A saline-alkali soil desalination system and a saline-alkali soil desalination method

Abstract

The present disclosure provides a saline-alkali soil desalination system and method, and relates to the technical field of saline-alkali soil treatment. The saline-alkali soil desalination system comprises: a salt water collecting subsystem arranged below the saline-alkali soil and used for collecting salt water of the saline-alkali soil; a purification subsystem connected with the salt water collecting subsystem through a pipeline and provided with a purification resin, the purification resin being used for purifying the salt water into pure water; a pure water pool connected with the purification subsystem through a pipeline and used for collecting the pure water; and a resin regeneration subsystem connected with the purification subsystem through a pipeline and used for converting the ineffective purification resin into effective purification resin. Secondary pollution to the environment can be avoided.

Description

Technical Field

[0001] This disclosure relates to the field of saline-alkali land management technology, and more specifically, to a saline-alkali land desalination system and method. Background Technology

[0002] Saline-alkali land contains a large amount of metal ions (such as calcium ions, magnesium ions, potassium ions, sodium ions, etc.) and acid radical ions (carbonate ions, bicarbonate ions, sulfate ions, chloride ions, etc.). These metal ions and acid radical ions combine to form salt in saline-alkali land, which affects the growth of crops in saline-alkali land.

[0003] Therefore, it is necessary to remediate saline-alkali land. The core of this remediation lies in effectively reducing the salinity of the topsoil and preventing the salt from rising with the capillary action of groundwater. Related technologies mainly rely on open ditches or underground pipes for drainage. However, while this method can temporarily lower the groundwater level, it merely transfers the salt elsewhere, causing secondary environmental pollution.

[0004] It should be noted that the information disclosed in the background section above is only used to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0005] This disclosure provides a desalination system and method for saline-alkali land, which can avoid secondary pollution to the environment.

[0006] According to one aspect of this disclosure, a desalination system for saline-alkali land is provided, comprising: A brine collection subsystem is located beneath the saline-alkali land and is used to collect brine from the saline-alkali land. A purification subsystem is connected to the brine collection subsystem via a pipeline and includes a purification resin for purifying the brine into pure water. A pure water tank is connected to the purification subsystem via pipelines and is used to collect the pure water; A resin regeneration subsystem is connected to the purification subsystem via piping and is used to convert failed purification resin into effective purification resin.

[0007] In one embodiment of this disclosure, the purification subsystem includes a cation exchange tower, a decarbonation tower, and an anion exchange tower connected in sequence via pipelines, and the purification resin includes a cation exchange resin and an anion exchange resin. The cation exchange resin is located in the cation exchange tower, the anion exchange resin is located in the anion exchange tower, and the decarbonation tower is equipped with a blower for injecting air into the inner cavity of the decarbonation tower.

[0008] In one embodiment of this disclosure, the resin regeneration subsystem includes a housing and a bipolar membrane, a first regeneration component, and a second regeneration component disposed within the housing; The bipolar membrane is located between the first regeneration component and the second regeneration component. The first regeneration component is used to convert the failed cation resin into a valid cation resin under the action of hydrogen ions dissociated from the bipolar membrane. The second regeneration component is used to convert the failed anion resin into a valid anion resin under the action of hydroxide ions dissociated from the bipolar membrane.

[0009] In one embodiment of this disclosure, the first regeneration component includes a first cation exchange membrane and a first anion exchange membrane spaced apart. The first cation exchange membrane is located between the bipolar membrane and the first anion exchange membrane. The bipolar membrane and the first cation exchange membrane form a cation exchange resin chamber. The first anion exchange membrane and the first cation exchange membrane form a first salt chamber. The first anion exchange membrane and the side wall of the housing form a cathode chamber. The cathode chamber contains hydroxide ions. The second regeneration component includes a second cation exchange membrane and a second anion exchange membrane spaced apart. The second anion exchange membrane is located between the bipolar membrane and the second cation exchange membrane. The bipolar membrane and the second anion exchange membrane form an anion exchange resin chamber. The second cation exchange membrane and the second anion exchange membrane form a second salt chamber. The first cation exchange membrane and the side wall of the tank form an anode chamber. The anode chamber contains hydrogen ions.

