Method for preparing Fenton-like catalytic material by taking coal gasification slag as raw material and application of Fenton-like catalytic material

Abstract

The invention discloses a method for preparing a Fenton-like catalytic material by taking coal gasification slag as a raw material and application of the Fenton-like catalytic material. The method comprises the following steps: carrying out water washing and acid leaching on the coal gasification slag, and drying to obtain pretreated coal gasification slag; the pretreated coal gasification slag and a nitrogen-containing activator solution are mixed and impregnated, and N-coal gasification slag suspension liquid is obtained; mixing a soluble iron (III) salt solution with the N-coal gasification slag suspension, carrying out solid-liquid separation after ultrasonic dispersion, drying a solid, and carrying out microwave activation in a nitrogen atmosphere to obtain Fe-N-coal gasification slag; the preparation method comprises the following steps: ultrasonically dispersing Fe-N-coal gasification slag in organic alcohol, adjusting the pH value to 7.5-9.5, adding a shell metal oxide, carrying out a stirring and heating reaction, carrying out solid-liquid separation after the reaction is finished, taking a solid, drying, and calcining in a nitrogen atmosphere to obtain the coal gasification slag-based Fenton-like catalytic material.

Description

Technical Field

[0001] This invention relates to the field of Fenton-like catalytic materials, specifically to a method and application for preparing Fenton-like catalytic materials using coal gasification slag as raw material. Background Technology

[0002] Coal gasification slag is an industrial byproduct generated during the coal gasification process. It consists of residual carbon and inorganic mineral components, primarily amorphous SiO2, amorphous Al2O3, CaO, Fe2O3, and MgO. Currently, the main method of treating coal gasification slag is stockpiling, which occupies a large amount of land resources and causes environmental pollution. To meet environmental protection requirements, coal gasification slag urgently needs to be utilized as a resource. The applicant already has relevant research experience in this area. For example, the applicant previously applied for and was granted a Chinese invention patent (ZL202210883700.4) for a superhydrophobic / superoleophilic adsorbent prepared from coal gasification slag, its preparation method, and its application.

[0003] Coal chemical wastewater has a complex composition and contains a large number of recalcitrant organic pollutants. Near-zero wastewater discharge is an inevitable choice for developing modern coal chemical industries in areas with water shortages or insufficient water environmental capacity.

[0004] Advanced oxidation processes are one of the effective methods for treating recalcitrant organic pollutants. Among these, Fenton-like oxidation utilizes transition metals and their oxides to generate highly reactive free radicals that degrade organic pollutants in water. The excellent specific surface area and active components such as Fe2O3 in coal gasification slag lay the foundation for its suitability as a Fenton-like catalytic material. To address the two major pollution sources in the coal chemical industry, this paper proposes a method to prepare Fenton-like catalytic materials using coal gasification slag as raw material to treat coal chemical wastewater, achieving the goal of treating waste with waste.

[0005] The following existing technologies were found through a search: The patent specification with publication number CN110465300A discloses a heterogeneous Fenton catalyst, its preparation method and application. The method involves acid treatment of coal gasification slag to obtain a first material; mixing the first material with a ferrous salt solution to obtain a second material; and calcining the second material to obtain the heterogeneous Fenton catalyst. Summary of the Invention

[0006] This invention provides a method for preparing Fenton-like catalytic materials using coal gasification slag as raw material and its application in coal chemical wastewater treatment. The prepared Fenton-like catalytic materials can adsorb and catalyze oxidation to remove recalcitrant organic pollutants in coal chemical wastewater.

