Plasma synergistic wet oxidation treatment of high concentration wastewater system and method

Abstract

The application discloses a kind of high concentration wastewater system and method treated by plasma cooperated with wet oxidation, inclined plate sedimentation tank, inclined plate sedimentation tank, plunger pump, heat exchanger are sequentially connected, heat exchanger is connected with plasma wet oxidation reaction tower, gas-liquid separator respectively, plasma wet oxidation reaction tower is connected with arc plasma torch, arc plasma torch is connected with high-pressure air compressor system, plasma power supply, deionized water cooling tower, deionized water pump respectively, deionized water cooling tower is connected with deionized water pump, gas-liquid separator is connected with liquid storage tank, deacidification tower respectively, deacidification tower, lye tank, lye circulating pump are sequentially connected.The application does not need to add catalyst, and the COD degradation efficiency is high;Without entering biochemical system for treatment, the water quality treated reaches standard;Processing efficiency is high, reaction time is short, device is small, land area is small, structure is compact, and it is convenient for management.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment technology, and in particular to a plasma-assisted wet oxidation system and method for treating high-concentration wastewater. Background Technology

[0002] With industrial development and product upgrading, the types and quantities of wastewater have increased rapidly, and the composition of industrial wastewater has become more complex, with some components being toxic. High-concentration organic wastewater mainly has the following characteristics:

[0003] (1) High concentration of organic matter. The COD in wastewater is generally above 2000 mg / L, and some even reach tens of thousands or hundreds of thousands of mg / L, but the BOD is low. The ratio of BOD to COD in many wastewaters is less than 0.3.

[0004] (2) Complex composition. The organic matter in the wastewater containing toxic substances is mostly aromatic compounds and heterocyclic compounds, and also contains sulfides, nitrogen compounds, heavy metals and toxic organic matter.

[0005] (3) High color and odor. Some wastewater emits a pungent odor, which has an adverse impact on the surrounding environment.

[0006] (4) Strong acid and strong alkalinity. At present, wastewater treatment mainly adopts coagulation sedimentation, advanced oxidation (electrocoagulation, ozone catalysis, photocatalysis and Fenton, etc.), and biochemical treatment technologies. To treat high-concentration wastewater to meet the discharge standards, multiple treatment technologies need to be used in combination, the process is long, and most importantly, if the wastewater quality changes, it is difficult to meet the discharge standards.

[0007] Plasma is an ionized gas composed of high-energy electrons, positive and negative ions, and other active particles. The high-energy electrons in plasma, along with excited and unstable particles, possess inherent instability. They plunder electrons from other unsaturated bonds, causing chemical bonds to break and forming the most stable and simplest compounds. Therefore, plasma exhibits autocatalytic properties, enabling many substances to undergo chemical reactions under conditions where they would otherwise be impossible. Plasma is also hailed by the environmental protection industry as the ultimate technology for hazardous waste treatment.

[0008] Wet oxidation is a method that introduces oxygen or air into wastewater under specific temperature and pressure conditions, decomposing the organic matter in the water into nitrogen, water vapor, carbon dioxide, ash, and residual organic matter. To improve wet oxidation efficiency, shorten reaction time, and reduce reaction pressure and temperature, catalysts are often introduced. This technology is then followed by biological treatment.

[0009] Currently, industry professionals have made initial attempts to use plasma to treat highly difficult wastewater.