[0010] In one embodiment of this disclosure, the resin regeneration subsystem further includes a first driving component, a second driving component, a cation resin collection tank, and an anion resin collection tank; The cation resin collection box is connected to the cation exchange resin chamber and is used to collect effective cation resin. The cation tower is connected to the cation exchange resin chamber through a first driving member. The first driving member is connected to the cation resin collection box and is used to transport the failed cation resin in the cation tower to the cation exchange resin chamber, and is also used to transport the effective cation resin in the cation resin collection box to the cation tower. The anion resin collection box is connected to the anion exchange resin chamber and is used to collect effective anion resin. The anion tower is connected to the anion exchange resin chamber via a second driving component. The second driving component is connected to the anion resin collection box and is used to transport the failed anion resin in the anion tower to the anion exchange resin chamber, and also to transport the effective anion resin in the anion resin collection box to the anion tower.

[0011] In one embodiment of this disclosure, the resin regeneration subsystem further includes a collection tank, wherein the first salt chamber and the second salt chamber are connected by a pipeline, and the collection tank is used to collect concentrated water from the first salt chamber and the second salt chamber.

[0012] In one embodiment of this disclosure, the saline-alkali land desalination system further includes a photovoltaic subsystem, which includes a frame, photovoltaic panels, a water collection tank, and control components. The frame is installed on saline-alkali land, the photovoltaic panel is installed on the frame, the water collection tank is located directly below the photovoltaic panel and is used to collect the condensate dripping from the photovoltaic panel, and the water collection tank is connected to the pure water tank through a pipeline. The control component includes a controller and a DC bus, and the photovoltaic panel is electrically connected to the controller. The controller is configured to transmit the electrical energy generated by the photovoltaic panel to the DC bus when the pH value of the brine flowing out of the anode is greater than 5, and / or when the conductivity of the pure water flowing out of the cathode is greater than 50 μS / cm, so that the DC bus supplies power to the resin regeneration subsystem.

[0013] In one embodiment of this disclosure, the brine collection subsystem includes a raw water tank and multiple collection pipes; The collection pipe is laid under the saline-alkali land, and the peripheral wall of the collection pipe has openings. The collection pipe is connected to the raw water tank through a pipeline, and the raw water tank is used to store the brine from the collection pipe.

[0014] In one embodiment of this disclosure, the saline-alkali land desalination system further includes an irrigation subsystem, which includes an irrigation pipe and an irrigation pump; The irrigation pipe is located in saline-alkali land and is connected to the pure water tank via the irrigation pump. The irrigation pump is used to transport pure water from the pure water tank to the irrigation pipe.

[0015] According to another aspect of this disclosure, a method for desalinizing saline-alkali land is provided, the desalinization method comprising: The brine in the raw water tank is converted into pure water by passing it through a cathodic tower, a decarbonation tower, and an anion tower. The pure water then flows into a pure water tank and is pumped into irrigation pipes to achieve the reinjection of saline-alkali land. When the pH value of the brine flowing out of the anode tower is greater than 5, and / or when the conductivity of the pure water flowing out of the cathode tower is greater than 50 μS / cm, the controller supplies power to the resin regeneration subsystem. Under the influence of an electric field, the resin regeneration subsystem converts the failed cation resin in the cation tower into effective cation resin and returns it to the cation tower, converts the failed anion resin in the anion tower into effective anion resin and returns it to the anion tower, and evaporates and crystallizes the concentrated water in the collection tank.

[0016] This saline-alkali land desalination system and method achieves a complete desalination cycle of "collection-purification-storage-resin regeneration," realizing closed-loop operation of saline-alkali land desalination. It solves the problems of low desalination efficiency and high cost caused by incomplete desalination processes and the inability to recycle resin in related technologies. Simultaneously, this saline-alkali land desalination system does not cause secondary pollution to the environment, and the synergistic effect of each subsystem ensures both effective collection and purification of brine and regeneration and reuse of the purified resin, improving the stability and practicality of the entire desalination system.

[0017] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this disclosure. Attached Figure Description

[0018] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure. It is obvious that the drawings described below are merely some embodiments of this disclosure, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0019] Figure 1 This is a schematic diagram of the overall structure of a saline-alkali land desalination system in one embodiment of this disclosure.

[0020] Figure 2 This is a partial structural diagram of a saline-alkali land desalination system in one embodiment of the present disclosure, intended to illustrate the collection pipes in the saline-alkali underground layer, the photovoltaic panels above the saline-alkali land, and the irrigation pipes.

[0021] Figure 3 This is a partial structural diagram of a saline-alkali land desalination system in one embodiment of the present disclosure, intended to illustrate the structure of the resin regeneration subsystem.

