A catalyst for simultaneously removing cyanide and organic matter from wastewater by permonosulfate oxidation method, and its preparation method and application

Abstract

The present application discloses a catalyst for the simultaneous removal of cyanide and organic matter from wastewater by persulfate oxidation, and its preparation method and application, which belongs to the field of chemistry and chemical engineering, specifically the field of catalyst preparation technology. The preparation method introduces metal oxides such as molybdenum, cerium, and vanadium as a substrate, and performs precise doping of cobalt and nickel and loading of precious metal nanoparticles. While ensuring uniform distribution of metal elements, the structural stability and anti-sintering ability of the catalyst are enhanced by surface modification, and the high efficiency performance is maintained for a long time under high temperature and complex reaction conditions. The catalyst prepared by the method is used in the simultaneous removal of cyanide (free cyanide and complex cyanide) and organic matter from wastewater by persulfate oxidation, and has excellent catalytic activity. For 100 pmm cyanide (free cyanide and complex cyanide) and 200 mg / LCOD organic matter in wastewater, the degradation rate can be extremely quickly reached to more than 90%, with excellent degradation effect and reaction rate.

Description

Technical Field

[0001] The present application relates to a catalyst for simultaneously removing cyanide and organic matter from wastewater by peroxymonosulfate oxidation method, and a preparation method and application thereof, and belongs to the field of chemistry and chemical engineering, specifically the field of catalyst preparation technology. Background Art

[0002] Permonosulfate oxidation is an advanced oxidation process. It uses permonosulfate as an oxidant to produce highly active free radicals through advanced oxidation reactions. These free radicals can quickly react with organic and inorganic pollutants in water, oxidizing and decomposing them into carbon dioxide, water and other harmless substances. This technology has the advantages of high treatment efficiency, strong adaptability and relatively mild operating conditions. Permonosulfate oxidation can effectively remove organic matter in water, such as dyes, herbicides, phenolic pollutants, personal care products and drug residues, and can also remove heavy metal ions, such as arsenate and chromate and other harmful substances. In addition, this technology can also disinfect and sterilize, remove pathogens in water, thereby improving water quality and protecting human health.

[0003] Since permonosulfate oxidation is excellent in treating refractory organic matter and heavy metal ions, it is widely used in industrial wastewater treatment, urban sewage treatment and other fields. With the improvement of environmental awareness and the improvement of water quality requirements, the application prospects of permonosulfate oxidation in the field of water treatment will be broader.

[0004] Compared with free cyanide, complex cyanide is more difficult to remove, mainly because complex cyanide is more chemically stable and is not easily destroyed by conventional oxidants. In contrast, the chemical properties of free cyanide are more active and easily oxidized and decomposed. In addition, the complex structure formed by complex cyanide and metal ions is complex, which requires more energy and more complex processes for its removal. Therefore, when treating cyanide-containing wastewater, the removal of complex cyanide is often a more difficult problem, and more efficient and targeted treatment methods are required. Conventional catalysts face multiple challenges in the treatment of wastewater containing complex cyanide. First, the chemical structure of complex cyanide is stable, especially the coordination bond with metal ions is difficult to destroy, making it difficult for oxidation reactions to completely decompose these compounds. Secondly, the diversity of complex cyanide (such as ferrocyanide, copper cyanide, etc.) makes a single catalyst perform inconsistently when treating different types of complex cyanide, and the treatment effects are uneven. In addition, conventional catalysts have poor oxidation selectivity for complex cyanide and are prone to induce side reactions, which makes it difficult to further degrade the intermediates generated during the oxidation process, increasing the complexity of subsequent treatment. Finally, due to the chemical stability of complex cyanide, more stringent conditions are required for its treatment, which increases the reaction energy consumption and cost. Summary of the invention

[0005] In order to solve the above technical problems, this application proposes a catalyst technology solution for the simultaneous removal of cyanide and organic matter in wastewater by persulfate oxidation. For wastewater containing complex cyanide, the catalyst significantly enhances the catalytic activity through the synthesis of multi-metal oxide precursors and nanoparticle loading. The porous structure is prepared by sol-gel method and high-temperature calcination, providing a larger specific surface area; the introduction of supported noble metal nanoparticles further enhances the effect of removing free cyanide and complex cyanide.