[0010] CN102418930A employs a combined molecular stripping and plasma incineration system for treating high-concentration organic wastewater. This involves removing low-molecular-weight organic matter through stripping, while incinerating large-molecular-weight organic matter and inorganic salts using plasma. The high incineration temperature (above 1000℃) and the low melting point of inorganic salts (mainly chlorides) cause them to melt and clog pipes, preventing the system from operating normally. CN105036251A and CN106517608A utilize non-thermal plasma to treat high-concentration organic wastewater. Non-thermal plasma, i.e., low-temperature plasma such as corona discharge, DBD, or glow discharge, has low efficiency and requires high electron cloud concentration under low pressure conditions, resulting in high energy consumption and low treatment efficiency. Besides plasma technology, wet oxidation technology is also used for treating high-concentration wastewater and is already operational in the paper, pharmaceutical, and chemical industries. However, wet oxidation technology has a relatively low COD removal rate and is generally used as a pretreatment technology for biochemical treatment. CN114772832A utilizes CO2 generated by a wet oxidation system to reduce scaling, which delays scaling but does not fundamentally address the low COD degradation efficiency of wet oxidation. CN206544962U, WO2015103811A1, CN212894326U, CN1876577B, CN115259456, CN1046761041A, CN104761041B, and KR1019990080272A all employ catalytic wet oxidation to treat high-concentration wastewater, using catalysts to accelerate the reaction efficiency. However, this leads to the release of heavy metals from the catalyst, causing secondary pollution of the wastewater (mainly heavy metal ion pollution from the catalyst). These heavy metals then enter the treated water, resulting in excessive levels of heavy metals in the discharged water. Therefore, it is necessary to capture and treat the heavy metals in the water, adding to the wastewater treatment cost. JP01307494A and JP101210097A both employ wet oxidation systems to treat high-nitrogen, high-concentration wastewater, converting nitrogen in the wastewater into ammonia for resource utilization. However, they do not address the low efficiency of wet oxidation reactions. CN211972063U and CN111115933A describe flameless flare oxidation towers, which are essentially wet oxidation reactors. These reactors use transition metal oxides such as manganese, chromium, cobalt, and nickel as catalysts, inevitably resulting in the release of metal ions during wastewater treatment, causing secondary pollution. CN217418414U uses microwave-assisted wet oxidation to treat high-concentration wastewater. While this improves COD degradation efficiency, it suffers from low microwave power supply efficiency and microwave radiation issues. CN10683630A uses ozone as a strong oxidant to enhance wet oxidation reaction efficiency, but this results in insufficient ozone utilization and ozone release, causing air pollution. Therefore, there is an urgent need for a catalyst-free wet oxidation technology with high degradation efficiency for high-concentration wastewater. Summary of the Invention

[0011] This invention addresses the problems of long process flow, low COD removal efficiency, and metal escape from catalysts in catalytic wet oxidation degradation of COD in existing high-concentration organic wastewater treatment processes. It provides a plasma-coordinated wet oxidation system and method for treating high-concentration wastewater. Utilizing the self-catalytic effect of active particles generated by electric arc plasma, and employing the principle of wet oxidation technology, it treats high-concentration wastewater with high COD degradation efficiency, mild reaction conditions, and no secondary waste generation. It is suitable for continuous industrial wastewater treatment.

[0012] To solve the above-mentioned technical problems, the technical solution of the present invention is: a plasma-coordinated wet oxidation system for treating high-concentration wastewater, comprising an inclined plate sedimentation tank, a plunger pump, and a heat exchanger connected in sequence. The heat exchanger is connected to a plasma wet oxidation reaction tower and a gas-liquid separator. The plasma wet oxidation reaction tower is connected to an electric arc plasma torch. The electric arc plasma torch is connected to a high-pressure air compressor system, a plasma power supply, a deionized water cooling tower, and a deionized water pump. The deionized water cooling tower is connected to the deionized water pump. The gas-liquid separator is connected to a liquid storage tank and a deacidification tower. The deacidification tower, an alkali tank, and an alkali circulation pump are connected in sequence. The plasma wet oxidation reaction tower includes a reaction chamber, which has a gas-liquid two-phase flow outlet, a high-concentration wastewater inlet, an electric arc plasma torch installation port, a pressure port, and a temperature port. The outer wall of the reaction chamber is covered with heat insulation material. An electromagnetic heating coil is wound around the outer wall of the heat insulation material.

[0013] Furthermore, the bottom of the reaction chamber is provided with a gas-liquid two-phase flow outlet, the top of the reaction chamber is provided with an arc plasma torch installation port and a pressure port, and the side wall of the reaction chamber is provided with a high-concentration wastewater inlet and a temperature port.

[0014] Furthermore, the high-concentration wastewater inlets are distributed in multiples around the circumference.

[0015] Furthermore, the electromagnetic heating coil is connected to a high-frequency heating power supply.

[0016] The plasma-assisted wet oxidation method for treating high-concentration wastewater includes two steps: startup and normal operation. Startup involves first treating the high-concentration wastewater in an inclined plate sedimentation tank with chemicals to remove suspended solids, then pumping it into the plasma wet oxidation reactor using a plunger pump. The pressure at the reactor's inlet is set to 1 MPa. A high-frequency heating power supply is then activated to raise the temperature in the reactor to 160°C, maintaining the pressure at 1 MPa throughout this heating process. Once the temperature reaches 160°C, the axial flow fan on the deionized water cooling tower, the deionized water pump, and the high-pressure air compressor system are started sequentially. After the high-pressure air compressor system has been running for 1 minute, the plasma power supply is activated, causing the arc plasma torch to convert air into plasma. When the temperature at the reactor's inlet reaches 200°C, the temperature is maintained at 200°C and the pressure at 1 MPa for 5 minutes, completing the startup process. After startup, the normal operation process begins.