[0022] Explanation of reference numerals in the attached figures: 01. Saline-alkali land; 1. Brine collection subsystem; 11. Raw water tank; 12. Collection pipe; 2. Purification subsystem; 21. Acid exchange tower; 22. Decarbonation tower; 23. Anion exchange tower; 24. Blower; 3. Pure water tank; 4. Resin regeneration subsystem; 41. Housing; 42. Bipolar membrane; 43. First regeneration component; 431. First cation exchange membrane; 432. First anion exchange membrane; 433. Cation exchange resin chamber; 434. First salt chamber; 435. Cathode chamber; 44. Second regeneration component; 441 442. Second cation exchange membrane; 443. Second anion exchange membrane; 444. Anion exchange resin chamber; 445. Second salt chamber; 446. Anode chamber; 47. First drive unit; 48. Second drive unit; 49. Cation resin collection box; 40. Anion resin collection box; 50. Collection pool; 51. Photovoltaic subsystem; 51. Control component; 511. Controller; 512. DC bus; 513. Inverter; 514. Battery; 52. Photovoltaic panel; 6. Irrigation subsystem; 61. Irrigation pipe; 62. Irrigation pump. Detailed Implementation

[0023] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, they are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the exemplary embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar structures, and therefore detailed descriptions of them will be omitted. Furthermore, the drawings are merely illustrative of this disclosure and are not necessarily drawn to scale.

[0024] Although relative terms such as "up" and "down" are used in this specification to describe the relative relationship of one component of an icon to another, these terms are used only for convenience, such as according to the orientation of the examples shown in the accompanying drawings. It is understood that if the device of the icon is flipped upside down, the component described as "up" will become the component described as "down." When a structure is "up" of another structure, it may mean that the structure is integrally formed on the other structure, or that the structure is "directly" mounted on the other structure, or that the structure is "indirectly" mounted on the other structure through another structure.

[0025] The terms “a,” “one,” “the,” “the,” and “at least one” are used to indicate the presence of one or more elements / components / etc.; the terms “including” and “having” are used to indicate an open-ended inclusion and to mean that there may be other elements / components / etc. in addition to the listed elements / components / etc.; the terms “first,” “second,” and “third,” etc., are used only as markers and are not a limitation on the number of objects.

[0026] This disclosure provides a desalination system for saline-alkali land. See also: Figure 1 The saline-alkali land desalination system includes a brine collection subsystem 1, a purification subsystem 2, a pure water tank 3, and a resin regeneration subsystem 4. The brine collection subsystem 1 is located below the saline-alkali land 01 and is used to collect the brine from saline-alkali land 01. The purification subsystem 2 is connected to the brine collection subsystem 1 via pipelines and contains purification resin used to purify the brine into pure water. The pure water tank 3 is connected to the purification subsystem 2 via pipelines and is used to collect pure water. The resin regeneration subsystem 4 is connected to the purification subsystem 2 via pipelines and is used to convert exhausted purification resin into effective purification resin.

[0027] Thus, this saline-alkali land desalination system achieves a complete desalination cycle of "collection-purification-storage-resin regeneration," realizing closed-loop operation of saline-alkali land desalination and solving the problems of low desalination efficiency and high cost caused by incomplete desalination processes and the inability to recycle resin in related technologies. At the same time, this saline-alkali land desalination system does not cause secondary pollution to the environment, and the synergistic effect of each subsystem ensures both effective collection and purification of brine and regeneration and reuse of purified resin, improving the stability and practicality of the entire desalination system.

[0028] In one embodiment of this disclosure, see Figure 1 and Figure 2 The brine collection subsystem 1 includes a raw water tank 11 and multiple collection pipes 12. The collection pipes 12 are laid beneath the saline-alkali land 01, and multiple collection pipes 12 can be connected to form a network. For example, the burial depth of the collection pipes 12 can be 0.8m to 1.8m, and the spacing between adjacent collection pipes 12 can be 5m to 20m. The peripheral wall of the collection pipes 12 has openings located on the peripheral wall of the collection pipes near the surface of the saline-alkali land 01, allowing brine from the saline-alkali land 01 to flow into the collection pipes 12. The collection pipes 12 are connected to the raw water tank 11 via pipelines. The raw water tank 11 is used to store the brine from the collection pipes 12, facilitating the storage of brine from the saline-alkali land 01 into the raw water tank 11. The purification subsystem 2 can purify the brine in the raw water tank 11, maintaining the feed stability of the purification subsystem 2.

[0029] Furthermore, a filter screen can be installed at the opening to pre-filter impurities in the brine, thereby improving the practicality of the brine collection subsystem 1.

[0030] Optionally, a water pump can be installed on the connecting pipe between the collection pipe 12 and the raw water tank 11. The driving force of the water pump facilitates the smooth flow of brine in the saline-alkali land 01 into the raw water tank 11 for storage, thereby improving the collection efficiency of brine.

