Composite three-dimensional adsorption material for treating dye wastewater and preparation method of composite three-dimensional adsorption material

Abstract

The invention provides a composite three-dimensional adsorption material for treating dye wastewater and a preparation method of the composite three-dimensional adsorption material, the composite three-dimensional adsorption material is of a three-dimensional grid structure, three-dimensional porous chitosan / graphene oxide aerogel is used as a framework, and a sheet-shaped modified electrostatic spinning cellulose acetate fiber membrane containing Fe3O4 ZIF-8 is loaded on the framework. The invention provides a composite three-dimensional adsorption material for treating dye wastewater, which adopts a physical adsorption method and utilizes the characteristics of high specific surface area, abundant porous structure and magnetic recoverability of the composite three-dimensional adsorption material to realize efficient adsorption of dyes in the wastewater.

Description

Technical Field

[0001] This invention relates to the field of dye adsorption, and more specifically to a composite three-dimensional adsorption material for treating dye wastewater. Background Technology

[0002] In recent years, with the rapid development of the domestic dyeing and printing industry, a large amount of untreated dyeing and printing wastewater has been directly discharged into the aquatic environment. The presence of dye molecules increases the color of the water, reduces light transmittance, decreases dissolved oxygen, interferes with the photosynthesis of aquatic plants, and ultimately damages the aquatic ecosystem. Furthermore, many dyes are biotoxic and easily accumulate in organisms, posing a significant threat to human health. Therefore, removing dyes from water has become a critical issue. However, most dyes have stable molecular structures and are difficult to biodegrade. Currently, extraction, electrolysis, biochemical methods, and adsorption methods are commonly used to treat dyeing and printing wastewater. Among these, adsorption has become a popular method for treating dye wastewater due to its simple operation and high adsorption efficiency. Commonly used adsorbents include activated carbon, resins, porous materials, zeolites, and biopolymers. Aerogels, due to their high specific surface area and ultra-high pore volume fraction, are often used as adsorbents for wastewater treatment. Graphene oxide aerogel, as a novel porous carbon material, has become a popular material in the field of dye adsorption due to its advantages such as large specific surface area, high porosity, and tunable structure. Chitosan contains abundant amino and hydroxyl groups, which provide additional adsorption sites, thereby enhancing the aerogel's adsorption capacity for various pollutants. Furthermore, ZIF-8 is a porous material formed by coordination bonds between metal ions or atomic clusters and organic ligands. Due to its large specific surface area, regular pore structure, and abundant functional groups, it can effectively treat dye wastewater.

[0003] Chinese patent CN201811032482 discloses a nanocellulose crosslinked graphene / chitosan aerogel and its preparation method. This method involves crosslinking dialdehyde nanocellulose, amino-modified graphene oxide, and chitosan to obtain a composite aerogel. The aerogel exhibits an adsorption efficiency of over 92% for Congo red dye; however, the aerogel obtained by this method has low porosity and cannot be recycled and reused, making it difficult to meet practical application requirements.

[0004] Chinese patent CN202410048322 discloses a method for preparing magnetic ZIF-8@graphene aerogel composite material. This method involves a hydrothermal reaction of a magnetic ZIF-8 particle suspension with a reducing agent to obtain a magnetic graphene hydrogel. This hydrogel is then successively immersed in inorganic zinc salt and 2-methylimidazole solutions, washed, and freeze-dried to obtain the magnetic ZIF-8@graphene aerogel composite material. While the introduction of magnetic particles solves the problem of difficult recycling of aerogels during use to some extent, structural defects such as carbon atom vacancies are easily generated during the hydrothermal reaction of graphene with the reducing agent, ultimately affecting the actual performance of the aerogel. Summary of the Invention

[0005] Technical problem to be solved: The purpose of this invention is to provide a composite three-dimensional adsorption material for treating dye wastewater. It adopts a physical adsorption method and utilizes the high specific surface area, abundant porous structure, and magnetic recyclability of the composite aerogel to achieve efficient adsorption of dyes in dyeing and printing wastewater.

[0006] Technical solution: A composite three-dimensional adsorption material for treating dye wastewater, wherein the composite three-dimensional adsorption material is a three-dimensional mesh structure, with a three-dimensional porous chitosan aerogel as the skeleton, and sheet-like modified electrospun acetate fiber membrane containing Fe3O4@ZIF-8 and graphene oxide loaded on the skeleton.

[0007] Preferably, the preparation method of the composite three-dimensional adsorption material for treating dye wastewater includes the following steps: S1. Weigh a certain amount of GO, add it to water, and sonicate to obtain a GO suspension; S2. A certain amount of sheet-modified electrospun acetate fiber membrane is added to the GO suspension to obtain a mixed suspension; S3. A certain amount of chitosan is added to an acetic acid solution and stirred to obtain a homogeneous chitosan / acetic acid solution; S4. Add the chitosan / acetic acid solution to the mixed suspension and stir magnetically for 100-180 min to form a gel; S5. Pour the above gel solution into a mold, place it in a magnetic field in an ice bath environment for 30-300 min, and then remove the magnetic field to obtain a gel solution oriented along the direction of the cellulose acetate membrane. S6. The above gel solution is directionally freeze-dried to obtain a composite aerogel; S7. Place the composite aerogel in a sealed, dry container containing hexadecyltrimethoxysilane and react at 140-180℃ for 100-180 min to obtain a hydrophobic composite aerogel.

[0008] Preferably, the method for preparing the sheet-like modified electrospun acetate fiber membrane includes the following steps: S11. Add Fe3O4@ZIF-8 powder to a mixed solution of N,N-dimethylacetamide and acetone at a volume ratio of 1:2, and sonicate to obtain a homogeneous solution with a mass fraction of 0.5-5 wt%. S12. Dissolve cellulose acetate in the above homogeneous solution and stir to obtain electrospinning solution A with a mass fraction of 2-15 wt%; S13. Take an appropriate amount of hydrophilic SiO2 powder and disperse it in a mixed solution of N,N-dimethylacetamide and acetone with a volume ratio of 1:2, and sonicate to obtain a SiO2 NPs dispersion with a mass fraction of 1-8 wt%. S14. Dissolve cellulose acetate in the above dispersion to obtain an electrospinning solution B with a mass fraction of 2-8 wt%; S15. Electrospinning is performed using the aforementioned electrospinning solution A to obtain a nascent electrospinned membrane; S16. Using the nascent electrospun membrane as the base layer, electrospinning is performed using the aforementioned spinning solution B to obtain a modified acetate electrospun fiber membrane. S17. The modified acetate electrospun fiber membrane is pulverized to obtain sheet-like modified electrospun acetate fiber membrane.

[0009] Preferably, the preparation method of Fe3O4@ZIF-8 includes the following steps: S21. Prepare dimethylimidazole solution and zinc nitrate hexahydrate solution separately; S22. Mix the iron(III) oxide solution and the dimethylimidazole solution to obtain the total solution; S23. The total solution was slowly added dropwise to the zinc nitrate hexahydrate solution, and the mixture was reacted in an ultrasonic water bath at 25-45 ℃ for 10-40 min to obtain Fe3O4@ZIF-8 powder.

