Multivalent bimetallic oxide ceramic catalyst as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of environmental protection, and particularly provides a multivalent bimetallic oxide ceramic catalyst as well as a preparation method and application thereof. According to the invention, industrial solid wastes such as electrolytic manganese residues are used as main raw materials, and a ceramic material with multivalent bimetallic active phases such as Mn3O4 / Fe3O4 or Mn3O4 / CuO is formed in situ through one-step blending molding and high-temperature sintering. The catalyst has a'micropore-mesopore-macropore 'three-stage through'honeycomb-capillary' double-channel structure, not only is pollutant adsorption and mass transfer facilitated, but also Mn, Fe and other elements contained in the catalyst and nitrogen in a carrier can form metal-nitrogen bonds, and the synergistic catalytic effect is enhanced. The method provided by the invention realizes high-value utilization of industrial solid waste, has the advantages of low raw material cost, simple process, suitability for large-scale production and the like, and provides a new path with remarkable environmental and economic benefits for solid waste recycling while efficiently degrading organic wastewater.

Description

Technical Field

[0001] This invention relates to the field of environmental protection technology, and in particular to a multivalent bimetallic oxide ceramic catalyst, its preparation method, and its application. Background Technology

[0002] With the rapid development of industries such as dyeing and printing, chemicals, pesticides, and pharmaceuticals, large quantities of high-concentration, recalcitrant, and toxic organic wastewater are generated. This type of wastewater typically exhibits high chemical oxygen demand (COD), deep color, and poor biodegradability. Traditional technologies such as biological methods, coagulation sedimentation, adsorption, and membrane separation all have limitations in terms of treatment efficiency, economics, and operational stability. Therefore, developing efficient, economical, and environmentally friendly organic wastewater treatment technologies has become a research hotspot in the field of environmental engineering.

[0003] Catalytic degradation technology can significantly reduce reaction activation energy, achieving the degradation of organic pollutants under mild conditions, and has advantages such as low energy consumption and wide applicability. Advanced oxidation technologies, through the strong oxidizing free radicals generated in the reaction system, can completely convert organic matter into carbon dioxide, water, and inorganic ions, thereby achieving efficient removal of pollutants. Common advanced oxidation processes include the Fenton process, photocatalysis, ozone oxidation, and persulfate activation. When catalytic degradation technology is used in conjunction with advanced oxidation technologies, it can significantly improve the utilization efficiency of oxidants. Catalysts perform excellently in activating persulfate to degrade organic pollutants such as dyes, achieving efficient removal in a short time. Patent CN119346153A reports a Fe, N co-doped nanotube-encapsulated microsphere material, whose three-dimensional structure facilitates adsorption and mass transfer, achieving a removal rate close to or reaching 100% when activating persulfate to degrade sulfamethoxazole. Patent CN120618425A develops a carbon-coated material for activating persulfate to degrade sulfadiazine, achieving a removal rate as high as 99.95%. Patent CN120861077A discloses a CoWO4 / In2O3 composite material that effectively promotes the separation of photogenerated electrons and holes, thereby improving the degradation efficiency of tetracycline antibiotics. Patent CN120618510A, on the other hand, prepares a magnetic Fe3O4 / Cu / nitrogen-doped carbon composite material in a one-step process, which exhibits both adsorption and catalytic degradation functions for methylene blue. Currently, improving the activation efficiency of oxidants such as persulfate and enhancing free radical generation remain important research directions for achieving efficient removal of recalcitrant organic matter.

[0004] On the other hand, a large amount of paving materials are needed in the construction of roads and industrial sites, as well as in the remediation of contaminated soil sites. In road construction, to improve material performance, various materials such as sand and gravel are usually mixed before paving. Patent CN1289734 discloses a highway subgrade material comprising 55%–80% sand, soil, gravel, or a mixture of two or more of these, 9%–30% lightly calcined magnesia, 10%–25% halogen flakes, and 0.55%–1.35% modifier. In the remediation of contaminated soil sites, solidifying agents can be added to solidify heavy metals in the soil. Patent CN108723080A discloses an in-situ remediation method for heavy metal-contaminated soil, which involves applying solidifying agents such as lime, fly ash, and apatite to the contaminated soil, then laying clay as an impermeable layer, followed by a topsoil layer, and finally planting vegetation on the topsoil layer to achieve the remediation of heavy metal-contaminated soil. However, further technological breakthroughs are still needed to adsorb or degrade organic matter and various heavy metals in roads and contaminated soil sites.

[0005] Meanwhile, large quantities of industrial solid waste, such as electrolytic manganese slag and red mud, are stockpiled, not only occupying land but also posing environmental risks such as heavy metal leaching. This type of solid waste is rich in components such as SiO2, Al2O3, and Fe2O3, possessing the potential for preparing ceramic materials. Ceramic materials, due to their high specific surface area, good mechanical strength, and corrosion resistance, are ideal catalyst carriers. In recent years, utilizing industrial solid waste to prepare ceramic carriers, adsorbent materials, catalysts, and laying materials has become an important direction for solid waste resource utilization. Patents CN102584316B and CN115403404A use electrolytic manganese slag as the main raw material, respectively preparing high-strength, high-porosity porous ceramics through programmed temperature-controlled sintering and foaming sintering, which can be used for adsorption and filtration. Patent CN109603849A uses waste rare earth-based denitrification catalysts as raw materials to prepare porous ceramic membrane carriers, which, after being loaded with nickel or silver, can be used for the catalytic reduction of pollutants such as nitrophenol and dyes in water. Patent CN121135333A discloses a composite filler material, its preparation method, and its application. The composite material is prepared using phosphogypsum, municipal solid waste incineration ash, alkaline activating materials, and aluminosilicate materials as raw materials and can be used for roadbed paving. Patent CN121021116A mixes red mud with modified fly ash, soil materials, accelerators, and dispersants to address the problems of low impermeability and mechanical properties in red mud roadbed materials.

