Catalyst for ozone catalytic degradation of ciprofloxacin in wastewater, and preparation method, regeneration method and use method thereof

Abstract

The invention relates to the technical field of wastewater treatment, in particular to a catalyst for ozone catalytic degradation of ciprofloxacin in wastewater as well as a preparation method, a regeneration method and a use method of the catalyst. The preparation method comprises the following steps: step (1), impregnating biochar in an iron salt solution in an equivalent volume manner to obtain a premix; (2) mixing kaolin and the premix, adding water, and then molding and granulating to obtain a raw blank; and (3) carrying out heat treatment on the raw material blank to prepare the catalyst for ozone catalytic degradation of ciprofloxacin in wastewater. The catalyst prepared by the preparation method disclosed by the invention is high in strength, the active center is efficiently distributed, and the catalytic ozonation efficiency is improved by more than 30%; the polymer is not easy to fall into liquid, is easy to recover, is high in environmental safety, and has a good application prospect.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of wastewater treatment, and in particular to a catalyst for catalytic degradation of ciprofloxacin in wastewater by ozone, a preparation method, a regeneration method and a use method of the catalyst. BACKGROUND

[0002] Advanced oxidation processes (AOPs) have attracted much attention in wastewater application technology. The application of AOPs in wastewater includes hydrogen peroxide (H2O2), ozone (O3), ultraviolet light and catalytic ozonation. In the process of catalytic ozonation, the addition of catalysts can promote the decomposition of ozone to produce more free hydroxyl radicals, so as to realize the degradation of organic pollutants in wastewater; and in the presence of catalysts, the utilization efficiency of ozone can also be improved. Heterogeneous catalytic ozonation is more selective than homogeneous catalytic ozonation because heterogeneous catalytic ozonation is economical, environmentally friendly and easy to separate after treatment. Iron-based materials are often used as catalysts for heterogeneous catalytic ozonation treatment process due to their simple preparation, high catalytic activity and the like. Other catalysts that can be used for wastewater treatment include Al2O3, activated carbon, zeolite and the like.

[0003] The patent application with the application number CN201710188141.4 discloses a preparation method and application of a nano-scale ozone oxidation catalyst. The nano-scale ozone oxidation catalyst prepared by the method is a nano-scale Sn / Ti composite material formed by the eutectic growth of SnO2 and TiO2 two metal oxides. The nano-scale ozone oxidation catalyst has high active component content, high pollutant removal rate, high catalytic activity, less active component loss and no influence on the activity of the catalyst. The catalyst has obvious catalytic effect on the catalytic ozonation treatment of antibiotic wastewater such as chloramphenicol wastewater, penicillin wastewater, erythromycin wastewater, streptomycin wastewater, vancomycin wastewater and pipemidic acid wastewater. The above method has high raw material cost and a complex preparation process, and the efficiency of the ozone catalytic oxidation degradation of antibiotics in wastewater needs to be further improved.

[0004] The patent application with the application number CN202210883512.1 discloses a preparation method and application of a manganese-loaded biochar material. The preparation method comprises the following steps: mixing biochar, KMnO4, (NH4)2C2O4 and water, loading manganese elements on the surface of the biochar at 150-250 DEG C for 20-30 hours, and repeating the loading once; the biochar is polystyrene carbon spheres; the prepared manganese-loaded biochar material has complete loading on the surface of the spheres, and the spheres can be reused by high-temperature calcination after catalytic oxidation. The patent relates to the utilization of biochar, but does not involve iron-based components and kaolin as the main raw material component.

[0005] In summary, there is no relevant research on the preparation of catalysts for catalytic degradation of ciprofloxacin in wastewater by coupling of biochar, kaolin and iron-containing components. SUMMARY

[0006] To solve the above problems in the prior art, the present application provides a catalyst for catalytic degradation of ciprofloxacin in wastewater, a preparation method, a regeneration method and a use method thereof.

