Seawater treatment system

Abstract

The utility model provides a seawater treatment system, and relates to the technical field of concentrated seawater resourceful treatment, a first nanofiltration system is used for separating monovalent and divalent salts in concentrated seawater and concentrating magnesium ions in the concentrated seawater, and a produced water treatment assembly is used for treating nanofiltration produced water formed by the first nanofiltration system; the concentrated water treatment assembly is used for treating nanofiltration concentrated water formed by the first nanofiltration system, adding a nitrogen source and a phosphorus source to form struvite and adding sodium carbonate to form calcium carbonate, so that components such as calcium, magnesium, sulfate radicals and bromine in the seawater can be effectively extracted, and salt in the seawater can be extracted and sold as refined salt; reasonable utilization of resources is achieved, and the technical problems that in the prior art, a concentrated seawater treatment mode seriously affects the ecological environment, and a large number of high-quality chemical resources contained in concentrated seawater are wasted are solved.

Description

Technical Field

[0001] The utility model relates to the technical field of concentrated seawater resource treatment, in particular to a seawater treatment system. Background Art

[0002] Water shortages have become a global issue. With socioeconomic development and population growth, the imbalance between water supply and demand is becoming increasingly prominent. Desalination has gradually become one of the most important technological solutions to address the current global freshwater shortage, and both the technology level and industrial scale of desalination have developed rapidly. Reverse osmosis membrane desalination technology, due to its simple operation, lack of phase change, and low energy consumption, has become one of the mainstream desalination technologies.

[0003] Furthermore, the impact of the desalination process and its products on the ecological environment is becoming an increasingly critical factor. Concentrated seawater, a byproduct of desalination equipment, has a high salinity, a complex chemical composition, and contains other chemicals added during the seawater pretreatment process. Improper treatment can pose a serious threat to the soil, groundwater, surface water, and marine ecosystems. Therefore, the scientific and rational treatment and comprehensive utilization of concentrated seawater are of great significance. In some special regions, such as the Bohai Rim, which lacks open sea areas, this has become a key bottleneck in the development of the desalination industry.

[0004] Traditional methods for treating concentrated seawater mainly include deep well injection, evaporation pond discharge, surface water discharge, deep-sea discharge, etc. These treatment methods not only have a serious impact on the ecological environment, but also waste a large amount of high-quality chemical resources contained in concentrated seawater. Utility Model Content

[0005] The purpose of the utility model is to provide a seawater treatment system to alleviate the technical problems that the concentrated seawater treatment method in the prior art not only has a serious impact on the ecological environment, but also wastes a large amount of high-quality chemical resources contained in the concentrated seawater.

[0006] The seawater treatment system provided by the utility model comprises: a first nanofiltration system, a produced water treatment component and a concentrated water treatment component;

[0007] Concentrated seawater is fed into the first nanofiltration system, and the first nanofiltration system is configured to separate monovalent and divalent salts in the concentrated seawater and concentrate magnesium ions in the concentrated seawater to form nanofiltration product water containing bromine and sodium chloride and nanofiltration concentrated water containing calcium, magnesium ions and sulfate;

[0008] The nanofiltration product water generated by the first nanofiltration system can enter the product water treatment component, and the product water treatment component is configured to concentrate and extract bromine and sodium chloride in the nanofiltration product water;

[0009] The nanofiltration concentrate formed by the first nanofiltration system can enter the concentrate treatment component, and the concentrate treatment component is configured to be able to add nitrogen source and phosphorus source to form struvite in the nanofiltration concentrate, and to be able to add sodium carbonate to form calcium carbonate in the nanofiltration concentrate.

[0010] In an alternative embodiment,

[0011] The water production treatment component includes a reverse osmosis device;

[0012] The reverse osmosis device is in communication with the first nanofiltration system. The nanofiltration product water generated by the first nanofiltration system can enter the reverse osmosis device. The reverse osmosis device is used to concentrate bromine and sodium chloride in the nanofiltration product water.

[0013] In an alternative embodiment,

[0014] The water production treatment component also includes a chlorine stripping device;

[0015] The chlorine stripping device is connected to the reverse osmosis device, and the concentrated liquid from the reverse osmosis device enters the chlorine stripping device. The chlorine stripping device is used to replace bromine with chlorine.

