Composite gas-liquid two-phase wavy flow plasma sewage continuous treatment system and method

Abstract

The application discloses a composite gas-liquid two-phase wave flow plasma sewage continuous treatment system and method, which comprises a plasma reactor, the plasma reactor comprises a treatment box, the bottom of the treatment box is paved with an anode plate, the top of the treatment box is paved with a PEEK (polyether ether ketone) engineering plastic insulating plate, and the upper surface of the PEEK engineering plastic insulating plate is provided with a cathode; a high-voltage pulse power source is connected between the anode plate and the cathode; the gap between the anode plate and the PEEK engineering plastic insulating plate forms a plasma sewage treatment zone; a sewage inlet and an air inlet are formed in the side wall of the treatment box at the upstream of the treatment zone, and a sewage outlet and an air outlet are formed in the side wall of the treatment box at the downstream of the treatment zone. The PEEK insulating plate is used as an insulating medium for plasma discharge, is more convenient to process, is not easy to break, is matched with the high-voltage pulse power source, and can control plasma discharge load through air induction, so that the plasma with large area, high efficiency and strong stability can be obtained on the sewage surface.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of plasma sewage treatment, in particular to a composite gas-liquid two-phase wave flow plasma sewage treatment system and method. BACKGROUND

[0002] Plasma sewage treatment technology is a kind of advanced oxidation process (AOP) that has emerged in recent years, which uses high-energy particles in plasma to generate various types of reactive oxygen species (ROS) that can effectively degrade microorganism-resistant organic waste liquid.

[0003] The effectiveness of plasma sewage treatment technology has been proven in many studies, and various types of plasma reactors have been developed. Water surface dielectric barrier discharge is one of them, which is characterized by direct contact between plasma generated on the water surface and sewage, high utilization rate of plasma and obvious degradation effect. However, the current water surface dielectric barrier discharge usually adopts sharp-point discharge, which cannot form a large range of plasma and efficient energy exchange, and the area is usually less than 10000mm 2 The experimental volume is limited to beaker experiments, which are only used for experimental research, and the structure is simple, and the large number of beneficial by-products of plasma cannot be utilized, and the processing capacity is different by several orders of magnitude from the market demand.

[0004] At the same time, the existing water surface dielectric barrier discharge (DBD) adopts high-voltage sinusoidal power supply. Although this kind of power supply can effectively generate plasma and is convenient for experimental research, the energy consumption and power are several times of the pulse power supply due to the continuous signal, which is not conducive to market application.

[0005] Therefore, the present application is proposed. SUMMARY

[0006] In order to solve the problems of the prior art, the present application provides a composite gas-liquid two-phase wave flow plasma sewage continuous treatment system and method. On the basis of the flat plate dielectric barrier discharge, through the design and control of the load insulating material, structure and discharge atmosphere, large-area stable gas-liquid two-phase plasma discharge can be realized, and by combining long-life gas-phase oxidation products and short-life liquid-phase oxidation products, composite oxidation treatment of sewage can be realized, which greatly improves the treatment effect of sewage.

[0007] The present application is realized by the following technical solutions:

[0008] In a first aspect, the present application provides a composite gas-liquid two-phase wave flow plasma sewage continuous treatment system, comprising a plasma reactor, wherein the plasma reactor comprises a treatment box, the bottom of the treatment box is paved with an anode plate, the top of the treatment box is paved with a PEEK (polyether ether ketone) engineering plastic insulating plate, and the upper surface of the PEEK engineering plastic insulating plate is provided with a cathode; a high-voltage pulse power source is connected between the anode plate and the cathode.

[0009] The gap between the anode plate and the PEEK engineering plastic insulating plate forms a plasma sewage treatment zone.

