Impurity removal and recycling system for high-salinity concentrated water

Abstract

The utility model belongs to the technical field of water treatment and recovery, and relates to a high-salt concentrated water impurity removal and recycling system which comprises a pretreatment unit, a first control valve, an electrocatalytic oxidation device, a second control valve, a third control valve, an ultrafiltration device, a nanofiltration unit, a sixth control valve, a seventh control valve, a caustic soda section fresh water tank, an acetylene section slurry preparation pool and an eighth control valve, the pretreatment unit is communicated with the electro-catalysis inlet through a first control valve; the pretreatment unit is communicated with the ultrafiltration inlet through a third control valve; the first electro-catalysis output port is communicated with the ultrafiltration inlet through a second control valve; a second electro-catalysis output port is communicated with a caustic soda section fresh water tank through an eighth control valve; the nanofiltration unit is communicated with the electro-catalysis inlet through a sixth control valve; the nanofiltration unit is communicated with a caustic soda section fresh water tank through a seventh control valve; and the nanofiltration unit is also respectively communicated with the ultrafiltration outlet and the acetylene section pulp preparation tank. The system disclosed by the utility model realizes high-efficiency impurity removal and recycling of the high-salt concentrated water, and is stable in operation and low in treatment cost.

Description

TECHNICAL FIELD

[0001] The utility model belongs to water treatment recovery technical field relates to a kind of high-salt concentrated water impurity removal recycling system. BACKGROUND

[0002] A large amount of high-salt concentrated water is generated in the production process of chlor-alkali, which has a high pH value, generally above 11, contains a large amount of inorganic ions (such as Ca 2+ , Mg 2+ , Na + , etc.), and contains a variety of heavy metal elements (such as Fe 2+ , Mn 2+ , etc.), in addition, the content of suspended solids in high-salt concentrated water is large, generally 100 mg / L to 200 mg / L. If discharged as wastewater, on the one hand, it will affect the growth of plants in water, deteriorate water quality, and also cause toxic effects on fish, resulting in a decrease or death in their number; on the other hand, when the concentration of dissolved heavy metals in water reaches a certain value, it will cause damage to the central nervous system of the human body and cause poisoning. Therefore, these high-salt concentrated water needs to be treated before discharge.

[0003] The traditional zero-discharge process uses evaporation crystallization to realize salt separation, specifically, high-concentration brine is exposed to sunlight, and after natural evaporation, the remaining salt is crystallized and precipitated at the bottom to form a salt heap, which can be recycled. Referring to the invention patent with publication number CN111977882A, a high-salt wastewater zero-discharge quality crystallization device and process is disclosed, which recycles valuable salts such as sodium chloride and sodium sulfate through evaporation crystallization, simplifies the process of the quality crystallization device, and reduces the operation difficulty of the quality crystallization. However, the existing evaporation crystallization uses an evaporator for crystallization, which causes the system to be unable to operate continuously and stably, consumes a large amount of steam for operation, and has a high cost. UTILITY MODEL CONTENT

[0004] In view of the technical problems of the existing high-concentration brine treatment system that cannot operate continuously and stably and has a high cost, the utility model provides a high-salt concentrated water impurity removal recycling system.

[0005] The utility model realizes efficient impurity removal of high-salt concentrated water through a pretreatment unit, an electro-catalytic oxidation device, an ultrafiltration device, a nanofiltration unit, and various control valves, and the clear water and concentrated water after impurity removal are respectively used in the caustic soda section and the acetylene section, the entire system can operate continuously and stably without steam consumption, and has a low treatment cost.

[0006] To achieve the above purpose, the utility model adopts the technical scheme of:

[0007] The system comprises a pretreatment unit, a first control valve, an electro-catalytic oxidation device, a second control valve, a third control valve, an ultrafiltration device, a nanofiltration unit, a sixth control valve, a seventh control valve, a caustic soda section freshwater tank, an acetylene section slurry preparation tank and an eighth control valve.

[0008] The electro-catalytic oxidation device is respectively provided with an electro-catalytic inlet, an electro-catalytic first outlet and an electro-catalytic second outlet.

