A magnetic composite material for antibiotic degradation and a method for preparing the same

Abstract

The application discloses a magnetic composite material for antibiotic degradation and a preparation method thereof, and belongs to the fields of metal organic framework material preparation and water treatment technology. The magnetic composite material is Co@Cu / C, and the preparation method is as follows: a Co / Cu-MOF precursor with high crystallinity is prepared through magnetic stirring at room temperature; after drying after impurity removal through washing, the obtained Co / Cu-MOF precursor is ground, placed into a tube furnace, calcined under a nitrogen atmosphere, and the magnetic Co@Cu / C composite material can be obtained after cooling. The magnetic composite material has the advantages of simple preparation process, low raw material cost, wide application range and easy recovery. When the magnetic composite material is used for degrading antibiotics, the efficiency is high and the magnetic composite material has anti-interference performance; for example, when catalyzing and degrading sulfamethoxazole, the removal rate can reach 96.8%, and the magnetic composite material can still maintain good degradation performance in the presence of inorganic ions SO4 2‑ , NO 3‑ , Cl ‑ and humic acid HA.

Description

Technical Field

[0001] This invention belongs to the fields of metal-organic framework material preparation and water treatment technology, specifically relating to a novel Cu-MOF-derived magnetic Co@Cu / C composite material for antibiotic degradation and its preparation method. Background Technology

[0002] Industrial and domestic wastewater, as well as the discharge of agricultural fertilizers and pesticides, are increasingly transferring pollutants into aquatic environments, thus raising critical questions about pollutant removal from wastewater. Antibiotics, a widely used drug, are being released into water in ever-increasing quantities and are frequently detected in rivers, sewage, and soil. Antibiotics have emerged as a widespread and significant pollutant and have been shown to induce the growth of drug-resistant bacteria and resistance genes. Given the potential threats antibiotics pose to organisms in aquatic environments and to human health, the safe and effective removal of these emerging pollutants is urgently needed.

[0003] Sulfonamide antibiotics, once introduced into the aquatic environment, exert a range of effects on microorganisms, aquatic animals, and human health. Studies have shown that sulfonamide antibiotics have varying degrees of ecotoxicological effects on organisms at different trophic levels, such as bacteria, algae, crustaceans, rotifers, and fish, with particularly significant effects on algae. In humans, sulfonamides exhibit neurotoxicity, directly related to neurological and psychiatric disorders such as abnormal intestinal transit function, sensory disturbances, and neuropsychiatric complications. After ingestion, sulfonamide antibiotics are absorbed by the human intestinal tissue and circulatory system, affecting immune function, the central and peripheral nervous systems; they also indirectly affect nervous system function through the gut microbiota. Furthermore, bacteria long-term exposure to sulfonamide antibiotics can develop resistance genes through gene mutations, which are then continuously spread through transformation, transduction, and conjugation transfer, leading to increased bacterial resistance and weakening their role in disease prevention and treatment, thus impacting human health. In recent years, the pollution of wastewater by sulfamethoxazole (SMX) has attracted widespread attention. As a common sulfonamide antibiotic, SMX has a long half-life and is difficult to biodegrade, making it persistent in the aquatic environment and difficult to completely remove using biological or conventional physical methods. There is an urgent need for efficient and energy-saving treatment methods to solve the problem of SMX-containing wastewater.

