Method for electrocatalytic degradation of tetracycline

Abstract

The application discloses a method for electrocatalytic degradation of tetracycline, which comprises the following steps: loading a Ni-based self-supporting electrode material or a Ni-Co-based self-supporting electrode material into a penetration type electrochemical reactor, the Ni-based self-supporting electrode material taking a nickel foam as a conductive framework, a nitrogen-doped carbon layer as a functional carrier and Ni as a catalytic center, the Ni-Co-based self-supporting electrode material taking a nickel foam as a conductive framework, a nitrogen-doped carbon layer as a functional carrier and Ni and Co as catalytic centers, then injecting wastewater containing tetracycline, and performing a degradation reaction by electrifying. The method for electrocatalytic degradation of tetracycline has the advantages of high mass transfer efficiency, high utilization rate of active sites of the catalyst, low loss of active components, good degradation effect on tetracycline and other antibiotic pollutants, good stability and the like, and is suitable for large-scale industrial application.

Description

Technical Field

[0001] This invention relates to the field of water treatment technology, and specifically to a method for electrocatalytic degradation of tetracycline. Background Technology

[0002] Typical antibiotics such as tetracycline possess strong chemical stability and are difficult to biodegrade. Furthermore, they may induce the spread of antibiotic resistance in bacteria, posing a significant potential threat to the ecological environment and human health. Therefore, developing efficient and stable technologies for treating antibiotic-contaminated wastewater is of great importance.

[0003] Electrocatalytic advanced oxidation (EAOPs) is a water treatment technology that uses electrical energy to drive electrode reactions and generate highly oxidizing active species (e.g., hydroxyl radicals ·OH) in situ to degrade organic pollutants. It offers advantages such as mild reaction conditions, strong oxidizing power, and ease of automation, showing great promise in the treatment of antibiotic-contaminated wastewater. However, when using traditional two-dimensional electrode systems for EAOPs, pollutants mainly reach the electrode surface through diffusion, resulting in low mass transfer efficiency and insufficient utilization of active sites, leading to low efficiency of the electrocatalytic reaction.

[0004] Flow-through electrochemical reaction systems enhance convective mass transfer by allowing wastewater to flow through the internal pores of the electrode, improving the contact efficiency between pollutants and active sites and thus effectively increasing the reaction rate. This overcomes the diffusion-limited mass transfer problem inherent in traditional two-dimensional electrode systems and has attracted widespread attention from researchers. However, most existing flow-through electrochemical reaction systems are constructed using commercially available porous materials or surface-loaded electrodes. The active components in the electrodes are mainly introduced through coating, impregnation, or loading, resulting in limited bonding between the active sites and the substrate. During long-term continuous operation, the electrodes suffer from problems such as easy loss of active components, rapid decline in structural stability, and insufficient utilization of internal active sites, severely impacting the long-term performance and engineering application potential of flow-through electrochemical reaction systems.

[0005] Therefore, it is of great significance to develop a method for treating antibiotic-contaminated wastewater that has high mass transfer efficiency, high utilization rate of catalyst active sites, minimal loss of active components, good degradation effect on tetracycline, and good stability. Summary of the Invention

[0006] The purpose of this invention is to provide a method for the electrocatalytic degradation of tetracycline.

[0007] The technical solution adopted in this invention is: A method for electrocatalytic degradation of tetracycline includes the following steps: Ni-based or Ni-Co-based self-supporting electrode materials are loaded into a through-type electrochemical reactor. The Ni-based self-supporting electrode material uses nickel foam as a conductive framework, nitrogen-doped carbon layer as a functional carrier, and Ni as a catalytic center. The Ni-Co-based self-supporting electrode material uses nickel foam as a conductive framework, nitrogen-doped carbon layer as a functional carrier, and Ni and Co as catalytic centers. Then, wastewater containing tetracycline is injected, and an electrolytic degradation reaction is carried out.

[0008] Preferably, the mass percentage of Ni in the Ni-based self-supporting electrode material is 0.5% to 5%.

[0009] Preferably, the Ni-based self-supporting electrode material is prepared by a method including the following steps: ammonium chloride, melamine and nickel foam are sequentially laid in a reaction vessel from bottom to top, and then calcined to obtain the Ni-based self-supporting electrode material.

[0010] Preferably, the calcination includes the following process: first, controlling the heating rate at 8℃ / min to 12℃ / min to raise the temperature from room temperature to 500℃ to 600℃, holding the temperature for 0.5h to 1h, then controlling the heating rate at 3℃ / min to 7℃ / min to continue raising the temperature to 800℃ to 1000℃, holding the temperature for 2h to 4h, and then naturally cooling to room temperature.

[0011] Preferably, the Ni-Co based self-supporting electrode material contains 0.5% to 10% Ni by mass and 0.5% to 5% Co by mass.

[0012] Preferably, the Ni-Co-based self-supporting electrode material is prepared by a method comprising the following steps: ammonium chloride, a melamine-cobalt chloride mixture and nickel foam are sequentially laid in a reaction vessel from bottom to top, and then calcined to obtain the Ni-Co-based self-supporting electrode material.

[0013] Preferably, the calcination includes the following process: first, controlling the heating rate at 8℃ / min to 12℃ / min to raise the temperature from room temperature to 500℃ to 600℃, holding the temperature for 0.5h to 1h, then controlling the heating rate at 3℃ / min to 7℃ / min to continue raising the temperature to 800℃ to 1000℃, holding the temperature for 2h to 4h, and then naturally cooling to room temperature.

[0014] Preferably, the through-type electrochemical reactor comprises, in sequence, a first perforated flange, a first perforated titanium sheet, a first electrode material mounting component, a perforated separator, a second electrode material mounting component, a second perforated titanium sheet, and a second perforated flange; the first perforated flange is connected to the inlet; the second perforated flange is connected to the outlet; and the first perforated flange, the first perforated titanium sheet, the perforated separator, the second perforated titanium sheet, and the second perforated flange all have through holes at their center positions.

