A metal-doped bismuth ferrite-based perovskite composite material, its preparation method and application

Abstract

This invention relates to the field of wastewater treatment technology, specifically to a metal-doped bismuth ferrite-based perovskite composite material, its preparation method, and its applications. The molecular formula of the metal-doped bismuth ferrite-based perovskite composite material is Bi. 1‑x A x Fe 1‑y B y O3; 0 ≤ x < 1, 0

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment technology, specifically to a metal-doped bismuth ferrite-based perovskite composite material, its preparation method, and its application. Background Technology

[0002] In recent years, antibiotics have been widely used in human production and daily life. The irrational use of antibiotics can easily induce antibiotic resistance genes (ARGs), leading to the continuous accumulation of antibiotics in the environment and posing a potential threat to ecosystems and human health. Traditional wastewater treatment processes mainly target traditional pollutants (nitrogen, phosphorus, COD, etc.) and are ineffective in removing recalcitrant and biotoxic antibiotics and ARGs. While ultrafiltration and disinfection technologies can remove drug-resistant bacteria and intracellular resistance genes (iARGs), their removal efficiency is limited. Furthermore, the inactivation process of drug-resistant bacteria can easily lead to the conversion of iARGs into extracellular resistance genes (eARGs), further exacerbating the risk of resistance gene spread. Therefore, there is an urgent need to develop a highly efficient method for removing antibiotics and ARGs from wastewater to reduce the adverse impact on the natural environment.

[0003] Advanced oxidation technologies (AORs) have shown excellent performance in removing antibiotics. They can activate persulfate through light, heat, and metal ions to achieve rapid and efficient oxidation of pollutants, which is of great significance for the remediation of antibiotic and ARG pollution. Among them, persulfate-based (PMS / PDS) AOR technology is considered an effective method for treating recalcitrant organic compounds due to its strong oxidizing power and high efficiency. However, the heterogeneous activation catalysts used to activate persulfate cannot be reused and are prone to causing secondary pollution, which limits its widespread application.

[0004] Perovskite-type composite metal oxides (general structural formula is) Due to its stable structure, abundant active sites, and the fact that its A and B sites can be partially or completely replaced by transition metals of different oxidation states and radii without destroying its crystal structure, cobalt-based perovskites have been widely used in catalytic oxidation in recent years. In persulfate activation studies, although cobalt-based perovskites exhibit the highest catalytic activity, the dissolved perovskites... The significant toxicity of iron limits its application. Although iron has slightly lower catalytic activity than cobalt, its lower toxicity and abundance on the Earth's surface make perovskite materials with iron as the active center a promising candidate for application.

[0005] Bismuth-iron perovskite ( As a typical iron-based These catalysts, due to their narrow band gap (Eg = 1.9~2.9 eV), can effectively activate oxidants such as hydrogen peroxide and persulfate for the degradation of organic pollutants. However, pure-phase catalysts... There are problems such as differences in the mobility of photo-generated carriers, slow Fe(III) / Fe(II) cycling rates, structural defect states, and low magnetization. Moreover, heterogeneous activation has disadvantages such as the difficulty in recycling metal ions, easy secondary pollution, increased treatment costs, and being greatly affected by the pH of the water body, which limits its application as a catalyst. In addition, the metal-doped based catalysts prepared by the sol-gel method are mostly in powder form, with problems such as difficult separation and recovery and easy aggregation and inactivation, and there is a further need to find methods that can improve the stability of the catalytic degradation system and the pollutant removal efficiency.

[0006] In summary, there is still room for improvement in the existing iron-based perovskites in terms of improving catalytic activity, regulating structural defects, and practical preparation processes. There is an urgent need to develop a catalytic material system that is highly efficient, stable, and easy to separate. SUMMARY OF THE INVENTION

[0007] In view of this, one of the purposes of the present invention is to provide a metal-doped bismuth ferrite-based perovskite composite material and its preparation method to solve the problems that existing heterogeneous catalytic materials are prone to inactivation and affect the pollutant removal efficiency, and can also solve the problems that existing heterogeneous catalytic materials are difficult to separate and recycle and are prone to cause secondary pollution. The second purpose of the present invention is to provide an application of a metal-doped bismuth ferrite-based perovskite composite material to solve the problem that existing sewage treatment processes are difficult to effectively remove antibiotics and ARGs that are difficult to degrade and have biological toxicity.

[0008] In order to achieve the above purposes, the technical scheme adopted by the present invention is as follows: A metal-doped bismuth ferrite-based perovskite composite material, the molecular formula of the metal-doped bismuth ferrite-based perovskite composite material is ; where 0≤x<1, 0<y<1, A is selected from strontium (Sr), and B is selected from manganese (Mn).

