A fenton-like catalyst and a method for preparing the same

Abstract

The present application relates to sewage treatment technical field, specifically relates to a kind of Fenton catalyst and its preparation method.The specific technical scheme is: high molecular organic material is dissolved in organic solvent, active carbon powder is added, after being stirred sufficiently, metal oxide or its salt with catalytic function is added, after water solidification, drying, calcination, catalyst is obtained;The amount of the high molecular organic material is 10~30wt%, and the high molecular organic material is at least one of cellulose acetate, cellulose acetate ester, polyethylene, polystyrene, polypropylene, polysulfone, polyether, polyamide, polycarbonate and acrylonitrile-styrene-butadiene copolymer.The present application solves the problems of catalyst active component in prior art, such as easy loss, unstable structure, complex preparation process, short deactivation period and difficult regeneration.

Description

Technical Field

[0001] The present invention relates to the technical field of sewage treatment, and in particular to a Fenton-like catalyst and a preparation method thereof. Background Art

[0002] High-concentration, recalcitrant, and highly saline wastewater, often originating from industries like the chemical and pharmaceutical industries, is difficult to treat due to its extremely high COD, complex composition, and high salt content that inhibits microorganisms. Traditional biological methods are therefore challenging to treat, making advanced oxidation technologies (ADTs) key. These technologies utilize active species such as highly oxidizing hydroxyl radicals to oxidize and decompose pollutants. These technologies include Fenton, Fenton-like, photocatalytic, ozone, and wet oxidation. Fenton-like technologies offer significant advantages, including high efficiency, adaptability, ease of operation, and cost-effectiveness, making them particularly valuable for high-salinity wastewater applications. The core of Fenton-like technologies lies in their catalysts, which come in a wide variety. Commonly available are iron-based zero-valent iron, iron oxides, and supported iron agents, as well as non-ferrous metals such as copper and manganese, and multimetallic composite catalysts such as Fe-Mn. Preparation methods are diverse, including impregnation, which is simple and low-cost, but has limited loading capacity; co-precipitation, which allows for uniform distribution of metal ions, but is difficult to control; sol-gel, which allows for precise synthesis but is complex; and hydrothermal, which produces highly active products but requires specialized equipment and demanding conditions.

[0003] During wastewater treatment, metal ion leaching is influenced by a variety of factors, including the material's chemical composition, crystal structure, surface properties, and environmental conditions such as temperature, pH, and solution composition. For example, in certain highly acidic or alkaline reaction systems, metal ions on the surface of metal oxide catalysts are more susceptible to leaching. Metal ion leaching can lead to reduced catalyst activity due to a decrease in the number of active sites. Furthermore, leached metal ions may cause side reactions in the reaction system, affecting reaction selectivity and product distribution.

[0004] In the development of the catalytic field, single-component and two-component metal catalysts play a key role and have different technical characteristics and applications. Single-component metal catalysts, represented by platinum, palladium, and nickel, have achieved remarkable results in basic reactions such as hydrogenation and dehydrogenation. Their catalysis is based on the bonding of the outer electron orbits of metal atoms with reactant molecules to induce activation and promote the reaction. However, with the increasing complexity of chemical synthesis, single-component catalysts have exposed many problems. In complex reaction systems, because there is only a single active center, the activity is difficult to improve, the selectivity is difficult to control, and the stability is poor. They are unable to meet the delicate requirements of multi-step reactions, and extreme conditions such as high temperature and high pressure will also damage the metal structure and reduce the catalytic performance.

[0005] Dual-component metal catalysts leverage the advantages of combining two metals to produce significant synergistic effects. For example, in the platinum-rhodium bimetallic catalyst used in automobile exhaust purification, platinum oxidizes carbon monoxide and hydrocarbons, while rhodium reduces nitrogen oxides. This synergistic effect has significantly boosted the development of dual-component catalysts, enabling them to address complex catalytic needs, expand their application range, and promote the continuous advancement of catalytic technology.

