CN111115922A - Seawater resource desalination device and method - Google Patents
Seawater resource desalination device and method Download PDFInfo
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- CN111115922A CN111115922A CN202010008464.2A CN202010008464A CN111115922A CN 111115922 A CN111115922 A CN 111115922A CN 202010008464 A CN202010008464 A CN 202010008464A CN 111115922 A CN111115922 A CN 111115922A
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- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F9/00—Multistage treatment of water, waste water or sewage
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- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/44—Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis
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- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/44—Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis
- C02F1/442—Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis by nanofiltration
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- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/46—Treatment of water, waste water, or sewage by electrochemical methods
- C02F1/469—Treatment of water, waste water, or sewage by electrochemical methods by electrochemical separation, e.g. by electro-osmosis, electrodialysis, electrophoresis
- C02F1/4693—Treatment of water, waste water, or sewage by electrochemical methods by electrochemical separation, e.g. by electro-osmosis, electrodialysis, electrophoresis electrodialysis
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- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/66—Treatment of water, waste water, or sewage by neutralisation; pH adjustment
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- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
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- C02F2103/08—Seawater, e.g. for desalination
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- C02F2209/00—Controlling or monitoring parameters in water treatment
- C02F2209/06—Controlling or monitoring parameters in water treatment pH
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- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F2301/00—General aspects of water treatment
- C02F2301/08—Multistage treatments, e.g. repetition of the same process step under different conditions
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- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A20/00—Water conservation; Efficient water supply; Efficient water use
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- Y02A20/131—Reverse-osmosis
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Abstract
The invention relates to a seawater resource desalting device and method, and relates to the technical field of seawater treatment. The seawater resource desalting device comprises a low-pressure membrane salt separating device, a boron removing device and an electrodialysis concentration device, wherein the low-pressure membrane salt separating device, the boron removing device and the further desalting device which can be used for selective desalting are respectively arranged, so that the salt in seawater can be subjected to gradient permeation step-by-step desalting and treatment, the salt in the seawater can be subjected to salt separation, concentration and resource utilization, and the desalination is performed step by using a membrane method under the condition of low pressure, so that the desalted water with the boron content meeting the standard is obtained, the seawater is subjected to resource treatment and comprehensive utilization, the seawater desalting cost is greatly reduced, and the problems of safe operation, operation cost, environment and overproof boron in the desalted seawater are effectively solved.
Description
Technical Field
The invention relates to the technical field of seawater treatment, in particular to a seawater resource desalting device and method.
Background
The seawater desalination, namely the seawater desalination is used for producing fresh water, is an open source increment technology for realizing water resource utilization, can increase the total amount of the fresh water, is not influenced by time, space and climate, and can ensure stable water supply such as drinking water of coastal residents and water supplement of industrial boilers. At present, the seawater desalination is mostly carried out by adopting a distillation method, an electrodialysis method or a high-pressure reverse osmosis method to prepare fresh water, the methods have high operating cost, the high-pressure reverse osmosis method has safety problems due to high pressure, the environmental problem and the low recovery rate are caused by the discharge of concentrated water, and the safety problem of drinking water caused by the overproof boron exists. Therefore, the research and development of an effective seawater desalination process have great significance for solving the problems of safe equipment operation, high operation cost and environment and carrying out boron removal effective treatment on the desalinated seawater. Excessive boron in drinking water can damage liver, kidney, lung, digestive organs, skin, eyes and central nervous system, and in addition, excessive boron can cause plant growth poisoning, resulting in yellow leaf fixation and abscission.
Disclosure of Invention
The invention provides a seawater resource desalting device and method, which can greatly reduce the comprehensive water production cost by performing resource treatment on seawater, ensure safer equipment operation by improving the water production process, perform boron removal treatment on the brine in the seawater desalination treatment process to obtain the desalted water with the boron content meeting the standard, and greatly solve the environmental problem.
According to a first aspect of the present invention, there is provided a desalination apparatus for recycling seawater, comprising:
a low-pressure membrane salt separation device for separating a sodium chloride solution in seawater;
the boron removal device is connected with the monovalent brine output side of the low-pressure membrane salt separation device and is used for boron removal treatment; and
and the electrodialysis concentration device is connected with the boron removal device and is used for concentrating and desalting the saline water after boron removal.
