A high-salt wastewater treatment system

Abstract

The present invention relates to the technical field of wastewater treatment, and in particular to a high-salt wastewater treatment system, comprising an air flotation system, a sludge storage tank, a filter press, a first extraction system, a second extraction system, a third extraction system and a vacuum pump group, wherein the air flotation system comprises an air flotation tank, in which a coagulation tank, an aeration tank, a flocculation sedimentation tank, a sludge tank, a clarification tank and a high-salt clean water tank are arranged from left to right, the feed end of the first extraction system is connected to the high-salt clean water tank, the feed end of the second extraction system is connected to the discharge end of the first extraction system, the feed end of the third extraction system is connected to the discharge end of the second extraction system, one end of the vacuum pump group is respectively connected to the first extraction system, the second extraction system and the third extraction system through a vacuum main pipe, and the other end of the vacuum pump group is connected to the high-salt clean water tank through a vacuum drain pipe. The high-salt clean water is extracted and processed step by step through multiple extraction systems to achieve the recovery and utilization of different salts.

Description

Technical Field

[0001] The invention relates to the technical field of wastewater treatment, and in particular to a high-salt wastewater treatment system. Background Art

[0002] In recent years, with the continuous expansion of my country's industrial scale, industrial water consumption has increased sharply. At the same time, the amount of wastewater generated has also increased rapidly, posing huge challenges to current wastewater treatment and recycling technologies.

[0003] In the industrial fields of chemical industry and intermediate production, the treatment of high-salt organic wastewater has always been a major problem in the road of environmental protection and sustainable development. This type of wastewater not only contains high concentrations of salt, such as inorganic salts such as sodium chloride and sodium sulfate, but also contains various complex organic substances, such as unreacted raw materials, reaction by-products and solvent residues. The presence of these components makes the treatment of high-salt organic wastewater extremely challenging.

[0004] High concentrations of salt pose a serious obstacle to conventional biological treatment processes. Biological treatment relies on the metabolic activity of microorganisms to degrade organic matter, but high-salt environments inhibit or even kill these microorganisms, resulting in a significant drop in treatment efficiency or even complete failure. Therefore, traditional activated sludge methods, biofilm methods, etc. are unable to cope with the treatment of high-salt organic wastewater. Summary of the invention

[0005] The purpose of the present invention is to provide a high-salt wastewater treatment system, which aims to solve the problem that the activated sludge method and the biofilm method cannot handle in the existing high-salt wastewater treatment process, and to achieve the recovery and utilization of salts by efficiently treating high-salt wastewater to achieve the purpose of emission standards or recycling.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is: a high-salt wastewater treatment system, including: a flotation system, the flotation system includes a flotation tank, and the flotation tank is provided with a coagulation tank, an aeration tank, a flocculation sedimentation tank, a sludge tank, a clarification tank and a high-salt clear water tank from left to right, and a water inlet pipe is provided on one side of the coagulation tank; a sludge storage tank, a stirring device is provided in the sludge storage tank, and the sludge storage tank is connected to the flocculation sedimentation tank and the sludge tank through pipelines; a filter press, the feed port of the filter press is connected to the sludge storage tank through a pipeline, and the discharge port of the filter press is connected to the sludge storage tank through a pipeline. The water inlet is connected to the aeration tank through a pipeline; the first extraction system, the feed end of the first extraction system is connected to the high-salt clean water tank through a pipeline; the second extraction system, the feed end of the second extraction system is connected to the discharge end of the first extraction system through a pipeline; the third extraction system, the feed end of the third extraction system is connected to the discharge end of the second extraction system through a pipeline; a vacuum pump group, one end of the vacuum pump group is connected to the first extraction system, the second extraction system and the third extraction system respectively through a vacuum main pipe, and the other end of the vacuum pump group is connected to the high-salt clean water tank through a vacuum drainage pipe.

