Structure for saline-alkali soil treatment and biological treatment method

Abstract

The present invention relates to the technical field of special soil bioremediation, and disclosed are a structure for saline-alkali soil treatment and a biological treatment method, solving the problem that the existing saline-alkali soil improvement method is single and has long improvement period, high cost and poor single-material effect. In the present invention, a collection layer, an anti-seepage layer, and a tillage layer are sequentially laid upwards from a saline-alkali soil layer; the anti-seepage layer and the collection layer are manufactured using biological materials, the tillage layer is improved, and a comprehensive treatment method comprising improvement of the upper tillage layer, seepage prevention of the lower portion, and collection of salt in the upper tillage layer and the lower saline-alkali soil layer is used, thus effectively reducing the content of harmful salt in the tillage layer, and improving the water holding capacity and air permeability of soil in the tillage layer. Moreover, a collection pipe network is buried below the tillage layer, and a collection pool is arranged at each pipe network node to collect salt, achieving resource utilization, and achieving the effect of permanently removing harmful salt components in saline-alkali soil.

Description

A structure and biological treatment method for saline-alkali soil treatment Technical Field

[0001] The present invention relates to the technical field of special soil bioremediation, in particular to a structure and a bioremediation method for saline-alkali soil remediation. Background Art

[0002] my country's vast and widespread saline-alkali soils are a major constraint on agricultural and animal husbandry development. The degree of salinization varies across regions. Furthermore, due to the thickness of saline-alkali soils in my country, salt in the lower layers continuously rises through capillary action, accelerating the deterioration of the topsoil, making their management more difficult. Treatment methods for saline-alkali soils primarily include phytoremediation, microbial remediation, and soil additives. However, these methods suffer from long treatment cycles, poor results, high costs, and low commercial value. Therefore, developing new, efficient, and integrated biological remediation methods is crucial for improving saline-alkali soils.

[0003] At present, the improvement methods of saline-alkali soil are single, with a long improvement cycle and high cost. In particular, the upward flow of saline-alkali soil in the lower layer leads to repeated salinization of the upper cultivated layer, making it impossible to completely improve the saline-alkali soil. Carrying out saline-alkali soil improvement and salt extraction and utilization will help to completely change the current situation of saline-alkali soil. At present, the main methods for saline-alkali soil treatment are to add organic fertilizers, bacterial fertilizers, compound fertilizers, biochar, biological bacteria and other conditioners to saline-alkali soil. These methods improve saline-alkali soil from the perspectives of soil conditioners, plant remediation and preparation of salt barriers, so as to reduce the amount of soda alkali in the soil. However, there are problems such as the large amount of biochar consumed in the anti-seepage layer, resulting in high cost, poor anti-seepage effect of a single material, high probability of failure during the application process, and high cost. In addition, the salt content in the upper cultivated layer decreases slowly, resulting in the inability to achieve rapid repair, low economic value, and high carbon emissions, which affect the improvement effect of saline-alkali soil and the growth of crops. Summary of the Invention

[0004] In order to solve the above-mentioned problems of the existing saline-alkali soil improvement methods being single, the improvement cycle being long, the cost being high, and the single material being ineffective, the present invention hereby proposes a structure and biological treatment method for saline-alkali soil treatment. The present invention adopts a comprehensive treatment method of improving the upper arable layer, preventing seepage in the lower part, and collecting salt in the upper arable layer and the lower saline-alkali soil layer, which effectively reduces the content of salts harmful to plants such as chlorides, sulfates, and carbonates in the upper arable layer, improves the water holding (water retention) capacity and air permeability (looseness) of the arable layer soil, and achieves rapid plant growth; at the same time, a collection pipe network and a collection pool are set up to collect salt, realize resource utilization, and achieve the effect of permanently removing harmful salt components in saline-alkali soil.

[0005] The present invention proposes a structure for saline-alkali soil treatment, which specifically includes a tillage layer, an anti-seepage layer, a collection layer and a saline-alkali soil layer. The collection layer is laid above the saline-alkali soil layer, and the collection layer is provided with a pipe network trough, and a collection pipe network is provided in the pipe network trough; an anti-seepage layer is laid above the collection layer in an area corresponding to the collection pipe network grid, and a tillage layer is laid above the anti-seepage layer and the collection pipe network; the thickness of the anti-seepage layer in each grid is high in the middle and low around, and the slope is inclined toward the collection pipe network; a collection pool is provided for every two adjacent grid nodes of the collection pipe network, and the collection pool is arranged at the grid node position, and several collection pools are connected to the collection pipe network; the inner wall of the collection pool is treated with anti-seepage, and the upper end passes through the tillage layer and is open.

[0006] Furthermore, the collection pipe network includes several collection pipes, some of which are arranged horizontally, and the other part of the collection pipes are arranged vertically, and the horizontally arranged collection pipes are connected to the vertically arranged collection pipes; the spacing between two horizontally adjacent collection pipes is 3.0-5.0m, and the spacing between two vertically adjacent collection pipes is 6.0-10.0m; the horizontal spacing between two adjacent collection pools is 6.0-10.0m, and the vertical spacing is 12-20m; the axis of the collection pipe and the highest point of the anti-seepage layer are on the same horizontal plane.

[0007] Furthermore, the collecting tube is a flower tube made of polyvinyl chloride with a diameter of 100-200 mm, a pore size of 8-15 mm in the flower tube wall, and a pore spacing of 5-8 mm; the flower tube is wrapped with a nylon mesh with a pore size of 2-5 mm.

[0008] Furthermore, the anti-seepage layer is sloped toward the collecting pipe, with a slope of 0.5-1.5‰.

[0009] Furthermore, an anti-seepage cushion layer is provided between the collecting pipe and the collecting layer, and both sides of the anti-seepage cushion layer are overlapped with the anti-seepage layer, and the overlap length is 0.5-1.5m.

[0010] Furthermore, the anti-seepage cushion layer adopts sodium bentonite waterproof blanket with a specification of 4000g / m 2 -5500g / m 2 .

[0011] Furthermore, the side length of the collection pool is 1.5-2.5m, the pool depth is 1.0-2.0m; the thickness of the tillage layer is 300-600mm.

[0012] A biological treatment method using the above-mentioned structure for saline-alkali soil treatment comprises the following steps: cleaning the cultivated layer and piling it to one side, then laying the collection layer and the anti-seepage layer in sequence, and laying the collection pipe network and the collection pool at the same time; the anti-seepage layer is made by mixing biochar powder, sodium bentonite, calcium bentonite, fly ash and saline-alkali soil, and then adding water to increase the moisture content to 25-35%. After mixing evenly, the mixture is laid in layers and rolled, with the first layer being 80-100 mm thick, and each subsequent layer being 40- 50mm, laid in 2-3 layers; add straw pellets, straw biochar pellets, zeolite and diatomaceous earth into the tillage layer and then restore it to its original position; when the anti-seepage layer leaks after more than 5 years of operation, take out the collecting layer and soak it in clean water for 12-24 hours, then clean the collecting layer, and dry the soaked solution and cleaning liquid in the sun to evaporate and concentrate the salt crystals before collecting; collect the liquid in the collection pool every 2 months from March to October; the collected liquid is first filtered, and then evaporated, concentrated and crystallized.

[0013] Furthermore, the straw particles added to the tillage layer have a particle size of 10-20 mm and an addition amount of 0.15-0.3 kg / m 2 The particle size of straw biochar particles is 1.0-5.0 mm, and the incorporation ratio in the tillage layer is 2.0-5.0%; the particle size of zeolite is 1.0-5.0 mm, and the particle size of diatomaceous earth is 0.1-1.5 mm; the addition amounts of zeolite and diatomaceous earth are 0.5-5.0% and 0.5-3.0% of the total mass of the tillage layer soil, respectively.

