Water treatment filtering material and preparation method thereof

Abstract

The invention discloses a water treatment filtering material and a preparation method thereof, and relates to the technical field of water treatment. When the water treatment filtering material is prepared, chitosan and 1, 4-dichloro-2-butene are subjected to a reaction through an emulsion curing method, and chitosan microspheres are prepared; enabling the chitosan microspheres and methyl iodide to react to prepare functionalized chitosan microspheres; the preparation method comprises the following steps: copolymerizing aniline, 3-vinyl aniline and 2, 9, 16, 23-tetraamino phthalocyanine, and depositing 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, the functionalized chitosan microspheres and the modified mesoporous titanium dioxide, and performing electrostatic spinning to obtain a polyamide membrane; and carrying out liquid reaction on acrylic acid on the polyamide membrane to obtain the water treatment filtering material. The prepared water treatment filtering material has excellent antibacterial performance, heavy metal adsorption performance, dye removal performance and durability.

Description

Technical Field

[0001] The 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, the problem of water pollution has also attracted global attention. According to the latest estimates, more than 1.2 billion people in the world do not have access to the most important component of life: clean drinking water. Industrial development, mining industries and environmental disasters have accelerated the growth of harmful wastewater in the environment.

[0003] Water pollution is divided into organic pollutants, inorganic pollutants and biological pollutants. Inorganic pollutants are mainly heavy metals, which enter the human body through water sources and chelate with organic components in the body to form complexes, thereby destroying cell structures or inactivating enzymes, which in turn lead to pathological changes. In addition, heavy metals are difficult to decompose and highly toxic, posing a great threat to human health; organic pollution is mainly organic dyes in industrial wastewater, which have high chroma, high toxicity, and are difficult to degrade, causing great harm to water bodies and soil; biological pollution is mainly pathogenic microorganisms, parasites, certain insects and other organisms entering the water body, or certain algae multiplying in large numbers, causing water quality deterioration, directly or indirectly endangering human health or affecting fishery production

[0004] Using filter materials to filter sewage is a common water treatment technology with the advantages of low energy consumption, simple process, small investment and light pollution. However, conventional filter materials only intercept pollutants through physical action, with low efficiency; or they have single performance and cannot effectively remove organic pollutants, inorganic pollutants and biological pollutants in sewage at the same time. Water in nature is constantly flowing, and the composition of pollutants in sewage is complex and diverse. Therefore, it is necessary to invent a water treatment filter material that has the properties of adsorbing heavy metals, removing dyes and antibacterial properties to achieve efficient purification of sewage. Summary of the invention

[0005] The object 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, wherein the water treatment filter material is prepared by reacting chitosan microspheres and methyl iodide to obtain functionalized chitosan microspheres; reacting pre-modified polyamide and maleic anhydride to obtain modified polyamide; preparing the modified polyamide, functionalized chitosan microspheres and modified mesoporous titanium dioxide into spinning solution, and electrospinning to obtain a polyamide membrane; and reacting acrylic acid with 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 using an emulsion curing method with 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 copolymers 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, the method 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°C and 100-200 r / min for 25-35 min, chitosan solution (0.4-0.6 times the mass of liquid paraffin) was added dropwise at a uniform rate within 5 min, stirring was continued for 20-30 min, 1,4-dichloro-2-butene (0.21-0.23 times the mass of liquid paraffin) was added, the temperature was raised to 40-42°C, stirring was continued for 1-1.2 h, pH was adjusted to 9-10 with 0.1 mol / L sodium hydroxide aqueous solution, stirring was continued for 2-2.4 h, and 1.5 volume of liquid paraffin was added. 3 to 1.5 times of acetone, ultrasonic for 4 to 6 minutes, and dried at 50 to 60°C for 7 to 8 hours under vacuum conditions to obtain chitosan microspheres; chitosan microspheres, sodium hydroxide aqueous solution with a mass fraction of 14% to 16%, sodium iodide, methyl iodide, and 1-methyl-2-pyrrolidone are mixed uniformly in a mass ratio of 1:(5 to 6):(2.2 to 2.4):(5 to 6):(28 to 30), stirred at 60 to 62°C and 100 to 200 r / min for 2 to 3 hours, filtered, washed with anhydrous ethanol for 3 to 5 times, and dried at 50 to 60°C for 9 to 10 hours under vacuum conditions 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% aqueous hydrochloric acid solution having a mass fraction of 46-50 times the mass of aniline, stir at 100-200 r / min for 8-10 min, add mesoporous titanium dioxide having a mass fraction of 1.4-1.6 times the mass of aniline, continue stirring for 6-8 min, uniformly add an initiator solution having a mass fraction of 1-1.2 times the mass of aniline dropwise within 10 min, continue stirring for 3-4 h, filter, wash with anhydrous ethanol and deionized water for 3-5 times each, and dry at 50-60°C under vacuum conditions for 10-12 h to obtain modified mesoporous titanium dioxide;

