A magnetite-polypyrrole composite conductive magnetic electrode, its preparation method and application, and a method for treating petrochemical wastewater.

Abstract

This invention relates to the field of wastewater treatment technology, providing a magnetite-polypyrrole composite conductive magnetic electrode, its preparation method, applications, and a method for treating petrochemical wastewater. The composite conductive magnetic electrode provided by this invention includes an electrode and a modification layer coating the electrode surface, the modification layer comprising magnetite and polypyrrole. The composite conductive magnetic electrode provided by this invention possesses excellent conductivity, magnetism, and high stability, fully leveraging the synergistic effect of magnetic and conductive materials to improve the efficiency of electrochemical reactions and significantly enhance the removal of organic pollutants from petrochemical wastewater. Using the electrode of this invention, efficient, green, and low-energy-consumption treatment of petrochemical wastewater can be achieved, showing broad application prospects in the fields of environmental protection and industrial wastewater treatment.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment technology, and in particular to a magnetite-polypyrrole composite conductive magnetic electrode, its preparation method and application, and a method for treating petrochemical wastewater. Background Technology

[0002] With the rapid development of the global economy and the advancement of industrialization and urbanization, wastewater treatment has gradually become a crucial link in environmental protection and sustainable resource utilization. Especially in the petrochemical industry, wastewater often contains large amounts of harmful substances, such as petroleum pollutants, heavy metal ions, and other organic pollutants. The discharge of these pollutants not only poses a serious threat to the environment but also affects human health and the balance of ecosystems. Therefore, developing an efficient, green, and low-consumption petrochemical wastewater treatment technology is particularly important.

[0003] Traditional wastewater treatment methods include physical, chemical, and biological methods. While these methods can remove pollutants from water to some extent, they still suffer from problems such as low efficiency, high energy consumption, high operating costs, and secondary pollution, and urgently require the support of new technologies and materials.

[0004] In recent years, water treatment technologies based on electrochemistry have received widespread attention due to their advantages of high efficiency, energy saving, and environmental friendliness. Electrochemical treatment of petrochemical wastewater involves using an electrolytic cell to generate an electrochemical reaction by passing electricity through electrode materials to purify the wastewater. In this process, the electrode materials play a crucial role. However, existing electrode materials are mostly single-material materials with insufficient conductivity and stability, resulting in low reaction efficiency and low pollutant removal rates during the electrochemical treatment process. Summary of the Invention

[0005] In view of this, the present invention provides a magnetite-polypyrrole composite conductive magnetic electrode, its preparation method and application, and a method for treating petrochemical wastewater. The composite conductive magnetic electrode provided by the present invention possesses excellent conductivity, magnetism, and high stability, exhibiting high reaction efficiency and high pollutant removal rate in the electrochemical treatment of wastewater.

[0006] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0007] A magnetite-polypyrrole composite conductive magnetic electrode includes an electrode and a modification layer covering the surface of the electrode; the modification layer includes magnetite and polypyrrole.

[0008] Preferably, the electrode is a graphite electrode.

[0009] The present invention also provides a method for preparing the magnetite-polypyrrole composite conductive magnetic electrode described above, comprising the following steps:

[0010] The electrode was immersed in a mixed solution of polyvinylpyrrolidone and ferric chloride, and then dried and pyrolyzed in sequence to obtain a magnetite-modified electrode.

[0011] The magnetite-modified electrode was immersed in a pyrrole-chitosan mixed solution for electrochemical deposition to obtain the magnetite-polypyrrole composite conductive magnetic electrode.

[0012] Preferably, the concentration of polyvinylpyrrolidone in the polyvinylpyrrolidone-ferric chloride mixed solution is 15-25 g / L, and the concentration of ferric chloride is 10-20 g / L; the impregnation time is 6-10 h.

[0013] Preferably, the pyrolysis temperature is 450–550°C, the time is 3–6 h, and the heating rate to the pyrolysis temperature is 3–8°C / min.

[0014] Preferably, the pyrrole-chitosan mixed solution is obtained by mixing chitosan solution and pyrrole; the solvent of the chitosan solution is acetic acid solution; the concentration of chitosan in the chitosan solution is 4-6 g / L; and the content of pyrrole in the polypyrrole-chitosan mixed solution is 7-9 mL / L.

