A catalytic wet oxidation catalytic material and a method for preparing the same

Abstract

The application discloses a catalytic wet oxidation catalytic material and a preparation method thereof. The catalytic wet oxidation catalytic material takes acid modified montmorillonite loaded with copper oxide and optional nano ferrous sulfide as a matrix layer, and the outer surface of the matrix layer is wrapped with an active layer which is alumina loaded with nano ferrous sulfide; the matrix layer and the active layer are in a core-shell structure; the weight of the copper oxide accounts for 2-10% of the weight of the catalytic material, and the weight of the nano ferrous sulfide accounts for 5-20% of the weight of the catalytic material. The application further provides a preparation method of the catalytic wet oxidation catalytic material. The catalytic material has excellent catalytic degradation capacity for organic pollutants when used for treating organic wastewater.

Description

Technical Field

[0001] This invention belongs to the field of catalytic materials technology, and in particular relates to a catalytic wet oxidation catalytic material and its preparation method. Background Technology

[0002] Addressing the challenge of degrading recalcitrant organic pollutants using conventional methods, advanced oxidation technologies (AOTs) have garnered increasing attention and become a hot research area due to their advantages such as strong oxidizing power, rapid reaction rate, and near-non-selectivity towards organic matter. AOTs primarily utilize free radicals with high oxidation potential and strong oxidizing properties, generated by oxidants such as hydrogen peroxide, ozone, percarbonate, and persulfate, to efficiently oxidize and degrade organic pollutants.

[0003] In advanced oxidation reactions, the activation of the oxidant requires the action of a catalytic material. Heterogeneous catalytic materials based on transition metals have attracted increasing attention, particularly molybdenum, cobalt, nickel, and copper-based catalysts with good activity. However, their high cost and secondary pollution caused by leaching limit their large-scale application. Researchers have found that using iron and iron-containing compounds as catalysts or supported catalyst active components offers advantages such as environmental friendliness and low cost, and is now considered a preferred activating material for advanced oxidation reactions.

[0004] CN202010287282.3 discloses a method for preparing and applying a clay mineral copper-based catalyst for catalytic wet oxidation, belonging to the fields of water treatment technology and environmental functional materials. The catalyst comprises the following components: clay minerals, with a content of 40 wt.%–80 wt.%; a forming agent, with a content of 10 wt.%–50 wt.%; alkaline earth metal oxides, with a content of 1 wt.%–20 wt.%; La₂O₃, with a content of 1 wt.%–20 wt.%; and CuO, with a content of 5 wt.%–30 wt.%. The clay mineral copper-based catalyst prepared using this invention utilizes the dispersing effect of clay minerals on the active component metal ions, which can further enhance the catalytic activity of the catalyst, achieving a phenol removal rate of over 95% and a TOC removal rate of over 85% for piperazine wastewater and triethylenediamine wastewater.

[0005] CN201210095369.6 discloses a method for pretreating nitrobenzene-containing wastewater using ferrous sulfide, belonging to the field of wastewater treatment technology. This invention involves crushing ferrous sulfide to a particle size of 50-60 mesh, exposing the fresh surface of the ferrous sulfide through water washing or acid washing, and then placing it in a reaction vessel. The reaction vessel is placed in an anaerobic or anoxic environment, allowing the ferrous sulfide to mix with the nitrobenzene wastewater. After a mixing and reaction for 60-180 minutes, the pretreatment of the nitrobenzene wastewater is completed. This invention uses inexpensive FeS to pretreat nitrobenzene-containing wastewater, is simple to operate, and has low cost. It achieves a highly efficient pretreatment effect of nitrobenzene in a short time, with a nitrobenzene removal rate of over 90%, significantly saving treatment costs. Summary of the Invention

[0006] To address the shortcomings of existing catalytic oxidation catalysts and their preparation methods, the core objective of this invention is to provide a catalytic wet oxidation catalytic material and its preparation method. The catalytic material uses acid-modified montmorillonite as the matrix material and exhibits excellent catalytic degradation ability for organic pollutants when used to treat wastewater containing organic matter.

[0007] I. This invention provides a catalytic wet oxidation catalyst material, wherein the catalytic wet oxidation catalyst material uses acid-modified montmorillonite loaded with copper oxide and optionally nano-ferrous sulfide as the matrix layer, and an active layer is wrapped on the outer surface of the matrix layer, the active layer being alumina loaded with nano-ferrous sulfide; the matrix layer and the active layer have a core-shell structure.

[0008] Furthermore, in the wet oxidation catalytic material according to the present invention, the weight of copper oxide is 2 to 10% of the weight of the catalytic material, and the weight of nano-ferrous sulfide is 5 to 20% of the weight of the catalytic material, based on the weight of the wet oxidation catalytic material.

[0009] Furthermore, in the wet oxidation catalytic material according to the present invention, the specific surface area of ​​the wet oxidation catalytic material is 120–600 m². 2 / g.

[0010] Furthermore, according to the catalytic wet oxidation catalytic material of the present invention, the catalytic wet oxidation catalytic material contains microporous-mesoporous composite channels, wherein the size of the microporous channels is 0.2-2 nm, and the pore volume of the microporous channels accounts for 50-80% of the total pore volume; the size of the mesoporous channels is 2-25 nm, and the pore volume of the mesoporous channels accounts for 20-50% of the total pore volume.

[0011] Furthermore, according to the catalytic wet oxidation catalytic material of the present invention, the weight of the substrate layer is 70-90% of the weight of the catalytic material, and the weight of the active layer is 10-30% of the weight of the catalytic material, based on the weight of the catalytic wet oxidation catalytic material.

