Preparation of two-component biochar composite material and application of two-component biochar composite material in activating persulfate to remove antibiotics in wastewater

Abstract

The invention discloses preparation of a two-component biochar composite material and application of the two-component biochar composite material to removal of antibiotics in wastewater by activating persulfate, and relates to a preparation method of the two-component biochar composite material. The invention aims to solve the problems that the existing biochar material has few surface active sites and limited catalytic ability to antibiotics in wastewater. The method comprises the following steps: 1, shearing, crushing, washing and drying a biomass material, and sieving after drying to obtain fine biomass material powder; 2, mixing and grinding the fine biomass material powder, metal salt and a pore-forming agent; and 3, placing the mixture in a tubular furnace, and carrying out pyrolysis in an inert atmosphere to obtain the bi-component biochar composite material. The bi-component biochar is synthesized through one-step pyrolysis, the preparation method is simple, operability is high, and the biochar is used for activating persulfate to remove antibiotics in wastewater.

Description

Technical Field

[0001] The invention belongs to the technical field of wastewater treatment, and in particular relates to the preparation of a two-component biochar composite material and the application of the same in activating persulfate to remove antibiotics in wastewater. Background Art

[0002] With the progress of industrialization, the mass production and use of various chemical products in modern industries has led to increasing public health and environmental pollution issues caused by emerging pollutants. In recent years, the large-scale production and use of antibiotics has resulted in residual contamination in environmental water. Due to their high discharge volume, high biotoxicity, and poor biodegradability, antibiotic wastewater poses a significant threat to human health and ecological safety. Therefore, the development of economical and efficient antibiotic wastewater treatment methods has become a research hotspot in the water treatment field. Numerous technologies have been developed for removing antibiotics from water, including adsorption, electrochemical processes, biological removal, persulfate advanced oxidation, and photocatalysis. Adsorption and persulfate advanced oxidation are considered effective technologies for removing harmful substances, attracting significant interest due to their simplicity, efficiency, and cost-effectiveness. However, issues such as adsorption saturation, high regeneration costs, and insufficient reaction rates require further improvement. Combining adsorption with persulfate advanced oxidation is an effective technology for removing antibiotics, leveraging the advantages of both. The synergistic effect of these two methods promotes effective contact between the target pollutants and the generated reactive free radicals, thereby increasing the reaction rate of the material. Therefore, constructing a dual-functional material with excellent adsorption capacity and persulfate advanced oxidation performance to "enrich and oxidize" antibiotic pollutants is of great significance to ecological stability and human health development.

[0003] Carbon-based materials are widely used for the removal of antibiotics in water due to their advantages such as large specific surface area, high porosity and strong reaction activity. Among them, biochar, as a new type of environmental functional material, can be obtained by pyrolyzing biomass waste under anaerobic conditions. Biochar has rich surface functional groups, low biological toxicity and high adsorption capacity, and has become one of the ideal adsorption materials for water purification and pollutant control. However, biochar materials have the problems of narrow adsorption range and adsorption saturation, which will be detrimental to the removal of pollutants. Biochar shows excellent performance in activating persulfate (PMS) to remove antibiotics and has the potential to be applied in pollution remediation or wastewater treatment. At the same time, biochar can play the role of electron donor and regulator in the process of activating persulfate because they have electron-rich functional groups, carbon-based planes and π-π * However, one of the main challenges of using biochar as a PMS activator is its poor reactivity due to the limited presence of redox-active moieties. Therefore, different forms of biochar modification are required to enhance the activation effect by creating synergistic effects between the different components in the system.

[0004] Although existing biochar-based materials have shown certain potential in persulfate activation, they have the following limitations: single metal modifications (such as Fe and Mn) have limited catalytic active sites and lack multi-metal synergistic effects; they rely on natural pyrolysis pore structure and have not systematically introduced pore-forming agents to optimize adsorption performance; there is insufficient systematic research on pyrolysis temperature, making it difficult to achieve precise control of material properties; and in actual wastewater treatment, the stability and adaptability under complex water quality conditions need to be verified.

[0005] In view of this, the present invention is proposed. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art, provide a preparation method for a two-component biochar composite material and its application in activating persulfate to remove antibiotics in wastewater, and solve the problems raised in the above background technology.