[0015] Preferably, the conditions for the electrochemical deposition include a current density of 3–7 mA / cm². 2 The deposition time is 18–22 min.

[0016] The present invention also provides the application of the magnetite-polypyrrole composite conductive magnetic electrode described in the above-described scheme or the magnetite-polypyrrole composite conductive magnetic electrode prepared by the preparation method described in the above-described scheme in the treatment of wastewater.

[0017] The present invention also provides a method for treating petrochemical wastewater, comprising the following steps:

[0018] In an external magnetic field, a two-electrode system is used to degrade petrochemical wastewater. The electrodes in the two-electrode system include a modified electrode and a counter electrode. The modified electrode is the magnetite-polypyrrole composite conductive magnetic electrode described in the above scheme or the magnetite-polypyrrole composite conductive magnetic electrode prepared by the preparation method described in the above scheme.

[0019] Preferably, during the degradation process, the voltage of the two-electrode system is 1.0–1.5V;

[0020] The magnetic field strength of the external magnetic field is 40–60 mT;

[0021] The method for applying the external magnetic field is as follows: place the rubidium magnet on both sides and the bottom of the two-electrode system, and control the magnetic field strength by changing the distance between the rubidium magnet and the two-electrode system.

[0022] This invention provides a magnetite-polypyrrole composite conductive magnetic electrode, comprising an electrode and a modification layer coating the electrode surface; the modification layer comprises magnetite and polypyrrole. This invention modifies the electrode material surface with magnetite and polypyrrole. Magnetite, as a conductive and magnetic material, can effectively enhance the electrode's electron transfer capability and improve its electrochemical reactivity. Furthermore, the magnetic characteristics of magnetite and the application of magnetic fields can strengthen the interaction between the electrode and pollutants in wastewater, further improving the treatment effect. Moreover, the magnetic responsiveness of magnetite facilitates positioning and removal via magnetic fields, enabling detachable operation and recycling of the electrode, reducing operating costs and extending its service life. Polypyrrole, as a conductive polymer, possesses excellent conductivity and stability, which can further promote the electron transfer efficiency on the electrode surface. The composite conductive magnetic electrode provided by this invention combines the excellent properties of magnetic and conductive materials, giving full play to the synergistic effect of magnetic and conductive materials. It also has strong stability and recyclability, and can effectively adsorb and catalytically degrade organic pollutants in petrochemical wastewater. Compared with traditional electrode materials, the composite conductive magnetic electrode of this invention has higher electrochemical reaction efficiency, which can significantly enhance the removal efficiency of organic pollutants in petrochemical wastewater and shorten the treatment time.

[0023] Meanwhile, the composite conductive magnetic electrode provided by this invention also possesses high chemical stability and mechanical strength, maintaining high processing efficiency and good structural integrity during long-term operation, thus extending the electrode's service life. This stability enables the electrode of this invention to operate continuously and efficiently in petrochemical wastewater treatment environments with varying TPH concentrations, reducing the frequency of equipment maintenance and replacement. Applying the composite conductive magnetic electrode of this invention to petrochemical wastewater treatment can effectively reduce energy consumption and environmental pollution, while simultaneously achieving efficient removal of pollutants from wastewater. It offers green and environmentally friendly advantages and has broad application prospects in the fields of environmental protection and industrial wastewater treatment.

[0024] This invention also provides a method for preparing the magnetite-polypyrrole composite conductive magnetic electrode described above. This invention employs a two-step method for the composite modification of magnetite and polypyrrole materials. First, magnetite is modified onto the surface of the electrode material via an impregnation-pyrolysis method, and then polypyrrole is modified via electrochemical deposition. The preparation method provided by this invention is simple to operate and easy to implement.