[0012] II. This invention also provides a method for preparing a catalytic wet oxidation catalyst, the method comprising the following steps:

[0013] (1) Modified montmorillonite was obtained by acid washing pretreatment with inorganic acid, followed by separation, washing and drying.

[0014] (2) The modified montmorillonite, copper precursor and additive A obtained in step (1) are mixed and then shaped, dried and calcined to obtain the carrier precursor;

[0015] (3) The carrier precursor obtained in step (2) is mixed with gelatin solution and then heat-treated to obtain a pretreated carrier precursor;

[0016] (4) Mix the aluminum-containing compound, additive B and the pretreated carrier precursor obtained in step (3), then introduce ammonium carbonate solution and mix well. The reaction is carried out at pH 7-9. After evaporation, washing, drying and calcination, catalytic precursor A is obtained.

[0017] (5) Mix the soluble ferrous salt solution and polysaccharide compound under an inert atmosphere, and then introduce the catalytic precursor obtained in step (4) to obtain catalytic precursor B;

[0018] (6) Under an inert atmosphere, the catalyst precursor B obtained in step (4), the sulfur-containing compound solution, and the surfactant are mixed and reacted at 60-80°C and pH 6-8. The catalyst material is then obtained by evaporation, drying, and calcination.

[0019] Furthermore, according to the preparation method of the catalytic wet oxidation catalytic material of the present invention, the montmorillonite in step (1) has a specific surface area of ​​25-150 m². 2 / g, pore volume 0.1~0.3cm³ 3 / g, with an average pore size of 1.8–2.4 nm.

[0020] Furthermore, according to the preparation method of the catalytic wet oxidation catalytic material of the present invention, the inorganic acid in step (1) is selected from at least one of hydrochloric acid, nitric acid, phosphoric acid, and sulfuric acid, and the molar concentration of the inorganic acid is 0.4 to 3.0 mol / L.

[0021] Furthermore, according to the preparation method of the catalytic wet oxidation catalytic material of the present invention, the process of pre-treating montmorillonite with inorganic acid in step (1) is to add montmorillonite to an inorganic acid solution for impregnation treatment, and then further wash the separated solid material with water until the filtrate is neutral and then dry it.

[0022] Furthermore, according to the preparation method of the catalytic wet oxidation catalytic material of the present invention, the drying temperature in step (1) is 70-120°C and the drying time is 3-12h; preferably the drying temperature is 80-110°C and the drying time is 4-8h.

[0023] Furthermore, according to the preparation method of the catalytic wet oxidation catalytic material of the present invention, the copper precursor in step (2) can be one or more of copper chloride, copper nitrate, copper sulfate, copper acetate, and copper oxide, preferably copper nitrate.

[0024] Furthermore, according to the preparation method of the catalytic wet oxidation catalytic material of the present invention, the auxiliary agent A in step (2) can be at least one of di-n-propylamine, diisopropylamine, tetraethylammonium bromide, and tetrapropylammonium bromide.

[0025] Furthermore, according to the preparation method of the catalytic wet oxidation catalytic material of the present invention, the mass ratio of acid-modified montmorillonite, copper precursor and auxiliary agent A in step (2) is 30-44:1.0-16:1.5-9.0.

[0026] Furthermore, according to the preparation method of the catalytic wet oxidation catalytic material of the present invention, the molding in step (2) can be any one of toothed sphere, sphere, irregular particle, clover, four-leaf clover and cylindrical.

[0027] Furthermore, according to the preparation method of the catalytic wet oxidation catalytic material of the present invention, the drying temperature in step (2) is 70-120°C and the drying time is 3-12h; preferably the drying temperature is 80-110°C and the drying time is 4-8h.

[0028] Furthermore, according to the preparation method of the catalytic wet oxidation catalytic material of the present invention, the calcination temperature in step (2) is 500-900℃ and the calcination time is 2-8h; preferably, the calcination temperature is 600-800℃ and the calcination time is 3-6h.

[0029] Furthermore, according to the preparation method of the catalytic wet oxidation catalytic material of the present invention, the heat treatment conditions in step (3) are: heat treatment temperature of 50-120℃ and treatment time of 3-12h; preferably, heat treatment temperature of 70-90℃ and treatment time of 4-6h.

[0030] Furthermore, according to the preparation method of the catalytic wet oxidation catalytic material of the present invention, the gelatin content in the gelatin solution in step (3) is 0.2wt% to 3.0wt%, and the volume of the gelatin solution is 0.7 to 1.0 times the water absorption volume of montmorillonite. The mixing treatment of the carrier precursor and the gelatin solution can be carried out under ultrasonic conditions, the ultrasonic conditions are 40kHz, and the treatment time is 0.2 to 2h.

[0031] Furthermore, according to the preparation method of the catalytic wet oxidation catalytic material of the present invention, wherein the auxiliary agent B in step (4) is at least one of polyethylene glycol, polyethylene glycol-polypropylene glycol-polyethylene glycol triblock polymer, dodecyltrimethylammonium bromide, hexadecyltrimethylammonium bromide, octadecyltrimethylammonium bromide, lauric acid, stearic acid and fatty alcohol polyoxyethylene ether, preferably polyethylene glycol, and further, the molecular weight of polyethylene glycol is 2000 to 8000.

[0032] Furthermore, according to the preparation method of the catalytic wet oxidation catalytic material of the present invention, the aluminum-containing compound in step (4) is at least one of aluminum nitrate, aluminum chloride, and aluminum sulfate, preferably aluminum nitrate.

