Device and method for rapidly degrading antibiotic wastewater through plasma generated by liquid-phase microwave discharge

Abstract

The invention discloses a device and a method for rapidly degrading antibiotics through plasma generated by microwave discharge in a liquid phase. The device comprises a liquid path conveying system, a microwave energy transmission discharging system, a reactor and a gas path control and liquid control system. The liquid path system sends antibiotic wastewater to be degraded to the reactor, the microwave system generates plasmas through discharging, the reactor degrades the wastewater through the plasmas, and the gas path and liquid outlet system regulates and controls degraded gas and water discharge after treatment. The device depends on a liquid-phase microwave discharge technology and has broad-spectrum degradation capacity. A high-temperature and high-pressure environment and an exogenous chemical reagent are not needed, instantaneous breakdown and deep mineralization of wastewater can be realized, and the problems of slow reaction, strong selectivity and easy secondary pollution of a traditional method are solved. The reactor can concentrate microwave energy, a treatment blind area is eliminated, a gas path and a liquid outlet system guarantee controllable discharge, and the service life of equipment is prolonged. The device is driven by electric energy in the whole process, is flexible to operate and provides a green and efficient technical path for antibiotic wastewater treatment.

Description

An apparatus and method for rapidly degrading antibiotic wastewater by generating plasma through liquid-phase microwave discharge. Technical Field

[0001] This invention relates to the field of antibiotic wastewater degradation technology, and in particular to an apparatus and method for rapidly degrading antibiotic wastewater by generating plasma through liquid-phase microwave discharge. Background Technology

[0002] The frequent use of antibiotics has led to their detection in water bodies. Their long-term residues are toxic to aquatic organisms and can induce bacteria to produce resistance genes. These genes can accumulate in the human body through the food chain, posing a potential threat to human health. Antibiotics are recognized as an emerging type of environmental pollutant, making research on antibiotic removal crucial and necessitating urgent efforts to control antibiotic pollution.

[0003] Current methods for treating antibiotics mainly include adsorption, membrane separation, ozone, photochemical, and electrochemical methods, as well as various combined degradation processes. Traditional antibiotic removal methods generally face the core dilemmas of "low efficiency, high cost, poor stability, and high risk of secondary pollution," making it difficult to economically and efficiently solve the increasingly serious problem of antibiotic pollution. Traditional treatment processes such as flocculation, sedimentation, and filtration used in wastewater treatment plants and water purification plants are also insufficient for effectively degrading this type of wastewater. Microwave discharge plasma technology is an emerging advanced oxidation process. This technology achieves stable and continuous generation of liquid-phase plasma, and combined with a highly efficient energy coupling mechanism, it significantly improves degradation efficiency. It combines treatment efficiency with environmental controllability, making it a highly efficient alternative to traditional biological and chemical degradation processes. By exciting plasma in a liquid using microwave energy, it generates active species such as hydroxyl radicals (·OH), which can efficiently mineralize organic pollutants. It has advantages such as fast reaction speed, no secondary pollution, and simple operation.

[0004] Patent CN110980895A discloses a method and apparatus for removing antibiotics from water by electroadsorption and degradation. This method combines electroadsorption with advanced electrochemical oxidation in steps to treat low-concentration antibiotic wastewater containing doxycycline, chlortetracycline, enrofloxacin, etc., at concentrations of 0.5–10 mg / L. An electrolytic cell using a Ti / TiO2NT-CuO anode and a titanium plate cathode is employed to enrich the antibiotics, followed by constant-current electrolytic degradation with Na2SO4 electrolyte to achieve rapid removal of low-concentration antibiotics. However, this technology has drawbacks: electrode preparation requires three steps—Ti substrate anodizing, Cu deposition, and high-temperature sintering—resulting in a complex process with high parameter control requirements, thus increasing costs; the single-batch treatment cycle is long, requiring 2–3 cycles in some cases, and the treatment efficiency needs improvement.

[0005] Patent CN116903100A discloses a method for enhancing the degradation of antibiotics in water using SPC through piezoelectric catalysis with precious opal. This method involves mixing precious opal and SPC at a mass ratio of 1-4:1, adding them to water containing tetracycline (5-1000 mg / L) to form a suspension, and then using piezoelectric catalysis at 20-60℃ and 100-700W microwaves to synergistically release hydrogen peroxide to degrade the antibiotics. The degradation rate reaches up to 85% in 4 hours. This simple process overcomes the drawbacks of classic Fenton's reagent. However, this method is limited to tetracycline, which is too specific; additional solid-liquid separation is required during the degradation process; and the reaction time is too long.

[0006] Therefore, in response to the need for antibiotic pollution control in water bodies, it is necessary to develop safe and efficient new antibiotic degradation technologies that can shorten the degradation cycle, improve removal efficiency, reduce energy consumption and the risk of secondary pollution, and be easy to operate and scale up. This can provide an economical and practical solution for the water treatment industry, generate significant economic benefits, and at the same time ensure water environmental quality, ecological stability and public health. It has important academic value, ecological benefits and social significance. Summary of the Invention

[0007] This invention provides a rapid degradation device and method based on microwave-excited high-energy electron plasma generation in a liquid solution. Liquid-phase microwave discharge plasma technology has significant advantages in antibiotic wastewater treatment. It utilizes the electron avalanche effect induced by a high-frequency electric field to generate high-density non-selective strong oxides such as hydroxyl radicals (·OH), HO2, and O in situ. Therefore, this device possesses excellent broad-spectrum degradation capabilities against different types and structures of antibiotic pollutants. Combined with a continuous flow operation system, this technology can achieve instantaneous breakdown and deep mineralization of complex wastewater without the need for high-temperature, high-pressure environments or exogenous chemical reagents. It effectively overcomes the bottlenecks of traditional biological or chemical methods, such as slow reaction rates, limited treatment targets (high selectivity), and the potential for secondary pollution. This provides an advanced treatment solution that combines broad-spectrum efficiency, environmental cleanliness, and engineering practicality to overcome the aforementioned problems.

[0008] To achieve the above objectives, the technical solution of the present invention is as follows: The present invention provides a rapid degradation device based on microwave-excited high-energy electron plasma generation in a liquid solution, comprising a liquid transport system, a microwave energy transmission and discharge system, a reactor, and a gas path control and liquid control system; the liquid transport system is used to transport antibiotic wastewater to the reactor; the microwave energy transmission and discharge system can generate plasma through microwave energy discharge; the reactor can utilize the plasma generated by the microwave energy transmission and discharge system to degrade the antibiotic wastewater; the gas path control and liquid control system is used to control the discharge of gas generated during the degradation of antibiotic wastewater in the reactor and the degraded water from the reactor.