[0009] Introducing Sr at the A site and Mn at the B site of the bismuth ferrite-based ( ) perovskite, using the difference in ionic radius and valence state to induce lattice distortion and generate oxygen vacancies, forming a "Sr-O-Mn" cooperative skeleton; this skeleton not only firmly anchors multi-valent metals such as Fe, Sr, and Mn in the lattice, inhibiting dissolution inactivation, but also in-situ constructs a high-density active centers, so that when the metal-doped bismuth ferrite-based perovskite composite material is used as a heterogeneous catalyst, it can continuously catalyze PMS to produce This achieves highly efficient mineralization of pollutants. Simultaneously, Sr doping suppresses Bi volatilization, and Mn cycling stabilizes lattice oxygen, maintaining the material's intact perovskite phase. The ferrite soft magnetic phase imparts superparamagnetism, allowing for second-level recovery with an external magnetic field and no secondary pollution. This single design simultaneously addresses the two major bottlenecks of "easy deactivation and difficult separation," providing a universally applicable perovskite platform for heterogeneous catalysis that is highly active, highly stable, and easily recoverable. It effectively solves the problems of easy deactivation and reduced pollutant removal efficiency in existing heterogeneous catalytic materials, as well as the difficulties in separation and recovery, which can easily lead to secondary pollution.

[0010] This invention also provides a method for preparing a metal-doped bismuth ferrite-based perovskite composite material, comprising the following steps: S1. Add bismuth salt, iron salt, A salt, B salt and organic acid to an organic solvent to obtain a reddish-brown sol; S2. Dry the reddish-brown sol to make a gel; S3. The gel is calcined to obtain a metal-doped bismuth ferrite-based perovskite composite material.

[0011] Metal-doped bismuth ferrite-based perovskite composites were prepared using the sol-gel method, thereby achieving molecular-scale fabrication. , , , It chelates with organic acids to form a uniform reddish-brown sol, which can be polymerized in situ at low temperatures to form a three-dimensional network gel. This network "freezes" the metal ions at atomic-level distances, and after calcination, it can be directly crystallized into single-phase perovskite, avoiding phase separation and particle size growth caused by high-temperature solid-phase diffusion. The reducing atmosphere released by the decomposition of organic acids induces oxygen vacancies and inhibits Bi volatilization, resulting in a uniform particle size distribution and a large specific surface area, thus exposing more active sites. The nanoscale and surface oxygen vacancies synergistically reduce charge transfer impedance, thereby improving the catalytic rate. High-purity, high-activity, and easily recyclable magnetic perovskite can be obtained at low temperatures, in a short process, without the need for complex equipment, achieving simultaneous optimization of performance and cost. The preparation method of this invention has the advantages of low synthesis temperature, simple process equipment, easy control of the reaction process, high uniformity and purity of the product, small particle size, and good dispersibility.

[0012] Preferably, the bismuth salt is selected from at least one of bismuth nitrate, bismuth sulfate, and bismuth nitrate pentahydrate.

[0013] Preferably, the iron salt is selected from at least one of ferric nitrate, elemental iron, and ferric nitrate nonahydrate.

[0014] Preferably, the A salt is selected from strontium nitrate.

[0015] Preferably, the B salt is selected from manganese nitrate.

[0016] Preferably, the organic acid is selected from at least one of citric acid, oxalic acid, and tartaric acid.

[0017] Preferably, the organic solvent is selected from at least one of anhydrous ethanol, ethylene glycol, acetone and glacial acetic acid.

[0018] Preferably, the organic solvent is selected from ethylene glycol, or a mixed solvent of ethylene glycol and glacial acetic acid, wherein the volume ratio of ethylene glycol to glacial acetic acid in the mixed solvent is 4:1 to 1:1.

[0019] Preferably, the volume ratio of ethylene glycol to glacial acetic acid in the mixed solvent of ethylene glycol and glacial acetic acid is 4:1, 3:1, 2:1 or 1:1.

[0020] Preferably, the drying temperature is 60~90℃.

[0021] Preferably, the drying temperature is 70°C.

[0022] Preferably, when x is 0 and y is 0.08, the calcination temperature is 450~700℃ and the time is 2h; or, when x is 0.1 and y is 0.08, the calcination temperature is 500~800℃ and the time is 2h.

