Method for desalting and dewatering emulsified nitrobenzene

Abstract

The application discloses a method for removing salt water from emulsified nitrobenzene, which comprises the following steps: using a reinforced separation tank, a booster pump and a membrane separation component, boosting the emulsified nitrobenzene, filtering the boosted emulsified nitrobenzene through a hydrophobic organic matter modified organic-inorganic composite membrane, refining the nitrobenzene after removing the salt water, returning the salt water rich nitrobenzene to the reinforced separation tank, separating the salt water and the nitrobenzene in the hydrophilic and hydrophobic fibers and particles of the reinforced separation zone, and recycling the organic matter through a nitrobenzene stripping tower containing a small amount of nitrobenzene, which belongs to the technical field of chemical product refining. The application is especially suitable for removing the salt water from the crude nitrobenzene after the water and alkali washing of the nitrobenzene, and has the advantages of simple device process, stable operation and high efficiency of removing the salt water.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of chemical product refining and purification, and particularly relates to a method for separating salt water from crude nitrobenzene after alkali washing of water in the production of nitrobenzene by nitration of benzene. BACKGROUND

[0002] Nitrobenzene is generally prepared by reacting benzene with mixed acid, and the nitration product of the mixed acid is crude nitrobenzene. The crude nitrobenzene usually contains residual acid and nitrophenol by-products, and the residual nitrophenol will bring danger to the subsequent process and must be removed. In industry, in order to reduce the risk of residual nitrophenol, alkali washing, water washing and other steps are required to convert the nitrophenol in the crude nitrobenzene into sodium salt and transfer it from the organic phase to the aqueous phase, and at the same time, the residual mixed acid is also converted into sodium salt and most of it is transferred to the aqueous phase.

[0003] However, after alkali washing and water washing, the nitrobenzene after separation is in an emulsified state, the residual water and sodium salt exist in the form of water-in-oil, and since the emulsion droplets are small, it is extremely difficult to break the emulsion. This part of residual sodium salt, after preheating into the refining system, will accumulate in the preheater and the distillation column pot during a long period of operation, and needs to be cleaned every day, and will scale in the initial distillation column and the distillation column pot and the reboiler, increasing the frequency of tar recovery and affecting the continuous production and production cost of the device. Frequent operation not only causes production fluctuations but also wastes a lot of manpower and material resources, and at the same time, the enrichment of sodium salt in the tar greatly increases the production of nitrobenzene tar, causing additional hazardous waste treatment costs.

[0004] The particle size of the emulsified nitrobenzene water droplets after standing for 5 hours was measured by microscope, and it was found that the total number of emulsified water droplets was 1.665 million per milliliter, of which the water droplets below 5 microns accounted for 81%, the water droplets between 5-15 microns accounted for about 17.5%, the water droplets between 15-25 microns accounted for about 1.5%, and the water droplets above 25 microns accounted for less than 0.1%.

[0005] In order to reduce the sodium salt content in the crude nitrobenzene, many attempts have been made by those skilled in the art, such as using intensified water alkali washing, coalescence separation, etc.

[0006] CN106278902B discloses a method for reducing the sodium salt content in crude nitrobenzene, which mainly improves the washing water and alkali solution, increases the water-oil ratio, and makes the sodium salt dissolve into the water phase as much as possible.

[0007] CN103664629B discloses a nitrobenzene washing and separation system, which further removes sodium salt and phenate in the organic phase by introducing the organic phase after neutralization water washing into a coalescence separator integrated by a fiber filter core, a plate separator and a combined separator.

[0008] CN1757630A discloses a nitrobenzene washing production device and washing production method, which adopts a tubular washer and separates by gravity settling. The effect of using strong water alkali washing is limited, the emulsification of nitrobenzene cannot be improved, and the entrainment of sodium salt and phenate cannot be solved. The emulsified nitrobenzene is treated by using a coalescing separator, and the effect is good in the initial operation. However, with the extension of operation time, sodium salt and phenate accumulate and block in fibers and plate holes, finally causing too large pressure difference and having to stop operation.