[0015] Preferably, the first perforated flange, the first electrode material mounting component, the perforated insulating plate, the second electrode material mounting component, and the second perforated flange are all made of polytetrafluoroethylene (PTFE).

[0016] Preferably, the concentration of tetracycline in the tetracycline-containing wastewater is 20 mg / L to 150 mg / L.

[0017] Preferably, the pH value of the tetracycline-containing wastewater is 3 to 9.

[0018] Preferably, the tetracycline-containing wastewater also contains electrolytes.

[0019] Preferably, the electrolyte is at least one of NaCl and Na2SO4.

[0020] Preferably, the concentration of electrolyte in the tetracycline-containing wastewater is 5 g / L to 20 g / L.

[0021] Preferably, the flow rate of the tetracycline-containing wastewater in the through-flow electrochemical reactor is 0.5 mL / min to 6 mL / min.

[0022] More preferably, the flow rate of the tetracycline-containing wastewater in the through-flow electrochemical reactor is 0.5 mL / min to 4 mL / min.

[0023] Preferably, the degradation reaction is carried out under conditions of an electric current of 20mA to 100mA.

[0024] The reaction principle of this invention: This invention achieves synergistic coupling of structural reinforcement, electronic regulation, and mass transfer enhancement by constructing Ni-based self-supporting electrode materials / Ni-Co-based self-supporting electrode materials and combining them with a flow-through electrochemical reactor. The foamed nickel (three-dimensional porous conductive framework) in the Ni-based / Ni-Co-based self-supporting electrode materials improves electron transport capacity and increases the contact efficiency between pollutants and active sites. The nitrogen-doped carbon layer helps stabilize the dispersion of active components and improves the conductivity of the electrode material. Ni can form a high-valence active structure during the reaction, thereby promoting the oxidative degradation of pollutants. Co can regulate the electronic structure around Ni and promote interfacial charge transfer, thereby increasing the generation efficiency of active oxide species and active chlorine species, thus accelerating reaction kinetics. Simultaneously, the flow-through reaction mode forces wastewater to flow through the interior of the electrode material, significantly enhancing the mass transfer process and improving the utilization rate of active sites, ultimately achieving efficient and stable degradation of various antibiotic pollutants such as tetracycline.

[0025] The beneficial effects of the present invention are: the electrocatalytic degradation method of tetracycline of the present invention has the advantages of high mass transfer efficiency, high utilization rate of active sites of catalyst, easy loss of active components, good degradation effect on tetracycline and other antibiotic pollutants, and good stability, and is suitable for large-scale industrial application.

[0026] Specifically: 1) This invention constructs Ni-based self-supporting electrode materials / Ni-Co-based self-supporting electrode materials, realizes the construction of carbon skeletons with metal components, forms a self-supporting three-dimensional structure, effectively enhances the structural integrity of the electrode materials, and, combined with a flow-through electrochemical reaction system, achieves synergistic optimization of material structure strengthening and mass transfer strengthening. 2) The Ni-based self-supporting electrode material / Ni-Co-based self-supporting electrode material constructed in this invention has good conductivity, abundant active sites and excellent structural stability, which can effectively improve the contact efficiency between pollutants and active sites. Compared with the traditional two-dimensional electrode system, it has higher degradation efficiency for antibiotics, better cycle stability and wider applicability to pollutants, and can achieve efficient and stable removal of various antibiotic pollutants such as tetracycline. 3) Compared with traditional planar electrodes and other three-dimensional electrode systems, the Ni-based self-supporting electrode material / Ni-Co-based self-supporting electrode material constructed in this invention does not require a binder and has the characteristics of stable structure, easy loss of active components and excellent continuous operation performance. Attached Figure Description

[0027] Figure 1 The diagram shows the structure and physical image of the through-type electrochemical reactor in this invention.

[0028] Figure 2 This is a TEM image of the Ni-based self-supporting electrode material in this invention.

[0029] Figure 3 This is a TEM image of the Ni-Co-based self-supporting electrode material in this invention.

[0030] Figure 4 This is the liquid chromatogram of tetracycline.

[0031] Figure 5 These are schematic diagrams and physical images of the electrocatalytic degradation device constructed in this invention. Detailed Implementation

[0032] The present invention will be further explained and described below with reference to specific embodiments.

[0033] The through-flow electrochemical reactors in Examples 1-26 and Comparative Examples 1-5 (structural schematics and physical images are shown in the figure) Figure 1As shown in the figure, a is a schematic diagram of the through-type electrochemical reactor, b and c are actual pictures of the through-type electrochemical reactor, and d is an actual picture of the electrode material placed in the through-type electrochemical reactor. It consists of a first perforated flange, a first perforated titanium sheet, a first electrode material placement component, a perforated isolation plate, a second electrode material placement component, a second perforated titanium sheet, and a second perforated flange arranged in sequence. The first perforated flange is connected to the water inlet; the second perforated flange is connected to the water outlet; the first perforated flange, the first perforated titanium sheet, the perforated isolation plate, the second perforated titanium sheet, and the second perforated flange all have through holes in the center; the first perforated flange, the first electrode material placement component, the perforated isolation plate, the second electrode material placement component, and the second perforated flange are all made of polytetrafluoroethylene.

[0034] The preparation method of the Ni-based self-supporting electrode material (denoted as Ni-NC) in Examples 1-26 and Comparative Examples 1-3 is as follows: 50g of ammonium chloride, 15g of melamine, and 1g of nickel foam with dimensions of 100mm×50mm×0.5mm are sequentially filled into a crucible (with dimensions of 100mm×50mm×35mm) from bottom to top, and a crucible sheet with dimensions of 99mm×49mm×16mm is placed on top of the nickel foam (bottom of the crucible sheet). The material is placed in a crucible and then placed in a tube furnace. The heating rate is controlled at 10℃ / min to raise the temperature from room temperature to 550℃ and hold for 0.5h. Then the heating rate is controlled at 5℃ / min to raise the temperature to 900℃ and hold for 3h. The material is then naturally cooled to room temperature and cut into a cylindrical shape (18mm in diameter and 5mm in thickness) to obtain a Ni-based self-supporting electrode material (carbon content of 87.7wt%, oxygen content of 1.2wt%, nitrogen content of 6.3wt%, and nickel content of 4.8wt%).