[0009] The pretreatment unit is communicated with the electro-catalytic inlet through the first control valve; the pretreatment unit is communicated with the ultrafiltration inlet through the third control valve; the electro-catalytic first outlet is communicated with the ultrafiltration inlet through the second control valve; and the electro-catalytic second outlet is communicated with the caustic soda section freshwater tank through the eighth control valve.

[0010] The nanofiltration unit is communicated with the electro-catalytic inlet through the sixth control valve; the nanofiltration unit is communicated with the caustic soda section freshwater tank through the seventh control valve; and the nanofiltration unit is also communicated with the ultrafiltration outlet and the acetylene section slurry preparation tank respectively.

[0011] Further limitation, the system further comprises a COD removal water tank; the second control valve is communicated with the ultrafiltration inlet through the COD removal water tank; and the sixth control valve is communicated with the electro-catalytic inlet through the COD removal water tank.

[0012] Further limitation, a fifth control valve is arranged between the COD removal water tank and the ultrafiltration inlet; and a fourth control valve is arranged between the COD removal water tank and the electro-catalytic inlet.

[0013] Further limitation, the system further comprises a nanofiltration water tank; the eighth control valve and the seventh control valve are both communicated with the caustic soda section freshwater tank through the nanofiltration water tank.

[0014] Further limitation, the system further comprises a filter device; the nanofiltration water tank is communicated with the caustic soda section freshwater tank through the filter device.

[0015] Further limitation, the nanofiltration water tank is provided with a TOC sampling port.

[0016] Further limitation, the system further comprises a nanofiltration concentrated water tank arranged between the nanofiltration unit and the acetylene section slurry preparation tank.

[0017] Further limited, the nanofiltration unit includes a first nanofiltration device and a second nanofiltration device communicated in sequence; the first nanofiltration device is communicated with the ultrafiltration outlet; the second nanofiltration device is communicated with the nanofiltration concentrated water pool; the first nanofiltration device and the second nanofiltration device are communicated with the nanofiltration water pool through the seventh control valve, and the first nanofiltration device and the second nanofiltration device are communicated with the COD removal water pool through the sixth control valve.

[0018] Further limited, the pretreatment unit includes a nanofiltration silicon removal high-density pool and a multi-medium filter communicated in sequence; the multi-medium filter is communicated with the first control valve and the third control valve respectively.

[0019] Further limited, a COD sampling port is arranged on the multi-medium filter.

[0020] Compared with the prior art, the beneficial effects of the technical scheme of the utility model are:

[0021] 1. The utility model discloses a pretreatment unit, electrocatalytic oxidation device, ultrafiltration device and nanofiltration unit to high concentration brine are handled, and the COD (chemical oxygen demand) and TOD (total oxygen demand) in light brine meet the requirement, can be used as fresh water and reuse to caustic soda section, and the nanofiltration concentrated water can be reused to the slurry preparation in acetylene section, realizes the edulcoration recycling utilization of high concentration brine, and the whole system does not need to consume steam, and the cost is low, and according to the content of COD in high concentration brine after pretreatment, the processing sequence of electrocatalytic oxidation device and ultrafiltration device is adjusted, if the COD content is higher, then first utilizes electrocatalytic oxidation and removes COD, if the COD is low, then first carries out ultrafiltration and nanofiltration treatment, and then carries out electrocatalytic oxidation and removes COD, ensures the removal efficiency of COD in high concentration brine and the continuous and stable operation of system.

[0022] 2. The utility model discloses a COD removal water pool, nanofiltration water pool and nanofiltration concentrated water pool, play the role of buffering, improve the continuity and stability of system operation.

[0023] 3. In the utility model, the nanofiltration unit includes a first nanofiltration device and a second nanofiltration device communicated in sequence, through two-stage nanofiltration treatment, not only realizes the efficient edulcoration of high concentration brine, but also reduces the processing cost to the maximum, ensures that the water quality meets the requirements, realizes the continuous treatment of high concentration brine, and enhances the operation stability.

