Application of three-dimensional BDD mesh electrode in degrading cefquinome

Abstract

The application of a three-dimensional BDD net film electrode in degrading cefquinome belongs to the technical field of degrading antibiotics. The present application aims to solve the problems of great difficulty and low degradation efficiency of the existing method in degrading cefquinome. The three-dimensional BDD net film electrode is used for degrading cefquinome. The three-dimensional BDD net film electrode is prepared by taking copper net as a substrate; the three-dimensional BDD net film is used as an electrode to electrochemically oxidize and degrade cefquinome in wastewater; it is verified that under the conditions of an initial concentration of 10 mg / L, a current intensity of 0.8 A, an electrolyte concentration of 0.1 mol / L, and an initial pH of cefquinome solution of 7, after 180 min of reaction, the degradation rate of cefquinome can reach more than 90%; the present application has the characteristics of high repeatability and high degradation efficiency.

Description

Technical Field

[0001] This invention belongs to the field of antibiotic degradation technology, specifically relating to the application of a three-dimensional BDD membrane electrode in the degradation of cefquinome. Background Technology

[0002] β-lactam antibiotics possess selective toxicity and good therapeutic effects, and are currently widely used in clinical medicine and animal husbandry. Cefquinome, a typical β-lactam antibiotic, has poor degradation ability under natural environmental conditions, and conventional treatment methods are insufficient for its complete removal. As antibiotic concentrations in environmental water bodies gradually increase, they can have a significant impact on the natural ecological environment and human health. Therefore, researching and developing green, energy-saving, and efficient water treatment technologies to remove antibiotics and other pollutants has significant practical value. Cefquinome (CFQ) is a fourth-generation cephalosporin antibiotic for animal use, with the chemical formula C6H2O. 23 H 24 N6O5S2, with a relative molecular mass of 528.6, is a white or pale yellow powder at room temperature. It is odorless, slightly soluble in water, and easily decomposes in hot and humid environments; therefore, it should be stored in a dry environment. Its aqueous solution has a pH of 7 and a solubility of 11–12 mg / mL, classifying it as an amphoteric compound. CFQ possesses a broad antibacterial spectrum and high antibacterial activity. Comparative analysis of the antibacterial activities of third-generation cephalosporins and CFQ revealed that CFQ exhibits a significant advantage over third-generation cephalosporins in antibacterial activity against Gram-positive bacteria. This finding provides strong scientific evidence for the further research and application of CFQ and offers a more effective drug option for the treatment of Gram-positive bacteria. CFQ shows good efficacy against many serious infections.

[0003] Currently, common methods for degrading CFQ include photocatalytic oxidation and biological methods.

[0004] Photocatalytic oxidation technology is a semiconductor-based environmentally friendly chemical treatment technology that has been widely researched and applied in recent years. It boasts advantages such as high efficiency, safety, and no secondary pollution. This technology uses photocatalysts to catalyze the generation of free radicals under light irradiation, thereby degrading organic matter. Simultaneously, it generates reactive oxygen species for oxidation reactions, converting harmful pollutants into harmless substances such as water and carbon dioxide. It is widely used in wastewater and waste gas treatment, air purification, and the treatment of organic synthesis wastewater. Photocatalytic oxidation technology not only has broad application prospects but has also become one of the current research hotspots in chemical treatment technologies. While photocatalytic reactions offer advantages in terms of efficiency and environmental friendliness, their performance is affected by many factors. In practical applications, the influence of factors such as light exposure time, meteorological conditions, and wastewater quality must be considered to achieve optimal catalytic reaction results. Furthermore, the preparation of photocatalysts is relatively time-consuming and costly; continuous improvement and optimization of the preparation process are necessary measures to increase catalytic reaction efficiency and reduce costs. Therefore, further in-depth research into the mechanism and influencing factors of photocatalytic reactions, and increased research and development efforts in photocatalyst preparation, can effectively promote the popularization and application of photocatalytic technology.