[0009] Furthermore, the reactor includes an outer cylinder, a top cover disposed on the top of the outer cylinder, and an inner cylinder disposed inside the outer cylinder. The bottom of the inner cylinder is provided with a plurality of fixing grooves that match the inner cylinders of different diameters. The ratio of the diameter of the inner cylinder to the diameter of the outer cylinder is 2:3-1:10. The volume of the outer cylinder is 1 to 10 L, and the volume of the inner cylinder is 0.5 to 8 L.

[0010] Furthermore, the microwave energy transmission and discharge system includes a microwave power supply, a magnetron, an isolator, a detection coupler, a three-pin adjuster, a waveguide, and a microwave discharge electrode connected in sequence. The output end of the three-pin adjuster is connected to the microwave discharge electrode via a coaxial cable. The microwave discharge electrode is vertically positioned at the bottom of the outer cylinder and is located at the position of the central axis of the outer cylinder and the inner cylinder. The detection coupler is also connected to a vector network analyzer.

[0011] Furthermore, the microwave discharge frequency is 2450MHz, the microwave wavelength λ is 12.24 cm, and the microwave power supply transmits power of 0.1 ~ 1.5 kW.

[0012] Furthermore, the microwave discharge electrode is made of tungsten, platinum-rhodium, or platinum-iridium alloy, and the diameter of the microwave discharge electrode is 1 to 10 mm.

[0013] Furthermore, a ternary gradient demister is provided inside the outer cylinder and at the top of the inner cylinder for drying the gas generated during the degradation process. The ternary gradient demister includes a shell, a porous flow equalization plate, an inverted V-shaped plate, and a double-layer wire mesh arranged sequentially from the bottom to the top of the shell. An air passage is provided between the inverted V-shaped plate and the inner wall of the shell. The porous flow equalization plate is used to uniformly distribute and rectify the airflow generated by the degradation of antibiotic wastewater and intercept coarse droplets in the airflow. The two ends of the inverted V-shaped plate are used to force the airflow after the removal of coarse droplets to change its flow direction, so that medium-sized droplets in the airflow after the removal of coarse droplets are thrown towards the plate wall of the inverted V-shaped plate for droplet separation. The double-layer wire mesh is used to filter out micron-sized tiny droplets in the airflow that enters through the air passage after the removal of medium-sized droplets.

[0014] Furthermore, the gas path control and liquid control system includes a gas path assembly and a liquid outlet assembly, both connected to the reactor; the gas path assembly is used to control the discharge of gas inside the reactor after demisting by the ternary gradient demister; the liquid outlet assembly is used to control the discharge of degraded liquid from the reactor; the gas path assembly includes an exhaust pump and an exhaust pipe connected at both ends to the demister and the exhaust pump respectively; the liquid outlet assembly includes an outlet pipeline, a water storage tank, and a second pressure sensor and a second water pump installed on the outlet pipeline, with both ends of the outlet pipeline connected to the inner cylinder and the water storage tank respectively; a pressure gauge is installed at the top of the reactor for real-time monitoring of the internal pressure of the reactor; the liquid path delivery system includes an inlet pipeline, a wastewater tank, and a first pressure sensor and a first water pump installed on the inlet pipeline, with both ends of the inlet pipeline connected to the inner cylinder and the wastewater tank respectively.

[0015] In another aspect, this invention provides a method for rapidly degrading antibiotic wastewater using the aforementioned liquid-phase microwave discharge plasma-generated device, comprising the following steps: Step 1: Activating the liquid transport system to transport the antibiotic wastewater to the reactor; Step 2: Activating the gas and liquid control system to drive the flow of mist-containing gas within the reactor and to extract the waste gas generated during the degradation process from the reactor; Step 3: Activating the microwave energy transmission discharge system to generate plasma using microwave energy discharge to degrade the antibiotic wastewater in the reactor; simultaneously activating the gas and liquid control system to extract the degraded liquid from the reactor and transport it to a storage tank; after a set time is reached, the device is shut down, and the degradation is complete.

[0016] Further, the specific method includes the following steps: Step one: Start the first water pump to continuously inject antibiotic wastewater from the wastewater tank into the inner cylinder of the reactor through the inlet pipe, so that a dynamic reaction flow field is formed around the microwave discharge electrode; Step two: Start the exhaust pump to drive the flow of mist-containing gas in the reactor, so that the mist-containing gas is rectified, uniformly distributed, inertially impacted, and intercepted and coalesced by the three-dimensional gradient demister at the top of the inner cylinder in sequence to achieve gas-liquid separation, and the dried exhaust gas is extracted from the reactor; Step three: Turn on the microwave power supply to drive the magnetic control The tube generates microwave energy, which passes sequentially through an isolator, a detection coupler, and a three-pin regulator. This energy is then directionally transmitted via a waveguide and coaxial cable to a microwave discharge electrode positioned along the axial center of the inner cylinder. This discharge electrode generates plasma within the inner cylinder, degrading the antibiotic wastewater. A vector network analyzer connected to the detection coupler monitors microwave transmission parameters and reflection in real time. A second water pump operates synchronously when the microwave power is turned on, continuously pumping the degraded liquid through an outlet pipe and transporting it to a storage tank. After a set time, all equipment is shut down, completing the antibiotic wastewater degradation process.

[0017] Further, in step one, the antibiotic wastewater includes one or more types of antibiotics, with a concentration of 0.01 to 100 mg / L; the volume of the inner cylinder is 0.5 to 8 L; in step three, the microwave discharge frequency is 2450 MHz, the microwave wavelength λ is 12.24 cm, the microwave power supply's transmission power is 0.1 to 1.5 kW, and the microwave discharge electrode diameter is 1 to 10 mm; the residence time of the antibiotic wastewater to be degraded in the reactor is 0.1 to 30 min, wherein the flow rate of the input and output water pumps is set to 100 to 60000 mL / min.

[0018] The beneficial effects of this invention are as follows: This invention discloses a device for the rapid degradation of antibiotic wastewater using liquid-phase microwave discharge plasma. It comprises a liquid transport system, a microwave energy transmission and discharge system, a reaction system, and a gas path control system, all working in synergy with a liquid control system. Leveraging the advantages of liquid-phase microwave discharge plasma technology, it generates high-density non-selective strong oxide species such as hydroxyl radicals, peroxy radicals, and atomic oxygen in situ through a high-frequency electric field-induced electron avalanche effect. This results in excellent broad-spectrum degradation capabilities, capable of addressing antibiotic pollutants of various types and structures. This device employs a continuous flow operation system, eliminating the need for high-temperature, high-pressure environments and exogenous chemical reagents, achieving instantaneous breakdown of complex wastewater. This effectively overcomes the bottlenecks of traditional biological and chemical methods, which are characterized by slow reactions, high selectivity, and susceptibility to secondary pollution. The reactor concentrates microwave energy, eliminates treatment blind spots, and improves the reaction efficiency between plasma and wastewater. The gas path control and liquid control system precisely regulate gas and liquid emissions, avoiding secondary pollution and extending the service life of key equipment components. The entire device is electrically driven and flexible in operation, providing a green and efficient technical path for antibiotic wastewater treatment. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 is a schematic diagram of the device for rapid degradation of antibiotic wastewater by generating plasma through liquid-phase microwave discharge according to the present invention; Figure 2 is a front view of the ternary gradient demister in the device of the present invention; Figure 3 is an auxiliary view of the ternary gradient demister in the device of the present invention; Figure 4 shows the degradation rate results of Examples 1-8.