[0024] 4. In the utility model, the pretreatment unit includes a nanofiltration silicon removal high-density pool and a multi-medium filter communicated in sequence, removes the silicon content in high concentration brine, and ensures that the turbidity of subsequent high concentration brine is less than 3, meets the water quality requirements of ultrafiltration and nanofiltration, and the system runs more stably. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1A high-salt concentrated water impurity removal and recycling system schematic diagram provided for example 1 is shown in the figure;

[0026] Figure 2 A high-salt concentrated water impurity removal and recycling system schematic diagram provided for example 2 is shown in the figure;

[0027] Figure 3 A high-salt concentrated water impurity removal and recycling system schematic diagram provided for example 3 is shown in the figure;

[0028] Figure 4 A high-salt concentrated water impurity removal and recycling system schematic diagram provided for example 4 is shown in the figure;

[0029] Wherein:

[0030] 10 - nanofiltration silicon removal high-density pool; 20 - multi-media filter; 30 - first control valve; 40 - electro-catalytic oxidation device; 50 - second control valve; 60 - third control valve; 70 - fourth control valve; 80 - COD removal product water pool; 90 - fifth control valve; 100 - ultrafiltration device; 110 - nanofiltration unit; 111 - first-stage nanofiltration device; 112 - second-stage nanofiltration device; 120 - nanofiltration product water pool; 130 - sixth control valve; 140 - seventh control valve; 150 - caustic soda section fresh water tank; 160 - filtration device; 170 - nanofiltration concentrated water pool; 180 - acetylene section slurry preparation pool; 190 - eighth control valve. DETAILED DESCRIPTION

[0031] The preferred embodiments of the present application are described in detail below with reference to the accompanying drawings, so that the advantages and features of the present application can be more easily understood by those skilled in the art, and the scope of protection of the present application is more clearly defined.

[0032] Example 1

[0033] Referring to Figure 1 The high-salt concentrated water impurity removal and recycling system provided by the present embodiment includes a pretreatment unit, a first control valve 30, an electro-catalytic oxidation device 40, a second control valve 50, a third control valve 60, an ultrafiltration device 100, a nanofiltration unit 110, a sixth control valve 130, a seventh control valve 140, a caustic soda section fresh water tank 150, an acetylene section slurry preparation pool 180, and an eighth control valve 190.

[0034] Preferably, the electro-catalytic oxidation device 40 is respectively provided with an electro-catalytic inlet, an electro-catalytic first output port, and an electro-catalytic second output port; and the ultrafiltration device 100 is respectively provided with an ultrafiltration inlet and an ultrafiltration outlet.

[0035] In this embodiment, the pretreatment unit is communicated with the electro-catalysis inlet through the first control valve 30; the pretreatment unit is communicated with the ultrafiltration inlet through the third control valve 60; the electro-catalysis first output port is communicated with the ultrafiltration inlet through the second control valve 50; and the electro-catalysis second output port is communicated with the caustic soda section fresh water tank 150 through the eighth control valve 190.

[0036] In this embodiment, the nanofiltration unit 110 is communicated with the electro-catalysis inlet through the sixth control valve 130; the nanofiltration unit 110 is communicated with the caustic soda section fresh water tank 150 through the seventh control valve 140; and the nanofiltration unit 110 is also communicated with the ultrafiltration outlet and the acetylene section slurry preparation tank 180 respectively.

[0037] In this embodiment, since the high-concentration brine contains a certain amount of COD, when the ultrafiltration and nanofiltration treatment is performed, the concentration after the ultrafiltration and nanofiltration causes the COD content to continuously increase, which will affect the stable operation of the nanofiltration membrane, and the qualified nanofiltration output brine cannot be guaranteed, so the COD in the high-concentration brine needs to be removed before entering the ultrafiltration and nanofiltration treatment again. Therefore, the high-salt concentrated water impurity removal and recycling system provided in this embodiment has two operation modes.

[0038] The first operation mode is: first entering the electro-catalytic oxidation device 40 for treatment, and then entering the ultrafiltration device 100 for treatment.

