Composite conductive film, method for producing the same, and application thereof

Abstract

The present disclosure provides a composite conductive film, a preparation method and application thereof, wherein the composite conductive film comprises: a metal microfiltration membrane substrate; a lead dioxide layer on the surface of the substrate by electrochemical deposition; and a transition metal oxide loaded on the lead dioxide layer, wherein the transition metal oxide is a microspherical skeleton structure, and the transition metal comprises any one of ruthenium, iridium, tin and nickel.

Description

Technical Field

[0001] This disclosure relates to the field of environmental engineering water treatment technology, and in particular to a composite conductive membrane, its preparation method and application, and more specifically to a composite conductive membrane and its preparation method, an electrocatalytic oxidation electrofiltration assembly composed of the composite conductive membrane, and a method for treating wastewater containing ammonia nitrogen or amino organics using the electrocatalytic oxidation electrofiltration assembly. Background Technology

[0002] Electrofiltration technology, as a highly efficient and environmentally friendly water treatment method, purifies water by driving the interaction between pollutants and electrodes through an electric field. It boasts advantages such as no secondary pollution and low energy consumption. Conductive membrane materials are a crucial component of electrofiltration technology, and their performance directly impacts the treatment effect; therefore, developing high-performance conductive membrane materials is of paramount importance.

[0003] Commonly used conductive film materials include carbon electrodes, boron-doped diamond electrodes (BDD electrodes), and lead dioxide electrodes (PbO2 electrodes). Among them, PbO2 electrodes have shown significant advantages in degrading organic pollutants due to their excellent conductivity and electrocatalytic activity. However, the performance of PbO2 electrodes in water containing inorganic nitrogen is limited: on the one hand, the single chlorine-mediated oxidation mechanism is difficult to remove ammonia nitrogen simultaneously; on the other hand, a passivation layer easily forms on the electrode surface, leading to a reduction in electrochemically active sites.

[0004] Therefore, there is an urgent need to develop novel conductive membrane materials that combine high nitrogen removal efficiency, anti-fouling properties, and structural stability in order to improve the application effect of electrofiltration technology in complex water treatment. Summary of the Invention

[0005] In view of this, the main objective of this disclosure is to provide a composite conductive film, its preparation method, and its application, in order to at least partially solve at least one of the aforementioned technical problems.

[0006] To achieve the above objectives, the technical solution disclosed herein is as follows:

[0007] In one aspect of this disclosure, a composite conductive film is provided, comprising:

[0008] Metal microfiltration membrane substrate;

[0009] A lead dioxide layer is deposited on the substrate surface using electrochemical deposition;

[0010] and transition metal oxides supported on the lead dioxide layer,

[0011] Among them, transition metal oxides have a micron-sized spherical framework structure.

[0012] Transition metals include any one of ruthenium, iridium, tin, and nickel.

[0013] As a second aspect of this disclosure, a method for preparing the above-mentioned composite conductive film is provided, comprising:

[0014] Gel powder was obtained by reverse suspension polymerization.

[0015] The gel powder was dispersed in an organic solvent and then mixed with a transition metal chloride salt to obtain a mixed reagent;

[0016] Using a lead plate as the anode and a metal microfiltration membrane as the cathode, electrochemical deposition is carried out in an acidic electrolyte to deposit a lead dioxide layer on the cathode surface, thus obtaining a lead dioxide / metal microfiltration membrane composite electrode.

[0017] The mixed reagent is coated onto a lead dioxide / metal microfiltration membrane composite electrode and calcined at 450~550℃ in an oxygen-containing atmosphere to thermally decompose the organic components in the mixed reagent, forming a transition metal oxide micron-sized spherical framework structure, thus obtaining a composite conductive film.

[0018] As a third aspect of this disclosure, an electrocatalytic oxidation electrofiltration assembly is provided, wherein the aforementioned composite conductive membrane is used as the anode and a stainless steel mesh is used as the cathode.

[0019] As another aspect of this disclosure, a method for treating wastewater containing ammonia nitrogen or amino organic compounds using the above-described electrocatalytic oxidation electrofiltration assembly is provided, comprising:

[0020] Adding chloride ions at a concentration of 10-100 mM to organic wastewater containing ammonia nitrogen or amino groups yields adjusted organic wastewater.