[0016] In an alternative embodiment,

[0017] The water production and treatment component also includes a first evaporation device;

[0018] The first evaporation device is connected to the chlorine stripping device, and the solution after bromine extraction in the chlorine stripping device enters the first evaporation device to evaporate and crystallize the solution to obtain sodium chloride crystals.

[0019] In an alternative embodiment,

[0020] The concentrated water treatment component includes a first reaction tank;

[0021] The first reaction tank is connected to the first nanofiltration system. The nanofiltration concentrated water formed by the first nanofiltration system enters the first reaction tank. The first reaction tank is configured to be able to be fed with a nitrogen source and a phosphorus source.

[0022] In an alternative embodiment,

[0023] The concentrated water treatment component also includes a first sedimentation tank;

[0024] The first sedimentation tank is connected to the first reaction tank, and the first sedimentation tank is used for precipitating and filtering the solution after the nitrogen source and the phosphorus source are added into the first reaction tank to form a struvite product.

[0025] In an alternative embodiment,

[0026] The concentrated water treatment component also includes a second reaction tank;

[0027] The second reaction tank is connected to the first sedimentation tank, and the solution filtered in the first sedimentation tank enters the second reaction tank. The second reaction tank is configured to be able to be fed with sodium carbonate.

[0028] In an alternative embodiment,

[0029] The concentrated water treatment component also includes a second sedimentation tank;

[0030] The second sedimentation tank is connected to the second reaction tank. The solution after sodium carbonate is added into the second reaction tank enters the second sedimentation tank. The second sedimentation tank is used for precipitation and filtration to form a calcium carbonate product.

[0031] In an alternative embodiment,

[0032] The seawater treatment system further includes a second nanofiltration system;

[0033] The second nanofiltration system is connected to the second sedimentation tank, and the solution in the second sedimentation tank can enter the second nanofiltration system. The second nanofiltration system is configured to separate monovalent and divalent ions in the solution flowing out of the second sedimentation tank, and the nanofiltration water produced by the second nanofiltration system enters the reverse osmosis device.

[0034] In an alternative embodiment,

[0035] The seawater treatment system further includes a second evaporator;

[0036] The second nanofiltration system is connected to the second evaporator, and the nanofiltration concentrated water formed by the second nanofiltration system enters the second evaporator. The second evaporator is used to evaporate the nanofiltration concentrated water formed by the second nanofiltration system to obtain sodium sulfate.

[0037] The seawater treatment system provided by the utility model separates monovalent and divalent salts in concentrated seawater and concentrates magnesium ions in the concentrated seawater through a first nanofiltration system; the produced water treatment component treats the nanofiltration produced water formed by the first nanofiltration system, concentrates and extracts bromine and sodium chloride in the nanofiltration produced water; the concentrated water treatment component treats the nanofiltration concentrated water formed by the first nanofiltration system, adds nitrogen and phosphorus sources to form struvite, and adds sodium carbonate to form calcium carbonate, which can effectively extract calcium, magnesium, sulfate, bromine and other components in seawater; the salt in the seawater can be extracted and sold as refined table salt, thereby realizing rational resource utilization and alleviating the technical problem that the concentrated seawater treatment method in the existing technology not only has a serious impact on the ecological environment, but also wastes a large amount of high-quality chemical resources contained in the concentrated seawater. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the specific implementation methods of the utility model or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0039] Figure 1 This is an overall flow chart of the seawater treatment system provided by an embodiment of the present utility model.

[0040] Icons: 1-first nanofiltration system; 2-reverse osmosis device; 3-chlorine stripping device; 4-first evaporation device; 5-first reaction tank; 6-first sedimentation tank; 7-second reaction tank; 8-second sedimentation tank; 9-second nanofiltration system; 10-second evaporator. DETAILED DESCRIPTION

[0041] The following is a clear and complete description of the technical solution of the present invention in conjunction with the accompanying drawings. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0042] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating positions or relationships, are based on the positions or relationships shown in the accompanying drawings and are intended solely to facilitate the description of this utility model and simplify the description. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0043] In the description of this utility model, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections, electrical connections; direct connections, indirect connections through an intermediate medium, and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on specific circumstances.