[0007] Preferably, the first extraction system comprises a first crystallization kettle, a first centrifugal separator and a first thickener, the exhaust port of the first crystallization kettle is connected to the vacuum main pipe through a vacuum pipe, the feed port of the first crystallization kettle is connected to the high-salt clean water pool through a pipeline, the discharge port of the first crystallization kettle is connected to the feed port of the first thickener through a pipeline, the discharge port of the first thickener is connected to the feed port of the first centrifugal separator through a pipeline, and the liquid outlet of the first centrifugal separator is connected to the feed end of the second extraction system through a pipeline.

[0008] Preferably, the second extraction system comprises a first heater, a first evaporation tank, a second crystallization kettle, a second thickener and a second centrifugal separator, the feed port of the first heater is connected to the liquid outlet of the first centrifugal separator through a pipeline, the discharge port of the first heater is connected to the feed port of the first evaporation tank through a pipeline, the exhaust port of the second crystallization kettle is connected to the vacuum main pipe through a vacuum pipe, the discharge port of the first evaporation tank is connected to the feed port of the second crystallization kettle through a pipeline, the discharge port of the second crystallization kettle is connected to the feed port of the second thickener through a pipeline, the discharge port of the second thickener is connected to the feed port of the second centrifugal separator through a pipeline, and the liquid outlet of the second centrifugal separator is connected to the feed end of the third extraction system through a pipeline.

[0009] Preferably, the third extraction system comprises a second heater, a second evaporation tank, a third crystallization kettle, a third thickener and a third centrifugal separator, the feed port of the second heater is connected to the liquid outlet of the second centrifugal separator through a pipeline, the discharge port of the second heater is connected to the feed port of the second evaporation tank through a pipeline, the exhaust port of the third crystallization kettle is connected to the vacuum main pipe through a vacuum pipe, the discharge port of the second evaporation tank is connected to the feed port of the third crystallization kettle through a pipeline, the discharge port of the third crystallization kettle is connected to the feed port of the third thickener through a pipeline, and the discharge port of the third thickener is connected to the feed port of the third centrifugal separator through a pipeline.

[0010] Preferably, the gas outlet of the first evaporation tank is connected to the first condenser through a pipeline, the outlet of the first condenser is connected to the first receiving tank through a pipeline, the discharge port of the first receiving tank is connected to the high-salt clean water tank through a pipeline, the gas outlet of the second evaporation tank is connected to the second condenser through a pipeline, the outlet of the second condenser is connected to the second receiving tank through a pipeline, and the discharge port of the second receiving tank is connected to the high-salt clean water tank through a pipeline.

[0011] Preferably, the exhaust ports of the first receiving tank and the second receiving tank are respectively connected to the vacuum main pipe through vacuum pipes.

[0012] Preferably, the flotation system also includes an air compressor and an air dissolving tank, the output end of the air dissolving tank is connected to the aeration equipment arranged in the aeration tank through a pipeline, the air inlet of the air dissolving tank is connected to the air compressor through a pipeline, the water inlet of the air dissolving tank is connected to the water inlet pipe, the water inlet pipe is provided with a first diverter valve, and the first diverter valve is connected to the high-salt clean water tank through a water pipe.

[0013] Preferably, water quality monitors are provided in the flocculation sedimentation tank and the clarification tank, a second diverter valve is provided on the water inlet pipe, and the second diverter valve is connected to the clarification tank via a reflux pipe.

[0014] After adopting the above technical solution, the beneficial effects of the present invention are:

[0015] It integrates multiple steps such as coagulation, aeration, flocculation sedimentation, sludge treatment, and extraction. It can efficiently treat high-salt wastewater. It extracts and treats high-salt clean water step by step through multiple extraction systems to achieve the recovery and utilization of different salts. It is of great significance to improve the wastewater treatment level in the chemical, intermediate and other industries. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0018] Figure 2 is a structural schematic diagram of the first extraction system;

[0019] Figure 3 is a structural schematic diagram of the second extraction system;

[0020] Figure 4 is a schematic structural diagram of the third extraction system;

[0021] Figure 5 Schematic diagram of the structure of the air flotation system.

