阅读说明：本技术 基于改性蛋壳的金属有机骨架化合物的制备方法及应用 (Preparation method and application of metal organic framework compound based on modified eggshell ) 是由 刘建强 钟钰瑜 潘莹 廖栋辉 张文凤 戴忠 陈谌 李宝红 李思 于 2021-10-11 设计创作，主要内容包括：本发明公开一种基于改性蛋壳的金属有机骨架化合物的制备方法及应用,制备方法包括以下步骤：1)对蛋壳清洗、干燥以及研磨过筛,得到蛋壳粉ES；2)制备改性蛋壳磁性材料Fe-(3)O-(4)-ES；3)制备金属有机骨架化合物Fe-(3)O-(4)-ES/ZIF-8；以上制备方法制得的金属有机骨架化合物作为药物污染物吸附剂吸附水体中的诺氟沙星；本发明所述制备方法简单,原料来源充足、生产成本低,适合扩大化生产要求,方便工业生产；该制备方法制备出来的金属有机骨架化合物对诺氟沙星具有很好的吸附能力,具有较好的脱附能力和循环利用能力,还具有磁性,通过磁铁能快速回收,回收便捷。(The invention discloses a preparation method and application of a metal organic framework compound based on a modified eggshell, wherein the preparation method comprises the following steps: 1) cleaning, drying, grinding and sieving eggshells to obtain eggshell powder ES; 2) preparation of modified eggshell magnetic material Fe 3 O 4 -ES; 3) preparation of the Metal-organic framework Compound Fe 3 O 4 -ES/ZIF-8; the metal organic framework compound prepared by the preparation method is used as a drug pollutant adsorbent to adsorb norfloxacin in water; the preparation method is simple, has sufficient raw material sources and low production cost, is suitable for expanded production requirements, and is convenient for industrial production; the metal organic framework compound prepared by the preparation method has good adsorption capacity on norfloxacin, good desorption capacity and recycling capacity, and magnetism, can be quickly recovered through a magnet, and is convenient to recover.)

1. A preparation method of a metal organic framework compound based on modified eggshells is characterized by comprising the following steps: the method comprises the following steps:

1) cleaning eggshells with distilled water, drying for 24h under the condition of 378K, and then grinding and sieving to obtain eggshell powder ES;

2) adding eggshell powder ES into methanol solution, performing ultrasonic treatment for 20 min to obtain suspension A, adding trimethylolmethane into suspension A, stirring for 3min to obtain mixed solution B, adding dopamine hydrochloride into mixed solution B under the condition of continuous stirring, and then dropwise adding Fe₃O₄A dispersion liquid; after 8 hours of polymerization, the precipitate was separated from the solution using a magnet to give particles C, which were then washed with water 3 times and then dried in an oven overnight to give a modified eggshell magnetic material Fe₃O₄-ES；

3) Modifying eggshell magnetic material Fe₃O₄Adding ES into a methanol solution containing zinc nitrate hexahydrate, stirring for 20-40 min to obtain a suspension D, adding the methanol solution containing 2-methylimidazole into the suspension D, reacting for 20-40 min, centrifuging, washing and drying to obtain the metal organic compoundFramework compound Fe₃O₄-ES/ZIF-8。

2. The method for preparing a metal-organic framework compound based on modified eggshells as claimed in claim 1, wherein: grinding and sieving in the step 1) to obtain the eggshell powder ES with the particle size of less than 0.075 mm.

3. The method for preparing a metal-organic framework compound based on modified eggshells as claimed in claim 1, wherein: the mass ratio of the eggshell powder ES, the trihydroxymethyl methane and the dopamine hydrochloride in the step 2) is 200: 61: 100.

4. the method for preparing a metal-organic framework compound based on modified eggshells as claimed in claim 1, wherein: the methanol solution and Fe in the step 2)₃O₄The volume ratio of the dispersion is 50: 3.

5. the method for preparing a metal-organic framework compound based on modified eggshells as claimed in claim 1, wherein: the molar ratio of the zinc nitrate hexahydrate to the 2-methylimidazole in the step 3) is 29: 120.

6. the method for preparing a metal-organic framework compound based on modified eggshells as claimed in claim 1, wherein: the modified eggshell magnetic material Fe in the step 3)₃O₄-the ratio of the mass of ES, the volume of the methanolic solution containing zinc nitrate hexahydrate and the volume of the methanolic solution containing 2-methylimidazole is 40: 13: 17.

7. the method for preparing a metal-organic framework compound based on modified eggshells as claimed in claim 1, wherein: the mass fraction of the methanol solution in the step 2) and the step 3) is 98%.