[0006] Furthermore, by introducing active components into solid waste-based ceramics, "waste-to-waste" catalysts and environmental remediation materials can be constructed. Patent CN119633801A synthesizes a photocatalytic material for the visible light degradation of formaldehyde by combining fly ash with bismuth vanadate. Patent CN118513047A uses fly ash and waste zinc-manganese battery core powder as raw materials to prepare a catalyst with both high adsorption and high photocatalytic activity. Patent CN118268022A utilizes the activation products of fly ash as a partial silicon-aluminum source to synthesize a Cu@SSZ-13 molecular sieve confined catalyst for the catalytic treatment of volatile organic compounds. However, current industrial solid waste modified catalytic materials still face problems such as single function, insufficient metal synergistic effect, and simple loading methods for active components that are easily lost, requiring further research and breakthroughs. Summary of the Invention

[0007] This invention provides a multivalent bimetallic oxide ceramic catalyst, its preparation method, and its application, with the aim of solving the aforementioned problems in the background art.

[0008] To achieve the above objectives, embodiments of the present invention provide a multivalent bimetallic oxide ceramic catalyst, its preparation method, and its application. The multivalent bimetallic oxide ceramic catalyst of the present invention uses industrial solid waste such as electrolytic manganese slag as the main raw material. Through one-step blending and high-temperature sintering, a ceramic material with multivalent bimetallic active phases such as Mn3O4 / Fe3O or Mn3O4 / CuO is formed in situ. This catalyst possesses a three-level interconnected "honeycomb-capillary" dual-channel structure of "micropore-mesopore-macropore," which not only facilitates pollutant adsorption and mass transfer, but also allows the contained Mn, Fe, and other elements to form metal-nitrogen bonds with nitrogen in the support, enhancing stability and synergistic catalytic effect. This catalyst maintains high activity over a wide pH range of 1-12, eliminating the need to adjust the wastewater pH. The Mn3O4 and Fe3O4 components possess strong microwave absorption capabilities, generating local hot spots under microwave radiation, significantly promoting free radical generation and increasing the degradation rate by 30%-50%. Furthermore, the ceramic framework endows the material with high mechanical strength (>4MPa) and excellent thermal / chemical stability, making it resistant to erosion and pulverization in fluidized beds, reusable, and eliminating the risk of heavy metal leaching. Compared to traditional activated carbon-based catalysts that rely on ozone synergy, are easily saturated, and have low strength, this invention achieves high-value utilization of industrial solid waste, offering advantages such as low raw material costs, simple processes, and suitability for large-scale production. While efficiently degrading organic wastewater, it provides a new pathway for solid waste resource recovery with significant environmental and economic benefits.

[0009] One aspect of the present invention provides a multivalent bimetallic oxide ceramic catalyst, which is made from industrial solid waste through calcination and loaded with nano-dispersed metal oxide active components. The metal oxide active components are embedded in the ceramic lattice or surface in a highly dispersed state, and there are no free metal elements or soluble salts, no risk of heavy metal leaching, and the phase is stable, making it suitable for long-term use. The pore structure of the catalyst is distributed in a three-level distribution of micropores, mesopores and macropores, which are interconnected to form a "honeycomb-capillary" dual continuous channel. The metal oxide active components are a combination of Mn3O4 and Fe3O4, or a combination of Mn3O4 and CuO.

[0010] Preferably, the catalyst has a specific surface area of ​​4-6 m². 2 / g, far exceeding that of traditional clay-sintered ceramics (0.5~2m). 2 / g); water absorption rate of 70%~100% (wt.%); apparent porosity of 70%~90% (vol.%); compressive strength greater than 4MPa; leaching toxicity test results meet the limits of the national standard "Integrated Wastewater Discharge Standard" (GB 8978-1996).

[0011] An embodiment of the present invention also provides a method for preparing a multivalent bimetallic oxide ceramic catalyst, comprising the following steps: S1: After uniformly mixing industrial solid waste with carbon, kaolin, dolomite and an aqueous solution containing manganese salt, the mixture is aged to obtain a mixture; the industrial solid waste is at least one of electrolytic manganese slag, manganese sulfate slag, and red mud; the aqueous solution containing manganese salt contains at least one of trivalent iron salt or divalent copper salt. S2: The mixture is granulated to obtain a green body, which is then dried; S3: The dried green body is oxidized and calcined, and then cooled to obtain a multivalent bimetallic oxide ceramic catalyst.

[0012] Preferably, the amount of char added is 10% to 30% of the mass of industrial solid waste, the amount of kaolin added is 2% to 10% of the mass of industrial solid waste, and the amount of dolomite added is 5% to 10% of the mass of industrial solid waste; the volume-to-mass ratio (mL / g) of the manganese salt aqueous solution to the industrial solid waste is 1:10 to 30.

[0013] More preferably, the electrolytic manganese slag and manganese sulfate slag comprise the following components: Al 1%~8%, Si 8%~20%, Fe 1%~5%, Ca 2%~12%, Mn 1%~5%, with the remainder being S and O; the red mud comprises the following components: Fe 5%~30%, Al 5%~15%, Si 5%~15%, Ca 2%~6%, Na 2%~12%, K 0.5%~2%, with the remainder being Mg, Ti, S and O; the charcoal comprises at least one of charcoal, coal or activated carbon.

[0014] Preferably, in step S1, Mn 2+ The molar concentration of ions is 0.4~2.0 mol / L; Fe 3+ ions or Cu 2+ The molar concentration of ions is 0.2~1.0 mol / L.

[0015] Preferably, in step S2, the drying temperature is 60~100℃ and the drying time is 4~6h.

[0016] Preferably, in step S3, the calcination process is as follows: the temperature is increased from room temperature to 500-700℃ at a heating rate of 5-10℃ / min and held for 1-2 hours, and then the temperature is increased to 900-1300℃ and held for 2-4 hours.

[0017] Another aspect of the present invention provides an application of a multivalent bimetallic oxide ceramic catalyst in the catalytic degradation of organic wastewater.

[0018] Preferably, the catalyst is applied to organic wastewater in conjunction with persulfate, and the catalytic degradation reaction is carried out under microwave radiation.

[0019] The persulfate mentioned includes at least one of potassium peroxymonosulfate, potassium persulfate, sodium peroxymonosulfate, or sodium persulfate.

[0020] More preferably, the catalyst and persulfate, under the enhanced coupling effect of microwave radiation, increase the degradation rate of methylene blue by 30% to 50%.

