Ternary organic-inorganic hybrid materials for adsorbing antibiotics in water and their preparation method

Abstract

This invention relates to a ternary organic-inorganic hybrid material for adsorbing antibiotics in water and its preparation method, belonging to the field of water treatment technology. The preparation method involves dissolving a certain amount of chitosan quaternary ammonium salt in water and mixing it evenly to obtain solution A; dissolving tannic acid in water and mixing it evenly to obtain solution B; dissolving zirconium chloride in water and mixing it evenly to obtain solution C; adding solution A to solution B and mixing evenly; slowly adding solution C dropwise while rapidly stirring and mixing evenly, and reacting at room temperature; precipitating the reacted sample with ethanol and washing it to obtain a gel-like solid sample; and drying the sample in an electrically heated constant-temperature drying oven. This material can efficiently adsorb three antibiotics in water, including ofloxacin, tetracycline, and erythromycin; the preparation process is green and mild, with a short cycle, low energy consumption, and good chemical stability.

Description

Technical Field

[0001] This application relates to a method for preparing a highly efficient antibiotic adsorbent material, and more specifically, to a novel chitosan-based ternary organic-inorganic hybrid material, belonging to the fields of material preparation and water treatment technology. Background Technology

[0002] Antibiotics, as an emerging pollutant, have attracted widespread attention globally. Their extensive use in human medicine, animal husbandry, and aquaculture has led to large quantities of antibiotics entering the environment, either unchanged or as metabolites. This has induced the emergence of drug-resistant bacteria and genes, posing a serious threat to ecosystems and public health. Commonly used antibiotics such as quinolones, tetracyclines, and macrolides are frequently detected in surface water, with concentrations of 13.86 μg / L, 2.66 μg / L, and 1.77 μg / L, respectively. In some areas, antibiotic pollution is particularly severe, with tetracycline and oxytetracycline concentrations reaching as high as 68.9 μg / L and 361 μg / L, respectively. Therefore, the efficient removal of antibiotics from water bodies is urgently needed.

[0003] Currently, conventional front-end water treatment processes (such as coagulation) have limited effectiveness in removing hydrophilic small-molecule antibiotics from water bodies. Advanced treatment technologies such as membrane separation are costly and prone to membrane fouling; advanced oxidation processes can degrade antibiotics, but suffer from high energy consumption and the generation of byproducts; and antibiotics are more easily removed by adsorption than by degradation. Therefore, adsorption is considered a more promising treatment technology due to its advantages of simple operation, low energy consumption, and easy material regeneration.

[0004] Commonly used adsorbents include activated carbon, ion exchange resins, carbon nanotubes, and metal-organic frameworks (MOFs), but they have limitations in antibiotic adsorption: activated carbon has low regeneration efficiency, ion exchange resins have narrow applicability, carbon nanotubes are expensive and have potential biotoxicity, and MOFs suffer from poor water stability and complex post-treatment. Therefore, to overcome these problems, it is crucial to develop a novel, efficient, stable, and environmentally friendly adsorbent material. Summary of the Invention

[0005] This application aims to address the problems of high raw material costs and susceptibility to pollution in the preparation of antibiotic adsorbent materials, as well as the long preparation time and high energy consumption. To this end, this application provides a method for preparing a ternary organic-inorganic hybrid material for highly efficient adsorption of antibiotics in water. This method is environmentally friendly, simple, energy-saving, and rapid, with a high adsorption rate, thus achieving efficient adsorption of antibiotics in surface water. The preparation conditions of this adsorbent material are mild, time-consuming, energy-efficient, and exhibit good stability.

[0006] To achieve the above objectives, this application provides a ternary organic-inorganic hybrid material for adsorbing antibiotics in water. The material is prepared by crosslinking chitosan quaternary ammonium salt and tannic acid with zirconium chloride and rapidly stirring in an aqueous solution at room temperature and pressure. Zirconium chloride and tannic acid form a metal-polyphenol network, and chitosan quaternary ammonium salt is bound to the metal-polyphenol network through hydrogen bonding, coordination, and electrostatic interactions. The material contains antibiotic adsorption sites.