[0007] In a first aspect, the present application provides a preparation method of a catalyst for catalytic degradation of ciprofloxacin in wastewater, comprising the following steps: Step (1), biochar is immersed in an iron salt solution in equal volume to obtain a premix; Step (2), kaolin is mixed with the premix and then formed and granulated after adding water to obtain green bodies; Step (3), the green bodies are heat treated to prepare a catalyst for catalytic degradation of ciprofloxacin in wastewater.

[0008] In an embodiment, the iron salt solution is a FeSO4 solution.

[0009] In an embodiment, the loading amount of FeSO4 is 2% to 8% based on the mass of biochar. Preferably, the fineness of the biochar is below 200 mesh; and the fineness of the kaolin is below 200 mesh.

[0010] In an embodiment, in the step (2), the water addition ratio is 10% to 20% of the weight of the solid phase; and in the step (2), the formed and granulated size is 5 mm to 10 mm. Preferably, the formed and granulated size is 5 mm.

[0011] In an embodiment, in the step 3, the heat treatment is: After drying at 80 to 100℃ for 2 to 5 hours, the temperature is raised to 1080 to 1350℃ at a temperature raising rate of 5 to 10℃ / min for anaerobic roasting for 2 to 3 hours; and the protective atmosphere of the anaerobic roasting is nitrogen, helium or carbon dioxide gas. Preferably, in the step 3, the heat treatment is: After drying at 85℃ for 8 hours, the temperature is raised to 1200℃ at a temperature raising rate of 10℃ / min for anaerobic roasting for 3 hours. Optionally, after the heat treatment, cooling is performed to room temperature at a temperature rate of <20℃ / min.

[0012] In an embodiment, the loading amount of FeSO4 is 5% by mass, based on the mass of the biochar; and the green body comprises 1-4% of the premix and 95-99% of kaolin by mass percentage; Preferably, the loading amount of FeSO4 is 5% by mass, based on the mass of the biochar; and the green body consists of 2% of the premix and 98% of kaolin by mass percentage.

[0013] In an embodiment, the biochar is prepared by: The garden waste is pyrolyzed at 400-600 DEG C for 30-60 min to obtain the biochar.

[0014] In a second aspect, the application provides a catalyst for catalytic degradation of ciprofloxacin in wastewater by ozone, which is prepared by the preparation method of the first aspect.

[0015] In a third aspect, the application provides a catalyst regeneration method for catalytic degradation of ciprofloxacin in wastewater by ozone, which is used to regenerate the catalyst of the second aspect, and comprises the following steps: The deactivated catalyst is heated at 600 DEG C for 0.5-1 h in an oxygen-free environment.

[0016] In a fourth aspect, the application provides a use method of the catalyst of the second aspect, which comprises the following steps: Ozone and the catalyst are added to the wastewater to be treated, and then the wastewater is treated at room temperature, wherein the concentration of the ozone is 25 g / Nm 3 .

[0017] Compared with the prior art, the catalyst provided by the application has high strength, is not easy to fall off in liquid, is easy to recover, has high environmental safety, and has good application prospect.

[0018] Other features and advantages of the application will be set forth in the following description, and in part will become apparent from the description, or can be learned by practice of the application. The objects and other advantages of the application will be realized and attained by the structures particularly pointed out in the written description and claims hereof as well as the appended drawings. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to make the technical solutions in the embodiments of the present application or the prior art clearer, the accompanying drawings needed in the embodiments or the prior art description will be briefly introduced. Obviously, the accompanying drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained from these drawings without any creative effort. In the following description, the positional relationship described in the drawings is the direction of the components shown in the drawings as the reference, unless otherwise specified.

