Saline-alkali water salt redistribution method based on artificial regulation and control of salinity gradient vertical layering

Abstract

The invention provides a saline-alkaline water salt redistribution method based on artificial regulation and control of salinity gradient vertical layering, and belongs to the technical field of saline-alkaline water utilization. The method comprises the following steps: extracting surface saline-alkali water or underground saline-alkali water; desalting the extracted saline-alkaline water by using a primary reverse osmosis system to obtain fresh water and concentrated saline-alkaline water; and recharging the concentrated saline-alkaline water to the bottom layer of the saline-alkaline water. According to the method, saline-alkali water resources are sustainably regenerated into fresh water resources by utilizing a saline-alkali water desalination technology and a bottom layer recharge technology of concentrated saline-alkali water, and under the condition that the total salt content of the saline-alkali water is not integrally changed, the salt content of the saline-alkali water is subjected to vertical spatial level redistribution by manually regulating and controlling the salinity gradient vertical layering, so that the salt content of the saline-alkali water is reduced, and the salt content of the saline-alkali water is reduced. The method has the dual functions of saline-alkali water resource development and utilization and salt ecological regulation and control, the purpose of saline-alkali land treatment or saline-alkali water comprehensive utilization can be achieved without depending on external fresh water, and the method has important popularization value in saline-alkali areas.

Description

Technical Field

[0001] The present invention relates to the technical field of saline-alkali water utilization, and in particular to a saline-alkali water salt redistribution method based on artificially regulating salinity gradient vertical stratification. Background Art

[0002] Saline water is a non-marine saltwater resource distributed in land areas with a mineralization range of 1g / L to 50g / L. It is widely present in nature and is characterized by high pH, ​​high carbonate alkalinity, an imbalance in the ratio of major ions, and a variety of water quality types. Furthermore, because saline-alkali land improvement often involves freshwater flooding to wash away salt, a large amount of "new" saline-alkali water is produced during this process, consuming a significant amount of precious freshwater resources. Furthermore, such land typically continues to become saline-alkali again, necessitating the continued consumption of large amounts of freshwater in the following year to achieve a low-salinity state for planting. In the long run, this saline-alkali land improvement method is unsustainable, and the scarcity of freshwater resources limits the effective management of saline-alkali land and regional development.

[0003] Since humans and animals cannot directly drink saline-alkali water, and agricultural planting usually cannot directly utilize surface or underground saline-alkali water, most saline-alkali land is forced to remain idle. Therefore, how to rationally and effectively develop and utilize saline-alkali land and saline-alkali water, an unconventional land resource, to alleviate or solve food security issues has become an urgent and difficult common problem facing the world. Currently, saline-alkali land improvement mainly adopts three methods:

[0004] (1) Using external freshwater to flood and wash away salt, thereby improving saline-alkali land. As mentioned above, this method trades external freshwater resources for farming opportunities, which is costly and unsustainable in the long run due to limited freshwater resources.

[0005] (2) Screening plants suitable for saline-alkali land or saline-alkali water to plant in the appropriate land. The difficulty lies in the high difficulty of germplasm screening, and the screening success rate is relatively lower for moderate to severe saline-alkali land, and the suitable plants are not necessarily crops.

[0006] (3) Saline water freezing and freezing method: a small amount of brackish water or fresh water is obtained by freezing and thawing saline water, and brackish water or fresh water is used for irrigation to improve saline-alkali land. The disadvantage of this method is that the salinity of the saline water must be less than 15‰, and the local area must have low-temperature freezing conditions. Due to the objective limitations of climate and hydrology, if artificial refrigeration is used to freeze saline water, it will consume too much energy and be costly, making it not universally applicable.

[0007] Desalination of saline water is the primary approach to resource utilization, utilizing various technologies to convert saline water into freshwater and more concentrated saline water. Desalination technologies share similarities with seawater desalination. Desalination technologies considered effective in practice fall into the following categories: First, distillation, including multi-stage flash distillation, compressed air distillation, and multiple-effect distillation; second, membrane methods, including reverse osmosis, nanofiltration, and electrodialysis; and third, other methods, such as freeze-freezing, solvent extraction, and dew-point evaporation. Overall, due to the high specific heat capacity of water, desalination technologies based on steam condensation or freeze-freezing consume significant energy. Compared to other technologies, reverse osmosis offers higher recovery rates, lower investment, and lower overall water production costs, making it the mainstream approach for desalination. Reportedly, 80% of desalination plants worldwide use reverse osmosis technology.