[0021] Preferably, the organic wastewater includes at least one of methylene blue wastewater, Sudan red wastewater, rhodamine B wastewater, methyl orange wastewater, xanthate wastewater, xanthate ester wastewater, and landfill leachate.

[0022] Preferably, the organic matter concentration in the organic wastewater is 20~200 mg / L, and the pH is 1.0~12.0; the catalyst dosage is 0.20~1.00 g / L; the catalytic degradation temperature during the catalytic degradation process is 20~60℃, and the catalytic degradation reaction time is 0.5~5.0 h.

[0023] More preferably, adding 0.25~3.00 mmol / L potassium persulfate during the catalytic degradation process results in an organic wastewater catalytic degradation rate of over 96%.

[0024] More preferably, the catalyst activates persulfate to degrade organic wastewater, and after five consecutive degradation-washing-drying cycles, the organic matter removal rate remains above 90%.

[0025] Another aspect of the present invention provides the application of a multivalent bimetallic oxide ceramic catalyst as a paving material in the paving of roadbeds, industrial sites, or soil-contaminated sites.

[0026] Preferably, during the construction of roads and industrial sites and the remediation of soil contaminated sites, it is mixed into sand and gravel and laid on roads, industrial sites or soil contaminated sites, which has the functions of water permeability, adsorption of pollutants and degradation of organic pollutants.

[0027] Preferably, the amount of the multivalent bimetallic oxide ceramic catalyst is 2% to 20% of the amount of sand and gravel.

[0028] The pollutants include organic pollutants and heavy metal ions, wherein the organic pollutants include xanthates, xanthate esters, humic substances, methylene blue, Sudan red, rhodamine B, or methyl orange, and the heavy metal ions include Cu. 2+ Pb 2+ Zn 2+ or Cd 2 + .

[0029] According to the free radical quenching experiment results, when the above catalyst degrades organic wastewater, the O2 content during the degradation process... ·- ·OH, SO4 ·- and 1 O2 and other substances can oxidize organic wastewater. 1 O2 plays a major role, and the specific reaction mechanism is as follows:

[0030] This invention presents a highly efficient catalytic material prepared by loading two metal active components onto a metal oxide ceramic support, combining the structural stability of the ceramic support with the synergistic catalytic effect of the bimetallic components. The catalyst preparation process is simple and efficient, and can utilize a high proportion of industrial solid waste for doping, achieving not only high-value utilization of solid waste but also effectively solving the current problems of low resource utilization rate and low added value of solid waste. Furthermore, the material is acid and alkali resistant, high-temperature resistant, reusable, and possesses both adsorption and catalytic degradation functions, providing a new technical approach for the resource utilization of industrial solid waste. It has the following beneficial effects: (1) In this catalyst, there is a synergistic catalytic effect between manganese-iron / copper bimetallic oxides, which can significantly improve the reaction efficiency. The ceramic framework structure helps to fully expose the active sites, thereby accelerating the degradation of pollutants. Among them, the Fe, Cu, Mn and other elements in compounds such as Mn3O4, CuO and Fe3O4 can form metal-nitrogen bonds (such as Cu–N, Fe–N) with nitrogen in the support, enhance the interaction between the metal and the support, and improve the stability of the catalyst. In addition, the catalyst has a three-level interconnected pore structure of "micropore-mesopore-macropore", which can capture pollutant molecules of different sizes through chemical adsorption or electrostatic interaction, and synergistically act with oxidants such as persulfate to catalyze the generation of free radicals, thereby achieving efficient degradation of pollutants.

[0031] (2) This catalyst maintains high catalytic activity over a wide pH range of 1 to 12, eliminating the need for repeated pH adjustments of the wastewater. Compared to traditional homogeneous Fenton catalysts (such as Fe...), 2+ It is only effective at pH 3-4, significantly broadening its applicable pH range. Simultaneously, the catalyst possesses high compressive strength, resisting erosion and pulverization in fluidized bed reactors, effectively solving the problems of difficult catalyst recovery and easy caking.

[0032] (3) The components such as Mn3O4 and Fe3O4 contained in the catalyst have ferromagnetic and magnetic loss capabilities, and their microwave absorption intensity is higher than that of common oxides such as Fe2O3 and MnO. Under microwave radiation, the catalyst surface generates local hot spots due to selective heating, which can promote the generation of more free radicals and active oxygen, thereby significantly improving the rate and efficiency of advanced oxidation reactions.

[0033] (4) Using industrial solid waste rich in elements such as iron and manganese as the main raw material, the amorphous metal oxides can be transformed into catalytically active crystalline phases such as Mn3O4 and Fe3O4 through high-temperature sintering, and a ceramic framework can be formed simultaneously to obtain high-value-added functional materials. Compared with traditional activated carbon-based catalysts, this catalyst does not rely on ozone for synergistic degradation, saving related equipment and operating costs; and it can still maintain stable pore structure in high temperature (>1000℃) and acid and alkaline environments. The material has acid resistance >95% and alkali resistance >97%, making it applicable to a wider range of conditions.

[0034] (5) The ceramic support has high strength and good compressive strength (compressive strength > 4MPa), is not easily broken, and is suitable for long-term operation. By controlling the pore-forming agent and sintering process, the pore size and pore volume can be precisely designed, thereby optimizing the catalytic performance. In contrast, activated carbon-based catalysts have low mechanical strength, are easily damaged and lost in fluidized beds or fixed beds, and are easily saturated by adsorption, requiring frequent regeneration.

[0035] (6) This invention uses industrial solid waste such as electrolytic manganese slag as raw materials, which is low in cost and simple in process, realizing the high-value utilization of solid waste and having both economic and environmental benefits. Traditional activated carbon-based catalysts are expensive, while this technology uses industrial solid waste for organic wastewater treatment, which helps to achieve synergistic treatment of solid waste and wastewater, reduce treatment costs and improve overall efficiency.