[0021] In the diagram: 1. Outer cylinder; 2. Top cover; 3. Inner cylinder; 4. Microwave power supply; 5. Magnetron; 6. Isolator; 7. Detection coupler; 8. Three-pin adjuster; 9. Waveguide; 10. Coaxial cable; 11. Microwave discharge electrode; 12. Vector network analyzer; 13. Porous flow equalization plate; 14. Inverted V-shaped plate; 15. Double-layer wire mesh; 17. Exhaust pump; 18. Exhaust pipe; 19. Liquid inlet pipe; 20. Wastewater tank; 21. First pressure sensor; 22. First water pump; 23. Liquid outlet pipe; 24. Water storage tank; 25. Second pressure sensor; 26. Second water pump; 27. Pressure gauge; 28. Coarse filter layer; 29. ​​Fine filter layer; 30. Three-dimensional gradient demister. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] The mechanism of this invention is as follows: This device for rapidly degrading antibiotic wastewater by generating plasma through liquid-phase microwave discharge utilizes microwave energy to create a high-intensity electric field near the electrodes, inducing ionization and dissociation of water molecules and forming a plasma region rich in various active species in situ. Specifically, the ·OH (hydroxyl radical) generated in process ① is the core active species for antibiotic degradation, with a standard redox potential as high as 2.8 V. It can non-selectively attack antibiotic molecules and destroy their chemical structure. Furthermore, the liquid-phase microwave discharge process ② also generates a large amount of hydrogen peroxide, which can be further converted into ·OH through pathways ③ and ④, further driving the antibiotic molecules to undergo chemical bond breaking, ring-opening reactions, and gradual oxidation, ultimately degrading them into CO2, H2O, and small molecule inorganic substances, achieving efficient mineralization of antibiotics.

[0024]

[0025] This invention utilizes a "microbubble-electron avalanche" breakdown mechanism induced by a high-frequency microwave electric field to directly generate high-density plasma in situ in a pure solution environment, without the need to introduce any external working gas or add chemical reagents, effectively reducing operating costs and system complexity. The high concentrations of highly oxidizing species generated in this process, such as hydroxyl radicals (·OH), peroxy radicals (HO2), atomic oxygen radicals (O), and hydrogen peroxide, exhibit non-selectivity, enabling instantaneous breakdown and deep mineralization of antibiotic pollutants with different structures and recalcitrant degradation capabilities, demonstrating excellent broad-spectrum degradation ability. Unlike traditional batch reactors, this invention constructs a continuous flow operation loop with balanced influent and effluent through dual-pump drive and pressure monitoring, achieving practical continuous treatment. The reactor adopts a corrosion-resistant double-cylinder coaxial structure, possessing engineering advantages such as resistance to high-temperature and strong oxidizing environments, compact structure, and modular expansion. Furthermore, through an internally adjustable media sleeve and a top sealing cover, it constructs a dynamic reaction chamber with variable geometric parameters. This invention utilizes an adjustable sleeve to construct the optimal reaction flow field, highly concentrating microwave energy in the confined discharge region to eliminate blind zones and significantly improve removal efficiency. The structure utilizes the gas-phase saturation zone formed by the top cover plate and the reflux mechanism to force volatile components to undergo phase change within the cavity and return to the liquid phase to participate in the reaction, thereby effectively solving the technical challenges of high-efficiency removal and low organic solvent loss.

[0026] This invention combines a "rectangular waveguide-coaxial converter" energy transmission structure, which ensures miniaturization of the equipment while effectively reducing microwave reflection loss and maximizing energy coupling to the discharge electrode. This solves the technical pain points of traditional microwave equipment, such as low energy utilization and easy damage to the magnetron due to load mismatch.

[0027] To address the challenges of reactor liquid-phase boiling and forced exhaust pump operation, this invention designs a dedicated ternary gradient composite demister consisting of a porous flow equalization plate, an inverted V-shaped plate, and a double-layer wire mesh. Through a three-stage mechanism of rectification, inertial collision, and interception / agglomeration, it effectively buffers airflow fluctuations caused by atmospheric pressure boiling. While ensuring smooth exhaust, it completely solves the problem of mist entrainment, effectively preventing acidic or corrosive waste liquids from entering the exhaust pump and gas path system. This significantly extends the service life of key components and avoids secondary pollution.

[0028] This invention is entirely electrically driven, relying on the "physical-chemical" synergistic degradation mechanism of a microwave discharge system. It overcomes the limitations of traditional biological or photocatalytic technologies, which are susceptible to environmental factors such as temperature and light, and possesses stable all-weather operation capabilities. The system supports instant start / stop and on-demand control, offering extremely high operational flexibility to adapt to intermittent or continuous industrial production needs. This microwave discharge degradation process requires no chemical reagents, avoiding the risk of secondary pollution at the source. Combined with a highly efficient microwave energy coupling design, it significantly improves energy utilization, providing a green, low-carbon, and efficient technical approach for antibiotic wastewater treatment.

[0029] Figure 1 shows an apparatus for rapidly degrading antibiotic wastewater by generating plasma through liquid-phase microwave discharge according to this embodiment. The apparatus includes: a liquid transport system, a microwave energy transmission discharge system, a reactor, and a gas and liquid control system. The liquid transport system transports the antibiotic wastewater to be degraded to the reactor. The microwave energy transmission discharge system generates plasma through microwave energy discharge. The reactor utilizes the plasma generated by the microwave energy transmission discharge system to degrade the antibiotic wastewater. The gas and liquid control system controls the discharge of gases generated during the degradation of the antibiotic wastewater from the reactor, as well as the degraded water.

[0030] Meanwhile, this device can be configured with a multi-unit parallel operation expansion structure, that is, by increasing the number of reactors in parallel, it can achieve large-scale continuous throughput and treatment of antibiotic wastewater.