[0033] Furthermore, according to the preparation method of the catalytic wet oxidation catalytic material of the present invention, the molar ratio of aluminum-containing compound to ammonium carbonate is 1:1 to 2, and the concentration of polyethylene glycol is 0.1wt% to 2.5wt%.

[0034] Furthermore, according to the preparation method of the catalytic wet oxidation catalytic material of the present invention, the reaction time in step (4) is 12 to 36 hours, and there is no particular limitation on the reaction temperature, which can be carried out at 15 to 35°C.

[0035] Furthermore, according to the preparation method of the catalytic wet oxidation catalytic material of the present invention, the evaporation in step (4) is carried out at 50-100°C for 24-48 hours.

[0036] Furthermore, according to the preparation method of the catalytic wet oxidation catalytic material of the present invention, the washing in step (4) is water washing, preferably using distilled water at a temperature of 70-95°C for several washes, specifically 2-4 washes.

[0037] Furthermore, according to the preparation method of the catalytic wet oxidation catalytic material of the present invention, the drying temperature in step (4) is 70-120°C and the drying time is 3-12h; preferably the drying temperature is 80-110°C and the drying time is 4-8h.

[0038] Furthermore, according to the preparation method of the catalytic wet oxidation catalytic material of the present invention, the calcination in step (4) is carried out at 400-750°C for 3-8 hours.

[0039] Furthermore, according to the preparation method of the catalytic wet oxidation catalytic material of the present invention, the soluble ferrous salt in step (5) can be selected from one or more mixtures of ferrous sulfate, ferrous chloride, ferrous acetate, ferrous lactate, ferrous gluconate, and ferrous glycinate.

[0040] Furthermore, according to the preparation method of the catalytic wet oxidation catalytic material of the present invention, the polysaccharide compound in step (5) is cellulose and / or starch, wherein the cellulose can be at least one of hydroxypropyl methylcellulose, carboxymethyl cellulose, methylcellulose, and ethylcellulose; and the starch can be at least one of corn starch, potato starch, and sweet potato starch.

[0041] Furthermore, according to the preparation method of the catalytic wet oxidation catalytic material of the present invention, the sulfur-containing compound in step (6) is selected from at least one of sodium sulfide and thioacetamide (CH3CSNH2).

[0042] Furthermore, according to the preparation method of the catalytic wet oxidation catalytic material of the present invention, the surfactant in step (6) is at least one of the Tween series surfactants and the Span series surfactants. Specifically, the Tween series surfactants can be at least one of Tween 20, Tween 40, Tween 60 and Tween 80; the Span series surfactants can be at least one of Span 20, Span 40, Span 60 and Span 80.

[0043] Furthermore, according to the preparation method of the catalytic wet oxidation catalytic material of the present invention, the evaporation in step (6) can be one of rotary evaporation and water bath heating evaporation.

[0044] Furthermore, according to the preparation method of the catalytic wet oxidation catalytic material of the present invention, the drying temperature in step (6) is 50-100°C and the drying time is 3-8h; preferably the drying temperature is 70-80°C and the drying time is 4-6h.

[0045] Furthermore, according to the preparation method of the catalytic wet oxidation catalytic material of the present invention, the calcination in step (6) is carried out under anaerobic conditions, the calcination temperature is 300-700℃, and the calcination time is 2-8h; preferably, the calcination temperature is 400-600℃ and the calcination time is 3-4h.

[0046] III. The present invention provides a catalytic wet oxidation catalytic material obtained by the above preparation method.

[0047] IV. The present invention provides a wastewater treatment process in which wastewater, oxidant and the catalytic wet oxidation material provided above or the catalytic wet oxidation material obtained by the above preparation method are brought into contact and reacted.

[0048] Furthermore, according to the wastewater treatment process of the present invention, the wastewater is wastewater containing organic pollutants, specifically selected from chemical wastewater, municipal wastewater, pharmaceutical wastewater, and dyeing and printing wastewater.

[0049] Furthermore, according to the wastewater treatment process of the present invention, the oxidant is one of ozone, hydrogen peroxide, persulfate, sodium hypochlorite, percarbonate, permanganate, and ferrate.

[0050] Furthermore, according to the wastewater treatment process of the present invention, the reaction can be carried out at room temperature, and the volume hourly space velocity is generally controlled at 0.2–3 h⁻¹. -1 The amount of oxidant added should be more than 0.5 times the theoretical amount of oxidant required for the wastewater.

[0051] Compared with the prior art, the catalytic wet oxidation catalytic material and its preparation method described in this invention have the following characteristics:

[0052] The preparation method of this invention uses montmorillonite as the inner layer support, which has the advantages of easy modification and easy molding. After the auxiliary components are calcined, micropores are formed, which can effectively adsorb and enrich pollutant molecules, improve the driving force of the reaction, and have better catalytic effect. The outer layer support of the catalyst is designed as a mesoporous material, which can provide reaction space for large organic molecules and allow small molecule pollutants to enter the inner catalytic matrix for reaction, reducing the limitation of pollutant diffusion.

[0053] The catalyst of this invention is designed as a two-stage catalysis. During the reaction, the oxidant and pollutant molecules first react with the outer ferrous sulfide to consume a portion of them. The concentrations of oxidant and organic pollutants that pass through the mesoporous channels and come into contact with copper oxide have been reduced. At this point, they undergo a catalytic reaction with copper oxide, which has a higher activation capacity, to deeply treat and degrade the pollutants.