[0023] The purposes of calcination are threefold: first, to remove impurities—by decomposing organic matter and oxides at high temperatures to improve product purity; second, to improve structure—by promoting grain growth, forming a porous structure, and enhancing catalytic or sensing performance; and third, to control crystal form—by stabilizing the crystal structure of bismuth ferrite to ensure its ferroelectric and antiferromagnetic properties.

[0024] Excessively high temperatures (>800℃) lead to excessive crystal growth, reducing specific surface area and potentially decreasing catalytic activity or electromagnetic properties. This also increases equipment wear and energy consumption. Conversely, excessively low temperatures (<500℃) result in incomplete reactions, impurities in the product, and unstable performance. Secondary calcination is required, increasing process complexity. Therefore, controlling the calcination temperature between 500 and 800℃ allows for the regulation of crystal purity and minimizing impurity content.

[0025] Preferably, step S1 includes: dissolving a bismuth salt in an organic solvent, then adding an iron salt, an A salt, a B salt, and an organic acid, and stirring at room temperature until a reddish-brown sol is formed.

[0026] The present invention also provides the application of the metal-doped bismuth ferrite-based perovskite composite material prepared by the method of the present invention as a catalytic material.

[0027] Preferably, the metal-doped bismuth ferrite-based perovskite composite material is loaded onto a carrier filter material to form a catalyst-carrier filter material composite material, which is then used as a catalyst in wastewater treatment for the catalytic removal of antibiotics and / or resistance genes by persulfate.

[0028] Preferably, the method for loading the metal-doped bismuth ferrite-based perovskite composite material onto the carrier filter material is impregnation-coating, coating, or spraying.

[0029] Preferably, the preparation method of the catalytic material-carrier filter material composite material includes the following steps: The carrier filter material is immersed in an acid solution to obtain a surface-activated carrier filter material; A metal-doped bismuth ferrite-based perovskite composite material and a binder were dispersed in a mixed solvent to obtain a suspension; A surface-activated carrier filter material was immersed in a suspension using a vacuum-assisted impregnation method to obtain a carrier filter material loaded with metal-doped bismuth ferrite-based perovskite composite material. The carrier filter material loaded with metal-doped bismuth ferrite-based perovskite composite material was air-dried and then calcined to obtain the catalyst material-carrier filter material composite material.

[0030] Preferably, the preparation method of the catalytic material-carrier filter material composite material includes the following steps: The carrier filter material is immersed in an acid solution to activate its surface, thereby increasing the number of hydroxyl groups and adsorption sites on the surface. Then, it is ultrasonically cleaned with deionized water and ethanol to remove dust and impurities from the surface and dried to obtain surface-activated carrier filter material. The metal-doped bismuth ferrite-based perovskite composite material and the binder are dispersed in a mixed solvent and subjected to vigorous stirring / ultrasound to form a uniform, stable and non-settling suspension. A surface-activated carrier filter material was immersed in a suspension using a vacuum-assisted impregnation method to obtain a carrier filter material loaded with metal-doped bismuth ferrite-based perovskite composite material. The carrier filter material loaded with metal-doped bismuth ferrite-based perovskite composite material was air-dried and then calcined to obtain the catalyst material-carrier filter material composite material.

[0031] Preferably, the acid solution is selected from nitric acid solution.

[0032] Preferably, the nitric acid solution is an aqueous nitric acid solution, and the concentration of nitric acid in the aqueous nitric acid solution is 1 mol / L.

[0033] Preferably, the temperature of the acid solution is 60°C.

[0034] Preferably, the soaking time is 6 hours.

[0035] Preferably, the adhesive is selected from at least one of polyvinyl alcohol, silica sol, and sodium carboxymethyl cellulose.

[0036] Preferably, the mixed solvent is selected from a mixture of ethanol and water.

[0037] Preferably, the vacuum degree of the vacuum-assisted impregnation is 0.08 MPa and the time is 30 min.

[0038] Preferably, the calcination is carried out in an air atmosphere at a temperature of 500°C for 2 hours.

[0039] Preferably, the antibiotic is selected from at least one of tetracycline, quinolone, ciprofloxacin, and sulfamethoxazole.

[0040] Preferably, the resistance gene is selected from at least one of tetX, qnrA, ermF and sul1.

[0041] Preferably, the persulfate is selected from one or both of sodium persulfate and sodium perdisulfate.

[0042] Preferably, the wastewater is pharmaceutical wastewater or effluent from a wastewater treatment plant.

[0043] Preferably, the concentration of antibiotics in the wastewater is 10~100 mg / L.

[0044] Preferably, the abundance of resistance genes in the wastewater is: .