[0031] This invention discloses a device for the rapid degradation of antibiotic wastewater by generating plasma through liquid-phase microwave discharge. Through the synergistic action of four main units—a liquid transport system, a microwave energy transmission and discharge system, a reactor, and a gas and liquid control system—it exhibits significant advantages in the field of liquid-phase microwave discharge plasma technology for treating antibiotic wastewater. The core of the microwave energy transmission and discharge system utilizes the electron avalanche effect induced by a high-frequency electric field to generate high-density non-selective strong oxide species such as hydroxyl radicals (·OH), peroxy radicals (HO2), and atomic oxygen (O) in situ within the wastewater system. These species possess extremely strong oxidizing activity and can efficiently act on different species. The device can degrade antibiotic pollutants of different types and structures, giving it excellent broad-spectrum degradation capabilities. The entire process requires no external working gas, no chemical reagents, and no high-temperature, high-pressure environment, effectively simplifying the overall structure, reducing operating costs and maintenance difficulty, and avoiding safety hazards associated with high-temperature, high-pressure conditions. The liquid delivery system stably and accurately delivers the antibiotic wastewater to the reactor, creating a continuous flow operation system with balanced influent and effluent, replacing traditional intermittent treatment modes, overcoming the efficiency limitations of batch processing, and meeting the practical needs of continuous, large-scale antibiotic wastewater treatment in industrial settings. This continuous flow operation system is deeply compatible with the plasma generation function of the microwave energy transmission discharge system. Through their synergistic effect, it can achieve instantaneous breakdown and deep mineralization of complex antibiotic wastewater without high-temperature, high-pressure environments or external chemical reagents. This effectively overcomes the technical bottlenecks of slow reaction rates in traditional biological treatment methods, strong selectivity and limited treatment targets in chemical treatment methods, and the tendency of both to generate secondary pollution, significantly improving the treatment efficiency and engineering application value of the device.

[0032] As the core processing chamber, the reactor can efficiently receive the plasma generated by the microwave energy transmission discharge system, providing a stable and controllable environment for the full reaction of plasma with antibiotic wastewater. By optimizing the internal structure to adapt to the characteristics of plasma action, microwave energy can be concentrated in the core reaction area, eliminating treatment blind spots, enhancing the contact reaction efficiency between strong oxide species and wastewater pollutants, further ensuring the removal rate and mineralization degree of pollutants, and ensuring that the degradation effect is stable and meets the standards.

[0033] The gas path control and liquid control system can precisely regulate the emission status of gases generated during the degradation process in the reactor and the discharged water after degradation. It ensures the orderly discharge of gases generated during the reaction, avoiding gas accumulation that could interfere with reaction stability, and enables the controlled discharge of the discharged water after degradation, facilitating subsequent compliance testing and secondary deep treatment. Simultaneously, a gas-phase reflux mechanism can be formed through a rational structural design, forcing volatile components to return to the liquid phase to participate in the reaction, reducing the loss of effective components, balancing degradation efficiency and resource utilization, avoiding secondary pollution caused by disordered emissions, extending the service life of key components such as the gas path and pumps, and improving the overall operational stability and reliability of the device.

[0034] The entire process of the device is driven by electricity, eliminating the dependence of traditional treatment technologies on chemical reagents and external environmental conditions. It is highly flexible in operation, enabling instant start-up and shutdown and on-demand control. It can adapt to the treatment needs of antibiotic wastewater under different working conditions such as intermittent and continuous operation, providing an efficient, green, low-carbon and sustainable technical path for antibiotic wastewater treatment.

[0035] Preferably, the reactor includes an outer cylinder 1, a top cover 2 disposed on the top of the outer cylinder 1, and an inner cylinder 3 disposed inside the outer cylinder 1. The bottom of the inner cylinder 1 is provided with a plurality of fixing grooves that match the inner cylinders 3 of different diameters. The diameter ratio of the inner cylinder 3 to the outer cylinder 1 is 2:3-1:10. The volume of the outer cylinder 1 is 1~10L, and the volume of the inner cylinder 3 is 0.5~8L.

[0036] The bottom of the outer cylinder 1 is equipped with several fixing grooves that match the inner cylinders 3 of different diameters, enabling convenient replacement and installation of the inner cylinders 3. By replacing the inner cylinders 3 with different specifications, the effective reaction chamber space of the reactor can be flexibly adjusted to adapt to the volume variation requirements of the inner cylinder 3 from 0.5 to 8L. The ratio of the diameter of the inner cylinder 3 to the diameter of the outer cylinder 1 is controlled within a reasonable range of 2:3 to 1:10. By adjusting this adjusting sleeve of the inner cylinder 3, the distribution range of the high-energy electric field can be precisely controlled, ensuring that the area through which the liquid flows is the microwave discharge generation zone, thus physically eliminating the blind zone that is not irradiated by microwaves, which is common in the center of traditional reactors. At the same time, adjusting the size of the inner cylinder 3 to match the microwave penetration depth ensures that the microwaves fully penetrate through the liquid inside the sleeve, making the microwave energy highly concentrated in the wastewater reaction area of ​​the inner cylinder 3, reducing energy dissipation and loss to the outer cylinder 1, significantly improving the plasma generation efficiency and the concentration of strong oxidizing species, enhancing the contact reaction effect between the plasma and the antibiotic wastewater, and thus improving the degradation rate of pollutants. The dotted line inside the inner cylinder 3 in Figure 1 represents the edge position of the inner cylinder after adjusting to a smaller size. The outer cylinder 1 has a volume of 1~10L and the inner cylinder 3 has a volume of 0.5~8L, allowing the volumes of the inner and outer cylinders 1 to be adjusted to match different processing scales and meet degradation requirements. The outer cylinder 1, together with the top cover 2, forms a sealed reaction environment. On the one hand, it prevents the disorderly escape of gases generated during the reaction, ensuring effective control of the gas phase by the gas path control and liquid control system, promoting the reflux and re-reaction of volatile components, and avoiding resource waste and secondary pollution. On the other hand, it reduces microwave energy leakage, further improving energy utilization, while isolating strong oxidizing species from contact with the external environment, reducing the risk of equipment corrosion and personnel safety hazards. The double-layer structure design of the inner and outer cylinders 1 allows the outer cylinder 1 to act as a protective layer to withstand high-temperature and strong oxidizing reaction conditions, extending the overall service life of the device. The inner cylinder 3, as the core reaction carrier, is easy to disassemble and assemble, facilitating subsequent cleaning, maintenance, and replacement, reducing equipment operation and maintenance costs.

[0037] In this design, the top cover 2 is made of stainless steel or quartz glass. Stainless steel is high-strength and resistant to strong oxidation and corrosion, ensuring the reactor's airtightness. Quartz glass has excellent microwave transmittance, not hindering microwave energy transmission, and also allows for real-time observation of the internal reaction conditions. The outer cylinder 1 is made of stainless steel, combining high-strength structural support with excellent corrosion resistance, able to withstand the high-temperature, strong-oxidizing environment during the reaction process, and also reducing microwave energy leakage, thus improving operational safety. The inner cylinder 3 is made of polytetrafluoroethylene (PTFE) or quartz. PTFE has extremely high chemical stability, resists corrosion from strong oxidizing agents, and its surface is not easily contaminated, facilitating cleaning and maintenance. Quartz has good microwave transmittance, ensuring that microwaves completely penetrate the liquid in the inner cylinder 3. Combined with size control, this further optimizes energy distribution, improving plasma generation efficiency and antibiotic wastewater degradation effects.