[0010] Preferably, the mass ratio of the sheet-like modified electrospun acetate fiber membrane to GO is 0.2-0.8; the mass ratio of GO to chitosan is 8-15; and the mass fraction of the acetic acid solution is 2-4 wt%.

[0011] Preferably, the magnetic field in S5 is a parallel magnetic field, and the magnets are two rectangular high-power neodymium magnets with a length of 80-120 mm, a width of 6-12 mm, a height of 10-16 mm, and a distance of 2-6 cm between the two magnets.

[0012] Preferably, the electrospinning temperature of the electrospinning solution A is 25±5℃, the spinning humidity is 50±5%, the spinning voltage is 8-12 kV, the spinning speed is 0.3-0.8 ml / h, and the receiving distance is 20 cm; the electrospinning temperature of the electrospinning solution B is 25±5℃, the spinning humidity is 50±5%, the spinning voltage is 8-12 kV, the spinning speed is 0.3-0.8 ml / h, and the receiving distance is 20 cm.

[0013] Preferably, the size of the sheet-like modified electrospun acetate fiber membrane in S13 is 1-2 cm. 2 .

[0014] Preferably, the mass ratio of dimethylimidazole to zinc nitrate hexahydrate is 1-15; the concentration of the iron oxide solution is 1-8 mg / ml, and the volume ratio of dimethylimidazole solution to iron oxide solution is 0.5-14; the volume ratio of the total solution to zinc nitrate hexahydrate solution is 1-2.

[0015] Beneficial effects: The composite three-dimensional adsorption material of the present invention has the following advantages: 1. The composite three-dimensional adsorption material in this invention is a three-dimensional grid structure, which uses a three-dimensional porous chitosan aerogel as a framework, on which sheet-like modified electrospun acetate cellulose membrane containing Fe3O4@ZIF-8 and graphene oxide are loaded. The introduction of Fe3O4@ZIF-8 particles enables the aerogel to be recycled under the action of an external magnetic field, thereby improving the recyclability of the composite aerogel; 2. The composite three-dimensional adsorption material in this invention is a three-dimensional grid structure, which uses a three-dimensional porous chitosan aerogel as a framework, on which sheet-like modified electrospun acetate fiber membrane containing Fe3O4@ZIF-8 and graphene oxide are loaded. Because chitosan has abundant active groups, introducing chitosan into traditional aerogels and combining it with graphene oxide can improve the tendency of graphene sheets to aggregate, thereby enhancing the dye adsorption performance of the composite aerogel. 3. This invention introduces sheet-like modified electrospun acetate fiber membranes into traditional aerogels. Due to the strong hydrogen bond interaction between the hydroxyl groups on the surface of the modified nanofiber membrane and the oxygen-containing groups on the graphene oxide sheets, the composite aerogel has excellent mechanical properties. Furthermore, the flexible graphene oxide sheets can tightly wrap the nanofibers, resulting in various sheet / nanofiber combinations. For example, multiple nanofibers can be adhered to the graphene oxide sheets, and longer nanofibers can also bridge multiple graphene oxide sheets, thereby constructing an interconnected porous network and improving the porosity of the composite aerogel. 4. This invention applies an external magnetic field to the gel solution to orient the Fe3O4@ZIF-8 nanofiber membrane, and controls the subsequent freeze-drying direction to be perpendicular to the applied magnetic field direction to construct a grid-like mesh, thereby enhancing the stability of the composite aerogel and meeting practical application requirements. Detailed Implementation

[0016] The present invention will be further described below with reference to embodiments. These embodiments are illustrative of the present invention, but the present invention is not limited to these embodiments: Example 1

[0017] A composite three-dimensional adsorption material for treating dye wastewater, wherein the composite three-dimensional adsorption material is a three-dimensional grid structure, which uses a three-dimensional porous chitosan / graphene oxide aerogel as a skeleton, and loads a sheet-like modified electrospun acetate fiber membrane containing Fe3O4@ZIF-8 on the skeleton.

[0018] The preparation method of the composite three-dimensional adsorption material includes the following steps: S1. Weigh 100 mg of GO, add it to water, and sonicate to obtain a GO suspension; S2. Add 20 mg of sheet-modified electrospun acetate cellulose membrane to the GO suspension to obtain a mixed suspension; S3. Add 2.5 mg of chitosan to a 2 wt% acetic acid solution and stir to obtain a homogeneous chitosan / acetic acid solution; S4. Add the chitosan / acetic acid solution to the mixed suspension and stir magnetically for 100 min to form a gel; S5. Pour the above gel solution into a mold and place it in an ice bath environment in a magnetic field consisting of two rectangular neodymium magnets with a length of 80 mm, a width of 6 mm, and a height of 10 mm, spaced 2 cm apart, for 30 min. Then remove the magnetic field to obtain a gel solution oriented along the direction of the cellulose acetate membrane. S6. The above gel solution was directionally freeze-dried at -60 ℃ for 20 h to obtain the composite aerogel. S7. Place the composite aerogel in a sealed dry container containing hexadecyltrimethoxysilane and react at 140 °C for 100 min to obtain a hydrophobic composite aerogel. The method for preparing the sheet-like modified electrospun acetate fiber membrane includes the following steps: S11. Fe3O4@ZIF-8 powder was added to a mixed solution of N,N-dimethylacetamide and acetone in a volume ratio of 1:2, and ultrasonicated to obtain a homogeneous solution with a mass fraction of 0.5 wt%. S12. Dissolve cellulose acetate in the above homogeneous solution and stir to obtain an electrospinning solution A with a mass fraction of 2 wt%. S13. Take an appropriate amount of hydrophilic SiO2 powder and disperse it in a mixed solution of N,N-dimethylacetamide and acetone with a volume ratio of 1:2, and sonicate to obtain a SiO2 NPs dispersion with a mass fraction of 1 wt%. S14. Dissolve cellulose acetate in the above dispersion to obtain electrospinning solution B with a mass fraction of 2 wt%; S15. Electrospinning was performed using the aforementioned electrospinning solution A at a spinning temperature of 20 ℃, a spinning humidity of 45%, a spinning voltage of 8 kV, a spinning speed of 0.3 ml / h, and a receiving distance of 20 cm to obtain a nascent electrospinned membrane. S16. Using the nascent electrospun membrane as the base layer, electrospinning was performed using the aforementioned spinning solution B. The spinning temperature was 25 ℃, the spinning humidity was 50%, the spinning voltage was 8 kV, the spinning speed was 0.3 ml / h, and the receiving distance was 20 cm to obtain a modified electrospun cellulose acetate membrane. S17. The modified acetate electrospun fiber membrane was pulverized to obtain a membrane with an area of ​​1 cm². 2 Sheet-shaped modified electrospun acetate fiber membrane; The preparation method of Fe3O4@ZIF-8 includes the following steps: S21. Prepare solutions by dissolving dimethylimidazolium and zinc nitrate hexahydrate in equal volumes of water at a mass ratio of 1:1. S22. Mix 70 ml of dimethylimidazole solution with 80 ml of ferric oxide solution with a concentration of 1 mg / ml to obtain the total solution; S23. Slowly add 150 ml of the total solution dropwise to 150 ml of zinc nitrate hexahydrate solution, and react in an ultrasonic water bath at 25 ℃ for 10 min to obtain Fe3O4@ZIF-8 powder.

