A wet oxidation method wastewater treatment system and method

Abstract

The application discloses a wet oxidation method wastewater treatment system and method, which comprises a multistage centrifugal pump, a preheater located downstream of the multistage centrifugal pump, a heater located downstream of the preheater, and a reactor located downstream of the heater. The rotation speed of the multistage centrifugal pump is far lower than 6600 rpm of a conventional high-speed pump, which can effectively reduce noise and vibration, delay the wear of a motor bearing, reduce equipment maintenance cost, and improve the stability and efficiency of the wet oxidation method. Meanwhile, the application adopts a tube heat exchanger, which reduces the explosion risk, improves the wastewater temperature, and greatly reduces the steam consumption of the subsequent heater. According to actual operation, 2.4 tons of 3.2 MPa steam can be saved per hour, and great economic benefits can be created per year. 3 The application adopts a Q235B and TA9 explosive clad plate reactor, and the comprehensive performance is better, and the long-term operation cost is greatly reduced.

Description

Technical Field

[0001] This invention belongs to the field of wastewater treatment technology, specifically relating to a wet oxidation wastewater treatment system and method. Background Technology

[0002] Currently, the high-pressure pumps used in traditional wet oxidation wastewater treatment processes are mostly high-speed pumps, often exceeding 6600 rpm. Due to this high speed, high-speed pumps exhibit significant noise and vibration during operation, and accelerate the wear and tear on the motor bearings. This not only increases the maintenance costs of the high-speed pump equipment but also negatively impacts the stability and efficiency of the process. Furthermore, high-speed pumps are ineffective when handling wastewater containing solid particles or with high viscosity, easily leading to clogging or wear. Therefore, for traditional wet oxidation wastewater treatment processes, there is an urgent need to find a more efficient, stable, and cost-effective solution for selecting high-pressure pumps.

[0003] A multistage centrifugal pump combines two or more centrifugal pumps with the same function. In terms of fluid channel structure, the pressure relief port of the first stage is connected to the inlet of the second stage, and the pressure relief port of the second stage is connected to the inlet of the third stage. This series connection forms a multistage centrifugal pump. A multistage centrifugal pump consists of multiple impellers connected in series, guide vanes (or volutes), a pump shaft, a balancing device (such as a balancing disc / drum), sealing rings, and a pump casing (segmented or split-case type). Each impeller is mounted on the same shaft, and as the liquid flows through each impeller stage sequentially, the energy is superimposed at each stage. Summary of the Invention

[0004] To improve the above-mentioned technical problems, the present invention provides a wet oxidation wastewater treatment system, which includes a multi-stage centrifugal pump;

[0005] A preheater located downstream of the multistage centrifugal pump;

[0006] The heater located downstream of the preheater;

[0007] and the reactor located downstream of the heater.

[0008] According to an embodiment of the present invention, the multistage centrifugal pump employs a 10-stage impeller.

[0009] In some embodiments, the motor of the multistage centrifugal pump is equipped with a frequency converter to regulate its speed. For example, the speed of the multistage centrifugal pump is 1400 to 2980 rpm, such as 1400 rpm, 1500 rpm, 1800 rpm, 2000 rpm, 2500 rpm, or 2980 rpm.

[0010] In some embodiments, the multistage centrifugal pump includes multistage impellers and a pump body. The pump body includes an inlet section, an outlet section, and a pump shaft. Five impellers are installed inside each of the inlet and outlet sections. All impellers are mounted on the pump shaft, and adjacent impellers are fixed with screws to prevent loosening. A baffle is provided between two adjacent impellers in the inlet and outlet sections. Along the wastewater flow direction, the fifth-stage impeller of the inlet section and the first-stage impeller of the outlet section are connected through a balance pipe.

[0011] In some implementations, the impellers of the intake and exhaust sections are oriented in opposite directions.

[0012] The wastewater, after being pressurized in the forward direction by the fifth stage impeller in the suction section, is then transported to the tail end impeller of the discharge section for further pressurization via a balance pipe (i.e., the pressurization method in the discharge section is opposite to the forward pressurization force in the suction section), and finally flows out from the fifth stage impeller in the discharge section.

[0013] In some implementations, the partition is provided with a reflux hole. The reflux hole on the partition between the discharge section and the suction section can solve the problem of equipment shutdown caused by outlet pressure in the discharge section (similar to a safety valve).

[0014] In some embodiments, the suction section is provided with a fluid inlet.

[0015] In some implementations, the discharge section is provided with a fluid outlet.