[0004] Advanced oxidation processes (AOPs) using peracetic acid (PAA) are considered effective technologies for antibiotic removal due to their high speed and removal efficiency. PAA, as a highly efficient oxidant, offers numerous advantages in treating organic pollutants. It possesses a high oxidation potential (E0 1.0-1.96V), effectively decomposing organic pollutants in water. Furthermore, PAA produces fewer byproducts during water treatment, and these byproducts are low in toxicity, reducing secondary pollution. Additionally, PAA exhibits high tolerance to different water substrates, making it suitable for wastewater treatment under varying water quality conditions. During degradation, the reactive oxygen species (ROS) generated by PAA can attack multiple functional groups of organic pollutants, achieving efficient degradation. Developing catalysts with high catalytic activity is a key factor in addressing these challenges. Metal-organic frameworks (MOFs), a new generation of crystalline porous materials with a porous structure formed by coordination bonds between metal ions or clusters and organic ligands, have been a research hotspot in coordination chemistry for the past 20 years. MOFs exhibit significant advantages in degrading organic pollutants, primarily due to their unique high specific surface area, designable porous structure, and excellent chemical stability. With a specific surface area as high as 1000 m² / g, MOFs provide abundant active sites for organic pollutants, effectively enhancing degradation efficiency. Their porous structure allows for selective adsorption and catalytic reactions, while the designability of the structure enables researchers to customize MOFs according to the characteristics of different pollutants to achieve optimal degradation results. Furthermore, the chemical stability of MOFs ensures that they maintain catalytic performance even under harsh environmental conditions, giving them enormous application potential in the field of organic pollutant degradation. Among numerous metal or metal oxide catalyst materials, the development of copper-based metal-organic frameworks is highly beneficial for activating peracetic acid to improve the catalytic activity of materials. Therefore, there is an urgent need to develop copper-based metal-organic frameworks for the removal of sulfonamide antibiotics from the aquatic environment.

[0005] In the prior art, there are some achievements in the preparation methods of Cu-MOF derived materials. For example, Chinese Patent Application No. 202310945093.4, published on December 15, 2023, discloses a patent document entitled "An SCN-Cu-MOF Nanomaterial and Its Preparation Method and Application." This patent proposes to modify copper-based metal-organic framework materials (Cu-MOF) with thiocyanate composites, synthesize SCN-Cu-MOF nanomaterials using a hydrothermal method, and apply SCN-Cu-MOF nanomaterials to the catalytic degradation of tetracycline. However, this material... The anti-interference ability and acid / alkali resistance are unclear, and the practical application effect is still uncertain. Furthermore, the synthesis cost of this material is high, and its recycling after use faces challenges, making practical application difficult. Chinese Patent Application No. 202311548896, published on February 23, 2024, discloses a patent document entitled "A Preparation Method of a Copper-Based Metal-Organic Framework Material for Olefin-Alkane Separation." This patent involves fixing a copper-based metal-organic framework containing divalent copper in a stable olefin gas stream and carrying out a reduction reaction to obtain a metal-organic framework adsorbent containing monovalent copper active components. However, this material may have the risk of desorption and is susceptible to environmental influences, easily causing secondary pollution. Chinese Patent No. 202411329819, published on October 29, 2024, discloses a patent document entitled "An Antibacterial Gallium-Copper Bimetallic MOF Nanomaterial and Its Preparation Method and Application." This invention provides an antibacterial gallium-copper bimetallic organic framework (Ga / Cu-MOF) nanomaterial. By adjusting the ion doping ratio, adding 2-methylimidazole and polyvinylpyrrolidone regulators, and adding trifluoroacetic acid to adjust the pH, gallium and copper were successfully integrated to prepare Ga / Cu-MOF nanomaterials. These materials were then used to load antibiotics to eliminate intracellular bacteria and biofilms in mouse skin defect infection models and rat osteomyelitis infection models. However, the preparation method of this material is complex, and its application in loading antibiotics to eliminate intracellular bacteria and biofilms differs significantly from that of sulfamethoxazole, which is a broad-spectrum antibiotic.

[0006] There are also related patents in the research technology of activated peracetic acid. For example, Chinese Patent No. 202410884472, published on October 11, 2024, discloses a patent entitled "Preparation of Iron-Nitrogen Doped Magnetic Wheat Straw Biochar and its Application in Degrading New Pollutants". This invention proposes a method for preparing iron-nitrogen doped magnetic wheat straw biochar and applies it to the degradation of diclofenac sodium by activated peracetic acid. However, the recyclability and stability of this material are unclear, and its actual application effect is unknown. Chinese Patent Application No. 202410983891, published on November 22, 2024, discloses a patent entitled "Method for Degrading Cefazolin Sodium by Activating Peracetic Acid with Reduced Hematite". This material has a relatively narrow pH range for effectively removing antibiotics, thus limiting the removal of antibiotics in acidic and alkaline environments.