[0031] In one embodiment of this disclosure, see Figure 1The purification subsystem 2 includes a cation exchange tower 21, a decarbonation tower 22, and an anion exchange tower 23 connected sequentially by pipelines. The purification resins include cation exchange resin and anion exchange resin. The cation exchange tower 21 is connected to the raw water tank 11 via pipelines. The cation exchange resin is located in the cation exchange tower 21, and the anion exchange resin is located in the anion exchange tower 23. The raw water tank 11 and the anion exchange tower 23 are connected by pipelines. The decarbonation tower 22 is equipped with a blower 24, which is used to inject air into the interior of the decarbonation tower 22. For example, the blower 24 can be a fan or a bellows. Because the cation exchange resin is strongly acidic and contains a large number of hydrogen ions, metal ions (such as sodium ions, potassium ions, etc.) in the brine will replace hydrogen ions in the cation exchange tower 21, resulting in the brine entering the decarbonation tower 22 containing more acidic components (such as hydrochloric acid, carbonic acid, sulfuric acid, etc.). Since carbonic acid is unstable and easily decomposes into carbon dioxide, carbon dioxide disulfide will increase the consumption of anion exchange resin. Therefore, a blower 24 is installed in the decarbonation tower 22. The blower 24 can blow out the free carbon dioxide in the brine from the decarbonation tower 22, thereby reducing the carbonate ions entering the anion exchange tower 23. Then, the brine containing acid radicals (such as sulfate ions, chloride ions, etc.) is passed into the anion exchange tower 23. Because the anion exchange resin is strongly alkaline and contains a large number of hydroxide ions, the acid radicals in the brine will replace the hydroxide ions in the anion exchange resin. The hydroxide ions combine with hydrogen ions to form water, thereby converting the brine into pure water. The pure water finally flows into the pure water tank 3 for storage.

[0032] Thus, the positive tower 21, negative tower 23, and decarbonation tower 22 achieve precise, step-by-step removal of salts. Compared to a single purification structure, this significantly improves the efficiency of brine purification and the purity of pure water, ensuring that the output pure water meets the irrigation standards for saline-alkali land (01 level) and facilitates subsequent pure water reinjection. The addition of decarbonation tower 22 and blower 24 effectively removes carbon dioxide and carbonate ions from the brine, preventing sediment buildup in negative tower 23 that could clog pipes, contaminate the resin, and consume it, thus extending the resin's lifespan, reducing maintenance costs, and avoiding the problem of sediment affecting purification efficiency.

[0033] Furthermore, in order to facilitate the discharge of carbon dioxide from the decarbonation tower 22, the decarbonation tower 22 has a carbon dioxide exhaust pipe, and the connecting pipe between the anolyte 21 and the decarbonation tower 22 is positioned higher than the installation position of the blower 24, so that the blower 24 can blow air onto the brine as it flows into the bottom of the decarbonation tower 22, thereby accelerating the discharge of carbon dioxide.

[0034] Furthermore, in order to avoid introducing additional carbon dioxide into the decarbonation tower 22, the air blown out by the blower 24 must not contain carbon dioxide.

[0035] Optionally, a water pump can be installed on the pipeline between the decarbonation tower 22 and the anion tower 23 to facilitate the smooth flow of brine in the purification subsystem 2.

[0036] Optionally, a pH meter can be installed inside the cation tower 21 to detect the pH value inside the cation tower 21, which helps determine whether the cation resin has failed. A conductivity meter can be installed inside the anion tower 23 to detect the conductivity of the pure water flowing out of the anion tower 23, which helps determine whether the anion resin has failed.

[0037] In one embodiment of this disclosure, see Figure 1 , Figure 3 The resin regeneration subsystem 4 includes a housing 41 and a bipolar membrane 42, a first regeneration component 43, and a second regeneration component 44 disposed within the housing 41. The bipolar membrane 42 is located between the first regeneration component 43 and the second regeneration component 44. The first regeneration component 43 converts spent cation resin into available cation resin under the action of hydrogen ions dissociated from the bipolar membrane 42. The second regeneration component 44 converts spent anion resin into available anion resin under the action of hydroxide ions dissociated from the bipolar membrane 42. Thus, through the cooperation of the bipolar membrane 42 with the first and second regeneration components 43 and 44, targeted regeneration of cation and anion resins is achieved, solving the problems of poor regeneration effect and inability to distinguish between cation and anion resin regeneration in existing purified resins. Regeneration using hydrogen and hydroxide ions dissociated from the bipolar membrane 42 eliminates the need for additional chemical regeneration agents, avoiding secondary pollution and reducing regeneration costs.