[0014] (3) Pre-modified polyamide, maleic anhydride, benzoquinone, 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 80-100 r / min for 6-7 h, and dried at 50-60° C. for 10-12 h under vacuum conditions to obtain modified polyamide;

[0015] (4) The modified polyamide, functionalized chitosan microspheres, modified mesoporous titanium dioxide, and N,N-dimethylformamide are 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 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, and dried at 58-62°C for 7-9 h under vacuum conditions to obtain a polyamide membrane; the polyamide membrane is 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 for 10-12 h under vacuum conditions 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 to 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 to 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: polyamide, formaldehyde, and N,N-dimethylformamide are uniformly mixed in a mass ratio of 1: (0.6-0.8): (20-24), and under nitrogen protection, the mixture is stirred at 70-80° C. and 80-100 r / min for 1-1.2 h, and then dried at 50-60° C. for 8-10 h under vacuum conditions to obtain the pre-modified polyamide.

[0021] As an optimization, the polyamide model 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: 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 beneficial effects achieved by the present invention are:

[0025] When preparing the water treatment filter material, the present invention uses 1,4-dichloro-2-butene as a crosslinking agent, and reacts chitosan with 1,4-dichloro-2-butene through an emulsion curing method to obtain chitosan microspheres; the chitosan microspheres and methyl iodide are reacted to obtain functionalized chitosan microspheres; aniline, 3-vinylaniline, and 2,9,16,23-tetraaminophthalocyanine are copolymerized and deposited on mesoporous titanium dioxide to obtain modified mesoporous titanium dioxide; polyamide and formaldehyde are reacted to obtain pre-modified polyamide; pre-modified polyamide and maleic anhydride are reacted to obtain modified polyamide; modified polyamide, functionalized chitosan microspheres, and modified mesoporous titanium dioxide are prepared into spinning solution, and polyamide membrane is obtained by electrostatic spinning; acrylic acid is reacted with liquid on the polyamide membrane to obtain the water treatment filter material.

[0026] Firstly, chitosan and 1,4-dichloro-2-butene were reacted with each other by emulsion curing method to obtain chitosan microspheres, and 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, which makes the membrane material not easily destroyed by external forces and improves the durability of the water treatment filter material; the chlorine atoms on 1,4-dichloro-2-butene react with the amino groups on the 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, which 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 to achieve the effect of adsorbing heavy metal ions 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 of mesoporous titanium dioxide with polyamide, so that the mesoporous titanium dioxide is evenly dispersed in the membrane material to avoid agglomeration, so as to give full play to the performance of mesoporous titanium dioxide in catalytic degradation of dyes, and further improve the performance of water treatment filter materials 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 adsorb cationic dyes, thereby improving the absorption of heavy metal ions in sewage by the water treatment filter material. The invention discloses a method for improving the adsorption capacity and removal capacity of water treatment filter materials. The method comprises the following steps: 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; 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 described embodiments 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 work are within the scope of protection of the present invention.

[0030] Embodiment 1:

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

[0032] (1) Chitosan and 2% acetic acid aqueous solution were mixed at a mass ratio of 1:28 to prepare a 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, chitosan solution 0.4 times the mass of liquid paraffin was added dropwise at a constant speed within 5 min, stirring was continued for 30 min, 1,4-dichloro-2-butene 0.21 times the mass of liquid paraffin was added, the temperature was raised to 40°C, stirring was continued for 1.2 h, and a 0.1 mol / L sodium hydroxide aqueous solution was used to prepare the chitosan solution. The pH of the solution was adjusted to 9, and 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. Under vacuum conditions, it was dried at 50°C for 8 hours to obtain chitosan microspheres. 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 100r / 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 a 3% aqueous hydrochloric acid solution are mixed uniformly in a mass ratio of 1:20 to prepare an initiator solution; aniline, 3-vinylaniline, and 2,9,16,23-tetraaminophthalocyanine are added in a molar ratio of 1:0.2:0.4 to a 3% aqueous hydrochloric acid solution with a mass fraction of 46 times the mass of aniline at 0°C, stirred at 100 r / min for 10 minutes, mesoporous titanium dioxide with a mass fraction of 1.4 times the mass of aniline is added, and stirring is continued for 8 minutes. Within 10 minutes, an initiator solution with a mass fraction of 1 times the mass of aniline is added dropwise at a uniform rate, and stirring is continued for 4 hours. The mixture is filtered, washed with anhydrous ethanol and deionized water for 5 times each, and dried at 50°C for 12 hours under vacuum conditions 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 80 r / min for 1.2 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 uniformly in a mass ratio of 1:1.2:0.03:20, stirred at 50°C and 80 r / min for 7 h, and dried at 50°C for 12 h under vacuum conditions to obtain modified polyamide;

