A hydrophilic magnetic polymer and a preparation method and application thereof

Abstract

The present disclosure provides a kind of hydrophilic magnetic polymer and its preparation method, application, the preparation method of the hydrophilic magnetic polymer, comprising: 3-amino-1,2,4-triazole is dissolved in deionized water, and 3-amino-1,2,4-triazole aqueous solution is obtained;The magnetic iron aluminum mixed hydroxide is added to deionized water, continuous stirring, after forming suspension, 3-amino-1,2,4-triazole aqueous solution is added, and after continuing to stir for a period of time, crosslinking agent is added, and after continuing to stir for a period of time, initiator is added, and a mixture is obtained;The mixture is transferred to an inert atmosphere environment, and polymerization reaction is carried out under the condition of 35-45 DEG C water bath, stirring;After reaction, the product is collected by magnet, and after washing, the hydrophilic magnetic polymer is obtained.

Description

Technical Field

[0001] This disclosure belongs to the field of aquaculture wastewater treatment technology, and relates to a hydrophilic magnetic polymer, its preparation method, and its application. Background Technology

[0002] China is a major aquaculture country with abundant fishery resources. According to the "China Fisheries Statistical Yearbook," in 2023, China's total aquaculture output reached 58.0961 million tons, a year-on-year increase of 4.39%. The rapid development of the aquaculture industry has also brought about significant environmental pollution problems, such as the discharge of aquaculture wastewater. The extensive use and even abuse of antibiotics in aquaculture, along with inefficient treatment, not only deteriorates the aquaculture environment and leads to drug resistance in fish, shrimp, and crabs, but aquaculture wastewater has also become one of the main sources of antibiotics in surface water.

[0003] Common antibiotics found in aquaculture wastewater include macrolide antibiotics (MAs), quinolone antibiotics (QNs), sulfonamides (SAs), and tetracyclines (TCs). In recent years, domestic and international research institutions have proposed methods for antibiotic remediation, such as physical elimination, photodegradation, chemical oxidation, microbial degradation, and phytoremediation. Adsorption is a commonly used method for antibiotic removal in wastewater treatment. However, traditional activated carbon adsorbents suffer from drawbacks such as large dosage and difficulty in subsequent separation. Therefore, strengthening the development of novel antibiotic adsorbents for aquaculture wastewater is crucial.

[0004] Magnetic polymer materials possess large specific surface areas and magnetic properties, enabling large-volume adsorption and rapid separation. However, most common magnetic polymer materials are synthesized in non-polar organic solvents, exhibiting optimal performance only in non-aqueous environments and are unsuitable for the adsorption of antibiotics in aqueous media, thus limiting their applicability. To overcome this limitation, hydrophilic magnetic polymers (HMPs) have become a research hotspot in recent years. Summary of the Invention

[0005] This disclosure provides a hydrophilic magnetic polymer, its preparation method, and its applications, which can effectively solve the above-mentioned problems.

[0006] This disclosure is implemented as follows:

[0007] In a first aspect, this disclosure provides a method for preparing a hydrophilic magnetic polymer, the method comprising:

[0008] Dissolve 3-amino-1,2,4-triazole in deionized water to obtain an aqueous solution of 3-amino-1,2,4-triazole;

[0009] The magnetic mixed hydroxide was added to deionized water and stirred continuously to form a suspension. Then, an aqueous solution of 3-amino-1,2,4-triazole was added and stirred for a period of time. Then, a crosslinking agent was added and stirred for a period of time. Finally, an initiator was added to obtain a mixture.

[0010] The mixture was transferred to an inert atmosphere and polymerized in a water bath at 35-45°C with stirring. After the reaction was completed, the product was collected with a magnet, washed and dried to obtain the hydrophilic magnetic polymer.

[0011] Secondly, this disclosure provides a hydrophilic magnetic polymer, wherein the hydrophilic magnetic polymer has a mesh-like porous structure;

[0012] The hydrophilic magnetic polymer includes:

[0013] A magnetic iron-aluminum mixed hydroxide, and a polymer layer coated on the surface of the magnetic iron-aluminum mixed hydroxide, wherein the polymer layer is obtained by polymerization reaction of 3-amino-1,2,4-triazole aqueous solution and dimethyl ethylene glycol acrylate;

[0014] The Fourier transform infrared spectrum of the hydrophilic magnetic polymer is shown below. Figure 1 As shown.

[0015] Thirdly, this disclosure provides the application of a hydrophilic magnetic polymer in adsorbing antibiotic drugs in aquaculture wastewater, wherein the antibiotic drug is at least one of quinolone drugs and tetracycline drugs.

[0016] The application of a hydrophilic magnetic polymer obtained by the preparation method described in the first aspect, or the hydrophilic magnetic polymer described in the second aspect, in the adsorption of antibiotics in aquaculture wastewater, wherein the antibiotic is at least one of quinolone drugs and tetracycline drugs.

[0017] The beneficial effects of this disclosure are:

[0018] This disclosure provides an HMP and its preparation method. The HMP can be synthesized in water, and the synthesized HMP has strong hydrophilicity. The preparation method is simple and easy to implement and does not require stringent experimental conditions.

[0019] Furthermore, in the HMP, the polymer layer formed on the MMH surface has an ideal gel-type network porous structure with a more loose spatial structure and a larger specific surface area, which makes the adsorption of target molecules by the HMP more complete and the internal mass transfer process more rapid.

[0020] Furthermore, the magnetization of the HMP reaches 7.6 emu / g, and under the action of an external magnetic field, the HMP dispersed in water can be rapidly separated within 10 seconds.