[0007] In order to solve the above technical problems, the basic concept of the technical solution adopted by the present invention is: The preparation of a two-component biochar composite material and its application in activating persulfate to remove antibiotics from wastewater include the following steps: Step 1: Shearing and crushing the biomass material, washing it with distilled water 1-5 times, and then drying it at a temperature of 50° C. to 100° C. After drying, passing it through a 50-200 mesh sieve to obtain a finely ground biomass material powder; wherein the biomass material is a mixture of one or more of ginkgo leaves, corn stalks, cow dung, and peanut shells; Step 2: mixing and grinding the finely ground biomass material powder with a metal salt and a pore-forming agent, wherein the metal salt is one or a mixture of FeSO4·7H2O, Co(NO3)2·6H2O, Ca(NO3)2·4H2O, Mg(NO3)2·6H2O, Mn(NO3)2·4H2O, La(NO3)3·6H2O, Ce(NO3)3·6H2O or CaCl2, and the pore-forming agent is one or a mixture of KH2PO4, KOH, NaOH, Na2CO3, K2CO3, NaHCO3, KHCO3 or ZnCl2; Step 3: Place the mixture in a tubular furnace, introduce inert gas into the tubular furnace, heat the mixture to 600°C-900°C at a heating rate of 3°C / min-10°C / min under the protection of the inert gas, and then pyrolyze at a temperature of 600°C-900°C under the protection of the inert gas atmosphere to obtain a two-component biochar composite material.

[0008] Preferably, in step 2, the mass ratio of the finely ground biomass material powder, the metal salt, and the pore-forming agent is (1-5) g: (0.5-3) g: (1-8) g, the finely ground biomass material powder is ginkgo leaves, the metal salt is Mg(NO3)2·6H2O, and the pore-forming agent is KHCO3.

[0009] Preferably, the pyrolysis temperature in step three is 700° C.-800° C., and a synergistic catalytic structure of MgO, K 2 CO 3 and carbon matrix is ​​formed in the composite material by regulating the heating rate and holding time.

[0010] Preferably, the metal oxide active sites in the composite material are evenly distributed in the pore structure of the biochar, with a specific surface area of ​​500-1000m 2 / g, the pore size distribution is between 2-100nm, and it also contains surface functional groups such as -OH, -COOH and Mg 2+ Metal active center.

[0011] Preferably, the inert gas in step 3 is nitrogen or argon, or a mixture of several of them.

[0012] Preferably, the pyrolysis time in step 1 is 0.5h-3h.

[0013] The present invention also provides a two-component biochar composite material for activating persulfate to remove antibiotics in wastewater. The two-component biochar composite material is prepared by the above-mentioned preparation method.

[0014] To achieve the above objectives, the present application also proposes an application of a two-component biochar composite material to activate persulfate to remove antibiotics from wastewater, comprising the following steps: A catalyst, namely a two-component biochar composite material, is added to water containing antibiotics. After adsorption equilibrium is reached, a persulfate solution, a peroxidant, is added. The persulfate solution can be activated by the two-component biochar composite material to produce various active oxygen species to remove antibiotics from wastewater. The oxidant persulfate solution is peroxymonosulfate (PMS, HSO5 - ); pollutant concentration is 2mg / L-50mg / L, solution volume is 10mL-200mL, the amount of oxidant persulfate is 20mg / L-1000mg / L, and the amount of catalyst is 3mg-100mg; The reaction device is a magnetic stirrer with a rotation speed of 200-800 rpm. Magnetic stirring can improve the contact between the catalyst and PMS. Other instruments with similar functions can achieve this technical effect, so there is no need to limit the choice of instrument. The antibiotics are tetracycline antibiotics, including tetracycline, oxytetracycline, and chlortetracycline; the catalyst dosage is 50 mg, the persulfate dosage is 400 mg / L, and under the condition of pH=7, the removal rate of 5 mg / L tetracycline can reach more than 98.5% within 60 minutes; The two-component biochar composite material can still maintain an antibiotic removal efficiency of more than 90% in river water, lake water and industrial wastewater, and the performance attenuation rate is less than 10% after five cycles.