[0006] The Chinese patent application with publication number CN110508286A discloses a method for preparing (Ni, Mg, Cu)Fe2O4 heterogeneous Fenton catalyst from nickel sulfide concentrate. This method realizes the effective utilization of mineral resources. It is prepared through leaching, pretreatment, coprecipitation-calcination and other steps. It has high catalytic activity. The photo-assisted heterogeneous Fenton reaction system composed of oxalic acid and visible light can efficiently degrade organic dyes. It is easy to recycle, reusable, and has low preparation cost, and has good application prospects. However, the process conditions have high control requirements, the leaching step has limitations on the treatment of components in the raw materials, and currently only the application scenario of organic dye treatment under a specific photo-assisted heterogeneous Fenton reaction system has been shown. The scope of application needs to be expanded and verified.

[0007] The Chinese patent application with publication number CN115337952A discloses a one-step synthesis method for iron-manganese bimetallic oxide-loaded nitrogen vacancy carbon nitride. Its advantages are that it adopts a one-step synthesis method with simple and efficient steps, high catalytic efficiency of FeMnOx / g-C3N4-VN, complete removal of sulfamethoxazole within 50 minutes, and the reaction rate is 6 times that of FeMnOx. The amount of metal ion dissolution is small, decreasing by 75% and 86% respectively. It also achieves the construction of a catalyst with high catalytic activity and low ion leaching, and has good application prospects in the field of persulfate advanced oxidation. However, its disadvantages are that the application range is narrow, the purity of raw materials and reaction conditions are stringent, and the application scenarios and condition control need to be expanded and improved. Summary of the Invention

[0008] In view of the shortcomings of the existing technology, the present invention provides a Fenton-like catalyst and a preparation method thereof, which solves the problems of easy loss of active components of the catalyst, unstable structure, complex process, short deactivation cycle and difficult regeneration in the existing technology.

[0009] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0010] The invention discloses a preparation method of a Fenton-like catalyst. The method comprises the following steps: dissolving a high molecular weight organic material in an organic solvent, adding activated carbon powder, stirring thoroughly, adding a metal oxide or a salt thereof having a catalytic function, solidifying the mixture through water, drying, and calcining to obtain the catalyst. The high molecular weight organic material is used in an amount of 10 to 30 wt %. The high molecular weight organic material is at least one of cellulose acetate, cellulose acetate esters, polyethylenes, polystyrenes, polypropylenes, polysulfones, polyethers, polyamides, polycarbonates, and acrylonitrile-styrene-butadiene copolymer (ABS resin).

[0011] Preferably, the organic solvent is at least one of N,N-dimethylacetamide, N,N-dimethylformamide, N-methylpyrrolidone, dimethyl sulfoxide, sulfolane, and acetonitrile.

[0012] Preferably, the mass ratio of the activated carbon to the high molecular organic material is 1:1 to 5:1, and the amount of the metal oxide or its salt having catalytic function is 1 to 20 wt%.

[0013] Preferably, the metal element in the metal oxide or salt thereof having a catalytic function is at least one of iron, copper, cerium, platinum, palladium, ruthenium, nickel, cobalt, manganese, lanthanum and yttrium.

[0014] Preferably, the high molecular weight organic material and the organic solvent are stirred and dissolved at a constant temperature of 10 to 80° C. for 8 to 12 hours; and the mixture is then allowed to stand for 8 to 12 hours to prepare a uniform solution.

[0015] Preferably, the drying temperature is 70-120° C., and the drying time is 2-6 hours.

[0016] Preferably, the calcination temperature is 100-800° C., and the calcination time is 10-60 minutes.

[0017] Correspondingly, a Fenton-like catalyst prepared by the above preparation method.

[0018] Correspondingly, a Fenton-like catalyst prepared by the above preparation method is used in treating sewage.

[0019] Preferably, the sewage contains o-toluenesulfonamide, and the concentration of o-toluenesulfonamide is 0.5-10 g / L.

