Bdd composite electrode, electrode preparation method and medical wastewater treatment equipment

Abstract

The application discloses a BDD composite electrode, an electrode preparation method and a medical wastewater treatment equipment, relates to the technical field of medical sewage treatment, and comprises a treatment pool and a pair of BDD composite electrodes. A lifting frame is vertically movably arranged on the top of the treatment pool, and the pair of BDD composite electrodes are arranged in the lifting frame. An inverted V-shaped filter screen is arranged below the pair of BDD composite electrodes, and a pair of elastic pull rods are arranged between the lifting frame and the inverted V-shaped filter screen. A residue collecting box is arranged on the two sides of the treatment pool and is in communication with the treatment pool. An abutting rod which is in abutting cooperation with the inverted V-shaped filter screen is elastically inserted into the communication part. A pair of residue scraping and smoothing assemblies are respectively arranged on the two sides of the top of the inverted V-shaped filter screen, and the residue scraping and smoothing assemblies are in friction transmission cooperation with the abutting rod. The inverted V-shaped filter screen can produce high-frequency micro-amplitude tremor in the vertical stroke through the elastic pull rod, the surface filter cake layer is destroyed, the effective flux of the filter screen is maintained, and then the residue scraping and smoothing assemblies are in friction transmission cooperation with the elastic pull rods.

Description

Technical Field

[0001] This invention relates to the field of medical wastewater treatment technology, specifically to a BDD composite electrode, an electrode preparation method, and medical wastewater treatment equipment. Background Technology

[0002] Boron-doped diamond electrodes can be used for electrochemical wastewater treatment. They have high oxidation capacity, can decompose organic matter and kill pathogens. Medical wastewater may contain complex components such as drug residues, bacteria, and viruses, and its treatment requires high efficiency and stability. Therefore, compared with traditional electrodes, boron-doped diamond electrodes (BDD) have many advantages such as wide window, low background current, good electrochemical stability, good mechanical properties, strong corrosion resistance, and good conductivity. They have a promising future in the field of electrochemical oxidation treatment of medical wastewater.

[0003] The existing patent application, with publication number CN220317491U and publication date January 9, 2024, is titled "An Electrochemical Wastewater Treatment Device." This patent includes an electrolytic water treatment tank, with a movable plate positioned above the top of the tank. A DC regulated power supply is fixedly installed on the top of the movable plate, and cathode and anode rods are fixedly connected to both sides of the bottom of the movable plate. This electrochemical wastewater treatment device utilizes the coordinated use of the electrolytic water treatment tank, cathode rod, movable plate, DC regulated power supply, electric telescopic rod, anode rod, an annular cleaning plate, an annular scraper, and connecting blocks. The annular cleaning plate drives the annular scraper to continuously scrape the outer wall of the anode rod vertically, preventing the condensate generated on the anode rod from forming scale before it can be scraped off. This solves the problem of anode rod passivation during the electrochemical reaction, which increases the resistance of the anode rod and reduces the electrochemical wastewater treatment effect.

[0004] The aforementioned applications have shortcomings. In traditional electrode structures, it is difficult to balance the conductivity and mechanical strength of the substrate. Single titanium substrates are prone to passivation, leading to a decrease in current efficiency. Nickel substrates have insufficient corrosion resistance, which can easily cause the dissolution of heavy metals. The thermal expansion coefficients of the gradient transition layer are poorly matched, and interface cracks are easily generated during high-temperature deposition, leading to the peeling off of the diamond layer. At the same time, in existing BDD electrode wastewater treatment systems, fibrous impurities and precipitates easily adhere to the electrode surface, forming a contamination layer that significantly reduces the efficiency of free radical generation. After treating multiple batches of wastewater, the degradation efficiency drops too much. Frequent manual cleaning leads to excessive equipment downtime, seriously affecting the continuity of treatment. Furthermore, in traditional multi-layer filtration structures, suspended solids easily form a dense accumulation layer on the filter screen surface after being trapped, causing a significant increase in filtration pressure difference. When the concentration of suspended solids in the wastewater is too high, conventional backwashing operations cannot effectively restore the flux, affecting the actual treatment efficiency. Summary of the Invention

[0005] The purpose of this invention is to provide a BDD composite electrode, an electrode preparation method, and a medical wastewater treatment device to overcome the shortcomings of the prior art.

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

[0007] A BDD composite electrode includes a composite substrate consisting of a nickel foam core and a titanium shell, wherein the titanium shell is formed into a porous structure by magnetron sputtering deposition.

[0008] The gradient transition layer consists of a TiN layer, an Nb layer, and an NbC layer in sequence.

