Water treatment filter material and preparation method thereof

Abstract

The present invention discloses a water treatment filter material and a preparation method thereof, and relates to the field of water treatment technology. When preparing the water treatment filter material, the present invention comprises the following steps: reacting chitosan with 1,4-dichloro-2-butene by an emulsion solidification method to obtain chitosan microspheres; reacting the chitosan microspheres with methyl iodide to obtain functionalized chitosan microspheres; copolymerizing aniline, 3-vinylaniline, and 2,9,16,23-tetraaminophthalocyanine and depositing them on mesoporous titanium dioxide to obtain modified mesoporous titanium dioxide; reacting polyamide with formaldehyde and maleic anhydride in sequence to obtain modified polyamide; preparing a spinning solution from the modified polyamide, functionalized chitosan microspheres, and modified mesoporous titanium dioxide, and electrospinning to obtain a polyamide membrane; and reacting acrylic acid with the polyamide membrane to obtain the water treatment filter material. The water treatment filter material prepared by the present invention has excellent antibacterial, heavy metal adsorption, dye removal, and durability properties.

Description

Technical Field

[0001] The present invention relates to the technical field of water treatment, in particular to a water treatment filter material and a preparation method thereof. Background Art

[0002] As the global economy booms, water pollution has also attracted global attention. Industrial development, mining, and environmental disasters have accelerated the growth of hazardous wastewater in the environment.

[0003] Water pollution is categorized into organic, inorganic, and biological pollutants. Inorganic pollutants primarily consist of heavy metals, which enter the human body through water sources and chelate with organic components to form complexes, thereby damaging cell structure or inactivating enzymes, leading to pathological changes. Heavy metals, coupled with their resistance to decomposition and high toxicity, pose a significant threat to human health. Organic pollution primarily consists of organic dyes in industrial wastewater, which are highly chromatic, toxic, and difficult to degrade, causing significant harm to water and soil. Biological pollution primarily involves the entry of pathogenic microorganisms, parasites, and certain insects into water bodies, or the proliferation of certain algae, which deteriorate water quality and directly or indirectly harm human health or affect fishery production.

[0004] Using filter materials to filter wastewater is a common water treatment technology, offering advantages such as low energy consumption, simple processes, minimal investment, and minimal pollution. However, conventional filter materials, which only physically intercept pollutants, are inefficient. Alternatively, they offer a single performance feature, failing to effectively remove all organic, inorganic, and biological pollutants from wastewater. Given the constant flow of water in nature, the composition of pollutants in wastewater is complex and diverse. Therefore, it is necessary to develop a water treatment filter material that simultaneously adsorbs heavy metals, removes dyes, and maintains antibacterial properties to achieve efficient wastewater purification. Summary of the Invention

[0005] The purpose of the present invention is to provide a water treatment filter material and a preparation method thereof to solve the problems existing in the prior art.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0007] A water treatment filter material is prepared by reacting chitosan microspheres with methyl iodide to obtain functionalized chitosan microspheres; reacting pre-modified polyamide with maleic anhydride to obtain modified polyamide; preparing a spinning solution from the modified polyamide, functionalized chitosan microspheres, and modified mesoporous titanium dioxide, and electrospinning to obtain a polyamide membrane; and reacting acrylic acid with the liquid on the polyamide membrane to obtain the water treatment filter material.

[0008] The chitosan microspheres are prepared by reacting chitosan with 1,4-dichloro-2-butene via an emulsion curing method using 1,4-dichloro-2-butene as a crosslinking agent.

[0009] The modified mesoporous titanium dioxide is prepared by copolymerizing aniline, 3-vinylaniline, and 2,9,16,23-tetraaminophthalocyanine and depositing the copolymerized copolymerized copolymerized aniline, 3-vinylaniline, and 2,9,16,23-tetraaminophthalocyanine on the mesoporous titanium dioxide.

[0010] The pre-modified polyamide is prepared by reacting polyamide and formaldehyde.

[0011] A method for preparing a water treatment filter material, comprising the following steps:

[0012] (1) Liquid paraffin and Span 80 were mixed in a mass ratio of (12-13):1, stirred at 10-30℃ and 100-200r / min for 25-35min, chitosan solution with a mass of 0.4-0.6 times that of liquid paraffin was added dropwise at a constant speed within 5min, and stirring was continued for 20-30min. 1,4-dichloro-2-butene with a mass of 0.21-0.23 times that of liquid paraffin was added, the temperature was raised to 40-42℃, stirring was continued for 1-1.2h, the pH was adjusted to 9-10 with a 0.1mol / L sodium hydroxide aqueous solution, stirring was continued for 2-2.4h, and liquid paraffin with a volume of 1. 3~1.5 times of acetone, ultrasonic for 4~6 minutes, and dried at 50~60℃ under vacuum conditions for 7~8 hours to obtain chitosan microspheres; chitosan microspheres, sodium hydroxide aqueous solution with a mass fraction of 14%~16%, sodium iodide, methyl iodide, and 1-methyl-2-pyrrolidone are mixed uniformly in a mass ratio of 1:(5~6):(2.2~2.4):(5~6):(28~30), stirred at 60~62℃, 100~200r / min for 2~3 hours, filtered, washed with anhydrous ethanol 3~5 times, and dried at 50~60℃ under vacuum conditions for 9~10 hours to obtain functionalized chitosan microspheres;

[0013] (2) At 0~2°C, add aniline, 3-vinylaniline, and 2,9,16,23-tetraaminophthalocyanine in a molar ratio of 1:(0.2~0.3):(0.4~0.5) to a 3%~5% hydrochloric acid aqueous solution with a mass fraction of 46~50 times the mass of aniline, stir at 100~200 r / min for 8~10 minutes, add mesoporous titanium dioxide with a mass fraction of 1.4~1.6 times the mass of aniline, continue stirring for 6~8 minutes, and uniformly add an initiator solution with a mass fraction of 1~1.2 times the mass of aniline dropwise within 10 minutes, continue stirring for 3~4 hours, filter, wash with anhydrous ethanol and deionized water 3~5 times each, and dry at 50~60°C under vacuum conditions for 10~12 hours to obtain modified mesoporous titanium dioxide;

[0014] (3) Pre-modified polyamide, maleic anhydride, benzoquinone, and N,N-dimethylformamide were mixed uniformly in a mass ratio of 1:(1.2~1.4):(0.03~0.05):(20~22), stirred at 50~60℃, 80~100r / min for 6~7h, and dried at 50~60℃ under vacuum conditions for 10~12h to obtain modified polyamide;

[0015] (4) Modified polyamide, functionalized chitosan microspheres, modified mesoporous titanium dioxide, and N,N-dimethylformamide were mixed uniformly in a mass ratio of 1:(0.06-0.08):(0.04-0.05):(6-7), and stirred at 100-120 r / min for 18-20 min at room temperature to prepare a spinning solution; the spinning solution was introduced into a spinning needle tube, and a metal roller with tin foil attached was used as a receiving device, and electrospinning was performed in an electrospinning machine, and dried at 58-62°C under vacuum conditions for 7-9 h to obtain a polyamide membrane; the polyamide membrane was immersed in the treatment solution, allowed to stand for 8-10 min, taken out, and kept warm at 70-80°C for 3-4 h, and dried at 58-62°C under vacuum conditions for 10-12 h to obtain a water treatment filter material.

