Preparation method of salt-resistant ozone catalyst

Abstract

The invention discloses a preparation method of a salt-resistant ozone catalyst. The preparation method comprises the following steps: S1, cleaning a substrate with deionized water, and drying for later use; s2, Fe (NO3) 3.9 H2O, Ce (NO3) 3.6 H2O, MnCl2 and a substrate are added into a container according to the proportion; s3, adding absolute ethyl alcohol and deionized water, and fully stirring to obtain a mixed solution; s4, placing the container in a reaction kettle, heating to a first temperature, preserving heat, taking out the container after the heat is preserved, and filtering to obtain a salt-tolerant ozone catalyst precursor; and S5, calcining the obtained salt-resistant ozone catalyst precursor in a muffle furnace, and cooling along with the furnace to obtain the salt-resistant ozone catalyst. According to the preparation method of the salt-tolerant ozone catalyst provided by the invention, the salt-tolerant ozone catalyst is prepared in one step through a hydrothermal method, the production process is simplified, and phenol organic matters in high-salt organic wastewater in the coal chemical industry are efficiently degraded by utilizing the synergistic effect of Fe (NO3) 3.9 H2O, Ce (NO3) 3.6 H2O and MnCl2, so that the catalytic efficiency is improved.

Description

Technical Field

[0001] The invention relates to the technical field of catalysts, and in particular to a method for preparing a salt-resistant ozone catalyst. Background Art

[0002] Coal chemical wastewater usually contains high concentrations of salt and difficult-to-degrade phenolic organic matter. If not effectively treated, these harmful substances will not only affect the ecological balance of the water body but also threaten human health. Therefore, how to efficiently remove these pollutants has become an important issue in the field of wastewater treatment.

[0003] Among many treatment methods, ozone oxidation technology is widely used in the purification of drinking water and high-salinity water due to its strong oxidizing ability. As an efficient oxidant, ozone can decompose complex organic pollutants into small molecular compounds that are more easily degradable, thereby significantly improving the biodegradability of wastewater. However, in practical applications, especially when treating high-salinity wastewater, conventional ozone catalysts often face problems such as reduced efficiency, deactivation, and even poisoning. This is mainly because salt may interfere with the work of the active sites of the catalyst, or compete with phenolic organic matter for active species in the reaction (such as hydroxyl radicals), thereby reducing the catalytic efficiency. Summary of the invention

[0004] In order to solve the problems existing in the prior art, the present disclosure provides a method for preparing a salt-resistant ozone catalyst.

[0005] The present disclosure provides a method for preparing a salt-tolerant ozone catalyst, comprising the following steps: S1: The substrate is cleaned with deionized water and dried for later use; S2: Add Fe(NO3)3·9H2O, Ce(NO3)3·6H2O, MnCl2 and the substrate in S1 into the container in proportion; S3: adding anhydrous ethanol and deionized water to the container of S2, and stirring thoroughly to obtain a mixed solution; S4: placing the container of S3 in a reactor, heating it to a first temperature and then keeping it warm, taking out the container after the insulation is completed, filtering it, and obtaining a salt-tolerant ozone catalyst precursor; S5: placing the salt-tolerant ozone catalyst precursor obtained in S4 in a muffle furnace for calcination, and cooling the furnace to obtain a salt-tolerant ozone catalyst.

[0006] In one embodiment of the present disclosure, the substrate in S1 is a spherical γ-Al2O3 with a diameter of 3-5 mm.

[0007] In one embodiment of the present disclosure, in step S2, the molar ratio of Fe(NO3)3·9H2O to the substrate is 1:1-2:1; The molar ratio of Ce(NO3)3·6H2O to the substrate is 1:1-2:1; The molar ratio of MnCl2 to substrate is 1:1-2:1.

[0008] In one embodiment of the present disclosure, in step S3, the molar ratio of the amount of anhydrous ethanol and deionized water to the sum of the amounts of Fe(NO3)3·9H2O, Ce(NO3)3·6H2O and MnCl2 is 1:1-2:1.

[0009] In one embodiment of the present disclosure, in the mixed solution of step S3, the mass percentages of Fe(NO3)3·9H2O, Ce(NO3)3·6H2O, and MnCl2 are 30%-50%, 30%-50%, and 10%-30%, respectively.

[0010] In one embodiment of the present disclosure, step S1 further includes adding the substrate and deionized water into an ultrasonic cleaning machine for oscillation cleaning, and then taking them out and drying them naturally at room temperature.

[0011] In one embodiment of the present disclosure, the ultrasonic cleaning machine needs to repeat the vibration cleaning 3-5 times, and each time takes 5-10 minutes.

[0012] In one embodiment of the present disclosure, the stirring time in step S3 is 6h-18h.

