Plasma sewage treatment device

Abstract

The invention relates to the technical field of sewage treatment devices, and discloses a plasma sewage treatment device which comprises a driving power supply and a reactor, the driving power supply comprises two sub power supply circuits which are connected in parallel, the output ends of the two sub power supply circuits are connected into an input circuit after the two sub power supply circuits are connected in parallel, and one sub power supply circuit comprises a direct-current power supply and an isolation inductor which are connected in series; the other sub-power circuit comprises a nanosecond pulse power supply and an isolation capacitor which are connected in series, the reactor comprises a shell and an array electrode structure connected in the shell, polluted liquid to be treated is contained in the shell, the array electrode structure comprises a plurality of single-plate electrodes which are connected in parallel, the single-plate electrodes are made of a PCB, and the single-plate electrodes are made of a metal material. The high-voltage end of the array electrode structure is connected with the input circuit and located in the air, the grounding end of the array electrode structure is connected with the grounding end of the direct-current power source and the grounding end of the nanosecond pulse power source and located in the polluted liquid to be treated, and the energy efficiency can be improved under the condition that it is guaranteed that plasma is normally generated.

Description

Technical Field

[0001] The present invention relates to the technical field of sewage treatment devices, and particularly to a plasma sewage treatment device. Background Art

[0002] During the process of industrial development, industrial wastewater with serious pollution is discharged, which contains a large amount of organic pollutants, seriously damaging the ecological environment and affecting national health. With the transformation of industrial development towards environmental protection and sustainable development, the low-pollution and high-efficiency removal of industrial wastewater is an urgent problem to be solved.

[0003] Atmospheric pressure non-thermal plasma is a promising advanced oxidation technology due to its simple and safe driving and rich active groups. The strongly oxidizing active groups ozone (O3), hydrogen peroxide (H2O2) and hydroxyl (OH) in the plasma can oxidize organic pollutants into non-toxic products such as CO2 and H2O without selectivity, with the advantages of no need for additional reagents, good treatment effect, no secondary pollution, safety and reliability.

[0004] Currently, some plasma treatment devices have emerged. Their structures are generally divided into two parts, one is the driving power supply, and the other is the discharge structure. The driving power supply includes using DC power supply, high-frequency AC power supply, and pulse power supply to drive the generation of plasma. Among them, the nanosecond pulse power supply is a type of pulse power supply, and the time scale of its signal is nanoseconds (10 -9 s). From the perspective of the entire system, the energy conversion of the entire sewage treatment can be divided into two stages: In the first stage, the system obtains energy from the power grid and converts it into high-frequency high-voltage pulses through pulse power technology. In this process, the energy is converted from electrical energy (AC) into electrical energy (pulse) and thermal energy. The thermal energy is mainly due to the switching of devices and their own losses. In the second stage, the pulsed voltage drives the generation of plasma to purify pollutants in water, and the energy is converted from electrical energy into chemical energy and internal energy. The chemical energy promotes the generation of active groups and the process of oxidizing organic substances. The energy efficiency driven by the nanosecond pulse power supply only improves the energy efficiency of the second stage, but the energy efficiency of the first stage is not considered. Therefore, the low energy efficiency of the first stage results in the overall energy efficiency of the system still being not high. Summary of the Invention

[0005] In order to solve the above technical problems, the present invention provides a plasma sewage treatment device that can improve the energy efficiency while ensuring the normal generation of plasma.

[0006] The present invention provides a plasma sewage treatment device, comprising: a driving power supply and a reactor. The driving power supply includes two parallel sub-power supply circuits. The output ends of the two parallel sub-power supply circuits are connected to an input circuit. One of the sub-power supply circuits includes a DC power supply and an isolation inductor connected in series, and the other sub-power supply circuit includes a nanosecond pulse power supply and an isolation capacitor connected in series. The reactor includes a housing and an array electrode structure connected inside it. The housing contains the polluted liquid to be treated. The array electrode structure includes a plurality of single-board electrodes connected in parallel. The single-board electrodes are made by PCB. The high-voltage end of the array electrode structure is connected to the input circuit and is located in the air. The grounding end of the array electrode structure is connected to the grounding ends of the DC power supply and the nanosecond pulse power supply and is located in the polluted liquid to be treated.