[0039] The specific working process of the first operation mode is: the high-salt concentrated water first enters the pretreatment unit for pretreatment. The function of the pretreatment unit is to remove the silicon and impurities in the high-salt concentrated water, so that the water quality turbidity is less than 3, which meets the water quality standard for the conventional nanofiltration membrane treatment in the field. At the same time, the COD content in the water quality discharged from the pretreatment unit is measured. If the COD content is greater than 100 mg / L, the third control valve 60, the sixth control valve 130 and the eighth control valve 190 are closed, and the first control valve 30, the second control valve 50 and the seventh control valve 140 are opened. The pretreated high-salt concentrated water enters the electro-catalytic oxidation device 40 from the electro-catalysis inlet through the first control valve 30, and the COD content in the pretreated high-salt concentrated water is removed by electro-catalytic oxidation. The electro-catalytic oxidation can remove the COD by generating hydroxyl radicals through electro-catalysis under a high salt content, and the operation is stable, and the removal rate can reach more than 90%. Then, the high-salt concentrated water flows out from the electro-catalysis first output port, enters the ultrafiltration device 100 from the ultrafiltration inlet through the second control valve 50, and is subjected to ultrafiltration treatment. Then, the high-salt concentrated water subjected to the ultrafiltration treatment enters the nanofiltration unit 110 from the ultrafiltration outlet, and is subjected to nanofiltration treatment to obtain fresh brine and nanofiltration concentrated water. The fresh brine is stored in the caustic soda section fresh water tank 150 for recycling, and the nanofiltration concentrated water is recycled in the acetylene section slurry preparation tank 180.

[0040] The second operation mode is: first entering the ultrafiltration device 100 for treatment, and then entering the electro-catalytic oxidation device 40 for treatment.

[0041] The specific working process of the second operation mode is as follows: the high-salt concentrated water first enters the pretreatment unit for pretreatment. The pretreatment unit is used to remove silicon and impurities in the high-salt concentrated water, so that the turbidity of the water quality is less than 3, which meets the water quality standard of the conventional nanofiltration membrane treatment in the field. Meanwhile, the COD content in the water quality discharged from the pretreatment unit is measured. When the COD content is less than or equal to 100 mg / L, the first control valve 30, the second control valve 50 and the seventh control valve 140 are closed, and the third control valve 60, the sixth control valve 130 and the eighth control valve 190 are opened. The pretreated high-salt concentrated water enters the ultrafiltration device 100 from the ultrafiltration inlet through the third control valve 60 for ultrafiltration treatment. Then, the high-salt concentrated water after the ultrafiltration treatment enters the nanofiltration unit 110 from the ultrafiltration outlet for nanofiltration treatment to obtain dilute brine and nanofiltration concentrated water. The nanofiltration concentrated water enters the slurry preparation tank 180 in the acetylene section for reuse. The dilute brine enters the electro-catalytic oxidation device 40 from the electro-catalysis inlet through the sixth control valve 130, and the COD in the dilute brine is removed by electro-catalytic oxidation. Then, the dilute brine flows out from the electro-catalytic second output port of the electro-catalytic oxidation device 40 and enters the caustic soda section dilute water tank 150 for storage and reuse.

[0042] In the embodiment, the high-concentration brine is treated by the pretreatment unit, the electro-catalytic oxidation device 40, the ultrafiltration device 100 and the nanofiltration unit 110, so that the high-concentration brine is treated by impurity removal, electro-catalytic oxidation, ultrafiltration and nanofiltration. The COD (chemical oxygen demand) and TOD (total oxygen demand) in the dilute brine meet the requirements, and the dilute brine can be reused in the caustic soda section. The nanofiltration concentrated water can be reused in the acetylene section for slurry preparation, so that the impurities in the high-concentration brine are recycled and utilized. The entire system does not need to consume steam, and the cost is low. According to the content of the COD in the high-concentration brine, the opening or closing of the first control valve 30, the second control valve 50, the third control valve 60, the sixth control valve 130, the seventh control valve 140 and the eighth control valve 190 is adjusted, so that the sequence of the front and rear treatment of the electro-catalytic oxidation device 40 and the ultrafiltration device 100 is realized, the removal efficiency of the COD in the high-concentration brine is ensured, the recycling of the high-concentration brine is realized, and the continuity and stability of the system operation are ensured.

