CN113354031A

CN113354031A - Nanofiltration device for sulfur-containing wastewater and use method thereof

Info

Publication number: CN113354031A
Application number: CN202110623361.1A
Authority: CN
Inventors: 李平; 张�杰; 宋培宇
Original assignee: Hangzhou Best Energy Saving Environmental Protection Technology Co ltd
Current assignee: Hangzhou Best Energy Saving Environmental Protection Technology Co ltd
Priority date: 2021-06-04
Filing date: 2021-06-04
Publication date: 2021-09-07
Anticipated expiration: 2041-06-04
Also published as: CN113354031B

Abstract

The invention discloses a nanofiltration device for sulfur-containing wastewater and a use method thereof, the nanofiltration device comprises a cylindrical shell, the bottom end of the outer surface of the cylindrical shell is fixedly connected with a bracket, the front and the back of the cylindrical shell are respectively provided with an arc-shaped clamping groove and a T-shaped sliding groove, the upper end of the cylindrical shell is fixedly connected with a fixed block, and a filtering mechanism is movably arranged in the cylindrical shell. The nanofiltration membrane for filtration is not fixed any more, and the operator can replace and clean the nanofiltration membrane.

Description

Nanofiltration device for sulfur-containing wastewater and use method thereof

Technical Field

The application relates to the technical field of nanofiltration, in particular to a nanofiltration device for sulfur-containing wastewater and a using method thereof.

Background

The principle of the membrane separation method is that salt water is pushed by the pressure difference at two sides of the membrane to carry out molecular selective permeation. The process adopts a selective nanofiltration membrane, so the process is also called a nanofiltration membrane method, the nanofiltration membrane has the characteristic of selectively separating divalent ions and high-valent ions, but monovalent ions can completely pass through the nanofiltration membrane. Under certain conditions, the retention rate of SO42 can reach 99%. The method has the disadvantages of high one-time investment, low operation cost, environmental protection and simple operation, and has two remarkable characteristics of molecular weight cut-off between UF and RO, 200-2000 with nanometer-scale pore diameter, and NF membrane with certain inorganic salt cut-off rate and different ion cut-off capacities for different valence states.

The common nanofiltration device for removing sulfur in wastewater has the following disadvantages: when the filter membrane is replaced, a large number of screws and shells need to be detached and enter the equipment for replacement, so that the replacement efficiency is low, and the operation time is long; after the wastewater is injected, the wastewater can firstly extrude the filter membrane to enable the filter membrane to deform a certain amount and then be filtered due to the ductility of the filter membrane, and an unnecessary time period exists;

therefore, the nanofiltration device for sulfur-containing wastewater and the use method thereof are provided, the stability of the device is improved, compared with the method of fixing the shell and the filtration device by using screws, the replacement efficiency is higher, the deformation amount is reduced, an area which cannot be touched by an operator cannot exist, and the replacement efficiency is improved.

Disclosure of Invention

The invention aims to provide a nanofiltration device for sulfur-containing wastewater and a using method thereof, so as to solve the problems in the background technology.

The embodiment of the application adopts the following technical scheme:

the utility model provides a sulfur-containing waste water is with receiving filter equipment, includes cylindric shell, the surface bottom fixedly connected with support of cylindric shell, arc draw-in groove and T type spout have all been seted up to the front and back of cylindric shell, the upper end fixedly connected with fixed block of cylindric shell, the inside activity of cylindric shell is provided with filtering mechanism.

Preferably, a circular groove is formed in the surface of the fixing block, a sliding rod is movably sleeved in the circular groove, two ends of the sliding rod are fixedly connected with check blocks, and a shifting lever is fixedly connected to the upper ends of the check blocks at the rear ends.

Preferably, two equal activity is provided with the arc slider in the arc draw-in groove, two the back of the body of arc slider is from the equal fixedly connected with arc strip in two sides, two the equal fixedly connected with connecting block of right-hand member of arc strip, two fixedly connected with holding rod, two between the connecting block the relative two sides of arc strip laminate with the front and back of cylindric shell respectively.

Preferably, the filtering mechanism comprises two circular rings and two circular plates, wherein a first pipe groove is formed in the middle of the plate surface of each circular plate, a second pipe groove is formed in the lower end of each circular plate located at the front end, a first circular pipe is fixedly sleeved in each first pipe groove, and a second circular pipe is fixedly sleeved in each second pipe groove.