[0044] The following is a detailed description of the specific embodiments of the present invention in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention and are not intended to limit the present invention.

[0045] like Figure 1 As shown, the seawater treatment system provided in this embodiment includes: a first nanofiltration system 1, a produced water treatment component and a concentrated water treatment component.

[0046] The concentrated seawater enters the first nanofiltration system 1, which separates the monovalent and divalent salts in the concentrated seawater and concentrates the magnesium ions in the concentrated seawater. The first nanofiltration system 1 forms nanofiltration product water containing bromine and sodium chloride and nanofiltration concentrated water containing calcium, magnesium ions and sulfate.

[0047] The nanofiltration water produced by the first nanofiltration system 1 can enter the water production treatment component, which is used to receive the nanofiltration water flowing out of the first nanofiltration system 1. The water production treatment component concentrates and extracts the bromine and sodium chloride in the nanofiltration water to obtain bromine products and sodium chloride products. The product after the sodium chloride is concentrated and crystallized can be used as edible salt.

[0048] The nanofiltration concentrate formed by the first nanofiltration system 1 can enter the concentrate treatment component, and a nitrogen source and a phosphorus source are added to the concentrate treatment component to form struvite in the nanofiltration concentrate, and sodium carbonate is added to the solution after the struvite is formed to form calcium carbonate in the nanofiltration concentrate, thereby realizing the formation of struvite products and calcium carbonate products from the nanofiltration concentrate.

[0049] The seawater treatment system provided in this embodiment separates monovalent and divalent salts from concentrated seawater and concentrates magnesium ions in the concentrated seawater through the first nanofiltration system 1. The produced water treatment component treats the nanofiltration produced water generated by the first nanofiltration system 1, concentrates and extracts bromine and sodium chloride in the nanofiltration produced water. The concentrated water treatment component treats the nanofiltration concentrated water generated by the first nanofiltration system 1, adds nitrogen and phosphorus sources to form struvite, and adds sodium carbonate to form calcium carbonate. This effectively extracts calcium, magnesium, sulfate, bromine, and other components from seawater. The salt in the seawater can be extracted and sold as refined table salt, thereby achieving rational resource utilization and alleviating the technical problem that the concentrated seawater treatment method in the prior art not only has a serious impact on the ecological environment, but also wastes a large amount of high-quality chemical resources contained in the concentrated seawater.

[0050] Regarding the specific structure of the water treatment components, specifically:

[0051] The water production treatment component includes a reverse osmosis device 2; the reverse osmosis device 2 is connected to the first nanofiltration system 1, and the nanofiltration water produced by the first nanofiltration system 1 can enter the reverse osmosis device 2, which concentrates the bromine and sodium chloride in the nanofiltration water.

[0052] The water treatment component also includes a chlorine stripping device 3; the chlorine stripping device 3 is connected to the reverse osmosis device 2, and the concentrated liquid after the reverse osmosis device 2 enters the chlorine stripping device 3, and the chlorine stripping device 3 uses chlorine to replace bromine.

[0053] The water treatment component also includes a first evaporation device 4; the first evaporation device 4 is connected to the chlorine stripping device 3, and the solution after bromine extraction in the chlorine stripping device 3 enters the first evaporation device 4. The first evaporation device 4 is specifically configured as an evaporator to evaporate and crystallize the solution to obtain sodium chloride crystals.

[0054] Regarding the structure of the concentrated water treatment component, specifically:

[0055] The concentrated water treatment component includes a first reaction tank 5; the first reaction tank 5 is connected to the first nanofiltration system 1, and the nanofiltration concentrated water formed by the first nanofiltration system 1 enters the first reaction tank 5. The first reaction tank 5 is configured to be able to be fed with a nitrogen source and a phosphorus source. Since the nanofiltration concentrated water is rich in divalent ions such as calcium, magnesium ions and sulfate, it reacts with the nitrogen source and phosphorus source to form struvite.