[0045] Preferably, the carrier filter material is selected from at least one of biochar, ceramic flakes and zeolite.

[0046] The beneficial effects of this invention are: The metal-doped bismuth ferrite-based perovskite composite material of the present invention, in bismuth ferrite-based ( The introduction of Sr at the A-site and Mn at the B-site of perovskite induces lattice distortion and generates oxygen vacancies by utilizing the difference in ionic radius and valence state, forming a "Sr-O-Mn" synergistic framework. This framework not only firmly anchors the multivalent metals Fe and Mn to the lattice and inhibits dissolution deactivation, but also constructs a high-density perovskite in situ. The active sites enable the metal-doped bismuth ferrite-based perovskite composite material to continuously catalyze the production of PMS when used as a heterogeneous catalyst. This enables highly efficient mineralization of pollutants. Simultaneously, Sr doping suppresses Bi volatilization, while Mn cycling stabilizes lattice oxygen, maintaining the material's intact perovskite phase. The ferrite soft magnetic phase imparts superparamagnetism, allowing for second-level recovery with an external magnetic field, eliminating secondary pollution. This single design simultaneously addresses the two major bottlenecks of "easy deactivation and difficult separation," providing a universally applicable perovskite platform for heterogeneous catalysis that is highly active, highly stable, and easily recoverable.

[0047] The method for preparing metal-doped bismuth ferrite-based perovskite composite materials of the present invention utilizes a sol-gel method to prepare metal-doped bismuth ferrite-based perovskite composite materials, thereby achieving molecular-scale synthesis. , , , It chelates with organic acids to form a uniform reddish-brown sol, which can polymerize in situ into a three-dimensional network gel at low temperatures. This network "freezes" the metal ions at atomic-level distances, allowing for direct crystallization into single-phase perovskite upon calcination, avoiding phase separation and particle size growth caused by high-temperature solid-phase diffusion. The reducing atmosphere released by the decomposition of organic acids induces oxygen vacancies while inhibiting Bi volatilization, resulting in a uniform particle size distribution and a large specific surface area, thus exposing more active sites. The nanoscale structure and surface oxygen vacancies synergistically reduce charge transfer impedance, thereby enhancing the catalytic rate. This technology has significant potential for widespread application in wastewater treatment. Attached Figure Description

[0048] Figure 1 The one prepared in Example 4 SEM image of biochar composite material (2.00 μm); Figure 2 The one prepared in Example 4 SEM image of biochar composite material (1.00 μm); Figure 3 The one prepared in Example 3 TEM image (500 nm) of biochar composite material; Figure 4 The one prepared in Example 3 TEM image (1000 nm) of biochar composite material. Figure 5 The one prepared in Example 4 TEM image (200 nm) of biochar composite material; Figure 6 The one prepared in Example 3 Degradation results of sulfamethoxazole by biochar composite material; Figure 7 The one prepared in Example 3 Degradation results of biochar composite material on the sul1 resistance gene; Figure 8 The one prepared in Example 4 Degradation results of tetracycline by biochar composite material; Figure 9 The one prepared in Example 4 Degradation results of quinolones by biochar composite materials; Figure 10 The one prepared in Example 4 Degradation results of biochar composite material on tetX and qnrA resistance genes. Detailed Implementation

[0049] The following description, with reference to preferred embodiments, illustrates the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be understood that the preferred embodiments are merely illustrative of the present invention and not intended to limit the scope of protection of the present invention. Example 1

[0050] A method for preparing a metal-doped bismuth ferrite-based perovskite composite material includes the following steps: S1. Weigh out the following according to the molar ratio of bismuth, iron, and manganese: 1:0.92:0.08. , and ; S2, weigh the sample taken from S1 Dissolve in 30 mL of ethylene glycol, stir magnetically at room temperature until completely dissolved, and then add the amount weighed in S1. and Add citric acid, then magnetically stir at room temperature until a reddish-brown sol is formed, resulting in a reddish-brown sol, wherein... , and The molar ratio of the substance of the substance to that of citric acid is 1:0.92:0.08:0.1; S3. Place the reddish-brown sol obtained in S2 in an oven at 70°C and dry it until it forms a gel. S4. The gel obtained in S3 is placed in a muffle furnace and calcined at 500℃ for 2 hours to obtain the calcined product. The sintered product is then ground into powder using an agate mortar to obtain a metal-doped bismuth ferrite-based perovskite composite material. . Example 2