[0013] In one embodiment of the present disclosure, the first temperature in step S4 is 100° C.-150° C., and the insulation time is 12 h-24 h.

[0014] In one embodiment of the present disclosure, the calcination temperature in step S5 is 400° C.-600° C., and the calcination time is 4 h-6 h.

[0015] The present disclosure provides a method for preparing a salt-tolerant ozone catalyst, which prepares the salt-tolerant ozone catalyst in one step by a hydrothermal method, thereby simplifying the production process and utilizing the synergistic effect of Fe(NO3)3·9H2O, Ce(NO3)3·6H2O, and MnCl2 to achieve efficient degradation of phenolic organic matter in high-salt organic wastewater from coal chemical industry, thereby improving the catalytic efficiency.

[0016] Further features and advantages of the present invention will become apparent from the following detailed description of exemplary embodiments of the present invention with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

[0018] Figure 1is a process flow chart of a method for preparing a salt-tolerant ozone catalyst provided in one embodiment of the present disclosure; Figure 2 This is a comparison chart of COD removal rates of different catalysts provided in an embodiment of the present disclosure in a high-salt environment of phenol simulated wastewater; Figure 3 This is a comparison chart of COD removal rates of different catalysts in actual coal chemical high-salt water provided by another embodiment of the present disclosure; Figure 4 This is a stability diagram of a salt-tolerant ozone catalyst provided in one embodiment of the present disclosure. DETAILED DESCRIPTION

[0019] In order to make the invention purpose, technical solution and beneficial technical effect of the present application clearer, the present application is described in detail below in conjunction with specific embodiments. It should be understood that the embodiments described in this specification are only for explaining the present application, not for limiting the present application.

[0020] For simplicity, only some numerical ranges are explicitly disclosed herein. However, any lower limit can be combined with any upper limit to form an unambiguous range; and any lower limit can be combined with other lower limits to form an unambiguous range, and any upper limit can be combined with any other upper limit to form an unambiguous range. In addition, although not explicitly stated, each point or single value between the range endpoints is included in the range. Thus, each point or single value can be combined as its own lower limit or upper limit with any other point or single value or with other lower limits or upper limits to form an unambiguous range.

[0021] In the description of this article, it should be noted that, unless otherwise specified, "above" and "below" are inclusive of the number itself, and "several" in "one or several" means two or more.

[0022] The above-mentioned summary of the invention of the present application is not intended to describe each disclosed embodiment or each implementation in the present application. The following description more specifically illustrates exemplary embodiments. In many places throughout the application, guidance is provided by a series of examples, which can be used in various combinations. In each example, enumeration is only used as a representative group and should not be interpreted as exhaustive.

[0023] First, the terms involved in one or more embodiments are explained.

[0024] COD: COD is the abbreviation of Chemical Oxygen Demand, which refers to the amount of oxidant required to be consumed when the reducing substances in the water are oxidized by strong oxidants under certain conditions, usually expressed in mg / L of oxygen. The COD value reflects the degree of organic pollution in the water. The larger the COD value, the more serious the organic pollution in the water.

[0025] like Figure 1 As shown, this embodiment provides a method for preparing a bimetallic catalyst, which specifically includes the following steps: S1: The substrate is cleaned with deionized water and dried for later use.

[0026] Specifically, the substrate in S1 uses spherical γ-Al2O3, which is a material with a high specific surface area and rich pore structure. The spherical design further optimizes its pore distribution and provides more active sites for loading active metal oxides, thereby improving the efficiency of the catalytic reaction. In order to prevent the influence of impurities on the substrate on subsequent reactions, it is necessary to use deionized water to clean the substrate in advance to remove dust, grease and other possible impurities on the surface. If these impurities remain on the surface of the substrate, they may interfere with subsequent chemical reactions, resulting in reduced catalyst activity or uneven distribution of active sites. Deionized water can ensure that the surface of the substrate reaches a high degree of cleanliness after cleaning, which is crucial for the subsequent adhesion and uniform distribution of the catalyst coating. By cleaning, the surface of the substrate can also be made more hydrophilic, which helps the chemical substances in the subsequent solution to be better adsorbed on the substrate.

[0027] S2: Add Fe(NO3)3·9H2O, Ce(NO3)3·6H2O, MnCl2 and the substrate in S1 into a container in proportion.