[0019] Example 2 A composite three-dimensional adsorption material for treating dye wastewater, wherein the composite three-dimensional adsorption material is a three-dimensional grid structure, which uses a three-dimensional porous chitosan / graphene oxide aerogel as a skeleton, and loads a sheet-like modified electrospun acetate fiber membrane containing Fe3O4@ZIF-8 on the skeleton. The preparation method of the composite three-dimensional adsorption material includes the following steps: S1. Weigh 100 mg of GO, add it to water, and sonicate to obtain a GO suspension; S2. Add 80 mg of sheet-modified electrospun acetate cellulose membrane to the GO suspension to obtain a mixed suspension; S3. Add 5.33 mg of chitosan to a 4 wt% acetic acid solution and stir to obtain a homogeneous chitosan / acetic acid solution; S4. Add the chitosan / acetic acid solution to the mixed suspension and stir magnetically for 180 min to form a gel; S5. Pour the above gel solution into a mold, place it in a magnetic field in an ice bath environment for 300 min, and then remove the magnetic field to obtain a gel solution oriented along the direction of the cellulose acetate membrane. S6. The above gel solution was directionally freeze-dried at -20 ℃ for 40 h to obtain a composite aerogel; S7. Place the composite aerogel in a sealed dry container containing hexadecyltrimethoxysilane and react at 180 °C for 180 min to obtain a hydrophobic composite aerogel. The method for preparing the sheet-like modified electrospun acetate fiber membrane includes the following steps: S11. Fe3O4@ZIF-8 powder was added to a mixed solution of N,N-dimethylacetamide and acetone in a volume ratio of 1:2, and ultrasonicated to obtain a homogeneous solution with a mass fraction of 5 wt%. S12. Dissolve cellulose acetate in the above homogeneous solution and stir to obtain electrospinning solution A with a mass fraction of 15 wt%; S13. Take an appropriate amount of hydrophilic SiO2 powder and disperse it in a mixed solution of N,N-dimethylacetamide and acetone with a volume ratio of 1:2, and sonicate to obtain a SiO2 NPs dispersion with a mass fraction of 8 wt%. S14. Dissolve cellulose acetate in the above dispersion to obtain an electrospinning solution B with a mass fraction of 8 wt%; S15. Electrospinning was performed using the aforementioned electrospinning solution A at a spinning temperature of 30 ℃, a spinning humidity of 55%, a spinning voltage of 12 kV, a spinning speed of 0.8 ml / h, and a receiving distance of 20 cm to obtain a nascent electrospinned membrane. S16. Using the nascent electrospun membrane as the base layer, electrospinning is performed using the aforementioned spinning solution B to obtain a modified electrospun cellulose acetate membrane. S17. The modified acetate electrospun fiber membrane was pulverized to obtain a 2 cm³ piece. 2 Sheet-shaped modified electrospun acetate fiber membrane; The preparation method of Fe3O4@ZIF-8 includes the following steps: S21. Prepare solutions by dissolving dimethylimidazolium and zinc nitrate hexahydrate in equal volumes of water at a mass ratio of 15:1. S22. Mix 140 ml of dimethylimidazole solution with 10 ml of ferric oxide solution with a concentration of 8 mg / ml to obtain the total solution; S23. Add 150 ml of the total solution dropwise slowly to 75 ml of zinc nitrate hexahydrate solution, and react in an ultrasonic water bath at 45 ℃ for 40 min to obtain Fe3O4@ZIF-8 powder.

[0020] Example 3 A composite three-dimensional adsorption material for treating dye wastewater, wherein the composite three-dimensional adsorption material is a three-dimensional grid structure, which uses a three-dimensional porous chitosan / graphene oxide aerogel as a skeleton, and loads a sheet-like modified electrospun acetate fiber membrane containing Fe3O4@ZIF-8 on the skeleton. The preparation method of the composite three-dimensional adsorption material includes the following steps: S1. Weigh 100 mg of GO, add it to water, and sonicate to obtain a GO suspension; S2. Add 30 mg of sheet-modified electrospun acetate cellulose membrane to the GO suspension to obtain a mixed suspension; S3. Add 3 mg of chitosan to a 3 wt% acetic acid solution and stir to obtain a homogeneous chitosan / acetic acid solution; S4 Add the chitosan / acetic acid solution to the mixed suspension and stir magnetically for 120 min to form a gel; S5. Pour the above gel solution into a mold and place it in an ice bath environment in a magnetic field consisting of two rectangular neodymium magnets with a length of 90 mm, a width of 8 mm, and a height of 10 mm, which are 3 cm apart, for 50 min. Then remove the magnetic field to obtain a gel solution that is oriented along the direction of the cellulose acetate membrane. S6. The above gel solution was directionally freeze-dried at -50 ℃ for 25 h to obtain a composite aerogel. S7. Place the composite aerogel in a sealed dry container containing hexadecyltrimethoxysilane and react at 150 °C for 110 min to obtain a hydrophobic composite aerogel. The method for preparing the sheet-like modified electrospun acetate fiber membrane includes the following steps: S11. Fe3O4@ZIF-8 powder was added to a mixed solution of N,N-dimethylacetamide and acetone in a volume ratio of 1:2, and ultrasonicated to obtain a homogeneous solution with a mass fraction of 2 wt%. S12. Dissolve cellulose acetate in the above homogeneous solution and stir to obtain an electrospinning solution A with a mass fraction of 2 wt%. S13. Take an appropriate amount of hydrophilic SiO2 powder and disperse it in a mixed solution of N,N-dimethylacetamide and acetone with a volume ratio of 1:2, and sonicate to obtain a SiO2 NPs dispersion with a mass fraction of 1 wt%. S14. Dissolve cellulose acetate in the above dispersion to obtain electrospinning solution B with a mass fraction of 2 wt%; S15. Electrospinning was performed using the aforementioned electrospinning solution A at a spinning temperature of 28 ℃, a spinning humidity of 50%, a spinning voltage of 8 kV, a spinning speed of 0.3 ml / h, and a receiving distance of 20 cm to obtain a nascent electrospinned membrane. S16. Using the nascent electrospun membrane as the base layer, electrospinning was performed using the aforementioned spinning solution B. The spinning temperature was 25 ℃, the spinning humidity was 50%, the spinning voltage was 9 kV, the spinning speed was 0.4 ml / h, and the receiving distance was 20 cm to obtain a modified electrospun cellulose acetate membrane. S17. The modified acetate electrospun fiber membrane was pulverized to obtain a membrane with an area of ​​1 cm². 2 Sheet-shaped modified electrospun acetate fiber membrane; The preparation method of Fe3O4@ZIF-8 includes the following steps: S21. Prepare solutions by dissolving dimethylimidazolium and zinc nitrate hexahydrate in equal volumes of water at a mass ratio of 3:1. S22. Mix 70 ml of dimethylimidazole solution with 80 ml of ferric oxide solution with a concentration of 2 mg / ml to obtain the total solution; S23. The total solution was slowly added dropwise to the zinc nitrate hexahydrate solution, and the mixture was reacted in an ultrasonic water bath at 30 °C for 20 min to obtain Fe3O4@ZIF-8 powder.