[0009] Based on the inorganic material science, ceramic membrane has incomparable advantages over other separation media such as filter press, centrifuge, diatomite and polymer membrane, such as good chemical stability, large mechanical strength, large treatment capacity, high separation precision and easy cleaning, and thus has good development prospect in recent years and is successfully used in separation of various products. The ceramic membrane is modified by using hydrophobic organic modification material, so that water in the organic solvent can be effectively removed.

[0010] The present application can continuously dehydrate and desalt the emulsified nitrobenzene, and continuously discharge salt water from the system. The particle and fiber in the reinforced separation zone can be cleaned at regular time by setting the backwash water inlet, backwash water outlet and spherical one-way valve group, so as to prevent the blockage of salt and other particle impurities. The present application has the advantages of high desalination and dehydration efficiency, good operation stability and simple process. SUMMARY

[0011] The present application aims to provide a method for desalination and dehydration of emulsified nitrobenzene. Based on the characteristics that the emulsified nitrobenzene after water alkali washing contains a certain amount of sodium salt and water, the inorganic ceramic membrane modified by hydrophobic organic material is used as a composite membrane separation component. The emulsified nitrobenzene is pressurized and then subjected to membrane separation dehydration and desalination. The nitrobenzene after desalination is sent to a refining system, and the nitrobenzene enriched with salt water is returned to the reinforced separation tank. The salt water containing a small amount of nitrobenzene is sent to a nitrobenzene stripping tower through the salt water outlet arranged at the bottom of the reinforced separation tank for further recovery of nitrobenzene.

[0012] The present application is implemented as follows: a method for desalination and dehydration of emulsified nitrobenzene, which uses a reinforced separation tank as a reinforced separation device for salt water and organic phase in nitrobenzene. The emulsified nitrobenzene containing water and inorganic sodium salt after water alkali washing is pressurized and then sent to a membrane separation component. A composite membrane with inorganic porous ceramic membrane as a support layer and an organic hydrophobic modification layer as a separation layer is used to separate salt water in the emulsified nitrobenzene. The nitrobenzene on the permeation side is sent to a refining system after the salt water is removed. The nitrobenzene emulsion on the retention side enriched with salt water is returned to the reinforced separation tank for separation of salt water and nitrobenzene. The salt water solution containing a small amount of nitrobenzene at the bottom of the reinforced separation tank is sent to recover nitrobenzene in the salt water.

[0013] Generally, the method for removing salt water from emulsified nitrobenzene adopts a reinforced separation tank, a nitrobenzene booster pump and a membrane separation assembly to remove salt water from the nitrobenzene, wherein the organic phase outlet of the reinforced separation tank is connected with the inlet of the nitrobenzene booster pump, the outlet of the nitrobenzene booster pump is connected with the inlet of the membrane separation assembly, and the salt water rich nitrobenzene on the interception side of the membrane separation assembly is connected with the membrane separation return liquid inlet of the reinforced separation tank.

[0014] The reinforced separation tank comprises, from top to bottom, a feed buffer zone, an organic phase standing zone, a first reinforced separation zone, a reinforced separation intermediate zone, a second reinforced separation zone and a salt water clarification zone.

[0015] The feed buffer zone of the reinforced separation tank is provided with a spherical one-way valve group, and the emulsified nitrobenzene enters the organic phase standing zone downward through the one-way valve group.

[0016] The organic phase standing zone of the reinforced separation tank is provided with an organic phase outlet and a backwash water outlet.

[0017] The first reinforced separation zone of the reinforced separation tank adopts a mixture of hydrophilic particles and hydrophobic particles with a particle size of 0.1 mm to 3 mm.

