Preparation method of vanadium slag-based photocatalytic material for deep degradation of antibiotic wastewater

Abstract

The application belongs to the technical field of catalytic material preparation, and particularly relates to a preparation method of a vanadium slag-based photocatalytic material for deeply degrading antibiotic wastewater, which takes carbon-containing vanadium slag as a base material, and obtains the target product through vacuum freeze drying, grinding, calcination and plasma activation. The catalyst can be widely applied to the deep treatment of various complex heavy metal wastewater, such as mining, smelting, electroplating, electrolysis, medical treatment and the like. The application can significantly improve the exposure of surface active sites of the vanadium slag-based catalyst, improve the degradation efficiency of tetracycline antibiotics, so that the removal rate of tetracycline antibiotics reaches more than 95% within 90 min, and no high-toxicity intermediate product is generated, thereby providing a photocatalytic material with excellent performance for removing antibiotics from water.

Description

Technical Field

[0001] This invention belongs to the field of catalytic material preparation technology, specifically relating to a method for preparing vanadium slag-based photocatalytic materials for the deep degradation of antibiotic wastewater. This method helps to degrade organic pollutants in water bodies while simultaneously addressing the issue of vanadium slag reuse, thereby reducing environmental pollution and solid waste emissions. Background Technology

[0002] Vanadium slag is a waste product generated during titanium dioxide production. It contains a large amount of various metallic elements such as vanadium, titanium, iron, aluminum, and carbon, as well as inorganic substances such as oxides and hydroxides. Directly discharging vanadium slag not only pollutes the environment but also wastes resources. Therefore, the proper treatment of vanadium slag is an essential way to reduce environmental pollution and resource waste caused by it.

[0003] Patent document CN109355515A discloses a method for vanadium extraction from calcified vanadium extraction tailings, aiming to solve the problems of high cost and low purity of vanadium pentoxide product from low-grade vanadium-containing raw materials. The method includes the following steps: roasting the calcified vanadium extraction tailings to obtain roasted clinker, acid leaching, collecting the leachate, adding a purification agent, performing solid-liquid separation, collecting the liquid phase, precipitating vanadium, and calcining to obtain vanadium pentoxide with a purity greater than 98%. Furthermore, this invention's vanadium extraction method also ensures that the impurity content in the tailings after vanadium extraction is ≤0.6%, and wastewater can be recycled.

[0004] Patent document CN109182760A discloses a method for recovering vanadium from vanadium extraction tailings after calcification roasting. This method aims to solve the technical problems of high difficulty in extracting vanadium from tailings remaining after primary vanadium extraction through calcification roasting, low vanadium leaching rates, and resource waste. The method involves controlling the moisture content of the vanadium extraction tailings to 30-35 wt%, drying and pulverizing them to obtain material A. Limestone is added to material A, controlling the calcium-vanadium ratio to 0.3-0.8, and the mixture is thoroughly mixed. After roasting and cooling, a roasted material is obtained. This roasted material is then ground and leached with sulfuric acid solution to obtain a vanadium extraction solution and vanadium extraction slag. This invention further extracts vanadium-containing components from the tailings through secondary roasting and leaching of primary vanadium extraction tailings, achieving full recovery and utilization of vanadium in the vanadium slag. The leaching rate can reach over 60%, avoiding resource waste.

[0005] The above methods involve vanadium pentoxide production through vanadium purification. However, vanadium slag has a complex composition, and purification suffers from environmental pollution, high energy consumption, and the inability to utilize other substances beyond the vanadium slag. Therefore, how to achieve high-quality utilization of vanadium slag has become a current research hotspot. However, reports on how to simultaneously reuse this waste are rare.

[0006] Antibiotic wastewater refers to wastewater containing antibiotic residues. Antibiotics, as widely used drugs, are applied extensively in medicine, animal husbandry, and fisheries. However, their residues are discharged into the environment during production and use, posing a potential threat to the environment and human health. The hazards mainly include: 1. Toxicity to aquatic organisms; 2. Impact on environmental microbial communities, potentially leading to increased antibiotic resistance; 3. Impact on human health, potentially leading to increased bacterial resistance and rendering antibiotic treatment ineffective. Currently, common antibiotics include penicillin, tetracycline, aminoglycosides, macrolides, and quinolones. In recent years, many researchers have studied methods for treating antibiotic wastewater to reduce antibiotic residues in the environment and protect environmental and human health. Among methods for treating antibiotic wastewater, photocatalysis is promising due to its advantages of mild conditions, high efficiency, and environmental friendliness. It can degrade recalcitrant pollutants such as organic pollutants and heavy metals into harmless substances. However, highly efficient photocatalysts are mainly composed of precious metals, resulting in high preparation costs. Meanwhile, there is little research on high-performance photocatalytic materials prepared using low-cost solid waste materials (vanadium slag). Summary of the Invention

[0007] The present invention aims to overcome the shortcomings of the prior art and provide a method for preparing vanadium slag-based photocatalytic materials for the deep degradation of antibiotic wastewater that is simple to operate, low in cost, and has a high efficiency in catalytic degradation.