[0015] After adopting the above technical solution, the present invention has the following beneficial effects compared with the prior art. Of course, any product implementing the present invention does not necessarily need to achieve all of the advantages described below at the same time: (1) The present invention adopts a method combining simple grinding with further pyrolysis to synthesize a two-component biochar composite material. The preparation method is simple and has strong operability. The prepared composite material has high activation performance.

[0016] (2) The two-component biochar composite material prepared in the present invention has great potential for the remediation of water bodies. At the same time, the effects of the mass ratio of metal salts and biomass, solution pH, persulfate concentration, antibiotic concentration, and the dosage of the two-component biochar composite material on water body remediation were studied, and an efficient solution was obtained.

[0017] (3) The dual-component biochar composite material of the present invention exhibits good removal effect over a wide pH range.

[0018] (4) The present invention has multi-component synergistic effect: the synergistic effect of MgO and K2CO3 (MgO provides alkaline sites to promote the decomposition of persulfate, and K2CO3 enhances electron transfer) increases the generation of active oxygen species (peroxides, superoxides, hydroxyl radicals) by more than 40%, and the removal efficiency is 30% higher than that of single metal modified biochar.

[0019] (5) The present invention has process innovation and cost advantages: the one-step synthesis simplifies the process and avoids complex pretreatment and post-treatment; the raw materials are solid waste (gingko leaves, corn stalks, cow dung and peanut shells) and cheap metal salts, and the cost is reduced by more than 50% compared with MOFs-based materials.

[0020] Improved environmental adaptability: The removal efficiency remains above 90% in the pH range of 3-11. It has good applicability in water bodies such as rivers, lakes and industrial wastewater. The removal rate can still reach 90% after 5 cycles.

[0021] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The drawings described below are only some embodiments. A person skilled in the art can derive other drawings based on these drawings without inventive effort. In the drawings: Figure 1 XRD patterns prepared in Examples 1, 2, and 3; Figure 2 The adsorption performance of the catalyst prepared in Example 1 for tetracycline; Figure 3 The tetracycline removal performance of the catalysts prepared in Examples 1 and 4 is compared.

[0023] Figure 4 This is the SEM image of the present invention.

[0024] It should be noted that these drawings and textual descriptions are not intended to limit the conceptual scope of the present invention in any way, but rather to illustrate the concept of the present invention for those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0025] The present invention will now be described in further detail with reference to the accompanying drawings.

[0026] See also Figure 1-4 As shown, in this embodiment, a preparation method of a two-component biochar composite material and its application in activating persulfate to remove antibiotics in wastewater is provided, comprising the following steps: Step 1: Shearing and crushing the biomass material, washing it with distilled water 1-5 times, and then drying it at a temperature of 50°C-100°C. After drying, passing it through a 50-200 mesh sieve to obtain a finely ground biomass powder; wherein the biomass material is a mixture of one or more of ginkgo leaves, corn stalks, cow dung, and peanut shells; and the pyrolysis time is 0.5h-3h; Step 2: Mixing and grinding the finely ground biomass material powder with a metal salt and a pore-forming agent, wherein the metal salt is one or a mixture of FeSO4·7H2O, Co(NO3)2·6H2O, Ca(NO3)2·4H2O, Mg(NO3)2·6H2O, Mn(NO3)2·4H2O, La(NO3)3·6H2O, Ce(NO3)3·6H2O or CaCl2, and the pore-forming agent is one or a mixture of KH2PO4, KOH, NaOH, Na2CO3, K2CO3, NaHCO3, KHCO3 or ZnCl2; the mass ratio of the finely ground biomass material powder, the metal salt and the pore-forming agent is (1-5) g: (0.5-3) g: (1-8) g, the finely ground biomass material powder is ginkgo leaves, the metal salt is Mg(NO3)2·6H2O, and the pore-forming agent is KHCO3; Step 3: Place the mixture in a tubular furnace, introduce inert gas into the tubular furnace, heat it to 600°C-900°C at a heating rate of 3°C / min-10°C / min under the protection of the inert gas, and then pyrolyze it at a temperature of 600°C-900°C and under the protection of an inert gas atmosphere to obtain a two-component biochar composite material; the pyrolysis temperature is 700°C-800°C, and by regulating the heating rate and holding time, a synergistic catalytic structure of MgO, K2CO3 and carbon matrix is ​​formed in the composite material; the inert gas is one or a mixture of nitrogen or argon.