[0036] (7) This invention employs a one-step molding process involving the blending of industrial solid waste, pore-forming agent, and metal precursor. In-situ doping with bimetals such as Mn-Cu and Mn-Fe, followed by fixation during sintering, forms a stable phase with multivalent metal oxides. This prevents the loss of active components and enhances catalytic activity. The prepared catalyst has advantages such as wide availability of raw materials, low cost, simple process, low energy consumption, and suitability for large-scale production. Simultaneously, it leverages the synergistic catalytic effect of multivalent bimetals, exhibiting high degradation efficiency, structural stability, and reusability. This not only provides an efficient solution for organic wastewater treatment but also opens up new avenues for the high-value utilization of industrial solid waste, demonstrating significant environmental, economic, and social benefits.

[0037] (8) The present invention uses a multivalent bimetallic oxide ceramic catalyst for paving roadbeds, industrial sites or soil-contaminated sites, which can effectively degrade pollutants and reduce environmental pollution. At the same time, the multivalent bimetallic oxide ceramic has a well-developed pore structure, which can increase air permeability and drainage. Attached Figure Description

[0038] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0039] Figure 1 A photograph of the manganese iron oxide ceramic catalyst prepared in Example 1 of the present invention; Figure 2 The X-ray diffraction pattern of the manganese iron oxide ceramic catalyst prepared in Example 1 of the present invention is shown below. Figure 3 The scanning electron microscope (SEM) image of the manganese iron oxide ceramic catalyst prepared in Example 1 of this invention is shown below. Figure 4 The scanning electron microscope-energy dispersive spectroscopy (SEM-EDS) spectrum of the manganese iron oxide ceramic catalyst prepared in Example 1 of this invention is shown below. Figure 5 This is a pore size distribution diagram of the manganese iron oxide ceramic catalyst prepared in Example 1 of the present invention; Figure 6 The X-ray diffraction pattern of the ceramic catalyst prepared in Comparative Example 1 of this invention is shown below. Figure 7 The image shows the scanning electron microscope (SEM) image of the ceramic catalyst prepared in Comparative Example 1 of this invention. Figure 8 The image shows the scanning electron microscope-energy dispersive spectroscopy (SEM-EDS) analysis spectrum of the ceramic catalyst prepared in Comparative Example 1 of this invention. Figure 9 The X-ray diffraction pattern of the iron oxide ceramic catalyst prepared in Comparative Example 2 of the present invention is shown. Figure 10 The X-ray diffraction pattern of the manganese oxide ceramic catalyst prepared in Comparative Example 3 of the present invention is shown. Figure 11 The Fourier transform infrared spectra of the manganese iron oxide ceramic catalyst before and after degradation of methylene blue in Application Example 1 of the present invention are shown below. Figure 12 The results of the repeatability degradation performance test of the manganese iron oxide ceramic catalyst on methylene blue in Application Example 6 of the present invention are shown. Figure 13 The results of the repeatability degradation performance test of the manganese copper oxide ceramic catalyst on Rhodamine B in Application Example 7 of the present invention are shown. Detailed Implementation

[0040] To make the technical problems, technical solutions and advantages of the present invention clearer, a detailed description will be given below in conjunction with the accompanying drawings and specific embodiments.

[0041] Unless otherwise defined, all technical terms used herein have the same meaning as commonly understood by those skilled in the art. The technical terms used herein are for the purpose of describing particular embodiments only and are not intended to limit the scope of the invention.

[0042] Unless otherwise specified, all raw materials, reagents, instruments and equipment used in this invention can be purchased from the market or prepared by existing methods.

[0043] This invention addresses existing problems by providing a multivalent bimetallic oxide ceramic catalyst, its preparation method, and its application.

[0044] The following will illustrate the process through specific examples and comparative examples. The electrolytic manganese slag used in this document comes from Guizhou Province, and its main elements and their mass content are: Al 5.38%, Si 10.35%, Fe 1.78%, Ca 7.24%, Mn 2.86%, S 6.35%. The manganese sulfate slag comes from a high-purity manganese sulfate plant in Guizhou Province, and its main elements and their mass content are: Al 6.18%, Si 12.15%, Fe 1.62%, Ca 8.28%, Mn 2.26%, S 5.85%. The red mud comes from Shanxi Province, and its main elements and their mass content are: Fe 12.03%, Al 13.37%, Si 11.12%, Ca 9.84%, Na 10.21%, K 0.64%. Example

[0045] This embodiment provides a method for preparing a manganese iron oxide ceramic catalyst, comprising the following steps: S1: Using electrolytic manganese slag as aggregate, add 15% activated carbon, 5% kaolin, and 8% dolomite. The volume ratio (mL / g) of the aqueous solution to the electrolytic manganese slag is 1:10. Add Fe-containing... 3+ 0.5 mol / L, Mn 2+ A 1.0 mol / L aqueous solution is mixed thoroughly and then aged to form a mixture. S2: The mixture in S1 is granulated by a granulator to obtain a green body, which is then dried at 80°C for 4 hours; S3: Place the green body obtained in S2 into a muffle furnace, and heat it at a rate of 10℃ / min, first from 25℃ to 600℃, hold for 2 hours, then continue to heat it to 1200℃, hold for 3 hours, cool it down and remove it to obtain the manganese iron oxide ceramic catalyst. (Product photo shown) Figure 1 As shown in the table, the prepared manganese iron oxide ceramic catalyst was subjected to leaching toxicity testing according to the national environmental protection standard "Leaching Toxicity of Solid Waste - Horizontal Oscillation Method" (HJ 557-2010). The test results and the maximum allowable concentration according to GB 8978-1996 are shown in Table 1. Table 1 shows that the leaching toxicity of the prepared manganese iron oxide ceramic catalyst meets the standard. The specific surface area of ​​the manganese iron oxide ceramic catalyst prepared in this example is 5.48 m². 2 The material has a water absorption rate of 86.24% (wt.%), an apparent porosity of 86.14% (vol.%), and a compressive strength of 4.23 MPa. Furthermore, the X-ray diffraction (XRD), scanning electron microscopy (SEM), and scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) spectra of the manganese iron oxide ceramic catalyst prepared in this embodiment are shown below. Figure 2 , Figure 3 and Figure 4 As shown. From Figure 2As can be seen, the manganese iron oxide ceramic catalyst contains metal oxides such as Fe3O4 and Mn3O4, and these metal oxides are uniformly dispersed in the ceramic framework in the form of nanocrystals (see...). Figure 3 and Figure 4 Both Fe3O4 and Mn3O4 are in mixed valence states, and their internal Fe... 2+ / Fe 3+ or Mn 2+ / Mn 3+ Coexistence, unobstructed electron hopping channels, enable efficient interfacial charge transfer, and Fe 3+ / Mn 3+ It can be reduced by surface defects or PMS, thus maintaining its catalytic activity. Meanwhile, the pore size distribution of the manganese iron oxide ceramic catalyst prepared in this embodiment is shown in the figure below. Figure 5 As shown, from Figure 5 As can be seen from the above, the manganese iron oxide ceramic catalyst exhibits a three-level distribution of "micropore-mesopore-macropore", which is beneficial for the efficient treatment of organic pollutants of different molecular sizes.