[0022] Figure numerals: 1-flotation system, 2-coagulation tank, 3-aeration tank, 4-sludge tank, 5-clarification tank, 6-high-salt clean water tank, 7-sludge storage tank, 8-filter press, 9-first extraction system, 10-second extraction system, 11-third extraction system, 12-vacuum main pipe, 13-vacuum pump group, 14-flocculation sedimentation tank, 15-first crystallization kettle, 16-first centrifugal separator, 17-first thickener, 18-first heater, 19-first evaporation tank, 20-second crystallization kettle, 21-second thickener, 22-second centrifugal separator, 23-first receiving tank, 24-first condenser, 25-second heater, 26-second evaporator, 27-third crystallizer, 28-third thickener, 29-third centrifugal separator, 30-second receiving tank, 31-second condenser, 32-water quality monitor, 33-air compressor, 34-dissolving tank, 35-first diverter valve, 36-water inlet pipe, 37-second diverter valve, 38-water pipe, 39-reflux pipe. DETAILED DESCRIPTION

[0023] The features and exemplary embodiments of various aspects of the present invention will be described in detail below. In order to make the purpose, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only configured to explain the present invention and are not configured to limit the present invention. For those skilled in the art, the present invention can be implemented without the need for some of these specific details. The following description of the embodiments is only to provide a better understanding of the present invention by illustrating examples of the present invention.

[0024] The directional words appearing in the following description are all directions shown in the figures, and do not limit the specific structure of the present invention. In the description of the present invention, it should also be noted that, unless otherwise clearly specified and limited, the terms "installation" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0025] like Figure 1-5 As shown, an embodiment of the present invention provides a high-salt wastewater treatment system, including a flotation system 1, a sludge storage tank 7, a filter press 8, a first extraction system 9, a second extraction system 10, a third extraction system 11 and a vacuum pump group 13.

[0026] The flotation system 1 includes a flotation tank, an air compressor 33 and an air dissolving tank 34, which are used to pre-treat high-salinity raw water, and can specifically remove suspended matter and solid impurities in the raw water, providing clearer water quality for subsequent treatment steps. From left to right, the flotation tank is provided with a coagulation tank 2, an aeration tank 3, a flocculation sedimentation tank 14, a sludge tank 4, a clarification tank 5 and a high-salinity clear water tank 6.

[0027] The coagulation tank 2 is provided with a stirring mechanism inside and a water inlet pipe is provided on one side of the tank wall. The coagulation tank 2 is connected to a dosing device (not shown) through a pipeline. The dosing device, under the control of a control module (not shown), adds coagulants, coagulant aids, etc. to the high-salinity wastewater in the coagulation tank 2 to destabilize the suspended matter and colloidal particles in the wastewater and aggregate with each other to form larger flocs, creating conditions for subsequent flotation separation.

[0028] The aeration tank 3 is provided with an aeration device inside, and the aeration device is connected to the output end of the aeration tank 34 through a pipeline. The high-pressure dissolved water produced by the aeration tank 34 is released through the aeration device. During the release process, due to the sudden drop in pressure, the gas dissolved in the water is rapidly precipitated to form a large number of tiny bubbles, which are attached to the flocculated suspended matter to form flocs and enter the flocculation sedimentation tank 14 together.

[0029] After the high-salinity raw water enters the flocculation sedimentation tank 14 from the aeration tank 3, a part of the flocs uses the buoyancy of bubbles to bring suspended matter, grease and other pollutants in the raw water to the surface to form scum, thereby achieving solid-liquid separation. The scum is scraped and sent to the sludge tank 4 by the scraper arranged on the top of the flocculation sedimentation tank 14; the other part of the flocs further grows and settles under the action of the flocculant, thereby removing most of the suspended matter and solid impurities in the high-salinity raw water.

[0030] After the wastewater is treated in the flocculation sedimentation tank 14, the suspended solids content will be significantly reduced and the water quality will be initially purified. Subsequently, the preliminarily treated wastewater will enter the clarification tank 5, allowing the remaining suspended solids and colloidal substances to have enough time to settle to the bottom of the flocculation sedimentation tank 14, further improving the clarity of the wastewater. The high-salinity clarified water in the clarification tank 5 overflows through the overflow weir to the high-salinity clear water tank 6 for storage for subsequent desalination treatment.