[0010] An air inlet is formed on the side wall of the treatment box upstream of the treatment zone, and a sewage inlet is formed on the bottom of the treatment box, and a sewage outlet and an air outlet are formed on the side wall of the treatment box downstream of the treatment zone; sewage enters the treatment zone from the sewage inlet, and after the water surface height is kept stable, a gas gap for gas flow is formed between the water surface and the PEEK engineering plastic insulating plate.

[0011] The PEEK engineering plastic insulating plate is used as an insulating medium instead of the traditional alumina ceramic for plasma discharge, which is more convenient to process and is not easy to break, and is matched with the high-voltage pulse power source, and the plasma discharge load is controlled by air induction, so that high-voltage low-current low-temperature plasma gas-liquid two-phase wave flow discharge can be realized, so that a large-area, high-efficiency and stable plasma can be obtained on the sewage surface.

[0012] In a specific embodiment, a flow slowing zone is arranged between the upstream of the treatment zone and the sewage inlet, and the flow slowing zone has a double-stage flow slowing structure, the first-stage flow slowing structure is a T-shaped outlet structure, and the second-stage flow slowing structure is a smooth flow slowing baffle.

[0013] Although the atmospheric low-temperature plasma discharge also adopts plate-to-plate surface discharge, a large-area stable plasma can be obtained, because the atmospheric plate-to-plate discharge does not have the interference of atmospheric fluctuation, and the discharge environment is stable. However, the application scenario of the present application is the surface of continuously flowing sewage, therefore, the present application innovatively designs a scheme of combining the double-stage flow slowing structure with the PEEK engineering plastic, which solves the problem of stable plasma discharge on the continuously flowing water surface, and realizes the formation of a stable large-size plasma in the water-gas two-phase continuous flowing medium.

[0014] The application sets two-stage slow flow structures at the sewage inlet, the first stage slow flow adopts the design of T-shaped outlet top cover, which can limit the vertical velocity of water flow and the velocity of water flow to the downstream, and the second stage slow flow adopts the form of smooth slow flow baffle, which can make the water flow entering the treatment area more gentle, and the height of the second stage slow flow is 15mm.

[0015] In a specific embodiment, the cathode is a silver cathode, which is connected to the upper surface of the PEEK polyether ether ketone engineering plastic insulating plate by coating.

[0016] Due to the particularity of DBD discharge, any form of air layer between the cathode and the anode will excite plasma, and the mechanical or adhesive bonding of the cathode and the insulating medium will cause air molecules to be ionized at the contact surface, resulting in energy loss and heating of the cathode and the insulating medium, which reduces the performance of the device. The application forms a cathode by coating silver on the surface of the PEEK polyether ether ketone engineering plastic insulating plate, which ensures that there is no air layer between silver and PEEK.

[0017] In a specific embodiment, the thickness of the PEEK polyether ether ketone engineering plastic insulating plate is 1.5mm, and the thickness of the cathode is 2mm.

[0018] In a specific embodiment, after the sewage enters the treatment area, the gas gap between the surface of the sewage and the PEEK polyether ether ketone engineering plastic insulating plate is 4mm.

[0019] In a specific embodiment, the working parameters of the high-voltage pulse power supply are: power supply output frequency 1000-10000Hz, voltage 15-30kV, pulse width 200-300ns.

[0020] The application designs the thickness of the insulating medium, the gas gap, the thickness of the cathode and the parameters of the high-voltage pulse power supply. Experiments show that under the conditions of a 1.5mm thick PEEK insulating plate, a 4mm thick gas gap, a power supply output frequency of 10000Hz, a voltage of 15-30kV (determined by water conductivity), and a pulse width of 200ns, a large area of stable plasma can be formed in a high-salt water surface with a conductivity range of 0-10000us / cm, and the discharge area can exceed 20000mm 2 , and the device can operate stably for a long time without problems such as water sample adsorption on the cathode and breakdown of the insulating material.

[0021] In a specific embodiment, the aeration tank is provided with an aeration disc at the bottom, and the sewage outlet is connected to the aeration tank, and the gas outlet is connected to the aeration disc through an aeration pipe.