[0027] Among them, the metal oxide active sites in the composite material are evenly distributed in the pore structure of biochar, with a specific surface area of ​​500-1000m 2 / g, the pore size distribution is between 2-100nm, and it also contains surface functional groups such as -OH, -COOH and Mg 2+ Metal active center.

[0028] In this embodiment, the above-mentioned two-component biochar composite material is used as a catalyst. The catalyst is added to the wastewater containing antibiotics. After adsorption equilibrium, a persulfate solution is added. The persulfate solution is peroxymonosulfate. The pollutant concentration is 2 mg / L-50 mg / L, the solution volume is 10 mL-200 mL, the amount of persulfate is 20 mg / L-1000 mg / L, the amount of catalyst is 3 mg-100 mg, and the pH of the reaction system is 3-11. The antibiotics are tetracycline antibiotics, including tetracycline, oxytetracycline, and chlortetracycline; the catalyst dosage is 50 mg, the persulfate dosage is 400 mg / L, and at pH = 7, the removal rate of 5 mg / L tetracycline can reach 98.5% within 60 minutes; The two-component biochar composite material can still maintain an antibiotic removal efficiency of more than 90% in river water, lake water and industrial wastewater, and the performance attenuation rate is less than 10% after five cycles.

[0029] The technical solutions of the present invention are not limited to the specific embodiments listed below, but also include any combination of the specific embodiments: Specific embodiment 1: This embodiment provides a method for preparing a two-component biochar composite material, comprising the following steps: (1) The biomass material is sheared and crushed, and washed with distilled water 1 to 5 times, and then dried at a temperature of 50°C to 100°C. After drying, the biomass material is sieved through a 50-200 mesh sieve to obtain a finely ground biomass material powder; (2) Mix and grind the finely ground biomass material powder with metal salt and pore-forming agent; (3) The mixture is placed in a tubular furnace, an inert gas is introduced into the tubular furnace, the temperature of the tubular furnace is raised to 600°C-900°C under the protection of the inert gas, and then pyrolysis is performed at a temperature of 600°C-900°C and under the protection of the inert gas atmosphere to obtain a two-component biochar composite material; wherein, the heating rate when the tubular furnace is raised to 600°C-900°C under the protection of the inert gas is 3°C / min-10°C / min; the pyrolysis time is 0.5h-3h.

[0030] Specific embodiment 2: This embodiment differs from specific embodiment 1 in that: in step 1, the biomass material is a mixture of one or more of ginkgo leaves, corn stalks, cow dung, and peanut shells, and the rest is the same as specific embodiment 1.

[0031] Specific embodiment 3: This embodiment differs from specific embodiments 1 or 2 in that in step 2, the metal salt is one or a mixture of FeSO4·7H2O, Co(NO3)2·6H2O, Ca(NO3)2·4H2O, Mg(NO3)2·6H2O, Mn(NO3)2·4H2O, La(NO3)3·6H2O, Ce(NO3)3·6H2O, or CaCl2. Other steps are the same as those in specific embodiments 1 or 2.

[0032] Specific embodiment 4: This embodiment differs from specific embodiments 1 to 3 in that in step 2, the pore-forming agent is one or a mixture of KH2PO4, KOH, NaOH, Na2CO3, K2CO3, NaHCO3, KHCO3, or ZnCl2. Other steps are the same as specific embodiments 1 to 3.

[0033] Specific embodiment 5: This embodiment differs from Specific embodiments 1 to 4 in that, in step 2, the mass ratio of the finely ground biomass material powder to the metal salt and pore-forming agent is (0.1-5) g: (0.1-5) g: (0.1-10) g. Other aspects are the same as Specific embodiments 1 to 4.

[0034] Specific embodiment 6: This embodiment differs from specific embodiments 1 to 5 in that in step 3, the inert gas is nitrogen or argon, or a mixture of several thereof. Other aspects are the same as specific embodiments 1 to 5.