8. The application of a metal organic framework compound based on modified eggshells is characterized in that: the metal-organic framework compound prepared by the preparation method of the metal-organic framework compound based on the modified eggshell as the drug pollutant adsorbent for adsorbing norfloxacin in the water body according to any one of claims 1 to 7.

9. Use of a modified eggshell based metal-organic framework compound according to claim 8, characterized in that: the metal-organic framework compound has magnetism.

Technical Field

The invention relates to the technical field of drug pollutant adsorbents, in particular to a preparation method and application of a metal organic framework compound based on modified eggshells.

Background

With the progress of society and the development of pharmaceutical industry, in recent decades, a plurality of drugs, drug metabolites and pharmaceutical excipient residues are detected in more and more water-based environments. The medicine mainly comprises antibiotics, hormones, anti-inflammatory drugs and the like, and the pharmaceutic adjuvant mainly comprises a solubilizer, a cosolvent, an emulsifier, a colorant, an adhesive and the like. The medicines, the medicine metabolites and the pharmaceutic adjuvants have complex structures and various components, and are slowly degraded under natural conditions. Meanwhile, with continuous production and use of people, more and more medicines, medicine metabolites and pharmaceutic adjuvants are discharged into water, and although the concentration of the currently detected medicines is far lower than the minimum concentration of the medicine effect, the substances can still have certain harm to human beings, animals, plants and ecosystems through the lasting contact of the water.

The prior method for removing the drug pollutants mainly comprises the functions of activated sludge adsorption, biodegradation, photocatalytic degradation, oxidation and the like, but the application of the method is limited due to respective defects. Activated sludge adsorption simply transfers the drug contaminants in the contaminated wastewater system to the soil, and does not completely remove the drug from the environment. Biodegradation and photocatalytic degradation are slow enough to not adequately counteract the increasing discharge of pharmaceutical contaminants into the water. However, the oxidation is difficult to be widely used due to its high cost consumption. In contrast, the adsorption method has the characteristics of simple operation, low cost, high efficiency, wide application and the like, and is suitable for removing the water body drug pollutants. At present, various materials can be used as adsorbents, such as activated carbon, carbon nanotubes, ion exchange resin, metal oxides and the like, but the carbon nanotubes have high production cost and are difficult to be applied on a large scale; the activated carbon is difficult to regenerate and difficult to recycle; the specific surface area of materials such as metal oxide, ion exchange resin and the like is small, and the adsorption effect is not ideal. Therefore, there is still a need to develop new materials with the advantages of good adsorption effect, low cost and recycling capability as adsorbents for removing drug pollutants in water.

Disclosure of Invention

The technical problem to be solved by the present invention is to provide a preparation method and application of a metal organic framework compound based on modified eggshells, aiming at the defects in the prior art, wherein the preparation method is simple, the yield is high, the metal organic framework compound has good stability to water, and the metal organic framework compound Fe prepared by the method is Fe₃O₄the-ES/ZIF-8 has good adsorption capacity on norfloxacin and is a metal organic framework compound Fe₃O₄the-ES/ZIF-8 has good desorption capacity and certain recycling capacity after adsorbing the drug pollutants, and the metal organic framework compound Fe₃O₄-ES/ZIF-8 is magnetic and can be rapidly recovered by a magnet, and a metal organic framework compound Fe₃O₄the-ES/ZIF-8 has potential application in the aspect of adsorbing drug residues in environmental water.

In order to solve the technical problems, the technical scheme of the invention is as follows:

a preparation method of a metal organic framework compound based on a modified eggshell comprises the following steps:

1) cleaning eggshells with distilled water, drying for 24h under the condition of 378K, and then grinding and sieving to obtain eggshell powder ES;

2) adding eggshell powder ES into methanol solution, performing ultrasonic treatment for 20 min to obtain suspension A, adding trimethylolmethane into suspension A, stirring for 3min to obtain mixed solution B, adding dopamine hydrochloride into mixed solution B under the condition of continuous stirring, and then dropwise adding Fe₃O₄A dispersion liquid; after 8 hours of polymerization, the precipitate was separated from the solution using a magnet to give particles C, which were then washed with water 3 times and then dried in an oven overnight to give a modified eggshell magnetic material Fe₃O₄-ES；

3) Modifying eggshell magnetic material Fe₃O₄Adding ES into a methanol solution containing zinc nitrate hexahydrate, stirring for 20-40 min to obtain a suspension D, adding the methanol solution containing 2-methylimidazole into the suspension D, reacting for 20-40 min, centrifuging, washing and drying to obtain a metal organic framework compound Fe₃O₄-ES/ZIF-8。

As a preferable scheme, the grain size of the eggshell ES obtained by grinding and sieving in the step 1) is less than 0.075 mm.