[0035] Transmission electron microscopy (TEM) image of Ni-based self-supporting electrode material (Ni-NC) as shown in the figure. Figure 2 (The left and right images are TEM images at different magnifications, and the right image also includes the particle size distribution of the metal nanoparticles.)

[0036] Depend on Figure 2 It can be seen that the Ni-based self-supporting electrode material has a carbon fiber structure, with the fibers bending and entangled with each other, and many tiny metal nanoparticles incorporated into it.

[0037] The preparation method of the Ni-Co based self-supporting electrode material (denoted as Ni-Co-NC) in Examples 1-26 and Comparative Examples 1-3 is as follows: 15g of ammonium chloride, 50.4g of melamine-cobalt chloride mixture (50g of melamine + 0.4g of anhydrous cobalt chloride), and 1g of nickel foam with dimensions of 100mm×50mm×0.5mm are sequentially filled into a crucible (with dimensions of 100mm×50mm×35mm) from bottom to top, and a crucible sheet with dimensions of 99mm×49mm×16mm is placed on the foam. Above the nickel plating (with the bottom of the crucible sheet sinking into the crucible), it is placed in a tube furnace. First, the heating rate is controlled at 10℃ / min to raise the temperature from room temperature to 550℃, and it is held at that temperature for 0.5h. Then, the heating rate is controlled at 5℃ / min to continue raising the temperature to 900℃, and it is held at that temperature for 3h. After naturally cooling to room temperature, it is cut into a cylindrical shape (diameter of 18mm and thickness of 5mm) to obtain Ni-Co based self-supporting electrode material (carbon content of 80.6wt%, oxygen content of 1.8wt%, nitrogen content of 7.8wt%, nickel content of 7.4wt%, and cobalt content of 2.4wt%).

[0038] TEM image of Ni-Co based self-supporting electrode material (Ni-Co-NC) is shown below. Figure 3 As shown.

[0039] Depend on Figure 3 It can be seen that Ni-Co based self-supporting electrode material has a fibrous structure and is not a uniform and dense structure. There are many sheet-like carbon layers on the surface.

[0040] The mesoporous carbon material (denoted as MCM) in Comparative Example 4 was prepared as follows: 45g of resorcinol and 18.75g of Pluronic acid were added. F127, 171 mL of anhydrous ethanol and 135 mL of deionized water were mixed and stirred at room temperature for 15 min. Then, 1.165 g of 1,6-hexanediamine was added and stirring was continued for 45 min. Then, 61.6 mL of formaldehyde solution (37 wt%) was added. After the solution turned milky white, stirring was continued for 20 min. The solution was then poured into a cylindrical mold (18 mm in diameter and 5 mm in thickness) and dried in an oven at 50 °C for 24 h. The temperature was then raised to 60 °C and dried for another 24 h. The temperature was then raised to 100 °C and cured for 12 h. Finally, the temperature was raised to 900 °C at a rate of 2 °C / min in an argon atmosphere and held for 2 h. The mixture was then allowed to cool naturally to room temperature to obtain a mesoporous carbon material (carbon content 95.0 wt%, oxygen content 4.4 wt%, nitrogen content 0.6 wt%).

[0041] The nitrogen-doped carbon felt (denoted as NFCF) in Comparative Example 5 was prepared as follows: The carbon felt was immersed in a formamide aqueous solution (75wt%), and then reacted at 160℃ for 12h. After cooling, it was placed in a tube furnace and heated to 900℃ at a heating rate of 10℃ / min in an argon atmosphere. The temperature was held for 2h and then naturally cooled to room temperature. The carbon felt was then cut into cylindrical shapes (diameter 18mm, thickness 5mm) to obtain nitrogen-doped carbon felt (carbon content 84.0wt%, oxygen content 13.4wt%, nitrogen content 2.6wt%).

[0042] Example 1: A method for electrocatalytic degradation of tetracycline (liquid chromatogram of tetracycline is shown in figure) Figure 4 As shown; the structural schematic diagram and physical image of the constructed electrocatalytic degradation device are as follows. Figure 5 As shown in the figure (a is a schematic diagram of the electrocatalytic degradation device, and b is a physical image of the electrocatalytic degradation device), the steps are as follows: Two Ni-based self-supporting electrode materials (Ni-NC) were loaded into a through-flow electrochemical reactor (filled into the first electrode material mounting component and the second electrode material mounting component, respectively). Then, 200 mL of tetracycline-containing wastewater (simulated wastewater, pH adjusted using 0.05 mol / L hydrochloric acid) with a tetracycline concentration of 80 mg / L, sodium chloride concentration of 20 g / L, and pH of 5 was pumped into the through-flow electrochemical reactor at a flow rate of 1 mL / min, and electricity was applied. The degradation reaction was carried out (the first and second porous titanium sheets were connected to the positive and negative electrodes, respectively). The current was set to 100mA, the timing was started, and after 2 hours of stable operation, the liquid sample from the outlet section was collected, filtered, and the filtrate was then analyzed using liquid chromatography (LC; the calculation method adopted was the external standard method, by plotting the corresponding standard curves of the corresponding substances, and then calculating the concentration of tetracycline after the reaction by combining the LC detection of the reaction solution) and a chemical oxygen demand (COD) analyzer (the COD removal rate was determined by the potassium dichromate digestion method).

[0043] According to the test results, the removal rate of tetracycline in this embodiment was 99.48%, and the removal rate of COD was 81.76%.

[0044] Note: Liquid chromatography detection: After the reaction was completed, 1 mL of the reaction solution was taken and filtered through a 0.22 μm organic filter membrane. Liquid chromatography conditions: Shimadzu LC-16 chromatographic column equipped with Eclipse Plus C18 column, column temperature 35℃, mobile composition 0.2 wt% formic acid solution and methanol solution (75:25, v / v), flow rate set to 0.5 mL / min, and detection wavelength 254 nm.