In one embodiment, the electrodialysis concentration device comprises a sodium chloride brine tank, the concentrate output side of the boron removal device is connected with a boron recovery device, and the water production side of the boron removal device is connected with the sodium chloride brine tank.
In one embodiment, a monovalent brine tank is connected to the monovalent brine output side of the low-pressure membrane salt separation device, and the input side of the boron removal device is connected to the output side of the monovalent brine tank.
In one embodiment, a first pH adjusting device for adjusting the pH value of the monovalent brine is arranged on a pipeline between the low-pressure membrane salt separating device and the monovalent brine tank.
In one embodiment, the electrodialysis concentration apparatus further comprises a homogeneous membrane electrodialysis unit and a sodium chloride high-salt water tank,
if the conductivity of the brine output by the first output end of the homogeneous membrane electrodialysis unit reaches a preset value, connecting the first output end of the homogeneous membrane electrodialysis unit with a salt manufacturing device;
and if the conductivity of the brine output by the first output end of the homogeneous membrane electrodialysis unit does not reach a preset value, connecting the first output end of the homogeneous membrane electrodialysis unit with the input side of the high-brine sodium chloride tank.
In one embodiment, the homogeneous membrane electrodialysis unit further comprises a first input, a second input, and a second output;
wherein the first input and the second input are connected to an output side of the sodium chloride brine tank and an output side of the sodium chloride high brine tank, respectively,
the second output end is respectively connected with the input side of the sodium chloride brine tank and the input side of the primary desalination water tank;
a first electric valve is arranged on a pipeline connecting the second output end with the input side of the primary desalination water tank; and a second electric valve is arranged on a pipeline connecting the second output end with the input side of the sodium chloride brine tank.
In one embodiment, the system further comprises a low-pressure membrane desalination device connected with the output side of the primary desalination water tank, wherein the desalinated water output side of the low-pressure membrane desalination device is connected with a secondary desalination water tank; a high desalination nanofiltration device is arranged on a pipeline which is connected with the strong brine output side of the low-pressure membrane desalination device and the input side of the primary desalination water tank;
and the high-salinity concentrated water output side of the high-desalination nanofiltration device is respectively connected with the input side of the sodium chloride brine tank and the input side of the sodium chloride high-salinity brine tank.
In one embodiment, still include the preceding processing apparatus that is used for filtering and purification treatment to sea water, preceding processing apparatus includes consecutive micro-filtration device and water purification case, the output side of water purification case with the low pressure membrane divides the input side of salt device to link to each other, the low pressure membrane divides the high price strong brine output side of salt device to link to each other with the input side of water purification case.
In one embodiment, the high-price strong brine output side of the low-pressure membrane salt separation device is respectively connected with a solid-liquid separation device and the clean water tank;
a third regulating valve is arranged on a pipeline connecting the high-price strong brine output side of the low-pressure membrane salt separating device with the solid-liquid separating device; when the conductivity of high-valence strong brine output by the high-valence strong brine of the low-pressure membrane salt separation device is higher than a preset value, a first flushing valve is opened to enable the high-valence strong brine to flow to the solid-liquid separation device;
a first flushing valve and a fourth regulating valve are arranged in parallel on a pipeline connecting the high-price strong brine output side of the low-pressure membrane salt separation device and the purified water tank;
and the water output side of the solid-liquid separation device is connected with the input side of the purified water tank.
According to a second aspect of the present invention, the present invention provides a method for desalinating seawater by using the seawater desalination device, which comprises the following steps:
separating monovalent salt from high-valent salt by a low-pressure membrane salt separating device,
the univalent brine separated in the low-pressure membrane salt separation device enters a boron removal device for boron removal treatment, the high-valence strong brine returns to the low-pressure membrane salt separation device again for cyclic separation, and when the conductivity of the high-valence strong brine is higher than a preset value, a first flushing valve is opened to discharge the high-valence strong brine outwards;
water produced by the boron removal device enters an electrodialysis concentration device for concentration treatment;
and preparing salt from the concentrated brine obtained after the concentration treatment by the electrodialysis concentration device, and further desalting the desalted water.
