Nano multi-metal magnetic catalytic wet oxidation catalytic material as well as preparation method and application thereof

Abstract

The invention provides a nano multi-metal magnetic catalytic wet oxidation catalytic material and a preparation method and application thereof.The method comprises the steps that ZnCl2, PbCl2, H2PtCl6, Pd (NH3) 4Cl2 and sodium hydroxide are mixed and dissolved with water, and a mixed solution A is obtained; adding water into K2Al2O4, K2SiO3 and sodium hydroxide, mixing and dissolving to obtain a mixed solution B; adding 3-methacryloyloxypropyltrimethoxysilane into the mixed solution A, and stirring until the solution is clear to obtain a mixed solution C; adding hexadecyl trimethyl ammonium bromide into the mixed solution B, and dissolving to obtain a mixed solution D; slowly mixing the mixed solution C and the mixed solution D, and stirring until the solution is clear to obtain a reaction solution; and mixing the nano ferroferric oxide with the reaction solution, and carrying out hydrothermal reaction to obtain the nano multi-metal magnetic catalytic material. Compared with a traditional wet oxidation system, the catalytic wet oxidation system applying the catalyst prepared by the method has the advantage that the efficiency is remarkably improved in the aspect of removing pollutants in the gasoline alkali washing waste liquid.

Description

Technical Field

[0001] The present invention belongs to the technical field of catalytic materials, and relates to a nano multi-metal magnetic catalytic wet air oxidation catalytic material, a preparation method thereof and an application thereof. Background Art

[0002] The gasoline caustic washing waste liquid mainly comes from the hydrocarbon refining process of oil refining and petrochemical enterprises. In this process, caustic liquor (such as NaOH or KOH) is used to remove acidic impurities such as mercaptans and hydrogen sulfide in gasoline. However, after caustic washing treatment, the waste liquid not only contains high concentrations of alkaline components, but also is rich in organic pollutants such as mercaptans, sulfides, phenols and some hydrocarbons. It has the characteristics of high alkalinity, high chemical oxygen demand (COD) and high sulfur content, and belongs to typical refractory organic wastewater. Due to its complex composition and strong stability, traditional biochemical treatment methods have poor removal effects on it, while physical and chemical treatments (such as acidification, flocculation, adsorption, etc.) can only partially remove pollutants, but are prone to secondary pollution. Therefore, the development of efficient, economical and environmentally friendly treatment technologies has become one of the current research hotspots.

[0003] Catalytic Wet Air Oxidation (CWAO) is an advanced oxidation technology suitable for the treatment of high-concentration organic wastewater. Its principle is to use a catalyst at a relatively high temperature (100 - 250 °C) and medium pressure (0.5 - 10 MPa) to promote the oxidative degradation of organic pollutants in the wastewater by air or oxygen, and finally convert them into CO2, H2O and harmless small-molecule substances. Compared with the traditional Wet Air Oxidation (WAO) technology, CWAO effectively reduces the reaction activation energy by introducing a catalyst, reduces the temperature and pressure required for the reaction, improves the degradation efficiency of pollutants, while reducing energy consumption and the generation of by-products, and effectively removes toxic and harmful substances in the wastewater.

[0004] The selection of the catalyst is crucial in the CWAO technology. Commonly used catalysts include transition metal oxides, noble metal catalysts and their composite catalysts, etc. By optimizing the properties of the catalyst, reaction conditions and operating parameters, the treatment efficiency of wastewater can be significantly improved and the treatment cost can be reduced. At present, the CWAO technology has achieved certain applications in the treatment of coking wastewater, pharmaceutical wastewater and phenol-containing wastewater. However, there are still many challenges in the treatment of gasoline caustic washing waste liquid. For example, sulfides in the waste liquid are prone to cause catalyst poisoning and affect the catalytic activity; in addition, high-concentration organic pollutants may cause catalyst carbon deposition or blockage problems. Therefore, the development of a catalyst system resistant to sulfide poisoning, with high activity and long life, and the optimization of process parameters to improve the degradation efficiency of CWAO for gasoline caustic washing waste liquid is an important research direction in this field. Summary of the Invention

[0005] To overcome the problems existing in the prior art, the present invention provides a nano multi-metal magnetic catalytic wet oxidation catalytic material, its preparation method and application to meet the treatment requirements of refractory ultra-high-concentration industrial organic wastewater.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] The present invention provides a preparation method of a nano multi-metal magnetic catalytic wet oxidation catalytic material, comprising the following steps: Dissolve zinc chloride (ZnCl2), lead chloride (PbCl2), chloroplatinic acid (H2PtCl6), tetraamminepalladium dichloride (Pd(NH3)4Cl2) and sodium hydroxide in water to obtain a mixed solution A; Dissolve potassium aluminate (K2Al2O4), potassium silicate (K2SiO3) and sodium hydroxide in water to obtain a mixed solution B; Add 3-methacryloxypropyltrimethoxysilane to the mixed solution A and stir until the solution is clear to obtain a mixed solution C; Add cetyltrimethylammonium bromide to the mixed solution B and dissolve it to obtain a mixed solution D; Slowly mix the mixed solution C and the mixed solution D and stir until the solution is clear to obtain a reaction solution; Mix nano-ferroferric oxide with the reaction solution and carry out a hydrothermal reaction to obtain a nano multi-metal magnetic catalytic material.

