Alkali-reducing and salt-eliminating saline-alkali land restoration system and laying method thereof

Abstract

The invention discloses a saline-alkali soil remediation system capable of reducing alkali and eliminating salt and a laying method of the saline-alkali soil remediation system, and relates to the technical field of saline-alkali soil remediation. The anti-seepage and salt-isolating structure comprises an anti-seepage and salt-isolating layer, and the anti-seepage and salt-isolating layer is pre-buried in the soil main body so as to divide the soil main body into a surface layer and an inner layer which are arranged in the vertical direction; at least part of the negative pressure air extracting device is deeply arranged in the surface layer; the salt discharging device comprises at least one salt discharging pipeline, the salt discharging pipeline is pre-buried in the surface layer and is communicated with the negative pressure air extractor, the part, facing the leaching device, of the outer surface of the salt discharging pipeline forms a water absorption side, and a plurality of water absorption holes are formed in the water absorption side; and a non-woven fabric is arranged in each water absorption hole and is used for leacheate to enter. The system can effectively repair the saline-alkali soil, so that the salinity of the saline-alkali soil is stabilized at the treatment requirement level.

Description

Technical Field

[0001] The invention relates to the technical field of saline-alkali soil restoration, and in particular to a saline-alkali land restoration system for reducing alkali and draining salt, and a laying method thereof. Background Art

[0002] Saline-alkali land is a general term for various saline soils and alkaline soils as well as soils with varying degrees of salinization and alkalization. Its characteristics are high soil salt content and high groundwater salt content. As water evaporates, salt will accumulate in the soil, causing the soil structure to deteriorate and the soil structure to become compacted.

[0003] The current strategies for saline-alkali soil remediation include equipment, development of efficient soil conditioners, improved soil desalination technology, plant planting and fertilizers, but their effects are not significant and the remediation efficiency is low. Summary of the invention

[0004] The main purpose of the present invention is to provide a saline-alkali land restoration system for reducing alkali and draining salt, aiming to solve the problem of low efficiency of saline-alkali soil restoration in the prior art.

[0005] To achieve the above-mentioned purpose, the present invention proposes a saline-alkali land remediation system for reducing alkali and removing salt, which is used to remediate the main body of soil, comprising:

[0006] A washing device, used for spraying liquid to the outside of the soil body so that the liquid penetrates downward from the surface of the soil body;

[0007] An impermeable salt-isolating structure, comprising an impermeable salt-isolating layer, wherein the impermeable salt-isolating layer is pre-buried in the soil body to separate the soil body into a surface layer and an inner layer arranged in an up-and-down direction;

[0008] a negative pressure suction device, the negative pressure suction device at least partially extending into the surface layer; and

[0009] The salt discharge device comprises at least one salt discharge pipe, wherein the salt discharge pipe is pre-buried in the surface layer and is connected to the negative pressure exhaust device, and the outer surface of the salt discharge pipe faces the elution device to form a water absorption side, and a plurality of water absorption holes are arranged on the water absorption side, and each of the water absorption holes is provided with a non-woven fabric for allowing the elution liquid to enter.

[0010] In one embodiment, the elution device includes a plurality of elution tubes arranged at intervals in a horizontal direction, the outer surface of each elution tube facing the salt discharge pipe forms a water outlet side, and a plurality of elution holes are arranged on the water outlet side.

[0011] In one embodiment, the interval between each two adjacent elution pipes is 0.5 to 1.5 m; and / or,

[0012] The inner diameter of each elution tube is 8 to 12 mm; and / or,

[0013] The interval between each two adjacent elution holes is 0.3-0.7 m; and / or,

[0014] The inner diameter of each elution hole is 2 to 5 mm.

[0015] In one embodiment, the salt discharge device comprises a plurality of the salt discharge pipes, the plurality of the salt discharge pipes are arranged at intervals in the horizontal direction, and the interval between each two adjacent salt discharge pipes is 4 to 6 m; and / or,

[0016] The distance between the salt discharge pipe and the upper surface of the soil body is 45 to 55 cm; and / or,

[0017] The salt discharge pipeline is arranged at an inclination, and its buried slope is 0.8% to 1.2%; and / or,

[0018] The inner diameter of the salt discharge pipe is 100-160 mm; and / or,

[0019] The opening rate of the salt discharge pipeline is 2% to 4%; and / or,

[0020] The inner diameter of each of the water absorption holes is 4 to 8 mm; and / or,

[0021] The interval between two adjacent water absorption holes is 1 to 3 cm.

[0022] In one embodiment, the saline-alkali land remediation system for reducing alkali and removing salt further comprises a filter layer disposed on the outer surface of the water absorption side of the salt discharge pipe, and the filter layer is used to prevent soil particles from entering the salt discharge pipe.

[0023] In one embodiment, the filter material of the filter layer comprises a mixture of sand, gravel and pebbles, the particle size of the sand is 0.5 to 2 mm, the particle size of the gravel is 2 to 4 mm, and the particle size of the pebbles is 4 to 8 mm; and / or,

[0024] The thickness of the filter layer is 80-100 mm.

[0025] In one embodiment, the negative pressure air extraction device includes an air extraction pump and a plurality of air extraction pipes arranged at intervals in a horizontal direction;

[0026] Each of the exhaust pipes extends in the up-down direction, with one end connected to the exhaust pump and the other end connected to the salt discharge pipe. At least one exhaust hole is arranged on the outer surface of the lower part of each of the exhaust pipes, and a filter is arranged in the exhaust hole to enable the exhaust pipe to absorb gas in the soil and prevent soil particles from clogging the exhaust hole.

[0027] In one embodiment, the inner diameter of each of the exhaust pipes is 60 to 80 mm; and / or,

[0028] The interval between two adjacent exhaust pipes is 4 to 6 m; and / or,

[0029] The interval between two adjacent air extraction holes is 8 to 10 cm; and / or,

[0030] The inner diameter of each of the air extraction holes is 4 to 8 mm.

[0031] In one embodiment, the distance between the impermeable salt-isolating layer and the upper surface of the soil body is 45 to 55 cm; and / or,

[0032] The thickness of the anti-seepage salt isolation layer is 10 to 20 cm; and / or,

[0033] The anti-seepage salt-isolating layer is formed by mixing saline-alkali soil, a curing agent, an alkali activator, sugarcane pith and water.