[0006] This application adopts the following technical solutions:

[0007] According to a first aspect of the present application, a method for preparing a catalyst for simultaneously removing cyanide and organic matter from wastewater by a persulfate oxidation method is provided, comprising the following steps:

[0008] S1, obtaining a precursor solution containing molybdate, cerium salt, vanadate and water;

[0009] S2. In a stirring state, a solution containing citric acid and water and an alkaline solution are successively added dropwise to the precursor solution obtained in step S1 to obtain a transparent sol, and the transparent sol is heated to obtain a precursor gel;

[0010] S3, drying the precursor gel obtained in step S2 to form a xerogel, and then calcining the xerogel to obtain a metal oxide precursor with a porous structure;

[0011] S4, mixing the metal oxide precursor obtained in step S3 with a solution containing cobalt salt, nickel salt and water, stirring and drying to obtain a metal oxide precursor loaded with metal ions;

[0012] S5, dispersing the metal oxide precursor loaded with metal ions obtained in step S4 in alcohol, adding noble metal nanoparticles to the alcohol and stirring evenly, ultrasonically treating, and drying to obtain a metal oxide precursor loaded with metal ions and nanoparticles;

[0013] S6. calcining the metal oxide precursor loaded with metal ions and nanoparticles obtained in step S5 to obtain the catalyst for simultaneously removing cyanide and organic matter from wastewater by permonosulfate oxidation method.

[0014] Optionally, in step S1, the usage ratio of molybdate, cerium salt, vanadate and water is 0.1~2g:0.1g~1g:0.2g~0.5g:100mL.

[0015] Optionally, the molybdate is selected from ammonium molybdate.

[0016] Optionally, the cerium salt is selected from cerium nitrate.

[0017] Optionally, the vanadate is selected from ammonium vanadate.

[0018] Optionally, in step S2, the ratio of the amount of water in step S1 to the amount of citric acid and water in step S2 is 100 mL: 0.1 g~2 g: 30 mL.

[0019] Optionally, in step S2, the concentration of the alkaline solution is 0.5 mol / L~2 mol / L.

[0020] Optionally, the alkaline solution is added dropwise until the pH of the transparent sol is 7.5-8.5.

[0021] Optionally, in step S2, the stirring time is 30 min to 180 min.

[0022] Optionally, in step S2, the heating temperature is 75°C~100°C.

[0023] Optionally, in step S3, the drying conditions include: the drying temperature is less than or equal to 150° C., and the drying time is 6 h to 24 h.

[0024] Optionally, in step S3, the calcination conditions include: a heating rate of 1°C / min to 5°C / min, a calcination temperature of 400°C to 650°C, and a calcination time of 3h to 6h.

[0025] Optionally, in step S4, the ratio of the amount of water in step S1 to the amount of cobalt salt, nickel salt and water in step S4 is 100 mL: 0.05 g~0.2 g: 0.05 g~0.2 g: 30 mL.

[0026] Optionally, in step S4, the cobalt salt is cobalt nitrate and the nickel salt is nickel nitrate.

[0027] Optionally, in step S4, the stirring time is 0.5h~2h.

[0028] Optionally, in step S5, the usage ratio of the noble metal nanoparticles to the water in step S1 is 0.01 g~0.1 g:100 mL.

[0029] Optionally, in step S5, the particle size of the noble metal nanoparticles is 4.5 nm to 5.5 nm.

[0030] Optionally, in step S5, the noble metal nanoparticles are selected from at least one of Pd nanoparticles and Pt nanoparticles.

[0031] Optionally, in step S5, the conditions for ultrasonic treatment include: the time of ultrasonic treatment is 0.5h~4h.

[0032] Optionally, in step S5, the stirring time is 1 h to 3 h.