[0051] A method for preparing a metal-doped bismuth ferrite-based perovskite composite material includes the following steps: S1. Weigh out the following components according to the molar ratio of bismuth, strontium, iron, manganese, and citric acid: 0.9:0.1:0.92:0.08:0.1. , , , And citric acid; S2, weigh the sample taken from S1 Dissolve in 30 mL of a mixed solvent of ethylene glycol and glacial acetic acid (volume ratio of ethylene glycol to glacial acetic acid is 2:1), stir magnetically at room temperature until completely dissolved, and then add the amount weighed in S1. , and Add citric acid, and then magnetically stir at room temperature until a reddish-brown sol is formed, thus obtaining a reddish-brown sol; S3. Place the reddish-brown sol obtained in S2 in an oven at 70°C and dry it until it forms a gel. S4. The gel obtained in S3 is placed in a muffle furnace and calcined at 600℃ for 2 hours to obtain the calcined product. The sintered product is then ground into powder using an agate mortar to obtain a metal-doped bismuth ferrite-based perovskite composite material. . Example 3

[0052] A method for preparing a catalytic material-carrier filter media composite material includes the following steps: S1. The cylindrical biochar carrier filter material is immersed in a dilute nitric acid aqueous solution with a temperature of 60℃ and a concentration of 1mol / L for 6 hours to activate the surface of the carrier filter material, thereby increasing the hydroxyl groups and adsorption sites on the surface of the carrier filter material. Then it is washed with deionized water and dried to obtain the surface-activated biochar carrier filter material. S2. Take 1g of the metal-doped bismuth ferrite-based perovskite composite material prepared in Example 1. 0.1g of sodium carboxymethyl cellulose binder was dispersed in a mixed solvent of 20mL ethanol and 5mL deionized water, and a stable suspension was formed by vigorous stirring and ultrasonic treatment. S3. The surface-activated biochar carrier filter material obtained in S1 is immersed in the suspension obtained in S2 using a vacuum-assisted impregnation method. The suspension is treated for 30 minutes under a vacuum of -0.08 MPa to allow the suspension to fully penetrate into the pores of the biochar carrier filter material. Then, the biochar carrier filter material is lifted out of the liquid surface at a constant speed to obtain a carrier filter material loaded with metal-doped bismuth ferrite-based perovskite composite material. S4. After air-drying the carrier filter material supported on metal-doped bismuth ferrite-based perovskite composite material, it is calcined in air at 500℃ for 2 hours to obtain the catalyst material. A catalytic material-carrier filter media composite material with a loading of approximately 15% and strong bonding, i.e. Biochar composite materials. Example 4

[0053] A method for preparing a catalytic material-carrier filter media composite material includes the following steps: S1. The cylindrical biochar carrier filter material is immersed in a dilute nitric acid aqueous solution with a temperature of 60℃ and a concentration of 1mol / L for 6 hours to activate the surface of the carrier filter material, thereby increasing the hydroxyl groups and adsorption sites on the surface of the carrier filter material. Then it is washed with deionized water and dried to obtain the surface-activated biochar carrier filter material. S2. Take 1g of the metal-doped bismuth ferrite-based perovskite composite material prepared in Example 2. 0.1g of sodium carboxymethyl cellulose binder was dispersed in a mixed solvent of 20mL ethanol and 5mL deionized water, and a stable suspension was formed by vigorous stirring and ultrasonic treatment. S3. The surface-activated biochar carrier filter material obtained in S1 is immersed in the suspension obtained in S2 using a vacuum-assisted impregnation method. The suspension is treated for 30 minutes under a vacuum of -0.08 MPa to allow the suspension to fully penetrate into the pores of the biochar carrier filter material. Then, the biochar carrier filter material is lifted out of the liquid surface at a constant speed to obtain a carrier filter material loaded with metal-doped bismuth ferrite-based perovskite composite material. S4. After air-drying the carrier filter material loaded with metal-doped bismuth ferrite-based perovskite composite material, calcinate it in air at 500℃ for 2 hours to obtain a catalyst-carrier filter material composite material with a catalyst material (metal-doped bismuth ferrite-based perovskite composite material) loading of approximately 15% and strong bonding. Biochar composite materials.

[0054] Detection and Analysis 1) Scanning electron microscopy test The sample prepared in Example 4 was examined using a scanning electron microscope. The biochar composite material was tested. The results are as follows: Figure 1 and Figure 2 As shown.

[0055] from Figure 1 and Figure 2 As can be seen from the observation, The biochar composite material exhibits uniformly morphologically aggregated nanoparticles with a particle size of approximately 1 µm. SEM energy dispersive spectroscopy data shows that... The presence of six elements—Bi, Sr, Fe, Mn, O, and C—on the surface of the biochar material indicates that Sr and Mn were successfully doped into it. Within the crystal, it is supported on biochar.