[0021] Furthermore, the HMP adsorption rate is fast, reaching adsorption equilibrium in 120s to 150s, with the equilibrium adsorption capacity of the antibiotic reaching 10.901mg / g. Attached Figure Description

[0022] To more clearly illustrate the technical solutions of the embodiments of this disclosure, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this disclosure and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 These are the FTIR images of iron and aluminum MMH and HMP provided in the embodiments of this disclosure.

[0024] Figure 2 Fe with different molar ratios 2+ / Al 3+ A comparison chart of the iron-aluminum MMH yields obtained from the reactants.

[0025] Figure 3 The HMP adsorption isotherm diagram provided in the embodiments of this disclosure.

[0026] Figure 4 The adsorption kinetics curve of HMP provided in the embodiments of this disclosure is shown.

[0027] Figure 5 The figure shows the pseudo-first-order adsorption kinetics of HMP provided in the embodiments of this disclosure.

[0028] Figure 6 The figure shows the fitting diagram of the pseudo-secondary adsorption kinetics of HMP provided in the embodiments of this disclosure.

[0029] Figure 7 A comparison chart of the adsorption capacity of HMP prepared with different molar ratios of ATA / EGDMA.

[0030] Figure 8 A comparison chart showing the adsorption capacity of HMP prepared at different polymerization reaction times.

[0031] Figure 9 The XRD patterns of iron and aluminum MMH and HMP provided in the embodiments of this disclosure.

[0032] Figure 10In the figures, (a) is a TEM image of iron-aluminum MMH provided in the embodiments of this disclosure; (b) is a TEM image of HMP (50 nm); and (c) is a TEM image of HMP (200 nm).

[0033] Figure 11 In the image, (a) is a SEM image of iron-aluminum MMH provided in the embodiments of this disclosure; and (b) is a SEM image of HMP.

[0034] Figure 12 VSM diagrams of iron and aluminum MMH and HMP provided in embodiments of this disclosure. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this disclosure, not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this disclosure without inventive effort are within the scope of protection of this disclosure. Therefore, the following detailed description of the embodiments of this disclosure provided in the accompanying drawings is not intended to limit the scope of the claimed disclosure, but merely represents selected embodiments of this disclosure. All other embodiments obtained by those skilled in the art based on the embodiments of this disclosure without inventive effort are within the scope of protection of this disclosure.

[0036] This disclosure provides a method for preparing a hydrophilic magnetic polymer, the method comprising:

[0037] Hydrophilic 3-amino-1,2,4-triazole (ATA) was dissolved in deionized water to obtain an aqueous solution of 3-amino-1,2,4-triazole.

[0038] Magnetic mixed hydroxides (MMH) were added to deionized water and stirred continuously to form a suspension. Then, an aqueous solution of 3-amino-1,2,4-triazole was added and stirred for a period of time. Next, a crosslinking agent was added and stirred for a period of time. Finally, an initiator was added to obtain a mixture.

[0039] The mixture was transferred to an inert atmosphere and polymerized in a water bath at 35-45°C with stirring. After the reaction was completed, the product was collected with a magnet, washed and dried to obtain the hydrophilic magnetic polymer.

[0040] In some embodiments, the crosslinking agent is at least one of dimethyl ethylene glycol acrylate (EGDMA), trimethylolpropane trimethacrylate, and dimethylhexanediol acrylate.

[0041] In some embodiments, the initiator is at least one selected from ammonium persulfate (APS), azobisisobutyronitrile (AIBN), and potassium persulfate.

[0042] In some embodiments, the MMH is stirred until fully dispersed for 10 minutes to prepare an MMH suspension.

[0043] In some embodiments, the MMH is stirred until it is completely dispersed, including stirring at 450-550 r / min.

[0044] In some embodiments, after the suspension is formed, an aqueous solution of 3-amino-1,2,4-triazole is added, and stirring is continued for a period of time, including a stirring time of 30 minutes.

[0045] In some embodiments, a crosslinking agent is then added, and stirring continues for a period of time, including a stirring time of 30 minutes.

[0046] In some embodiments, the molar ratio of 3-amino-1,2,4-triazole to the crosslinking agent is 1:4.5-5.5.

[0047] In some embodiments, the molar ratio of 3-amino-1,2,4-triazole to the crosslinking agent is 1:4.8-5.2.

[0048] In some embodiments, the molar ratio of 3-amino-1,2,4-triazole to the crosslinking agent is 1:4.5, 1:4.6, 1:4.7, 1:4.8, 1:4.9, 1:5, 1:5.1, 1:5.2, 1:5.3, 1:5.4, or 1:5.5.

[0049] In some embodiments, transferring the mixture to an inert atmosphere includes: the inert atmosphere being a nitrogen atmosphere.

[0050] In some embodiments, the polymerization reaction is carried out in a water bath at 35-45°C with stirring, including stirring at 250-350 r / min.

[0051] In some implementations, the polymerization reaction time is 4.5-5.5 hours.

[0052] In some implementations, the polymerization reaction time is 4.8-5.2 hours.

[0053] In some embodiments, the polymerization reaction time is 4.5h, 4.6h, 4.7h, 4.8h, 4.9h, 5h, 5.1h, 5.2h, 5.3h, 5.4h, or 5.5h.

[0054] In some embodiments, the product is washed and then dried, including drying at 80°C for 5 hours.

[0055] In some embodiments, the product is washed and dried to obtain the hydrophilic magnetic polymer, including: sieving the dried product through a 150-mesh standard inspection sieve to obtain the hydrophilic magnetic polymer with a diameter greater than 0.1 mm.

[0056] Materials with too small a diameter will float on the water surface, which is not conducive to subsequent separation.

[0057] In some embodiments, the magnetic mixed hydroxide is a magnetic iron-aluminum mixed hydroxide.