[0017] The beneficial effects of this invention are:

[0018] 1. The plasma-assisted wet oxidation method for treating high-concentration wastewater has a wide range of applications and is particularly suitable for highly toxic and difficult-to-degrade wastewater.

[0019] 2. The plasma-coordinated wet oxidation method for treating high-concentration wastewater does not require the addition of a catalyst. Utilizing the self-catalytic properties of plasma, the COD degradation efficiency reaches up to 99%.

[0020] 3. The high-concentration wastewater is treated by plasma-coordinated wet oxidation, which eliminates the need for biological treatment. The treated water meets the GB18918 Class A discharge standard.

[0021] 4. The plasma-coordinated wet oxidation method for treating high-concentration wastewater has high treatment efficiency, short reaction time, small equipment size, small footprint, compact structure, and is easy to manage.

[0022] 5. The plasma-coordinated wet oxidation method is used to treat high-concentration wastewater. No secondary pollutants are generated. C is oxidized into carbon dioxide, and halides and sulfides are oxidized into inorganic chlorides and sulfides, which are absorbed in the post-treatment unit. No nitrogen oxides, HCl, SO2, or CO are emitted.

[0023] 6. The plasma-coordinated wet oxidation method for treating high-concentration wastewater has a unit cost that is 20% lower than that of catalytic wet oxidation technology under the same feed conditions.

[0024] 7. The plasma-coordinated wet oxidation method for treating high-concentration wastewater has lower reaction temperature and pressure than catalytic wet oxidation under the same feed conditions, resulting in higher safety. Attached Figure Description

[0025] Figure 1 This is a system diagram of the present invention;

[0026] Figure 2 yes Figure 1 Local magnification Figure 1 ;

[0027] Figure 3 yes Figure 1 Local magnification Figure 2 ;

[0028] Figure 4 This is a schematic diagram of a plasma wet oxidation reaction tower.

[0029] The components are as follows: 1-Plunger pump; 2-Inclined plate sedimentation tank; 3-Plasma wet oxidation reaction tower; 4-Electric arc plasma torch; 5-High pressure air compressor system; 6-Plasma power supply; 7-Deionized water cooling tower; 8-Deionized water pump; 9-Heat exchanger; 10-Gas-liquid separator; 11-Liquid storage tank; 12-Deacidification tower; 13-Alkali tank; 14-Alkali circulation pump; 301-Gas-liquid two-phase flow outlet; 302-Reaction chamber; 303-Electromagnetic heating coil; 304-Insulation material; 305-High concentration wastewater inlet; 306-Electric arc plasma torch installation port; 307-High frequency heating power supply; 308-Pressure port; 309-Temperature port. Detailed Implementation

[0030] The following is in conjunction with the appendix Figure 1-4 The specific embodiments of the present invention will be further described below.

[0031] A plasma-assisted wet oxidation system for treating high-concentration wastewater includes an inclined plate sedimentation tank 2, a plunger pump 1, and a heat exchanger 9 connected in sequence. The heat exchanger 9 is connected to a plasma wet oxidation reaction tower 3 and a gas-liquid separator 10. The plasma wet oxidation reaction tower 3 is connected to an electric arc plasma torch 4, which is connected to a high-pressure air compressor system 5, a plasma power supply 6, a deionized water cooling tower 7, and a deionized water pump 8. The deionized water cooling tower 7 is connected to the deionized water pump 8. The gas-liquid separator 10 is connected to a liquid storage tank 11 and a deacidification tower 12. The deacidification tower 12 and an alkali tank 13 are also connected. Alkali circulation pumps 14 are connected in sequence; the plasma wet oxidation reaction tower 3 includes a reaction chamber 302, with a gas-liquid two-phase flow outlet 301 at the bottom of the reaction chamber 302, an arc plasma torch installation port 306 and a pressure port 308 at the top of the reaction chamber 302, and a high-concentration wastewater inlet 305 and a temperature port 309 on the side wall of the reaction chamber 302. The high-concentration wastewater inlets 305 are distributed in multiples on the circumference. The outer wall of the reaction chamber 302 is covered with heat insulation material 304. An electromagnetic heating coil 303 is wound around the outer wall of the heat insulation material 304, and the electromagnetic heating coil 303 is connected to a high-frequency heating power supply 307.