As a preferable scheme, the mass ratio of the eggshell powder ES, the trimethylolmethane and the dopamine hydrochloride in the step 2) is 200: 61: 100.

as a preferable scheme, the methanol solution and Fe in the step 2)₃O₄The volume ratio of the dispersion is 50: 3.

as a preferable scheme, the molar ratio of the zinc nitrate hexahydrate to the 2-methylimidazole in the step 3) is 29: 120.

as a preferable scheme, the modified eggshell magnetic material Fe in the step 3)₃O₄-the ratio of the mass of ES, the volume of the methanolic solution containing zinc nitrate hexahydrate and the volume of the methanolic solution containing 2-methylimidazole is 40: 13: 17.

as a preferable scheme, the mass fraction of the methanol solution in the step 2) and the step 3) is 98%.

The metal organic framework compound prepared by the preparation method of the metal organic framework compound based on the modified eggshell is used as a drug pollutant adsorbent to adsorb norfloxacin in water.

Preferably, the metal-organic framework compound has magnetic properties.

The invention has the beneficial effects that: the preparation method of the metal organic framework compound based on the modified eggshell is simple, has sufficient raw material sources and low production cost, is suitable for expanded production requirements, and is convenient for industrial production; the metal organic framework compound prepared by the preparation method of the metal organic framework compound based on the modified eggshell has good adsorption capacity on norfloxacin, and the metal organic framework compound still has good adsorption capacity on norfloxacin in an acid environment; the metal organic framework compound has better desorption capacity and recycling capacity after adsorbing the drug pollutants; the metal organic framework compound has magnetism, can be quickly recovered through a magnet, and is convenient to recover.

Drawings

FIG. 1 shows a metal-organic framework compound Fe before adsorption₃O₄-ES/ZIF-8 (FEZ), metal organic framework compound Fe after saturation of adsorbing norfloxacin₃O₄-ES/ZIF-8 (FEZ), metal organic framework compound Fe after saturation of circulating adsorption norfloxacin₃O₄-ES/ZIF-8 (FEZ), modified eggshell magnetic material Fe₃O₄-X-ray diffraction patterns of ES, metal organic framework compound ZIF-8 and eggshell ES;

FIG. 2 shows a metal organic framework compound Fe before adsorption₃O₄-ES/ZIF-8 (FEZ), metal organic framework compound Fe after saturation of adsorbing norfloxacin₃O₄-ES/ZIF-8 (FEZ), modified eggshell magnetic material Fe₃O₄-infrared spectrogram of ES, metallo-organic framework compound ZIF-8 and eggshell ES;

FIG. 3 shows a metal organic framework compound Fe before adsorption₃O₄-ES/ZIF-8 (FEZ), metal organic framework compound Fe after saturation of adsorbing norfloxacin₃O₄-nitrogen adsorption of ES/ZIF-8 (FEZ) and of a metal organic framework compound ZIF-8 with removal of the figure;

FIG. 4 shows a metal organic framework compound Fe₃O₄-ES/ZIF-8 (FEZ), modified eggshell magnetic material Fe₃O₄-scanning electron micrographs of ES, metal organic framework compound ZIF-8 and eggshell ES;

FIG. 5 shows a metal organic framework compound Fe₃O₄-hysteresis loop of ES/ZIF-8 (FEZ);

FIG. 6 shows different amounts of Fe₃O₄-ES/ZIF-8 (FEZ) adsorption profile of norfloxacin;

FIG. 7 shows a metal organic framework compound Fe₃O₄-ES/ZIF-8 (FEZ) profile of adsorption of norfloxacin at different concentrations;

FIG. 8 shows a metal organic framework compound Fe₃O₄-ES/ZIF-8 (FEZ) adsorption profile of norfloxacin in different pH environments;

FIG. 9 shows a metal organic framework compound Fe₃O₄-ES/ZIF-8 (FEZ) adsorption profile of norfloxacin at different temperatures;

FIG. 10 shows a metal organic framework compound Fe₃O₄Analysis of norfloxacin adsorption on ES/ZIF-8 (FEZ) cycle.

Detailed Description

The structural and operational principles of the present invention are explained in further detail below with reference to the accompanying drawings.

