A structure for saline-alkali soil treatment and a biological treatment method

Abstract

The application discloses a structure and a biological treatment method for saline-alkali soil treatment, relates to the field of special soil biological remediation technology, and solves the problems of single treatment method, long treatment period, high cost and poor effect of single material of the existing saline-alkali soil improvement method. The application is sequentially provided with a collection layer, an anti-seepage layer and a ploughing layer from the saline-alkali soil layer upwards; the anti-seepage layer and the collection layer are made of biological materials, and the ploughing layer is improved; the comprehensive treatment method of improving the upper ploughing layer, preventing seepage of the lower part, collecting salt in the upper ploughing layer and the lower saline-alkali soil layer is adopted, the content of harmful salt in the ploughing layer is effectively reduced, and the water retention capacity and the air permeability (looseness) of the ploughing layer soil are improved. Meanwhile, the collection pipe network is buried under the ploughing layer, the collection pool is arranged at the pipe network nodes, salt is collected, resource utilization is realized, and the effect of permanently removing harmful salt components in the saline-alkali soil is realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of special soil bioremediation, in particular to a structure and biological treatment method for saline-alkali soil treatment. BACKGROUND

[0002] The saline-alkali soil area in China is large and widely distributed, which is one of the main factors restricting the development of agriculture and animal husbandry; there are certain differences in the degree of salinization of saline-alkali soil in different regions, in addition, due to the large thickness of saline-alkali soil in China, the salt in the lower layer of saline-alkali soil continuously returns upward through capillary, which accelerates the deterioration of the surface cultivated layer soil, increasing the difficulty of saline-alkali soil treatment; the methods for treating saline-alkali soil mainly include plant remediation, microbial remediation and soil additive improvement, etc., which have problems of long treatment cycle, poor effect, high cost and low industrial value, etc. Therefore, it is of great significance to develop a new efficient comprehensive biological treatment method for saline-alkali soil improvement.

[0003] At present, the method for improving saline-alkali soil is single, the improvement cycle is long, the cost is high, especially the upward of the lower layer of saline-alkali soil leads to the repeated salinization of the upper layer of cultivated layer, thereby resulting in the failure to completely improve the saline-alkali soil, and the development of saline-alkali soil improvement and salt extraction and utilization is helpful to completely change the present situation of saline-alkali soil. At present, the method for treating saline-alkali soil mainly adds organic fertilizer, bacterial fertilizer, compound fertilizer, biochar, biological bacteria and other conditioning agents in the saline-alkali soil, which improves the saline-alkali soil from the perspective of soil improver, plant remediation and preparation of salt barrier layer, reduces the amount of soda alkali in the soil, but has problems of high cost due to large consumption of biochar of the anti-seepage layer, poor anti-seepage effect of single material, high cost and high failure probability in the application process, in addition, the salt content in the upper layer of cultivated layer is reduced slowly, which has problems of failure to achieve rapid repair, low economic value, large carbon emission, etc., thereby affecting the improvement effect of saline-alkali soil and the growth of crops. SUMMARY

[0004] In order to solve the problems of single method, long improvement cycle, high cost and poor effect of single material of the existing saline-alkali soil improvement method mentioned above, a structure and biological treatment method for saline-alkali soil treatment are provided. The present application adopts the comprehensive treatment method of upper layer of cultivated layer improvement, lower anti-seepage, salt collection in the upper layer of cultivated layer and the lower layer of saline-alkali soil, which effectively reduces the content of harmful salts such as chloride, sulfate and carbonate in the upper layer of cultivated layer, improves the water holding capacity and air permeability of the cultivated layer soil, and realizes the rapid growth of plants; at the same time, the collection pipe network and collection pool are set to collect salt, realize resource utilization, and achieve the effect of permanently removing harmful salt components in saline-alkali soil.

[0005] The application provides a structure for saline-alkali soil treatment, which specifically comprises a ploughing layer, an anti-seepage layer, a collecting layer and a saline-alkali soil layer, the collecting layer is arranged above the saline-alkali soil layer, the collecting layer is provided with a pipe network groove, and the pipe network groove is provided with a collecting pipe network; the anti-seepage layer is arranged above the area in each grid of the collecting pipe network, the anti-seepage layer and the collecting pipe network are provided with the ploughing layer; the thickness of the anti-seepage layer in each grid is higher in the middle and lower at the four sides, and the slope surface is inclined to the collecting pipe network; one collecting pool is arranged at each adjacent two grid nodes of the collecting pipe network, the collecting pool is arranged at the grid node position, and the plurality of collecting pools and the collecting pipe network are communicated; the inner side wall of the collecting pool is subjected to anti-seepage treatment, and the upper end penetrates through the ploughing layer and is open.

[0006] Further, the collecting pipe network comprises a plurality of collecting pipes, part of the collecting pipes are arranged transversely, and the other part of the collecting pipes are arranged longitudinally, the transversely arranged collecting pipes and the longitudinally arranged collecting pipes are connected; the distance between two transversely adjacent collecting pipes is 3.0-5.0 m, the distance between two longitudinally adjacent collecting pipes is 6.0-10.0 m; the transverse distance between two adjacent collecting pools is 6.0-10.0 m, and the longitudinal distance is 12-20 m; the axis of the collecting pipe and the highest point of the anti-seepage layer are located on the same horizontal plane.

[0007] Further, the collecting pipe adopts a flower pipe, the material is polyvinyl chloride, the diameter is 100-200 mm, the hole diameter of the flower pipe wall is 8-15 mm, and the hole distance is 5-8 mm; the flower pipe is wrapped with nylon net one, and the hole diameter of the nylon net one is 2-5 mm.

[0008] Further, the anti-seepage layer has a slope to the direction of the collecting pipe, and the slope is 0.5-1.5 ‰.

[0009] Further, an anti-seepage cushion layer is arranged between the collecting pipe and the collecting layer, the anti-seepage cushion layer is overlapped with the anti-seepage layer on both sides, and the overlapping length is 0.5-1.5 m.

[0010] Further, the anti-seepage cushion layer adopts a sodium-based bentonite waterproof blanket, and the specification is 4000 g / m 2 -5500 g / m 2 .

[0011] Further, the length of the collecting pool is 1.5-2.5 m, the pool depth is 1.0-2.0 m, and the thickness of the ploughing layer is 300-600 mm.