[0035] (4) Modified polyamide, functionalized chitosan microspheres, modified mesoporous titanium dioxide, and N,N-dimethylformamide were mixed uniformly in a mass ratio of 1:0.06:0.04:6, stirred at 100 r / min for 20 min at room temperature to prepare a spinning solution; the spinning solution was introduced into a spinning needle tube, 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 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 to obtain a polyamide membrane; acrylic acid, potassium persulfate, and deionized water were mixed uniformly 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 obtain a water treatment filter material.

[0036] Embodiment 2:

[0037] A method for preparing a water treatment filter material, the method 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 a chitosan solution; liquid paraffin and Span 80 were mixed at a mass ratio of 12.5:1, stirred at 20°C and 150 r / min for 30 min, chitosan solution 0.5 times the mass of liquid paraffin was added dropwise at a uniform rate within 5 min, stirring was continued for 25 min, 1,4-dichloro-2-butene 0.22 times the mass of liquid paraffin was added, the temperature was raised to 41°C, stirring was continued for 1.1 h, and the pH was adjusted with a 0.1 mol / 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, dry at 55℃ for 7.5h under vacuum conditions to obtain chitosan microspheres; mix chitosan microspheres, 15% sodium hydroxide aqueous solution, sodium iodide, iodomethane, and 1-methyl-2-pyrrolidone in a mass ratio of 1:5.5:2.3:5.5:29, stir at 61℃, 150r / min for 2.5h, filter, wash with anhydrous ethanol 4 times, and dry at 55℃ for 9.5h under vacuum conditions to obtain functionalized chitosan microspheres;

[0039] (2) ammonium persulfate and a 4% aqueous hydrochloric acid solution are mixed uniformly in a mass ratio of 1:25 to prepare an initiator solution; aniline, 3-vinylaniline, and 2,9,16,23-tetraaminophthalocyanine are added in a molar ratio of 1:0.25:0.45 to a 4% aqueous hydrochloric acid 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 is added, and stirring is continued for 7 minutes. Within 10 minutes, an initiator solution with a mass fraction of 1.1 times that of aniline is added dropwise at a uniform rate, and stirring is continued for 3.5 hours. The mixture is filtered, washed with anhydrous ethanol and deionized water 4 times each, and dried at 55°C for 11 hours under vacuum conditions 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) The 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 room temperature at 110 r / min for 19 min 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 to perform electrospinning in an electrospinning machine, and the ambient temperature was set to 30° C. and the relative humidity was set to 50%. The spinning voltage is 19 kV, the receiving distance is 20 cm, the propulsion rate is 0.075 mL / h, and the polyamide membrane is obtained by drying at 60°C for 8 hours under vacuum conditions. Acrylic acid, potassium persulfate, and deionized water are mixed evenly in a mass ratio of 1:0.04:31 to prepare a treatment liquid. The polyamide membrane is 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] Embodiment 3:

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

[0044] (1) Chitosan and 3% acetic acid aqueous solution were mixed at a mass ratio of 1:30 to prepare a 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 0.6 times the mass of liquid paraffin was added dropwise at a constant speed within 5 min, stirring was continued for 20 min, 1,4-dichloro-2-butene 0.23 times the mass 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 aqueous solution was used to prepare the chitosan solution. The pH of the solution 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. Under vacuum conditions, it was dried at 60°C for 7 hours to obtain chitosan microspheres. 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 200r / 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 a 5% aqueous hydrochloric acid solution are mixed uniformly in a mass ratio of 1:30 to prepare an initiator solution; aniline, 3-vinylaniline, and 2,9,16,23-tetraaminophthalocyanine are added in a molar ratio of 1:0.3:0.5 to a 5% aqueous hydrochloric acid 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 is added, and stirring is continued for 6 minutes. Within 10 minutes, an initiator solution with a mass fraction of 1.2 times that of aniline is added dropwise at a uniform rate, and stirring is continued for 3 hours. The mixture is filtered, washed with anhydrous ethanol and deionized water for 5 times each, and dried at 60°C for 10 hours under vacuum conditions to obtain modified mesoporous titanium dioxide;

