Organic wastewater degradation device system and method based on photocatalysis and plasma discharge

Abstract

The invention provides an organic wastewater degradation device system and method based on photocatalysis and plasma discharge. The device system comprises a three-dimensional photocatalysis and plasma synergistic degradation reaction device and a wastewater aeration treatment device, the degradation reaction device comprises an inner cylinder and an outer cylinder which are coaxially arranged, a plasma discharge inner electrode, a plasma discharge outer electrode, a glow discharge electrode, a wastewater conveying pipeline, a pulse xenon lamp and a spiral xenon lamp, and the first plasma generation cavity, the wastewater aeration treatment device and the wastewater conveying pipeline are sequentially communicated. According to the device system provided by the invention, a coaxial surrounding type plasma discharge structure is designed, gas-liquid secondary degradation is formed on the organic wastewater, glow discharge is designed on the two sides of a pipeline to enable a spiral xenon lamp to emit light, uniform three-dimensional xenon light degradation is formed by combining a pulse xenon lamp, and further through the synergistic effect of photocatalysis and a plasma field, the gas-liquid secondary degradation of the organic wastewater is realized. The degradation process of organic matters is enhanced, and the degradation efficiency of organic wastewater is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of organic wastewater treatment, and relates to a treatment device for organic wastewater, in particular to a system and method for degrading organic wastewater based on photocatalysis and plasma discharge. Background Art

[0002] With the acceleration of the industrialization process, the problem of wastewater discharge containing highly toxic and difficult-to-degrade organic pollutants has become increasingly severe. Traditional degradation technologies, such as biological methods, chemical oxidation methods, and physical adsorption methods, face bottlenecks such as high costs, low efficiency, and high risks of secondary pollution. Therefore, developing efficient, economical, and environmentally friendly organic matter degradation technologies has become a key task in environmental governance.

[0003] In recent years, using photocatalysis and plasma discharge technologies for green and efficient catalysis has been a research hotspot. Plasma is a high-energy state generated by the interaction of charged particles and neutral gas molecules. During the discharge process, various active substances can be generated, such as free radicals, ozone, nitrogen oxides, etc., thereby rapidly degrading organic matter. The photocatalysis technology is based on the photochemical reaction of semiconductor photocatalysts under light illumination. By reacting electrons with water or oxygen to generate strongly oxidizing substances, deep degradation without chemical additives can be achieved, and it has the property of being renewable.

[0004] However, there are significant technical shortcomings in the design of existing organic wastewater degradation treatment devices.

[0005] CN106006831A discloses an anti-pollution continuous three-dimensional photocatalytic sewage treatment device based on an ultraviolet lamp array. The photocatalytic units are arranged in parallel in an array form to achieve continuous photocatalysis. However, in this structure, ultraviolet light cannot evenly cover the entire reaction cavity, resulting in the wastewater in the cavity not being able to uniformly receive the catalytic degradation effect of the light source.

[0006] CN115259276A discloses a centrifugal photocatalytic wastewater degradation device and its use method. The device inserts ultraviolet lamp tubes in the reaction box body and sets up a multi-stage catalytic structure. However, the ultraviolet lamp tubes are located in the center of the box body, and when organic wastewater is filled into the reaction box body, when the chromaticity of the organic wastewater is relatively high, ultraviolet light cannot completely penetrate the wastewater, resulting in low photocatalytic degradation efficiency.

[0007] CN117865330A discloses a wastewater degradation device based on dielectric barrier discharge coupled with optical waveguide catalysis. A copper rod and ceramic medium are arranged in the outer tube of the device to form a plasma discharge area in the outer tube. When the wastewater passes through the plasma discharge area, degradation is achieved through the active substances of dielectric barrier discharge and ultraviolet light.

[0008] CN115215467A discloses a plasma catalytic oxidation treatment device and method. In this device, a photocatalytic zone and a multifunctional catalytic oxidation zone are formed, and wastewater is degraded through plasma oxidation and catalytic oxidation in sequence.

[0009] There are obvious defects in the current photocatalytic degradation technology for organic wastewater. On the one hand, the yield of plasma active substances is low and the energy utilization rate is insufficient, while photocatalysis is limited by uneven light source distribution and poor light transmittance of wastewater. On the other hand, in each treatment stage, a single technology is actually used, and it is difficult to further improve the degradation effect.

[0010] Therefore, it is urgent to achieve efficient and uniform degradation of organic pollutants through innovative device design and technology synergy mechanism. Summary of the Invention

[0011] The purpose of the present invention is to provide an organic wastewater degradation device system based on photocatalysis and plasma discharge, innovatively design the degradation device for organic wastewater, enable photocatalysis and plasma to act synergistically to degrade organic wastewater, and improve the treatment efficiency of organic wastewater.