[0054] This invention first loads copper oxide as the active component, followed by ferrous sulfide as the active component. This allows copper ions, upon dissolving from the inner layer, to react with the ferrous sulfide, undergoing a displacement reaction to form less soluble copper sulfide, while simultaneously generating ferrous ions. Therefore, this catalyst effectively reduces copper ion dissolution, preventing secondary pollution. Furthermore, the copper sulfide and ferrous ions generated by the in-situ displacement reaction are also excellent catalytic oxidation catalysts, maintaining the catalyst's long-term effectiveness. Detailed Implementation

[0055] The preparation method of the present invention will be further illustrated below with reference to specific embodiments, but the scope of the present invention is not limited to the scope of these embodiments.

[0056] In this paper, the ultrasonic conditions were 40 kHz frequency and 150 W power.

[0057] Example 1

[0058] Preparation of catalyst A1: Modified montmorillonite was obtained by soaking montmorillonite in 2.0 mol / L hydrochloric acid for 4 h, washing it with distilled water, and drying it at 110 °C for 6 h. Weigh 72g of modified montmorillonite and mix it with copper chloride and tetrapropylammonium bromide in a mass ratio of 36.0:12.5:2.5. Add water, knead, and extrude into a cylindrical shape. Place the sample in an oven at 110℃ to dry the moisture, and then calcine it in a muffle furnace at 650℃ for 4 hours to obtain material I. Measure 25ml of a 2.0% gelatin solution and pour it into material I. Sonicate and vibrate for 1 hour, then dry at 80℃ for 4 hours to obtain material II. Dissolve aluminum nitrate in 180ml of water to prepare a 1.3mol / L solution, then add 2.0g of polyethylene glycol to fully dissolve it to form a mixed solution. Immerse material II in this solution. After complete immersion, add 100ml of a 3.5mol / L ammonium carbonate solution. Adjust the pH of the reaction system to 7.5 with ammonia. After reacting at room temperature (25℃, the same below) for 26 h, the mixture was evaporated at a constant temperature of 68℃ for 36 h, washed with hot water at 80℃, dried at 80℃, and then calcined in a muffle furnace at 550℃ for 4 h to obtain material III. Ferrous sulfate was dissolved in 120 ml of water to prepare a 0.9 mol / L solution. Under nitrogen protection, 0.2 g of methylcellulose was added and stirred evenly. Material III was then immersed in this solution for thorough impregnation. Under inert gas protection, 0.03 g of Tween 40 was added to a 1.14 mol / L sodium sulfide solution and mixed evenly. This mixture was then slowly added to the solution containing material III. The pH of the system was adjusted to 7.0, and the reaction was carried out at 75℃ for 1.6 h. After rotary evaporation, the mixture was vacuum dried at 75℃ to remove moisture, and then calcined at 450℃ for 3 h in a nitrogen atmosphere to obtain catalyst A1.

[0059] Example 2

[0060] Preparation of catalyst A2: Modified montmorillonite was obtained by immersing montmorillonite in 3.0 mol / L hydrochloric acid for 2 h, washing with distilled water, and drying at 80℃ for 8 h. 75 g of modified montmorillonite was weighed and mixed according to the following ratio: montmorillonite: copper oxide: Dipropylamine was mixed in a mass ratio of 37.5:4.0:3.5, water was added, and the mixture was kneaded and extruded into a clover shape. The sample was dried in an oven at 100°C, and then calcined in a muffle furnace at 680°C for 3 hours to obtain material I. 22 ml of a 1.1% gelatin solution was added to material I, sonicated for 1 hour, and then dried at 90°C for 6 hours to obtain material II. Aluminum nitrate was dissolved in 150 ml of water to prepare a 1.7 mol / L solution, and then an ethanol solution containing 2.2 g of stearic acid was added and stirred thoroughly to form a mixed solution. Material II was immersed in this solution, and after complete immersion, 150 ml of a 2.6 mol / L ammonium carbonate solution was added dropwise. The pH of the reaction system was adjusted to 8.5 with ammonia water, and the reaction was carried out at room temperature. After 20 hours, the mixture was evaporated at a constant temperature of 70℃ for 32 hours, washed with hot water at 85℃, dried at 90℃, and then calcined in a muffle furnace at 650℃ for 3 hours to obtain material III. Ferrous acetate was dissolved in 120 ml of water to prepare a 0.5 mol / L solution. Under nitrogen protection, 0.1 g of corn starch was added and stirred evenly. Material III was then immersed in this solution for thorough impregnation. Under inert gas protection, 0.01 g of Tween 80 was added to a 0.4 mol / L thioacetamide solution and mixed evenly. This mixture was then slowly added to the solution containing material III. The pH of the system was adjusted to 6.8, and the reaction was carried out at 78℃ for 1.0 h. After removing moisture by rotary evaporation, the mixture was vacuum dried at 80℃ and then calcined at 400℃ for 3 hours under a nitrogen atmosphere to obtain catalyst A2.

