Application of modified MIL-101 in adsorption removal of sulfonamide antibiotics in water system

Abstract

The modified MIL-101 is used for adsorbing and removing sulfonamide antibiotics in a water system, and belongs to the field of water treatment. According to the novel application of the MIL-101-X material, X is fatty amine and is used for adsorbing and removing sulfonamide antibiotics in a water system. The principle is that a skeleton structure of a series of modified MIL-101 materials can generate pi-pi interaction with benzene rings in antibiotic molecules, alkyl chains pointing to the interior of pore channels in the series of modified MIL-101 materials contain rich C-H bonds, and N and O heteroatoms in the antibiotic molecules can be attracted to form hydrogen bonds through H-bond interaction, so that the antibiotic activity is improved. Therefore, the sulfonamide antibiotics in the aqueous solution can be well adsorbed in the pore channels of the material. The preparation method of the material is simple, equal-proportion amplification production can be easily achieved, and the material has high water stability, acid-base stability and heat stability. The adsorbent has a remarkable adsorption effect on sulfonamide antibiotics in water, especially sulfasalazine, and has a good recycling potential.

Description

Technical Field

[0001] The invention relates to the technical field of metal organic frameworks and to application of a novel modified MIL-101 material. The MOF material has a microporous structure and can adsorb and remove sulfonamide antibiotics in a water system. Technical Background

[0002] Sulfonamide antibiotics include sulfasalazine, sulfamethoxazole, sulfapyridine, etc. They are a class of widely used synthetic broad-spectrum antibiotics, which mainly achieve antibacterial effects by inhibiting the synthesis of bacterial folate and nucleic acid, and play an important role in clinical medicine and livestock and poultry farming. However, sulfonamides and other antibiotics are easily discharged into rivers, lakes and groundwater through drugs, agriculture, and sewage treatment, causing damage to the water ecology, and may also cause the emergence of various drug-resistant bacteria, posing a serious threat to the ecological environment and human health.

[0003] Generally, conventional treatment methods for sulfonamide antibiotics in water mainly include photocatalytic degradation, biodegradation, adsorption and membrane separation technology, among which adsorption has attracted widespread attention due to its significant advantages such as simple operation, high treatment efficiency, no secondary pollution and low energy consumption. However, these adsorbents only transfer antibiotics to a new phase, do not completely eliminate antibiotics, easily cause secondary pollution, and have disadvantages such as high cost and short service life. The photocatalytic method is too expensive for the complete mineralization of antibiotics and may produce toxic byproducts; the biodegradation method has poor treatment effect on antibiotics, and antibiotics have an inhibitory effect on the growth of microorganisms. The biodegradation method can only remove part of the antibiotics, and the removal effect is not ideal; the activated sludge method has good water treatment effect and stable operation and is widely used, but the operation cost is high and the removal efficiency is not high; the membrane separation technology has high efficiency and simple operation, such as ultrafiltration, reverse osmosis and microfiltration, but the investment cost is high and the operation energy consumption is high. At the same time, the concentration of sulfonamide antibiotics in the environment is relatively low, so the current traditional adsorbents have limited ability to remove antibiotics. Therefore, it is particularly important to develop adsorbents with high adsorption capacity and strong ultimate adsorption capacity for sulfonamide antibiotics.

[0004] Metal-Organic Frameworks (MOFs) are a new type of porous material, which is formed by metal ions or metal clusters and organic ligands through complexation, and has high porosity and specific surface area. Due to the characteristics of porous MOF materials such as designable structure, easy modification and adjustment of pores, and large specific surface area, it is easy to prepare MOF materials with high adsorption capacity and trace adsorption capacity. It has developed rapidly in the adsorption and removal of environmental pollutants such as heavy metal ions, persistent organic pollutants, pesticides, and veterinary drugs.

[0005] Sulfonamide antibiotics all have the structural characteristics of a benzene ring, a para-amino group and a sulfonamide group. Based on this structural feature, MIL-101(Cr) with bare metal sites and large specific surface area was selected and post-synthesizedly modified with 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, and to explore its adsorption and removal effect on sulfonamide antibiotics. Summary of the invention

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

[0007] To achieve the above-mentioned purpose, the present invention provides a series of new uses of MIL-101-X materials synthesized by an improved solvothermal method (method), wherein X=fatty amines, preferably pro, hex, dod, oct, chex, HMTA, TEDA, wherein pro is propylamine (Propylamine=pro), hex is n-hexylamine (n-Hexylamine=hex), dod is n-dodecylamine (n-Dodecylamine=dod), oct is n-octadecylamine (Octadecanamine=oct), chex is cyclohexylamine (Cyclohexylamine=chex), HMTA is hexamethylenetetramine (HMTA), TEDA is triethylenediamine (Triethylenediamine=TEDA), and dod is further preferred.

[0008] The present invention adopts the series of MIL-101-X materials to adsorb and remove sulfonamide antibiotics in a water system, and is used for static adsorption or filling filtration penetration adsorption. The sulfonamide antibiotics are one or more of sulfasalazine, sulfamethoxazole, etc.