[0025] This invention also provides a method for treating petrochemical wastewater, comprising the following steps: degrading the petrochemical wastewater using a two-electrode system in an external magnetic field, wherein the electrodes in the two-electrode system include a modified electrode and a counter electrode; the modified electrode is the magnetite-polypyrrole composite conductive magnetic electrode described in the above-mentioned scheme. This invention, through the combination of magnetism and conductivity, can effectively improve the pollutant removal efficiency. By applying an external magnetic field, it can further promote the migration of pollutants and electron transfer on the electrode surface, optimize the electrochemical reaction process, accelerate the reaction rate, promote the degradation of pollutants, and reduce energy consumption during the treatment process. Furthermore, the method provided by this invention is characterized by simple operation and easy maintenance; the electrode surface is not easily completely clogged by pollutants, cleaning and maintenance are relatively simple, and the cost of using and replacing the equipment is low. Furthermore, the method provided by this invention has a high degree of system integration, enabling it to adapt to wastewater treatment needs of different scales and operating conditions. It is not only suitable for the treatment of petrochemical wastewater, but can also be adjusted and optimized according to the properties of the wastewater. For example, pollutant enrichment can be controlled by adjusting the applied magnetic field strength (40-60mT); electron transfer rate and reaction rate can be adjusted by adjusting the external voltage; and the composite electrode structure of this invention is flexible, allowing the size, number, and arrangement of the electrodes to be selected according to the concentration of organic matter in the wastewater. Through the above adjustments, it can adapt to the treatment needs of various types and pollutant concentrations of wastewater, and has broad application prospects.

[0026] In summary, the method provided by this invention not only significantly improves the treatment efficiency of petrochemical wastewater but also reduces energy consumption and enhances system stability, providing an important reference for the optimization and application of electrochemical water treatment technology. Furthermore, while achieving high-efficiency treatment, this invention promotes the development of wastewater treatment technology towards low-carbon and stable directions, opening up new paths for improving the green, efficient, and sustainable level and application prospects of petrochemical wastewater treatment. It possesses significant innovation and practical application value in the field of petrochemical wastewater treatment technology. Attached Figure Description

[0027] Figure 1 This is a schematic diagram illustrating the preparation of a magnetite-polypyrrole composite conductive magnetic electrode and its application in treating petrochemical wastewater according to the present invention.

[0028] Figure 2 The curves show the changes in total petroleum hydrocarbon content in petrochemical wastewater at different time points;

[0029] Figure 3 The changes in the removal rate of total petroleum hydrocarbons in petrochemical wastewater at different time points are shown. Detailed Implementation

[0030] The present invention provides a magnetite-polypyrrole composite conductive magnetic electrode, comprising an electrode and a modification layer covering the surface of the electrode; the modification layer comprises magnetite and polypyrrole.

[0031] In this invention, the magnetite is specifically nano-magnetite; the electrode is preferably a graphite electrode; specifically, a graphite electrode sheet.

[0032] In this invention, the modification layer specifically includes a magnetite layer modified on the electrode surface and a polypyrrole film modified on the surface of the magnetite layer.

[0033] In this invention, magnetite is a material with good electrical conductivity and magnetism, and polypyrrole, as a conductive polymer, has good electrical conductivity and chemical stability. Moreover, it is low in cost, has high conductivity in the doped state, and is easy to prepare on a large scale. This invention combines magnetite and polypyrrole, which can give full play to the advantages of both, not only providing excellent electrical conductivity and magnetism, but also increasing the surface area of ​​the electrode, thereby effectively improving the efficiency of the electrochemical treatment process.

[0034] The present invention also provides a method for preparing the magnetite-polypyrrole composite conductive magnetic electrode described above, comprising the following steps:

[0035] The electrode was immersed in a mixed solution of polyvinylpyrrolidone and ferric chloride, and then dried and pyrolyzed in sequence to obtain a magnetite-modified electrode.

[0036] The magnetite-modified electrode was immersed in a pyrrole-chitosan mixed solution for electrochemical deposition to obtain the magnetite-polypyrrole composite conductive magnetic electrode.

[0037] This invention involves immersing an electrode in a mixed solution of polyvinylpyrrolidone and ferric chloride, followed by sequential drying and pyrolysis, to obtain a magnetite-modified electrode. In this invention, the electrode is preferably pretreated before immersion. The pretreatment is preferably chemical cleaning or physical cleaning; the chemical cleaning is preferably acid solution cleaning, and the physical cleaning is preferably grinding or ultrasonic cleaning. This invention removes oxides and impurities from the electrode surface through pretreatment, thereby improving its surface affinity.