[0007] Optionally, the nanosecond pulse power supply outputs a high-frequency nanosecond pulse signal, with a pulse width of <100 ns, a rise time of <10 ns, a fall time of <20 ns, a repetition frequency of 1 kHz - 10 kHz, and a voltage amplitude of 0.5 - 3 kV.

[0008] Optionally, the output voltage of the DC power supply is 5 kV - 10 kV direct current, and the voltage fluctuation is <0.5%.

[0009] Optionally, a current-limiting resistor is connected to the input circuit.

[0010] Optionally, the single-board electrode includes a high-voltage electrode and a ground electrode integrated on an insulating board. The high-voltage electrode includes a plurality of needle electrodes arranged side by side on the insulating board, and there is a gap between the needle electrodes and the ground electrode.

[0011] Optionally, the thickness of a single needle electrode is 35 μm, the width is 0.1 mm, and the distance between two adjacent needle electrodes is 1 mm - 20 mm.

[0012] Optionally, the thickness of the ground electrode is 35 μm, the width is 100 mm, and the height is 2 mm.

[0013] Optionally, an air layer, a liquid layer, a barrier layer, and a gas layer are sequentially arranged in the housing from top to bottom. The liquid in the liquid layer is the polluted liquid to be treated, and the gas in the gas layer is air containing active groups. The barrier layer can prevent the liquid in the liquid layer from penetrating into the gas layer and can also allow the gas to pass through. An air outlet and an air inlet are respectively opened on the housing, and the air outlet and the air inlet are connected through a gas circulation pipeline. The air layer is communicated with the air outlet, and the gas layer is communicated with the air inlet.

[0014] Optionally, an air layer and a liquid layer are sequentially arranged in the housing from top to bottom. The liquid in the liquid layer is the contaminated liquid to be treated. A bubbling component is arranged in the liquid layer to generate bubbles in the liquid layer. An air outlet and an air inlet are respectively formed in the housing, and the air outlet and the air inlet are connected through a gas circulation pipeline. The air layer is communicated with the air outlet, and the gas layer is communicated with the air inlet.

[0015] Optionally, a liquid inlet and a liquid outlet are respectively formed in the housing, the liquid inlet and the liquid outlet are connected through a liquid circulation pipeline, the liquid outlet is communicated with the bottom layer of the liquid layer, and the liquid inlet is connected with a flow buffering component which is communicated with the surface of the liquid layer.

[0016] The technical solution provided by the embodiment of the present invention has the following advantages compared with the prior art: A plasma sewage treatment device provided by an embodiment of the present invention uses a nanosecond pulse power supply in series with an isolation capacitor and a DC power supply in series with an isolation inductor as the driving source of the plasma. Thus, the voltage at both ends of the reactor is composed of a DC voltage and a nanosecond pulse voltage. The voltage at both ends of the reactor remains unchanged while the voltage of the nanosecond pulse power supply decreases, thereby reducing the energy consumed by the nanosecond pulse power supply and improving the energy efficiency of the entire system. The cost, power loss and voltage of the nanosecond pulse power supply are positively correlated, and the increasing trend is non-linear. Therefore, reducing the voltage of the nanosecond pulse power supply helps to reduce the cost and improve the energy efficiency. However, if the voltage is too low, the plasma cannot be generated or the degree of ionization of the plasma is too low. Therefore, the single-board electrode is made by PCB, and its extremely small-sized high-voltage electrode can be realized to generate an extremely uneven electric field, and the plasma can be generated at a low voltage. The modular single-board electrode is designed by using PCB technology, and multiple modules are connected in parallel to generate a large-volume plasma, thereby improving the energy efficiency. Description of the Drawings

[0017] Figure 1 It is a schematic structural diagram of a plasma sewage treatment device provided by an embodiment of the present invention; Figure 2 It is a schematic structural diagram of the single-board electrode provided by an embodiment of the present invention; Figure 3 It is a schematic structural diagram of the array electrode structure provided by an embodiment of the present invention.

[0018] Description of the Reference Numerals: 1. High-voltage electrode; 2. Ground electrode; 3. Gap. Detailed Embodiment

[0019] The following combines the drawings to describe in detail a specific embodiment of the present invention, but it should be understood that the protection scope of the present invention is not limited by the specific embodiment.