[0005] Biological treatment technology primarily utilizes the metabolic processes of microorganisms in the environment, as well as the interactions between microorganisms and specific dissolved organic molecules, to transform organic matter into microbial cytoplasm and new organisms, thereby accelerating the degradation and removal of organic matter. Biological treatment technology is favored by relevant industries due to its relatively low operating costs and ability to be used on a large scale. Currently, biological treatment technology has significant advantages and application prospects, especially in treating wastewater containing antibiotics, where it is a relatively effective treatment method with multiple advantages such as environmental friendliness, safety, and greenness. Through techniques such as strain screening and fermentation processes, based on the principles of biotechnology, organic matter in antibiotic wastewater can be oxidized and degraded, achieving a purification effect.

[0006] Boron-doped diamond (BDD) is well known to possess excellent physical and chemical properties, a wide potential window, and low background current. Furthermore, BDD exhibits stable electrochemical performance and excellent chemical inertness. Therefore, BDD is considered an attractive electrode material. However, most existing boron-doped diamond electrodes are two-dimensional boron-doped diamonds, which exhibit unsatisfactory degradation performance. Summary of the Invention

[0007] The purpose of this invention is to solve the problems of high difficulty and low degradation efficiency of existing methods for degrading cefquinoxime, and to provide a three-dimensional BDD mesh electrode for degrading cefquinoxime.

[0008] A three-dimensional BDD mesh electrode is used to degrade cefquinoxime.

[0009] Advantages of this invention:

[0010] I. This invention prepares a three-dimensional BDD mesh electrode using a copper mesh as a substrate; the three-dimensional BDD mesh electrode is used as an electrode for the electrochemical oxidation and degradation of cefquinoxime in wastewater. It has been verified that under the conditions of an initial concentration of 10 mg / L, a current intensity of 0.8 A, an electrolyte concentration of 0.1 mol / L, and an initial pH of 7 for the cefquinoxime solution, the degradation rate of cefquinoxime can reach more than 90% after a reaction of 180 min.

[0011] Second, this invention has the characteristics of high repeatability and high degradation efficiency. Attached Figure Description

[0012] Figure 1 SEM image of the three-dimensional BDD mesh electrode prepared in Example 1;

[0013] Figure 2 for Figure 1 Enlarged view of a portion of the grid structure;

[0014] Figure 3 XRD pattern of the three-dimensional BDD mesh electrode prepared in Example 1;

[0015] Figure 4 Raman spectrum of the three-dimensional BDD mesh electrode prepared in Example 1;

[0016] Figure 5 A physical image of the three-dimensional BDD mesh electrode prepared in Example 1;

[0017] Figure 6 Image showing the change in the removal rate of cefquinoxime using the three-dimensional BDD mesh electrode prepared in Example 1 as a function of initial concentration;

[0018] Figure 7 This is an image showing the change in the removal rate of cefuroxime by the three-dimensional BDD mesh electrode prepared in Example 1 as a function of current density in Application Example 2;

[0019] Figure 8 This is an image showing the change in the removal rate of cefquinoxime by the three-dimensional BDD mesh electrode prepared in Example 1 as a function of electrolyte concentration in Application Example 3;

[0020] Figure 9 This is an image showing the change in the removal rate of cefquinoxime by the three-dimensional BDD mesh electrode prepared in Example 1 as a function of pH value in Application Example 4;

[0021] Figure 10 This is an image showing the temperature-dependent degradation rate of cefquinoxime using the three-dimensional BDD mesh electrode prepared in Example 1, as described in Application Example 5.

[0022] Figure 11The three-dimensional BDD mesh electrode prepared for Example 1 was tested under optimal conditions with a current intensity of 30 mA / cm. 2 The graph shows the change in TOC removal rate over time under the conditions of an initial concentration of 25 mg / L, an electrolyte concentration of 0.1 mol / L, and an initial pH of 7.

[0023] Figure 12 The three-dimensional BDD mesh electrode prepared for Example 1 was tested under optimal conditions with a current intensity of 30 mA / cm. 2 The toxicity analysis diagram of the intermediate product under the conditions of initial concentration of 25 mg / L, electrolyte concentration of solution of 0.1 mol / L, and initial pH of solution of 7. Detailed Implementation

[0024] Specific Implementation Method 1: This implementation method uses a three-dimensional BDD mesh electrode to degrade cefquinoxime.