[0007] In the research technology of sulfamethoxazole removal, some good methods already exist. For example, Chinese patent application No. 202211256009, published on January 20, 2023, entitled "A preparation method and application of sulfamethoxazole biochar adsorbent", synthesizes a novel FeN co-doped biochar by one-step pyrolysis of palm fiber, urea and FeSO4·7H2O for adsorbing sulfamethoxazole. However, compared with metal-organic framework materials, biochar materials have weaker catalytic activity, longer catalytic time and lower selectivity, and are difficult to regenerate. Chinese Patent Application No. 202411249933, published on October 11, 2024, discloses a patent document entitled "Method for Removing Sulfamethoxazole from Water by In-situ Etched Carbon Felt Modified with Iron Phosphate". This method uses a ruthenium-iridium-titanium electrode as the anode and an FeP@ECC electrode as the cathode to remove sulfamethoxazole from the target wastewater. Compared with this patent, this method has high energy loss, may produce harmful byproducts, has stringent requirements for reaction conditions, and is not easy to implement industrially. Summary of the Invention

[0008] In view of the shortcomings and deficiencies of existing technologies for removing antibiotics from water and the poor anti-interference performance of catalysts, the purpose of this invention is to provide a magnetic composite material for antibiotic degradation in order to solve the above problems.

[0009] To solve the above problems, the present invention adopts the following technical solution.

[0010] This invention provides a magnetic composite material for antibiotic degradation, the magnetic composite material being Co@Cu / C, and its preparation method specifically includes the following steps:

[0011] (1) Preparation of Co / Cu-MOF: Copper acetate monohydrate and cobalt chloride hexahydrate were dissolved in anhydrous ethanol to obtain solution A; 2,5-dihydroxyterephthalic acid was dissolved in anhydrous ethanol to obtain solution B; then solution B was slowly added dropwise to solution A at room temperature; the mixture was stirred under a magnetic stirrer for 24 h, and the precipitate was obtained after centrifugation; the precipitate obtained after centrifugation was washed with anhydrous ethanol and dried to obtain Co / Cu-MOF.

[0012] The molar ratio of copper acetate monohydrate to cobalt chloride hexahydrate is 2.3 to 19:1.

[0013] (2) Preparation of magnetic Co5@Cu / C composite material: The obtained Co / Cu-MOF was ground and then placed in a tube furnace for calcination. After cooling, the derived magnetic Co@Cu / C composite material was obtained.

[0014] Furthermore, in step (1), the molar ratio of copper acetate monohydrate to cobalt chloride hexahydrate is 4:1.

[0015] Furthermore, in step (1), the drying conditions are: drying overnight at 60°C.

[0016] Furthermore, in step (2), the calcination conditions are: calcining at 600°C for 120 min at a heating rate of 2°C / min under N2 atmosphere, followed by cooling at room temperature.

[0017] The magnetic Co@Cu / C composite material obtained by the above preparation method can be used in the removal of antibiotics from water.

[0018] Furthermore, the antibiotic is sulfamethoxazole.

[0019] The specific principles of this invention are speculated as follows:

[0020] SMX molecules in the wastewater are first adsorbed onto the surface of the porous structure of the derived magnetic Co@Cu / C composite material. The Cu and Co species and surface functional groups in the magnetic Co@Cu / C composite material are the main active sites for PAA activation. ·OH groups are generated in the reaction system. 1 O2 and RO·, among which 1 O2 plays a dominant role in the degradation of SMX. These highly oxidizing free radicals destroy the SMX structure through oxidation reactions, ultimately leading to degradation.

[0021] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0022] (1) The magnetic Co@Cu / C composite material of the present invention can effectively remove SMX from water. Under the conditions of initial SMX concentration of 10 mg / L, original SMX solution pH = 7.28, PAA dosage of 0.5 mM, and material dosage of 100 mg / L, the SMX removal rate of the activated PAA by the magnetic Co@Cu / C composite material after 30 min of reaction is 96.8%, and the reaction process can reach equilibrium in 5 min.

[0023] (2) The magnetic Co@Cu / C composite material of the present invention has high efficiency in degrading antibiotics, and the material has anti-interference properties when catalyzing the degradation of SMX, in the presence of NO3- ions. - SO4 2- Cl - Furthermore, it can maintain good degradation performance even in the presence of humic acid (HA), and its removal of SMX from water is less affected by the acidity or alkalinity of the environment.