[0008] Seawater desalination technology can be used to desalinate saline-alkali water, but the disposal of concentrated saline-alkali water produced during the desalination process remains a difficult problem. It has not yet been promoted due to cost limitations or environmental pollution caused by the discharge of concentrated saline-alkali water. Depending on whether the total amount of salt in the ecosystem changes, the disposal of concentrated saline-alkali water can be divided into two major treatment methods: keeping the total amount of salt unchanged and reducing the total amount of salt. The existing treatment method for keeping the total amount of salt unchanged is to directly discharge concentrated saline-alkali water into the environment, but this will inevitably pollute the environment and aggravate secondary salinization in the area where concentrated saline-alkali water is discharged. This method is unsustainable. The treatment idea for reducing the total amount of salt is to concentrate and dehydrate the concentrated saline-alkali water to make industrial salt. Due to the large specific heat capacity of water, the method used to reduce the total amount of salt consumes a lot of energy and has high costs, while industrial salts such as NaCl have a low return rate. As a result, this method has high ecological value but is in a loss-making state in terms of economic benefits, and has no market promotion value. Therefore, whether it is possible to find a new method to treat the concentrated saline-alkali water generated during the desalination process is a common and difficult problem facing saline-alkali water desalination, saline-alkali land management and their promotion and application, and it is also an international problem. Summary of the Invention

[0009] The object of the present invention is to provide a method for redistributing salt in saline-alkali water based on artificially regulating vertical stratification of salinity gradient, wherein the fresh water generated by desalination of saline-alkali water can be used for saline-alkali land treatment, domestic water, etc. by using a primary reverse osmosis system, and the associated concentrated saline-alkali water is directly recharged to the bottom of the underground saline-alkali water aquifer or the bottom of the surface saline-alkali water, and the salinity gradient vertical stratification is artificially regulated. As the desalination of saline-alkali water continues, the salinity at the bottom of the underground saline-alkali water aquifer or the bottom of the surface saline-alkali water is the highest, while the salinity of the saline-alkali water at a higher water level maintains the original level to meet the demand for continuous desalination of saline-alkali water, and saline-alkali water can be sustainably utilized to produce fresh water, so that when the total salinity of the saline-alkali water remains unchanged, the salinity of the saline-alkali water is redistributed at the vertical spatial level by artificially regulating vertical stratification of the salinity gradient, thereby achieving the dual functions of saline-alkali water resource development and salt ecological regulation, and realizing the effective utilization of saline-alkali land treatment and saline-alkali water. The present invention is completely independent of external fresh water. It utilizes saline-alkali water desalination technology and bottom reinjection technology of concentrated saline-alkali water. Without changing the total amount of salinity in the saline-alkali water, it realizes the redistribution of saline-alkali water salt by artificially regulating the vertical stratification of the salinity gradient. Not only can saline-alkali water resources be sustainably regenerated into freshwater resources, thereby achieving the purposes of saline-alkali water desalination, saline-alkali land management and comprehensive utilization of saline-alkali water, but also because the method does not aim at a high recovery rate of saline-alkali water desalination and does not require a reverse osmosis concentrated water reflow process, the cost of saline-alkali water desalination is reduced, and the risk of reverse osmosis membrane scaling and clogging in the saline-alkali water desalination process is avoided. The method has great promotion value in saline-alkali areas.

[0010] To achieve the above object, the present invention provides a method for redistributing salt in saline-alkali water based on artificially controlled vertical stratification of salinity gradient, comprising the following steps:

[0011] Step S1, extracting saline water;

[0012] Step S2: using a primary reverse osmosis system to desalinate the extracted saline water to obtain fresh water and concentrated saline water;

[0013] Step S3: refilling the concentrated saline-alkali water into the bottom layer of the saline-alkali water.

[0014] Preferably, in step S1, the saline water is underground saline water or surface saline water.

[0015] Preferably, in step S2, the yield of fresh water obtained through the primary reverse osmosis membrane is 30-45%.

[0016] Preferably, in step S2, the salinity of the associated concentrated saline water obtained after reverse osmosis desalination is not higher than 35‰.

[0017] Preferably, in step S3, when the extracted saline water is underground saline water, the concentrated saline water recharge location is the bottom of the phreatic layer; when the extracted saline water is surface saline water, the concentrated saline water recharge location is the bottom layer of the surface saline water.

