Micro-nano ozone oxidation high-salinity wastewater treatment system and treatment method thereof

Abstract

The invention relates to a micro-nano ozone oxidation high-salinity wastewater treatment system and a treatment method thereof. The system comprises an oxygen supply system, an ozone generator, a gas-liquid mixing pump, a wastewater system, a dissolved air tank, a micro-nano bubble generator and a catalytic reaction tank, the gas-liquid mixing pump mixes and pressurizes the salt-containing wastewater and ozone and then sends the mixture into the dissolved air tank, and the ozone reacts with the salt-containing wastewater in the dissolved air tank to remove COD in the wastewater; the mixed medium in the dissolved air tank passes through the micro-nano bubble generator to form micro-nano bubbles, the micro-nano bubbles enter the catalytic reaction tank, the catalytic filler reacts with the salt-containing wastewater to further remove COD in the wastewater, and produced water formed by the reaction in the catalytic reaction tank enters the produced water tank. Three modes of gas-liquid two-phase annular flow, gas-liquid mixing pump high-pressure dissolved gas and micro-nano bubble generator mechanical cutting are combined to form a micro-nano ozone oxidation system which is large in number, small in bubble average diameter, large in gas-liquid contact area and good in apparent mass transfer.

Description

Technical Field

[0001] The present invention relates to the field of environmental protection, and in particular to a micro-nano ozone oxidation high-salt wastewater treatment system and a treatment method thereof. Background Art

[0002] In recent years, with the popularization of water resource recycling and zero wastewater discharge in various industries, the problem of removing organic pollutants (measured in COD, Chemical Oxygen Demand) in highly concentrated brine environments has become increasingly prominent. For example, coking wastewater, coal chemical wastewater, pharmaceutical wastewater, and electroplating wastewater often use biochemical treatment at the front end. The middle stage uses a double membrane method to treat the biochemical produced water and then reuse the recycled water. The back end uses a multi-stage membrane concentration method to repeatedly concentrate and separate the membrane concentrate in the recycled water. The clear liquid is reused again, and the high-salt membrane concentrate is evaporated, crystallized, or dried to achieve full water resource reuse and near-zero wastewater discharge.

[0003] In the above process, although the COD of the biochemical effluent meets the relevant standards and requirements, its concentration value varies according to different industries, but usually does not exceed 80 mg / L. However, with the double membrane concentration in the reclaimed water reuse system and the multiple concentration of the membrane concentrate for reclaimed water reuse, the COD value in the high-salt concentrate often exceeds 1000 mg / L. On the one hand, it has a great impact on the quality of the salt output of subsequent evaporation and crystallization, affecting the whiteness and purity of the product salt; on the other hand, it also has a great impact on the water quality of the evaporation condensate. Some volatile COD will be converted into secondary steam at high temperature and enter the condensate, affecting the water quality of the condensate, making it impossible to directly reuse water resources.

[0004] In order to solve the problem of COD in highly concentrated brine, the current mainstream treatment methods include Fenton oxidation, activated carbon adsorption, resin adsorption, electrochemical oxidation, and ozone oxidation. Among them, the Fenton oxidation method will introduce ferrous salts and sulfate ions, which is equivalent to introducing other impurities for the recovery of non-sulfate wastewater, resulting in affected salt recovery quality; the adsorption capacity of the activated carbon adsorption method is limited, and the activated carbon is frequently replaced. At the same time, in a high-salt environment, it is easy to cause the activated carbon to become compacted and fail quickly, and its processing cost is high. After replacement, the activated carbon is classified as hazardous waste, and its disposal cost is high; the resin adsorption method is mainly effective in removing low-concentration COD. Under high-concentration COD and high-salt environments, the resin adsorption capacity is limited, and its desorption and regeneration waste liquid still needs to be treated. It is essentially a physical removal. Removal rather than complete mineralization; electrochemical oxidation often has better effects under conditions of high-salt wastewater, however, the problems of plate scaling, plate corrosion, and hydrogen and oxygen evolution cannot be solved, and when the COD concentration is high, its power consumption is also extremely high; ozone oxidation method has been widely used, but in high-salt systems, ordinary ozone is often not effective. It is usually combined with high-efficiency catalysts for catalysis at different catalytic sites. However, the mass transfer efficiency and effective utilization rate of ozone are often not good, resulting in insufficient COD removal effect, and the remaining ozone is often removed by exhaust gas destruction, and the ozone is not fully utilized. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the shortcomings of the existing technology and provide a micro-nano ozone oxidation high-salt wastewater treatment system and a treatment method thereof, so as to solve the technical problem that the mass transfer efficiency and effective utilization rate of ozone in the current process of using ozone to treat high-salt wastewater are not high, resulting in insufficient COD removal effect.