[0025] Specific Implementation Method Two: This implementation method differs from Specific Implementation Method One in that: a three-dimensional BDD membrane electrode for degrading cefquinome is specifically completed according to the following steps:

[0026] Wastewater containing cefquinoxime was added to an electrolytic cell, with K₂SO₄ added as the electrolyte. A three-dimensional BDD mesh electrode was used as the positive electrode, and a Pt platinum sheet was used as the negative electrode. The current intensity was 15 mA / cm². 2 ~45mA / cm 2 After degradation for a period of time, wastewater with cefquinoxime removed is obtained. Other steps are the same as in Specific Implementation Method 1.

[0027] Specific Implementation Method Three: This implementation method differs from Specific Implementation Method One or Two in that the concentration of cefquinoxime in the wastewater containing cefquinoxime is 25 mg / L to 100 mg / L. The other steps are the same as in Specific Implementation Method One or Two.

[0028] Specific Implementation Method Four: This implementation method differs from Specific Implementation Methods One to Three in that the pH value of the wastewater containing cefquinoxime is 3 to 11. The other steps are the same as in Specific Implementation Methods One to Three.

[0029] Specific Implementation Method Five: This implementation method differs from Specific Implementation Methods One to Four in that the degradation time is 30 min to 180 min. The other steps are the same as in Specific Implementation Methods One to Four.

[0030] Specific Implementation Method Six: This implementation method differs from Specific Implementation Methods One to Five in that the dosage of K₂SO₄ is 0.02 mol / L to 0.1 mol / L. The other steps are the same as in Specific Implementation Methods One to Five.

[0031] Specific Implementation Method Seven: This implementation method differs from Specific Implementation Methods One through Six in that the distance between the positive and negative electrodes is fixed at 2cm. The other steps are the same as in Specific Implementation Methods One through Six.

[0032] Specific Implementation Method Eight: This implementation method differs from Specific Implementation Methods One through Seven in that it involves a method for preparing a three-dimensional BDD mesh electrode, specifically completed according to the following steps:

[0033] 1. Cut the copper mesh to obtain the growth substrate for the diamond mesh film;

[0034] 2. The growth substrate of the diamond mesh film is cleaned, and then the growth substrate of the diamond mesh film is immersed in a suspension containing nanodiamond powder and sonicated to obtain a substrate loaded with nanodiamond powder.

[0035] 3. The substrate loaded with nanodiamond powder is placed in deionized water for ultrasonic cleaning to obtain the pretreated substrate;

[0036] IV. Using H2, CH4, and B as gas sources, boron-doped polycrystalline diamond is grown on the pretreated substrate using microwave plasma chemical vapor deposition to obtain a three-dimensional BDD mesh electrode. Other steps are the same as in embodiments one through seven.

[0037] Specific Implementation Method Nine: This implementation method differs from Specific Implementation Methods One to Eight in that the volume ratio of H2, CH4, and B in step four is 200:8:2.5. The other steps are the same as in Specific Implementation Methods One to Eight.

[0038] Specific Implementation Method Ten: This implementation method differs from Specific Implementation Methods One through Nine in that: in step four, the microwave power in the microwave plasma chemical vapor deposition method is 500W to 3800W, the diamond electrode growth temperature is 620℃ to 640℃, the working pressure is 12200 Torr to 12500 Torr, and the time is 8h to 10h. The other steps are the same as in Specific Implementation Methods One through Nine.

[0039] The beneficial effects of the present invention are verified through the following embodiments:

[0040] Example 1: A method for preparing a three-dimensional BDD mesh electrode for degrading cefquinome, specifically comprising the following steps:

[0041] 1. Cut the copper mesh to obtain the growth substrate for the diamond mesh film;

[0042] The growth substrate for the diamond mesh film described in step one has dimensions of 1.5cm × 0.3cm;

[0043] 2. The growth substrate of the diamond mesh film is cleaned, and then the growth substrate of the diamond mesh film is immersed in a suspension containing nanodiamond powder and sonicated for 20 minutes to obtain a substrate loaded with nanodiamond powder.

[0044] In step two, the growth substrate of the diamond mesh is ultrasonically cleaned with deionized water for 10 minutes.