[0058] In some embodiments, the method for preparing the magnetic iron-aluminum mixed hydroxide includes:

[0059] Ferrous ammonium sulfate hexahydrate and aluminum chloride hexahydrate were completely dissolved in deionized water. Then, an alkaline solution was added to adjust the pH of the solution to 9.5-10.5. A co-precipitation reaction was carried out under stirring. After the reaction was completed, the product was collected with a magnet. After washing the product, the magnetic iron-aluminum mixed hydroxide was obtained.

[0060] In some embodiments, adding an alkaline solution to adjust the pH of the solution to 9.5-10.5 includes adding an alkaline solution to adjust the pH of the solution to 10.

[0061] In some embodiments, the coprecipitation reaction is carried out under stirring conditions, including stirring at 450-550 r / min for 10 min.

[0062] In some embodiments, the alkaline solution is an aqueous solution of NaOH.

[0063] In some implementations, a low-supersaturation coprecipitation method is used for the coprecipitation reaction.

[0064] In some embodiments, the molar ratio of ferrous ammonium sulfate hexahydrate to aluminum chloride hexahydrate is not less than 2:1.

[0065] In some embodiments, the molar ratio of ferrous ammonium sulfate hexahydrate to aluminum chloride hexahydrate is 2-3:1.

[0066] In some embodiments, the molar ratio of ferrous ammonium sulfate hexahydrate to aluminum chloride hexahydrate is 2:1, 2.2:1, 2.4:1, 2.6:1, 3:1, 3.5:1, or 4:1.

[0067] In some embodiments, after the reaction is complete, the mixture is allowed to stand and separate into layers, the supernatant is discarded, and the black product is collected using a magnet.

[0068] In some embodiments, an appropriate amount of deionized water with a pH of 7 is added to the upper layer of the magnetic iron-aluminum mixed hydroxide and stored at room temperature for later use.

[0069] This invention provides a hydrophilic magnetic polymer, wherein the hydrophilic magnetic polymer has a mesh-like porous structure;

[0070] The hydrophilic magnetic polymer includes:

[0071] A magnetic iron-aluminum mixed hydroxide, and a polymer layer coated on the surface of the magnetic iron-aluminum mixed hydroxide, wherein the polymer layer is obtained by polymerization reaction of 3-amino-1,2,4-triazole aqueous solution and dimethyl ethylene glycol acrylate;

[0072] The Fourier transform infrared spectrum of the hydrophilic magnetic polymer is shown below. Figure 1 As shown.

[0073] This invention provides an application of the hydrophilic magnetic polymer in any of the above embodiments in adsorbing antibiotics in aquaculture wastewater, wherein the antibiotic is at least one of quinolones and tetracyclines.

[0074] In some embodiments, the antibiotic is a tetracycline.

[0075] In some embodiments, the tetracycline drug includes at least one of doxycycline, oxytetracycline, and tetracycline.

[0076] In some embodiments, the quinolone drug includes at least one of dalofopinion, nalidixic acid, ciprofloxacin, difloxacin, sparfloxacin, pipemidic acid, ofloxacin, flumethin, enoxacin, sarafloxacin, norfloxacin, pefloxacin, enrofloxacin, fleroxacin, lomefloxacin, olbifloxacin, and mabofloxacin.

[0077] In some embodiments, the antibiotic is a quinolone.

[0078] In some embodiments, the quinolone drug includes at least one of dalofopinol, nalidixic acid, ciprofloxacin, difluorofloxacin, sparfloxacin, pipemidic acid, ofloxacin, flumethylquine, and enoxacin.

[0079] In some embodiments, the concentration of the antibiotic is not less than 0.8 μg / mL.

[0080] In some embodiments, the concentration of the antibiotic is 0.8-1.2 μg / mL.

[0081] In some embodiments, the concentration of the antibiotic is 0.8 μg / mL, 0.9 μg / mL, 1 μg / mL, 1.1 μg / mL, or 1.2 μg / mL.

[0082] Chemicals and reagents

[0083] Dimethyl ethylene glycol acrylate (EGDMA, GR grade, Guangdong Wengjiang Chemical Reagent Co., Ltd.); Trimethylolpropane trimethacrylate (95% purity, Shanghai Maclean Biochemical Technology Co., Ltd.); Dimethyl hexane glycol acrylate (HPLC, Wuhan Xinyang Ruihe Chemical Technology Co., Ltd.); 3-amino-1,2,4-triazole (ATA, 96% purity, Shanghai Aladdin Reagent Co., Ltd.); Ammonium persulfate (APS, 99.99% purity, Shanghai Aladdin Reagent Co., Ltd.); Azobisisobutyronitrile (98% purity, Shanghai Aladdin Reagent Co., Ltd.); Potassium persulfate (99.5% purity, Shanghai Aladdin Reagent Co., Ltd.); Ferrous(II)ammonium sulfate hexahydrate ((NH4)2Fe(SO4) 2· 6H2O, purity 99.99%, Shanghai Aladdin Reagent Co., Ltd.; aluminum chloride hexahydrate (AlCl₂) 3· 6H2O (purity 99.99%, Shanghai Aladdin Reagent Co., Ltd.); sodium hydroxide (NaOH, AR grade, Xilong Scientific Co., Ltd.); sodium dihydrogen phosphate (AR grade, Xilong Scientific Co., Ltd.); acetonitrile (chromatographic grade, Merck, Germany), methanol (chromatographic grade, Fisher Scientific, UK), formic acid (AR grade, Merck, Germany) and glacial acetic acid (AR grade, Shanghai Aladdin Reagent Co., Ltd.); Oasis HLB solid phase extraction column (200mg / 6mL, Waters Corporation, USA).