[0020] The present invention has the following beneficial effects:

[0021] 1. The present invention has significant advantages in synthesizing composite activated carbon by using polymer organic materials as catalyst carriers. It can create a stable environment for active sites, prevent the loss of active ingredients to ensure stable catalytic performance, and ensure stable production efficiency and product quality. With its own strength and stability, it can cope with harsh conditions through precise process control, maintain structural integrity, ensure the exposure of active sites and smooth catalytic reactions. In addition, because there is almost no deactivation, the regeneration process is eliminated. When the catalyst is depleted to a certain extent, the catalyst can be directly replenished, which can simplify the operation and maintenance links and improve production efficiency.

[0022] 2. The preparation process of the present invention has low dependence on complex parameters, the process is simplified, and the manpower and material costs are greatly reduced, which is conducive to large-scale industrial application; in terms of environmental protection, the preparation process is relatively clean.

[0023] 3. The shape and other properties of the catalyst can be customized as needed, and its function can be enhanced by adding metal oxides or their salts to meet diverse industrial needs; the loss of catalysts can be reduced, costs can be reduced, an economic closed loop can be built, resource waste can be reduced, and the cost-effectiveness of the catalyst throughout its life cycle can be optimized.

[0024] 4. The catalyst prepared by the present invention exhibits extraordinary properties in multiple key aspects. First, ions do not dissolve during use, fundamentally eliminating the problem of catalyst deactivation caused by ion loss. Once put into use, it does not require repeated regeneration operations, maintaining a high-efficiency catalytic state for a long time and providing a solid guarantee for continuous industrial production. Second, the shape and pore size of the activated carbon can be precisely controlled, perfectly formed according to predetermined requirements. At the same time, the pore structure can be meticulously regulated. It can create an appropriate pore size distribution and porosity based on the strict standards for adsorbed molecular size in various industrial scenarios such as specific impurity adsorption in chemical production and harmful gas adsorption and purification in the environmental protection field. This ensures that the activated carbon can operate efficiently under different working conditions, with high catalytic site activity and excellent overall catalytic performance. Third, the catalyst is extremely convenient to use, completely eliminating the tedious regeneration process and the need for repeated filling and removal of the catalyst tank, significantly reducing labor and time costs, and better meeting the actual needs of large-scale engineering applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a SEM image of the CeFeCuOx / AC catalyst prepared in Example 1;

[0026] Figure 2 TEM image of the CeFeCuOx / AC catalyst prepared in Example 1;

[0027] Figure 3 Flow chart of wastewater treatment using the CeFeCuOx / AC catalyst prepared in Example 1;

[0028] Figure 4is the removal efficiency at different OTSA concentrations;

[0029] Figure 5 The effect of different reaction systems on the degradation rate of OTSA;

[0030] Figure 6 The active species produced during microwave-induced catalytic oxidation by different quenchers;

[0031] Figure 7 The effect of the number of times the catalyst is used on the removal rate of OTSA and COD during the degradation of high-concentration OTSA;

[0032] Figure 8 The effect of the number of times the catalyst was used on the removal rate of OTSA and COD during the degradation of medium-concentration OTSA;

[0033] Figure 9 This figure shows the effect of the number of times the catalyst is used on the removal rate of OTSA and COD during the degradation of low-concentration OTSA. DETAILED DESCRIPTION

[0034] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0035] Unless otherwise specified, the technical means used in the embodiments are conventional means well known to those skilled in the art.

[0036] The invention discloses a preparation method of a Fenton-like catalyst. The specific process is as follows: adding a high-molecular organic material to an organic solvent, stirring for 8 to 12 hours to dissolve at a constant temperature of 10 to 80°C, and then standing the mixture for 8 to 12 hours to prepare a uniform solution; then adding activated carbon (AC) powder, stirring thoroughly, and then adding a metal oxide or a salt thereof with a catalytic function; after water solidification (shaping can be performed during solidification to prepare catalysts of different shapes), drying at 70 to 120°C for 2 to 6 hours, and then calcining at 100 to 800°C for 10 to 60 minutes to obtain the catalyst; the high-molecular organic material is used in an amount of 10 to 30% by weight, the activated carbon and the high-molecular organic material have a mass ratio of 1:1 to 5:1, and the metal oxide or the salt thereof with a catalytic function is used in an amount of 1 to 20% by weight. When multiple metal oxides or salts thereof with a catalytic function are used, the amounts thereof are respectively 1 to 20% by weight.