[0046] Table 1 Leaching toxicity of manganese iron oxide ceramic catalysts

[0047] Example 2 This embodiment provides a method for preparing a manganese iron oxide ceramic catalyst, comprising the following steps: S1: Using electrolytic manganese slag as aggregate, add 20% charcoal powder, 8% kaolin, and 8% dolomite. The volume ratio (mL / g) of the aqueous solution to the electrolytic manganese slag is 1:20. Add Fe-containing... 3+ 1.0 mol / L, Mn 2+ A 2.0 mol / L aqueous solution is mixed thoroughly and then aged to form a mixture. S2: The mixture in S1 is granulated by a granulator to obtain a green body, which is then dried at 70°C for 5 hours. S3: The green body obtained in S2 is placed in a muffle furnace, and the temperature is increased at a rate of 10℃ / min, first from 25℃ to 600℃ and held for 2 hours, then increased to 1100℃ and held for 4 hours. After cooling, it is removed to obtain the manganese iron oxide ceramic catalyst. The manganese iron oxide ceramic catalyst prepared in this example has a water absorption rate of 82.84% (wt.%), an apparent porosity of 83.14% (vol.%), and a compressive strength of 5.03 MPa.

[0048] Example 3 This embodiment provides a method for preparing a manganese copper oxide ceramic catalyst, comprising the following steps: S1: Using electrolytic manganese slag as aggregate, add 25% charcoal powder, 8% kaolin, and 6% dolomite. The volume ratio (mL / g) of the aqueous solution to the electrolytic manganese slag is 1:10. Add Cu-containing... 2+ 1.0 mol / L, Mn 2+ A 2.0 mol / L aqueous solution is mixed thoroughly and then aged to form a mixture. S2: The mixture in S1 is granulated by a granulator to obtain a green body, which is then dried at 80°C for 5 hours. S3: The green body obtained in S2 is placed in a muffle furnace, and the temperature is increased at a rate of 10℃ / min, first from 25℃ to 600℃ and held for 2 hours, then increased to 1200℃ and held for 4 hours. After cooling, it is removed to obtain the manganese copper oxide ceramic catalyst. The manganese copper oxide ceramic catalyst prepared in this example has a water absorption rate of 79.54% (wt.%), an apparent porosity of 86.84% (vol.%), and a compressive strength of 5.43 MPa.

[0049] Example 4 This embodiment provides a method for preparing a manganese iron oxide ceramic catalyst, comprising the following steps: S1: Using manganese sulfate slag as aggregate, add 25% activated carbon, 10% kaolin, and 6% dolomite. The volume ratio (mL / g) of the aqueous solution to the electrolytic manganese slag is 1:15. Add Fe-containing... 3+ 0.5 mol / L, Mn 2+ A 1.0 mol / L aqueous solution is mixed thoroughly and then aged to form a mixture. S2: The mixture in S1 is granulated by a granulator to obtain a green body, which is then dried at 80°C for 4 hours; S3: The green body obtained in S2 is placed in a muffle furnace, and the temperature is increased at a rate of 10℃ / min, first from 25℃ to 600℃ and held for 2 hours, then increased to 1200℃ and held for 3 hours. After cooling, it is removed to obtain the manganese iron oxide ceramic catalyst. The manganese iron oxide ceramic catalyst prepared in this example has a water absorption rate of 76.54% (wt.%), an apparent porosity of 81.94% (vol.%), and a compressive strength of 4.13 MPa.

[0050] Example 5 This embodiment provides a method for preparing a manganese iron oxide ceramic catalyst, comprising the following steps: S1: Using red mud as aggregate, add 20% activated carbon, 8% kaolin, and 10% dolomite. Add Fe-containing... (The sentence is incomplete and requires more context to translate accurately. It can be left as is.) 3+ 0.5 mol / L, Mn 2+A 1.0 mol / L aqueous solution is mixed thoroughly and then aged to form a mixture. S2: The mixture in S1 is granulated by a granulator to obtain a green body, which is then dried at 80°C for 4 hours; S3: The green body obtained in S2 is placed in a muffle furnace, and the temperature is increased at a rate of 10℃ / min, first from 25℃ to 600℃ and held for 2 hours, then increased to 1200℃ and held for 3 hours. After cooling, it is removed to obtain the manganese iron oxide ceramic catalyst. The manganese iron oxide ceramic catalyst prepared in this example has a water absorption rate of 79.54% (wt.%), an apparent porosity of 84.34% (vol.%), and a compressive strength of 6.18 MPa.

[0051] Comparative Examples 1 to 4 Comparative Examples 1-4 provide methods for preparing ceramic catalysts or single metal oxide ceramic catalysts. Except for the aqueous solution, the electrolytic manganese slag, other additives, and preparation process are the same as in Example 1. The added pure water or aqueous solution and the obtained products are shown in Table 2.

[0052] Table 2

[0053] The XRD, SEM, and SEM-EDS spectra of the ceramic catalyst obtained in Comparative Example 1 are shown below. Figure 6 , Figure 7 and Figure 8 As shown. Compared with Example 1, it can be seen that no oxide phases of iron and manganese were detected in the ceramic product without added metals, but trace amounts of iron and manganese elements were still present in the product (see Example 1). Figure 8 Meanwhile, compared with Example 1, it can be seen that Comparative Examples 2 and 3 only added ferric chloride solution and manganese acetate solution, respectively, and the corresponding XRD analysis spectra of the ceramic catalysts are as follows: Figure 9 and 10 As shown, the prepared ceramic products contain only single metal oxides of Fe2O3 and Mn2O3, respectively. Their metal elements are all in a single high-valence state, lacking low-valence metal sites. They rely on surface hydroxyl groups or light to excite holes, resulting in weak activation ability. Furthermore, Fe2O3 and Mn2O3 have weaker microwave absorption capabilities than Fe3O4 and Mn3O4, which leads to the catalytic degradation ability of single metal oxide ceramic catalysts being lower than that of multivalent bimetallic oxide ceramic catalysts.