Preferably, a T-shaped sliding rod is fixedly connected between the two circular plates, the T-shaped sliding rod is movably clamped in the T-shaped sliding groove, and the plate diameters of the two circular plates are matched with the inner diameter of the cylindrical shell.

Preferably, two opposite surfaces of the two circular plates are fixedly connected with two opposite surfaces of the two circular rings respectively, an annular groove is formed in the upper end of the outer ring surface of each circular ring, strip-shaped grooves are formed in the front and rear groove surfaces of each annular groove, and a through groove is formed in the left end and the right end of the inner ring surface of each circular ring.

Preferably, two arc-shaped plates are movably arranged in each annular groove, the front arc surface and the rear arc surface of each arc-shaped plate are fixedly connected with sliding strips, each sliding strip is movably arranged in the corresponding strip-shaped groove, two opposite arc surfaces of the two arc-shaped plates on the same side in the front and the rear are fixedly connected with short rods, and the short rods are movably sleeved in the corresponding through grooves.

Preferably, the rod end of each short rod is fixedly connected with a semicircular plate, two adjacent semicircular plates are combined into a complete limiting ring, a positioning ring is movably arranged in the limiting ring and fixedly arranged on a circular plate, the inner wall of the limiting ring is tightly abutted to the outer ring surface of the positioning ring, and four limiting rods are fixedly connected between the two semicircular plates on the same side.

The invention aims to solve another technical problem of providing a using method of a nanofiltration device for sulfur-containing wastewater, which comprises the following steps:

1): an operator pulls the sliding rod rightwards through the shifting rod, so that the sliding rod slides rightwards without limiting the movement of the connecting block, and at the moment, the operator enables the arc-shaped strip to slide downwards along the track of the arc-shaped sliding block sliding in the arc-shaped clamping groove through the holding rod, so that the front notch and the rear notch of the T-shaped sliding groove are opened;

2): an operator pulls the whole filtering mechanism forwards, a T-shaped sliding rod slides in a T-shaped sliding groove until a circular plate positioned at the rear end reaches the edge of the front opening of the cylindrical shell, the arc-shaped plate is pushed upwards at the moment, the arc-shaped plate slides upwards in the annular groove through the sliding strip, the opening of the through groove is opened, the limiting rods are pulled towards two sides at the moment to drive the semicircular plates to separate from each other, the inner wall of the semicircular plate is separated from the outer annular surface of the positioning ring, the nanofiltration membrane for filtering is not fixed at the moment, and the operator replaces and cleans the nanofiltration membrane;

3): after the nanofiltration membrane is replaced, the two steps are operated in reverse, the whole device is reset, the normal nanofiltration of the sulfur-containing wastewater is carried out, the salt water enters the nanofiltration device after the pressure of the salt water is increased by a high-pressure pump, most of sulfate radical ions are intercepted under a high-pressure state, chloride ions and sodium ions smoothly pass through the membrane, so that the sodium ions with the valence of 1 and the chloride ions with the valence of-1 are separated from the sulfate radicals with the valence of-2, a penetrating fluid containing a small amount of sulfate radicals and a concentrated solution containing more sulfate radical ions are obtained, a sodium sulfate solution with required mass concentration can be obtained after multi-stage concentration and separation, and finally the sodium sulfate solution returns to a salt water system, so that the purpose of removing the sulfate radicals is achieved.

The embodiment of the application adopts at least one technical scheme which can achieve the following beneficial effects:

one of them, operating personnel pulls the slide bar through the driving lever right, make the slide bar slide right no longer restrict the removal of connecting block, operating personnel can make the arc strip slide downwards along the gliding orbit of arc slider in the arc draw-in groove through the holding rod this moment, make the notch open the removal that no longer restricts T type slide bar around the T type spout, avoided the device when receiving to strain because the vibrations of equipment and other factors lead to the cylindric shell of filter mechanism roll-off, improved the stability of device.