[0061] Example 3

[0062] Preparation of catalyst A3: Modified montmorillonite was obtained by immersing montmorillonite in 1.5 mol / L sulfuric acid for 5 h, washing with distilled water, and drying at 90 °C for 8 h. 76 g of modified montmorillonite was weighed and mixed according to a mass ratio of montmorillonite:copper sulfate:tetrapropylammonium bromide of 38.0:9.1:9.0. Water was added, the mixture was kneaded, and extruded into a four-leaf clover shape. The sample was dried in an oven at 85 °C and then calcined in a muffle furnace at 720 °C for 6 h to obtain material I. 20 ml of a 1.5% gelatin solution was added to material I, ultrasonicated for 1.5 h, and then dried at 85 °C for 5 h to obtain material II. Aluminum nitrate was dissolved in 120 ml of water to prepare a 1.3 mol / L solution, and 1.5 g of polyethylene glycol was added to fully dissolve it to form a mixed solution. Material II was immersed in this solution. After complete immersion, 50 ml of a 4.4 mol / L ammonium carbonate solution was added dropwise. The reaction mixture was then rinsed with ammonia water. The pH of the system was adjusted to 8.7, and after reacting at room temperature for 26 hours, it was evaporated at 75℃ for 38 hours. After washing with hot water at 80℃, it was dried at 90℃ and then calcined at 680℃ for 3 hours to obtain material III. Ferrous chloride was dissolved in 100 ml of water to prepare a 1.0 mol / L solution. Under nitrogen protection, 0.1 g of carboxymethyl cellulose was added and stirred evenly. Material III was then immersed in this solution for thorough impregnation. Under nitrogen protection, 0.02 g of Span 60 was added to a 0.7 mol / L sodium sulfide solution and mixed evenly. This mixture was then slowly added to the solution containing material III. The pH of the system was adjusted to 7.2, and the reaction was carried out at 65℃ for 2 hours. After rotary evaporation, it was dried under vacuum at 80℃ and then calcined at 400℃ for 4 hours under a nitrogen atmosphere to obtain catalyst A3.

[0063] Example 4

[0064] Preparation of Catalyst A4: Modified montmorillonite was obtained by immersing montmorillonite in 2.5 mol / L hydrochloric acid for 2 h, washing with distilled water, and drying at 100℃ for 7 h. 72 g of modified montmorillonite was weighed and mixed according to a mass ratio of montmorillonite:copper acetate:tetraethylammonium bromide of 36.0:7.6:6.5. Water was added, the mixture was kneaded, and extruded into a cylindrical shape. The sample was dried in an oven at 90℃ and then calcined in a muffle furnace at 600℃ for 4 h to obtain material I. 25 ml of a 1.3% gelatin solution was added to material I, and the mixture was ultrasonically vibrated for 2 h. It was then dried at 80℃ for 5 h to obtain material II. Aluminum nitrate was dissolved in 200 ml of water to prepare a 1.9 mol / L solution. 3.0 g of polyethylene glycol was added and dissolved completely to form a mixed solution. Material II was immersed in this solution. After complete immersion, 50 ml of a 4.4 mol / L ammonium carbonate solution was added dropwise. The reaction system was then diluted with ammonia water. The pH value was adjusted to 8, and the mixture was reacted at room temperature for 28 hours. Then, it was rotary evaporated at 75°C for 30 hours, washed with hot water at 85°C, dried at 90°C, and calcined in a muffle furnace at 620°C for 6 hours to obtain material III. Ferrous sulfate was dissolved in 120 ml of water to prepare a 0.7 mol / L solution. Under nitrogen protection, 0.2 g of corn starch was added and stirred until homogeneous. Material III was then immersed in this solution for thorough impregnation. Under inert gas protection, 0.01 g of Span 80 was added to a 0.85 mol / L sodium sulfide solution and mixed thoroughly. This mixture was then slowly added to the solution containing material III. The pH value of the system was adjusted to 7.5, and the mixture was reacted at 70°C for 1.6 hours. After rotary evaporation, it was vacuum dried at 70°C for 6 hours and then calcined at 450°C for 3 hours under nitrogen atmosphere to obtain catalyst A4.

[0065] Example 5

[0066] Preparation of catalyst A5: Modified montmorillonite was obtained by immersing montmorillonite in 2.3 mol / L nitric acid for 3 h, washing with distilled water, and drying at 110 °C for 6 h. 68 g of modified montmorillonite was weighed and mixed according to a mass ratio of montmorillonite:copper nitrate:diisopropylamine of 34.0:3.7:4.5. Water was added, the mixture was kneaded, and extruded into cylindrical shapes. The samples were dried in an oven at 85 °C and then calcined in a muffle furnace at 650 °C for 4 h to obtain material I. 23 ml of a 1.0% gelatin solution was added to material I, ultrasonicated for 1 h, and then dried at 90 °C for 4 h to obtain material II. Aluminum nitrate was dissolved in 150 ml of water to prepare a 1.3 mol / L solution. 1.8 g of hexadecyltrimethylammonium bromide was added and dissolved completely to form a mixed solution. Material II was immersed in this solution. After complete immersion, 100 ml of a 3.5 mol / L ammonium carbonate solution was added dropwise. The pH of the reaction system was adjusted using ammonia water. The pH was adjusted to 7.8, and the mixture was reacted at room temperature for 28 hours. Then, it was rotary evaporated at 85°C for 30 hours, washed with hot water at 85°C, dried at 95°C, and calcined at 650°C for 4 hours to obtain material III. Ferrous chloride was dissolved in 150 ml of water to prepare a 1.1 mol / L solution. Under nitrogen protection, 0.2 g of hydroxypropyl methylcellulose was added and stirred until homogeneous. Material III was then immersed in this solution for thorough impregnation. Under nitrogen protection, 0.03 g of Span 40 was added to a 2.0 mol / L thioacetamide solution and mixed thoroughly. This mixture was then slowly added to the solution containing material III. The pH was adjusted to 7.5, and the mixture was reacted at 75°C for 1.4 hours. After rotary evaporation, it was vacuum dried at 78°C for 6 hours and then calcined at 400°C for 3 hours under a nitrogen atmosphere to obtain catalyst A5.