[0014] Furthermore, the raw material of the straw biochar particles is one or a mixture of corn straw peel, sorghum straw peel, sesame straw, cotton straw, sunflower straw and soybean straw.

[0015] Furthermore, the mixed mass ratio of biochar powder, sodium bentonite, calcium bentonite, fly ash and saline-alkali soil in the anti-seepage layer is 3:0.5:1.0:2.0:93.5-6.5:1.5:3.5:6.5:82; the viscosity of sodium bentonite is greater than 60mPa·s, the sieve residue of 75μm particle size is less than 1.5%, and the filtration loss is less than 14cm 3 ; The fly ash fineness is less than 30%, and the loss on ignition is less than 8.0%; the total mass fraction of silicon dioxide, aluminum oxide and iron oxide in the fly ash is greater than 70%, the mass fraction of free calcium oxide is less than 4%, and the mass fraction of sulfur trioxide is less than 3%.

[0016] Furthermore, the biochar powder raw material is one or a mixture of corn straw, rice straw and wheat straw.

[0017] Furthermore, the rolling pressure of the anti-seepage layer is 50-150 kPa, and the compaction coefficient is 0.92-0.96.

[0018] Furthermore, the collection layer is composed of nylon mesh 2 and filler, the filler is placed in nylon mesh 2, the pore size of nylon mesh 2 is 2-4mm, and the filler is laid with a thickness of 50-100mm; the filler is biochar with a particle size of 5-15mm, and the biochar raw material is wood.

[0019] A method for preparing straw biochar particles for the above-mentioned biological treatment method includes the following steps: pyrolyzing a mixture of one or more of corn straw peel, sorghum straw peel, sesame straw, cotton straw, sunflower straw and soybean straw at 400-600°C for 1.0-3.0 hours.

[0020] A method for preparing biochar powder for the above-mentioned biological treatment method comprises the following steps: pyrolyzing a mixture of one or more of corn straw pith, rice straw and wheat straw at 350-550°C for 1.0-3.5 hours, crushing the mixture to a particle size of less than 0.5 mm, and simultaneously adding 15-35% of wood biochar powder with a particle size of less than 0.5 mm after screening, and mixing the mixture; the wood biochar is prepared by pyrolyzing wood at 450-550°C for 1.5-2.0 hours.

[0021] A method for preparing a filler for the above-mentioned biological treatment method comprises the following steps: firstly preparing the raw material of the filler biochar in the collection layer by pyrolysis at 550-650° C. for 1.5-2.5 hours; then modifying it with 0.05-0.2 mol / L potassium hydroxide for 24-48 hours and washing it to neutrality; then modifying it with a mixed solution of 0.001-0.05 mol / L potassium permanganate and 0.005-0.05 mol / L nitric acid for 24-72 hours and washing it thoroughly and drying it; and finally soaking it in a mixed solution of 1.5-6.5% sodium bentonite and 1.0-4.0% calcium bentonite for 20-50 hours, washing it, and drying it to prepare the filler.

[0022] The beneficial effects of the structure and biological treatment method for saline-alkali soil treatment described in the present invention are:

[0023] (1) The structure and biological treatment method for saline-alkali soil treatment described in the present invention use a biomaterial composite preparation as the anti-seepage layer material, and utilize the interaction between biochar powder with high ash content and sodium bentonite, calcium bentonite, fly ash and clay particles in saline-alkali soil to form a cohesive body. Under the action of rolling, the anti-seepage ability, strength and plasticity are significantly improved. The permeability coefficient is measured to be less than 5×10 -11m / s, plant roots are not likely to damage this layer; because the amount of added materials is small and they are conventional materials, the cost is low; the anti-seepage layer has good durability, and the anti-seepage capacity of the soil anti-seepage layer is 2-3 times higher than that of the traditional method using only biochar, the cost is reduced by 50%, and the durability is increased by more than 1 times, effectively preventing the saline-alkali soil layer from returning, thereby ensuring the continuous reduction of the salt content in the cultivated layer and ensuring the effective improvement of this layer of soil;

[0024] (2) The structure and biological treatment method for saline-alkali soil treatment described in the present invention collects salt from the upper tillage layer and the lower saline-alkali soil layer by setting up a collection pipe network and a collection pool, thereby permanently removing harmful salts from the soil. The collection layer is recovered after long-term operation (more than 5 years) when the anti-seepage layer fails. When the anti-seepage layer is repaired, the salts adsorbed and crystallized in the collection layer are recovered as raw materials for industrial production. The collection layer has a physical and chemical adsorption effect on the salt components contained in the soil and has a strong effect on removing salts from the soil. The method uses cheap biomass materials to effectively repair saline-alkali soil without introducing new pollutants. The collection of salt achieves high economic benefits and solves the problem of shortage of raw materials related to industrial production.

[0025] (3) The structure and biological treatment method for saline-alkali soil treatment described in the present invention are as follows: the tillage layer is improved with a composite conditioner (straw particles, straw biochar particles, zeolite particles and diatomaceous earth particles) to improve the soil's water retention, permeability and organic matter content, which is more conducive to plant growth; under the action of rainfall, salt in the tillage layer is collected through pipes and collection pools to achieve a rapid reduction in the salt content in the soil; a comprehensive method is used to treat the saline-alkali soil in the tillage layer to solve the technical problem of low salt removal efficiency in saline-alkali soil with different degrees of salinization, reduce the soil salt content, and improve the soil's air permeability and water retention capacity. After two years of rainfall, the harmful salt content in the soil is reduced by more than 80%, the soil's water retention capacity is increased by 30%, and the soil's air permeability (permeability) is increased by more than 70%. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The drawings constituting a part of this application are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0027] In the attached figure:

[0028] FIG1 is a cross-sectional layout diagram of a structure for saline-alkali soil treatment according to the present invention;

[0029] FIG2 is a plan view of a structure for saline-alkali soil treatment according to the present invention;

[0030] FIG3 is a cross-sectional view of a collection pool for saline-alkali soil treatment according to the present invention;

[0031] Among them: 1-cultivation layer, 2-anti-seepage layer, 3-collection layer, 4-saline-alkali soil layer, 5-anti-seepage cushion layer, 6-collection pipe, 7-collection pool, 8-anti-seepage side wall. DETAILED DESCRIPTION

[0032] The specific embodiments of the present invention are further described in detail below with reference to the accompanying drawings:

[0033] Specific implementation method one:

[0034] Refer to Figures 1 to 3 for a detailed description of this embodiment. The structure for saline-alkali soil treatment described in this embodiment specifically includes a tillage layer 1, an impermeable layer 2, a collection layer 3, and a saline-alkali soil layer 4. The collection layer 3 is laid above the saline-alkali soil layer 4, and the collection layer 3 is provided with a pipe network trough, and the pipe network trough is provided with a collection pipe network; the impermeable layer 2 is laid above the collection layer 3 in the area corresponding to the collection pipe network grid, and the tillage layer 1 is laid above the impermeable layer 2 and the collection pipe network; the thickness of the impermeable layer 2 in each grid is high in the middle and low around, and the slope is inclined toward the collection pipe network; a collection pool 7 is set for every two adjacent grid nodes of the collection pipe network, and the collection pool 7 is set at the grid node position, and several collection pools 7 are connected to the collection pipe network; the inner wall 8 of the collection pool 7 is treated with impermeable treatment, and the upper end passes through the tillage layer 1 and is open.

[0035] The collecting pipe network includes several collecting pipes 6, some of which are arranged horizontally, and the other part of the collecting pipes 6 are arranged vertically, and the horizontally arranged collecting pipes 6 are connected to the vertically arranged collecting pipes 6; the spacing between two horizontally adjacent collecting pipes 6 is 3.0m, and the spacing between two vertically adjacent collecting pipes 6 is 6.0m; the horizontal spacing between two adjacent collecting pools 7 is 6.0m, and the vertical spacing is 12m; the collecting pipes 6 are buried in a concealed manner, and the axis of the collecting pipe 6 and the highest point of the anti-seepage layer 2 are on the same horizontal plane.