[0012] A biological treatment method using the structure for saline-alkali soil treatment described above, comprising the following steps: after the plough layer is cleaned, it is piled on one side, then the collection layer and the impermeable layer are laid in turn, while the collection pipe network and the collection pool are laid; the impermeable layer is made by mixing biochar powder, sodium bentonite, calcium bentonite, fly ash and saline-alkali soil, then adding water to moisten to a water content of 25-35%, after uniform mixing, it is laid in layers and rolled, the first layer is laid to a thickness of 80-100mm, then each layer is laid to a thickness of 40-50mm, a total of 2-3 layers are laid; after the plough layer is mixed with straw particles, straw biochar particles, zeolite and diatomite, it is restored to its original position; when the impermeable layer leaks after the collection layer has been in operation for more than 5 years, the collection layer is taken out and soaked in clean water for 12-24 hours, then the collection layer is cleaned, the solution after soaking and the cleaning liquid are dried and evaporated to concentrate and crystallize the salts, then the salts are collected; the liquid in the collection pool is collected every 2 months from March to October; the collected liquid is first filtered, then evaporated, concentrated and crystallized.

[0013] Further, the particle size of the straw particles mixed in the plough layer is 10-20mm, and the mixing amount is 0.15-0.3kg / m 2 ; the particle size of the straw biochar particles is 1.0-5.0mm, and the mixing ratio in the plough layer is 2.0-5.0%; the particle size of the zeolite is 1.0-5.0mm, and the particle size of the diatomite is 0.1-1.5mm; the addition amount of the zeolite and the diatomite is 0.5-5.0% and 0.5-3.0% of the total mass of the plough layer soil, respectively.

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

[0015] Further, the mixing mass ratio of the biochar powder, the sodium bentonite, the calcium bentonite, the fly ash and the saline-alkali soil in the impermeable layer is 3:0.5:1.0:2.0:93.5~6.5:1.5:3.5:6.5:82; the viscosity of the sodium bentonite is greater than 60mPa·s, the sieve residue amount at 75μm particle size is less than 1.5%, and the filtration loss is less than 14cm 3 ; the fineness of the fly ash is less than 30%, and the loss on ignition is less than 8.0%; the total mass fraction of silicon dioxide, diatomic aluminum oxide and diatomic 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] Further, the raw material of the biochar powder is a mixture of one or more of the pulp of corn straw, rice straw and wheat straw.

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

[0018] Further, the collection layer is composed of nylon net two and filler, the filler is placed in the nylon net two, the aperture of the nylon net two is 2-4 mm, and the laying thickness of the filler is 50-100 mm; the filler adopts biochar with a particle size of 5-15 mm, and the raw material of the biochar is wood.

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

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

[0021] A filler preparation method for the above-mentioned biological treatment method, comprising the following steps: the raw material of the filler biochar in the collection layer is first pyrolyzed at 550-650 DEG C for 1.5-2.5 hours; then modified by 0.05-0.2 mol / L potassium hydroxide for 24-48 hours, washed to neutral, and then modified by 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, washed clean and dried; finally, soaked in a mixed solution of 1.5-6.5% sodium-based bentonite and 1.0-4.0% calcium-based bentonite for 20-50 hours, washed and dried.

[0022] The structure and biological treatment method for saline-alkali soil treatment have the following advantages:

[0023] (1) The structure and biological treatment method for saline-alkali soil treatment use a biological material composite preparation as the impermeable layer material, utilize the interaction of the biochar powder with high ash content, sodium-based bentonite, calcium-based bentonite, fly ash and clay particles in the saline-alkali soil to form a cohesive body, and under the action of rolling, the impermeability, strength and plasticity are significantly improved, and the permeability coefficient is lower than 5*10 -11The layer is not easy to be damaged by plant roots; the added material is in small amount and is a conventional material, so the cost is low; the anti-seepage layer has good durability, the anti-seepage ability of the soil anti-seepage layer is 2-3 times higher than that of the traditional method using biochar, the cost is reduced by 50%, the durability is increased by more than 1 times, the salt layer is effectively prevented from returning, so that the salt content in the plough layer is continuously reduced, and the effective improvement of the soil in the layer is ensured;

[0024] (2) The structure and biological treatment method for saline-alkali soil treatment, by setting the collection pipe network and the collection pool, the salt in the upper plough layer and the lower saline-alkali soil layer is collected, and the harmful salt in the soil is permanently removed; the recovery of the collection layer is after long-term operation (more than 5 years), when the anti-seepage layer fails, the anti-seepage layer is repaired, and the salt adsorbed and crystallized in the collection layer is recovered as industrial raw materials; 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 the salt in the soil; the method uses cheap biomass materials to effectively repair the saline-alkali soil, without bringing new pollutants; the salt collection obtains high economic benefits, and solves the problem of shortage of industrial production raw materials;

[0025] (3) The structure and biological treatment method for saline-alkali soil treatment, the plough layer is improved by using a composite conditioner (straw particles, straw biochar particles, zeolite particles and diatomite particles), the water retention, permeability and organic matter content of the soil are improved, and the growth of plants is more beneficial; under the action of rainfall, the salt in the plough layer is collected through the pipeline and the collection pool, and the salt content in the soil is rapidly reduced; the comprehensive method is used to treat the saline-alkali soil in the plough layer, the technical problem of low salt removal efficiency in different degrees of saline-alkali soil is solved, the salt content of the soil is reduced, and the air permeability and water retention capacity of the soil are improved; after two years of rainfall, the harmful salt content in the soil is reduced by more than 80%, the water retention capacity of the soil is improved by 30%, and the air permeability (permeability) of the soil is improved by more than 70%. BRIEF DESCRIPTION OF DRAWINGS

[0026] The accompanying drawings, which form a part of this application, are included to provide a further understanding of the application, and are incorporated in and constitute a part of this application. The embodiments of the application illustrated in the drawings, and their description, are presented to add generic structure for public

[0027] In the drawings:

[0028] Fig. 1 is a cross-sectional arrangement drawing of the structure for saline-alkali soil treatment according to the application;

[0029] Fig. 2 is a planar arrangement drawing of the structure for saline-alkali soil treatment according to the application;

[0030] Fig. 3A collection pool profile layout for saline-alkali soil treatment according to the present application;

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

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

[0034] Reference Figs. 1-3 This embodiment specifically describes a structure for saline-alkali soil treatment, which specifically comprises a cultivation layer 1, an impervious layer 2, a collection layer 3, and a saline-alkali soil layer 4. The saline-alkali soil layer 4 is paved with the collection layer 3, which is provided with a pipe network groove, and the pipe network groove is provided with a collection pipe network. The collection layer 3 is paved with the impervious layer 2 corresponding to the area within the grid of the collection pipe network, and the impervious layer 2 and the collection pipe network are paved with the cultivation layer 1. The thickness of the impervious layer 2 in each grid is higher in the middle and lower at the four corners, and the slope surface is inclined toward the collection pipe network. One collection pool 7 is arranged at each adjacent two grid nodes of the collection pipe network, and the collection pool 7 is arranged at the grid node position. The collection pool 7 is connected with the collection pipe network, and the inner side wall 8 of the collection pool 7 is impervious, and the upper end penetrates through the cultivation layer 1 and is open.