[0024] (3) The preparation process of this invention is simple. Co / Cu-MOF is synthesized by stirring at room temperature, and magnetic Co@Cu / C composite material is synthesized by temperature-controlled calcination. The raw material cost is low, the removal efficiency is high, the application range is wide, and the material is magnetic and easy to recycle. Attached Figure Description

[0025] Figure 1 The magnetic Co obtained according to Example 3 of the present invention 20 Scanning electron microscope image of the Cu / C composite material morphology.

[0026] Figure 2 The magnetic Co obtained according to Example 3 of the present invention 20 Comparison test results of the Cu / C composite material on the degradation of SMX by activated PAA.

[0027] Figure 3 The magnetic Co obtained according to Example 3 of the present invention 20 The effect of Cu / C composite material on the degradation and removal of SMX by activated PAA under different initial solution pH values ​​is shown in the figure.

[0028] Figure 4 The magnetic Co obtained according to Example 3 of the present invention 20 @Cu / C composite material recycling test diagram.

[0029] Figure 5 The magnetic Co obtained according to Example 3 of the present invention 20 @Cu / C composite material activates PAA degradation SMX anti-Cl - Performance test chart.

[0030] Figure 6 The magnetic Co obtained according to Example 3 of the present invention20 @Cu / C composite material activates PAA to degrade SMX and resist NO3 - Performance test chart.

[0031] Figure 7 The magnetic Co obtained according to Example 3 of the present invention 20 @Cu / C composite material activates PAA, degrades SMX, and resists SO4. 2- Performance test chart.

[0032] Figure 8 The magnetic Co obtained according to Example 3 of the present invention 20 @Cu / C composite material activated PAA degradation SMX humic acid resistance test diagram. Detailed Implementation

[0033] The technical solution of the present invention will be further described in detail below with reference to specific embodiments, but this is not intended to limit the present invention.

[0034] Example 1

[0035] This embodiment provides a method for preparing a magnetic Co@Cu / C composite material for activating PAA to degrade antibiotics (wherein the cobalt doping amount is 5%, i.e., the molar ratio of Cu(OAc)2·H2O to CoCl2·6H2O is 95:5), and the material is named Co5@Cu / C. The method includes the following steps:

[0036] Preparation of Co / Cu-MOF: 0.3793 g Cu(OAc)₂·H₂O and 0.0238 g CoCl₂·6H₂O were dissolved in 25 ml of anhydrous ethanol to form solution A, and 0.2 g DHTP was dissolved in 10 ml of anhydrous ethanol to form solution B. Solution B was then slowly added dropwise to solution A at room temperature. The mixture was stirred with a magnetic stirrer for 24 h, and the precipitate was obtained after centrifugation. The precipitate was centrifuged four times with anhydrous ethanol. Finally, it was dried overnight at 60 °C to obtain Co / Cu-MOF.

[0037] Preparation of magnetic Co5@Cu / C composite material: The obtained Co / Cu-MOF was placed in a tube furnace and calcined under N2 atmosphere. The temperature was increased to 600℃ at a heating rate of 2℃ / min and calcined for 120min. The temperature was then lowered to room temperature and the product was collected to obtain the magnetic Co5@Cu / C composite material.

[0038] Example 2

[0039] This embodiment provides a method for preparing a magnetic Co@Cu / C composite material for activating PAA-degrading antibiotics (wherein the cobalt doping amount is 10%, i.e., the molar ratio of Cu(OAc)2·H2O to CoCl2·6H2O is 90:10), and the material is named Co. 10 The method described in @Cu / C includes the following steps:

[0040] Preparation of Co / Cu-MOF: 0.3594 g Cu(OAc)₂·H₂O and 0.0476 g CoCl₂·6H₂O were dissolved in 25 ml of anhydrous ethanol to form solution A, and 0.2 g DHTP was dissolved in 10 ml of anhydrous ethanol to form solution B. Solution B was then slowly added dropwise to solution A at room temperature. The mixture was stirred with a magnetic stirrer for 24 h, and centrifuged to obtain a precipitate. The precipitate was centrifuged four times and then purified of anhydrous ethanol. Finally, it was dried overnight at 60 °C to obtain Co / Cu-MOF.