[0018] Therefore, the present invention adopts the above-mentioned method for redistributing salinity in saline-alkali water based on artificially controlling the vertical stratification of salinity gradient, and the beneficial technical effects are as follows:

[0019] (1) Unlike the traditional freshwater flooding and salt suppression method, which requires freshwater from external freshwater, the water used for saline-alkali land improvement involved in the present invention comes from saline-alkali water and is completely independent of external freshwater. It is suitable for saline-alkali areas with limited freshwater resources, especially those with a shortage of freshwater. The method has strong universality. Compared with the "suitable land for planting" method, the present invention actively improves saline-alkali land rather than passively adapting to saline-alkali land. The freshwater generated by the present invention can actively improve saline-alkali land into arable land suitable for planting conventional crops. There is no need to carry out salt-alkali tolerant germplasm screening and creation. It is applicable to the improvement of all saline-alkali lands and has universality. Moreover, since the freshwater resources generated can effectively improve saline-alkali land, crops can be planted in the same year. The present invention has good timeliness. The "suitable planting for the land" approach is essentially the passive adaptation of plants to saline-alkali land. It requires "selecting more salt-alkali-tolerant plants to adapt to saline-alkali land" according to the salinity of different saline-alkali lands. This approach has the disadvantages of a long cycle, high difficulty, and a large workload. For severely saline-alkali lands, it is even more difficult to breed good varieties. Even if the breeding is successful, it often takes several years of planting to effectively improve the saline-alkali land. The "suitable planting for the land" approach has poor timeliness and universality in the management of saline-alkali land.

[0020] (2) Due to the large specific heat capacity of water, the traditional freezing method consumes a lot of energy and is costly to obtain low-salinity water for irrigation. In addition, the salinity of the saline-alkali water used cannot exceed 15‰, or it needs to rely on climate factors, which is highly seasonal and not suitable for the entire agricultural production season. The application scenarios are limited. However, the method used in the present invention is applicable to all mild, moderate, and severe saline-alkali lands. The salinity of saline-alkali water can exceed 15‰. The method used in the present invention can be used in all seasons, and more fresh water can be produced according to demand during the agricultural production season. It has strong universality and great promotion value in saline-alkali areas.

[0021] (3) Existing methods only use saline-alkali water as a water source and only "take" it, without performing other operations on the saline-alkali water "reservoir" itself. However, the present invention re-injects concentrated saline-alkali water produced during the desalination process into the bottom layer to achieve "replenishment". Unlike the principle of separating salt from saline-alkali water through high-energy-consuming methods such as distillation, the present invention does not change the total salt content in the saline-alkali water body; unlike the discharge of concentrated saline-alkali water to the surface, which will aggravate the salinization of the surface, the present invention re-injects concentrated saline-alkali water into the saline-alkali water "reservoir" instead of discharging it to the surface, so it will not aggravate the salinization of the surface and will not pollute the surface ecological environment; the present invention creatively artificially regulates the salt content in the saline-alkali water "reservoir" to form a salinity gradient vertical stratification to achieve salt redistribution.

[0022] Specifically, a new balance of salt spatial distribution is formed by artificial regulation, in which the salinity of the bottom saline water layer is high and the salinity of the non-bottom layer (i.e., the higher water layer) is low and stable. In this artificially regulated salinity gradient vertical stratification system, the concentrated saline water layer with high salinity will spontaneously move the saline water layer with low salinity to the surface or the water surface. This process is non-energy-consuming and can sustainably utilize the non-bottom low-salinity saline water for saline water desalination. It will not occur that those skilled in the art believe that after the concentrated saline water is recharged into the water body, the recharge process mixes the water bodies of two salinities, resulting in the salinity of the non-bottom water layer in the saline water "reservoir" becoming higher, ultimately increasing the load of the reverse osmosis membrane, accelerating the loss of the membrane, affecting the service life of the membrane, and reducing the problem of fresh water yield. The method used in the present invention can achieve the stability and sustainability of the entire system.

[0023] In addition, since the existing methods only "take" from the saline-alkali water "reservoir", the method used in the present invention "replenishes" the saline-alkali water "reservoir". By reinjecting concentrated saline-alkali water, it will not only not cause secondary salinization of the surface, but also slow down or even avoid the decline in saline-alkali water levels, and avoid the occurrence of geological disasters such as ground collapse. Compared with the existing methods, this method has obvious ecological and environmental advantages.

