-bis(3-aminopropyl)tetramethyldisiloxane are mixed in a mass ratio of 1:(0.3-0.4), stirred at 65-75° C. and 100-200 rpm for 10-20 min, trifluoromethylsulfonic acid (0.01-0.02 times the mass of 1,3,5,7-tetramethylcyclotetrasiloxane) is added, stirring is continued for 5-7 h, anhydrous sodium carbonate is added to adjust the pH to 6-7, and then filtered, and distilled at 105-115° C. and 0.1-0.3 MPa for 1-2 h to obtain the aminosiloxane.

5. The method for preparing a sewage treatment membrane according to claim 2, wherein: The preparation process of the functionalized aminosiloxane in step (3) is as follows: aminosiloxane, 2-vinylimidazole, 1-allylhydantoin, chloroplatinic acid and toluene are mixed in a mass ratio of 1:(0.7-0.9):(1.1-1.2):(0.01-0.03):(3-5), stirred in a nitrogen atmosphere at 90-100° C. and 200-400 rpm for 4-6 hours, activated carbon with a mass of 0.3-0.5 times that of the aminosiloxane is added, the mixture is allowed to stand for 25-35 minutes, filtered, and rotary evaporated at 50-70° C. for 1-2 hours to obtain the functionalized aminosiloxane.

6. The method for preparing a sewage treatment membrane according to claim 2, characterized in that: The preparation process of the sewage treatment membrane in step (4) is as follows: p-phenylenediamine, functionalized aminosiloxane, pyromellitic anhydride and N-methylpyrrolidone are mixed in a mass ratio of 1: (1-2): (2-3): (27-29), stirred in a nitrogen atmosphere at 20-30 ° C and 100-200 rpm for 5-7 hours, modified nano-titanium dioxide with a mass of 0.02-0.03 times that of p-phenylenediamine is added, and allowed to stand for 19-21 hours, zinc nitrate hexahydrate with a mass of 0.01-0.02 times that of p-phenylenediamine is added, stirred for 5-15 minutes, and applied with a scraper to The membrane was 100-200 μm thick, allowed to stand at 0-5° C. for 7-9 h, allowed to stand in deionized water at 4-6° C. for 7-9 h, freeze-dried, heated to 190-210° C. at a rate of 7-9° C. / min, allowed to stand for 1-2 h, then heated to 290-310° C., allowed to stand for 0.5-1.5 h, naturally cooled to room temperature, immersed in a sodium hypochlorite solution with a mass fraction of 0.2%-0.5%, ultrasonicated at 30-40° C. for 55-65 min, taken out, washed with deionized water for 3-5 times, and dried at 55-65° C. for 11-13 h to obtain a sewage treatment membrane.

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