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

[0047] (4) The modified polyamide, functionalized chitosan microspheres, modified mesoporous titanium dioxide, and N,N-dimethylformamide were mixed uniformly in a mass ratio of 1:0.08:0.05:7, stirred at room temperature at 120 r / min for 18 min to prepare a spinning solution; the spinning solution was introduced into a spinning needle tube, a metal roller with tin foil attached was used as a receiving device, and electrospinning was performed in an electrospinning machine, and 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 to obtain a polyamide membrane; acrylic acid, potassium persulfate, and deionized water were mixed uniformly 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 obtain a water treatment filter material.

[0048] Comparative Example 1:

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

[0050] Comparative Example 2:

[0051] The preparation method of the water treatment filter material in Comparative Example 2 is different from that in Example 2 in that step (1) is different. Step (1) is modified as follows: chitosan and an aqueous solution of acetic acid having a mass fraction of 2% are mixed uniformly at a mass ratio of 1:28 to prepare a chitosan solution; liquid paraffin and Span 80 are mixed uniformly at a mass ratio of 12:1, stirred at 10°C and 100 r / min for 35 min, chitosan solution with a mass of 0.4 times that of liquid paraffin is added dropwise at a uniform speed within 5 min, stirring is continued for 30 min, 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 h , adjust the pH to 9 with a sodium hydroxide aqueous solution with a concentration of 0.1 mol / L, continue stirring for 2.4 hours, add acetone with a volume of 1.3 times that of liquid paraffin, ultrasonicate for 6 minutes, dry at 50°C for 8 hours under vacuum conditions to obtain chitosan microspheres; mix chitosan microspheres, sodium hydroxide aqueous solution with a mass fraction of 14%, sodium iodide, methyl iodide, and 1-methyl-2-pyrrolidone in a mass ratio of 1:5:2.2:5:28, stir at 60°C, 100r / min for 3 hours, filter, wash with anhydrous ethanol 3 times, and dry at 50°C for 10 hours under vacuum conditions to obtain functionalized chitosan microspheres. The remaining steps are the same as in Example 2.

[0052] Comparative Example 3:

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

[0054] Comparative Example 4:

[0055] The preparation method of the water treatment filter material in Comparative Example 4 is different from that in Example 2 in that step (2) is not performed, and step (4) is modified as follows: the 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, 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 was set to 50%, the spinning voltage was set to 19 kV, the receiving distance was set to 20 cm, the propulsion rate was set to 0.075 mL / h, and the polyamide membrane was dried at 60°C for 8 hours under vacuum conditions; acrylic acid, potassium persulfate, and deionized water were mixed evenly at 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. The remaining steps are the same as in Example 2.

[0056] Comparative Example 5:

[0057] The preparation method of the water treatment filter material in Comparative Example 5 is different 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, 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, the propulsion rate to 0.075 mL / h, and the film was dried at 60°C for 8 h under vacuum conditions to obtain a polyamide membrane. Acrylic acid, potassium persulfate, and deionized water were mixed evenly at 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, and kept warm at 75°C for 3.5 hours. Under vacuum conditions, it was dried at 60°C for 11 hours to obtain a water treatment filter material.

[0058] Comparative Example 6:

[0059] The difference between the preparation method of the water treatment filter material of Comparative Example 6 and Example 2 lies in the difference in step (4). Step (4) is modified as follows: the modified polyamide, functionalized chitosan microspheres, modified mesoporous titanium dioxide, and N,N-dimethylformamide are mixed uniformly 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 the spinning needle tube, a metal roller with tin foil attached is used as a receiving device, and electrospinning is carried out in an electrospinning machine, the ambient temperature is set to 30°C, the relative humidity is 50%, the spinning voltage is 19 kV, the receiving distance is 20 cm, the propulsion rate is 0.075 mL / h, and 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 evenly at a mass ratio of 1:2000 to prepare a copper nitrate aqueous solution. The copper nitrate aqueous solution was filtered using the embodiment and the comparative example respectively, and each group was filtered 3 times. 0.5 mL of the filtered copper nitrate aqueous solution was taken with a pipette, and then diluted to 5 mL with a 2% nitric acid aqueous solution. The remaining copper ion concentration in the copper nitrate aqueous solution was measured by atomic absorption spectrometry, and the heavy metal adsorption rate was calculated; heavy metal adsorption rate = (copper ion original concentration - copper ion residual concentration) / copper ion original concentration × 100%. The results are shown in Table 1.