[0024] (4) The present invention utilizes a reverse osmosis system to desalinate saline-alkali water, but does not pursue a high recovery rate of the reverse osmosis membrane system, thereby avoiding the risk of reverse osmosis membrane scaling and clogging during the desalination process of saline-alkali water. In addition, only a first-stage reverse osmosis system is required, and no reverse osmosis concentrated water reflux process is required, further reducing costs and reducing operational links.

[0025] (5) The method for treating concentrated saline-alkali water produced during the desalination of saline-alkali water used in the present invention has the characteristics of low energy consumption, simple operation, and good recycling performance, and has outstanding sustainable development. It provides a new solution to the common and difficult problems faced by saline-alkali water desalination, saline-alkali land management, saline-alkali water comprehensive utilization and their promotion and application, and has great promotion value in saline-alkali areas. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a schematic diagram of underground saline water before salt distribution;

[0027] Figure 2 This is a schematic diagram of the salt distribution of underground saline water;

[0028] Figure 3 This is a schematic diagram of surface saline-alkali water before salt distribution;

[0029] Figure 4 Schematic diagram of salt distribution in surface saline-alkali water. DETAILED DESCRIPTION

[0030] The technical solution of the present invention is further described below with reference to the accompanying drawings and embodiments.

[0031] Unless otherwise defined, technical or scientific terms used in the present invention shall have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs.

[0032] Example 1

[0033] Taking the underground saline-alkali water in Aral City as an example, the 50m and 100m underground are both the aquifers of saline-alkali water. The recharge well at 100m underground is located 100m south of the 50m underground pumping well. The main water ion indicators of the original water samples of the saline-alkali water in the two places are shown in Table 1.

[0034] Table 1 Main water ion indicators after desalination of saline water and redistribution of salt (concentration unit: mg / L)

[0035] <![CDATA[Na + ]]> <![CDATA[K + ]]> <![CDATA[Ca 2+ ]]> <![CDATA[Mg 2+ ]]> <![CDATA[Cl - ]]> <![CDATA[SO4 2- ]]> 50m underground saline water 2277.0 43.6 441.2 212.6 2963.8 2211.6 Reverse osmosis water production from 50m underground saline water 157.8 0.0 0.0 0.0 243.6 0.0 Reverse osmosis associated concentrated saline water 3984.3 79.7 805.0 387.1 5154.6 4027.1 100m underground saline water in the recharge well before recharge 2275.4 44.2 442.8 213.3 2965.4 2213.1 50m underground saline water after recharge 2275.0 44.1 442.9 213.1 2965.2 2209.2

[0036] like Figure 1 The figure shows a schematic diagram of underground saline-alkali water distribution before salt distribution. Saline-alkali water is extracted from a pumping well 50 m below ground level. After microfiltration to remove particles, the water passes through a booster pump and a safety filter. It is then pressurized by a high-pressure pump to form high-pressure saline-alkali water, which then enters a reverse osmosis membrane module. This produces reverse osmosis product water with a recovery rate of approximately 45%. The main ion indicators of this high-pressure concentrated saline-alkali water are shown in Table 1. This high-pressure concentrated saline-alkali water is then transported to a recharge well 100 m below ground level for recharge. The recharge well recharges 200 tons of concentrated saline-alkali water daily. After 30 days of continuous recharge, the main ion indicators of the saline-alkali water 50 m below ground level are shown in Table 1.

[0037] like Figure 2 Figure 2 shows the redistribution of salt in underground saline-alkali water. The color at the bottom becomes darker, indicating a higher salt concentration at the bottom.

[0038] Example 2

[0039] Taking a surface saline-alkali water in Aral City as an example, the main water ion indicators of the original water sample of the surface saline-alkali water are shown in Table 2.

[0040] Table 2 Main water ion indicators after surface saline-alkali water desalination and salt redistribution (concentration unit: mg / L)

[0041]

[0042]

[0043] like Figure 3Figure 2 shows a schematic diagram of surface saline-alkali water distribution before the salt distribution. Saline-alkali water was extracted from 50 cm below the surface. After microfiltration to remove particles, it was desalinated using a reverse osmosis membrane system. This produced reverse osmosis product water with a recovery rate of approximately 30% (the product water quality met the GB / T 14848-2017 Class III standard) and associated concentrated saline-alkali water. The water quality indicators were stable, as shown in Table 2. The concentrated saline-alkali water generated during the desalination process was transported to the bottom of the water for recharge. 200 tons of concentrated saline-alkali water were recharged daily. After 30 days of recharge, the main water ion indicators of the saline-alkali water at 50 cm below the bottom recharge pipe and 50 cm below the water surface are shown in Table 2. Subsequently, the concentrated saline-alkali water was recharged at the surface, 30 m south of the pumping point, with the recharge pipe facing downward. After 5 days of surface recharge, the main water ion indicators of the saline-alkali water at 50 cm below the recharge pipe and at the bottom of the water are shown in Table 2.