[0034] The present invention also provides a method for laying a saline-alkali land repair system for reducing alkali and draining salt. Based on the aforementioned saline-alkali land repair system for reducing alkali and draining salt, the saline-alkali land repair system for reducing alkali and draining salt further comprises a filter layer arranged on the outer surface of the water absorption side of the salt drainage pipeline, and the filter layer is used to prevent soil particles from entering the salt drainage pipeline;

[0035] The laying method of the saline-alkali land repair system for reducing alkali and draining salt comprises the following steps:

[0036] S10, removing part of the saline-alkali soil in the surface layer of the soil body to form a concave portion in the surface layer of the soil body;

[0037] S20, laying an impermeable salt-isolating layer at the bottom of the concave portion, and backfilling above the impermeable salt-isolating layer to obtain a first soil layer structure;

[0038] S30, laying a salt discharge pipeline above the first soil layer structure, and performing a second backfill on the side of the water absorption side of the salt discharge pipeline to cover it and expose the water absorption side of the salt discharge pipeline;

[0039] S40, laying a filter layer on the water absorption side of the salt discharge pipe, and backfilling above the filter layer so that the concave portion is filled to obtain a second soil layer structure;

[0040] S50: laying a washing device on the surface of the second soil layer structure.

[0041] The technical solution of the present invention adopts a leaching device to spray liquid into the soil body so that the liquid penetrates downward from the surface of the soil body. The soil body satisfies the characteristics of saline-alkali land, so the leaching liquid that penetrates contains the salt in the soil body; an impermeable salt-isolating structure is pre-buried in the soil body to separate the soil body into a surface layer and an inner layer arranged in the upper and lower directions. The impermeable salt-isolating layer can cut off the connection between the moisture in the lower part (i.e., the inner layer of the soil body) and the upper part (i.e., the surface layer of the soil body), inhibiting the salt in the moisture in the lower part from entering the upper part, thereby effectively inhibiting the increase of salt in the surface soil in the upper part; a salt-draining pipe is pre-buried in the soil surface layer, and the salt-draining pipe The multiple water absorption holes arranged on the water absorption side of the channel can receive the leaching liquid containing salt in the surface soil, and the leaching liquid is discharged along the salt discharge pipe; in addition, by arranging non-woven fabric in each water absorption hole, soil particles can be effectively prevented from entering or blocking the water absorption port; by connecting the salt discharge pipe with the negative pressure suction device, when the negative pressure suction device is in operation, the air in the salt discharge pipe and even the air in the soil near the water absorption hole will be sucked away through the water absorption hole of the salt discharge pipe, so that a pressure difference is formed between the inside of the salt discharge pipe and the soil outside it, so that the leaching liquid containing salt in the soil outside it enters the salt discharge pipe through the water absorption hole, thereby improving the removal efficiency of salt in the surface soil. The above-mentioned remediation system discharges the salt in the surface soil quickly and efficiently through the joint arrangement of the leaching device, the salt discharge device and the negative pressure suction device, realizes the purification of the surface soil, and further inhibits the salt in the inner soil from evaporating upward with the water by arranging the anti-seepage salt isolation layer in the bottom layer of the surface soil. Therefore, the present invention ensures that the salt content in the soil reaches the stable value required for saline-alkali land management (ie, soil salt content <0.2%) by taking the two measures of accelerating the discharge of surface salt and inhibiting the evaporation of inner salt. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0043] Figure 1 A schematic diagram of the structure of an embodiment of a saline-alkali land remediation system for reducing alkali and removing salt provided by the present invention;

[0044] Figure 2 For the present invention Figure 1 A partial enlarged view of middle A.

[0045] Description of Figure Numbers:

[0046] 100. A saline-alkali land restoration system for reducing alkali and removing salt; 1. Leaching device; 11. Leaching pipe; 2. Anti-seepage salt-isolating structure; 21. Anti-seepage salt-isolating layer; 3. Negative pressure suction device; 31. Suction pipe; 311. Suction hole; 312. Filter; 4. Salt-removing device; 41. Salt-removing pipeline; 411. Water absorption hole; 5. Filter layer; a. Surface layer; b. Inner layer.

[0047] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0048] To make the purpose, technical scheme and advantages of the embodiment of the present invention clearer, the technical scheme in the embodiment of the present invention will be described clearly and completely below. If the specific conditions are not specified in the embodiment, it is carried out according to the normal conditions or the conditions recommended by the manufacturer. If the reagents or instruments used do not specify the manufacturer, they are all conventional products that can be purchased commercially. In addition, the meaning of "and / or" appearing in the full text includes three parallel schemes, taking "A and / or B" as an example, including scheme A, or scheme B, or schemes that A and B meet at the same time. In addition, the technical schemes between the various embodiments can be combined with each other, but must be based on the ability of ordinary technicians in the field to achieve. When the combination of technical solutions is contradictory or cannot be achieved, it should be considered that the combination of such technical solutions does not exist, and is not within the scope of protection required by the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in the field without making creative work belong to the scope of protection of the present invention.

[0049] Saline-alkali land is a general term for various saline soils and alkaline soils as well as soils with varying degrees of salinization and alkalization. Its characteristics are high soil salt content and high groundwater salt content. As water evaporates, salt will accumulate in the soil, causing the soil structure to deteriorate and the soil structure to become compacted.

[0050] The current strategies for saline-alkali soil remediation include equipment, development of efficient soil conditioners, improved soil desalination technology, plant planting and fertilizers, but their effects are not significant and the remediation efficiency is low.

[0051] In view of this, if Figure 1 As shown, the present invention provides a saline-alkali land remediation system 100 for reducing alkali and removing salt, which is used to remediate the main body of soil, comprising:

[0052] A washing device 1, used for spraying liquid to the outside of the soil body so that the liquid penetrates downward from the surface of the soil body;

[0053] The impermeable salt-isolating structure 2 comprises an impermeable salt-isolating layer 21, wherein the impermeable salt-isolating layer 21 is pre-buried in the soil body to separate the soil body into a surface layer a and an inner layer b arranged in an up-down direction;

[0054] A negative pressure suction device 3, wherein the negative pressure suction device 3 is at least partially embedded in the surface layer a; and a salt discharge device 4, wherein the salt discharge device 4 includes at least one salt discharge pipe 41, wherein the salt discharge pipe 41 is pre-buried in the surface layer a and is connected to the negative pressure suction device 3, wherein the outer surface of the salt discharge pipe 41 is toward the elution device 1 to form a water absorption side, wherein a plurality of water absorption holes 411 are arranged on the water absorption side, and each of the water absorption holes 411 is provided with a non-woven fabric for allowing the elution liquid to enter.