[0009] A multi-level structured BDD layer with micron-sized pores and a nanocone array on its surface, wherein the height of the nanocones is 300-500 nm and the spacing is 50-100 nm.

[0010] The brazing reinforcement layer comprises a high-entropy alloy brazing filler metal and an in-situ generated CeO2 passivation film. The interfacial bonding strength of the electrode is ≥180MPa, and the specific surface area is ≥15.8m² / g.

[0011] Preferably, the total thickness of the gradient transition layer is 2.0-3.0 μm, wherein the thickness of the TiN layer accounts for 10-15%, the thickness of the Nb layer accounts for 15-20%, and the thickness of the NbC layer accounts for 65-75%.

[0012] A method for preparing a BDD composite electrode includes the following steps:

[0013] Step 1: Preparation of composite substrate. The foamed nickel is immersed in 5-8% HCl and ultrasonically cleaned for 15-30 minutes. A titanium layer is deposited under the conditions of magnetron sputtering power of 400-600W and Ar gas pressure of 0.3-0.8Pa. Subsequently, it is etched in 3-7% HF solution to form a porous titanium shell.

[0014] Step 2: Gradient transition layer deposition. A TiN layer is deposited by PECVD at 200-400W RF power. Then, a 0.4-0.6μm pure niobium layer and a 1.2-1.8μm NbC gradient layer are deposited sequentially by multi-target sputtering. The carbon flux is linearly increased from 10sccm to 30sccm.

[0015] Step 3: BDD layer construction. In a hot-filament CVD reactor, the CH4 / H2 volume ratio is controlled at 2-4% and the boron doping concentration is 4000-6000ppm to grow an 8-12μm thick BDD layer.

[0016] Step 4: Multi-level structure etching. Femtosecond laser is used to form micron-sized vias at a scanning speed of 5-15 mm / s. Then, Ar / N2 mixed plasma is used to form a nanocone array through etching at a power density of 0.5-1.5 W / cm.

[0017] Step 5: Interface strengthening treatment. High-entropy alloy brazing filler metal is coated onto the interface using powder metallurgy. After vacuum brazing, the finished electrode is obtained.

[0018] Preferably, in step two, the deposition rate of the NbC gradient layer is controlled at 0.08-0.12 μm / min, in step four, the bias voltage of the plasma etching is -50 to -100V, and in step five, the particle size D90 of the solder powder is ≤5μm, and the Ce element content is 0.5-1.2wt%.

[0019] A medical wastewater treatment device includes a treatment tank and at least one pair of the aforementioned BDD composite electrodes. A lifting frame is vertically and movably installed on the top of the treatment tank. The pair of BDD composite electrodes are installed in the lifting frame. An inverted V-shaped filter screen is located below the pair of BDD composite electrodes. A pair of elastic pull rods are installed between the lifting frame and the inverted V-shaped filter screen. Sludge collection boxes connected to both sides of the treatment tank are installed thereon, and abutment rods that abut against the inverted V-shaped filter screen are elastically inserted into the connection points. A pair of waste sludge scraping components are respectively installed on the top two sides of the inverted V-shaped filter screen, and the waste sludge scraping components are driven by friction with the abutment rods. A locking component is horizontally installed on the top of the elastic pull rods, and the two are connected to each other. The BDD composite electrodes have slots that match the locking components. When the lifting frame moves the inverted V-shaped filter screen upward and abuts against the abutment rods, the elastic pull rods move upward independently, driving the waste sludge scraping components to run, and then the locking components are pulled out of the slots.

[0020] Preferably, the inner walls of the lifting frame are slidably connected to the outer walls of the treatment tank on both sides. The treatment tank is equipped with a first shaft and a second shaft distributed vertically. A drive motor connected to the end of the first shaft is installed outside the treatment tank. A transmission belt is installed between the first shaft and the second shaft. Transmission gears are fixedly connected to both ends of the first shaft. A driven rack that meshes with the transmission gears is vertically fixedly connected to one side of the lifting frame. A pair of abutting cams are fixedly connected to the second shaft below the inverted V-shaped filter screen.

[0021] Preferably, the bottom of the elastic pull rod passes through the inverted V-shaped filter screen and is equipped with an abutment spring, the top of which contacts the bottom surface of the inverted V-shaped filter screen.

[0022] Preferably, the waste scraping assembly includes multiple drive shafts rotatably mounted on the top surface of the inverted V-shaped filter screen. Each drive shaft is connected to the others by a number of chains. A drive ring is fixedly sleeved on one of the drive shafts. An anti-slip strip that rubs against the drive ring is vertically embedded on one side of the elastic pull rod. Several scraper strips are installed on the outside of two adjacent chains.