[0035] The collection pipe network comprises a plurality of collection pipes 6, a part of the collection pipes 6 are arranged transversely, and the other part of the collection pipes 6 are arranged longitudinally. The transversely arranged collection pipes 6 are connected with the longitudinally arranged collection pipes 6. The spacing between two transversely adjacent collection pipes 6 is 3.0 m, and the spacing between two longitudinally adjacent collection pipes 6 is 6.0 m. The transverse spacing between two adjacent collection pools 7 is 6.0 m, and the longitudinal spacing is 12 m. The collection pipes 6 are arranged in a buried manner, and the axis of the collection pipes 6 and the highest point of the impervious layer 2 are on the same horizontal plane.

[0036] The collection pipes 6 adopt a flower pipe, the material is polyvinyl chloride (PVC), the diameter is 100 mm, the hole diameter of the flower pipe wall is 8 mm, and the hole spacing is 5 mm. The flower pipe is wrapped with nylon net one, and the hole diameter of the nylon net one is 2 mm.

[0037] The impervious layer 2 is inclined to the direction of the collection pipe 6, and the inclination is 0.5 ‰.

[0038] An impervious cushion layer 5 is arranged between the collection pipe 6 and the collection layer 3, and the impervious cushion layer 5 is overlapped with the impervious layer 2 on both sides, and the overlapping length is 0.5 m. The impervious cushion layer 5 adopts a sodium-based bentonite waterproof blanket with a specification of 4000 g / m 2 .

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

[0040] A biological treatment method using the structure for saline-alkali soil treatment described above, comprising the following steps: after the tillage layer 1 is cleaned, it is stacked on one side, and then the collection layer 3 and the impermeable layer 2 are laid in turn, while the collection pipe network and the collection pool 7 are laid; the impermeable layer 2 is made by mixing biochar powder, sodium-based bentonite, calcium-based bentonite, fly ash and saline-alkali soil, then adding water to increase the moisture content to 25%, uniformly mixing, layering and rolling; the first layer is laid to a thickness of 80 mm, and then each layer is laid to a thickness of 40 mm, for a total of 2 layers; after the tillage layer 1 is mixed with straw particles, straw biochar particles, zeolite and diatomite, it is returned to its original position; when the impermeable layer 2 leaks after the collection layer 3 has been in operation for more than 5 years, the collection layer 3 is removed and soaked in clean water for 12 hours, then the collection layer 3 is cleaned; the solution after soaking and the cleaning liquid are dried and evaporated to concentrate the salt crystals, then collected; the liquid in the collection pool 7 is collected every 2 months from March to October; the collected liquid is first filtered, then evaporated and concentrated to crystallize.

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

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

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

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

[0046] The collecting layer 3 is composed of nylon net 2 and filler, the filler is placed in the nylon net 2, the aperture of the nylon net 2 is 2-4mm, and the laying thickness of the filler is 50mm; the filler is biochar with particle size of 5-15mm, and the raw material of the biochar is branch.

[0047] A method for preparing the straw biochar particles used in the above-mentioned biological treatment method, comprising the following steps: pyrolyzing the peel of corn straw at 400℃ for 3.0 hours.

[0048] A method for preparing the biochar powder used in the above-mentioned biological treatment method, comprising the following steps: pyrolyzing the pulp of corn straw at 350℃ for 3.5 hours, crushing to a particle size of less than 0.5mm, and mixing with 15% of carbon powder with a particle size of less than 0.5mm screened from woody biochar, wherein the woody biochar is prepared by pyrolyzing branch at 450℃ for 2.0 hours.

[0049] A method for preparing the filler used in the above-mentioned biological treatment method, comprising the following steps: collecting the raw material branch of the filler biochar of the collecting layer 3, pyrolyzing at 550℃ for 2.5 hours to prepare; then modifying with 0.05mol / L potassium hydroxide for 48 hours, washing to neutral, modifying with a mixture of 0.001mol / L potassium permanganate and 0.005mol / L nitric acid for 72 hours, washing clean, and drying; finally, soaking in a mixture of 1.5% sodium-based bentonite and 4.0% calcium-based bentonite for 20 hours, washing and drying to prepare.

[0050] After adopting the scheme of the embodiment, the soil water content is increased by 45.6%, the soil permeability (air permeability) is increased by 1 times, the total salt content is reduced by 45.2% in the first year, and by 86.3% of the initial value in the second year, the surface vegetation grows luxuriantly, and the biomass is increased by more than 2 times per year; the permeability coefficient of the impermeable layer 2 is less than 5×10 -11 m / s, and the impermeability is strong; the collecting pool 7 collects 165kg / 1000m 2 of salt (chloride salt, carbonate salt, sulfate salt), and realizes resource utilization. Specific implementation method two:

[0052] Reference Figs. 1-3Specifically illustrate the present embodiment. The structure for saline-alkali soil treatment described in the present embodiment specifically comprises a ploughing layer 1, an anti-seepage 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, the collection layer 3 is provided with a pipe network groove, and the pipe network groove is provided with a collection pipe network; the anti-seepage layer 2 is laid above the region in the collection layer 3 corresponding to the region in the collection pipe network, the anti-seepage layer 2 and the collection pipe network are laid above the ploughing layer 1; the thickness of the anti-seepage layer 2 in each grid is higher in the middle and lower at the four sides, and the slope surface is inclined toward the collection pipe network; one collection pool 7 is arranged at each adjacent two grid nodes of the collection pipe network, the collection pool 7 is arranged at the grid node position, and the plurality of collection pools 7 are communicated with the collection pipe network; the inner side wall 8 of the collection pool 7 is subjected to anti-seepage treatment, and the upper end penetrates through the ploughing layer 1 and is open.

[0053] The collection pipe network comprises a plurality of collection pipes 6, a part of the collection pipes 6 are arranged transversely, another part of the collection pipes 6 are arranged longitudinally, and the transversely arranged collection pipes 6 and the longitudinally arranged collection pipes 6 are connected; the spacing between two transversely adjacent collection pipes 6 is 5.0 m, and the spacing between two longitudinally adjacent collection pipes 6 is 10.0 m; the transverse spacing between two adjacent collection pools 7 is 10.0 m, and the longitudinal spacing is 20 m; the collection pipes 6 are arranged in a buried manner, and the axis of the collection pipes 6 and the highest point of the anti-seepage layer 2 are on the same horizontal plane.

[0054] The collection pipes 6 adopt a flower pipe, the material is polyvinyl chloride (PVC), the diameter is 200 mm, the hole diameter of the flower pipe wall is 15 mm, and the hole spacing is 8 mm; the flower pipe is wrapped with nylon net one, and the hole diameter of the nylon net one is 5 mm.

[0055] The anti-seepage layer 2 is inclined to the direction of the collection pipe 6, and the inclination is 1.5 ‰.