[0018] The hydrophilic particles include but are not limited to ceramic, kaolin, alumina, silicon oxide, zirconium oxide and titanium oxide, and the hydrophobic particles include but are not limited to polyethylene, polyvinyl chloride, polystyrene, polypropylene, polytetrafluoroethylene and other fluorine-containing polymers.

[0019] The reinforced separation intermediate zone of the reinforced separation tank is provided with a membrane separation return liquid inlet.

[0020] The second reinforced separation zone of the reinforced separation tank adopts a mesh-shaped filler woven by hydrophilic fibers and hydrophobic fibers at a ratio of 1:1.

[0021] The hydrophilic fibers include but are not limited to natural fibers such as silk, wool, rabbit hair, cotton and hemp, and synthetic fibers such as viscose fibers, and the hydrophobic fibers include but are not limited to polyester, nylon, spandex and polypropylene.

[0022] The salt water clarification zone of the reinforced separation tank is provided with a backwash water inlet and a salt water outlet.

[0023] The membrane material of the membrane separation assembly adopts an organic-inorganic composite membrane, which comprises a support layer and a separation layer, the support layer is one of alpha-alumina and beta-alumina, and the separation layer is an organic hydrophobic modification layer prepared by grafting modification of one of alumina, zirconium oxide, titanium oxide and silicon oxide with a hydrophobic organic substance.

[0024] The hydrophobic organic matter is selected from one of octyltrimethoxysilane, tridecyltrimethoxysilane, hexadecyltrimethoxysilane, octadecyltrichlorosilane, n-butyl dimethyl chlorosilane, trimethyl chlorosilane, and octyl chlorosilane.

[0025] Advantages and effects of the present application: the method for desalting and dewatering emulsified nitrobenzene of the present application combines the enhanced separation device with the membrane separation assembly, and after the emulsified nitrobenzene is pressurized, under the filtration and permeation of the inorganic ceramic composite membrane after the hydrophobic modification of the organic matter, the nitrobenzene and the salt water are separated, and are discharged from the permeation side of the separation membrane, and the nitrobenzene with rich salt water is subjected to demulsification and coalescence under the action of the hydrophilic and hydrophobic particles and the hydrophilic and hydrophobic fibers arranged in the hydrophobic and hydrophilic zone of the enhanced separation tank, and the salt water is separated from the emulsion and is discharged from the bottom of the enhanced separation tank. Compared with the traditional water and alkali washing and coalescence separation for dewatering and desalting, the present application has the advantages of simple process flow, stable operation, and high dewatering and desalting efficiency, and is particularly suitable for the dewatering and desalting of the emulsified nitrobenzene after the water and alkali washing of the crude nitrobenzene in the production of nitrobenzene. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 The figure is a process flow diagram for implementing the method for desalting and dewatering emulsified nitrobenzene of the present application.

[0027] In the figure, 1 is an enhanced separation tank, 2 is a nitrobenzene pressurizing pump, and 3 is a membrane separation assembly.

[0028] Figure 2 The figure is a structural diagram of the enhanced separation tank in the embodiment.

[0029] In the figure, 1-1 is an emulsified nitrobenzene inlet, 1-2 is a spherical one-way valve group, 1-3 is a backwashing water outlet, 1-4 is a membrane separation return liquid inlet, 1-5 is a salt water outlet, 1-6 is a feeding buffer zone, 1-7 is an organic phase standing zone, 1-8 is an organic phase outlet, 1-9 is a primary enhanced separation zone, 1-10 is an enhanced separation intermediate zone, 1-11 is a secondary enhanced separation zone, 1-12 is a backwashing water inlet, and 1-13 is a salt water clarification zone.

[0030] Figure 3 The figure is a comparison diagram of the state of emulsified nitrobenzene before and after the membrane separation assembly in the embodiment.