[0020] Figure 1 The figure for the influence of the calcination temperature provided by the embodiment of the present application on the strength of the catalyst; Figure 2 The SEM photo of the catalyst for the ozone catalytic degradation of ciprofloxacin in wastewater provided by the embodiment 5 (1200℃) of the present application; Figure 3 The TEM photo of the catalyst for the ozone catalytic degradation of ciprofloxacin in wastewater provided by the embodiment 5 (1200℃) of the present application; Figure 4 The photo of the product obtained by calcining at a roasting temperature higher than 1200℃ for 3 hours under the same conditions of the embodiments 1-5 of the present application. DETAILED DESCRIPTION

[0021] In the description of the present application, it should be noted that all the terms (including technical terms and scientific terms) used in the present application have the same meaning as that generally understood by the ordinary skilled person in the field to which the present application belongs, and should not be understood as a limitation on the present application; it should be further understood that the terms used in the present application should be understood as having the same meaning as the terms in the context of the present specification and the related field, and should not be understood in an idealized or overly formal sense, unless otherwise defined in the present application.

[0022] In order to reduce the cost of the ozone catalyst, improve the treatment efficiency, and expand the use of the garden pyrolysis biochar and kaolin, the present application provides a preparation method of a catalyst for the ozone catalytic degradation of ciprofloxacin in wastewater, which provides a new catalytic material for the ozone catalytic degradation of antibiotic organic pollutants in organic wastewater. The preparation cost of the catalyst is greatly reduced, and the high-value resource utilization of kaolin and biochar is realized. The treatment effect on the antibiotic-containing wastewater which is difficult to degrade is good.

[0023] In the first aspect, the present application provides a preparation method of a catalyst for the ozone catalytic degradation of ciprofloxacin in wastewater, which comprises the following steps: Step (1), the biochar is immersed in an iron salt solution in an equal volume to obtain a premix; Step (2), the kaolin is mixed with the premix and then formed and granulated after adding water to obtain a green body; Step (3), the raw blank is prepared for catalytic degradation of ciprofloxacin in wastewater by ozone after heat treatment.

[0024] Firstly, the present application can make the iron ions in the iron salt solution penetrate into the pore structure of the biochar by the method of equal volume impregnation, forming iron-based active sites. These active sites can significantly improve the activity of the catalyst in the process of catalytic degradation by ozone, and promote the degradation of organic pollutants such as ciprofloxacin. Secondly, the present application uses iron ions as the catalytic active center, which can accelerate the decomposition of ozone to produce hydroxyl radicals and other strong oxidizing species, while biochar can act as a carrier and stabilizer to maintain the structural stability and catalytic activity of the catalyst. Further, the present application can obtain raw blanks with uniform structure and high strength by using the premix of kaolin, activated carbon and iron salt solution after impregnation. This structure is conducive to the stability and catalytic performance of the catalyst in the subsequent heat treatment process, and can maintain the integrity of the catalyst, reduce the wear and loss of the catalyst during subsequent processing and use.

[0025] In an embodiment, the iron salt solution is FeSO4 solution. Iron is a transition metal with unfilled d orbitals, and has unique electronic structure and coordination characteristics, which can provide or accept electrons and participate in redox cycles through variable oxidation states; in the present application, the inventors found that FeSO4 solution is particularly selected as the iron salt solution, on the one hand because of its stable molecular structure, and more importantly, it is easier to load on activated carbon and has significant catalytic treatment effect on refractory antibiotics. The mass concentration of the FeSO4 solution is in the range of 1% to 3%, for example, 1%, 2%, 3%, or any point value between any two of the above.

[0026] In a preferred embodiment, the loading amount of FeSO4 is 2% to 8% based on the mass of biochar, which can be 2%, 3%, 4%, 5%, 6%, 7%, 8%, or any point value between any two of the above. Controlling the loading amount can achieve the maximum catalytic degradation function. If the loading amount is too low, the degradation efficiency will be low; if the loading amount is too large, it will have a negative impact on the porous structure of biochar, not only increasing the cost, but also reducing the degradation efficiency.