[0028] Specifically, Fe(NO3)3·9H2O, Ce(NO3)3·6H2O and MnCl2 are the active component sources of the catalyst. Among them, Fe is a common transition metal with good redox properties, which can effectively promote the decomposition of ozone into oxygen and generate free radicals, thereby accelerating the degradation of organic pollutants; Mn oxide shows a wide range of catalytic activity for a variety of organic pollutants, especially suitable for complex wastewater and waste gas systems; and Ce has unique redox properties (Ce 4+ / Ce 3+ ), can provide electron buffering during the reaction, prevent excessive oxidation of the catalyst surface, and maintain the high activity of the catalyst. The synergistic effect of the three oxides and the substrate in proportion can achieve efficient degradation of phenolic organic matter in high-salt organic wastewater from coal chemical industry and improve its biodegradability.

[0029] S3: Add anhydrous ethanol and deionized water to the container of S2, and stir thoroughly to obtain a mixed solution.

[0030] Specifically, Fe(NO3)3·9H2O, Ce(NO3)3·6H2O, and MnCl2 need to be dissolved in a solvent in order to be evenly distributed on the surface of the substrate. Anhydrous ethanol and deionized water can be used as solvents to effectively dissolve these metal salts and form a uniform solution, which helps to avoid the above metal salts from agglomerating or unevenly distributing on the surface of the substrate. Among them, anhydrous ethanol is a polar organic solvent. Compared with using only deionized water, anhydrous ethanol can significantly increase the solubility of these solutes, ensuring that they can be completely dissolved and evenly distributed in the solution. Anhydrous ethanol has a lower viscosity and good fluidity, which helps the above solutes to be better dispersed in the solution and avoid the occurrence of agglomeration.

[0031] S4: placing the container of S3 in a reactor, heating it to a first temperature and then keeping it warm, taking out the container after the insulation is completed, filtering it, and obtaining a salt-tolerant ozone catalyst precursor; Specifically, the reaction kettle is heated to the first temperature and then kept warm. This process is to allow the chemical reaction to proceed more fully and evenly, so as to obtain a high-quality catalyst precursor. During the hydrothermal process, different metal oxides can be cross-linked or crystallized to a certain extent, thereby enhancing the mechanical strength and stability of the catalyst coating. That is to say, during this process, Fe(NO3)3·9H2O, Ce(NO3)3·6H2O, and MnCl2 will gradually be converted into corresponding metal oxides or multi-metal oxides and loaded on the spherical γ-Al2O3 substrate. Among them, Fe in the multi-metal oxide is a common transition metal with good redox properties. It can effectively promote the decomposition of ozone into oxygen and generate free radicals, thereby accelerating the degradation of organic pollutants; Mn in the multi-metal oxide exhibits a wide range of catalytic activity for a variety of organic pollutants, and is particularly suitable for complex wastewater and exhaust systems; and Ce in the multi-metal oxide has unique redox properties (Ce 4+ / Ce 3+ ), can be in Ce 4+ and Ce 3+ The three metal oxides can convert between the two, provide electron buffering during the reaction, promote the adsorption and activation of oxygen, and thus improve the oxidation ability of the catalyst. The synergistic effect of the three metal oxides can achieve efficient degradation of phenolic organic matter in high-salt organic wastewater from coal chemical industry and improve its biodegradability.

[0032] S5: placing the salt-tolerant ozone catalyst precursor obtained in S4 in a muffle furnace for calcination, and cooling the furnace to obtain a salt-tolerant ozone catalyst.

[0033] Specifically, the calcination temperature of 400°C-600°C during the calcination process helps the precursor to undergo further chemical reactions and makes the crystal structure of the generated metal oxide more perfect, thereby improving its catalytic activity and selectivity. By adjusting the calcination temperature and time, the grain size of the generated metal oxide can be controlled. Smaller grain size usually means higher specific surface area and more active sites, thereby enhancing the catalytic performance of the catalyst.

[0034] The present invention provides a method for preparing a salt-resistant ozone catalyst, which prepares a multi-metal Fe-Mn-Ce oxide supported on a γ-Al2O3 substrate in one step by a one-step hydrothermal method, thereby simplifying the production process and making the entire synthesis process simpler and more efficient. The catalyst prepared by the present invention specifically includes a γ-Al2O3 substrate with a porous structure, wherein a plurality of metal oxides are uniformly loaded in the pores and on the surface thereof, and these metal oxides mainly include iron oxide, cerium oxide and manganese oxide. These oxides can exist alone or in a variety of combinations on the substrate to form a complex multi-metal oxide system.