[0031] In the figure, the right bottle is the state of emulsified nitrobenzene without the membrane separation assembly, and the left side is the state after the membrane separation assembly. IMPLEMENTATION

[0032] The present application is further described below in combination with the embodiments and the drawings. EMBODIMENT

[0033] The method for desalting and dewatering emulsified nitrobenzene refers to the attached Figure 1, the reinforced separation tank 1 is used as a reinforced separation device for salt water and organic phase in nitrobenzene, the emulsified nitrobenzene containing water and inorganic sodium salt after alkali washing is sent into the membrane separation assembly 3 after being pressurized by the emulsified nitrobenzene booster pump 2, the composite membrane with inorganic porous ceramic membrane as a support layer and an organic hydrophobic modified layer as a separation layer is used to separate the salt water in the emulsified nitrobenzene, the nitrobenzene with the salt water removed on the permeation side is sent to a refining device, and the nitrobenzene emulsion with the salt water enriched on the interception side is returned to the reinforced separation tank to separate the salt water and the nitrobenzene, and the salt water solution containing a small amount of nitrobenzene at the bottom of the reinforced separation tank is sent to recover the nitrobenzene in the salt water.

[0034] In the embodiment, the reinforced separation tank 1, the nitrobenzene booster pump 2 and the membrane separation assembly 3 are used to remove the salt water in the nitrobenzene, wherein the organic phase outlet of the reinforced separation tank 1 is connected with the inlet of the nitrobenzene booster pump 2, the outlet of the nitrobenzene booster pump 2 is connected with the inlet of the membrane separation assembly 3, and the salt water enriched nitrobenzene on the interception side of the membrane separation assembly 3 is connected with the membrane separation return liquid inlet of the reinforced separation tank 1.

[0035] The structure of the reinforced separation tank in the embodiment is shown in Fig. 1. Figure 2 From top to bottom, the reinforced separation tank is sequentially provided with a feeding buffer zone 1-6, an organic phase standing zone 1-7, a first reinforced separation zone 1-9, a reinforced separation intermediate zone 1-10, a second reinforced separation zone 1-11 and a salt water clarification zone 1-13.

[0036] The feeding buffer zone 1-6 of the reinforced separation tank is provided with a spherical one-way valve group 1-2, and the emulsified nitrobenzene enters the organic phase standing zone 1-7 downward through the one-way valve group, and the organic phase standing zone is provided with an organic phase outlet 1-8 and a backwashing water outlet 1-3.

[0037] The first reinforced separation zone 1-9 of the reinforced separation tank adopts a mixture of hydrophilic particles and hydrophobic particles with a particle size of 0.1mm-3mm in spherical or other shapes.

[0038] The reinforced separation intermediate zone 1-10 of the reinforced separation tank is provided with a membrane separation return liquid inlet 1-4.

[0039] The second reinforced separation zone 1-11 of the reinforced separation tank adopts a mesh-shaped filler woven by hydrophilic fibers and hydrophobic fibers at a ratio of 1:1.

[0040] The salt water clarification zone 1-13 of the reinforced separation tank is provided with a backwashing water inlet 1-12 and a salt water outlet 1-5.

[0041] The emulsified nitrobenzene desalination and water removal method of the embodiment is as follows: when the system is in normal operation, the backwash water inlet and outlet are closed, the emulsified nitrobenzene enters the feed buffer zone of the intensified separation tank, then enters the organic phase standing zone through the set spherical one-way valve group, enters the nitrobenzene booster pump through the organic phase outlet set in the organic phase standing zone, is introduced into the membrane separation assembly through the outlet of the nitrobenzene booster pump, the salt water and nitrobenzene are separated in the first and second intensified separation zones, and the salt water is discharged from the salt water outlet set at the bottom of the salt water clarification zone and is sent to the nitrobenzene stripping tower. The permeation side of the membrane separation assembly is the nitrobenzene from which the salt water is removed and which is sent to the refining.