[0055] In the technical solution of the present invention, a leaching device 1 is used to spray liquid into the soil body so that the liquid penetrates downward from the surface of the soil body. The soil body satisfies the characteristics of saline-alkali land, so the leaching liquid that penetrates contains the salt in the soil body; an impermeable salt-isolating structure 2 is pre-buried in the soil body to separate the soil body into a surface layer a and an inner layer b arranged in the upper and lower directions. The impermeable salt-isolating layer 21 can cut off the connection between the moisture in the lower part (i.e., the inner layer b of the soil body) and the upper part (i.e., the surface layer a of the soil body), inhibiting the salt in the moisture in the lower part from entering the upper part, thereby effectively inhibiting the increase of salt in the soil in the upper surface layer a; a salt-discharging pipe 41 is pre-buried in the soil surface layer a, and the upper surface of the salt-discharging pipe 41 on the water absorption side The multiple water absorption holes 411 provided can receive the eluent containing the salt in the surface layer a soil, and the eluent is discharged along the salt discharge pipe 41; in addition, by providing a non-woven fabric in each water absorption hole 411, soil particles can be effectively prevented from entering or blocking the water absorption port; by connecting the salt discharge pipe 41 with the negative pressure exhaust device 3, when the negative pressure exhaust device 3 is in operation, the air in the salt discharge pipe 41 and even the air in the soil near the water absorption hole 411 will be extracted through the water absorption hole 411 of the salt discharge pipe 41, so that a pressure difference is formed between the inside of the salt discharge pipe 41 and the soil outside it, so that the eluent containing salt in the soil outside it enters the salt discharge concealed pipe through the water absorption hole 411, thereby improving the removal efficiency of salt in the surface layer a soil. The above-mentioned repair system discharges the salt in the surface layer a soil quickly and efficiently through the joint arrangement of the elution device 1, the salt discharge device 4 and the negative pressure exhaust device 3, thereby purifying the surface layer a soil, and further suppresses the salt in the inner layer b soil from evaporating upward with the water by setting the impermeable salt isolation layer 21 in the bottom layer of the surface layer a soil. Therefore, the present invention ensures that the salt content in the soil reaches the stable value required for saline-alkali land management (i.e., soil salt content <0.2%) by the two measures of accelerating the discharge of salt in the surface layer a and suppressing the evaporation of salt in the inner layer b. The surface layer a of the main body of the soil can be used for planting after being repaired by the repair system of the present invention.

[0056] It should be noted that if Figure 1 As shown, the length of the salt discharge pipe 41 extends in the horizontal direction, and the left end and the right end thereof each have an opening, one of which is blocked and the other is connected to the waste liquid pool.

[0057] In one embodiment, the rinsing device 1 includes a plurality of rinsing pipes 11 arranged at intervals in the horizontal direction, and the outer surface of each rinsing pipe 11 facing the salt discharge pipe 41 forms a water outlet side, and a plurality of rinsing holes are arranged on the water outlet side. Figure 1 As shown, the elution device 1 can be arranged on the surface of the soil body (i.e., the upper surface of the surface layer a), or the elution device 1 can be arranged at a certain distance above the surface of the soil body, so as to achieve the purpose of spraying the soil body. The lower surface of each elution pipe 11 is the water outlet side, and the multiple elution holes arranged on the water outlet side are used to spray elution liquid to the soil body. The elution liquid can dissolve the salt in the soil body. Therefore, the elution liquid will take away the salt in the soil body during the process of flowing downward into the salt discharge pipe 41 under the action of gravity, so that the salt in the soil body is reduced. The elution pipe 11 can be arranged one-to-one with the salt discharge pipe 41 (such as Figure 1 As shown in the figure), they may not be arranged one by one, as long as the eluent can smoothly enter the salt discharge pipe 41. Preferably, a salt discharge pipe 41 is arranged directly below each of the eluent pipes 11, that is, one by one.

[0058] In one embodiment, the interval between each two adjacent elution pipes 11 is 0.5-1.5 m. The interval between each two adjacent elution pipes 11 within the range of 0.5-1.5 m can ensure that the cost of the elution pipes 11 is saved while achieving a better spraying effect and increasing the area of ​​the soil body surface wetted by the elution liquid.

[0059] In one embodiment, the inner diameter of each elution pipe 11 is 8-12 mm. The inner diameter of each elution pipe 11 within the range of 8-12 mm can ensure a high internal pressure, and the eluent covers a larger area of ​​the main soil surface after being sprayed, thereby increasing the spraying area.

[0060] In one embodiment, the interval between each two adjacent elution holes is 0.3-0.7 m. The interval between each two adjacent elution holes is within the range of 0.3-0.7 m to ensure that the elution liquid can effectively contact the soil body and dissolve the salt in the soil body.

[0061] In one embodiment, the inner diameter of each of the elution holes is 2 to 5 mm. The inner diameter of each of the elution holes is within the range of 2 to 5 mm to ensure smooth outflow of the liquid, without being blocked due to a hole that is too small, or causing too fast a flow rate or too large a flow rate due to a hole that is too large, thereby effectively controlling the distribution and spraying of the elution liquid.

[0062] In one embodiment, the salt discharge device 4 includes a plurality of salt discharge pipes 41, which are arranged at intervals in the horizontal direction, and the interval between each two adjacent salt discharge pipes 41 is 4 to 6 meters. The interval between each two adjacent salt discharge pipes 41 within the range of 4 to 6 meters can prevent the salt discharge pipes 41 from interfering with each other and maintain the stability of the repair system; in addition, it can also ensure that the eluent containing the main salt of the soil is evenly discharged from the soil into the salt discharge pipe 41 to avoid local accumulation.

[0063] In one embodiment, the distance between the salt discharge pipe 41 and the upper surface of the soil body is 45-55 cm. The distance between the salt discharge pipe 41 and the upper surface of the soil body within the range of 45-55 cm can avoid damage to the soil body structure, ensure that the salt discharge pipe 41 is not easily damaged by mechanical farming, and facilitate regular maintenance by maintenance personnel.

[0064] In one embodiment, the salt discharge pipe 41 is inclined, and its buried slope is 0.8% to 1.2%. The salt discharge pipe 41 is inclined to facilitate the rapid outflow of the eluent containing salt water to the outlet. The buried slope of the salt discharge pipe 41 in the range of 0.8% to 1.2% can ensure that the eluent therein flows out naturally along the inside of the salt discharge pipe 41, reducing the accumulation of the eluent in the salt discharge pipe 41; the existence of the slope can also assist in removing solid salts and impurities in the salt discharge pipe 41, and maintain the patency of the salt discharge pipe 41.