[0067] Comparative Example 1

[0068] Preparation of catalyst B1: 100g of cylindrical activated carbon was weighed, and copper sulfate was used as the copper source to impregnate the activated carbon carrier. The loading of copper oxide active component was 4%. The sample was dried at 80℃ for 8h and then calcined in a muffle furnace at 600℃ for 4h to obtain material B1.

[0069] Comparative Example 2

[0070] Preparation of catalyst B2: Repeat the preparation process of catalyst A1, but do not impregnate the copper-containing matrix with gelatin solution after obtaining material I. The remaining steps are the same to obtain catalyst B2.

[0071] Comparative Example 3

[0072] Preparation of catalyst B3: Montmorillonite was soaked in 1.5 mol / L sulfuric acid for 5 h, washed with distilled water, dried at 90 °C for 8 h, and then calcined at 500 °C for 4 h to obtain modified montmorillonite. Weigh 76g of modified montmorillonite and mix it with tetrapropylammonium bromide at a mass ratio of 10.8:3.0. Add water, knead, and extrude into a four-leaf clover shape. Place the sample in an oven at 75℃ to dry the moisture, and then calcine it in a muffle furnace at 520℃ for 6 hours to obtain material I. Measure 20ml of a 1.5% gelatin solution and pour it into material I. Sonicate the mixture for 1.5 hours, then dry it at 85℃ for 5 hours to obtain material II. Dissolve aluminum nitrate in 120ml of water to prepare a 1.3mol / L solution, then add 1.5g of polyethylene glycol to fully dissolve it to form a mixed solution. Immerse material II in this solution. After complete immersion, add 50ml of a 4.4mol / L ammonium carbonate solution. Adjust the pH of the reaction system to 8.7 with ammonia. React at room temperature for 26 hours, then evaporate at 75℃ for 38 hours. Use 80... After washing with hot water at ℃, the sample was dried at 90℃ and then calcined at 680℃ for 3 hours to obtain material III. Material III was added to a copper chloride solution for impregnation at a copper oxide to montmorillonite mass ratio of 10.8:3.1. The sample was dried at 80℃ for 5 hours and then calcined at 500℃ for 4 hours in a muffle furnace to obtain material IV. Ferrous chloride was dissolved in 100 ml of water to prepare a 1.0 mol / L solution. Under nitrogen protection, 0.1 g of carboxymethyl cellulose was added and stirred evenly. Material IV was then immersed in this solution for thorough impregnation. Under nitrogen protection, 0.02 g of Span 60 was added to a 0.7 mol / L sodium sulfide solution and mixed evenly. This mixture was then slowly added to the solution containing material III. The pH of the system was adjusted to 7.2, and the reaction was carried out at 65℃ for 2 hours. After rotary evaporation, the mixture was vacuum dried at 80℃ and then calcined at 400℃ for 4 hours under a nitrogen atmosphere to obtain catalyst B3.

[0073] Comparative Example 4

[0074] Preparation of catalyst B4: Weigh 40g of commercially available clover-shaped SBA-15 support, dissolve ferrous sulfate in 120ml of oxygen-free water to prepare a 0.7mol / L solution, add 0.2g of corn starch under nitrogen protection and stir well, then immerse the support in the solution for thorough impregnation; under inert gas protection, add 0.01g of Span 80 to a 0.85mol / L sodium sulfide solution and mix well, then slowly add to the solution containing the support, adjust the pH of the system to 7.5, react at 70℃ for 1.6h, rotary evaporate, vacuum dry at 85℃ for 5h, and then calcine at 450℃ for 3h under nitrogen atmosphere to obtain catalyst B4.

[0075] Example 6

[0076] Fill a cylindrical plexiglass reactor with 60cm of [material / material]. 3Catalyst A1 was introduced into the wastewater containing scarlet dye with an initial TOC of approximately 103 mg / L from the bottom pipe, with a space velocity of 1 h⁻¹. -1 Ozone was introduced as an oxidant at a dosage of 450 mg / L. After the TOC in the effluent stabilized, the TOC removal rate was measured to be 86%. The copper ion concentrations in the effluent are shown in Table 1.

[0077] Example 7

[0078] Fill a cylindrical plexiglass reactor with 50cm of [material / material]. 3 Catalyst A2 was introduced into the bottom pipe into methylene blue dye wastewater with an initial TOC of approximately 87 mg / L. The pH of the wastewater was adjusted to 3.2 with sulfuric acid, and the space velocity was 0.5 h⁻¹. -1 Hydrogen peroxide was introduced as an oxidant at a dosage of 500 mg / L. After the TOC in the effluent stabilized, the TOC removal rate was measured, and the removal rate was 87%. The copper ion concentrations in the effluent are shown in Table 1.

[0079] Example 8

[0080] Fill a cylindrical plexiglass reactor with 100cm of water. 3 Catalyst A3 was introduced into pharmaceutical wastewater with an initial TOC of approximately 53 mg / L through the bottom inlet at a space velocity of 2.0 h⁻¹. -1 Sodium persulfate and ozone were introduced as oxidants at dosages of 500 mg / L and 80 mg / L, respectively. After the TOC in the effluent stabilized, the TOC removal rate was measured at 78%. The copper ion concentrations in the effluent are shown in Table 1.

[0081] Example 9

[0082] Fill a cylindrical plexiglass reactor with 80cm of [material / material]. 3 Catalyst A4 was introduced into chemical wastewater with an initial TOC of approximately 219 mg / L through the bottom inlet at a space velocity of 0.4 h⁻¹. -1 Sodium persulfate and hydrogen peroxide were introduced as oxidants at dosages of 2000 mg / L and 150 mg / L, respectively. After the TOC in the effluent stabilized, the TOC removal rate was measured at 67%. The copper ion concentrations in the effluent are shown in Table 1.