Compared with the prior art, the invention has the advantages that: the low-pressure membrane salt separating device, the boron removing device and the further desalting device which can be used for selective desalting are respectively arranged, salt in seawater can be subjected to gradient permeation step-by-step desalting and can be treated, seawater salt can be subjected to salt separation, concentration and resource utilization, and membrane method step-by-step desalting is utilized under the low-pressure condition, so that desalted water with the boron content meeting the standard is obtained, seawater is subjected to resource treatment and comprehensive utilization, the seawater desalting cost is greatly reduced, and the problems of safe operation, running cost, environment and overproof of boron in desalted seawater are effectively solved.
Drawings
The invention will be described in more detail hereinafter on the basis of embodiments and with reference to the accompanying drawings.
FIG. 1 is a schematic structural diagram of a seawater desalination plant for recycling in an embodiment of the present invention.
Description of the drawings:
1-low pressure membrane salt separating device; 11-monovalent brine tank; 12-a first pH adjustment device; 13-a first flush valve; 14-a fourth regulating valve;
2-a boron removal device; 21-a second high pressure pump; 22-a first regulating valve; 23-a second flush valve;
3-an electrodialysis concentration device; 31-sodium chloride brine tank; 32-a homogeneous membrane electrodialysis unit; 33-sodium chloride high-salt water tank; 34-a water return valve; 35-brine drain valve; 36-a third high pressure pump; 37-a first electrically operated valve; 38-second electrically operated valve; 39-primary desalination water tank;
4-a boron recovery unit;
5-a salt making device;
6-a high desalting nanofiltration device; 61-a water replenishing valve; 62-a second regulating valve; 63-low pressure membrane desalination plant;
7-pretreatment equipment; 71-a microfiltration device; 72-a clean water tank; 73-a booster pump; 74-a first high pressure pump;
8-a secondary desalination water tank;
9-a solid-liquid separation device; 91-a stirrer; 92-a first pH adjustment device; 93-a solid-liquid separator; 94-a booster pump; 95-a filter press; 96-third regulating valve.
Detailed Description
The invention will be further explained with reference to the drawings.
As shown in fig. 1, according to a first aspect of the present invention, the present invention provides a seawater desalination plant, comprising a low pressure membrane salt separation device 1, a boron removal device 2 and an electrodialysis concentration device 3. Wherein, the low-pressure membrane salt separation device 1 is used for separating a sodium chloride solution in seawater; the boron removal device 2 is connected with the monovalent brine output side of the low-pressure membrane salt separation device 1 and used for boron removal treatment, and the electrodialysis concentration device 3 is connected with the boron removal device 2 and used for concentrating and desalting the brine after boron removal.
Specifically, the electrodialysis concentration device 3 comprises a sodium chloride brine tank 31, the concentrated water output side of the boron removal device 2 is connected with the boron recovery device 4, and the connected pipeline is provided with a first regulating valve 22, and the on-off of the first regulating valve 22 is controlled. In addition, the pipeline that the two link to each other is still connected in parallel has the washing pipeline, is provided with second flushometer 23 on the washing pipeline, can wash boron removal device 2 through opening second flushometer 23.
The water producing side of the boron removal device 2 is connected to a sodium chloride brine tank 31. Therefore, the concentrated water obtained after the treatment by the boron removing device 2 enters the boron recovery device 4 to recover boron, and the obtained sodium chloride brine enters the sodium chloride brine tank 31 to be subjected to resource treatment.
Further, a monovalent brine tank 11 is connected to the monovalent brine output side of the low-pressure membrane salt separation device 1, and the input side of the boron removal device 2 is connected to the output side of the monovalent brine tank 11 via a second high-pressure pump 21. Monovalent salt (such as sodium chloride) and high-valence salt (such as magnesium chloride, calcium chloride and the like) can be separated by the low-pressure membrane salt separation device 1, and monovalent brine enters a monovalent brine tank 11 and then enters the boron removal device 2 for boron removal treatment. Wherein the monovalent brine tank 11 can buffer the downstream boron removal device 2.
Further, a first pH adjusting device 12 for adjusting the pH of the liquid is provided on a pipe between the low pressure membrane salt separating device 1 and the monovalent brine tank 11. The first pH adjusting device 12 may be an alkaline tank carrying sodium hydroxide solution.
Because boron is mainly stored in the form of boric acid in waterAt this point. Boric acid is a soluble solid with a solubility of 55g8L at 25 c because boron is an electron deficient structure and boric acid is a weak acid. The pKa value can be kept low (2 mg. L)-1) In this case, the boronic acid is predominantly present as a mononuclear molecule B (OH)3And B (OH)4Two forms exist. When the pH is greater than the pKa of the boronic acid, most of the boronic acid is present in ionic form. The pH of the monovalent brine entering the monovalent brine tank 11 is thus adjusted by the first pH adjusting means 12 to ensure that boric acid therein is present in ionic form to facilitate its removal.
