MS-MIL-53-PAN material for removing cobalt ions from wastewater and preparation method thereof

Abstract

The invention relates to the technical field of wastewater treatment, and in particular to an MS-MIL-53-PAN material for removing cobalt ions from wastewater and a preparation method thereof. The material is prepared from the following raw materials: molecular sieve MS, aminopropyltrimethoxysilane APS, bromoacetic acid, terephthalic acid and polyacrylonitrile PAN. The preparation method comprises the following steps: reacting the molecular sieve MS, aminopropyltrimethoxysilane APS and bromoacetic acid to obtain a carboxylated molecular sieve MS-COOH; reacting the carboxylated molecular sieve MS-COOH with terephthalic acid; and preparing the MS-MIL-53-PAN material for removing cobalt ions from wastewater by electrostatic spinning. The prepared MS-MIL-53-PAN material for removing cobalt ions from wastewater can be effectively used to treat cobalt ion radioactive wastewater, thereby reducing the threat to human health and environmental safety.

Description

Technical Field

[0001] The invention relates to the technical field of wastewater treatment, in particular to an MS-MIL-53-PAN material for removing cobalt ions from wastewater and a preparation method thereof. Background Art

[0002] Cobalt ion 60 Co is a commonly used radionuclide that can emit high-energy gamma rays and is therefore widely used in industry, agricultural production, medicine, and scientific research. 60 The use of Co also generates a large amount of radioactive waste, which poses a direct or indirect threat to human health and environmental safety. 60 The problem of Co radioactive wastewater treatment requires finding an effective method to remove 60 Co's method.

[0003] At present, there are two methods for separating cobalt ions: solvent extraction and ion exchange resin. However, both methods require the use of organic matter as a carrier for extraction or separation, and organic matter has poor ability to resist radiation and is easily decomposed and ineffective under strong radiation conditions. The precipitation method needs to be carried out under high pH, ​​high temperature and the presence of strong oxidants, and the cost is relatively high. The membrane separation method has high requirements for the quality of the influent water and requires pretreatment. In contrast, the adsorption method has the advantages of good treatment effect, simple process flow and convenient operation, so it is a better method for treating cobalt ions.

[0004] However, current adsorbents are 60 The adsorption amount of Co is low and the adsorption effect is poor. Therefore, it is urgent to propose an adsorbent with high stability and good adsorption capacity. Summary of the invention

[0005] The purpose of the present invention is to provide a MS-MIL-53-PAN material for removing cobalt ions from wastewater and a preparation method thereof, which can be effectively used to treat cobalt ion radioactive wastewater, thereby reducing the threat to human health and environmental safety.

[0006] To achieve the above object, the present invention adopts an MS-MIL-53-PAN material for removing cobalt ions from wastewater, which is prepared from the following raw materials:

[0007] Molecular sieve MS, aminopropyltrimethoxysilane APS, bromoacetic acid, terephthalic acid and polyacrylonitrile PAN.

[0008] The present invention also provides a method for preparing a MS-MIL-53-PAN material for removing cobalt ions from wastewater, comprising the following steps:

[0009] After adding aminopropyltrimethoxysilane APS and bromoacetic acid to the molecular sieve MS, the carboxylated molecular sieve MS-COOH is obtained by reaction;

[0010] The carboxylated molecular sieve MS-COOH and terephthalic acid are placed in a reactor for hydrothermal reaction to obtain a carboxylic acid functionalized molecular sieve-based metal-organic framework material MS-MIL-53;

[0011] With polyacrylonitrile (PAN) as the matrix and molecular sieve-based metal-organic framework (MS-MIL-53) as the filler, carboxylic acid-functionalized molecular sieve-based metal-organic framework (MOF) nanofiber material MS-MIL-53-PAN was prepared by electrospinning.