[0033] Optionally, in step S6, the calcination conditions include: a heating rate of 3°C / min to 6°C / min, a calcination temperature of 550°C to 700°C, and a calcination time of 1h to 3h.

[0034] According to another aspect of the present application, a catalyst for simultaneously removing cyanide and organic matter from wastewater by permonosulfate oxidation method is provided, and the catalyst for simultaneously removing cyanide and organic matter from wastewater by permonosulfate oxidation method is prepared by the above-mentioned preparation method.

[0035] According to another aspect of the present application, there is also provided a catalyst for simultaneously removing cyanide and organic matter in wastewater by permonosulfate oxidation method and its application in the treatment of wastewater containing complex cyanide. The catalyst for simultaneously removing cyanide and organic matter in wastewater by permonosulfate oxidation method is prepared by the above-mentioned preparation method or is selected from the above-mentioned catalyst for simultaneously removing cyanide and organic matter in wastewater by permonosulfate oxidation method.

[0036] The complex cyanide-containing wastewater of the present application includes free cyanide, complex cyanide, and organic matter.

[0037] The beneficial effects of this application include:

[0038] The catalyst provided in the present application for the simultaneous removal of cyanide and organic matter from wastewater by persulfate oxidation has excellent catalytic activity. For 100 pmm cyanide (free cyanide and complex cyanide) and 200 mg / LCOD organic matter in wastewater, it can quickly reach a degradation rate of more than 90%, and has excellent degradation effect and reaction rate. The preparation method of the catalyst cleverly combines a variety of metal elements, showing a high degree of scientific design and process innovation. By introducing metal oxides such as molybdenum, cerium, and vanadium as a substrate, it not only provides a porous structure and a wide range of active sites for the catalyst, but also enables it to have excellent redox properties; the precise doping of cobalt and nickel further enhances the catalytic activity and electron transfer ability, making it perform well in heterogeneous catalysis. In addition, the loading of precious metal nanoparticles such as platinum or palladium greatly improves the selectivity and rate of the catalytic reaction. This method, while ensuring the uniform distribution of metal elements, strengthens the structural stability and anti-sintering ability of the catalyst through surface modification, so that it can maintain high efficiency for a long time under high temperature and complex reaction conditions. The entire preparation process maximizes performance through the clever combination of multiple metal elements and has high commercial value. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 This is a diagram showing the effect of removing total cyanide by the permonosulfate oxidation method for different samples in Test Example 1.

[0040] Figure 2 This is a diagram showing the effect of removing total cyanide by the permonosulfate oxidation method for different samples in Test Example 2.

[0041] Figure 3 This is a diagram showing the effect of removing total cyanide from COD using the permonosulfate oxidation method for different samples in Test Example 3. DETAILED DESCRIPTION

[0042] The present application is described in detail below with reference to embodiments, but the present application is not limited to these embodiments.

[0043] Unless otherwise specified, the raw materials in the examples of this application were purchased through commercial channels.

[0044] Unless otherwise specified, conventional methods were used for testing and instrument settings were those recommended by the manufacturer.

[0045] According to one embodiment of the present application, the present application provides a catalyst for simultaneously removing cyanide (free cyanide and complex cyanide) and organic matter in wastewater by a persulfate oxidation method, and the preparation steps are as follows: first, dissolving ammonium molybdate tetrahydrate, cerium nitrate hexahydrate and ammonium vanadate in deionized water to form a uniform mixed solution A; then, using a sol-gel method, adding solution A dropwise into a reaction container containing deionized water and citric acid, adjusting the pH to 8, obtaining a transparent sol B, and heating it to gel; then, vacuum drying the precursor gel to form a dry gel, and evaporating the mixture in a muffle furnace. A porous metal oxide precursor is calcined in the reaction mixture; subsequently, solution C (containing cobalt nitrate hexahydrate, nickel nitrate hexahydrate and deionized water) is added to the metal oxide precursor and stirred to uniformly disperse the doped metal to form a composite material with high active sites; the precursor powder and the supported Pd nanoparticles are fully mixed in ethanol, and the dispersibility of the nanoparticles is improved by ultrasonic treatment; finally, the catalyst with the supported nanoparticles is calcined under nitrogen protection to enhance its structural stability and exposure of active sites, and finally ground to obtain a catalyst for permonosulfate oxidation method.