[0007] The preparation method of the above-mentioned ternary organic-inorganic hybrid material for adsorbing antibiotics in water includes the following steps:

[0008] (1) Dissolve chitosan quaternary ammonium salt with a degree of substitution of 30-50% in water, mix well to obtain solution A, the concentration of solution A is 15-25 wt%;

[0009] (2) Dissolve tannic acid in water and mix well to obtain solution B, the concentration of which is 5-15 wt%.

[0010] (3) Dissolve zirconium chloride in water and mix well to obtain solution C, the concentration of solution C being 0.01-0.25 g / mL;

[0011] (4) Mix solution A with solution B and stir quickly until the mixture is homogeneous to obtain a mixed solution. The mass ratio of chitosan quaternary ammonium salt to tannic acid in the mixed solution is 1.5~2.5:1.

[0012] (5) Slowly add solution C to the mixed solution. The total amount of zirconium chloride added is 0.02-0.15:1 by mass of tannic acid. Stir quickly while adding the solution. Continue stirring at room temperature for 20-60 minutes to allow the solution to react fully.

[0013] (6) After the reaction is complete, the precipitate is separated and washed thoroughly with an organic solvent to obtain a gel-like sample;

[0014] (7) The ternary organic-inorganic hybrid material for adsorbing antibiotics in water is obtained by heating and drying the gel sample.

[0015] Preferably, the degree of substitution of chitosan quaternary ammonium salt used in step (1) is 40%.

[0016] Preferably, the concentration of solution A in step (1) is 20 wt%.

[0017] Preferably, the concentration of solution B in step (2) is 10 wt%.

[0018] Preferably, the concentration of the zirconium chloride aqueous solution in step (3) is 0.1 g / mL.

[0019] Preferably, the mass ratio of chitosan quaternary ammonium salt to tannic acid in the mixed solution in step (4) is 2:1.

[0020] Preferably, the dropping rate of solution C in step (5) is 0.5-2.5 mL / min.

[0021] Preferably, in step (6), the precipitate is separated by centrifugation, and the organic solvent is anhydrous ethanol.

[0022] Preferably, the heating and drying process is carried out in an electric constant temperature drying oven in step (7).

[0023] This application describes the rapid preparation of a novel chitosan-based ternary organic-inorganic hybrid material under ambient temperature and pressure conditions. Using environmentally friendly raw materials, chitosan quaternary ammonium salt and tannic acid, and zirconium chloride as a crosslinking agent to accelerate the formation of a polyphenol network, this novel chitosan-based ternary organic-inorganic hybrid material is rapidly prepared at room temperature. This material is used for the efficient removal of antibiotics from water. This application first selects abundant and environmentally friendly chitosan quaternary ammonium salt (QCS) and tannic acid (TA) as core raw materials. The strong positive charge of chitosan quaternary ammonium salt helps to capture negatively charged antibiotic molecules, while the abundant phenolic hydroxyl groups in tannic acid not only serve as strong coordination sites, but its benzene ring can also form π-π conjugation with the aromatic ring of antibiotics, playing a synergistic role in antibiotic removal. ZrCl4 is introduced as a crosslinking agent to form a stable metal-polyphenol network with tannic acid. Simultaneously, chitosan quaternary ammonium salt is embedded through electrostatic interactions, coordination interactions, and hydrogen bonding to construct a ternary organic-inorganic hybrid material, QCS-Zr-TA.

[0024] In summary, compared with existing adsorbent materials, this application has the following advantages:

[0025] 1. The reaction raw materials and solvents are green and environmentally friendly: This application uses natural organic chitosan quaternary ammonium salt and tannic acid as raw materials and water as solvent, which makes the reaction system have better green and environmentally friendly characteristics.