[0045] 3. The substrate loaded with nanodiamond powder was placed in deionized water and ultrasonically cleaned for 3 seconds to obtain the pretreated substrate.

[0046] IV. Using H2, CH4 and B as gas sources, boron-doped polycrystalline diamond was grown on the pretreated substrate by microwave plasma chemical vapor deposition to obtain a three-dimensional BDD mesh electrode.

[0047] The volume ratio of H2, CH4, and B mentioned in step four is 200:8:2.5;

[0048] In step four, the microwave plasma chemical vapor deposition method uses 3800W, a diamond electrode growth temperature of 620℃~630℃, a working pressure of 12200Torr~12500Torr, and a time of 12h.

[0049] Figure 1 SEM image of the three-dimensional BDD mesh electrode prepared in Example 1;

[0050] Figure 2 for Figure 1 Enlarged view of a portion of the grid structure;

[0051] from Figures 1-2 As can be seen, the three-dimensional BDD mesh electrode for degrading cefquinoxime prepared in Example 1 exhibits a mesh structure. The diamond particles are dense, with an average size of approximately 1.35 μm.

[0052] Figure 3 XRD pattern of the three-dimensional BDD mesh electrode prepared in Example 1;

[0053] from Figure 3 It can be seen that the three-dimensional BDD mesh electrode prepared in Example 1 has high growth quality and is composed of (111) diamond grains.

[0054] Figure 4 Raman spectrum of the three-dimensional BDD mesh electrode prepared in Example 1;

[0055] from Figure 4 It can be seen that the three-dimensional BDD mesh electrode prepared in Example 1 has a 1332 cm⁻¹ diameter. -1 The peak at 1210 cm⁻¹ is a characteristic peak of diamond, with a sharp peak shape, indicating good quality diamond film growth.-1 The broad peak at 1580 cm⁻¹ is due to the introduction of boron atoms with diameters larger than carbon atoms, which alters the BDD crystal structure and causes changes in phonon scattering and Brillouin Raman scattering. Furthermore, at 1580 cm⁻¹... -1 The presence of this phenomenon is caused by the non-diamond phase (graphite phase) at the grain boundaries.

[0056] Optimal conditions for the electrochemical degradation of cefquinoxime were selected. Single-factor experiments were conducted to determine the range of optimal conditions. The experimental factors controlled in the single-factor experiments included initial antibiotic concentration, current intensity, electrolyte concentration, initial pH of the solution, and temperature. Each of these factors was investigated individually. The degradation solution was then analyzed. High-performance liquid chromatography (HPLC) can achieve highly sensitive and accurate detection and analysis of cefquinoxime content. The concentration of cefquinoxime was calculated based on the detected peak area. The mobile phase was a mixture of acetonitrile and ultrapure water (88:12). The flow rate used was 0.5 mL / min. -1 The detection wavelength was 270 nm. The injection volume was 10 μL. The column temperature was set to 35 °C, and the residence time was 10 minutes.

[0057] The change in total organic carbon (TOC) during the electro-cefoquinoxime experiment was detected as a basis for judging the degree of mineralization of the organic matter. A TOC analyzer was used to analyze the solution during the electrochemical degradation process. After three repeated tests to eliminate errors, the TOC content of the sample was obtained by calculating the difference between total carbon and inorganic carbon. Under optimal cefquinoxime electrolysis conditions, samples were taken at several time points (30 min, 60 min, 90 min, 120 min, 150 min, and 180 min) to measure the TOC values ​​at each time point. The TOC removal rate of the solution was calculated.

[0058] The optimal conditions for the electrochemical degradation of cefquinoxime were selected, and the range of optimal conditions was determined by single-factor experiments. The experimental factors controlled by the single-factor experiments included the initial antibiotic concentration, current intensity, electrolyte concentration, initial pH of the solution, and temperature. Each of these factors was investigated one by one.