[0056] The anti-seepage mat layer 5 is arranged between the collection pipe 6 and the collection layer 3, the anti-seepage mat layer 5 is overlapped on both sides of the anti-seepage layer 2, and the overlapping length is 1.5 m; the anti-seepage mat layer 5 adopts a sodium-based bentonite waterproof blanket, and the specification is 5500 g / m 2 .

[0057] The length of the collection pool 7 is 2.5 m, and the pool depth is 1.0 m; the thickness of the ploughing layer 1 is 600 mm.

[0058] A biological treatment method using the structure for saline-alkali soil treatment described above, comprising the following steps: after the plough layer 1 is cleaned, it is piled on one side, then the collection layer 3 and the impermeable layer 2 are laid in turn, while the collection pipe network and the collection pool 7 are laid; the impermeable layer 2 is made by mixing biochar powder, sodium-based bentonite, calcium-based bentonite, fly ash and saline-alkali soil, then adding water to moisten to a water content of 35%, after uniform mixing, it is laid in layers and rolled, the first layer is laid to a thickness of 100 mm, then each layer is laid to a thickness of 50 mm, a total of 3 layers; after the plough layer 1 is mixed with straw particles, straw biochar particles, zeolite and diatomite, it is restored to its original position; when the impermeable layer 2 leaks after the collection layer 3 has been in operation for more than 5 years, the collection layer 3 is removed and soaked in clean water for 24 hours, then the collection layer 3 is cleaned, the solution after soaking and the cleaning liquid are dried and evaporated to concentrate and crystallize the salts, then the salts are collected; the liquid in the collection pool 7 is collected every 2 months from March to October; the collected liquid is first filtered, then evaporated, concentrated and crystallized.

[0059] The particle size of the straw particles mixed in the plough layer 1 is 10-20 mm, and the mixing amount is 0.3 kg / m 2 ; the particle size of the straw biochar particles is 1.0-5.0 mm, and the mixing ratio in the plough layer 1 is 5.0%; the particle size of the zeolite is 1.0-5.0 mm, and the particle size of the diatomite is 0.1-1.5 mm; the addition amounts of the zeolite and the diatomite are 5% and 0.5% of the total mass of the soil in the plough layer 1, respectively.

[0060] The raw material of the straw biochar particles is the skin of corn straw and the skin of sorghum straw.

[0061] The mixing mass ratio of the biochar powder, the sodium-based bentonite, the calcium-based bentonite, the fly ash and the saline-alkali soil in the impermeable layer 2 is 6.5:1.5:3.5:6.5:82; the viscosity of the sodium-based bentonite is greater than 60 mPa·s, the sieve residue amount at 75 μm is less than 1.5%, the filtration loss is less than 14 cm 3 , and the viscosity is measured by a tester at a rotating speed of 600 r / min; the fineness of the fly ash is less than 30%, the loss on ignition is less than 8.0%, and the fineness is measured by the 45 μm square hole sieve residue method; the total mass fraction of silicon dioxide (SiO2), di-aluminum trioxide and di-iron trioxide 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 the core of corn straw and the straw of rice straw.

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

[0064] The collecting layer 3 is composed of nylon net 2 and filler, the filler is placed in the nylon net 2, the aperture of the nylon net 2 is 2-4 mm, and the laying 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 straw biochar particle preparation method for the above-mentioned biological treatment method, comprising the following steps: pyrolyzing a mixture of corn straw skin and sorghum straw skin at 600 DEG C for 1.0 hours.

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

[0067] A filler preparation method for the above-mentioned biological treatment method, comprising the following steps: first pyrolyzing the raw material wood of the filler biochar of the collecting layer 3 at 650 DEG C for 1.5 hours to prepare; then modifying with 0.2 mol / L potassium hydroxide for 24 hours, washing to neutral, modifying with a mixture of 0.05 mol / L potassium permanganate and 0.05 mol / L nitric acid for 24 hours, washing clean, and drying; finally, soaking in a mixture of 6.5% sodium-based bentonite and 1.0% calcium-based bentonite for 50 hours, washing and drying to prepare.

[0068] After the scheme of the embodiment is used for treatment, the soil moisture content is increased by 55.2%, the soil permeability (air permeability) is increased by 1.5 times, the total salt content is reduced by 38.2% in the first year, and by 82.7% of the initial value in the second year, the surface vegetation grows luxuriantly, and the biomass is increased by more than 2 times per year; the permeability coefficient of the impermeable layer 2 is less than 4*10 -11 m / s, and the impermeability is strong; the collecting pool 7 collects 185 kg / 1000m 2 of salt (chloride salt, carbonate salt), and realizes resource utilization. Specific embodiment three:

[0070] Referring to Figs. 1-3Specifically illustrate the present embodiment. The structure for saline-alkali soil treatment described in the present embodiment specifically comprises a ploughing 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 groove, and the pipe network groove is provided with a collection pipe network; the anti-seepage layer 2 is laid on the region in the collection layer 3 corresponding to the region in the collection pipe network, the anti-seepage layer 2 and the collection pipe network are provided with the ploughing layer 1; the thickness of the anti-seepage layer 2 in each grid is higher in the middle and lower at the four sides, and the slope surface is inclined toward the collection pipe network; one collection pool 7 is arranged at each adjacent two grid nodes of the collection pipe network, the collection pool 7 is arranged at the grid node position, and the plurality of collection pools 7 are communicated with the collection pipe network; the inner side wall 8 of the collection pool 7 is subjected to anti-seepage treatment, and the upper end penetrates through the ploughing layer 1 and is open.

[0071] The collection pipe network comprises a plurality of collection pipes 6, a part of the collection pipes 6 are arranged transversely, another part of the collection pipes 6 are arranged longitudinally, and the transversely arranged collection pipes 6 and the longitudinally arranged collection pipes 6 are connected; the spacing between two transversely adjacent collection pipes 6 is 4 m, and the spacing between two longitudinally adjacent collection pipes 6 is 8 m; the transverse spacing between two adjacent collection pools 7 is 8.0 m, and the longitudinal spacing is 16 m; the collection pipes 6 are arranged in a buried manner, and the axis of the collection pipes 6 and the highest point of the anti-seepage layer 2 are on the same horizontal plane.

[0072] The collection pipes 6 adopt flower pipes, the material is polyvinyl chloride (PVC), the diameter is 150 mm, the hole diameter of the flower pipe wall is 10 mm, and the hole spacing is 7 mm; the flower pipe is wrapped with nylon net one, and the hole diameter of the nylon net one is 3 mm.

[0073] The anti-seepage layer 2 is inclined to the direction of the collection pipe 6, and the inclination is 1.5 ‰.