[0084] Sulfapyridine, sulfadiazine, sulfamethoxazole, sulfathiazole, sulfamerazine, sulfisoxazole, sulfamethizol, sulfamethazine, sulfamethoxypyrimidine, sulfachloropyridazine, sulfachinoxalin, sulfadoxine, and sulfadimethoxine, with a purity greater than 95%; pipemidic acid, nalidixic acid, and oxolinic acid. The following are listed: acid, flumequine, norfloxacin, ciprofloxacin, enrofloxacin, fleroxacin, enoxacin, pefloxacin, lomefloxacin hydrochloride, danofoxin mesylate, ofloxacin, sparfloxacin, difloxacin hydrochloride, cinoxacin, orbifloxacin, and marbofloxacin, with a purity greater than 92%; Sarafloxacin hydrochloride, with a purity greater than 87%; and oxytetracycline hydrochloride. The standards, including tetracycline hydrochloride and doxycycline hydrochloride, with a purity greater than 90%, were purchased from Manhag (Shanghai) Biotechnology Co., Ltd. All the above standards were prepared into 200 μg / mL standard stock solutions with methanol and stored at -20℃ protected from light (the weighed mass of the standards is a corrected mass, equivalent to 200 μg / mL of each active ingredient).Then, prepare standard mixed solutions of sulfonamide antibiotics, quinolone antibiotics, and tetracycline antibiotics at 20 μg / mL using methanol, and store them at -20℃ protected from light.

[0085] Taking the tetracycline antibiotic standard mixture as an example, the tetracycline antibiotic standard mixture includes all the tetracycline antibiotics in the above-mentioned standards, namely oxytetracycline hydrochloride, tetracycline hydrochloride, and doxycycline hydrochloride. Furthermore, the concentration of each antibiotic in the antibiotic standard mixture is the same, at 20 μg / mL.

[0086] Instruments and equipment

[0087] The system includes: TSQ Quantum Ultra high-performance liquid chromatography-tandem mass spectrometer with an electric spray ionization source (Thermo Fisher Scientific (FEI), USA); IRAffinity-1 Fourier transform infrared spectroscopy scanner (Shimadzu Corporation, Japan); Nova Nano SEM scanning electron microscope (Thermo Fisher Scientific (FEI), USA); Talos F200s transmission electron microscope (Thermo Fisher Scientific (FEI), USA); 7410 vibrating sample magnetometer (LakeShore, USA); LC-ES-60SH mechanical stirrer (Shanghai Lichen Bangxi Instrument Technology Co., Ltd.); MS3 vortex mixer (IKA GmbH, Germany); LC-WB-2 constant temperature water bath (Shanghai Lichen Bangxi Instrument Technology Co., Ltd.); MT008-C vacuum glove box (Changsha Miqi Instrument Equipment Co., Ltd.); DHG-9245A electric heating forced-air drying oven (Shanghai Yiheng Scientific Instrument Co., Ltd.); Milli-Q water purification system; and 150-mesh standard test sieve (Shangyu Yinhe Testing Instrument Factory).

[0088] HPLC-MS / MS conditions

[0089] Chromatographic conditions: CAPCELL PAK-MGⅡC18 column (2.1 mm × 150 mm × 5 μm); column temperature 35 ℃; flow rate 0.25 mL / min; injection volume 5 μL; mobile phase: A is 0.005 mol / L ammonium acetate to 0.1% formic acid aqueous solution, B is 0.1% formic acid methanol; elution gradient: 0–5 min (10%–90% B), 5–9 min (90%–100% B), 9–10 min (100%–10% B), 10–15 min (10% B).

[0090] Mass spectrometry conditions: electrospray ionization source, positive ion detection mode, spray voltage: 3500V, sheath gas pressure: 241KPa, auxiliary gas pressure: 2L / min, ion transport capillary temperature: 320℃, selected reaction monitoring (SRM), mother ion, daughter ion and collision energy are listed in Table 1, Q1 half peak width: 0.7u, Q3 half peak width: 0.7u, collision gas pressure: argon, 0.2Pa.

[0091] Table 1. Selection of parent ion, daughter ion, and collision energy for reaction monitoring.

[0092]

[0093] Note: "*" indicates quantitative ions.

[0094] Examples 1-3

[0095] Preparation of iron-aluminum MMH

[0096] Iron-aluminum MMH was prepared at room temperature using a low-supersaturation co-precipitation method.

[0097] Weigh out (NH4)2Fe(SO4)2·6H2O and 2.41 g (10 mmol) AlCl3·6H2O, and add them separately to 400 mL of deionized water. Stir mechanically until completely dissolved. Then, quickly add 50 mL of 3 mol / L NaOH aqueous solution to maintain the pH at approximately 10. Stir mechanically at 500 rpm for 10 min. After the reaction is complete, allow the mixture to stand and separate into layers. Discard the supernatant, collect the black product using a magnet, and wash it three times with 400 mL of deionized water to obtain iron-aluminum MMH.

[0098] In Examples 1-3, the amounts of (NH4)2Fe(SO4)2·6H2O used were 11.76g (30mmol), 7.84g (20mmol), and 3.92g (10mmol), respectively.

[0099] The prepared iron-aluminum MMH was transferred to a 50mL wide-mouth bottle, and an appropriate amount of deionized water with a pH of 7 was added to the top layer. It was then stored at room temperature for later use.

[0100] The products after magnetic separation and washing in Examples 1-3 were freeze-dried and their yield was measured.

[0101] Fe with different molar ratios 2+ / Al 3+ The impact on iron and aluminum MMH production, such as Figure 2 As shown, when the molar ratio increases to 2:1, the iron-aluminum MMH production remains basically constant.

[0102] Examples 4-8

[0103] Preparation of HMP

[0104] Weigh 10±0.02g of the iron-aluminum MMH prepared in Example 2 into a 250mL wide-mouth Erlenmeyer flask, add 100mL of deionized water, and mechanically stir at 500r / min until completely dispersed for 10min to prepare an iron-aluminum MMH suspension.