[0036] The collecting tube 6 is a flower tube made of polyvinyl chloride (PVC), with a diameter of 100 mm, an 8 mm pore size on the flower tube wall, and a 5 mm pore spacing; the flower tube is wrapped with a nylon mesh with a 2 mm pore size.

[0037] The anti-seepage layer 2 is sloped toward the collecting pipe 6, with a slope of 0.5‰.

[0038] An anti-seepage cushion layer 5 is provided between the collecting pipe 6 and the collecting layer 3. The two sides of the anti-seepage cushion layer 5 overlap with the anti-seepage layer 2, and the overlap length is 0.5m. The anti-seepage cushion layer 5 is made of sodium bentonite waterproof blanket with a specification of 4000g / m 2 .

[0039] The collecting pool 7 has a side length of 1.5 m and a pool depth of 2.0 m; the cultivating layer 1 has a thickness of 300 mm.

[0040] A biological treatment method using the above-mentioned structure for saline-alkali soil treatment comprises the following steps: cleaning the tillage layer 1 and piling it to one side, then sequentially laying a collection layer 3 and an anti-seepage layer 2, and simultaneously laying a collection pipe network and a collection tank 7; the anti-seepage layer 2 is formed by mixing biochar powder, sodium bentonite, calcium bentonite, fly ash, and saline-alkali soil, humidifying it with water to a moisture content of 25%, and then evenly mixing and laying it in layers and rolling it, the first layer being 80 mm thick, and each subsequent layer being 40 mm thick, for a total of two layers; adding straw pellets, straw biochar pellets, zeolite, and diatomaceous earth to the tillage layer 1 and then restoring it to its original position; if the anti-seepage layer 2 of the collection layer 3 leaks after more than five years of operation, the collection layer 3 is removed and soaked in clean water for 12 hours, and then the collection layer 3 is cleaned, the soaked solution and the cleaning liquid are aired to evaporate and concentrate the salt crystals, and then collected; the liquid in the collection tank 7 is collected every two months from March to October; the collected liquid is first filtered and then evaporated, concentrated, and crystallized.

[0041] The straw particles added to the tillage layer 1 have a particle size of 10-20 mm and an addition amount of 0.15 kg / m 2 The particle size of straw biochar particles is 1.0-5.0 mm, and the incorporation ratio in the tillage layer 1 is 2.0%; the particle size of zeolite is 1.0-5.0 mm, and the particle size of diatomaceous earth is 0.1-1.5 mm; the addition amounts of zeolite and diatomaceous earth are 0.5% and 3.0% of the total mass of the soil in the tillage layer 1, respectively.

[0042] The raw material of the straw biochar particles is the husk of corn straw.

[0043] The mixed mass ratio of biochar powder, sodium bentonite, calcium bentonite, fly ash and saline-alkali soil in the anti-seepage layer 2 is 3:0.5:1.0:2.0:93.5; the viscosity of sodium bentonite (600r / min) is greater than 60mPa·s, the sieve residue of 75μm particle size is less than 1.5%, and the filtration loss is less than 14cm 3 The viscosity is measured by a testing instrument at a rotation speed of 600r / min; the fineness of the fly ash is less than 30% as determined by the 45μm square hole sieve residue method, and the loss on ignition is less than 8.0%; the total mass fraction of silicon dioxide (SiO2), aluminum oxide and iron oxide in the fly ash is greater than 70%, the mass fraction of free calcium oxide is less than 4%, and the mass fraction of sulfur trioxide is less than 3%.

[0044] The raw material of the biochar powder is the pulp of corn stalks.

[0045] The rolling pressure of the anti-seepage layer 2 is 50 kPa, and the compaction coefficient is 0.92-0.93.

[0046] The collecting layer 3 is composed of a second nylon mesh and a filler. The filler is placed in the second nylon mesh. The aperture of the second nylon mesh is 2-4 mm, and the thickness of the filler is 50 mm. The filler is biochar with a particle size of 5-15 mm, and the raw material of the biochar is tree branches.

[0047] A method for preparing straw biochar particles for the above-mentioned biological treatment method comprises the following steps: pyrolyzing corn straw husk at 400° C. for 3.0 hours.

[0048] A method for preparing biochar powder for the above-mentioned biological treatment method includes the following steps: pyrolyzing corn stalks at 350°C for 3.5 hours, crushing the pulp to a particle size of less than 0.5 mm, and simultaneously adding 15% of wood biochar powder with a particle size of less than 0.5 mm after screening, and mixing. The wood biochar is prepared by pyrolyzing branches at 450°C for 2.0 hours.

[0049] A method for preparing a filler for the above-mentioned biological treatment method includes the following steps: the raw material branches of the filler biochar of the collection layer 3 are first prepared by pyrolysis at 550°C for 2.5 hours; then they are modified with 0.05mol / L potassium hydroxide for 48 hours and washed to neutrality, then modified with a mixed solution of 0.001mol / L potassium permanganate and 0.005mol / L nitric acid for 72 hours, washed clean and dried; finally, they are soaked in a mixed solution of 1.5% sodium bentonite and 4.0% calcium bentonite for 20 hours, then washed and dried.

[0050] After adopting the scheme of this embodiment, the soil moisture content increased by 45.6%, the soil permeability (air permeability) increased by 1 time, the total salt content decreased by 45.2% in the first year, and the total salt content decreased by 86.3% of the initial value in the second year. The surface vegetation grew lushly, and the biomass increased by more than 2 times each year. The permeability coefficient of the anti-seepage layer 2 was less than 5×10 -11 m / s, with strong anti-seepage ability; the collection capacity of the 7 collection pools for salt (chloride, carbonate, sulfate) is 165kg / 1000m 2 , realizing resource utilization.

[0051] Specific implementation method 2:

[0052] Refer to Figures 1 to 3 for a detailed description of this embodiment. The structure for saline-alkali soil treatment described in this embodiment specifically includes a tillage layer 1, an impermeable layer 2, a collection layer 3, and a saline-alkali soil layer 4. The collection layer 3 is laid above the saline-alkali soil layer 4, and the collection layer 3 is provided with a pipe network trough, and the pipe network trough is provided with a collection pipe network; the impermeable layer 2 is laid above the collection layer 3 in the area corresponding to the collection pipe network grid, and the tillage layer 1 is laid above the impermeable layer 2 and the collection pipe network; the thickness of the impermeable layer 2 in each grid is high in the middle and low around, and the slope is inclined toward the collection pipe network; a collection pool 7 is set for every two adjacent grid nodes of the collection pipe network, and the collection pool 7 is set at the grid node position, and several collection pools 7 are connected to the collection pipe network; the inner wall 8 of the collection pool 7 is treated with impermeable treatment, and the upper end passes through the tillage layer 1 and is open.

[0053] The collecting pipe network includes several collecting pipes 6, some of which are arranged horizontally, and the other part of the collecting pipes 6 are arranged vertically, and the horizontally arranged collecting pipes 6 are connected to the vertically arranged collecting pipes 6; the spacing between two horizontally adjacent collecting pipes 6 is 5.0m, and the spacing between two vertically adjacent collecting pipes 6 is 10.0m; the horizontal spacing between two adjacent collecting pools 7 is 10.0m, and the vertical spacing is 20m; the collecting pipes 6 are buried in a concealed manner, and the axis of the collecting pipe 6 and the highest point of the anti-seepage layer 2 are on the same horizontal plane.

[0054] The collecting tube 6 is a flower tube made of polyvinyl chloride (PVC), with a diameter of 200 mm, a pore size of 15 mm on the flower tube wall, and a pore spacing of 8 mm; the flower tube is wrapped with a nylon mesh with a pore size of 5 mm.

[0055] The anti-seepage layer 2 is sloped toward the collecting pipe 6 with a slope of 1.5‰.