[0023] Preferably, the locking assembly includes a cylinder communicating with the interior of the elastic pull rod, a locking tongue adapted to the slot is movably sleeved in the cylinder, a piston rod is elastically embedded in the elastic pull rod, and a retaining ring is fixedly connected to the inner wall of the treatment pool to prevent the piston rod and the elastic pull rod from moving upward together.

[0024] Preferably, an annular descaling blade is movably installed inside the treatment tank. The annular descaling blade is located between the lifting frame and the BDD composite electrode, and a push cam for intermittently lifting the annular descaling blade is installed on the first shaft.

[0025] In the above technical solution, by innovating the electrode structure and equipment linkage mechanism, a three-dimensional conductive network is constructed using a foamed nickel / titanium composite substrate, which reduces the bulk resistance. A gradient transition layer is designed to achieve a continuous transition of the thermal expansion coefficient, improving the interfacial bonding strength. A multi-level structured BDD layer is constructed. The synergistic effect of micron-sized pores and nano-cones increases the hydroxyl radical yield to several times that of traditional electrodes. At the same time, the inverted V-shaped filter screen is lifted by an elastic pull rod, which generates high-frequency micro-amplitude vibrations during the vertical stroke of the inverted V-shaped filter screen, destroying the formation of the surface filter cake layer and maintaining the effective throughput of the filter screen. Then, the waste slag scraping component and the elastic pull rod are used for friction transmission. When the inverted V-shaped filter screen reaches the slag collection box, the waste slag scraping component is driven by the elastic pull rod to scrape the impurities attached to the filter screen towards the slag collection box, realizing a directional collection mode. Furthermore, after the lifting frame moves further upward with the elastic pull rod, the BDD composite electrode can be quickly detached, allowing it to be easily removed from the lifting frame. While ensuring the stability of high current transmission, the electrode maintenance time is shortened.

[0026] It should be understood that the foregoing general description and the following detailed description are exemplary and illustrative only, and are not intended to limit this disclosure.

[0027] This application provides an overview of various implementations or examples of the technology described in this disclosure, and is not a full disclosure of the entire scope or all features of the disclosed technology. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0029] Figure 1 This is a schematic diagram of the overall structure of a BDD composite electrode according to the present invention;

[0030] Figure 2 This is a schematic diagram of the overall structure of a medical wastewater treatment device according to the present invention;

[0031] Figure 3 This is a top view of the treatment tank in a medical wastewater treatment device according to the present invention;

[0032] Figure 4 This is a schematic diagram of the lifting frame in a medical wastewater treatment device according to the present invention;

[0033] Figure 5 This is a schematic diagram of the internal structure of the treatment tank in a medical wastewater treatment device according to the present invention;

[0034] Figure 6 This is a schematic diagram showing the connection between the elastic tension rod and the inverted V-shaped filter screen in a medical wastewater treatment device of the present invention;

[0035] Figure 7 This is a schematic diagram of the elastic tension rod in a medical wastewater treatment device of the present invention;

[0036] Figure 8 This is a partial cross-sectional view of the elastic tension rod in a medical wastewater treatment device of the present invention.

[0037] Explanation of reference numerals in the attached figures:

[0038] 1. BDD composite electrode; 101. Composite substrate; 102. Gradient transition layer; 103. Multi-level structured BDD layer; 104. Brazing reinforcement layer; 105. Slot; 2. Treatment tank; 201. Abutment rod; 202. First shaft; 203. Second shaft; 204. Transmission belt; 205. Transmission gear; 206. Abutment cam; 207. Retaining ring; 208. Pushing cam; 209. Drive motor; 21. 0. Impeller; 3. Lifting frame; 301. Driven rack; 4. Inverted V-shaped filter screen; 5. Elastic pull rod; 501. Abutment spring; 502. Anti-slip strip; 503. Piston rod; 504. Connecting sleeve; 6. Slag collection box; 7. Waste slag scraping assembly; 701. Drive shaft; 702. Drive ring; 703. Chain; 704. Scraper; 8. Locking assembly; 801. Cylinder; 802. Locking tongue; 9. Annular descaling knife. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this disclosure. All other embodiments obtained by those skilled in the art based on the described embodiments of this disclosure without creative effort are within the scope of protection of this disclosure.

[0040] Please see Figure 1 An embodiment of the present invention provides a BDD composite electrode, comprising:

[0041] The composite substrate 101 consists of a nickel foam core and a titanium shell, with the titanium shell forming a porous structure through magnetron sputtering deposition.