[0021] Example 4 A composite three-dimensional adsorption material for treating dye wastewater, wherein the composite three-dimensional adsorption material is a three-dimensional grid structure, which uses a three-dimensional porous chitosan / graphene oxide aerogel as a skeleton, and loads a sheet-like modified electrospun acetate fiber membrane containing Fe3O4@ZIF-8 on the skeleton. The preparation method of the composite three-dimensional adsorption material includes the following steps: S1. Weigh 80 mg of GO, add it to water, and sonicate to obtain a GO suspension; S2. Add 40 mg of sheet-modified electrospun acetate cellulose membrane to the GO suspension to obtain a mixed suspension; S3. Add 3.3 mg of chitosan to a 3 wt% acetic acid solution and stir to obtain a homogeneous chitosan / acetic acid solution; S3. Add the chitosan / acetic acid solution to the mixed suspension and stir magnetically for 120 min to form a gel; S4. Pour the above gel solution into a mold and place it in an ice bath environment in a magnetic field consisting of two rectangular neodymium magnets with a length of 90 mm, a width of 8 mm, and a height of 10 mm, which are 3 cm apart, for 50 min. Then remove the magnetic field to obtain a gel solution that is oriented along the direction of the cellulose acetate membrane. S5. The above gel solution was directionally freeze-dried at -50 ℃ for 25 h to obtain a composite aerogel. S6. Place the composite aerogel in a sealed dry container containing hexadecyltrimethoxysilane and react at 150 °C for 110 min to obtain a hydrophobic composite aerogel. The method for preparing the sheet-like modified electrospun acetate fiber membrane includes the following steps: S11. Fe3O4@ZIF-8 powder was added to a mixed solution of N,N-dimethylacetamide and acetone in a volume ratio of 1:2, and ultrasonicated to obtain a homogeneous solution with a mass fraction of 2 wt%. S12. Dissolve cellulose acetate in the above homogeneous solution and stir to obtain an electrospinning solution A with a mass fraction of 2 wt%. S13. Take an appropriate amount of hydrophilic SiO2 powder and disperse it in a mixed solution of N,N-dimethylacetamide and acetone with a volume ratio of 1:2, and sonicate to obtain a SiO2 NPs dispersion with a mass fraction of 3 wt%. S14. Dissolve cellulose acetate in the above dispersion to obtain electrospinning solution B with a mass fraction of 2 wt%; S15. Electrospinning was performed using the aforementioned electrospinning solution A at a spinning temperature of 28 ℃, a spinning humidity of 55%, a spinning voltage of 8 kV, a spinning speed of 0.3 ml / h, and a receiving distance of 20 cm to obtain a nascent electrospinned membrane. S16. Using the nascent electrospun membrane as the base layer, electrospinning was performed using the aforementioned spinning solution B. The spinning temperature was 25 ℃, the spinning humidity was 50%, the spinning voltage was 12 kV, the spinning speed was 0.4 ml / h, and the receiving distance was 20 cm to obtain a modified electrospun cellulose acetate membrane. S17. The modified acetate electrospun fiber membrane was pulverized to obtain a membrane with an area of ​​1 cm². 2 Sheet-shaped modified electrospun acetate fiber membrane; The preparation method of Fe3O4@ZIF-8 includes the following steps: S21. Prepare solutions by dissolving dimethylimidazolium and zinc nitrate hexahydrate in equal volumes of water at a mass ratio of 5:1. S22. Mix 130 ml of dimethylimidazole solution with 20 ml of ferric oxide solution with a concentration of 4 mg / ml to obtain the total solution; S23. The total solution was slowly added dropwise to the zinc nitrate hexahydrate solution, and the mixture was reacted in an ultrasonic water bath at 30 °C for 30 min to obtain Fe3O4@ZIF-8 powder.

[0022] Example 5 A composite three-dimensional adsorption material for treating dye wastewater, wherein the composite three-dimensional adsorption material is a three-dimensional grid structure, which uses a three-dimensional porous chitosan / graphene oxide aerogel as a skeleton, and loads a sheet-like modified electrospun acetate fiber membrane containing Fe3O4@ZIF-8 on the skeleton. The preparation method of the composite three-dimensional adsorption material includes the following steps: S1. Weigh 100 mg of GO, add it to water, and sonicate to obtain a GO suspension; S2. Add 60 mg of sheet-modified electrospun acetate cellulose membrane to the GO suspension to obtain a mixed suspension; S3. Add 6 mg of chitosan to a 4 wt% acetic acid solution and stir to obtain a homogeneous chitosan / acetic acid solution; S4. Add the chitosan / acetic acid solution to the mixed suspension and stir magnetically for 110 min to form a gel; S5. Pour the above gel solution into a mold and place it in an ice bath environment in a magnetic field consisting of two rectangular neodymium magnets with a length of 100 mm, a width of 10 mm, and a height of 12 mm, which are 3 cm apart, for 60 min. Then remove the magnetic field to obtain a gel solution that is oriented along the direction of the cellulose acetate membrane. S6. The above gel solution was directionally freeze-dried at -40 ℃ for 30 h to obtain a composite aerogel. S7. Place the composite aerogel in a sealed dry container containing hexadecyltrimethoxysilane and react at 160 °C for 100 min to obtain a hydrophobic composite aerogel.

[0023] The method for preparing the sheet-like modified electrospun acetate fiber membrane includes the following steps: S11. Fe3O4@ZIF-8 powder was added to a mixed solution of N,N-dimethylacetamide and acetone in a volume ratio of 1:2, and ultrasonicated to obtain a homogeneous solution with a mass fraction of 3 wt%. S12. Dissolve cellulose acetate in the above homogeneous solution and stir to obtain an electrospinning solution A with a mass fraction of 2 wt%. S13. Take an appropriate amount of hydrophilic SiO2 powder and disperse it in a mixed solution of N,N-dimethylacetamide and acetone with a volume ratio of 1:2, and sonicate to obtain a SiO2 NPs dispersion with a mass fraction of 4 wt%. S14. Dissolve cellulose acetate in the above dispersion to obtain electrospinning solution B with a mass fraction of 4 wt%; S15. Electrospinning was performed using the aforementioned electrospinning solution A at a spinning temperature of 28 ℃, a spinning humidity of 50%, a spinning voltage of 10 kV, a spinning speed of 0.6 ml / h, and a receiving distance of 20 cm to obtain a nascent electrospinned membrane. S16. Using the nascent electrospun membrane as the base layer, electrospinning was performed using the aforementioned spinning solution B. The spinning temperature was 25 ℃, the spinning humidity was 50%, the spinning voltage was 11 kV, the spinning speed was 0.5 ml / h, and the receiving distance was 20 cm to obtain a modified electrospun cellulose acetate membrane. S17. The modified acetate electrospun fiber membrane was pulverized to obtain a membrane with an area of ​​2 cm². 2 Sheet-shaped modified electrospun acetate fiber membrane; The preparation method of Fe3O4@ZIF-8 includes the following steps: S21. Prepare solutions by dissolving dimethylimidazolium and zinc nitrate hexahydrate in equal volumes of water at a mass ratio of 6:1. S22. Mix 110 ml of dimethylimidazole solution with 40 ml of ferric oxide solution with a concentration of 2 mg / ml to obtain the total solution; S23. The total solution was slowly added dropwise to the zinc nitrate hexahydrate solution, and the mixture was reacted in an ultrasonic water bath at 20 °C for 20 min to obtain Fe3O4@ZIF-8 powder.