[0035] Furthermore, the synergistic effect between the three metal oxides of Fe, Ce and Mn is crucial to improving the activity, selectivity and stability of the catalyst. Cerium oxide has unique redox properties and can 4+ / Ce 3+ The reversible conversion of cerium oxide provides additional electrons or holes. This property enables cerium oxide to effectively store and release oxygen during the reaction, thereby enhancing the overall redox ability of the catalyst. Iron oxide also has good redox properties, especially under high temperature conditions. 3+ / Fe 2+ The conversion can promote the generation of hydroxyl radicals (·OH), which is an important active species in the ozone decomposition process. The interaction between cerium oxide and iron oxide can significantly enhance the redox ability of the catalyst. For example, cerium oxide can stabilize Fe in iron oxide by providing additional electrons. 3+ / Fe 2+ The ozone activation efficiency of the catalyst is enhanced by the oxidation state of manganese oxide, which produces more hydroxyl radicals (·OH), further improving the degradation effect of organic matter. Manganese oxide has abundant surface oxygen vacancies and multiple oxidation states, which enables it to effectively adsorb and activate ozone molecules. In addition, manganese oxide can also promote the formation of active sites of other metal oxides by adjusting the electronic structure of the catalyst.

[0036] The catalyst of the present invention utilizes the synergistic effect between the three oxides of iron, cerium and manganese to significantly improve the degradation efficiency of phenolic organic matter in high-salt organic wastewater of coal chemical industry. This synergistic effect effectively overcomes the interference problem that organic matter and salt may cause to the active sites of the catalyst in a high-salt environment, and prevents the catalytic efficiency of the catalyst from decreasing and the life of the catalyst from being shortened.

[0037] In addition, the present invention uses a specific proportion of metal oxides to ensure that the components can better cooperate with each other and achieve higher catalytic activity. During the ozone catalytic oxidation process, the catalyst can induce ozone decomposition to generate a large number of hydroxyl radicals (·OH) with higher redox potential, thereby achieving complete mineralization of organic matter in the wastewater. This not only improves the wastewater treatment effect, but also extends the service life of the catalyst and reduces operating costs.

[0038] In one embodiment of the present disclosure, the substrate in S1 is a spherical γ-Al2O3 with a diameter of 3-5 mm.

[0039] Specifically, γ-Al2O3 is a material with a high specific surface area and rich pore structure. The spherical design further optimizes its pore distribution, providing more active sites for loading active metal oxides, thereby improving the efficiency of the catalytic reaction. The spherical design can effectively reduce the mutual friction between catalyst particles, reduce the risk of breakage, and extend the service life of the catalyst. It helps to evenly disperse the precursor on the surface of the carrier, avoiding the problem of excessive or low local concentration that may be caused by irregularly shaped carriers.

[0040] In addition, compared with other types of carrier materials, the production cost of γ-Al2O3 is relatively low. Using γ-Al2O3 as a catalyst carrier can not only improve the activity, stability and service life of the catalyst, but also reduce costs and simplify the preparation process.

[0041] In one embodiment of the present disclosure, in step S2, the molar ratio of Fe(NO3)3·9H2O to the substrate is 1:1-2:1; the molar ratio of Ce(NO3)3·6H2O to the substrate is 1:1-2:1; and the molar ratio of MnCl2 to the substrate is 1:1-2:1.

[0042] Specifically, by controlling the molar ratio of Fe(NO3)3·9H2O, Ce(NO3)3·6H2O and MnCl2 to the substrate, it is possible to ensure that these active components are evenly distributed on the γ-Al2O3 substrate. The even distribution helps to increase the number of active sites of the catalyst and improve the catalytic performance, and the appropriate molar ratio can prevent the precursor from agglomerating on the substrate surface. In this embodiment, the molar ratio of Fe(NO3)3·9H2O to the substrate is preferably 1:1-2:1; the molar ratio of Ce(NO3)3·6H2O to the substrate is 1:1-2:1; the molar ratio of MnCl2 to the substrate is 1:1-2:1. Under this molar ratio condition, Fe(NO3)3·9H2O, Ce(NO3)3·6H2O and MnCl2 can better combine with the substrate surface to form a stable structure, which helps to improve the thermal stability and chemical stability of the catalyst and ensure the long-term activity of the catalyst.

[0043] By controlling the molar ratio, the loading amount of active components can also be optimized to avoid aggregation of active components or clogging of the pore structure of the substrate due to excessive loading. This helps to improve the dispersion of active components and maximize their utilization efficiency. An appropriate molar ratio can reduce unnecessary waste of raw materials and reduce the production cost of the catalyst.

[0044] In one embodiment of the present disclosure, in step S3, the molar ratio of the amount of anhydrous ethanol and deionized water to the sum of the amounts of Fe(NO3)3·9H2O, Ce(NO3)3·6H2O and MnCl2 is 1:1-2:1.