[0006] The technical solution adopted by the present invention to solve its technical problem is:

[0007] First aspect:

[0008] Provided is a micro-nano ozone oxidation high-salt wastewater treatment system, including

[0009] Oxygen supply system, ozone generator, gas-liquid mixing pump, wastewater system, dissolved air tank, micro-nano bubble generator and catalytic reaction tank;

[0010] The oxygen supply system is connected to the ozone generator to supply oxygen to the ozone generator. The wastewater system and the ozone generator are both connected to a gas-liquid mixing pump, which is connected to a dissolving tank. The tail gas generated by the reaction is discharged from the top of the catalytic reaction tank. The gas-liquid mixing pump mixes the salt-containing wastewater and ozone and then pressurizes them and sends them to the dissolving tank. The ozone reacts with the salt-containing wastewater in the dissolving tank to remove COD in the wastewater.

[0011] The inlet of the micro-nano bubble generator is connected to the air dissolving tank, and the outlet thereof is connected to the catalytic reaction tank. The catalytic reaction tank is connected to the pH adjustment device and the water production tank. A catalytic filler is provided in the catalytic reaction tank, and the tail gas generated by the reaction is discharged from the top of the catalytic reaction tank. The mixed medium in the air dissolving tank passes through the micro-nano bubble generator to form micro-nano bubbles and then enters the catalytic reaction tank. The catalytic filler reacts with the salt-containing wastewater to further remove COD in the wastewater. The produced water formed by the reaction in the catalytic reaction tank enters the water production tank.

[0012] Furthermore, the height of the catalytic reaction tank is 3 to 8 meters, wherein the volume of the catalytic filler accounts for 1 / 3 to 1 / 2 of the volume of the entire reaction tank.

[0013] Furthermore, the oxygen supply system includes an air compressor, a cold dryer and an oxygen generator. The inlet of the cold dryer is connected to the air compressor, and the outlet is connected to the oxygen generator, and the oxygen generator is connected to the ozone generator.

[0014] Furthermore, the oxygen supply system includes a liquid oxygen storage tank and a pressurized gasification device, wherein the inlet of the pressurized gasification device is connected to the liquid oxygen storage tank, and the outlet thereof is connected to the ozone generator.

[0015] Furthermore, the gas dissolving tank and the catalytic reaction tank are both connected to an exhaust gas collecting device, and the exhaust gas collecting device is connected to an aerobic tank of the biochemical system.

[0016] Furthermore, the ozone generator is connected to a heat exchanger, and the heat exchanger is connected to a cooling device.

[0017] Second aspect:

[0018] A method for treating high-salt wastewater is provided, which uses the above-mentioned micro-nano ozone oxidation high-salt wastewater treatment system. The process is as follows:

[0019] Oxygen is supplied to the ozone generator through the oxygen supply system. The pressure of the oxygen source received by the ozone generator is 0.4-0.7 MPa, and the ozone concentration range produced is 80-220 mg / L;

[0020] The ozone and salt-containing wastewater from the wastewater system are mixed and pressurized with water and gas through a gas-liquid mixing pump and then enter the dissolved air tank. The pressure in the dissolved air tank is 0.3-0.4MPa, and the COD removal rate in the dissolved air tank is 30-60%.