[0046] According to one embodiment of the present application, the preparation method of the catalyst for simultaneously removing cyanide (free cyanide and complex cyanide) and organic matter from wastewater by the permonosulfate oxidation method provided in the present application specifically comprises the steps of:

[0047] S1. Preparation of precursor solution: Dissolve ammonium molybdate tetrahydrate, cerium nitrate hexahydrate and ammonium vanadate in deionized water respectively, and fully dissolve each component under magnetic stirring to obtain a uniform mixed solution A.

[0048] S2. Preparation of composite precursor by sol-gel method: Solution A is added dropwise into a reaction vessel containing deionized water and citric acid, and the mixture is stirred, and sodium hydroxide solution is slowly added dropwise to adjust the pH to 8. The solution gradually becomes a transparent sol, and stirring is continued until a uniform sol B is obtained. Sol B is heated to gelate it, and a precursor gel is obtained.

[0049] S3, drying and calcining: the precursor gel is vacuum dried to form a solid dry gel, and then the dry gel is calcined in a muffle furnace to obtain a metal oxide precursor with a porous structure.

[0050] S4, metal doping and loading: Add solution C (cobalt nitrate hexahydrate, nickel nitrate hexahydrate and deionized water) to the prepared metal oxide precursor and stir to ensure uniform dispersion and ensure that the doped metal is evenly distributed on the oxide substrate. This step helps to form a composite material with high active sites.

[0051] S5. Nanoparticle loading and modification: Precursor powder was dispersed in ethanol, loaded Pd nanoparticles were added, and stirred to ensure uniform loading. Ultrasonic treatment was used to fully disperse the nanoparticles on the catalyst substrate to further enhance the activity of the catalyst.

[0052] S6. Final calcination: calcine the catalyst loaded with nanoparticles under nitrogen protection to further enhance the structural stability of the catalyst and the exposure of active sites; grind after calcination to obtain a catalyst for simultaneous removal of free cyanide and complex cyanide by permonosulfate oxidation method.

[0053] As an embodiment, the addition ratio of the ammonium molybdate tetrahydrate, the cerium nitrate hexahydrate, the ammonium vanadate, and the deionized water is 0.1~2g: 0.1g~1g: 0.2g~0.5g: 100mL.

[0054] As an implementation mode, the addition ratio of citric acid and deionized water in the reaction container in S2 is 0.1g~2g:30mL; the concentration of sodium hydroxide solution is 0.5mol / L~2mol / L; the stirring time is 30min~180min; and the heating temperature is 75℃~100℃.

[0055] As an implementation mode, the vacuum drying temperature in S3 is not higher than 150°C, and the time is 6h~24h; the calcination temperature is 400°C~650°C, the calcination time is 3h~6h, and the heating rate of the calcination process is 1~5°C / min.

[0056] As an implementation mode, the addition ratio of cobalt nitrate hexahydrate, nickel nitrate hexahydrate and deionized water in S4 is 0.05g~0.2g:0.05g~0.2g:30mL; and the stirring time is 0.5h~2h.

[0057] As an implementation mode, the amount of supported Pd nanoparticles in S5 is 0.01 g to 0.1 g; the particle size of supported Pd nanoparticles is about 5 nm; the stirring time is 1 to 3 h; and the ultrasonic treatment is 0.5 h to 4 h.

[0058] As an implementation mode, the calcination temperature in S5 is 550°C to 700°C, the calcination time is 1h to 3h, and the heating rate during the calcination process is 3°C / min to 6°C / min.

[0059] The catalyst provided in the present application for simultaneously removing cyanide (free cyanide and complex cyanide) and organic matter in wastewater by permonosulfate oxidation method has excellent catalytic activity. For 100pmm cyanide (free cyanide and complex cyanide) and 200mg / LCOD organic matter in wastewater, it can quickly achieve a degradation rate of more than 90%, and has excellent degradation effect and reaction rate.