[0045] Specifically, the molar ratio of the amount of anhydrous ethanol and deionized water to the sum of the amounts of Fe(NO3)3·9H2O, Ce(NO3)3·6H2O and MnCl2 is 1:1 to 2:1. This ratio can significantly improve the solubility of active components such as Fe(NO3)3·9H2O, Ce(NO3)3·6H2O and MnCl2. The appropriate amount of solvent can ensure that these active components are completely dissolved to form a uniform solution, avoiding the problem of excessively high or low local concentrations. This also helps to avoid the agglomeration of the precursor in the solution and ensures that it is evenly distributed on the surface of the substrate. The appropriate amount of solvent adjusts the viscosity and fluidity of the solution, making it have good fluidity without being too thin to cause the loss of active components. This moderate viscosity helps the solution to better adhere to the surface of the substrate and penetrate into the microporous structure of the substrate.

[0046] In one embodiment of the present disclosure, in the mixed solution of step S3, the mass percentages of Fe(NO3)3·9H2O, Ce(NO3)3·6H2O, and MnCl2 are 30%-50%, 30%-50%, and 10%-30%, respectively.

[0047] Specifically, since different metal oxides have different catalytic active sites, by adjusting the mass percentage of Fe(NO3)3·9H2O, Ce(NO3)3·6H2O, and MnCl2, the number of active sites in the final catalyst can be adjusted, thereby optimizing its catalytic performance.

[0048] Furthermore, the synergistic effect between the three metal oxides of Fe, Ce and Mn is crucial to improving the activity, selectivity and stability of the catalyst. Cerium oxide has unique redox properties and can 4+ / Ce 3+ The reversible conversion of cerium oxide provides additional electrons or holes. This property enables cerium oxide to effectively store and release oxygen during the reaction, thereby enhancing the overall redox ability of the catalyst. Iron oxide also has good redox properties, especially under high temperature conditions. 3+ / Fe 2+ The conversion can promote the generation of hydroxyl radicals (·OH), which is an important active species in the ozone decomposition process. The interaction between cerium oxide and iron oxide can significantly enhance the redox ability of the catalyst. For example, cerium oxide can stabilize Fe in iron oxide by providing additional electrons. 3+ / Fe 2+ The ozone activation efficiency of the catalyst is enhanced by the oxidation state of manganese oxide, which produces more hydroxyl radicals (·OH), further improving the degradation effect of organic matter. Manganese oxide has abundant surface oxygen vacancies and multiple oxidation states, which enables it to effectively adsorb and activate ozone molecules. In addition, manganese oxide can also promote the formation of active sites of other metal oxides by adjusting the electronic structure of the catalyst.

[0049] Furthermore, cerium oxide has a strong ability to resist chlorine poisoning and can effectively resist the interference of salt on the active sites of the catalyst. It can protect the active sites of the catalyst from damage by adsorbing and neutralizing harmful substances such as chloride ions. Manganese oxide has a strong salt resistance and can maintain a high catalytic activity in a high-salt environment. It can also protect the active sites of the catalyst from damage by adsorbing and neutralizing harmful ions in the salt. Although iron oxide is easily interfered by salt in a high-salt environment, its synergistic effect with cerium oxide and manganese oxide can significantly improve its salt resistance, thereby maintaining a high catalytic efficiency.

[0050] In summary, the synergistic effect between the three metal oxides of Fe, Ce and Mn can significantly enhance the salt tolerance of the catalyst. Cerium oxide and manganese oxide can protect the active sites of iron oxide from damage by adsorbing and neutralizing harmful ions in salt, thereby maintaining a high catalytic efficiency.

[0051] In one embodiment of the present disclosure, step S1 further includes adding the substrate and deionized water into an ultrasonic cleaning machine for oscillation cleaning, and then taking them out and drying them naturally at room temperature.

[0052] Specifically, ultrasonic cleaning can effectively remove dust, grease and other possible impurities on the surface of the substrate. If these impurities remain on the surface of the substrate, they may interfere with subsequent chemical reactions, resulting in reduced catalyst activity or uneven distribution. High-purity deionized water combined with ultrasonic cleaning can ensure that the substrate surface reaches a high degree of cleanliness, which is crucial for the subsequent adhesion and uniform distribution of the catalyst coating. Ultrasonic cleaning can make the substrate surface more hydrophilic, which helps the chemical substances in the subsequent solution to better adsorb on the substrate, thereby promoting the formation of a uniform coating. The cleaned substrate surface has better wettability and adsorption capacity, which helps the precursor to be evenly distributed on the substrate and avoids the problem of excessive or low local concentration. There are no residual impurities or contaminants on the substrate surface after ultrasonic cleaning, thereby preventing the precursor from agglomerating on the substrate surface and ensuring that each active component can form a well-dispersed coating on the substrate surface.

[0053] In one embodiment of the present disclosure, when an ultrasonic cleaning machine performs vibration cleaning, it needs to be repeated 3-5 times, and each time takes 5-10 minutes.