[0016] In some implementations, seals are provided at both ends of the pump shaft.

[0017] Existing multistage pumps are prone to damage due to excessive flow during use. The present invention addresses this by using a variable frequency drive to control the pump's output in a multistage centrifugal pump motor.

[0018] According to an embodiment of the present invention, the preheater is a shell-and-tube heat exchanger.

[0019] In some embodiments, the tube-side medium of the preheater is wastewater pressurized by a multi-stage centrifugal pump. For example, the wastewater includes 20% brine, 4000-5000 ppm organic matter, excess oxygen, a catalyst (preferably a copper-containing catalyst, exemplarily copper chloride), and hydrochloric acid.

[0020] In some embodiments, the shell-side medium of the preheater is derived from water obtained after the wet oxidation reaction in the reactor. For example, it may contain 20% brine, excess oxygen, a catalyst (preferably a copper-containing catalyst, exemplarily copper chloride), and hydrochloric acid.

[0021] In some embodiments, the preheater's tube-side medium inlet is located at the bottom of the tubes, and the tube-side medium outlet is located at the top of the tubes. By employing a low inlet and high outlet design, buoyancy is used to force oxygen to rise with the fluid and exit the tubes.

[0022] In some implementations, the preheater's tube side is a straight tube or a U-shaped tube. The absence of dead zones helps to ensure uniform flow velocity (turbulent flow) of the medium within the tubes, thus suppressing carbon buildup.

[0023] According to an embodiment of the present invention, the reactor uses a Q235B and TA9 explosion composite plate.

[0024] Explosive cladding is an advanced composite technology that utilizes the high-pressure shock wave generated by an explosive explosion to cause instantaneous plastic deformation and metallurgical bonding between two or more metal sheets. The instantaneous high pressure (up to tens of thousands of megapascals) and high-speed impact (1000–3000 m / s) generated by the explosive explosion cause the cladding metal (such as titanium or stainless steel) and the base metal (such as carbon steel) to collide at high speed within an extremely short time (microseconds). The intense plastic deformation at the collision interface generates heat (local temperatures can reach 30%–50% of the metal's melting point), forming a metallurgical bonding layer. During the collision, oxides and impurities on the metal surface are removed by the high-speed jet, forming a clean bonding surface. Under the action of the shock wave, the interface forms a periodic waveform structure (wavelength typically 0.1–2 mm), increasing the bonding area and improving shear resistance. Atomic diffusion and local micro-melting achieve metallurgical bonding at the interface, with a bonding strength approaching that of the base material.

[0025] According to an embodiment of the present invention, the reactor further includes components required for the catalytic wet oxidation reaction. These components include, but are not limited to, one or more selected from an inlet unit, an outlet unit, a feed unit, a discharge unit, and an instrumentation unit. Those skilled in the art will understand that when the reactor is equipped with the above-mentioned components, the components should not affect the airtightness of the reactor. For this purpose, the components can be connected to the reactor by welding, flanges, and / or piping. It should be understood that the structure and function of the components are known in the art. For example, the inlet unit and outlet unit can be used to introduce oxygen and / or air to enable the catalytic wet oxidation reaction. The feed unit can be used to introduce wastewater that needs to be treated, and the discharge unit can be used to discharge reaction products or undesirable residues. The instrumentation unit can be used to display or monitor the process parameters of the reactor.

[0026] In some implementations, the instrumentation unit includes a temperature sensor, a pressure sensor, an online TOC analyzer, an online pH meter, an online copper ion detector, and a level sensor. Preferably, the temperature sensor, pressure sensor, and level sensor are interlocked.

[0027] According to an embodiment of the present invention, the treatment system further includes a wastewater storage unit located upstream of the multi-stage centrifugal pump. For example, the wastewater storage unit is a wastewater tank.

[0028] According to an embodiment of the present invention, the processing system further includes a steam delivery unit located upstream of the heater, the steam delivery unit being connected to the heater.

[0029] According to an embodiment of the present invention, the processing system further includes a flash tank located downstream of the heater, the inlet of the flash tank being connected to the condensate outlet of the heater.

[0030] The present invention also provides a wastewater treatment method, comprising subjecting the wastewater to a catalytic wet oxidation reaction in the above-mentioned treatment system to achieve wastewater purification.

[0031] According to an embodiment of the present invention, the wastewater is pressurized by a multi-stage centrifugal pump and then transported to a preheater. For example, the wastewater includes 20% brine, 4000-5000 ppm organic matter, excess oxygen, a catalyst (preferably a copper-containing catalyst, exemplarily copper chloride), and hydrochloric acid.