[0038] Preferably, the microwave energy transmission discharge system includes a microwave power supply 4, a magnetron 5, an isolator 6, a detection coupler 7, a three-pin adjuster 8, a waveguide 9, and a microwave discharge electrode 11 connected in sequence. The output end of the three-pin adjuster 8 is connected to the microwave discharge electrode 11 via a coaxial cable 10. The microwave discharge electrode 11 is vertically positioned at the bottom of the outer cylinder 1 and at the position of the central axis of the outer cylinder 1 and the inner cylinder 3, so that microwave energy is uniformly radiated to the wastewater system in the inner cylinder 3, thereby improving the contact reaction effect between plasma and antibiotic wastewater. The detection coupler 7 is also connected to a vector network analyzer 12.

[0039] Specifically, the microwave discharge system converts microwave energy from a rectangular waveguide transmission mode to a coaxial transmission mode and couples it to the discharge electrode via a standard interface with a 50-ohm characteristic impedance.

[0040] Microwave power supply 4 is electrically connected to magnetron 5, used to input electrical energy into magnetron 5. Magnetron 5 converts the electrical energy input from microwave power supply 4 into microwave energy and transmits it to isolator 6. Isolator 6 blocks reflected microwaves generated during transmission from flowing back to magnetron 5, preventing reflected energy from damaging magnetron 5, thus protecting the microwave source components and ensuring stable unidirectional energy transmission. Subsequently, the microwave energy enters detection coupler 7, which samples and couples the forward-transmitted microwave energy to extract core transmission parameters such as microwave power and frequency. Simultaneously, the sampled signal is transmitted to vector network analyzer 12 for parameter monitoring. Data support is provided; then the microwave energy flows through the three-pin regulator 8, which is used to adjust the impedance matching state of the microwave transmission link, offset the energy loss caused by load mismatch, and ensure that the microwave energy is transmitted to the subsequent components with optimal efficiency; then the microwave energy passes through the waveguide 9, which serves as a directional transmission channel for microwave energy, and can accurately transmit the microwave energy output by the magnetron 5 to the three-pin regulator 8, while also providing an adaptation carrier for the subsequent conversion from rectangular waveguide transmission mode to coaxial transmission mode; the microwave energy regulated by the three-pin regulator 8 completes the conversion from rectangular waveguide transmission mode to coaxial transmission mode through the waveguide 9, and then is coupled through a standard interface with a 50-ohm characteristic impedance, and fed into the microwave discharge electrode 11 through the coaxial cable 10. The microwave discharge electrode 11 receives the microwave energy transmitted by the coaxial cable 10. Because it is located at the central axis of the outer cylinder 1 and the inner cylinder 3, it can concentrate the microwave energy on the wastewater system of the inner cylinder 3, and generate plasma through the discharge effect, realizing the conversion and efficient utilization of microwave energy into plasma energy for the degradation of antibiotic wastewater.

[0041] Microwave power supply 4 drives magnetron 5 to generate microwave energy. This energy passes sequentially through isolator 6 (protecting the source), detection coupler 7 (for signal sampling), and three-pin regulator 8 (for impedance matching). It is then transmitted via waveguide 9 and converted to coaxial mode, finally fed to electrodes at the bottom of the reactor via coaxial cable 10 to excite plasma. Simultaneously, vector network analyzer 12 is connected to detection coupler 7 to monitor microwave transmission parameters and reflection in real time. Microwave transmission parameters include forward transmission power, operating frequency, transmission loss, and voltage standing wave ratio (VSWR); reflection-related parameters include reflected power and reflection coefficient.

[0042] This microwave energy transmission and discharge system achieves efficient transmission, precise control, and stable conversion of microwave energy through the orderly connection and functional coordination of its components, greatly improving the overall performance of the device. The design, featuring a rectangular waveguide and coaxial transmission mode adaptation and a 50-ohm standard interface coupling, ensures low-loss coupling of microwave energy during transmission. This facilitates connection to commonly used microwave generators or detection equipment, enhancing the system's versatility and modularity. The standard interface, combined with the impedance matching function of the three-pin adjuster 8, effectively reduces microwave reflection and transmission losses, ensuring maximum coupling of microwave energy to the discharge electrode. This addresses the pain points of traditional microwave equipment, such as low energy utilization and easy damage to core components due to load mismatch. The isolator 6 effectively protects the magnetron 5, extending the lifespan of core components and reducing maintenance costs. The combined operation of the detection coupler 7 and the vector network analyzer 12 enables real-time monitoring of microwave transmission parameters and reflection, facilitating timely adjustments to the operating status and ensuring energy transmission stability and plasma generation efficiency. The microwave discharge electrode 11, located on the central axis and extending into the inner cylinder 3, concentrates microwave energy in the wastewater reaction area. Adapting to the structure of the inner and outer cylinders 1 of the reactor, it further enhances the interaction between plasma and wastewater, providing reliable energy support for the efficient degradation of antibiotic wastewater.

[0043] Preferably, the microwave discharge electrode 11 has a discharge frequency of 2450MHz, a microwave wavelength λ of 12.24 cm, and a microwave source emission power of 0.1~1.5 kW. The selection of a 2450MHz microwave discharge frequency, corresponding to a 12.24cm microwave wavelength, is advantageous for the localized concentration and efficient absorption of microwave energy in liquid wastewater, enabling the rapid establishment of a high-intensity electric field sufficient to induce breakdown within the liquid. Simultaneously, this wavelength is highly compatible with the dimensions of the inner cylinder 3 of the device and the microwave penetration depth of the liquid system, ensuring that microwave energy fully acts on the wastewater, efficiently exciting plasma and stably generating strong oxidizing species such as hydroxyl radicals, providing a reliable guarantee for the rapid degradation of antibiotic wastewater.

[0044] The adjustable transmission power of 0~1.5kW precisely matches the treatment needs of antibiotic wastewater of different volumes and concentrations, ensuring the degradation effect of antibiotic wastewater. Preferably, the microwave discharge electrode 11 is made of tungsten, platinum-rhodium, or platinum-iridium alloy, and the diameter of the microwave discharge electrode 11 is 1~10 mm. Using tungsten, platinum-rhodium, or platinum-iridium alloy as the material of the microwave discharge electrode 11 can effectively reduce electrode sputtering loss during the liquid phase discharge process. At the same time, these materials have excellent high temperature resistance and strong oxidation corrosion resistance, and can withstand the extreme working conditions generated by plasma discharge, which can significantly improve the electrode's resistance to loss and service life, reduce the frequency of electrode replacement, and reduce the long-term operation and maintenance costs of the equipment. By setting the electrode diameter to 1~10 mm, it can be precisely adapted to microwave source emission power of 0.1~1.5 kW. This ensures that the electrode can withstand the heat load generated by the microwave electric field and avoids electrode damage due to power fluctuations. It can also form a stable electric field emission point in the liquid medium and maintain a continuous and uniform discharge channel. Combined with the installation layout of the electrode central axis, it further optimizes the microwave energy density distribution and ensures the stability of plasma generation efficiency and antibiotic wastewater degradation effect.