[0012] To achieve the purpose of this invention, the following technical solutions are adopted:

[0013] In the first aspect, the present invention provides an organic wastewater degradation device system based on photocatalysis and plasma discharge, and the organic wastewater degradation device system includes:

[0014] A three-dimensional photocatalysis and plasma synergistic degradation reaction device and a wastewater aeration treatment device;

[0015] The three-dimensional photocatalysis and plasma synergistic degradation reaction device includes:

[0016] An inner cylinder and an outer cylinder arranged coaxially, and a hollow structure is formed between the inner cylinder and the outer cylinder;

[0017] A plasma discharge inner electrode, and the plasma discharge inner electrode forms a hollow structure along the inner wall of the inner cylinder, so that a first plasma generation chamber is formed inside the inner cylinder;

[0018] A plasma discharge outer electrode, and the plasma discharge outer electrode forms a hollow structure along the inner wall of the outer cylinder, so that the hollow structure between the inner cylinder and the outer cylinder forms a second plasma generation chamber;

[0019] A glow discharge electrode, which is arranged in the second plasma generation chamber and is oppositely arranged at both axial ends of the inner cylinder;

[0020] A pulsed xenon lamp, which is located in the second plasma generation chamber and forms a hollow annular structure along the inner wall of the inner cylinder;

[0021] A wastewater delivery pipeline, which is arranged in the second plasma generation chamber and located between the glow discharge electrodes arranged oppositely, and forms a spiral structure along the outer edge of the inner cylinder body;

[0022] A spiral xenon lamp, which is arranged in the wastewater delivery pipeline and extends axially along the wastewater delivery pipeline in a spiral shape;

[0023] The first plasma generation chamber, the wastewater aeration treatment device and the wastewater delivery pipeline are communicated in sequence.

[0024] The innovative structural design of the degradation device provided by the present invention adopts a nested structure of a plasma discharge inner electrode and an outer electrode, and the electrodes are distributed in a surrounding structure, thus forming two coaxial hollow cavities as dielectric barrier layers. By using the dielectric barrier discharge technology, active substances such as ozone and hydroxyl radicals are generated in the middle cavity and the flow pipeline. The ozone generated from the air in the middle cavity acts on the organic wastewater, enabling the first degradation of the organic wastewater at the beginning of operation. Subsequently, in the flow pipeline, the active substances generated by the plasma are used for the second degradation process again. At the same time, the glow discharge electrodes on both sides of the flow pipeline trigger glow discharge to act on the xenon lamp in the wastewater delivery pipeline, and the pulsed xenon lamp in the cavity jointly forms a three-dimensional light around the pipeline, so that the light source surrounds the entire flow pipeline. And under the action of the electric field, the glow light source formed by xenon gas is stronger and more penetrating. Under the action of xenon light, the organic wastewater reacts with electrons and water or oxygen to generate strongly oxidizing substances. And, xenon light also acts as a catalyst at the same time. The oxidizing active species generated by the plasma and the free radicals generated by the photocatalyst can act synergistically to produce a stronger oxidation effect, promoting the complete degradation of organic matter, thereby completing the degradation of organic wastewater and significantly improving the degradation efficiency of organic matter.

[0025] Preferably, the plasma discharge inner electrode includes a plasma discharge inner positive electrode and a plasma discharge inner negative electrode that are opposite to each other along the axial direction of the inner cylinder body.

[0026] Preferably, the plasma discharge outer electrode includes a plasma discharge outer positive electrode and a plasma discharge outer negative electrode that are opposite to each other along the axial direction of the inner cylinder body.

[0027] In the present invention, the positive electrode of the plasma discharge inner electrode and the positive electrode of the plasma discharge outer electrode are in a relative position, so that the negative electrode of the plasma discharge inner electrode and the positive electrode of the plasma discharge outer electrode are on the same side of the axis. The negative electrode of the plasma discharge inner electrode and the negative electrode of the plasma discharge outer electrode are in a relative position, so that the positive electrode of the plasma discharge inner electrode and the negative electrode of the plasma discharge outer electrode are on the same side of the axis.

[0028] Preferably, the glow discharge electrodes are all in a hollow annular shape and are sleeved on the outer periphery of the inner cylinder.

[0029] In the present invention, the arrangement of the electrodes is a positive-negative relative type. The spiral pipeline is always in the plasma electric field, and the distance between the gas-liquid mixture in the spiral pipeline flow channel and the electrodes is equal everywhere, realizing stable plasma discharge.

[0030] Preferably, the wastewater aeration treatment device includes a liquid storage container and an aeration device arranged in the liquid storage container.

[0031] In the present invention, the first plasma generation chamber is connected to the aeration device through a gas pipeline, and the liquid storage container is connected to the wastewater delivery pipeline through a liquid pipeline.

[0032] In the present invention, the aeration device is a conventional aeration device in the art, and its function is to form bubbles of gas in the liquid. The present invention does not limit its specific structure herein, as long as it can achieve the function of aeration.

[0033] Preferably, the device system further includes a power supply unit.

[0034] Preferably, the power supply unit includes a plasma discharge power supply, a glow discharge power supply, and a pulsed xenon lamp power supply.

[0035] Preferably, the plasma discharge power supply is respectively connected to the plasma discharge inner electrode and the plasma discharge outer electrode.