[0043] Referring to Figure 4 The pretreatment unit of the embodiment includes the nanofiltration silicon removal high-density tank 10 and the multi-medium filter 20 which are sequentially communicated. The multi-medium filter 20 is communicated with the first control valve 30 and the third control valve 60 respectively.

[0044] In the embodiment, the high-salt-concentration water desilication and recycling system further comprises a dosing pipe arranged on the high-salt-concentration desilication tank 10, and a reagent is added into the dosing pipe to remove the silicon in the high-salt-concentration water. Preferably, the reagent added into the dosing pipe comprises liquid caustic soda, magnesium oxide, polyferric chloride (PFC), polyacrylamide (PAM) and hydrochloric acid. The silicon is removed by the liquid caustic soda, the magnesium oxide, the polyferric chloride (PFC) and the polyacrylamide (PAM), and then the pH value is adjusted to 7-8 by the hydrochloric acid so as to meet the requirements of the subsequent process. In the implementation, the amount of the reagent is designed according to the impurity content in the high-salt-concentration water and the water quality requirement after the impurities are removed, and is not limited in the protection scope of the recycling system, so the specific amount of the reagent is not limited. The high-salt-concentration water after the impurities are removed is further filtered by the multi-medium filter 20 to remove the impurities in the high-salt-concentration water, so as to ensure that the turbidity is less than 3.

[0045] In the embodiment, a COD sampling port is arranged on the multi-medium filter 20, and sampling is performed through the COD sampling port to measure the COD content in the water filtered by the multi-medium filter 20. The first operating mode or the second operating mode is selected according to the size of the COD content to remove the impurities in the high-salt-concentration water and recycle the high-salt-concentration water.

[0046] Embodiment 2

[0047] Referring to Figure 2 On the basis of the embodiment 1, the high-salt-concentration water desilication and recycling system further comprises a COD-removing water tank 80, the second control valve 50 is communicated with the ultrafiltration inlet through the COD-removing water tank 80, and the sixth control valve 130 is communicated with the electro-catalytic oxidation inlet through the COD-removing water tank 80.

[0048] In the embodiment, the COD-removing water tank 80 plays a buffering role on the high-salt-concentration water entering the ultrafiltration device 100 or the electro-catalytic oxidation device 40.

[0049] Preferably, the fifth control valve 90 is arranged between the COD-removing water tank 80 and the ultrafiltration inlet, and the fourth control valve 70 is arranged between the COD-removing water tank 80 and the electro-catalytic oxidation inlet.

[0050] The high-salt-concentration water desilication and recycling system further comprises a nanofiltration water tank 120, and the eighth control valve 190 and the seventh control valve 140 are both communicated with the caustic soda section fresh water tank 150 through the nanofiltration water tank 120.

[0051] In the embodiment, the nanofiltration water tank 120 plays a buffering role on the fresh salt water entering the caustic soda section fresh water tank 150.

[0052] When the first operation mode is adopted, the fifth control valve 90 is opened, and the fourth control valve 70 is closed; the high-concentration brine treated by the electro-catalytic oxidation device 40 first flows out from the electro-catalytic first output port, enters the COD-removing water pool 80 through the second control valve 50, and then enters the ultrafiltration device 100 from the ultrafiltration inlet through the fifth control valve 90 for ultrafiltration treatment; and the dilute brine treated by the nanofiltration unit 110 enters the nanofiltration water pool 120 through the seventh control valve 140, so as to realize the reuse of the dilute brine.

[0053] When the second operation mode is adopted, the fifth control valve 90 is closed, and the fourth control valve 70 is opened; the dilute brine treated by the nanofiltration unit 110 enters the COD-removing water pool 80 through the sixth control valve 130, and then enters the electro-catalytic oxidation device 40 from the electro-catalytic inlet through the fourth control valve 70, so as to remove the COD in the dilute brine by electro-catalytic oxidation, and then the dilute brine flows into the nanofiltration water pool 120 through the eighth control valve 190, so as to realize the reuse of the dilute brine.

[0054] Embodiment 3

[0055] Referring to Figure 3 On the basis of Embodiment 3, the high-salt-concentration water impurity removal and recycling system provided in the embodiment further comprises a filtration device 160; and the nanofiltration water pool 120 is in communication with the caustic soda section dilute water tank 150 through the filtration device 160.

