Modified MIL-101 is used for the adsorption and removal of sulfonamide antibiotics in water systems.

Abstract

Modified MIL-101 is used for the adsorption and removal of sulfonamide antibiotics in water systems, belonging to the field of water treatment. A new application of MIL-101-X material, where X = aliphatic amines, is for the adsorption and removal of sulfonamide antibiotics in water systems. The principle is that the skeletal structure of the series of modified MIL-101 materials can generate π-π interactions with the benzene rings in antibiotic molecules. In addition, the alkyl chains pointing inwards in the MIL-101 materials contain abundant C-H bonds, which can attract N and O heteroatoms in antibiotic molecules to form hydrogen bonds through H-bond interactions. Therefore, the adsorption of sulfonamide antibiotics in aqueous solutions can be effectively achieved within the pores of this material. The preparation method of this material is simple, and it can be easily scaled up to a uniform scale. It has strong water stability, acid-base stability, and thermal stability. It has a significant adsorption effect on sulfonamide antibiotics in water, especially sulfasalazine, and has good recycling potential.

Description

Technical Field

[0001] This invention relates to the field of metal-organic framework technology and to the application of a novel modified MIL-101 material, which has a microporous structure and can adsorb and remove sulfonamide antibiotics from aqueous systems. Technical Background

[0002] Sulfonamide antibiotics, including sulfasalazine, sulfamethoxazole, and sulfapyridine, are a class of widely used synthetic broad-spectrum antibiotics. They primarily exert their antibacterial effect by inhibiting the synthesis of folic acid and nucleic acids in bacteria, playing an important role in clinical medicine and livestock farming. However, sulfonamides and other antibiotics can easily enter rivers, lakes, and groundwater through pharmaceutical, agricultural, and wastewater treatment processes, causing damage to aquatic ecosystems and potentially leading to the emergence of various drug-resistant bacteria, posing a serious threat to the ecological environment and human health.

[0003] Conventional methods for treating sulfonamide antibiotics in water typically include photocatalytic degradation, biodegradation, adsorption, and membrane separation. Adsorption, in particular, has attracted widespread attention due to its simple operation, high efficiency, lack of secondary pollution, and low energy consumption. However, these adsorbents merely transfer antibiotics to a new phase without completely eliminating them, potentially causing secondary pollution and suffering from drawbacks such as high cost and short lifespan. Photocatalysis is too costly for complete antibiotic mineralization and may produce toxic byproducts. Biodegradation is ineffective, and since antibiotics inhibit microbial growth, it only removes a portion of the antibiotics, resulting in unsatisfactory removal. Activated sludge processes are widely used due to their good water treatment performance and stable operation, but they are costly and have low removal efficiency. Membrane separation technologies, including ultrafiltration, reverse osmosis, and microfiltration, offer high efficiency and simple operation, but require high investment and consume significant energy. Furthermore, the concentration of sulfonamide antibiotics in the environment is relatively low, limiting the removal capacity of current traditional adsorbents. Therefore, it is particularly important to develop adsorbents with high adsorption capacity and strong limiting adsorption ability for sulfonamide antibiotics.

[0004] Metal-organic frameworks (MOFs) are a novel type of porous material formed by the complexation of metal ions or metal clusters with organic ligands, exhibiting high porosity and specific surface area. Due to the designable structure, easily modifiable and tunable pores, and large specific surface area of ​​porous MOFs, it is easy to prepare MOF materials with high adsorption capacity and trace adsorption capabilities. Their application in the adsorption and removal of environmental pollutants such as heavy metal ions, persistent organic pollutants, pesticides, and veterinary drugs has developed rapidly.

[0005] Sulfonamide antibiotics all possess a structural feature of a benzene ring, a para-amino group, and a sulfonamide group. Based on this structural characteristic, MIL-101(Cr), which has a bare metal site and a large specific surface area, was selected and post-synthesized using propylamine (PRO), n-hexylamine (HEX), cyclohexylamine (CHEX), dodecylamine (DOD), octadecylamine (OCT), hexamethylenetetramine (HMTA), and triethylenediamine (TEDA) to enhance the interaction between the MOF framework and sulfonamide antibiotics. The adsorption and removal efficiency of sulfonamide antibiotics was then investigated. Summary of the Invention

[0006] The purpose of this invention is to use a series of MIL-101 materials modified with different aliphatic amines and MIL-101 itself to adsorb sulfonamide antibiotics, so as to solve the problem of removing sulfonamide antibiotics from water systems.