[0016] As an optimization, the preparation method of the chitosan solution in step (1) is: chitosan and an acetic acid aqueous solution with a mass fraction of 2% to 3% are uniformly mixed in a mass ratio of 1:(28-30) to prepare a chitosan solution.

[0017] As an optimization, the chitosan has a deacetylation degree of 92% and a weight average molecular weight of 50 kDa.

[0018] As an optimization, the preparation method of the initiator solution in step (2) is: ammonium persulfate and a hydrochloric acid aqueous solution with a mass fraction of 3% to 5% are mixed uniformly in a mass ratio of 1:(20-30) to prepare an initiator solution.

[0019] As an optimization, the particle size of the mesoporous titanium dioxide in step (2) is 800 nm, and the manufacturer is Nanjing Jike Biotechnology Co., Ltd.

[0020] As an optimization, the preparation method of the pre-modified polyamide in step (3) is as follows: polyamide, formaldehyde, and N,N-dimethylformamide are uniformly mixed in a mass ratio of 1:(0.6~0.8):(20~24), and the mixture is stirred at 70~80°C and 80~100 r / min for 1~1.2 h under nitrogen protection, and dried at 50~60°C for 8~10 h under vacuum conditions to obtain the pre-modified polyamide.

[0021] As an optimization, the polyamide type is PA66 101L.

[0022] As an optimization, the preparation method of the treatment liquid in step (4) is: acrylic acid, potassium persulfate, and deionized water are uniformly mixed in a mass ratio of 1: (0.03~0.05): (30~32) to prepare the treatment liquid.

[0023] As an optimization, the process parameters of the electrospinning in step (4) are as follows: setting the ambient temperature to 29-31°C, the relative humidity to 45%-55%, the spinning voltage to 18-20 kV, the receiving distance to 19-21 cm, and the propulsion rate to 0.07-0.08 mL / h.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] When preparing a water treatment filter material, the present invention comprises the following steps: using 1,4-dichloro-2-butene as a crosslinking agent, reacting chitosan with 1,4-dichloro-2-butene through an emulsion solidification method to obtain chitosan microspheres; reacting the chitosan microspheres with methyl iodide to obtain functionalized chitosan microspheres; copolymerizing aniline, 3-vinylaniline, and 2,9,16,23-tetraaminophthalocyanine and depositing the copolymerized copolymers on mesoporous titanium dioxide to obtain modified mesoporous titanium dioxide; reacting polyamide with formaldehyde to obtain pre-modified polyamide; reacting the pre-modified polyamide with maleic anhydride to obtain modified polyamide; preparing a spinning solution by mixing the modified polyamide, the functionalized chitosan microspheres, and the modified mesoporous titanium dioxide, and performing electrostatic spinning to obtain a polyamide membrane; and reacting acrylic acid with the polyamide membrane to obtain the water treatment filter material.

[0026] First, chitosan and 1,4-dichloro-2-butene were reacted with each other via an emulsion curing method using 1,4-dichloro-2-butene as a cross-linking agent to prepare chitosan microspheres. Carbon-carbon double bonds were introduced into the chitosan microspheres. The carbon-carbon double bonds introduced into the chitosan microspheres can copolymerize with acrylic acid during the liquid reaction of the polyamide membrane, so that the functionalized chitosan microspheres form a cross-linked network structure in the water treatment filter material, making the membrane material less susceptible to damage by external forces and improving the durability of the water treatment filter material; the chlorine atoms on 1,4-dichloro-2-butene reacted with the amino groups on the chitosan to convert the primary amines on the chitosan into secondary and tertiary amines; the chitosan microspheres were reacted with methyl iodide to convert the secondary and tertiary amines on the chitosan, as well as the residual primary amines, into quaternary ammonium salts. Quaternary ammonium salts are cationic antibacterial agents. The quaternary ammonium salt structure generated on the functionalized chitosan microspheres can improve the antibacterial properties of the water treatment filter material.

[0027] Secondly, aniline, 3-vinylaniline and 2,9,16,23-tetraaminophthalocyanine are copolymerized and deposited on mesoporous titanium dioxide through chemical oxidation to obtain modified mesoporous titanium dioxide; a polyaniline structure is generated on the modified mesoporous titanium dioxide, and a carbon-carbon double bond and a phthalocyanine structure are introduced. The polyaniline structure has a good complex adsorption effect on heavy metal ions, which can improve the performance of water treatment filter materials in adsorbing heavy metal ions. The phthalocyanine structure can form coordination bonds with metal ions such as copper, iron, cobalt, zinc, and manganese in sewage to generate metal phthalocyanine, which can degrade organic dyes through photocatalytic oxidation; the introduced phthalocyanine structure not only adsorbs heavy metal ions in sewage, but also generates metal phthalocyanine in sewage. The photocatalytic degradation of dyes can achieve the effect of removing dyes from sewage; the carbon-carbon double bonds introduced on the modified mesoporous titanium dioxide enable the modified mesoporous titanium dioxide to participate in the copolymerization of acrylic acid when the polyamide membrane reacts with liquid, so that the modified mesoporous titanium dioxide forms a cross-linked network structure in the water treatment filter material, making the membrane material not easily damaged by external forces, thereby improving the durability of the water treatment filter material. Mesoporous titanium dioxide can photocatalytically degrade dyes, and the mesoporous titanium dioxide is modified to improve the compatibility between mesoporous titanium dioxide and polyamide, so that the mesoporous titanium dioxide is evenly dispersed in the membrane material to avoid agglomeration, and the performance of mesoporous titanium dioxide in catalytically degrading dyes is fully exerted, further improving the water treatment filter material's performance in removing dyes.