[0105] Weigh 336.3 mg (4 mmol) of ATA into a 250 mL Erlenmeyer flask, dissolve it in 100 mL of deionized water, and add it to the aforementioned wide-mouth Erlenmeyer flask. Continue mechanical stirring for 30 min, then add the crosslinking agent EGDMA, and continue stirring for another 30 min under the same conditions. Then, quickly add 1.00 g of initiator APS. Transfer the mixture to a pre-filled nitrogen-filled vacuum glove box and polymerize it at 40 °C in a water bath at 300 rpm for 5 h. After the reaction is complete, discard the supernatant, collect the product, and wash it three times with 100 mL of deionized water. Then dry it at 80 °C for 5 h. The dried product is sieved through a 150-mesh (0.1 mm) standard sieve to obtain HMP with a diameter greater than 0.1 mm, which is stored at room temperature for later use.

[0106] In Examples 4-8, the amounts of crosslinking agent EGDMA used were 2.28 mL (12 mmol), 3.04 mL (16 mmol), 3.8 mL (20 mmol), 4.56 mL (24 mmol), and 5.32 mL (28 mmol), respectively.

[0107] Examples 9-12

[0108] The difference between Examples 9-12 and Example 6 is that the polymerization reaction times are 3h, 4h, 6h and 7h, respectively.

[0109] The products after magnetic separation and washing in Examples 6 and 9-12 were freeze-dried and their yields were weighed. It was found that the HMP yield gradually increased with the increase of polymerization time, and the HMP yield tended to stabilize after the polymerization time reached 6 hours.

[0110] Example 10

[0111] Static adsorption experiment

[0112] Measure 10 mL of deionized water into a 50 mL test tube, and add standard mixed solutions of sulfonamide antibiotics, quinolone antibiotics, and tetracycline antibiotics respectively to prepare mixed antibiotic solutions. The concentrations of each antibiotic in the mixed antibiotic solutions are listed in Table 2.

[0113] Table 2 Concentrations of various antibiotics in the mixed antibiotic solution

[0114]

[0115]

[0116] The pH of the solution was adjusted to 6-8, and then 5 mg of HMP prepared in Example 6 was added. The solution was vortexed at 2000 r / min for 120 s. The supernatant was obtained by magnetic separation, and the pH of the supernatant was adjusted to 4 with a 3% formic acid solution.

[0117] Take 1 mL of supernatant, add 0.25 mL of methanol, vortex mix at 2000 r / min for 30 s, filter through a 0.22 μm filter membrane, and detect by HPLC-MS / MS. Perform the determination in triplicate.

[0118] Calculate the adsorption capacity Q. The formula for calculating the adsorption capacity (1) is as follows:

[0119]

[0120] Where V (mL) is the solution volume, m (mg) is the mass of the adsorbent HMP, and C0 and C2 are... e (μg / mL) represent the initial concentration and equilibrium concentration of the solution, respectively.

[0121] To realistically simulate the conditions of actual aquaculture wastewater, the pH of the simulation solution was adjusted to match that of the wastewater (pH 6-8). The simulation solution also contained common aquaculture wastewater drugs such as sulfonamides, quinolones, and tetracyclines. Under these conditions, a static adsorption experiment was conducted to simultaneously adsorb multiple drugs, and the selectivity of the adsorbent material was investigated.

[0122] Under constant temperature and pH conditions of 6-8, the adsorption capacity of HMP in solutions of sulfonamides, quinolones, and tetracyclines of different mass concentrations was determined.

[0123] Experimental results show that HMP cannot effectively adsorb sulfonamide drugs, but as the initial drug concentration increases, the adsorption capacity of HMP for quinolone and tetracycline drugs gradually increases.

[0124] like Figure 3 As shown, when the drug concentration increases to 0.8 μg / mL, the adsorption capacity of HMP for quinolones and tetracyclines tends to saturate, reaching its maximum, with an equilibrium adsorption capacity Q of 10.901 mg / g. This may be because the higher initial concentration provides a stronger driving force for quinolones and tetracyclines, overcoming the mass transfer resistance between the solid and liquid phases, thereby increasing the contact time and collision frequency between the quinolones and tetracyclines and the adsorbent, and increasing the chance of binding to the active sites of HMP.

[0125] like Figure 3 As shown, the equilibrium adsorption capacity of HMP for each drug varies significantly. Specifically: Q 多西环素(1.460mg / g)>Q 土霉素 (1.211mg / g)>Q 四环素 (0.856mg / g)>Q 达氟沙星 (0.749mg / g)>Q 萘啶酸 (0.694mg / g)>Q 环丙沙星 (0.633mg / g)>Q 二氟沙星 (0.616mg / g)>Q 司帕沙星 (0.581mg / g)>Q 吡哌酸 (0.576mg / g)>Q 氧氟沙星 (0.530mg / g)>Q 氟甲喹 (0.521mg / g)>Q 依诺沙星 (0.509mg / g)>Q 沙拉沙星 (0.417mg / g)>Q 诺氟沙星 (0.365mg / g)>Q 培氟沙星 (0.291mg / g)>Q 恩诺沙星 (0.264mg / g)>Q 氟罗沙星 (0.243mg / g)>Q 洛美沙星 (0.227mg / g)>Q 奥比沙星 (0.192mg / g)>Q 马波沙星 (0.181 mg / g).

[0126] This indicates that under the condition that the pH value of the aquaculture effluent is 6-8, HMP has the characteristic of preferentially adsorbing tetracycline and quinolone drugs. In contrast, HMP basically does not adsorb sulfonamide drugs, and the adsorption capacity for tetracycline drugs is significantly better than that for quinolone drugs.