[0037] The temperature of the water curing is 10-90° C., and the pores of the catalyst are regulated by controlling the temperature of the water curing.

[0038] The polymer organic material is at least one of cellulose acetate, cellulose acetate esters, polyethylene, polystyrene, polypropylene, polysulfone, polyether, polyamide, polycarbonate, and acrylonitrile-styrene-butadiene copolymer (ABS resin). The organic solvent is at least one of N,N-dimethylacetamide, N,N-dimethylformamide, N-methylpyrrolidone, dimethyl sulfoxide, sulfolane, and acetonitrile. The metal element in the catalytic metal oxide or its salt is at least one of iron, copper, cerium, platinum, palladium, ruthenium, nickel, cobalt, manganese, lanthanum, and yttrium. For example, iron includes ferric oxide, ferric oxide, ferric chloride, ferrous chloride, ferric nitrate, and ferric phosphate; for example, copper includes copper oxide, copper chloride, copper nitrate, and copper sulfate.

[0039] A Fenton-like catalyst prepared by the above-mentioned preparation method is used to treat wastewater containing o-toluenesulfonamide. The o-toluenesulfonamide concentration is 0.5-10 g / L. The degradation of OTSA is carried out using microwave-induced degradation combined with an oxidant (H2O2). The microwave power is 500-700 W, the duration is 1.5-10 minutes, and the amount of H2O2 added is 50-100 mL / L, at a concentration of 30%.

[0040] The present invention will be further described below with reference to specific embodiments.

[0041] Example 1

[0042] Preparation of Fenton-like catalysts:

[0043] (1) Prepare a total mass of 100 g of solution. Each combination of polymer organic materials is weighed so that the polymer organic materials account for 10-30 wt% of the mixed system. When dimethylformamide is used as the organic solvent and is combined with polysulfone, accurately weigh 20 g of polysulfone and slowly add an appropriate amount of N,N-dimethylformamide. Stir at 10-80°C for 8-12 h using a magnetic stirrer to fully dissolve the polysulfone. Then, let the mixture stand for 8-12 h to prepare a uniform, stable solution with a mass fraction of 20%.

[0044] (2) After filtering through a 50-mesh sieve, carefully add activated carbon powder (with a mass ratio of 2:1 to the selected high molecular weight organic material) and continue stirring to completely blend it with the solution.

[0045] (3) Adding various metal oxides with catalytic functions such as (Fe3O4), copper (CuO), and cerium (CeO2) with mass fractions of 1 to 20 wt% to the fully stirred mixture, and then pouring it into a square mold.

[0046] (4) The mold is water-cured together, and the water temperature is controlled at 20°C. After it is cured and detached from the mold, the cured polymer mixture is immersed in deionized water. After 12 to 24 hours of soaking and curing, the organic solvent is completely transferred to the water. Use a paper cutter to cut the mixture into square particles with a side length of 5 mm.

[0047] (5) Dry in a beaker in a water bath at 60-80°C until there is no water stain on the surface, then place it in an oven at 70-120°C for 2-6 hours, and then calcine it at 500°C in a muffle furnace for 20 minutes. The polysulfone undergoes moderate carbonization and structural rearrangement, and the metal oxide simultaneously completes the crystal transformation and optimized activation of the active sites, thereby obtaining a catalyst.