[0028] Finally, polyamide and formaldehyde are reacted to obtain pre-modified polyamide, and hydroxyl groups are introduced into the side chains of the pre-modified polyamide; the hydroxyl groups introduced into the side chains of the pre-modified polyamide are reacted with maleic anhydride to obtain modified polyamide, and carbon-carbon double bonds and carboxyl groups are introduced into the modified polyamide; the introduction of carbon-carbon double bonds enables the modified polyamide to participate in the copolymerization of acrylic acid when the polyamide membrane reacts with liquid, so that the molecular chains of the modified polyamide form a cross-linked network structure in the water treatment filter material, making the membrane material not easily destroyed by external forces, thereby improving the durability of the water treatment filter material; the carboxyl groups introduced into the side chains of the modified polyamide can chelate with heavy metal ions and can also adsorb cationic dyes, thereby improving the water treatment filter material's absorption of heavy metal ions in sewage. The invention relates to a method for improving the adsorption capacity and the removal capacity of dyes of water treatment filter materials. The modified polyamide, functionalized chitosan microspheres and modified mesoporous titanium dioxide are prepared into a spinning solution, and a polyamide membrane is prepared by electrospinning. The acrylic acid is reacted with the liquid on the polyamide membrane to prepare a water treatment filter material. The carbon-carbon double bonds on the acrylic acid are polymerized with the carbon-carbon double bonds on the modified mesoporous titanium dioxide, functionalized chitosan microspheres and modified polyamide to form a cross-linked network structure inside the membrane material, which improves the durability of the water treatment filter material and introduces a large number of carboxyl groups on the membrane material. The carboxyl groups can chelate heavy metal ions in sewage and adsorb cationic dyes, thereby further improving the adsorption capacity of the water treatment filter material for heavy metal ions in sewage and the removal capacity of dyes. DETAILED DESCRIPTION

[0029] 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.

[0030] Example 1

[0031] A method for preparing a water treatment filter material, comprising the following steps:

[0032] (1) Chitosan and 2% acetic acid aqueous solution were mixed at a mass ratio of 1:28 to prepare chitosan solution; liquid paraffin and Span 80 were mixed at a mass ratio of 12:1, stirred at 100 r / min for 35 min at 10 ° C, and chitosan solution with a mass of 0.4 times that of liquid paraffin was added dropwise at a constant speed within 5 min. Stirring was continued for 30 min, and 1,4-dichloro-2-butene with a mass of 0.21 times that of liquid paraffin was added. The temperature was raised to 40 ° C, and stirring was continued for 1.2 h. The mixture was dissolved in 0.1 mol / L sodium hydroxide solution. The pH of the solution was adjusted to 9, and the stirring was continued for 2.4 hours. Acetone 1.3 times the volume of liquid paraffin was added, and ultrasonication was performed for 6 minutes. The mixture was dried at 50°C for 8 hours under vacuum conditions to obtain chitosan microspheres. The chitosan microspheres, a 14% sodium hydroxide aqueous solution, sodium iodide, methyl iodide, and 1-methyl-2-pyrrolidone were mixed uniformly in a mass ratio of 1:5:2.2:5:28, stirred at 60°C and 100 r / min for 3 hours, filtered, washed with anhydrous ethanol 3 times, and dried at 50°C for 10 hours under vacuum conditions to obtain functionalized chitosan microspheres.

[0033] (2) Ammonium persulfate and 3% hydrochloric acid aqueous solution were mixed at a mass ratio of 1:20 to prepare an initiator solution; aniline, 3-vinylaniline, and 2,9,16,23-tetraaminophthalocyanine were added at a molar ratio of 1:0.2:0.4 to a 3% hydrochloric acid aqueous solution with a mass fraction of 46 times that of aniline at 0°C, stirred at 100 r / min for 10 minutes, mesoporous titanium dioxide with a mass fraction of 1.4 times that of aniline was added, and stirring was continued for 8 minutes. Initiator solution with a mass fraction of 1 times that of aniline was added dropwise at a uniform rate within 10 minutes, and stirring was continued for 4 hours. The mixture was filtered, washed with anhydrous ethanol and deionized water 5 times each, and dried at 50°C under vacuum conditions for 12 hours to obtain modified mesoporous titanium dioxide;

[0034] (3) Polyamide, formaldehyde and N,N-dimethylformamide were mixed uniformly in a mass ratio of 1:0.6:20, stirred at 70°C and 80r / min for 1.2h under nitrogen protection, and dried at 50°C for 10h under vacuum conditions to obtain pre-modified polyamide; pre-modified polyamide, maleic anhydride, benzoquinone and N,N-dimethylformamide were mixed uniformly in a mass ratio of 1:1.2:0.03:20, stirred at 50°C and 80r / min for 7h, and dried at 50°C for 12h under vacuum conditions to obtain modified polyamide;

[0035] (4) Modified polyamide, functionalized chitosan microspheres, modified mesoporous titanium dioxide, and N,N-dimethylformamide were mixed evenly in a mass ratio of 1:0.06:0.04:6, stirred at 100 r / min for 20 min at room temperature to prepare a spinning solution; the spinning solution was introduced into the spinning needle tube, and a metal roller with tin foil attached was used as a receiving device. Electrospinning was performed in an electrospinning machine. The ambient temperature was set to 29 °C, the relative humidity was 45%, the spinning voltage was 18 kV, the receiving distance was 19 cm, the propulsion rate was 0.07 mL / h, and the polyamide membrane was dried at 58 °C for 9 h under vacuum conditions; acrylic acid, potassium persulfate, and deionized water were mixed evenly in a mass ratio of 1:0.03:30 to prepare a treatment solution; the polyamide membrane was immersed in the treatment solution, allowed to stand for 10 min, taken out, kept warm at 70 °C for 4 h, and dried at 58 °C for 12 h under vacuum conditions to prepare a water treatment filter material.

[0036] Example 2

[0037] A method for preparing a water treatment filter material, comprising the following steps:

[0038] (1) Chitosan and 2.5% acetic acid aqueous solution were mixed at a mass ratio of 1:29 to prepare chitosan solution; liquid paraffin and Span 80 were mixed at a mass ratio of 12.5:1, stirred at 20°C and 150r / min for 30min, chitosan solution with a mass of 0.5 times that of liquid paraffin was added dropwise at a constant speed within 5min, and stirring was continued for 25min. 1,4-dichloro-2-butene with a mass of 0.22 times that of liquid paraffin was added, the temperature was raised to 41°C, stirring was continued for 1.1h, and the pH was adjusted with a 0.1mol / L sodium hydroxide aqueous solution. H to 9.5, continue stirring for 2.2h, add acetone 1.4 times the volume of liquid paraffin, ultrasonicate for 5min, and dry at 55℃ for 7.5h under vacuum conditions to obtain chitosan microspheres; chitosan microspheres, 15% sodium hydroxide aqueous solution, sodium iodide, iodomethane, and 1-methyl-2-pyrrolidone are mixed uniformly in a mass ratio of 1:5.5:2.3:5.5:29, stirred at 61℃ and 150r / min for 2.5h, filtered, washed with anhydrous ethanol 4 times, and dried at 55℃ for 9.5h under vacuum conditions to obtain functionalized chitosan microspheres;