Secondly, operating personnel stimulates whole filtering mechanism forward, T type slide bar slides in T type spout and arrives barrel head edge department before the cylindric shell until the plectane that is located the rear end, upwards promote the arc this moment, slide in the strip type inslot through the draw runner and make the arc upwards slide in the ring channel, it is open to make logical groove notch, can make the gag lever post drive half-round plate to both sides pulling gag lever post this moment and separate each other, make half-round plate inner wall and the outer anchor ring face separation of holding ring, the nanofiltration membrane of filtering usefulness does not receive fixed the clearance of changing again this moment, accomplish the change of filter membrane through mechanical linkage, compare and utilize the screw to carry out shell and filter equipment's fixed, change efficiency is higher.

Thirdly, only need the above-mentioned step of contrary operation to make whole device reset after the change is accomplished, carry out the normal receiving and filtration that contains sulphur waste water, whole dismouting process does not have the part can break away from equipment, has improved the efficiency of dismouting and has avoided the part to lose simultaneously and cause the loss, influences normally receiving and filtering.

Fourthly, the deformation area of the filter membrane is limited by the limiting rods, so that after the sulfur-bearing wastewater enters, the filter membrane is extruded by water pressure and then expanded, the wastewater is directly filtered after being filled, the deformation amount is reduced, and the filtering efficiency is improved.

Fifthly, because the area that the gag lever post encloses is located cylindric shell mid portion for the filter membrane can carry out all-round filtration, operating personnel's when making the filter membrane be located the centre also be convenient for change operation, can not have the area that operating personnel can't touch, improves change efficiency.

Drawings

The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the application and together with the description serve to explain the application and not to limit the application. In the drawings:

FIG. 1 is a schematic view of the overall structure of the present invention;

FIG. 2 is a schematic structural view of a cylindrical shell according to the present invention;

FIG. 3 is an enlarged view of the structure of FIG. 2 at A according to the present invention;

FIG. 4 is a schematic structural view of a circular plate according to the present invention;

FIG. 5 is a schematic structural view of a T-shaped slide bar according to the present invention;

FIG. 6 is a schematic view of a retaining ring according to the present invention;

FIG. 7 is a schematic view of the structure of the ring of the present invention;

FIG. 8 is a schematic view of the structure of the curved plate of the present invention;

FIG. 9 is an enlarged view of the structure of FIG. 6 at B according to the present invention;

in the figure: 1. a cylindrical housing; 2. a circular plate; 3. a T-shaped chute; 4. an arc-shaped clamping groove; 5. a support; 6. an arc-shaped strip; 7. a holding rod; 8. connecting blocks; 9. an arc-shaped sliding block; 10. a circular groove; 11. a deflector rod; 12. a slide bar; 13. a stopper; 14. a fixed block; 15. a circular ring; 16. a first round pipe; 17. a second round pipe; 18. a pipe groove II; 19. a pipe groove I; 20. a T-shaped slide bar; 21. a positioning ring; 22. a semicircular plate; 23. a short bar; 24. an arc-shaped plate; 25. a limiting rod; 26. a slide bar; 27. a through groove; 28. an annular groove; 29. a strip-shaped groove.

Detailed Description

In order to make the objects, technical solutions and advantages of the present application more apparent, the technical solutions of the present application will be described in detail and completely with reference to the following specific embodiments of the present application and the accompanying drawings. It should be apparent that the described embodiments are only some of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

The technical solutions provided by the embodiments of the present application are described in detail below with reference to the accompanying drawings.

Referring to fig. 1 to 9, the present invention provides a nanofiltration device for sulfur-containing wastewater, comprising: comprises a cylindrical shell 1, a bracket 5 is fixedly connected to the bottom end of the outer surface of the cylindrical shell 1, arc clamping grooves 4 and T-shaped sliding grooves 3 are respectively arranged on the front and the back of the cylindrical shell 1, a fixed block 14 is fixedly connected to the upper end of the cylindrical shell 1, a filtering mechanism is movably arranged in the cylindrical shell 1, a circular groove 10 is arranged on the surface of the fixed block 14, a sliding rod 12 is movably sleeved in the circular groove 10, two ends of the sliding rod 12 are respectively and fixedly connected with a stop block 13, a deflector rod 11 is fixedly connected to the upper end of the stop block 13 positioned at the rear end, arc sliding blocks 9 are respectively and movably arranged in the two arc clamping grooves 4, arc strips 6 are respectively and fixedly connected to the two opposite surfaces of the two arc sliding blocks 9, connecting blocks 8 are respectively and fixedly connected to the right ends of the two arc strips 6, a holding rod 7 is fixedly connected between the two connecting blocks 8, and the two opposite surfaces of the two arc strips 6 are respectively attached to the front and back surfaces of the cylindrical shell 1, an operator pulls the sliding rod 12 rightwards through the shifting lever 11, so that the sliding rod 12 slides rightwards without limiting the movement of the connecting block 8, and at the moment, the operator can make the arc-shaped strip 6 slide downwards along the track of the arc-shaped sliding block 9 sliding in the arc-shaped clamping groove 4 through the holding rod 7, so that the front notch and the rear notch of the T-shaped sliding groove 3 are opened and the movement of the T-shaped sliding rod 20 is not limited;