In one embodiment, the electrodialysis concentration unit 3 further comprises a homogeneous membrane electrodialysis unit 32 and a high sodium chloride brine tank 33, the homogeneous membrane electrodialysis unit 32 being selectively connected to the high sodium chloride brine tank 33 and the salt plant 5. Specifically, the connection mode is controlled by the conductivity of the brine, and if the conductivity of the brine output by the first output end c of the homogeneous membrane electrodialysis unit 32 reaches a preset value, the first output end c of the homogeneous membrane electrodialysis unit 32 is connected with the salt manufacturing device 5; if the conductivity of the brine output from the first output c of the homogeneous membrane electrodialysis unit 32 does not reach the preset value, the first output c of the homogeneous membrane electrodialysis unit 32 is connected to the input side of the high brine tank 33 of sodium chloride. In this way, the output of the homogeneous membrane electrodialysis unit 32 can be precisely controlled.
Further, a saline water discharge valve 35 is arranged on a pipeline between the first output end c of the homogeneous membrane electrodialysis unit 32 and the salt manufacturing device 5; a return valve 34 is arranged on a pipeline between the first output end c of the homogeneous membrane electrodialysis unit 32 and the input side of the sodium chloride high-salt water tank 33, and selective conduction of the homogeneous membrane electrodialysis unit 32, the sodium chloride high-salt water tank 33 and the salt manufacturing device 5 can be realized by controlling the opening and closing of the brine discharge valve 35 and the return valve 34.
Furthermore, the homogeneous membrane electrodialysis unit 32 comprises a first input b, a second input a and a second output d; wherein the first input b and the second input a are connected to the output side of the sodium chloride brine tank 31 and the output side of the sodium chloride high brine tank 33, respectively, and the second output d is connected to the input side of the sodium chloride brine tank 31 and the input side of the primary desalination water tank 39.
A first electric valve 37 is arranged on a pipeline connecting the second output end d with the input side of the primary desalination water tank 39; a second electrically operated valve 38 is provided on the conduit connecting the second output d to the input side of the sodium chloride brine tank 31. The output of the second output port d can be controlled by controlling the opening and closing of the first motor-operated valve 37 and the second motor-operated valve 38.
For example, when the conductivity of the fluid output from the second output d reaches a preset value, the second electric valve 38 is opened, and the output enters the sodium chloride brine tank 31 for secondary treatment, and when the conductivity of the fluid output from the second output d is lower than the preset value, the first electric valve 37 is opened, and the output enters the primary desalination water tank 39.
The sodium chloride brine in the sodium chloride brine tank 31 flows through the homogeneous membrane electrodialysis unit 32 to be ion-transferred for desalination, and anions and cations can pass through the anion and cation membranes of the homogeneous membrane electrodialysis unit 32 and can be transferred to the sodium chloride high brine tank 33, when the brine conductivity reaches a preset value, the brine discharge valve 35 is opened, and then the concentrated brine enters the salt manufacturing device 5 for salt manufacturing.
The ion exchange membrane in the homogeneous membrane electrodialysis unit 32 is a homogeneous membrane, and the electrochemical performance is excellent, which is not described herein again.
The seawater resource desalination device also comprises a low-pressure membrane desalination device 63 connected with the output side of the primary desalination water tank 39, and the desalinated water obtained after the processing of the seawater resource desalination device by the homogeneous membrane electrodialysis unit 32 enters the primary desalination water tank 39 to be relayed and then enters the low-pressure desalination device 6 for processing. A third high-pressure pump 36 is arranged on a pipeline between the output side of the primary desalination water tank 39 and the output side of the low-pressure desalination device 6, so that the desalinated water is output to the low-pressure desalination device 6.