[0038] It should be noted that ineffective cation resin refers to cation resin containing a large amount of metal ions, while ineffective anion resin refers to anion resin containing a large amount of acid radical ions.

[0039] Specifically, see Figure 1 , Figure 3 The first regeneration component 43 includes a first cation exchange membrane 431 and a first anion exchange membrane 432 spaced apart. The first cation exchange membrane 431 is located between the bipolar membrane 42 and the first anion exchange membrane 432. The bipolar membrane 42 and the first cation exchange membrane 431 form a cation exchange resin chamber 433. The first anion exchange membrane 432 and the first cation exchange membrane 431 form a first salt chamber 434. The first anion exchange membrane 432 and the side wall of the housing 41 form a cathode chamber 435, which contains hydroxide ions. Under the action of an electric field, the bipolar membrane 42 can dissociate water to generate hydrogen ions and hydroxide ions. The hydrogen ions enter the cation exchange resin chamber 433 and replace the metal ions (such as sodium ions) in the exhausted cation exchange resin. The metal ions pass through the first cation exchange membrane 431 and enter the first salt chamber 434, thereby regenerating the exhausted cation exchange resin in the cation exchange resin chamber 433 into effective cation exchange resin.

[0040] The second regeneration component 44 includes a second cation exchange membrane 441 and a second anion exchange membrane 442 spaced apart. The second anion exchange membrane 442 is located between the bipolar membrane 42 and the second cation exchange membrane 441. The bipolar membrane 42 and the second anion exchange membrane 442 form an anion exchange resin chamber 443. The second cation exchange membrane 441 and the second anion exchange membrane 442 form a second salt chamber 444. The first cation exchange membrane 431 and the side wall of the housing 41 form an anode chamber 445, which contains hydrogen ions. Under the action of an electric field, the bipolar membrane 42 can dissociate water to generate hydrogen ions and hydroxide ions. The hydroxide ions enter the anion exchange resin chamber 443 and replace the acid radical ions (such as chloride ions) in the exhausted anion resin. The acid radical ions pass through the second anion exchange membrane 442 and enter the second salt chamber 444, thereby regenerating the exhausted anion resin in the anion exchange resin chamber 443 into effective anion resin.

[0041] Further, see Figure 1 , Figure 3 The resin regeneration subsystem 4 also includes a first drive unit 45, a second drive unit 46, a cation resin collection tank 47, and an anion resin collection tank 48. The cation resin collection tank 47 is connected to the cation exchange resin chamber 433 via a pipeline and is used to collect effective cation resin. The cation tower 21 is connected to the cation exchange resin chamber 433 via the first drive unit 45, which is also connected to the cation resin collection tank 47 via a pipeline. The first drive unit 45 is used to transport the depleted cation resin in the cation tower 21 to the cation exchange resin chamber 433, and also to transport the effective cation resin in the cation resin collection tank 47 to the cation tower 21. When the cation resin in the cation tower 21 becomes depleted, the first drive unit 45 can transport the depleted cation resin in the cation exchange resin chamber 433. Under the action of the first regeneration component 43, the depleted cation resin is converted into effective cation resin and stored in the cation resin collection tank 47, facilitating the return of the effective cation resin to the cation tower 21 via the first drive unit 45.

[0042] The anion resin collection tank 48 is connected to the anion exchange resin chamber 443 and is used to collect effective anion resin. The anion tower 23 is connected to the anion exchange resin chamber 443 via a second drive unit 46, which is also connected to the anion resin collection tank 48. The second drive unit 46 is used to transport the failed anion resin in the anion tower 23 to the anion exchange resin chamber 443, and also to transport the effective anion resin in the anion resin collection tank 48 to the anion tower 23. When the anion resin in the anion tower 23 becomes unusable, the second drive unit 46 can transport the unusable anion resin in the anion tower 23 to the anion exchange resin chamber 443. Under the action of the second regeneration component 44, the unusable anion resin is converted into effective anion resin and stored in the anion resin collection tank 48, so that the effective anion resin can be returned to the anion tower 23 via the first drive unit 45.

[0043] Optionally, the first drive component 45 and the second drive component 46 can be equipment such as a hydraulic jet or a delivery pump to facilitate the timely delivery of anion and cation resins.

[0044] Optionally, see Figure 1 , Figure 3 The resin regeneration subsystem 4 may further include a collection tank 49. The first salt chamber 434 and the second salt chamber 444 are connected by pipelines. The collection tank 49 is used to collect the concentrated water from the first salt chamber 434 and the second salt chamber 444. Since the concentrated water in the first salt chamber 434 is weakly alkaline and the concentrated water in the second salt chamber 444 is weakly acidic, mixing and collecting them can neutralize the concentrated water, reducing secondary pollution caused by discharge. The concentrated water in the collection tank 49 can be used to extract salts through evaporation and crystallization, which is beneficial for environmental protection.