[0056] An anti-seepage cushion layer 5 is provided between the collecting pipe 6 and the collecting layer 3. The two sides of the anti-seepage cushion layer 5 overlap with the anti-seepage layer 2, and the overlap length is 1.5m. The anti-seepage cushion layer 5 adopts a sodium bentonite waterproof blanket with a specification of 5500g / m 2 .

[0057] The collecting pool 7 has a side length of 2.5 m and a pool depth of 1.0 m; the cultivating layer 1 has a thickness of 600 mm.

[0058] A biological treatment method using the above-mentioned structure for saline-alkali soil treatment comprises the following steps: cleaning the tillage layer 1 and piling it to one side, then sequentially laying a collection layer 3 and an anti-seepage layer 2, and simultaneously laying a collection pipe network and a collection tank 7; the anti-seepage layer 2 is formed by mixing biochar powder, sodium bentonite, calcium bentonite, fly ash, and saline-alkali soil, humidifying it with water to a moisture content of 35%, and then evenly mixing and laying it in layers and rolling it, the first layer being 100 mm thick, and each subsequent layer being 50 mm thick, for a total of three layers; adding straw pellets, straw biochar pellets, zeolite, and diatomaceous earth to the tillage layer 1 and then restoring it to its original position; if the anti-seepage layer 2 of the collection layer 3 leaks after more than five years of operation, the collection layer 3 is removed and soaked in clean water for 24 hours, and then cleaned, the soaked solution and the cleaning liquid are air-dried to evaporate and concentrate the salts and crystallize, and then collected; the liquid in the collection tank 7 is collected every two months from March to October; the collected liquid is first filtered and then evaporated, concentrated, and crystallized.

[0059] The straw particles added to the tillage layer 1 have a particle size of 10-20 mm and an addition amount of 0.3 kg / m 2 The particle size of straw biochar particles is 1.0-5.0 mm, and the incorporation ratio in the tillage layer 1 is 5.0%; the particle size of zeolite is 1.0-5.0 mm, and the particle size of diatomaceous earth is 0.1-1.5 mm; the addition amounts of zeolite and diatomaceous earth are 5% and 0.5% of the total mass of the soil in the tillage layer 1, respectively.

[0060] The raw materials of the straw biochar particles are the skin of corn straw and the skin of sorghum straw.

[0061] The mixed mass ratio of biochar powder, sodium bentonite, calcium bentonite, fly ash and saline-alkali soil in the anti-seepage layer 2 is 6.5:1.5:3.5:6.5:82; the viscosity of sodium bentonite is greater than 60mPa·s, the sieve residue of 75μm particle size is less than 1.5%, and the filtration loss is less than 14cm 3 The viscosity is measured by a testing instrument at a rotation speed of 600r / min; the fly ash fineness is less than 30%, the loss on ignition is less than 8.0%, and the fineness is determined by the 45μm square hole sieve residue method; the total mass fraction of silicon dioxide (SiO2), aluminum oxide and iron oxide in the fly ash is greater than 70%, the mass fraction of free calcium oxide is less than 4%, and the mass fraction of sulfur trioxide is less than 3%.

[0062] The raw material of the biochar powder is a mixture of corn stalks and rice straw.

[0063] The rolling pressure of the anti-seepage layer 2 is 150 kPa, and the compaction coefficient is 0.94-0.96.

[0064] The collecting layer 3 is composed of a second nylon mesh and a filler. The filler is placed in the second nylon mesh. The aperture of the second nylon mesh is 2-4 mm, and the thickness of the filler is 100 mm. The filler is biochar with a particle size of 5-15 mm, and the raw material of the biochar is wood.

[0065] A method for preparing straw biochar particles for the above-mentioned biological treatment method comprises the following steps: pyrolyzing a mixture of corn straw peels and sorghum straw peels at 600° C. for 1.0 hour.

[0066] A method for preparing biochar powder for the above-mentioned biological treatment method comprises the following steps: pyrolyzing a mixture of corn stalk pith and rice straw at 550°C for 1.0 hour, crushing the mixture to a particle size of less than 0.5 mm, and simultaneously adding 35% of wood biochar powder with a particle size of less than 0.5 mm after screening, and mixing the mixture; the wood biochar is prepared by pyrolyzing wood at 550°C for 1.5 hours.

[0067] A method for preparing a filler for the above-mentioned biological treatment method includes the following steps: first, pyrolyzing the raw material wood of the filler biochar of the collection layer 3 at 650°C for 1.5 hours to prepare it; then, modifying it with 0.2mol / L potassium hydroxide for 24 hours, washing it to neutrality, then modifying it with a mixed solution of 0.05mol / L potassium permanganate and 0.05mol / L nitric acid for 24 hours, washing it thoroughly, and then drying it; finally, soaking it in a mixed solution of 6.5% sodium bentonite and 1.0% calcium bentonite for 50 hours, washing it, and drying it to prepare it.

[0068] After treatment with the solution of this embodiment, the soil moisture content increased by 55.2%, the soil permeability (air permeability) increased by 1.5 times, the total salt content decreased by 38.2% in the first year, and the total salt content decreased by 82.7% of the initial value in the second year. The surface vegetation grew lushly, and the biomass increased by more than 2 times each year. The permeability coefficient of the anti-seepage layer 2 was less than 4×10 -11 m / s, with strong anti-seepage ability; the collection capacity of the 7 collection pools for salt (chloride, carbonate) is 185kg / 1000m 2 , realizing resource utilization.

[0069] Specific implementation method three:

[0070] Refer to Figures 1 to 3 for a detailed description of this embodiment. The structure for saline-alkali soil treatment described in this embodiment specifically includes a tillage layer 1, an impermeable layer 2, a collection layer 3, and a saline-alkali soil layer 4. The collection layer 3 is laid above the saline-alkali soil layer 4, and the collection layer 3 is provided with a pipe network trough, and the pipe network trough is provided with a collection pipe network; the impermeable layer 2 is laid above the collection layer 3 in the area corresponding to the collection pipe network grid, and the tillage layer 1 is laid above the impermeable layer 2 and the collection pipe network; the thickness of the impermeable layer 2 in each grid is high in the middle and low around, and the slope is inclined toward the collection pipe network; a collection pool 7 is set for every two adjacent grid nodes of the collection pipe network, and the collection pool 7 is set at the grid node position, and several collection pools 7 are connected to the collection pipe network; the inner wall 8 of the collection pool 7 is treated with impermeable treatment, and the upper end passes through the tillage layer 1 and is open.

[0071] The collecting pipe network includes several collecting pipes 6, some of which are arranged horizontally, and the other part of the collecting pipes 6 are arranged vertically, and the horizontally arranged collecting pipes 6 are connected to the vertically arranged collecting pipes 6; the spacing between two horizontally adjacent collecting pipes 6 is 4m, and the spacing between two vertically adjacent collecting pipes 6 is 8m; the horizontal spacing between two adjacent collecting pools 7 is 8.0m, and the vertical spacing is 16m; the collecting pipes 6 are buried in a concealed manner, and the axis of the collecting pipe 6 and the highest point of the anti-seepage layer 2 are on the same horizontal plane.

[0072] The collecting tube 6 is a flower tube made of polyvinyl chloride (PVC), with a diameter of 150 mm, a pore diameter of 10 mm on the flower tube wall, and a pore spacing of 7 mm; the flower tube is wrapped with a nylon mesh with a pore diameter of 3 mm.

[0073] The anti-seepage layer 2 is sloped toward the collecting pipe 6 with a slope of 1.5‰.

[0074] An anti-seepage cushion layer 5 is provided between the collecting pipe 6 and the collecting layer 3. The two sides of the anti-seepage cushion layer 5 overlap with the anti-seepage layer 2, and the overlap length is 0.8m. The anti-seepage cushion layer 5 adopts a sodium bentonite waterproof blanket with a specification of 5000g / m 2 .