[0065] In one embodiment, the inner diameter of the salt discharge pipe 41 is 100-160 mm. The inner diameter of the salt discharge pipe 41 within the range of 100-160 mm can withstand a greater external load without being easily damaged, and can also reduce the probability of solid particles such as salt and soil being deposited in the pipe, thereby reducing the risk of pipe blockage.

[0066] In one embodiment, the opening rate of the salt discharge pipe 41 is 2% to 4%. The opening rate of the salt discharge pipe 41 within the range of 2% to 4% can ensure smooth salt discharge, while avoiding excessive opening rate, which leads to poor mechanical properties of the salt discharge pipe 41 and reduced bearing capacity of the salt discharge pipe 41. The total area of ​​the openings (i.e., holes for water to flow through) on the salt discharge pipe 41 accounts for the proportion of the surface area of ​​the salt discharge pipe 41.

[0067] In one embodiment, the inner diameter of each of the water absorption holes 411 is 4 to 8 mm. The inner diameter of each of the water absorption holes 411 within the range of 4 to 8 mm can ensure that the water in the soil body is fully absorbed; if the opening is too small, the water absorption speed is slow and the salt discharge speed is slow; if the opening is too large, the mechanical properties of the salt discharge pipe 41 deteriorate and there is a risk of collapse.

[0068] In one embodiment, the interval between two adjacent water absorption holes 411 is 1-3 cm. The interval between two adjacent water absorption holes 411 in the range of 1-3 cm can ensure that the water in the soil body is absorbed while not damaging the mechanical properties of the salt discharge pipe 41.

[0069] In one embodiment, the saline-alkali land remediation system 100 for reducing alkali and removing salt further comprises a filter layer disposed on the outer surface of the water absorption side of the salt discharge pipe 41, and the filter layer is used to prevent soil particles from entering the salt discharge pipe 41. By providing the filter layer, large particles in the main body of soil can be prevented from entering the salt discharge pipe 41, thereby avoiding the loss of the main body of soil, and at the same time, the salt discharge pipe 41 can be prevented from being blocked, which affects the salt discharge efficiency of the salt discharge pipe 41.

[0070] In one embodiment, the filter material of the filter layer includes a mixture of sand, crushed stone and pebbles, wherein the particle size of the sand is 0.5 to 2 mm, the particle size of the crushed stone is 2 to 4 mm, and the particle size of the pebbles is 4 to 8 mm. By adjusting the particle sizes of the sand, crushed stone and pebbles, the pore size of the filter layer can be reduced to block large solid particles in the soil body while allowing water to quickly pass through the filter layer.

[0071] In one embodiment, the thickness of the filter layer is 80-100 mm. The thickness of the filter layer within the range of 80-100 mm can ensure that water quickly passes through the filter layer under the premise of blocking the soil, and avoid the filter layer being too thick, causing water to accumulate in the filter layer, resulting in reduced water absorption efficiency.

[0072] In one embodiment, the negative pressure suction device 3 includes a suction pump and a plurality of suction pipes 31 arranged at intervals in the horizontal direction; each of the suction pipes 31 extends in the up-down direction, one end of which is connected to the suction pump and the other end of which is connected to the salt discharge pipe 41; at least one suction hole 311 is provided on the outer surface of the lower part of each of the suction pipes 31; a filter 312 is provided in the suction hole 311, so that the suction pipe 31 can absorb the gas in the soil and prevent the soil particles from blocking the suction hole 311. When the suction pump starts to operate, the gas in the exhaust pipe and the gas in the soil body outside the suction hole 311 are extracted through the suction pipe 31, so that the pressure inside the salt discharge pipe 41 and the suction pipe 31 is relatively low. At this time, the soil body is connected to the external environment with a high pressure, and a pressure difference is formed between the two, so that the air in the soil body and the eluent quickly enter the negative pressure space formed by the salt discharge pipe 41 and the suction pipe 31, which promotes the discharge of the eluent containing salt and improves the salt discharge efficiency.

[0073] In one embodiment, the inner diameter of each of the air extraction pipes 31 is 60-80 mm. The inner diameter of each of the air extraction pipes 31 is within the range of 60-80 mm, which can ensure that the air in the main soil body near the salt discharge pipe 41, the air extraction pipe 31 and the air extraction hole 311 is quickly extracted, and a negative pressure space is quickly formed in the pipe; at the same time, large solid particles in the main soil body are prevented from entering the air extraction pipe 31.

[0074] In one embodiment, the interval between two adjacent air extraction pipes 31 is 4 to 6 meters. The interval between two adjacent air extraction pipes 31 within the range of 4 to 6 meters can ensure that the air in the soil body near the air extraction hole 311 can be quickly sucked into the air extraction pipe 31, ensuring high air extraction efficiency while saving costs.

[0075] In one embodiment, the interval between two adjacent air extraction holes 311 is 8 to 10 cm. The interval between two adjacent air extraction holes 311 within the range of 8 to 10 cm can ensure that the air in the soil body near the air extraction holes 311 can be evenly and efficiently extracted, and prevent solid matter in the soil from entering the tube.

[0076] In one embodiment, the inner diameter of each of the air extraction holes 311 is 4 to 8 mm. The inner diameter of each of the air extraction holes 311 within the range of 4 to 8 mm can ensure that the air in the soil body near the air extraction hole 311 can be efficiently extracted, and prevent large particles of solid matter in the soil from entering the pipe and affecting the air extraction efficiency.

[0077] In one embodiment, the distance between the impermeable salt-isolating layer 21 and the upper surface of the soil body is 45 to 55 cm. The distance between the impermeable salt-isolating layer 21 and the upper surface of the soil body within the range of 45 to 55 cm can effectively prevent the salt in the inner layer b from rising to the soil surface layer a with water through capillary action, and provide a more abundant and suitable planting space (i.e., the surface layer a of the soil body).

[0078] In one embodiment, the thickness of the impermeable salt-isolating layer 21 is 10 to 20 cm. The thickness of the impermeable salt-isolating layer 21 within the range of 10 to 20 cm can effectively cut off the connection between the moisture in the inner layer b and the surface layer a, prevent the salt content in the surface layer a from rising again, and achieve the purpose of inhibiting the soil desalination in the surface layer a. In addition, by limiting the thickness of the impermeable salt-isolating layer 21, it can better adapt to the movement and deformation of the surface and underground, have a certain plasticity, and maintain its integrity and anti-seepage effect; at the same time, the impermeable salt-isolating layer 21 has a certain elasticity, which can absorb and relieve the stress and deformation on the surface and underground, and reduce the risk of leakage. Leakage refers to the phenomenon that liquid or gas flows from one area to another without permission through defects, gaps or other weak links in materials, structures or devices.