[0045] Optionally, see Figure 1 , Figure 3 The bipolar membrane 42 has a cavity, and the pure water tank 3 is connected to the cavity of the bipolar membrane 42 through a pipeline so that the pure water tank 3 can supply water to the resin regeneration subsystem 4, thereby improving the utilization rate of pure water in the pure water tank 3.

[0046] In one embodiment of this disclosure, see Figure 1 , Figure 2 The saline-alkali land desalination system also includes a photovoltaic subsystem 5, which includes a frame (not shown in the accompanying drawings), photovoltaic panels 52, a water collection tank (not shown in the accompanying drawings), and a control component 51. The frame is mounted on the saline-alkali land 01, the photovoltaic panels 52 are mounted on the frame, and the water collection tank is located directly below the photovoltaic panels 52 to collect condensate dripping from them. The water collection tank is connected to the pure water tank 3 via a pipeline. The control component 51 includes a controller 511 and a DC bus 512. The photovoltaic panels 52 are electrically connected to the controller 511. The controller 511 is electrically connected to the DC bus 512. The controller 511 is configured to transmit the electrical energy generated by the photovoltaic panels 52 to the DC bus 512 when the pH value of the brine flowing out of the positive tower 21 is greater than 5, and / or when the conductivity of the pure water flowing out of the negative tower 23 is greater than 50 μS / cm, so that the DC bus 512 supplies power to the resin regeneration subsystem 4.

[0047] Thus, the photovoltaic subsystem 5 achieves clean utilization of solar energy, providing renewable energy for the resin regeneration subsystem 4. This solves the problems of high energy consumption and reliance on traditional electricity in existing desalination systems, reduces system operating costs, and meets energy-saving requirements. The water collection tank collects condensate from the photovoltaic panels 52 and flows it into the pure water tank 3, realizing water resource recycling and improving the system's water resource utilization rate. The intelligent control function of the control component 51 can detect the resin failure status in real time and automatically trigger photovoltaic power supply, realizing automated resin regeneration without manual monitoring and operation. This solves the problems of inaccurate manual judgment of resin failure and untimely regeneration start-up, improving the system's automation level and operational stability, while ensuring the purification effect of the purification subsystem 2.

[0048] Optionally, the frame may include an angle adjustment mechanism. During the day, the angle adjustment mechanism can adjust the angle of the photovoltaic panel 52 to track the sun and improve the power generation efficiency of the photovoltaic panel 52. At night, the angle adjustment mechanism can adjust the angle of the photovoltaic panel 52 so that the angle between the photovoltaic panel 52 and the saline-alkali land 01 is 70°~90°, so that the condensate from the photovoltaic panel 52 flows into the water collection tank and is finally stored in the pure water tank 3 for later use.

[0049] Optionally, a water pump can be installed on the pipeline between the water collection tank and the pure water tank 3 to facilitate the collection of condensate from the water collection tank into the pure water tank 3.

[0050] Further, see Figure 1 The control component 51 also includes an inverter 513 and a battery 514. The inverter 513 and battery 514 are electrically connected to the controller 511. The inverter 513 can be connected to an AC load, such as a water pump or blower 24, so that the electricity generated by the photovoltaic panel 52 can power the AC load. The battery 514 can convert the electrical energy from the photovoltaic panel 52 into chemical energy for storage, so as to subsequently power other equipment.

[0051] Furthermore, the photovoltaic subsystem 5 can supply power to the electrical settings in the desalination system, thereby reducing power supply costs. The main energy consumption of the saline-alkali land desalination system is supplied by its own photovoltaic system, and the dynamic balance of generation, consumption, and storage is achieved through intelligent management. It is especially suitable for remote saline-alkali land area 01 with weak or no power grid coverage.

[0052] In one embodiment of this disclosure, see Figure 1The saline-alkali land desalination system also includes an irrigation subsystem 6, which comprises an irrigation pipe 61 and an irrigation pump 62. The irrigation pipe 61 is located on the saline-alkali land 01 and connected to a pure water tank 3 via the irrigation pump 62. The irrigation pump 62 is used to transport pure water from the pure water tank 3 to the irrigation pipe 61. The irrigation subsystem 6 enables direct reinjection of the desalinated pure water, solving the problem of inefficient use of pure water from the pure water tank 3 for saline-alkali land 01 improvement and resource waste. The cooperation between the irrigation pump 62 and the irrigation pipe 61 ensures that pure water is evenly delivered to the soil of the saline-alkali land 01, diluting the remaining salt in the soil and accelerating the desalination process, while also replenishing soil moisture, improving soil physicochemical properties, and promoting crop growth. Furthermore, it perfects the closed-loop treatment of the entire desalination system, ensuring efficient utilization of the desalinated pure water, continuously extracting salt from the soil and converting it into solid salt resources, achieving permanent eradication and avoiding secondary pollution.