[0045] Determination of COD by potassium dichromate digestion method: Take one tube of COD pre-prepared reagent (commercially available), add 2 mL of reaction solution, shake well, wait for it to cool to room temperature, and then put it into a digester (Hash DRB200) for digestion. Set the temperature to 150℃ and the time to 2 hours. Allow it to cool naturally, and then put it into a measuring instrument (Hash DR1010) for measurement.

[0046] Example 2: A method for electrocatalytic degradation of tetracycline, comprising the following steps: Two Ni-Co-based self-supporting electrode materials (Ni-Co-NC) were loaded into a permeation electrochemical reactor. Then, 400 mL of tetracycline-containing wastewater (simulated wastewater) with a tetracycline concentration of 120 mg / L, a sodium chloride concentration of 20 g / L, and a pH of 5 was pumped into the permeation electrochemical reactor at a flow rate of 3 mL / min. The degradation reaction was initiated by applying an electric current of 100 mA and timing was started. After 2 hours of stable operation, a liquid sample was collected from the outlet section, filtered, and the filtrate was analyzed using a liquid chromatograph and a chemical oxygen demand analyzer.

[0047] According to the test results, the removal rate of tetracycline in this embodiment was 98.91%, and the removal rate of COD was 72.02%.

[0048] Example 3: A method for electrocatalytic degradation of tetracycline, comprising the following steps: Two Ni-based self-supporting electrode materials (Ni-NC) were loaded into a permeation electrochemical reactor. Then, 200 mL of tetracycline-containing wastewater (simulated wastewater) with a tetracycline concentration of 80 mg / L, a sodium chloride concentration of 20 g / L, and a pH of 5 was introduced into the permeation electrochemical reactor via a peristaltic pump at a flow rate of 1 mL / min. The degradation reaction was initiated by applying an electric current of 60 mA and timing was started. After 2 hours of stable operation, a liquid sample was collected from the outlet section, filtered, and the filtrate was analyzed using a liquid chromatograph and a chemical oxygen demand analyzer.

[0049] According to the test results, the removal rate of tetracycline in this embodiment was 99.48%, and the removal rate of COD was 69.67%.

[0050] Example 4: A method for electrocatalytic degradation of tetracycline, comprising the following steps: Two Ni-based self-supporting electrode materials (Ni-NC) were loaded into a permeation electrochemical reactor. Then, 200 mL of tetracycline-containing wastewater (simulated wastewater) with a tetracycline concentration of 80 mg / L, a sodium chloride concentration of 20 g / L, and a pH of 5 was introduced into the permeation electrochemical reactor via a peristaltic pump at a flow rate of 1 mL / min. The degradation reaction was initiated by applying an electric current of 30 mA and timing was started. After 2 hours of stable operation, a liquid sample was collected from the outlet section, filtered, and the filtrate was analyzed using a liquid chromatograph and a chemical oxygen demand analyzer.

[0051] According to the test results, the removal rate of tetracycline in this embodiment was 98.63%, and the removal rate of COD was 40.54%.

[0052] Example 5: A method for electrocatalytic degradation of tetracycline, comprising the following steps: Two Ni-Co-based self-supporting electrode materials (Ni-Co-NC) were loaded into a permeation electrochemical reactor. Then, 400 mL of tetracycline-containing wastewater (simulated wastewater) with a tetracycline concentration of 120 mg / L, a sodium chloride concentration of 20 g / L, and a pH of 5 was introduced into the permeation electrochemical reactor via a peristaltic pump at a flow rate of 3 mL / min. The degradation reaction was initiated by applying an electric current of 20 mA and timing was started. After 2 hours of stable operation, a liquid sample was collected from the outlet section, filtered, and the filtrate was analyzed using a liquid chromatograph and a chemical oxygen demand analyzer.

[0053] According to the test, the removal rate of tetracycline in this embodiment was 55.93%, and the removal rate of COD was 22.02%.

[0054] Example 6: A method for electrocatalytic degradation of tetracycline, comprising the following steps: Two Ni-Co based self-supporting electrode materials (Ni-Co-NC) were loaded into a permeation electrochemical reactor. Then, 400 mL of tetracycline-containing wastewater (simulated wastewater) with a tetracycline concentration of 120 mg / L, a sodium chloride concentration of 20 g / L, and a pH of 5 was introduced into the permeation electrochemical reactor via a peristaltic pump at a flow rate of 3 mL / min. The degradation reaction was initiated by applying an electric current of 80 mA and timing was started. After 2 hours of stable operation, a liquid sample was collected from the outlet section, filtered, and the filtrate was analyzed using a liquid chromatograph and a chemical oxygen demand analyzer.

[0055] According to the test results, the removal rate of tetracycline in this embodiment was 98.72%, and the removal rate of COD was 66.22%.

[0056] Example 7: A method for electrocatalytic degradation of tetracycline, comprising the following steps: Two Ni-based self-supporting electrode materials (Ni-NC) were loaded into a permeation electrochemical reactor. Then, 400 mL of tetracycline-containing wastewater (simulated wastewater) with a tetracycline concentration of 120 mg / L, a sodium chloride concentration of 20 g / L, and a pH of 5 was pumped into the permeation electrochemical reactor at a flow rate of 3 mL / min. The degradation reaction was initiated by applying an electric current of 80 mA and timing was started. After 2 hours of stable operation, a liquid sample was collected from the outlet section, filtered, and the filtrate was analyzed using a liquid chromatograph and a chemical oxygen demand analyzer.

[0057] According to the test results, the removal rate of tetracycline in this embodiment was 87.20%, and the removal rate of COD was 36.78%.

[0058] Example 8: A method for electrocatalytic degradation of tetracycline, comprising the following steps: Two Ni-based self-supporting electrode materials (Ni-NC) were loaded into a permeation electrochemical reactor. Then, 200 mL of tetracycline-containing wastewater (simulated wastewater) with a tetracycline concentration of 80 mg / L, a sodium chloride concentration of 20 g / L, and a pH of 3 was introduced into the permeation electrochemical reactor via a peristaltic pump at a flow rate of 0.5 mL / min. The degradation reaction was initiated by applying an electric current of 20 mA and timing was started. After 2 hours of stable operation, a liquid sample was collected from the outlet section, filtered, and the filtrate was analyzed using a liquid chromatograph and a chemical oxygen demand analyzer.