[0022] In a specific embodiment, the nitrogen molecular sieve device is connected to the front end of the gas inlet, and the working gas is air.

[0023] In the sewage treatment system, the oxidizing substances generated by the plasma discharge can be divided into short-life liquid-phase oxidation products and long-life gas-phase oxidation products according to the life and the position of action. The short-life liquid-phase oxidation products are mainly hydroxyl radicals, which are formed by high-energy electrons entering the water from the plasma, and can directly oxidize the pollutants in the water. The long-life gas-phase oxidation products are mainly ozone, which is formed by the plasma in the gas gap. The nitrogen molecular sieve device creates an oxygen-rich environment in the gas gap, and the plasma discharge generates ozone and other oxidizing substances in the gas gap. The generated ozone and other oxidizing substances enter the aeration tank with the gas and dissolve into the sewage through the aeration disc, and are used for secondary oxidation of the pollutants in the water, thereby forming a composite gas-liquid two-phase wavy flow plasma sewage treatment process.

[0024] In a specific embodiment, the water inlet speed of the sewage inlet is 10-100 L / h, and the gas inlet flow rate of the gas inlet is 1 L / min.

[0025] In a second aspect, the application also provides a composite gas-liquid two-phase wavy flow plasma sewage continuous treatment method, which comprises the following steps:

[0026] 1) connecting the anode plate in the plasma reactor to the high-voltage output end of the high-voltage pulse power supply, and connecting the cathode to the ground output end of the high-voltage pulse power supply;

[0027] 2) starting the water pump, making the sewage to be treated pass into the treatment tank from the sewage inlet, and then pass out from the sewage outlet and enter the aeration tank, adjusting the valve at the sewage inlet to ensure that the water flow speed is 10-100 L / h, and observing the treatment tank to ensure that the water flow in the treatment area is smooth and stable;

[0028] 3) starting the air pump and opening the aeration disc valve, making the working gas pass into the aeration tank from the gas inlet, and then pass out from the gas outlet and enter the aeration disc;

[0029] 4) starting the power supply, and setting the power supply parameter output frequency to 1000-10000 Hz, the voltage to 15-30 kV, and the pulse width to 200-300 ns.

[0030] Compared with the prior art, the application has the following advantages and beneficial effects:

[0031] 1. The composite gas-liquid two-phase wavy flow plasma sewage continuous treatment system and method provided by the embodiment of the present application can realize large-area stable gas-liquid two-phase plasma discharge on the basis of flat plate water surface dielectric barrier discharge, and can realize composite oxidation treatment of sewage by combining long-life gas phase oxidation products and short-life liquid phase oxidation products, thereby greatly improving the sewage treatment effect.

[0032] 2. The composite gas-liquid two-phase wavy flow plasma sewage continuous treatment system and method provided by the embodiment of the present application can realize high-voltage low-current low-temperature plasma gas-liquid two-phase wavy flow discharge by using PEEK polyether ether ketone engineering plastic insulation plate to replace traditional aluminum oxide ceramic as the insulation medium of plasma discharge, and by controlling the plasma discharge load through air induction, so that large-area, high-efficiency and high-stability plasma can be obtained on the sewage surface.

[0033] 3. The composite gas-liquid two-phase wavy flow plasma sewage continuous treatment system and method provided by the embodiment of the present application can ensure that there is no gas layer between silver and PEEK by adopting a method of forming a cathode by attaching silver on the surface of the PEEK polyether ether ketone engineering plastic insulation plate in a plated manner, thereby avoiding ionization of the contact surface of the two, and thus ensuring the performance of the device.