[0012] Among them, after adding aminopropyltrimethoxysilane APS and bromoacetic acid to the molecular sieve MS, the carboxylated molecular sieve MS-COOH is obtained by reaction:

[0013] Weigh molecular sieve MS powder and dry it at 180°C for 5h, then put it into a flask containing 100mL of anhydrous toluene, add aminopropyltrimethoxysilane APS, and reflux in an oil bath under nitrogen protection to obtain amino molecular sieve MS;

[0014] Aminated molecular sieve MS and bromoacetic acid are placed in a flask, deionized water is added as a solvent, the pH of the solution is adjusted to neutral, and the solution is stirred at room temperature to obtain a carboxylated molecular sieve MS-COOH.

[0015] Among them, after adding aminopropyltrimethoxysilane APS and bromoacetic acid to the molecular sieve MS, the carboxylated molecular sieve MS-COOH is obtained by reaction:

[0016] The weight of molecular sieve MS is 1-8 g, the weight of aminopropyltrimethoxysilane APS is 1-4 g, and the weight of bromoacetic acid is 2-6 g.

[0017] Wherein, in the step of placing the carboxylated molecular sieve MS-COOH and terephthalic acid in a reactor for hydrothermal reaction to obtain the carboxylic acid functionalized molecular sieve-based metal-organic framework material MS-MIL-53:

[0018] The weight of phthalic acid is 2~4g, and the temperature of the hydrothermal reaction is 100~200°.

[0019] Among them, in the step of using polyacrylonitrile PAN as a matrix and molecular sieve-based metal-organic framework material MS-MIL-53 as a filler to prepare carboxylic acid functionalized molecular sieve-based metal-organic framework nanofiber material MS-MIL-53-PAN by electrospinning:

[0020] Polyacrylonitrile PAN and molecular sieve-based metal-organic framework material MS-MIL-53 are uniformly mixed in dimethylformamide DMF solution, stirred evenly and allowed to stand to eliminate bubbles.

[0021] Among them, in the step of using polyacrylonitrile PAN as a matrix and molecular sieve-based metal-organic framework material MS-MIL-53 as a filler to prepare carboxylic acid functionalized molecular sieve-based metal-organic framework nanofiber material MS-MIL-53-PAN by electrospinning:

[0022] The weight of polyacrylonitrile PAN is 2~4g, and the weight of molecular sieve-based metal-organic framework material MS-MIL-53 is 2~4g.

[0023] Among them, in the step of using polyacrylonitrile PAN as a matrix and molecular sieve-based metal-organic framework material MS-MIL-53 as a filler to prepare carboxylic acid functionalized molecular sieve-based metal-organic framework nanofiber material MS-MIL-53-PAN by electrospinning:

[0024] The spinning parameters of electrospinning were 12 kV and 0.0020 mm / s.

[0025] The invention discloses an MS-MIL-53-PAN material for removing cobalt ions from wastewater and a preparation method thereof. The invention comprises the following steps: adding aminopropyltrimethoxysilane APS and bromoacetic acid to a molecular sieve MS to react and obtain a carboxylated molecular sieve MS-COOH; placing the carboxylated molecular sieve MS-COOH and terephthalic acid in a reactor for hydrothermal reaction to obtain a carboxylic acid functionalized molecular sieve-based metal-organic framework material MS-MIL-53; using polyacrylonitrile PAN as a matrix and the molecular sieve-based metal-organic framework material MS-MIL-53 as a filler, obtaining a carboxylic acid functionalized molecular sieve-based metal-organic framework nanofiber material MS-MIL-53-PAN by electrospinning, and finally obtaining the MS-MIL-53-PAN material for removing cobalt ions from wastewater. When the MS-MIL-53-PAN material for removing cobalt ions from wastewater is used to remove cobalt ions from wastewater, the cobalt-containing 2+ The pH value of the wastewater is adjusted to 4.0-9.0, and the MS-MIL-53-PAN material for removing cobalt ions from wastewater is added at a temperature of 5°C-40°C to remove the cobalt ions in the wastewater. 2+ Wastewater is treated by adsorption, and Co 2+ The time is not less than 2h. The prepared MS-MIL-53-PAN material for removing cobalt ions from wastewater has the characteristics of stable structure, low price and easy recycling. The adsorption capacity of cobalt ions can reach 106.4 mg / g, and it is effectively used to treat cobalt ion radioactive wastewater, thereby reducing the threat to human health and environmental safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0027] Figure 1 It is a step flow chart of Example 1 of the present invention.