[0008] Further, in the mixed solution A, the mass ratio of zinc chloride to lead chloride is 1:1.05 - 1.25, the mass ratio of zinc chloride to chloroplatinic acid is 1:0.75 - 0.95, the mass ratio of zinc chloride to tetraamminepalladium dichloride is 1:0.65 - 0.85, and the mass ratio of zinc chloride to sodium hydroxide is 1:1.5 - 3; The mass ratio of zinc chloride to water is 1:8 - 15, preferably 1:10.

[0009] Further, the mass-volume ratio of 3-methacryloxypropyltrimethoxysilane to the mixed solution A is 18 - 25 g:1 L.

[0010] Further, in the mixed solution B, the mass ratio of potassium aluminate to potassium silicate is 1:1.2 - 1.5, the mass ratio of potassium aluminate to sodium hydroxide is 1:1.8 - 2.2; The mass ratio of potassium aluminate to water is 1:10 - 20, preferably 1:15.

[0011] Further, the mass-volume ratio of cetyltrimethylammonium bromide to the mixed solution B is 0.045 - 0.080 g:1 L.

[0012] Further, the mass-volume ratio of nano-ferroferric oxide to the reaction solution is 8 - 15 g:1 L.

[0013] Further, the mixing mass ratio of the mixed solution C and the mixed solution D is 1:1.2 - 1.8.

[0014] Furthermore, the hydrothermal reaction temperature is 160 - 180 °C, and the reaction time is 12 - 18 h.

[0015] Furthermore, after the hydrothermal reaction is completed, the reaction system is cooled to room temperature. Subsequently, the product is washed with methanol and pure water until the pH value of the washing liquid is 7 - 7.5. After drying to constant weight, the final product is obtained.

[0016] (2) The present invention also provides a nano - multi - metal magnetic catalytic wet oxidation catalytic material, which is prepared by the preparation method described above.

[0017] (3) The present invention also provides the application of the catalytic material prepared by the method described above in the catalytic wet oxidation treatment of gasoline caustic washing waste liquid. The application method is as follows: adding the catalytic material into the gasoline caustic washing waste liquid and heating for reaction; the reaction temperature is 150 - 195 °C, the reaction time is 0.5 - 2.5 hours, and the dosage of the catalytic material in the gasoline caustic washing waste liquid is 0.60 - 2.85 g / L.

[0018] The beneficial effects of the present invention are as follows:

[0019] Compared with the prior art, the novel nano - multi - metal magnetic catalytic wet oxidation catalyst of the present invention can be applied to the catalytic wet oxidation treatment of gasoline caustic washing waste liquid. Compared with the traditional wet oxidation system, the catalytic wet oxidation system of the present invention shows a significant improvement in the efficiency of removing pollutants from gasoline caustic washing waste liquid. Experiments prove that under the conditions of a temperature of 195 °C, a reaction time of 2.5 hours, an oxygen partial pressure of 1.8 MPa, and a catalyst dosage of 2.85 g / L, the catalytic wet oxidation system shows excellent treatment effects on gasoline caustic washing waste liquid with an initial sulfide concentration of 11965 mg / L, an oil - type concentration of 2378 mg / L, and a COD concentration of 190127 mg / L. Specifically, the removal rates of sulfide, oil - type, and COD are as high as 99.99%, 94.95%, and 96.57% respectively. After treatment, the concentrations of sulfide, oil - type, and COD in the effluent are reduced to 1 mg / L, 120 mg / L, and 6521 mg / L respectively. This nano - multi - metal magnetic catalytic material not only shows high - efficient performance in the treatment of gasoline caustic washing waste liquid, but also has broad application prospects in the treatment of refractory and high - concentration organic waste liquids in other industrial fields due to its unique catalytic characteristics and wide applicability. Description of the Drawings

[0020] Figure 1 It is the scanning electron microscope image of the catalyst sample Mag = 2.00 k synthesized in Example 1;

[0021] Figure 2 It is the scanning electron microscope image of the catalyst sample Mag = 10.00 k synthesized in Example 1;

[0022] Figure 3 SEM image of the catalyst sample Mag = 5.00k synthesized in Example 2;

[0023] Figure 4 SEM image of the catalyst sample Mag = 8.00k synthesized in Example 2;

[0024] Figure 5 SEM image of the catalyst sample Mag = 8.00k synthesized in Example 3;

[0025] Figure 6 SEM image of the catalyst sample Mag = 12.00k synthesized in Example 3. Detailed implementation mode

[0026] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0027] Example 1

[0028] This example provides a nano multi-metal magnetic catalytic wet oxidation catalytic material, and its preparation method includes the following steps:

[0029] Step 1: Mix and dissolve zinc chloride, lead chloride, chloroplatinic acid, dichlorotetraamminepalladium and sodium hydroxide in water (the mass ratio of zinc chloride, lead chloride, chloroplatinic acid, dichlorotetraamminepalladium, sodium hydroxide to water is 1:1.05:0.75:0.65:1.5:10) to obtain a mixed solution A.