Example 1

Preparation of the Metal-organic framework Compound Fe₃O₄-ES/ZIF-8（FEZ）

1) Cleaning the membrane removed eggshell with distilled water, drying for 24h under the condition of 378K, grinding and sieving to obtain eggshell powder ES, wherein the grain size of the eggshell powder ES after grinding and sieving is less than 0.075 mm;

2) 400mg of eggshell powder ES are added to 100mL of methanol solutionPerforming ultrasonic treatment for 20 min to obtain suspension A, adding 122mg of trimethylolmethane into the suspension A, stirring for 3min to obtain mixed solution B, adding 200mg of dopamine hydrochloride into the mixed solution B under the condition of continuous stirring, and dropwise adding 6mLFe₃O₄A dispersion liquid; after 8 hours of polymerization, the precipitate was separated from the solution using a magnet to give particles C, which were then washed with water 3 times and then dried overnight in an oven at 60 ℃ to give Fe as a modified eggshell magnetic material₃O₄-ES；

3) Adding 20mg of modified eggshell magnetic material Fe3O4-ES into 6.5mL of methanol solution containing 2.9 mmol of zinc nitrate hexahydrate, stirring for 30min to obtain suspension D, then adding 8.5mL of methanol solution containing 12 mmol of 2-methylimidazole into suspension D, reacting for 30min, centrifuging, washing for 3 times by deionized water and methanol, and drying to obtain a metal organic framework compound Fe3O4-ES/ZIF-8 (FEZ).

Wherein the mass fraction of the methanol solution is 98%.

Comparative example 1

Preparation of modified eggshell magnetic material Fe₃O₄-ES

Adding 400mg of eggshell powder ES into 100mL of methanol solution for ultrasonic treatment for 20 min to obtain suspension A, adding 122mg of trimethylolmethane into the suspension A, stirring for 3min to obtain mixed solution B, adding 200mg of dopamine hydrochloride into the mixed solution B under the condition of continuous stirring, and then dropwise adding 6mLFe₃O₄A dispersion liquid; after 8 hours of polymerization, the precipitate was separated from the solution using a magnet to give particles C, which were then washed with water 3 times and then dried overnight in an oven at 60 ℃ to give Fe as a modified eggshell magnetic material₃O₄-ES。

Wherein the mass fraction of the methanol solution is 98%.

Comparative example 2

Preparation of metal organic framework compound ZIF-8

Mixing 6.5mL of methanol solution containing 2.9 mmol of zinc nitrate hexahydrate and 8.5mL of methanol solution containing 12 mmol of 2-methylimidazole, reacting for 30min, centrifuging, washing with methanol for 3 times, and drying to obtain the metal organic framework compound ZIF-8.

Wherein the mass fraction of the methanol solution is 98%.

Comparative example 3

Preparation of metal organic framework compound Fe after saturation of adsorbing norfloxacin₃O₄-ES/ZIF-8（FEZ）

1) Weighing 100.0mg of norfloxacin standard substance, dissolving in 100mL of water to prepare 1g/L mother solution;

2) taking 1mL of norfloxacin mother liquor to fix the volume to 100mL to obtain the initial concentration C₀Is 10mg/L norfloxacin solution, then the norfloxacin solution is put into a 200mL beaker, and 50mg of metal organic framework compound Fe is weighed₃O₄-ES/ZIF-8 was added to a beaker containing a norfloxacin solution, and then placed in a constant temperature shaker (model SHZ-82, manufactured by Shanghai Crystal jar instruments Ltd., Ltd.) and shaken at a shaking speed of 130rpm for 6 hours, followed by centrifugation at 12000r/min using a centrifuge (model H1850R, manufactured by Hunan instruments laboratory Equipment development Ltd., Hunan instruments Ltd.), for 3 minutes, and dried to obtain a norfloxacin-adsorbed saturated Fe metal-organic framework compound₃O₄-ES/ZIF-8（FEZ）。

Metal organic framework compound Fe before adsorption used in experiments 1-10₃O₄-ES/ZIF-8 (FEZ) is prepared in example 1, and the eggshell ES is the modified eggshell magnetic material Fe prepared in step 1) in example 1₃O₄ES is prepared by the comparative example 1, and the metal organic framework compound ZIF-8 is prepared by the comparative example 2 and adsorbs the metal organic framework compound Fe after norfloxacin saturation₃O₄-ES/ZIF-8 (FEZ) was prepared for comparative example 3.

Experiment 1

P-XRD experiment

The experimental steps are as follows: respectively using an X-ray diffractometer to adsorb Fe which is a metal organic framework compound before adsorption₃O₄-ES/ZIF-8 (FEZ), metal organic framework compound Fe after saturation of adsorbing norfloxacin₃O₄-ES/ZIF-8 (FEZ), metal organic framework compound Fe after saturation of circulating adsorption norfloxacin₃O₄-ES/ZIF-8（FEZ）Modified eggshell magnetic material Fe₃O₄-ES, a metal organic framework compound ZIF-8 and eggshell ES. (wherein, the metal organic framework compound Fe after saturation of norfloxacin is circularly adsorbed₃O₄-ES/ZIF-8 (FEZ) is a metal organic framework compound Fe cyclically adsorbing norfloxacin for 3 times in experiment 10₃O₄-ES/ZIF-8（FEZ）。）

The experimental results are as follows: as shown in fig. 1.