[0042] Gradient transition layer 102, which sequentially comprises a TiN layer, an Nb layer and an NbC layer;

[0043] The multi-level structured BDD layer 103 has micron-sized pores and a nanocone array on its surface. The height of the nanocones is 300-500 nm and the spacing is 50-100 nm.

[0044] The brazing reinforcement layer 104 includes a high-entropy alloy brazing filler metal and an in-situ generated CeO2 passivation film. The interfacial bonding strength of the electrode is ≥180MPa, and the specific surface area is ≥15.8m² / g.

[0045] Specifically, by innovating the electrode structure, a three-dimensional conductive network is constructed using a foamed nickel / titanium composite substrate, reducing bulk resistance. A gradient transition layer is designed to achieve a continuous transition in the coefficient of thermal expansion, enhancing interfacial bonding strength. A multi-level structured BDD layer is constructed, and the synergistic effect of micron-sized pores and nano-cones increases the yield of hydroxyl radicals to several times that of traditional electrodes. The foamed nickel / titanium composite substrate, through its interpenetrating pore structure, improves the uniformity of current density distribution, and the effective working area of ​​the electrode is many times the geometric area, reducing the energy consumption per unit volume of wastewater treatment compared to traditional Ti / BDD electrodes. The TiN / Nb / NbC gradient layer reduces interfacial thermal stress and maintains structural integrity even when the electrolyte temperature changes abruptly. Combined with a CeO2 passivation film, corrosion current density can be suppressed. The multi-level structured BDD layer synergistically catalyzes and extends the wastewater retention time, enhancing the mass transfer and diffusion of organic matter.

[0046] In a further embodiment of the present invention, the total thickness of the gradient transition layer 102 is 2.0-3.0 μm, wherein the thickness of the TiN layer accounts for 10-15%, the thickness of the Nb layer accounts for 15-20%, and the thickness of the NbC layer accounts for 65-75%. This optimized scheme, through the thinning of the gradient transition layer 102 and the precise control of its composition, ensures corrosion resistance and conductivity while improving the reliability of the electrode interface to industrial-grade requirements (ISO 18278-1 standard), and is particularly suitable for the continuous electrolytic treatment of high-salt and high-temperature medical wastewater.

[0047] A method for preparing the above-mentioned BDD composite electrode includes the following steps:

[0048] Step 1: Preparation of composite substrate 101. Immerse nickel foam in 5-8% HCl and ultrasonically clean for 15-30 minutes. Deposit a titanium layer under magnetron sputtering power of 400-600W and Ar gas pressure of 0.3-0.8Pa. Then, etch in 3-7% HF solution to form a porous titanium shell.

[0049] Step 2: Deposition of gradient transition layer 102. A TiN layer is deposited by PECVD at 200-400W RF power. Then, a 0.4-0.6μm pure niobium layer and a 1.2-1.8μm NbC gradient layer are deposited sequentially by multi-target sputtering. The carbon flux is linearly increased from 10sccm to 30sccm.

[0050] Step 3: BDD layer construction. In a hot-filament CVD reactor, the CH4 / H2 volume ratio is controlled at 2-4% and the boron doping concentration is 4000-6000ppm to grow an 8-12μm thick BDD layer.

[0051] Step 4: Multi-level structure etching. Femtosecond laser is used to form micron-sized vias at a scanning speed of 5-15 mm / s. Then, Ar / N2 mixed plasma is used to form a nanocone array through etching at a power density of 0.5-1.5 W / cm.

[0052] Step 5: Interface strengthening treatment. High-entropy alloy brazing filler metal is coated onto the interface using powder metallurgy. After vacuum brazing, the finished electrode is obtained.

[0053] In a further embodiment of the present invention, the deposition rate of the NbC gradient layer in step two is controlled at 0.08-0.12 μm / min, the bias voltage of the plasma etching in step four is -50 to -100V, and the particle size D90 of the solder powder in step five is ≤5μm, and the Ce element content is 0.5-1.2wt%.

[0054] Specifically, this electrode achieves efficient wastewater treatment through multi-dimensional synergistic effects. The three-dimensional conductive network constructed by the foamed nickel / titanium composite substrate reduces the bulk resistance. The gradient transition layer 102 (TiN / Nb / NbC) suppresses interfacial stress through the continuous transition of the thermal expansion coefficient. Combined with the CeO2 passivation film, the corrosion rate is controlled below 0.01 mm / a. The micron-sized pores extend the wastewater retention time, thereby improving the COD removal rate in the wastewater and extending the electrode lifespan, meeting industrial-grade stability requirements.