[0026] 2. Simple and rapid preparation method: This application provides a method for rapidly preparing novel chitosan-based ternary organic-inorganic hybrid materials at room temperature and pressure by adding zirconium chloride as a crosslinking agent to quickly form a polyphenol network. This avoids the problems of high raw material cost and easy pollution in the preparation of traditional adsorbents, as well as high energy consumption and long preparation time.

[0027] 3. Achieving efficient antibiotic removal: This application constructs a novel chitosan-based ternary organic-inorganic hybrid material to prepare adsorption materials with adsorption sites of different characteristics, thereby achieving efficient removal of antibiotics and solving the problems of low efficiency and poor selectivity.

[0028] 4. Excellent stability and strong practicality: The novel chitosan-based ternary organic-inorganic hybrid material prepared in this application has high adsorption capacity, good stability, recyclability and wide pH range, which improves the practicality of the material. Attached Figure Description

[0029] Appendix Figure 1 This is a flowchart of the preparation method for the ternary organic-inorganic hybrid material in Example 1;

[0030] Appendix Figure 2 The diagram shows the state and dispersion of the ternary organic-inorganic hybrid material prepared in Example 1 in water.

[0031] Appendix Figure 3 SEM image of the ternary organic-inorganic hybrid material prepared in Example 1;

[0032] Appendix Figure 4 The infrared spectrum of the ternary organic-inorganic hybrid material prepared in Example 1;

[0033] Appendix Figure 5 This is a graph showing the effect of the dosage of ternary organic-inorganic hybrid material on the antibiotic removal rate in Example 2.

[0034] Appendix Figure 6 The graph shows the effect of adsorption time of the ternary organic-inorganic hybrid material on antibiotic removal rate in Example 2.

[0035] Appendix Figure 7 This is the adsorption kinetics diagram of the ternary organic-inorganic hybrid material in Example 2;

[0036] Appendix Figure 8 This is the adsorption isotherm diagram of the ternary organic-inorganic hybrid material in Example 2;

[0037] Appendix Figure 9 The adsorption thermodynamic diagram of the ternary organic-inorganic hybrid material in Example 2;

[0038] Appendix Figure 10 This is a graph showing the effect of different pH values ​​on the antibiotic removal efficiency of the ternary organic-inorganic hybrid material in Example 2.

[0039] Appendix Figure 11 The graph shows the effect of coexisting humic acid on the antibiotic removal efficiency of the ternary organic-inorganic hybrid material in Example 2.

[0040] Appendix Figure 12 The graph shows the effect of coexisting anions on the antibiotic removal efficiency of the ternary organic-inorganic hybrid material in Example 2.

[0041] Appendix Figure 13The graph shows the effect of coexisting cations on the antibiotic removal efficiency of the ternary organic-inorganic hybrid material in Example 2. Detailed Implementation

[0042] To enable those skilled in the art to better understand the preparation and application methods of this application, the technical solution of this application will be further described below in conjunction with specific embodiments.

[0043] Example 1

[0044] The preparation method of the ternary organic-inorganic hybrid material for adsorbing antibiotics in water provided in this embodiment is as follows:

[0045] 20 g of chitosan quaternary ammonium salt with a substitution degree of 40% was added to 100 mL of water and stirred until dissolved. 10 g of tannic acid was added to 100 mL of water and stirred until dissolved. The two solutions were mixed thoroughly, and 0.03 g / mL of zirconium chloride solution was slowly added dropwise at a rate of 1.0 mL / min while stirring rapidly until homogeneous. A total of 35 mL of zirconium chloride solution was added, and the reaction was continued at room temperature for 30 min with stirring. After the reaction, the precipitate was centrifuged, precipitated with anhydrous ethanol, washed three times, and then dried in a 60℃ electric thermostatic drying oven. The final product obtained was the ternary organic-inorganic hybrid material for adsorbing antibiotics from water.

[0046] As attached Figure 1 The diagram shown is a flowchart of the preparation method in this embodiment. Zirconium chloride and tannic acid form a metal polyphenol network, which is then bound to chitosan quaternary ammonium salt through hydrogen bonding, coordination and electrostatic interactions, and contains abundant antibiotic adsorption sites.