[0036] Preferably, the glow discharge power supply is connected to the glow discharge electrode.

[0037] Preferably, the pulsed xenon lamp power supply is connected to the pulsed xenon lamp.

[0038] Preferably, the device system further includes a fluid power unit.

[0039] Preferably, the fluid power unit includes an air pump and a hydraulic pump.

[0040] Preferably, the air pump is arranged between the first plasma generation chamber and the wastewater aeration treatment device.

[0041] Preferably, the hydraulic pump is arranged between the wastewater aeration treatment device and the wastewater delivery pipeline.

[0042] In a second aspect, the present invention provides an organic wastewater degradation method based on photocatalysis and plasma discharge. The organic wastewater degradation method uses the organic wastewater degradation device system described in the first aspect.

[0043] Preferably, the organic wastewater degradation method includes the following steps:

[0044] The plasma discharge inner electrode, the plasma discharge outer electrode, and the glow discharge electrode are respectively energized to form a reaction electric field. The pulsed xenon lamp is energized to emit light. The spiral xenon lamp in the wastewater delivery pipeline forms a glow under the glow discharge electric field. Air is introduced into the first plasma generation chamber, and degradation active substances are generated through plasma discharge. The gas containing the degradation active substances is introduced into the wastewater aeration treatment device to aerate the wastewater to be degraded, generating the wastewater to be degraded containing microbubbles. Then, the wastewater to be degraded containing microbubbles is introduced into the wastewater delivery pipeline, so that the wastewater to be degraded is degraded under the action of the plasma electric field and the three-dimensional light.

[0045] In the present invention, the first plasma generation chamber is connected to the wastewater delivery pipeline, and the degradation of the wastewater in the wastewater delivery pipeline is the main degradation process. Therefore, the flow rate of the gas introduced into the first plasma generation chamber is kept the same as the flow rate of the wastewater in the wastewater delivery pipeline.

[0046] In the present invention, the technical principle of plasma discharge is as follows:

[0047] Plasma is a mixed gas composed of electrons, ions, and neutral particles, which is macroscopically electrically neutral, magnetoelectric on a small scale, and has a collective effect. The molecules and atoms of substances can be ionized by thermal ionization, photoionization, and collision ionization to generate plasma.

[0048] When a gas-liquid two-phase fluid is introduced between the positive and negative electrodes, after the applied AC voltage exceeds the breakdown voltage of the fluid, a plasma discharge phenomenon occurs.

[0049] The coaxial double-cylinder dielectric barrier plasma discharge technology is adopted, and the calculation formula of the voltage applied between the plates is as follows:

[0050]

[0051] Among them, V is the voltage between the plates, in kV; E g is the voltage intensity of the gas in the discharge gap, in kV / cm; t is the thickness of the plate, in cm; l gl is the discharge distance when a gas-liquid two-phase flow is introduced between the two plates, in cm; ε is the dielectric constant of the gas; ε d is the dielectric constant of the barrier medium.

[0052] The discharge distance when a gas-phase two-phase fluid is introduced between the two plates is related to the volume fraction of the gas phase, and the calculation formula of the discharge distance is as follows:

[0053] l g l = c·l g

[0054] Among them, c is the gas volume fraction between the two electrodes, and the value of c ranges from 0 to 1, which needs to be determined through experiments; l g is the discharge distance when there is only gas between the two electrodes.

[0055] When degrading organic wastewater, too low a voltage may lead to unstable or discontinuous discharge, while too high a voltage may lead to too strong a discharge, increasing the energy consumption of the system and the wear of the electrodes.

[0056] In the present invention, the technical principle of glow discharge is as follows:

[0057] By applying an electric field across the gas as an excitation, gas molecules will generate a discharge phenomenon, generating a considerable amount of plasma field. At the same time, this plasma field will emit glow, that is, ultraviolet light, which is called the glow discharge phenomenon.

[0058] The calculation principle of the applied voltage of glow discharge is as follows:

[0059] According to Paschen's law, when the voltage between the discharge electrodes increases, the tube current increases accordingly. At a certain threshold voltage (breakdown voltage) V b , there is a sudden increase in the tube current, and gas breakdown occurs. Therefore, the relationship between the breakdown voltage and the gas pressure and the electrode plate gap is as follows:

[0060]

[0061] Among them, V b is the breakdown voltage; A and B are gas type coefficients; P is the gas pressure; d is the electrode plate gap; γ se is the secondary electron emission coefficient.

[0062] The breakdown voltage V b is a function of the Pd product, and there is a minimum breakdown voltage at a specific Pd value.

[0063] The breakdown voltages of different gases are different. The breakdown voltages of inert gases (such as argon and neon) are relatively low, while the breakdown voltages of molecular gases such as nitrogen and oxygen are relatively high. If used for plasma processing or chemical reactions, oxygen, nitrogen or a mixed gas may be selected. The choice of electrode material will affect the secondary electron emission coefficient (γse) and the stability of the discharge. The surface roughness of the electrode will affect the local electric field strength and reduce the breakdown voltage, but may lead to uneven discharge. Surface contamination (such as oil stains and oxides) will affect secondary electron emission and discharge characteristics. Therefore, the electrode surface needs to be cleaned.