[0059] Application Example 1: The degradation of cefquinoxime in wastewater using the three-dimensional BDD membrane electrode prepared in Example 1 was accomplished according to the following steps:

[0060] 100 mL of cefquinoxime modeling wastewater with pH 7 and different concentrations (25 mg / L, 50 mg / L, 75 mg / L, and 100 mg / L) was added to an electrolytic cell. 1.4204 g of K₂SO₄ (0.1 mol / L) was added as the electrolyte. The three-dimensional BDD mesh electrode prepared in Example 1 was used as the positive electrode, and a Pt platinum sheet was used as the negative electrode. The spacing between the positive and negative electrode plates was fixed at 2 cm. The wastewater temperature was 25 °C and the current intensity was 30 mA / cm. 2 The degradation process lasted from 0 min to 180 min. Samples were taken at several time points (30 min, 60 min, 90 min, 120 min, 150 min, and 180 min) during this period, and the TOC values ​​at each time point were measured. The TOC removal rate of the solution was then calculated. (See attached figure.) Figure 6 As shown;

[0061] Figure 6 Image showing the change in the removal rate of cefquinoxime using the three-dimensional BDD mesh electrode prepared in Example 1 as a function of initial concentration;

[0062] from Figure 6 As can be seen, the higher the initial concentration of cefquinoxime, the lower the removal rate within the same time period. This is because, under a fixed electrolyte concentration and current density, the concentration of degradation free radicals generated per unit time is fixed, and the degradation amount is fixed. The lower the concentration, the higher the percentage. Therefore, this invention selects an initial concentration of 25 mg / L as the ideal experimental condition.

[0063] Application Example 2: The degradation of cefquinoxime in wastewater using the three-dimensional BDD membrane electrode prepared in Example 1 was accomplished according to the following steps:

[0064] 100 mL of cefquinoxime modeling wastewater with pH 7 and a concentration of 25 mg / L was added to an electrolytic cell. 1.4204 g of K₂SO₄ (0.1 mol / L) was added as the electrolyte. The three-dimensional BDD mesh electrode prepared in Example 1 was used as the positive electrode, and a Pt platinum sheet was used as the negative electrode. The distance between the positive and negative electrode plates was fixed at 2 cm. The electrolysis was conducted at a wastewater temperature of 25 °C and different current intensities (current densities of 15 mA / cm²). 2 30mA / cm 2 45mA / cm 2 The degradation process was carried out from 0 min to 180 min. Samples were taken at several time points (30 min, 60 min, 90 min, 120 min, 150 min, and 180 min) during this process, and the TOC values ​​at each time point were measured. The TOC removal rate of the solution was calculated. (See figure) Figure 7 As shown;

[0065] Figure 7This is an image showing the change in the removal rate of cefuroxime by the three-dimensional BDD mesh electrode prepared in Example 1 as a function of current density in Application Example 2;

[0066] As shown in Figure 7, the removal rate of cefquinoxime is positively correlated with the current intensity; as the current intensity gradually increases, the removal rate of cefquinoxime also gradually increases. When the current intensity is 45 mA / cm², the removal rate of cefquinoxime is significantly higher. 2 At the specified current intensities, the removal rate was 79% after 120 minutes of electrolysis, significantly better than the other two current intensities. This is because higher current intensities generate more degradation free radicals more quickly, thus increasing the degradation rate. To verify the effectiveness of this condition for subsequent treatment, the experiment was conducted for 180 minutes, at which point the current was 45 mA / cm². 2 Under these conditions, the removal rate of cefquinoxime remained the highest among several current conditions, reaching 45 mA / cm at 180 min. 2 Under current conditions, the removal rate of cefquinoxime was 100%, compared to a current intensity of 30 mA / cm². 2 The small difference in removal rates under the two conditions indicates that, under the same electrolyte concentration, a higher current intensity results in a higher inter-plate voltage, which exacerbates electrode side reactions and reduces current efficiency. Simultaneously, a higher current leads to greater energy consumption and causes some electrical energy to be converted into heat, further reducing current efficiency. Therefore, this invention selects 30 mA / cm². 2 The current density is taken as the ideal current condition.