[0034] 4. The composite gas-liquid two-phase wavy flow plasma sewage continuous treatment system and method provided by the embodiment of the present application can realize large-area stable plasma on the high-salt water surface in the conductivity range of 0-10000 us / cm by designing the thickness of the insulation medium, the gas gap, the thickness of the cathode and the parameters of the high-voltage pulse power supply, and experiments show that the device can stably operate for a long time without problems such as cathode water sample adsorption and insulation material breakdown. 2

[0035] 5. The composite gas-liquid two-phase wavy flow plasma sewage continuous treatment system and method provided by the embodiment of the present application can realize composite oxidation treatment of sewage by combining short-life liquid phase oxidation products mainly formed by high-energy electrons in the plasma entering the water, and long-life gas phase oxidation products such as ozone generated by plasma discharge in the gas gap, thereby greatly improving the sewage treatment effect. BRIEF DESCRIPTION OF DRAWINGS

[0036] ​In order to more clearly illustrate the technical solutions of the exemplary embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some of the embodiments of the present application, and therefore should not be considered as limiting the scope, and for those of ordinary skill in the art, other related drawings can also be obtained without creative labor.

[0037] Figure 1 The structure schematic diagram of the plasma sewage continuous treatment system provided by the embodiment of the present application is shown in the figure.

[0038] Figure 2 The structure schematic diagram of the plasma reactor provided by the embodiment of the present application is shown in the figure.

[0039] Figure 3 The structure diagram of the slow flow area provided by the embodiment of the present application is shown in the figure.

[0040] Figure 4 The structure diagram of the first slow flow area provided by the embodiment of the present application is shown in the figure.

[0041] The drawings and component marks are as follows:

[0042] 1-plasma reactor, 2-treatment box, 3-anode plate, 4-PEEK polyether ether ketone engineering plastic insulation plate, 5-cathode, 6-treatment area, 7-sewage inlet, 8-air inlet, 9-sewage outlet, 10-air outlet, 11-aeration tank, 12-aeration disc, 13-aeration pipe. DETAILED DESCRIPTION

[0043] In order to make the purpose, technical solutions and advantages of the present application more clear and understandable, the following will further describe the present application in combination with the embodiments and drawings. The exemplary embodiments of the present application and the description thereof are only used to explain the present application, and should not be considered as limiting the present application.

[0044] In the following description, a large number of specific details are set forth in order to provide a thorough understanding of the present application. However, it is apparent to those of ordinary skill in the art that the present application can be implemented without using these specific details. In other embodiments, in order to avoid obscuring the present application, well-known materials or methods are not specifically described.

[0045] Reference throughout this specification to "one embodiment", "an embodiment", "one example", or "an example", means that a particular feature, structure, or characteristic described in connection with the embodiment or example is included in at least one embodiment of the application. Thus, appearances of the phrases "in one embodiment", "in an embodiment", "in one example", or "in an example" in various places throughout this specification are not necessarily all referring to the same embodiment or example. Furthermore, the particular features, structures, or characteristics can be combined in any suitable

[0046] In the description of the application, the terms "front", "back", "left", "right", "top", "bottom", "vertical", "horizontal", "high", "low", "inner", "outer", and the like, indicate the orientation or position relationship based on the orientation or position relationship shown in the drawings, only for the convenience of describing the application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the scope of protection of the application.

[0047] Embodiment 1

[0048] As shown in Figure 1 and Figure 2 The embodiment of the application provides a composite gas-liquid two-phase wavy flow plasma sewage continuous treatment system, which comprises a plasma reactor 1, the plasma reactor 1 comprises a treatment box 2, the bottom of the treatment box 2 is paved with a 200mm*300mm*3mm stainless steel anode plate 3, the top of the treatment box 2 is paved with a 300mm*400mm*1.5mm PEEK polyether ether ketone engineering plastic insulating plate 4, and the upper surface of the PEEK polyether ether ketone engineering plastic insulating plate 4 is plated with a 260mm*360mm*2mm silver cathode 5; the center of the silver cathode 5 and the center of the stainless steel anode plate 3 are on the same vertical line. There is a plastic top cover above the PEEK polyether ether ketone engineering plastic insulating plate, which is used for protecting the cathode.