[0044] like Figure 4 Figure 2 shows the redistribution of salt in surface saline-alkaline water. The bottom of the surface water layer darkens after the redistribution, indicating a higher salt concentration at the bottom.

[0045] Through the above method, after saline-alkali water is treated by a reverse osmosis membrane module, no salt precipitation occurs at the reverse osmosis membrane interface. The resulting reverse osmosis water can be directly used for saline-alkali land remediation, domestic water, irrigation water, etc. Saline-alkali water desalination can be achieved using reverse osmosis membranes, distillation, nanofiltration, ultrafiltration, or a combination of these methods. The ultimate goal is to obtain fresh water (or saline-alkali water with reduced salinity) or a more concentrated saline-alkali water.

[0046] At the same time, this method can be used for the comprehensive utilization of underground saline-alkali water with different geology and origins, such as deserts, Gobi deserts, and seashores with seawater backflow.

[0047] Example 3

[0048] At the base located at the northern edge of the Taklimakan Desert, four kilometers away from K104 of the No. 1 Highway in Tazhong, the 14th Regiment of Aral City, its typical desert saline-alkali land characteristics are high underground saline-alkali water level (the salinity of underground saline-alkali water is 9‰), white saline-alkali crystals covering the surface, and extremely sparse vegetation. On April 7, 2025, an excavator was used to level out 1.2 acres of experimental field. Since April 8, the fresh water prepared in Example 1 was used for flooding and washing salt, with a total irrigation of 166m 3 After the saltwater had fully infiltrated, comprehensive renovations were implemented on the experimental field on April 14, including the application of base fertilizer, rotary tillage to loosen the soil, land leveling, the laying of drip irrigation tape, and covering with plastic film. At the same time, sowing and transplanting were completed: a portable seed drill was used to sow the Heilongjiang soybean variety "Heihe 35" as well as local peanut, cotton, and corn seeds. Local sweet potato seedlings were also transplanted, and conventional planting and management were carried out.

[0049] The results of the planting showed that:

[0050] May 4: The overall germination rate of all types of seeds reached 70%.

[0051] May 26: Observations showed that soybean plants were about 20 cm tall and had entered the flowering and podding stage. Some soybean plants that had emerged and grown earlier had already formed pods. Peanut plants were about 10 cm tall (some were flowering), cotton plants were about 15 cm tall, corn plants were about 50 cm tall, and sweet potato plants were about 10 cm tall.

[0052] June 4: The soybean plant height increased to about 40cm, and the pods that had formed began to enter the grain-filling stage. The beans gradually became full, and many flowers had formed pods. The overall plant was in full bloom. The peanut plant height was about 12cm, and the flowering ratio increased. The cotton plant height was about 20cm. The corn plant height was about 80cm. The sweet potato plant height was about 15cm. All crops grew well overall.

[0053] June 9: The soybean plant height increased to about 55cm, and the beans became increasingly full (the fuller beans can be seen when the pods are peeled off). All the early flowering plants have formed pods, and the subsequent ones have also begun to enter the flowering and pod-forming period; the peanut plant height is about 14cm, and the flowering ratio has increased; the cotton plant height is about 30cm; the corn plant height is about 120cm; the sweet potato plant height is about 20cm; all crops are growing well overall.

[0054] The above results fully prove that:

[0055] Actively improve saline-alkali land: Using the fresh water generated by the present invention to flood and wash away salt can effectively improve severely saline-alkali land into arable land suitable for the growth of conventional crops.

[0056] Crop growth performance is normal: the test crops (including non-salt-alkali tolerant varieties such as Heihe 35 soybean) not only successfully emerged, but also completed the normal growth and development cycle, including growth, flowering and fruiting.

[0057] The technology is highly universal: This technology does not rely on the screening and creation of specific salt- and alkali-tolerant germplasm and is universally applicable to conventional crops.

[0058] The improvement timeliness is good: after using the fresh water salt washing method of the present invention, crops can be planted and harvested in the same year, which significantly shortens the saline-alkali land improvement cycle.