[0009] Through static adsorption and penetration experiments, it can be known that the MIL-101-X series materials have excellent performance in adsorbing sulfonamide antibiotics in water. The material can penetrate and adsorb 200-500mL of sulfasalazine solution with a concentration of ppm. For example, every 2-10mg of the MIL-101-X series material can treat 200-500mL of sulfasalazine solution to achieve a good effect, even close to 100% removal rate, and has good application value in trace adsorption of sulfonamide antibiotics. The treatment temperature range is widely 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. In addition, the alkyl chain pointing to the inside of the pores in the MIL-101-dod material can attract nitrogen and oxygen atoms in the antibiotic molecules to form hydrogen bonds, so the static adsorption of sulfonamide antibiotics in aqueous solution can be well achieved inside the pores of the material. The material has a simple preparation process, strong stability, has a significant adsorption effect on sulfonamide antibiotics in water, and has good potential for recycling. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 The specific reaction formula for modifying MIL-101 with a series of fatty amines is shown in FIG.

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

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

[0014] Figure 4 Schematic diagram of the effluent concentration of the breakthrough experiment of 5 mg MIL-101-dod material with an initial concentration of 5 ppm of sulfasalazine at room temperature. DETAILED DESCRIPTION

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

[0016] Regarding the MIL-101-X material synthesized by the improved solvothermal method, the modifier used is the corresponding fatty amine compound. Please refer to ZL202110556561X.

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

[0018] Figure 1 The specific reaction formula for modifying MIL-101 with a series of fatty amines is shown in FIG.

[0019] The synthetic modification method of the modified MIL-101 material of the present invention mainly comprises the following steps:

[0020] (1) Activation of materials: Preheat MIL-101 in an oven at 160°C for no less than 4 hours to remove the water molecules on the central metal site to obtain activated MIL-101;

[0021] (2) Preparation of modified MIL-101(Cr)-X with primary amine-modified metal sites: X (X = pro, hex, dod, oct, chex, hmta, teda) and a protic organic solvent are mixed evenly and added to a high-pressure reactor under nitrogen protection, followed by adding the MIL-101(Cr) activated by calcination at 160°C in step (1), and nitrogen protection is filled again, and heated to 80-120°C for reaction for 20-26 hours;

[0022] (3) Purification: After step (2), the impurities were washed away with 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°C to obtain the successfully modified MIL-101-X;

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

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

[0025] Example 1: Static adsorption of sulfonamide antibiotics

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

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

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

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

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

[0031] The above results show that the above-mentioned MIL-101-X has a certain adsorption effect on sulfonamide antibiotics. Among them, the MIL-101-dod material can completely adsorb and remove sulfasalazine within 1 hour (reaching a removal rate of 100%), and achieve a removal rate of 95% 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 bodies.

[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 with pure quartz sand in a quartz tube with a length of 12 cm and an inner diameter of 2 mm.

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

[0035] Figure 4 Schematic diagram of the effluent concentration of the breakthrough experiment of 5 mg MIL-101-dod material for a sulfasalazine solution with an initial concentration of 5 ppm at room temperature.

[0036] The above results show that milligram-level MIL-101-dod samples have a good adsorption effect on sulfonamide antibiotics. 5 mg of MIL-101-dod sample can purify about 260 mL of 5 ppm sulfasalazine solution. Moreover, the concentration of sulfasalazine in the first 260 mL of filtrate is extremely low, and the ultraviolet spectrometer can hardly detect its absorbance. After 260 mL, the concentration of sulfasalazine in the filtrate gradually increases. The experiment shows that MIL-101-dod has excellent trace adsorption performance for sulfonamide antibiotics.

[0037] The above contents are only preferred examples of the present invention, but the present invention should not be limited to the contents disclosed in the examples. Therefore, any equivalent or modified contents completed without departing from the spirit disclosed in the present invention shall fall within the scope of protection of the present invention.

Claims

1. Use of a series of MIL-101-X materials synthesized by improved solvothermal method, X = fatty amines, for adsorption and removal of sulfonamide antibiotics in water systems.

2. The use according to claim 1, characterized in that X=one or more of pro, hex, dod, oct, chex, HMTA, TEDA, wherein pro is propylamine (Propylamine=pro), hex is n-hexylamine (n-Hexylamine=hex), dod is n-dodecylamine (n-Dodecylamine=dod), oct is n-octadecylamine (Octadecanamine=oct), chex is cyclohexylamine (Cyclohexylamine=chex), HMTA is hexamethylenetetramine (HMTA), and TEDA is triethylenediamine (Triethylenediamine=TEDA).

3. The use according to claim 1, characterized in that X=dod.

4. The use according to claim 1, characterized in that The sulfonamide antibiotics are one or more of sulfasalazine, sulfamethoxazole and the like.

5. The use according to claim 1, characterized in that: Used for static adsorption or filled filter penetration adsorption.

6. The use according to claim 5, characterized in that The maximum adsorption capacity of the material corresponding to the static adsorption treatment of sulfasalazine solution with a concentration of ppm is 350 to 450 mg / g.

7. The use according to claim 5, characterized in that Every 2 to 10 mg of the material corresponds to 200 to 500 mL of a sulfasalazine solution having a concentration of ppm.

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

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