[0060] Example 1

[0061] This embodiment provides a method for preparing a catalyst for simultaneously removing cyanide (free cyanide and complex cyanide) and organic matter from wastewater by a persulfate oxidation process. The specific preparation steps are as follows:

[0062] Preparation of S1 precursor solution: Dissolve 0.15 g of ammonium molybdate tetrahydrate, 0.5 g of cerium nitrate hexahydrate and 0.3 g of ammonium vanadate in 100 mL of deionized water respectively, and fully dissolve each component under magnetic stirring to obtain a uniformly mixed precursor solution A.

[0063] S2 Preparation of composite precursor by sol-gel method: Solution A was added dropwise into a reaction vessel containing 30 mL of deionized water and 0.15 g of citric acid, stirred for 60 min, and 1 mol / L sodium hydroxide solution was slowly added to adjust the pH to 8. The solution gradually turned into a transparent sol, and stirring was continued until a uniform sol B was obtained. Sol B was heated to 80 °C to gelate it to obtain a precursor gel.

[0064] S3 Drying and calcination: The precursor gel was vacuum dried at 100°C for 12 hours to form a solid dry gel. The dry gel was then calcined in a muffle furnace at 500°C for 4 hours to obtain a porous metal oxide precursor. The heating rate during the calcination process was 5°C / min.

[0065] S4 Metal doping and loading: Add solution C (0.1 g cobalt nitrate hexahydrate, 0.1 g nickel nitrate hexahydrate and 30 mL deionized water) to the prepared metal oxide precursor and stir for 1 h to ensure uniform dispersion and ensure that the doped metal is evenly distributed on the oxide substrate. This step helps to form a composite material with highly active sites.

[0066] S5 Nanoparticle Loading and Modification: Precursor powder was dispersed in ethanol, 0.05 g of supported Pd nanoparticles with a particle size of about 5 nm were added, and stirred for 2 h to ensure uniform loading. Ultrasonic treatment was performed for 1 h to fully disperse the nanoparticles on the catalyst substrate, further improving the activity of the catalyst.

[0067] S6 final calcination: The catalyst loaded with nanoparticles was calcined at 600°C for 2h under nitrogen protection, with a heating rate of 5°C / min during the calcination process to further enhance the structural stability of the catalyst and the exposure of active sites; after calcination, it was ground to obtain a catalyst for the simultaneous removal of cyanide (free cyanide and complex cyanide) and organic matter in wastewater by permonosulfate oxidation method, and the sample was recorded as A1.

[0068] Example 2

[0069] This embodiment provides a method for preparing a catalyst for simultaneously removing cyanide (free cyanide and complex cyanide) and organic matter from wastewater by a persulfate oxidation process. The specific preparation steps are as follows:

[0070] Preparation of S1 precursor solution: Dissolve 1 g of ammonium molybdate tetrahydrate, 0.4 g of cerium nitrate hexahydrate and 0.3 g of ammonium vanadate in 100 mL of deionized water respectively, and fully dissolve each component under magnetic stirring to obtain a uniform mixed solution A.

[0071] S2 Preparation of composite precursor by sol-gel method: Solution A was added dropwise into a reaction vessel containing 30 mL of deionized water and 0.5 g of citric acid, stirred for 60 min, and 1 mol / L sodium hydroxide solution was slowly added to adjust the pH to 8. The solution gradually turned into a transparent sol, and stirring was continued until a uniform sol B was obtained. Sol B was heated to 80 °C to gelate it to obtain a precursor gel.

[0072] S3 Drying and calcination: The precursor gel was vacuum dried at 105°C for 14 hours to form a solid dry gel. The dry gel was then calcined at 500°C in a muffle furnace for 4 hours to obtain a porous metal oxide precursor. The heating rate during the calcination process was 5°C / min.