[0021] The adjusted organic wastewater was passed through an electrocatalytic oxidation and electrofiltration unit with a residence time of 0.8 min to 1.5 min, at a temperature of 5 to 40 mA·cm⁻¹. -2 The adjusted organic wastewater was subjected to electrocatalytic oxidation treatment at a current density of [value missing].

[0022] According to embodiments of this disclosure, a composite conductive membrane is provided, using a metal microfiltration membrane as a substrate. The specific surface area is significantly increased by utilizing the pore structure of the metal microfiltration membrane, providing support for subsequent deposition. Lead dioxide is uniformly deposited on the surface of the metal microfiltration membrane using an electrochemical deposition method, while ensuring the high flux and stability of the metal microfiltration membrane. Furthermore, a transition metal oxide with a micron-sized spherical framework structure is loaded onto the membrane. This framework structure allows the active sites of both lead dioxide and the transition metal oxide to be fully exposed simultaneously, thereby synergistically enhancing the electrochemical performance of the composite conductive membrane. Attached Figure Description

[0023] Figure 1 This is a flowchart of the preparation method of the composite conductive film disclosed herein;

[0024] Figure 2This is a schematic diagram illustrating the preparation of the composite conductive film disclosed herein;

[0025] Figure 3 This is a scanning electron microscope image of the composite conductive film in Embodiment 1 of this disclosure;

[0026] Figure 4 The nitrogen balance bar charts show the degradation effect of the electrocatalytic oxidation electrofiltration components on acetaminophen in Examples 2-4 and Comparative Examples 1-2 of this disclosure.

[0027] Figure 5 This invention relates to the electrocatalytic oxidation electrofiltration components in Examples 2-4 and Comparative Examples 1-2 of this disclosure, and their effects on NH4+ at different residence times in the electrofiltration system. + -N removal rate line graph. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this disclosure clearer, the following detailed description is provided in conjunction with specific embodiments.

[0029] The endpoints and any values ​​of the ranges disclosed in this disclosure are not limited to the precise ranges or values, and such ranges or values ​​should be understood to include values ​​close to such ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be regarded as specifically disclosed in this disclosure.

[0030] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this disclosure. The terms “comprising,” “including,” etc., as used herein indicate the presence of the stated features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0031] In the process of developing this disclosure, it was discovered that lead dioxide (PbO2) electrodes commonly used in electrofiltration technology have limitations when treating complex aquatic environments. Especially when treating water containing inorganic nitrogen, lead dioxide electrodes rely on the oxidation and degradation of organic pollutants by a single hydroxyl radical, making it difficult to achieve simultaneous removal of organic matter and ammonia nitrogen, thus limiting their application in wastewater treatment. To address this, this disclosure proposes a composite conductive membrane, its preparation method, and its applications.

[0032] The composite conductive membrane disclosed herein uses a metal microfiltration membrane as a substrate, utilizing its pore structure to significantly increase the specific surface area, providing support for subsequent deposition. PbO2 is uniformly deposited on the surface of the metal microfiltration membrane via electrochemical deposition, ensuring the uniformity of the PbO2 layer while avoiding membrane pore blockage, thus guaranteeing the high flux and stability of the metal microfiltration membrane. Furthermore, a transition metal oxide with a micron-sized spherical framework structure is further loaded. This framework structure allows for the simultaneous and full exposure of the active sites of both PbO2 and the transition metal oxide, thereby synergistically enhancing the electrochemical performance of the electrode. Under the condition of added chloride ions, the composite conductive membrane can efficiently generate chloroxygen radicals, changing the traditional oxidation method that relies solely on hydroxyl radicals. Chloroxygen radicals have stronger oxidizing power and selectivity, enabling rapid degradation of organic pollutants and effective removal of ammonia nitrogen, achieving simultaneous removal of multiple pollutants in complex water conditions. In addition, the composite conductive membrane of this disclosure has low preparation cost, simple process, and is easy to scale up. It exhibits excellent efficiency in removing organic matter and ammonia nitrogen, without generating secondary pollution, and has low energy consumption, making it suitable for large-scale application in wastewater treatment, with significant economic and environmental benefits.

[0033] According to one embodiment of this disclosure, a composite conductive film is provided, comprising:

[0034] The microfiltration membrane substrate; a lead dioxide layer electrochemically deposited on the substrate surface; and a transition metal oxide supported on the lead dioxide layer, wherein the transition metal oxide has a micron-sized spherical framework structure, and the transition metal includes any one of ruthenium, iridium, tin, and nickel.