[0024] Example 6 A composite three-dimensional adsorption material for treating dye wastewater, wherein the composite three-dimensional adsorption material is a three-dimensional grid structure, which uses a three-dimensional porous chitosan / graphene oxide aerogel as a skeleton, and loads a sheet-like modified electrospun acetate fiber membrane containing Fe3O4@ZIF-8 on the skeleton. The preparation method of the composite three-dimensional adsorption material includes the following steps: S1. Weigh 100 mg of GO, add it to water, and sonicate to obtain a GO suspension; S2. Add 50 mg of sheet-modified electrospun acetate cellulose membrane to the GO suspension to obtain a mixed suspension; S3. Add 4.58 mg of chitosan to a 3 wt% acetic acid solution and stir to obtain a homogeneous chitosan / acetic acid solution; S4. Add the chitosan / acetic acid solution to the mixed suspension and stir magnetically for 110 min to form a gel; S5. Pour the above gel solution into a mold and place it in an ice bath environment in a magnetic field consisting of two rectangular neodymium magnets with a length of 100 mm, a width of 10 mm, and a height of 12 mm, which are 3 cm apart, for 60 min. Then remove the magnetic field to obtain a gel solution that is oriented along the direction of the cellulose acetate membrane. S6. The above gel solution was directionally freeze-dried at -40 ℃ for 30 h to obtain a composite aerogel. S7. Place the composite aerogel in a sealed dry container containing hexadecyltrimethoxysilane and react at 160 °C for 100 min to obtain a hydrophobic composite aerogel. The method for preparing the sheet-like modified electrospun acetate fiber membrane includes the following steps: S11. Fe3O4@ZIF-8 powder was added to a mixed solution of N,N-dimethylacetamide and acetone in a volume ratio of 1:2, and ultrasonicated to obtain a homogeneous solution with a mass fraction of 3 wt%. S12. Dissolve cellulose acetate in the above homogeneous solution and stir to obtain an electrospinning solution A with a mass fraction of 2 wt%. S13. Take an appropriate amount of hydrophilic SiO2 powder and disperse it in a mixed solution of N,N-dimethylacetamide and acetone with a volume ratio of 1:2, and sonicate to obtain a SiO2 NPs dispersion with a mass fraction of 4 wt%. S14. Dissolve cellulose acetate in the above dispersion to obtain electrospinning solution B with a mass fraction of 4 wt%; S15. Electrospinning was performed using the aforementioned electrospinning solution A at a spinning temperature of 28 ℃, a spinning humidity of 50%, a spinning voltage of 10 kV, a spinning speed of 0.6 ml / h, and a receiving distance of 20 cm to obtain a nascent electrospinned membrane. S16. Using the nascent electrospun membrane as the base layer, electrospinning was performed using the aforementioned spinning solution B. The spinning temperature was 25 ℃, the spinning humidity was 50%, the spinning voltage was 12 kV, the spinning speed was 0.3 ml / h, and the receiving distance was 20 cm to obtain a modified electrospun cellulose acetate membrane. S17. The modified acetate electrospun fiber membrane was pulverized to obtain a membrane with an area of ​​2 cm². 2 Sheet-shaped modified electrospun acetate fiber membrane; The preparation method of Fe3O4@ZIF-8 includes the following steps: S21. Prepare solutions by dissolving dimethylimidazolium and zinc nitrate hexahydrate in equal volumes of water at a mass ratio of 6:1. S22. Mix 110 ml of dimethylimidazole solution with 40 ml of ferric oxide solution with a concentration of 2 mg / ml to obtain the total solution; S23. The total solution was slowly added dropwise to the zinc nitrate hexahydrate solution, and the mixture was reacted in an ultrasonic water bath at 20 °C for 20 min to obtain Fe3O4@ZIF-8 powder.

[0025] Comparative Example 1 The difference between Comparative Example 1 and Example 6 is that no external magnetic field was applied to the gel solution, and it was directly freeze-dried.

[0026] A composite three-dimensional adsorption material for treating dye wastewater, wherein the composite three-dimensional adsorption material is a three-dimensional grid structure, which uses a three-dimensional porous chitosan / graphene oxide aerogel as a skeleton, and loads a sheet-like modified electrospun acetate fiber membrane containing Fe3O4@ZIF-8 on the skeleton. The preparation method of the composite three-dimensional adsorption material includes the following steps: S1. Weigh 100 mg of GO, add it to water, and sonicate to obtain a GO suspension; S2. Add 50 mg of sheet-modified electrospun acetate cellulose membrane to the GO suspension to obtain a mixed suspension; S3. Add 4.58 mg of chitosan to a 3 wt% acetic acid solution and stir to obtain a homogeneous chitosan / acetic acid solution; S4. Add the chitosan / acetic acid solution to the mixed suspension and stir magnetically for 110 min to form a gel; S5. The above gel solution was directionally freeze-dried at -40 ℃ for 30 h to obtain a composite aerogel. S6. Place the composite aerogel in a sealed dry container containing hexadecyltrimethoxysilane and react at 160 °C for 100 min to obtain a hydrophobic composite aerogel. The method for preparing the sheet-like modified electrospun acetate fiber membrane includes the following steps: S11. Fe3O4@ZIF-8 powder was added to a mixed solution of N,N-dimethylacetamide and acetone in a volume ratio of 1:2, and ultrasonicated to obtain a homogeneous solution with a mass fraction of 3 wt%. S12. Dissolve cellulose acetate in the above homogeneous solution and stir to obtain an electrospinning solution A with a mass fraction of 2 wt%. S13. Take an appropriate amount of hydrophilic SiO2 powder and disperse it in a mixed solution of N,N-dimethylacetamide and acetone with a volume ratio of 1:2, and sonicate to obtain a SiO2 NPs dispersion with a mass fraction of 4 wt%. S14. Dissolve cellulose acetate in the above dispersion to obtain electrospinning solution B with a mass fraction of 4 wt%; S15. Electrospinning was performed using the aforementioned electrospinning solution A at a spinning temperature of 28 ℃, a spinning humidity of 50%, a spinning voltage of 10 kV, a spinning speed of 0.6 ml / h, and a receiving distance of 20 cm to obtain a nascent electrospinned membrane. S16. Using the nascent electrospun membrane as the base layer, electrospinning was performed using the aforementioned spinning solution B. The spinning temperature was 25 ℃, the spinning humidity was 50%, the spinning voltage was 12 kV, the spinning speed was 0.3 ml / h, and the receiving distance was 20 cm to obtain a modified electrospun cellulose acetate membrane. S17. The modified acetate electrospun fiber membrane was pulverized to obtain a membrane with an area of ​​2 cm². 2 Sheet-shaped modified electrospun acetate fiber membrane; The preparation method of Fe3O4@ZIF-8 includes the following steps: S21. Prepare solutions by dissolving dimethylimidazolium and zinc nitrate hexahydrate in equal volumes of water at a mass ratio of 6:1. S22. Mix 110 ml of dimethylimidazole solution with 40 ml of ferric oxide solution with a concentration of 2 mg / ml to obtain the total solution; S23. The total solution was slowly added dropwise to the zinc nitrate hexahydrate solution, and the mixture was reacted in an ultrasonic water bath at 20 °C for 20 min to obtain Fe3O4@ZIF-8 powder.