[0079] In one embodiment, the anti-seepage salt-isolating layer 21 is formed by mixing saline-alkali soil, a curing agent, an alkali activator, sugarcane pith and water. The anti-seepage salt-isolating layer 21 has a small permeability coefficient, that is, good anti-seepage performance, which can prevent the lower salt-containing steam from evaporating upward.

[0080] The present invention also provides a method for laying a saline-alkali land repair system 100 for reducing alkali and draining salt. Based on the aforementioned saline-alkali land repair system 100 for reducing alkali and draining salt, the saline-alkali land repair system 100 for reducing alkali and draining salt further comprises a filter layer disposed on the outer surface of the water absorption side of the salt drainage pipe 41, and the filter layer is used to prevent soil particles from entering the salt drainage pipe 41;

[0081] The laying method of the saline-alkali land remediation system 100 for reducing alkali and removing salt comprises the following steps:

[0082] S10, removing part of the saline-alkali soil in the surface layer a of the soil body to form a concave portion in the surface layer a of the soil body;

[0083] S20, laying an impermeable salt-isolating layer 21 at the bottom of the concave portion, and backfilling above the impermeable salt-isolating layer 21 to obtain a first soil layer structure;

[0084] S30, laying a salt discharge pipe 41 above the first soil layer structure, and performing a second backfill on the side of the water absorption side of the salt discharge pipe 41 to cover it, and making the water absorption side of the salt discharge pipe 41 exposed;

[0085] S40, laying a filter layer on the water absorption side of the salt discharge pipe 41, and backfilling above the filter layer so that the concave portion is filled to obtain a second soil layer structure;

[0086] S50, laying a washing device 1 on the surface of the second soil layer structure.

[0087] In the above-mentioned laying method, backfill is performed after laying the impermeable salt-isolating layer 21, backfill is performed after laying the salt-discharging pipe 41, and backfill is performed after laying the filter layer. Through three backfillings, the supporting structure between the impermeable salt-isolating layer 21, the salt-discharging pipe 41 and the filter layer is strengthened, and the mechanical properties of the saline-alkali land remediation system 100 for reducing alkali and discharging salt are improved. At the same time, each structure can function separately and cooperate with each other to filter and absorb the water in the main body of the soil into the drainage pipe; by laying the elution device 1 on the surface of the second soil layer structure, the salt in the second soil layer structure can be dissolved and absorbed into the drainage pipe with water, thereby reducing the salt in the main body of the soil.

[0088] It should be noted that, in step S30, specifically, a salt discharge pipe 41 is laid above the first soil layer structure, and the air extraction pipe 31 is connected to the water suction side of the salt discharge pipe 41, so that the other side of the air extraction pipe 31 is outside the soil body and connected to an air pump, that is, the water suction side of the salt discharge pipe 41 not only has a water suction hole 411 but also has a connecting hole with the same aperture as the air extraction pipe 31 for the air extraction pipe 31 to be connected to the salt discharge pipe 41, and the salt discharge pipe 41 and the air extraction pipe 31 may also be integrally formed.

[0089] In one embodiment of the present invention, the method for preparing the anti-seepage salt isolation layer 21 material comprises the following steps:

[0090] The slag, fly ash and desulfurized gypsum are dried to constant weight and then sieved;

[0091] The dried slag, fly ash and desulfurized gypsum are mixed and ball-milled to obtain a mixed powder;

[0092] Stirring the agglomerated saline-alkali soil into loose granular saline-alkali soil;

[0093] Adding the mixed powder to the granular saline-alkali soil to obtain a premix;

[0094] adding an alkali activator, sugarcane fiber and water to the premix to obtain a mixed material;

[0095] The mixed material is spread flat, rolled repeatedly until it becomes a block, and dried and solidified to obtain the anti-seepage salt isolation layer 21 material.

[0096] In one embodiment of the present invention, the step of mixing desulfurized gypsum, slag and fly ash to obtain a mixed powder comprises:

[0097] Desulfurized gypsum, slag and fly ash are dried at 100-110°C to constant weight and then sieved. Desulfurized gypsum, slag and fly ash are then mixed in a certain proportion and stirred at a medium speed of 100-400 r / min for 5-10 minutes to obtain a mixed powder.

[0098] In one embodiment of the present invention, the step of ball milling the mixed powder comprises:

[0099] The mixed powder is put into a ball mill and ball-milled for 60-90 minutes to obtain a ball-milled mixed powder.

[0100] In one embodiment of the present invention, the step of stirring the agglomerated saline-alkali soil into loose granular saline-alkali soil comprises:

[0101] The agglomerated saline-alkali soil is stirred and mixed at a medium speed of 100 to 400 r / min for 5 to 10 minutes to form granular saline-alkali soil.

[0102] In one embodiment of the present invention, the step of adding the mixed powder to the saline-alkali soil and stirring and mixing to obtain a premix comprises:

[0103] The mixed powder is added to the saline-alkali soil, and the mixture is stirred and mixed at a high speed of 600 to 1000 r / min for 15 to 20 minutes.

[0104] In one embodiment of the present invention, the content of the curing agent is 20-25% of the total mass of the saline-alkali soil, the content of water is 15-20% of the total mass of the saline-alkali soil, the content of sugarcane pith is 1-2% of the total mass of the saline-alkali soil, and the activator is Ca(OH)2, accounting for 0.5% of the total mass of the curing agent.

[0105] In one embodiment of the present invention, the step of adding Ca(OH)2 to the premix, stirring and mixing with water and sugarcane pith to obtain a mixed material comprises:

[0106] Ca(OH)2 is prepared into a saturated solution with distilled water, and then mixed with sugarcane pith and added into the premix, and stirred at a high speed of 600-1000 r / min for 15-20 minutes to obtain a mixed material.

[0107] In one embodiment of the present invention, the mixed material is spread flat and then repeatedly rolled into a block shape and dried and solidified to prepare the impermeable salt isolation layer 21 material:

[0108] The thickness of the blocks formed by rolling the mixed material is not less than 10 cm.

[0109] The technical solution of the present invention is further described in detail below in conjunction with specific embodiments and drawings. It should be understood that the following embodiments are only used to explain the present invention and are not used to limit the present invention.