[0041] Magnetic Co 10 @Cu / C Composite Material Preparation: The obtained Co / Cu-MOF was placed in a tube furnace and calcined under N2 atmosphere. The temperature was increased to 600℃ at a heating rate of 2℃ / min and calcined for 120 min. The temperature was then lowered to room temperature, and the product was collected to obtain magnetic Co. 10 @Cu / C composite material.

[0042] Example 3

[0043] This embodiment provides a method for preparing a magnetic Co@Cu / C composite material for activating PAA to degrade antibiotics (wherein the cobalt doping amount is 20%, i.e., the molar ratio of Cu(OAc)2·H2O to CoCl2·6H2O is 80:20), and the material is named Co. 20 The method described in @Cu / C includes the following steps:

[0044] Preparation of Co / Cu-MOF: 0.3194 g Cu(OAc)₂·H₂O and 0.0952 g CoCl₂·6H₂O were dissolved in 25 ml of anhydrous ethanol to form solution A, and 0.2 g DHTP was dissolved in 10 ml of anhydrous ethanol to form solution B. Solution B was then slowly added dropwise to solution A at room temperature. The mixture was stirred with a magnetic stirrer for 24 h, and centrifuged to obtain a precipitate. The precipitate was centrifuged four times and then ethanol-distilled four times. Finally, it was dried overnight at 60 °C to obtain Co / Cu-MOF.

[0045] Magnetic Co 20@Cu / C Composite Material Preparation: The obtained Co / Cu-MOF was placed in a tube furnace and calcined under N2 atmosphere. The temperature was increased to 600℃ at a heating rate of 2℃ / min and calcined for 120 min. The temperature was then lowered to room temperature, and the product was collected to obtain magnetic Co. 20 @Cu / C composite material.

[0046] Figure 1 The magnetic Co prepared in this embodiment 20 Scanning electron microscope image of the Cu / C composite material morphology.

[0047] Example 4

[0048] This embodiment provides a method for preparing a magnetic Co@Cu / C composite material for activating PAA to degrade antibiotics (wherein the cobalt doping content is 30%, i.e., the molar ratio of Cu(OAc)2·H2O to CoCl2·6H2O is 70:30), and the material is named Co. 30 The method described in @Cu / C includes the following steps:

[0049] Preparation of Co / Cu-MOF: 0.2795 g Cu(OAc)₂·H₂O and 0.1428 g CoCl₂·6H₂O were dissolved in 25 ml of anhydrous ethanol to form solution A, and 0.2 g DHTP was dissolved in 10 ml of anhydrous ethanol to form solution B. Solution B was then slowly added dropwise to solution A at room temperature. The mixture was stirred with a magnetic stirrer for 24 h, and centrifuged to obtain a precipitate. The precipitate was centrifuged four times with anhydrous ethanol. Finally, it was dried overnight at 60 °C to obtain Co / Cu-MOF.

[0050] Magnetic Co 30 @Cu / C Composite Material Preparation: The obtained Co / Cu-MOF was placed in a tube furnace and calcined under N2 atmosphere. The temperature was increased to 600℃ at a heating rate of 2℃ / min and calcined for 120 min. The temperature was then lowered to room temperature, and the product was collected to obtain magnetic Co. 30 @Cu / C composite material.

[0051] The catalysts prepared in Examples 1-4 were subjected to tests on the degradation of SMX by activated peracetic acid. The initial SMX concentration was 10 mg / L, the initial SMX pH was 7.28, the PAA dosage was 0.5 mM, the catalyst dosage was 100 mg / L, the oxidation degradation time was 8 min, the water temperature was 25℃, and the shaking speed was 200 rpm / min. The test data show that the magnetic Co@Cu / C composite materials obtained in Examples 1-4 of this invention have a significant effect on the degradation of SMX by activated peracetic acid (as shown in Table 1).

[0052] Table 1. Experimental results of SMX removal by activated peracetic acid in different embodiments.

[0053]

[0054] Example 5

[0055] This embodiment is the magnetic Co prepared in Example 3. 20 @Cu / C composite material activated PAA catalytic degradation of SMX removal rate test.