[0031] The air inlet of the gas dissolving tank 34 is connected to the air compressor 33 through a pipeline, and the water inlet of the gas dissolving tank 34 is connected to the water inlet pipe 36 with a pump group, and the water inlet pipe 36 is provided with a first diverter valve 35, and the first diverter valve 35 is connected to the high-salt clean water tank 6 through a water pipe 38. A second diverter valve 37 is provided on the water inlet pipe, and the second diverter valve 37 is connected to the clarification tank 5 through a return pipe 39. The clarification tank 5 and the flocculation sedimentation tank 14 are both provided with a water quality monitor 32, and the water quality monitor 32 is a floating type, which can detect the water quality and the height of the pool water in the corresponding pool. The water quality monitor 32 in the clarification tank 5 mainly detects the water quality of the top water body to ensure the cleanliness of the high-salt clarified water overflowing into the high-salt clean water tank 6. The water quality monitor 32 in the flocculation sedimentation tank 14 monitors the size of bubbles and the thickness of scum while detecting the water quality.

[0032] In the early stage of high-salinity wastewater treatment, high-salinity clarified water is not stored in the high-salinity clear water tank 6. At this time, the first diverter valve 35 switches the opening and closing direction, and the external water (such as tap water) is sent to the dissolved air tank 34 under the action of the pump and forms dissolved air water with the air from the air compressor 33. As time goes by, the high-salinity clarified water in the high-salinity clear water tank 6 gradually accumulates. When the water quality monitor 32 detects that the water volume meets the standard, the first diverter valve 35 switches the opening and closing direction again, and the high-salinity clarified water in the high-salinity clear water tank 6 is sent to the dissolved air tank 34 under the action of the pump, forming a water cycle and reducing external water use.

[0033] The water quality monitor 32 will feed back the test results of the water quality to the control module in real time. The control module will automatically adjust the dosage and type of the dosing equipment according to the test results (the proportion of salt in high-salt wastewater varies. When the content of a certain salt is extremely small, it is not worth recovering, and direct discharge without treatment will affect the environment. At this time, the type of drug can be controlled to react with the salt and generate precipitation to achieve solid-liquid separation), the opening and closing amount of the second diverter valve 37 (control the amount of high-salt raw water entering), and the air content of the dissolved water in the dissolved air tank 34 is adjusted by controlling the power of the air compressor 33 and the pump group (thereby adjusting the amount of bubbles generated by the aeration equipment), and part of the water in the clarification tank 5 is returned to the coagulation tank 2 for further treatment through the opening and closing of the second diverter valve 37, thereby realizing real-time monitoring and dynamic adjustment of the water quality conditions.

[0034] The flocculation sedimentation tank 14 and the sludge tank 4 are the main sources of sludge generation. Through the action of the sludge pump, the collected sludge is transported to the sludge storage tank 7 along the pipeline for storage. The sludge storage tank 7 is provided with a stirring device, which can reduce the harmfulness of the sludge by adding external drugs. When treating the sludge, the sludge treated with drugs in the sludge storage tank 7 is transported to the filter press 8 along the pipeline through the action of the sludge pump. During the filtration process of the filter press 8, the squeezed water in the sludge is discharged through the drain port of the filter press 8 and transported to the aeration tank 3 through the pipeline, and finally a relatively dry mud cake is obtained.

[0035] The feed end of the first extraction system 9 is connected to the high-salt clean water tank 6 through a pipeline, the feed end of the second extraction system 10 is connected to the discharge end of the first extraction system 9 through a pipeline, the feed end of the third extraction system 11 is connected to the discharge end of the second extraction system 10 through a pipeline, one end of the vacuum pump group 13 is respectively connected to the first extraction system 9, the second extraction system 10 and the third extraction system 11 through a vacuum main pipe 12, and the other end of the vacuum pump group 13 is connected to the high-salt clean water tank 6 through a vacuum drainage pipe.