[0007] To achieve the above objectives, this invention provides a series of new uses for MIL-101-X materials synthesized by an improved solvothermal method, where X = aliphatic amines, preferably pro, hex, dod, oct, chex, HMTA, and TEDA, wherein pro is propylamine (Propylamine = Pro), hex is n-hexylamine (n-Hexylamine = Hex), dod is n-Dodecylamine (n-Dodecylamine = Dod), oct is octadecanamine (Octadecanamine = Octt), chex is cyclohexylamine (Cyclohexylamine = Chex), HMTA is hexamethylenetetramine (HMTA), and TEDA is triethylenediamine (Triethylenediamine = TEDA), with dod being even more preferred.

[0008] This invention uses the MIL-101-X series of materials for adsorption and removal of sulfonamide antibiotics in water systems, for static adsorption or packed filter breakthrough adsorption, wherein the sulfonamide antibiotics are one or more of sulfasalazine, sulfamethoxazole, etc.

[0009] Static adsorption and breakthrough experiments demonstrate that the MIL-101-X series material exhibits excellent adsorption performance for sulfonamide antibiotics in water. This material can effectively treat 200–500 mL of sulfasalazine solution with a concentration at the ppm level. For example, 2–10 mg of the MIL-101-X series material can treat 200–500 mL of sulfasalazine solution with good results, even approaching 100% removal rate. It has significant application value in the trace adsorption of sulfonamide antibiotics. The treatment temperature range is wide, from room temperature to 50℃.

[0010] The principle is that the effective pore size of the modified MIL-101, especially MIL-101-dod, is comparable to the molecular size of sulfonamide antibiotics. Furthermore, the alkyl chains pointing inwards in the pores of MIL-101-dod can attract nitrogen and oxygen heteroatoms in the antibiotic molecules to form hydrogen bonds. Therefore, static adsorption of sulfonamide antibiotics in aqueous solution can be effectively achieved within the pores of this material. The preparation process of this material is simple, it has strong stability, exhibits significant adsorption effects on sulfonamide antibiotics in water, and has good potential for recycling. Attached Figure Description

[0011] Figure 1 The chemical formulas for the specific reactions of modifying MIL-101 with a series of aliphatic amines are shown.

[0012] Figure 2 The graph shows the removal efficiency of 1 mg MIL-101-X material after static adsorption experiment on 4 mL of sulfamethoxazole aqueous solution with an initial concentration of 10 ppm at room temperature.

[0013] Figure 3 The graph shows the removal efficiency of 1 mg MIL-101-X material after static adsorption experiment on 4 mL of sulfasalazine aqueous solution with an initial concentration of 40 ppm at room temperature.

[0014] Figure 4 This is a schematic diagram of the effluent concentration in a breakthrough experiment of 5 mg MIL-101-dod material at room temperature for an initial concentration of 5 ppm of sulfasalazine. Detailed Implementation

[0015] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments, but the present invention is not limited to the following embodiments.

[0016] Regarding the modified solvothermal synthesis of MIL-101-X material, the modifier used is the corresponding aliphatic amine compound. See ZL202110556561X.

[0017] Preferably, the mass ratio of MIL-101 to the modifier is 1:1 to 1:2, and generally the modifier is in excess.

[0018] Figure 1 The chemical formulas for the specific reactions of modifying MIL-101 with a series of aliphatic amines are shown.

[0019] The method for synthesizing and modifying the above-mentioned modified MIL-101 material of the present invention mainly includes the following steps:

[0020] (1) Activation material: MIL-101 is placed in an oven at 160℃ for no less than 4 hours to remove water molecules from the central metal site to obtain activated MIL-101;

[0021] (2) Preparation of primary amine-modified metal site modified MIL-101(Cr)-X: Mix X (X = pro, hex, dod, oct, chex, hmta, teda) with proton organic solvent and add it to a high-pressure reactor under nitrogen protection. Then add the MIL-101(Cr) activated by calcination at 160℃ in step (1), fill with nitrogen protection again, and heat to 80-120℃ for 20-26 hours.

[0022] (3) Purification: After step (2) is completed, impurities are washed away by N,N-dimethylformamide (DMF), ethyl acetate (EA) and petroleum ether (PE) in sequence. The product is purified by centrifugation at 10,000 rpm and dried in an oven at 80-120℃ to obtain successfully modified MIL-101-X.

[0023] Preferably, the solvent is an aprotic organic solvent.

[0024] Preferably, the aprotic organic solvent is one or more of cyclohexane or toluene.