[0032] According to an embodiment of the present invention, the speed of the multistage centrifugal pump is 1400 to 2980 rpm, for example 1400 rpm, 1500 rpm, 1800 rpm, 2000 rpm, 2500 rpm or 2980 rpm.

[0033] According to an embodiment of the present invention, the method includes pressurizing the wastewater in the wastewater storage unit through a multi-stage centrifugal pump and then transporting it to a preheater for preheating, then heating it in a heater, and then entering a reactor for catalytic wet oxidation reaction to achieve wastewater purification.

[0034] According to an embodiment of the present invention, the operating temperature of the reactor is between 150-300°C, for example 150°C, 180°C, 200°C, 220°C, 240°C, 270°C, 280°C or 300°C, and the pressure of the reactor is between 4 and 7 MPa.

[0035] According to an embodiment of the present invention, during the catalytic wet oxidation reaction, the pH value of the wastewater is between 0.8 and 1.4, for example 0.8, 0.9, 1.0, 1.1, 1.2, 1.3 or 1.4.

[0036] According to an embodiment of the present invention, the catalyst used in the catalytic wet oxidation reaction can be any catalyst known in the art for use in catalytic wet oxidation methods, preferably a copper-containing catalyst. For example, the copper ion content is between 1000-3000 ppm.

[0037] The beneficial effects of this invention:

[0038] (1) This invention applies a multi-stage centrifugal pump (preferably with a 10-stage impeller and a rotational speed set at 1400–2980 rpm) to a wet oxidation wastewater treatment process. The rotational speed of this multi-stage centrifugal pump is significantly lower than the 6600 rpm or higher of traditional high-speed pumps. By reducing the rotational speed, noise and vibration can be effectively reduced, while simultaneously delaying the wear of motor bearings, thereby lowering equipment maintenance costs. The multi-stage centrifugal pump of this invention can improve the stability and efficiency of the wet oxidation process. In practical applications, the multi-stage centrifugal pump of this invention not only performs excellently in treating wastewater containing solid particles and high viscosity, but also maintains stable performance and low maintenance requirements during long-term operation. Compared with traditional high-speed pumps, the multi-stage centrifugal pump of this invention has significant advantages in reducing energy consumption and extending service life.

[0039] (2) This invention employs a shell-and-tube heat exchanger. The tube-side medium is wastewater pressurized by a multi-stage centrifugal pump, while the shell-side medium comes from water obtained after the wet oxidation reaction in the reactor. The tube side adopts a low inlet (bottom) and high outlet (top) layout, utilizing buoyancy to promote oxygen to rise with the fluid and exit the tube side. The tube side consists of straight / U-shaped tubes, eliminating dead zones and ensuring uniform flow velocity (turbulent flow), thus suppressing carbon buildup. The preheater of this invention reduces the risk of explosion, increases the wastewater temperature, and significantly reduces the steam consumption of subsequent heaters. Based on actual operation, every 20m³ of steam is used. 3 Wastewater treatment can save 2.4 tons of 3.2MPa steam per hour, generating huge economic benefits annually.

[0040] (3) The present invention uses Q235B and TA9 explosion composite plate reactor. Compared with traditional loose-lined plate reactor, the pressure resistance life of the explosion composite plate of the present invention can reach up to 100,000 hours under the working conditions of 6.6MPa and 280℃. It has high weld strength (weld strength retention rate ≥90%), strong resistance to thermal fatigue (interface strength up to 200-400MPa (shear)), better overall performance, and significantly reduced long-term operating costs. Attached Figure Description

[0041] Figure 1 This is a schematic diagram of the structure of a wet oxidation wastewater treatment system according to the present invention;

[0042] Figure 2 This is a schematic diagram of a multistage centrifugal pump.

[0043] In the diagram: 1. Wastewater storage unit; 2. Multistage centrifugal pump; 201. Pump body; 202. Impeller; 203. Pump shaft; 204. Bearing housing; 205. Seal; 206. Fluid inlet; 207. Fluid outlet; 208. Balance pipe; 209. Reflux hole; 3. Preheater; 4. Heater; 5. Reactor; 6. Steam delivery unit; 7. Flash tank. Detailed Implementation

[0044] The technical solution of the present invention will be further described in detail below with reference to specific embodiments. It should be understood that the following embodiments are merely illustrative and explanatory of the present invention, and should not be construed as limiting the scope of protection of the present invention. All technologies implemented based on the above content of the present invention are covered within the scope of protection intended by the present invention.