[0030] Step 2: Mix and dissolve potassium aluminate, potassium silicate and sodium hydroxide in water (the mass ratio of potassium aluminate, potassium silicate, sodium hydroxide to water is 1:1.3:2.0:15) to obtain a mixed solution B.

[0031] Step 3: Add 3-methacryloxypropyltrimethoxysilane to the mixed solution A (the addition amount of 3-methacryloxypropyltrimethoxysilane in 1 L of the mixed solution A is 20 g), and stir until the solution is clear to obtain a mixed solution C.

[0032] Step 4: Add cetyltrimethylammonium bromide to the mixed solution B (the addition amount of cetyltrimethylammonium bromide in 1 L of the mixed solution B is 0.045 g), and dissolve to obtain a mixed solution D;

[0033] Step 5: Slowly mix the mixed solution C and the mixed solution D (the mixing mass ratio is 1:1.2), and stir until the solution is clear to obtain a reaction solution;

[0034] Step 6: Mix the nano-ferroferric oxide with the reaction solution (the mass-volume ratio of nano-ferroferric oxide to the reaction solution is 8 g:1 L), and transfer them together to a hydrothermal reaction kettle for hydrothermal reaction. The hydrothermal reaction temperature is 160 °C, and the reaction time is 15 h.

[0035] Step 7: After the hydrothermal reaction is completed, cool the reaction system to room temperature, and then wash the product with methanol and pure water until the pH value of the washing solution is 7-7.5. After drying to constant weight, the final product, the nano-multimetal magnetic catalytic material, is obtained.

[0036] Example 2

[0037] This example provides a nano-multimetal magnetic catalytic wet oxidation catalytic material, and its preparation method includes the following steps:

[0038] Step 1: Add zinc chloride, lead chloride, chloroplatinic acid, dichlorotetraamminepalladium and sodium hydroxide to water and mix them for dissolution (the mass ratio of zinc chloride, lead chloride, chloroplatinic acid, dichlorotetraamminepalladium, sodium hydroxide, and water is 1:1.15:0.85:0.75:1.8:10) to obtain a mixed solution A.

[0039] Step 2: Add potassium aluminate, potassium silicate and sodium hydroxide to water and mix them for dissolution (the mass ratio of potassium aluminate, potassium silicate, sodium hydroxide, and water is 1:1.2:1.8:15) to obtain a mixed solution B.

[0040] Step 3: Add 3-methacryloxypropyltrimethoxysilane to the mixed solution A (the addition amount of 3-methacryloxypropyltrimethoxysilane in 1 L of the mixed solution A is 25 g), and stir until the solution is clear to obtain a mixed solution C.

[0041] Step 4: Add cetyltrimethylammonium bromide to the mixed solution B (the addition amount of cetyltrimethylammonium bromide in 1 L of the mixed solution B is 0.080 g), and dissolve it to obtain a mixed solution D;

[0042] Step 5: Slowly mix the mixed solution C and the mixed solution D (the mixing mass ratio is 1:1.5), and stir until the solution is clear to obtain a reaction solution;

[0043] Step 6: Mix the nano-ferroferric oxide with the reaction solution (the mass-volume ratio of nano-ferroferric oxide to the reaction solution is 10 g:1 L), and transfer them together to a hydrothermal reaction kettle for hydrothermal reaction. The hydrothermal reaction temperature is 180 °C, and the reaction time is 12 h.

[0044] Step 7: After the hydrothermal reaction is completed, cool the reaction system to room temperature. Then wash the product with methanol and pure water until the pH value of the washing solution is 7 - 7.5. After drying to constant weight, the final product, the nano multi-metal magnetic catalytic material, is obtained.

[0045] Example 3

[0046] This example provides a nano multi-metal magnetic catalytic wet oxidation catalytic material, and its preparation method includes the following steps:

[0047] Step 1: Mix and dissolve zinc chloride, lead chloride, chloroplatinic acid, dichlorotetraamminepalladium and sodium hydroxide in water (the mass ratio of zinc chloride, lead chloride, chloroplatinic acid, dichlorotetraamminepalladium, sodium hydroxide to water is 1:1.25:0.95:0.85:3:10) to obtain a mixed solution A.

[0048] Step 2: Mix and dissolve potassium aluminate, potassium silicate and sodium hydroxide in water (the mass ratio of potassium aluminate, potassium silicate, sodium hydroxide to water is 1:1.5:2.2:15) to obtain a mixed solution B.

[0049] Step 3: Add 3-methacryloxypropyltrimethoxysilane to the mixed solution A (the addition amount of 3-methacryloxypropyltrimethoxysilane in 1 L of the mixed solution A is 25 g), and stir until the solution is clear to obtain a mixed solution C.

[0050] Step 4: Add cetyltrimethylammonium bromide to the mixed solution B (the addition amount of cetyltrimethylammonium bromide in 1 L of the mixed solution B is 0.080 g), and dissolve to obtain a mixed solution D;

[0051] Step 5: Slowly mix the mixed solution C and the mixed solution D (the mixing mass ratio is 1:1.8), and stir until the solution is clear to obtain a reaction solution;

[0052] Step 6: Mix nano-ferroferric oxide with the reaction solution (the mass-volume ratio of nano-ferroferric oxide to the reaction solution is 15 g:1 L), and transfer them together to a hydrothermal reaction kettle for hydrothermal reaction. The hydrothermal reaction temperature is 180 °C, and the reaction time is 18 h.