[0027] Preferably, the fineness of the biochar is below 200 mesh; the fineness of the kaolin is below 200 mesh.

[0028] In an embodiment, in the step (2), the water adding ratio is 10%~20% of the weight of the solid phase, for example, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20% or any value between them, preferably 15%; in the step (2), the forming granulation size is 5mm~10mm, for example, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm or any value between them. Preferably, the forming granulation size is 5mm.

[0029] In an embodiment, in the step 3, the heat treatment is: After drying at 80~100℃ for 2~5h, the temperature is raised to 1080~1350℃ at a rate of 5~10℃ / min for 2~3h of oxygen-free roasting; the protective atmosphere of the oxygen-free roasting is nitrogen, helium or carbon dioxide gas; wherein the temperature of the oxygen-free roasting can be specifically 1080℃, 1100℃, 1150℃, 1200℃, 1250℃, 1300℃, or a point value between any two of the above. The temperature of the oxygen-free roasting is preferably 1200℃, compared to a temperature between 1000℃ and 1200℃, or a temperature below 1000℃, the use of a temperature of 1200℃ can significantly improve the catalytic strength of the catalyst.

[0030] Preferably, in the step 3, the heat treatment is: After drying at 85℃ for 8h, the temperature is raised to 1200℃ at a rate of 10℃ / min for 3h of oxygen-free roasting; Optionally, after the heat treatment, cooling to room temperature, the temperature rate of cooling is <20℃ / min.

[0031] In an embodiment, the loading amount of FeSO4 is 5% based on the mass of the biochar; the raw blank comprises 1%~4% of the premix and 95%~99% of kaolin in terms of mass percentage, the content of the premix can be specifically 1%, 2%, 3%, 4%, etc., or a point value between any two of the above; the content of the kaolin can be specifically 95%, 96%, 97%, 98%, 99%, 100% or any value between them. Preferably, the loading amount of FeSO4 is 5% based on the mass of the biochar; the raw blank consists of 2% of the premix and 98% of kaolin in terms of mass percentage.

[0032] In an embodiment, the preparation method of the biochar is: The garden waste is pyrolyzed at 400-600℃ for 30-60min to obtain biochar; the pyrolysis temperature may be, for example, 400℃, 450℃, 500℃, 550℃, 600℃, or any value therebetween.

[0033] In a second aspect, the present application provides a catalyst for catalytic degradation of ciprofloxacin in wastewater by ozone, which is prepared by the preparation method of the first aspect.

[0034] In a third aspect, the present application provides a catalyst regeneration method for catalytic degradation of ciprofloxacin in wastewater by ozone, which is used to regenerate the catalyst of the second aspect, and comprises the following steps: The deactivated catalyst is heated at 600℃ under anaerobic condition for 0.5-1h.

[0035] In a specific embodiment of the present application, the deactivated catalyst is placed in a tube furnace and heated to 600℃ at a heating rate of 10℃ / min, and then kept at constant temperature for 0.5-1h under anaerobic condition, so as to realize regeneration.

[0036] The results show that, when CKL+8%Fe@BC is used, the CIP degradation rate of the catalyst can be maintained at 98.46%, 97.81%, 97.14%, 96.61%, 94.72% and 93.79% from the first cycle to the sixth cycle, respectively, and therefore, even after six cycles, the overall removal efficiency of CKL+8%Fe@BC is still more than 90% (i.e. 93.79%).

[0037] Preparation steps of CKL+8%Fe@BC: The kaolin (KL) is ground and passed through a 200-mesh sieve (0.074 mm) to obtain powdered CKL; 2 g of FeSO4·7H2O is dissolved in 100 mL of water, and then 8 g of BC is added to the solution and stirred for 30 min to obtain 8%Fe@BC; 8%Fe@BC is loaded into 92 g of CKL to prepare 100 g of CKL+8%Fe@BC.