[0054] Application Example 1 This application example uses the manganese iron oxide ceramic catalyst prepared in Example 1 to test the degradation of methylene blue, specifically including the following steps: 100 mL of a 100 mg / L methylene blue solution was placed in a 250 mL Erlenmeyer flask. Manganese iron oxide ceramic catalyst was added at a concentration of 0.6 g / L. After stirring thoroughly, 0.50 mmol / L potassium persulfate was added to adjust the pH to 7.0. The mixture was stirred at 25 °C for 3.0 h, resulting in a methylene blue degradation rate of 99.03%. The Fourier transform infrared (FT-IR) spectra of the manganese iron oxide ceramic catalyst before and after degradation are shown below. Figure 11 As shown. From Figure 11 As can be seen from the data, after the degradation of methylene blue by manganese iron oxide ceramic catalysts, the intensity of the O–H absorption band decreases due to the consumption of surface hydroxyl groups during the generation of reactive oxygen species. At 1580 cm⁻¹... -1 (Benzothiazine ring C=C skeletal vibration) and 1350cm - ¹ No characteristic infrared absorption peak of methylene blue was observed at (C–N antisymmetric stretching vibration of –N(CH3)2), but at 723 cm⁻¹... -1 and 690cm -1 A new infrared absorption peak appeared, indicating that the manganese iron oxide ceramic catalyst has a catalytic degradation effect on methylene blue.

[0055] Application Example 2 This application example uses the manganese iron oxide ceramic catalyst prepared in Example 6 to conduct a free radical quenching experiment on the degradation process of methylene blue, specifically including the following steps: The difference from Application Example 1 is that after adding potassium persulfate, ethanol, tert-butanol, p-benzoquinone, and L-histidine were added respectively, while other conditions remained unchanged; after adding the above quenchers, the degradation rates of methylene blue were 88.97%, 87.93%, 67.15%, and 18.81%, respectively. According to the free radical quenching experiment results, O2 during the degradation process... ·- ·OH, SO4 ·- and 1 O2 and other substances can oxidize organic wastewater. 1 O2 plays a major role.

[0056] Application Example 3 This application example uses the manganese iron oxide ceramic catalyst prepared in Example 2 to test the degradation of Sudan Red. The specific steps are as follows: 100 mL of a 100 mg / L Sudan Red solution was placed in a 250 mL Erlenmeyer flask. A manganese iron oxide ceramic catalyst was added at a concentration of 0.6 g / L. After stirring thoroughly, 0.50 mmol / L potassium peroxymonosulfate was added to adjust the pH to 12.0. The mixture was stirred at 25 °C for 3.0 h, resulting in a Sudan Red degradation rate of 98.62%. This demonstrates that the manganese iron oxide ceramic catalyst, in conjunction with potassium peroxymonosulfate, can promote the degradation of Sudan Red solution.

[0057] Application Example 3 In this application example, the manganese copper oxide ceramic catalyst prepared in Example 3 was used to test the degradation of Rhodamine B. The specific steps are as follows: 100 mL of 100 mg / L Rhodamine B solution was placed in a 250 mL Erlenmeyer flask. A manganese copper oxide ceramic catalyst was added at a concentration of 0.6 g / L. After stirring thoroughly, 0.50 mmol / L potassium peroxymonosulfate was added to adjust the pH to 8.0. The mixture was stirred at 25 °C for 3.0 h, resulting in a Rhodamine B degradation rate of 96.72%. This demonstrates that the manganese copper oxide ceramic catalyst, in conjunction with potassium peroxymonosulfate, can promote the degradation of Rhodamine B solution.

[0058] Application Example 4 This application example uses the manganese iron oxide ceramic catalyst prepared in Example 4 to test the degradation of methylene blue, specifically including the following steps: Take 100 mL of 100 mg / L methylene blue solution and place it in a 250 mL Erlenmeyer flask. Add manganese iron oxide ceramic catalyst at a concentration of 0.6 g / L. After stirring evenly, add 0.50 mmol / L potassium persulfate to adjust the pH to 7.0. Stir at 25 °C for 3.0 h. The degradation rate of methylene blue is 98.16%.

[0059] Application Example 5 This application example uses the manganese iron oxide ceramic catalyst prepared in Example 5 to test the degradation of Sudan Red solution, specifically including the following steps: 100 mL of a 100 mg / L Sudan Red solution was placed in a 250 mL Erlenmeyer flask. A manganese iron oxide ceramic catalyst was added at a concentration of 0.6 g / L. After stirring thoroughly, 0.50 mmol / L potassium peroxymonosulfate was added to adjust the pH to 5.0. The mixture was stirred at 25 °C for 3.0 h, resulting in a Sudan Red degradation rate of 97.85%. This verifies that the manganese iron oxide ceramic catalyst synergistically promotes the degradation of Sudan Red solution with potassium peroxymonosulfate.