[0032] The plasma-assisted wet oxidation method for treating high-concentration wastewater includes two steps: startup and normal operation. During startup, the high-concentration wastewater undergoes chemical precipitation in an inclined plate sedimentation tank 2 to remove suspended solids. Then, it is pumped by a plunger pump 1 into the plasma wet oxidation reactor 3, and the pressure at the pressure port 308 in the reactor 3 is set to 1 MPa. The high-frequency heating power supply 307 is then activated to heat the temperature in the plasma wet oxidation reactor 3 to 160°C, maintaining the pressure at 1 MPa throughout this heating process. The process continues until the temperature in the plasma wet oxidation reactor 3 reaches... At 160℃, the axial flow fan on the deionized water cooling tower 7, the deionized water pump 8, and the high-pressure air compressor system 5 are started sequentially. One minute after the high-pressure air compressor system 5 starts, the plasma power supply 6 is started, causing the arc plasma torch 4 to convert air into plasma (including free electrons, metastable and excited state positive and negative oxygen particles, metastable and excited state positive and negative nitrogen particles, UV, and photons). When the temperature at inlet 309 of the plasma wet oxidation reaction tower 3 reaches 200℃, the temperature is maintained at 200℃ and the pressure at 1MPa for 5 minutes to complete the start-up process. After the start-up process is completed, normal operation begins. Normal operation refers to the high-concentration wastewater being processed according to... Figure 1 The process shown involves high-concentration wastewater being treated by a pretreatment unit and then by a plasma wet oxidation unit. Under the autocatalytic action of plasma active particles and the synergistic effect of wet oxidation, organic matter is degraded. The degraded gas-liquid two-phase material is then treated by a post-treatment unit before being discharged in compliance with standards.

[0033] The specific implementation process is as follows:

[0034] High-concentration wastewater enters the mixing chamber of inclined plate sedimentation tank 2, and reagents are added to the mixing chamber (the type of reagent varies depending on the suspended solids and heavy metal ions in the wastewater). The agitator is started for uniform mixing at a speed of 40-100 r / min. After uniform mixing, the wastewater enters the reaction chamber, where agitation is initiated to ensure thorough reaction between the reagents and wastewater. The agitator speed is 40-100 r / min, and the reaction time is 10-30 minutes. After thorough reaction, the wastewater enters the sedimentation separation chamber, which is equipped with inclined plates. The Reynolds number of the wastewater in the sedimentation separation chamber is less than 400, and the hydraulic load is 9-30 m. 3 / m 2The wastewater retention time is 20-40 minutes. The flocs formed by the wastewater and the reagents are separated in the inclined tube zone. The suspended solids and heavy metal precipitates fall to the bottom of the inclined tube zone under gravity and are scraped to the sludge zone by the scraper of the sludge scraper. Then, they are transported to the sludge tank by external force. The wastewater with suspended solids and heavy metals removed enters the water chamber and is pumped by the plunger pump 1 through the heat exchanger 9 (at this time, the heat exchanger 9 has no heat exchange function during the start-up stage) to the designated liquid level of the plasma wet oxidation reaction tower 3. The outlet valve of the gas-liquid two-phase flow outlet 301 of the plasma wet oxidation reaction tower 3 and the plunger pump 1 are closed. The high-frequency heating power supply 307 is started to heat the temperature in the plasma wet oxidation reaction tower 3 to 160°C. During this heating process, the pressure in the plasma wet oxidation reaction tower 3 is maintained at 1MPa. When the temperature in the plasma wet oxidation reaction tower 3 reaches 160℃, the axial flow fan on the deionized water cooling tower 7, the deionized water pump 8, and the high-pressure air compressor system 5 are started sequentially. After the high-pressure air compressor system 5 has been running for 1 minute, the plasma power supply 6 is started, causing the arc plasma torch 4 to convert air into plasma. When the temperature at the temperature port 309 of the plasma wet oxidation reaction tower 3 reaches 200℃, the temperature is maintained at 200℃ (with a deviation of 50℃), and the pressure is maintained at 1MPa for 5 minutes to complete the start-up process. During the start-up process, due to the operation of the arc plasma, the power of the high-frequency heating power supply 307 should be appropriately reduced to maintain the temperature in the plasma wet oxidation reaction tower 3 at 200℃. At this point, the start-up phase is complete.