[0049] The anode plate 3 and the cathode 5 are connected with a high-voltage pulse power supply;

[0050] The gap between the anode plate 3 and the PEEK polyether ether ketone engineering plastic insulating plate 4 forms a plasma sewage treatment area 6;

[0051] An air inlet 8 is provided on the side wall of the upstream treatment tank 2 of the treatment zone 6, and a sewage inlet 7 is provided at the bottom. A sewage outlet 9 and an air outlet 10 are provided on the side wall of the downstream treatment tank 2 of the treatment zone 6. Sewage enters the treatment zone from the sewage inlet. After the water level is kept stable, a gas gap is formed between the water surface and the PEEK polyether ether ketone engineering plastic insulation board for gas to flow through.

[0052] This invention uses PEEK (polyether ether ketone) engineering plastic insulating board instead of traditional alumina ceramic as the insulating medium for plasma discharge. This makes it easier to process and less prone to breakage. It is also compatible with high-voltage pulse power supplies. At the same time, by controlling the plasma discharge load through induced draft, it can achieve high-voltage, low-current, low-temperature plasma gas-liquid two-phase wave discharge, thereby obtaining large-area, high-efficiency, and highly stable plasma on the surface of sewage.

[0053] In a specific implementation, such as Figure 3 and Figure 4 A slow-flow zone is provided between the upstream of the treatment zone 6 and the sewage inlet 7. The slow-flow zone has a two-stage slow-flow structure. The first stage slow-flow structure is a T-shaped outlet structure, and the second stage slow-flow structure is a smooth slow-flow baffle.

[0054] This invention incorporates a two-stage slow-flow structure at the wastewater inlet. The first stage employs a T-shaped distributor to limit the vertical velocity and downstream velocity of the water flow. The second stage utilizes a smooth, baffle-like design to further smooth the water flow into the treatment zone. The second stage has a height of 15mm. This two-stage slow-flow structure ensures that the water surface in the treatment zone remains stable even when water pressure fluctuations occur at the inlet, thus guaranteeing that the width of the gas gap is unaffected by the inlet water pressure.

[0055] In one specific embodiment, the cathode 5 is a silver cathode, which is connected to the upper surface of the PEEK polyether ether ketone engineering plastic insulation board 4 by means of a coating.

[0056] Due to the unique nature of DBD discharge, any form of gas layer between the cathode and anode will excite plasma. Traditional methods of mechanically bonding or adhesively attaching the cathode to the insulating medium result in the ionization of air molecules at the contact surface, leading to energy loss and heating of both the cathode and the insulating medium, thus reducing device performance. This invention, by employing a coating method to attach silver to the surface of a PEEK (polyetheretherketone) engineering plastic insulating board to form the cathode, ensures that no gas layer exists between the silver and the PEEK.

[0057] In one specific embodiment, the thickness of the PEEK polyetheretherketone engineering plastic insulating board 4 is 1.5 mm, and the thickness of the cathode 5 is 2 mm.

[0058] In a specific embodiment, the gas gap between the surface of the sewage and the PEEK polyether ether ketone engineering plastic insulation plate 4 is 4mm after the sewage enters the treatment zone.

[0059] In a specific embodiment, the working parameters of the high-voltage pulse power supply are as follows: power supply output frequency 1000-10000Hz, voltage 15-30kV, pulse width 200-300ns.

[0060] The present application designs the thickness of the insulation medium, the gas gap, the thickness of the cathode, and the parameters of the high-voltage pulse power supply. Experiments show that under the conditions of a 1.5mm-thick PEEK insulation plate and a 4mm-thick gas gap, the power supply output is 10000Hz in frequency, 15-30kV in voltage determined by the water conductivity, and 200ns in pulse width, which can form a large-area stable plasma in a high-salt water surface with a conductivity ranging from 0 to 10000us / cm, and the discharge area can exceed 20000mm 2 , and the device can operate stably for a long time without problems such as water-like adsorption of the cathode and breakdown of the insulation material.