[0053] Step 7: After the hydrothermal reaction is completed, cool the reaction system to room temperature. Then wash the product with methanol and pure water until the pH value of the washing solution is 7 - 7.5. After drying to constant weight, the final product, the nano multi-metal magnetic catalytic material, is obtained.

[0054] Application Example 1:

[0055] Use the nano multi-metal magnetic catalytic material prepared in Example 1 for catalytic wet oxidation treatment of gasoline caustic washing waste liquid.

[0056] The treatment method is as follows: Add 1000 mL of gasoline caustic washing waste liquid into a 2 L hydraulic lifting reactor, add the catalytic material prepared in Example 1 (the dosage of the catalytic material in the gasoline caustic washing waste liquid is 0.60 - 2.85 g / L), fully mix and then seal the reaction system. Start the catalytic wet oxidation reaction at 150 - 195 °C, keep continuous stirring during the reaction process, keep the oxygen partial pressure at 1.8 MPa, and control the reaction temperature through the circulating condensed water system. After the reaction is completed, naturally cool the system to room temperature, then take samples to analyze the contents of sulfide, petroleum substances and COD in the reaction solution, and compare with the wet oxidation treatment results without using the catalyst to evaluate the degradation effect of the catalyst prepared by the present invention.

[0057] Among them, the initial sulfide concentration of the gasoline caustic washing waste liquid is 10235 mg / L, the petroleum substances are 2860 mg / L, and the COD concentration is 197640 mg / L. The sulfide concentration is determined by the iodometric method, the petroleum substances are determined by the non-dispersive infrared method, and the COD is determined by the potassium dichromate method. The determination results are shown in Table 1.

[0058] According to the treatment effect of the catalytic wet oxidation system on gasoline caustic washing waste liquid under different reaction conditions shown in Table 1, the wet oxidation system (without catalyst group) showed relatively ideal efficiency in removing sulfides. However, the removal rates of petroleum substances and COD in the waste liquid were relatively low. With the extension of the reaction time, whether it was the wet oxidation system (without catalyst group) or the catalytic wet oxidation system (applying the catalyst group of Example 1), the removal efficiency of pollutants showed a certain degree of improvement. However, the improvement amplitude of the wet oxidation system was relatively limited, while the catalytic wet oxidation system showed significant superiority in treating pollutants in gasoline caustic washing waste liquid. Specifically, under the conditions of a reaction temperature of 150 °C and a reaction time of 2.5 hours, the removal rate of sulfides by the wet oxidation system was 64.68%, while the removal rates of petroleum substances and COD were only 14.38% and 25.80% respectively. In contrast, after adding 1.0 g / L of catalyst under the same conditions, the removal rates of sulfides, petroleum substances and COD by the catalytic wet oxidation system were significantly increased to 96.54%, 50.25% and 58.08% respectively, which were increased by 31.86%, 35.87% and 32.28% respectively compared with the wet oxidation system without adding catalyst. When the catalyst dosage was further increased to 2.5 g / L, under the conditions of 150 °C and a reaction time of 2.5 hours, the removal rates of sulfides, petroleum substances and COD by the catalytic wet oxidation system reached 99.89%, 62.36% and 68.65% respectively, which were increased by 35.21%, 47.98% and 42.85% respectively compared with the wet oxidation system without adding catalyst. When the reaction temperature was increased to 180 °C, the removal efficiency of pollutants by the catalytic wet oxidation system was further improved. Under the conditions of a reaction time of 2.5 hours and a catalyst dosage of 1.0 g / L, the removal rates of sulfides, petroleum substances and COD reached 99.99%, 67.46% and 75.06% respectively; while under the same reaction time, when the catalyst dosage was 2.5 g / L, the removal rates of sulfides, petroleum substances and COD reached 99.98%, 78.43% and 85.94% respectively. In summary, increasing the catalyst dosage and the reaction temperature both have a significant promoting effect on the catalytic wet oxidation system in treating pollutants in gasoline caustic washing waste liquid, which indicates that in practical applications, by optimizing the catalyst dosage and the reaction temperature, the removal efficiency of the catalytic wet oxidation system for pollutants in gasoline caustic washing waste liquid can be effectively improved.

[0059] Table 1 - Treatment effect of catalytic wet oxidation system on gasoline caustic washing waste liquid under different reaction conditions

[0060]

[0061]

[0062] Application Example 2:

[0063] The nano-multimetal magnetic catalytic material prepared in Example 1 was used for catalytic wet air oxidation treatment of gasoline caustic washing waste liquid.

[0064] The treatment method was as follows: 1000 mL of gasoline caustic washing waste liquid was added to a 2 L hydraulic lifting reactor, and the catalytic material prepared in Example 1 was added (the dosage of the catalytic material in the gasoline caustic washing waste liquid was 0.60 - 2.85 g / L). After thorough mixing, the reaction system was sealed, and the catalytic wet air oxidation reaction was initiated at 150 - 195 °C. During the reaction process, continuous stirring was maintained, the oxygen partial pressure was maintained at 1.8 MPa, and the reaction temperature was controlled through a circulating condensed water system. After the reaction was completed, the system was naturally cooled to room temperature. Subsequently, samples were taken to analyze the contents of sulfide, petroleum substances, and COD in the reaction solution, and the results were compared with those of wet air oxidation treatment without using the catalyst to evaluate the degradation effect of the catalyst prepared in the present invention.