[0020] In the description of the present invention, it should be understood that the orientation or positional relationships indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "axial", "radial", "circumferential", etc. are based on the orientation or positional relationships shown in the drawings. These are only for the convenience of describing the technical solutions of the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present invention.

[0021] A plasma processing device generally has two parts in its structure. One part is the driving power supply, and the other part is the discharge structure. The driving power supply includes using a DC power supply, a high-frequency AC power supply, and a pulse power supply to drive the generation of plasma. Among them, the nanosecond pulse power supply is a type of pulse power supply, and the time scale of its signal is nanoseconds (10 -9 s). From the perspective of the entire system, the energy conversion of the entire sewage treatment can be divided into two stages: In the first stage, the system obtains energy from the power grid and converts it into high-frequency high-voltage pulses through pulse power technology. In this process, the energy is converted from electrical energy (AC) into electrical energy (pulse) and thermal energy. The thermal energy is mainly due to the switching of devices and their own losses; in the second stage, the pulsed voltage drives the generation of plasma to purify the pollutants in the water, and the energy is converted from electrical energy into chemical energy and internal energy. The chemical energy promotes the generation of active groups and the process of oxidizing organic substances. The energy efficiency driven by the nanosecond pulse power supply only improves the energy efficiency of the second stage, but the energy efficiency of the first stage is not considered. Therefore, the low energy efficiency of the first stage results in the still low energy efficiency of the entire system.

[0022] Therefore, an embodiment of the present invention provides a plasma sewage treatment device that can improve the energy efficiency while ensuring the normal generation of plasma.

[0023] At least one embodiment of the present invention provides a plasma sewage treatment device, including: a driving power supply and a reactor connected together. The driving power supply includes two parallel sub-power supply circuits. After the two parallel sub-power supply circuits are connected in parallel, the output ends are connected to the input circuit. One of the sub-power supply circuits includes a DC power supply and an isolation inductor connected in series, and the other sub-power supply circuit includes a nanosecond pulse power supply and an isolation capacitor connected in series. The reactor includes a housing and an array electrode structure connected inside it. The housing contains the polluted liquid to be treated. The array electrode structure includes a plurality of single-board electrodes connected in parallel. The single-board electrodes are made by PCB. The high-voltage end of the array electrode structure is connected to the input circuit, and the high-voltage end is located in the air. The grounding end of the array electrode structure is connected to the grounding ends of the DC power supply and the nanosecond pulse power supply, and the grounding end is located in the polluted liquid to be treated.

[0024] In the plasma sewage treatment device provided by the above-mentioned embodiment of the present invention, a nanosecond pulse power supply is connected in series with an isolation capacitor and a DC power supply is connected in series with an isolation inductor as the driving source of the plasma, so that the voltage across the reactor is composed of a DC voltage and a nanosecond pulse voltage. The voltage across the reactor remains unchanged while the voltage of the nanosecond pulse power supply decreases, thereby reducing the energy consumed by the nanosecond pulse power supply and improving the energy efficiency of the entire system.

[0025] The present invention will be described below through several specific embodiments. To keep the following description of the embodiments of the present invention clear and concise, detailed descriptions of known functions and known components may be omitted. When any component of the embodiments of the present invention appears in more than one drawing, the component may be denoted by the same reference numeral in each drawing.