[0027] Comparative Example 2 The difference between Comparative Example 2 and Example 6 is that porous chitosan was used as the aerogel framework, and graphene oxide was not added.

[0028] A composite three-dimensional adsorption material for treating dye wastewater, wherein the composite three-dimensional adsorption material is a three-dimensional grid structure, which uses three-dimensional porous chitosan aerogel as a skeleton, and loads a sheet-like modified electrospun acetate fiber membrane containing Fe3O4@ZIF-8 on the skeleton. The preparation method of the composite three-dimensional adsorption material includes the following steps: S1. Add 50 mg of sheet-like modified electrospun acetate fiber membrane to a 3 wt% acetic acid solution to obtain a suspension; S2. Add 4.58 mg of chitosan to the suspension and stir magnetically for 110 min to form a gel; S3. Pour the above gel solution into a mold and place it in an ice bath environment in a magnetic field consisting of two rectangular neodymium magnets with a length of 100 mm, a width of 10 mm, and a height of 12 mm, which are 3 cm apart, for 60 min. Then remove the magnetic field to obtain a gel solution that is oriented along the direction of the cellulose acetate membrane. S4. The above gel solution was directionally freeze-dried at -40 ℃ for 30 h to obtain the composite aerogel. S5. Place the composite aerogel in a sealed dry container containing hexadecyltrimethoxysilane and react at 160 °C for 100 min to obtain a hydrophobic composite aerogel. The method for preparing the sheet-like modified electrospun acetate fiber membrane includes the following steps: S11. Fe3O4@ZIF-8 powder was added to a mixed solution of N,N-dimethylacetamide and acetone in a volume ratio of 1:2, and ultrasonicated to obtain a homogeneous solution with a mass fraction of 3 wt%. S12. Dissolve cellulose acetate in the above homogeneous solution and stir to obtain an electrospinning solution A with a mass fraction of 2 wt%. S13. Take an appropriate amount of hydrophilic SiO2 powder and disperse it in a mixed solution of N,N-dimethylacetamide and acetone with a volume ratio of 1:2, and sonicate to obtain a SiO2 NPs dispersion with a mass fraction of 4 wt%. S14. Dissolve cellulose acetate in the above dispersion to obtain electrospinning solution B with a mass fraction of 4 wt%; S15. Electrospinning was performed using the aforementioned electrospinning solution A at a spinning temperature of 28 ℃, a spinning humidity of 50%, a spinning voltage of 10 kV, a spinning speed of 0.6 ml / h, and a receiving distance of 20 cm to obtain a nascent electrospinned membrane. S16. Using the nascent electrospun membrane as the base layer, electrospinning was performed using the aforementioned spinning solution B. The spinning temperature was 25 ℃, the spinning humidity was 50%, the spinning voltage was 12 kV, the spinning speed was 0.3 ml / h, and the receiving distance was 20 cm to obtain a modified electrospun cellulose acetate membrane. S17. The modified acetate electrospun fiber membrane was pulverized to obtain a membrane with an area of ​​2 cm². 2 Sheet-shaped modified electrospun acetate fiber membrane.

[0029] The preparation method of Fe3O4@ZIF-8 includes the following steps: S21. Prepare solutions by dissolving dimethylimidazolium and zinc nitrate hexahydrate in equal volumes of water at a mass ratio of 6:1. S22. Mix 110 ml of dimethylimidazole solution with 40 ml of ferric oxide solution with a concentration of 2 mg / ml to obtain the total solution; S23. The total solution was slowly added dropwise to the zinc nitrate hexahydrate solution, and the mixture was reacted in an ultrasonic water bath at 20 °C for 20 min to obtain Fe3O4@ZIF-8 powder.

[0030] Comparative Example 3 The difference between Comparative Example 3 and Example 6 is that Fe3O4@ZIF-8 particles were not added.

[0031] A composite three-dimensional adsorption material for treating dye wastewater, wherein the composite three-dimensional adsorption material is a three-dimensional grid structure, which uses three-dimensional porous chitosan / graphene oxide aerogel as a skeleton, and a sheet-like modified electrospun acetate fiber membrane is loaded on the skeleton. The preparation method of the composite three-dimensional adsorption material includes the following steps: S1. Weigh 100 mg of GO, add it to water, and sonicate to obtain a GO suspension; S2. Add 50 mg of sheet-modified electrospun acetate cellulose membrane to the GO suspension to obtain a mixed suspension; S3. Add 4.58 mg of chitosan to a 3 wt% acetic acid solution and stir to obtain a homogeneous chitosan / acetic acid solution; S4. Add the chitosan / acetic acid solution to the mixed suspension and stir magnetically for 110 min to form a gel; S5. The above gel solution was directionally freeze-dried at -40 ℃ for 30 h to obtain a composite aerogel. S6. Place the composite aerogel in a sealed, dry container containing hexadecyltrimethoxysilane and react at 160 °C for 100 min to obtain a hydrophobic composite aerogel.

[0032] The method for preparing the sheet-like modified electrospun acetate fiber membrane includes the following steps: S11. Dissolve cellulose acetate in the above homogeneous solution and stir to obtain an electrospinning solution A with a mass fraction of 2 wt%. S12. Take an appropriate amount of hydrophilic SiO2 powder and disperse it in a mixed solution of N,N-dimethylacetamide and acetone with a volume ratio of 1:2, and sonicate to obtain a SiO2 NPs dispersion with a mass fraction of 4 wt%. S13. Dissolve cellulose acetate in the above dispersion to obtain electrospinning solution B with a mass fraction of 4 wt%; S14. Electrospinning was performed using the aforementioned electrospinning solution A at a spinning temperature of 28 ℃, a spinning humidity of 50%, a spinning voltage of 10 kV, a spinning speed of 0.6 ml / h, and a receiving distance of 20 cm to obtain a nascent electrospinned membrane. S15. Using the nascent electrospun membrane as the base layer, electrospinning was performed using the aforementioned spinning solution B. The spinning temperature was 25 ℃, the spinning humidity was 50%, the spinning voltage was 12 kV, the spinning speed was 0.3 ml / h, and the receiving distance was 20 cm to obtain a modified electrospun cellulose acetate membrane. S16. The modified acetate electrospun fiber membrane was pulverized to obtain a membrane with an area of ​​2 cm². 2 Sheet-shaped modified electrospun acetate fiber membrane.

[0033] Comparative Example 4 The difference between Comparative Example 4 and Example 6 is that no sheet-like modified electrospun acetate fiber membrane containing Fe3O4@ZIF-8 was added.