[0045] Unless otherwise stated, the raw materials and reagents used in the following examples are commercially available products or can be prepared by known methods.

[0046] Example 1

[0047] Reference Figure 1 A wet oxidation wastewater treatment system, comprising a multi-stage centrifugal pump 2;

[0048] Preheater 3 is located downstream of multistage centrifugal pump 2;

[0049] Heater 4 is located downstream of preheater 3;

[0050] And reactor 5, located downstream of heater 4.

[0051] Multistage centrifugal pump

[0052] The multistage centrifugal pump 2 uses a 10-stage impeller 202, and the motor of the multistage centrifugal pump 2 is equipped with a frequency converter to regulate the speed. For example, the speed of the multistage centrifugal pump 2 is 2980 rpm.

[0053] The multistage centrifugal pump 2 includes multistage impellers 202 and a pump body 201. The pump body 201 includes a suction section, a discharge section, and a pump shaft 203. Five impellers 202 are installed inside the suction section and the discharge section. All impellers 202 are mounted on the pump shaft 203. Adjacent impellers 202 are fixed with screws to prevent loosening. A baffle is provided between two adjacent impellers 202 in the suction section and the discharge section. A return hole 209 is provided on the baffle. Along the wastewater flow direction, the fifth stage impeller 202 in the suction section and the first stage impeller 202 in the discharge section are connected through a balance pipe 208.

[0054] The impellers 202 in the suction section and the discharge section are in opposite directions.

[0055] Wastewater, pressurized in the forward direction by the fifth-stage impeller 202 in the suction section, is then transported via the balance pipe 208 to the tail-end impeller in the discharge section for further pressurization (i.e., the pressurization method in the discharge section is opposite to the forward pressurization force in the suction section), and finally flows out from the fifth-stage impeller 202 in the discharge section. A return flow hole 209 is located on the partition between the discharge and suction sections, which can be used to solve the problem of equipment shutdown caused by pressure buildup at the discharge outlet (similar to a safety valve).

[0056] The suction section is provided with a fluid inlet 206, and the discharge section is provided with a fluid outlet 207.

[0057] Seals 205 are provided at both ends of the pump shaft 203.

[0058] [Preheater]

[0059] Preheater 3 uses a shell-and-tube heat exchanger (double tube pass, double shell pass, fixed tube sheet heat exchanger) manufactured by Senmatsu (Jiangsu) Heavy Industry Co., Ltd.

[0060] The tube-side medium of the preheater 3 is wastewater pressurized by the multi-stage centrifugal pump 2. For example, the wastewater includes 20% brine, 4000-5000 ppm organic matter, excess oxygen, catalyst (preferably a copper-containing catalyst, exemplarily copper chloride), and hydrochloric acid.

[0061] The shell-side medium of preheater 3 comes from water obtained after the wet oxidation reaction in the reactor. For example, it contains 20% brine, excess oxygen, a catalyst (preferably a copper-containing catalyst, exemplarily copper chloride), and hydrochloric acid.

[0062] The tube-side medium inlet of preheater 3 is located at the bottom of the tubes, and the tube-side medium outlet is located at the top of the tubes. By adopting a low inlet and high outlet design, the buoyancy effect is used to make oxygen rise with the fluid and be discharged from the tubes.

[0063] The tubes of preheater 3 are either straight or U-shaped. This eliminates dead zones and helps ensure uniform flow velocity (turbulent flow) of the medium within the tubes, thus suppressing carbon buildup.

[0064] Reactor

[0065] Reactor 5 uses an explosion-proof composite plate made of Q235B and TA9 materials, manufactured by Senmatsu (Jiangsu) Heavy Industry Co., Ltd.

[0066] Reactor 5 also includes components required for the catalytic wet oxidation reaction. These components include, but are not limited to, one or more selected from an inlet unit, an outlet unit, a feed unit, a discharge unit, and an instrumentation unit. When the reactor is equipped with the above-mentioned components, the components can be connected to the reactor via welding, flanges, and / or piping. It should be understood that the structure and function of these components are known in the art.

[0067] The intake and exhaust units can be used to introduce oxygen and / or air to enable the catalytic wet oxidation reaction.

[0068] The feeding unit can be used to introduce wastewater that needs to be treated, and the discharging unit can be used to discharge reaction products or unwanted residues.

[0069] The instrumentation unit can be used to display or monitor the process parameters of the reactor.