[0065] Among them, the initial sulfide concentration in the gasoline caustic washing waste liquid was 11532 mg / L, the petroleum substances were 2575 mg / L, and the COD concentration was 191290 mg / L. The sulfide concentration was determined by the iodometric method, the petroleum substances were determined by the non-dispersive infrared method, and the COD was determined by the potassium dichromate method. The determination results are shown in Table 2.

[0066] According to the experimental data in Table 2, the catalytic wet air oxidation system shows a significant improvement in efficiency compared to the traditional wet air oxidation system in removing pollutants from gasoline caustic washing waste liquid. In the traditional wet air oxidation system without adding a catalyst, when the reaction temperature is 160 °C and the reaction time is 2.5 hours, the removal rates of sulfides, petroleum substances, and COD are 78.75%, 23.90%, and 29.54% respectively. However, when the catalyst dosage is introduced at 0.8 g / L, under the same reaction conditions, the removal rates of the above three pollutants by the catalytic wet air oxidation system are respectively increased to 98.89%, 53.78%, and 62.76%. Compared with the traditional wet air oxidation system without adding a catalyst, the removal rates are increased by 20.14%, 29.88%, and 33.22% respectively. Further increasing the catalyst concentration to 2.3 g / L, under the same reaction conditions, the removal rates of sulfides, petroleum substances, and COD by the catalytic wet air oxidation system reach 99.98%, 67.93%, and 73.90% respectively. Compared with the traditional wet air oxidation system without adding a catalyst, the removal rates are increased by 21.23%, 44.03%, and 44.36% respectively. When the reaction temperature is increased to 190 °C, the removal efficiency of the catalytic wet air oxidation system for pollutants in gasoline caustic washing waste liquid is further enhanced. Under the conditions of a catalyst dosage of 0.8 g / L and a reaction time of 2.5 hours, the removal rates of sulfides, petroleum substances, and COD by the catalytic wet air oxidation system reach 99.96%, 73.90%, and 80.76% respectively. Compared with the traditional wet air oxidation system without adding a catalyst at 160 °C, the removal rates are increased by 21.21%, 50.00%, and 51.22% respectively. When the catalyst dosage is increased to 2.3 g / L, under the same reaction conditions, the removal rates of the three pollutants by the catalytic wet air oxidation system are respectively increased to 99.99%, 84.76%, and 87.09%. Compared with the traditional wet air oxidation system without adding a catalyst at 160 °C, the removal rates are increased by 21.24%, 60.86%, and 57.55% respectively. In summary, compared with the traditional wet air oxidation system, the catalytic wet air oxidation system of the present invention shows a significant improvement in efficiency in removing pollutants from gasoline caustic washing waste liquid.

[0067] Table 2 - Treatment effect of catalytic wet air oxidation system on gasoline caustic washing waste liquid under different reaction conditions

[0068]

[0069]

[0070] Application Example 3:

[0071] The nano-multimetal magnetic catalytic material prepared in Example 2 is used for catalytic wet air oxidation treatment of gasoline caustic washing waste liquid.

[0072] The treatment method is as follows: 1000mL of gasoline alkali washing waste liquid is added to a 2L hydraulic lift reactor, the catalytic material prepared in Example 2 is added (the amount of the catalytic material added to the gasoline alkali washing waste liquid is 0.60-2.85g / L), the reaction system is sealed after sufficient mixing, and the catalytic wet oxidation reaction is started at 150-195°C, continuous stirring is maintained during the reaction, the oxygen partial pressure is maintained at 1.8MPa, and the reaction temperature is controlled by a circulating condensed water system. After the reaction is completed, the system is naturally cooled to room temperature, and then the sulfide, petroleum and COD content in the solution after the reaction are sampled and analyzed, and compared with the wet oxidation treatment results without using a catalyst to evaluate the degradation effect of the catalyst prepared by the present invention.

[0073] Among them, the initial sulfide concentration of gasoline alkali washing waste liquid is 12645 mg / L, petroleum is 3126 mg / L, and COD concentration is 187843 mg / L. The sulfide concentration is determined by iodine titration, petroleum is determined by non-dispersive infrared method, and COD is determined by potassium dichromate method. The results are shown in Table 3.