[0110] Example 1

[0111] This embodiment provides a comprehensive improvement system for saline-alkali land, and its preparation method includes the following steps:

[0112] Step 1: Use an excavator to remove the saline-alkali soil to be improved to form a concave part with a digging depth of 65-70cm;

[0113] Step 2: Laying of the impermeable salt-isolating layer 21. The process includes the following steps:

[0114] The slag, fly ash and desulfurized gypsum are dried to constant weight and then sieved;

[0115] The dried slag, fly ash and desulfurized gypsum are mixed and ball-milled to obtain a mixed powder;

[0116] Stirring the agglomerated saline-alkali soil into loose granular saline-alkali soil;

[0117] Adding the mixed powder to the granular saline-alkali soil to obtain a premix;

[0118] adding an alkali activator, sugarcane fiber and water to the premix to obtain a mixed material;

[0119] The mixed material is spread flat, rolled repeatedly until it becomes a block, and dried and solidified to obtain the anti-seepage salt isolation layer 21 material.

[0120] The slag, fly ash and desulfurized gypsum are stirred and mixed to obtain a mixed powder, wherein the slag accounts for 60% of the total mass of the dry soil, the fly ash accounts for 25%, and the desulfurized gypsum accounts for 15%. The specific steps are: drying the slag, desulfurized gypsum and fly ash at 100-110°C to constant weight and then sieving, and then stirring the desulfurized gypsum and fly ash at a medium speed of 100-400r / min for 5-10 minutes to obtain a mixed powder;

[0121] The mixed powder was placed in a ball mill and milled for 60 minutes to obtain a ball-milled mixed powder;

[0122] The agglomerated saline-alkali soil excavated in the first step is stirred into loose granular saline-alkali soil, specifically comprising the following steps: stirring and mixing the agglomerated soil at a medium speed of 100 to 400 r / min for 5 to 10 minutes to form loose granular saline-alkali soil;

[0123] Adding a mixed powder consisting of slag, fly ash and desulfurized gypsum to the granular saline-alkali soil, stirring and mixing to obtain a premix, the specific steps are: adding the mixed powder to the saline-alkali soil, stirring and mixing at a high speed of 600 to 1000 r / min for 15 to 20 minutes;

[0124] The step of adding Ca(OH)2 to the premix, stirring and mixing with water and sugarcane pith to obtain a mixed material, wherein the content of the curing agent is 20-25% of the total mass of the saline-alkali soil, the content of water is 15-20% of the total mass of the saline-alkali soil, the content of the sugarcane pith is 1-2% of the total mass of the saline-alkali soil, and the activator is Ca(OH)2, accounting for 0.5% of the total mass of the curing agent. The specific steps are: using distilled water to prepare Ca(OH)2 into a saturated solution of Ca(OH)2, then mixing it evenly with the sugarcane pith and adding it to the premix, stirring it at a high speed of 600-1000r / min for 15-20min to obtain a mixed material;

[0125] The mixed material is spread flat and repeatedly rolled until it becomes a block and dried and solidified to obtain an impermeable salt isolation layer 21 material;

[0126] Step 3: Lay the salt-discharging pipe 41 above the impermeable salt-isolating layer 21. First, carry out the first backfill of saline-alkali soil above the salt-isolating layer, with a backfill thickness of about 30-40cm, and then arrange a layer of sand and gravel filter material with a thickness of about 30-50mm and different particle sizes at the location where the salt-discharging pipe 41 is laid. Lay the salt-discharging pipe 41 above the filter material. The salt-discharging pipe 41 is a PE corrugated pipe with a diameter of 100-160mm. The distance between each pipe is 5m, the buried slope is 1%, and a layer of non-woven fabric is wrapped around the outside of the salt-discharging pipe 41;

[0127] Step 4: Connect the vacuum exhaust pipe 31 to the reserved hole on the upper part of the salt discharge pipe. After the connection, use a salt-alkali resistant adhesive to bond the salt discharge pipe to the exhaust pipe 31 and wrap it tightly with non-woven fabric. The salt-alkali resistant adhesive is American IPS transparent glue WELD-ON 717.

[0128] Step 5: Continue to carry out the second backfill of saline-alkali soil on both sides of the salt drainage pipe, and lay a filter layer consisting of 2-4 layers of sand, gravel and pebbles on the upper part of the pipe. The filter layer is laid in an inverted cone shape;

[0129] Step 6: Carry out the third backfill of saline-alkali soil on the upper part of the sand filter layer;

[0130] Step 7: Lay a drip irrigation pipe every 1m on the soil surface. The drip irrigation pipe is a PE hose with a diameter of 10mm and a hole every 0.5m at the bottom of the pipe.

[0131] Example 2

[0132] This embodiment provides a comprehensive improvement system for saline-alkali land, and its preparation method includes the following steps:

[0133] Step 1: Use an excavator to remove the saline-alkali soil to be improved to form a concave part with a digging depth of 65-70cm;

[0134] Step 2: Laying of the impermeable salt-isolating layer 21. The process includes the following steps:

[0135] The slag, fly ash and desulfurized gypsum are dried to constant weight and then sieved;

[0136] The dried slag, fly ash and desulfurized gypsum are mixed and ball-milled to obtain a mixed powder;

[0137] Stirring the agglomerated saline-alkali soil into loose granular saline-alkali soil;

[0138] Adding the mixed powder to the granular saline-alkali soil to obtain a premix;

[0139] adding an alkali activator, sugarcane fiber and water to the premix to obtain a mixed material;

[0140] The mixed material is spread flat, rolled repeatedly until it becomes a block, and dried and solidified to obtain the anti-seepage salt isolation layer 21 material.

[0141] The slag, fly ash and desulfurized gypsum are stirred and mixed to obtain a mixed powder, wherein the slag accounts for 55% of the total mass of dry soil, the fly ash accounts for 25%, and the desulfurized gypsum accounts for 20%. The specific steps are: drying the slag, desulfurized gypsum and fly ash at 100-110°C to constant weight and then sieving, and then stirring the desulfurized gypsum and fly ash at a medium speed of 100-400r / min for 5-10 minutes to obtain a mixed powder;

[0142] The mixed powder was placed in a ball mill and milled for 75 minutes to obtain a ball-milled mixed powder;

[0143] The agglomerated saline-alkali soil excavated in the first step is stirred into loose granular saline-alkali soil, specifically comprising the following steps: stirring and mixing the agglomerated soil at a medium speed of 100 to 400 r / min for 5 to 10 minutes to form loose granular saline-alkali soil;

[0144] Adding a mixed powder consisting of slag, fly ash and desulfurized gypsum to the granular saline-alkali soil, stirring and mixing to obtain a premix, the specific steps are: adding the mixed powder to the saline-alkali soil, stirring and mixing at a high speed of 600 to 1000 r / min for 15 to 20 minutes;