[0035] After the start-up phase is completed, the normal operation phase begins. This involves opening the valve at the gas-liquid two-phase outlet 301 of the plasma wet oxidation reactor 3 and starting the plunger pump 1. High-concentration wastewater and added reagents are introduced into the mixing chamber of the inclined plate settling tank 2. Reagents are added to the mixing chamber (the amount of reagent varies depending on the suspended solids and heavy metal ions in the wastewater). The agitator is started for uniform mixing at a speed of 40-100 r / min. After uniform mixing, the mixture enters the reaction chamber, where agitation is resumed to ensure a thorough reaction between the reagents and wastewater. The agitator speed is 40-100 r / min, and the reaction time is 10-30 min. After the wastewater and reagents have fully reacted, it enters the settling separation chamber, which is equipped with inclined tubes. The Reynolds number of the wastewater in the settling separation chamber is less than 400, and the settling time is 9-30 m. 3 / m 2The wastewater retention time is 20-40 minutes. The flocs formed by the wastewater and the reagents are separated in the inclined tube zone. The suspended solids and heavy metals fall to the bottom of the inclined tube zone under gravity and are scraped to the sludge zone by the scraper of the sludge scraper. Then, they are transported to the sludge tank by external force. The wastewater with suspended solids and heavy metals removed enters the water chamber and is transported by the plunger pump 1 to the heat exchanger 9. After exchanging heat with the high-temperature liquid from the plasma wet oxidation reaction tower 3, it enters the plasma wet oxidation reaction tower 3 for COD degradation reaction. Wastewater, pressurized by plunger pump 1 and heated by heat exchanger 9, enters the feed spray nozzle of plasma wet oxidation tower 3, forming a mist within the tower. To prevent nozzle clogging, spiral nozzles are used, evenly arranged circumferentially, in multiples of 2 or 3. The nozzles are solid, with angles of 60° and 90°. The plasma torch uses air as the working gas, sourced from high-pressure air compressor system 5. The air pressure is 0.2 MPa higher than that of plasma wet oxidation tower 3. The air undergoes oil and dust removal before being fed into the arc plasma generator. Under the influence of the electric field generated by plasma power supply 6, the air ionizes oxygen and nitrogen in the air within the cavity of arc plasma torch 4, creating high-energy electrons, oxygen positive and negative particles, ozone, nitrogen positive and negative particles, ultraviolet light, and other active particles. The plasma containing these active particles exits the arc plasma torch 4. A plasma active zone is formed at the inlet; the plasma active particles react fully with the high-concentration wastewater, oxidizing COD into carbon dioxide, water, hydrogen chloride, sulfur dioxide, and nitrogen (nitrogen-containing organic matter); the reaction pressure of the plasma wet oxidation reactor 3 is 0.1-10 MPa, the temperature is 60-300℃, and the reaction time is 10-30 min; deionized water is used for plasma cooling. After heat exchange between the deionized water in the water chamber of the plasma torch and the arc channel of the plasma torch, the deionized water enters the deionized water cooling tower 7. After being cooled and heated by the air drawn in by the fan in the deionized water cooling tower 7, the deionized water is pumped into the arc plasma torch 4 by the deionized water pump 8. The wastewater is formed into a two-phase fluid of water and gas after passing through the plasma wet oxidation reactor 3. The two-phase fluid exchanges heat with the wastewater in the pretreatment unit through the heat exchanger 9 and then enters the post-treatment unit. After heat exchange with wastewater, the gas-liquid two-phase flow enters the gas-liquid separator 10 of the post-treatment unit for gas-liquid separation. The separated liquid enters the liquid storage tank 11 for discharge. The separated gas enters the deacidification tower 12, where alkaline solution is used to absorb the acidic gas in the gas. A certain concentration of alkaline solution stored in the alkaline solution tank 13 is neutralized and removed by the alkaline solution circulation pump 14. The deacidified gas is then discharged.

[0036] Example 1

[0037] The wastewater was treated to have a total cyanide concentration of 4500 mg / L and a COD concentration of 120580 mg / L. The treatment conditions were as follows: the inclined plate sedimentation tank 2 used PAC and PAM as reagents; the frequency of the medium frequency power supply was 4 kHz; the power of the electric arc plasma torch 4 was 100 kW; the pressure of the plasma wet oxidation reaction tower 3 was 1.2 MPa; the temperature was 220 ℃; and the reaction time was 20 min. Under these conditions, the COD in the effluent was 21 mg / L and the total cyanide concentration was 0.2 mg / L.