[0045] Preferably, a ternary gradient demister for drying the gas generated during the degradation process is provided inside the outer cylinder 1 and at the top of the inner cylinder 3, as shown in Figures 2-3. The ternary gradient demister includes a shell, a porous flow equalization plate 13, an inverted V-shaped plate 14, and a double-layer wire mesh 15 arranged sequentially from the bottom to the top of the shell. An air passage 16 is provided between the inverted V-shaped plate 14 and the inner wall of the shell. The porous flow equalization plate 13 is used to evenly distribute and rectify the airflow generated by the degradation of antibiotic wastewater and intercept coarse droplets in the airflow. The two ends of the inverted V-shaped plate 14 are used to force the airflow after removing coarse droplets to change its flow direction, so that medium-sized droplets in the airflow after removing coarse droplets are thrown towards the plate wall of the inverted V-shaped plate 14 for droplet separation. The double-layer wire mesh 15 is used to filter out micron-sized tiny droplets in the airflow that enters through the air passage 16 after removing medium-sized droplets.

[0046] Specifically, the demister adopts a three-stage composite structure consisting of a porous flow equalization plate 13, an inverted V-shaped plate 14, and a double-layer wire mesh 15. This structure constructs a gradient demister mechanism that integrates rectification, inertial collision, and interception of agglomeration. Combined with gravity reflux, it achieves efficient removal of droplets from coarse to micron-sized droplets step by step. The demister's precision and efficiency are significantly superior to single-structure demister components, effectively solving the problem of mist entrainment under conditions of reactor liquid-phase boiling and forced exhaust pumping. The coarse droplet size range is greater than or equal to 100 μm (mainly targeting large droplets larger than 500 μm); the medium-sized droplet size range is 10-100 μm; and the micron-sized droplet size range is 1-10 μm (with core capture of 3-5 μm). Specifically, the porous flow equalization plate 13 adopts a φ3~φ4 mm aperture and an equilateral triangular staggered arrangement design, combined with the inverted V-shaped plate 14 (30~50 mm). The mm spacing setting eliminates local airflow dead zones and high-speed areas through throttling effect, achieving uniform airflow distribution and laying the foundation for subsequent demisting. It also effectively intercepts coarse droplets through inertial collision, while reserving sufficient space for airflow recombination to prevent turbulence from affecting the demisting effect. The inverted V-shaped plate 14 uses a 90°~100° blade angle (the angle between two blades), and maintains a 40~50 mm gap between the inverted V-shaped plate 14 and the upper wire mesh. This forces the airflow to change direction, using centrifugal force and inertia to throw medium-sized droplets towards the plate wall for separation. It has the dual function of high-load liquid removal and protection of the upper wire mesh, effectively preventing secondary entrainment and improving overall demisting stability. The double-layer wire mesh 15 adopts a composite design of a coarse filter layer 28 and a fine filter layer 29, with a total thickness of 30~50 mm. Specifications of mm and wire diameter of 0.20~0.25mm (flat or round wire) are available to meet the requirements of deep demisting: The coarse filter layer has a relatively large wire diameter and high porosity, which can realize droplet coalescence and avoid channel blockage; the fine filter layer has a relatively small wire diameter and high density, which captures tiny mist droplets through inertial impaction, interception and Brownian diffusion effect, and serves as the final control layer to ensure the dryness of the outlet gas and ensure thorough demisting.

[0047] Preferably, the gas path control and liquid control system includes a gas path assembly and a liquid outlet assembly, both connected to the reactor; the gas path assembly is used to control the discharge of gas inside the reactor after demisting by the ternary gradient demister; the liquid outlet assembly is used to control the discharge of degraded liquid from the reactor; the gas path assembly includes an exhaust pump 17 and an exhaust pipe 18 connected at both ends to the demister and the exhaust pump respectively; the liquid outlet assembly includes an outlet pipe 23, a water storage tank 24, and a second pressure sensor 25 and a second water pump 26 installed on the outlet pipe, with both ends of the outlet pipe connected to the inner cylinder 3 and the water storage tank respectively; a pressure gauge 27 is installed on the top of the reactor for real-time monitoring of the internal pressure of the reactor; the liquid path delivery system includes an inlet pipe 19, a wastewater tank 20, and a first pressure sensor 21 and a first water pump 22 installed on the inlet pipe, with both ends of the inlet pipe connected to the inner cylinder 3 and the wastewater tank respectively.

[0048] In addition, this solution is equipped with conventional flow meters and temperature sensors to monitor and precisely control the fluid flow rate in the inlet and outlet pipelines and the wastewater temperature in the reactor in real time. This ensures that key process parameters such as liquid residence time, reaction temperature, and gas-liquid ratio remain stable within the set range during the reaction, guaranteeing the continuity, consistency, and efficiency of the plasma degradation reaction. The gas path component uses an exhaust pump and exhaust pipe in conjunction with a demister for smooth exhaust, and a pressure gauge monitors the internal pressure in real time to maintain stability. The liquid path delivery system and the outlet component use corresponding water pumps, pressure sensors, and flow meters to achieve continuous wastewater inflow and outflow and parameter control. All these components work together to form a closed-loop system, ensuring a stable and efficient degradation process.

[0049] Furthermore, it also includes a control system, which is electrically connected to the microwave power supply 4, the exhaust pump, the first pressure sensor, the first water pump, the second pressure sensor, the second water pump, and the vector network analyzer. The control system is used to collect the operating parameters of each device in real time (microwave power, gas-liquid pressure, microwave transmission parameters, etc.), automatically adjust the output of the microwave power supply 4, the speed of the exhaust pump, and the operating status of the inlet and outlet water pumps according to the preset process logic, and correct the microwave transmission impedance matching in a coordinated manner. At the same time, it provides alarm prompts for abnormal parameters. The control system of the back-tapping device realizes the fully automated closed-loop control of the entire process, reduces manual intervention, ensures the coordinated and stable operation of each system, avoids the impact of parameter fluctuations on the degradation effect, and improves the convenience of operation and processing accuracy.

[0050] The control system is existing technology, so its process and logic for regulating other devices will not be elaborated here.