[0028] Figure 2 It is a step flow chart of Example 2 of the present invention.

[0029] Figure 3 It is the XRD diagram of the MS-MIL-53-PAN material for removing cobalt ions from wastewater and its intermediates of the present invention;

[0030] Figure 4 It is a SEM picture of the MS-MIL-53-PAN material for removing cobalt ions from wastewater and its intermediates of the present invention;

[0031] Figure 5 It is the EDS diagram of the MS-MIL-53-PAN material for removing cobalt ions in waste water and its intermediates of the present invention.

[0032] Figure 6 This is a result diagram showing the effect of different pH values ​​on the adsorption of cobalt ions by the MS-MIL-53-PAN material and its intermediates for removing cobalt ions from wastewater;

[0033] Figure 7 1. It is a result diagram showing the effect of different temperatures on the adsorption of cobalt ions by the MS-MIL-53-PAN material for removing cobalt ions from wastewater according to the present invention;

[0034] Figure 8 This is a result diagram showing the effect of different time periods on the adsorption of cobalt ions by the MS-MIL-53-PAN material for removing cobalt ions from wastewater;

[0035] Fig. 9 This is a graph showing the effect of different cobalt ion concentrations on the adsorption of cobalt ions by the MS-MIL-53-PAN material for removing cobalt ions from wastewater according to the present invention. DETAILED DESCRIPTION

[0036] The present invention provides an MS-MIL-53-PAN material for removing cobalt ions from wastewater, which is prepared from the following raw materials:

[0037] Molecular sieve MS, aminopropyltrimethoxysilane APS, bromoacetic acid, terephthalic acid and polyacrylonitrile PAN.

[0038] Example 1, please refer to Figure 1 The present invention provides a method for preparing a MS-MIL-53-PAN material for removing cobalt ions from wastewater, comprising the following steps:

[0039] S1: Weigh 5 g of molecular sieve MS powder and dry it at 180 °C for 5 h, then place it in a flask containing 100 mL of anhydrous toluene, add 2 g of aminopropyltrimethoxysilane APS, and reflux in an oil bath under nitrogen protection to obtain an amino molecular sieve MS;

[0040] S2: 2 g of aminated molecular sieve MS and 4 g of bromoacetic acid were placed in a flask, deionized water was added as a solvent, the pH of the solution was adjusted to neutral, and stirred at room temperature to obtain a carboxylated molecular sieve MS-COOH;

[0041] S3: 1g of carboxylated molecular sieve MS-COOH and 3g of terephthalic acid were placed in a reactor for hydrothermal reaction at a temperature of 120° and a reaction time of 24h to obtain a carboxylic acid functionalized molecular sieve-based metal-organic framework material MS-MIL-53;

[0042] S4: Using 4g polyacrylonitrile PAN as the matrix and 2g molecular sieve-based metal-organic framework material MS-MIL-53 as the filler, polyacrylonitrile PAN and molecular sieve-based metal-organic framework material MS-MIL-53 were uniformly mixed in dimethylformamide DMF solution, stirred evenly and allowed to stand to eliminate bubbles, and the spinning parameters of electrospinning were set to 12kV, 0.0020mm / s, and carboxylic acid functionalized molecular sieve-based metal-organic framework nanofiber material MS-MIL-53-PAN was obtained by electrospinning.