[0007] The specific technical solution is as follows: In a first aspect, the present invention provides a method for preparing Fenton-like catalysts using coal gasification slag as raw material, see [link to previous section]. Figure 1The steps include: (1) The coal gasification slag is washed with water, acid-leached and then dried to obtain pretreated coal gasification slag; (2) The pretreated coal gasification slag is mixed and impregnated with a nitrogen-containing activator solution to obtain an N-coal gasification slag suspension; the nitrogen-containing activator is one or more of potassium amide, sodium amide, and tetraethylenepentamine. (3) Mix the soluble iron (III) salt solution with the N-coal gasification slag suspension, disperse by ultrasonication, separate the solid and liquid, take the solid, dry it, and place it under a nitrogen atmosphere for microwave activation to obtain Fe-N-coal gasification slag; (4) Disperse Fe-N-coal gasification slag ultrasonically in an organic alcohol, adjust the pH to 7.5~9.5 (e.g., 8.5), add shell metal oxide and stir and heat to react. After the reaction is completed, separate the solid and liquid, dry the solid and calcine it under a nitrogen atmosphere to obtain coal gasification slag-based Fenton catalyst material; the shell metal oxide is one or more of copper oxide, aluminum oxide, zinc oxide, iron oxide, cuprous oxide and iron(II,III) oxide.

[0008] In step (1), it is preferable to use an acid solution containing one or more of HF, HCl, and HNO3 for the acid leaching. The acid concentration in the acid solution is preferably 0.1~3 mol / L. The mass ratio of the coal gasification slag to the acid solution is preferably 1:1~5.

[0009] In step (1), the acid leaching is preferably carried out at room temperature.

[0010] In step (1), the acid leaching time is preferably 12 to 24 hours.

[0011] In step (2), the concentration of the nitrogen-containing activator solution is preferably 1~100 mmol / L, such as 10 mmol / L, 40 mmol / L, 60 mmol / L, etc.

[0012] In step (2), the mass ratio of the pretreated coal gasification slag to the nitrogen-containing activator solution is preferably 1:1 to 5, for example, 1:3.

[0013] In step (2), the impregnation is preferably carried out at room temperature.

[0014] In step (2), the soaking time is preferably 12 to 24 hours.

[0015] In step (3), the soluble iron(III) salt is preferably one or more of FeCl3, Fe(NO3)3, and Fe2(SO4)3.

[0016] In step (3), the concentration of the soluble iron(III) salt solution is preferably 1~20 mmol / L, such as 5 mmol / L, 10 mmol / L, 15 mmol / L, etc.

[0017] In step (3), the mass ratio of the pretreated coal gasification slag in the N-coal gasification slag suspension to the soluble iron (III) salt solution is preferably 1:0.2~5, for example 1:1, 1:2, etc.

[0018] In step (3), the microwave power for microwave activation is preferably 500~800 W (e.g., 600 W), and the time is preferably 30~60 min.

[0019] In step (4), the organic alcohol is preferably one or more of methanol, ethanol, and isopropanol.

[0020] In step (4), the mass ratio of the Fe-N-coal gasification slag to the organic alcohol is preferably 1:1 to 4, for example 1:2, 1:2.5, etc.

[0021] In step (4), it is preferable to adjust the pH to 7.5-9.5 using ammonia. The concentration of the ammonia is preferably 1-3 mol / L.

[0022] In step (4), the mass ratio of the shell metal oxide to the Fe-N-coal gasification slag is preferably 1:0.2~2, for example 1:1.

[0023] In step (4), the stirring speed of the stirring and heating reaction is preferably 500 rpm.

[0024] In step (4), the temperature of the stirring and heating reaction is preferably 40~50℃, more preferably 45℃, and the time is preferably 30~60 min.

[0025] In step (4), the calcination temperature is preferably 800℃ and the time is preferably 60 min.

[0026] Preferably, in steps (3) and (4), the ultrasonic dispersion is performed at room temperature for 10 to 30 minutes.

[0027] Preferably, in steps (1), (3), and (4), the drying temperature is 90~120℃ and the time is 60~120 min.

[0028] In a second aspect, the present invention provides a coal gasification slag-based Fenton-like catalyst prepared by the method described in the first aspect of preparing Fenton-like catalysts using coal gasification slag as raw material.

[0029] Thirdly, the present invention provides the application of the coal gasification slag-based Fenton-like catalytic material described in the second aspect for the adsorption-catalytic oxidation synergistic treatment of organic pollutants in coal chemical wastewater.