[0008] To solve the above-mentioned technical problems, the present invention is implemented as follows:

[0009] A method for preparing vanadium slag-based photocatalytic materials for deep degradation of antibiotic wastewater involves using carbon-containing vanadium slag as the base material and obtaining the target product through vacuum freeze-drying, grinding, calcination, and plasma activation.

[0010] As a preferred embodiment, the method for preparing vanadium slag-based photocatalytic materials for the deep degradation of antibiotic wastewater is characterized by the following specific steps:

[0011] (1) Take carbon-containing vanadium slag, add it to deionized water, stir, and place it in a vacuum freeze dryer for freeze drying until constant weight; to prevent the high-temperature hydrolysis of TiCl4 contained in the vanadium slag.

[0012] (2) Grind the product obtained in step (1);

[0013] (3) Place the product obtained in step (2) in a tube furnace for calcination, cooling, grinding, and sieving;

[0014] (4) Add the product from step (3) to the dispersant and continue stirring at a certain temperature for a certain time, and freeze dry under vacuum at a certain temperature until constant weight;

[0015] (5) The product obtained in step (4) is placed in a dielectric barrier discharge plasma reaction tube for activation to obtain the target product.

[0016] Furthermore, in step (1), the carbon-containing vanadium slag is a solid waste material, weighing 10g, with 150mL of deionized water added, and the freeze-drying treatment temperature is -10 to -50℃.

[0017] Furthermore, in step (2), the grinding mesh size is 60 to 80 mesh.

[0018] Furthermore, in step (3), calcination is carried out in an N2 atmosphere at a temperature of 600–1000°C for 1–2 hours and at a heating rate of 5°C / min.

[0019] Furthermore, in step (4), the dispersant is a compound of CTAB, sodium hexametaphosphate and sodium tartrate.

[0020] Furthermore, the mass ratio of the dispersant compound is CTAB: sodium hexametaphosphate: tartaric acid 2-4: 3-5: 2-4.

[0021] Further, in step (4), the product of step (3) is added to a dispersant and then dissolved in 30-50 mL of deionized water. The reaction temperature is set to 0-10℃ and the reaction time is 6-18 h. The product after reaction is freeze-dried at low temperature to constant weight at a temperature of -10 to -50℃.

[0022] Further, in step (5), the product obtained in step (4) is placed in a dielectric barrier discharge plasma reaction tube and treated with a power of 60-100W for 10-30 minutes in an O2 atmosphere of 50 mL / min.

[0023] This invention utilizes vanadium slag as a raw material to prepare a catalytic material. The raw material itself is a solid waste material, and the prepared catalytic material does not generate additional waste while having the advantages of high efficiency in degrading pollutants and long service life. This catalytic material can perform deep treatment of pollutants in water under visible light. Experiments have proven that this catalytic material can effectively solve the problem of antibiotic wastewater treatment that has been troubling us, and achieve the standard discharge of antibiotic wastewater.

[0024] This invention can significantly improve the exposure of surface active sites of vanadium slag-based catalysts, enhance the degradation efficiency of tetracycline antibiotics, and achieve a removal rate of over 95% for tetracycline antibiotics within 90 minutes, without generating highly toxic intermediate products. It provides a high-performance photocatalytic material for the removal of antibiotics from water.

[0025] Compared with the prior art, the present invention has the following characteristics:

[0026] 1. This invention employs freeze-drying, tubular furnace calcination, and plasma activation technology, which is simple to operate and easy to promote and apply; the vanadium slag used is widely available and inexpensive, making it suitable for industrial production.

[0027] 2. The present invention uses plasma activation method, which helps to significantly improve the surface tension and hydrophilicity of the material, and further increase the contact area between the material and water pollutants.

[0028] 3. The method of this invention is simple and has excellent catalytic degradation ability of target pollutants. It has the advantages of low price, simple operation and long service life. It can be used to treat antibiotic wastewater of a certain concentration and the product has a wide range of applications.

[0029] 4. The present invention uses low-temperature freeze-drying technology to pretreat vanadium slag, which can further reduce the particle size of vanadium slag and stabilize its internal structure.