[0074] The anti-seepage pad layer 5 is arranged between the collection pipe 6 and the collection layer 3, the anti-seepage pad layer 5 is overlapped on both sides of the anti-seepage layer 2, and the overlapping length is 0.8 m; the anti-seepage pad layer 5 adopts sodium-based bentonite waterproof blanket, and the specification is 5000 g / m 2 .

[0075] The length of the collection pool 7 is 2.0 m, and the depth is 1.5 m; the thickness of the ploughing layer 1 is 500 mm.

[0076] A biological treatment method using the structure for saline-alkali soil treatment described above, comprising the following steps: after the plough layer 1 is cleaned, it is piled on one side, then the collection layer 3 and the impermeable layer 2 are laid in turn, while the collection pipe network and the collection pool 7 are laid; the impermeable layer 2 is made by mixing biochar powder, sodium bentonite, calcium bentonite, fly ash and saline-alkali soil, then adding water to moisten to a water content of 30%, after uniform mixing, it is laid in layers and rolled, the first layer is laid to a thickness of 90mm, then each layer is laid to a thickness of 45mm, a total of 2 layers; after the plough layer 1 is mixed with straw particles, straw biochar particles, zeolite and diatomite, it is restored to its original position; when the impermeable layer 2 leaks after the collection layer 3 has been in operation for more than 5 years, the collection layer 3 is removed and soaked in clean water for 16 hours, then the collection layer 3 is cleaned, the solution after soaking and the cleaning liquid are dried and evaporated to concentrate the salt crystals, then collected; the liquid in the collection pool 7 is collected every 2 months from March to October; the collected liquid is first filtered, then evaporated and concentrated to crystallize.

[0077] The particle size of the straw particles mixed in the plough layer 1 is 10-20mm, and the mixing amount is 0.2kg / m 2 ; the particle size of the straw biochar particles is 1.0-5.0mm, and the mixing ratio in the plough layer 1 is 3.0%; the particle size of the zeolite is 1.0-5.0mm, and the particle size of the diatomite is 0.1-1.5mm; the addition amount of the zeolite and the diatomite is 2% and 2.5% of the total mass of the soil in the plough layer 1 respectively.

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

[0079] The mixing mass ratio of the biochar powder, sodium bentonite, calcium bentonite, fly ash and saline-alkali soil in the impermeable layer 2 is 6.5:1.5:3.5:6.5:82; the viscosity of the sodium bentonite is greater than 60mPa·s, the sieve residue amount at 75μm particle size is less than 1.5%, 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%, the loss on ignition is less than 8.0%, the fineness is measured by the 45μm square hole sieve residue method; the total mass fraction of silicon dioxide (SiO2), di-aluminum trioxide and di-iron trioxide 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 a mixture of one or more of the husks of corn straw, rice straw and wheat straw.

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

[0082] The collection layer 3 is composed of nylon net 2 and filler, the filler is placed in the nylon net 2, the aperture of the nylon net 2 is 2-4 mm, and the laying thickness of the filler is 80 mm; the filler adopts biochar with a particle size of 5-15 mm, and the raw material of the biochar is branch.

[0083] A straw biochar particle preparation method for the above-mentioned biological treatment method, comprising the following steps: pyrolyzing a mixture of one or more of the corn straw skin, the sorghum straw skin, the sesame straw, the cotton straw, the sunflower straw and the soybean straw at 500 DEG C for 2.0 hours.

[0084] A biochar powder preparation method for the above-mentioned biological treatment method, comprising the following steps: pyrolyzing a mixture of corn straw pulp and wheat straw at 450 DEG C for 2.5 hours to prepare, crushing to a particle size of less than 0.5 mm, and mixing 30% of carbon powder with a particle size of less than 0.5 mm screened from woody biochar, wherein the woody biochar is prepared by pyrolyzing branch at 500 DEG C for 1.8 hours.

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

[0086] After the soil is treated by the scheme of the embodiment, the water content of the soil is increased by 43.9%, the soil permeability (air permeability) is increased by 2.0 times, the total salt content is reduced by 47.5% in the first year and by 86.1% of the initial value in the second year, the surface vegetation grows luxuriantly, and the biomass is increased by more than 2.6 times per year; the permeability coefficient of the impervious layer 2 is less than 4*10 -11 m / s, and the impervious ability is strong; the collection pool 7 collects 205 kg / 1000m 2 of salt (chloride salt, carbonate salt), and realizes resource utilization. Specific implementation method four:

[0088] Reference Figs. 1-3Specifically illustrate the present embodiment. The structure for saline-alkali soil treatment described in the present embodiment specifically comprises a ploughing layer 1, an anti-seepage 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, the collection layer 3 is provided with a pipe network groove, and the pipe network groove is provided with a collection pipe network; the anti-seepage layer 2 is laid above the region in the collection layer 3 corresponding to the region in the collection pipe network, the anti-seepage layer 2 and the collection pipe network are laid above the ploughing layer 1; the thickness of the anti-seepage layer 2 in each grid is higher in the middle and lower at the four sides, and the slope surface is inclined toward the collection pipe network; one collection pool 7 is arranged at each adjacent two grid nodes of the collection pipe network, the collection pool 7 is arranged at the grid node position, and the plurality of collection pools 7 are communicated with the collection pipe network; the inner side wall 8 of the collection pool 7 is subjected to anti-seepage treatment, and the upper end penetrates through the ploughing layer 1 and is open.

[0089] The collection pipe network comprises a plurality of collection pipes 6, a part of the collection pipes 6 are arranged transversely, another part of the collection pipes 6 are arranged longitudinally, and the transversely arranged collection pipes 6 and the longitudinally arranged collection pipes 6 are connected; the spacing between two transversely adjacent collection pipes 6 is 4.5 m, and the spacing between two longitudinally adjacent collection pipes 6 is 9.0 m; the transverse spacing between two adjacent collection pools 7 is 9.0 m, and the longitudinal spacing is 18 m; the collection pipes 6 are arranged in a buried manner, and the axis of the collection pipes 6 and the highest point of the anti-seepage layer 2 are on the same horizontal plane.

[0090] The collection pipes 6 adopt flower pipes, the material is polyvinyl chloride (PVC), the diameter is 180 mm, the hole diameter of the flower pipe wall is 12 mm, and the hole spacing is 7 mm; the flower pipe is wrapped with nylon net one, and the hole diameter of the nylon net one is 4 mm.

[0091] The anti-seepage layer 2 is inclined to the direction of the collection pipe 6, and the inclination is 0.9 ‰.

[0092] The anti-seepage pad layer 5 is arranged between the collection pipe 6 and the collection layer 3, the anti-seepage pad layer 5 is overlapped on both sides of the anti-seepage layer 2, and the overlapping length is 1.0 m; the anti-seepage pad layer 5 adopts sodium-based bentonite waterproof blanket, and the specification is 4500 g / m 2 .