[0070] Instrumentation Unit

[0071] The instrument unit includes a temperature sensor, a pressure sensor, an online TOC analyzer, an online pH meter, an online copper ion detector, and a liquid level sensor. Preferably, the temperature sensor, pressure sensor, and liquid level sensor are interlocked.

[0072] The treatment system also includes a wastewater storage unit 1 located upstream of the multi-stage centrifugal pump 3. For example, the wastewater storage unit 1 is a wastewater tank.

[0073] The processing system also includes a steam delivery unit 6 located upstream of the heater 4, which is connected to the heater 4.

[0074] The processing system also includes a flash tank 7 located downstream of heater 4, with its inlet connected to the condensate outlet of heater 4. The condensate from heater 4 enters flash tank 7, which produces 0.2 MPa steam as a byproduct.

[0075] Example 2

[0076] A wastewater treatment method includes, in the treatment system of Example 1, pressurizing wastewater (including 20% ​​brine, 4000-5000 ppm organic matter, excess oxygen, copper chloride catalyst, and hydrochloric acid, etc.) through a multi-stage centrifugal pump 2 (10-stage impeller, speed set at 2980 rpm) and conveying it at a flow rate of 24 t / h to a preheater 3 (the heat exchange tubes of the preheater are straight tubes, 19.05 mm × 2.11 mm × 8500 mm) to preheat it to 180°C, then entering a heater 4 to be heated to 210°C, and then entering a reactor 5 (manufactured by Senmatsu (Jiangsu) Heavy Industry Co., Ltd., made of Q235B and TA9 explosion composite plate, reaction temperature 260°C, time 4 h, pressure 4.3 MPa) for catalytic wet oxidation reaction to achieve wastewater purification.

[0077] The wastewater treatment system was put into operation in November 2021. An internal inspection of reactor 5 was conducted in June 2022, and no abnormalities were found; it was operating well. A second internal inspection of reactor 5 was conducted in May 2023, and again, no abnormalities were found; it was operating well. As of May 2025, reactor 5 of this treatment system has not experienced any weld tears or other abnormalities.

[0078] Comparative Example 1

[0079] A wastewater treatment method, compared with Example 2, differs only in that the multi-stage centrifugal pump 2 is replaced with a vertical two-stage high-speed pump with a head of 485m and a flow rate of 27m³ / h. 3 The motor has a power of 120kw and a rated speed of 8076rpm.

[0080] Everything else is the same as in Example 2.

[0081] Comparative Example 2

[0082] A wastewater treatment method, compared to Example 2, differs only in that the shell-and-tube preheater 3 is replaced with a plate-and-shell heat exchanger manufactured by Vadrus of Finland. Wherein:

[0083] The design pressure is 6.6 MPa and the temperature is 270℃.

[0084] Structure type:

[0085] The plate side medium is wastewater pressurized by a multi-stage centrifugal pump (20% brine, 4000-5000 ppm organic matter, excess oxygen, copper chloride, hydrochloric acid, etc.); the shell side medium is water after the oxidation reactor reaction is completed (20% brine, excess oxygen, copper chloride, hydrochloric acid, etc.).

[0086] Everything else is the same as in Example 2.

[0087] In this comparative example, the plate-side medium is wastewater containing organic matter. The introduction of high-pressure pure oxygen poses a risk of explosion due to the potential for localized oxygen accumulation and reaction with organic matter. Furthermore, the complex flow channels of the plate-shell heat exchanger and the corrugated structure of the plates create numerous dead zones, allowing oxygen to accumulate in localized areas (such as plate edges or corrugation troughs), forming an explosive gas mixture. Simultaneously, the uneven flow velocity distribution along the plate side results in oxygen concentrations reaching 10-15% in low-velocity regions (the lower explosive limit is typically 5-8%). High-temperature decomposition of organic matter leads to carbon buildup and blockage along the plates. Because the plates are fully welded together, mechanical cleaning is impossible, severely impacting heat exchange efficiency. Moreover, blockage necessitates increasing the steam output. Based on actual operating data, the heat exchanger temperature rise after blockage drops from the initial 110℃ to 40℃. Therefore, to ensure effective wastewater treatment, the subsequent heaters must increase their steam output, requiring an additional 2.4 tons of 3.2MPa steam per hour (calculated based on a wastewater treatment capacity of 24 tons / hour).

[0088] Comparative Example 3

[0089] A wastewater treatment method, which differs from Example 2 only in that the Q235B and TA9 explosion composite plate (produced by Senmatsu (Jiangsu) Heavy Industry Co., Ltd.) of reactor 5 is replaced with a loose lining plate (loose lining structure (Q235B+TA9)).