[0127] Dynamic adsorption experiment

[0128] Measure 10 mL of deionized water into a 50 mL test tube, and add mixed standard solutions of quinolone and tetracycline antibiotics respectively to prepare a mixed antibiotic solution with a concentration of 0.50 μg / mL for both quinolone and tetracycline antibiotics. Adjust the pH of the solution to neutral, add 5 mg of HMP prepared in Example 6, and vortex at 2000 r / min for 10 s, 30 s, 60 s, 90 s, 120 s, 150 s, and 180 s respectively. Obtain the supernatant by magnetic separation, and adjust the pH of the supernatant to 4 with a 3% formic acid solution.

[0129] Take 1 mL of supernatant, add 0.25 mL of methanol, vortex mix at 2000 r / min for 30 s, filter through a 0.22 μm filter membrane, and detect by HPLC-MS / MS. Perform three parallel determinations and calculate the adsorption capacity Q.

[0130] To further evaluate the adsorption mechanism, the adsorption kinetics of quinolone and tetracycline drugs on HMP were investigated. The experimental data were fitted using two of the most common kinetic models: pseudo-first-order equations and pseudo-second-order equations. The mathematical expressions for these two models are shown in equations (2) and (3).

[0131] ln(Q e -Q t )=lnQ e -k1t (2)

[0132]

[0133] Among them, Q e and Q t K1 and K2 are the amounts of drug adsorbed on HMP at equilibrium and time t (s), respectively (mg / g), where k1 is the first-order rate constant (g / mg / s) and k2 is the second-order rate constant (g / mg / s).

[0134] To investigate the saturation adsorption time of HMP for quinolone and tetracycline drugs, dynamic adsorption experiments were conducted, and the results are as follows: Figure 4 As shown, the kinetic adsorption curves exhibit a trend of initially increasing gradually and then stabilizing. This indicates that in the initial stage of adsorption, the adsorbent has abundant active sites, enabling it to quickly bind to drugs in the aquaculture wastewater. As adsorption progresses, the solution concentration decreases, the number of unbound sites on the adsorbent decreases, and the adsorption rate decreases. Notably, the adsorbent reaches adsorption equilibrium within 120-150 seconds, indicating that it has a very rapid adsorption rate for quinolones and tetracyclines.

[0135] Figure 5 and Figure 6 The figures are the fitted graphs obtained using the dynamic model, and the processed dynamic parameters are shown in Table 3.

[0136] Table 3 Adsorption kinetic fitting parameters

[0137]

[0138]

[0139] Table 3 shows that the correlation coefficients of the pseudo-second-order adsorption kinetic model are significantly higher than those of the pseudo-first-order adsorption kinetic model. This indicates that the pseudo-second-order model can more accurately describe the adsorption behavior of the adsorbent on the drug in aquaculture wastewater. The equilibrium adsorption capacity Q of the pseudo-second-order adsorption kinetics was then calculated based on the model. e The data are detailed in Table 3. These calculated values ​​are compared with the actual adsorption amount Q observed in the experiment. eThe results are very close, further validating the accuracy of the pseudo-second-order adsorption kinetic model. This indicates that the adsorption of quinolone and tetracycline drugs by this adsorbent is mainly based on chemisorption, rather than simple physical adsorption. This chemisorption involves chemical bonding between the adsorbent and the target molecule, resulting in stronger binding forces. Electrostatic interactions are also involved, and chemisorption is the main factor limiting the adsorption rate. Simultaneously, this also means that mass transfer processes in solution are not involved during adsorption, thus further improving adsorption efficiency and stability.

[0140] Example 11

[0141] In the polymerization process, crosslinking agents are a crucial factor in preparing stable polymers. They play a role in controlling the polymer morphology, the stability of binding sites, and mechanical stability. Therefore, the amount of vinyl-containing binary crosslinking agent EGDMA also affects the adsorption capacity of HMP. The effect of the molar ratio of ATA to EGDMA on the adsorption capacity of the prepared HMP was investigated. The experimental method for determining the adsorption capacity of HMP was the same as described in Example 10, and the adsorption capacity of HMP prepared in Examples 4-8 was measured respectively.

[0142] Experimental results are as follows Figure 7 As shown, the HMP exhibits the highest adsorption capacity when the molar ratio of ATA to EGDMA is 1:5. The adsorption capacity decreases with increasing EGDMA content. This may be because excessively high concentrations of EGDMA lead to greater polymer cross-linking, resulting in a denser spatial structure rather than the ideal gel-like network structure. Therefore, a 1:5 molar ratio is the optimal molar ratio for ATA / EGDMA. Under this condition, the resulting HMP spatial structure is more porous with a larger specific surface area, allowing for more complete adsorption of target molecules and a more rapid internal mass transfer process.

[0143] Under the optimal molar ratio of ATA / EGDMA, the effect of polymerization time on the adsorption capacity of the prepared HMP was investigated. The experimental method for determining the adsorption capacity of HMP was the same as that described in Example 10. The adsorption capacity of HMP prepared in Examples 6 and 9-12 was determined, respectively, with an initial drug concentration of 0.5 μg / mL.

[0144] Experimental results are as follows Figure 8 As shown, the adsorption capacity of HMP first increases and then decreases with increasing polymerization time. When the polymerization time is 5 hours, ATA and EGDMA react fully, and the polymer layer formed at this time has an ideal gel-type network porous structure, resulting in the maximum adsorption capacity. However, when the polymerization time exceeds 5 hours, the adsorption capacity decreases. This may be because the excessive polymerization time leads to excessive self-polymerization of ATA, forming a thicker polymer layer, which increases the resistance to HMP adsorption of target molecules. Therefore, 5 hours is selected as the optimal polymerization time for preparing HMP.

[0145] Example 12

[0146] The HMP prepared in Example 6 was added to aquaculture wastewater, causing antibiotic contaminants in the wastewater to be adsorbed onto the material surface, thereby achieving removal. The removal efficiency of HMP on antibiotic contaminants in actual aquaculture wastewater was investigated.