[0061] The insulation medium thickness used in the present application to achieve large-area discharge is 1.5mm. If the insulation medium thickness is increased, for example, to 2mm, the discharge area will decrease, and if the thickness is reduced, the PEEK insulation plate will be easily damaged, which cannot guarantee long-term operation.

[0062] The gas gap used in the present application to achieve large-area discharge is 4mm. If the gas gap is increased, for example, to 5mm, the discharge area will decrease significantly, and if the gas gap is reduced, for example, to 3mm, the phenomenon of sewage adsorption to the lower surface of the PEEK will easily occur during the gas gap discharge process.

[0063] In a specific embodiment, the aeration tank 11 is also included, the bottom of the aeration tank 11 is provided with an aeration disc 12, the sewage outlet 9 is connected with the aeration tank 11, and the gas outlet 10 is connected with the aeration disc 12 through an aeration pipe 13. The waterway design of the aeration tank is low-in and high-out, and a 100L volume can provide a 6min residence time, and the gas is refined into small bubbles by the aeration disc at the bottom of the aeration tank.

[0064] In a specific embodiment, the front end of the gas inlet 8 is connected with a nitrogen molecular sieve device, and the working gas is air.

[0065] The sewage treatment system in the application, the oxidizing substances generated by the plasma discharge can be divided into short-life liquid-phase oxidation products and long-life gas-phase oxidation products according to the life and the position of action. The short-life liquid-phase oxidation products are mainly hydroxyl radicals, which are formed by high-energy electrons in the plasma entering water, and can directly oxidize the pollutants in water. The long-life gas-phase oxidation products are mainly ozone, which is formed by the plasma in the gas atmosphere in the gas gap. The nitrogen molecular sieve device creates an oxygen-rich environment in the gas gap, and the plasma discharge generates ozone and other oxidizing substances in the gas gap. The generated ozone and other oxidizing substances enter the aeration tank with the gas through the aeration disc and dissolve into the sewage, and are used for secondary oxidation of the pollutants in the water, thereby forming a composite gas-liquid two-phase wavy flow plasma sewage treatment process.

[0066] In a specific embodiment, the water inlet speed of the sewage inlet 7 is 10-100 L / h, and the gas inlet flow rate of the gas inlet 8 is 1 L / min.

[0067] Example 2

[0068] The embodiment of the application provides a composite gas-liquid two-phase wavy flow plasma sewage continuous treatment method, which comprises the following steps:

[0069] 1) connecting the anode plate in the plasma reactor 1 to the high-voltage output end of the high-voltage pulse power supply, and connecting the cathode to the ground output end of the high-voltage pulse power supply;

[0070] 2) turning on the water pump, making the sewage to be treated pass into the sewage inlet of the treatment tank, pass out of the sewage outlet and enter the aeration tank, adjusting the valve at the sewage inlet to ensure that the water flow speed is 10-100 L / h, and observing the treatment tank to ensure that the water flow in the treatment area is smooth and stable;

[0071] 3) turning on the air pump and opening the aeration disc valve, making the working gas pass into the gas inlet, pass out of the gas outlet and enter the aeration disc;

[0072] 4) turning on the power supply, setting the power supply parameter output frequency to 1000-10000 Hz, the voltage to 15-30 kV, and the pulse width to 200-300 ns.

[0073] Example 3

[0074] The embodiment of the application provides a composite gas-liquid two-phase wavy flow plasma sewage continuous treatment system, the parameter setting of the power supply is that the voltage is 22 kv, the pulse width is 200 ns, the frequency is 10 kHz, the water sample conductivity is 5840 us / cm, the thickness of the PEEK polyether ether ketone engineering plastic insulating plate is 1.5 mm, and the gas gap is 4 mm. Through testing, the discharge area is 36000 mm 2 .