[0093] The length of the collection pool 7 is 1.8 m, and the depth is 1.5 m; the thickness of the ploughing layer 1 is 500 mm.

[0094] A biological treatment method using the structure for saline-alkali soil treatment described above, comprising the following steps: after the plough layer 1 is cleaned, it is piled on one side, then the collection layer 3 and the impermeable layer 2 are laid in turn, while the collection pipe network and the collection pool 7 are laid; the impermeable layer 2 is made by mixing biochar powder, sodium-based bentonite, calcium-based bentonite, fly ash and saline-alkali soil, then adding water to moisten to a water content of 32%, after uniform mixing, it is laid in layers and rolled, the first layer is laid to a thickness of 85mm, then each layer is laid to a thickness of 50mm, a total of 3 layers; after the plough layer 1 is mixed with straw particles, straw biochar particles, zeolite and diatomite, it is restored to its original position; when the impermeable layer 2 leaks after the collection layer 3 has been in operation for more than 5 years, the collection layer 3 is removed and soaked in clean water for 22 hours, then the collection layer 3 is cleaned, the solution after soaking and the cleaning liquid are dried and evaporated to concentrate and crystallize the salts, then the salts are collected; the liquid in the collection pool 7 is collected every 2 months from March to October; the collected liquid is first filtered, then evaporated, concentrated and crystallized.

[0095] The particle size of the straw particles mixed in the plough layer 1 is 10-20mm, and the mixing amount is 0.2kg / m 2 ; the particle size of the straw biochar particles is 1.0-5.0mm, and the mixing ratio in the plough layer 1 is 3.5%; the particle size of the zeolite is 1.0-5.0mm, and the particle size of the diatomite is 0.1-1.5mm; the addition amounts of the zeolite and the diatomite are 4.5% and 2.8% of the total mass of the soil in the plough layer 1, respectively.

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

[0097] The mixing mass ratio of the biochar powder, sodium-based bentonite, calcium-based bentonite, fly ash and saline-alkali soil in the impermeable layer 2 is 4:1.5:2.5:2.5:89.5; the viscosity of the sodium-based bentonite is greater than 60mPa·s, the 75μm particle size sieve residue amount is less than 1.5%, and the filtration loss is less than 14cm 3 ; the viscosity is measured by a tester at a rotation speed of 600r / min; the fineness of the fly ash 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), di-aluminum trioxide and di-iron trioxide 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 raw material of the biochar powder is a mixture of rice straw and wheat straw.

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

[0100] The collection layer 3 nylon net 2 and the filler are composed, the filler is placed in the nylon net 2, the aperture of the nylon net 2 is 2-4mm, and the laying thickness of the filler is 90mm; the filler adopts the biochar with a particle size of 5-15mm, and the raw material of the biochar is branch.

[0101] A straw biochar particle preparation method for the above-mentioned biological treatment method, comprising the following steps: pyrolyzing a mixture of sorghum straw skin and sesame straw at 550 DEG C for 1.5 hours.

[0102] A biochar powder preparation method for the above-mentioned biological treatment method, comprising the following steps: pyrolyzing a mixture of rice straw and wheat straw at 450 DEG C for 2.0 hours to prepare, crushing to a particle size of less than 0.5mm, and mixing with 23% of carbon powder with a particle size of less than 0.5mm screened from woody biochar, wherein the woody biochar is prepared by pyrolyzing branch at 500 DEG C for 1.7 hours.

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

[0104] After the scheme of the embodiment is used for treatment, the soil moisture content is increased by 38.6%, the soil permeability (air permeability) is increased by 1.6 times, the total salt content is reduced by 40.6% in the first year, the total salt content is reduced by 86.9% of the initial value in the second year, the surface vegetation grows luxuriantly, and the biomass is increased by more than 2.3 times per year; the permeability coefficient of the impermeable layer 2 is less than 3x10 -11 m / s, the impermeability is strong; the collection pool 7 collects 209kg / 1000m 2 of salt (chloride salt, carbonate salt), and realizes resource utilization. Specific implementation method five:

[0106] Referring to Figs. 1-3Specifically illustrate the present embodiment. The structure for saline-alkali soil treatment described in the present embodiment specifically comprises a ploughing layer 1, an anti-seepage 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, the collection layer 3 is provided with a pipe network groove, and the pipe network groove is provided with a collection pipe network; the anti-seepage layer 2 is laid above the region in the collection layer 3 corresponding to the region in the collection pipe network, the anti-seepage layer 2 and the collection pipe network are laid above the ploughing layer 1; the thickness of the anti-seepage layer 2 in each grid is higher in the middle and lower at the four sides, and the slope surface is inclined toward the collection pipe network; one collection pool 7 is arranged at each adjacent two grid nodes of the collection pipe network, the collection pool 7 is arranged at the grid node position, and the plurality of collection pools 7 are communicated with the collection pipe network; the inner side wall 8 of the collection pool 7 is subjected to anti-seepage treatment, and the upper end penetrates through the ploughing layer 1 and is open.

[0107] The collection pipe network comprises a plurality of collection pipes 6, a part of the collection pipes 6 are arranged transversely, another part of the collection pipes 6 are arranged longitudinally, and the transversely arranged collection pipes 6 and the longitudinally arranged collection pipes 6 are connected; the spacing between two transversely adjacent collection pipes 6 is 3.5 m, the spacing between two longitudinally adjacent collection pipes 6 is 7.0 m; the transverse spacing between two adjacent collection pools 7 is 7.0 m, and the longitudinal spacing is 14 m; the collection pipes 6 are arranged in a buried manner, and the axis of the collection pipes 6 and the highest point of the anti-seepage layer 2 are on the same horizontal plane.

[0108] The collection pipes 6 adopt flower pipes, the material is polyvinyl chloride (PVC), the diameter is 200 mm, the hole diameter of the flower pipe wall is 15 mm, and the hole spacing is 8 mm; the flower pipe is wrapped with nylon net one, and the hole diameter of the nylon net one is 5 mm.

[0109] The anti-seepage layer 2 is inclined to the direction of the collection pipe 6, and the inclination is 0.7 ‰.

[0110] The anti-seepage pad layer 5 is arranged between the collection pipe 6 and the collection layer 3, the anti-seepage pad layer 5 is overlapped on both sides of the anti-seepage layer 2, and the overlapping length is 1.2 m; the anti-seepage pad layer 5 adopts sodium-based bentonite waterproof blanket, and the specification is 5100 g / m 2 .

[0111] The length of the collection pool 7 is 1.9 m, and the depth is 1.5 m; the thickness of the ploughing layer 1 is 450 mm.