[0145] The step of adding Ca(OH)2 to the premix, stirring and mixing with water and sugarcane pith to obtain a mixed material, wherein the content of the curing agent is 20-25% of the total mass of the saline-alkali soil, the content of water is 15-20% of the total mass of the saline-alkali soil, the content of the sugarcane pith is 1-2% of the total mass of the saline-alkali soil, and the activator is Ca(OH)2, accounting for 0.5% of the total mass of the curing agent. The specific steps are: using distilled water to prepare Ca(OH)2 into a saturated solution of Ca(OH)2, then mixing it evenly with the sugarcane pith and adding it to the premix, stirring it at a high speed of 600-1000r / min for 15-20min to obtain a mixed material;

[0146] The mixed material is spread flat and repeatedly rolled until it becomes a block and dried and solidified to obtain an impermeable salt isolation layer 21 material;

[0147] Step 3: Lay the salt-discharging pipe 41 above the impermeable salt-isolating layer 21. First, carry out the first backfill of saline-alkali soil above the salt-isolating layer, with a backfill thickness of about 30-40cm, and then arrange a layer of sand and gravel filter material with a thickness of about 30-50mm and different particle sizes at the location where the salt-discharging pipe 41 is laid. Lay the salt-discharging pipe 41 above the filter material. The salt-discharging pipe 41 is a PE corrugated pipe with a diameter of 100-160mm. The distance between each pipe is 5m, the buried slope is 1%, and a layer of non-woven fabric is wrapped around the outside of the salt-discharging pipe 41;

[0148] Step 4: Connect the vacuum exhaust pipe 31 to the reserved hole on the upper part of the salt discharge pipe. After the connection, use a salt-alkali resistant adhesive to bond the salt discharge pipe to the exhaust pipe 31 and wrap it tightly with non-woven fabric. The salt-alkali resistant adhesive is American IPS transparent glue WELD-ON 717.

[0149] Step 5: Continue to carry out the second backfill of saline-alkali soil on both sides of the salt drainage pipe, and lay a filter layer consisting of 2-4 layers of sand, gravel and pebbles on the upper part of the pipe. The filter layer is laid in an inverted cone shape;

[0150] Step 6: Carry out the third backfill of saline-alkali soil on the upper part of the sand filter layer;

[0151] Step 7: Lay a drip irrigation pipe every 1m on the soil surface. The drip irrigation pipe is a PE hose with a diameter of 10mm and a hole every 0.5m at the bottom of the pipe.

[0152] Example 3

[0153] This embodiment provides a comprehensive improvement system for saline-alkali land, and its preparation method includes the following steps:

[0154] Step 1: Use an excavator to remove the saline-alkali soil to be improved to form a concave part with a digging depth of 65-70cm;

[0155] Step 2: Laying of the impermeable salt-isolating layer 21. The process includes the following steps:

[0156] The slag, fly ash and desulfurized gypsum are dried to constant weight and then sieved;

[0157] The dried slag, fly ash and desulfurized gypsum are mixed and ball-milled to obtain a mixed powder;

[0158] Stirring the agglomerated saline-alkali soil into loose granular saline-alkali soil;

[0159] Adding the mixed powder to the granular saline-alkali soil to obtain a premix;

[0160] adding an alkali activator, sugarcane fiber and water to the premix to obtain a mixed material;

[0161] The mixed material is spread flat, rolled repeatedly until it becomes a block, and dried and solidified to obtain the anti-seepage salt isolation layer 21 material.

[0162] The slag, fly ash and desulfurized gypsum are stirred and mixed to obtain a mixed powder, wherein the slag accounts for 50% of the total mass of the dry soil, the fly ash accounts for 30%, and the desulfurized gypsum accounts for 20%. The specific steps are: drying the slag, desulfurized gypsum and fly ash at 100-110°C to constant weight and then sieving, and then stirring the desulfurized gypsum and fly ash at a medium speed of 100-400r / min for 5-10 minutes to obtain a mixed powder;

[0163] The mixed powder was placed in a ball mill and milled for 90 minutes to obtain a ball-milled mixed powder;

[0164] The agglomerated saline-alkali soil excavated in the first step is stirred into loose granular saline-alkali soil, specifically comprising the following steps: stirring and mixing the agglomerated soil at a medium speed of 100 to 400 r / min for 5 to 10 minutes to form loose granular saline-alkali soil;

[0165] Adding a mixed powder consisting of slag, fly ash and desulfurized gypsum to the granular saline-alkali soil, stirring and mixing to obtain a premix, the specific steps are: adding the mixed powder to the saline-alkali soil, stirring and mixing at a high speed of 600 to 1000 r / min for 15 to 20 minutes;

[0166] The step of adding Ca(OH)2 to the premix, stirring and mixing with water and sugarcane pith to obtain a mixed material, wherein the content of the curing agent is 20-25% of the total mass of the saline-alkali soil, the content of water is 15-20% of the total mass of the saline-alkali soil, the content of the sugarcane pith is 1-2% of the total mass of the saline-alkali soil, and the activator is Ca(OH)2, accounting for 0.5% of the total mass of the curing agent. The specific steps are: using distilled water to prepare Ca(OH)2 into a saturated solution of Ca(OH)2, then mixing it evenly with the sugarcane pith and adding it to the premix, stirring it at a high speed of 600-1000r / min for 15-20min to obtain a mixed material;

[0167] The mixed material is spread flat and repeatedly rolled until it becomes a block and dried and solidified to obtain an impermeable salt isolation layer 21 material;

[0168] Step 3: Lay the salt-discharging pipe 41 above the impermeable salt-isolating layer 21. First, carry out the first backfill of saline-alkali soil above the salt-isolating layer, with a backfill thickness of about 30-40cm, and then arrange a layer of sand and gravel filter material with a thickness of about 30-50mm and different particle sizes at the location where the salt-discharging pipe 41 is laid. Lay the salt-discharging pipe 41 above the filter material. The salt-discharging pipe 41 is a PE corrugated pipe with a diameter of 100-160mm. The distance between each pipe is 5m, the buried slope is 1%, and a layer of non-woven fabric is wrapped around the outside of the salt-discharging pipe 41;

[0169] Step 4: Connect the vacuum exhaust pipe 31 to the reserved hole on the upper part of the salt discharge pipe. After the connection, use a salt-alkali resistant adhesive to bond the salt discharge pipe to the exhaust pipe 31 and wrap it tightly with non-woven fabric. The salt-alkali resistant adhesive is American IPS transparent glue WELD-ON 717.