[0075] Example 4

[0076] The embodiment of the present application provides a composite gas-liquid two-phase wave flow plasma sewage continuous treatment system, the parameter setting of the power supply is 25kv of voltage, 200ns of pulse width, 10kHz of frequency, the water sample conductivity is 5840us / cm, the PEEK polyether ether ketone engineering plastic insulation plate thickness is 1.5mm, the gas gap is 4mm, through testing, the discharge area is 42000mm 2 .

[0077] Example 5

[0078] The embodiment of the present application provides a composite gas-liquid two-phase wave flow plasma sewage continuous treatment system, the parameter setting of the power supply is 24kv of voltage, 200ns of pulse width, 10kHz of frequency, the water sample conductivity is 6440us / cm, the PEEK polyether ether ketone engineering plastic insulation plate thickness is 1.5mm, the gas gap is 4mm, through testing, the discharge area is 38720mm 2 .

[0079] Example 6

[0080] The embodiment of the present application provides a composite gas-liquid two-phase wave flow plasma sewage continuous treatment system, the parameter setting of the power supply is 24kv of voltage, 200ns of pulse width, 10kHz of frequency, the water sample conductivity is 6440us / cm, the PEEK polyether ether ketone engineering plastic insulation plate thickness is 2mm, the gas gap is 4mm, through testing, the discharge area is 30480mm 2 .

[0081] From the results of example 3 to example 5, the composite gas-liquid two-phase wave flow plasma sewage treatment system can generate 20000mm 2 The discharge area of the above.

[0082] From example 5 and example 6, when the PEEK polyether ether ketone engineering plastic insulation plate thickness is 2mm, compared with the insulation plate with a thickness of 1.5mm, the discharge area decreases by 20%.

[0083] Example 7

[0084] The embodiment of the present application provides a composite gas-liquid two-phase wave flow plasma sewage continuous treatment system, which is used for treating sewage of a certain printing and dyeing wastewater treatment plant, wherein the cod of the effluent of the sedimentation tank is 356mg / L, and the cod is reduced to 162mg / L after being treated by the system.

[0085] Under the same conditions, if the aeration tank of the present application is closed and only the plasma reactor is started to treat the water sample, the cod is reduced to 220mg / L.

[0086] Example 8

[0087] The embodiment of the present application provides a composite gas-liquid two-phase wave flow plasma sewage continuous treatment system, which is used for treating industrial wastewater, and the cod of the wastewater is 65000 mg / L, and the cod is reduced to 9700 mg / L after the wastewater is treated by the system.

[0088] Under the same conditions, if the aeration tank of the present application is closed, and only the plasma reactor is opened to treat the water sample, the cod is reduced to 18900 mg / L.

[0089] Example 9

[0090] The embodiment of the present application provides a composite gas-liquid two-phase wave flow plasma sewage continuous treatment system, the parameter setting of the power supply is that the voltage is 26kv, the pulse width is 200ns, the frequency is 10kHz, the water sample conductivity is 5840us / cm, the thickness of the PEEK polyether ether ketone engineering plastic insulating plate is 1.5mm, and the gas gap is 5mm, and through test, the discharge area is 14800mm 2 .

[0091] Example 10

[0092] The embodiment of the present application provides a composite gas-liquid two-phase wave flow plasma sewage continuous treatment system, the parameter setting of the power supply is that the voltage is 24kv, the pulse width is 200ns, the frequency is 10kHz, the water sample conductivity is 5840us / cm, the thickness of the PEEK polyether ether ketone engineering plastic insulating plate is 1.5mm, and the gas gap is 5mm, and through test, the discharge area is 14340mm 2 .