[0035] According to embodiments of this disclosure, the transition metal used includes any one of ruthenium, iridium, tin, and nickel. These transition metal oxides possess excellent conductivity and high catalytic activity, and maintain structural stability during high-temperature calcination (450~550℃). This ensures the high efficiency and stability of the composite conductive membrane in electrochemical reactions, making it suitable for complex electrochemical water treatment processes.

[0036] According to embodiments of this disclosure, the composite conductive membrane uses a metal microfiltration membrane as a substrate. The high conductivity of the metal material provides a good electron transport channel for subsequent electrochemical deposition, ensuring rapid charge transfer on the electrode surface and thus improving the efficiency of the electrochemical reaction. Simultaneously, the pore structure of the microfiltration membrane forms a well-developed pore network, significantly increasing the effective specific surface area and providing a low-resistance path for the transport of reactants. Lead dioxide is deposited on the surface of the metal microfiltration membrane via electrochemical deposition, allowing the lead dioxide to form a continuous conductive layer on the membrane surface, maintaining the open state of the substrate's pore structure, ensuring charge transport efficiency, and simultaneously maintaining the high-flux characteristics of the membrane material. Based on this, a transition metal oxide with a micron-sized spherical framework structure is loaded. The open channels between the spherical framework and the substrate pores form a continuous and interconnected mass transfer network, effectively shortening the mass transport distance and thus improving mass transfer efficiency. At the same time, the surface of the framework significantly increases the density of active sites, providing more reaction sites for the electrochemical reaction, allowing the active sites of lead dioxide and transition metal oxide to be fully exposed simultaneously, thereby synergistically improving the electrochemical performance of the composite conductive membrane.

[0037] According to embodiments of this disclosure, the average pore size of the composite conductive membrane is 1~3 μm, for example, it can be 1 μm, 1.5 μm, 2 μm, 2.5 μm, 3 μm, etc. A composite conductive membrane with an appropriate pore size range can effectively balance filtration performance and conductivity, while reducing membrane fouling, thereby improving the electrofiltration efficiency and service life of the composite conductive membrane. The Faraday efficiency is 67%~90%, for example, it can be 67%, 70%, 75%, 80%, 85%, 89%, 90%, etc. The composite conductive membrane has a high Faraday efficiency, which allows for more efficient utilization of charge during the electrochemical reaction process, reducing energy loss, thereby significantly improving pollutant removal efficiency and overall electrofiltration performance.

[0038] According to embodiments of this disclosure, the mass ratio of lead dioxide to transition metal oxide is (1~9):(9~1), for example, 1:9, 2:8, 4:6, 5:5, 6:4, 8:2, 9:1, etc. By adjusting the ratio of lead dioxide to transition metal oxide, dynamic matching between the conductive network and the catalytic active sites is achieved, thereby optimizing the overall electrochemical performance of the composite film. The lead dioxide layer thickness is 50-200 μm, for example, 50 μm, 80 μm, 100 μm, 150 μm, 200 μm, etc. By controlling the thickness of the PbO2 layer, conductivity can be ensured while avoiding the increase in mechanical stress and internal resistance caused by an excessively thick coating.

[0039] According to another embodiment of this disclosure, a method for preparing the above-described composite conductive film is provided. Figure 1 This is a flowchart illustrating the preparation method of the composite conductive film disclosed herein. Figure 1 As shown, the preparation method includes:

[0040] Gel powder was obtained by reverse suspension polymerization.

[0041] The gel powder was dispersed in an organic solvent and then mixed with a transition metal chloride salt to obtain a mixed reagent;

[0042] Using a lead plate as the anode and a metal microfiltration membrane as the cathode, electrochemical deposition is carried out in an acidic electrolyte to deposit a lead dioxide layer on the cathode surface, thus obtaining a lead dioxide / metal microfiltration membrane composite electrode.

[0043] The mixed reagent is coated onto a lead dioxide / metal microfiltration membrane composite electrode and calcined at 450~550℃ in an oxygen-containing atmosphere to thermally decompose the organic components in the mixed reagent, forming a transition metal oxide micron-sized spherical framework structure, thus obtaining a composite conductive film.