[0021] The mixed medium in the dissolved air tank enters the micro-nano bubble generator, and the wastewater forms micro-nano bubbles with a bubble size of 40 to 60 μm. Then it enters the catalytic reaction tank from the bottom. After passing through the catalytic reaction tank, the salt-containing wastewater enters the water production tank, and the color is completely removed. The overall COD removal rate reaches more than 75%.

[0022] Furthermore, the tail gas generated by the gas dissolving tank and the catalytic reaction tank during operation is collected by the tail gas collecting device and then enters the aerobic tank of the biochemical system.

[0023] The beneficial effects of the present invention are:

[0024] 1. The present invention combines three methods: gas-liquid two-phase annular flow, high-pressure dissolved gas in a gas-liquid mixing pump, and mechanical cutting by a micro-nano bubble generator to form a micro-nano ozone oxidation system with a large number of bubbles, a small average bubble diameter, a large gas-liquid contact area, and good apparent mass transfer.

[0025] 2. There are two sources of oxygen in the present invention. One is the oxygen source obtained by removing water and impurities from air and passing it through an oxygen generator. The other is the oxygen source obtained by vaporizing liquid oxygen. The variety of oxygen sources allows the system to be used in different regions and occasions.

[0026] 3. The ozone and high-salt wastewater in the present invention can both be adjusted in flow and flow rate through their respective regulating valves. In order to better form micro-nano bubbles, the optimal ozone flow rate and wastewater flow rate are explored;

[0027] 4. In order to effectively ensure the gas-liquid contact time and mass transfer efficiency, the catalytic reaction tank is 3 to 8 meters high. The catalyst volume accounts for 1 / 3 to 1 / 2 of the entire reaction tank volume. The reaction tank is also equipped with an acid-base adjustment device to ensure that all organic pollutants can be oxidized under the most appropriate pH conditions.

[0028] 5. The ozone tail gas involved in the present invention is collected and used to supplement the dissolved oxygen in the aerobic tank in the front-end biochemical system. Through interlocking control, it replaces or partially replaces the operation of the aeration fan in the aerobic tank, effectively reducing the energy consumption of the aeration fan in the aerobic tank, while fully utilizing the ozone and avoiding air pollution. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The present invention will be further described below with reference to the accompanying drawings.

[0030] Figure 1 This is a diagram of the micro-nano ozone oxidation high-salt wastewater treatment system of the present invention; DETAILED DESCRIPTION

[0031] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0032] The present application provides a micro-nano ozone oxidation high-salt wastewater treatment system, which is described in detail below. It should be noted that the description order of the following embodiments does not limit the preferred order of the embodiments of this application. In the following embodiments, the description of each embodiment has its own emphasis. For parts not described in detail in a certain embodiment, please refer to the relevant description of other embodiments.

[0033] In order to solve the technical problem in the prior art of using ozone to treat high-salt wastewater, that is, the mass transfer efficiency and effective utilization rate of ozone are not high, resulting in insufficient COD removal effect, an embodiment of the present application provides a micro-nano ozone oxidation high-salt wastewater treatment system, which is described in detail below.

[0034] like Figure 1 As shown, a micro-nano ozone oxidation high-salt wastewater treatment system includes

[0035] Oxygen supply system, ozone generator, gas-liquid mixing pump, wastewater system, dissolved air tank, micro-nano bubble generator and catalytic reaction tank;

[0036] The oxygen supply system is connected to the ozone generator to supply oxygen to the ozone generator. The wastewater system and the ozone generator are both connected to a gas-liquid mixing pump, which is connected to a dissolving tank. The tail gas generated by the reaction is discharged from the top of the catalytic reaction tank. The gas-liquid mixing pump mixes the salt-containing wastewater and ozone and then pressurizes them and sends them to the dissolving tank. The ozone reacts with the salt-containing wastewater in the dissolving tank to remove COD in the wastewater.