the filtering mechanism comprises two circular rings 15 and two circular plates 2, wherein the middle parts of the plate surfaces of the two circular plates 2 are respectively provided with a first pipe groove 19, the lower end of the circular plate 2 positioned at the front end is provided with a second pipe groove 18, the first pipe grooves 19 are respectively and fixedly sleeved with a first circular pipe 16, the second pipe grooves 18 are respectively and fixedly sleeved with a second circular pipe 17, a T-shaped sliding rod 20 is fixedly connected between the two circular plates 2, the T-shaped sliding rod 20 is movably clamped in the T-shaped sliding groove 3, the plate diameters of the two circular plates 2 are matched with the inner diameter of the cylindrical shell 1, two opposite surfaces of the two circular plates 2 are respectively and fixedly connected with two opposite surfaces of the two circular rings 15, the upper end of the outer ring surface of each circular ring 15 is provided with a circular groove 28, the front groove surface and the rear groove surface of each circular groove 28 are respectively provided with a strip-shaped groove 29, the left end and the right end of the inner ring surface of each circular ring 15 are respectively provided with a through groove 27, two arc-shaped plates 24 are movably arranged in each circular groove 28, the front arc-shaped plates 24 are respectively and the front arc-shaped strips 26, each sliding strip 26 is movably arranged in a corresponding strip-shaped groove 29, two opposite arc surfaces of two arc plates 24 on the same side in front and back are fixedly connected with a short rod 23, the short rod 23 is movably sleeved in a corresponding through groove 27, the rod end of each short rod 23 is fixedly connected with a semi-circular plate 22, two adjacent semi-circular plates 22 are combined into a complete limiting ring, a positioning ring 21 is movably arranged in the limiting ring, the positioning ring 21 is fixedly arranged on a circular plate 2, the inner wall of the limiting ring is tightly abutted to the outer annular surface of the positioning ring 21, an operator pulls the whole filtering mechanism forwards, a T-shaped sliding rod 20 slides in a T-shaped sliding groove 3 until the circular plate 2 at the back end reaches the edge of the front cylinder opening of the cylindrical shell 1, the arc plates 24 are pushed upwards at the moment, the arc plates 24 slide upwards in the strip-shaped grooves 28 through the sliding strips 26, the notches of the through grooves 27 are opened, the limiting rods 25 are pulled towards two sides at the moment, so that the limiting rods 25 can drive the semi-circular plates 22 to separate from each other, make semicircle board 22 inner wall and the outer anchor ring of holding ring 21 separate, the nanofiltration membrane of filtering usefulness this moment no longer receives to be fixed can change the clearance, only need reverse the above-mentioned step of operation after the change completion and can make whole device reset, carry out the normal nanofiltration that contains sulphur waste water, control four gag lever posts 25 of fixedly connected with between two semicircle boards 22 of homonymy.