[0038] Example 2

[0039] The treatment process was designed for landfill leachate with a COD of 9200 mg / L and a color of 5000. The operating conditions were as follows: Inclined plate sedimentation tank 2 used PAC, PAM, Na2S, and Na2CO3 as reagents; the medium-frequency power supply was 3 kHz; the electric arc plasma torch 4 had a power of 50 kW; and the plasma wet oxidation reaction tower 3 operated at a pressure of 0.8 MPa, a temperature of 280℃, and a reaction time of 25 min. Under these conditions, the effluent from the treatment system had a COD of 15 mg / L and a color of 60.

[0040] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A system for treating high concentration wastewater by plasma synergic wet oxidation process, characterized in that, The wastewater system comprises a inclined plate sedimentation tank (2), the inclined plate sedimentation tank (2), a plunger pump (1) and a heat exchanger (9) are sequentially connected, the heat exchanger (9) is connected with a plasma wet oxidation reaction tower (3) and a gas-liquid separator (10) respectively, the plasma wet oxidation reaction tower (3) is connected with an electric arc plasma torch (4), the electric arc plasma torch (4) is connected with a high-pressure air compressor system (5), a plasma power supply (6), a deionized water cooling tower (7) and a deionized water pump (8) respectively, the deionized water cooling tower (7) is connected with the deionized water pump (8), the gas-liquid separator (10) is connected with a liquid storage tank (11) and a deacidification tower (12) respectively, the deacidification tower (12), a lye tank (13) and a lye circulating pump (14) are sequentially connected. The plasma wet oxidation reaction tower (3) comprises a reaction chamber (302), the reaction chamber (302) is provided with a gas-liquid two-phase flow outlet (301), a high-concentration wastewater inlet (305), an electric arc plasma torch mounting port (306), a pressure port (308) and a temperature port (309), and the outer wall of the reaction chamber (302) is coated with a heat insulation material (304); the outer wall of the heat insulation material (304) is wound with an electromagnetic heating coil (303).

2. The system for treating high concentration wastewater by plasma synergic wet oxidation process according to claim 1, wherein The bottom of the reaction chamber (302) is provided with the gas-liquid two-phase flow outlet (301), the top of the reaction chamber (302) is provided with the electric arc plasma torch mounting port (306) and the pressure port (308), and the sidewall of the reaction chamber (302) is provided with the high-concentration wastewater inlet (305) and the temperature port (309).

3. The system for treating high concentration wastewater by plasma synergic wet oxidation process according to claim 2, characterized in that, The high-concentration wastewater inlets (305) are arranged uniformly in the circumferential direction, and the number is a multiple of 2 or 3.

4. The system for treating high concentration wastewater by plasma synergic wet oxidation process according to claim 1, wherein The electromagnetic heating coil (303) is connected with a high-frequency heating power supply (307).

5. A method for treating high concentration wastewater by plasma in conjunction with wet oxidation, characterized by, The wastewater system has two steps of starting and normal operation; in the starting step, the high-concentration wastewater is first subjected to a dosing reaction and deposition to remove solid-phase suspended matters in the inclined plate sedimentation tank (2), and then is pumped into the plasma wet oxidation reaction tower (3) by the plunger pump (1), the pressure of the pressure port (308) in the plasma wet oxidation reaction tower (3) is 1MPa, the high-frequency heating power supply (307) is started, the temperature in the plasma wet oxidation reaction tower (3) is heated to 160℃, and the pressure in the plasma wet oxidation reaction tower (3) is kept at 1MPa during the heating process; when the temperature in the plasma wet oxidation reaction tower (3) reaches 160℃, the axial flow fan on the deionized water cooling tower (7), the deionized water pump (8) and the high-pressure air compressor system (5) are started in sequence; after the high-pressure air compressor system (5) is started for 1min, the plasma power supply (6) is started, the electric arc plasma torch (4) converts air into plasma, when the temperature of the temperature meter of the temperature port (309) of the plasma wet oxidation reaction tower (3) reaches 200℃, the temperature is kept at 200℃ and the pressure is kept at 1MPa for 5min, and the starting process is completed. After the start-up process is completed, the normal operation process is entered; the high-concentration wastewater is treated by the pretreatment unit, and then is treated by the plasma wet oxidation unit, and under the self-catalysis of the plasma active particles and the synergistic effect of the wet oxidation, the organic matters are degraded.

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