[0030] 5. This invention can be widely applied to various polluted water bodies, such as printing and dyeing, pharmaceuticals and other fields. Attached Figure Description

[0031] The present invention will now be described in detail through specific embodiments. These embodiments are provided to enable a more thorough understanding of the invention and to fully convey the scope of the invention to those skilled in the art. As used throughout the specification and claims, the terms "comprising" or "including" are open-ended and are interpreted as "comprising but not limited to". The following description is a preferred embodiment for carrying out the invention; however, this description is intended to illustrate the general principles of the specification and is not intended to limit the scope of the invention. The scope of protection of the invention is determined by the appended claims. Unless otherwise specified, all reagents and materials used in the present invention are commercially available.

[0032] Figure 1 This is the SEM image of the vanadium slag-based photocatalytic material of the present invention. Detailed Implementation

[0033] Example 1

[0034] (1) Take 10g of carbon vanadium slag, add 150mL of deionized water, and freeze dry at -40℃ in a vacuum freeze dryer until constant weight.

[0035] (2) Collect the product from step (1), grind it, and pass the ground product through an 80-mesh sieve.

[0036] (3) The product in step (2) was calcined in a tube furnace at 600°C for 2 hours in a N2 atmosphere, with a heating rate of 5°C / min.

[0037] (4) Add a mixture of CTAB, sodium hexametaphosphate and sodium tartrate as a dispersant. The ratio of the dispersant mixture is CTAB: sodium hexametaphosphate: tartaric acid = 3:4:3. Dissolve the mixture in 50 mL of deionized water and stir. Keep the reaction temperature at 10 °C and the reaction time is 12 h. Then freeze dry at -40 °C in a vacuum freeze dryer until constant weight.

[0038] (5) The product collected in step (4) was placed in a dielectric barrier discharge plasma reaction tube and treated for 30 min at 100 W power in an O2 atmosphere of 50 mL / min. The prepared photocatalyst achieved an 85% removal rate of the target pollutant tetracycline at 10 mg / L after 90 min of treatment. After 10 cycles of catalytic reaction, the tetracycline removal rate decreased to 75%.

[0039] Example 2

[0040] (1) Take 10g of carbon vanadium slag, add 150mL of deionized water, and freeze dry at -40℃ in a vacuum freeze dryer until constant weight.

[0041] (2) Collect the product from step (1), grind it, and pass the ground product through an 80-mesh sieve.

[0042] (3) The product in step (2) was calcined in a tube furnace at 700°C for 2 hours in a N2 atmosphere, with a heating rate of 5°C / min.

[0043] (4) Add a mixture of CTAB, sodium hexametaphosphate and sodium tartrate as a dispersant. The ratio of the dispersant mixture is CTAB: sodium hexametaphosphate: tartaric acid = 3:4:3. Dissolve the mixture in 50 mL of deionized water and stir. Keep the reaction temperature at 10 °C and the reaction time is 12 h. Then freeze dry at -40 °C in a vacuum freeze dryer until constant weight.

[0044] (5) The product collected in step (4) was placed in a dielectric barrier discharge plasma reaction tube and treated for 30 min at 100 W power in an O2 atmosphere of 50 mL / min. The prepared photocatalyst achieved an 89% removal rate of the target pollutant tetracycline at 10 mg / L after 90 min of treatment. After 10 cycles of catalytic reaction, the tetracycline removal rate decreased to 78%.

[0045] Example 3

[0046] (1) Take 10g of carbon vanadium slag, add 150mL of deionized water, and freeze dry at -40℃ in a vacuum freeze dryer until constant weight.

[0047] (2) Collect the product from step (1), grind it, and pass the ground product through an 80-mesh sieve.

[0048] (3) Calcine the product in step (2) in a tube furnace at 800°C for 2 hours in a N2 atmosphere, with a heating rate of 5°C / min.

[0049] (4) Add a mixture of CTAB, sodium hexametaphosphate and sodium tartrate as a dispersant. The ratio of the dispersant mixture is CTAB: sodium hexametaphosphate: tartaric acid = 3:4:3. Dissolve the mixture in 50 mL of deionized water and stir. Keep the reaction temperature at 10 °C and the reaction time is 12 h. Then freeze dry at -40 °C in a vacuum freeze dryer until constant weight.

[0050] 5) The product collected in step (4) was placed in a dielectric barrier discharge plasma reaction tube and treated for 30 min at 100 W power in an O2 atmosphere at a flow rate of 50 mL / min. The prepared photocatalyst achieved a 98% removal rate of the target pollutant tetracycline at a concentration of 10 mg / L after 90 min of treatment. After 10 cycles of catalytic reaction, the tetracycline removal rate decreased to 90%.

[0051] Example 4

[0052] (1) Take 10g of carbon vanadium slag, add 150mL of deionized water, and freeze dry at -40℃ in a vacuum freeze dryer until constant weight.