[0037] The inlet of the micro-nano bubble generator is connected to the air dissolving tank, and the outlet thereof is connected to the catalytic reaction tank. The catalytic reaction tank is connected to the pH adjustment device and the water production tank. A catalytic filler is provided in the catalytic reaction tank, and the tail gas generated by the reaction is discharged from the top of the catalytic reaction tank. The mixed medium in the air dissolving tank passes through the micro-nano bubble generator to form micro-nano bubbles and then enters the catalytic reaction tank. The catalytic filler reacts with the salt-containing wastewater to further remove COD in the wastewater. The produced water formed by the reaction in the catalytic reaction tank enters the water production tank.

[0038] Specifically, as an optional implementation of the catalytic reaction tank in this embodiment, the height of the catalytic reaction tank is 3 to 8 meters, wherein the volume of the catalytic filler accounts for 1 / 3 to 1 / 2 of the volume of the entire reaction tank.

[0039] Specifically, as an optional implementation of the oxygen supply system in this embodiment, the oxygen supply system includes an air compressor, a cold dryer and an oxygen generator. The inlet of the cold dryer is connected to the air compressor, and the outlet is connected to the oxygen generator. The oxygen generator is connected to an ozone generator.

[0040] The oxygen supply system is provided by an air compressor with a pressure of 0.4~0.8MPa. After the compressed air passes through the cold-drying impurity removal equipment, the condensed water and impurities in the air are removed and then enters the oxygen concentrator. The oxygen pressure output by the oxygen concentrator is 0.3~0.6MPa, and the oxygen purity is 90%~95%, and then enters the ozone generator.

[0041] Specifically, as another optional implementation of the oxygen supply system in this embodiment, the oxygen supply system includes a liquid oxygen storage tank and a pressurized gasification device, wherein the inlet of the pressurized gasification device is connected to the liquid oxygen storage tank, and the outlet thereof is connected to the ozone generator.

[0042] The oxygen supply system is stored in liquid oxygen tanks with a pressure of 0.8 to 1.6 MPa. A pressurized gasification device is provided at the outlet of the liquid oxygen tank. For southern regions with higher ambient temperatures, air heating gasification is used. For northern regions with lower ambient temperatures, electric heating gasification is used. The oxygen is converted into gas and then enters the ozone generator.

[0043] Specifically, as an optional implementation in this embodiment, the gas dissolving tank and the catalytic reaction tank are both connected to a tail gas collection device, and the tail gas collection device is connected to an aerobic tank of the biochemical system.

[0044] In this embodiment, the ozone generator is connected to a heat exchanger, which is in turn connected to a cooling device. The cooling device can be a water chiller or other cooling method, such as air cooling in northern China. The heat exchanger and cooling device ensure that the operating temperature of the ozone generator is controlled within 40°C.

[0045] Specifically, as an optional implementation in this embodiment, the ozone generator outlet is equipped with an ozone concentration detector, a gas flow meter and a regulating valve, and the ozone flow rate and flow rate entering the gas-liquid mixing pump are adjusted by the regulating valve;

[0046] The outlet of the wastewater delivery pump of the wastewater system is equipped with a liquid flow meter and a regulating valve, and the liquid flow and flow rate entering the gas-liquid mixing pump are regulated by the regulating valve.

[0047] Specifically, as an optional implementation scheme in this embodiment, the gas-liquid mixing pump adopts a jet pump or a booster pump, the flow rate of water entering the jet pump / boost pump is 1.0m / s~2.5m / s, and the flow rate of ozone gas entering the jet pump / boost pump is 14m / s~25m / s.