[0056] In the embodiment, the dilute brine stored in the nanofiltration water pool 120 is divided into two routes, one of which is directly introduced into the caustic soda section dilute water tank 150, and the other of which is introduced into the caustic soda section dilute water tank 150 after being filtered by the filtration device 160.

[0057] In implementation, a TOC sampling port is arranged on the nanofiltration water pool 120, and the TOC (total organic carbon) content of the dilute brine in the nanofiltration water pool 120 is measured; when the TOC is ≤10 mg / L, the dilute brine is directly introduced into the caustic soda section dilute water tank 150 for reuse; and when the TOC is >10 mg / L, the dilute brine is introduced into the filtration device 160 to reduce the TOC content, and then introduced into the caustic soda section dilute water tank 150 for reuse.

[0058] Preferably, the filtration device 160 is an activated carbon filtration device, which can well remove the TOC in the dilute brine, and ensure that the water quality of the dilute brine meets the water requirement of the caustic soda section. Preferably, the TOC in the dilute brine is less than 10 mg / L, the pH is 7-8, and the chloride ion content is greater than 15000 mg / L.

[0059] The high-salt-concentration water impurity removal and recycling system provided in the embodiment further comprises a nanofiltration concentrated water pool 170 arranged between the nanofiltration unit 110 and the acetylene section slurry preparation pool 180.

[0060] In the embodiment, the nanofiltration concentrated water tank 170 plays a buffering role on the nanofiltration concentrated water entering the acetylene section slurry preparation tank 180.

[0061] Embodiment 4

[0062] Referring to Figure 4 In the high-salt concentrated water impurity removal and recycling system provided in the embodiment 3, the nanofiltration unit 110 comprises a first-stage nanofiltration device 111 and a second-stage nanofiltration device 112 which are sequentially communicated; the first-stage nanofiltration device 111 is communicated with the ultrafiltration outlet; the second-stage nanofiltration device 112 is communicated with the nanofiltration concentrated water tank 170; the first-stage nanofiltration device 111 and the second-stage nanofiltration device 112 are both communicated with the nanofiltration water production tank 120 through the seventh control valve 140, and the first-stage nanofiltration device 111 and the second-stage nanofiltration device 112 are both communicated with the COD removal water tank 80 through the sixth control valve 130.

[0063] In the embodiment, the high-concentration salt water treated by the ultrafiltration device 100 is first introduced into the first-stage nanofiltration device 111 for first-stage nanofiltration treatment, to obtain first-stage dilute salt water and first-stage concentrated water; the first-stage concentrated water is continuously introduced into the second-stage nanofiltration device 112 for second-stage nanofiltration treatment, to obtain second-stage dilute salt water and second-stage concentrated water; the second-stage concentrated water is buffered by the nanofiltration concentrated water tank 170 and then introduced into the acetylene section slurry preparation tank 180 for recycling; for the first-stage dilute salt water and the second-stage dilute salt water, when the first running mode is adopted, the first-stage dilute salt water and the second-stage dilute salt water are both introduced into the nanofiltration water production tank 120 through the seventh control valve 140, and then recycled to the caustic soda section dilute water tank 150; when the second running mode is adopted, the first-stage dilute salt water and the second-stage dilute salt water are both introduced into the COD removal water tank 80 through the sixth control valve 130, and then introduced into the electro-catalytic oxidation device 40 through the fourth control valve 70; after the COD is removed by electro-catalytic oxidation, the dilute salt water is directly introduced into the nanofiltration water production tank 120 through the eighth control valve 190, to realize recycling of the dilute salt water.

[0064] In the embodiment, the dilute salt water mainly contains monovalent ions after two-stage nanofiltration desalting, and can be used in the caustic soda section; the nanofiltration concentrated water is sent to the acetylene section for recycling, to solve the problems of unstable operation and high cost of evaporation crystallization, further reduce the production investment cost, and further ensure stable operation of the system.

[0065] The above only describes the embodiments of the present application, and does not limit the patent range of the present application, and any equivalent structure or equivalent process conversion according to the content of the present application specification and drawings, or direct or indirect application in other related technical fields, are also included in the patent protection range of the present application.