[0042] When the system needs to be backwashed, the backwash water is introduced from the backwash water inlet, passes through the salt water clarification zone, enters the second intensified separation zone to dissolve the inorganic salt accumulated in the fiber mesh, then enters the first intensified separation zone through the intensified separation intermediate zone to dissolve the inorganic salt accumulated in the small particles, and then enters the organic phase standing zone. The water flow from bottom to top impacts the spherical one-way valve group set in the feed buffer zone to make the valve closed, and the water flow is discharged from the backwash water outlet set in the organic phase standing zone, mixed with the salt water outlet, and then sent to the nitrobenzene stripping tower. Example 1

[0043] The emulsified nitrobenzene after the water and alkali washing of a 50,000 tons / year nitrobenzene device contains 1% of water and 20 mg / L of sodium ions. The device of the embodiment is used, 0.2 mm ceramic and 0.5 mm polyethylene particles are set in the first intensified separation zone of the intensified separation tank at a weight ratio of 1:1, the mesh filler made of hydrophilic natural fiber wool and hydrophobic fiber polyester is set in the second intensified separation zone of the intensified separation tank, the membrane material of the membrane separation assembly is an organic-inorganic composite membrane, the support layer is α-aluminum oxide, and the separation layer is prepared by modifying silicon oxide with octyltrimethoxysilane. After the emulsified nitrobenzene is separated by the membrane separation assembly, the water content of the nitrobenzene from which the salt water is removed on the permeation side is reduced to 0.2%, and the sodium ion content is reduced to 5.3 mg / L. Example 2

[0044] The emulsified nitrobenzene after water and alkali washing of a 100,000 tons / year nitrobenzene device was tested to have a water content of 1.5% and a sodium ion content of 35 mg / L. Using the device of the example, 0.1 mm ceramic and 1.5 mm polyvinyl chloride particles were arranged in the first-stage intensified separation zone of the intensified separation tank at a weight ratio of 1:1; a mesh-shaped filler made of hydrophilic natural fiber rabbit hair and hydrophobic fiber spandex was arranged in the second-stage intensified separation zone of the intensified separation tank; the membrane material of the membrane separation assembly was an organic-inorganic composite membrane, the support layer was α-aluminum oxide, and the separation layer was prepared by modifying aluminum oxide with hexadecyl trimethoxysilane. After the emulsified nitrobenzene was separated by the membrane separation assembly, the nitrobenzene on the permeation side, from which the salt water was removed, was tested to have a water content of 0.45% and a sodium ion content of 8.2 mg / L. Example 3

[0045] The emulsified nitrobenzene after water and alkali washing of a 100,000 tons / year nitrobenzene device was tested to have a water content of 0.8% and a sodium ion content of 18 mg / L. Using the device of the example, 1.0 mm ceramic and 0.1 mm polypropylene particles were arranged in the first-stage intensified separation zone of the intensified separation tank at a weight ratio of 1:1; a mesh-shaped filler made of hydrophilic natural fiber hemp and hydrophobic fiber nylon was arranged in the second-stage intensified separation zone of the intensified separation tank; the membrane material of the membrane separation assembly was an organic-inorganic composite membrane, the support layer was β-aluminum oxide, and the separation layer was prepared by modifying zirconium oxide with tridecyl trimethoxysilane. After the emulsified nitrobenzene was separated by the membrane separation assembly, the nitrobenzene on the permeation side, from which the salt water was removed, was tested to have a water content of 0.17% and a sodium ion content of 4.9 mg / L. Example 4

[0046] The emulsified nitrobenzene after water and alkali washing of a 150,000 tons / year nitrobenzene device was tested to have a water content of 1.2% and a sodium ion content of 26 mg / L. Using the device of the example, 0.5 mm titanium oxide and 2 mm polystyrene particles were arranged in the first-stage intensified separation zone of the intensified separation tank at a weight ratio of 1:1; a mesh-shaped filler made of hydrophilic natural fiber silk and hydrophobic fiber polypropylene was arranged in the second-stage intensified separation zone of the intensified separation tank; the membrane material of the membrane separation assembly was an organic-inorganic composite membrane, the support layer was β-aluminum oxide, and the separation layer was prepared by modifying silicon oxide with octadecyl trichlorosilane. After the emulsified nitrobenzene was separated by the membrane separation assembly, the nitrobenzene on the permeation side, from which the salt water was removed, was tested to have a water content of 0.31% and a sodium ion content of 7.3 mg / L. Example 5