[0074] According to the experimental data in Table 2, the addition of catalyst has a significant effect on the efficiency of the wet oxidation system in treating pollutants in gasoline alkali washing wastewater. Under the conditions of catalyst amount of 1.2g / L, reaction temperature of 165℃ and reaction time of 2.5 hours, the removal rates of sulfide, petroleum and COD in gasoline alkali washing wastewater by the catalytic wet oxidation system reached 99.95%, 60.31% and 69.54%, respectively. Compared with the conventional wet oxidation system without adding catalyst under the same conditions, the removal rates were increased by 13.52%, 34.44% and 36.56%, respectively. When the catalyst amount was increased to 2.6g / L, under similar reaction conditions, the removal rate of pollutants in gasoline alkali washing wastewater by the catalytic wet oxidation system was further improved. Compared with the conventional wet oxidation system without adding catalyst, the removal rate of sulfide was close to complete, and the removal rates of petroleum and COD were increased by 46.99% and 46.00%, respectively. When the reaction temperature was further increased to 195℃, the removal effect of pollutants by the catalytic wet oxidation system was significantly enhanced. Under the conditions of 1.2 g / L catalyst and 2.5 hours reaction time, the removal rates of sulfide, petroleum and COD in gasoline alkali washing waste liquid by the catalytic wet oxidation system reached 99.99%, 82.85% and 86.86%, respectively. When the catalyst amount was increased to 2.6 g / L, the removal rate of sulfide was nearly complete, and the removal rates of petroleum and COD reached 92.88% and 95.06%, respectively. Compared with the conventional wet oxidation system without adding catalyst under the same conditions and at a temperature of 165°C, the removal rates were increased by 67.01% and 62.08%, respectively. The experimental results show that compared with the conventional wet oxidation system, the catalytic wet oxidation system of the present invention shows a significant improvement in efficiency in removing pollutants from gasoline alkali washing waste liquid.

[0075] Table 3 - Treatment effect of catalytic wet oxidation system on gasoline alkaline washing wastewater under different reaction conditions

[0076]

[0077]

[0078] Application example 4:

[0079] The nano multi-metal magnetic catalytic material prepared in Example 2 was used for catalytic wet oxidation treatment of gasoline alkali washing waste liquid.

[0080] The treatment method is as follows: 1000mL of gasoline alkali washing waste liquid is added to a 2L hydraulic lift reactor, the catalytic material prepared in Example 2 is added (the amount of the catalytic material added to the gasoline alkali washing waste liquid is 0.60-2.85g / L), the reaction system is sealed after sufficient mixing, and the catalytic wet oxidation reaction is started at 150-195°C, continuous stirring is maintained during the reaction, the oxygen partial pressure is maintained at 1.8MPa, and the reaction temperature is controlled by a circulating condensed water system. After the reaction is completed, the system is naturally cooled to room temperature, and then the sulfide, petroleum and COD content in the solution after the reaction are sampled and analyzed, and compared with the wet oxidation treatment results without using a catalyst to evaluate the degradation effect of the catalyst prepared by the present invention.

[0081] Among them, the initial sulfide concentration of gasoline alkali washing waste liquid is 13532mg / L, petroleum is 2612mg / L, and COD concentration is 197643mg / L. The sulfide concentration is determined by iodine titration, petroleum is determined by non-dispersive infrared method, and COD is determined by potassium dichromate method. The results are shown in Table 4.

[0082] According to the experimental data in Table 4, it can be clearly observed that in the catalytic wet air oxidation system, the introduction of the catalyst and the increase in reaction temperature both significantly enhance the removal efficiency of pollutants in the gasoline caustic washing waste liquid. In particular, the removal effect of sulfides shows an extremely obvious upward trend. When the catalyst dosage is set at 1.4 g / L, the temperature is controlled at 155 °C, and the reaction time lasts for 2.5 hours, the catalytic wet air oxidation system can almost completely remove sulfides in the gasoline caustic washing waste liquid. At the same time, the removal rates of petroleum substances and COD reach 60.32% and 64.65% respectively, which are 41.36% and 37.07% higher than those of the conventional wet air oxidation system under the same conditions. Further increasing the catalyst dosage to 2.4 g / L while keeping the other conditions unchanged, the removal effect of the catalytic wet air oxidation system on pollutants is further optimized. Sulfides are still almost completely removed, and the removal rates of petroleum substances and COD are increased to 70.05% and 74.08% respectively, which are 51.09% and 46.5% higher than those of the wet air oxidation system. When the reaction temperature rises to 185 °C, the pollutant removal ability of the catalytic wet air oxidation system for the gasoline caustic washing waste liquid is more significantly enhanced. Under the conditions of a catalyst dosage of 1.4 g / L and a reaction time of 2.5 hours, the removal rate of sulfides in this system is close to 100%, and the removal rates of petroleum substances and COD are increased to 79.42% and 82.17% respectively, which are 60.46% and 54.59% higher than those of the wet air oxidation system at 155 °C under similar conditions. If the catalyst dosage is further increased to 2.4 g / L on this basis and the reaction time is still 2.5 hours, the removal rates of petroleum substances and COD by the catalytic wet air oxidation system can be further increased to 87.38% and 93.92% respectively, which are 68.42% and 66.34% higher than those of the wet air oxidation system at 155 °C under similar conditions.

[0083] Table 4 - Treatment effect of catalytic wet air oxidation system on gasoline caustic washing waste liquid under different reaction conditions

[0084]

[0085]

[0086] Application Example 5:

[0087] The nano-multimetal magnetic catalytic material prepared in Example 3 was used for catalytic wet air oxidation treatment of gasoline caustic washing waste liquid.