[0075] The collecting pool 7 has a side length of 2.0 m and a pool depth of 1.5 m; the cultivating layer 1 has a thickness of 500 mm.

[0076] A biological treatment method using the above-mentioned structure for saline-alkali soil treatment comprises the following steps: cleaning the tillage layer 1 and piling it to one side, then sequentially laying a collection layer 3 and an anti-seepage layer 2, and simultaneously laying a collection pipe network and a collection tank 7; the anti-seepage layer 2 is formed by mixing biochar powder, sodium bentonite, calcium bentonite, fly ash, and saline-alkali soil, humidifying it with water to a moisture content of 30%, and then evenly mixing and laying it in layers and rolling it, the first layer being 90 mm thick, and each subsequent layer being 45 mm thick, for a total of two layers; adding straw pellets, straw biochar pellets, zeolite, and diatomaceous earth to the tillage layer 1 and then restoring it to its original position; if the anti-seepage layer 2 of the collection layer 3 leaks after more than five years of operation, the collection layer 3 is removed and soaked in clean water for 16 hours, and then the collection layer 3 is cleaned, the soaked solution and the cleaning liquid are aired to evaporate and concentrate the salt crystals, and then collected; the liquid in the collection tank 7 is collected every two months from March to October; the collected liquid is first filtered and then evaporated, concentrated, and crystallized.

[0077] The straw particles added to the tillage layer 1 have a particle size of 10-20 mm and an addition amount of 0.2 kg / m 2 The particle size of straw biochar particles is 1.0-5.0 mm, and the incorporation ratio in the tillage layer 1 is 3.0%; the particle size of zeolite is 1.0-5.0 mm, and the particle size of diatomaceous earth is 0.1-1.5 mm; the addition amounts of zeolite and diatomaceous earth are 2% and 2.5% of the total mass of the soil in the tillage layer 1, respectively.

[0078] The raw material of the straw biochar particles is a mixture of one or more of corn straw peel, sorghum straw peel, sesame straw, cotton straw, sunflower straw and soybean straw.

[0079] The mixed mass ratio of biochar powder, sodium bentonite, calcium bentonite, fly ash and saline-alkali soil in the anti-seepage layer 2 is 6.5:1.5:3.5:6.5:82; the viscosity of sodium bentonite is greater than 60mPa·s, the sieve residue of 75μm particle size is less than 1.5%, and the filtration loss is less than 14cm 3 The viscosity is measured by a testing instrument at a rotation speed of 600r / min; the fly ash fineness is less than 30%, the loss on ignition is less than 8.0%, and the fineness is determined by the 45μm square hole sieve residue method; the total mass fraction of silicon dioxide (SiO2), aluminum oxide and iron oxide in the fly ash is greater than 70%, the mass fraction of free calcium oxide is less than 4%, and the mass fraction of sulfur trioxide is less than 3%.

[0080] The raw material of the biochar powder is one or a mixture of corn straw soil, rice straw and wheat straw.

[0081] The rolling pressure of the anti-seepage layer 2 is 80 kPa, and the compaction coefficient is 0.93-0.95.

[0082] The collecting layer 3 is composed of a second nylon mesh and a filler. The filler is placed in the second nylon mesh. The aperture of the second nylon mesh is 2-4 mm, and the thickness of the filler is 80 mm. The filler is biochar with a particle size of 5-15 mm, and the raw material of the biochar is tree branches.

[0083] A method for preparing straw biochar particles for the above-mentioned biological treatment method includes the following steps: pyrolyzing a mixture of one or more of corn straw peels, sorghum straw peels, sesame straw, cotton straw, sunflower straw and soybean straw at 500°C for 2.0 hours.

[0084] A method for preparing biochar powder for the above-mentioned biological treatment method includes the following steps: pyrolyzing a mixture of corn stalk pith and wheat straw at 450°C for 2.5 hours, crushing the mixture to a particle size of less than 0.5 mm, and simultaneously adding 30% of sieving wood biochar with a particle size of less than 0.5 mm to mix the mixture. The wood biochar is prepared by pyrolyzing tree branches at 500°C for 1.8 hours.

[0085] A method for preparing a filler for the above-mentioned biological treatment method includes the following steps: first, pyrolyzing the raw material branches of the filler biochar of the collection layer 3 at 600°C for 2.0 hours to prepare; then, modifying them with 0.1mol / L potassium hydroxide for 32 hours, washing them to neutrality, then modifying them with a mixed solution of 0.02mol / L potassium permanganate and 0.01mol / L nitric acid for 35 hours, washing them thoroughly, and drying them; finally, soaking them in a mixed solution of 4.5% sodium bentonite and 3.0% calcium bentonite for 30 hours, washing them, and drying them to prepare the filler.

[0086] After treatment with the solution of this embodiment, the soil moisture content increased by 43.9%, the soil permeability (air permeability) increased by 2.0 times, the total salt content decreased by 47.5% in the first year, and the total salt content decreased by 86.1% of the initial value in the second year. The surface vegetation grew lushly, and the biomass increased by more than 2.6 times each year. The permeability coefficient of the anti-seepage layer 2 was less than 4×10 -11 m / s, with strong anti-seepage ability; the collection capacity of the 7 collection pools for salt (chloride, carbonate) is 205kg / 1000m 2 , realizing resource utilization.

[0087] Specific implementation method four:

[0088] Refer to Figures 1 to 3 for a detailed description of this embodiment. The structure for saline-alkali soil treatment described in this embodiment specifically includes a tillage layer 1, an impermeable layer 2, a collection layer 3, and a saline-alkali soil layer 4. The collection layer 3 is laid above the saline-alkali soil layer 4, and the collection layer 3 is provided with a pipe network trough, and the pipe network trough is provided with a collection pipe network; the impermeable layer 2 is laid above the collection layer 3 in the area corresponding to the collection pipe network grid, and the tillage layer 1 is laid above the impermeable layer 2 and the collection pipe network; the thickness of the impermeable layer 2 in each grid is high in the middle and low around, and the slope is inclined toward the collection pipe network; a collection pool 7 is set for every two adjacent grid nodes of the collection pipe network, and the collection pool 7 is set at the grid node position, and several collection pools 7 are connected to the collection pipe network; the inner wall 8 of the collection pool 7 is treated with impermeable treatment, and the upper end passes through the tillage layer 1 and is open.

[0089] The collecting pipe network includes several collecting pipes 6, some of which are arranged horizontally, and the other part of the collecting pipes 6 are arranged vertically, and the horizontally arranged collecting pipes 6 are connected to the vertically arranged collecting pipes 6; the spacing between two horizontally adjacent collecting pipes 6 is 4.5m, and the spacing between two vertically adjacent collecting pipes 6 is 9.0m; the horizontal spacing between two adjacent collecting pools 7 is 9.0m, and the vertical spacing is 18m; the collecting pipes 6 are buried in a concealed manner, and the axis of the collecting pipe 6 and the highest point of the anti-seepage layer 2 are on the same horizontal plane.

[0090] The collecting tube 6 is a flower tube made of polyvinyl chloride (PVC), with a diameter of 180 mm, a pore diameter of 12 mm, and a pore spacing of 7 mm; the flower tube is wrapped with a nylon mesh with a pore diameter of 4 mm.

[0091] The anti-seepage layer 2 is sloped toward the collecting pipe 6, with a slope of 0.9‰.

[0092] An anti-seepage cushion layer 5 is provided between the collecting pipe 6 and the collecting layer 3. The two sides of the anti-seepage cushion layer 5 overlap with the anti-seepage layer 2, and the overlap length is 1.0m. The anti-seepage cushion layer 5 adopts a sodium bentonite waterproof blanket with a specification of 4500g / m 2 .

[0093] The collecting pool 7 has a side length of 1.8 m and a pool depth of 1.5 m; the cultivating layer 1 has a thickness of 500 mm.