[0030] Compared with the prior art, the beneficial effects of this invention are as follows: 1) This invention uses one or more of potassium amide, sodium amide, and tetraethylenepentamine as nitrogen-containing activators. By incorporating specific nitrogen-containing groups into the amorphous carbon matrix of coal gasification slag, the invention utilizes the higher electronegativity of nitrogen atoms than carbon to induce a redistribution of local charges around carbon atoms, thereby enhancing their conductivity and generating new active sites. Simultaneously, by anchoring metal ions through specific nitrogen-containing groups, a fast electron channel is constructed between the carbon-nitrogen-metal layers, generating a local interfacial micro-electric field on the surface of the coal gasification slag, promoting the generation of active oxygen, and improving catalytic efficiency.

[0031] 2) This invention uses one or more of copper oxide, aluminum oxide, zinc oxide, iron oxide, cuprous oxide, and iron(II,III) oxide as shell metal oxides. By loading these specific shell metal oxides onto the surface of coal gasification slag under pH conditions of 7.5 to 9.5, the interfacial effect between the coal gasification slag and the metal oxide shell is utilized to induce hydrogen peroxide and pollutant molecules to pass through the metal oxide shell and react at the interface between the coal gasification slag and the metal oxide shell, thereby reducing the dissolution of metal ions in the coal gasification slag and enhancing the stability of the catalytic material.

[0032] 3) This invention provides a method for preparing Fenton-like catalysts using coal gasification slag as raw material. By using coal gasification slag-based Fenton-like catalysts to treat organic pollutants in coal chemical wastewater, this invention provides an effective way to achieve the goal of solid waste resource utilization and near-zero wastewater discharge. Attached Figure Description

[0033] Figure 1 This is a schematic flowchart of a method for preparing Fenton-like catalysts using coal gasification slag as raw material according to the present invention. Detailed Implementation

[0034] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Operating methods not specifically specified in the following embodiments are generally performed under conventional conditions or as recommended by the manufacturer.

[0035] Example 1: 1.0 kg of coal gasification slag was washed with tap water and then placed in a constant temperature drying oven and dried at 90°C. Subsequently, the dried coal gasification slag was mixed with 1.0 mol / L HCl solution at a mass ratio of 1:2 and impregnated for 24 h. After washing away the surface acid solution residue with tap water, it was placed in a constant temperature drying oven and dried at 90°C to obtain the pretreated coal gasification slag.

[0036] The pretreated coal gasification slag was mixed with 10.0 mmol / L potassium amino solution at a mass ratio of 1:3 and impregnated for 24 h. Then, 5.0 mmol / L FeCl3 solution at a mass ratio of 1:1 with the pretreated coal gasification slag was added. After ultrasonic dispersion for 10 min, the mixture was filtered, dried, and then microwave activated at 600 W for 30 min under a nitrogen atmosphere to obtain Fe-N-coal gasification slag.

[0037] Anhydrous ethanol at a mass ratio of 2:1 to Fe-N-coal gasification slag was added to Fe-N-coal gasification slag, and ultrasonic dispersion was performed for 10 min. Ammonia water was added to adjust the pH to 7.5, and Fe3O4 at a mass ratio of 1:1 to Fe-N-coal gasification slag was added. The mixture was stirred and heated at 45℃ and 500 rpm for 30 min. After filtration and drying, the mixture was calcined at 800℃ for 60 min under a nitrogen atmosphere to obtain a coal gasification slag-based Fenton catalyst.

[0038] Example 2: 1.0 kg of coal gasification slag was washed with tap water and then placed in a constant temperature drying oven and dried at 90°C. Subsequently, the dried coal gasification slag was mixed with 2.0 mol / L HCl solution at a mass ratio of 1:2 and impregnated for 24 h. After washing away the surface acid solution residue with tap water, it was placed in a constant temperature drying oven and dried at 90°C to obtain the pretreated coal gasification slag.