[0051] The method for rapidly degrading antibiotic wastewater using the liquid-phase microwave discharge plasma-generated device includes the following steps: Step 1: Constructing a dynamic flow field for energy focusing: Start the first water pump to extract the antibiotic wastewater from the wastewater tank. After real-time monitoring of the fluid state through the inlet pipe equipped with the first pressure sensor 21, continuously transport it to the interior of the inner cylinder 3 of the reactor in the microwave discharge system. Utilizing the geometric constraint of the inner cylinder 3, a dynamic reaction flow field for energy focusing is constructed around the microwave discharge electrode 11 to ensure that the antibiotic wastewater to be degraded is in full contact with the microwave energy. The antibiotic wastewater includes one or more types of antibiotics, with an antibiotic concentration of 0.01 ~ 100 mg / L. The volume of the inner cylinder 3 is 0.5 ~ 8 L.

[0052] Step 2, Composite Mechanism Gas-Liquid Separation and Exhaust: Start the exhaust pump, and use the pressure difference generated by it to drive the mist-containing gas in the reactor to flow to the top of the reactor. The mist-containing gas flows through the interior of the three-dimensional gradient demister, and is uniformly rectified by the bottom porous baffle plate, inertially separated by the middle inverted V-shaped plate, and intercepted and aggregated by the top double-layer wire mesh, so as to achieve multi-stage drying of the mist-containing gas. The dried exhaust gas is extracted and discharged from the outer cylinder 1 of the reactor.

[0053] Step 3: Microwave Excitation and Closed-Loop Monitoring: The microwave power supply is turned on, driving the magnetron 5 to generate microwave energy. This energy passes sequentially through the isolator 6, the detection coupler 7, and the three-pin regulator 8, and is then directionally transmitted via a waveguide and coaxial cable to the microwave discharge electrodes 11 arranged along the axial center of the outer and inner cylinders of the reactor. This causes the microwave discharge electrodes 11 to generate plasma within the inner cylinder 3, degrading the antibiotic wastewater. Simultaneously, a vector network analyzer connected to the detection coupler 7 monitors the microwave transmission parameters and reflection in real time to ensure efficient microwave energy feeding into the electrodes. When the microwave power supply 4 is turned on, the second water pump operates synchronously, continuously extracting the degraded liquid through the outlet pipeline and transporting it to the storage tank, thus establishing a dual-pump driven inlet-outlet water balance system for continuous degradation. After the set time is reached, all equipment is shut down, and the antibiotic wastewater degradation is complete.

[0054] In step three, the microwave discharge frequency is 2450MHz, the microwave wavelength λ is 12.24 cm, the microwave source emission power is 0.1 ~ 1.5 kW, and the microwave discharge electrode 11 has a diameter of 1 ~ 10 mm; the residence time of the antibiotic wastewater to be degraded in the reactor is 0.1 ~ 30 min, and the flow rate of the input and output water pumps is set to 100 ~ 60000 mL / min.

[0055] This invention discloses an apparatus and method for rapidly degrading antibiotic wastewater using liquid-phase microwave discharge plasma generation. Ofloxacin (OFX) and tetracycline (TC) were used for testing. Examples of implementation are as follows: Example 1: An experiment was conducted using the above apparatus and method to degrade antibiotic wastewater: A first water pump was started to continuously transport ofloxacin wastewater with a concentration of 20 mg / L through the inlet pipe into an inner cylinder with an effective volume of 1L within the reactor. Simultaneously, a ternary gradient demister and an exhaust pump were activated. The microwave power was set to 300 W, and the electrode diameter to 3 mm, for microwave discharge within the inner cylinder. During this period, a second water pump operated synchronously, continuously extracting the liquid flowing through the discharge area through the outlet pipe and transporting it to a storage tank. The residence time of the antibiotic wastewater in the reactor was 10 min, with the input and output water pump flow rates set to 100 mL / min.

[0056] Example 2: This example differs from Example 1 in that the microwave power is adjusted to 400W.

[0057] Example 3 differs from Example 1 in that the microwave power is adjusted to 500W.

[0058] Example 4 differs from Example 1 in that OFX is 5 mg / L in this example.

[0059] Example 5 differs from Example 1 in that OFX is 50 mg / L in this example.

[0060] Example 6 differs from Example 1 in that the sleeve volume is 2 L in this example.

[0061] Example 7: This example differs from Example 1 in that the electrode diameter is 1 mm.

[0062] Example 8 differs from Example 1 in that a tetracycline (TC) solution is introduced in this example.

[0063] The degradation results of Examples 1-8 are shown in Figure 4. As can be seen from Figure 4, the degradation efficiency of Examples 1-8 all reached over 70% within a short time (10 min). Specifically, at the same initial concentration (20 mg / L OFX), the degradation rate of Examples 1-3 gradually increased as the microwave power increased from 300 W to 500 W, indicating that increasing the microwave power can enhance the plasma generation intensity, thereby improving the antibiotic degradation efficiency. Comparing Examples 1 (20 mg / L OFX), 4 (5 mg / L OFX), and 5 (50 mg / L OFX), the lower the initial concentration, the higher the degradation rate, indicating that high-concentration wastewater increases the difficulty of degradation and requires higher power or longer residence time to ensure the treatment effect. The degradation rate of Example 6 (2 L inner cylinder) is higher than that of Example 1 (1 L inner cylinder), indicating that within a reasonable volume range that adapts to the microwave penetration depth, the device can still maintain a high degradation efficiency under different reaction chambers, demonstrating good volume adaptability. The degradation rates of Example 1 (ofloxacin) and Example 8 (tetracycline) both reached over 70%, indicating that the device has a high degradation capacity for different types of antibiotics, and its degradation effect on tetracycline is better than that ofloxacin, demonstrating broad-spectrum applicability.

[0064] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A device for rapidly degrading antibiotic wastewater by generating plasma through liquid-phase microwave discharge, characterized in that, The system includes a liquid transport system, a microwave energy transmission and discharge system, a reactor, and a gas and liquid control system. The liquid transport system is used to transport antibiotic wastewater to the reactor. The microwave energy transmission and discharge system can generate plasma through microwave energy discharge. The reactor can utilize the plasma generated by the microwave energy transmission and discharge system to degrade the antibiotic wastewater. The gas path control and liquid control system is used to control the gas generated during the degradation of antibiotic wastewater in the reactor and the discharge of the degraded water from the reactor.