[0067] Application Example 3: The degradation of cefquinoxime in wastewater using the three-dimensional BDD membrane electrode prepared in Example 1 was accomplished according to the following steps:

[0068] 100 mL of cefquinoxime modeling wastewater with pH 7 and a concentration of 30 mg / L was added to an electrolytic cell. Different masses of K₂SO₄ (K₂SO₄ concentrations controlled at 0.02 mol / L, 0.05 mol / L, and 0.1 mol / L, respectively) were added to the solution as the electrolyte. The three-dimensional BDD mesh electrode prepared in Example 1 was used as the positive electrode, and a Pt platinum sheet was used as the negative electrode. The distance between the positive and negative electrode plates was fixed at 2 cm. The wastewater temperature was 25 °C and the current intensity was 30 mA / cm². 2 The degradation process lasted from 0 min to 180 min. Samples were taken at several time points (30 min, 60 min, 90 min, 120 min, 150 min, and 180 min) during this period, and the TOC values ​​at each time point were measured. The TOC removal rate of the solution was then calculated. (See attached figure.) Figure 8 As shown;

[0069] Figure 8 This is an image showing the change in the removal rate of cefquinoxime by the three-dimensional BDD mesh electrode prepared in Example 1 as a function of electrolyte concentration in Application Example 3;

[0070] from Figure 8 It can be seen that as the electrolyte concentration increases, the removal rate of cefquinoxime also shows an increasing trend. At 180 min, the removal rates of cefquinoxime at electrolyte concentrations of 0.02 mol / L, 0.05 mol / L, and 0.1 mol / L were 83.5%, 89.56%, and 95.7%, respectively. Lower electrolyte concentrations lead to poor solution conductivity, requiring a higher voltage to be applied across the electrodes while maintaining a constant current. This increases side reactions in the electrolysis process, reducing current efficiency and consequently decreasing the degradation rate of cefquinoxime. However, the removal rate does not increase indefinitely with increasing concentration. Continuously increasing the inorganic salt content in the electrolyte solution will increase subsequent treatment costs and damage the electrodes. Therefore, a reasonable electrolyte concentration needs to be selected based on energy consumption.

[0071] Application Example 4: The degradation of cefquinoxime in wastewater using the three-dimensional BDD membrane electrode prepared in Example 1 was accomplished according to the following steps:

[0072] 100 mL of cefquinoxime modeling wastewater with different pH values ​​(pH=3, pH=7, pH=11) and a concentration of 25 mg / L was added to an electrolytic cell. 1.4204 g of K₂SO₄ (0.1 mol / L) was added as the electrolyte. The three-dimensional BDD mesh electrode prepared in Example 1 was used as the positive electrode, and a Pt platinum sheet was used as the negative electrode. The spacing between the positive and negative electrode plates was fixed at 2 cm. The wastewater temperature was 25 °C and the current intensity was 30 mA / cm. 2 The degradation process lasted from 0 min to 180 min. Samples were taken at several time points (30 min, 60 min, 90 min, 120 min, 150 min, and 180 min) during this period, and the TOC values ​​at each time point were measured. The TOC removal rate of the solution was then calculated. (See attached figure.) Figure 9 As shown;

[0073] Figure 9 This is an image showing the change in the removal rate of cefquinoxime by the three-dimensional BDD mesh electrode prepared in Example 1 as a function of pH value in Application Example 4;

[0074] from Figure 9 It can be seen that the removal rate of cefquinoxime is higher when the initial pH of the solution is 7 than when the initial pH is 11. At 180 minutes of experiment, the initial pH of the solution is 7, and the removal rate of cefquinoxime at this point is higher than when the initial pH is 3 or 11. The slightly stronger degradation effect under acidic conditions compared to alkaline conditions indicates that no pH adjustment is needed; these are the most suitable initial electrolysis conditions.

[0075] Application Example 5: To investigate the changing trend of organic matter mineralization degree in the electrocephaloquine oxime experiment, the total organic carbon (TOC) content in the solution was tested. This was specifically accomplished according to the following steps:

[0076] 100 mL of cefquinoxime modeling wastewater with pH = 7 and a concentration of 30 mg / L was added to an electrolytic cell. 1.4204 g of K₂SO₄ (0.1 mol / L) was added to the solution. The three-dimensional BDD mesh electrode for cefquinoxime degradation prepared in Example 1 was used as the positive electrode, and a Pt platinum sheet was used as the negative electrode. The spacing between the positive and negative electrode plates was fixed at 2 cm. The current intensity was 30 mA / cm² at different wastewater temperatures (25℃, 40℃, or 55℃). 2 The degradation process lasted from 0 min to 180 min. Samples were taken at several time points (30 min, 60 min, 90 min, 120 min, 150 min, and 180 min) during this period, and the TOC values ​​at each time point were measured. The TOC removal rate of the solution was then calculated. (See attached figure.) Figure 10 As shown;

[0077] Figure 10 This is an image showing the temperature-dependent degradation rate of cefquinoxime using the three-dimensional BDD mesh electrode prepared in Example 1, as described in Application Example 5.