[0083] Example 10

[0084] Fill a cylindrical plexiglass reactor with 100cm of water. 3 Catalyst A5 was introduced from the bottom of the pipe into municipal wastewater with an initial TOC of approximately 1036 mg / L at a space velocity of 0.5 h⁻¹. -1 Ozone was introduced as an oxidant at a dosage of 3000 mg / L. After the TOC in the effluent stabilized, the TOC removal rate was measured at 65%. The copper ion concentrations in the effluent are shown in Table 1.

[0085] Comparative Example 5

[0086] Example 6 was repeated, but the catalyst was replaced with B1, and the TOC removal rate reached 77%. The copper ion values ​​in the effluent are shown in Table 1.

[0087] Comparative Example 6

[0088] Example 3 was repeated, but the catalyst was changed to B2, and the TOC removal rate reached 70%. The copper ion values ​​in the effluent are shown in Table 1.

[0089] Comparative Example 7

[0090] Example 5 was repeated, but the catalyst was changed to B3, and the TOC removal rate reached 56%. The copper ion values ​​in the effluent are shown in Table 1.

[0091] Comparative Example 8

[0092] Repeat Example 2, but replace the catalyst with B4, and the TOC removal rate reaches 75%.

[0093] Table 1. Amount of copper ions dissolved in the reaction water

[0094] Example 6 Example 7 Example 8 Example 9 Example 10 Comparative Example 5 Comparative Example 6 Comparative Example 7 Cu μg / L 108 326 119 77 124 1588 355 1988

Claims

1. A catalytic wet oxidation catalyst, wherein the catalytic wet oxidation catalyst uses acid-modified montmorillonite supported on copper oxide and optionally nano-ferrous sulfide as a matrix layer, and an active layer is coated on the outer surface of the matrix layer, the active layer being alumina supported on nano-ferrous sulfide; the matrix layer and the active layer have a core-shell structure; based on the weight of the catalytic wet oxidation catalyst, the weight of copper oxide is 2-10% of the weight of the catalyst, and the weight of nano-ferrous sulfide is 5-20% of the weight of the catalyst; the catalytic wet oxidation catalyst contains microporous-mesoporous composite channels, wherein the size of the microporous channels is 0.2-2 nm, and the pore volume of the microporous channels accounts for 50-80% of the total pore volume; the size of the mesoporous channels is 2-25 nm, and the pore volume of the mesoporous channels accounts for 20-50% of the total pore volume; the specific surface area of ​​the catalytic wet oxidation catalyst is 120-600 m². 2 / g; Micropores are distributed in the matrix layer, and mesopores are distributed in the active layer.

2. The catalytic wet oxidation catalyst material according to claim 1, wherein, Based on the weight of the catalytic material for wet oxidation, the weight of the substrate layer is 70-90% of the weight of the catalytic material, and the weight of the active layer is 10-30% of the weight of the catalytic material.

3. A method for preparing a catalytic wet oxidation catalyst, the method comprising the following steps: (1) Modified montmorillonite was obtained by acid washing and pretreatment with inorganic acid, followed by separation and drying. (2) The modified montmorillonite, copper precursor and additive A obtained in step (1) are mixed and then shaped, dried and calcined to obtain the carrier precursor. Additive A is at least one of di-n-propylamine, diisopropylamine, tetraethylammonium bromide and tetrapropylammonium bromide. (3) The carrier precursor obtained in step (2) is mixed with gelatin solution and then heat-treated to obtain a pretreated carrier precursor; (4) Mix the aluminum-containing compound, additive B, and the pretreated carrier precursor obtained in step (3), then introduce the ammonium carbonate solution and mix. React at pH 7-9. After evaporation, washing, drying and calcination, catalytic precursor A is obtained. Additive B is at least one of polyethylene glycol, polyethylene glycol-polypropylene glycol-polyethylene glycol triblock polymer, dodecyltrimethylammonium bromide, hexadecyltrimethylammonium bromide, octadecyltrimethylammonium bromide, lauric acid, stearic acid and fatty alcohol polyoxyethylene ether. (5) Mix the soluble ferrous salt solution and the polysaccharide compound under an inert atmosphere, and then introduce the catalytic precursor A obtained in step (4) to obtain catalytic precursor B; the polysaccharide compound is cellulose and / or starch; (6) Under an inert atmosphere, the catalyst precursor B obtained in step (5), the sulfur-containing compound solution, and the surfactant are mixed and reacted at 60-80°C and pH 6-8. The catalyst material is then obtained by evaporation, drying, and calcination.

4. The method for preparing the catalytic wet oxidation catalyst material according to claim 3, wherein, The specific surface area of ​​the montmorillonite in step (1) is 25–150 m². 2 / g, pore volume 0.1~0.3cm³ 3 / g, with an average pore size of 1.8–2.4 nm.

5. The method for preparing the catalytic wet oxidation catalyst according to claim 3, wherein, The inorganic acid in step (1) is selected from at least one of hydrochloric acid, nitric acid, phosphoric acid, and sulfuric acid, and the molar concentration of the inorganic acid is 0.4 to 3.0 mol / L.

6. The method for preparing the catalytic wet oxidation catalyst material according to claim 3, wherein, The copper precursor in step (2) is one or more of copper chloride, copper nitrate, copper sulfate, copper acetate, and copper oxide.