[0039] The pretreated coal gasification slag was mixed with 40.0 mmol / L potassium amino solution at a mass ratio of 1:3 and impregnated for 24 h. Then, 10.0 mmol / L FeCl3 solution at a mass ratio of 2:1 to the pretreated coal gasification slag was added. After ultrasonic dispersion for 10 min, the mixture was filtered, dried, and then microwave activated at 600 W for 30 min under a nitrogen atmosphere to obtain Fe-N-coal gasification slag.

[0040] Anhydrous ethanol at a mass ratio of 2.5:1 to Fe-N-coal gasification slag was added, and the mixture was ultrasonically dispersed for 10 min. The pH was adjusted to 8.5 with ammonia water, and Fe3O4 at a mass ratio of 1:1 to Fe-N-coal gasification slag was added. The mixture was stirred and heated at 45℃ and 500 rpm for 30 min. After filtration and drying, the mixture was calcined at 800℃ for 60 min under a nitrogen atmosphere to obtain a coal gasification slag-based Fenton catalyst.

[0041] Example 3: 1.0 kg of coal gasification slag was washed with tap water and then placed in a constant temperature drying oven and dried at 90°C. Subsequently, the dried coal gasification slag was mixed with 3.0 mol / L HCl solution at a mass ratio of 1:2 and impregnated for 24 h. After washing away the surface acid solution residue with tap water, it was placed in a constant temperature drying oven and dried at 90°C to obtain the pretreated coal gasification slag.

[0042] The pretreated coal gasification slag was mixed with 60.0 mmol / L potassium amino solution at a mass ratio of 1:3 and impregnated for 24 h. Then, 15.0 mmol / L FeCl3 solution at a mass ratio of 2:1 to the pretreated coal gasification slag was added. After ultrasonic dispersion for 10 min, the mixture was filtered, dried, and then microwave activated at 600 W for 30 min under a nitrogen atmosphere to obtain Fe-N-coal gasification slag.

[0043] Anhydrous ethanol at a mass ratio of 2.5:1 to Fe-N-coal gasification slag was added, and the mixture was ultrasonically dispersed for 10 min. The pH was adjusted to 9.5 with ammonia water, and Fe2O3 at a mass ratio of 1:1 to Fe-N-coal gasification slag was added. The mixture was stirred and heated at 45℃ and 500 rpm for 30 min. After filtration and drying, the mixture was calcined at 800℃ for 60 min under a nitrogen atmosphere to obtain a coal gasification slag-based Fenton catalyst.

[0044] Example 4: 1.0 kg of coal gasification slag was washed with tap water and then placed in a constant temperature drying oven and dried at 90°C. Subsequently, the dried coal gasification slag was mixed with 1.0 mol / L HNO3 solution at a mass ratio of 1:1 and impregnated for 24 h. After washing away the surface acid solution residue with tap water, it was placed in a constant temperature drying oven and dried at 90°C to obtain the pretreated coal gasification slag.

[0045] The pretreated coal gasification slag was mixed with 10.0 mmol / L potassium amino solution at a mass ratio of 1:3 and impregnated for 24 h. Then, 10.0 mmol / L Fe(NO3)3 solution at a mass ratio of 2:1 to the pretreated coal gasification slag was added. After ultrasonic dispersion for 10 min, the mixture was filtered, dried, and then microwave activated at 600 W for 30 min under a nitrogen atmosphere to obtain Fe-N-coal gasification slag.

[0046] Anhydrous ethanol at a mass ratio of 2.5:1 to Fe-N-coal gasification slag was added, and the mixture was ultrasonically dispersed for 10 min. The pH was adjusted to 8.5 with ammonia water, and Fe3O4 at a mass ratio of 1:1 to Fe-N-coal gasification slag was added. The mixture was stirred and heated at 45℃ and 500 rpm for 30 min. After filtration and drying, the mixture was calcined at 800℃ for 60 min under a nitrogen atmosphere to obtain a coal gasification slag-based Fenton catalyst.

[0047] Example 5: 1.0 kg of coal gasification slag was washed with tap water and then placed in a constant temperature drying oven and dried at 90°C. Subsequently, the dried coal gasification slag was mixed with 2.0 mol / L HNO3 solution at a mass ratio of 1:2 and impregnated for 24 h. After washing away the surface acid solution residue with tap water, it was placed in a constant temperature drying oven and dried at 90°C to obtain the pretreated coal gasification slag.