[0055] Please see Figure 1-8This invention provides a medical wastewater treatment device, comprising a treatment tank 2 and at least one pair of BDD composite electrodes 1, one of which is the anode and the other is the cathode. A lifting frame 3 is vertically and movably installed on the top of the treatment tank 2, and the pair of BDD composite electrodes 1 are installed in the lifting frame 3. An inverted V-shaped filter screen 4 is located below the pair of BDD composite electrodes 1, and a pair of elastic pull rods 5 are installed between the lifting frame 3 and the inverted V-shaped filter screen 4. Sludge collection boxes 6 are installed on both sides of the treatment tank 2 and are connected to it, with elastically inserted parts at the connection points that abut against the inverted V-shaped filter screen 4. A pair of waste scraping components 7 are installed on the top two sides of the inverted V-shaped filter screen 4, respectively, and the waste scraping components 7 and the abutment rod 201 are driven by friction. A locking component 8 is installed horizontally on the top of the elastic pull rod 5 and the two are connected to each other. A slot 105 matching the locking component 8 is opened on the BDD composite electrode 1. When the lifting frame 3 moves the inverted V-shaped filter screen 4 upward and abuts the abutment rod 201, the elastic pull rod 5 moves upward alone to drive the waste scraping components 7 to run, and then the locking component 8 is pulled out from the slot 105.

[0056] Specifically, during equipment operation, wastewater is treated via the BDD composite electrode 1. After multiple batches of treatment are completed, the BDD composite electrode 1 and the inverted V-shaped filter screen 4 can be raised via the lifting frame 3. When the elastic pull rod 5 pulls the inverted V-shaped filter screen 4, since it is not rigidly connected to the inverted V-shaped filter screen 4, the inverted V-shaped filter screen 4 can vibrate under the action of water flow. The impact of water flow and its own vibration effectively peel off most of the filter cake layer. When the inverted V-shaped filter screen 4 rises to the inlet of the slag collection box 6, the abutment rod 201 is inserted into the groove reserved in the inner wall of the treatment tank 2. One end of the abutment rod 201 is fixedly connected to a connecting spring in the groove, and the other end has a symmetrical inclined abutment surface. Because the inverted V-shaped filter screen 4 is abutted by the abutment rod 201, the abutment rod 201... If the abutment rod 201 is not completely pushed into the groove by the inverted V-shaped filter screen 4, only the elastic pull rod 5 will rise alone. The upward movement of the elastic pull rod 5 will drive the waste scraping component 7 on the inverted V-shaped filter screen 4 to quickly push the filter residue into the slag collection box 6, avoiding insufficient collection due to vibration. Then, after the lifting frame 3 is raised, the elastic pull rod 5, which has risen to a certain height, can release the locking component 8 from the electrode. The top of the BDD composite electrode 1 is fixed to the lifting frame 3 by a threaded connection. When the locking component 8 is inserted into the slot 105, the BDD composite electrode 1 cannot be disassembled. However, as long as the lifting frame 3 is raised to a suitable height, the locking component 8 can be removed from the slot 105, and the disassembly of both electrodes can be completed quickly.

[0057] Compared with existing technologies, this invention innovates the electrode structure and equipment linkage mechanism by using a foamed nickel / titanium composite matrix to construct a three-dimensional conductive network, thereby reducing bulk resistance. A gradient transition layer is designed to achieve a continuous transition in the coefficient of thermal expansion, enhancing interfacial bonding strength. A multi-level BDD layer is constructed, and the synergistic effect of micron-sized pores and nano-cones increases the yield of hydroxyl radicals to several times that of traditional electrodes. Simultaneously, the inverted V-shaped filter screen 4 is lifted by an elastic pull rod 5, enabling it to generate high-frequency micro-amplitude vibrations during its vertical stroke, disrupting the formation of the surface filter cake layer and maintaining the effective throughput of the filter screen. Then, the waste scraping assembly 7 and the elastic pull rod 5 are used for frictional transmission. When the inverted V-shaped filter screen 4 reaches the sludge collection box 6, the waste sludge scraping assembly 7, driven by the elastic pull rod 5, scrapes away the impurities attached to the filter screen in the direction of the sludge collection box 6, realizing a directional collection mode. Furthermore, after the lifting frame 3 moves further upward with the elastic pull rod 5, the BDD composite electrode 1 can be quickly detached, allowing it to be easily removed from the lifting frame 3. While ensuring the stability of high current transmission, the electrode maintenance time is shortened. Through the synergistic innovation of mechanical vibration, directional sludge scraping, and rapid disassembly and assembly, the throughput of medical wastewater treatment is improved, and the electrode maintenance cost is reduced. It is particularly suitable for continuous treatment scenarios of medical wastewater containing high concentrations of biofilm and colloidal impurities.