[0026] Reference Figure 1 , Figure 1 is a schematic structural diagram of a plasma sewage treatment device provided by an embodiment of the present invention. As Figure 1As shown in the figure, an embodiment of the present invention provides a plasma sewage treatment device, which includes a driving power source and a reactor connected together. The reactor is used to generate plasma and treat polluted liquid. The driving power source includes two sub-power source circuits connected in parallel. After the two sub-power source circuits are connected in parallel, the output ends are connected to the input circuit. The input circuit transmits electrical energy to the array electrode structure of the reactor. One of the sub-power source circuits includes a DC power source and an isolation inductor connected in series. The DC power source can provide a stable DC voltage to maintain the basic discharge of the plasma. The isolation inductor is used to isolate the interference between the DC power source and the nanosecond pulse power source to ensure the stability of the DC power source. The other sub-power source circuit includes a nanosecond pulse power source and an isolation capacitor connected in series. The nanosecond pulse power source can generate high-frequency nanosecond pulse signals to excite high-energy plasma. The isolation capacitor is used to isolate the interference between the nanosecond pulse power source and the DC power source and transmit high-frequency pulse signals at the same time. The reactor includes a housing and an array electrode structure connected inside it. The housing contains the polluted liquid to be treated. The array electrode structure includes a plurality of single-board electrodes connected in parallel. The design of the array electrode structure makes the plasma distribution uniform and improves the treatment efficiency. The single-board electrode is made by PCB, that is, a very thin copper skin is attached to the surface of the insulating material on the printed circuit board. The thickness of the copper skin is generally 35μm, and the minimum width of the conventional process is 0.1mm. Using it, a high-voltage electrode with extremely small size can be realized, generating an extremely uneven electric field, and plasma can be generated at a low voltage. The modular array electrode structure is designed by using PCB technology, and multiple modules are connected in parallel to generate large-volume plasma. The high-voltage end of the array electrode structure is connected to the input circuit, and the high-voltage end is located in the air to generate plasma discharge. The grounding end of the array electrode structure is connected to the grounding ends of the DC power source and the nanosecond pulse power source, and the grounding end is located in the polluted liquid to be treated to form a complete circuit loop.

[0027] An embodiment of the present invention provides a plasma sewage treatment device that uses a nanosecond pulse power source in series with an isolation capacitor and a DC power source in series with an isolation inductor as the driving source of the plasma. Thus, the voltage across the reactor is jointly composed of the DC voltage and the nanosecond pulse voltage. The voltage across the reactor remains unchanged while the voltage of the nanosecond pulse power source decreases, thereby reducing the energy loss of the nanosecond pulse power source and improving the energy efficiency of the entire system. The cost, power loss, and voltage of the nanosecond pulse power source are positively correlated, and the increasing trend is non-linear. Therefore, reducing the voltage of the nanosecond pulse power source helps to reduce costs and improve energy efficiency. However, if the voltage is too low, plasma cannot be generated or the degree of ionization of the plasma is too low. Therefore, the single-board electrode is made by PCB. Using it, a high-voltage electrode with extremely small size can be realized, generating an extremely uneven electric field, and plasma can be generated at a low voltage. The modular single-board electrode is designed by using PCB technology, and multiple modules are connected in parallel to generate large-volume plasma, thereby improving the energy efficiency.

[0028] Specifically, the nanosecond pulse power supply is one of the key components in the plasma sewage treatment device. The high-frequency nanosecond pulse signal it outputs has specific technical parameters, which can effectively excite high-energy plasma, thereby improving the sewage treatment efficiency. In this embodiment, the nanosecond pulse power supply outputs a high-frequency nanosecond pulse signal with a pulse width of <100 ns. The short pulse width can generate plasma with high power density, enhance the generation efficiency of active substances, and the shorter pulse width helps reduce energy loss and improve the efficiency of the power supply. The rise time is <10 ns. The fast rise time can quickly establish a strong electric field, promote the rapid excitation of plasma, and the shorter rise time helps improve the steepness of the pulse signal, enabling more energy to be deposited in high-energy electrons. The fall time is <20 ns. The fast fall time can quickly end the pulse signal, avoid energy waste, and the shorter fall time helps reduce the decay time of plasma and improve the treatment efficiency. The repetition frequency is 1 kHz - 10 kHz. The higher repetition frequency can continuously excite plasma to ensure the continuity of sewage treatment. The frequency-adjustable design enables the power supply to adapt to different treatment requirements and optimize the energy utilization rate. The voltage amplitude is 0.5 - 3 kV.

[0029] The DC power supply is an important component in the plasma sewage treatment device. The direct current it outputs provides a stable basic electric field for the generation of plasma. Specifically, in this embodiment, the output voltage of the DC power supply is 5 kV - 10 kV direct current. The high voltage can establish a strong electric field to promote the initial excitation and stable maintenance of plasma. The adjustable voltage range enables the DC power supply to adapt to different treatment requirements, such as adjusting for different pollutant concentrations or liquid conductivities. The voltage fluctuation is <0.5%. The low voltage fluctuation ensures the stability of the electric field, thereby guaranteeing the continuous generation and efficient reaction of plasma. The high stability reduces energy loss and improves the overall efficiency of the power supply. The output terminal of the DC power supply is connected to an inductor L to isolate the pulse signal.