[0034] A composite three-dimensional adsorption material for treating dye wastewater is characterized in that: the composite three-dimensional adsorption material is a three-dimensional grid structure, which uses three-dimensional porous chitosan / graphene oxide aerogel as a framework; The preparation method of the composite three-dimensional adsorption material includes the following steps: S1. Weigh 100 mg of GO, add it to water, and sonicate to obtain a GO suspension; S2. Add 4.58 mg of chitosan to a 3 wt% acetic acid solution and stir to obtain a homogeneous chitosan / acetic acid solution; S3. Add the chitosan / acetic acid solution to the mixed suspension and stir magnetically for 110 min to form a gel; S4. Pour the above gel solution into a mold and place it in an ice bath environment in a magnetic field consisting of two rectangular neodymium magnets with a length of 100 mm, a width of 10 mm, and a height of 12 mm, which are 3 cm apart, for 60 min. Then remove the magnetic field to obtain a gel solution that is oriented along the direction of the cellulose acetate membrane. S5. The above gel solution was directionally freeze-dried at -40 ℃ for 30 h to obtain a composite aerogel. S6. Place the composite aerogel in a sealed, dry container containing hexadecyltrimethoxysilane and react at 160 °C for 100 min to obtain a hydrophobic composite aerogel.

[0035] Comparative Example 5 The difference between Comparative Example 5 and Example 6 is that the electrospun acetate fiber membrane was not modified.

[0036] A composite three-dimensional adsorption material for treating dye wastewater, wherein the composite three-dimensional adsorption material is a three-dimensional grid structure, which uses a three-dimensional porous chitosan / graphene oxide aerogel as a skeleton, and loads a sheet-like electrospun acetate fiber membrane containing Fe3O4@ZIF-8 on the skeleton. S1. Weigh 100 mg of GO, add it to water, and sonicate to obtain a GO suspension; S2. Add 50 mg of sheet-like electrospun acetate cellulose membrane to the GO suspension to obtain a mixed suspension; S3. Add 4.58 mg of chitosan to a 3 wt% acetic acid solution and stir to obtain a homogeneous chitosan / acetic acid solution; S4. Add the chitosan / acetic acid solution to the mixed suspension and stir magnetically for 110 min to form a gel; S5. Pour the above gel solution into a mold and place it in an ice bath environment in a magnetic field consisting of two rectangular neodymium magnets with a length of 100 mm, a width of 10 mm, and a height of 12 mm, which are 3 cm apart, for 60 min. Then remove the magnetic field to obtain a gel solution that is oriented along the direction of the cellulose acetate membrane. S6. The above gel solution was directionally freeze-dried at -40 ℃ for 30 h to obtain a composite aerogel. S7. Place the composite aerogel in a sealed dry container containing hexadecyltrimethoxysilane and react at 160 °C for 100 min to obtain a hydrophobic composite aerogel. The method for preparing the sheet-like electrospun acetate fiber membrane includes the following steps: S11. Fe3O4@ZIF-8 powder was added to a mixed solution of N,N-dimethylacetamide and acetone in a volume ratio of 1:2, and ultrasonicated to obtain a homogeneous solution with a mass fraction of 3 wt%. S12. Dissolve cellulose acetate in the above homogeneous solution and stir to obtain an electrospinning solution with a mass fraction of 2 wt%. S13. Electrospinning was performed using the aforementioned electrospinning solution at a spinning temperature of 28 ℃, a spinning humidity of 50%, a spinning voltage of 10 kV, a spinning speed of 0.6 ml / h, and a receiving distance of 20 cm to obtain an electrospinned membrane. S15. The acetate electrospun fiber membrane was pulverized to obtain a membrane with an area of ​​2 cm². 2 Sheet-shaped electrospun acetate fiber membrane; The preparation method of Fe3O4@ZIF-8 includes the following steps: S21. Prepare solutions by dissolving dimethylimidazolium and zinc nitrate hexahydrate in equal volumes of water at a mass ratio of 6:1. S22. Mix 110 ml of dimethylimidazole solution with 40 ml of ferric oxide solution with a concentration of 2 mg / ml to obtain the total solution; S23. The total solution was slowly added dropwise to the zinc nitrate hexahydrate solution, and the mixture was reacted in an ultrasonic water bath at 20 °C for 20 min to obtain Fe3O4@ZIF-8 powder.

[0037] Comparative Example 6 The difference between Comparative Example 6 and Example 6 is that the composite aerogel was not modified to be hydrophobic.

[0038] A composite three-dimensional adsorption material for treating dye wastewater. The composite three-dimensional adsorption material is a three-dimensional grid structure, which uses three-dimensional porous chitosan / graphene oxide aerogel as a skeleton, and loads a sheet-like modified electrospun acetate fiber membrane containing Fe3O4@ZIF-8 on the skeleton. The preparation method of the composite three-dimensional adsorption material includes the following steps: S1. Weigh 100 mg of GO, add it to water, and sonicate to obtain a GO suspension; S2. Add 50 mg of sheet-modified electrospun acetate cellulose membrane to the GO suspension to obtain a mixed suspension; S3. Add 4.58 mg of chitosan to a 3 wt% acetic acid solution and stir to obtain a homogeneous chitosan / acetic acid solution; S4. Add the chitosan / acetic acid solution to the mixed suspension and stir magnetically for 110 min to form a gel; S5. Pour the above gel solution into a mold and place it in an ice bath environment in a magnetic field consisting of two rectangular neodymium magnets with a length of 100 mm, a width of 10 mm, and a height of 12 mm, which are 3 cm apart, for 60 min. Then remove the magnetic field to obtain a gel solution that is oriented along the direction of the cellulose acetate membrane. S6. The above gel solution was directionally freeze-dried at -40 ℃ for 30 h to obtain a composite aerogel. The method for preparing the sheet-like modified electrospun acetate fiber membrane includes the following steps: S11. Fe3O4@ZIF-8 powder was added to a mixed solution of N,N-dimethylacetamide and acetone in a volume ratio of 1:2, and ultrasonicated to obtain a homogeneous solution with a mass fraction of 3 wt%. S12. Dissolve cellulose acetate in the above homogeneous solution and stir to obtain an electrospinning solution A with a mass fraction of 2 wt%. S13. Take an appropriate amount of hydrophilic SiO2 powder and disperse it in a mixed solution of N,N-dimethylacetamide and acetone with a volume ratio of 1:2, and sonicate to obtain a SiO2 NPs dispersion with a mass fraction of 4 wt%. S14. Dissolve cellulose acetate in the above dispersion to obtain electrospinning solution B with a mass fraction of 4 wt%; S15. Electrospinning was performed using the aforementioned electrospinning solution A at a spinning temperature of 28 ℃, a spinning humidity of 50%, a spinning voltage of 10 kV, a spinning speed of 0.6 ml / h, and a receiving distance of 20 cm to obtain a nascent electrospinned membrane. S16. Using the nascent electrospun membrane as the base layer, electrospinning was performed using the aforementioned spinning solution B. The spinning temperature was 25 ℃, the spinning humidity was 50%, the spinning voltage was 12 kV, the spinning speed was 0.3 ml / h, and the receiving distance was 20 cm to obtain a modified electrospun cellulose acetate membrane. S17. The modified acetate electrospun fiber membrane was pulverized to obtain a membrane with an area of ​​2 cm². 2 Sheet-shaped modified electrospun acetate fiber membrane; The preparation method of Fe3O4@ZIF-8 includes the following steps: S21. Prepare solutions by dissolving dimethylimidazole and zinc nitrate hexahydrate in equal volumes of water at a mass ratio of 6:1. S22. Mix 110 ml of dimethylimidazole solution with 40 ml of ferric oxide solution with a concentration of 2 mg / ml to obtain the total solution; S23. The total solution was slowly added dropwise to the zinc nitrate hexahydrate solution, and the mixture was reacted in an ultrasonic water bath at 20 °C for 20 min to obtain Fe3O4@ZIF-8 powder.