[0038] The above mixture is shaped and granulated to a size of 5 mm. After drying at 80-100℃ for 2-5 hours, it is subjected to anaerobic calcination at a heating rate of 5-10℃ / min to a temperature of 1080-1350℃ for 2-3h; the protective atmosphere of the anaerobic calcination is nitrogen, helium or carbon dioxide gas; after the heat treatment, the temperature is cooled to room temperature at a rate of <20℃ / min; finally, a new catalyst is obtained.

[0039] It should be noted that the term “deactivated catalyst” refers to a catalyst with a catalytic degradation performance of less than 50%.

[0040] In a fourth aspect, the present application provides a method for using the catalyst according to the second aspect, comprising the following steps: The ozone and the catalyst are added to the wastewater to be treated, and then the treatment is carried out at room temperature, the concentration of the ozone is 25 g / Nm 3 .

[0041] In a specific embodiment of the present application, an equal amount of 200 mL ciprofloxacin solution with a concentration of 80 mg / L and 10 g catalyst prepared in the embodiment of the present application are added to a 250 mL quartz column reactor (45 mm x 150 mm), and ozone with a concentration of 25 g / Nm 3 , a flow rate of 0.5 L / min is introduced; wherein the water passes through the catalyst layer from top to bottom and is discharged from the bottom after treatment; the ozone is introduced from the bottom to the top, and after catalytic reaction through the catalyst layer, it is discharged from the top, realizing the catalytic oxidation treatment of antibiotics in wastewater.

[0042] To make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be described clearly and completely below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. As long as the technical features designed in different embodiments of the present application do not conflict with each other, they can be combined with each other. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the present application.

[0043] Preparation of biochar: Biochar is obtained by pyrolyzing garden waste at 400-600 ℃ for 30-60 min, and the garden waste can be, for example, branches, trunks, straws, woodworking waste, leaves, flowers, lawn clippings, and discarded flower plants; in this embodiment, biochar is obtained by pyrolyzing branches at 600 ℃ for 30 min, and is ready for use.

[0044] Embodiments 1-5 Embodiments 1-5 respectively provide catalysts for catalytic degradation of ciprofloxacin in wastewater by ozone, and the preparation method of the catalysts comprises the following steps: Step 1, equal volume of 200 mesh biochar is immersed in FeSO4 solution to obtain a premix, and the loading amount of FeSO4 is 5% based on the mass of biochar. In specific implementation, the preparation method of the premix is as follows: 2 g FeSO4·7H2O is dissolved in 100 mL water, then 8 g biochar is added to the solution and stirred for 30 min. Then, the solution is heated at 100 ℃ to evaporate water, and the premix is obtained.

[0045] Step 2, the kaolin is mixed with the premix in a mass ratio of 98%:2 after water is added, and then is formed and granulated, wherein the forming and granulating can be carried out by disc granulation or roll forming and extrusion granulation, to obtain green bodies with a size of 5 mm, the water addition ratio is 15% of the weight of the solid phase, and the; Step 3, after drying at 85℃ for 8 hours, examples 1-5 are subjected to oxygen-free calcination at a temperature increasing rate of 10℃ / min to 400℃ (example 1), 600℃ (example 2), 800℃ (example 3), 1000℃ (example 4) and 1200℃ (example 5) for 3h, and then are cooled to room temperature at a cooling rate of 10℃ / min; Examples 1-5 are loaded with 5% FeSO4 by an equal-volume impregnation method, and then are mixed with kaolin at an addition ratio of 2% to serve as green bodies, and are calcined at a calcination temperature of 400℃, 600℃, 800℃, 1000℃ and 1200℃ for 3 hours, and the change rule of the strength of the obtained catalysts is shown in Fig. 1, which is due to the influence of raw material components, when the temperature is too low, sintering cannot be formed, and the obtained catalyst has low strength; when the temperature is too high, the pyrolysis of inorganic components is sufficient, a fine honeycomb-like microporous structure is formed, and the physical support capacity is enhanced, therefore, the strength of the material obtained at 1200℃ is high; when the temperature exceeds 1200℃, over-burning and melting phenomenon is prone to occur, and energy is wasted.