[0035] The following embodiments of the present invention are described in detail. The following embodiments are implemented on the premise of the technical solution of the present invention, and detailed implementation plans and specific operating processes are given, but the protection scope of the present invention is not limited to the following embodiments. Example

[0036] The present invention provides a method for preparing a two-component biochar composite material, comprising the following steps: (1) The biomass material is sheared and crushed, washed with distilled water three times, and then dried at a temperature of 80°C. After drying, the biomass material is sieved through a 100-mesh sieve to obtain a fine powder of the biomass material; wherein the biomass material is ginkgo leaves; (2) Mix and grind the finely ground biomass material powder with a metal salt and a pore-forming agent; wherein the metal salt is Mg(NO3)2·6H2O; the pore-forming agent is KHCO3; and the mass ratio of the finely ground biomass material powder to the metal salt and the pore-forming agent is 1g:1g:1g; (3) The dried mixture is placed in a tubular furnace, an inert gas is introduced into the tubular furnace, the tubular furnace is heated to 700°C under the protection of the inert gas, and then pyrolyzed at a temperature of 700°C and under the protection of an inert gas atmosphere to obtain a two-component biochar composite material; wherein the inert gas is nitrogen; the heating rate when the tubular furnace is heated to 700°C under the protection of the inert gas is 5°C / min; and the pyrolysis time is 2h.

[0037] The obtained two-component biochar composite material was named KMBC (1:1:1)-700.

[0038] To verify the structure and performance of the two-component biochar composite material in this example, the structures of the samples prepared in Examples 1, 2, and 3 were analyzed and measured.

[0039] from Figure 1 It can be seen that after the introduction of Mg(NO3)2·6H2O into the biomass, the XRD spectrum of MBC (1:1) shows the diffraction peak of MgO; after the introduction of KHCO3, the XRD spectrum of KBC (1:1) shows the diffraction peak of K2CO3; after the simultaneous introduction of Mg(NO3)2·6H2O and KHCO3, the XRD spectrum of KMBC (1:1:1) shows the diffraction peaks of MgO and K2CO3, indicating that the synthesized biochar composite material mainly includes two components: MgO and K2CO3.

[0040] The catalysts in Examples 1, 2, and 3 can be replaced in turn by KMBC (1:1:1)-700, MBC (1:1), and KBC (1:1). The adsorption of tetracycline by the catalyst KMBC (1:1:1)-700 alone is shown in Figure 2. Figure 2 As shown in Figure 2, it can be proved that under the same conditions, KMBC (1:1:1)-700 has a smaller adsorption capacity for tetracycline. When only PMS is present, no obvious degradation and removal of tetracycline occurs, which indicates that PMS is stable and cannot produce enough active species to trigger degradation and removal reactions (such as Figure 2 shown) The pyrolysis temperature of the two-component biochar composite material was investigated (e.g. Figure 3(As shown in the figure), KMBC (1:1:1)-700 / PMS showed better tetracycline removal efficiency than KMBC (1:1:1)-800 / PMS. At 60 minutes, the tetracycline removal efficiencies of KMBC (1:1:1)-700 and KMBC (1:1:1)-800 activated PMS were 98.5% and 91.3%, respectively.

[0041] Figure 4 From the SEM images, it can be seen that KMBC (1:1:1)-700 has irregular pores, a rough surface and uniformly dispersed nanoparticles on the surface, which is conducive to exposing more active sites for effective removal of antibiotics. Example

[0042] The present invention provides a method for preparing a two-component biochar composite material, comprising the following steps: (1) The biomass material is sheared and crushed, washed with distilled water three times, and then dried at a temperature of 80°C. After drying, the biomass material is sieved through a 100-mesh sieve to obtain a fine powder of the biomass material; the biomass material is ginkgo leaves; (2) Mix and grind the finely ground biomass material powder with a metal salt and a pore-forming agent; the metal salt is Mg(NO3)2·6H2O; no pore-forming agent is added; the mass ratio of the finely ground biomass material powder to the metal salt is 1g:1g; (3) The dried mixture is placed in a tubular furnace, an inert gas is introduced into the tubular furnace, the tubular furnace is heated to 700°C under the protection of the inert gas, and then pyrolyzed at a temperature of 700°C and under the protection of an inert gas atmosphere to obtain a two-component biochar composite material; wherein the inert gas is nitrogen; the heating rate when the tubular furnace is heated to 700°C under the protection of the inert gas is 5°C / min; and the pyrolysis time is 2h.