[0044] Figure 2 This is a schematic diagram illustrating the preparation of the composite conductive film disclosed herein.

[0045] like Figure 2 As shown, a lead dioxide layer is deposited on a metal microfiltration membrane using an electrochemical deposition process to cover the substrate surface while preserving the pore structure, resulting in a lead dioxide / metal microfiltration membrane composite electrode. Using a template method, a mixed reagent is coated onto the surface of the lead dioxide / metal microfiltration membrane composite electrode and then calcined (e.g., at 500°C for 3 hours). The organic components in the mixed reagent undergo pyrolysis, completely removing the organic components, while simultaneously promoting the diffusion of transition metal oxides through the surface to form a micron-sized spherical framework, ultimately yielding a composite conductive film.

[0046] According to embodiments of this disclosure, the calcination temperature is 450~550℃, for example, 450℃, 470℃, 500℃, 530℃, 550℃, etc. This temperature range ensures that the organic components in the mixed reagent are completely decomposed and removed by heat, while avoiding sintering or crystal transformation of the transition metal oxide framework structure due to excessively high temperatures, thereby obtaining a transition metal oxide micron-sized spherical framework structure. This micron-sized spherical framework structure is loaded on a lead dioxide layer, allowing both lead dioxide active sites and transition metal oxide active sites to be exposed simultaneously, enhancing the electrochemical activity of the composite conductive film and enabling it to exhibit good performance during electrocatalytic oxidation.

[0047] According to embodiments of this disclosure, gel powder prepared by reverse suspension polymerization provides a template carrier for the uniform loading of transition metal oxides. An electrochemical deposition process is used to form a dense and porous lead dioxide conductive layer on the surface of the metal microfiltration membrane through a directional migration mechanism of anodic lead plate dissolution and cathodic deposition. This not only maintains the porosity of the metal microfiltration membrane substrate but also constructs a highly efficient electron transport network, thereby significantly improving the conductivity and stability of the electrode. In the calcination process, by controlling the calcination temperature, pyrolysis of organic components and in-situ crystallization of transition metal oxides are achieved under an oxygen-containing atmosphere. While completely removing organic components, this process promotes the formation of a micron-sized spherical framework of transition metal oxides through surface diffusion. This not only retains high specific surface area and porosity but also significantly increases the exposure of active sites. The resulting composite conductive membrane, with the metal microfiltration membrane as a substrate, simultaneously exposes the active sites of lead dioxide and transition metal oxides, resulting in excellent performance during electrocatalytic oxidation. In addition, the preparation method disclosed herein has good economic and environmental advantages: low preparation cost, simple process, no secondary pollution, and low energy consumption, providing an efficient, stable and sustainable solution for complex water quality treatment.

[0048] According to embodiments of this disclosure, the reverse suspension polymerization method includes: adding methacrylic acid and methylenebisacrylamide to an organic solvent containing a surfactant composite system, followed by adding tetraacrylamide methyl ethylenediamine to react and obtain an organic gel. The surfactant composite system includes Span 80 and Tween 80, and the organic solvent includes at least one of cyclohexane and isopropanol. The organic gel is then acid-washed, dried, and ground to obtain a gel powder.

[0049] According to embodiments of this disclosure, the reverse suspension polymerization method, in practice, includes the following steps:

[0050] Mix Span 80 and Tween 80 in a mass ratio of (1~9): (9~1) to obtain a surfactant composite system.

[0051] Under inert gas protection, the surfactant complex system is dissolved in cyclohexane, mixed using a vortex mixer, and then subjected to a thorough emulsification reaction to obtain reactant A. Optionally, the amount of surfactant complex system added ranges from 2 to 5 mL, the volume of cyclohexane ranges from 0.25 to 1.25 mL, and the rotation speed of the vortex mixer is 100 to 500 r·min. -1 400 r·min is preferred -1 ;

[0052] An aqueous solution of methacrylic acid and methylenebisacrylamide was added to reactant A. After an interval of 10-30 min, tetraacrylamide methyl ethylenediamine was added to react for 1-3 h to obtain an organic gel.

[0053] The organic gel was washed repeatedly with dilute hydrochloric acid, ethanol, and water in alternating cycles to remove unreacted monomers and oligomers. After standing at room temperature for 0–24 hours and air-drying, it was ground in a mortar and pestle to obtain a white gel powder. Optionally, the particle size after grinding was 300 mesh.