[0064] Compared with the prior art, the present invention has the following beneficial effects:

[0065] (1) By designing a coaxial surrounding plasma discharge structure, and arranging the plasma electrodes in a positive-negative relative manner, a two-fold ozone degradation of gas-liquid for organic wastewater is formed.

[0066] (2) By designing a glow discharge structure on both the upper and lower sides of the pipeline, the spiral xenon lamp and the annular pulsed xenon lamp jointly form a uniform three-dimensional photocatalytic degradation. Moreover, the xenon light source is stronger and more penetrating, so that the entire range of the wastewater conveying pipeline can be irradiated. At the same time, under the synergistic effect of photocatalysis and the plasma electric field, the degradation process of organic matter can be strengthened, and the degradation efficiency of organic wastewater can be improved. Description of the Drawings

[0067] Figure 1 is a schematic structural diagram of the organic wastewater degradation device system based on photocatalysis and plasma discharge provided in Embodiment 1;

[0068] Figure 2 is a schematic structural diagram of the three-dimensional photocatalytic and plasma synergistic degradation reaction device provided in Embodiment 1;

[0069] Figure 3 is a top view structural diagram of the three-dimensional photocatalytic and plasma synergistic degradation reaction device provided in Embodiment 1;

[0070] Figure 4 is a schematic diagram of the power connection mode of the three-dimensional photocatalytic and plasma synergistic degradation reaction device provided in Embodiment 1;

[0071] Among them, 1 is the three-dimensional photocatalytic and plasma synergistic degradation reaction device; 11 is the top cover; 12 is the bottom cover; 13 is the inner cylinder side wall; 14 is the outer cylinder side wall; 15 is the first plasma generation chamber; 16 is the second plasma generation chamber; 151 is the gas inlet; 152 is the gas outlet; 161 is the wastewater inlet; 162 is the wastewater outlet; 17 is the inner plasma discharge electrode; 171 is the inner positive plasma discharge electrode; 172 is the inner negative plasma discharge electrode; 18 is the outer plasma discharge electrode; 181 is the outer positive plasma discharge electrode; 182 is the outer negative plasma discharge electrode; 191 is the glow discharge positive electrode; 192 is the glow discharge negative electrode; 110 is the annular pulsed xenon lamp; 111 is the spiral xenon lamp; 112 is the wastewater conveying pipeline; 2 is the wastewater aeration treatment device; 21 is the aeration device; 3 is the wastewater collection tank; 4 is the plasma discharge power supply; 5 is the glow discharge power supply; 6 is the pulsed xenon lamp power supply; 7 is the air pump; 8 is the hydraulic pump. Detailed Embodiments

[0072] The technical solutions of the present invention will be further described below through specific embodiments. Those skilled in the art should understand that the embodiments are only for helping to understand the present invention and should not be regarded as specific limitations on the present invention.

[0073] Example 1

[0074] This example provides an organic wastewater degradation device system based on photocatalysis and plasma discharge.

[0075] The organic wastewater degradation device system includes:

[0076] A three-dimensional photocatalysis and plasma synergistic degradation reaction device 1, a wastewater aeration treatment device 2, a wastewater collection tank 3, a power supply unit, and a fluid power unit.

[0077] The three-dimensional photocatalysis and plasma synergistic degradation reaction device 1 includes:

[0078] A top cover 11, a bottom cover 12, an inner cylinder side wall 13, and an outer cylinder side wall 14. The inner cylinder side wall 13 and the outer cylinder side wall 14 are two hollow cylindrical structures of the same height. The inner cylinder side wall 13 is located inside the outer cylinder side wall 14 and is coaxially arranged with the outer cylinder side wall 14, so that a hollow structure is formed between the inner cylinder side wall 13 and the outer cylinder side wall 14. The two ends of the inner cylinder side wall 13 and the outer cylinder side wall 14 are respectively joined and sealed with the top cover 11 and the bottom cover 12. The top cover 11 and the bottom cover 12 are fixedly connected by bolts, and gaskets are provided on the mating surfaces of the bolts with the top cover 11 and the bottom cover 12 to ensure the airtightness of the cavity. Finally, an inner cylinder is formed between the inner cylinder side wall 13 and the top cover 11 and the bottom cover 12. The inside of the inner cylinder is the first plasma generation chamber 15. An outer cylinder is formed between the outer cylinder side wall 14 and the top cover 11 and the bottom cover 12. The hollow structure formed between the inner cylinder and the outer cylinder is the second plasma generation chamber 16.