[0043] The obtained two-component biochar composite material was named MBC.

[0044] The MBC prepared by the above method was used as a catalyst to activate persulfate to remove antibiotic contamination in water. The oxidant persulfate solution was peroxymonosulfate (PMS, HSO₅⁻). The optimal conditions for pollutant concentration, oxidant dosage, and catalyst dosage were: a pollutant concentration of 20 mg / L (solution volume 100 mL), an oxidant dosage of 400 mg / L, a solution pH of 7, and a catalyst dosage of 20 mg. The antibiotics in the wastewater were primarily tetracycline, and the removal efficiency was 90.8%. Example

[0045] The present invention provides a method for preparing a two-component biochar composite material, comprising the following steps: (1) The biomass material is sheared and crushed, washed with distilled water three times, and then dried at a temperature of 80°C. After drying, the biomass material is sieved through a 100-mesh sieve to obtain a fine powder of the biomass material; wherein the biomass material is ginkgo leaves; (2) Mix and grind the finely ground biomass material powder with metal salt and pore-forming agent; wherein no metal salt is added; the pore-forming agent is KHCO3; the mass ratio of the finely ground biomass material powder to the pore-forming agent is 1g:1g; (3) The dried mixture is placed in a tubular furnace, an inert gas is introduced into the tubular furnace, the tubular furnace is heated to 700°C under the protection of the inert gas, and then pyrolyzed at a temperature of 700°C and under the protection of an inert gas atmosphere to obtain a two-component biochar composite material; wherein the inert gas is nitrogen; the heating rate when the tubular furnace is heated to 700°C under the protection of the inert gas is 5°C / min; and the pyrolysis time is 2h.

[0046] The obtained two-component biochar composite material was named KBC.

[0047] KBC prepared by the above method was used as a catalyst to activate persulfate to remove antibiotic contamination in water. The oxidant persulfate solution was peroxymonosulfate (PMS, HSO₅⁻). The optimal conditions for pollutant concentration, oxidant dosage, and catalyst dosage were: a pollutant concentration of 20 mg / L (solution volume 100 mL), an oxidant dosage of 400 mg / L, a solution pH of 7, and a catalyst dosage of 20 mg. The antibiotics in the wastewater were primarily tetracycline, and the removal efficiency was 86.3%. Example

[0048] The present invention provides a method for preparing a two-component biochar composite material, comprising the following steps: (1) The biomass material is sheared and crushed, washed with distilled water three times, and then dried at a temperature of 80°C. After drying, the biomass material is sieved through a 100-mesh sieve to obtain a fine powder of the biomass material; wherein the biomass material is ginkgo leaves; (2) Mix and grind the finely ground biomass material powder with a metal salt and a pore-forming agent; the metal salt is Mg(NO3)2·6H2O; the pore-forming agent is KHCO3; the mass ratio of the finely ground biomass material powder to the metal salt and the pore-forming agent is 1g:1g::1g; (3) The dried mixture is placed in a tubular furnace, an inert gas is introduced into the tubular furnace, the tubular furnace is heated to 800°C under the protection of the inert gas, and then pyrolyzed at a temperature of 800°C and under the protection of an inert gas atmosphere to obtain a two-component biochar composite material; wherein the inert gas is nitrogen; the heating rate when the tubular furnace is heated to 800°C under the protection of the inert gas is 5°C / min; and the pyrolysis time is 2h.

[0049] The obtained two-component biochar composite material was named KMBC (1:1:1)-800.