[0030] Refer again to Figure 1 , and a current-limiting resistor is connected to the input circuit. The current-limiting resistor R, as the output terminal of the entire drive power supply, is connected to the isolation inductor L and isolation capacitor C inside the drive power supply at one end and to the reactor at the other end, and can limit the output current of the power supply to avoid damage to the drive power supply caused by excessive current.

[0031] Refer to Figure 2 and Figure 3 , Figure 2 is a schematic structural diagram of the single-board electrode provided by the embodiment of the present invention. Figure 3 is a schematic structural diagram of the array electrode structure provided by the embodiment of the present invention, as shown in Figure 2 and Figure 3As shown in the figure, the single-board electrode includes a high-voltage electrode 1 and a ground electrode 2 integrated on an insulating board. The high-voltage electrode 1 includes a plurality of needle electrodes arranged side by side on the insulating board, and there is a gap 3 between the needle electrodes and the ground electrode 2.

[0032] Compared with the existing electrodes, the single-board electrode in the embodiment of the present invention is processed and realized by using PCB technology. The PCB electrode has a mature processing technology and high precision in small sizes. Using PCB technology increases the repeatability of realizing the microelectrode structure. The microelectrode structure helps to generate plasma under low-voltage drive, thereby improving the energy efficiency of the entire system. The PCB technology is to deposit a thin layer of metal on an insulating material board. The thin metal can be regarded as a microelectrode. The high-voltage electrode and the ground electrode are mechanically fixedly connected through the insulating board, while ensuring that the voltages of the two electrodes are insulated from each other. The entire electrode structure is fixed on an insulating board. The electrode structure is two mutually insulated thin metal layers. At the same time, a window is opened between the two electrodes, but there is a certain connecting part reserved in the area far from the two electrodes, and there is a gas gap between the two electrodes. The parallel connection of the single-board electrodes constitutes an array electrode structure. The inter-board connection of the electrodes is realized by metal studs and metal gaskets. In one application example, a plasma region with an area of 2500 mm 2 ×2 is generated. The entire array electrode structure is located in the plasma discharge layer (air layer) and the liquid layer and is fixed by a fixture. During the fixing process, it is ensured that the ground electrode is immersed in the liquid layer, and there is a certain air gap 3 between the liquid layer and the high-voltage electrode 1. The array electrode structure is electrically connected to a power supply to generate a highly inhomogeneous background electric field in the gas gap, thereby driving the generation of a large volume of plasma. There are two different electric potentials on the single-board electrode, high voltage and ground. During the treatment process, the ground electrode is immersed in the liquid layer to form a water cathode structure. The high-voltage electrode is connected to a high voltage potential to form a background electric field in the gas gap. The ground electrode 2 can also be a conventional metal plate.

[0033] The design parameters of a single needle electrode play a crucial role in the plasma sewage treatment device, and its size and arrangement directly affect the generation efficiency and distribution uniformity of the plasma.

[0034] In the embodiment of the present invention, the thickness of a single needle electrode is 35 μm. The thinner electrode can generate a higher electric field strength at a lower voltage, which is beneficial to the excitation of plasma. The thin electrode reduces the material usage, lowers the overall weight and cost of the device. The thin electrode is easier to achieve complex arrangements and layouts to meet the design requirements of different reactors. The width is 0.1 mm. The narrower width makes it easier for the electrode tip to concentrate the electric field and promote the local generation of plasma. The distance between two adjacent needle electrodes is 1 mm - 20 mm. The reasonable distance design ensures the uniform distribution of plasma in the reactor, avoiding the phenomenon of local overstrength or overweakness. The appropriate distance enables the effective superposition of the electric fields of adjacent electrodes, enhancing the overall strength of the plasma. The adjustable range of the distance (1 mm - 20 mm) allows the electrode arrangement to adapt to different treatment requirements, such as adjusting for different pollutant concentrations or liquid conductivities.