[0060] Application Example 6 This application example uses the manganese iron oxide ceramic catalyst prepared in Example 1 to perform a repeatable degradation test on methylene blue. The specific steps are as follows: (1) First degradation: Take 100 mL of 100 mg / L methylene blue solution and put it into a 250 mL conical flask. Add manganese iron oxide ceramic catalyst at 0.6 g / L. After stirring evenly, add 0.50 mmol / L potassium persulfate to adjust the pH to 7.0. Stir at 25℃ for 3.0 h, test the concentration of methylene blue after degradation, and calculate the degradation rate. (2) Catalyst recovery and regeneration: The reaction suspension from step (1) was filtered, the filter residue was washed with a large amount of deionized water, the filter residue was dried in an oven at 90°C for 6.0 h, then calcined in a muffle furnace at 300°C for 1 h, cooled and ground to obtain the second-cycle manganese iron oxide ceramic catalyst. (3) Cyclic degradation experiment: Repeat steps (1) and (2) for a total of 5 cycles. Test the methylene blue concentration after each degradation and calculate the degradation rate for each degradation process. The degradation rate data are shown in [reference needed]. Figure 12 .from Figure 12 It can be seen that after 5 cycles, the manganese iron oxide ceramic catalyst of this invention retains more than 91% of its activity in degrading methylene blue, confirming that the in-situ doped multivalent bimetallic oxide structure can effectively inhibit the loss of active components and has excellent cycling stability. The above verifies that the manganese iron oxide ceramic catalyst, in synergy with potassium persulfate cycling, promotes the degradation of methylene blue.

[0061] Application Example 7 In this application example, the manganese copper oxide ceramic catalyst prepared in Example 3 was used to conduct a repeatability degradation test of Rhodamine B. The specific steps are as follows: (1) First degradation operation: Take 100 mL of 100 mg / L Rhodamine B solution and put it into a 250 mL Erlenmeyer flask. Add manganese copper oxide ceramic catalyst at 0.6 g / L. After stirring evenly, add 0.50 mmol / L potassium persulfate to adjust the pH to 8.0. Stir at 25℃ for 3.0 h, test the concentration of Rhodamine B after degradation, and calculate the degradation rate. (2) Catalyst recovery and regeneration: The reaction suspension from step (1) was filtered, the filter residue was washed with a large amount of deionized water, the filter residue was dried in an oven at 90°C for 5 hours, then calcined in a muffle furnace at 300°C for 2 hours, cooled and ground to obtain the second-cycle manganese copper oxide ceramic catalyst. (3) Cyclic degradation experiment: Repeat steps (1) and (2) for a total of 5 cycles. Test the concentration of Rhodamine B after each degradation and calculate the degradation rate for each degradation process. The degradation rate data are shown in [reference to relevant data]. Figure 13 .from Figure 13 It can be seen that after 5 cycles, the manganese copper oxide ceramic catalyst of this invention retains more than 90% of its activity in degrading Rhodamine B, confirming that the in-situ doped multivalent bimetallic oxide structure can effectively inhibit the loss of active components and has excellent cycling stability. The above verifies that the manganese copper oxide ceramic catalyst, in synergy with potassium persulfate cycling, promotes the degradation of Rhodamine B solution.

[0062] Application Example 8 This application example uses the manganese iron oxide ceramic catalyst prepared in Example 1 to test the degradation of Sudan Red under microwave radiation. The specific steps are as follows: 100 mL of a 100 mg / L Sudan Red solution was placed in a 250 mL Erlenmeyer flask. A manganese iron oxide ceramic catalyst was added at a concentration of 0.6 g / L. After stirring thoroughly, 0.50 mmol / L potassium peroxymonosulfate was added to adjust the pH to 7.0. The mixture was stirred at 25 °C for 1.5 h, resulting in a Sudan Red degradation rate of 99.56%. The experimental results show that under microwave radiation conditions, a higher catalytic degradation efficiency can be achieved in a shorter time. Under microwave assistance, especially at a microwave radiation intensity of 450 W / L, the manganese iron oxide ceramic catalyst synergistically promotes the degradation of Sudan Red solution with potassium peroxymonosulfate.

[0063] Application Example 9 This application example uses the manganese iron oxide ceramic catalyst prepared in Example 2 to test the degradation of Rhodamine B under microwave radiation. The specific steps are as follows: 100 mL of 100 mg / L Rhodamine B solution was placed in a 250 mL Erlenmeyer flask. A manganese iron oxide ceramic catalyst was added at a concentration of 0.6 g / L. After stirring thoroughly, 0.50 mmol / L potassium peroxymonosulfate was added to adjust the pH to 12.0. The mixture was stirred at 25 °C for 2.0 h, resulting in a Rhodamine B degradation rate of 99.12%. Under microwave assistance, especially at a microwave radiation intensity of 600 W / L, the manganese iron oxide ceramic catalyst synergistically promoted the degradation of Rhodamine B solution with potassium peroxymonosulfate.

[0064] Application Example 10 This application example uses the manganese copper oxide ceramic catalyst prepared in Example 3 to test the degradation of xanthate under microwave radiation. The specific steps are as follows: 100 mL of a 100 mg / L xanthate solution was placed in a 250 mL Erlenmeyer flask. A manganese copper oxide ceramic catalyst was added at a concentration of 0.6 g / L. After stirring thoroughly, 0.50 mmol / L potassium persulfate was added to adjust the pH to 3.0. The mixture was stirred at 25 °C for 1.5 h, resulting in a xanthate degradation rate of 99.12%. Under microwave assistance, especially at a microwave radiation intensity of 800 W / L, the manganese copper oxide ceramic catalyst synergistically promoted the degradation of xanthate solution with potassium persulfate.

[0065] Comparative ratios 5 to 8 The ceramic and single-metal oxide ceramic catalysts prepared in Comparative Examples 1 to 4 were used to degrade organic wastewater. The catalytic degradation experimental methods were the same as those in Application Examples 1 to 4. The catalytic degradation experimental results are shown in Table 3.

[0066] Table 3

[0067] Table 3 shows that the catalytic degradation experiment results of Comparative Example 5 indicate that the ceramic catalyst's degradation rate of methylene blue was only 58.79%, demonstrating that the ceramic catalyst prepared from manganese slag without any metal additives possesses a certain catalytic degradation ability, but it is lower than that of the polyvalent bimetallic oxide ceramic catalyst. This is because the ceramic catalyst contains a certain amount of iron and manganese, but lacks iron oxides and manganese oxides, which affects its degradation effect. The catalytic degradation experiment results of Comparative Examples 6-8 show that the single-metal oxide ceramic catalyst significantly improved the degradation rate of organic pollutants compared to the ceramic catalyst, but it was still significantly lower than that of the polyvalent bimetallic oxide ceramic catalyst.