In addition, the strong brine output side of the low-pressure membrane desalination device 63 is connected with the input side of the primary desalination water tank 39, a high-salinity desalination and nanofiltration device 6 is arranged on a pipeline connected with the strong brine output side of the low-pressure membrane desalination device and the input side of the primary desalination water tank 39, and the high-salinity strong brine output side of the high-salinity desalination and nanofiltration device 6 is respectively connected with the input side of the sodium chloride brine tank 31 and the input side of the sodium chloride high-salinity brine. A regulating valve 62 is arranged on a pipeline connecting the high-salinity concentrated water output side of the high-desalination nanofiltration device 6 with the input side of the sodium chloride brine tank 31, and a water replenishing valve 61 is arranged on a pipeline connecting the high-salinity concentrated water output side of the high-desalination nanofiltration device 6 with the input side of the sodium chloride high-salinity brine tank 33. The opening of the water replenishing valve 61 is controlled by the liquid level of the sodium chloride high-salt water tank 33, and during operation, high-concentration salt water of the high-desalting and nanofiltration device 6 enters the sodium chloride salt water tank 31 through the regulating valve 62 for circular treatment. .
The desalted water output side of the low-pressure membrane desalting device 63 is connected with the secondary desalting water tank 8, and the desalted water after secondary treatment can be stored and used.
The seawater resource desalination device also comprises a pretreatment device 7 for filtering and purifying seawater, wherein the pretreatment device 7 comprises a booster pump 73, a microfiltration device 71, a purified water tank 72 and a first high-pressure pump 74 which are connected in sequence, seawater is pumped into the microfiltration device 71 through the booster pump 73 for filtering and purifying treatment, and purified water obtained after treatment is input into the purified water tank 72 so as to avoid influencing downstream components.
The outlet side of the clean water tank 72 is connected to the inlet side of the low-pressure membrane salt separator 1 via a first high-pressure pump 74 in order to pump clean water into the low-pressure membrane salt separator 1. The high-price strong brine output side of the low-pressure membrane salt separation device 1 is connected with the input side of the purified water tank 72, so that the strong brine is circulated to carry out salt separation treatment.
The high-price strong brine output side of the low-pressure membrane salt separation device 1 is respectively connected with a solid-liquid separation device 9 and a clean water tank 72. The high-price strong brine output side of the low-pressure membrane salt separation device 1 is connected with a pipeline of the clean water tank 72, and a first flushing valve 13 and a fourth regulating valve 14 are arranged in parallel.
A third regulating valve 96 is arranged on a pipeline connecting the high-price strong brine output side of the low-pressure membrane salt separating device 1 with the solid-liquid separating device 9; when the conductivity of the high-valence strong brine output by the high-valence strong brine of the low-pressure membrane salt separation device 1 is higher than a preset value, the third regulating valve 96 is opened to enable the high-valence strong brine to flow to the solid-liquid separation device 9.
The solid-liquid separation device 9 includes a stirrer 91 connected to the high-valence strong brine output side of the low-pressure membrane salt separation device 1, a booster pump 94 connected to the stirrer 91, and a solid-liquid separator 93 connected to the high-pressure pump. The stirrer 91 is also connected to a second pH adjusting device 92, and the pH value of the high-valence concentrated brine in the stirrer 91 is adjusted by the second pH adjusting device 92. For example, the second pH adjusting device 92 may adjust the pH of the high-valence concentrated brine to be between 9 and 10 by dissolving calcium oxide. Preferably, the pH value of the high-valence concentrated brine is 9.5.
After the stirrer 91 stirs the high-valence concentrated brine with the pH value of 9.5 uniformly, the booster pump 94 inputs the concentrated brine into the solid-liquid separator 93 for solid-liquid separation, the solid output side of the solid-liquid separator 93 is connected with the filter press 95, and the liquid output side of the solid-liquid separator 93 is connected with the input side of the purified water tank 72.
Therefore, the solids (such as calcium sulfate, magnesium hydroxide, etc.) separated by the solid-liquid separator 93 are fed to a filter press 95 to be press-filtered into a cake, and the separated liquid is fed to the clean water tank 72 to be recycled for treatment.
According to a first aspect of the present invention, the present invention provides a method for desalinating seawater by using the seawater desalination device, which comprises the following steps:
in the first step, the seawater is filtered and purified by a pretreatment device 7.
And secondly, separating monovalent salt from high-valent salt from the pretreated seawater by using a low-pressure membrane salt separation device 1.
And thirdly, feeding the monovalent brine separated in the low-pressure membrane salt separation device 1 into a boron removal device 2 for boron removal treatment.