[0039] (2) Ammonium persulfate and 4% hydrochloric acid aqueous solution were mixed at a mass ratio of 1:25 to prepare an initiator solution; aniline, 3-vinylaniline, and 2,9,16,23-tetraaminophthalocyanine were added at a molar ratio of 1:0.25:0.45 to a 4% hydrochloric acid aqueous solution with a mass fraction of 48 times that of aniline at 1°C, stirred at 150 r / min for 9 minutes, mesoporous titanium dioxide with a mass fraction of 1.5 times that of aniline was added, and stirring was continued for 7 minutes. Initiator solution with a mass fraction of 1.1 times that of aniline was added dropwise at a uniform rate within 10 minutes, and stirring was continued for 3.5 hours. The mixture was filtered, washed with anhydrous ethanol and deionized water 4 times each, and dried at 55°C under vacuum conditions for 11 hours to obtain modified mesoporous titanium dioxide;

[0040] (3) Polyamide, formaldehyde, and N,N-dimethylformamide were mixed uniformly in a mass ratio of 1:0.7:22, stirred at 75°C and 90 r / min for 1.1 h under nitrogen protection, and dried at 55°C for 9 h under vacuum conditions to obtain pre-modified polyamide; pre-modified polyamide, maleic anhydride, benzoquinone, and N,N-dimethylformamide were mixed uniformly in a mass ratio of 1:1.3:0.04:21, stirred at 55°C and 90 r / min for 6.5 h, and dried at 55°C for 11 h under vacuum conditions to obtain modified polyamide;

[0041] (4) Modified polyamide, functionalized chitosan microspheres, modified mesoporous titanium dioxide, and N,N-dimethylformamide were mixed uniformly in a mass ratio of 1:0.07:0.045:6.5, and stirred at 110 r / min for 19 min at room temperature to prepare a spinning solution; the spinning solution was introduced into the spinning needle tube, and a metal roller with tin foil attached was used as a receiving device. Electrospinning was performed in an electrospinning machine, and the ambient temperature was set to 30°C and the relative humidity was 50%. The spinning voltage was 19 kV, the receiving distance was 20 cm, the propulsion rate was 0.075 mL / h, and the polyamide membrane was dried at 60°C for 8 h under vacuum conditions. Acrylic acid, potassium persulfate, and deionized water were mixed evenly in a mass ratio of 1:0.04:31 to prepare a treatment liquid. The polyamide membrane was immersed in the treatment liquid, allowed to stand for 9 minutes, taken out, kept warm at 75°C for 3.5 hours, and dried at 60°C for 11 hours under vacuum conditions to obtain a water treatment filter material.

[0042] Example 3

[0043] A method for preparing a water treatment filter material, comprising the following steps:

[0044] (1) Chitosan and 3% acetic acid aqueous solution were mixed at a mass ratio of 1:30 to prepare chitosan solution; liquid paraffin and Span 80 were mixed at a mass ratio of 13:1, stirred at 30°C and 200 r / min for 25 min, chitosan solution with a mass of 0.6 times that of liquid paraffin was added dropwise at a constant speed within 5 min, and stirring was continued for 20 min. 1,4-dichloro-2-butene with a mass of 0.23 times that of liquid paraffin was added, the temperature was raised to 42°C, stirring was continued for 1 h, and a 0.1 mol / L sodium hydroxide solution was used to dissolve the chitosan solution. The pH of the liquid was adjusted to 10, and the stirring was continued for 2 hours. Acetone 1.5 times the volume of liquid paraffin was added, and ultrasonication was performed for 4 minutes. The mixture was dried at 60°C for 7 hours under vacuum conditions to obtain chitosan microspheres. The chitosan microspheres, a 16% sodium hydroxide aqueous solution, sodium iodide, methyl iodide, and 1-methyl-2-pyrrolidone were mixed uniformly in a mass ratio of 1:6:2.4:6:30, stirred at 62°C and 200 r / min for 2 hours, filtered, washed with anhydrous ethanol 5 times, and dried at 60°C for 9 hours under vacuum conditions to obtain functionalized chitosan microspheres.

[0045] (2) Ammonium persulfate and 5% hydrochloric acid aqueous solution were mixed at a mass ratio of 1:30 to prepare an initiator solution; aniline, 3-vinylaniline, and 2,9,16,23-tetraaminophthalocyanine were added at a molar ratio of 1:0.3:0.5 to a 5% hydrochloric acid aqueous solution with a mass fraction of 50 times that of aniline at 2°C, stirred at 200 r / min for 8 minutes, mesoporous titanium dioxide with a mass fraction of 1.6 times that of aniline was added, and stirring was continued for 6 minutes. Initiator solution with a mass fraction of 1.2 times that of aniline was added dropwise at a uniform rate within 10 minutes, and stirring was continued for 3 hours. The mixture was filtered, washed with anhydrous ethanol and deionized water 5 times each, and dried at 60°C under vacuum conditions for 10 hours to obtain modified mesoporous titanium dioxide;

[0046] (3) Polyamide, formaldehyde and N,N-dimethylformamide were mixed evenly in a mass ratio of 1:0.8:24, stirred at 80°C and 100 r / min for 1 h under nitrogen protection, and dried at 50°C for 10 h under vacuum conditions to obtain pre-modified polyamide; pre-modified polyamide, maleic anhydride, benzoquinone and N,N-dimethylformamide were mixed evenly in a mass ratio of 1:1.4:0.05:22, stirred at 60°C and 100 r / min for 6 h, and dried at 60°C for 10 h under vacuum conditions to obtain modified polyamide;

[0047] (4) Modified polyamide, functionalized chitosan microspheres, modified mesoporous titanium dioxide, and N,N-dimethylformamide were mixed evenly in a mass ratio of 1:0.08:0.05:7, stirred at 120 r / min for 18 min at room temperature to prepare a spinning solution; the spinning solution was introduced into the spinning needle tube, and a metal roller with tin foil attached was used as a receiving device, and electrospinning was performed in an electrospinning machine. The ambient temperature was set to 31 °C, the relative humidity was 55%, the spinning voltage was 20 kV, the receiving distance was 21 cm, the propulsion rate was 0.08 mL / h, and the polyamide membrane was dried at 62 °C for 7 h under vacuum conditions; acrylic acid, potassium persulfate, and deionized water were mixed evenly in a mass ratio of 1:0.05:32 to prepare a treatment solution; the polyamide membrane was immersed in the treatment solution, allowed to stand for 8 min, taken out, kept warm at 80 °C for 3 h, and dried at 62 °C for 10 h under vacuum conditions to prepare a water treatment filter material.