[0054] Specifically, a single ultrasonic cleaning may not completely remove all impurities on the substrate surface, especially those contaminants embedded in micropores or with strong adsorption. Through multiple cleanings, the substrate surface and its microporous structure can be gradually cleaned in depth to ensure that all impurities are completely removed. Some stubborn contaminants such as grease, organic matter or other chemical residues may require multiple ultrasonic treatments to be completely removed. Repeated cleaning helps to avoid the impact of these residues on subsequent reactions.

[0055] In one embodiment of the present disclosure, the stirring time in step S3 is 6 hours to 18 hours.

[0056] Specifically, through long-term stirring, Fe(NO3)3·9H2O, Ce(NO3)3·6H2O and MnCl2 can be evenly dispersed in the solution and can be evenly adsorbed on the surface of the γ-Al2O3 substrate, which can avoid the problem of local concentration being too high or too low and ensure the uniform distribution of each active component on the substrate. Long-term stirring helps prevent the precursor particles from agglomerating in the solution, allowing the precursor to form a well-dispersed coating on the substrate surface, improving the catalytic performance of the catalyst.

[0057] In one embodiment of the present disclosure, the first temperature in step S4 is 100° C.-150° C., and the insulation time is 12 h-24 h.

[0058] Specifically, in the temperature range of 100℃-150℃, active components such as Fe(NO3)3·9H2O, Ce(NO3)3·6H2O, and MnCl2 begin to decompose. During this process, the water and other volatile components in the solution are gradually removed to form the corresponding metal oxides. For precursors containing water of crystallization (such as Fe(NO3)3·9H2O and Ce(NO3)3·6H2O), hydrothermal treatment under this condition helps to gradually remove the water of crystallization and avoid excessive gas generation during subsequent high-temperature calcination, which may lead to structural damage to the material. Long-term heat preservation ensures that the active components can be evenly distributed on the surface of the substrate and can fully react chemically, which helps to form a uniform coating and avoid the problem of excessive or low local concentrations.

[0059] In one embodiment of the present disclosure, the calcination temperature in step S5 is 400° C.-600° C., and the calcination time is 4 h-6 h.

[0060] Specifically, appropriate calcination temperature and time are crucial to regulating the pore structure of the catalyst. First, high-temperature calcination (400℃-600℃) can promote the development of microporous and mesoporous structures, thereby significantly increasing the specific surface area and pore volume of the catalyst and improving the mass transfer efficiency. However, too high a temperature may cause particle sintering, which will not only reduce the specific surface area but also reduce the activity of the catalyst. Therefore, calcination within the moderate temperature range of 400℃-600℃ can ensure sufficient pore formation while effectively avoiding the problem of excessive sintering.

[0061] In addition, rapid cooling may lead to the destruction of the catalyst structure, while slow cooling helps to maintain the integrity of the catalyst crystal structure and the stability of the pore structure. During the high-temperature calcination process, certain thermal stresses may be generated inside the catalyst. If these stresses are not properly released, they may cause cracks or other defects in the catalyst during the cooling process. Through furnace cooling, these thermal stresses can be effectively released, the catalyst structure can be prevented from being damaged, and the stability and reliability of its performance can be ensured. Reasonable calcination temperature (400℃-600℃) combined with sufficient calcination time, combined with furnace cooling measures, can not only optimize the pore structure of the catalyst, but also maximize its specific surface area, mass transfer efficiency and overall stability, and ultimately prepare a high-performance salt-resistant ozone catalyst.

[0062] like Figure 2-Figure 3 As shown, the following experimental examples further illustrate a method for preparing a salt-tolerant ozone catalyst disclosed in the present invention: The salt-tolerant ozone catalyst was prepared according to the following steps: S1: Clean and dry a spherical γ-Al2O3 substrate with a diameter of 3-5 mm using deionized water; S2: 40% Fe(NO3)3·9H2O, 40% Ce(NO3)3·6H2O, 10% MnCl2 and 20g γ-Al2O3 were weighed and added into the container; S3: Add 100 ml of anhydrous ethanol and 100 ml of deionized water to the beaker in S2 and stir for 12 h to obtain a mixed solution; S4: placing the mixed solution in a reactor and heating it for 12 hours, filtering it to obtain a Fe-Mn-Ce@γ-Al2O3 catalyst precursor; S5: The Fe-Mn-Ce@γ-Al2O3 catalyst precursor obtained after treatment in S4 was placed in a muffle furnace, calcined at 400°C for 4h, and cooled in the furnace to obtain a Fe-Mn-Ce@γ-Al2O3 salt-resistant ozone catalyst.