[0047] As attached Figure 2 As shown, the novel chitosan-based ternary organic-inorganic hybrid material was prepared. The material is in powder form, stable in water, and will settle on its own after being shaken, making it easy to separate.

[0048] As attached Figure 3 The image shown is a SEM image of a ternary organic-inorganic hybrid material. It can be seen that the sample exhibits a nanoparticle structure with a basically regular morphology.

[0049] As attached Figure 4 The image shows the infrared spectrum of a ternary organic-inorganic hybrid material. The spectrum indicates that the sample exhibits high infrared spectral density at 1021 cm⁻¹. -1 1156cm -1 2895cm -1 The peaks of CO, COC, and CH stretching vibrations of -CH3 on the QCS sugar ring backbone are present at 1498 cm⁻¹. -1 A characteristic peak due to the CH bending vibration of the quaternary ammonium group is present at 1609.31 cm⁻¹; in addition, a characteristic peak is observed at 1609.31 cm⁻¹.-1 1701.87cm -1 1610cm -1 The presence of vibrational peaks in the C=C benzene ring skeleton of TA after displacement, stretching vibrations of C=O, and stretching vibration peaks generated by the -NH2 group of QCS indicates that QCS and TA are connected by hydrogen bonds. The sample peaks at 750 / 836.47 cm⁻¹... -1 The peak at this point may be due to Zr-N / Zr-O tensile vibration and in-plane bending vibration, indicating that Zr... 4+ It forms a coordination complex with the amino group of QCS and the phenolic hydroxyl group of TA; due to Zr 4+ Coordination with the -OH group of TA; originally, TA was located at 1315 cm⁻¹. -1 The in-plane bending vibration peak of phenol COH at the point of origin splits, and the electron cloud of COH changes, potentially generating phenol oxide anions, which combine with the quaternary ammonium groups of QCS through electrostatic interactions.

[0050] Example 2

[0051] This embodiment tests the application of the ternary organic-inorganic hybrid material prepared in Example 1 in the removal of antibiotics from water. The experimental procedure and results are as follows:

[0052] (1) Sample dosage experiment

[0053] The prepared adsorbent samples (i.e., ternary organic-inorganic hybrid materials, the same below) were added to 100 mL of 100 μg / L antibiotic solutions (ofloxacin OFX, tetracycline TET, erythromycin ERY) in Erlenmeyer flasks at dosages of 25-200 mg / L. The solutions were kept at 25℃ and 150 rpm for 12 h under constant temperature and shaking conditions. After the adsorption experiment, 5 mL of the adsorbed solution was taken, filtered through a 0.22 μm nylon membrane, and the antibiotic content was determined by LC-MS. The optimal dosage was selected for subsequent adsorption experiments based on the experimental results.

[0054] The results are attached. Figure 5 As shown, from Figure 5 As can be seen, the antibiotic removal rate increases with the increase of dosage from 25 to 100 mg / L; after 100 mg / L, further increases in the dosage of adsorbent dosing do not result in a significant change in the removal rate, so 100 mg / L is set as the dosage for subsequent experiments.

[0055] (2) Adsorption time experiment

[0056] Adsorption experiments were conducted at different times with an adsorbent sample dosage of 100 mg / L. The antibiotic concentration in the water was 100 μg / L. The solution was kept at 25℃ and 150 rpm for constant temperature shaking for 1 min, 5 min, 10 min, 30 min, 60 min, 90 min, 120 min, 180 min, 240 min, 360 min, 480 min, 600 min, and 720 min, respectively. The antibiotic content in the solution was determined according to the method in (1).

[0057] The results are attached. Figure 6 As shown, the material achieved a 95% removal rate for ofloxacin and tetracycline in the first 30 minutes and a nearly 100% removal rate in 90 minutes, while erythromycin achieved a 92% removal rate in the first 30 minutes and reached adsorption equilibrium in 180 minutes, with nearly 100% removal.