[0048] In this embodiment, an exhaust valve and a pressure sensor interlock are provided on the top of the dissolved air tank. When the pressure exceeds the rated pressure, the exhaust valve automatically opens, and the exhausted gas is collected by the exhaust gas collection device and enters the aerobic tank of the biochemical system. On the one hand, it can provide aerobic microorganisms with a sufficient concentration of oxygen, saving the energy consumption of the fan of the aerobic biochemical system. On the other hand, it can ensure that the generated ozone exhaust does not affect the ambient air.

[0049] In this embodiment, the catalytic filler is an ozone catalyst, which can be directly purchased from the market.

[0050] In this system, low-pressure salt wastewater conveying pipes are made of PE / UPVC / CPVC / PP, etc. The gas-liquid mixed medium pipeline after the jet pump or booster pump adopts corrosion-resistant pressure pipes such as 316L / duplex stainless steel / titanium, and the dissolved air tank and catalytic reaction tower are corrosion-resistant pressure tanks such as 316L / duplex stainless steel / titanium.

[0051] Another embodiment of the present application provides a method for treating high-salt wastewater, which is described in detail below.

[0052] A method for treating high-salt wastewater, using the above-mentioned micro-nano ozone oxidation high-salt wastewater treatment system, the process is as follows:

[0053] Oxygen is supplied to the ozone generator through the oxygen supply system. The pressure of the oxygen source received by the ozone generator is 0.4-0.7 MPa, and the ozone concentration range produced is 80-220 mg / L;

[0054] The ozone and salt-containing wastewater from the wastewater system are mixed and pressurized with water and gas through a gas-liquid mixing pump and then enter the dissolved air tank. The pressure in the dissolved air tank is 0.3-0.4MPa, and the COD removal rate in the dissolved air tank is 30-60%.

[0055] The mixed medium in the dissolved air tank enters the micro-nano bubble generator, and the wastewater forms micro-nano bubbles with a bubble size of 40 to 60 μm. Then it enters the catalytic reaction tank from the bottom. After passing through the catalytic reaction tank, the salt-containing wastewater enters the water production tank, and the color is completely removed. The overall COD removal rate reaches more than 75%.

[0056] In this embodiment, the tail gas generated by the gas dissolving tank and the catalytic reaction tank during operation is collected by the tail gas collecting device and then enters the aerobic tank of the biochemical system.

[0057] Taking 1t / h high-salt wastewater as an example, the salt content is 8%, the COD is 1500mg / L, and the oxygen source is air passing through an air compressor, the specific implementation method of the present invention is as follows:

[0058] 1) Start the air compressor, the air output of the air compressor is about 3.0Nm 3 / min~3.3Nm 3 / min, gas production pressure is 0.7MPa~0.8MPa;

[0059] 2) Start the cold-drying impurity removal machine to reduce the compressed air temperature to 2°C to 8°C, so that the water content in the air tends to saturate and achieve the purpose of water removal. Its matching adsorption tank also achieves the purpose of impurity removal at the same time.

[0060] 3) Start the PSA oxygen generator with an oxygen production capacity of 30 Nm3 / h to 37 Nm3 / h and an oxygen purity of 90 wt% to 95 wt%;

[0061] 4) Start the cooling device, the cooling device is cooling water, the cooling water temperature is 28℃~32℃, the cooling water volume is 6.8m 3 / h~8.8m 3 / h.

[0062] 5) Start the ozone generator, the ozone generator gas output is 27.1Nm 3 / h~33.8Nm 3 / h, the ozone amount is 3kg / h~4kg / h, and the ozone concentration is 8wt%~10wt%.

[0063] 6) Start the wastewater transfer pump and the dissolved air pump / booster pump. Adjust the wastewater regulating valve to control the wastewater flow rate to the dissolved air pump / booster pump to 1m³ / h. Adjust the ozone regulating valve to control the wastewater flow rate to the dissolved air pump / booster pump to approximately 35Nm³ / h. To ensure flow rate, the wastewater pipe diameter should be DN15 or DN20, and the ozone pipe diameter should be DN25 or DN32.