[0039] Performance testing The performance of the materials obtained in the embodiments and comparative examples of the present invention was tested, and the results are shown in the table below.

[0040] Table 1. Adsorption capacity of composite three-dimensional adsorption materials for different dyes

[0041] Table 2. Reusability of Composite Three-Dimensional Adsorption Materials for Adsorption Capacity of Different Dyes

[0042] Note: The concentration of each dye solution in Table 1 above is 200 mg / L; The adsorption recovery rate of the composite aerogel in Table 2 above = ×100% Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A composite three-dimensional adsorption material for treating dye wastewater, characterized by: The composite three-dimensional adsorption material is a three-dimensional grid structure, which takes a three-dimensional porous chitosan / graphene oxide aerogel as a skeleton, and is loaded with Fe3O4@ZIF-8-containing sheet-shaped modified electrostatic spinning cellulose acetate film on the skeleton.

2. The preparation method of the composite three-dimensional adsorption material for treating dye wastewater according to claim 1, characterized in that, The method comprises the following steps: S1. A certain amount of GO is weighed and added into water to obtain a GO suspension by ultrasonic treatment; S2. A certain amount of sheet-shaped modified electrostatic spinning cellulose acetate film is added into the GO suspension to obtain a mixed suspension; S3. A certain amount of chitosan is added into an acetic acid solution and stirred to obtain a chitosan / acetic acid homogeneous solution; S4. The chitosan / acetic acid solution is added into the GO suspension, and is magnetically stirred for 100-180 min to form a gel; S5. The gel solution is poured into a mold, and is placed in a magnetic field in an ice bath environment for 30-300 min, and then the magnetic field is removed to obtain a gel solution which is oriented and arranged along the direction of the cellulose acetate film; S6. The gel solution is directionally freeze-dried to obtain a composite aerogel; S7. The composite aerogel is placed in a sealed dry container containing hexadecyltrimethoxysilane, and is reacted at 140-180 ℃ for 100-180 min to obtain a hydrophobic composite aerogel.

3. The method of claim 2, wherein the preparation of the composite three-dimensional adsorbent material for treating dye wastewater is characterized by, The method for preparing the sheet-shaped modified electrostatic spinning cellulose acetate film comprises the following steps: S11. Fe3O4@ZIF-8 powder is added into a mixed solution of N,N dimethylacetamide and acetone in a volume ratio of 1:2, and a homogeneous solution with a mass fraction of 0.5-5 wt% is obtained by ultrasonic treatment; S12. Cellulose acetate is dissolved in the homogeneous solution to obtain electrospinning solution A with a mass fraction of 2-15 wt% by stirring; S13. A certain amount of hydrophilic SiO2 powder is dispersed in a mixed solution of N,N dimethylacetamide and acetone in a volume ratio of 1:2, and a SiO2 NPs dispersion liquid with a mass fraction of 1-8 wt% is obtained by ultrasonic treatment; S14. Cellulose acetate is dissolved in the dispersion liquid to obtain electrospinning solution B with a mass fraction of 2-8 wt%; S15. The aforementioned electrospinning solution A is used for electrospinning to obtain a nascent electrospun film; S16. The aforementioned electrospinning solution B is used for electrospinning with the nascent electrospun film as a base layer to obtain a modified electrostatic spinning cellulose acetate film; S17. The modified electrostatic spinning cellulose acetate film is crushed to obtain sheet-shaped modified electrostatic spinning cellulose acetate film.

4. The method of claim 3, wherein the preparation of the composite three-dimensional adsorbent material for treating dye wastewater is characterized by, The method for preparing the Fe3O4@ZIF-8 comprises the following steps: S21. Dimethylimidazole solution and zinc nitrate hexahydrate solution are respectively prepared; S22. Ferroferric oxide solution and dimethylimidazole solution are mixed to obtain a total solution; S23. The total solution is slowly added dropwise into the zinc nitrate hexahydrate solution, and is reacted in an ultrasonic water bath at 25-45 ℃ for 10-40 min to obtain Fe3O4@ZIF-8 powder.

5. The method of claim 2, wherein the preparation of the composite three-dimensional adsorbent material for treating dye wastewater is characterized by: The mass ratio of the sheet-shaped modified electrostatic spinning cellulose acetate film to GO is 0.2-0.8; the mass ratio of GO to chitosan is 8-15; and the mass fraction of the acetic acid solution is 2-4 wt%.

6. The method of claim 2, wherein the preparation of the composite three-dimensional adsorbent material for treating dye wastewater is characterized by: The freeze-drying in S5 is performed at-60~-20 ℃ for 20-40 h.

7. The method according to claim 2, wherein the preparation method of the composite three-dimensional adsorption material for treating dye wastewater is characterized in that: The magnetic field in S5 is a parallel magnetic field, and the magnets are two rectangular strong neodymium magnets with a length of 80-120 mm, a width of 6-12 mm, and a height of 10-16 mm, and the distance between the two magnets is 2-6 cm.

8. The method according to claim 3, wherein the preparation method of the composite three-dimensional adsorption material for treating dye wastewater is characterized in that: The spinning temperature of the electrospinning liquid A is 25±5 DEG C, the spinning humidity is 50±5%, the spinning voltage is 8-12 kV, the spinning speed is 0.3-0.8 ml / h, and the receiving distance is 20 cm; the spinning temperature of the electrospinning liquid B is 25±5 DEG C, the spinning humidity is 50±5%, the spinning voltage is 8-12 kV, the spinning speed is 0.3-0.8 ml / h, and the receiving distance is 20 cm.

9. The method according to claim 3, wherein the preparation method of the composite three-dimensional adsorption material for treating dye wastewater is characterized in that: The size of the sheet-like modified electrospun cellulose acetate membrane in S17 is 1-2 cm 2 .

10. The method of claim 4, wherein the preparation of the composite three-dimensional adsorbent material for treating dye wastewater is characterized by: The mass ratio of the dimethyl imidazole to the zinc nitrate hexahydrate is 1-15; the concentration of the ferroferric oxide solution is 1-8 mg / ml, the volume ratio of the dimethyl imidazole solution to the ferroferric oxide solution is 0.5-14, and the volume ratio of the total solution to the zinc nitrate hexahydrate solution is 1-2.

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