7. The method for preparing the catalytic wet oxidation catalyst according to claim 3 or 6, wherein, The copper precursor in step (2) is copper nitrate.

8. The method for preparing the catalytic wet oxidation catalyst material according to claim 3, wherein, The drying temperature in step (1) is 70-120℃ and the drying time is 3-12h.

9. The method for preparing the catalytic wet oxidation catalyst material according to claim 3, wherein, The drying temperature in step (1) is 80-110℃ and the drying time is 4-8h.

10. The method for preparing the catalytic wet oxidation catalyst material according to claim 3, wherein, The mass ratio of modified montmorillonite, copper precursor and additive A in step (2) is 30-44:1.0-16:1.5-9.

0.

11. The method for preparing the catalytic wet oxidation catalyst material according to claim 3, wherein, The drying temperature in step (2) is 70-120℃ and the drying time is 3-12h.

12. The method for preparing the catalytic wet oxidation catalyst material according to claim 3, wherein, The drying temperature in step (2) is 80-110℃ and the drying time is 4-8h.

13. The method for preparing the catalytic wet oxidation catalytic material according to claim 3, wherein, The roasting temperature in step (2) is 500-900℃ and the roasting time is 2-8h.

14. The method for preparing the catalytic wet oxidation catalyst material according to claim 3, wherein, The roasting temperature in step (2) is 600-800℃ and the roasting time is 3-6h.

15. The method for preparing the catalytic wet oxidation catalyst material according to claim 3, wherein, The gelatin content in the gelatin solution in step (3) is 0.2wt% to 3.0wt%.

16. The method for preparing the catalytic wet oxidation catalyst material according to claim 3, wherein, In step (4), the auxiliary agent B is polyethylene glycol, with a molecular weight of 2000 to 8000.

17. The method for preparing the catalytic wet oxidation catalyst material according to claim 3, wherein, The aluminum-containing compound in step (4) is at least one of aluminum nitrate, aluminum chloride, and aluminum sulfate.

18. The method for preparing the catalytic wet oxidation catalyst material according to claim 3, wherein, The aluminum-containing compound in step (4) is aluminum nitrate.

19. The method for preparing the catalytic wet oxidation catalyst material according to claim 3, wherein, The molar ratio of aluminum-containing compound to ammonium carbonate is 1:1 to 2, and the concentration of polyethylene glycol is 0.1wt% to 2.5wt%.

20. The method for preparing the catalytic wet oxidation catalyst material according to claim 3, wherein, The evaporation in step (4) is carried out at 50-100℃ for 24-48 hours.

21. The method for preparing the catalytic wet oxidation catalyst material according to claim 3, wherein, The drying temperature in step (4) is 70-120℃ and the drying time is 3-12h.

22. The method for preparing the catalytic wet oxidation catalytic material according to claim 3, wherein, The drying temperature in step (4) is 80-110℃ and the drying time is 4-8h.

23. The method for preparing the catalytic wet oxidation catalytic material according to claim 3, wherein, The roasting in step (4) is carried out at 400-750℃ for 3-8 hours.

24. The method for preparing the catalytic wet oxidation catalyst material according to claim 3, wherein, The soluble ferrous salt in step (5) is selected from one or more of ferrous sulfate, ferrous chloride, ferrous acetate, ferrous lactate, ferrous gluconate, and ferrous glycinate.

25. The method for preparing the catalytic wet oxidation catalyst material according to claim 3, wherein, In step (5), the cellulose is at least one of hydroxypropyl methylcellulose, carboxymethylcellulose, methylcellulose, and ethylcellulose; and the starch is at least one of corn starch, potato starch, and sweet potato starch.

26. The method for preparing the catalytic wet oxidation catalytic material according to claim 3, wherein, The sulfur-containing compound in step (6) is selected from at least one of sodium sulfide and thioacetamide.

27. The method for preparing the catalytic wet oxidation catalyst material according to claim 3, wherein, The surfactant in step (6) is at least one of the Tween series surfactants and the Span series surfactants. The Tween series surfactant is at least one of Tween 20, Tween 40, Tween 60 and Tween 80; the Span series surfactant is at least one of Span 20, Span 40, Span 60 and Span 80.

28. The method for preparing the catalytic wet oxidation catalytic material according to claim 3, wherein, The evaporation in step (6) is one of rotary evaporation or water bath heating evaporation.

29. The method for preparing the catalytic wet oxidation catalyst material according to claim 3, wherein, The drying temperature in step (6) is 50-100℃ and the drying time is 3-8h.

30. The method for preparing the catalytic wet oxidation catalytic material according to claim 3, wherein, The drying temperature in step (6) is 70-80℃ and the drying time is 4-6h.

31. The method for preparing the catalytic wet oxidation catalyst material according to claim 3, wherein, The calcination in step (6) is carried out under anaerobic conditions, with a calcination temperature of 300-700℃ and a calcination time of 2-8h.

32. The method for preparing the catalytic wet oxidation catalytic material according to claim 3, wherein, The calcination in step (6) is carried out under anaerobic conditions, with a calcination temperature of 400-600℃ and a calcination time of 3-4 hours.

33. A wastewater treatment process in which wastewater, an oxidant, and a catalytic wet oxidation catalyst as described in any one of claims 1-2 or a catalytic wet oxidation catalyst prepared by any one of claims 3-32 are brought into contact and reacted.

34. The wastewater treatment process according to claim 33, wherein, The oxidant is one of ozone, hydrogen peroxide, persulfate, sodium hypochlorite, percarbonate, permanganate, or ferrate.