[0073] S4 Metal doping and loading: Add solution C (0.1 g cobalt nitrate hexahydrate, 0.1 g nickel nitrate hexahydrate and 30 mL deionized water) to the prepared metal oxide precursor and stir for 1 h to ensure uniform dispersion and ensure that the doped metal is evenly distributed on the oxide substrate. This step helps to form a composite material with highly active sites.

[0074] S5 Nanoparticle Loading and Modification: Precursor powder was dispersed in ethanol, 0.1 g of supported Pd nanoparticles with a particle size of about 5 nm were added, and stirred for 2 h to ensure uniform loading. Ultrasonic treatment was performed for 1 h to fully disperse the nanoparticles on the catalyst substrate, further improving the activity of the catalyst.

[0075] S6 final calcination: The catalyst loaded with nanoparticles was calcined at 600°C for 2h under nitrogen protection, with a heating rate of 5°C / min during the calcination process to further enhance the structural stability of the catalyst and the exposure of active sites; after calcination, it was ground to obtain a catalyst for the simultaneous removal of cyanide (free cyanide and complex cyanide) and organic matter in wastewater by permonosulfate oxidation method, and the sample was recorded as A2.

[0076] Comparative Example 1

[0077] The difference from Example 1 is that S3: the dry gel is calcined in a muffle furnace at 1000° C. for 6 h.

[0078] The rest is the same as Example 1, and the sample is denoted as B1.

[0079] Comparative Example 2

[0080] The difference from Example 2 is that S6: the catalyst loaded with nanoparticles is calcined at 300° C. for 1 h under nitrogen protection.

[0081] The rest is the same as Example 2, and the sample is denoted as B2.

[0082] Test Example 1

[0083] Use deionized water to prepare a water sample with a total cyanide content of 100 ppm (50 ppm free cyanide + 50 ppm complex cyanide), take 200 mL of the water sample into a conical flask, add 50 mg of the catalyst, and after ultrasonication for 1 min, place the conical flask in a 25°C (room temperature) water bath shaker (speed 190 rpm) and record it as the reaction zero point, add 0.5 mL of PMS solution (potassium persulfate complex salt concentration is 0.24 g / mL) into the reaction system to start the reaction, and sample once every 60 min (sample 1 mL with a pipette, filter with a filter head into a plastic centrifuge tube pre-filled with 0.1 mL of sulfite solution, the sulfite solution concentration is 5 g / 100 mL, mainly used as a reaction terminator), and the total reaction time is 600 min.

[0084] Figure 1 The figures are the effects of removing total cyanide by permonosulfate oxidation method for different samples. It can be seen that under the reaction time of 600 min, both Examples 1 and 2 can quickly reach a degradation rate of more than 90%, with excellent degradation effect and reaction rate; while the degradation effect of the two comparative examples is extremely poor, and the reaction rate is slow.

[0085] Test Example 2

[0086] Use deionized water to prepare a water sample with a total cyanide content of 100ppm and a m-cresol COD content of 200mg / L (50ppm free cyanide + 50ppm complex cyanide), take 200mL of the water sample into a conical flask, add 50mg of the catalyst, and after ultrasonication for 1min, place the conical flask in a 25℃ (room temperature) water bath shaker (speed 190rpm) and record it as the reaction zero point, add 0.5mL PMS solution (potassium persulfate complex salt concentration of 0.24g / mL) into the reaction system to start the reaction, sample once every 60min (sample 1mL with a pipette, filter with a filter head into a plastic centrifuge tube pre-filled with 0.1mL of sulfite solution, the sulfite solution concentration is 5g / 100mL, mainly used as a reaction terminator), and the total reaction time is 600min.

[0087] Figure 2 This is the effect diagram of removing total cyanide by permonosulfate oxidation method for different samples. Figure 3 The figures are the effects of removing total cyanide from COD by permonosulfate oxidation method for different samples. It can be seen that under the reaction time of 600 min, Examples 1 and 2 can quickly achieve a degradation rate of more than 90% for total cyanide and COD, and have excellent degradation effect and reaction rate; while the two comparative examples have extremely poor degradation effects for total cyanide and COD, and the reaction rate is slow.