[0059] According to the test results, the removal rate of tetracycline in this embodiment was 96.35%, and the removal rate of COD was 56.77%.

[0060] Example 9: A method for electrocatalytic degradation of tetracycline, comprising the following steps: Two Ni-based self-supporting electrode materials (Ni-NC) were loaded into a permeation electrochemical reactor. Then, 400 mL of tetracycline-containing wastewater (simulated wastewater) with a tetracycline concentration of 80 mg / L, a sodium chloride concentration of 5 g / L, and a pH of 3 was pumped into the permeation electrochemical reactor at a flow rate of 3 mL / min. The degradation reaction was initiated by applying an electric current of 20 mA and the timing was started. After 2 hours of stable operation, a liquid sample was collected from the outlet section, filtered, and the filtrate was analyzed using a liquid chromatograph and a chemical oxygen demand analyzer.

[0061] According to the test results, the removal rate of tetracycline in this embodiment was 60.27%, and the removal rate of COD was 38.59%.

[0062] Example 10: A method for electrocatalytic degradation of tetracycline, comprising the following steps: Two Ni-based self-supporting electrode materials (Ni-NC) were loaded into a permeation electrochemical reactor. Then, 400 mL of tetracycline-containing wastewater (simulated wastewater) with a tetracycline concentration of 80 mg / L, a sodium chloride concentration of 20 g / L, and a pH of 3 was pumped into the permeation electrochemical reactor at a flow rate of 2 mL / min. The degradation reaction was initiated by applying an electric current of 50 mA and timing was started. After 2 hours of stable operation, a liquid sample was collected from the outlet section, filtered, and the filtrate was analyzed using a liquid chromatograph and a chemical oxygen demand analyzer.

[0063] According to the test results, the removal rate of tetracycline in this embodiment was 90.11%, and the removal rate of COD was 51.32%.

[0064] Example 11: A method for electrocatalytic degradation of tetracycline, comprising the following steps: Two Ni-based self-supporting electrode materials (Ni-NC) were loaded into a permeation electrochemical reactor. Then, 400 mL of tetracycline-containing wastewater (simulated wastewater with pH adjusted using 0.05 mol / L sodium hydroxide solution, containing 80 mg / L tetracycline, 20 g / L sodium chloride, and pH 9) was pumped into the permeation electrochemical reactor at a flow rate of 2 mL / min. The degradation reaction was initiated with an electric current of 50 mA. After 2 hours of stable operation, a liquid sample was collected from the outlet section, filtered, and the filtrate was analyzed using a liquid chromatograph and a chemical oxygen demand analyzer.

[0065] According to the test results, the removal rate of tetracycline in this embodiment was 71.54%, and the removal rate of COD was 45.09%.

[0066] Example 12: A method for electrocatalytic degradation of tetracycline, comprising the following steps: Two Ni-based self-supporting electrode materials (Ni-NC) were loaded into a permeation electrochemical reactor. Then, 400 mL of tetracycline-containing wastewater (simulated wastewater with pH adjusted by a 0.05 mol / L sodium hydroxide solution) containing 80 mg / L tetracycline, 20 g / L sodium chloride, and pH 7 was pumped into the permeation electrochemical reactor at a flow rate of 2 mL / min. The degradation reaction was initiated with an electric current of 50 mA. After 2 hours of stable operation, a liquid sample was collected from the outlet section, filtered, and the filtrate was analyzed using a liquid chromatograph and a chemical oxygen demand analyzer.

[0067] According to the test results, the removal rate of tetracycline in this embodiment was 88.21%, and the removal rate of COD was 51.02%.

[0068] Example 13: A method for electrocatalytic degradation of tetracycline, comprising the following steps: Two Ni-based self-supporting electrode materials (Ni-NC) were loaded into a permeation electrochemical reactor. Then, 400 mL of tetracycline-containing wastewater (simulated wastewater) with a tetracycline concentration of 80 mg / L, a sodium chloride concentration of 20 g / L, and a pH of 5 was pumped into the permeation electrochemical reactor at a flow rate of 3 mL / min. The degradation reaction was initiated by applying an electric current of 50 mA and timing was started. After 2 hours of stable operation, a liquid sample was collected from the outlet section, filtered, and the filtrate was analyzed using a liquid chromatograph and a chemical oxygen demand analyzer.

[0069] According to the test results, the removal rate of tetracycline in this embodiment was 77.78%, and the removal rate of COD was 40.22%.

[0070] Example 14: A method for electrocatalytic degradation of tetracycline, comprising the following steps: Two Ni-based self-supporting electrode materials (Ni-NC) were loaded into a permeation electrochemical reactor. Then, 600 mL of tetracycline-containing wastewater (simulated wastewater) with a tetracycline concentration of 80 mg / L, a sodium chloride concentration of 20 g / L, and a pH of 5 was pumped into the permeation electrochemical reactor at a flow rate of 5 mL / min. The degradation reaction was initiated by applying an electric current of 50 mA and timing was started. After 2 hours of stable operation, a liquid sample was collected from the outlet section, filtered, and the filtrate was analyzed using a liquid chromatograph and a chemical oxygen demand analyzer.

[0071] According to the test results, the removal rate of tetracycline in this embodiment was 40.52%, and the removal rate of COD was 26.78%.

[0072] Example 15: A method for electrocatalytic degradation of tetracycline, comprising the following steps: Two Ni-based self-supporting electrode materials (Ni-NC) were loaded into a permeation electrochemical reactor. Then, 200 mL of tetracycline-containing wastewater (simulated wastewater) with a tetracycline concentration of 80 mg / L, a sodium chloride concentration of 20 g / L, and a pH of 5 was introduced into the permeation electrochemical reactor via a peristaltic pump at a flow rate of 0.5 mL / min. The degradation reaction was initiated by applying an electric current of 50 mA and timing was started. After 2 hours of stable operation, a liquid sample was collected from the outlet section, filtered, and the filtrate was analyzed using a liquid chromatograph and a chemical oxygen demand analyzer.