[0048] Comparative Example 1:

[0049] The preparation method of the water treatment filter material in Comparative Example 1 differs from that in Example 2 in that step (1) is modified as follows: chitosan and a 2% acetic acid aqueous solution are mixed uniformly in a mass ratio of 1:28 to prepare a chitosan solution; liquid paraffin and Span 80 are mixed uniformly in a mass ratio of 12:1, stirred at 10°C and 100 r / min for 35 minutes, chitosan solution 0.4 times the mass of liquid paraffin is added dropwise at a uniform rate over 5 minutes, stirring is continued for 30 minutes, 1,4-dichloro-2-butene 0.21 times the mass of liquid paraffin is added, the temperature is raised to 40°C, stirring is continued for 1.2 hours, the pH is adjusted to 9 with a 0.1 mol / L sodium hydroxide aqueous solution, stirring is continued for 2.4 hours, acetone 1.3 times the volume of liquid paraffin is added, ultrasonication is performed for 6 minutes, and drying is performed at 50°C under vacuum conditions for 8 hours to prepare functionalized chitosan microspheres. The remaining steps are the same as in Example 2.

[0050] Comparative Example 2:

[0051] The preparation method of the water treatment filter material in Comparative Example 2 differs from that in Example 2 in that step (1) is different. Step (1) is modified as follows: chitosan and an aqueous acetic acid solution with a mass fraction of 2% are mixed uniformly in a mass ratio of 1:28 to prepare a chitosan solution; liquid paraffin and Span 80 are mixed uniformly in a mass ratio of 12:1, stirred at 10°C and 100 r / min for 35 minutes, chitosan solution with a mass of 0.4 times that of liquid paraffin is added dropwise at a uniform speed within 5 minutes, stirring is continued for 30 minutes, 1,4-dichlorobutane with a mass of 0.21 times that of liquid paraffin is added, the temperature is raised to 40°C, and stirring is continued for 1.2 hours. The pH was adjusted to 9 with a 0.1 mol / L sodium hydroxide aqueous solution, and stirring was continued for 2.4 hours. Acetone (1.3 times the volume of liquid paraffin) was added, and the mixture was ultrasonicated for 6 minutes. The mixture was then dried at 50°C under vacuum for 8 hours to produce chitosan microspheres. The chitosan microspheres were then mixed with a 14% sodium hydroxide aqueous solution, sodium iodide, methyl iodide, and 1-methyl-2-pyrrolidone in a mass ratio of 1:5:2.2:5:28, stirred at 60°C and 100 rpm for 3 hours, filtered, washed three times with anhydrous ethanol, and dried at 50°C under vacuum for 10 hours to produce functionalized chitosan microspheres. The remaining steps were the same as in Example 2.

[0052] Comparative Example 3:

[0053] The preparation method of the water treatment filter material in Comparative Example 3 differs from that in Example 2 only in step (2). Step (2) is modified as follows: ammonium persulfate and a 4% hydrochloric acid aqueous solution are uniformly mixed in a mass ratio of 1:25 to prepare an initiator solution; aniline and 3-vinylaniline are added in a molar ratio of 1:0.25 to a 4% hydrochloric acid aqueous solution having a mass fraction of 48 times that of aniline at 1°C, stirred at 150 r / min for 9 minutes, mesoporous titanium dioxide having a mass fraction of 1.5 times that of aniline is added, and stirring is continued for 7 minutes. The initiator solution having a mass fraction of 1.1 times that of aniline is added dropwise at a uniform rate over 10 minutes, and stirring is continued for 3.5 hours. The product is filtered, washed with anhydrous ethanol and deionized water 4 times each, and dried at 55°C under vacuum for 11 hours to obtain modified mesoporous titanium dioxide. The remaining steps are the same as in Example 2.

[0054] Comparative Example 4:

[0055] The preparation method of the water treatment filter material in Comparative Example 4 differs from that in Example 2 in that step (2) is not performed, and step (4) is modified as follows: modified polyamide, functionalized chitosan microspheres, mesoporous titanium dioxide, and N,N-dimethylformamide are uniformly mixed in a mass ratio of 1:0.07:0.045:6.5, stirred at room temperature at 110 r / min for 19 min, and prepared into a spinning solution; the spinning solution is introduced into a spinning needle tube, and a metal roller with tin foil attached is used as a receiving device, and electrospinning is performed in an electrospinning machine. The ambient temperature was set at 30°C, the relative humidity was 50%, the spinning voltage was 19 kV, the receiving distance was 20 cm, and the propulsion rate was 0.075 mL / h. The polyamide membrane was dried at 60°C under vacuum for 8 hours to produce a polyamide membrane. Acrylic acid, potassium persulfate, and deionized water were mixed in a mass ratio of 1:0.04:31 to prepare a treatment solution. The polyamide membrane was immersed in the treatment solution and allowed to stand for 9 minutes. The membrane was then removed and kept at 75°C for 3.5 hours. Finally, the membrane was dried at 60°C under vacuum for 11 hours to produce a water treatment filter material. The remaining steps were the same as in Example 2.

[0056] Comparative Example 5:

[0057] The preparation method of the water treatment filter material in Comparative Example 5 differs from that in Example 2 in that step (3) is not performed, and step (4) is modified as follows: polyamide, functionalized chitosan microspheres, modified mesoporous titanium dioxide, and N,N-dimethylformamide are uniformly mixed in a mass ratio of 1:0.07:0.045:6.5, stirred at room temperature at 110 r / min for 19 min, and prepared into a spinning solution; the spinning solution is introduced into a spinning needle tube, and a metal roller with tin foil attached is used as a receiving device, and electrospinning is performed in an electrospinning machine. The ambient temperature was set to 30°C, the relative humidity to 50%, the spinning voltage to 19 kV, the receiving distance to 20 cm, and the propulsion rate to 0.075 mL / h. The polyamide membrane was dried at 60°C for 8 h under vacuum conditions. Acrylic acid, potassium persulfate, and deionized water were mixed uniformly in a mass ratio of 1:0.04:31 to prepare a treatment liquid. The polyamide membrane was immersed in the treatment liquid, allowed to stand for 9 minutes, taken out, kept warm at 75°C for 3.5 hours, and dried at 60°C for 11 hours under vacuum conditions to prepare a water treatment filter material.