[0048] The pretreated coal gasification slag was mixed with 40.0 mmol / L potassium amino solution at a mass ratio of 1:3 and impregnated for 24 h. Then, 10.0 mmol / L Fe(NO3)3 solution at a mass ratio of 2:1 to the pretreated coal gasification slag was added. After ultrasonic dispersion for 10 min, the mixture was filtered, dried, and then microwave activated at 600 W for 30 min under a nitrogen atmosphere to obtain Fe-N-coal gasification slag.

[0049] Anhydrous ethanol at a mass ratio of 2.5:1 to Fe-N coal gasification slag was added, and the mixture was ultrasonically dispersed for 10 min. The pH was adjusted to 8.5 with ammonia water, and CuO at a mass ratio of 1:1 to Fe-N coal gasification slag was added. The mixture was stirred and heated at 45℃ and 500 rpm for 30 min. After filtration and drying, the mixture was calcined at 800℃ for 60 min under a nitrogen atmosphere to obtain a coal gasification slag-based Fenton catalyst.

[0050] Example 6: 1.0 kg of coal gasification slag was washed with tap water and then placed in a constant temperature drying oven and dried at 90°C. Subsequently, the dried coal gasification slag was mixed with 2.0 mol / L HCl solution at a mass ratio of 1:2 and impregnated for 24 h. After washing away the surface acid solution residue with tap water, it was placed in a constant temperature drying oven and dried at 90°C to obtain the pretreated coal gasification slag.

[0051] The pretreated coal gasification slag was mixed with 60.0 mmol / L potassium amino solution at a mass ratio of 1:3 and impregnated for 24 h. Then, 10.0 mmol / L Fe(NO3)3 solution at a mass ratio of 2:1 to the pretreated coal gasification slag was added. After ultrasonic dispersion for 10 min, the mixture was filtered, dried, and then microwave activated at 600 W for 30 min under a nitrogen atmosphere to obtain Fe-N-coal gasification slag.

[0052] Anhydrous ethanol at a mass ratio of 2.5:1 to Fe-N-coal gasification slag was added, and the mixture was ultrasonically dispersed for 10 min. The pH was adjusted to 8.5 with ammonia water, and Cu2O at a mass ratio of 1:1 to Fe-N-coal gasification slag was added. The mixture was stirred and heated at 45℃ and 500 rpm for 30 min. After filtration and drying, the mixture was calcined at 800℃ for 60 min under a nitrogen atmosphere to obtain a coal gasification slag-based Fenton catalyst.

[0053] Comparative Example 1: The only difference from Example 6 is that Cu2O is not added; all other aspects are the same, resulting in a coal gasification slag-based Fenton catalyst.

[0054] Comparative Example 2: The only difference from Example 6 is that the nitrogen-containing activator potassium amino solution is not added; all other aspects are the same, resulting in a coal gasification slag-based Fenton catalyst.

[0055] Comparative Example 3: The only difference from Example 6 is that the nitrogen-containing activator potassium amino solution and Cu2O are not added; all other aspects are the same, resulting in a coal gasification slag-based Fenton catalyst.

[0056] Comparative Example 4: The only difference from Example 6 is that the nitrogen-containing activator potassium amino solution and Fe(NO3)3 are not added; all other aspects are the same, resulting in a coal gasification slag-based Fenton catalyst.

[0057] Comparative Example 5: The only difference from Example 6 is that the nitrogen-containing activator potassium amino solution, Fe(NO3)3 and Cu2O are not added, while the rest are the same, and a coal gasification slag-based Fenton catalyst material is obtained.

[0058] Test Example 1: The coal gasification slag-based Fenton-like catalysts prepared in Examples 1-6 and Comparative Examples 1-5 were subjected to Fenton-like catalytic degradation of phenol. The test conditions were as follows: 200 mL of phenol solution with a concentration of 100 mg / L and 1 g of coal gasification slag-based Fenton-like catalyst were added to a beaker and stirred at 500 rpm with a magnetic stirrer. After reaching adsorption equilibrium, 0.8 mmol of H2O2 was added, and the reaction was carried out for 120 min. The mixture was then filtered, and the COD and phenol concentration in the filtrate were measured.