[0054] According to embodiments of this disclosure, the ratio of gel powder to organic solvent is 1:(1.5~3), for example, 1:1.5, 1:2, 1:2.5, 1:3, etc. The ratio of gel powder to transition metal salt is 1:(2~3), for example, 1:2, 1:2.2, 1:2.5, 1:2.7, 1:3, etc. By controlling the ratio of gel powder to transition metal salt, a suitable ratio ensures that the transition metal salt is fully converted into transition metal oxide during high-temperature calcination.

[0055] According to embodiments of this disclosure, the metal microfiltration membrane includes any one of titanium membrane, stainless steel membrane, nickel membrane, and aluminum membrane, and the average pore size range of the metal microfiltration membrane can be, for example, 0.1~10 μm. The metal microfiltration membrane possesses good mechanical strength and chemical stability, effectively filtering suspended solids and particulate matter in water while ensuring the high efficiency and stability of the electrofiltration process.

[0056] According to embodiments of this disclosure, electrochemical deposition is performed in an acidic electrolyte. In practical applications, the acidic electrolyte can be, for example, a mixture of lead nitrate (Pb(NO3)2) and sodium fluoride (NaF). The current density during electrochemical deposition is 30–60 mA·cm⁻¹. -2 For example, it can be 30 mA·cm -2 35mA·cm -2 40mA·cm -2 50mA·cm -2 60mA·cm -2 The electrochemical deposition time is 0.5 to 2 hours, for example, 0.5 hours, 1 hour, 1.3 hours, 1.5 hours, 2 hours, etc. By precisely controlling the electrochemical deposition parameters, a controllable deposition rate of the lead dioxide layer can be ensured. A suitable deposition time can guarantee the sufficient growth of PbO2 crystals, while avoiding mechanical stress accumulation caused by excessive deposition thickness.

[0057] According to another embodiment of this disclosure, an electrocatalytic oxidation electrofiltration assembly is provided, wherein the aforementioned composite conductive membrane is used as the anode and a stainless steel mesh is used as the cathode.

[0058] In the electrocatalytic oxidation electrofiltration assembly, a porous resistor sheet can be provided between the cathode and the anode, or the cathode and the anode can be placed in two different compartments to isolate the cathode and the anode.

[0059] According to another embodiment of this disclosure, a method for treating wastewater containing ammonia nitrogen or amino organic compounds using the above-described electrocatalytic oxidation electrofiltration assembly is provided, comprising:

[0060] Adding chloride ions at a concentration of 10-100 mM to organic wastewater containing ammonia nitrogen or amino groups yields adjusted organic wastewater.

[0061] The adjusted organic wastewater was passed through an electrocatalytic oxidation and electrofiltration unit with a residence time of 0.8 min to 1.5 min, at a temperature of 5 to 40 mA·cm⁻¹. -2 The adjusted organic wastewater was subjected to electrocatalytic oxidation treatment at a current density of [value missing].

[0062] According to embodiments of this disclosure, the concentration of chloride ions added to the organic wastewater is 10-100 mM, for example, 10 mM, 30 mM, 50 mM, 70 mM, 100 mM, etc. By adding chloride ions, highly reactive chlorine species such as chloroxygen radicals and hypochlorous acid can be generated in situ during the subsequent electrocatalytic process, thereby significantly enhancing the oxidative degradation capacity for ammonia nitrogen and organic pollutants. The residence time of the organic wastewater through the electrocatalytic oxidation electrofiltration module is 0.8 min-1.5 min, for example, 0.8 min, 1 min, 1.1 min, 1.3 min, 1.5 min, etc. The residence time is achieved by adjusting the ratio of the influent flow rate to the membrane module volume, ensuring sufficient contact between pollutants and the active sites on the electrode surface, while avoiding incomplete oxidation due to excessively short residence time. The current density during the electrocatalytic oxidation treatment is 5-40 mA·cm⁻¹. -2 For example, it can be 5 mA·cm -2 10mA·cm -2 20mA·cm -2 30mA·cm -2 40mA·cm -2 The current density and chloride ion concentration are synergistically regulated to trigger the chloride-mediated oxidation pathway, achieving simultaneous removal of ammonia nitrogen and organic pollutants while inhibiting the formation of byproducts.