[0147] Transfer 200 mL of aquaculture wastewater, filter through a 0.45 μm filter membrane, add 25 mg of HMP, vortex at 2000 r / min for 120 s, and magnetically separate to obtain the supernatant. Adjust the pH of the supernatant to 4 with a 3% formic acid solution. Transfer 50 mL of this supernatant, add 1.5 mL of methanol, mix well, and prepare for sample loading.

[0148] The Oasis HLB solid-phase extraction column was pre-activated sequentially with 6 mL of methanol and 6 mL of water, then loaded with the sample at a flow rate of 4 mL / min. The column was rinsed with 5 mL of water, dried under vacuum for 5 min, and eluted with 8 mL of methanol. All eluent was collected in a glass tube and dried under nitrogen at 45°C. 1 mL of a pH 4.0 water-acetonitrile solution (8:2, v / v) was added and the solution was dissolved by sonication. The solution was then filtered through a 0.22 μm filter before analysis by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS / MS).

[0149] The composition of antibiotic pollutants in actual aquaculture wastewater and their removal rates are shown in Table 4.

[0150] Table 4. Removal efficiency of antibiotic pollutants in actual aquaculture wastewater.

[0151]

[0152] As can be seen from Table 4:

[0153] (1) HMP has a significant adsorption effect on quinolone and tetracycline antibiotics.

[0154] (2) Tetracycline antibiotics have better adsorption properties than quinolone antibiotics, and the actual test results are similar to those of the simulation experiment.

[0155] (3) After 120s vortex adsorption, the removal efficiency of antibiotic pollutants in aquaculture tail water can reach more than 65%. HMP has a high removal rate of antibiotic pollutants.

[0156] (4) The adsorption capacity of 25mg HMP is lower than the maximum adsorption capacity in the static adsorption experiment in Example 10. This may be related to the fact that the actual tailwater volume is large and the adsorption time is short, so that HMP cannot be completely dispersed and adsorbed.

[0157] The results of practical applications show that the HMP provided in this disclosure has a high surface area, excellent magnetic saturation properties, strong hydrophilicity, and low synthesis cost, and has great application prospects in the removal of antibiotic pollutants in aquaculture wastewater.

[0158] Example 13

[0159] Characterization of the iron-aluminum MMH obtained in Example 2 and the MHP obtained in Example 6

[0160] X-ray diffraction (XRD)

[0161] Iron oxides have four crystal structures, among which γ-Fe₂O₃ and Fe₃O₄ have roughly the same crystal structure, both belonging to the inverse spinel structure. The XRD patterns of iron-aluminum MMH and HMP are shown below. Figure 9 As shown.

[0162] pass Figure 9 It can be seen that both materials exhibit diffraction peaks at 30.4°, 35.8°, 43.2°, 53.7°, 57.5°, and 63.1°, corresponding to the (220), (311), (400), (422), (511), and (440) crystal planes of γ-Fe₂O₃, respectively. The diffraction peaks at 21.3° and 36.8° correspond to the (110) and (311) crystal planes of γ-Al(OH)₃, respectively. The HMP XRD results are highly consistent with those of γ-Fe₂O₃ (39-1346) and γ-Al(OH)₃ (7-0324), indicating that the products are fully crystalline γ-Fe₂O₃ and γ-Al(OH)₃. The results show that the polymer layer was successfully coated onto the iron-aluminum MMH surface. Because the surface of the iron-aluminum MMH particles in HMP is coated with a polymer layer, the intensity of all diffraction peaks in HMP is weaker than that of iron-aluminum MMH, but the physical structure of iron-aluminum MMH does not change during the polymerization process.

[0163] Fourier Transform Infrared Spectroscopy (FTIR)

[0164] The FTIR spectra of iron and aluminum MMH and HMP are as follows: Figure 1 As shown. 800cm -1 The following absorption peaks are caused by the ferrite and aluminum oxy-oxide tensile and bending vibrations of the iron-aluminum MMH. The 3000-3700 cm⁻¹ peaks are... -1 The broad peak between 1630cm -1 The characteristic absorption peak at 3200-3500 cm⁻¹ is the OH bond vibration peak of water, as can be seen from the FTIR spectrum of HMP. -1 Nearby (NH stretching), 1610-1660cm -1 Nearby (C=N) and 1318cm -1 1260cm -1The peaks of (aromatic secondary amines) are all characteristic absorption peaks of ATA, while the 950 cm⁻¹ peak is... -1 860cm -1 The characteristic absorption peak at the point is caused by the out-of-plane bending vibration of the triazole-substituted CH, indicating that ATA participates in the polymerization reaction.

[0165] 1728cm -1 (C=O stretching) and 1100-1200cm -1 The characteristic absorption peak of EGDMA near (COC stretching) confirms the presence of the crosslinking agent in the polymer.

[0166] The FTIR spectrum results confirm that HMP has been successfully prepared.

[0167] Transmission electron microscopy (TEM) and scanning electron microscopy (SEM)

[0168] To further reveal the microscopic characteristics of iron-aluminum MMH and HMP materials, high-resolution images of both were obtained using transmission electron microscopy and scanning electron microscopy.

[0169] Figure 10 These are TEM images of iron-aluminum MMH and HMP. Their morphological characteristics were studied using transmission electron microscopy. Figure 10 As shown in (a), particles of varying sizes and irregular shapes were observed in the TEM image of the MMH. Compared to Figure 10 (a), Figure 10 (b) The presence of an additional light gray outer layer indicates that a polymer layer has been successfully prepared on the iron-aluminum MMH surface. Figure 10 (c) It can be seen that the synthesized HMP after polymerization has a distinct network porous structure.