[0063] Table 1

[0064]

[0065]

[0066] 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.

[0067] 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 heavy metal ions in water treatment filter materials.

[0068] By comparison, the heavy metal adsorption rates of Examples 1 to 3 are greater than that of Comparative Example 5, indicating that 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 carboxyl groups are introduced into the modified polyamide; the carboxyl groups introduced into the side chains 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.

[0069] 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 spinning solution, and the polyamide membrane is obtained by electrospinning; the acrylic acid is reacted with the liquid on the polyamide membrane to obtain the 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, and a large number of carboxyl groups are introduced into the membrane material, and 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.

[0070] Test Example 2

[0071] Dye removal performance test

[0072] Test method: 15g of the embodiment and the comparative example were immersed in a 10% copper nitrate aqueous solution, ultrasonically vibrated for 10 minutes, taken out, and dried at 50°C for 10 hours under vacuum conditions to obtain a test sample; methylene blue and deionized water were mixed to prepare a methylene blue solution with a concentration of 10 mg / L; the test sample was added to a test tube containing 50 ml of the methylene blue solution to prepare a test sample; a photochemical reactor was used to adsorb for 3 hours under dark conditions, and then a 500W xenon light source was turned on for photocatalytic degradation. After 3 hours, 2 ml of the solution was extracted from the test tube for centrifugation, and the absorbance of the solution was measured to obtain the methylene blue concentration at this time, and the removal rate of methylene blue was calculated. The results are shown in Table 2.

[0073] Table 2

[0074]

[0075] 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.

[0076] 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 mesoporous titanium dioxide is modified to improve the compatibility of mesoporous titanium dioxide with polyamide, so that the mesoporous titanium dioxide is evenly dispersed in the membrane material to avoid agglomeration, so as to give full play to the performance of mesoporous titanium dioxide in catalytically degrading dyes, and improve the ability of water treatment filter materials to remove dyes from sewage.

[0077] By comparison, the methylene blue removal rates of Examples 1 to 3 are greater than that of Comparative Example 5, indicating that 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 carboxyl groups are introduced into the modified polyamide; the carboxyl groups introduced into the side chains of the modified polyamide can adsorb cationic dyes, thereby improving the ability of the water treatment filter material to remove dyes in sewage.

[0078] 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 spinning solution, and the polyamide membrane is obtained by electrospinning; the acrylic acid is reacted with the liquid on the polyamide membrane to obtain the 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, and a large number of carboxyl groups are introduced into the membrane material, and the carboxyl groups can adsorb cationic dyes, thereby improving the water treatment filter material's ability to remove dyes in sewage.

[0079] Test Example 3

[0080] Antimicrobial performance testing

[0081] Test method: The examples and comparative examples were cut into 10 mm × 10 mm samples and sterilized by ultraviolet irradiation for 5 h; the Escherichia coli strains were activated and prepared to a concentration of 3 × 10 4 cfu / ml bacterial suspension; put the sample into the bacterial suspension, shake at 300r / min for 5min at room temperature, take 1ml of the bacterial suspension and dilute it to 100 times, take 1ml of the diluted bacterial suspension and inoculate it into agar medium, culture it at 37℃ for 16h, count the colonies according to the method in GB / T15979, and calculate the antibacterial rate, antibacterial 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.

[0082] Table 3

[0083] Antibacterial rate (%) Antibacterial rate (%) Example 1 99.97 Comparative Example 1 71.33 Example 2 99.98 Comparative Example 2 99.93 Example 3 99.96 Comparative Example 3 99.89 Comparative Example 4 99.92 Comparative Example 5 99.91 Comparative Example 6 99.87

[0084] 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.

[0085] 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 iodomethane to convert the secondary amines, tertiary amines, and residual primary amines on the chitosan into quaternary ammonium salts, which are cationic antibacterial agents. The quaternary ammonium salt structure generated on the functionalized chitosan microspheres can improve the antibacterial properties of water treatment filtration materials.