[0059] The COD removal rate of the coal gasification slag-based Fenton catalyst obtained in Example 1 was 85.30%, and the phenol removal rate was 96.87%.

[0060] The COD removal rate of the coal gasification slag-based Fenton catalyst obtained in Example 2 was 91.25%, and the phenol removal rate was 99.96%.

[0061] The COD removal rate of the coal gasification slag-based Fenton catalyst obtained in Example 3 was 90.88%, and the phenol removal rate was 98.21%.

[0062] The COD removal rate of the coal gasification slag-based Fenton catalyst obtained in Example 4 was 81.70%, and the phenol removal rate was 89.65%.

[0063] The COD removal rate of the coal gasification slag-based Fenton catalyst obtained in Example 5 was 86.51%, and the phenol removal rate was 92.00%.

[0064] The COD removal rate of the coal gasification slag-based Fenton catalyst obtained in Example 6 was 91.73%, and the phenol removal rate was 99.54%.

[0065] The COD removal rate of the coal gasification slag-based Fenton catalyst obtained in Comparative Example 1 was 90.28%, and the phenol removal rate was 96.47%.

[0066] The COD removal rate of the coal gasification slag-based Fenton catalyst obtained in Comparative Example 2 was 34.93%, and the phenol removal rate was 38.21%.

[0067] The COD removal rate of the coal gasification slag-based Fenton catalyst obtained in Comparative Example 3 was 26.05%, and the phenol removal rate was 26.36%.

[0068] The COD removal rate of the coal gasification slag-based Fenton catalyst obtained in Comparative Example 4 was 34.12%, and the phenol removal rate was 37.80%.

[0069] The COD removal rate of the coal gasification slag-based Fenton catalyst obtained in Comparative Example 5 was 25.59%, and the phenol removal rate was 25.17%.

[0070] The test examples of this invention involve adsorption and catalysis. During adsorption, the coal gasification slag-based Fenton catalyst acts as an adsorbent, adsorbing intact phenol molecules. Phenol molecules may also undergo surface polymerization on the adsorbent surface, generating intermediate products that are larger and have lower oxidation states than phenol molecules. These intermediate products may partially desorb back into the solution and be detected by COD testing. However, they may no longer have intact phenolic hydroxyl structures and therefore not be detected by the phenol determination method. Alternatively, although they may be adsorbed and removed, their theoretical COD contribution per unit mass is higher than that of the original phenol molecules. Therefore, the COD removal rate in Comparative Example 5 is slightly higher than the phenol removal rate.

[0071] The test results of Examples 1-6 show that the coal gasification slag-based Fenton catalysts obtained in Examples 2 and 6 have higher COD and phenol removal rates and better catalytic effects.

[0072] The comparison between Comparative Examples 5 and 3, and between Comparative Examples 4 and 2, shows that without a nitrogen-containing activator, the introduction of Fe(III) alone does not significantly improve the Fenton catalytic activity of the material. However, with a nitrogen-containing activator (see Comparative Example 1), the Fenton catalytic activity of the material is significantly improved compared to Comparative Examples 3 and 5, demonstrating the synergistic effect of the nitrogen-containing activator and Fe(III) in the system of this invention.

[0073] Test Example 2: Example 6: The Fenton-like catalyst based on coal gasification slag prepared in Comparative Example 1 was subjected to a cycle stability test. The test conditions were the same as those in Example 1. After reacting for 120 min, the catalyst was filtered and recovered. Cyclic tests were then conducted under the same conditions. A total of 5 cycles were performed. After each cycle, the COD and phenol concentrations in the solution were measured.

[0074] The COD removal rate of the coal gasification slag-based Fenton catalyst obtained in Example 6 was 85.09% and the phenol removal rate was 87.40% after 5 cycles.