[0050] KMBC (1:1:1)-800 prepared by the above method was used as a catalyst to activate persulfate to remove antibiotic contamination in water. The oxidant persulfate solution was peroxymonosulfate (PMS, HSO₅⁻). The pollutant concentration, oxidant dosage, and catalyst dosage were as follows: 5 mg / L (solution volume 100 mL), 400 mg / L (oxidant), 50 mg (pH 7), and 70 mg (catalyst). The antibiotics in the wastewater were primarily tetracycline, with a removal efficiency of 91.3%. Example

[0051] The present invention provides a method for preparing a two-component biochar composite material, comprising the following steps: (1) The biomass material is sheared and crushed, washed with distilled water three times, and then dried at a temperature of 80°C. After drying, the biomass material is sieved through a 100-mesh sieve to obtain a fine powder of the biomass material; wherein the biomass material is cow dung; (2) Mix and grind the finely ground biomass material powder with a metal salt and a pore-forming agent; wherein the metal salt is Mg(NO3)2·6H2O; the pore-forming agent is KHCO3; and the mass ratio of the finely ground biomass material powder to the metal salt and the pore-forming agent is 1g:1g:1g; (3) The dried mixture is placed in a tubular furnace, an inert gas is introduced into the tubular furnace, the tubular furnace is heated to 700°C under the protection of the inert gas, and then pyrolyzed at a temperature of 700°C and under the protection of an inert gas atmosphere to obtain a two-component biochar composite material; wherein the inert gas is nitrogen; the heating rate when the tubular furnace is heated to 700°C under the protection of the inert gas is 5°C / min; and the pyrolysis time is 2h.

[0052] The obtained two-component biochar composite material was named KMNC (1:1:1)-700.

[0053] The KMNC (1:1:1)-700 prepared by the above method is used as a catalyst in the activation of persulfate to remove antibiotic contamination in water. The oxidant persulfate solution is peroxymonosulfate (PMS, HSO5 - The pollutant concentration, oxidant dosage, and catalyst dosage are as follows: 5 mg / L (100 mL solution), 400 mg / L oxidant, 7 pH, and 50 mg catalyst. The antibiotics in the wastewater are primarily tetracycline, with a removal efficiency of 95%. Example

[0054] The present invention provides a method for preparing a two-component biochar composite material, comprising the following steps: (1) The biomass material is sheared and crushed, washed with distilled water three times, and then dried at a temperature of 80°C. After drying, the biomass material is sieved through a 100-mesh sieve to obtain a fine powder of the biomass material; wherein the biomass material is ginkgo leaves; (2) Mix and grind the finely ground biomass material powder with a metal salt and a pore-forming agent; wherein the metal salt is Co(NO3)2·6H2O; the pore-forming agent is KOH; and the mass ratio of the finely ground biomass material powder to the metal salt and the pore-forming agent is 1g:1g:1g; (3) The dried mixture is placed in a tubular furnace, an inert gas is introduced into the tubular furnace, the tubular furnace is heated to 700°C under the protection of the inert gas, and then pyrolyzed at a temperature of 700°C and under the protection of an inert gas atmosphere to obtain a two-component biochar composite material; wherein the inert gas is nitrogen; the heating rate when the tubular furnace is heated to 700°C under the protection of the inert gas is 5°C / min; and the pyrolysis time is 2h.

[0055] The obtained two-component biochar composite material was named KCBC (1:1:1)-700.

[0056] The KCBC (1:1:1)-700 prepared by the above method is used as a catalyst in the activation of persulfate to remove antibiotic contamination in water. The oxidant persulfate solution is peroxymonosulfate (PMS, HSO5 - The pollutant concentration, oxidant dosage, and catalyst dosage were as follows: 5 mg / L (100 mL solution), 400 mg / L oxidant, 7 pH, and 50 mg catalyst. The primary antibiotic in the wastewater was tetracycline, with a removal efficiency of 83.4%.

[0057] The present invention is not limited to the above-described embodiments. Any structural changes made under the guidance of the present invention, which have the same or similar technical solutions as the present invention, should be understood to fall within the scope of protection of the present invention. The technologies, shapes, and structural parts not described in detail in the present invention are all well-known technologies.