2. The apparatus for rapidly degrading antibiotic wastewater by generating plasma through liquid-phase microwave discharge according to claim 1, characterized in that, The reactor includes an outer cylinder (1), a top cover (2) located on the top of the outer cylinder (1), and an inner cylinder (3) located inside the outer cylinder (1). The bottom of the inner cylinder (1) is provided with several fixing grooves that match the inner cylinders (3) of different diameters. The diameter ratio of the inner cylinder (3) to the outer cylinder (1) is 2:3-1:

10. The volume of the outer cylinder (1) is 1~10 L, and the volume of the inner cylinder (3) is 0.5~8 L.

3. The apparatus for rapidly degrading antibiotic wastewater by generating plasma through liquid-phase microwave discharge according to claim 2, characterized in that, The microwave energy transmission and discharge system includes a microwave power supply (4), a magnetron (5), an isolator (6), a detection coupler (7), a three-pin adjuster (8), a waveguide (9), and a microwave discharge electrode (11) connected in sequence. The output end of the three-pin adjuster (8) is connected to the microwave discharge electrode (11) via a coaxial cable (10). The microwave discharge electrode (11) is vertically located at the bottom inside the outer cylinder (1) and is located at the position of the central axis of the outer cylinder (1) and the inner cylinder (3). The detection coupler (7) is also connected to a vector network analyzer (12).

4. The apparatus for rapidly degrading antibiotic wastewater by generating plasma through liquid-phase microwave discharge according to claim 3, characterized in that, The microwave discharge frequency is 2450MHz, the microwave wavelength λ is 12.24 cm, and the microwave power supply transmits power from 0.1 to 1.5 kW.

5. The apparatus for rapidly degrading antibiotic wastewater by generating plasma through liquid-phase microwave discharge according to claim 3, characterized in that, The microwave discharge electrode (11) is made of tungsten, platinum-rhodium or platinum-iridium alloy, and the diameter of the microwave discharge electrode (11) is 1 ~ 10 mm.

6. The apparatus for rapidly degrading antibiotic wastewater by generating plasma through liquid-phase microwave discharge according to claim 4, characterized in that, The outer cylinder (1) and the top of the inner cylinder (3) are provided with a ternary gradient demister (30) for drying the gas generated during the degradation process. The ternary gradient demister includes a shell, a porous flow equalization plate (13), an inverted V-shaped plate (14) and a double-layer wire mesh (15) arranged sequentially from the bottom to the top of the shell. An air passage (16) is provided between the inverted V-shaped plate (14) and the inner wall of the shell. The porous flow equalization plate (13) is used to uniformly distribute and rectify the airflow generated by the degradation of antibiotic wastewater and intercept coarse droplets in the airflow. The two ends of the inverted V-shaped plate (14) are used to force the airflow after removing coarse droplets to change its flow direction, so that medium-sized droplets in the airflow after removing coarse droplets are thrown towards the plate wall of the inverted V-shaped plate (14) for droplet separation. The double-layer wire mesh (15) is used to filter the micron-sized tiny droplets in the airflow that enters through the air passage (16) after removing medium-sized droplets.

7. The apparatus for rapidly degrading antibiotic wastewater by generating plasma through liquid-phase microwave discharge according to claim 6, characterized in that, The gas path control and liquid control system includes a gas path assembly and a liquid outlet assembly, both connected to the reactor. The gas path assembly is used to control the discharge of gas inside the reactor after it has been demisted by the ternary gradient demister. The liquid outlet assembly is used to control the discharge of degraded liquid from the reactor. The gas path assembly includes an exhaust pump (17) and an exhaust pipe (18) with its two ends connected to the demister and the exhaust pump, respectively. The liquid outlet assembly includes an outlet pipeline (23), a water storage tank (24), and a second pressure sensor (25) and a second water pump (26) installed on the outlet pipeline. The two ends of the outlet pipeline are connected to the inner cylinder (3) and the water storage tank, respectively. A pressure gauge (27) is installed on the top of the reactor for real-time monitoring of the internal pressure of the reactor. The liquid path delivery system includes an inlet pipeline (19), a wastewater tank (20), and a first pressure sensor (21) and a first water pump (22) installed on the inlet pipeline. The two ends of the inlet pipeline are connected to the inner cylinder (3) and the wastewater tank, respectively.

8. A method for degrading antibiotic wastewater using the apparatus for rapidly degrading antibiotic wastewater by generating plasma through liquid-phase microwave discharge according to any one of claims 1-7, characterized in that, Includes the following steps: Step 1: Activate the liquid delivery system to transport antibiotic wastewater to the reactor; Step 2: Activate the gas and liquid control system to drive the flow of mist-containing gas within the reactor and extract the waste gas generated during the degradation process from the reactor; Step 3: Activate the microwave energy transmission and discharge system to generate plasma using microwave energy discharge to degrade the antibiotic wastewater within the reactor; simultaneously, activate the gas and liquid control system to extract the degraded liquid from the reactor and transport it to a storage tank; after the set time is reached, the device is shut down, and the degradation is complete.

9. The method for degrading antibiotic wastewater according to claim 8, characterized in that, The specific method includes the following steps: Step 1: Start the first water pump to continuously inject antibiotic wastewater from the wastewater tank into the inner cylinder (3) of the reactor through the inlet pipe, so that a dynamic reaction flow field is formed around the microwave discharge electrode (11); Step 2: Start the exhaust pump to drive the flow of mist-containing gas in the reactor, so that the mist-containing gas is rectified, uniformly distributed, inertial collision, intercepted and agglomerated by the three-element gradient demister at the top of the inner cylinder (3) in sequence to achieve gas-liquid separation, and the dried waste gas is extracted from the reactor; Step 3: Turn on the microwave power supply (4) to drive the magnetron (5) to generate microwave energy, and the microwave energy depends on After passing through the isolator (6), detection coupler (7), and three-pin adjuster (8), the liquid is then directionally transmitted through the waveguide (9) and coaxial cable (10) to the microwave discharge electrode (11) arranged along the axial center of the inner cylinder (3), so that the microwave discharge electrode (11) generates plasma in the inner cylinder (3) to degrade the antibiotic wastewater. The vector network analyzer (12) connected to the detection coupler (7) monitors the microwave transmission parameters and reflection in real time. When the microwave power supply (4) is turned on, the second water pump runs synchronously to continuously extract the degraded liquid through the outlet pipeline and transport it to the water storage tank. After the set time is reached, all equipment is turned off, and the antibiotic wastewater degradation is completed.

10. The method for degrading antibiotic wastewater according to claim 9, characterized in that, In step one, the antibiotic wastewater includes one or more types of antibiotics, and the concentration of the antibiotics is 0.01 ~ 100 mg / L; the volume of the inner cylinder (3) is 0.5 ~ 8 L; in step three, the microwave discharge frequency is 2450MHz, the microwave wavelength λ is 12.24 cm, the emission power of the microwave power supply is 0.1 ~ 1.5 kW, and the diameter of the microwave discharge electrode (11) is 1 ~ 10 mm; the residence time of the antibiotic wastewater to be degraded in the reactor is 0.1 ~ 30 min, and the flow rate of the input and output water pumps is set to 100 ~ 60000 mL / min.

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