[0093] The above specific embodiments further specifically describe the purposes, technical solutions and beneficial effects of the present application, and it should be understood that the above description is only a specific embodiment of the present application, and is not used to limit the protection scope of the present application, and any modification, equivalent replacement, improvement, etc. within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A composite gas-liquid two-phase wavy flow plasma sewage continuous treatment system, characterized in that, The application relates to a sewage continuous treatment system, which comprises a plasma reactor (1), wherein the plasma reactor (1) comprises a treatment box (2), the bottom of the treatment box (2) is paved with an anode plate (3), the top of the treatment box (2) is paved with a PEEK (polyether ether ketone) engineering plastic insulating plate (4), the upper surface of the PEEK engineering plastic insulating plate (4) is provided with a cathode (5), and a high-voltage pulse power source is connected between the anode plate (3) and the cathode (5). The gap between the anode plate (3) and the PEEK engineering plastic insulating plate (4) forms a plasma sewage treatment area (6). An air inlet (8) is arranged on the side wall of the treatment box (2) upstream of the treatment area (6), a sewage inlet (7) is arranged on the bottom of the treatment box (2), a sewage outlet (9) and an air outlet (10) are arranged on the side wall of the treatment box (2) downstream of the treatment area (6). A slow flow area is arranged between the upstream of the treatment area (6) and the sewage inlet (7), the slow flow area has a double-stage slow flow structure, the first-stage slow flow structure is a T-shaped outlet structure, and the second-stage slow flow structure is a smooth slow flow baffle. The cathode (5) is a silver cathode which is connected to the upper surface of the PEEK engineering plastic insulating plate (4) through a plating film. The gas gap between the surface of sewage and the PEEK engineering plastic insulating plate (4) is 4 mm after the sewage enters the treatment area.

2. The complex gas-liquid two-phase wavy flow plasma sewage continuous treatment system according to claim 1, characterized in that, The thickness of the PEEK engineering plastic insulating plate (4) is 1.5 mm, and the thickness of the cathode (5) is 2 mm.

3. The composite gas-liquid two-phase wavy flow plasma sewage continuous treatment system according to claim 1, characterized in that, The working parameters of the high-voltage pulse power source are as follows: power output frequency 1000-10000 Hz, voltage 15-30 kV, and pulse width 200-300 ns.

4. The composite gas-liquid two-phase wavy flow plasma sewage continuous treatment system according to claim 1, characterized in that, The sewage continuous treatment system further comprises an aeration box (11), the bottom of the aeration box (11) is provided with an aeration disc (12), the sewage outlet (9) is connected with the aeration box (11), and the air outlet (10) is connected with the aeration disc (12) through an aeration pipe.

5. The composite gas-liquid two-phase wavy flow plasma sewage continuous treatment system according to claim 1, characterized in that, The front end of the air inlet (8) is connected with a nitrogen molecular sieve device, and air is used as the working medium gas.

6. The complex gas-liquid two-phase wavy flow plasma sewage continuous treatment system according to claim 1, characterized in that, The water inlet speed of the sewage inlet (7) is 10-100 L / h, and the air inlet flow of the air inlet (8) is 1 L / min.

7. A method for continuous treatment of sewage by a compound gas-liquid two-phase wavy flow plasma, characterized in that, The sewage continuous treatment system comprises the following steps: 1) connecting the anode plate of the plasma reactor (1) of the sewage continuous treatment system to the high-voltage output end of the high-voltage pulse power source, and connecting the cathode to the grounding output end of the high-voltage pulse power source; 2) starting a water pump, making the sewage to be treated pass into the sewage inlet of the treatment box, being discharged from the sewage outlet and entering the aeration box, adjusting the valve at the sewage inlet to ensure that the water flow speed is 10-100 L / h, and observing the treatment box to ensure that the water flow in the treatment area is smooth and stable; 3) starting an air pump and opening the aeration disc valve, making the working medium gas pass into the air inlet, being discharged from the air outlet and entering the aeration disc; 4) starting the power source, and setting the power source parameter output frequency to 1000-10000 Hz, the voltage to 15-30 kV, and the pulse width to 200-300 ns.

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