[0043] In this embodiment, first weigh 5g of molecular sieve MS powder and dry it at 180°C for 5h, then place it in a flask containing 100mL of anhydrous toluene, add 2g of aminopropyltrimethoxysilane APS, and reflux in an oil bath under nitrogen protection to obtain an amino molecular sieve MS; then place 2g of the amino molecular sieve MS and 4g of bromoacetic acid in a flask, add deionized water as a solvent, adjust the pH of the solution to neutral, and stir at room temperature to obtain a carboxylated molecular sieve MS-COOH; then place 1g of the carboxylated molecular sieve MS-COOH and 3g of terephthalic acid in a reactor for hydrothermal reaction, the temperature of the hydrothermal reaction is 120°, and the reaction time is 24h to obtain a carboxylic acid functionalized molecular sieve-based metal-organic framework material MS-MIL-5 3; finally, 4g polyacrylonitrile PAN is used as a matrix and 2g molecular sieve-based metal-organic framework material MS-MIL-53 is used as a filler. The polyacrylonitrile PAN and the molecular sieve-based metal-organic framework material MS-MIL-53 are uniformly mixed in a dimethylformamide DMF solution, stirred evenly and allowed to stand to eliminate bubbles, and the spinning parameters of the electrospinning are set to 12kV, 0.0020mm / s, and the carboxylic acid functionalized molecular sieve-based metal-organic framework nanofiber material MS-MIL-53-PAN is obtained by electrospinning; finally, the MS-MIL-53-PAN material for removing cobalt ions in wastewater is obtained. When the MS-MIL-53-PAN material for removing cobalt ions in wastewater is used to remove cobalt ions in wastewater, the Co-containing 2+ The pH value of the wastewater is adjusted to 4.0-9.0, and the MS-MIL-53-PAN material for removing cobalt ions from wastewater is added at a temperature of 5°C-40°C to remove the cobalt ions in the wastewater. 2+ Wastewater is treated by adsorption, and Co 2+ The time is not less than 2h. The prepared MS-MIL-53-PAN material for removing cobalt ions from wastewater has the characteristics of stable structure, low price and easy recycling. The adsorption capacity of cobalt ions can reach 106.4 mg / g, and it is effectively used to treat cobalt ion radioactive wastewater, thereby reducing the threat to human health and environmental safety.

[0044] Example 2, please refer to Figure 2 The present invention provides a method for preparing a MS-MIL-53-PAN material for removing cobalt ions from wastewater, comprising the following steps:

[0045] S1: Weigh 2 g of molecular sieve MS powder and dry it at 180 °C for 5 h, then place it in a flask containing 100 mL of anhydrous toluene, add 4 g of aminopropyltrimethoxysilane APS, and reflux in an oil bath under nitrogen protection to obtain an amino molecular sieve MS;

[0046] S2: 1 g of aminated molecular sieve MS and 1.5 g of bromoacetic acid were placed in a flask, deionized water was added as a solvent, the pH of the solution was adjusted to neutral, and stirred at room temperature to obtain a carboxylated molecular sieve MS-COOH;

[0047] S3: 1g of carboxylated molecular sieve MS-COOH and 2g of terephthalic acid were placed in a reactor for hydrothermal reaction at a temperature of 120° and a reaction time of 24h to obtain a carboxylic acid functionalized molecular sieve-based metal-organic framework material MS-MIL-53;

[0048] S4: Using 2g polyacrylonitrile PAN as the matrix and 2g molecular sieve-based metal-organic framework material MS-MIL-53 as the filler, polyacrylonitrile PAN and molecular sieve-based metal-organic framework material MS-MIL-53 were uniformly mixed in dimethylformamide DMF solution, stirred evenly and allowed to stand to eliminate bubbles, and the spinning parameters of electrospinning were set to 12kV, 0.0020mm / s, and carboxylic acid functionalized molecular sieve-based metal-organic framework nanofiber material MS-MIL-53-PAN was obtained by electrospinning.