[0038] In this invention, the concentration of polyvinylpyrrolidone in the polyvinylpyrrolidone-ferric chloride mixed solution is preferably 15-25 g / L, specifically 20 g / L, and the concentration of ferric chloride is preferably 10-20 g / L, specifically 15 g / L; the solvent of the polyvinylpyrrolidone-ferric chloride mixed solution is water; the preparation method of the polyvinylpyrrolidone-ferric chloride mixed solution preferably includes: adding polyvinylpyrrolidone and ferric chloride to water, stirring for 2-4 hours, preferably 3 hours, to obtain the polyvinylpyrrolidone-ferric chloride mixed solution; the polyvinylpyrrolidone is preferably PVP-K30; the ferric chloride is preferably FeCl3·6H2O; and the water is preferably deionized water.

[0039] In this invention, the immersion time is preferably 6 to 10 hours, specifically 7 hours, 8 hours, or 9 hours; the immersion is preferably carried out at room temperature; this invention does not have special requirements on the amount of polyvinylpyrrolidone-ferric chloride mixed solution used during immersion, as long as it is sufficient to immerse the electrode; after immersion, the electrode is preferably removed and dried; the drying is preferably natural air drying, and the drying time is preferably 12 to 24 hours.

[0040] In this invention, the pyrolysis temperature is preferably 450-550°C, specifically 500°C; the pyrolysis time is preferably 3-6 hours, specifically 5 hours; the heating rate to the pyrolysis temperature is preferably 3-8°C / min, specifically 5°C / min; and the pyrolysis is preferably carried out in a muffle furnace.

[0041] After obtaining the magnetite-modified electrode, the present invention immerses the magnetite-modified electrode in a pyrrole-chitosan mixed solution for electrochemical deposition to obtain the magnetite-polypyrrole composite conductive magnetic electrode. In the present invention, the pyrrole-chitosan mixed solution is preferably obtained by mixing a chitosan solution and pyrrole; the solvent of the chitosan solution is preferably an acetic acid solution, and the concentration of the acetic acid solution is preferably 2 wt%; the concentration of chitosan in the chitosan solution is preferably 4-6 g / L, specifically 5 g / L; the content of pyrrole in the pyrrole-chitosan mixed solution is preferably 7-9 mL / L, specifically 8 mL / L; in a specific embodiment of the present invention, it is preferable to first disperse chitosan in an acetic acid solution to obtain a chitosan solution, and then ultrasonically disperse pyrrole in the chitosan solution; the present invention, by adding chitosan, can promote the deposition rate of pyrrole and improve the stability of the deposition process.

[0042] In this invention, the electrochemical deposition conditions preferably include a current density of 3–7 mA / cm². 2 Specifically, it can be 5mA / cm 2 The deposition time is 18–22 min, specifically 20 min. During the electrochemical deposition process, pyrrole forms a stable polypyrrole conductive film on the surface of the magnetite-modified layer, resulting in a magnetite-polypyrrole composite conductive magnetic electrode.

[0043] This invention also provides the application of the magnetite-polypyrrole composite conductive magnetic electrode described in the above-described scheme or the magnetite-polypyrrole composite conductive magnetic electrode prepared by the preparation method described in the above-described scheme in wastewater treatment; the wastewater is preferably petrochemical wastewater. In this invention, the magnetite-polypyrrole composite conductive magnetic electrode has excellent stability and conductivity, enabling the system to maintain high treatment efficiency during long-term operation while reducing energy consumption; the use of magnetic materials also makes pollutant recovery more efficient, reducing secondary pollution and waste generation; this invention, by combining magnetic and conductive properties, can effectively improve pollutant removal efficiency.

[0044] The present invention also provides a method for treating petrochemical wastewater, comprising the following steps:

[0045] In an external magnetic field, a two-electrode system is used to degrade petrochemical wastewater. The electrodes in the two-electrode system include a modified electrode and a counter electrode. The modified electrode is the magnetite-polypyrrole composite conductive magnetic electrode described in the above scheme or the magnetite-polypyrrole composite conductive magnetic electrode prepared by the preparation method described in the above scheme.