[0056] The magnetic Co prepared in Example 3 20 @Cu / C composite material is used to synergistically activate PAA degradation of SMX, as detailed below:

[0057] Weigh 5mg of magnetic Co 20 The Cu / C composite material was placed in a 100 mL glass bottle, and 50 mL of SMX (initial concentration 10 mg / L) solution was added. The pH of the SMX stock solution was 7.28, and the PAA dosage was 0.5 mmol / L. The degradation experiment was conducted in a constant temperature water bath shaker at 200 rpm / min. At regular intervals, 2 mL of the reaction solution was taken, filtered through a 0.45 μm filter membrane, and quenched with 100 mM sodium thiosulfate. The experiment lasted for 8 min. The concentration change was measured using high-performance liquid chromatography (HPLC), and the degradation rate was calculated. Figure 2 As shown, when the material prepared in Example 3 is used to activate PAA to degrade SMX, the degradation rate can reach 96.8% after 8 minutes.

[0058] Example 6

[0059] This embodiment is the magnetic Co in Example 3. 20 The removal rate of SMX by the @Cu / C composite material in different pH ranges was tested. For example... Figure 3 As shown, the pH range of the reaction system solution was adjusted to 3–11, and the magnetic Co... 20 The Cu / C composite material still exhibits good catalytic degradation performance.

[0060] Example 7

[0061] This embodiment is the magnetic Co prepared in Example 3. 20 Recyclability test of Cu / C composite materials.

[0062] In practical applications, catalysts not only need to be highly efficient and convenient, but also need to be reusable and have good stability. Magnetic Co 20 The degradation effect of the Cu / C composite material on SMX during 4 reuses is as follows: Figure 4As shown, the degradation rates of SMX after four reuses were 96.8%, 95%, 90%, and 88.8%, respectively. The catalyst still exhibits good removal efficiency for SMX even after four reuses.

[0063] Comparative Example

[0064] This comparative example is the magnetic Co prepared in Example 3. 20 Anti-interference test of @Cu / C composite material during PAA activation and SMX degradation.

[0065] During the degradation performance test in Example 5, 1-20 mmol / L of interfering ions Cl were added respectively. - NO 3- SO4 2- Or 1-20 mg / L humic acid, such as Figure 5-8 As shown, 20 mmol / L Cl was added to the system respectively. - NO 3- SO4 2 The degradation rates of SMX after using 20 mg / L humic acid were 85.6%, 91.8%, 90%, and 82.2%, respectively, demonstrating that the material has strong anti-interference ability.

Claims

1. A magnetic composite material for antibiotic degradation, characterized in that, The magnetic composite material is Co@Cu / C, and its preparation includes the following steps: (1) Preparation of Co / Cu-MOF: Copper acetate monohydrate and cobalt chloride hexahydrate were dissolved in anhydrous ethanol to obtain solution A; 2,5-dihydroxyterephthalic acid was dissolved in anhydrous ethanol to obtain solution B; then solution B was slowly added dropwise to solution A at room temperature; the mixture was stirred under a magnetic stirrer for 24 h, and the precipitate was obtained after centrifugation; The precipitate obtained after centrifugation was washed with anhydrous ethanol and dried to obtain Co / Cu-MOF; The molar ratio of copper acetate monohydrate to cobalt chloride hexahydrate is 2.3~19 : 1; Preparation of magnetic Co5@Cu / C composite material: The obtained Co / Cu-MOF was ground and then calcined in a tube furnace. After cooling, the derived magnetic Co@Cu / C composite material was obtained. The calcination refers to: heating to 600℃ for 120 minutes at a heating rate of 2℃ / min under N2 atmosphere, and then cooling down at room temperature.

2. The magnetic composite material for antibiotic degradation as described in claim 1, characterized in that, In step (1), the molar ratio of copper acetate monohydrate to cobalt chloride hexahydrate is 4:

1.

3. The magnetic composite material for antibiotic degradation as described in claim 1, characterized in that, In step (1), the drying refers to drying overnight at 60°C.

4. The application of the magnetic composite material as described in any one of claims 1-3 in the removal of antibiotics from water.

5. The application of the magnetic composite material as described in claim 4 in the removal of antibiotics from water, characterized in that, The antibiotic in question is sulfamethoxazole.

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