[0058] (3) Adsorption kinetics experiment

[0059] Based on the results of experiment (2), pseudo-first-order and pseudo-second-order dynamic models were fitted to the experimental results.

[0060] The results are attached. Figure 7 As shown, Figure 7 (a) shows the pseudo-first-order fitting plot of the sample adsorption kinetics, and (b) shows the pseudo-second-order fitting plot of the sample adsorption kinetics. Based on the fitting data, the correlation coefficients of the pseudo-first-order and pseudo-second-order kinetic models were obtained, revealing that the parameters of the pseudo-second-order kinetic model can better describe the adsorption process (R0). 2 =0.9999), indicating that the removal of antibiotics from water by the novel chitosan-based organic-inorganic hybrid material relies more on chemical adsorption.

[0061] (4) Adsorption isotherm experiment

[0062] Different initial concentrations of antibiotics were set, namely 0.5, 1, 3, 5, 50 and 100 mg / L. Following the method in (1), the adsorbent sample was added at a concentration of 100 mg / L, and the solution was kept at 25°C and 150 rmp under constant temperature shaking. After the adsorption was completed, the antibiotic content in the solution was measured, and the data were fitted using the Langmuir model and the Freundlich model.

[0063] The experimental results are attached. Figure 8 As shown, Figure 8In the figure, (a) is the adsorption isotherm of ofloxacin, (b) is the adsorption isotherm of tetracycline, and (c) is the adsorption isotherm of erythromycin. It can be seen from the figure that for OFX and TET, the Langmuir model has a higher correlation when the initial concentration is less than 10 mg / L, while the Freundlich model fits better at higher initial concentrations. This is because at high concentrations, the monolayer sites on the adsorbent surface gradually become saturated, and antibiotic molecules begin to form multilayer stacks on the adsorbed molecules. At this point, it is multilayer adsorption, and more secondary adsorption sites are utilized, which better fits the Freundlich model. Figure 8 In (c), for erythromycin, the correlation R in the Langmuir model is... 2 =0.9999, with a maximum fitted adsorption capacity of 462.51 mg / g, indicating that the adsorption process is dominated by monolayer adsorption. This is because the large molecular size of erythromycin hinders diffusion and makes it easier to be adsorbed on the surface. According to the Langmuir model fitting results, it can be seen that the adsorption capacities of different types of antibiotics differ significantly (OFX 107.72 mg / g, TET 217.59 mg / g, ERY 462.51 mg / g), which is a phenomenon caused by differences in molecular structure and adsorption mechanism.

[0064] (5) Adsorption thermodynamics experiment

[0065] Adsorption experiments were conducted at different temperatures (25℃, 35℃, 45℃) with an adsorbent sample dosage of 100 mg / L. The antibiotic concentration in the water was 100 μg / L. The samples were kept at 25℃ and 150 rpm for 4 hours under constant temperature shaking. The data obtained were used for thermodynamic analysis.

[0066] The results are attached. Figure 9 As shown, the adsorption of OFX and TET is significantly affected by temperature, with the removal rate increasing with increasing temperature; however, temperature has virtually no effect on the adsorption of ERY. Based on the thermodynamic parameters calculated from the ln K⁻¹ / T curve fitting results (Tables 1, 2, and 3), it was found that for the adsorption of OFX and TET, ΔG < 0 and ΔH > 0, indicating a spontaneous endothermic process; however, for the adsorption of erythromycin, ΔG > 0 and ΔH > 0, indicating a spontaneous exothermic process.

[0067] Table 1. Thermodynamic data of ofloxacin adsorption

[0068]

[0069] Table 2. Thermodynamic data of tetracycline adsorption

[0070]

[0071] Table 3. Adsorption thermodynamic data of erythromycin

[0072]

[0073] (6) Material stability analysis experiment

[0074] Adsorption experiments were conducted within a pH range of 3-10 to investigate the effect of different pH conditions on antibiotic removal efficiency. Besides pH affecting antibiotic removal, surface water contains natural organic matter and many coexisting ions, such as Cl-. - SO4 2- NO3 - HCO3 - K + Ca 2+ Na + Mg 2+ This will compress the electric double layer and compete for adsorption sites, thus leading to a decrease in adsorption capacity. With the initial antibiotic concentration fixed at 100 μg / L, different concentrations (0-50 mg / L) of humic acid (HA) were added to investigate the effect of humic acid concentration on adsorption; the same concentration (50 mg / L) of different types of coexisting ions was added to investigate the effect of ion type on adsorption.