Claims

1. Preparation of a two-component biochar composite material and its application in activating persulfate to remove antibiotics from wastewater, characterized in that: The following steps are involved: Step 1: Shearing and crushing the biomass material, washing it with distilled water 1-5 times, and then drying it at a temperature of 50° C. to 100° C. After drying, passing it through a 50-200 mesh sieve to obtain a finely ground biomass material powder; wherein the biomass material is a mixture of one or more of ginkgo leaves, corn stalks, cow dung, and peanut shells; Step 2: mixing and grinding the finely ground biomass material powder with a metal salt and a pore-forming agent, wherein the metal salt is one or a mixture of FeSO4·7H2O, Co(NO3)2·6H2O, Ca(NO3)2·4H2O, Mg(NO3)2·6H2O, Mn(NO3)2·4H2O, La(NO3)3·6H2O, Ce(NO3)3·6H2O or CaCl2, and the pore-forming agent is one or a mixture of KH2PO4, KOH, NaOH, Na2CO3, K2CO3, NaHCO3, KHCO3 or ZnCl2; Step 3: Place the mixture in a tubular furnace, introduce inert gas into the tubular furnace, heat the mixture to 600°C-900°C at a heating rate of 3°C / min-10°C / min under the protection of the inert gas, and then pyrolyze at a temperature of 600°C-900°C under the protection of the inert gas atmosphere to obtain a two-component biochar composite material.

2. The preparation of a two-component biochar composite material according to claim 1 and its application in activating persulfate to remove antibiotics from wastewater, characterized in that: In step 2, the mass ratio of the finely ground biomass material powder, the metal salt, and the pore-forming agent is (1-5) g: (0.5-3) g: (1-8) g, the finely ground biomass material powder is ginkgo leaves, the metal salt is Mg(NO3)2·6H2O, and the pore-forming agent is KHCO3.

3. The preparation of a two-component biochar composite material according to claim 1 or 2 and its application in activating persulfate to remove antibiotics from wastewater, characterized in that: In step three, the pyrolysis temperature is 700°C-800°C. By regulating the heating rate and holding time, a synergistic catalytic structure of MgO, K2CO3 and carbon matrix is ​​formed in the composite material.

4. The preparation of a two-component biochar composite material according to any one of claims 1 to 3 and its use in activating persulfate to remove antibiotics from wastewater, characterized in that: The metal oxide active sites in the composite material are evenly distributed in the pore structure of biochar, with a specific surface area of ​​500-1000m 2 / g, the pore size distribution is between 2-100 nm, and it also contains surface functional groups such as -OH, -COOH and Mg 2+ Metal active center.

5. The preparation of a two-component biochar composite material according to claim 4 and its use in activating persulfate to remove antibiotics from wastewater, characterized in that: The above two-component biochar composite material is used as a catalyst, and the catalyst is added to the wastewater containing antibiotics. After adsorption equilibrium is reached, a persulfate solution is added, and the persulfate solution is peroxymonosulfate; The pollutant concentration is 2 mg / L-50 mg / L, the solution volume is 10 mL-200 mL, the dosage of persulfate is 20 mg / L-1000 mg / L, the dosage of catalyst is 3 mg-100 mg, and the pH of the reaction system is 3-11.

6. The preparation of a two-component biochar composite material according to claim 4 and its use in activating persulfate to remove antibiotics from wastewater, characterized in that: The antibiotics are tetracycline antibiotics, including tetracycline, oxytetracycline, and chlortetracycline; the catalyst dosage is 50 mg, the persulfate dosage is 400 mg / L, and under the condition of pH=7, the removal rate of 5 mg / L tetracycline can reach 98.5% within 60 minutes.

7. The preparation of a two-component biochar composite material according to claim 4 and its use in activating persulfate to remove antibiotics from wastewater, characterized in that: The two-component biochar composite material can still maintain an antibiotic removal efficiency of more than 90% in river water, lake water and industrial wastewater, and the performance attenuation rate is less than 10% after five cycles.

8. The preparation of a two-component biochar composite material and its use in activating persulfate to remove antibiotics from wastewater according to claim 1, characterized in that: The inert gas in step 3 is nitrogen or argon or a mixture of several thereof.

9. The preparation of a two-component biochar composite material and its use in activating persulfate to remove antibiotics from wastewater according to claim 1, characterized in that: The pyrolysis time in step 1 is 0.5h-3h.

Images