Experiment 2

Infrared spectroscopy experiment

The experimental steps are as follows: respectively carrying out Fourier transform infrared spectroscopy on metal organic framework compounds Fe before adsorption₃O₄-ES/ZIF-8 (FEZ), metal organic framework compound Fe after saturation of adsorbing norfloxacin₃O₄-ES/ZIF-8 (FEZ), modified eggshell magnetic material Fe₃O₄-ES, a metal organic framework compound ZIF-8 and eggshell ES.

The experimental results are as follows: as shown in fig. 2.

Experiment 3

Adsorption experiment of specific surface area

The experimental steps are as follows: respectively using a specific surface area adsorption instrument to adsorb the metal organic framework compound Fe before adsorption₃O₄-ES/ZIF-8 (FEZ), metal organic framework compound Fe after saturation of adsorbing norfloxacin₃O₄Specific surface area measurements were carried out on ES/ZIF-8 (FEZ) and the metal organic framework compound ZIF-8.

The experimental results are as follows: as shown in fig. 3.

Experiment 4

Scanning electron microscope experiment

The experimental steps are as follows: respectively aligning metal organic framework compound Fe by using scanning electron microscope₃O₄-ES/ZIF-8 (FEZ), modified eggshell magnetic material Fe₃O₄And carrying out shape measurement on-ES, a metal organic framework compound ZIF-8 and eggshell ES.

The experimental results are as follows: as shown in FIG. 4, wherein A is a 10 μm electron micrograph of a metal organic framework compound ZIF-8; b is a 1-micron electron microscope image of the eggshell ES; c is modified eggshell magnetFerrous material Fe₃O₄2 μm electron micrograph of ES; d is a metal organic framework compound Fe₃O₄1 μm electron micrograph of ES/ZIF-8 (FEZ).

Experiment 5

Magnetization curve experiment

The experimental steps are as follows: magnetic measuring instrument for metal organic framework compound Fe₃O₄ES/ZIF-8 (FEZ) for magnetic assays.

The experimental results are as follows: as shown in fig. 5.

Experiment 6

Metal organic framework compound Fe with different feeding amounts₃O₄Adsorption experiment of-ES/ZIF-8 (FEZ) on norfloxacin

The experimental steps are as follows:

1) weighing 100.0mg of norfloxacin standard, dissolving in 100mL of water to prepare 1g/L norfloxacin mother solution;

2) taking 1mL of norfloxacin mother liquor to fix the volume to 100mL to obtain the initial concentration C₀As a 10mg/L norfloxacin solution, the norfloxacin solution was placed in a 200mL beaker, and 40mg, 50mg, and 60mg of an adsorbent (a metal organic framework compound Fe)₃O₄-ES/ZIF-8 (FEZ)) was added to the norfloxacin solution, and the resulting mixture was placed in a constant temperature shaker (model SHZ-82, Shanghai Crystal jar apparatus manufacturing Co., Ltd.) at a temperature of 25 ℃ and shaken at a shaking speed of 130rpm for 6 hours; in the reaction process, taking out 4mL of mixed solution from the reaction system every 5 minutes in the first 30 minutes, taking out 4mL of mixed solution from the reaction system every 30 minutes after 30 minutes, placing the taken-out mixed solution in a centrifuge (model H1850R, Hunan instrument laboratory development Co., Ltd., of the manufacturer) and centrifuging for 3min at the rotating speed of 12000r/min to remove the adsorbent to obtain norfloxacin supernatant;

3) diluting the norfloxacin mother liquor obtained in the step 1) into norfloxacin standard solutions with the concentrations of 4mg/L, 6mg/L, 8mg/L, 10mg/L and 12mg/L by using water, measuring the absorbance of the norfloxacin standard solution at 277nm by using an ultraviolet spectrophotometer (model UV-650, Shanghai Mei spectral instruments, Ltd.), recording data and drawing a norfloxacin standard curve;

4) measuring absorbance of the norfloxacin supernatant obtained in step 2 at 277nm with an ultraviolet spectrophotometer (model UV-650, Shanghai Mei spectral instruments, Ltd.), comparing with norfloxacin standard curve to obtain norfloxacin concentration, and calculating adsorption efficiency according to adsorption formula（C₀Indicates the initial concentration of norfloxacin, C_tRepresenting the concentration of norfloxacin at the time t), calculating the adsorption efficiency, recording data, and drawing to obtain an experimental result.