[0036] The first extraction system 9 includes a first crystallization kettle 15, a first centrifugal separator 16 and a first thickener 17. The high-salt clarified water in the high-salt clear water pool 6 is transported to the feed port of the first crystallization kettle 15 through a pipeline system, and a refrigerant is introduced into the jacket of the first crystallization kettle 15 to reduce the temperature in the kettle. The exhaust port of the first crystallization kettle 15 is connected to the vacuum main pipe 12 through a vacuum pipeline to increase the vacuum degree in the kettle. When the temperature in the first crystallization kettle 15 is reduced to a certain extent by the refrigerant in the jacket, some salts in the high-salt clarified water reach an oversaturated state, and a large amount of salt crystals will gradually accumulate in the first crystallization kettle 15. After the crystallization is completed, the crystals and the remaining mother liquor are transported to the first thickener 17 through a pipeline system to increase the concentration of crystal particles and reduce the solid content in the mother liquor. Subsequently, the crystals and the mother liquor are transported to the first centrifugal separator 16 through a pipeline system to achieve effective separation of the crystals and the mother liquor, and obtain salt one (such as mirabilite) and mother liquor one.

[0037] The second extraction system 10 includes a first heater 18, a first evaporation tank 19, a second crystallization kettle 20, a second thickener 21 and a second centrifugal separator 22. The mother liquor 1 separated by the first centrifugal separator 16 is transported to the first heater 18 through a pipeline system for heating to increase the temperature. The first evaporation tank 19 performs an evaporation operation on the heated mother liquor 1, and concentrates the remaining solution by vaporizing part of the water to increase the concentration of salts in the solution. The concentrated mother liquor 1 is transported to the second crystallization kettle 20 through a pipeline system, and a heat medium is introduced into the jacket of the second crystallization kettle 20 to increase the temperature in the kettle. The exhaust port of the second crystallization kettle 20 is connected to the vacuum main pipe 12 through a vacuum pipeline to increase the vacuum degree in the kettle. Under the combined effect of the temperature increase and the vacuum degree increase, the mother liquor in the second crystallization kettle 20 begins to crystallize. After the crystallization process is completed, the crystals and the remaining mother liquor 1 are transported to the second thickener 21 through a pipeline system to increase the concentration of crystal particles and reduce the solid content in the mother liquor 1. Subsequently, the crystals and the mother liquor 1 are transported to the second centrifugal separator 22 through the pipeline system to achieve effective separation of the crystals and the mother liquor 1, thereby obtaining salt 2 (such as sodium sulfate) and mother liquor 2.

[0038] The third extraction system 11 includes a second heater 25, a second evaporation tank 26, a third crystallization kettle 27, a third thickener 28 and a third centrifugal separator 29. The mother liquor 2 separated by the second centrifugal separator 22 is transported to the second heater 25 through a pipeline system for heating to increase the temperature. The second evaporation tank 26 performs an evaporation operation on the heated mother liquor 2, and concentrates the remaining solution by vaporizing part of the water to increase the concentration of salts in the solution. The concentrated mother liquor 2 is transported to the third crystallization kettle 27 through a pipeline system, and a heat medium is introduced into the jacket of the third crystallization kettle 27 to increase the temperature in the kettle. The exhaust port of the third crystallization kettle 27 is connected to the vacuum main pipe 12 through a vacuum pipeline to increase the vacuum degree in the kettle. Under the combined effect of temperature increase and vacuum increase, the mother liquor 2 in the third crystallization kettle 27 begins to crystallize. After the crystallization process is completed, the crystals and the remaining mother liquor 2 are transported to the third thickener 28 through a pipeline system to increase the concentration of crystal particles and reduce the solid content in the mother liquor 2. Subsequently, the crystals and the mother liquor 2 are transported to the third centrifugal separator 29 through the pipeline system to achieve effective separation of the crystals and the mother liquor 2, thereby obtaining salt 3 (such as sodium chloride) and mother liquor 3 (i.e., the final treated water).