[0063] After basic characterization of Fe-Mn-Ce@γ-Al2O3 material, it was subjected to target wastewater degradation test: Example 1 The prepared Fe-Mn-Ce@γ-Al2O3 ozone catalyst was added into a phenol solution containing 200 mg / L chemical oxygen demand (COD), and the experiment was carried out in the presence of 10,000 mg / L chloride ions.

[0064] The specific experimental steps are: Step a: Open the oxygen cylinder and pre-blow the ozone generator for 5 minutes to ensure a stable gas flow.

[0065] Step b: Passing phenol wastewater containing chloride ions into an ozone catalytic reactor.

[0066] Step c: adding Fe-Mn-Ce@γ-Al2O3 ozone catalyst into the reactor.

[0067] Step d: ozone was introduced into the ozone catalytic reactor at a rate of 200 ml / min, and the reaction time was 30 min.

[0068] Step e: A sampling port is reserved on the side wall of the ozone catalytic reactor. Samples are taken from the sampling port regularly during the experiment to measure various indicators.

[0069] After the reaction stabilized, the COD content in the phenol wastewater at the sampling port was measured, and the removal rate of COD in the phenol wastewater was found to be higher than 80%.

[0070] Comparative Example 1 The difference between this comparative example and Example 1 is that: a blank group experiment control is performed without adding a catalyst, and after the reaction is stable, the COD content in the phenol wastewater at the sampling port is measured, and the removal rate of COD in the phenol wastewater is obtained to be less than 60%.

[0071] Comparative Example 2 The difference between this comparative example and experimental example 1 is that the Fe-Mn-Ce@γ-Al2O3 in step c is replaced by Fe2O3@γ-Al2O3. After the reaction is stable, the COD content in the phenol wastewater at the sampling port is measured, and the COD removal rate in the phenol wastewater is slightly higher than 60%.

[0072] Comparative Example 3 The difference between this comparative example and experimental example 1 is that the Fe-Mn-Ce@γ-Al2O3 in step c is replaced by Fe-Ce@γ-Al2O3. After the reaction is stable, the COD content in the phenol wastewater at the sampling port is measured, and the COD removal rate in the phenol wastewater is obtained to be higher than 70%.

[0073] Obviously, if Figure 2 As shown, the removal rate of organic pollutants by Fe-Mn-Ce@γ-Al2O3 ozone catalyst is obviously higher than that of the blank group, single-component Fe2O3@γ-Al2O3 ozone catalyst and double-component Fe-Ce@γ-Al2O3 ozone catalyst.

[0074] Example 2 The prepared Fe-Mn-Ce@γ-Al2O3 ozone catalyst was added to actual coal chemical high-salt wastewater for experiments.

[0075] The specific experimental steps are: Step a: Open the oxygen cylinder and pre-blow the ozone generator for 5 minutes to ensure a stable gas flow.

[0076] Step b: passing actual coal chemical high-salt wastewater into an ozone catalytic reactor.

[0077] Step c: adding Fe-Mn-Ce@γ-Al2O3 ozone catalyst into the reactor.

[0078] Step d: ozone was introduced into the ozone catalytic reactor at a rate of 200 ml / min, and the reaction time was 30 min.

[0079] Step e: A sampling port is reserved on the side wall of the ozone catalytic reactor. Samples are taken from the sampling port regularly during the experiment to measure various indicators.

[0080] After the reaction stabilized, the COD content in the wastewater at the sampling port was measured. The measurement results showed that the COD removal rate in the phenol wastewater was higher than 40%.

[0081] Comparative Example 1 The difference between this comparative example and Example 2 is that: a blank group experiment was performed without adding a catalyst. After the reaction stabilized, the COD content in the actual coal chemical high-salt wastewater at the sampling port was measured, and the removal rate of COD in the actual coal chemical high-salt wastewater was found to be less than 20%.

[0082] Comparative Example 2 The difference between this comparative example and experimental example 2 is that the Fe-Mn-Ce@γ-Al2O3 in step c is replaced by Fe@γ-Al2O3. After the reaction is stable, the COD content in the actual coal chemical high-salt wastewater at the sampling port is measured, and the COD removal rate in the actual coal chemical high-salt wastewater is less than 30%.

[0083] Comparative Example 3 The difference between this comparative example and experimental example 2 is that the Fe-Mn-Ce@γ-Al2O3 in step c is replaced by Fe-Ce@γ-Al2O3. After the reaction is stable, the COD content in the actual coal chemical high-salt wastewater at the sampling port is measured, and the COD removal rate in the actual coal chemical high-salt wastewater is less than 40%.

[0084] Obviously, if Figure 3 As shown, the removal rate of organic pollutants in actual coal chemical high-salt wastewater by Fe-Mn-Ce@γ-Al2O3 ozone catalyst is obviously higher than that of the blank group, single-component Fe@γ-Al2O3 ozone catalyst and dual-component Fe-Ce@γ-Al2O3 ozone catalyst.