[0046] The SEM and TEM photos of the catalyst for catalytic degradation of ciprofloxacin in wastewater by ozone provided by example 5 (1200℃) are shown in Figure 2 and Figure 3 .

[0047] It is found that the strength of the catalyst is obviously improved with the increase of the calcination temperature, especially when the temperature exceeds 1200℃, vitrification phenomenon occurs, and therefore the strength of the obtained catalyst material is obviously improved, but if the sintering temperature continues to increase and exceeds the above-mentioned temperature, melting state occurs, the prepared material has no catalytic performance, and the properties are shown in Figure 4 , the catalyst loses activity and porosity; that is, when the calcination temperature is 1200℃, the strength of the catalyst is about 0.45Mpa.

[0048] Examples 6-8 The difference between examples 6-8 and examples 1-5 is only that: 1, the calcination temperature of examples 6-8 is 1200℃; 2, in examples 6-8, the addition ratio of the premix in step (2) is 1%, 2%, 3% and 4% respectively.

[0049] After impregnation of biochar with 5% FeSO4, 1%, 2%, 3%, and 4% of the impregnated biochar were mixed with kaolin as raw materials, and then calcined at 1200°C for 3 hours to obtain new catalysts Kao+1%(BC+5%Fe), Kao+2%(BC+5%Fe), and Kao+3%(BC+5%Fe), wherein Kao refers to kaolin, BC refers to activated carbon, and Fe refers to FeSO4.

[0050] The initial TOC value and pH value of the ciprofloxacin solution were 49.92 mg / L and 6.43, respectively.

[0051] In a 250 mL quartz column reactor (45 mm x 150 mm), an equal amount of 200 mL ciprofloxacin solution with a concentration of 80 mg / L and 10 g of catalyst were added, and the ozone concentration was 25 g / Nm 3 with a flow rate of 0.5 L / min. The content of ciprofloxacin in the wastewater before and after treatment was determined at different reaction times, as shown in the table below, and the removal rates were 97.23%, 99.02%, and 97.61% at 10 min, respectively. Therefore, the pollutant removal capacity of the biochar impregnated with 2% FeSO4 is stronger, and the degradation rate is faster, with a removal rate of 99.02%, which has good application value. Further, as shown in Table 1, when the addition ratio of the premix in step (2) is 2%, the removal rate is 85.64% at 2 min and 98.36% at 5 min, which is much higher than that of other examples.

[0052] Table 1 Effect of FeSO4 impregnated biochar addition ratio on CIP catalytic degradation rate / %

[0053] Examples 9-12 The catalyst prepared in Example 7 was used for catalytic oxidation experiments at ozone concentrations of 15 g / Nm 3 (Example 10), 20 g / Nm 3 (Example 11), 25 g / Nm 3 (Example 12), and 30 g / Nm 3 (Example 13), and the reaction time was 20 minutes. As shown in the table below, the removal rates of ciprofloxacin were 92%, 97.42%, 99.02%, and 99%, respectively. Therefore, when the ozone concentration is 25 g / Nm 3 , the removal rate of ciprofloxacin in the wastewater reaches 99.02% at a degradation time of 10 min; and at this ozone concentration, the catalytic degradation rates at 2 min and 5 min are much higher than those of other examples.

[0054] Table 2 Effect of ozone concentration on CIP catalytic degradation rate / %

[0055] Example 13 The catalyst prepared in Example 7 was subjected to a repeated use test, as shown in the following table; the experimental results show that the prepared catalyst Kao+2%(BC+5%Fe) sample after five cycles, the degradation rate at 2min, 5min and 10min was 72.42%, 94.48% and 98.53% respectively. This shows that within 10min reaction time, the CIP removal rate can still be kept >98%, indicating that the catalyst has high efficient and stable catalytic performance.