[0035] The design parameters of the ground electrode 2 are of great significance in the plasma sewage treatment device. Its size and structure directly affect the distribution of the electric field and the generation efficiency of plasma.

[0036] In the embodiment of the present invention, the thickness of the ground electrode 2 is 35 μm. The thinner electrode reduces the material usage, lowers the overall weight and cost of the device. The thin electrode is easier to achieve complex shapes and layouts to meet the design requirements of different reactors. The thin electrode helps to optimize the electric field distribution and improve the plasma generation efficiency. The width is 100 mm. The wider electrode can provide a larger contact area to ensure sufficient contact with the polluted liquid. The wide electrode helps to form a uniform electric field distribution and improve the overall strength of the plasma. The wide electrode design increases the mechanical strength of the electrode and improves the stability and durability of the device. The height is 2 mm.

[0037] Refer again to Figure 1 , an air layer, a liquid layer, a barrier layer and a gas layer are sequentially arranged in the housing from top to bottom. The liquid in the liquid layer is the polluted liquid to be treated. The gas in the gas layer is the air containing active groups. The barrier layer can prevent the liquid in the liquid layer from penetrating into the gas layer and can allow the gas to pass through. An air outlet and an air inlet are respectively opened on the housing. The air outlet and the air inlet are connected through a gas circulation pipeline. The air layer is communicated with the air outlet, and the gas layer is communicated with the air inlet.

[0038] The outer shell provides a relatively sealed environment to prevent the active groups in the plasma from diffusing freely into the atmospheric environment, improving the utilization rate of the active groups. Internally, it is divided into four layers from top to bottom: an air layer, a liquid layer, a barrier layer, and a gas layer. The air layer is the plasma discharge layer, providing the background gas for plasma discharge. The barrier layer can be a sand core, expanded polytetrafluoroethylene, or polyvinylidene fluoride. The barrier layer can be a material with a tightly packed sand core but with microscopic pores, which can prevent the liquid in the liquid layer from penetrating into the gas layer while allowing the gas in the gas layer to form fine bubbles and enter the liquid layer, so that the active groups generated in the plasma discharge layer can contact the liquid layer more fully through gas circulation, improving the treatment efficiency. The long-lived active groups generated in the plasma will accumulate in the background gas. If directly discharged, it will cause waste. Therefore, a gas circulation pipeline is designed to pump the gas in the plasma discharge layer to the gas layer through a pump, form small bubbles in the gas layer through the sand core, and transfer them to the liquid layer to improve the utilization efficiency. At the same time, to accelerate the gas circulation, an air inlet is added to continuously and slowly update the background gas in the plasma discharge layer. The air outlet is used to stabilize the air pressure of the background gas, prevent gas accumulation from changing the air pressure and causing pressure on the inner wall of the outer shell, and at the same time promote the utilization efficiency of the long-lived active groups in the gas layer, thereby improving the energy efficiency of the entire system and the treatment efficiency.

[0039] As an alternative solution, an air layer and a liquid layer are sequentially arranged in the outer shell from top to bottom. The liquid in the liquid layer is the contaminated liquid to be treated. A bubbling component such as an aerator is arranged in the liquid layer to generate bubbles in the liquid layer. An air outlet and an air inlet are respectively provided on the outer shell. The air outlet and the air inlet are connected through a gas circulation pipeline. The air layer is communicated with the air outlet, and the gas layer is communicated with the air inlet, so that the active groups generated in the plasma discharge layer can contact the liquid layer more fully through gas circulation, improving the treatment efficiency.

[0040] As an alternative solution, a liquid inlet and a liquid outlet are respectively provided on the outer shell. The liquid inlet and the liquid outlet are connected through a liquid circulation pipeline. The liquid outlet is communicated with the bottom layer of the liquid layer, and the liquid inlet is connected with a flow buffering component, and the flow buffering component is communicated with the surface of the liquid layer. The liquid in the liquid layer is circulated by a pump to ensure sufficient contact between the active groups and the organic pollutants. The liquid inlet and the liquid outlet of the liquid layer are located on both sides of the reactor. The liquid outlet is located at the bottom layer of the liquid layer, and the liquid inlet is input to the surface of the liquid layer through the flow buffering component. The flow buffering component offsets the kinetic energy of the pumped contaminated liquid, making the water surface in the liquid layer change less and avoiding the water surface contacting the high-voltage electrode.