When the conductivity of the high-valence strong brine output by the high-valence strong brine of the low-pressure membrane salt separation device 1 is higher than a preset value, the high-valence strong brine flows to the solid-liquid separation device 9 for solid-liquid separation, wherein the separated solid enters a filter press 95 for pressure filtration to form a cake, and the separated liquid enters a purified water tank 72 for circulation treatment.
When the conductivity of the high-valence strong brine output by the high-valence strong brine of the low-pressure membrane salt separation device 1 is lower than a preset value, the high-valence strong brine enters the purified water tank 72 again and further returns to the low-pressure membrane salt separation device 1 for circular separation.
And fourthly, the water produced by the boron removal device 2 enters the electrodialysis concentration device 3 for concentration treatment, and the concentrated water obtained by boron removal of the boron removal device 2 enters the boron recovery device 4 for recovery treatment.
Fifthly, the strong brine after the concentration treatment by the electrodialysis concentration device 3 enters a salt making device 5 for making salt, and the desalted water enters a low-pressure membrane desalting device 63 for further desalting treatment.
Sixthly, the desalted water obtained from the low-pressure membrane desalting device 63 enters the secondary desalting water tank 8 for storage, the desalted water is directly used desalted water, and the obtained monovalent strong brine is returned to the sodium chloride brine tank 31 or the sodium chloride high brine tank 33 for circular treatment.
It can be seen from the above steps that by respectively arranging the low-pressure membrane salt separation device, the boron removal device and the further desalination device which can carry out selective desalination, the salt in the seawater can be subjected to gradient permeation and step-by-step desalination and treatment, the seawater salt can be subjected to salt separation, concentration and resource utilization, and the membrane method is used for step-by-step desalination under the low-pressure condition, so that the desalinated water with the boron content meeting the standard is obtained, the seawater is subjected to resource treatment and comprehensive utilization, the seawater desalination cost is greatly reduced, and the problems of safe operation, operation cost, environment and overproof of boron in the desalinated seawater are effectively solved.
While the invention has been described with reference to a preferred embodiment, various modifications may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In particular, the technical features mentioned in the embodiments can be combined in any way as long as there is no structural conflict. It is intended that the invention not be limited to the particular embodiments disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.
Claims (10)
1. A seawater resource desalination device is characterized by comprising:
a low-pressure membrane salt separation device (1) for separating a sodium chloride solution in seawater;
the boron removal device (2) is connected with the monovalent brine output side of the low-pressure membrane salt separation device (1) and is used for boron removal treatment; and
and the electrodialysis concentration device (3) is connected with the boron removal device (2) and is used for concentrating and desalting the saline water after boron removal.
2. The seawater desalination apparatus as claimed in claim 1, wherein the electrodialysis concentration apparatus (3) comprises a sodium chloride brine tank (31), the concentrated water output side of the boron removal apparatus (2) is connected with a boron recovery apparatus (4), and the water production side of the boron removal apparatus (2) is connected with the sodium chloride brine tank (31).
3. A seawater desalination plant as claimed in claim 2, characterized in that the monovalent brine tank (11) is connected to the monovalent brine output side of the low pressure membrane salt separation device (1), and the input side of the boron removal device (2) is connected to the output side of the monovalent brine tank (11).
4. A seawater desalination plant as claimed in claim 3, characterized in that the pipeline between the low pressure membrane salt separation device (1) and the monovalent brine tank (11) is provided with a first pH adjusting device (12) for adjusting the pH of monovalent brine.
5. The seawater desalination apparatus as claimed in claim 3 or 4, wherein the electrodialysis concentration apparatus (3) further comprises a homogeneous membrane electrodialysis unit (32) and a high-salt water tank (33) of sodium chloride,
wherein, if the conductivity of the saline water output by the first output end of the homogeneous membrane electrodialysis unit (32) reaches a preset value, the first output end of the homogeneous membrane electrodialysis unit (32) is connected with a salt manufacturing device (5);
if the conductivity of the brine output by the first output end of the homogeneous membrane electrodialysis unit (32) does not reach a preset value, the first output end of the homogeneous membrane electrodialysis unit (32) is connected with the input side of the sodium chloride high-brine tank (33).