[0056] Table 3 Regeneration performance of catalyst

[0057] In summary, compared with the prior art, the catalyst provided by the present application has high strength, efficient active center distribution, and ozone catalytic oxidation efficiency improvement of more than 30%; it is not easy to fall off in liquid and is easy to recover, and has high environmental safety, and has good application prospect.

[0058] In addition, those skilled in the art should understand that although there are many problems in the prior art, each embodiment or technical solution of the present application can only be improved in one or several aspects, and it is not necessary to solve all the technical problems listed in the prior art or background art at the same time. Those skilled in the art should understand that what is not mentioned in a claim should not be regarded as a limitation on the claim.

[0059] Finally, it should be pointed out that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solution deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for preparing a catalyst for the ozone catalytic degradation of ciprofloxacin in wastewater, characterized in that, Includes the following steps: Step (1): Impregnate an equal volume of biochar in an iron salt solution to obtain a premix; Step (2): Mix kaolin with the premix, add water, and then granulate to obtain raw material blanks; Step (3): After heat treatment, the raw material blank is used to obtain a catalyst for the ozone catalytic degradation of ciprofloxacin in wastewater.

2. The catalyst preparation method according to claim 1, characterized in that, The iron salt solution is an FeSO4 solution.

3. The catalyst preparation method according to claim 2, characterized in that, Based on the mass of biochar, the loading was calculated using the mass of FeSO4, with the FeSO4 loading being 2% to 8%. Preferably, the fineness of the biochar is below 200 mesh; the fineness of the kaolin is below 200 mesh.

4. The catalyst preparation method according to claim 1, characterized in that, In step (2), the water addition ratio is 10% to 20% of the solid phase weight; in step (2), the granulation size is 5 mm to 10 mm. Preferably, the granulation size is 5 mm.

5. The catalyst preparation method according to claim 1, characterized in that, In step 3, the heat treatment is as follows: After drying at 80~100℃ for 2~5 hours, the temperature is increased to 1080~1350℃ at a heating rate of 5~10℃ / min for 2~3 hours of oxygen-free calcination; the protective atmosphere for the oxygen-free calcination is nitrogen, helium or carbon dioxide gas. Preferably, in step 3, the heat treatment is as follows: After drying at 85℃ for 8 hours, the temperature was increased to 1200℃ at a heating rate of 10℃ / min for 3 hours of anaerobic calcination. Optionally, after the heat treatment, the room temperature is cooled at a rate of <20°C / min.

6. The catalyst preparation method according to claim 1, characterized in that, Based on the mass of biochar, the loading is calculated based on the mass of FeSO4, and the loading of FeSO4 is 5%; by mass percentage, the raw material contains 1% to 4% premix and 95% to 99% kaolin. Preferably, the loading amount is calculated based on the mass of biochar and the mass of FeSO4, wherein the FeSO4 loading amount is 5%; The raw material blank consists of 2% premix and 98% kaolin by weight percentage.

7. The catalyst preparation method according to claim 1, characterized in that, The method for preparing the biochar is as follows: Biochar is obtained by pyrolyzing garden waste at 400-600℃ for 30-60 minutes.

8. A catalyst for the ozone catalytic degradation of ciprofloxacin in wastewater, prepared by the method according to any one of claims 1 to 7.

9. A method for regenerating a catalyst for the ozone catalytic degradation of ciprofloxacin in wastewater, used to regenerate the catalyst as described in claim 8, characterized in that, Includes the following steps: The deactivated catalyst was heated at 600℃ in an oxygen-free environment for 0.5~1h.

10. A method of using the catalyst according to claim 8, characterized in that, Includes the following steps: Ozone and a catalyst were added to the wastewater to be treated, followed by treatment at room temperature. The concentration of ozone was 25 g / Nm³. 3 .

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