[0048] (6) Catalyst (CeFeCuO x / AC) was cooled and then soaked in deionized water for 1-2 hours to remove the ash and interfering ions on the surface, and then transferred to a drying oven. The specific surface area of ​​the prepared catalyst was 80.601m 2 / g, pore volume 0.075cm 3 / g, average pore size 3.740nm.

[0049] Prepared CeFeCuO x The scanning electron microscope (SEM) image of the / AC catalyst is shown in Figure 2. Figure 1 As shown in the image on the right (higher magnification), after metal oxide loading, the catalyst's surface exhibits smaller particles than those on the activated carbon support, due to the presence of a large number of metal oxide nanoparticles. Observation at even higher magnification reveals numerous active particles dispersed across the surface. Although the support appears relatively uniform, some aggregated particles are present, confirming successful loading of the active ingredient.

[0050] Figure 2 Demonstrated CeFeCuO x Transmission electron microscopy (TEM) image of the AC catalyst material. It can be seen that Fe, Cu and Ce are uniformly dispersed on the carbon skeleton. In addition, in CeFeCuO xIn the high-resolution transmission electron microscopy (HRTEM) image of / AC, lattice fringes of ferroferric oxide (Fe3O4) with (220) crystal plane (interplanar spacing d = 0.16nm), copper oxide (CuO) with (11-2) crystal plane (interplanar spacing d = 0.25nm), and cerium dioxide (CeO2) with (220) crystal plane (interplanar spacing d = 0.26nm) were observed. Lattice fringes of activated carbon (AC) with (002) crystal plane (interplanar spacing d = 0.15nm) were also observed. These results indicate that the prepared CeFeCuO x / AC has good crystallinity and is evenly distributed on the AC skeleton.

[0051] Example 2

[0052] With the continuous development of the pharmaceutical industry, sulfonamides, a class of important drugs, possess diverse therapeutic benefits, including antibacterial, anti-carbonic anhydrase, and diuretic properties. Among them, o-toluenesulfonamide (OTSA) is an organic compound that is not only a crucial precursor in drug preparation but also widely used as a key raw material for the synthesis of artificial fibers, dyes, and plastic additives. Therefore, wastewater containing o-toluenesulfonamide generated during chemical production processes requires treatment.

[0053] The process of catalyst treatment of wastewater is as follows Figure 3 shown.

[0054] 1. Microwave-induced catalytic degradation of OTSA was conducted at a set microwave power. The procedure was as follows: 100 mL of OTSA solution (10 g / L, initial pH 4.0), 60% (v / v) catalyst, and 100 mL of 30% H₂O₂ were added to a 500 mL three-necked flask equipped with a condenser reflux device. After microwave irradiation (700 W, 10 min), the supernatant was aspirated with a syringe and filtered through a 0.45 μm aqueous filter membrane to prepare samples for testing.

[0055] 2. Effects of different OTSA concentrations

[0056] The removal efficiency at different OTSA concentrations can reflect the oxidation capacity of the system. Under the optimal operating parameters mentioned in the above operation 1, such as Figure 4As shown in the figure, as the OTSA concentration increases, the removal rates of OTSA and COD gradually decrease. This is because at lower OTSA concentrations, the number of free radicals exceeds the number of OTSA molecules, resulting in a higher degradation efficiency. On the contrary, when the initial OTSA concentration is high, more OTSA will be adsorbed on the pores and surface of the catalyst, occupying the active sites of H2O2, ultimately reducing the OTSA degradation efficiency. For example, when the initial OTSA concentration is 2 g / L, the removal efficiencies of OTSA and COD are 99.67% and 91.3%, respectively, which are 8.6% and 10.2% higher than those at 10 g / L, respectively. Although high-concentration OTSA solutions can quickly capture free radicals to improve their utilization efficiency, the efficiency of free radical generation is reduced, resulting in a decrease in the overall degradation rate.