[0079] A plasma discharge inner electrode 17. The plasma discharge inner electrode 17 is divided into a plasma discharge inner positive electrode 171 and a plasma discharge inner negative electrode 172. The plasma discharge inner positive electrode 171 forms a semi-circular structure with an arc angle of 180° along the inner wall of the inner cylinder. The plasma discharge inner negative electrode 172 starts from one end of the plasma discharge inner positive electrode 171 and forms a semi-circular structure with an arc angle of 180° along the inner wall of the inner cylinder, and is connected to the other end of the plasma discharge inner positive electrode 171, so that the two ends of the plasma discharge inner positive electrode 171 and the plasma discharge inner negative electrode 172 are connected to form a hollow cylinder. Grooves are opened on the top cover 11 at the positions corresponding to the inner positive electrode and the inner negative electrode for plugging with the two electrode plates, and are fixed by the groove bolts on the bottom cover 12.

[0080] The plasma discharge outer electrode 18 is divided into a plasma discharge outer positive electrode 181 and a plasma discharge outer negative electrode 182. The plasma discharge outer positive electrode 181 forms a semi-circular structure with an arc angle of 180° along the inner wall of the outer cylinder. The plasma discharge outer negative electrode 182 starts from one end of the plasma discharge outer positive electrode 181 and forms a semi-circular structure with an arc angle of 180° along the inner wall of the outer cylinder, connecting to the other end of the plasma discharge outer positive electrode 181, so that the two ends of the plasma discharge outer positive electrode 181 and the plasma discharge outer negative electrode 182 are connected to form a hollow cylinder. Grooves are opened on the top cover 11 at the positions corresponding to the outer positive electrode and the outer negative electrode for inserting with the two electrode plates, and are fixed by the clamping groove bolts on the bottom cover 12. The plasma discharge inner positive electrode 171 and the plasma discharge outer positive electrode 181 are in a relative position. Similarly, the plasma discharge inner negative electrode 172 and the plasma discharge outer negative electrode 182 are also in a relative position, so that the plasma discharge inner negative electrode 172 and the plasma discharge outer positive electrode 181 are on the same side of the inner cylinder axis, and the plasma discharge inner positive electrode 171 and the plasma discharge outer negative electrode 182 are on the same side of the inner cylinder axis.

[0081] The glow discharge electrode is divided into a glow discharge positive electrode 191 and a glow discharge negative electrode 192. Both the glow discharge positive electrode 191 and the glow discharge negative electrode 192 are in a hollow ring shape and are sleeved on the outer periphery of the inner cylinder, thus located in the second plasma generation chamber 16, and are respectively fixed at both ends in the axial direction of the inner cylinder through fixing bosses.

[0082] The annular pulsed xenon lamp 110 is located in the second plasma generation chamber 16, inside the plasma discharge outer electrode 18, and forms a hollow ring structure along the inner wall of the inner cylinder.

[0083] The spiral xenon lamp 111 is located in the second plasma generation chamber 16. Starting from one end in the axial direction of the inner cylinder, it spirally winds around the outer periphery of the inner cylinder until the other end in the axial direction of the inner cylinder, so that the spiral part of the spiral xenon lamp is located between the glow discharge positive electrode 191 and the glow discharge negative electrode 192.

[0084] The waste water delivery pipeline 112 is located in the second plasma generation chamber 16. The outer wall of the waste water delivery pipeline 112 is formed by wrapping the spiral xenon lamp 111, so that the waste water delivery pipeline 112 also spirally winds around the outer periphery of the inner cylinder, and the spiral xenon lamp 111 is located in the waste water delivery pipeline 112. The spiral part of the waste water delivery pipeline 112 is located between the glow discharge positive electrode 191 and the glow discharge negative electrode 192.

[0085] A gas inlet 151 is provided on the top cover of the top of the first plasma generation chamber 15, and a gas outlet 152 is provided on the bottom cover of the bottom of the first plasma generation chamber 15, so that gas can flow into and out of the first plasma generation chamber 15.

[0086] A wastewater inlet 161 is provided on the top cover of the top of the second plasma generation chamber 16, and a wastewater outlet 162 is provided on the bottom cover of the bottom of the second plasma generation chamber. Both ends of the wastewater delivery pipeline 112 are respectively connected to the wastewater inlet 161 and the wastewater outlet 162.

[0087] The wastewater aeration treatment device 2 includes a liquid storage tank and an aeration device 21 provided in the liquid storage tank.

[0088] The power supply unit includes a plasma discharge power supply 4, a glow discharge power supply 5, and a pulsed xenon lamp power supply 6.

[0089] In this device, the power supply unit is the plasma discharge power supply 4, the glow discharge power supply 5, and the pulsed xenon lamp power supply 6. As Figure 4 shown, the connection method is as follows: The negative electrode of the plasma discharge power supply 4 is connected to the inner negative electrode 172 and the outer negative electrode 182 of the plasma discharge through a wire, and the positive electrode of the plasma discharge power supply 4 is connected to the inner positive electrode 171 and the outer positive electrode 181 of the plasma discharge through a wire, thereby realizing plasma discharge. The glow discharge power supply 5 is connected to the glow discharge positive electrode 191 and the glow discharge negative electrode 192 through wires respectively to realize the glow discharge of the spiral xenon lamp 111. The pulsed xenon lamp power supply 6 is connected to the annular pulsed xenon lamp 110 to generate xenon light, which together with the xenon light generated by the spiral xenon lamp 111 forms a three-dimensional xenon light.