The experimental results are as follows: as is clear from FIG. 6, 50mg of the metal-organic framework compound Fe₃O₄ES/ZIF-8 (FEZ) vs. initial concentration C₀The norfloxacin solution with 10mg/L has the best adsorption effect, and the metal organic framework compound Fe with 50mg is used₃O₄ES/ZIF-8 (FEZ) vs. initial concentration C₀The highest adsorption efficiency of norfloxacin solution with 10mg/L can reach 80.13 percent.

Experiment 7

Metal organic framework compound Fe₃O₄Adsorption experiment of-ES/ZIF-8 (FEZ) on norfloxacin at different concentrations

The experimental steps are as follows:

1) weighing 100.0mg of norfloxacin standard, dissolving in 100mL of water to prepare 1g/L norfloxacin mother solution;

2) taking 1mL, 2 mL and 3 mL of norfloxacin mother liquor, and respectively diluting to 100mL to obtain initial concentration C₀For norfloxacin solutions of 10mg/L, 20 mg/L and 30 mg/L, the norfloxacin solution was placed in a 200mL beaker, and 50mg of the adsorbent (metal organic framework compound Fe)₃O₄-ES/ZIF-8 (FEZ)) was added to the norfloxacin solution, and the resulting mixture was placed in a constant temperature shaker (model SHZ-82, Shanghai Crystal jar apparatus manufacturing Co., Ltd.) at a temperature of 25 ℃ and shaken at a shaking speed of 130rpm for 6 hours; during the reaction, 4mL of the mixed solution was taken out of the reaction system every 5 minutes for the first 30 minutes, 4mL of the mixed solution was taken out of the reaction system every 30 minutes after 30 minutes, and the taken-out mixture was mixedPlacing the solution in a centrifuge (model H1850R, Hunan apparatus laboratory development Co., Ltd. of the manufacturer, Hunan apparatus) at a rotation speed of 12000r/min, centrifuging for 3min to remove the adsorbent to obtain norfloxacin supernatant;

3) diluting the norfloxacin mother liquor obtained in the step 1) into norfloxacin standard solutions with the concentrations of 4mg/L, 6mg/L, 8mg/L, 10mg/L and 12mg/L by using water, measuring the absorbance of the norfloxacin standard solution at 277nm by using an ultraviolet spectrophotometer (model UV-650, Shanghai Mei spectral instruments, Ltd.), recording data and drawing a norfloxacin standard curve;

4) measuring absorbance of the norfloxacin supernatant obtained in step 2 at 277nm with an ultraviolet spectrophotometer (model UV-650, Shanghai Mei spectral instruments, Ltd.), comparing with norfloxacin standard curve to obtain norfloxacin concentration, and calculating adsorption efficiency according to adsorption formula（C₀Indicates the initial concentration of norfloxacin, C_tRepresenting the concentration of norfloxacin at the time t), calculating the adsorption efficiency, recording data, and drawing to obtain an experimental result.

The experimental results are as follows: as can be seen from FIG. 7, the metal-organic framework compound Fe₃O₄When the dosage of the-ES/ZIF-8 (FEZ) is 50mg, the adsorption efficiency of the norfloxacin solution is reduced along with the increase of the concentration of the norfloxacin solution, and when the norfloxacin concentration is 10mg/L, the metal organic framework compound Fe₃O₄The highest adsorption efficiency of the-ES/ZIF-8 (FEZ) on the norfloxacin solution can reach 80.94 percent.

Experiment 8

Metal organic framework compound Fe₃O₄Adsorption experiment of-ES/ZIF-8 (FEZ) on norfloxacin in different pH environments

The experimental steps are as follows:

1) weighing 100.0mg of norfloxacin standard, dissolving in 100mL of water to prepare 1g/L norfloxacin mother solution;

2) taking 1mL of norfloxacin mother liquor, and respectively diluting to 100mL to obtain initial concentrateDegree C₀The norfloxacin solution was placed in a 200mL beaker for 10mg/L of norfloxacin solution, the pH of the norfloxacin solution was adjusted to 4, 5 and 6 with hydrochloric acid solution, respectively, and 50mg of adsorbent (metal organic framework compound Fe) was weighed₃O₄-ES/ZIF-8 (FEZ)) was added to the norfloxacin solution, and the resulting mixture was placed in a constant temperature shaker (model SHZ-82, Shanghai Crystal jar apparatus manufacturing Co., Ltd.) at a temperature of 25 ℃ and shaken at a shaking speed of 130rpm for 6 hours; in the reaction process, taking out 4mL of mixed solution from the reaction system every 5 minutes in the first 30 minutes, taking out 4mL of mixed solution from the reaction system every 30 minutes after 30 minutes, placing the taken-out mixed solution in a centrifuge (model H1850R, Hunan instrument laboratory development Co., Ltd., of the manufacturer) and centrifuging for 3min at the rotating speed of 12000r/min to remove the adsorbent to obtain norfloxacin supernatant;