[0057] 3. Influence of different reaction systems

[0058] like Figure 5 As shown, MW, H2O2, AC and CeFeCuO x Single factors such as microwave irradiation (MW) and AC had no significant effect on the degradation rate of OTSA. Thermal effects, catalytic adsorption, and H2O2 oxidation alone resulted in minimal OTSA degradation, with COD removal rates of only 5.7%, 10.1%, 13.3%, and 15.1%, respectively. In the dual-factor reaction system, microwaves induced the generation of a small number of free radicals from hydrogen peroxide, slightly increasing the degradation rate. The interaction of MW with the original catalyst (AC) and the three-component catalyst generated high-temperature hotspots, increasing the degradation rates by 13.3% and 17.6%, respectively. When the catalyst was combined with hydrogen peroxide in the absence of MW irradiation, the oxidation process was slow and the reaction time was short, resulting in low COD removal rates. The combined action of microwaves, oxidants, and catalysts achieved optimal degradation, reaching optimal results within 6 minutes. Compared to activated carbon, the degradation efficiency of CeFeCuOx / AC was significantly increased by 36.8%. This is because the original catalyst lacks active metal components, which hinder the Fenton reaction in the system, resulting in reduced degradation efficiency. The MW-assisted Fenton-like reaction, combined with a metal oxide-loaded catalyst and hydrogen peroxide, significantly shortened the reaction time and enhanced the Fenton-like process.

[0059] Next, the microwave-enhanced Fenton-like catalytic oxidation mechanism was further explored. In the microwave-assisted Fenton reaction process of organic matter degradation, CeFeCuO x / AC catalyst produces electron-hole pairs under microwave irradiation, promoting the activation of H2O2 to produce free radicals. Metal ions participate in electron transfer to form a redox cycle to continuously activate H2O2. Organic matter is oxidized and mineralized after contact with free radicals, and ultimately produces water, carbon dioxide, nitrogen and sulfuric acid, achieving complete degradation of carbon and nitrogen. At the same time, it emphasizes the key role of electron transfer and each element in the reaction.

[0060] 4. Free Radical Capture Experiment

[0061] In the microwave (MW) induced catalytic oxidation system, hydroxyl radicals (·OH), electrons (e - ), holes (h + ) and superoxide anion radicals (·O2 - ) is considered to be the main active species for removing organic pollutants. The active species produced during microwave-induced catalytic oxidation were studied using p-benzoquinone (p-BQ), isopropyl alcohol (IPA), silver nitrate (AgNO3), potassium iodide (KI) and ascorbic acid (VC) as quenchers. Figure 6 As shown, the inhibitory effect is ranked as follows: OH>e - >h + >·O2 - OH was identified as the main free radical in the microwave-induced H2O2 catalytic oxidation process. After the introduction of p-benzoquinone, potassium iodide, silver nitrate and isopropyl alcohol, the COD removal rate dropped to 87.7%, 82.4%, 79.5% and 32.5%, respectively. This is because under MW irradiation, metal oxides are excited to generate electron-hole pairs (e - / h + ), water (H2O) and hydroxide ions (OH - ) and holes (h + ) reacts to generate ·OH and ·O2 - ·OH can be indirectly generated. In addition, MW induces the formation of active sites on the catalyst surface, which is conducive to the generation of ·OH by H2O2 at these sites. The addition of VC significantly inhibits the degradation efficiency of OTSA, which indicates that it can effectively quench all free radicals. Therefore, ·OH plays a dominant role in the degradation process, while e - 、h + and O2 - Play a secondary role.

[0062] Example 3

[0063] 1. Degradation of high concentration OTSA

[0064] The process conditions were as follows: OTSA concentration of 10 g / L; MW power of 700 W; duration of 2 minutes; H₂O₂ dosage of 100 mL / L; pH of 4; carbon column height of 50 cm; and initial temperature of 25°C. The OTSA solution was introduced from the bottom of the reaction column. While maintaining constant microwave power and duration, the microwave power and duration were adjusted. The OTSA concentration and COD removal rate of the effluent were measured, and degradation changes during repeated use were observed.