[0075] The COD removal rate of the coal gasification slag-based Fenton catalyst obtained in Comparative Example 1 was 24.97% and the phenol removal rate was 22.83% after two cycles.

[0076] Furthermore, it should be understood that after reading the above description of the present invention, those skilled in the art can make various alterations or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims.

Claims

1. A method for preparing Fenton-like catalysts using coal gasification slag as raw material, characterized in that, Including the following steps: (1) The coal gasification slag is washed with water, acid-leached and then dried to obtain pretreated coal gasification slag; (2) The pretreated coal gasification slag is mixed and impregnated with a nitrogen-containing activator solution to obtain an N-coal gasification slag suspension; the nitrogen-containing activator is one or more of potassium amide, sodium amide, and tetraethylenepentamine. (3) Mix the soluble iron (III) salt solution with the N-coal gasification slag suspension, disperse by ultrasonication, separate the solid and liquid, take the solid, dry it, and place it under a nitrogen atmosphere for microwave activation to obtain Fe-N-coal gasification slag; (4) Disperse Fe-N-coal gasification slag ultrasonically in an organic alcohol, adjust the pH to 7.5~9.5, add shell metal oxide and stir and heat to react. After the reaction is completed, separate the solid and liquid, take the solid, dry it and calcine it under a nitrogen atmosphere to obtain coal gasification slag-based Fenton catalyst material; the shell metal oxide is one or more of copper oxide, aluminum oxide, zinc oxide, iron oxide, cuprous oxide and iron tetroxide.

2. The method for preparing Fenton-like catalysts using coal gasification slag as raw material according to claim 1, characterized in that, In step (1): The acid leaching is carried out using a solution containing one or more of the following acids: HF, HCl, and HNO3. The acid concentration in the acid solution is 0.1~3 mol / L; The mass ratio of the coal gasification slag to the acid solution is 1:1~5; The acid leaching is carried out at room temperature; The acid leaching time is 12-24 hours.

3. The method for preparing Fenton-like catalysts using coal gasification slag as raw material according to claim 1, characterized in that, In step (2): The concentration of the nitrogen-containing activator solution is 1~100 mmol / L; The mass ratio of the pretreated coal gasification slag to the nitrogen-containing activator solution is 1:1~5; The impregnation is carried out at room temperature; The soaking time is 12-24 hours.

4. The method for preparing Fenton-like catalysts using coal gasification slag as raw material according to claim 1, characterized in that, In step (3): The soluble iron(III) salt is one or more of FeCl3, Fe(NO3)3, and Fe2(SO4)3; The concentration of the soluble iron(III) salt solution is 1~20 mmol / L; The mass ratio of the pretreated coal gasification slag to the soluble iron(III) salt solution in the N-coal gasification slag suspension is 1:0.2~5; The microwave activation process involves a microwave power of 500-800 W and a duration of 30-60 min.

5. The method for preparing Fenton-like catalysts using coal gasification slag as raw material according to claim 1, characterized in that, In step (4): The organic alcohol is one or more of methanol, ethanol, and isopropanol; The mass ratio of the Fe-N-coal gasification slag to the organic alcohol is 1:1~4; Adjust the pH to 7.5-9.5 using ammonia. The concentration of the ammonia water is 1~3 mol / L.

6. The method for preparing Fenton-like catalysts using coal gasification slag as raw material according to claim 1, characterized in that, In step (4): The mass ratio of the shell metal oxide to the Fe-N-coal gasification slag is 1:0.2~2; The stirring speed for the stirring and heating reaction is 500 rpm; The stirring and heating reaction is carried out at a temperature of 40-50°C for 30-60 minutes. The calcination temperature was 800℃ and the time was 60 min.

7. The coal gasification slag-based Fenton-like catalyst material prepared by the method for preparing Fenton-like catalyst materials using coal gasification slag as raw material according to any one of claims 1 to 6.

8. The application of the coal gasification slag-based Fenton catalytic material according to claim 7 for the adsorption-catalytic oxidation synergistic treatment of organic pollutants in coal chemical wastewater.

Images