[0112] A biological treatment method using the structure for saline-alkali soil treatment described above, comprising the following steps: after the plough layer 1 is cleaned, it is piled on one side, then the collection layer 3 and the impermeable layer 2 are laid in turn, while the collection pipe network and the collection pool 7 are laid; the impermeable layer 2 is made by mixing biochar powder, sodium-based bentonite, calcium-based bentonite, fly ash and saline-alkali soil, then adding water to moisten to a water content of 30.5%, uniformly mixing and then laying and rolling in layers, the first layer is laid to a thickness of 95mm, then each layer is laid to a thickness of 45mm, a total of 3 layers; the plough layer 1 is restored to its original position after mixing in straw particles, straw biochar particles, zeolite and diatomite; when the impermeable layer 2 leaks after the collection layer 3 has been in operation for more than 5 years, the collection layer 3 is removed and soaked in clean water for 16.5 hours, then the collection layer 3 is cleaned, the solution after soaking and the cleaning liquid are dried and evaporated to concentrate and crystallize the salts, then collected; the liquid in the collection pool 7 is collected every 2 months from March to October; the collected liquid is first filtered, then evaporated, concentrated and crystallized.

[0113] The particle size of the straw particles mixed in the plough layer 1 is 10-20mm, and the mixing amount is 0.18kg / m 2 ; the particle size of the straw biochar particles is 1.0-5.0mm, and the mixing ratio in the plough layer 1 is 2.5%; the particle size of the zeolite is 1.0-5.0mm, and the particle size of the diatomite is 0.1-1.5mm; the addition amounts of the zeolite and the diatomite are 2.8% and 1.5% of the total mass of the soil in the plough layer 1, respectively.

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

[0115] The mixing mass ratio of the biochar powder, sodium-based bentonite, calcium-based bentonite, fly ash and saline-alkali soil in the impermeable layer 2 is 4.5:1.0:3.0:5.0:86.5; the viscosity of the sodium-based bentonite is greater than 60mPa·s, the sieve residue amount at 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%, 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), di-aluminum trioxide and di-iron trioxide 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 raw material of the biochar powder is a mixture of rice straw and wheat straw.

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

[0118] The collecting layer 3 is composed of nylon net 2 and fillers, the fillers are placed in the nylon net 2, the aperture of the nylon net 2 is 2-4 mm, and the laying thickness of the fillers is 60 mm; the fillers adopt biochar with a particle size of 5-15 mm, and the raw material of the biochar is wood.

[0119] A straw biochar particle preparation method for the above-mentioned biological treatment method, comprising the following steps: pyrolyzing a mixture of cotton straw and soybean straw at 550 DEG C for 1.5 hours.

[0120] A biochar powder preparation method for the above-mentioned biological treatment method, comprising the following steps: pyrolyzing a mixture of rice straw and wheat straw at 400 DEG C for 2.5 hours to prepare, crushing to a particle size of less than 0.5 mm, and mixing with 26% of wood biochar powder with a particle size of less than 0.5 mm, wherein the wood biochar is prepared by pyrolyzing branches at 520 DEG C for 1.6 hours.

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

[0122] After the scheme of the embodiment is used for treatment, the soil water content is increased by 36.3%, the soil permeability (air permeability) is increased by 2.3 times, the total salt content is reduced by 32.1% in the first year, and by 81.9% of the initial value in the second year, the surface vegetation grows luxuriantly, and the biomass is increased by more than 1.8 times per year; the permeability coefficient of the impermeable layer 2 is less than 5*10 -11 m / s, and the impermeability is strong; the collecting pool 7 collects 161.5 kg / 1000 m 2 of salt (chloride salt, carbonate salt), and realizes resource utilization.

[0123] In summary of the above-mentioned implementation cases, the structure and biological treatment method for saline-alkali soil treatment adopt a biological material composite preparation as an impermeable layer material, utilize the interaction of the biochar powder with high ash content, sodium-based bentonite, calcium-based bentonite, fly ash and clay particles in the saline-alkali soil to form a cohesive body, and under the action of rolling, the impermeability, strength and plasticity are significantly improved, and the permeability coefficient is less than 5*10 -11The layer is not easy to be damaged by plant roots; the added material is in small amount and is a conventional material, so the cost is low; the impermeable layer has good durability, the soil impermeable layer has 2-3 times higher impermeable capacity than the traditional method using only biochar, the cost is reduced by 50%, the durability is improved by more than 1 times, the salt in the saline-alkali soil layer is effectively prevented from returning, so that the salt content in the plough layer is continuously reduced, and the effective improvement of the soil in the layer is ensured;

[0124] The structure and biological treatment method for saline-alkali soil treatment can realize the collection of salt in the upper plough layer and the lower saline-alkali soil layer through the collection pipe network and the collection pool, and realize the permanent removal of harmful salts in the soil; the recovery of the collection layer is after long-term operation (more than 5 years), when the impermeable layer fails, the collection layer adsorbed crystalline salt is recovered as industrial raw materials when the impermeable layer is repaired; the collection layer has a strong physical and chemical adsorption effect on the salt components contained in the soil, and has a strong effect on removing the salts in the soil; the method uses cheap biomass materials to effectively repair the saline-alkali soil, without bringing new pollutants; the collection of salt can obtain high economic benefits, and solve the problem of shortage of related raw materials for industrial production;

[0125] The structure and biological treatment method for saline-alkali soil treatment can realize the collection of salt in the upper plough layer and the lower saline-alkali soil layer through the collection pipe network and the collection pool, and realize the permanent removal of harmful salts in the soil; the recovery of the collection layer is after long-term operation (more than 5 years), when the impermeable layer fails, the collection layer adsorbed crystalline salt is recovered as industrial raw materials when the impermeable layer is repaired; the collection layer has a strong physical and chemical adsorption effect on the salt components contained in the soil, and has a strong effect on removing the salts in the soil; the method uses cheap biomass materials to effectively repair the saline-alkali soil, without bringing new pollutants; the collection of salt can obtain high economic benefits, and solve the problem of shortage of related raw materials for industrial production;