[0047] The emulsified nitrobenzene after water and alkali washing of a 100,000 tons / year nitrobenzene device was tested to have a water content of 1.8% and a sodium ion content of 41 mg / L. The device of the example was used, a 3 mm kaolin and 0.3 mm polytetrafluoroethylene particle mixture with a weight ratio of 1:1 was arranged in the first-stage intensified separation zone of the intensified separation tank, a mesh-shaped filler made of hydrophilic natural fiber cotton silk and hydrophobic fiber polyester was arranged in the second-stage intensified separation zone of the intensified separation tank, the membrane material of the membrane separation assembly was an organic-inorganic composite membrane, the support layer was α-alumina, and the separation layer was made of titanium oxide modified by n-butyl dimethyl chlorosilane. After the emulsified nitrobenzene was separated by the membrane separation assembly, the nitrobenzene on the permeation side from which the brine was removed was tested to have a water content of 0.46% and a sodium ion content of 8.6 mg / L. Example 6

[0048] The emulsified nitrobenzene after water and alkali washing of a 200,000 tons / year nitrobenzene device was tested to have a water content of 0.9% and a sodium ion content of 15 mg / L. The device of the example was used, a 3 mm silicon oxide and 0.3 mm polyvinylidene fluoride particle mixture with a weight ratio of 1:1 was arranged in the first-stage intensified separation zone of the intensified separation tank, a mesh-shaped filler made of hydrophilic natural fiber cotton silk and hydrophobic fiber chlorofiber was arranged in the second-stage intensified separation zone of the intensified separation tank, the membrane material of the membrane separation assembly was an organic-inorganic composite membrane, the support layer was α-alumina, and the separation layer was made of alumina modified by trimethyl chlorosilane. After the emulsified nitrobenzene was separated by the membrane separation assembly, the nitrobenzene on the permeation side from which the brine was removed was tested to have a water content of 0.35% and a sodium ion content of 4.1 mg / L. Example 7

[0049] The emulsified nitrobenzene after water and alkali washing of a 50,000 tons / year nitrobenzene device was tested to have a water content of 1.6% and a sodium ion content of 26 mg / L. The device of the example was used, a 1.5 mm zirconium oxide and 0.6 mm polypropylene particle mixture with a weight ratio of 1:1 was arranged in the first-stage intensified separation zone of the intensified separation tank, a mesh-shaped filler made of hydrophilic synthetic fiber viscose fiber and hydrophobic fiber polypropylene fiber was arranged in the second-stage intensified separation zone of the intensified separation tank, the membrane material of the membrane separation assembly was an organic-inorganic composite membrane, the support layer was β-alumina, and the separation layer was made of titanium oxide modified by octyl chlorosilane. After the emulsified nitrobenzene was separated by the membrane separation assembly, the nitrobenzene on the permeation side from which the brine was removed was tested to have a water content of 0.40% and a sodium ion content of 7.5 mg / L.

[0050] The emulsified nitrobenzene after water alkali washing is pressurized by a nitrobenzene booster pump and is sent into a composite membrane separation assembly modified by inorganic ceramic membranes and hydrophobic organic matters, the nitrobenzene after salt water removal is sent to a refining system, and the nitrobenzene rich in salt water is returned to a strengthened separation tank for strengthened separation, and the salt water is discharged from the system through a salt water outlet at the bottom of a salt water clarification zone of the strengthened separation tank and is sent to a nitrobenzene stripping tower. The application has high removal efficiency of salt water in the emulsified nitrobenzene, can be continuously and stably operated for a long time, has a simple process compared with the water alkali washing strengthening process, and is convenient to operate. The application is particularly suitable for desalination and water removal of the emulsified nitrobenzene after water alkali washing in a nitrobenzene production process.