[0056] 2) Transmission electron microscopy (TEM) test The sample prepared in Example 3 was examined using transmission electron microscopy. Biochar composite material, and the one prepared in Example 4. The biochar composite material was tested. The results are as follows: Figures 3 to 5 As shown.

[0057] from Figure 3 and Figure 4 Observations show that the perovskite portion of the material consists of aggregated nanoparticles, while the biochar consists of micron-sized particles with a diameter of approximately 0.5-1 µm. The presence of five elements—Bi, Fe, Mn, O, and C—on the surface of the biochar composite material indicates that Mn was successfully doped into it. Within the crystal, it is supported on biochar.

[0058] from Figure 5 Observations show that the perovskite portion of the material consists of aggregated nanoparticles, while the biochar consists of micron-sized particles with a diameter of approximately 0.5-1 µm. The biochar composite material surface contains six elements: Bi, Sr, Fe, Mn, O, and C, indicating that Sr and Mn were successfully doped into the surface. Within the crystal, it is supported on biochar.

[0059] 3) Antibiotic and resistance gene degradation test The product obtained in Example 3 Biochar composite materials are used to remove sulfamethoxazole and sul1 resistance genes from pharmaceutical wastewater.

[0060] The specific operating steps are as follows: The product obtained in Example 3 Biochar composite material is filled in a continuous flow fixed bed reactor; Pharmaceutical wastewater was used as the influent system for the reaction. The initial concentration of sulfamethoxazole in the pharmaceutical wastewater was 50 mg / L, and the initial abundance of the sul1 resistance gene was 1.0 × 10⁻⁶. 6 copies / mL; Sodium persulfate was added to the reaction feed water system to make the concentration of sodium persulfate in the reaction feed water system 10 mmol / L; Under normal temperature and pressure conditions, the reaction feed water system is uniformly flowed through a continuous flow fixed bed reactor at a flow rate with a hydraulic residence time of 30 min to start the catalytic degradation reaction, so as to catalytically degrade sulfamethoxazole and sul1 resistance gene in the reaction feed water system to obtain the reaction effluent system.

[0061] In order to investigate The stability of the biochar composite material was assessed through five consecutive cyclic experiments. Samples of the reaction effluent were taken at different time points, filtered through a microporous membrane, and then quenched with 1 mL of methanol. The sulfamethoxazole content in the water samples was determined using high-performance liquid chromatography (HPLC), and the sul1 resistance gene content was quantitatively detected using qPCR. Combined with the initial content in the pharmaceutical wastewater, the degradation results of sulfamethoxazole and the sul1 resistance gene were calculated. Figure 6 and Figure 7 As shown.

[0062] from Figure 6 Analysis shows that the sample obtained in Example 3... Biochar composite material, used as a catalyst, catalyzed the removal rate of sulfamethoxazole from pharmaceutical wastewater using sodium persulfate up to 98.2%. After five consecutive cycles, the removal rate of sulfamethoxazole in the pharmaceutical wastewater was 92.0% in the second cycle, 88.0% in the third cycle, 78.6% in the fourth cycle, and remained stable at 70.8% even in the fifth cycle, thus proving the effectiveness of the material prepared in Example 3. The biochar composite material, used as a catalyst, exhibits good stability in catalyzing the degradation of sulfamethoxazole in pharmaceutical wastewater by sodium persulfate, thus proving the effectiveness of the method described in this invention. Biochar composite materials can achieve efficient removal of antibiotics from wastewater.

[0063] from Figure 7 Analysis shows that the sample obtained in Example 3... The biochar composite material, used as a catalyst, catalyzed the removal rate of the sul1 resistance gene from pharmaceutical wastewater using sodium persulfate, reaching 92.5%. After five consecutive cycles, the removal rate of the sul1 resistance gene in the pharmaceutical wastewater was 88.1% in the second cycle, 82.4% in the third cycle, 79.9% in the fourth cycle, and remained stable at 78.5% until the fifth cycle, thus proving the effectiveness of the material prepared in Example 3. The biochar composite material, used as a catalyst, exhibits good stability in catalyzing the degradation of the sul1 resistance gene in pharmaceutical wastewater by sodium persulfate, thus proving the effectiveness of the method described in this invention. Biochar composite materials can achieve efficient removal of resistance genes from wastewater.