[0078] Figure 11 The three-dimensional BDD mesh electrode prepared for Example 1 was tested under optimal conditions with a current intensity of 30 mA / cm. 2 The graph shows the change in TOC removal rate over time under the conditions of an initial concentration of 25 mg / L, an electrolyte concentration of 0.1 mol / L, and an initial pH of 7.

[0079] from Figure 11 It can be seen that the TOC removal rate of cefquinoxime solution gradually increased with electrolysis time in the experiment. The removal rate in the early stage of the experiment was better than that in the later stage, indicating that the TOC removal rate at 180 min was 75.24%. The overall mineralization degree was low. It is considered that the electrolysis process only produced an oxidation effect on some functional groups of the molecular structure. The main structure is relatively stable and difficult to oxidize.

[0080] Figure 11 The wastewater temperature was 25°C. Due to the formation of a large number of intermediate products during electrolysis, it was necessary to assess their potential environmental risks. This invention used EcoSAR software to perform toxicity analysis on cefquinoxime and its intermediate products. Figure 12 As shown, green represents non-toxic, yellow represents harmful, orange represents toxic, and red represents highly toxic. It can be observed that the toxicity of the electrolyte solution generally decreases with increasing electrolysis time.

Claims

1. An application of a three-dimensional BDD mesh electrode, characterized in that... A three-dimensional BDD (Browser-Diffuse-Degradation) membrane electrode is used to degrade cefquinome, specifically by the following steps: Wastewater containing cefquinoxime was added to an electrolytic cell, with K₂SO₄ added as the electrolyte. A three-dimensional BDD mesh electrode was used as the positive electrode, and a Pt platinum sheet was used as the negative electrode. The current intensity was 15 mA / cm². 2 ~45mA / cm 2 Degradation was carried out for 30 to 180 minutes to obtain wastewater in which cefquinoxime was removed; The concentration of cefquinoxime in the wastewater containing cefquinoxime is 25 mg / L to 100 mg / L; The pH value of the wastewater containing cefquinoxime is 3-11; The dosage of K2SO4 is 0.02 mol / L to 0.1 mol / L.

2. The application of a three-dimensional BDD mesh electrode according to claim 1, characterized in that... The distance between the positive and negative electrodes is fixed at 2cm.

3. The application of a three-dimensional BDD mesh electrode according to claim 1, characterized in that... The method for preparing a three-dimensional BDD mesh electrode is specifically completed according to the following steps:

1. Cut the copper mesh to obtain the growth substrate for the diamond mesh film; 2. The growth substrate of the diamond mesh film is cleaned, and then the growth substrate of the diamond mesh film is immersed in a suspension containing nanodiamond powder and sonicated to obtain a substrate loaded with nanodiamond powder.

3. The substrate loaded with nanodiamond powder is placed in deionized water for ultrasonic cleaning to obtain the pretreated substrate; IV. Using H2, CH4 and B as gas sources, boron-doped polycrystalline diamond was grown on a pretreated substrate by microwave plasma chemical vapor deposition to obtain a three-dimensional BDD mesh electrode.

4. The application of a three-dimensional BDD mesh electrode according to claim 3, characterized in that... The volume ratio of H2, CH4 and B mentioned in step four is 200:8:2.

5.

5. The application of a three-dimensional BDD mesh electrode according to claim 3, characterized in that... In step four, the microwave power of the microwave plasma chemical vapor deposition method is 500W~3800W, the diamond electrode growth temperature is 620℃~640℃, the working pressure is 12200Torr~12500Torr, and the time is 8h~10h.

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