[0058] Comparative Example 6:

[0059] The preparation method of the water treatment filter material of Comparative Example 6 differs from that of Example 2 in that step (4) is different. Step (4) is modified as follows: modified polyamide, functionalized chitosan microspheres, modified mesoporous titanium dioxide, and N,N-dimethylformamide are uniformly mixed in a mass ratio of 1:0.07:0.045:6.5, stirred at room temperature at 110 r / min for 19 min, and prepared into a spinning solution; the spinning solution is introduced into a spinning needle tube, a metal roller with tin foil attached is used as a receiving device, and electrospinning is performed in an electrospinning machine, the ambient temperature is set to 30°C, the relative humidity is set to 50%, the spinning voltage is set to 19 kV, the receiving distance is set to 20 cm, the propulsion rate is set to 0.075 mL / h, and the spinning is dried at 60°C for 8 h under vacuum conditions to obtain a water treatment filter material.

[0060] Test Example 1

[0061] Test of heavy metal adsorption performance

[0062] Test method: Copper nitrate and deionized water were mixed at a mass ratio of 1:2000 to prepare a copper nitrate aqueous solution. The copper nitrate aqueous solution was filtered using the Example and Comparative Example, with each group undergoing filtration three times. 0.5 mL of the filtered copper nitrate aqueous solution was pipetted and diluted to 5 mL with 2% nitric acid aqueous solution. The residual copper ion concentration in the copper nitrate aqueous solution was measured using atomic absorption spectrometry, and the heavy metal adsorption rate was calculated: heavy metal adsorption rate = (original copper ion concentration - residual copper ion concentration) / original copper ion concentration × 100%. The results are shown in Table 1.

[0063] Table 1

[0064]

[0065] From the comparison of the experimental data of Examples 1 to 3 and Comparative Examples 1 to 6 in Table 1, it can be found that the water treatment filter material prepared by the present invention has good heavy metal adsorption performance.

[0066] By comparison, the heavy metal adsorption rates of Examples 1 to 3 are greater than those of Comparative Examples 3 to 4, and the heavy metal adsorption rate of Comparative Example 3 is greater than that of Comparative Example 4, indicating that modified mesoporous titanium dioxide is prepared by copolymerizing aniline, 3-vinylaniline, and 2,9,16,23-tetraaminophthalocyanine through chemical oxidation and depositing them on mesoporous titanium dioxide; a polyaniline structure is generated on the modified mesoporous titanium dioxide, and a phthalocyanine structure is introduced; the polyaniline structure has a good complexing adsorption effect on heavy metal ions, and can improve the performance of water treatment filter materials in adsorbing heavy metal ions; the phthalocyanine structure can form coordination bonds with metal ions such as copper, iron, cobalt, zinc, and manganese in sewage to generate metal phthalocyanine, thereby improving the adsorption performance of water treatment filter materials for heavy metal ions.

[0067] By comparison, the heavy metal adsorption rates of Examples 1 to 3 are greater than that of Comparative Example 5, indicating that a pre-modified polyamide is prepared by reacting polyamide and formaldehyde, and a hydroxyl group is introduced on the side chain of the pre-modified polyamide; the hydroxyl group introduced on the side chain of the pre-modified polyamide is reacted with maleic anhydride to prepare a modified polyamide, and a carboxyl group is introduced on the modified polyamide; the carboxyl group introduced on the side chain of the modified polyamide can chelate with heavy metal ions, thereby improving the adsorption capacity of the water treatment filter material for heavy metal ions in sewage.

[0068] By comparison, the heavy metal adsorption rates of Examples 1 to 3 are greater than that of Comparative Example 6, indicating that the modified polyamide, functionalized chitosan microspheres, and modified mesoporous titanium dioxide are prepared into a spinning solution and electrospun to produce a polyamide membrane; acrylic acid is reacted with the liquid on the polyamide membrane to produce a water treatment filter material; the carbon-carbon double bonds on the acrylic acid are polymerized with the carbon-carbon double bonds on the modified mesoporous titanium dioxide, functionalized chitosan microspheres, and modified polyamide, introducing a large number of carboxyl groups on the membrane material. The carboxyl groups can chelate heavy metal ions in sewage, thereby further enhancing the adsorption capacity of the water treatment filter material for heavy metal ions in sewage.

[0069] Test Example 2

[0070] Dye removal performance test

[0071] Testing method: 15g of the Example and Comparative Example were immersed in a 10% copper nitrate aqueous solution and ultrasonically vibrated for 10 minutes. The samples were removed and dried under vacuum at 50°C for 10 hours to obtain test samples. Methylene blue was mixed with deionized water to prepare a 10mg / L methylene blue solution. The test sample was added to a test tube containing 50ml of the methylene blue solution to prepare a test sample. The sample was adsorbed in the dark for 3 hours using a photochemical reactor. After that, photocatalytic degradation was performed using a 500W xenon lamp. After 3 hours, 2ml of the solution was extracted from the test tube and centrifuged. The absorbance of the solution was measured to determine the methylene blue concentration at that time, and the methylene blue removal rate was calculated. The results are shown in Table 2.

[0072] Table 2

[0073]

[0074] From the comparison of the experimental data of Examples 1 to 3 and Comparative Examples 1 to 6 in Table 2, it can be found that the water treatment filter material prepared by the present invention has good performance in removing dyes.

[0075] By comparison, the methylene blue removal rates of Examples 1 to 3 are greater than those of Comparative Examples 3 to 4, and the methylene blue removal rate of Comparative Example 3 is greater than that of Comparative Example 4, indicating that modified mesoporous titanium dioxide is prepared by copolymerizing aniline, 3-vinylaniline, and 2,9,16,23-tetraaminophthalocyanine through chemical oxidation and depositing them on mesoporous titanium dioxide; a phthalocyanine structure is introduced into the modified mesoporous titanium dioxide, and the phthalocyanine structure can form a coordination bond with copper ions in sewage to generate copper phthalocyanine, which can photocatalytically degrade organic dyes; thereby achieving the removal of dyes from sewage; mesoporous titanium dioxide can photocatalytically degrade dyes, and the mesoporous titanium dioxide is modified to improve the compatibility between mesoporous titanium dioxide and polyamide, so that the mesoporous titanium dioxide is uniformly dispersed in the membrane material to avoid agglomeration, fully exerting the performance of mesoporous titanium dioxide in catalytically degrading dyes, and improving the ability of water treatment filter materials to remove dyes from sewage.