[0064] The product obtained in Example 4 Biochar composite materials are used for the synergistic removal of typical antibiotics (tetracyclines and quinolones) and resistance genes (tetX and qnrA) from domestic sewage. The specific operating steps are as follows: The product obtained in Example 4 Biochar composite material is filled in a continuous flow fixed bed reactor; Using the secondary effluent from an actual wastewater treatment plant as the influent system, the initial concentrations of tetracycline and quinolone in the secondary effluent were 40.0 mg / L and 35.0 mg / L, respectively. The initial concentrations of the tetX resistance gene and qnrA resistance gene were also [not specified]. and ; Sodium persulfate was added to the reaction feed water system to make the concentration of sodium persulfate in the reaction feed water system 5 mmol / L; Under normal temperature and pressure conditions, the reaction feed water system is uniformly flowed through a continuous flow fixed bed reactor at a flow rate with a hydraulic retention time of 40 min to start the catalytic degradation reaction, so as to catalytically degrade tetracycline, quinolone, tetX resistance gene and qnrA resistance gene in the reaction feed water system to obtain the reaction effluent system.

[0065] In order to investigate The stability of the biochar composite material was assessed through four consecutive cyclic experiments. Samples of the effluent system at different time points were taken, filtered through a microporous membrane, and quenched with 1 mL of methanol. The contents of tetracycline and quinolone in the water samples were determined using high-performance liquid chromatography (HPLC). The contents of the tetX resistance gene and qnrA resistance gene in the water samples were quantitatively detected using qPCR. Combined with the initial contents in the secondary effluent of the wastewater treatment plant, the degradation results of tetracycline, quinolone, tetX resistance gene, and qnrA resistance gene were calculated. Figures 8 to 10 As shown.

[0066] from Figure 8 Analysis shows that the sample obtained in Example 4... Biochar composite material, used as a catalyst, catalyzed the removal rate of tetracycline from the secondary effluent of an actual wastewater treatment plant by sodium persulfate to 98.5%. After four consecutive cycles, the removal rate of tetracycline in the secondary effluent of the actual wastewater treatment plant was 95.1% in the second cycle, 87.6% in the third cycle, and remained at 78.9% in the fourth cycle.

[0067] from Figure 9 Analysis shows that the sample obtained in Example 4... Biochar composite material, used as a catalyst, catalyzed the removal rate of quinolones in the secondary effluent of an actual wastewater treatment plant by sodium persulfate to 97.8%. After four consecutive cycles, the removal rate of quinolones in the secondary effluent of the actual wastewater treatment plant was 94.5% in the second cycle, 86.3% in the third cycle, and remained at 77.5% in the fourth cycle.

[0068] from Figure 10 Analysis shows that the sample obtained in Example 4... Biochar composite material, used as a catalyst, catalyzed the removal rates of tetX and qnrA resistance genes in the secondary effluent of an actual wastewater treatment plant by sodium persulfate, reaching 85.7% and 84.3%, respectively. After four consecutive cycles, the removal rates of tetX and qnrA genes in the secondary effluent of the actual wastewater treatment plant were 83.9% and 80.2% in the second cycle, 81.1% and 79.8% in the third cycle, and remained at 80.4% and 77.51% in the fourth cycle.

[0069] In summary, the metal-doped bismuth ferrite-based perovskite composite material of the present invention is a highly versatile, catalytically effective, stable, and eco-friendly metal-doped bismuth ferrite-based perovskite catalytic material. As a catalyst for persulfate, it can achieve efficient removal of antibiotics and ARGs from wastewater.

[0070] The preparation method of the bimetallic (Sr, Mn) doped bismuth ferrite-based perovskite catalytic material of the present invention has the advantages of simple preparation, multiple reactive sites, high catalytic performance, strong stability, and wide reaction pH range.

[0071] The catalytic material-carrier filter media composite material of this invention involves loading a bismuth ferrite-based perovskite catalytic material onto the surface of filter materials such as biochar, ceramic sheets, and zeolite to form a catalytic material-carrier composite system. This system acts as a catalyst for persulfate degradation, efficiently degrading various types of antibiotics, including tetracyclines, quinolones, ciprofloxacin, and sulfamethoxazole, in pharmaceutical wastewater and domestic sewage. It simultaneously removes corresponding resistance genes such as tetX, qnrA, ermF, and sulA. The system exhibits excellent recyclability, produces no secondary pollution, and demonstrates good ecological safety. It has significant potential for widespread application in the field of wastewater treatment technology.

[0072] The above embodiments are merely preferred embodiments provided to fully illustrate the present invention, and the scope of protection of the present invention is not limited thereto. Equivalent substitutions or modifications made by those skilled in the art based on the present invention are all within the scope of protection of the present invention.