[0073] According to the test results, the removal rate of tetracycline in this embodiment was 97.62%, and the removal rate of COD was 50.98%.

[0074] Example 16: A method for electrocatalytic degradation of tetracycline, comprising the following steps: Two Ni-based self-supporting electrode materials (Ni-NC) were loaded into a permeation electrochemical reactor. Then, 200 mL of tetracycline-containing wastewater (simulated wastewater) with a tetracycline concentration of 20 mg / L, a sodium chloride concentration of 20 g / L, and a pH of 5 was introduced into the permeation electrochemical reactor via a peristaltic pump at a flow rate of 1 mL / min. The degradation reaction was initiated by applying an electric current of 50 mA and timing was started. After 2 hours of stable operation, a liquid sample was collected from the outlet section, filtered, and the filtrate was analyzed using a liquid chromatograph and a chemical oxygen demand analyzer.

[0075] According to the test, the removal rate of tetracycline in this embodiment was 99.69%, and the removal rate of COD was 55.60%.

[0076] Example 17: A method for electrocatalytic degradation of tetracycline, comprising the following steps: Two Ni-based self-supporting electrode materials (Ni-NC) were loaded into a permeation electrochemical reactor. Then, 200 mL of tetracycline-containing wastewater (simulated wastewater) with a tetracycline concentration of 100 mg / L, a sodium chloride concentration of 20 g / L, and a pH of 5 was introduced into the permeation electrochemical reactor via a peristaltic pump at a flow rate of 1 mL / min. The degradation reaction was initiated by applying an electric current of 50 mA and timing was started. After 2 hours of stable operation, a liquid sample was collected from the outlet section, filtered, and the filtrate was analyzed using a liquid chromatograph and a chemical oxygen demand analyzer.

[0077] According to the test results, the removal rate of tetracycline in this embodiment was 78.65%, and the removal rate of COD was 49.01%.

[0078] Example 18: A method for electrocatalytic degradation of tetracycline, comprising the following steps: Two Ni-Co based self-supporting electrode materials (Ni-Co-NC) were loaded into a permeation electrochemical reactor. Then, 400 mL of tetracycline-containing wastewater (simulated wastewater) with a tetracycline concentration of 120 mg / L, a sodium chloride concentration of 20 g / L, and a pH of 5 was introduced into the permeation electrochemical reactor via a peristaltic pump at a flow rate of 3 mL / min. The degradation reaction was initiated by applying an electric current of 80 mA and timing was started. After 2 hours of stable operation, a liquid sample was collected from the outlet section, filtered, and the filtrate was analyzed using a liquid chromatograph and a chemical oxygen demand analyzer.

[0079] According to the test results, the removal rate of tetracycline in this embodiment was 98.64%, and the removal rate of COD was 55.54%.

[0080] Example 19: A method for electrocatalytic degradation of tetracycline, comprising the following steps: Two Ni-Co-based self-supporting electrode materials (Ni-Co-NC) were loaded into a permeation electrochemical reactor. Then, 400 mL of tetracycline-containing wastewater (simulated wastewater) with a tetracycline concentration of 120 mg / L, a sodium chloride concentration of 10 g / L, and a pH of 5 was introduced into the permeation electrochemical reactor via a peristaltic pump at a flow rate of 3 mL / min. The degradation reaction was initiated by applying an electric current of 80 mA and timing was started. After 2 hours of stable operation, a liquid sample was collected from the outlet section, filtered, and the filtrate was analyzed using a liquid chromatograph and a chemical oxygen demand analyzer.

[0081] According to the test results, the removal rate of tetracycline in this embodiment was 74.43%, and the removal rate of COD was 45.67%.

[0082] Example 20: A method for electrocatalytic degradation of tetracycline, comprising the following steps: Two Ni-Co-based self-supporting electrode materials (Ni-Co-NC) were loaded into a permeation electrochemical reactor. Then, 400 mL of tetracycline-containing wastewater (simulated wastewater) with a tetracycline concentration of 120 mg / L, a sodium chloride concentration of 20 g / L, and a pH of 3 was pumped into the permeation electrochemical reactor at a flow rate of 3 mL / min. The degradation reaction was initiated by applying an electric current of 80 mA and timing was started. After 2 hours of stable operation, a liquid sample was collected from the outlet section, filtered, and the filtrate was analyzed using a liquid chromatograph and a chemical oxygen demand analyzer.

[0083] According to the test results, the removal rate of tetracycline in this embodiment was 86.75%, and the removal rate of COD was 50.23%.

[0084] Example 21: A method for electrocatalytic degradation of tetracycline, comprising the following steps: Two Ni-Co based self-supporting electrode materials (Ni-Co-NC) were loaded into a permeation electrochemical reactor. Then, 400 mL of tetracycline-containing wastewater (simulated wastewater) with a tetracycline concentration of 120 mg / L, a sodium chloride concentration of 20 g / L, and a pH of 9 was introduced into the permeation electrochemical reactor via a peristaltic pump at a flow rate of 3 mL / min. The degradation reaction was initiated by applying an electric current of 80 mA and timing was started. After 2 hours of stable operation, a liquid sample was collected from the outlet section, filtered, and the filtrate was analyzed using a liquid chromatograph and a chemical oxygen demand analyzer.

[0085] According to the test, the removal rate of tetracycline in this embodiment was 71.78%, and the removal rate of COD was 44.77%.

[0086] Example 22: A method for electrocatalytic degradation of tetracycline, comprising the following steps: Two Ni-Co-based self-supporting electrode materials (Ni-Co-NC) were loaded into a permeation electrochemical reactor. Then, 400 mL of tetracycline-containing wastewater (simulated wastewater) with a tetracycline concentration of 120 mg / L, a sodium chloride concentration of 20 g / L, and a pH of 7 was introduced into the permeation electrochemical reactor via a peristaltic pump at a flow rate of 3 mL / min. The degradation reaction was initiated by applying an electric current of 80 mA and timing was started. After 2 hours of stable operation, a liquid sample was collected from the outlet section, filtered, and the filtrate was analyzed using a liquid chromatograph and a chemical oxygen demand analyzer.