6. The desalination apparatus as claimed in claim 5, wherein the homogeneous membrane electrodialysis unit (32) further comprises a first input, a second input, and a second output;
wherein the first input and the second input are connected to an output side of the sodium chloride brine tank (31) and an output side of the sodium chloride high brine tank (33), respectively,
the second output end is respectively connected with the input side of the sodium chloride brine tank (31) and the input side of the primary desalination water tank (39);
a first electric valve (37) is arranged on a pipeline of the second output end connected with the input side of the primary desalination water tank (39); and a second electric valve (38) is arranged on a pipeline of the second output end connected with the input side of the sodium chloride brine tank (31).
7. The seawater desalination apparatus as claimed in claim 5, further comprising a low-pressure membrane desalination apparatus (63) connected to the output side of the primary desalination water tank (39), wherein the output side of the low-pressure membrane desalination apparatus (63) is connected to the secondary desalination water tank (8); a high desalination and nanofiltration device (6) is arranged on a pipeline connecting the strong brine output side of the low pressure membrane desalination device (63) and the input side of the primary desalination water tank (39);
and the high-salinity concentrated water output side of the high-desalination nanofiltration device (6) is respectively connected with the input side of the sodium chloride brine tank (31) and the input side of the sodium chloride high-salinity brine tank (33).
8. A seawater desalination plant as claimed in any one of claims 1 to 4, further comprising a pretreatment device (7) for filtering and purifying seawater, wherein the pretreatment device (7) comprises a microfiltration device (71) and a purified water tank (72) which are connected in sequence, the output side of the purified water tank (72) is connected with the input side of the low-pressure membrane salt separation device (1), and the output side of the high-valence strong brine of the low-pressure membrane salt separation device (1) is connected with the input side of the purified water tank (72).
9. The seawater desalination apparatus as claimed in claim 8, wherein the high-price strong brine output side of the low-pressure membrane salt separation device (1) is respectively connected with a solid-liquid separation device (9) and the purified water tank (72);
a third regulating valve (96) is arranged on a pipeline connecting the high-price strong brine output side of the low-pressure membrane salt separating device (1) with the solid-liquid separating device (9); when the conductivity of the high-valence strong brine output by the high-valence strong brine of the low-pressure membrane salt separation device (1) is higher than a preset value, a third regulating valve (96) is opened to enable the high-valence strong brine to flow to the solid-liquid separation device (9);
a first flushing valve (13) and a fourth regulating valve (14) are arranged in parallel on a pipeline connecting the high-price strong brine output side of the low-pressure membrane salt separation device (1) with the purified water tank (72);
the water output side of the solid-liquid separation device (9) is connected with the input side of the purified water tank (72).
10. A method for desalinating seawater by using the seawater resource desalination apparatus as defined in any one of claims 1 to 9, comprising the steps of:
a low-pressure membrane salt separating device (1) is adopted to separate monovalent salt from high-valent salt from the pretreated seawater,
the separated monovalent brine in the low-pressure membrane salt separation device (1) enters a boron removal device (2) for boron removal treatment, the high-valence strong brine returns to the low-pressure membrane salt separation device (1) again for circular separation, and when the conductivity of the high-valence strong brine is higher than a preset value, a first flushing valve (13) is opened to discharge the high-valence strong brine outwards;
water produced by the boron removal device (2) enters an electrodialysis concentration device (3) for concentration treatment;
the strong brine concentrated by the electrodialysis concentration device (3) is used for preparing salt, and the primarily desalted water enters a low-pressure membrane desalting device (63) for further desalting.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010008464.2A CN111115922A (en) | 2020-01-06 | 2020-01-06 | Seawater resource desalination device and method |
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| Application Number | Priority Date | Filing Date | Title |
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| CN202010008464.2A CN111115922A (en) | 2020-01-06 | 2020-01-06 | Seawater resource desalination device and method |
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| CN111115922A true CN111115922A (en) | 2020-05-08 |
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| CN202010008464.2A Withdrawn CN111115922A (en) | 2020-01-06 | 2020-01-06 | Seawater resource desalination device and method |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116177557A (en) * | 2023-01-13 | 2023-05-30 | 格尔木藏格锂业有限公司 | Method for preparing borax from wastewater containing boron discharged from electrodialysis process section |
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2020
- 2020-01-06 CN CN202010008464.2A patent/CN111115922A/en not_active Withdrawn
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116177557A (en) * | 2023-01-13 | 2023-05-30 | 格尔木藏格锂业有限公司 | Method for preparing borax from wastewater containing boron discharged from electrodialysis process section |
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