[0049] In this embodiment, first, 2 g of molecular sieve MS powder is weighed and dried at 180° C. for 5 h, then placed in a flask containing 100 mL of anhydrous toluene, 4 g of aminopropyltrimethoxysilane APS is added, and refluxed in an oil bath under nitrogen protection to obtain an amination molecular sieve MS; then 1 g of the amination molecular sieve MS and 1.5 g of bromoacetic acid are placed in a flask, deionized water is added as a solvent, the pH of the solution is adjusted to neutral, and stirred at room temperature to obtain a carboxylated molecular sieve MS-COOH; then 1 g of the carboxylated molecular sieve MS-COOH and 2 g of terephthalic acid are placed in a reactor for hydrothermal reaction, the temperature of the hydrothermal reaction is 120°, and the reaction time is 24 h to obtain a carboxylic acid functionalized molecular sieve-based metal-organic framework material MS-MIL- 53; finally, 2g of polyacrylonitrile PAN is used as a matrix and 2g of molecular sieve-based metal-organic framework material MS-MIL-53 is used as a filler, polyacrylonitrile PAN and molecular sieve-based metal-organic framework material MS-MIL-53 are uniformly mixed in a dimethylformamide DMF solution, stirred evenly and allowed to stand to eliminate bubbles, and the spinning parameters of the electrospinning are set to 12kV, 0.0020mm / s, and the carboxylic acid functionalized molecular sieve-based metal-organic framework nanofiber material MS-MIL-53-PAN is obtained by electrospinning; finally, the MS-MIL-53-PAN material for removing cobalt ions in wastewater is obtained, and when the MS-MIL-53-PAN material for removing cobalt ions in wastewater is used to remove cobalt ions in wastewater, the Co-containing 2+The pH value of the wastewater is adjusted to 4.0-9.0, and the MS-MIL-53-PAN material for removing cobalt ions from wastewater is added at a temperature of 5°C-40°C to remove the cobalt ions in the wastewater. 2+ Wastewater is treated by adsorption, and Co 2+ The time is not less than 2h. The prepared MS-MIL-53-PAN material for removing cobalt ions from wastewater has the characteristics of stable structure, low price and easy recycling. The adsorption capacity of cobalt ions can reach 106.4 mg / g, and it is effectively used to treat cobalt ion radioactive wastewater, thereby reducing the threat to human health and environmental safety.

[0050] In the following examples, the cobalt-containing waste liquids of different concentrations are all simulated cobalt-containing waste liquids. The commercially available CoCl2 is first prepared into a 1000 mg / L cobalt-containing solution and then diluted to the required concentration. The MS-MIL-53-PAN material for removing cobalt ions from waste water is used to conduct adsorption research on the cobalt-containing waste liquid, and the influence of various factors on it is investigated. Figure 3 It is the XRD diagram of MS-MIL-53-PAN material and its intermediates for removing cobalt ions from wastewater; Figure 4 It is the SEM image of MS-MIL-53-PAN material and its intermediates for removing cobalt ions from wastewater; Figure 5 It is the EDS graph of MS-MIL-53-PAN material and its intermediates for removing cobalt ions from wastewater; Figure 6 This is a graph showing the effect of different pH values ​​on the adsorption of cobalt ions by MS-MIL-53-PAN materials and their intermediates for removing cobalt ions from wastewater; Figure 7 This is the result graph of the effect of different temperatures on the adsorption of cobalt ions by MS-MIL-53-PAN material for removing cobalt ions from wastewater; Figure 8 This is a graph showing the effect of different time periods on the adsorption of cobalt ions by the MS-MIL-53-PAN material for removing cobalt ions from wastewater; Fig. 9 This is the result diagram of the effect of different cobalt ion concentrations on the adsorption of cobalt ions by MS-MIL-53-PAN materials for removing cobalt ions from wastewater. The specific implementation details are as follows: Example

[0051] The effect of different pH values ​​on the adsorption of cobalt ions by the MS-MIL-53-PAN material for removing cobalt ions from wastewater is shown in FIG. Figure 6As shown. Take several portions of 50 mL of cobalt-containing solution with a concentration of 10 mg / L, adjust the pH to a certain value with 0.2 mol / L NaOH solution or 0.1 mol / L hydrochloric acid solution, and then add 10 mg of the MS-MIL-53-PAN material for removing cobalt ions from wastewater, and then place it in a constant temperature oscillator at 25°C. After oscillating at 150 rpm for 6 hours, take about 4 mL of the mixed solution, centrifuge it at 10,000 rpm on a centrifuge for 5 minutes, take 1 mL of the supernatant in a 25 mL volumetric flask, add 1 mL of acetic acid-sodium acetate buffer solution with a pH of 4.5 and 1 mL of 4g / L nitroso-R salt solution, make up to volume with distilled water, and determine the cobalt ion content with a UV-visible spectrophotometer. The results are as shown in Figure 6 As shown, when pH is 9, the adsorption capacity of cobalt ions by UIO-66-Schiffbase can reach 43.6 mg / g. Example