The working principle is as follows: an operator pulls the slide rod 12 rightwards through the shift lever 11, so that the slide rod 12 slides rightwards without limiting the movement of the connecting block 8, at the moment, the operator can make the arc-shaped strip 6 slide downwards along the track that the arc-shaped slide block 9 slides in the arc-shaped clamping groove 4 through the holding rod 7, so that the front and rear notches of the T-shaped sliding groove 3 are opened without limiting the movement of the T-shaped slide rod 20, at the moment, the operator pulls the whole filtering mechanism forwards, the T-shaped slide rod 20 slides in the T-shaped sliding groove 3 until the circular plate 2 positioned at the rear end reaches the edge of the front opening of the cylindrical shell 1, at the moment, the arc-shaped plate 24 is pushed upwards, the arc-shaped plate 24 slides upwards in the annular groove 28 through the sliding strip 26, so that the notch of the through groove 27 is opened, at the moment, the limiting rods 25 are pulled to both sides, so that the limiting rods 25 can drive the semicircular plates 22 to be separated from each other, and the inner wall of the semicircular plate 22 is separated from the outer annular surface of the positioning ring 21, the nanofiltration membrane for filtration is not fixed any more, so that the nanofiltration membrane can be replaced and cleaned, and the whole device can be reset only by reversely operating the steps after replacement is finished, so that normal nanofiltration of sulfur-containing wastewater is performed.

A using method of a nanofiltration device for sulfur-containing wastewater comprises the following steps:

1): an operator pulls the sliding rod 12 rightwards through the shifting rod 11, so that the sliding rod 12 slides rightwards without limiting the movement of the connecting block 8, and at the moment, the operator enables the arc-shaped strip 6 to slide downwards along the track of the arc-shaped sliding block 9 sliding in the arc-shaped clamping groove 4 through the holding rod 7, so that the front notch and the rear notch of the T-shaped sliding groove 3 are opened;

2): an operator pulls the whole filtering mechanism forwards, the T-shaped sliding rod 20 slides in the T-shaped sliding groove 3 until the circular plate 2 positioned at the rear end reaches the edge of the front opening of the cylindrical shell 1, the arc-shaped plate 24 is pushed upwards at the moment, the arc-shaped plate 24 slides upwards in the annular groove 28 through the sliding strip 26 sliding in the strip-shaped groove 29, the opening of the through groove 27 is opened, the limiting rods 25 are pulled towards two sides at the moment, the limiting rods 25 can drive the semicircular plates 22 to separate from each other, the inner wall of the semicircular plate 22 is separated from the outer annular surface of the positioning ring 21, the nanofiltration membrane for filtering is not fixed at the moment, and the operator replaces and cleans the nanofiltration membrane;

As will be appreciated by one skilled in the art, embodiments of the present invention may be provided as a method, system, or computer program product. Accordingly, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product embodied on one or more computer-usable storage media having computer-usable program code embodied in the medium.

It should also be noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.

The above description is only an example of the present application and is not intended to limit the present application. Various modifications and changes may occur to those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the claims of the present application.

Claims

1. A nanofiltration device for sulfur-containing wastewater comprises a cylindrical shell (1), and is characterized in that: the bottom end of the outer surface of the cylindrical shell (1) is fixedly connected with a support (5), the front and the rear surfaces of the cylindrical shell (1) are provided with arc-shaped clamping grooves (4) and T-shaped sliding grooves (3), and the upper end of the cylindrical shell (1) is fixedly connected with a fixing block (14);

the inside of the cylindrical shell (1) is movably provided with a filtering mechanism.

2. The nanofiltration device for sulfur-containing wastewater according to claim 1, wherein: circular slot (10) have been seted up on the surface of fixed block (14), slide bar (12) have been cup jointed in circular slot (10) internalization, the equal fixedly connected with dog (13) in both ends of slide bar (12), be located the rear end the upper end fixedly connected with driving lever (11) of dog (13).

3. The nanofiltration device for sulfur-containing wastewater according to claim 1, wherein: two equal activity is provided with arc slider (9), two in arc draw-in groove (4) the back of the body of arc slider (9) is from equal fixedly connected with arc strip (6) in both sides, two the equal fixedly connected with connecting block (8) of right-hand member of arc strip (6), two fixedly connected with holding rod (7) between connecting block (8), two the relative two sides of arc strip (6) laminate with the front and back of cylindric shell (1) respectively.

4. The nanofiltration device for sulfur-containing wastewater according to claim 1, wherein: the filter mechanism includes two rings (15) and two plectanes (2), two tub one (19) has all been seted up to the face middle part of plectane (2), is located the front end tub two (18) have been seted up to the lower extreme of plectane (2), two tub one (16) has all been cup jointed to the internal fixation of tub one (19), tub two (18) internal fixation has cup jointed pipe two (17).