[0094] A biological treatment method using the above-mentioned structure for saline-alkali soil treatment comprises the following steps: cleaning the tillage layer 1 and piling it to one side, then sequentially laying a collection layer 3 and an anti-seepage layer 2, and simultaneously laying a collection pipe network and a collection tank 7; the anti-seepage layer 2 is formed by mixing biochar powder, sodium bentonite, calcium bentonite, fly ash, and saline-alkali soil, humidifying it with water to a moisture content of 32%, and then evenly mixing and laying it in layers and rolling it, with the first layer being 85 mm thick and each subsequent layer being 50 mm thick, for a total of three layers; adding straw pellets, straw biochar pellets, zeolite, and diatomaceous earth to the tillage layer 1 and then restoring it to its original position; if the anti-seepage layer 2 of the collection layer 3 leaks after more than five years of operation, the collection layer 3 is removed and soaked in clean water for 22 hours, and then cleaned, the soaked solution and the cleaning liquid are aired to evaporate and concentrate the salts and crystallize, and then collected; the liquid in the collection tank 7 is collected every two months from March to October; the collected liquid is first filtered and then evaporated, concentrated, and crystallized.

[0095] The straw particles added to the tillage layer 1 have a particle size of 10-20 mm and an addition amount of 0.2 kg / m 2 The particle size of straw biochar particles is 1.0-5.0 mm, and the incorporation ratio in the tillage layer 1 is 3.5%; the particle size of zeolite is 1.0-5.0 mm, and the particle size of diatomaceous earth is 0.1-1.5 mm; the addition amounts of zeolite and diatomaceous earth are 4.5% and 2.8% of the total mass of the soil in the tillage layer 1, respectively.

[0096] The raw material of the straw biochar particles is a mixture of sorghum straw peel and sesame straw.

[0097] The mixed mass ratio of biochar powder, sodium bentonite, calcium bentonite, fly ash and saline-alkali soil in the anti-seepage layer 2 is 4:1.5:2.5:2.5:89.5; the viscosity of sodium bentonite is greater than 60mPa·s, the sieve residue of 75μm particle size is less than 1.5%, and the filtration loss is less than 14cm 3 The viscosity is measured by a testing instrument at a rotation speed of 600r / min; the fly ash fineness is less than 30%, the loss on ignition is less than 8.0%, and the fineness is determined by the 45μm square hole sieve residue method; the total mass fraction of silicon dioxide (SiO2), aluminum oxide and iron oxide in the fly ash is greater than 70%, the mass fraction of free calcium oxide is less than 4%, and the mass fraction of sulfur trioxide is less than 3%.

[0098] The biochar powder raw material is a mixture of rice straw and wheat straw.

[0099] The rolling pressure of the anti-seepage layer 2 is 120 kPa, and the compaction coefficient is 0.95-0.96.

[0100] The collecting layer 3 is composed of nylon mesh 2 and filler, the filler is placed in the nylon mesh 2, the pore size of the nylon mesh 2 is 2-4mm, and the filler is laid with a thickness of 90mm; the filler is biochar with a particle size of 5-15mm, and the raw material of the biochar is tree branches.

[0101] A method for preparing straw biochar particles for the above-mentioned biological treatment method comprises the following steps: pyrolyzing a mixture of sorghum straw peel and sesame straw at 550° C. for 1.5 hours.

[0102] A method for preparing biochar powder for the above-mentioned biological treatment method includes the following steps: pyrolyzing a mixture of rice straw and wheat straw at 450°C for 2.0 hours, crushing the mixture to a particle size of less than 0.5 mm, and simultaneously adding 23% of wood biochar powder with a particle size of less than 0.5 mm after screening, and mixing the mixture. The wood biochar is prepared by pyrolyzing tree branches at 500°C for 1.7 hours.

[0103] A method for preparing a filler for the above-mentioned biological treatment method includes the following steps: first, pyrolyzing the raw material branches of the filler biochar of the collection layer 3 at 600°C for 1.8 hours to prepare; then, modifying them with 0.08mol / L potassium hydroxide for 42 hours, washing them to neutrality, then modifying them with a mixed solution of 0.03mol / L potassium permanganate and 0.01mol / L nitric acid for 56 hours, washing them thoroughly, and drying them; finally, soaking them in a mixed solution of 4.8% sodium bentonite and 1.5% calcium bentonite for 35 hours, washing them, and drying them to prepare the filler.

[0104] After treatment with the solution of this embodiment, the soil moisture content increased by 38.6%, the soil permeability (air permeability) increased by 1.6 times, the total salt content decreased by 40.6% in the first year, and the total salt content decreased by 86.9% of the initial value in the second year. The surface vegetation grew lushly, and the biomass increased by more than 2.3 times each year. The permeability coefficient of the anti-seepage layer 2 was less than 3×10 -11 m / s, with strong anti-seepage ability; the collection capacity of the 7 collection pools for salt (chloride, carbonate) is 209kg / 1000m 2 , realizing resource utilization.

[0105] Specific implementation method five:

[0106] Refer to Figures 1 to 3 for a detailed description of this embodiment. The structure for saline-alkali soil treatment described in this embodiment specifically includes a tillage layer 1, an impermeable layer 2, a collection layer 3, and a saline-alkali soil layer 4. The collection layer 3 is laid above the saline-alkali soil layer 4, and the collection layer 3 is provided with a pipe network trough, and the pipe network trough is provided with a collection pipe network; the impermeable layer 2 is laid above the collection layer 3 in the area corresponding to the collection pipe network grid, and the tillage layer 1 is laid above the impermeable layer 2 and the collection pipe network; the thickness of the impermeable layer 2 in each grid is high in the middle and low around, and the slope is inclined toward the collection pipe network; a collection pool 7 is set for every two adjacent grid nodes of the collection pipe network, and the collection pool 7 is set at the grid node position, and several collection pools 7 are connected to the collection pipe network; the inner wall 8 of the collection pool 7 is treated with impermeable treatment, and the upper end passes through the tillage layer 1 and is open.

[0107] The collecting pipe network includes several collecting pipes 6, some of which are arranged horizontally, and the other part of the collecting pipes 6 are arranged vertically, and the horizontally arranged collecting pipes 6 are connected to the vertically arranged collecting pipes 6; the spacing between two horizontally adjacent collecting pipes 6 is 3.5m, and the spacing between two vertically adjacent collecting pipes 6 is 7.0m; the horizontal spacing between two adjacent collecting pools 7 is 7.0m, and the vertical spacing is 14m; the collecting pipes 6 are buried in a concealed manner, and the axis of the collecting pipe 6 and the highest point of the anti-seepage layer 2 are on the same horizontal plane.

[0108] The collecting tube 6 is a flower tube made of polyvinyl chloride (PVC), with a diameter of 200 mm, a pore size of 15 mm on the flower tube wall, and a pore spacing of 8 mm; the flower tube is wrapped with a nylon mesh with a pore size of 5 mm.

[0109] The anti-seepage layer 2 is sloped toward the collecting pipe 6 with a slope of 0.7‰.

[0110] An anti-seepage cushion layer 5 is provided between the collecting pipe 6 and the collecting layer 3. The two sides of the anti-seepage cushion layer 5 overlap with the anti-seepage layer 2, and the overlap length is 1.2m. The anti-seepage cushion layer 5 adopts a sodium bentonite waterproof blanket with a specification of 5100g / m 2 .

[0111] The collecting pool 7 has a side length of 1.9 m and a pool depth of 1.5 m; the cultivating layer 1 has a thickness of 450 mm.