[0059] It should be noted that in the saline-alkali water redistribution system of the present invention, fluids transported between various components of the device can generally be transported through pipelines, unless otherwise specified. Furthermore, when additional power is required during the transport process, suitable power equipment such as pumps and fans can be added to the required pipelines. Furthermore, suitable valves can be added to the pipelines, if necessary, to control the flow direction of the fluid.

[0060] It is worth noting that any details not described in this invention are prior art and are well known to those skilled in the art. In reverse osmosis systems, the method of this invention can be used even with salinity levels exceeding 35‰ or a freshwater yield exceeding 45%, as long as there is no scaling or membrane blockage. This method can also be combined with salt production from concentrated saline water to achieve comprehensive development and utilization of saline-alkali land and water.

[0061] Therefore, the present invention adopts the above-mentioned method for redistributing salt in saline-alkali water based on artificially controlled vertical stratification of salinity gradient, and utilizes saline-alkali water desalination technology. The fresh water generated by desalination of saline-alkali water can be used for saline-alkali land management or as domestic water and other freshwater-related production and living purposes. The associated concentrated saline-alkali water is directly recharged to the bottom of the underground saline-alkali water aquifer or the bottom layer of the surface saline-alkali water, and the salinity gradient vertical stratification is artificially controlled. As the desalination of saline-alkali water continues, the salinity at the bottom of the aquifer or the bottom of the surface saline-alkali water is the highest. By utilizing the natural characteristics of high-salinity and high-density saline-alkali water, the reinjected associated concentrated saline-alkali water can spontaneously migrate the low-salinity saline-alkali water above it to the surface or the water surface, so that the salinity of the saline-alkali water at a higher water level can be maintained at the original level to meet the demand for continuous desalination of saline-alkali water. Saline-alkali water can be sustainably used to produce fresh water, so that under the condition that the total salinity of the saline-alkali water remains unchanged, the salinity gradient vertical stratification can be artificially controlled to redistribute the salinity of the saline-alkali water at the vertical spatial level, thereby having the dual functions of saline-alkali water resource development and salt ecological regulation, and realizing saline-alkali land improvement or comprehensive utilization of saline-alkali water. This method does not rely on external desalination at all. Water can be used for comprehensive utilization of saline-alkali land or saline-alkali water. By utilizing saline-alkali water desalination technology and bottom reinjection technology of concentrated saline-alkali water, the saline-alkali water salt can be redistributed by artificially controlling the vertical stratification of the salinity gradient without changing the total amount of salinity in the saline-alkali water. This method can not only sustainably regenerate saline-alkali water resources into freshwater resources, thereby achieving the goals of saline-alkali water desalination, saline-alkali land management and comprehensive utilization of saline-alkali water, but also because this method does not aim at a high recovery rate of saline-alkali water desalination, does not require a reverse osmosis concentrated water return process, thus reducing the cost of saline-alkali water desalination, avoiding the risk of reverse osmosis membrane scaling and clogging during the saline-alkali water desalination process, and improving the stability and sustainability of the entire system. It has great promotion value in saline-alkali areas.

[0062] 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 the same. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solutions of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for redistributing salt in saline-alkali water based on artificially regulating salinity gradient vertical stratification, characterized in that: The following steps are involved: Step S1, extracting saline water; Step S2: using a primary reverse osmosis system to desalinate the extracted saline water to obtain fresh water and concentrated saline water; Step S3: refilling the concentrated saline-alkali water into the bottom layer of the saline-alkali water.

2. The method for redistributing salt in saline-alkali water based on artificially controlled salinity gradient vertical stratification according to claim 1, characterized in that: In step S1, the saline water is underground saline water or surface saline water.

3. The method for redistributing salt in saline-alkali water based on artificially controlling salinity gradient vertical stratification according to claim 1, characterized in that: In step S2, the fresh water yield obtained by the primary reverse osmosis membrane is 30-45% or the reverse osmosis membrane is not fouled or blocked.

4. The method for redistributing salt in saline-alkali water based on artificially controlled salinity gradient vertical stratification according to claim 1, characterized in that: In step S3, when the extracted saline-alkali water is underground saline-alkali water, the concentrated saline-alkali water is recharged at the bottom of the phreatic layer; when the extracted saline-alkali water is surface saline-alkali water, the concentrated saline-alkali water is recharged at the bottom of the surface saline-alkali water.

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