[0058] In a further embodiment of the present invention, the inner walls of the lifting frame 3 are slidably connected to the outer walls of the treatment pool 2 on both sides. Limiting blocks are fixedly connected to both sides of the treatment pool 2. A vertical groove matching the limiting blocks is provided on the inner wall of the lifting frame 3. A first shaft 202 and a second shaft 203 distributed vertically are installed in the treatment pool 2. A drive motor 209 connected to the end of the first shaft 202 is installed outside the treatment pool 2. A transmission belt 204 is installed between the first shaft 202 and the second shaft 203. Transmission gears 205 are fixedly connected to both ends of the first shaft 202. A driven rack 301 meshing with the transmission gear 205 is vertically fixedly connected to one side of the lifting frame 3. A pair of abutting cams 206 are fixedly connected to the second shaft 203 below the inverted V-shaped filter screen 4. An impeller 210 is also added to the middle of the second shaft 203. Specifically, the drive motor 209 can drive the first shaft 202 and the second shaft 203. 3. During the rotation of the first shaft 202, its transmission gear 205 meshes with the driven rack 301 on the lifting frame 3. The rising and falling of the lifting frame 3 can be adjusted by the forward and reverse rotation of the first shaft 202. If the inverted V-shaped filter screen 4, pulled by the lifting frame 3 through the elastic pull rod 5, rests on the abutting cam 206, then when the second shaft 203 and the first shaft 202 rotate synchronously, the abutting cam 206 can intermittently lift the inverted V-shaped filter screen 4, causing the inverted V-shaped filter screen 4 to vibrate continuously. At the same time, the impeller 210 moves the water flow, allowing the debris attached to the inverted V-shaped filter screen 4 to be removed under the impact of the water flow. This makes it easier to quickly recover the waste residue when the inverted V-shaped filter screen 4 is lifted to the slag collection box 6. In addition, the closer the inverted V-shaped filter screen 4 is to the second shaft 203 below, the greater its own amplitude; the farther away from the second shaft 203, the smaller its own amplitude, thus achieving dynamic slag removal and cleaning.

[0059] In a further embodiment of the present invention, the bottom of the elastic pull rod 5 passes through the inverted V-shaped filter screen 4 and is equipped with an abutment spring 501. The top of the abutment spring 501 contacts the bottom surface of the inverted V-shaped filter screen 4. Specifically, the pressure brought by the inverted V-shaped filter screen 4 and the elastic pull rod 5 form a resonant system. When the lifting frame 3 moves vertically, the abutment spring 501 is subjected to a composite alternating load of gravity of the inverted V-shaped filter screen 4 and water flow impact. Through periodic compression and rebound, the mechanical energy is converted into high-frequency micro-amplitude vibration, which destroys the cohesion of the filter cake layer. During the slag scraping stage, the elastic potential energy accumulated by the abutment spring 501 makes it easier for the attached impurities to be peeled off by the waste slag scraping component 7. At the same time, the stiffness of the abutment spring 501 and the insertion of the elastic pull rod 5 work together to suppress lateral vibration, ensuring the accuracy of the slag scraping trajectory and making the equipment throughput maintenance rate more durable.

[0060] In a further embodiment of the present invention, the waste residue scraping assembly 7 includes multiple drive shafts 701 rotatably mounted on the top surface of the inverted V-shaped filter screen 4. Each drive shaft 701 is connected to the others by a number of chains 703. A drive ring 702 is fixedly sleeved on one of the drive shafts 701. An anti-slip strip 502 is vertically embedded on one side of the elastic pull rod 5, which is in frictional transmission with the drive ring 702. A number of scraper strips 704 are installed on the outside of two adjacent chains 703. Specifically, when the elastic pull rod 5 rises and falls, the frictional transmission between the anti-slip strip 502 and the drive ring 702 converts the vertical motion into the rotation of the drive shaft 701, causing the chains 703 to drive the scraper strips 704 to slide along the surface of the inverted V-shaped filter screen 4. The blade of the scraper strip 704 applies a shearing force to the filter residue. Combined with the elastic force of the abutment spring 501, it can scrape off colloidal clumps of various particle sizes, improve the cleaning effect, ensure that no residue is missed, and allow impurities to be concentrated and pushed into the slag collection box 6 along the inverted V-shaped filter screen 4.