[0112] A biological treatment method using the above-mentioned structure for saline-alkali soil treatment comprises the following steps: cleaning the cultivated layer 1 and piling it to one side, then laying the collection layer 3 and the anti-seepage layer 2 in sequence, and laying the collection pipe network and the collection pool 7 at the same time; the anti-seepage layer 2 is made of a mixture of biochar powder, sodium bentonite, calcium bentonite, fly ash and saline-alkali soil, and then adding water to increase the moisture content to 30.5%. After mixing evenly, the mixture is laid in layers and rolled. The thickness of the first layer is 95 mm, and the thickness of each subsequent layer is 45 mm. m, with a total of 3 layers; straw pellets, straw biochar pellets, zeolite and diatomaceous earth are added to the tillage layer 1 and then restored to the original position; when the anti-seepage layer 2 leaks after the collection layer 3 has been in operation for more than 5 years, the collection layer 3 is taken out and soaked in clean water for 16.5 hours, and then the collection layer 3 is cleaned. The soaked solution and the cleaning liquid are dried in the sun to evaporate and concentrate the salt crystals and then collected; the liquid in the collection pool 7 is collected every 2 months from March to October; the collected liquid is first filtered and then evaporated, concentrated and crystallized.

[0113] The straw particles added to the tillage layer 1 have a particle size of 10-20 mm and an addition amount of 0.18 kg / m 2 The particle size of straw biochar particles is 1.0-5.0 mm, and the incorporation ratio in the tillage layer 1 is 2.5%; the particle size of zeolite is 1.0-5.0 mm, and the particle size of diatomaceous earth is 0.1-1.5 mm; the addition amounts of zeolite and diatomaceous earth are 2.8% and 1.5% of the total mass of the soil in the tillage layer 1, respectively.

[0114] The raw material of the straw biochar particles is a mixture of cotton straw and soybean straw.

[0115] The mixed mass ratio of biochar powder, sodium bentonite, calcium bentonite, fly ash and saline-alkali soil in the anti-seepage layer 2 is 4.5:1.0:3.0:5.0:86.5; the viscosity of sodium bentonite is greater than 60mPa·s, the sieve residue of 75μm particle size is less than 1.5%, and the filtration loss is less than 14cm 3 The viscosity is measured by a testing instrument at a rotation speed of 600r / min; the fly ash fineness is less than 30%, the loss on ignition is less than 8.0%, and the fineness is determined by the 45μm square hole sieve residue method; the total mass fraction of silicon dioxide (SiO2), aluminum oxide and iron oxide in the fly ash is greater than 70%, the mass fraction of free calcium oxide is less than 4%, and the mass fraction of sulfur trioxide is less than 3%.

[0116] The biochar powder raw material is a mixture of rice straw and wheat straw.

[0117] The rolling pressure of the anti-seepage layer 2 is 110 kPa, and the compaction coefficient is 0.94-0.95.

[0118] The collecting layer 3 is composed of a second nylon mesh and a filler. The filler is placed in the second nylon mesh. The aperture of the second nylon mesh is 2-4 mm, and the thickness of the filler is 60 mm. The filler is biochar with a particle size of 5-15 mm, and the raw material of the biochar is wood.

[0119] A method for preparing straw biochar particles for the above-mentioned biological treatment method comprises the following steps: pyrolyzing a mixture of cotton straw and soybean straw at 550° C. for 1.5 hours.

[0120] A method for preparing biochar powder for the above-mentioned biological treatment method includes the following steps: pyrolyzing a mixture of rice straw and wheat straw at 400°C for 2.5 hours, crushing the mixture to a particle size of less than 0.5 mm, and simultaneously adding 26% of wood biochar powder with a particle size of less than 0.5 mm after screening, and mixing the mixture. The wood biochar is prepared by pyrolyzing tree branches at 520°C for 1.6 hours.

[0121] A method for preparing a filler for the above-mentioned biological treatment method includes the following steps: first, pyrolyzing the raw material wood of the filler biochar of the collection layer 3 at 550°C for 2.5 hours to prepare it; then, modifying it with 0.05mol / L potassium hydroxide for 48 hours, washing it to neutrality, then modifying it with a mixed solution of 0.001mol / L potassium permanganate and 0.005mol / L nitric acid for 72 hours, washing it thoroughly, and drying it; finally, soaking it in a mixed solution of 3.2% sodium bentonite and 2.2% calcium bentonite for 23 hours, washing it, and drying it to prepare it.

[0122] After treatment with the solution of this embodiment, the soil moisture content increased by 36.3%, the soil permeability (air permeability) increased by 2.3 times, the total salt content decreased by 32.1% in the first year, and the total salt content decreased by 81.9% of the initial value in the second year. The surface vegetation grew lushly, and the biomass increased by more than 1.8 times each year. The permeability coefficient of the anti-seepage layer 2 was less than 5×10 -11 m / s, with strong anti-seepage ability; the collection capacity of the 7 collection pools for salt (chloride, carbonate) is 161.5kg / 1000m 2 , realizing resource utilization.

[0123] In summary of the above implementation cases, the structure and biological treatment method for saline-alkali soil treatment described in the present invention use a biomaterial composite preparation as the anti-seepage layer material, and utilize the interaction between biochar powder with high ash content and sodium bentonite, calcium bentonite, fly ash and clay particles in saline-alkali soil to form a cohesive body. Under the action of rolling, the anti-seepage ability, strength and plasticity are significantly improved. The permeability coefficient is measured to be less than 5×10 -11m / s, plant roots are not likely to damage this layer; because the amount of added materials is small and they are conventional materials, the cost is low; the anti-seepage layer has good durability, and the anti-seepage capacity of the soil anti-seepage layer is 2-3 times higher than that of the traditional method using only biochar, the cost is reduced by 50%, and the durability is increased by more than 1 times, effectively preventing the saline-alkali soil layer from returning, thereby ensuring the continuous reduction of the salt content in the cultivated layer and ensuring the effective improvement of this layer of soil;

[0124] The structure and biological treatment method for saline-alkali soil treatment described in the present invention collects salt from the upper tillage layer and the lower saline-alkali soil layer by providing a collection pipe network and a collection pool, thereby permanently removing harmful salts from the soil. The collection layer is recovered after long-term operation (more than 5 years) and when the anti-seepage layer fails. When the anti-seepage layer is repaired, the salts adsorbed and crystallized in the collection layer are recovered as raw materials for industrial production. The collection layer has a physical and chemical adsorption effect on the salt components contained in the soil, and has a strong effect on removing salts from the soil. The method uses inexpensive biomass materials to effectively repair saline-alkali soil without introducing new pollutants. The collection of salt achieves high economic benefits and solves the problem of shortage of raw materials related to industrial production.

[0125] The structure and biological treatment method for saline-alkali soil treatment described in the present invention adopt a composite conditioner (straw particles, straw biochar particles, zeolite particles and diatomaceous earth particles) to improve the soil's water retention, permeability and organic matter content, which is more conducive to plant growth; under the action of rainfall, salt in the cultivated layer is collected through pipes and collection pools to achieve a rapid reduction in the salt content in the soil; a comprehensive method is used to treat the saline-alkali soil in the cultivated layer to solve the technical problem of low salt removal efficiency in saline-alkali soil with varying degrees of salinization, reduce the soil salt content, and simultaneously improve the soil's air permeability and water retention capacity. After two years of rainfall, the harmful salt content in the soil is reduced by more than 80%, the soil's water retention capacity is increased by 30%, and the soil's air permeability (permeability) is increased by more than 70%.

[0126] The specific embodiments described above further illustrate the objectives, technical solutions, and beneficial effects of the present invention. It should be understood that the above description is merely a specific embodiment of the present invention and is not intended to limit the invention. Reasonable combinations of the features described in the above embodiments are also possible. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention shall be included in the scope of protection of the present invention.