[0053] In one embodiment of this disclosure, valves may be provided on each connecting pipeline to facilitate the opening and closing of the connecting pipeline.

[0054] The desalination system for saline-alkali land ultimately produces improved land, green electricity, irrigation fresh water, and recyclable chemical salt raw materials, realizing multi-level utilization of water and soil resources and solar energy, and significantly improving the overall benefits and sustainability of the project.

[0055] This disclosure also provides a method for desalinating saline-alkali land, applied to the aforementioned saline-alkali land desalination system. The desalination method includes: In step S100, the brine in the raw water tank is converted into pure water by passing it through a cathodic tower, a decarbonation tower, and an anion tower in sequence and then flows into a pure water tank. The pure water is then transported to the irrigation pipe by an irrigation pump to achieve the reinjection of the saline-alkali land. In step S200, when the pH value of the brine flowing out of the anolyte is greater than 5, and / or when the conductivity of the pure water flowing out of the anion tower is greater than 50 μS / cm, the controller supplies power to the resin regeneration subsystem. In step S300, under the action of an electric field, the resin regeneration subsystem converts the failed cation resin in the cation tower into effective cation resin and returns it to the cation tower, converts the failed anion resin in the anion tower into effective anion resin and returns it to the anion tower, and evaporates and crystallizes the concentrated water in the collection tank.

[0056] Thus, this desalination method achieves a cyclical operation of "brine purification - pure water reinjection - resin regeneration - concentrated water treatment," with a simple process and high operability, solving the problems of cumbersome processes, low automation, and low resource utilization in existing desalination methods. Intelligent triggering of resin regeneration ensures timely restoration of resin activity, guaranteeing stable desalination efficiency; pure water reinjection enables simultaneous desalination and soil improvement; and concentrated water evaporation and crystallization achieve salt resource recovery, balancing desalination effectiveness, environmental friendliness, and economic efficiency. The entire method requires no manual intervention, has a high degree of automation, reduces labor intensity, and is suitable for desalination treatment of various moderate to severe saline-alkali lands, with a wide range of applications, achieving high efficiency, energy saving, and environmental protection in the desalination process.

[0057] In one embodiment of this disclosure, the desalination method further includes: In step S400, during the day, the angle adjustment mechanism adjusts the angle of the photovoltaic panel to track sunlight. At night, the angle adjustment mechanism adjusts the angle of the photovoltaic panel so that the condensate from the photovoltaic panel flows into the water collection tank.

[0058] It should be noted that although the steps of the desalination method in this disclosure are described in a specific order in the accompanying drawings, this does not require or imply that the steps must be performed in that specific order, or that all the steps shown must be performed to achieve the desired result. Additional or alternative steps may be omitted, multiple steps may be combined into one step, and / or one step may be broken down into multiple steps.

[0059] Other embodiments of this disclosure will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this disclosure are indicated by the appended claims.

Claims

1. A desalination system for saline-alkali land, characterized in that, include: A brine collection subsystem is located beneath the saline-alkali land and is used to collect brine from the saline-alkali land. A purification subsystem is connected to the brine collection subsystem via a pipeline and includes a purification resin for purifying the brine into pure water. A pure water tank is connected to the purification subsystem via pipelines and is used to collect the pure water; A resin regeneration subsystem is connected to the purification subsystem via piping and is used to convert failed purification resin into effective purification resin.

2. The saline-alkali land desalination system according to claim 1, characterized in that, The purification subsystem includes a cation tower, a decarbonation tower, and an anion tower connected in sequence by pipelines, and the purification resin includes cation resin and anion resin. The cation exchange resin is located in the cation exchange tower, the anion exchange resin is located in the anion exchange tower, and the decarbonation tower is equipped with a blower for injecting air into the inner cavity of the decarbonation tower.

3. The saline-alkali land desalination system according to claim 2, characterized in that, The resin regeneration subsystem includes a housing and a bipolar membrane, a first regeneration component, and a second regeneration component disposed within the housing; The bipolar membrane is located between the first regeneration component and the second regeneration component. The first regeneration component is used to convert the failed cation resin into a valid cation resin under the action of hydrogen ions dissociated from the bipolar membrane. The second regeneration component is used to convert the failed anion resin into a valid anion resin under the action of hydroxide ions dissociated from the bipolar membrane.