[0090] Everything else is the same as in Example 2.

[0091] The following table shows the problems that occurred in the oxidation reactor of this treatment system during the period of operation from April 2017 to April 2021:

[0092] time Oxidation reactor problem description April 2017 During the initial hydrostatic test, the weld at the cone corner of the upper head tore. June 2017 During the second hydrostatic test, the weld at the cone corner of the upper head tore. November 2018 Initial hot-state test revealed point leakage at the T-weld of the upper head. December 2018 The second hot test revealed a banded leak in the butt weld of the upper head. September 2019 After one week of formal material feeding and operation, the longitudinal weld in the middle section tore. February 2020 A through-crack was found in the fillet weld between the fourth-level tray support and the cylinder. June 1, 2020 A total of 15 cracks were detected at the weld, including 2 through cracks. September 8, 2020 There were a total of 4 defects in the weld, including 2 through cracks. November 2020 A total of 12 cracks were detected at the weld, including 8 through cracks. April 2021 A total of 9 cracks were detected at the weld, including 3 through cracks.

[0093] The embodiments of the present invention have been described above. However, the present invention is not limited to the above embodiments. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for wastewater treatment, characterized in that, The method includes a wet oxidation wastewater treatment system in which wastewater in a wastewater storage unit is pressurized by a multi-stage centrifugal pump and then transported to a preheater for preheating, then enters a heater for heating, and then enters a reactor for catalytic wet oxidation reaction to achieve wastewater purification. The wet oxidation wastewater treatment system includes multi-stage centrifugal pumps; A preheater located downstream of the multistage centrifugal pump; The heater located downstream of the preheater; and a reactor located downstream of the heater; the reactor uses Q235B and TA9 explosion-proof composite plates; The multistage centrifugal pump uses a 10-stage impeller; The motor of the multi-stage centrifugal pump is equipped with a frequency converter to regulate its speed; The speed of the multistage centrifugal pump is 1400~2980 rpm; The multistage centrifugal pump includes multiple impellers and a pump body. The pump body includes a suction section, a discharge section, and a pump shaft. Five impellers are installed inside each of the suction and discharge sections. All impellers are mounted on the pump shaft, and adjacent impellers are fixed with screws to prevent loosening. A baffle is provided between two adjacent impellers in the suction and discharge sections. Along the wastewater flow direction, the fifth-stage impeller of the suction section and the first-stage impeller of the discharge section are connected through a balance pipe. The impellers in the suction section and the discharge section are oriented in opposite directions; The partition plate is provided with reflux holes; The suction section is provided with a fluid inlet; The discharge section is equipped with a fluid outlet; The pump shaft is equipped with seals at both ends; The tube-side medium of the preheater is wastewater pressurized by a multi-stage centrifugal pump. The shell-side medium of the preheater comes from the water obtained after the wet oxidation reaction in the reactor is completed; The tube-side medium inlet of the preheater is located at the bottom of the tubes, and the tube-side medium outlet is located at the top of the tubes. The tubes of the preheater are either straight or U-shaped.

2. The method as described in claim 1, characterized in that, The water after the wet oxidation reaction in the reactor contains 20% brine, excess oxygen, catalyst, and hydrochloric acid.

3. The method as described in claim 2, characterized in that, The catalyst is a copper ion-containing catalyst.

4. The method according to any one of claims 1-3, characterized in that, The reactor also includes components required for the catalytic wet oxidation reaction; the components include, but are not limited to, one or more selected from the following: an air inlet unit, an air outlet unit, a feed unit, a discharge unit, and an instrumentation unit.

5. The method according to any one of claims 1-3, characterized in that, The treatment system also includes a wastewater storage unit located upstream of the multi-stage centrifugal pump.

6. The method according to any one of claims 1-3, characterized in that, The processing system also includes a steam delivery unit located upstream of the heater, the steam delivery unit being connected to the heater.

7. The method according to any one of claims 1-3, characterized in that, The processing system also includes a flash tank located downstream of the heater, the inlet of which is connected to the condensate outlet of the heater.

8. The method as described in claim 1, characterized in that, The reactor operates at a temperature between 150-300℃ and a pressure between 4 and 7 MPa. And / or, during the catalytic wet oxidation reaction, the pH value of the wastewater is between 0.8 and 1.4; And / or, the catalyst used in the catalytic wet oxidation reaction is a copper-containing catalyst with a copper ion content between 1000-3000 ppm.

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