[0064] 7) Open the inlet valve of the ozone dissolved air tank, and the gas-liquid mixed medium mixed by the dissolved air pump / boosting pump directly enters the dissolved air tank, and control the pressure in the dissolved air tank to 0.3MPa~0.4MPa.

[0065] 8) For saline wastewater, the COD removal rate is approximately 30% to 50%, and the COD concentration in the highly concentrated brine is approximately 750mg / L to 1050mg / L. At this point, the color is almost completely removed.

[0066] 9) A small amount of carbon dioxide gas is produced during the oxidation process of COD. At the same time, as the mixed medium continues to enter, the pressure in the dissolved air tank continues to rise, and some ozone gas breaks away from the liquid surface and reaches the upper part of the tank body. When the pressure exceeds 0.4MPa, the tank top exhaust valve automatically opens, and the tail gas collection fan automatically opens. When the tail gas fan outlet pressure reaches 0.05MPa, the automatic control interlock directly lowers the aeration fan frequency of the biochemical system aerobic tank. At the same time, the aeration fan frequency and the aerobic tank dissolved oxygen meter are interlocked. When the dissolved oxygen meter value is lower than 2mg / L, the aeration fan frequency is gradually increased to ensure that the dissolved oxygen meter value is between 2.5mg / L and 4.5mg / L. When the pressure in the dissolved air tank is lower than 0.4MPa, the tail gas collection fan stops running and the top exhaust valve automatically closes.

[0067] 10) Turn on the micro-nano bubble generator, and the mixed medium in the dissolved air tank enters the micro-nano bubble generator. The inlet section of the releaser is a suddenly contracting throttle port, the middle section is a gradually expanding variable spiral cutting port, and the end is a scraper-type mechanical cutting structure. Through the action of these three sections, high-density, small-diameter micro-nano ozone bubbles are formed, and the bubble size is 40nm to 60um.

[0068] 11) Micro-nano ozone bubbles enter from the bottom of the catalytic reaction tank, pass through the catalytic packing support layer, and directly contact the catalyst. At a pH of 10.5, the dense active sites of the catalyst further activate ozone and hydroxyl radicals, further removing COD from the high-salinity wastewater. If further removal is required, a two- or three-stage ozone catalytic reaction tank can be set up for step-by-step reaction.

[0069] 12) The water from the catalytic reaction tank directly enters the water production tank and serves as the raw material for evaporation and crystallization.

[0070] The various devices selected in this application (components whose specific structures are not described) are all universal standard parts or components known to those skilled in the art, and their structures and principles can be known to those skilled in the art through technical manuals or conventional experimental methods.

[0071] In the description of the embodiments of the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0072] In the description of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limitations on the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0073] In the several embodiments provided in this application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. The device embodiments described above are merely schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some communication interface, the indirect coupling or communication connection of the device or unit can be electrical, mechanical or other forms.

[0074] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0075] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0076] With the above-described preferred embodiments of the present invention as a guide, and with reference to the above description, relevant personnel are fully capable of making various changes and modifications without departing from the technical scope of this invention. The technical scope of this invention is not limited to the contents of the specification and must be determined according to the scope of the claims.