[0063] According to embodiments of this disclosure, the electrocatalytic oxidation electrofiltration assembly of this disclosure is used to treat organic wastewater, significantly improving wastewater treatment efficiency and achieving efficient simultaneous removal of ammonia nitrogen and organic pollutants from complex wastewater. By controlling chloride ion concentration, current density, and residence time, the stability and reliability of the treatment process are ensured, making it suitable for various complex water quality conditions, reducing energy consumption and by-product generation, and improving the economic efficiency and environmental friendliness of the treatment process.

[0064] In the electrocatalytic oxidation process, the composite conductive film serves as the anode. Its surface PbO2 and transition metal oxides are simultaneously exposed at the reaction interface, providing more reactive sites and significantly enhancing the electrode's catalytic activity. The synergistic effect promotes the efficient generation of chloroxygen radicals (ClO·) and hydroxyl radicals (·OH). Chloride ions (Cl...) are present in the system. - When ), Cl on the surface of transition metal oxides - The chloroxygen radicals are preferentially adsorbed and oxidized to generate reactive species. These radicals have a stronger oxidizing ability on the carbon skeleton of organic matter, preferentially attacking C-C or CH bonds, thus effectively disrupting the structure of organic pollutants. Furthermore, the hydroxyl radicals generated during the anodic electrocatalysis process further enhance the degradation efficiency of pollutants through oxidation. After the organic pollutants are effectively degraded, the chloroxygen radicals further participate in the oxidation of ammonia nitrogen (NH3-N), converting it into nitrogen gas (N2) and water (H2O).

[0065] Furthermore, the porous structure of the electrode surface effectively enhances mass transfer efficiency. The convective motion of water through the electrode materials (EMs) reduces the diffusion boundary layer to a scale comparable to the pore radius, significantly improving the mass transfer rate and Faraday efficiency of electrocatalytic oxidation. This efficient mass transfer and reaction mechanism enables the composite conductive membrane to exhibit superior performance during electrocatalytic oxidation, achieving efficient and simultaneous removal of ammonia nitrogen and organic pollutants from complex wastewater.

[0066] To make the objectives, technical solutions, and advantages of this disclosure clearer, the following detailed description is provided in conjunction with specific embodiments and accompanying drawings. Unless otherwise specified, specific techniques or conditions in the embodiments are conventional methods and can be performed according to the techniques or conditions described in the literature in this field or according to the product manual.

[0067] Example 1:

[0068] Embodiment 1 of this disclosure provides a composite conductive membrane and an electrocatalytic oxidation electrofiltration component. The method for preparing the composite conductive membrane includes the following steps:

[0069] Step S101: Mix Span 80 and Tween 80 at a mass ratio of 2:8 to obtain a surfactant composite system.

[0070] Step S102: Under nitrogen (N2) protection, dissolve 2 mL of the surfactant complex system in 1 mL of cyclohexane, and vortex mix at 400 rpm. -1 After mixing at a certain speed, reactant A is obtained.

[0071] Step S103: Add 1.4 g of methacrylic acid and 1.4 g of methylenebisacrylamide to reactant A, and after an interval of 30 min, add 0.8 g of tetraacrylamide methyl ethylenediamine and react for 2 h to obtain an organic gel;

[0072] Step S104: Wash the organic gel three times alternately with dilute hydrochloric acid, ethanol and water, let it stand at room temperature for 24 hours, let it air dry naturally, and then grind it with a mortar and pestle to obtain a white gel powder with a particle size of 300 mesh.

[0073] Step S200: Disperse the gel powder in isopropanol at a mass ratio of 1:2, then add ruthenium trichloride (RuCl3) and mix. The ratio of gel powder to RuCl3 is 1:2.5. Sonicate for 30 minutes to obtain the mixed reagent.

[0074] Step S300: Electrochemical deposition is performed using a lead plate as the anode and a titanium microfiltration membrane (Ti-M) as the cathode in a mixed electrolyte of Pb(NO3)2 and NaF at a current density of 5 mA·cm⁻¹. -2 Stir at a constant speed for 15 minutes to deposit a lead dioxide layer on the cathode surface, thus obtaining a lead dioxide / metal microfiltration membrane composite electrode.