[0039] The gas outlet of the first evaporation tank 19 is connected to the first condenser 24 through a pipeline, the outlet of the first condenser 24 is connected to the first receiving tank 23 through a pipeline, and the discharge port of the first receiving tank 23 is connected to the high-salt clean water tank 6 through a pipeline. The gas outlet of the second evaporation tank 26 is connected to the second condenser 31 through a pipeline, the outlet of the second condenser 31 is connected to the second receiving tank 30 through a pipeline, and the discharge port of the second receiving tank 30 is connected to the high-salt clean water tank 6 through a pipeline. The exhaust ports of the first receiving tank 23 and the second receiving tank 30 are respectively connected to the vacuum main pipe 12 through vacuum pipes to improve the vacuum degree.

[0040] In the first evaporation tank 19 and the second evaporation tank 26, the water in the solution is evaporated into water vapor by heating, and the concentration of the solute gradually increases. In the first condenser 24 and the second condenser 31, the water vapor contacts the cooling medium (such as cold water, air, etc.), releases heat and condenses into liquid water (containing a certain amount of salt solute). The condensed water enters the first receiving tank 23 and the second receiving tank 30 through pipelines for temporary storage and buffering. After accumulating to a certain extent, the condensed water is discharged into the high-salt clean water tank 6 through the pipeline system.