[0052] The effect of different temperatures on the adsorption of cobalt ions by the MS-MIL-53-PAN material for removing cobalt ions from wastewater is shown in FIG. Figure 7 Take several portions of 50 mL cobalt-containing solution with a pH of 8.3, a concentration of 10 mg / L, and add 10 mg of the MS-MIL-53-PAN material for removing cobalt ions from wastewater, and then shake at 150 rpm for 6 hours at different temperatures, and then measure the cobalt ion content with a UV-visible spectrophotometer. The results are shown in Figure 7 As shown, with the increase of temperature, the adsorption amount of cobalt ions by MS-MIL-53-PAN gradually increases. At 318K, the adsorption amount can reach 45.0mg / g. Example

[0053] The effect of different adsorption times on the adsorption of cobalt ions by the MS-MIL-53-PAN material for removing cobalt ions from wastewater is shown in FIG. Figure 8 Take several portions of 50 mL cobalt-containing solution with a pH of 8.3, a concentration of 10 mg / L, and add 10 mg of the MS-MIL-53-PAN material for removing cobalt ions from wastewater, then shake at 25°C at 150 rpm for several hours, and then measure the cobalt ion content with a UV-visible spectrophotometer. The results are shown in Figure 8 As shown, after 12 hours of adsorption, the adsorption amount of cobalt ions by the MS-MIL-53-PAN material for removing cobalt ions from wastewater reached equilibrium. Example

[0054] The effect of the MS-MIL-53-PAN material for removing cobalt ions from wastewater on the adsorption of cobalt ions at different concentrations is as follows: Fig. 9As shown. Take several portions of 50 mL cobalt-containing solutions with different concentrations (10 mg / L~60 mg / L) and pH 8.3, and then add 10 mg of the MS-MIL-53-PAN material for removing cobalt ions from wastewater, and then oscillate at 25°C at 150 rpm for 24 hours, and then use a UV-visible spectrophotometer to determine the cobalt ion content. The results are shown in Fig. 9 As shown, using the Langmuir isotherm adsorption model to simulate, the maximum adsorption capacity can reach 106.4 mg / g.

[0055] What is disclosed above is only a preferred embodiment of the present invention, and it certainly cannot be used to limit the scope of rights of the present invention. Ordinary technicians in this field can understand that all or part of the processes of the above embodiment and equivalent changes made according to the claims of the present invention still fall within the scope of the invention.

Claims

1. A MS-MIL-53-PAN material for removing cobalt ions from wastewater, characterized in that: The invention is prepared from the following raw materials: Molecular sieve MS, aminopropyltrimethoxysilane APS, bromoacetic acid, terephthalic acid and polyacrylonitrile PAN; The method for preparing the MS-MIL-53-PAN material for removing cobalt ions from wastewater by using the above raw materials comprises the following steps: After adding aminopropyltrimethoxysilane APS and bromoacetic acid to the molecular sieve MS, the carboxylated molecular sieve MS-COOH is obtained by reaction; The carboxylated molecular sieve MS-COOH and terephthalic acid are placed in a reactor for hydrothermal reaction to obtain a carboxylic acid functionalized molecular sieve-based metal-organic framework material MS-MIL-53; With polyacrylonitrile (PAN) as the matrix and molecular sieve-based metal-organic framework (MS-MIL-53) as the filler, carboxylic acid-functionalized molecular sieve-based metal-organic framework (MOF) nanofiber material MS-MIL-53-PAN was prepared by electrospinning.