[0075] Step S400: The mixed reagent is coated on the lead dioxide / metal microfiltration membrane composite electrode and calcined at 500°C for 2 h in an oxygen atmosphere to thermally decompose the organic components in the mixed reagent, forming a ruthenium oxide (RuO2) micron spherical framework structure, and obtaining a composite conductive film RuO2@PbO2-M with a mass ratio of lead dioxide to RuO2 of 6:4.

[0076] Electrocatalytic oxidation and electrofiltration components:

[0077] Using a RuO2@PbO2-M composite conductive film as the anode, the effective electrode area of ​​the anode is 17.35 cm². 2 Using stainless steel mesh of the same size as the cathode, an electrocatalytic oxidation electrofiltration component Z1 was constructed.

[0078] Figure 3 This is a scanning electron microscope image of the composite conductive film in Embodiment 1 of this disclosure.

[0079] like Figure 3 As shown, the composite conductive film RuO2@PbO2-M has a distinct framework structure.

[0080] Example 2

[0081] This disclosure provides a method for preparing a composite conductive film in Example 2, which differs from Example 1 in that a composite conductive film 0.2RuO2@PbO2-M with a mass ratio of lead dioxide and RuO2 of 2:8 is prepared.

[0082] Electrocatalytic oxidation and electrofiltration components:

[0083] Using a 0.2RuO2@PbO2-M composite conductive film as the anode, the effective electrode area of ​​the anode is 17.35 cm². 2 Using stainless steel mesh of the same size as the cathode, an electrocatalytic oxidation electrofiltration component Z2 was constructed.

[0084] Example 3

[0085] This disclosure provides a method for preparing a composite conductive film in Embodiment 3, which differs from Embodiment 1 in that: a composite conductive film 0.25RuO2@PbO2-M with a mass ratio of lead dioxide to RuO2 of 2.5:7.5 is prepared.

[0086] Electrocatalytic oxidation and electrofiltration components:

[0087] Using a 0.25RuO2@PbO2-M composite conductive film as the anode, the effective electrode area of ​​the anode is 17.35 cm². 2 Using stainless steel mesh of the same size as the cathode, an electrocatalytic oxidation electrofiltration component Z3 was constructed.

[0088] Example 4

[0089] This disclosure provides a method for preparing a composite conductive film in Example 4, which differs from Example 1 in that a composite conductive film 0.3RuO2@PbO2-M with a mass ratio of lead dioxide and RuO2 of 3:7 is prepared.

[0090] Electrocatalytic oxidation and electrofiltration components:

[0091] Using a 0.3RuO2@PbO2-M composite conductive film as the anode, the effective electrode area of ​​the anode is 17.35 cm². 2 Using stainless steel mesh of the same size as the cathode, an electrocatalytic oxidation electrofiltration component Z4 was constructed.

[0092] Comparative Example 1

[0093] Comparative Example 1 of this disclosure provides an electrocatalytic oxidation electrofiltration component, which differs from Example 1 in that: a titanium nanofiltration membrane is used as the anode and a stainless steel mesh of the same size is used as the cathode to construct the electrocatalytic oxidation electrofiltration component Z5.

[0094] Comparative Example 2

[0095] Comparative Example 2 of this disclosure provides an electrocatalytic oxidation electrofiltration component, which differs from Example 1 in that a lead dioxide membrane is used as the anode and a stainless steel mesh of the same size is used as the cathode to construct the electrocatalytic oxidation electrofiltration component Z6.

[0096] Prepare simulated wastewater containing ammonia nitrogen or amino organic pollutants, with p-acetaminophen as the target pollutant, at a concentration of 100 mg·L⁻¹. -1 The stock solution was supplemented with 50 mM chloride ions at a pH of 3. The electrocatalytic oxidation electrofiltration units from Examples 2-4 and Comparative Examples 1-2 were used to treat simulated organic pollutants containing ammonia nitrogen (or amino groups).

[0097] Figure 4 The nitrogen balance bar charts show the degradation effect of the electrocatalytic oxidation electrofiltration components on acetaminophen in Examples 2-4 and Comparative Examples 1-2 of this disclosure.

[0098] Figure 5 This invention relates to the electrocatalytic oxidation electrofiltration components in Examples 2-4 and Comparative Examples 1-2 of this disclosure, and their effects on NH4+ at different residence times in the electrofiltration system. + -N removal rate line graph.