[0061] In a further embodiment of the present invention, the locking assembly 8 includes a cylinder 801 connected to the interior of the elastic pull rod 5. The elastic pull rod 5 is hollow inside, and the air passage inside the rod is connected to the cylinder 801. A locking tongue 802 adapted to the slot 105 is movably sleeved in the cylinder 801. A piston rod 503 is elastically embedded inside the elastic pull rod 5. An elastic element is installed at the bottom of the piston rod 503. A connecting sleeve 504 connected to the bottom of the piston rod 503 is movably sleeved outside the elastic pull rod 5. A retaining ring 207 for preventing the piston rod 503 and the elastic pull rod 5 from moving upward together is fixedly connected to the inner wall of the treatment pool 2. The retaining ring 207 is sleeved outside the elastic pull rod 5, and its inner wall contacts the outer wall of the elastic pull rod 5. The retaining ring 207 abuts against the connecting sleeve 504. Specifically, during the lifting process of the lifting frame 3, since the retaining ring 207 is sleeved outside the elastic pull rod 5, it can ensure that the lifting frame 3 as a whole will not deviate excessively when rising. When the lifting frame 3 is raised to the electrode separation height, the piston rod 503 is blocked by the retaining ring 207 and moves downward relative to the elastic pull rod 5, drawing the gas in the cylinder 801 into the elastic pull rod 5, causing the locking tongue 802 to retract towards the inside of the cylinder 801, allowing the locking tongue 802 to leave the slot 105 on the BDD composite electrode 1. The overall unlocking is smooth and seamless, and the operation is convenient by utilizing the upward stroke of the lifting frame 3. When installing the electrode, the lifting frame 3 with the elastic pull rod 5 needs to be kept at the unlocking height of the locking component 8 first. The electrode is installed first, and then the slot 105 is aligned with the position of the locking tongue 802. When the elastic pull rod 5 descends, the piston rod 503 is reset under the push of the elastic element and pushes some gas into the cylinder 801, thereby pushing the locking tongue 802 to automatically insert into the slot 105 to complete the locking of the electrode, ensuring that the electrode does not loosen under large shaking and high current, and avoiding accidental detachment of the electrode.

[0062] In a further embodiment of the present invention, an annular descaling blade 9 is movably installed inside the treatment tank 2. The annular descaling blade 9 is located between the lifting frame 3 and the BDD composite electrode 1, and a push cam 208 for intermittently lifting the annular descaling blade 9 is installed on the first shaft 202. The annular descaling blade 9 is located on the lifting path of the BDD composite electrode 1, and a counterweight plate is installed on the annular descaling blade 9. Specifically, when the first shaft 202 rotates, it not only drives the BDD composite electrode 1 to rise together, but also allows the annular scraper blade with a fixed height to thoroughly scrape and clean the surface of the moving BDD electrode. The push cam 208 can intermittently lift the annular descaling blade 9, and the annular descaling blade 9 will automatically fall under the action of gravity, so that the impurities remaining on the blade during the scraping of the annular descaling blade 9 are shaken off onto the inverted V-shaped filter screen 4, so that they can enter the slag collection box 6 together with the waste residue on the inverted V-shaped filter screen 4.

[0063] The foregoing has only described certain exemplary embodiments of the present invention by way of illustration. Undoubtedly, those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the foregoing drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A BDD composite electrode, characterized in that, include: The composite substrate (101) is composed of a nickel foam core and a titanium shell, wherein the titanium shell has a porous structure; The gradient transition layer (102) comprises a TiN layer, an Nb layer and an NbC layer in sequence, and the total thickness of the gradient transition layer (102) is 2.0-3.0 μm; A multi-level structured BDD layer (103) with micron-sized pores and a nanocone array on its surface; The brazing reinforcement layer (104) includes a high-entropy alloy brazing filler metal and an in-situ generated CeO2 passivation film.

2. The BDD composite electrode according to claim 1, characterized in that, The thickness of the TiN layer accounts for 10-15%, the thickness of the Nb layer accounts for 15-20%, and the thickness of the NbC layer accounts for 65-75%.

3. A method for preparing a BDD composite electrode as described in any one of claims 1-2, characterized in that, Includes the following steps: Step 1: Preparation of composite substrate (101): Immerse nickel foam in 5-8% HCl and ultrasonically clean for 15-30 minutes. Deposit titanium layer under magnetron sputtering power of 400-600W and Ar gas pressure of 0.3-0.8Pa. Then, etch in 3-7% HF solution to form a porous titanium shell. Step 2: Gradient transition layer (102) deposition. A TiN layer was deposited by PECVD at a radio frequency power of 200-400W. Then, a 0.4-0.6μm pure niobium layer and a 1.2-1.8μm NbC gradient layer were deposited sequentially by multi-target sputtering. The carbon flux was linearly increased from 10sccm to 30sccm. Step 3: BDD layer construction. In a hot-filament CVD reactor, the CH4 / H2 volume ratio is controlled at 2-4% and the boron doping concentration is 4000-6000ppm to grow an 8-12μm thick BDD layer. Step 4: Multi-level structure etching. Femtosecond laser is used to form micron-sized vias at a scanning speed of 5-15 mm / s. Then, Ar / N2 mixed plasma is used to form a nanocone array through etching at a power density of 0.5-1.5 W / cm. Step 5: Interface strengthening treatment. High-entropy alloy brazing filler metal is coated onto the interface using powder metallurgy. After vacuum brazing, the finished electrode is obtained.