[0170] The morphology and size of iron-aluminum MMH and HMP were further analyzed using scanning electron microscopy. Figure 11 As shown in (a), the iron-aluminum MMH exhibits a spherical morphology and is tightly aggregated together. Figure 11 As shown in (b), after polymerization, HMP particles have irregular shapes, uneven sizes, and increased particle size.

[0171] Magnetic property analysis

[0172] The magnetic properties of iron and aluminum MMH and HMP were tested using a vibrating sample magnetometer.

[0173] Figure 12 The hysteresis curves (VSM) for iron and aluminum MMH and HMP are shown. From... Figure 12As can be observed, both tested materials exhibit a centrosymmetric state, a common characteristic of ferromagnetic materials. Further analysis reveals the presence of saturation magnetization and hysteresis loops in the curves, both important features indicating that the prepared iron-aluminum MMH and HMP possess superparamagnetic properties. Superparamagnetism is a special magnetic state that allows these materials to be rapidly attracted to a magnet under the influence of an external magnetic field and to quickly lose magnetism after the external magnetic field is removed. Specifically, the magnetization of iron-aluminum MMH and HMP are 11.4 and 7.6 emu / g, respectively. This indicates that the magnetic strength of the material gradually decreases with the increase of the polymer shell structure. This decrease can be attributed to the shielding effect of the polymer shell on the surface of iron-aluminum MMH; that is, the presence of the polymer shell weakens the material's response to external magnetic fields. Under the influence of an external magnetic field, HMP can achieve rapid separation within 10 seconds. This result fully demonstrates that the polymer possesses good magnetism and can meet the rapid separation requirements in practical applications.

[0174] This disclosure provides a hydrophilic organic polymer (HMP) for adsorbing antibiotics in aquaculture wastewater, using iron-aluminum MMH as a carrier, ATA as a functional monomer, EGDMA as a crosslinking agent, APS as an initiator, and water as a porogen. Characterization and adsorption experiments demonstrate that the synthesized HMP exhibits strong hydrophilicity and a rapid adsorption rate, reaching adsorption equilibrium in 120–150 s. The equilibrium adsorption capacity of HMP is 10.901 mg / g, and the adsorption of antibiotic pollutants in aquaculture wastewater conforms to a pseudo-second-order kinetic adsorption model, indicating that the adsorption behavior is primarily chemisorption. Application of HMP in the treatment of antibiotic pollutants in actual aquaculture wastewater demonstrates that HMP can rapidly separate antibiotic pollutants under a magnetic field, achieving a removal efficiency of over 65%.

[0175] Therefore, HMP, with its high specific surface area, excellent adsorption capacity, and low preparation cost, is expected to become one of the outstanding antibiotic pollutant removers in aquaculture wastewater. Furthermore, the novel green preparation method of HMP will provide new ideas for the development of better magnetic adsorption materials.

[0176] The above description is merely a preferred embodiment of this disclosure and is not intended to limit this disclosure. Various modifications and variations can be made to this disclosure by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this disclosure should be included within the protection scope of this disclosure.

Claims

1. A method for preparing a hydrophilic magnetic polymer, characterized in that, The preparation method includes: Dissolve 3-amino-1,2,4-triazole in deionized water to obtain an aqueous solution of 3-amino-1,2,4-triazole; The magnetic mixed hydroxide was added to deionized water and stirred continuously to form a suspension. Then, an aqueous solution of 3-amino-1,2,4-triazole was added and stirred for a period of time. Then, dimethyl ethylene glycol acrylate was added and stirred for a period of time. Finally, an initiator was added to obtain a mixture. The mixture was transferred to an inert atmosphere and polymerized in a water bath at 35-45°C with stirring. After the reaction was completed, the product was collected with a magnet, washed and dried to obtain the hydrophilic magnetic polymer.

2. The preparation method according to claim 1, characterized in that, The magnetic mixed hydroxide is a magnetic iron-aluminum mixed hydroxide.

3. The preparation method according to claim 2, characterized in that, The preparation method of the magnetic iron-aluminum mixed hydroxide includes: Ferrous ammonium sulfate hexahydrate and aluminum chloride hexahydrate were completely dissolved in deionized water. Then, an alkaline solution was added to adjust the pH of the solution to 9.5-10.

5. A co-precipitation reaction was carried out under stirring. After the reaction was completed, the product was collected with a magnet. After washing the product, the magnetic iron-aluminum mixed hydroxide was obtained.

4. The preparation method according to claim 3, characterized in that, The molar ratio of ferrous ammonium sulfate hexahydrate to aluminum chloride hexahydrate is not less than 2:

1.

5. The preparation method according to claim 1, characterized in that, The molar ratio of 3-amino-1,2,4-triazole to dimethyl ethylene glycol acrylate is 1:4.5-5.

5.

6. The preparation method according to claim 1, characterized in that, The polymerization reaction time is 4.5-5.5 h.

7. A hydrophilic magnetic polymer, characterized in that, The hydrophilic magnetic polymer has a mesh-like porous structure; The hydrophilic magnetic polymer includes: A magnetic iron-aluminum mixed hydroxide, and a polymer layer coated on the surface of the magnetic iron-aluminum mixed hydroxide, the polymer layer being obtained by polymerization reaction of 3-amino-1,2,4-triazole aqueous solution and dimethyl ethylene glycol acrylate.

8. The application of the hydrophilic magnetic polymer obtained by the preparation method according to any one of claims 1-6, or the hydrophilic magnetic polymer according to claim 7, in the adsorption of antibiotics in aquaculture effluent, characterized in that, The antibiotic is at least one of quinolone drugs or tetracycline drugs.

9. The application as described in claim 8, characterized in that, The antibiotic is a tetracycline.

10. The application as described in claim 8, characterized in that, The concentration of the antibiotic is not less than 0.8 µg / mL.

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