[0076] By comparison, the methylene blue removal rates of Examples 1 to 3 are greater than that of Comparative Example 5, indicating that a pre-modified polyamide is prepared by reacting polyamide and formaldehyde, and a hydroxyl group is introduced into the side chain of the pre-modified polyamide; the hydroxyl group introduced into the side chain of the pre-modified polyamide is reacted with maleic anhydride to prepare a modified polyamide, and a carboxyl group is introduced into the modified polyamide; the carboxyl group introduced into the side chain of the modified polyamide can adsorb cationic dyes, thereby improving the ability of the water treatment filter material to remove dyes in sewage.

[0077] By comparison, the methylene blue removal rates of Examples 1 to 3 are greater than that of Comparative Example 6, indicating that the modified polyamide, functionalized chitosan microspheres, and modified mesoporous titanium dioxide are prepared into a spinning solution and electrospun to produce a polyamide membrane; acrylic acid is reacted with the liquid on the polyamide membrane to produce a water treatment filter material; the carbon-carbon double bonds on the acrylic acid are polymerized with the carbon-carbon double bonds on the modified mesoporous titanium dioxide, functionalized chitosan microspheres, and modified polyamide, introducing a large number of carboxyl groups on the membrane material. The carboxyl groups can adsorb cationic dyes, thereby improving the water treatment filter material's ability to remove dyes from sewage.

[0078] Test Example 3

[0079] Antibacterial performance testing

[0080] Test method: Cut the examples and comparative examples into 10mm×10mm samples and sterilize them with ultraviolet radiation for 5h; activate the Escherichia coli strain and prepare it to a concentration of 3×10 4 CFU / mL bacterial suspension; place the sample in the bacterial suspension and shake at 300 rpm for 5 minutes at room temperature. Take 1 mL of the bacterial suspension and dilute it 100-fold. Take 1 mL of the diluted bacterial suspension and inoculate it onto agar medium. Incubate at 37°C for 16 hours. Count the colonies according to the method in GB / T 15979, and calculate the inhibition rate: inhibition rate = (average colony count before sample shaking - average colony count after sample shaking) / average colony count before sample shaking × 100%. The results are shown in Table 3.

[0081] Table 3

[0082]

[0083] From the comparison of the experimental data of Examples 1 to 3 and Comparative Examples 1 to 6 in Table 3, it can be found that the water treatment filter material prepared by the present invention has good antibacterial properties.

[0084] By comparison, the antibacterial rates of Examples 1 to 3 are greater than that of Comparative Example 1, indicating that chitosan microspheres are prepared by reacting chitosan with 1,4-dichloro-2-butene by an emulsion curing method using 1,4-dichloro-2-butene as a cross-linking agent, and the chlorine atoms on 1,4-dichloro-2-butene react with the amino groups on chitosan to convert the primary amines on the chitosan into secondary amines and tertiary amines; the chitosan microspheres are reacted with methyl iodide to convert the secondary amines, tertiary amines, and residual primary amines on the chitosan into quaternary ammonium salts. Quaternary ammonium salts are cationic antibacterial agents, and the quaternary ammonium salt structure generated on the functionalized chitosan microspheres can improve the antibacterial properties of water treatment filter materials.

[0085] Test Example 4

[0086] Durability testing

[0087] Test method: According to GB / T13022, the examples and comparative examples were cut into standard specimens of 20 mm x 100 mm, and the tensile strength of the standard specimens was tested on an electronic universal testing machine. The results are shown in Table 4.

[0088] Table 4

[0089]

[0090] From the comparison of the experimental data of Examples 1 to 3 and Comparative Examples 1 to 6 in Table 4, it can be found that the water treatment filter material prepared by the present invention has good durability.

[0091] By comparison, the tensile strength of Examples 1 to 3 is greater than that of Comparative Example 2, indicating that chitosan microspheres are prepared by reacting chitosan with 1,4-dichloro-2-butene via an emulsion curing method using 1,4-dichloro-2-butene as a cross-linking agent, and carbon-carbon double bonds are introduced into the chitosan microspheres. The carbon-carbon double bonds introduced into the chitosan microspheres can copolymerize with acrylic acid during the liquid reaction of the polyamide membrane, so that the functionalized chitosan microspheres form a cross-linked network structure in the water treatment filter material, making the membrane material less easily destroyed by external forces, thereby improving the durability of the water treatment filter material.

[0092] By comparison, the tensile strength of Examples 1 to 3 is greater than that of Comparative Example 4, indicating that modified mesoporous titanium dioxide is prepared by copolymerizing aniline, 3-vinylaniline, and 2,9,16,23-tetraaminophthalocyanine through chemical oxidation and depositing them on mesoporous titanium dioxide; carbon-carbon double bonds are introduced on the modified mesoporous titanium dioxide; the carbon-carbon double bonds introduced on the modified mesoporous titanium dioxide enable the modified mesoporous titanium dioxide to participate in the copolymerization of acrylic acid during the liquid reaction of the polyamide membrane, so that the modified mesoporous titanium dioxide forms a cross-linked network structure in the water treatment filter material, making the membrane material not easily destroyed by external forces, thereby improving the durability of the water treatment filter material.

[0093] By comparison, the tensile strength of Examples 1 to 3 is greater than that of Comparative Example 5, indicating that a pre-modified polyamide is prepared by reacting polyamide and formaldehyde, and a hydroxyl group is introduced into the side chain of the pre-modified polyamide; the hydroxyl group introduced into the side chain of the pre-modified polyamide is reacted with maleic anhydride to prepare a modified polyamide, and a carbon-carbon double bond is introduced into the modified polyamide; the introduction of the carbon-carbon double bond enables the modified polyamide to participate in the copolymerization of acrylic acid when the polyamide membrane reacts with liquid, so that the modified polyamide forms a cross-linked network structure in the water treatment filter material, making the membrane material not easily destroyed by external forces, thereby improving the durability of the water treatment filter material.

[0094] By comparison, the tensile strength of Examples 1 to 3 is greater than that of Comparative Example 6, indicating that the modified polyamide, functionalized chitosan microspheres, and modified mesoporous titanium dioxide are prepared into a spinning solution and electrospun to produce a polyamide membrane; acrylic acid is reacted with the liquid on the polyamide membrane to produce a water treatment filter material; the carbon-carbon double bonds on the acrylic acid are polymerized with the carbon-carbon double bonds on the modified mesoporous titanium dioxide, functionalized chitosan microspheres, and modified polyamide to form a cross-linked network structure inside the membrane material, making the membrane material not easily destroyed by external forces, thereby improving the durability of the water treatment filter material.