[0088] The above are only a few embodiments of the present application and do not constitute any form of limitation to the present application. Although the present application is disclosed as above with preferred embodiments, it is not intended to limit the present application. Any technician familiar with the profession, without departing from the scope of the technical solution of the present application, using the technical content disclosed above to make slight changes or modifications are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A method for preparing a catalyst for simultaneously removing free cyanide, complex cyanide and meta-phenol in wastewater by permonosulfate oxidation, characterized in that: The steps include: S1, obtaining a precursor solution containing molybdate, cerium salt, vanadate and water; S2. In a stirring state, a solution containing citric acid and water and an alkaline solution are successively added dropwise to the precursor solution obtained in step S1 to obtain a transparent sol, and the transparent sol is heated to obtain a precursor gel; S3, drying the precursor gel obtained in step S2 to form a xerogel, and then calcining the xerogel to obtain a metal oxide precursor with a porous structure; S4, mixing the metal oxide precursor obtained in step S3 with a solution containing cobalt salt, nickel salt and water, stirring and drying to obtain a metal oxide precursor loaded with metal ions; S5, dispersing the metal oxide precursor loaded with metal ions obtained in step S4 in alcohol, adding noble metal nanoparticles to the alcohol and stirring evenly, ultrasonically treating, and drying to obtain a metal oxide precursor loaded with metal ions and nanoparticles; S6, calcining the metal oxide precursor loaded with metal ions and nanoparticles obtained in step S5 to obtain the catalyst for simultaneously removing cyanide and organic matter from wastewater by permonosulfate oxidation method; In step S3, the calcination conditions include: a heating rate of 1°C / min to 5°C / min, a calcination temperature of 400°C to 650°C, and a calcination time of 3h to 6h; In step S6, the calcination conditions include: a heating rate of 3°C / min to 6°C / min, a calcination temperature of 550°C to 700°C, and a calcination time of 1h to 3h.

2. The preparation method according to claim 1, characterized in that: In step S1, the usage ratio of molybdate, cerium salt, vanadate and water is 0.1-2 g: 0.1-1 g: 0.2-0.5 g: 100 mL.

3. The preparation method according to claim 1, characterized in that: The ratio of the amount of water in step S1 to the amount of citric acid and water in step S2 is 100 mL: 0.1 g~2 g: 30 mL.

4. The preparation method according to claim 1, characterized in that: In step S2, the concentration of the alkaline solution is 0.5 mol / L to 2 mol / L; The amount of the alkaline solution is to add the alkaline solution dropwise until the pH value of the transparent sol reaches 7.5-8.

5.

5. The preparation method according to claim 1, characterized in that: The ratio of the amount of water in step S1 to the amount of cobalt salt, nickel salt and water in step S4 is 100 mL: 0.05 g~0.2 g: 0.05 g~0.2 g: 30 mL.

6. The preparation method according to claim 1, characterized in that: In step S5, the ratio of the noble metal nanoparticles to the water in step S1 is 0.01 g to 0.1 g: 100 mL; In step S5, the particle size of the noble metal nanoparticles is 4.5 nm to 5.5 nm.

7. A catalyst for simultaneously removing free cyanide, complex cyanide and meta-phenol from wastewater by permonosulfate oxidation, characterized in that: The catalyst for simultaneously removing free cyanide, complex cyanide and meta-phenol from wastewater by permonosulfate oxidation is prepared by the preparation method described in any one of claims 1 to 6.

8. Use of a catalyst for simultaneously removing free cyanide, complex cyanide and meta-phenol in wastewater by permonosulfate oxidation in the treatment of wastewater containing complex cyanide, characterized in that: The catalyst for simultaneously removing free cyanide, complex cyanide and meta-phenol from wastewater by permonosulfate oxidation method is prepared by the preparation method described in any one of claims 1 to 6 or is selected from the catalyst for simultaneously removing free cyanide, complex cyanide and meta-phenol from wastewater by permonosulfate oxidation method described in claim 7.

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