3) diluting the norfloxacin mother liquor obtained in the step 1) into norfloxacin standard solutions with the concentrations of 4mg/L, 6mg/L, 8mg/L, 10mg/L and 12mg/L by using water, measuring the absorbance of the norfloxacin standard solution at 277nm by using an ultraviolet spectrophotometer (model UV-650, Shanghai Mei spectral instruments, Ltd.), recording data and drawing a norfloxacin standard curve;

4) measuring absorbance of the norfloxacin supernatant obtained in step 2 at 277nm with an ultraviolet spectrophotometer (model UV-650, Shanghai Mei spectral instruments, Ltd.), comparing with norfloxacin standard curve to obtain norfloxacin concentration, and calculating adsorption efficiency according to adsorption formula（C₀Indicates the initial concentration of norfloxacin, C_tRepresenting the concentration of norfloxacin at the time t), calculating the adsorption efficiency, recording data, and drawing to obtain an experimental result.

The experimental results are as follows: as can be seen from FIG. 8, the concentration of norfloxacin solution was 10mg/L, and the metal-organic framework compound Fe was present₃O₄The dosage of the-ES/ZIF-8 (FEZ) is 50mg, and when the pH value of the norfloxacin solution is 5, the metal organic framework compound Fe₃O₄The best effect of the adsorption efficiency of the-ES/ZIF-8 (FEZ) on the norfloxacin solution is achieved, and in this case, the metal organic framework compound Fe₃O₄The highest adsorption efficiency of the-ES/ZIF-8 (FEZ) on the norfloxacin solution can reach 78.15 percent.

Experiment 9

Metal organic framework compound Fe₃O₄Adsorption experiment of-ES/ZIF-8 (FEZ) on norfloxacin at different temperatures

The experimental steps are as follows:

1) weighing 100.0mg of norfloxacin standard, dissolving in 100mL of water to prepare 1g/L norfloxacin mother solution;

2) taking 1mL of norfloxacin mother liquor, and respectively diluting to 100mL to obtain initial concentration C₀The norfloxacin solution was placed in a 200mL beaker as a 10mg/L norfloxacin solution, and 50mg of an adsorbent (metal organic framework compound Fe)₃O₄-ES/ZIF-8 (FEZ)) was added to the norfloxacin solution, and the resulting mixture was placed in a constant temperature shaker (model SHZ-82, manufactured by Shanghai Crystal jar apparatus manufacturing Co., Ltd.) at 25 ℃, 35 ℃, 45 ℃ and 55 ℃ and shaken at a shaking speed of 130rpm for 6 hours; in the reaction process, taking out 4mL of mixed solution from the reaction system every 5 minutes in the first 30 minutes, taking out 4mL of mixed solution from the reaction system every 30 minutes after 30 minutes, placing the taken-out mixed solution in a centrifuge (model H1850R, Hunan instrument laboratory development Co., Ltd., of the manufacturer) and centrifuging for 3min at the rotating speed of 12000r/min to remove the adsorbent to obtain norfloxacin supernatant;

3) diluting the norfloxacin mother liquor obtained in the step 1) into norfloxacin standard solutions with the concentrations of 4mg/L, 6mg/L, 8mg/L, 10mg/L and 12mg/L by using water, measuring the absorbance of the norfloxacin standard solution at 277nm by using an ultraviolet spectrophotometer (model UV-650, Shanghai Mei spectral instruments, Ltd.), recording data and drawing a norfloxacin standard curve;

4) measuring absorbance of the norfloxacin supernatant obtained in step 2 at 277nm with an ultraviolet spectrophotometer (model UV-650, Shanghai Mei spectral instruments, Ltd.), and comparing with norfloxacin standard curve to obtain norfloxacinNorfloxacin concentration of the supernatant of the ofloxacin, adsorption efficiency formula according to the adsorption quantity formula（C₀Indicates the initial concentration of norfloxacin, C_tRepresenting the concentration of norfloxacin at the time t), calculating the adsorption efficiency, recording data, and drawing to obtain an experimental result.

The experimental results are as follows: as can be seen from FIG. 9, at a norfloxacin concentration of 10mg/L, the metal-organic framework compound Fe₃O₄When the dosage of the-ES/ZIF-8 (FEZ) is 50mg, the adsorption efficiency of norfloxacin solution is reduced along with the increase of temperature, and when the temperature is 25 ℃, the metal organic framework compound Fe₃O₄The best adsorption effect of-ES/ZIF-8 (FEZ) on norfloxacin solution is achieved, and the metal organic framework compound Fe₃O₄The highest adsorption efficiency of the-ES/ZIF-8 (FEZ) on the norfloxacin solution can reach 80.92 percent.