[0088] The treatment method is as follows: 1000mL of gasoline alkali washing waste liquid is added to a 2L hydraulic lift reactor, the catalytic material prepared in Example 3 is added, the reaction system is sealed after sufficient mixing, and the catalytic wet oxidation reaction is started at 150-195°C, continuous stirring is maintained during the reaction, the oxygen partial pressure is maintained at 1.8MPa, and the reaction temperature is controlled by a circulating condensed water system. After the reaction is completed, the system is naturally cooled to room temperature, and then the sulfide, petroleum and COD contents in the solution after the reaction are sampled and analyzed, and compared with the wet oxidation treatment results without using a catalyst to evaluate the degradation effect of the catalyst prepared by the present invention.

[0089] Among them, the initial sulfide concentration of gasoline alkali washing waste liquid is 13532 mg / L, petroleum is 2612 mg / L, and COD concentration is 197643 mg / L. The sulfide concentration is determined by iodine titration, petroleum is determined by non-dispersive infrared method, and COD is determined by potassium dichromate method. The results are shown in Table 5.

[0090] According to the experimental data in Table 5, the catalytic wet oxidation system shows significant performance advantages over the traditional wet oxidation system in treating pollutants in gasoline alkali washing wastewater. Under the experimental conditions of catalyst amount of 1.7 g / L, temperature of 170 ° C, and reaction time of 2.5 hours, the catalytic wet oxidation system has successfully achieved complete removal of sulfides, and the removal rates of petroleum and COD reached 69.95% and 75.95%, respectively. Compared with the traditional wet oxidation system under the same conditions, the removal rates increased by 41.54% and 40.13%, respectively. When the catalyst amount was further increased to 2.8 g / L, under the same reaction time and temperature conditions, the removal rates of petroleum and COD in the catalytic wet oxidation system increased to 80.45% and 82.06%, respectively. Compared with the traditional wet oxidation system, the removal rates increased by 52.04% and 46.24%, respectively. In addition, with the increase of reaction temperature, the removal efficiency of the catalytic wet oxidation system is further enhanced. Under the conditions of temperature of 190℃, catalyst amount of 2.8g / L and reaction time of 2.5 hours, the removal rates of petroleum and COD by the catalytic wet oxidation system reached 91.86% and 93.98% respectively. Compared with the traditional wet oxidation system at 170℃ under similar conditions, the removal rates were increased by 63.45% and 58.16% respectively.

[0091] Table 5 - Treatment effect of catalytic wet oxidation system on gasoline alkaline washing wastewater under different reaction conditions

[0092]

[0093]

[0094] Application Example 6:

[0095] The nano-multimetal magnetic catalytic material prepared in Example 3 was used for catalytic wet air oxidation treatment of gasoline caustic washing waste liquid.

[0096] The treatment method was as follows: 1000 mL of gasoline caustic washing waste liquid was added into a 2 L hydraulic lift reactor, and the catalytic material prepared in Example 3 was added. After sufficient mixing, the reaction system was sealed, and the catalytic wet air oxidation reaction was started at 150 - 195 °C. During the reaction process, continuous stirring was maintained, the oxygen partial pressure was maintained at 1.8 MPa, and the reaction temperature was controlled by a circulating condensed water system. After the reaction ended, the system was naturally cooled to room temperature. Subsequently, samples were taken to analyze the contents of sulfide, petroleum substances, and COD in the reaction solution, and a comparison was made with the wet air oxidation treatment results without using the catalyst to evaluate the degradation effect of the catalyst prepared in the present invention.

[0097] Among them, the initial sulfide concentration in the gasoline caustic washing waste liquid was 11965 mg / L, the petroleum substances were 2378 mg / L, and the COD concentration was 190127 mg / L. The sulfide concentration was measured by the iodometric method, the petroleum substances were measured by the non-dispersive infrared method, and the COD was measured by the potassium dichromate method. The measurement results are shown in Table 6.

[0098] According to the experimental data in Table 6, when using the catalytic wet air oxidation system to treat gasoline caustic washing waste liquid, it was significantly superior to the traditional wet air oxidation system without adding a catalyst in terms of pollutant removal efficiency. Specifically, under the conditions of a catalyst dosage of 0.65 g / L, a reaction temperature of 175 °C, and a reaction time of 2.5 hours, the catalytic wet air oxidation system almost completely removed the sulfide in the waste liquid, and at the same time, the removal rates of petroleum substances and COD reached 58.83% and 67.39% respectively. Compared with the traditional wet air oxidation system, they were increased by 27.79% and 28.32% respectively. When the catalyst dosage was increased to 2.85 g / L, under the same conditions, the removal rates of petroleum substances and COD by the catalytic wet air oxidation system were increased to 77.53% and 84.21% respectively. Compared with the traditional wet air oxidation system, they were increased by 37.28% and 45.14% respectively. In addition, when the catalyst dosage remained unchanged, by further increasing the reaction temperature of the catalytic wet air oxidation system, the pollutant removal rate would be further increased. For example, under the conditions of a catalyst dosage of 2.85 g / L, a temperature of 185 °C, and a reaction time of 2.5 hours, the removal rates of petroleum substances and COD by the catalytic wet air oxidation system were increased to 86.03% and 89.04% respectively; while under the conditions of a temperature of 195 °C and a reaction time of 2.5 hours, the removal rates of petroleum substances and COD by the catalytic wet air oxidation system were further increased to 94.95% and 96.57% respectively.