[0065] like Figure 7As shown in the figure, as the number of degradation uses increases, the OTSA and COD removal rates gradually decrease, falling to 68.7% and 71.2%, respectively, by the fifth use, while the carbon loss rate increases from the initial 2.4% to 20.4%. This is because the catalyst's activity may decrease after long-term use, which in turn leads to changes in reaction conditions and affects degradation efficiency. As the number of uses increases, organic matter or other substances produced during the reaction may accumulate on the catalyst surface, forming a carbon layer that hinders the contact between the catalyst and the target substances in the wastewater, thereby reducing reaction efficiency.

[0066] 2. Degradation of medium concentration OTSA

[0067] The process conditions were as follows: OTSA concentration of 1 g / L; microwave power of 500 W; reaction time of 1.5 min; H₂O₂ dosage of 50 mL / L; pH of 4; carbon column height of 50 cm; and initial temperature of 25°C. The OTSA solution was introduced from the bottom of the reaction column. While maintaining constant microwave power and duration, the microwave power and duration were adjusted. The OTSA concentration and COD removal rate of the effluent were measured, and degradation changes with repeated use were observed.

[0068] like Figure 8 As shown in the figure, with the increase of degradation cycles, the OTSA and COD removal efficiencies gradually decreased, and by the fifth cycle, they dropped to 83.7% and 71.5%, respectively. The carbon loss rate increased from the initial 1.6% to 12.4%.

[0069] 3. Degradation of low concentration OTSA

[0070] The process conditions were as follows: OTSA concentration of 50 mg / L; microwave power of 500 W; reaction time of 1.5 min; H₂O₂ dosage of 50 mL / L; pH of 4; carbon column height of 50 cm; and initial temperature of 25°C. The OTSA solution was introduced from the bottom of the reaction column. While maintaining constant microwave power and duration, the microwave power and duration were adjusted. The OTSA concentration and COD removal rate of the effluent were measured, and degradation changes with repeated use were observed.

[0071] like Figure 9 As shown, the removal rates of OTSA and COD gradually decreased with increasing use, falling to 88.6% and 77.2%, respectively, by the fifth use, while the carbon loss rate increased from an initial 0.8% to 9.5%. Under low concentration conditions, after five cycles, the removal rates of OTSA and COD decreased by 6% and 14.8%, respectively. This demonstrates the excellent reusability of CeFeCuOx / AC.

[0072] The embodiments described above are merely descriptions of preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by persons skilled in the art should fall within the scope of protection defined by the claims of the present invention.

Claims

1. A method for preparing a Fenton-like catalyst, characterized in that: The catalyst is obtained by dissolving a high molecular weight organic material in an organic solvent, adding activated carbon powder, stirring thoroughly, adding a metal oxide with a catalytic function, and then curing with water, drying, and calcining. The amount of the high molecular weight organic material is 10 to 30 wt%, the mass ratio of the activated carbon to the high molecular weight organic material is 1:1 to 5:1, the amount of the metal oxide with a catalytic function is 1 to 20 wt%, and the temperature for curing with water is 10 to 90°C. The polymer organic material is a polysulfone; the organic solvent is at least one of N,N-dimethylacetamide, N,N-dimethylformamide, N-methylpyrrolidone, dimethyl sulfoxide, sulfolane, and acetonitrile; the metal element in the metal oxide having a catalytic function is iron, copper, or cerium; the polymer organic material and the organic solvent are stirred at a constant temperature of 10 to 80° C. for 8 to 12 hours to dissolve; and the mixture is allowed to stand for 8 to 12 hours to prepare a uniform solution. The drying temperature is 70-120° C., and the drying time is 2-6 hours; the calcination temperature is 100-800° C., and the calcination time is 10-60 minutes.

2. A Fenton-like catalyst prepared by the preparation method according to claim 1.

3. Use of the Fenton-like catalyst prepared by the preparation method according to claim 1 in treating sewage, wherein the sewage contains o-toluenesulfonamide and the concentration of the o-toluenesulfonamide is 0.5-10 g / L.

Images