[0046] In this invention, the content of petroleum hydrocarbons (TPH) in the petrochemical wastewater is preferably 50-300 mg / L, and more preferably 80-150 mg / L.

[0047] In this invention, the counter electrode is preferably an unmodified electrode, specifically an unmodified graphite electrode.

[0048] In this invention, during the degradation process, the voltage of the two electrode system is preferably 1.0 to 1.5V, specifically 1.2V.

[0049] In this invention, the magnetic field strength of the external magnetic field is preferably 40-60 mT, specifically 50 mT; the preferred method of applying the external magnetic field is to place a rubidium magnet on both sides and the bottom of the two-electrode system, and control the magnetic field strength by changing the distance between the rubidium magnet and the two-electrode system. In this invention, applying an external magnetic field not only enhances the adsorption capacity of magnetite for pollutants, but also accelerates the migration of pollutants on the electrode surface through the guiding effect of the magnetic field, thereby optimizing the electrochemical degradation process. During the electrochemical reaction, the external magnetic field can enhance the conductivity of the electrodes, promote electron transfer, and improve the reaction rate and efficiency. Furthermore, the magnetic field can also induce local changes in current distribution on the electrode surface, thereby improving the removal effect of pollutants. When treating petrochemical wastewater containing organic pollutants and heavy metal ions, the application of an external magnetic field can not only improve the pollutant removal rate, but also effectively reduce secondary pollution, further enhancing the greenness and economy of wastewater treatment.

[0050] The technical solutions of this invention will be clearly and completely described below with reference to the embodiments thereof. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0051] Example 1

[0052] according to Figure 1 The process described above involves preparing a magnetite-polypyrrole composite conductive magnetic electrode and using it to treat petrochemical wastewater. The specific steps are as follows:

[0053] 1) Preparation of magnetite-polypyrrole composite conductive magnetic electrode

[0054] Preparation of magnetite-modified graphite sheet electrodes: PVPK30 and FeCl3·6H2O were dissolved in deionized water to prepare a solution with a PVP K30 concentration of 20 g / L and a FeCl3·6H2O concentration of 15 g / L. The solution was stirred for 3 hours until homogeneous. A graphite sheet electrode (6.0 cm in length, 1.0 cm in width, with an effective reaction area of ​​approximately 4.5 cm²) was then prepared. 2 The graphite sheet was immersed in the prepared solution for 8 hours to allow the solution to fully penetrate the surface of the graphite sheet. Afterward, the electrode was removed and dried overnight at room temperature. Then, the graphite sheet electrode was placed in a muffle furnace and pyrolyzed at 500°C for 5 hours at a heating rate of 5°C / min. Through heating, a magnetite-modified layer was formed, resulting in a magnetite-modified graphite sheet electrode.

[0055] Preparation of a magnetite-polypyrrole composite conductive magnetic electrode: Chitosan (5 g / L) was dispersed in an acetic acid solution, and pyrrole (8 mL / L) was ultrasonically dispersed into the same solution. After thorough mixing, an electrochemical deposition solution containing polypyrrole was prepared. A magnetite-modified graphite sheet electrode was immersed in the electrochemical deposition solution, and electrochemical deposition was performed by applying an electric current. The current density for electrochemical deposition was 5 mA / cm². 2 The deposition time was 20 minutes. During the electrochemical reaction, polypyrrole formed a stable conductive film on the surface of the magnetite-modified layer, resulting in a magnetite-polypyrrole composite conductive magnetic electrode.

[0056] 2) Methods for treating petrochemical wastewater

[0057] The total petroleum hydrocarbon content in the petrochemical wastewater to be treated is 100 mg / L.

[0058] The magnetite-polypyrrole composite conductive magnetic electrode and the unmodified graphite sheet electrode were used as two electrodes in the reactor, forming a two-electrode system. The reactor was placed in an artificially created external magnetic field for wastewater treatment. During the treatment process, an external voltage of 1.2V was applied to promote the degradation of harmful substances in the petrochemical wastewater through electrochemical reactions. To enhance the reaction efficiency of the electrodes, rubidium magnets were placed on both sides and the bottom of the reactor to generate a static magnetic field. By adjusting the distance between the magnets and the electrode system, the magnetic field strength was controlled to 50mT. This treatment group was designated PF.