[0090] The fluid power unit includes an air pump 7 and a hydraulic pump 8.

[0091] The first plasma generation chamber 15, the air pump 7, the wastewater aeration treatment device 2, the hydraulic pump 8, the wastewater delivery pipeline 112, and the wastewater collection tank 3 are connected in sequence. Specifically, the first plasma generation chamber 15 is connected to the air pump 7 through the gas outlet 152, the air pump 7 is connected to the aeration device 21 in the wastewater aeration treatment device 2, the liquid storage tank of the wastewater aeration treatment device 2 is connected to the hydraulic pump 8, the hydraulic pump 8 and the wastewater delivery pipeline 112 are communicated through the wastewater inlet 161, and the wastewater delivery pipeline 112 and the wastewater collection tank 3 are communicated through the wastewater outlet 162.

[0092] In this embodiment, the plasma power supply uses a plasma AC power supply of model Summan CTP-2000K. The materials of the top cover, bottom cover, side wall of the inner cavity, and side wall of the outer cavity are all non-insulating materials. Polytetrafluoroethylene material is selected, and metal materials are avoided to prevent interference with the plasma discharge electrode and the glow discharge electrode. To ensure that the wastewater delivery pipeline in the device can be penetrated by xenon light and the spiral xenon lamp can be placed in the wastewater delivery pipeline, the outer shell of the wastewater delivery pipeline is made of polyethylene film.

[0093] In this embodiment, for plasma discharge, the thickness of the electrode plate is 2 cm, the discharge distance when a gas-liquid two-phase fluid is introduced between the two electrode plates is 4 cm, the dielectric constant of the gas is 1, and the dielectric constant of quartz glass is 3.7. According to Paschen's law, under standard atmospheric pressure, the breakdown voltage of the gas is 30 kV / cm. Finally, the minimum voltage applied between the electrode plates is calculated to be 92.4 kV.

[0094] Therefore, in this embodiment, the voltage finally applied to the plasma discharge electrode is 93 kV.

[0095] In this embodiment, for glow discharge, the spiral xenon lamp is filled with xenon gas. The gas type constant A of xenon gas is 15 (1 / (Pa·m)), B is 250 (V / (Pa·m)), the gas pressure P of xenon gas is 70 kPa, the electrode material is aluminum metal, and the secondary electron emission coefficient γ se is 0.1, and the gap d between the electrode plates is 80 cm. The minimum voltage for glow discharge time is calculated to be 98.2 kV.

[0096] Therefore, in this embodiment, the voltage finally applied to the glow discharge electrode is 100 kV. The voltage acting on the annular xenon lamp is also 100 kV.

[0097] This embodiment also provides an organic wastewater degradation method based on photocatalysis and plasma discharge. The organic wastewater degradation method uses the organic wastewater degradation device system based on photocatalysis and plasma discharge. The organic wastewater degradation method includes the following steps:

[0098] (1) After the spiral xenon lamp 111 is filled with xenon gas, it is sealed with a piston. The air pump 7 and the plasma discharge power supply 4 are turned on, and the air outside the system is introduced into the first plasma generation chamber 15 at a speed of 0.8 L / min to receive plasma discharge in the first plasma generation chamber 15 to generate a gaseous mixture of ozone and air;

[0099] (2) The gaseous mixture is introduced into the aeration device 21 through a pipeline to perform aeration treatment on the organic wastewater to form organic wastewater rich in microbubbles;

[0100] (3) Open the wastewater inlet 161 and the wastewater outlet 162, and at the same time, turn on the hydraulic pump 8. The hydraulic pump 8 pumps the organic wastewater rich in microbubbles in the wastewater aeration treatment device 2, and enters the wastewater inlet 161 at a speed of 0.8 L / min, and then flows into the wastewater delivery pipeline 112;

[0101] (4) Turn on the glow discharge power supply 5 and the pulsed xenon lamp power supply 6. The organic wastewater rich in microbubbles enters the wastewater delivery pipeline 112. The spiral xenon lamp 111 and the annular pulsed xenon lamp 110 jointly generate three-dimensional xenon light through glow discharge. Plasma discharge generates active substances such as ozone and hydroxyl radicals in the wastewater. The synergistic effect of xenon light and plasma degrades the organic matter in the wastewater;

[0102] (5) After the pipeline is filled with the solution, the degraded organic wastewater overflows from the wastewater outlet 162 to the wastewater collection tank 3 by the water pressure;

[0103] (6) Detect the pollutant removal rate of the degraded wastewater and adjust the flow rate of the hydraulic pump in real time.

[0104] Comparative Example 1

[0105] This comparative example provides a device system for degrading organic wastewater. Compared with Example 1, the plasma discharge inner electrode is not provided in the three-dimensional photocatalysis and plasma synergistic degradation reaction device, and the rest are the same as those in Example 1.