Claims

1. A micro-nano ozone oxidation high-salt wastewater treatment system, characterized by: include Oxygen supply system, ozone generator, gas-liquid mixing pump, wastewater system, dissolved air tank, micro-nano bubble generator and catalytic reaction tank; The oxygen supply system is connected to the ozone generator to supply oxygen to the ozone generator. The wastewater system and the ozone generator are both connected to a gas-liquid mixing pump, which is connected to a dissolving tank. The tail gas generated by the reaction is discharged from the top of the catalytic reaction tank. The gas-liquid mixing pump mixes the salt-containing wastewater and ozone and then pressurizes them and sends them to the dissolving tank. The ozone reacts with the salt-containing wastewater in the dissolving tank to remove COD in the wastewater. The inlet of the micro-nano bubble generator is connected to the air dissolving tank, and the outlet thereof is connected to the catalytic reaction tank. The catalytic reaction tank is connected to the pH adjustment device and the water production tank. A catalytic filler is provided in the catalytic reaction tank, and the tail gas generated by the reaction is discharged from the top of the catalytic reaction tank. The mixed medium in the air dissolving tank passes through the micro-nano bubble generator to form micro-nano bubbles and then enters the catalytic reaction tank. The catalytic filler reacts with the salt-containing wastewater to further remove COD in the wastewater. The produced water formed by the reaction in the catalytic reaction tank enters the water production tank.

2. The micro-nano ozone oxidation high-salt wastewater treatment system according to claim 1 is characterized in that: The catalytic reaction tank has a height of 3 to 8 meters, wherein the volume of the catalytic filler accounts for 1 / 3 to 1 / 2 of the volume of the entire reaction tank.

3. The micro-nano ozone oxidation high-salt wastewater treatment system according to claim 1 is characterized in that: The oxygen supply system includes an air compressor, a cold dryer and an oxygen generator. The inlet of the cold dryer is connected to the air compressor, and the outlet is connected to the oxygen generator. The oxygen generator is connected to an ozone generator.

4. The micro-nano ozone oxidation high-salt wastewater treatment system according to claim 1 is characterized in that: The oxygen supply system includes a liquid oxygen storage tank and a pressurized gasification device. The inlet of the pressurized gasification device is connected to the liquid oxygen storage tank, and the outlet of the pressurized gasification device is connected to the ozone generator.

5. The micro-nano ozone oxidation high-salt wastewater treatment system according to claim 1 is characterized in that: The gas dissolving tank and the catalytic reaction tank are both connected to a tail gas collecting device, and the tail gas collecting device is connected to an aerobic pool of a biochemical system.

6. The micro-nano ozone oxidation high-salt wastewater treatment system according to claim 1 is characterized in that: The ozone generator is connected to a heat exchanger, and the heat exchanger is connected to a cooling device.

7. The micro-nano ozone oxidation high-salt wastewater treatment system according to claim 1 is characterized in that: The ozone generator outlet is equipped with an ozone concentration detector, a gas flow meter and a regulating valve, and the ozone flow and flow rate entering the gas-liquid mixing pump are adjusted by the regulating valve; The outlet of the wastewater delivery pump of the wastewater system is equipped with a liquid flow meter and a regulating valve, and the liquid flow and flow rate entering the gas-liquid mixing pump are regulated by the regulating valve.

8. A method for treating high-salt wastewater, characterized in that: The micro-nano ozone oxidation high-salt wastewater treatment system according to any one of claims 1 to 7 is used, and the process method is as follows: Oxygen is supplied to the ozone generator through the oxygen supply system. The pressure of the oxygen source received by the ozone generator is 0.4-0.7 MPa, and the ozone concentration range produced is 80-220 mg / L; The ozone and salt-containing wastewater from the wastewater system are mixed and pressurized with water and gas through a gas-liquid mixing pump and then enter the dissolved air tank. The pressure in the dissolved air tank is 0.3-0.4MPa, and the COD removal rate in the dissolved air tank is 30-60%. The mixed medium in the dissolved air tank enters the micro-nano bubble generator, and the wastewater forms micro-nano bubbles with a bubble size of 40 to 60 μm. Then it enters the catalytic reaction tank from the bottom. After passing through the catalytic reaction tank, the salt-containing wastewater enters the water production tank, and the color is completely removed. The overall COD removal rate reaches more than 75%.

9. The method for treating high-salt wastewater according to claim 8, wherein: The tail gas generated by the gas dissolving tank and the catalytic reaction tank during the working process is collected by the tail gas collecting device and then enters the aerobic pool of the biochemical system.

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