[0059] During reactor operation, samples of the treated petrochemical wastewater were taken and tested at different time points. The samples were centrifuged for 5 minutes at 12,000 rpm. The supernatant was filtered through a 0.45 μm filter membrane to remove impurities. After extraction, the samples were tested by gas chromatography, and the concentration of petroleum hydrocarbons in the petrochemical wastewater to be treated was calculated.

[0060] Comparative Example 1

[0061] The process is the same as in Example 1, except that the electrode is not modified with polypyrrole. Petrochemical wastewater is treated with an unmodified polypyrrole electrode (i.e., a magnetite-modified graphite sheet electrode) under the same treatment conditions as in Example 1. This treatment group is labeled PO.

[0062] Comparative Example 2

[0063] The process is the same as in Example 1, except that the electrode is not modified with magnetite. Petrochemical wastewater is treated with an electrode that is not modified with magnetite (i.e., a polypyrrole-modified graphite sheet electrode) under the same conditions as in Example 1. This treatment group is labeled FO.

[0064] Comparative Example 3

[0065] The process is the same as in Example 1, except that the electrode is not modified with any material; unmodified graphite sheet electrodes are used to treat petrochemical wastewater under the same conditions as in Example 1. This treatment group is labeled Con.

[0066] Test case

[0067] Figure 2 The curves represent the changes in total petroleum hydrocarbon content in petrochemical wastewater at different time points, where PF, PO, FO, and Con represent the treatment methods of different experimental groups: PF represents Example 1 (magnetite-polypyrrole composite conductive magnetic electrode group), PO represents Comparative Example 1 (magnetite-modified electrode group only), FO represents Comparative Example 2 (polypyrrole-modified electrode group only), and Con represents Comparative Example 3 (unmodified electrode group). Figure 2It can be seen that the TPH concentration decreased significantly faster in Example 1 (PF group) than in the other control groups during the treatment process. The TPH concentration in the PF group decreased most significantly, dropping to approximately 40 mg / L after 20 hours, and further to below 20 mg / L after 40 hours, indicating that the composite conductive magnetic electrode of the present invention has a significant advantage in the removal of petroleum hydrocarbons. The TPH concentration decrease rate in the PO and FO groups was slightly lower than that in the PF group, with the TPH concentration remaining at approximately 30 mg / L and 40 mg / L respectively after 40 hours. The Con group showed the worst degradation effect, with the TPH concentration still close to 60 mg / L after 40 hours, indicating that the treatment effect of the traditional graphite electrode is limited.

[0068] Figure 3 This shows the changes in the removal rate of total petroleum hydrocarbons in petrochemical wastewater at different time points. From... Figure 3 It can be seen that the total petroleum hydrocarbon removal rate gradually increases with time. The removal rate of Example 1 exceeded 60% by the 6th hour. After 30 hours of treatment, the total petroleum hydrocarbon removal rate of Example 1 (PF group) reached 92%, while Comparative Example 1 (PO group) and Comparative Example 2 (FO group) achieved 80% and 75%, respectively. The unmodified graphite electrode group (Con group) had the lowest removal rate, indicating that the treatment effect relying solely on traditional electrode materials is relatively limited. The total petroleum hydrocarbon removal rate of Example 1 was significantly higher than that of the other groups, indicating that the magnetite-polypyrrole composite conductive magnetic electrode can significantly improve the treatment effect. Figure 3 The data also show that the removal efficiency of the PF group was superior to that of the control group throughout the treatment process, especially exhibiting a faster removal rate in the early stage (6h to 24h). As the treatment time increased, the advantage of the PF group became more pronounced, demonstrating the high efficiency and stability of the magnetite-polypyrrole composite conductive magnetic electrode in treating petrochemical wastewater. These data suggest that the magnetite-polypyrrole composite conductive magnetic electrode effectively promotes microbial enrichment and accelerates electrochemical reactions by improving the electrode's conductivity and magnetism, thereby significantly improving the removal efficiency of petroleum hydrocarbons from petrochemical wastewater. The electrode in Example 1 demonstrated excellent performance in petrochemical wastewater treatment, providing a highly efficient and environmentally friendly treatment solution.