[0095] 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 water treatment filter material, characterized in that: The water treatment filter material is prepared by reacting chitosan microspheres with methyl iodide to obtain functionalized chitosan microspheres; reacting pre-modified polyamide with maleic anhydride to obtain modified polyamide; preparing a spinning solution from the modified polyamide, functionalized chitosan microspheres, and modified mesoporous titanium dioxide, and electrospinning to obtain a polyamide membrane; and reacting acrylic acid with the liquid on the polyamide membrane to obtain the water treatment filter material. The chitosan microspheres are prepared by reacting chitosan with 1,4-dichloro-2-butene via an emulsion curing method using 1,4-dichloro-2-butene as a crosslinking agent. The modified mesoporous titanium dioxide is prepared by copolymerizing aniline, 3-vinylaniline, and 2,9,16,23-tetraaminophthalocyanine and depositing the copolymerized copolymerized copolymerized aniline, 3-vinylaniline, and 2,9,16,23-tetraaminophthalocyanine on the mesoporous titanium dioxide. The pre-modified polyamide is prepared by reacting polyamide and formaldehyde.

2. A method for preparing a water treatment filter material, characterized in that: The preparation method of the water treatment filter material comprises the following preparation steps: (1) Liquid paraffin and Span 80 were mixed in a mass ratio of (12-13):1, stirred at 10-30℃ and 100-200r / min for 25-35min, chitosan solution with a mass of 0.4-0.6 times that of liquid paraffin was added dropwise at a constant speed within 5min, and stirring was continued for 20-30min. 1,4-dichloro-2-butene with a mass of 0.21-0.23 times that of liquid paraffin was added, the temperature was raised to 40-42℃, stirring was continued for 1-1.2h, the pH was adjusted to 9-10 with a 0.1mol / L sodium hydroxide aqueous solution, stirring was continued for 2-2.4h, and liquid paraffin with a volume of 1. 3~1.5 times of acetone, ultrasonic for 4~6 minutes, and dried at 50~60℃ under vacuum conditions for 7~8 hours to obtain chitosan microspheres; chitosan microspheres, sodium hydroxide aqueous solution with a mass fraction of 14%~16%, sodium iodide, methyl iodide, and 1-methyl-2-pyrrolidone are mixed uniformly in a mass ratio of 1:(5~6):(2.2~2.4):(5~6):(28~30), stirred at 60~62℃, 100~200r / min for 2~3 hours, filtered, washed with anhydrous ethanol 3~5 times, and dried at 50~60℃ under vacuum conditions for 9~10 hours to obtain functionalized chitosan microspheres; (2) At 0~2°C, add aniline, 3-vinylaniline, and 2,9,16,23-tetraaminophthalocyanine in a molar ratio of 1:(0.2~0.3):(0.4~0.5) to a 3%~5% hydrochloric acid aqueous solution with a mass fraction of 46~50 times the mass of aniline, stir at 100~200 r / min for 8~10 minutes, add mesoporous titanium dioxide with a mass fraction of 1.4~1.6 times the mass of aniline, continue stirring for 6~8 minutes, and uniformly add an initiator solution with a mass fraction of 1~1.2 times the mass of aniline dropwise within 10 minutes, continue stirring for 3~4 hours, filter, wash with anhydrous ethanol and deionized water 3~5 times each, and dry at 50~60°C under vacuum conditions for 10~12 hours to obtain modified mesoporous titanium dioxide; (3) Pre-modified polyamide is prepared by reacting polyamide and formaldehyde; pre-modified polyamide, maleic anhydride, quinone, and N,N-dimethylformamide are uniformly mixed in a mass ratio of 1:(1.2~1.4):(0.03~0.05):(20~22), stirred at 50~60°C and 80~100r / min for 6~7h, and dried at 50~60°C under vacuum conditions for 10~12h to obtain modified polyamide; (4) Modified polyamide, functionalized chitosan microspheres, modified mesoporous titanium dioxide, and N,N-dimethylformamide were mixed uniformly in a mass ratio of 1:(0.06-0.08):(0.04-0.05):(6-7), and stirred at 100-120 r / min for 18-20 min at room temperature to prepare a spinning solution; the spinning solution was introduced into a spinning needle tube, and a metal roller with tin foil attached was used as a receiving device. Electrospinning was performed in an electrospinning machine, and dried at 58-62°C under vacuum conditions for 7-9 h to obtain a polyamide membrane; The polyamide membrane was immersed in the acrylic acid treatment solution, allowed to stand for 8-10 minutes, taken out, kept warm at 70-80°C for 3-4 hours, and dried at 58-62°C for 10-12 hours under vacuum conditions to obtain a water treatment filter material.

3. The method for preparing a water treatment filter material according to claim 2, wherein: The preparation method of the chitosan solution in step (1) is as follows: chitosan and an acetic acid aqueous solution with a mass fraction of 2% to 3% are uniformly mixed in a mass ratio of 1:(28-30) to prepare a chitosan solution.

4. The method for preparing a water treatment filter material according to claim 3, wherein: The chitosan has a deacetylation degree of 92% and a weight-average molecular weight of 50 kDa.

5. The method for preparing a water treatment filter material according to claim 2, wherein: The preparation method of the initiator solution in step (2) is as follows: ammonium persulfate and a hydrochloric acid aqueous solution with a mass fraction of 3% to 5% are mixed uniformly in a mass ratio of 1:(20-30) to prepare an initiator solution.

6. The method for preparing a water treatment filter material according to claim 2, wherein: The particle size of the mesoporous titanium dioxide in step (2) is 800 nm.

7. The method for preparing a water treatment filter material according to claim 2, wherein: The preparation method of the pre-modified polyamide in step (3) is as follows: polyamide, formaldehyde and N,N-dimethylformamide are uniformly mixed in a mass ratio of 1:(0.6~0.8):(20~24), stirred at 70~80°C and 80~100r / min for 1~1.2h under nitrogen protection, and dried at 50~60°C for 8~10h under vacuum conditions to obtain the pre-modified polyamide.

8. The method for preparing a water treatment filter material according to claim 7, characterized in that: The polyamide type is PA66 101L.

9. The method for preparing a water treatment filter material according to claim 2, wherein: The preparation method of the acrylic acid treatment liquid in step (4) is: acrylic acid, potassium persulfate, and deionized water are uniformly mixed in a mass ratio of 1: (0.03-0.05): (30-32) to prepare the acrylic acid treatment liquid.

10. The method for preparing a water treatment filter material according to claim 2, wherein: The process parameters of the electrospinning in step (4) are as follows: setting the ambient temperature to 29-31°C, the relative humidity to 45%-55%, the spinning voltage to 18-20 kV, the receiving distance to 19-21 cm, and the propulsion rate to 0.07-0.08 mL / h.

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