Claims

1. A system for removing impurities and recycling high-salinity concentrated water, characterized in that, It includes a pretreatment unit, a first control valve (30), an electrocatalytic oxidation device (40), a second control valve (50), a third control valve (60), an ultrafiltration device (100), a nanofiltration unit (110), a sixth control valve (130), a seventh control valve (140), a caustic soda section desalination tank (150), an acetylene section slurry mixing tank (180), and an eighth control valve (190); The electrocatalytic oxidation device (40) is provided with an electrocatalytic inlet, an electrocatalytic first outlet and an electrocatalytic second outlet; the ultrafiltration device (100) is provided with an ultrafiltration inlet and an ultrafiltration outlet. The pretreatment unit is connected to the electrocatalytic inlet via the first control valve (30); the pretreatment unit is connected to the ultrafiltration inlet via the third control valve (60); the first output port of the electrocatalytic unit is connected to the ultrafiltration inlet via the second control valve (50); the second output port of the electrocatalytic unit is connected to the desalination tank (150) of the caustic soda section via the eighth control valve (190). The nanofiltration unit (110) is connected to the electrocatalytic inlet via the sixth control valve (130); the nanofiltration unit (110) is connected to the caustic soda section desalination tank (150) via the seventh control valve (140); the nanofiltration unit (110) is also connected to the ultrafiltration outlet and the acetylene section slurry mixing tank (180) respectively.

2. The high-salinity concentrated water removal and recycling system according to claim 1, characterized in that, The high-salt concentrated water purification and recycling system also includes a COD-removing product water tank (80); the second control valve (50) is connected to the ultrafiltration inlet via the COD-removing product water tank (80); and the sixth control valve (130) is connected to the electrocatalytic inlet via the COD-removing product water tank (80).

3. The high-salinity concentrated water removal and recycling system according to claim 2, characterized in that, A fifth control valve (90) is installed between the COD removal product water tank (80) and the ultrafiltration inlet; a fourth control valve (70) is installed between the COD removal product water tank (80) and the electrocatalytic inlet.

4. The high-salinity concentrated water removal and recycling system according to claim 3, characterized in that, The high-salt concentrated water purification and recycling system also includes a nanofiltration product water tank (120); the eighth control valve (190) and the seventh control valve (140) are both connected to the caustic soda section desalination tank (150) via the nanofiltration product water tank (120).

5. The high-salinity concentrated water removal and recycling system according to claim 4, characterized in that, The high-salt concentrated water purification and recycling system also includes a filtration device (160); the nanofiltration permeate tank (120) is connected to the caustic soda section desalination tank (150) through the filtration device (160).

6. The high-salinity concentrated water removal and recycling system according to claim 5, characterized in that, A TOC sampling port is provided on the nanofiltration permeate tank (120).

7. The high-salinity concentrated water removal and recycling system according to claim 6, characterized in that, The high-salt concentrated water removal and recycling system also includes a nanofiltration concentrated water tank (170) located between the nanofiltration unit (110) and the acetylene section mixing tank (180).

8. The high-salinity concentrated water removal and recycling system according to claim 7, characterized in that, The nanofiltration unit (110) includes a primary nanofiltration device (111) and a secondary nanofiltration device (112) connected in sequence; the primary nanofiltration device (111) is connected to the ultrafiltration outlet; the secondary nanofiltration device (112) is connected to the nanofiltration concentrate tank (170); both the primary nanofiltration device (111) and the secondary nanofiltration device (112) are connected to the nanofiltration permeate tank (120) via a seventh control valve (140); and both the primary nanofiltration device (111) and the secondary nanofiltration device (112) are connected to the COD removal permeate tank (80) via a sixth control valve (130).

9. The high-salinity concentrated water removal and recycling system according to claim 1, characterized in that, The pretreatment unit includes a nanofiltration high-density silica removal tank (10) and a multi-media filter (20) connected in sequence; the multi-media filter (20) is connected to a first control valve (30) and a third control valve (60) respectively.

10. The high-salinity concentrated water removal and recycling system according to claim 9, characterized in that, The multi-media filter (20) is provided with a COD sampling port.

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