[0106] This comparative example also provides a method for degrading organic wastewater. Using the device system for degrading organic wastewater, the operating steps of the method are the same as those in Example 1.

[0107] Comparative Example 2

[0108] This comparative example provides a device system for degrading organic wastewater. Compared with Example 1, the plasma discharge outer electrode is not provided in the three-dimensional photocatalysis and plasma synergistic degradation reaction device, and the rest are the same as those in Example 1.

[0109] This comparative example also provides a method for degrading organic wastewater. Using the device system for degrading organic wastewater, the operating steps of the method are the same as those in Example 1.

[0110] Comparative Example 3

[0111] This comparative example provides a device system for degrading organic wastewater. Compared with Example 1, the glow discharge electrode and the glow discharge power supply are not provided in the three-dimensional photocatalysis and plasma synergistic degradation reaction device, and the rest are the same as those in Example 1.

[0112] This comparative example also provides a method for degrading organic wastewater. Using the device system for degrading organic wastewater, no glow discharge is applied in this method, and the remaining operation steps are the same as those in Example 1.

[0113] Comparative Example 4

[0114] This comparative example provides a device system for degrading organic wastewater. Compared with Example 1, in the three-dimensional photocatalysis and plasma synergistic degradation reaction device, the annular pulsed xenon lamp and the xenon lamp power supply are not provided, and the rest are the same as those in Example 1.

[0115] This comparative example also provides a method for degrading organic wastewater. Using the device system for degrading organic wastewater, the annular xenon lamp light source is not applied in this method, and the remaining operation steps are the same as those in Example 1.

[0116] Comparative Example 5

[0117] This comparative example provides a device system for degrading organic wastewater. Compared with Example 1, the plasma discharge outer electrode is divided into a plasma discharge outer positive electrode and a plasma discharge outer negative electrode. Both the plasma discharge outer positive electrode and the plasma discharge outer negative electrode are in a hollow annular shape, sleeved on the outer periphery of the inner cylinder body, and thus located in the second plasma generation cavity, and are respectively fixed at both ends in the axial direction of the inner cylinder body through fixed bosses. The glow discharge electrode is divided into a glow discharge positive electrode and a glow discharge negative electrode. The glow discharge positive electrode forms a semi-circular structure with an arc angle of 180° along the inner wall of the outer cylinder body. The glow discharge negative electrode forms a semi-circular structure with an arc angle of 180° along the inner wall of the outer cylinder body starting from one end of the glow discharge positive electrode and is connected to the other end of the glow discharge positive electrode, so that the two ends of the glow discharge positive electrode and the glow discharge negative electrode are connected to form a hollow cylinder. The rest are the same as those in Example 1, that is, the structures of the plasma discharge outer electrode and the glow discharge electrode are swapped.

[0118] This comparative example also provides a method for degrading organic wastewater. Using the device system for degrading organic wastewater, the remaining operation steps are the same as those in Example 1.

[0119] The device system and method provided by the examples and comparative examples are used to degrade and treat organic wastewater. The composition content of the organic wastewater is as follows: humic acid / fulvic acid: 50 mg / L, lignin derivatives (paper-making or wood-processing wastewater): 20 mg / L, synthetic organic matter, dye / pigment residues (textile and printing wastewater): 5 mg / L, surfactants (detergent and chemical industry wastewater): 10 mg / L, organic acids and alcohols (food processing and fermentation wastewater): 200 mg / L (calculated as COD), proteins and fats (domestic sewage): 10 mg / L, iron / manganese ions (color-developed after oxidation): 1 mg / L, benzene series and phenols (chemical industry wastewater): 2 mg / L, ammonia nitrogen (domestic sewage): 5 mg / L. The total organic carbon (TOC) analysis method is used to analyze the components of the wastewater before and after degradation, and the removal rate of organic matter is calculated and listed in Table 1.

[0120] Table 1

[0121] Removal rate (%) Example 1 98 Comparative Example 1 87 Comparative Example 2 84 Comparative Example 3 88 Comparative Example 4 91 Comparative Example 5 78

[0122] As can be seen from Table 1, by comparing Example 1 with Comparative Examples 1-5, the device system provided by the present invention achieves good degradation and removal effects of organic matter when degrading and treating organic wastewater with various complex components, and the degradation rate is as high as 98%. When plasma discharge, glow discharge or xenon lamp three-dimensional light is lacking, the removal effect deteriorates significantly. When the glow discharge part does not generate three-dimensional light jointly with the annular pulsed xenon lamp, the removal rate also decreases significantly, indicating that while the three play a role in degrading organic matter respectively, they also produce a synergistic mechanism to further improve the degradation effect. When the glow discharge electrode and the plasma discharge electrode in the device are interchanged, due to the different length, width and height of the device, that is, the voltages required when the electrodes are at the left and right ends and the upper and lower ends are different, and the requirements of the corresponding discharge part cannot be met, resulting in a significant reduction in the removal rate.