[0170] Step 5: Continue to carry out the second backfill of saline-alkali soil on both sides of the salt drainage pipe, and lay a filter layer consisting of 2-4 layers of sand, gravel and pebbles on the upper part of the pipe. The filter layer is laid in an inverted cone shape;

[0171] Step 6: Carry out the third backfill of saline-alkali soil on the upper part of the sand filter layer;

[0172] Step 7: Lay a drip irrigation pipe every 1m on the soil surface. The drip irrigation pipe is a PE hose with a diameter of 10mm and a hole every 0.5m at the bottom of the pipe.

[0173] The above are only preferred embodiments of the present invention, and do not limit the patent scope of the present invention. For those skilled in the art, the present invention may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the patent protection scope of the present invention.

Claims

1. A saline-alkali land remediation system for reducing alkali and removing salt, used for remediating the main body of soil, characterized in that: include: A washing device, used for spraying liquid to the outside of the soil body so that the liquid penetrates downward from the surface of the soil body; An impermeable salt-isolating structure, comprising an impermeable salt-isolating layer, wherein the impermeable salt-isolating layer is pre-buried in the soil body to separate the soil body into a surface layer and an inner layer arranged in an up-and-down direction; a negative pressure suction device, the negative pressure suction device at least partially extending into the surface layer; and The salt discharge device comprises at least one salt discharge pipe, wherein the salt discharge pipe is pre-buried in the surface layer and is connected to the negative pressure exhaust device, and the outer surface of the salt discharge pipe faces the elution device to form a water absorption side, and a plurality of water absorption holes are arranged on the water absorption side, and each of the water absorption holes is provided with a non-woven fabric for allowing the elution liquid to enter.

2. The saline-alkali land remediation system for reducing alkali and removing salt according to claim 1, characterized in that: The rinsing device comprises a plurality of rinsing tubes arranged at intervals in the horizontal direction, the outer surface of each rinsing tube facing the salt discharge pipeline forms a water outlet side, and a plurality of rinsing holes are arranged on the water outlet side.

3. The saline-alkali land remediation system for reducing alkali and removing salt according to claim 2, characterized in that: The interval between each two adjacent elution pipes is 0.5 to 1.5 m; and / or, The inner diameter of each elution tube is 8 to 12 mm; and / or, The interval between each two adjacent elution holes is 0.3-0.7 m; and / or, The inner diameter of each elution hole is 2 to 5 mm.

4. The saline-alkali land remediation system for reducing alkali and removing salt according to claim 1, characterized in that: The salt discharge device comprises a plurality of salt discharge pipes, the plurality of salt discharge pipes are arranged at intervals in the horizontal direction, and the interval between each two adjacent salt discharge pipes is 4 to 6 m; and / or, The distance between the salt discharge pipe and the upper surface of the soil body is 45 to 55 cm; and / or, The salt discharge pipeline is arranged at an inclination, and its buried slope is 0.8% to 1.2%; and / or, The inner diameter of the salt discharge pipe is 100-160 mm; and / or, The opening rate of the salt discharge pipeline is 2% to 4%; and / or, The inner diameter of each of the water absorption holes is 4 to 8 mm; and / or, The interval between two adjacent water absorption holes is 1 to 3 cm.

5. The saline-alkali land remediation system for reducing alkali and removing salt according to claim 1, characterized in that: The saline-alkali land remediation system for reducing alkali and removing salt further comprises a filter layer arranged on the outer surface of the water absorption side of the salt-discharging pipeline, and the filter layer is used to prevent soil particles from entering the salt-discharging pipeline.

6. The saline-alkali land remediation system for reducing alkali and removing salt according to claim 5, characterized in that: The filter material of the filter layer comprises a mixture of sand, gravel and pebbles, wherein the particle size of the sand is 0.5 to 2 mm, the particle size of the gravel is 2 to 4 mm, and the particle size of the pebbles is 4 to 8 mm; and / or, The thickness of the filter layer is 80-100 mm.

7. The saline-alkali land remediation system for reducing alkali and removing salt according to claim 1, characterized in that: The negative pressure air extraction device comprises an air extraction pump and a plurality of air extraction pipes arranged at intervals in the horizontal direction; Each of the exhaust pipes extends in the up-down direction, with one end connected to the exhaust pump and the other end connected to the salt discharge pipe. At least one exhaust hole is arranged on the outer surface of the lower part of each of the exhaust pipes, and a filter is arranged in the exhaust hole to enable the exhaust pipe to absorb gas in the soil and prevent soil particles from clogging the exhaust hole.

8. The saline-alkali land remediation system for reducing alkali and removing salt according to claim 7, characterized in that: The inner diameter of each of the exhaust pipes is 60 to 80 mm and / or, The interval between two adjacent exhaust pipes is 4 to 6 m; and / or, The interval between two adjacent air extraction holes is 8 to 10 cm; and / or, The inner diameter of each of the air extraction holes is 4 to 8 mm.

9. The saline-alkali land remediation system for reducing alkali and removing salt according to claim 1, characterized in that: The distance between the anti-seepage salt-isolating layer and the upper surface of the soil body is 45 to 55 cm; and / or, The thickness of the anti-seepage salt isolation layer is 10 to 20 cm; and / or, The anti-seepage salt-isolating layer is formed by mixing saline-alkali soil, a curing agent, an alkali activator, sugarcane pith and water.

10. A method for laying a saline-alkali land repair system for reducing alkali and draining salt, based on the saline-alkali land repair system for reducing alkali and draining salt as claimed in any one of claims 1 to 9, characterized in that: The saline-alkali land restoration system for reducing alkali and removing salt further comprises a filter layer arranged on the outer surface of the water absorption side of the salt discharge pipeline, wherein the filter layer is used to prevent soil particles from entering the salt discharge pipeline; The laying method of the saline-alkali land repair system for reducing alkali and draining salt comprises the following steps: S10, removing part of the saline-alkali soil in the surface layer of the soil body to form a concave portion in the surface layer of the soil body; S20, laying an impermeable salt-isolating layer at the bottom of the concave portion, and backfilling above the impermeable salt-isolating layer to obtain a first soil layer structure; S30, laying a salt discharge pipeline above the first soil layer structure, and performing a second backfill on the side of the water absorption side of the salt discharge pipeline to cover it and expose the water absorption side of the salt discharge pipeline; S40, laying a filter layer on the water absorption side of the salt discharge pipe, and backfilling above the filter layer so that the concave portion is filled to obtain a second soil layer structure; S50: laying a washing device on the surface of the second soil layer structure.

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