5. The nanofiltration device for sulfur-containing wastewater according to claim 4, wherein: two fixedly connected with T type slide bar (20) between plectane (2), T type slide bar (20) activity joint is in T type spout (3), two the board footpath of plectane (2) matches with the internal diameter of cylindric shell (1).

6. The nanofiltration device for sulfur-containing wastewater according to claim 4, wherein: two opposite surfaces of the two circular plates (2) are fixedly connected with two opposite surfaces of the two circular rings (15) respectively, an annular groove (28) is formed in the upper end of the outer annular surface of each circular ring (15), strip-shaped grooves (29) are formed in the front and rear groove surfaces of each annular groove (28), and through grooves (27) are formed in the left end and the right end of the inner annular surface of each circular ring (15).

7. The nanofiltration device for sulfur-containing wastewater according to claim 6, wherein: two arc-shaped plates (24) are movably arranged in each annular groove (28), the front arc surface and the rear arc surface of each arc-shaped plate (24) are fixedly connected with sliding strips (26), and each sliding strip (26) is movably arranged in a corresponding strip-shaped groove (29).

8. The nanofiltration device for sulfur-containing wastewater according to claim 7, wherein: two arc surfaces opposite to each other of the arc plates (24) on the same side in the front and the back are fixedly connected with short rods (23), and the short rods (23) are movably sleeved in the corresponding through grooves (27).

9. The nanofiltration device for sulfur-containing wastewater according to claim 8, wherein: the rod end of each short rod (23) is fixedly connected with a semicircular plate (22), two adjacent semicircular plates (22) are combined into a complete limiting ring, a positioning ring (21) is movably arranged in the limiting ring, the positioning ring (21) is fixedly arranged on a circular plate (2), the inner wall of the limiting ring is tightly abutted against the outer ring surface of the positioning ring (21), and four limiting rods (25) are fixedly connected between the two semicircular plates (22) on the same side.

10. A method for using a nanofiltration device for sulfur-containing wastewater is characterized by comprising the following steps: a nanofiltration device for sulfur-containing wastewater according to any one of claims 1 to 9, comprising the steps of:

: an operator pulls the sliding rod (12) rightwards through the shifting rod (11), so that the sliding rod (12) slides rightwards without limiting the movement of the connecting block (8), and at the moment, the operator enables the arc-shaped strip (6) to slide downwards along the track of the arc-shaped sliding block (9) sliding in the arc-shaped clamping groove (4) through the holding rod (7), so that the front notch and the rear notch of the T-shaped sliding groove (3) are opened;

: an operator pulls the whole filtering mechanism forwards, a T-shaped sliding rod (20) slides in a T-shaped sliding groove (3) until a circular plate (2) positioned at the rear end reaches the edge of a front opening of a cylindrical shell (1), the arc-shaped plate (24) is pushed upwards at the moment, the arc-shaped plate (24) slides upwards in an annular groove (28) through a sliding strip (26) sliding in a strip-shaped groove (29), the opening of a through groove (27) is opened, the limiting rods (25) are pulled towards two sides at the moment to drive the semi-circular plates (22) to separate from each other, the inner wall of the semi-circular plate (22) is separated from the outer annular surface of the positioning ring (21), the nanofiltration membrane for filtering is not fixed at the moment, and the operator replaces and cleans the nanofiltration membrane;

: after the nanofiltration membrane is replaced, the two steps are operated in reverse, the whole device is reset, the normal nanofiltration of the sulfur-containing wastewater is carried out, the salt water enters the nanofiltration device after the pressure of the salt water is increased by a high-pressure pump, most of sulfate radical ions are intercepted under a high-pressure state, chloride ions and sodium ions smoothly pass through the membrane, so that the sodium ions with the valence of 1 and the chloride ions with the valence of-1 are separated from the sulfate radicals with the valence of-2, a penetrating fluid containing a small amount of sulfate radicals and a concentrated solution containing more sulfate radical ions are obtained, a sodium sulfate solution with required mass concentration can be obtained after multi-stage concentration and separation, and finally the sodium sulfate solution returns to a salt water system, so that the purpose of removing the sulfate radicals is achieved.