[0123] In summary, the device system provided by the present invention forms a gas-liquid two-stage degradation of organic wastewater by designing a coaxial surrounding plasma discharge structure, forms a uniform three-dimensional light degradation jointly with the glow discharge structure designed on both sides of the pipeline and the annular pulsed xenon lamp, and the xenon lamp light source is stronger and more penetrating. Under the synergistic action of photocatalysis and plasma field, the degradation process of organic matter is strengthened, and the degradation efficiency of organic wastewater is improved.

[0124] The applicant declares that the above description is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention fall within the protection scope and the disclosure scope of the present invention.

Claims

1. An organic wastewater degradation device system based on photocatalysis and plasma discharge, characterized in that: The organic wastewater degradation device system comprises: Stereoscopic photocatalysis and plasma synergistic degradation reaction device and wastewater aeration treatment device; The stereoscopic photocatalysis and plasma synergistic degradation reaction device comprises: An inner cylinder and an outer cylinder are coaxially arranged, and a hollow structure is formed between the inner cylinder and the outer cylinder; A plasma discharge inner electrode, wherein the plasma discharge inner electrode forms a hollow structure along the inner wall of the inner cylinder, so that a first plasma generating chamber is formed inside the inner cylinder; A plasma discharge outer electrode, wherein the plasma discharge outer electrode forms a hollow structure along the inner wall of the outer cylinder, so that the hollow structure between the inner cylinder and the outer cylinder forms a second plasma generation chamber; A glow discharge electrode, which is disposed in the second plasma generating chamber and is disposed opposite to each other at two axial ends of the inner cylinder; A pulse xenon lamp, the pulse xenon lamp is located in the second plasma generating chamber and forms a hollow annular structure along the inner wall of the inner cylinder; A wastewater conveying pipeline, which is arranged in the second plasma generating chamber and between the oppositely arranged glow discharge electrodes, and forms a spiral structure along the outer edge of the inner cylinder; A spiral xenon lamp, which is arranged in the wastewater conveying pipeline and extends in a spiral shape along the axial direction of the wastewater conveying pipeline; The first plasma generating chamber, the wastewater aeration treatment device and the wastewater conveying pipeline are connected in sequence.

2. The organic wastewater degradation device system according to claim 1, characterized in that: The plasma discharge inner electrode comprises a plasma discharge inner positive electrode and a plasma discharge inner negative electrode which are opposite to each other along the axial direction of the inner cylinder.

3. The organic wastewater degradation device system according to claim 1 or 2, characterized in that: The plasma discharge outer electrode comprises a plasma discharge outer positive electrode and a plasma discharge outer negative electrode which are opposite to each other along the axial direction of the inner cylinder.

4. The organic wastewater degradation device system according to any one of claims 1 to 3, characterized in that: The glow discharge electrodes are all hollow ring-shaped and sleeved on the outer circumference of the inner cylinder.

5. The organic wastewater degradation device system according to any one of claims 1 to 4, characterized in that: The wastewater aeration treatment device comprises a liquid storage container and an aeration device arranged in the liquid storage container.

6. The organic wastewater degradation device system according to any one of claims 1 to 5, characterized in that: The organic wastewater degradation device system also includes a power supply unit.

7. The organic wastewater degradation device system according to claim 6, characterized in that: The power supply unit includes a plasma discharge power supply, a glow discharge power supply and a pulse xenon lamp power supply; Preferably, the plasma discharge power supply is connected to the plasma discharge inner electrode and the plasma discharge outer electrode respectively; Preferably, the glow discharge power supply is connected to the glow discharge electrode; Preferably, the pulse xenon lamp power supply is connected to the pulse xenon lamp.

8. The organic wastewater degradation device system according to any one of claims 1 to 7, characterized in that: The organic wastewater degradation device system also includes a fluid power unit; Preferably, the fluid power unit comprises an air pump and a hydraulic pump; Preferably, the air pump is arranged between the first plasma generating chamber and the wastewater aeration treatment device; Preferably, the hydraulic pump is arranged between the wastewater aeration treatment device and the wastewater conveying pipeline.

9. A method for degrading organic wastewater based on photocatalysis and plasma discharge, characterized in that: The organic wastewater degradation method uses the organic wastewater degradation device system based on photocatalysis and plasma discharge as described in any one of claims 1 to 8.

10. The method for degrading organic wastewater according to claim 9, characterized in that: The organic wastewater degradation method comprises the following steps: The plasma discharge inner electrode, the plasma discharge outer electrode and the glow discharge electrode are energized respectively to form a reaction electric field, the pulse xenon lamp is energized to emit light, and the spiral xenon lamp in the wastewater conveying pipeline forms a glow under the glow discharge electric field. Air is introduced into the first plasma generating chamber to generate degradation active substances through plasma discharge, and the gas containing the degradation active substances is introduced into the wastewater aeration treatment device to aerate the wastewater to be degraded to generate wastewater to be degraded containing microbubbles, and then the wastewater to be degraded containing microbubbles is introduced into the wastewater conveying pipeline, so that the wastewater to be degraded is degraded under the synergistic effect of the plasma electric field and the stereoscopic light.

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