[0086] Test Example 4

[0087] Durability test

[0088] Test method: According to GB / T13022, the examples and comparative examples were cut into standard specimens of 20 mm×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.

[0089] Table 4

[0090]

[0091]

[0092] 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.

[0093] 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 by 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, so that the membrane material is 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 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 allow the modified mesoporous titanium dioxide to participate in the copolymerization of acrylic acid during the polyamide membrane liquid reaction, 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.

[0095] By comparison, the tensile strength of Examples 1 to 3 is greater than that of Comparative Example 5, indicating that 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 are introduced into the modified polyamide; the introduction of carbon-carbon double bonds allows 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 less easily destroyed by external forces, thereby improving the durability of the water treatment filter material.

[0096] 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 the polyamide membrane is obtained by electrospinning; the acrylic acid is reacted with the liquid on the polyamide membrane to obtain the 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.

[0097] 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 and methyl iodide to obtain functionalized chitosan microspheres; reacting pre-modified polyamide and maleic anhydride to obtain modified polyamide; preparing the modified polyamide, functionalized chitosan microspheres and modified mesoporous titanium dioxide into spinning solution, and electrospinning to obtain a polyamide membrane; and reacting acrylic acid with 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 using an emulsion curing method with 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 copolymers 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°C and 100-200 r / min for 25-35 min, chitosan solution (0.4-0.6 times the mass of liquid paraffin) was added dropwise at a uniform rate within 5 min, stirring was continued for 20-30 min, 1,4-dichloro-2-butene (0.21-0.23 times the mass of liquid paraffin) was added, the temperature was raised to 40-42°C, stirring was continued for 1-1.2 h, pH was adjusted to 9-10 with 0.1 mol / L sodium hydroxide aqueous solution, stirring was continued for 2-2.4 h, and 1.5 volume of liquid paraffin was added. 3 to 1.5 times of acetone, ultrasonic for 4 to 6 minutes, and dried at 50 to 60°C for 7 to 8 hours under vacuum conditions to obtain chitosan microspheres; chitosan microspheres, sodium hydroxide aqueous solution with a mass fraction of 14% to 16%, sodium iodide, methyl iodide, and 1-methyl-2-pyrrolidone are mixed uniformly in a mass ratio of 1:(5 to 6):(2.2 to 2.4):(5 to 6):(28 to 30), stirred at 60 to 62°C and 100 to 200 r / min for 2 to 3 hours, filtered, washed with anhydrous ethanol for 3 to 5 times, and dried at 50 to 60°C for 9 to 10 hours under vacuum conditions 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% aqueous hydrochloric acid solution having a mass fraction of 46-50 times the mass of aniline, stir at 100-200 r / min for 8-10 min, add mesoporous titanium dioxide having a mass fraction of 1.4-1.6 times the mass of aniline, continue stirring for 6-8 min, uniformly add an initiator solution having a mass fraction of 1-1.2 times the mass of aniline dropwise within 10 min, continue stirring for 3-4 h, filter, wash with anhydrous ethanol and deionized water for 3-5 times each, and dry at 50-60°C under vacuum conditions for 10-12 h to obtain modified mesoporous titanium dioxide; (3) Pre-modified polyamide, maleic anhydride, benzoquinone, 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 80-100 r / min for 6-7 h, and dried at 50-60° C. for 10-12 h under vacuum conditions to obtain modified polyamide; (4) The modified polyamide, functionalized chitosan microspheres, modified mesoporous titanium dioxide, and N,N-dimethylformamide are 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 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, and dried at 58-62°C for 7-9 h under vacuum conditions to obtain a polyamide membrane; the polyamide membrane is 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 for 10-12 h under vacuum conditions to obtain a water treatment filter material.

3. The method for preparing a water treatment filter material according to claim 2, characterized in that: 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 to 30) to prepare a chitosan solution.

4. The method for preparing a water treatment filter material according to claim 3, characterized in that: 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, characterized in that: 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 to 30) to prepare an initiator solution.

6. The method for preparing a water treatment filter material according to claim 2, characterized in that: 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, characterized in that: 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); under nitrogen protection, the mixture is stirred at 70-80°C and 80-100 r / min for 1-1.2 h; and under vacuum conditions, the mixture is dried at 50-60°C for 8-10 h to obtain the pre-modified polyamide.

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

9. The method for preparing a water treatment filter material according to claim 2, characterized in that: 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.

10. The method for preparing a water treatment filter material according to claim 2, characterized in that: The process parameters of the electrospinning in step (4) are: 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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