Claims

1. A structure for saline-alkali soil treatment, characterized in that: The invention comprises a cultivation layer (1), an anti-seepage layer (2), a collection layer (3) and a saline-alkali soil layer (4); the collection layer (3) is laid on the saline-alkali soil layer (4); the collection layer (3) is provided with a pipe network trough, and a collection pipe network is arranged in the pipe network trough; an anti-seepage layer (2) is laid on the collection layer (3) in an area corresponding to the collection pipe network grid; the cultivation layer (1) is laid on the anti-seepage layer (2) and the collection pipe network; the thickness of the anti-seepage layer (2) in each grid is high in the middle and low around, and the slope is inclined toward the collection pipe network; a collection pool (7) is arranged for every two adjacent grid nodes of the collection pipe network, the collection pool (7) is arranged at the grid node position, and a plurality of collection pools (7) are connected to the collection pipe network; the inner side wall (8) of the collection pool (7) is treated with anti-seepage, and the upper end passes through the cultivation layer (1) and is open.

2. The structure for treating saline-alkali soil according to claim 1, characterized in that: The collecting pipe network comprises a plurality of collecting pipes (6), a part of the collecting pipes (6) are arranged transversely, and another part of the collecting pipes (6) are arranged longitudinally, and the transversely arranged collecting pipes (6) are connected to the longitudinally arranged collecting pipes (6); the spacing between two transversely adjacent collecting pipes (6) is 3.0-5.0 m, and the spacing between two longitudinally adjacent collecting pipes (6) is 6.0-10.0 m; the transverse spacing between two adjacent collecting pools (7) is 6.0-10.0 m, and the longitudinal spacing is 12-20 m; the axis of the collecting pipe (6) and the highest point of the anti-seepage layer (2) are on the same horizontal plane.

3. The structure for treating saline-alkali soil according to claim 2, characterized in that: The collecting tube (6) is a flower tube made of polyvinyl chloride with a diameter of 100-200 mm, a pore size of 8-15 mm on the flower tube wall, and a pore spacing of 5-8 mm; the flower tube is wrapped with a nylon mesh with a pore size of 2-5 mm.

4. The structure for treating saline-alkali soil according to claim 2, characterized in that: The anti-seepage layer (2) is sloped toward the collecting pipe (6), with a slope of 0.5-1.5‰.

5. The structure for treating saline-alkali soil according to claim 2, characterized in that: An anti-seepage cushion layer (5) is arranged between the collecting pipe (6) and the collecting layer (3), and both sides of the anti-seepage cushion layer (5) are overlapped with the anti-seepage layer (2), and the overlap length is 0.5-1.5m.

6. The structure for treating saline-alkali soil according to claim 5, characterized in that: The anti-seepage cushion layer (5) is made of sodium-based bentonite waterproof blanket with a specification of 4000g / m 2 -5500g / m 2 .

7. The structure for treating saline-alkali soil according to claim 1, characterized in that: The collecting pool (7) has a side length of 1.5-2.5 m and a pool depth of 1.0-2.0 m; the cultivation layer (1) has a thickness of 300-600 mm.

8. A biological treatment method using the structure for saline-alkali soil treatment according to claim 1, characterized in that: The following steps are involved: The tillage layer (1) is cleaned and piled to one side, and then the collection layer (3) and the anti-seepage layer (2) are laid in sequence, and the collection pipe network and the collection pool (7) are laid at the same time; the anti-seepage layer (2) is made of biochar powder, sodium bentonite, calcium bentonite, fly ash and saline-alkali soil, and then water is added to increase the moisture content to 25-35%. After mixing evenly, the mixture is laid in layers and rolled. The thickness of the first layer is 80-100 mm, and the thickness of each subsequent layer is 40-50 mm, and a total of 2-3 layers are laid; on the tillage layer ( 1) is added with straw particles, straw biochar particles, zeolite and diatomaceous earth and then restored to the original position; when the anti-seepage layer (2) leaks after the collection layer (3) has been in operation for more than 5 years, the collection layer (3) is taken out and soaked in clean water for 12-24 hours, and then the collection layer (3) is cleaned, and the soaked solution and the cleaning liquid are dried in the sun to evaporate and concentrate the salt crystals and then collected; the liquid in the collection pool (7) is collected every 2 months from March to October; the collected liquid is first filtered, and then evaporated, concentrated and crystallized.

9. The biological treatment method of the structure for saline-alkali soil treatment according to claim 8, characterized in that: The straw particles added to the tillage layer (1) have a particle size of 10-20 mm and an addition amount of 0.15-0.3 kg / m 2 The particle size of the straw biochar particles is 1.0-5.0 mm, and the incorporation ratio in the tillage layer (1) is 2.0-5.0%; the particle size of the zeolite is 1.0-5.0 mm, and the particle size of the diatomaceous earth is 0.1-1.5 mm; the addition amounts of zeolite and diatomaceous earth are 0.5-5.0% and 0.5-3.0% of the total mass of the soil in the tillage layer (1), respectively.

10. The biological treatment method of the structure for treating saline-alkali soil according to claim 9, characterized in that: The raw material of the straw biochar particles is one or a mixture of corn straw peel, sorghum straw peel, sesame straw, cotton straw, sunflower straw and soybean straw.

11. The biological treatment method of the structure for treating saline-alkali soil according to claim 8, characterized in that: The mixed mass ratio of biochar powder, sodium bentonite, calcium bentonite, fly ash and saline-alkali soil in the anti-seepage layer (2) is 3:0.5:1.0:2.0:93.5-6.5:1.5:3.5:6.5:82; the viscosity of sodium bentonite is greater than 60mPa·s, the 75μm particle size sieve residue is less than 1.5%, and the filtration loss is less than 14cm 3 ; The fly ash fineness is less than 30%, and the loss on ignition is less than 8.0%; the total mass fraction of silicon dioxide, aluminum oxide and iron oxide in the fly ash is greater than 70%, the mass fraction of free calcium oxide is less than 4%, and the mass fraction of sulfur trioxide is less than 3%.

12. The biological treatment method of the structure for saline-alkali soil treatment according to claim 11, characterized in that: The raw material of the biochar powder is one or a mixture of corn straw, rice straw and wheat straw.

13. The biological treatment method of the structure for treating saline-alkali soil according to claim 8, characterized in that: The rolling pressure of the anti-seepage layer (2) is 50-150 kPa, and the compaction coefficient is 0.92-0.

96.

14. The biological treatment method of the structure for treating saline-alkali soil according to claim 8, characterized in that: The collecting layer (3) is composed of a second nylon mesh and a filler, wherein the filler is placed inside the second nylon mesh, the aperture of the second nylon mesh is 2-4 mm, and the thickness of the filler is 50-100 mm; the filler is biochar with a particle size of 5-15 mm, and the raw material of the biochar is wood.

15. A method for preparing straw biochar particles for the biological treatment method according to claim 10, characterized in that: The following steps are involved: The method is prepared by pyrolyzing one or a mixture of corn straw peel, sorghum straw peel, sesame straw, cotton straw, sunflower straw and soybean straw at 400-600° C. for 1.0-3.0 hours.

16. A method for preparing biochar powder for the bioremediation method according to claim 12, characterized in that: The following steps are involved: A mixture of one or more of corn straw pulp, rice straw and wheat straw is prepared by pyrolyzing at 350-550°C for 1.0-3.5 hours, and then crushed to a particle size of less than 0.5 mm, and 15-35% of wood biochar charcoal powder with a particle size of less than 0.5 mm is added and mixed; the wood biochar is prepared by pyrolyzing wood at 450-550°C for 1.5-2.0 hours.

17. A method for preparing a filler for the bioremediation method according to claim 14, characterized in that: The following steps are involved: The raw material of the filler biochar in the collection layer (3) is first prepared by pyrolysis at 550-650°C for 1.5-2.5 hours; then modified with 0.05-0.2mol / L potassium hydroxide for 24-48 hours and washed to neutrality, then modified with a mixed solution of 0.001-0.05mol / L potassium permanganate and 0.005-0.05mol / L nitric acid for 24-72 hours, washed and dried; finally, soaked in a mixed solution of 1.5-6.5% sodium bentonite and 1.0-4.0% calcium bentonite for 20-50 hours, washed and dried.

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