2. A method for preparing a MS-MIL-53-PAN material for removing cobalt ions from wastewater, comprising preparing the MS-MIL-53-PAN material for removing cobalt ions from wastewater as claimed in claim 1, characterized in that: The steps include: After adding aminopropyltrimethoxysilane APS and bromoacetic acid to molecular sieve MS, the carboxylated molecular sieve MS-COOH is obtained by reaction; The carboxylated molecular sieve MS-COOH and terephthalic acid are placed in a reactor for hydrothermal reaction to obtain a carboxylic acid functionalized molecular sieve-based metal-organic framework material MS-MIL-53; With polyacrylonitrile (PAN) as the matrix and molecular sieve-based metal-organic framework (MS-MIL-53) as the filler, carboxylic acid-functionalized molecular sieve-based metal-organic framework (MOF) nanofiber material MS-MIL-53-PAN was prepared by electrospinning.

3. The method for preparing the MS-MIL-53-PAN material for removing cobalt ions from wastewater according to claim 2, characterized in that: After adding aminopropyltrimethoxysilane APS and bromoacetic acid to molecular sieve MS, the carboxylated molecular sieve MS-COOH is obtained by reaction: Weigh molecular sieve MS powder and dry it at 180°C for 5h, then put it into a flask containing 100mL of anhydrous toluene, add aminopropyltrimethoxysilane APS, and reflux in an oil bath under nitrogen protection to obtain amino molecular sieve MS; Aminated molecular sieve MS and bromoacetic acid are placed in a flask, deionized water is added as a solvent, the pH of the solution is adjusted to neutral, and the solution is stirred at room temperature to obtain a carboxylated molecular sieve MS-COOH.

4. The method for preparing the MS-MIL-53-PAN material for removing cobalt ions from wastewater according to claim 3, characterized in that: After adding aminopropyltrimethoxysilane APS and bromoacetic acid to molecular sieve MS, the carboxylated molecular sieve MS-COOH is obtained by reaction: The weight of molecular sieve MS is 1-8 g, the weight of aminopropyltrimethoxysilane APS is 1-4 g, and the weight of bromoacetic acid is 2-6 g.

5. The method for preparing the MS-MIL-53-PAN material for removing cobalt ions from wastewater according to claim 2, characterized in that: In the step of placing the carboxylated molecular sieve MS-COOH and terephthalic acid in a reactor for hydrothermal reaction to obtain the carboxylic acid functionalized molecular sieve-based metal-organic framework material MS-MIL-53: The weight of phthalic acid is 2~4g.

6. The method for preparing the MS-MIL-53-PAN material for removing cobalt ions from wastewater according to claim 2, characterized in that: In the step of preparing carboxylic acid functionalized molecular sieve-based metal-organic framework nanofiber material MS-MIL-53-PAN by electrospinning using polyacrylonitrile PAN as a matrix and molecular sieve-based metal-organic framework material MS-MIL-53 as a filler: Polyacrylonitrile PAN and molecular sieve-based metal-organic framework material MS-MIL-53 are uniformly mixed in dimethylformamide DMF solution, stirred evenly and allowed to stand to eliminate bubbles.

7. The method for preparing the MS-MIL-53-PAN material for removing cobalt ions from wastewater according to claim 6, characterized in that: In the step of preparing carboxylic acid functionalized molecular sieve-based metal-organic framework nanofiber material MS-MIL-53-PAN by electrospinning using polyacrylonitrile PAN as a matrix and molecular sieve-based metal-organic framework material MS-MIL-53 as a filler: The weight of polyacrylonitrile PAN is 2~4g, and the weight of molecular sieve-based metal-organic framework material MS-MIL-53 is 2~4g.

8. The method for preparing the MS-MIL-53-PAN material for removing cobalt ions from wastewater according to claim 2, characterized in that: In the step of preparing carboxylic acid functionalized molecular sieve-based metal-organic framework nanofiber material MS-MIL-53-PAN by electrospinning using polyacrylonitrile PAN as a matrix and molecular sieve-based metal-organic framework material MS-MIL-53 as a filler: The spinning parameters of electrospinning were 12 kV and 0.0020 mm / s.

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