Experiment 10

Metal organic framework compound Fe₃O₄Cyclic adsorption experiment of-ES/ZIF-8 (FEZ) on norfloxacin

The experimental steps are as follows:

1) weighing 100.0mg of norfloxacin standard, dissolving in 100mL of water to prepare 1g/L norfloxacin mother solution;

2) taking 1mL of norfloxacin mother liquor, and respectively diluting to 100mL to obtain initial concentration C₀The norfloxacin solution was placed in a 200mL beaker as a 10mg/L norfloxacin solution, and 50mg of an adsorbent (metal organic framework compound Fe)₃O₄-ES/ZIF-8 (FEZ)) is added into the norfloxacin solution, and the mixture is placed in a constant temperature shaking table (model SHZ-82, Shanghai Crystal jar apparatus manufacturing Co., Ltd. of the manufacturer) with the temperature of 25 ℃ and shaken at the shaking speed of 130rpm for 6h, and the adsorbent in the norfloxacin solution is collected by a magnet to obtain a metal organic framework compound Fe which adsorbs saturation of norfloxacin₃O₄-ES/ZIF-8 (FEZ) and norfloxacin supernatant;

3) the metal organic framework compound which is saturated by adsorbing norfloxacin and obtained in the step 2)Fe₃O₄-ES/ZIF-8 (FEZ) was stirred in a 100ml beaker containing 60ml of absolute ethanol for 8 hours, and the metal organic framework compound Fe in the absolute ethanol was added with a magnet₃O₄-ES/ZIF-8 (FEZ) collection at 60^oDrying in an oven of C overnight to obtain a desorbed metal organic framework compound Fe₃O₄-ES/ZIF-8（FEZ）；

4) Weighing 50mg of desorbed metal organic framework compound Fe obtained in the step 3)₃O₄-ES/ZIF-8 (FEZ) is placed at the initial concentration C₀Placing 10mg/L norfloxacin solution in a constant temperature shaking table (model SHZ-82, manufactured by Okinawa instruments Ltd., Shanghai, Ltd.) at 25 deg.C, shaking at 130rpm for 6h, collecting adsorbent in norfloxacin solution with magnet to obtain saturated metal organic framework compound Fe adsorbing norfloxacin₃O₄-ES/ZIF-8 (FEZ) and norfloxacin supernatant;

5) repeating the steps 3) -4) for 3 times, respectively measuring the absorbance of the norfloxacin supernatant obtained in the step 2) and the norfloxacin supernatant obtained in the step 4) at 277nm by using an ultraviolet spectrophotometer (the model is UV-650, Shanghai Mei spectral instrument, Inc.), and recording data;

6) diluting the norfloxacin mother liquor obtained in the step 1) into norfloxacin standard solutions with the concentrations of 4mg/L, 6mg/L, 8mg/L, 10mg/L and 12mg/L by using water, measuring the absorbance of the norfloxacin standard solution at 277nm by using an ultraviolet spectrophotometer (model UV-650, Shanghai Mei spectral instruments, Ltd.), recording data and drawing a norfloxacin standard curve;

7) respectively comparing the absorbance of the norfloxacin supernatant obtained in the step 2) and the absorbance of the norfloxacin supernatant obtained in the step 4) at 277nm with a norfloxacin standard curve to obtain the norfloxacin concentration of the norfloxacin supernatant, and obtaining an adsorption efficiency formula according to an adsorption quantity formula（C₀Indicates the initial concentration of norfloxacin, C_tTo representThe concentration of norfloxacin at the time t), calculating the adsorption efficiency, recording data, and drawing to obtain an experimental result.

The experimental results are as follows: as can be seen from FIG. 10, the concentration of norfloxacin solution was 10mg/L, and the metal-organic framework compound Fe was present₃O₄The dosage of-ES/ZIF-8 (FEZ) is 50mg, and the temperature is 25 ℃, the metal organic framework compound Fe₃O₄The adsorption efficiency of the-ES/ZIF-8 (FEZ) on the norfloxacin solution is reduced along with the increase of the cycle number, and a metal organic framework compound Fe₃O₄The adsorption efficiency of-ES/ZIF-8 (FEZ) on norfloxacin solution decreased by 21.5% after three cycles.

The above description is only a preferred embodiment of the present invention, and all the minor modifications, equivalent changes and modifications made to the above embodiment according to the technical solution of the present invention are within the scope of the technical solution of the present invention.