4. The method for preparing a BDD composite electrode according to claim 3, characterized in that, In step two, the deposition rate of the NbC gradient layer is controlled at 0.08-0.12 μm / min, and in step four, the bias voltage of the plasma etching is -50 to -100V.

5. A medical wastewater treatment device, characterized in that, It includes a treatment tank (2) and at least one pair of BDD composite electrodes (1) as described in any one of claims 1-2, wherein a lifting frame (3) is vertically and movably mounted on the top of the treatment tank (2), and the pair of BDD composite electrodes (1) are mounted in the lifting frame (3); An inverted V-shaped filter screen (4) is located below a pair of BDD composite electrodes (1), and a pair of elastic pull rods (5) are installed between the lifting frame (3) and the inverted V-shaped filter screen (4). Both sides of the treatment tank (2) are equipped with slag collection boxes (6) that are connected to them, and abutment rods (201) that abut against the inverted V-shaped filter screen (4) are elastically inserted at the connection point. A pair of waste scraping components (7) are respectively installed on the top two sides of the inverted V-shaped filter screen (4), and the waste scraping components (7) are driven by friction with the abutment rod (201); The locking assembly (8) is horizontally mounted on the top of the elastic pull rod (5) and the two are connected to each other. The BDD composite electrode (1) has a slot (105) that matches the locking assembly (8). When the lifting frame (3) moves the inverted V-shaped filter screen (4) upward and abuts against the abutment rod (201), the elastic pull rod (5) moves upward alone to drive the waste scraping assembly (7) to run, and then the locking assembly (8) is pulled out of the slot (105).

6. The medical wastewater treatment equipment according to claim 5, characterized in that, The inner walls of the lifting frame (3) are slidably connected to the outer walls of the treatment pool (2) on both sides. The treatment pool (2) is equipped with a first shaft (202) and a second shaft (203) distributed vertically. The treatment pool (2) is equipped with a drive motor (209) connected to the end of the first shaft (202) on the outside. A transmission belt (204) is installed between the first shaft (202) and the second shaft (203). Transmission gears (205) are fixedly connected to both ends of the first shaft (202). A driven rack (301) meshing with the transmission gear (205) is vertically fixedly connected to one side of the lifting frame (3). A pair of abutting cams (206) are fixedly connected to the second shaft (203) below the inverted V-shaped filter screen.

7. The medical wastewater treatment equipment according to claim 5, characterized in that, The bottom of the elastic pull rod (5) passes through the inverted V-shaped filter screen (4) and is equipped with an abutment spring (501). The top of the abutment spring (501) contacts the bottom surface of the inverted V-shaped filter screen (4).

8. The medical wastewater treatment equipment according to claim 5, characterized in that, The waste scraping assembly (7) includes multiple drive shafts (701) rotatably mounted on the top surface of the inverted V-shaped filter screen (4). Each drive shaft (701) is connected to the others by a number of chains (703). A drive ring (702) is fixedly sleeved on one of the drive shafts (701). An anti-slip strip (502) that rubs against the drive ring (702) is vertically embedded on one side of the elastic pull rod (5). A number of scraper strips (704) are installed on the outside of two adjacent chains (703).

9. A medical wastewater treatment device according to claim 5, characterized in that, The locking assembly (8) includes a cylinder (801) that communicates with the interior of the elastic pull rod (5). A locking tongue (802) that is adapted to the slot (105) is movably sleeved in the cylinder (801). A piston rod (503) is elastically embedded in the elastic pull rod (5). A retaining ring (207) is fixedly connected to the inner wall of the treatment pool (2) to prevent the piston rod (503) from moving upward together with the elastic pull rod (5).

10. A medical wastewater treatment device according to claim 6, characterized in that, The treatment tank (2) is equipped with an annular descaling blade (9), which is located between the lifting frame (3) and the BDD composite electrode (1), and a push cam (208) for intermittently lifting the annular descaling blade (9) is installed on the first shaft (202).

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