Claims

1. A method for desalting and dewatering emulsified nitrobenzene, characterized by The removal of salt water in nitrobenzene is realized by using a reinforced separation tank, a nitrobenzene booster pump and a membrane separation assembly, wherein the organic phase outlet of the reinforced separation tank is connected with the inlet of the nitrobenzene booster pump, the outlet of the nitrobenzene booster pump is connected with the inlet of the membrane separation assembly, and the salt water-rich nitrobenzene on the rejection side of the membrane separation assembly is connected with the membrane separation return liquid inlet of the reinforced separation tank; the emulsified nitrobenzene after alkali washing enters the reinforced separation tank, the reinforced separation tank is used as a reinforced separation device for salt water and organic phase in nitrobenzene, the organic phase out of the reinforced separation tank is pressurized by the nitrobenzene booster pump and then sent to the membrane separation assembly, the inorganic porous ceramic membrane is used as a support layer and the organic hydrophobic modification layer is used as a separation layer to separate the salt water in the emulsified nitrobenzene, the nitrobenzene from which the salt water is removed on the permeation side is sent to a refining device, the nitrobenzene emulsion enriched with salt water on the rejection side is returned to the reinforced separation tank for separation of salt water and nitrobenzene, and the salt water solution containing a small amount of nitrobenzene at the bottom of the reinforced separation tank is sent to recover nitrobenzene in the salt water. The reinforced separation tank comprises, from top to bottom, a feed buffer zone, an organic phase standing zone, a first reinforced separation zone, a reinforced separation intermediate zone, a second reinforced separation zone and a salt water clarification zone. The support layer inorganic porous ceramic membrane is selected from one of alpha-alumina and beta-alumina, and the separation layer is an organic hydrophobic modification layer prepared by grafting modification of one of alumina, zirconia, titania and silica.

2. The method for removing water and salt from nitrobenzene emulsion according to claim 1, characterized in that The feed buffer zone of the reinforced separation tank is provided with a spherical one-way valve group, and the emulsified nitrobenzene enters the organic phase standing zone downward through the one-way valve group.

3. The method of claim 1, wherein the method further comprises The first reinforced separation zone of the reinforced separation tank adopts a mixture of hydrophilic particles and hydrophobic particles with a particle size of 0.1mm-3mm in spherical or other shapes.

4. The method of claim 3, wherein the method further comprises The hydrophilic particles are selected from one or more of ceramic, kaolin, alumina, silica, zirconia and titania, and the hydrophobic particles are selected from one or more of polyethylene, polyvinyl chloride, polystyrene, polypropylene, polytetrafluoroethylene and other fluorine-containing polymers.

5. The method of claim 1, wherein the method further comprises The reinforced separation intermediate zone of the reinforced separation tank is provided with a membrane separation return liquid inlet, and the salt water clarification zone of the reinforced separation tank is provided with a backwash water inlet and a salt water outlet.

6. The method of claim 1, wherein the method further comprises The second reinforced separation zone of the reinforced separation tank adopts a mesh filler woven by hydrophilic fibers and hydrophobic fibers at a ratio of 1:

1.

7. The method of claim 6, wherein the method further comprises The hydrophilic fibers are selected from one or more of natural fibers such as silk, wool, rabbit hair, cotton and hemp, and synthetic fibers such as viscose; and the hydrophobic fibers are selected from one or more of polyester, nylon, spandex, polypropylene and chlorofiber.

8. The method of claim 1, wherein the method further comprises The hydrophobic organic matter is selected from one of octyltrimethoxysilane, tridecyltrimethoxysilane, hexadecyltrimethoxysilane, octadecyltrichlorosilane, n-butyl dimethyl chlorosilane, trimethylchlorosilane and octylchlorosilane.

Images