[0025] Example 1: Static adsorption of sulfonamide antibiotics

[0026] Step 1: Weigh the milligram level MIL-101-X sample and add it to a glass bottle containing a fixed volume of sulfasalazine and sulfamethoxazole aqueous solution at a fixed concentration of ppm. Let it stand in a constant temperature water bath for 1 hour for adsorption.

[0027] Step 2: Filter the above mixture through a filter membrane and retain the supernatant to remove any residual solid adsorbent in the mixture so as not to affect the determination of the ultraviolet spectrum. Transfer the supernatant to a new glass bottle for testing.

[0028] Step 3: Measure the concentration change of the above solution using an ultraviolet spectrometer, with a scanning wavelength range of 200nm-500nm.

[0029] Figure 2 The graph shows the removal efficiency of 1 mg MIL-101-X material after static adsorption experiment on 4 mL of sulfamethoxazole aqueous solution with an initial concentration of 10 ppm at room temperature.

[0030] Figure 3 The graph shows the removal efficiency of 1 mg MIL-101-X material after static adsorption experiment on 4 mL of sulfasalazine aqueous solution with an initial concentration of 40 ppm at room temperature.

[0031] The above results indicate that MIL-101-X has a certain adsorption effect on sulfonamide antibiotics. Among them, MIL-101-dod material can completely adsorb and remove sulfasalazine (achieving a 100% removal rate) within 1 hour, and achieve a 95% removal rate for sulfamethoxazole within 1 hour. It has good trace static adsorption performance for sulfonamide antibiotics and has good application prospects in the field of adsorption and removal of sulfonamide antibiotics in water.

[0032] Example 2: Penetration and Adsorption of Sulfonamide Antibiotics

[0033] Step 1: Accurately weigh milligram-level MIL-101-dod sample, mix it evenly with quartz sand, and then fill it into a quartz tube with a length of 12cm and an inner diameter of 2mm, alternating it with pure quartz sand.

[0034] Step 2: Prepare a ppm-level solution of sulfasalazine at a predetermined concentration and pass it through a quartz tube filled with MIL-101-dod sample at a rate of 1–10 mL / 20 min. The solution flows in from the bottom and out from the top of the tube. Collect 4 mL of the filtrate each time and determine its concentration using a UV spectrometer (wavelength 200 nm–500 nm, slit width 5 nm).

[0035] Figure 4 This is a schematic diagram of the effluent concentration in a breakthrough experiment of 5 mg MIL-101-dod material at room temperature against an initial concentration of 5 ppm sulfasalazine solution.

[0036] The above results indicate that milligram-level MIL-101-dod samples exhibit good adsorption effects on sulfonamide antibiotics. 5 mg of MIL-101-dod can purify approximately 260 mL of a 5 ppm sulfasalazine solution. Furthermore, the concentration of sulfasalazine in the first 260 mL of filtrate is extremely low, almost undetectable by UV spectroscopy; the concentration only gradually increases after 260 mL. This demonstrates that MIL-101-dod possesses excellent trace adsorption performance for sulfonamide antibiotics.

[0037] The above description is merely a preferred embodiment of the present invention, but the present invention should not be limited to the content disclosed in this embodiment. Therefore, any equivalent or modified versions made without departing from the spirit of the present invention fall within the scope of protection of the present invention.

Claims

1. The use of a modified solvothermal synthesized MIL-101(Cr)-X material, X = dod, for treating sulfasalazine solutions; The preparation method of the above-mentioned modified solvothermal method for synthesizing MIL-101(Cr)-X material includes the following steps: (1) Activation material: MIL-101(Cr) was placed in an oven at 160°C for no less than 4 hours to remove water molecules from the central metal site to obtain activated MIL-101(Cr); (2) Preparation of primary amine-modified metal site modified MIL-101(Cr)-X: X is mixed with proton organic solvent and added to high pressure reactor, X = dod, dod is n-dodecylamine, nitrogen protection is applied, then MIL-101(Cr) activated by calcination at 160℃ in step (1) is added, nitrogen protection is applied again, and the mixture is heated to 80-120℃ for 20-26 hours. (3) Purification: After step (2), impurities were washed away by N,N-dimethylformamide (DMF), ethyl acetate (EA), and petroleum ether (PE) in sequence. The product was purified by centrifugation at 10,000 rpm and dried in an oven at 80-120℃ to obtain successfully modified MIL-101(Cr)-X. The solvent is one or a mixture of cyclohexane or toluene.

2. The use according to claim 1, characterized in that, 1 mg of MIL-101(Cr)-X material was used to treat 4 mL of sulfasalazine aqueous solution with an initial concentration of 40 ppm.

3. The use according to claim 1, characterized in that, The processing temperature range is wide, from room temperature to 50℃.

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