[0099] Table 6 - Treatment effect of catalytic wet air oxidation system on gasoline caustic washing waste liquid under different reaction conditions

[0100]

[0101]

[0102] By comprehensively analyzing Figures 1 to 6 , it can be found that due to the differences in the preparation processes, there are certain differences in the microstructures of the catalysts provided by the present invention. Specifically, Figure 1 and Figure 2 show the catalyst prepared in Example 1, which presents a micron-scale rod-like structure with a length between 1 and 10 microns, a width of about 0.5 to 1 micron, and some fine particles unevenly distributed on the surface of the micron rods. Figure 3 and Figure 4 present the catalyst prepared in Example 2, whose microstructure is also micron rod-like, and there are also small particles unevenly distributed on the micron rods. Figure 5 and Figure 6 reveal the catalyst prepared in Example 3, whose structure is also micron rod-like, and the fine particles are also unevenly distributed on the micron rods. Although there are differences in the microstructures of the catalysts, the catalysts of the present invention show stable treatment effects during the treatment process of gasoline caustic washing waste liquid. In practical applications, the catalyst can efficiently remove pollutants in the waste liquid, and the removal rates of sulfides, petroleum substances, and COD are all stable above 90%, significantly reducing the concentration of pollutants in the waste liquid, thereby effectively reducing the potential harm of such waste liquid to the environment.

[0103] The above is only the preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions falling within the idea of the present invention belong to the protection scope of the present invention. It should be noted that for those of ordinary skill in the art, several improvements and refinements made without departing from the principle of the present invention should be regarded as within the protection scope of the present invention.

Claims

1. A preparation method of a nano multi-metal magnetic catalytic wet oxidation catalytic material, characterized in that It includes the following steps: Mix zinc chloride, lead chloride, chloroplatinic acid, diamminedichloropalladium and sodium hydroxide with water and dissolve them to obtain a mixed solution A; Mix potassium aluminate, potassium silicate and sodium hydroxide with water and dissolve them to obtain a mixed solution B; Add 3-methacryloxypropyltrimethoxysilane to the mixed solution A and stir until the solution becomes clear to obtain a mixed solution C; Add cetyltrimethylammonium bromide to the mixed solution B and dissolve it to obtain a mixed solution D; Slowly mix the mixed solution C and the mixed solution D and stir until the solution becomes clear to obtain a reaction solution; Mix nano-ferroferric oxide with the reaction solution and carry out a hydrothermal reaction to obtain a nano-multimetal magnetic catalytic material.

2. The preparation method of the nano-multimetal magnetic catalytic wet oxidation catalytic material according to claim 1, wherein in the mixed solution A, the mass ratio of zinc chloride to lead chloride is 1:1.05 - 1.25, the mass ratio of zinc chloride to chloroplatinic acid is 1:0.75 - 0.95, the mass ratio of zinc chloride to diamminedichloropalladium is 1:0.65 - 0.85, the mass ratio of zinc chloride to sodium hydroxide is 1:1.5 - 3; the mass ratio of zinc chloride to water is 1:8 - 15.

3. The preparation method of the nano-multimetal magnetic catalytic wet oxidation catalytic material according to claim 1, wherein the mass-volume ratio of 3-methacryloxypropyltrimethoxysilane to the mixed solution A is 18 - 25 g:1 L.

4. The preparation method of the nano-multimetal magnetic catalytic wet oxidation catalytic material according to claim 1, wherein in the mixed solution B, the mass ratio of potassium aluminate to potassium silicate is 1:1.2 - 1.5, the mass ratio of potassium aluminate to sodium hydroxide is 1:1.8 - 2.2; the mass ratio of potassium aluminate to water is 1:10 - 20.

5. The preparation method of the nano-multimetal magnetic catalytic wet oxidation catalytic material according to claim 1, wherein the mass-volume ratio of cetyltrimethylammonium bromide to the mixed solution B is 0.045 - 0.080 g:1 L.

6. The preparation method of the nano-multimetal magnetic catalytic wet oxidation catalytic material according to claim 1, wherein the mixing mass ratio of the mixed solution C and the mixed solution D is 1:1.2 - 1.

8.

7. The preparation method of the nano-multimetal magnetic catalytic wet oxidation catalytic material according to claim 1, wherein the mass-volume ratio of the nano-ferroferric oxide to the reaction solution is 8 - 15 g:1 L; the hydrothermal reaction temperature is 160 - 180 °C, and the reaction time is 12 - 18 h.

8. The nano-multimetal magnetic catalytic wet oxidation catalytic material prepared by the method according to any one of claims 1 - 7.

9. The application of the catalytic material prepared by the method according to any one of claims 1 - 7 in the catalytic wet oxidation treatment of gasoline caustic washing waste liquid.

10. The application according to claim 9, wherein The application method is: Add the catalytic material to the gasoline caustic washing waste liquid and heat for reaction; The reaction temperature is 150 - 195 °C, the reaction time is 0.5 - 2.5 hours, and the dosage of the catalytic material in the spent lye of gasoline caustic washing is 0.60 - 2.85 g / L.

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