[0041] According to the embodiments of the present invention as described above, these embodiments do not describe all the details in detail, nor do they limit the invention to specific embodiments. Obviously, many modifications and changes can be made based on the above description. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can make good use of the present invention and the modified use based on the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for treating high-salt wastewater, characterized in that: The high-salt wastewater treatment method utilizes a high-salt wastewater treatment system to treat the high-salt wastewater. The high-salt wastewater treatment system comprises an air flotation system (1), a sludge storage tank (7), a filter press (8), a first extraction system (9), a second extraction system (10), a third extraction system (11) and a vacuum pump group (13). The air flotation system (1) comprises an air flotation tank. The air flotation tank is provided with a coagulation tank (2), an aeration tank (3), a flocculation sedimentation tank (14), a sludge tank (4), a clarification tank (5) and a high-salt clear water tank (6) from left to right. A water inlet pipe is provided on one side of the coagulation tank (2). A stirring device is provided in the sludge storage tank (7). The sludge storage tank (7) is connected to the flocculation sedimentation tank (14) and the sludge tank (4) through pipelines. One end of the vacuum pump group (13) is connected to a vacuum main pipe (12). The other end of the vacuum pump group (13) is connected to the high-salt clear water tank (6) through a vacuum drainage pipe. The first extraction system (9) comprises a first crystallization kettle (15), a first centrifugal separator (16) and a first thickener (17). The high-salt clarified water in the high-salt clear water pool (6) is transported to the first crystallization kettle (15) through a pipeline. A refrigerant is introduced into the jacket of the first crystallization kettle (15) to reduce the temperature in the kettle. The exhaust port of the first crystallization kettle (15) is connected to the vacuum main pipe (12) through a vacuum pipeline. Under low temperature and low pressure, part of the salt in the high-salt clarified water in the first crystallization kettle (15) reaches an oversaturated state and gradually accumulates a large amount of salt crystals. After crystallization is completed, the crystals and the remaining mother liquor are transported to the first thickener (17) through a pipeline system to increase the concentration of crystal particles and reduce the solid content in the mother liquor. The crystals and the mother liquor are transported to the first centrifugal separator (16) through a pipeline system to achieve effective separation of the crystals and the mother liquor to obtain salt one and mother liquor one. The second extraction system (10) comprises a first heater (18), a first evaporation tank (19), a second crystallization kettle (20), a second thickener (21) and a second centrifugal separator (22). The mother liquor 1 separated by the first centrifugal separator (16) is transported to the first heater (18) through a pipeline system to be heated to increase the temperature. The first evaporation tank (19) evaporates the heated mother liquor 1 to concentrate the remaining solution by vaporizing part of the water, thereby increasing the concentration of salts in the solution. The gas outlet of the first evaporation tank (19) is connected to a first condenser (24) through a pipeline. In the first condenser 24, water vapor contacts a cooling medium, releases heat and condenses into liquid water. The condensed water enters the first receiving tank (23) through a pipeline for temporary storage and buffering. After accumulating to a certain level, the water vapor is discharged through the first receiving tank (23). The condensed water is discharged into a high-salt clear water pool (6) through a pipeline system, and the concentrated mother liquor 1 is transported to a second crystallization kettle (20) through a pipeline system. A heat medium is introduced into the jacket of the second crystallization kettle (20) to increase the temperature in the kettle. The exhaust port of the second crystallization kettle (20) is connected to a vacuum main pipe (12) through a vacuum pipeline to increase the vacuum degree in the kettle. Under the combined effect of the temperature increase and the vacuum degree increase, the mother liquor in the second crystallization kettle (20) begins to crystallize. After the crystallization process is completed, the crystals and the remaining mother liquor 1 are transported to a second thickener (21) through a pipeline system to increase the concentration of crystal particles and reduce the solid content in the mother liquor 1. Subsequently, the crystals and the mother liquor 1 are transported to a second centrifuge (22) through a pipeline system to achieve effective separation of the crystals and the mother liquor 1, thereby obtaining salt 2 and mother liquor 2; The third extraction system (11) comprises a second heater (25), a second evaporation tank (26), a third crystallization kettle (27), a third thickener (28) and a third centrifugal separator (29). The mother liquor 2 separated by the second centrifugal separator (22) is transported to the second heater (25) through a pipeline system for heating to increase the temperature. The second evaporation tank (26) performs an evaporation operation on the heated mother liquor 2, and concentrates the remaining solution by vaporizing part of the water, thereby increasing the concentration of salts in the solution. The gas outlet of the second evaporation tank (26) is connected to a second condenser (31) through a pipeline. In the second condenser (31), water vapor contacts a cooling medium, releases heat and condenses into liquid water. The condensed water enters the second receiving tank (30) through a pipeline for temporary storage and buffering. After accumulating to a certain level, the condensed water is discharged into the high-salt clear water pool (6) through the pipeline system. The exhaust ports of the second receiving tank (30) are connected to the vacuum main pipe (12) through vacuum pipes to increase the vacuum degree. The concentrated mother liquor 2 is transported to the third crystallization kettle (27) through the pipeline system. A heat medium is introduced into the jacket of the third crystallization kettle (27) to increase the temperature in the kettle. The exhaust port of the third crystallization kettle (27) is connected to the vacuum main pipe (12) through the vacuum pipe to increase the vacuum degree in the kettle. Under the combined effect of the temperature increase and the vacuum degree increase, the mother liquor 2 in the third crystallization kettle (27) begins to crystallize. After the crystallization process is completed, the crystals and the remaining mother liquor 2 are transported to the third thickener (28) through the pipeline system to increase the concentration of the crystal particles and reduce the solid content in the mother liquor 2. Subsequently, the crystals and the mother liquor 2 are transported to the third centrifuge (29) through the pipeline system to achieve effective separation of the crystals and the mother liquor 2 to obtain Salt 3 and Mother Liquor 3.

2. The method for treating high-salt wastewater according to claim 1, characterized in that: The flotation system (1) further comprises an air compressor (33) and an air dissolving tank (34); the output end of the air dissolving tank (34) is connected to an aeration device arranged in an aeration tank (3) via a pipeline; the air inlet of the air dissolving tank (34) is connected to the air compressor (33) via a pipeline; the water inlet of the air dissolving tank (34) is connected to a water inlet pipe (36); a first diverter valve (35) is arranged on the water inlet pipe (36); and the first diverter valve (35) is connected to a high-salinity clean water tank (6) via a water pipe (38).

3. The method for treating high-salt wastewater according to claim 2, characterized in that: The flocculation sedimentation tank (14) and the clarification tank (5) are both provided with a water quality monitor (32), and the water inlet pipe is provided with a second diverter valve (37), and the second diverter valve (37) is connected to the clarification tank (5) via a return pipe (39).

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