[0099] like Figure 4 and Figure 5 As shown, the electrocatalytic oxidation electrofiltration components with composite conductive membranes prepared by the method of this disclosure in Examples 2-4 of this disclosure exhibit a higher removal rate of acetaminophen within 60 minutes. Compared to single hydroxyl radical oxidation attacks on organic matter by titanium nanofiltration membranes and lead dioxide membranes, the electrocatalytic oxidation electrofiltration components in Examples 2-4 of this disclosure utilize chlorohydroxyl radicals and chloride ions to mediate and jointly attack organic matter and ammonia nitrogen pollutants, effectively targeting NH4+. + -N removal rate (C NH4 + -Nout Both the speed and the rate are significantly improved.

[0100] The specific embodiments described above further illustrate the purpose, technical solutions, and beneficial effects of this disclosure. It should be understood that the above descriptions are merely specific embodiments of this disclosure and are not intended to limit this disclosure. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this disclosure should be included within the protection scope of this disclosure.

Claims

1. A composite conductive film, characterized in that, The composite conductive film includes: Metal microfiltration membrane substrate; A lead dioxide layer is deposited electrochemically on the surface of the substrate; and transition metal oxides supported on the lead dioxide layer, The transition metal oxide has a micron-sized spherical framework structure. The transition metal includes any one of ruthenium, iridium, tin, and nickel.

2. The composite conductive film according to claim 1, characterized in that, The composite conductive film has an average pore size of 1~3μm and a Faraday efficiency of 67%~90%.

3. The composite conductive film according to claim 1, characterized in that, The mass ratio of lead dioxide to transition metal oxide is (1~9):(9~1). The lead dioxide layer has a thickness of 50-200 μm.

4. A method for preparing a composite conductive film as described in any one of claims 1 to 3, characterized in that, The preparation method includes: Gel powder was obtained by reverse suspension polymerization. The gel powder was dispersed in an organic solvent and then mixed with a transition metal chloride salt to obtain a mixed reagent; Using a lead plate as the anode and a metal microfiltration membrane as the cathode, electrochemical deposition is performed in an acidic electrolyte to deposit a lead dioxide layer on the cathode surface, thus obtaining a lead dioxide / metal microfiltration membrane composite electrode. The mixed reagent is coated onto the lead dioxide / metal microfiltration membrane composite electrode and calcined at 450~550℃ in an oxygen-containing atmosphere to thermally decompose the organic components in the mixed reagent, forming a transition metal oxide micron-sized spherical framework structure, thus obtaining the composite conductive membrane.

5. The preparation method according to claim 4, characterized in that, The reverse suspension polymerization method includes: Methacrylic acid and methylenebisacrylamide were added to an organic solvent containing a surfactant complex system, and then tetraacrylamide methyl ethylenediamine was added to react and an organic gel was obtained. The organic gel was acid-washed, dried, and ground to obtain the gel powder.

6. The preparation method according to claim 4, characterized in that, The surfactant complex system includes Span 80 and Tween 80. The organic solvent includes at least one of cyclohexane and isopropanol.

7. The preparation method according to claim 4, characterized in that, The ratio of the gel powder to the organic solvent is 1:(1.5~3); The ratio of the gel powder to the transition metal chloride salt is 1:(2~3).

8. The preparation method according to claim 4, characterized in that, The metal microfiltration membrane includes any one of titanium membrane, stainless steel membrane, nickel membrane, and aluminum membrane. The current density during the electrochemical deposition process is 30~60 mA·cm. -2 The time is 0.5~2 hours.

9. An electrocatalytic oxidation electrofiltration assembly, characterized in that, The electrocatalytic oxidation electrofiltration assembly uses the composite conductive membrane described in any one of claims 1 to 3 as the anode and a stainless steel mesh as the cathode.

10. A method for treating wastewater containing ammonia nitrogen or amino organic compounds using the electrocatalytic oxidation electrofiltration assembly as described in claim 9, characterized in that, The method includes: Adding chloride ions at a concentration of 10-100 mM to organic wastewater containing ammonia nitrogen or amino groups yields adjusted organic wastewater. The adjusted organic wastewater is passed through the electrocatalytic oxidation and electrofiltration assembly with a residence time of 0.8 min to 1.5 min, at a temperature of 5 to 40 mA·cm⁻¹. -2 The adjusted organic wastewater was subjected to electrocatalytic oxidation treatment at a current density of [value missing].

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