[0087] According to the test results, the removal rate of tetracycline in this embodiment was 63.68%, and the removal rate of COD was 40.98%.

[0088] Example 23: A method for electrocatalytic degradation of tetracycline, comprising the following steps: Two Ni-Co-based self-supporting electrode materials (Ni-Co-NC) were loaded into a permeation electrochemical reactor. Then, 400 mL of tetracycline-containing wastewater (simulated wastewater) with a tetracycline concentration of 80 mg / L, a sodium chloride concentration of 20 g / L, and a pH of 5 was introduced into the permeation electrochemical reactor via a peristaltic pump at a flow rate of 3 mL / min. The degradation reaction was initiated by applying an electric current of 80 mA and timing was started. After 2 hours of stable operation, a liquid sample was collected from the outlet section, filtered, and the filtrate was analyzed using a liquid chromatograph and a chemical oxygen demand analyzer.

[0089] According to the test results, the removal rate of tetracycline in this embodiment was 97.00%, and the removal rate of COD was 56.91%.

[0090] Example 24: A method for electrocatalytic degradation of tetracycline, comprising the following steps: Two Ni-Co-based self-supporting electrode materials (Ni-Co-NC) were loaded into a permeation electrochemical reactor. Then, 400 mL of tetracycline-containing wastewater (simulated wastewater) with a tetracycline concentration of 150 mg / L, a sodium chloride concentration of 20 g / L, and a pH of 5 was introduced into the permeation electrochemical reactor via a peristaltic pump at a flow rate of 3 mL / min. The degradation reaction was initiated by applying an electric current of 80 mA and timing was started. After 2 hours of stable operation, a liquid sample was collected from the outlet section, filtered, and the filtrate was analyzed using a liquid chromatograph and a chemical oxygen demand analyzer.

[0091] According to the test results, the removal rate of tetracycline in this embodiment was 68.77%, and the removal rate of COD was 40.39%.

[0092] Example 25: A method for electrocatalytic degradation of tetracycline, comprising the following steps: Two Ni-Co based self-supporting electrode materials (Ni-Co-NC) were loaded into a permeation electrochemical reactor. Then, 800 mL of tetracycline-containing wastewater (simulated wastewater) with a tetracycline concentration of 120 mg / L, a sodium chloride concentration of 20 g / L, and a pH of 5 was introduced into the permeation electrochemical reactor via a peristaltic pump at a flow rate of 6 mL / min. The degradation reaction was initiated by applying an electric current of 80 mA and timing was started. After 2 hours of stable operation, a liquid sample was collected from the outlet section, filtered, and the filtrate was analyzed using a liquid chromatograph and a chemical oxygen demand analyzer.

[0093] According to the test results, the removal rate of tetracycline in this embodiment was 60.00%, and the removal rate of COD was 32.37%.

[0094] Example 26: A method for electrocatalytic degradation of tetracycline, comprising the following steps: Two Ni-Co-based self-supporting electrode materials (Ni-Co-NC) were loaded into a permeation electrochemical reactor. Then, 600 mL of tetracycline-containing wastewater (simulated wastewater) with a tetracycline concentration of 120 mg / L, a sodium chloride concentration of 20 g / L, and a pH of 5 was pumped into the permeation electrochemical reactor at a flow rate of 4 mL / min. The degradation reaction was initiated by applying an electric current of 80 mA and timing was started. After 2 hours of stable operation, a liquid sample was collected from the outlet section, filtered, and the filtrate was analyzed using a liquid chromatograph and a chemical oxygen demand analyzer.

[0095] According to the test, the removal rate of tetracycline in this embodiment was 86.00%, and the removal rate of COD was 49.90%.

[0096] Comparative Example 1: A method for degrading tetracycline, comprising the following steps: Two Ni-Co based self-supporting electrode materials (Ni-Co-NC) were loaded into a permeation electrochemical reactor. Then, 400 mL of tetracycline-containing wastewater (simulated wastewater) with a tetracycline concentration of 120 mg / L, a sodium chloride concentration of 20 g / L, and a pH of 5 was introduced into the permeation electrochemical reactor through a peristaltic pump. The flow rate was set to 3 mL / min, and the timer was started. After 2 hours of stable operation, a liquid sample was collected from the outlet section, filtered, and the filtrate was analyzed using a liquid chromatograph and a chemical oxygen demand analyzer.

[0097] The test results showed that the removal rate of tetracycline in this comparative example was 33.60%, and the removal rate of COD was 30.23%.

[0098] Comparative Example 2: A method for degrading tetracycline, comprising the following steps: Two Ni-based self-supporting electrode materials (Ni-NC) were loaded into a permeation electrochemical reactor. Then, 200 mL of tetracycline-containing wastewater (simulated wastewater) with a tetracycline concentration of 80 mg / L, a sodium chloride concentration of 20 g / L, and a pH of 5 was introduced into the permeation electrochemical reactor via a peristaltic pump at a flow rate of 1 mL / min. Timing was started, and after 2 hours of stable operation, a liquid sample was collected from the outlet section, filtered, and the filtrate was analyzed using a liquid chromatograph and a chemical oxygen demand analyzer.

[0099] The test results showed that the removal rate of tetracycline in this comparative example was 37.38%, and the removal rate of COD was 12.77%.

[0100] Comparative Example 3: A method for electrocatalytic degradation of tetracycline, comprising the following steps: Two Ni-based self-supporting electrode materials (Ni-NC) were immersed in 6 mol / L hydrochloric acid and stirred for 12 h. After being removed, washed and dried, they were loaded into a permeation electrochemical reactor. 200 mL of tetracycline-containing wastewater (simulated wastewater) with a tetracycline concentration of 80 mg / L, sodium chloride concentration of 20 g / L, and pH of 5 was pumped into the permeation electrochemical reactor at a flow rate of 1 mL / min. The degradation reaction was initiated with an electric current of 60 mA. After 2 h of stable operation, a liquid sample was collected from the outlet section, filtered, and the filtrate was analyzed using a liquid chromatograph and a chemical oxygen demand analyzer.