[0069] In addition, the electrode prepared in Example 1 was used to treat petrochemical wastewater with a TPH concentration of 50 mg / L. The treatment conditions were the same as in step 2) of Example 1. After 40 hours of treatment, the results showed that the TPH concentration in the petrochemical wastewater was reduced to 4 mg / L and the TPH removal rate was 92%.

[0070] The electrode prepared in Example 1 was used to treat petrochemical wastewater with a TPH concentration of 300 mg / L. The treatment conditions were the same as in step 2) of Example 1. After 40 hours of treatment, the results showed that the TPH concentration in the petrochemical wastewater decreased to 32 mg / L, and the TPH removal rate was 89%. These results indicate that the composite conductive magnetic electrode of the present invention can operate efficiently in petrochemical wastewater treatment environments with different TPH concentrations and has a wide range of applications.

[0071] The results of the above embodiments demonstrate that the magnetite-polypyrrole composite conductive magnetic electrode provided by this invention possesses excellent conductivity, magnetism, and stability, fully leveraging the synergistic effect of magnetic and conductive materials. Furthermore, the application of an external magnetic field further optimizes the pollutant removal effect. This invention not only overcomes the limitations of electrode materials in traditional electrochemical treatment methods but also enables efficient treatment of petrochemical wastewater under green, low-energy, and high-efficiency conditions. It provides an innovative solution for the wastewater treatment field, promoting the green, low-energy, and high-efficiency development of wastewater treatment technology and improving the intelligence level and system stability of wastewater treatment.

[0072] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing a magnetite-polyazole composite conductive magnetic electrode, characterized by, Includes the following steps: The electrode was immersed in a mixed solution of polyvinylpyrrolidone and ferric chloride, and then dried and pyrolyzed in sequence to obtain a magnetite-modified electrode. The magnetite-modified electrode was immersed in a pyrrole-chitosan mixed solution for electrochemical deposition to obtain the magnetite-polypyrrole composite conductive magnetic electrode.

2. The preparation method according to claim 1, characterized in that, The concentration of polyvinylpyrrolidone in the polyvinylpyrrolidone-ferric chloride mixed solution is 15~25 g / L, and the concentration of ferric chloride is 10~20 g / L; the impregnation time is 6~10 h.

3. The preparation method according to claim 1, characterized in that, The pyrolysis temperature is 450~550℃, the time is 3~6 h, and the heating rate to the pyrolysis temperature is 3~8℃ / min.

4. The preparation method according to claim 1, characterized in that, The pyrrole-chitosan mixed solution is obtained by mixing chitosan solution and pyrrole; the solvent of the chitosan solution is acetic acid solution; the concentration of chitosan in the chitosan solution is 4~6 g / L; and the content of pyrrole in the polypyrrole-chitosan mixed solution is 7~9 mL / L.

5. The preparation method according to claim 1, characterized in that, The conditions of the electrochemical deposition include: current density is 3~7 mA / cm 2 , and deposition time is 18~22 min.

6. The magnetite-polypyrrole composite conductive magnetic electrode prepared by the preparation method according to any one of claims 1 to 5, characterized in that, It includes an electrode and a modification layer covering the surface of the electrode; the modification layer includes magnetite and polypyrrole.

7. The magnetite-polypyrrole composite conductive magnetic electrode according to claim 6, characterized in that, The electrode is a graphite electrode.

8. The application of the magnetite-polypyrrole composite conductive magnetic electrode according to claim 6 or 7 in wastewater treatment.

9. A method for treating petrochemical wastewater, characterized in that, Includes the following steps: In an external magnetic field, a two-electrode system is used to degrade petrochemical wastewater. The electrodes in the two-electrode system include a modified electrode and a counter electrode. The modified electrode is the magnetite-polypyrrole composite conductive magnetic electrode as described in claim 6 or 7.

10. The method according to claim 9, characterized in that, During the degradation process, the voltage of the two-electrode system is 1.0~1.5 V; The magnetic field strength of the external magnetic field is 40~60mT; The method for applying the external magnetic field is as follows: place the rubidium magnet on both sides and the bottom of the two-electrode system, and control the magnetic field strength by changing the distance between the rubidium magnet and the two-electrode system.

Images