[0126] The above specific embodiments further illustrate the purpose, technical solutions and advantages of the present application. It should be understood that the above description is only a specific embodiment of the present application and is not intended to limit the application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A structure for saline soil reclamation, characterized by: It comprises a ploughing layer (1), an anti-seepage layer (2), a collection layer (3) and a saline soil layer (4), the saline soil layer (4) is paved with the collection layer (3), the collection layer (3) is provided with a pipe network groove, and the pipe network groove is provided with a collection pipe network; the anti-seepage layer (2) is paved on the collection layer (3) corresponding to the area in the grid of the collection pipe network, the anti-seepage layer (2) and the collection pipe network are paved with the ploughing layer (1); the thickness of the anti-seepage layer (2) in each grid is high in the middle and low at the four sides, and the slope surface is inclined to the collection pipe network; one collection pool (7) is arranged at each adjacent two grid nodes of the collection pipe network, the collection pool (7) is arranged at the grid node position, and the plurality of collection pools (7) are communicated with the collection pipe network; the inner side wall (8) of the collection pool (7) is subjected to anti-seepage treatment, and the upper end penetrates through the ploughing layer (1) and is open; The collection pipe network comprises a plurality of collection pipes (6), a part of the collection pipes (6) are arranged transversely, another part of the collection pipes (6) are arranged longitudinally, the transversely arranged collection pipes (6) are connected with the longitudinally arranged collection pipes (6); the spacing between two transversely adjacent collection pipes (6) is 3.0-5.0 m, the spacing between two longitudinally adjacent collection pipes (6) is 6.0-10.0 m; the transverse spacing between two adjacent collection pools (7) is 6.0-10.0 m, and the longitudinal spacing is 12-20 m; the axis of the collection pipe (6) and the highest point of the anti-seepage layer (2) are on the same horizontal plane; The anti-seepage layer (2) has a slope towards the collection pipe (6), and the slope is 0.5-1.5 ‰; An anti-seepage cushion layer (5) is arranged between the collection pipe (6) and the collection layer (3), the anti-seepage cushion layer (5) is overlapped on both sides of the anti-seepage layer (2), and the overlapping length is 0.5-1.5 m; Straw particles, straw biochar particles, zeolite and diatomite are mixed in the ploughing layer (1); the anti-seepage layer (2) is formed by mixing biochar powder, sodium-based bentonite, calcium-based bentonite, fly ash and saline soil, and then adding water to increase the moisture content to 25-35%; the collection layer (3) is composed of nylon net two and a filler, the filler is arranged in the nylon net two, the aperture of the nylon net two is 2-4 mm, and the laying thickness of the filler is 50-100 mm; the filler adopts biochar with a particle size of 5-15 mm, and the raw material of the biochar is wood.

2. The structure for the treatment of saline soil according to claim 1, characterized in that: The collection pipe (6) adopts a flower pipe, the material is polyvinyl chloride, the diameter is 100-200 mm, the aperture of the flower pipe wall is 8-15 mm, and the hole spacing is 5-8 mm; the flower pipe is wrapped with nylon net one, and the aperture of the nylon net one is 2-5 mm.

3. The structure for the treatment of saline soil according to claim 1, characterized in that: The impermeable cushion (5) is made of sodium bentonite waterproof blanket with a specification of 4000g / m 2 -5500g / m 2 .

4. The structure for the management of saline soils according to claim 1, characterized in that: The side length of the collection pool (7) is 1.5-2.5 m, and the pool depth is 1.0-2.0 m; the thickness of the ploughing layer (1) is 300-600 mm.

5. A biological treatment method using the structure for the treatment of saline soil according to claim 1, characterized in that: It comprises the following steps: After the plough layer (1) is cleaned, it is stacked on one side, and then the collection layer (3) and the impermeable layer (2) are laid in turn, while the collection pipe network and the collection pool (7) are laid; the impermeable layer (2) is uniformly mixed and then laid in layers and rolled, the first layer is laid to a thickness of 80-100 mm, and then each layer is laid to a thickness of 40-50 mm, and a total of 2-3 layers are laid; the plough layer (1) is restored to the original position; when the impermeable 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; the solution after soaking and the cleaning liquid are dried and evaporated to concentrate and crystallize salts, 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.

6. The bio-remediation method of the structure for the treatment of saline soils according to claim 5, characterized in that: The particle size of the straw incorporated in the plough layer (1) is 10-20 mm, and the incorporation amount is 0.15-0.3 kg / m 2 The particle size of the straw biochar is 1.0-5.0 mm, and the incorporation ratio in the plough 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 diatomite is 0.1-1.5 mm; the addition amount of the zeolite and the diatomite is 0.5-5.0% and 0.5-3.0% of the total mass of the soil in the plough layer (1) respectively.

7. The bio-remediation method of the structure for the treatment of saline soils according to claim 6, characterized in that: The raw material of the straw biochar particles is a mixture of one or more of the husks of corn stalks, the husks of sorghum stalks, sesame stalks, cotton stalks, sunflower stalks and soybean stalks.

8. The bio-remediation method of the structure for the treatment of saline soils according to claim 5, characterized in that: The mixed mass ratio of the biochar powder, sodium-based bentonite, calcium-based bentonite, fly ash and saline-alkali soil in the anti-infiltration layer (2) is 3:0.5:1.0:2.0:93.5-6.5:1.5:3.5:6.5:82; the sodium-based bentonite has a viscosity greater than 60 mPa·s, a 75 μm particle size screen residue less than 1.5%, and a filtration loss less than 14 cm 3 ; the fly ash has a fineness less than 30%, a loss on ignition less than 8.0%; the total mass fraction of silicon dioxide, diatomic aluminum oxide and diatomic 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%.

9. The bio-remediation method of the structure for the treatment of saline soils according to claim 8, characterized in that: The raw material of the biochar powder is a mixture of one or more of the pith of corn stalks, rice straw and wheat straw.

10. The bio-remediation method of the structure for the treatment of saline soils according to claim 5, characterized in that: The rolling pressure of the impermeable layer (2) is 50-150 kPa, and the compaction coefficient is 0.92-0.

96.

11. A method for preparing the straw biochar granules for use in the biological control method of claim 7, characterized in that: The method comprises the following steps: The mixture of one or more of the husks of corn stalks, the husks of sorghum stalks, sesame stalks, cotton stalks, sunflower stalks and soybean stalks is pyrolyzed at 400-600℃ for 1.0-3.0 hours to prepare.

12. A method for preparing biochar powder for use in the bio-remediation method of claim 9, the method comprising: The method comprises the following steps: The mixture of one or more of the pith of corn stalks, rice straw and wheat straw is pyrolyzed at 350-550℃ for 1.0-3.5 hours to prepare, and then crushed to a particle size of less than 0.5 mm, while mixing in 15-35% of carbon powder with a particle size of less than 0.5 mm sieved from woody biochar; the woody biochar is prepared by pyrolyzing wood at 450-550℃ for 1.5-2.0 hours. ​ 13. A method for preparing a filler for use in the bio-remediation method of claim 5, characterized by: The method comprises the following steps: The raw material of the filler biochar in the collection layer (3) is first pyrolyzed at 550-650℃ for 1.5-2.5 hours to prepare; then it is modified by 0.05-0.2 mol / L potassium hydroxide for 24-48 hours, washed to neutral, and then modified by a mixture of 0.001-0.05 mol / L potassium permanganate and 0.005-0.05 mol / L nitric acid for 24-72 hours, washed clean and dried; finally, it is soaked in a mixture of 1.5-6.5% sodium-based bentonite and 1.0-4.0% calcium-based bentonite for 20-50 hours, washed and dried to prepare.

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