[0075] The results are attached. Figure 10 As shown, the removal rate of antibiotics by the adsorbent remained at a high level within a pH range of 3-10. Under acidic conditions, both the antibiotics and the adsorbent were positively charged, and the removal was mainly achieved through hydrogen bonding and π-π conjugation. Under weakly alkaline conditions, the antibiotics were negatively charged, while the material remained positively charged. At this point, electrostatic interactions also participated, but hydrogen bonding and π-π conjugation were inhibited.

[0076] As attached Figure 11 As shown, low concentrations (≤10 mg / L) of humic acid have no effect on antibiotic adsorption, while high concentrations have a slight effect. This is because humic acid competes with the adsorbent for binding. Figure 12 , 13 As shown, in the coexisting anion (Cl... - SO4 2- NO3 - ) and coexisting cations (K + Ca 2+ Na + Mg 2+ In the presence of HCO3, the removal effect of antibiotics was not significantly affected, while with the presence of HCO3... - As the concentration increases, the effect on the adsorption effect of antibiotics becomes more and more significant. This is because the solution is strongly alkaline, and on the one hand, the presence of OH groups... -It competes with antibiotics for active adsorption sites; on the other hand, hydrogen bonding and π-π interactions are affected under strongly alkaline conditions. In summary, this material is not easily affected by coexisting ions and natural organic matter, exhibits excellent pH stability, and has great application potential.

[0077] Example 3

[0078] The preparation method of the ternary organic-inorganic hybrid material for adsorbing antibiotics in water provided in this embodiment is as follows:

[0079] 22 g of chitosan quaternary ammonium salt with a substitution degree of 35% was added to 70 mL of water and stirred until dissolved. 10 g of tannic acid was added to 80 mL of water and stirred until dissolved. The two solutions were mixed thoroughly, and 0.1 g / mL of zirconium chloride solution was slowly added dropwise at a rate of 0.8 mL / min while stirring rapidly until homogeneous. A total of 10 mL of zirconium chloride solution was added, and the reaction was continued at room temperature for 40 min with stirring. After the reaction, the precipitate was centrifuged, precipitated with anhydrous ethanol, washed three times, and then dried in a 60℃ electric thermostatic drying oven. The final product was the ternary organic-inorganic hybrid material for adsorbing antibiotics in water.

[0080] Example 4

[0081] The preparation method of the ternary organic-inorganic hybrid material for adsorbing antibiotics in water provided in this embodiment is as follows:

[0082] 18g of chitosan quaternary ammonium salt with a substitution degree of 45% was added to 80mL of water and stirred until dissolved. 10g of tannic acid was added to 90mL of water and stirred until dissolved. The two solutions were mixed thoroughly, and 0.2g / mL of zirconium chloride solution was slowly added dropwise at a rate of 1.5mL / min while stirring rapidly until homogeneous. A total of 7mL of zirconium chloride solution was added, and the reaction was continued at room temperature for 50min. After the reaction, the precipitate was centrifuged, precipitated with anhydrous ethanol, washed three times, and then dried in a 60℃ electric thermostatic drying oven. The final product was the ternary organic-inorganic hybrid material for adsorbing antibiotics in water.

[0083] In summary, the highly efficient antibiotic adsorbent material prepared in this application is rapidly prepared using a green, environmentally friendly, simple, and energy-saving method. This achieves the rapid, room-temperature, and atmospheric-pressure preparation of a novel chitosan-based organic-inorganic hybrid material, which is then used for the efficient removal of antibiotics from surface water. Examples 1, 3, and 4 successfully demonstrated the preparation of the adsorbent material, and the product was characterized in Example 1. Furthermore, Example 2 showed that the adsorbent sample prepared in Example 1 achieved highly efficient removal of antibiotics from water. In water containing 100 μg / L of antibiotics, the antibiotic removal rate reached nearly 100% after treatment with the adsorbent sample.