[0101] The test results showed that the removal rate of tetracycline in this comparative example was 33.42%, and the removal rate of COD was 10.77%.

[0102] Comparative Example 4: A method for electrocatalytic degradation of tetracycline, comprising the following steps: Two pieces of mesoporous carbon material (MCM) were packed into a permeation electrochemical reactor. Then, 200 mL of tetracycline-containing wastewater (simulated wastewater) with a tetracycline concentration of 80 mg / L, a sodium chloride concentration of 20 g / L, and a pH of 5 was introduced into the permeation electrochemical reactor via a peristaltic pump at a flow rate of 1 mL / min. The degradation reaction was initiated by applying an electric current of 60 mA and timing was started. After 2 hours of stable operation, a liquid sample was collected from the outlet section, filtered, and the filtrate was analyzed using a liquid chromatograph and a chemical oxygen demand analyzer.

[0103] The test results showed that the removal rate of tetracycline in this comparative example was 38.92%, and the removal rate of COD was 19.17%.

[0104] Comparative Example 5: A method for electrocatalytic degradation of tetracycline, comprising the following steps: Two pieces of nitrogen-doped carbon felt (NFCF) were packed into a permeation electrochemical reactor. Then, 200 mL of tetracycline-containing wastewater (simulated wastewater) with a tetracycline concentration of 80 mg / L, a sodium chloride concentration of 20 g / L, and a pH of 5 was pumped into the permeation electrochemical reactor at a flow rate of 1 mL / min. The degradation reaction was initiated by applying an electric current of 60 mA and timing was started. After 2 hours of stable operation, a liquid sample was collected from the outlet section, filtered, and the filtrate was analyzed using a liquid chromatograph and a chemical oxygen demand analyzer.

[0105] The test results showed that the removal rate of tetracycline in this comparative example was 31.62%, and the removal rate of COD was 24.17%.

[0106] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A method for electrocatalytic degradation of tetracycline, characterized in that, Includes the following steps: Ni-based or Ni-Co-based self-supporting electrode materials are loaded into a through-type electrochemical reactor. The Ni-based self-supporting electrode material uses nickel foam as a conductive framework, nitrogen-doped carbon layer as a functional carrier, and Ni as a catalytic center. The Ni-Co-based self-supporting electrode material uses nickel foam as a conductive framework, nitrogen-doped carbon layer as a functional carrier, and Ni and Co as catalytic centers. Then, wastewater containing tetracycline is injected, and an electrolytic degradation reaction is carried out.

2. The method for electrocatalytic degradation of tetracycline according to claim 1, characterized in that: The mass percentage of Ni in the Ni-based self-supporting electrode material is 0.5% to 5%.

3. The method for electrocatalytic degradation of tetracycline according to claim 2, characterized in that: The Ni-based self-supporting electrode material is prepared by a method including the following steps: ammonium chloride, melamine and nickel foam are sequentially laid in a reaction vessel from bottom to top, and then calcined to obtain the Ni-based self-supporting electrode material.

4. The method for electrocatalytic degradation of tetracycline according to claim 3, characterized in that: The calcination process includes the following steps: first, the heating rate is controlled at 8℃ / min to 12℃ / min to raise the temperature from room temperature to 500℃ to 600℃, and the temperature is held for 0.5h to 1h; then, the heating rate is controlled at 3℃ / min to 7℃ / min to continue raising the temperature to 800℃ to 1000℃, and the temperature is held for 2h to 4h; and then the temperature is naturally cooled to room temperature.

5. The method for electrocatalytic degradation of tetracycline according to claim 1, characterized in that: The Ni-Co based self-supporting electrode material contains 0.5% to 10% Ni by mass and 0.5% to 5% Co by mass.

6. The method for electrocatalytic degradation of tetracycline according to claim 5, characterized in that: The Ni-Co-based self-supporting electrode material is prepared by a method including the following steps: ammonium chloride, melamine-cobalt chloride mixture and nickel foam are sequentially laid in a reaction vessel from bottom to top, and then calcined to obtain the Ni-Co-based self-supporting electrode material.

7. The method for electrocatalytic degradation of tetracycline according to claim 6, characterized in that: The calcination process includes the following steps: first, the heating rate is controlled at 8℃ / min to 12℃ / min to raise the temperature from room temperature to 500℃ to 600℃, and the temperature is held for 0.5h to 1h; then, the heating rate is controlled at 3℃ / min to 7℃ / min to continue raising the temperature to 800℃ to 1000℃, and the temperature is held for 2h to 4h; and then the temperature is naturally cooled to room temperature.

8. The method for electrocatalytic degradation of tetracycline according to any one of claims 1 to 7, characterized in that: The permeable electrochemical reactor comprises, in sequence, a first perforated flange, a first perforated titanium sheet, a first electrode material mounting component, a perforated isolation plate, a second electrode material mounting component, a second perforated titanium sheet, and a second perforated flange; the first perforated flange is connected to the inlet; the second perforated flange is connected to the outlet; the first perforated flange, the first perforated titanium sheet, the perforated isolation plate, the second perforated titanium sheet, and the second perforated flange all have through holes at their center positions.

9. The method for electrocatalytic degradation of tetracycline according to any one of claims 1 to 7, characterized in that: The concentration of tetracycline in the tetracycline-containing wastewater is 20 mg / L to 150 mg / L; and / or, the pH value of the tetracycline-containing wastewater is 3 to 9; and / or, the flow rate of the tetracycline-containing wastewater in the through-flow electrochemical reactor is 0.5 mL / min to 6 mL / min.

10. The method for electrocatalytic degradation of tetracycline according to any one of claims 1 to 7, characterized in that: The degradation reaction is carried out under conditions of current ranging from 20mA to 100mA.

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