Claims

1. A metal-doped bismuth ferrite-based perovskite composite material, characterized in that, The molecular formula of the metal-doped bismuth ferrite-based perovskite composite material is Bi. 1-x A x Fe 1-y B y O3; Among them, 0 ≤ x < 1, 0 < y < 1, A is selected from strontium (Sr), and B is selected from manganese (Mn).

2. A method for preparing a metal-doped bismuth ferrite-based perovskite composite material as described in claim 1, characterized in that, It includes the following steps: S1. Add bismuth salt, iron salt, A salt, B salt and organic acid into an organic solvent to obtain a red-brown sol; S2. Dry the red-brown sol to make a gel; S3. Calcinate the gel to obtain a metal-doped bismuth ferrite-based perovskite composite material.

3. The method for preparing the metal-doped bismuth ferrite-based perovskite composite material according to claim 2, characterized in that, The bismuth salt is selected from at least one of bismuth nitrate, bismuth sulfate and bismuth nitrate pentahydrate; And / or, the iron salt is selected from at least one of iron nitrate, iron单质 and ferric nitrate nonahydrate; And / or, the A salt is selected from strontium nitrate; And / or, the B salt is selected from manganese nitrate; And / or, the organic acid is selected from at least one of citric acid, oxalic acid and tartaric acid; And / or, the organic solvent is selected from at least one of absolute ethanol, ethylene glycol, acetone and glacial acetic acid.

4. The method for preparing the metal-doped bismuth ferrite-based perovskite composite material according to claim 2, characterized in that, The drying temperature is 60~90°C; And / or, when x is 0 and y is 0.08, the calcination temperature is 450~700°C and the time is 2 h, or when x is 0.1 and y is 0.08, the calcination temperature is 500~800°C and the time is 2 h.

5. The method for preparing the metal-doped bismuth ferrite-based perovskite composite material according to claim 2, characterized in that, In S1, it includes: dissolve the bismuth salt in the organic solvent, then add the iron salt, A salt, B salt and organic acid, and stir at room temperature until a red-brown sol is formed.

6. Application of a metal-doped bismuth ferrite-based perovskite composite material prepared by the preparation method according to any one of claims 2 to 5 as a catalytic material.

7. The application according to claim 6, characterized in that, Application of using the metal-doped bismuth ferrite-based perovskite composite material loaded on a carrier filter material to make a catalytic material-carrier filter material composite material as a catalytic material in sewage treatment for catalytic removal of antibiotics and / or resistance genes.

8. The application according to claim 7, characterized in that, The preparation method of the catalytic material-carrier filter material composite material includes the following steps: Soak the carrier filter material in an acid solution to obtain a surface-activated carrier filter material; Disperse the metal-doped bismuth ferrite-based perovskite composite material and an adhesive in a mixed solvent to obtain a suspension; Use vacuum-assisted impregnation method to immerse the surface-activated carrier filter material in the suspension to obtain a carrier filter material loaded with the metal-doped bismuth ferrite-based perovskite composite material; Air-dry and then calcinate the carrier filter material loaded with the metal-doped bismuth ferrite-based perovskite composite material to obtain a catalytic material-carrier filter material composite material.

9. The application according to claim 8, characterized in that, The acid solution is selected from nitric acid solution; And / or, the temperature of the acid solution is 60°C; And / or, the soaking time is 6 h; And / or, the adhesive is selected from at least one of polyvinyl alcohol, silica sol and sodium carboxymethyl cellulose; And / or, the mixed solvent is selected from a mixed solvent of ethanol and water; And / or, the vacuum degree of the vacuum-assisted impregnation is 0.08 MPa and the time is 30 min; And / or, the calcination is carried out in an air atmosphere at a temperature of 500°C, and the calcination time is 2 h.

10. The application according to claim 7, characterized in that, The antibiotics are selected from at least one of tetracycline, quinolone, ciprofloxacin and sulfamethoxazole; And / or, the resistance genes are selected from at least one of tetX, qnrA, ermF and sul1; And / or, the persulfate is selected from one or both of sodium monopersulfate and sodium disulfate; It should be noted that "铁单质" in the original text is directly translated as "iron单质" here. It might be a misspelling in the original Chinese text. If it should be "iron", please adjust it accordingly. And / or, the wastewater is pharmaceutical wastewater or effluent from a wastewater treatment plant; And / or, the carrier filter material is selected from at least one of biochar, ceramic flakes and zeolite.

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