[0085] Example 3 In order to determine the stability of the Fe-Mn-Ce@γ-Al2O3 ozone catalyst, the Fe-Mn-Ce@γ-Al2O3 ozone catalyst prepared in the above example was tested several times, and the COD concentration in the initial wastewater and the COD concentration in the wastewater after each treatment were measured. The stability diagram of the salt-tolerant ozone catalyst was obtained, as shown in FIG. Figure 4 As shown, the ordinate is the ratio of the COD concentration in the treated wastewater to the COD concentration in the initial wastewater, and the abscissa is the reaction time. An experiment was conducted every 30 minutes, and a total of five experiments were conducted. Specifically, after each experiment, the Fe-Mn-Ce@γ-Al2O3 ozone catalyst used in the previous experiment was added to the new wastewater for the experiment, and the above steps were repeated.

[0086] according to Figure 4 As shown, the removal rate of organic pollutants after repeating the experiment five times remains at a higher level than the first time. The above results show that the Fe-Mn-Ce@γ-Al2O3 ozone catalyst provided by the present invention is a stable ozonation catalyst with high catalytic activity and good stability.

[0087] The present invention provides a method for preparing a salt-tolerant ozone catalyst, which prepares the salt-tolerant ozone catalyst in one step by a hydrothermal method, simplifies the production process, and utilizes the synergistic effect of Fe(NO3)3·9H2O, Ce(NO3)3·6H2O, and MnCl2 to achieve efficient degradation of phenolic organic matter in high-salt organic wastewater from coal chemical industry, thereby improving the catalytic efficiency.

[0088] Embodiments of the present invention have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or technical improvements in the marketplace, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein. The scope of the present invention is defined by the appended claims.

Claims

1. A method for preparing a salt-tolerant ozone catalyst, characterized in that: The steps include: S1: The substrate is cleaned with deionized water and dried for later use; S2: Add Fe(NO3)3·9H2O, Ce(NO3)3·6H2O, MnCl2 and the substrate in S1 into the container in proportion; S3: adding anhydrous ethanol and deionized water to the container of S2, and stirring thoroughly to obtain a mixed solution; S4: placing the container of S3 in a reactor, heating it to a first temperature and then keeping it warm, taking out the container after the insulation is completed, filtering it, and obtaining a salt-tolerant ozone catalyst precursor; S5: placing the salt-tolerant ozone catalyst precursor obtained in S4 in a muffle furnace for calcination, and cooling the furnace to obtain a salt-tolerant ozone catalyst.

2. The method for preparing a salt-tolerant ozone catalyst according to claim 1, characterized in that: The substrate in S1 is spherical γ-Al2O3 with a diameter of 3-5 mm.

3. The method for preparing a salt-tolerant ozone catalyst according to claim 2, characterized in that: In step S2, the molar ratio of Fe(NO3)3·9H2O to the substrate is 1:1-2:1; The molar ratio of Ce(NO3)3·6H2O to the substrate is 1:1-2:1; The molar ratio of MnCl2 to substrate is 1:1-2:

1.

4. The method for preparing a salt-tolerant ozone catalyst according to claim 3, characterized in that: In step S3, the molar ratio of the amount of anhydrous ethanol and deionized water to the sum of the amounts of Fe(NO3)3·9H2O, Ce(NO3)3·6H2O and MnCl2 is 1:1-2:

1.

5. The method for preparing a salt-tolerant ozone catalyst according to claim 4, characterized in that: In the mixed solution of step S3, the mass percentages of Fe(NO3)3·9H2O, Ce(NO3)3·6H2O, and MnCl2 are 30%-50%, 30%-50%, and 10%-30%, respectively.

6. The method for preparing a salt-tolerant ozone catalyst according to claim 1, characterized in that: Step S1 also includes adding the substrate and deionized water into an ultrasonic cleaning machine for oscillation cleaning, and then taking them out and drying them naturally at room temperature.

7. The method for preparing a salt-tolerant ozone catalyst according to claim 6, characterized in that: When the ultrasonic cleaning machine performs vibration cleaning, it needs to be repeated 3-5 times, and each time takes 5-10 minutes.

8. The method for preparing a salt-tolerant ozone catalyst according to claim 1, characterized in that: The stirring time in step S3 is 6h-18h.

9. The method for preparing a salt-tolerant ozone catalyst according to claim 1, characterized in that: The first temperature in step S4 is 100° C.-150° C., and the insulation time is 12 h-24 h.

10. The method for preparing a salt-tolerant ozone catalyst according to claim 1, characterized in that: The calcination temperature in step S5 is 400° C.-600° C., and the calcination time is 4 h-6 h.

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