[0053] (2) Collect the product from step (1), grind it, and pass the ground product through an 80-mesh sieve.

[0054] (3) Calcine the product in step (2) in a tube furnace at 900°C for 2 hours in a N2 atmosphere, with a heating rate of 5°C / min.

[0055] (4) Add a mixture of CTAB, sodium hexametaphosphate and sodium tartrate as a dispersant. The ratio of the dispersant mixture is CTAB: sodium hexametaphosphate: tartaric acid 3:4:3. Dissolve the mixture in 50 mL of deionized water and stir. Keep the reaction temperature at 10 °C. Freeze dry at -40 °C in a vacuum freeze dryer until constant weight.

[0056] (5) The product collected in step (4) was placed in a dielectric barrier discharge plasma reaction tube and treated for 30 min at 100 W power in an O2 atmosphere of 50 mL / min. The prepared photocatalyst achieved a 92% removal rate of the target pollutant tetracycline at 10 mg / L after 90 min of treatment. After 10 cycles of catalytic reaction, the tetracycline removal rate decreased to 87%.

[0057] Example 5

[0058] (1) Take 10g of carbon vanadium slag, add 150mL of deionized water, and freeze dry at -40℃ in a vacuum freeze dryer until constant weight.

[0059] (2) Collect the product from step (1), grind it, and pass the ground product through an 80-mesh sieve.

[0060] (3) Calcine the product in step (2) in a tube furnace at 1000℃ for 2 hours in a N2 atmosphere, with a heating rate of 5℃ / min.

[0061] (4) Add a mixture of CTAB, sodium hexametaphosphate and sodium tartrate as a dispersant. The ratio of the dispersant mixture is CTAB: sodium hexametaphosphate: tartaric acid 3:4:3. Dissolve the mixture in 50 mL of deionized water and stir. Keep the reaction temperature at 10℃ and the reaction time at 12 h. Then freeze dry at -40℃ in a vacuum freeze dryer until constant weight.

[0062] (5) The product collected in step (4) was placed in a dielectric barrier discharge plasma reaction tube and treated for 30 min at 100 W power in an O2 atmosphere of 50 mL / min. The prepared photocatalyst achieved an 87% removal rate of the target pollutant tetracycline at 10 mg / L after 90 min of treatment. After 10 cycles of catalytic reaction, the tetracycline removal rate decreased to 75%.

[0063] Experimental results

[0064] The vanadium slag-based photocatalyst prepared in Example 3 was examined by scanning electron microscopy, and the results are as follows: Figure 1 As shown in the figure, the prepared catalyst material contains carbon lamellar structures and metal oxide particles, and the metal particles are well dispersed.

[0065] The photocatalytic performance of the materials in Examples 1 to 5 was compared, and it was found that the tetracycline removal rate of Example 3 was the highest. After 10 cycles, the tetracycline removal rate could still be maintained at 90%, and the catalyst performance was the best.

[0066] It is understood that the above specific description of the present invention is only for illustrating the present invention and is not limited to the technical solutions described in the embodiments of the present invention. Those skilled in the art should understand that modifications or equivalent substitutions can still be made to the present invention to achieve the same technical effect; as long as the use needs are met, they are all within the protection scope of the present invention.

Claims

1. A method for preparing a vanadium slag-based photocatalytic material for deep degradation of antibiotic wastewater, characterized in that, Comprise the following specific steps: (1) Take carbon-containing vanadium slag and add deionized water, stir, and place in a vacuum freeze-drying box for freeze-drying treatment until constant weight; the carbon-containing vanadium slag is a solid waste material, 10 g in weight is taken, the deionized water is added in an amount of 150 mL, and the freeze-drying treatment temperature is -10 to -50℃; (2) The product obtained in step (1) is ground; the grinding mesh is 60 to 80 mesh; (3) The product obtained in step (2) is placed in a tube furnace and calcined in an N2 atmosphere, the calcination temperature is 600 to 1000℃, the calcination time is 1 to 2 h, the heating rate is 5℃ / min, it is cooled, ground, and sieved; (4) The product of step (3) is added to a dispersant and dissolved in 30 to 50 mL of deionized water, the reaction temperature is set to 0 to 10℃, and the reaction time is 6 to 18 h; the product after reaction is freeze-dried at low temperature until constant weight, the temperature is -10 to -50℃; the dispersant is a compound of CTAB, sodium hexametaphosphate, and sodium tartrate; the mass ratio of the dispersant compound is CTAB:sodium hexametaphosphate:sodium tartrate 2 to 4:3 to 5:2 to 4; (5) The product obtained in step (4) is placed in a dielectric barrier discharge plasma reaction tube and treated in an O2 atmosphere of 50 mL / min at a power of 60 to 100 W for 10 to 30 min.

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