[0084] Therefore, through the above embodiments, it is demonstrated that this application provides a method for preparing a highly efficient antibiotic adsorbent material. This preparation method has a short preparation time, mild preparation conditions, and the prepared adsorbent material has a highly efficient removal effect on antibiotics and good stability.

Claims

1. A method for preparing a ternary organic-inorganic hybrid material for adsorbing antibiotics in water, characterized in that: The material is prepared by crosslinking chitosan quaternary ammonium salt and tannic acid with zirconium chloride in an aqueous solution under rapid stirring at room temperature and pressure; wherein zirconium chloride and tannic acid form a metal-polyphenol network, and chitosan quaternary ammonium salt is bound to the metal-polyphenol network through hydrogen bonding, coordination and electrostatic interaction; the material contains antibiotic adsorption sites. The preparation method of the material includes the following steps: (1) Dissolve chitosan quaternary ammonium salt with a degree of substitution of 30-50% in water, mix well to obtain solution A, the concentration of solution A is 15-25 wt%; (2) Dissolve tannic acid in water and mix well to obtain solution B, the concentration of solution B being 5-15 wt%; (3) Dissolve zirconium chloride in water and mix well to obtain solution C, the concentration of solution C being 0.01-0.25 g / mL; (4) Mix solution A with solution B and stir quickly until the mixture is homogeneous to obtain a mixed solution. The mass ratio of chitosan quaternary ammonium salt to tannic acid in the mixed solution is 1.5~2.5:

1. (5) Slowly add solution C to the mixed solution. The total amount of zirconium chloride added is 0.02-0.15:1 by mass of tannic acid. Stir quickly while adding the solution. Continue stirring at room temperature for 20-60 minutes to allow the solution to react fully. (6) After the reaction is complete, the precipitate is separated and washed thoroughly with an organic solvent to obtain a gel-like sample; (7) The ternary organic-inorganic hybrid material for adsorbing antibiotics in water is obtained by heating and drying the gel sample.

2. The preparation method of the ternary organic-inorganic hybrid material for adsorbing antibiotics in water according to claim 1, characterized in that: The degree of substitution of chitosan quaternary ammonium salt used in step (1) is 40%.

3. The preparation method of the ternary organic-inorganic hybrid material for adsorbing antibiotics in water according to claim 1, characterized in that: In step (1), the concentration of solution A is 20 wt%.

4. The method for preparing the ternary organic-inorganic hybrid material for adsorbing antibiotics in water according to claim 1, characterized in that: In step (2), the concentration of solution B is 10 wt%.

5. The preparation method of the ternary organic-inorganic hybrid material for adsorbing antibiotics in water according to claim 1, characterized in that: In step (3), the concentration of the zirconium chloride aqueous solution is 0.1 g / mL.

6. The preparation method of the ternary organic-inorganic hybrid material for adsorbing antibiotics in water according to claim 1, characterized in that: In step (4), the mass ratio of chitosan quaternary ammonium salt to tannic acid in the mixed solution is 2:

1.

7. The preparation method of the ternary organic-inorganic hybrid material for adsorbing antibiotics in water according to claim 1, characterized in that: In step (5), the dropping rate of solution C is 0.5-2.5 mL / min.

8. The method for preparing the ternary organic-inorganic hybrid material for adsorbing antibiotics in water according to claim 1, characterized in that: In step (6), the precipitate is separated by centrifugation, and the organic solvent is anhydrous ethanol.

9. The method for preparing the ternary organic-inorganic hybrid material for adsorbing antibiotics in water according to claim 1, characterized in that: In step (7), the heating and drying process is carried out in an electric constant temperature drying oven.

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