[0056] The concentrated water treatment component also includes a first sedimentation tank 6; the first sedimentation tank 6 is connected to the first reaction tank 5. After the nitrogen source and phosphorus source are added to the first reaction tank 5, the solution enters the first sedimentation tank 6 and is filtered and precipitated in the first sedimentation tank 6 to form a struvite product.

[0057] The concentrated water treatment component also includes a second reaction tank 7; the second reaction tank 7 is connected to the first sedimentation tank 6, and the solution filtered by the first sedimentation tank 6 enters the second reaction tank 7. Sodium carbonate can be added to the second reaction tank 7, and the sodium carbonate reacts with the calcium ions in the nanofiltration concentrated water to form calcium carbonate.

[0058] The concentrated water treatment component also includes a second sedimentation tank 8; the second sedimentation tank 8 is connected to the second reaction tank 7. After the second reaction tank 7 is added with sodium carbonate, the solution enters the second sedimentation tank 8. The second sedimentation tank 8 precipitates and filters the solution to obtain a calcium carbonate product.

[0059] Based on the above, in an optional embodiment, the seawater treatment system further includes a second nanofiltration system 9; the second nanofiltration system 9 is connected to the second sedimentation tank 8, and the solution in the second sedimentation tank 8 can enter the second nanofiltration system 9. The second nanofiltration system 9 can separate the monovalent and divalent ions of the solution flowing out of the second sedimentation tank 8 to form nanofiltration product water and nanofiltration concentrated water. The nanofiltration product water formed by the second nanofiltration system 9 enters the reverse osmosis device 2. After being treated by the reverse osmosis device 2, the product water can meet the standards for reuse.

[0060] In an optional embodiment, the seawater treatment system further includes a second evaporator 10; the second nanofiltration system 9 is connected to the second evaporator 10, and the nanofiltration concentrated water formed by the second nanofiltration system 9 enters the second evaporator 10, and the second evaporator 10 evaporates the nanofiltration concentrated water formed by the second nanofiltration system 9 to obtain a sulphur dioxide product.

[0061] The utility model provides a seawater treatment system, and the overall process is as follows: concentrated seawater preferentially enters the first nanofiltration system 1 for separation of one and two salts and concentration of magnesium ions. The nanofiltration product water formed by the first nanofiltration system 1 contains a small amount of bromine and a large amount of sodium chloride. The bromine and sodium chloride are concentrated by the reverse osmosis device 2. The concentrated solution then enters the chlorine stripping system, where chlorine is used to replace the bromine for bromine extraction.

[0062] After bromine extraction, the solution enters the first evaporation unit 4 for evaporation and crystallization to produce sodium chloride crystals, which can be sold as edible salt. The concentrated nanofiltration water produced by the first nanofiltration system 1 is rich in divalent ions such as calcium, magnesium, and sulfate. The concentrated nanofiltration water preferentially enters the first reaction tank 5, where nitrogen and phosphorus sources are added to form struvite. The struvite product is then filtered through the first sedimentation tank 6 by sedimentation and filtration.

[0063] Then, sodium carbonate is added to the second reaction tank 7, and then filtered and precipitated through the second precipitation tank 8 to obtain a calcium carbonate product, which is then separated into monovalent and divalent ions through the second nanofiltration system 9. The nanofiltration water is returned to the front-end reverse osmosis device 2, and the nanofiltration concentrated water enters the second evaporation device to obtain the sodium sulfate product.

[0064] The seawater treatment system provided by the utility model has the following advantages:

[0065] (1) The system equipment is simple and easy to operate;

[0066] (2) It can effectively extract calcium, magnesium, sulfate, bromine and other components from seawater. The salt in the seawater can be extracted and sold as refined salt. The produced water can meet the standards for reuse, thus achieving rational resource utilization and environmental friendliness.

[0067] (3) It solves the problem of ecological damage and environmental pollution caused by the discharge of concentrated seawater, and has good economic and social benefits.