[0068] Application Example 11 Sand and gravel were mixed with the polyvalent bimetallic oxide ceramic catalyst from Example 1 as a substrate. The sand and gravel had a particle size range of 0.2–1 mm, and the polyvalent bimetallic oxide ceramic catalyst had a particle size range of 0.1–0.5 mm. The amount of polyvalent bimetallic oxide ceramic catalyst was 10% of the amount of sand and gravel. The mixture was packed into a Φ20 mm × 300 mm adsorption column to a height of 200 mm. A 10 mg / L concentration of Pb was then added... 2+ The solution was added to the adsorption column at a flow rate of 1 mL / min using a constant flow pump. The permeate was collected using a graduated cylinder every 5 minutes, and the time and volume of each collection were recorded. This mixture was used to treat Pb. 2+ The adsorption rate was 85.86%, indicating good adsorption performance. The water permeability rate was 0.85 mL / min, indicating good water permeability of the material.

[0069] Application Example 12 Except for the xanthate solution being 10 mg / L, the experimental materials and methods were the same as in Application Example 11. The xanthate solution was added to the adsorption column using a constant flow pump at a flow rate of 1 mL / min. The permeate was collected using a graduated cylinder, with collection times and volumes recorded every 5 minutes. The roadbed material exhibited a xanthate degradation rate of 95.16%, indicating good catalytic degradation performance. The water permeability rate was 0.86 mL / min, indicating good water permeability of the material.

[0070] Comparative examples 9 to 10 The performance of sand and gravel without the addition of polyvalent bimetallic oxide ceramic catalyst was determined using the experimental methods of Application Examples 11 and 12. The experimental results are shown in Table 4.

[0071] Table 4

[0072] Table 4 shows that the experimental results of Comparative Example 9 indicate that sand and gravel affect Pb. 2+The adsorption rate was 25.09%, and the water permeation rate was 0.51 mL / min. Compared to Application Example 11, its adsorption rate for Pb was significantly higher. 2+ The adsorption rate and water permeability were significantly reduced, which is because the adsorption sites and porosity of the material were significantly reduced without the addition of the polyvalent bimetallic oxide ceramic catalyst. Comparative Example 10 showed that the roadbed material without the polyvalent bimetallic oxide ceramic catalyst had a xanthate degradation rate of 8.35% and a water permeability of 0.42 mL / min. Compared with Application Example 12, both the degradation rate and water permeability of xanthate were significantly reduced. This is mainly due to the lack of highly catalytically active phases such as Mn3O4 and Fe3O4 in the material, which affected its degradation effect.

[0073] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A multivalent bimetallic oxide ceramic catalyst, characterized in that, The catalyst is produced by roasting industrial solid waste and loaded with nano-dispersed metal oxide active components. The metal oxide active components are embedded in the ceramic lattice or surface in a highly dispersed state. The pore structure of the catalyst is distributed in three levels: micropores, mesopores and macropores, which are interconnected to form a "honeycomb-capillary" dual continuous channel. The metal oxide active components are a combination of Mn3O4 and Fe3O4, or a combination of Mn3O4 and CuO.

2. The multivalent bimetallic oxide ceramic catalyst according to claim 1, characterized in that, The catalyst has a specific surface area of ​​4-6 m². 2 / g, water absorption rate of 70%~100% (wt.%), apparent porosity of 70%~90% (vol.%), and compressive strength greater than 4MPa.

3. A method for preparing a multivalent bimetallic oxide ceramic catalyst, characterized in that, Includes the following steps: S1: After uniformly mixing industrial solid waste with carbon, kaolin, dolomite and an aqueous solution containing manganese salt, the mixture is aged to obtain a mixture; the industrial solid waste is at least one of electrolytic manganese slag, manganese sulfate slag, and red mud; the aqueous solution containing manganese salt contains at least one of trivalent iron salt or divalent copper salt. S2: The mixture is granulated to obtain a green body, which is then dried; S3: The dried green body is oxidized and calcined, and then cooled to obtain a multivalent bimetallic oxide ceramic catalyst.

4. The method for preparing a multivalent bimetallic oxide ceramic catalyst according to claim 3, characterized in that, The amount of char added is 10% to 30% of the mass of industrial solid waste, the amount of kaolin added is 2% to 10% of the mass of industrial solid waste, and the amount of dolomite added is 5% to 10% of the mass of industrial solid waste; the volume-to-mass ratio of the manganese salt aqueous solution to the industrial solid waste is 1:10 to 30.

5. The method for preparing a multivalent bimetallic oxide ceramic catalyst according to claim 3, characterized in that, The electrolytic manganese slag and manganese sulfate slag comprise the following components: Al 1%~8%, Si 8%~20%, Fe 1%~5%, Ca 2%~12%, Mn 1%~5%, with the remainder being S and O; the red mud comprises the following components: Fe 5%~30%, Al 5%~15%, Si 5%~15%, Ca 2%~6%, Na 2%~12%, K 0.5%~2%, with the remainder being Mg, Ti, S and O; the charcoal comprises at least one of charcoal, coal or activated carbon.

6. The method for preparing a multivalent bimetallic oxide ceramic catalyst according to claim 3, characterized in that, In step S1, Mn 2+ The molar concentration of ions is 0.4~2.0 mol / L; Fe 3+ ions or Cu 2+ The molar concentration of ions is 0.2~1.0 mol / L.

7. The method for preparing a multivalent bimetallic oxide ceramic catalyst according to claim 3, characterized in that, In step S2, the drying temperature is 60~100℃ and the drying time is 4~6h.

8. The method for preparing a multivalent bimetallic oxide ceramic catalyst according to claim 3, characterized in that, In step S3, the calcination process is as follows: the temperature is increased from room temperature to 500-700℃ at a heating rate of 5-10℃ / min and held for 1-2 hours, and then the temperature is increased to 900-1300℃ and held for 2-4 hours.

9. The application of a multivalent bimetallic oxide ceramic catalyst in the catalytic degradation of organic wastewater, characterized in that, The multivalent bimetallic oxide ceramic catalyst was applied to organic wastewater in combination with persulfate, and the catalytic degradation reaction was carried out under microwave radiation.

10. The application of a multivalent bimetallic oxide ceramic catalyst as a paving material in the paving of roadbeds, industrial sites or soil-contaminated sites.

Images