[0041] The above are only several specific embodiments of the present invention. However, the embodiments of the present invention are not limited thereto, and any changes that can be conceived by those skilled in the art should fall within the protection scope of the present invention.

Claims

1. A plasma wastewater treatment device, characterized in that: include: Driving power supply and reactor; The driving power supply comprises two sub-power supply circuits connected in parallel, and the output ends of the two sub-power supply circuits are connected in parallel to the input circuit, wherein one of the sub-power supply circuits comprises a DC power supply and an isolation inductor connected in series, and the other sub-power supply circuit comprises a nanosecond pulse power supply and an isolation capacitor connected in series; The reactor includes a shell and an array electrode structure connected to the inside thereof, wherein the shell contains contaminated liquid to be treated, and the array electrode structure includes a plurality of single-plate electrodes connected in parallel, wherein the single-plate electrodes are made of PCB, and the high-voltage end of the array electrode structure is connected to an input circuit, and the high-voltage end is located in the air, and the ground end of the array electrode structure is connected to the ground end of a DC power supply and a nanosecond pulse power supply, and the ground end is located in the contaminated liquid to be treated.

2. The plasma wastewater treatment device according to claim 1, characterized in that: The nanosecond pulse power supply outputs a high-frequency nanosecond pulse signal with a pulse width of <100ns, a rise time of <10ns, a fall time of <20ns, a repetition frequency of 1kHz-10kHz, and a voltage amplitude of 0.5-3kV.

3. The plasma wastewater treatment device according to claim 1, characterized in that: The output voltage of the DC power supply is 5kV-10kV DC, and the voltage fluctuation is <0.5%.

4. The plasma wastewater treatment device according to claim 1, characterized in that: The input circuit is connected with a current limiting resistor.

5. The plasma wastewater treatment device according to claim 1, characterized in that: The single-plate electrode comprises a high-voltage electrode (1) and a ground electrode (2) integrated on an insulating plate, wherein the high-voltage electrode (1) comprises a plurality of needle electrodes arranged side by side on the insulating plate, and a gap (3) is provided between the needle electrodes and the ground electrode (2).

6. The plasma wastewater treatment device according to claim 5, characterized in that: The thickness of a single needle electrode is 35 μm, the width is 0.1 mm, and the distance between two adjacent needle electrodes is 1 mm-20 mm.

7. The plasma wastewater treatment device according to claim 5, characterized in that: The ground electrode (2) has a thickness of 35 μm, a width of 100 mm and a height of 2 mm.

8. The plasma wastewater treatment device according to claim 1, characterized in that: An air layer, a liquid layer, a barrier layer and a gas layer are arranged in sequence from top to bottom in the shell. The liquid in the liquid layer is the contaminated liquid to be treated, and the gas in the gas layer is air containing active groups. The barrier layer can prevent the liquid in the liquid layer from penetrating into the gas layer, while allowing the gas to pass through. An air outlet and an air inlet are respectively opened on the shell, and the air outlet and the air inlet are connected by a gas circulation pipeline. The air layer is connected to the air outlet, and the gas layer is connected to the air inlet.

9. The plasma wastewater treatment device according to claim 1, characterized in that: An air layer and a liquid layer are sequentially arranged in the shell from top to bottom. The liquid in the liquid layer is the contaminated liquid to be treated. A bubbling component is arranged in the liquid layer to generate bubbles in the liquid layer. An air outlet and an air inlet are respectively opened on the shell. The air outlet and the air inlet are connected by a gas circulation pipeline. The air layer is connected to the air outlet, and the gas layer is connected to the air inlet.

10. The plasma wastewater treatment device according to claim 8 or 9, characterized in that: The shell is provided with a liquid inlet and a liquid outlet respectively, the liquid inlet and the liquid outlet are connected through a liquid circulation pipeline, the liquid outlet is connected to the bottom layer of the liquid layer, the liquid inlet is connected to a slow flow component, and the slow flow component is connected to the surface of the liquid layer.

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