[0068] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A seawater treatment system, characterized in that: include: A first nanofiltration system (1), a produced water treatment component and a concentrated water treatment component; Concentrated seawater is fed into the first nanofiltration system (1), and the first nanofiltration system (1) is configured to separate monovalent and divalent salts in the concentrated seawater and concentrate magnesium ions in the concentrated seawater to form nanofiltration product water containing bromine and sodium chloride and nanofiltration concentrated water containing calcium, magnesium ions and sulfate; The nanofiltration product water generated by the first nanofiltration system (1) can enter the product water treatment component, and the product water treatment component is configured to concentrate and extract bromine and sodium chloride in the nanofiltration product water; The nanofiltration concentrate formed by the first nanofiltration system (1) can enter the concentrate treatment component, and the concentrate treatment component is configured to be able to add nitrogen source and phosphorus source to form struvite in the nanofiltration concentrate, and to be able to add sodium carbonate to form calcium carbonate in the nanofiltration concentrate.

2. The seawater treatment system according to claim 1, characterized in that: The water production treatment component includes a reverse osmosis device (2); The reverse osmosis device (2) is in communication with the first nanofiltration system (1), and the nanofiltration product water formed by the first nanofiltration system (1) can enter the reverse osmosis device (2). The reverse osmosis device (2) is used to concentrate bromine and sodium chloride in the nanofiltration product water.

3. The seawater treatment system according to claim 2, characterized in that: The water production treatment component further includes a chlorine stripping device (3); The chlorine stripping device (3) is connected to the reverse osmosis device (2), and the concentrated liquid from the reverse osmosis device (2) enters the chlorine stripping device (3). The chlorine stripping device (3) is used to replace bromine with chlorine.

4. The seawater treatment system according to claim 3, characterized in that: The water production and treatment component further includes a first evaporation device (4); The first evaporation device (4) is connected to the chlorine stripping device (3), and the solution after bromine extraction in the chlorine stripping device (3) enters the first evaporation device (4) to evaporate and crystallize the solution to obtain sodium chloride crystals.

5. The seawater treatment system according to claim 2, characterized in that: The concentrated water treatment component includes a first reaction tank (5); The first reaction tank (5) is connected to the first nanofiltration system (1), and the nanofiltration concentrated water formed by the first nanofiltration system (1) enters the first reaction tank (5). The first reaction tank (5) is configured to be able to be fed with a nitrogen source and a phosphorus source.

6. The seawater treatment system according to claim 5, characterized in that: The concentrated water treatment component further includes a first sedimentation tank (6); The first sedimentation tank (6) is connected to the first reaction tank (5), and the first sedimentation tank (6) is used to precipitate and filter the solution after the nitrogen source and phosphorus source are added to the first reaction tank (5) to form a struvite product.

7. The seawater treatment system according to claim 6, characterized in that: The concentrated water treatment component further includes a second reaction tank (7); The second reaction tank (7) is connected to the first sedimentation tank (6), and the solution filtered in the first sedimentation tank (6) enters the second reaction tank (7). The second reaction tank (7) is configured to be able to be fed with sodium carbonate.

8. The seawater treatment system according to claim 7, characterized in that: The concentrated water treatment component further includes a second sedimentation tank (8); The second sedimentation tank (8) is connected to the second reaction tank (7), and the solution after sodium carbonate is added to the second reaction tank (7) enters the second sedimentation tank (8). The second sedimentation tank (8) is used for precipitation and filtration to form a calcium carbonate product.

9. The seawater treatment system according to claim 8, characterized in that: The seawater treatment system further comprises a second nanofiltration system (9); The second nanofiltration system (9) is connected to the second sedimentation tank (8), and the solution in the second sedimentation tank (8) can enter the second nanofiltration system (9). The second nanofiltration system (9) is configured to separate monovalent and divalent ions from the solution flowing out of the second sedimentation tank (8). The nanofiltration water produced by the second nanofiltration system (9) enters the reverse osmosis device (2).

10. The seawater treatment system according to claim 9, characterized in that: The seawater treatment system further comprises a second evaporator (10); The second nanofiltration system (9) is connected to the second evaporator (10), and the nanofiltration concentrated water formed by the second nanofiltration system (9) enters the second evaporator (10). The second evaporator (10) is used to evaporate the nanofiltration concentrated water formed by the second nanofiltration system (9) to obtain sodium sulfate.

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