4. The saline-alkali land desalination system according to claim 3, characterized in that, The first regeneration component includes a first cation exchange membrane and a first anion exchange membrane spaced apart. The first cation exchange membrane is located between the bipolar membrane and the first anion exchange membrane. The bipolar membrane and the first cation exchange membrane form a cation exchange resin chamber. The first anion exchange membrane and the first cation exchange membrane form a first salt chamber. The first anion exchange membrane and the side wall of the housing form a cathode chamber. The cathode chamber contains hydroxide ions. The second regeneration component includes a second cation exchange membrane and a second anion exchange membrane spaced apart. The second anion exchange membrane is located between the bipolar membrane and the second cation exchange membrane. The bipolar membrane and the second anion exchange membrane form an anion exchange resin chamber. The second cation exchange membrane and the second anion exchange membrane form a second salt chamber. The first cation exchange membrane and the side wall of the tank form an anode chamber. The anode chamber contains hydrogen ions.

5. The saline-alkali land desalination system according to claim 4, characterized in that, The resin regeneration subsystem also includes a first driving component, a second driving component, a cation resin collection box, and an anion resin collection box; The cation resin collection box is connected to the cation exchange resin chamber and is used to collect effective cation resin. The cation tower is connected to the cation exchange resin chamber through a first driving member. The first driving member is connected to the cation resin collection box and is used to transport the failed cation resin in the cation tower to the cation exchange resin chamber, and is also used to transport the effective cation resin in the cation resin collection box to the cation tower. The anion resin collection box is connected to the anion exchange resin chamber and is used to collect effective anion resin. The anion tower is connected to the anion exchange resin chamber via a second driving component. The second driving component is connected to the anion resin collection box and is used to transport the failed anion resin in the anion tower to the anion exchange resin chamber, and also to transport the effective anion resin in the anion resin collection box to the anion tower.

6. The saline-alkali land desalination system according to claim 4, characterized in that, The resin regeneration subsystem also includes a collection tank, and the first salt chamber and the second salt chamber are connected by a pipeline. The collection tank is used to collect the concentrated water in the first salt chamber and the second salt chamber.

7. The saline-alkali land desalination system according to claim 2, characterized in that, The saline-alkali land desalination system also includes a photovoltaic subsystem, which includes a frame, photovoltaic panels, a water collection tank, and control components. The frame is installed on saline-alkali land, the photovoltaic panel is installed on the frame, the water collection tank is located directly below the photovoltaic panel and is used to collect the condensate dripping from the photovoltaic panel, and the water collection tank is connected to the pure water tank through a pipeline. The control component includes a controller and a DC bus, and the photovoltaic panel is electrically connected to the controller. The controller is configured to transmit the electrical energy generated by the photovoltaic panel to the DC bus when the pH value of the brine flowing out of the anode is greater than 5, and / or when the conductivity of the pure water flowing out of the cathode is greater than 50 μS / cm, so that the DC bus supplies power to the resin regeneration subsystem.

8. The saline-alkali land desalination system according to claim 1, characterized in that, The brine collection subsystem includes a raw water tank and multiple collection pipes; The collection pipe is laid under the saline-alkali land, and the peripheral wall of the collection pipe has openings. The collection pipe is connected to the raw water tank through a pipeline, and the raw water tank is used to store the brine from the collection pipe.

9. The saline-alkali land desalination system according to any one of claims 1 to 8, characterized in that, The saline-alkali land desalination system also includes an irrigation subsystem, which includes irrigation pipes and irrigation pumps; The irrigation pipe is located in saline-alkali land and is connected to the pure water tank via the irrigation pump. The irrigation pump is used to transport pure water from the pure water tank to the irrigation pipe.

10. A method for desalinating saline-alkali land, characterized in that, The desalination method includes: The brine in the raw water tank is converted into pure water by passing it through a cathodic tower, a decarbonation tower, and an anion tower. The pure water then flows into a pure water tank and is pumped into irrigation pipes to achieve the reinjection of saline-alkali land. When the pH value of the brine flowing out of the anode tower is greater than 5, and / or when the conductivity of the pure water flowing out of the cathode tower is greater than 50 μS / cm, the controller supplies power to the resin regeneration subsystem. Under the influence of an electric field, the resin regeneration subsystem converts the failed cation resin in the cation tower into effective cation resin and returns it to the cation tower, converts the failed anion resin in the anion tower into effective anion resin and returns it to the anion tower, and evaporates and crystallizes the concentrated water in the collection tank.

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