Solid waste landfill crack combination self-repairing material based on microbial mineralization and application

Abstract

The invention discloses a solid waste landfill crack combination self-repairing material based on microbial mineralization and application, and belongs to the field of environmental geotechnical engineering. The method comprises the steps that firstly, a klebsiella liquid and a calcium source cementing liquid are prepared, grouting holes are formed in the side slope, the bacterial liquid and the cementing liquid are injected in batches, and internal cracks are filled with a microorganism induced calcium carbonate precipitation (MICP) technology; and then, a fiber reinforced guniting material formed by compounding field soil, active magnesium oxide and chopped fibers is adopted to spray and cover the surface layer of the slope, and a compact sealing layer is formed through carbon dioxide carbonization. By combining internal MICP curing and surface layer fiber reinforced magnesium oxide carbonization sealing, a synergistic protection system with strong inside and tough outside is constructed, the anti-permeability and stability of the slope are improved, meanwhile, the toughness, crack resistance and long-term durability of a surface layer sealing layer are remarkably enhanced, and the service life of the slope is prolonged. And the method is particularly suitable for slope treatment of projects with high anti-seepage requirements such as solid waste landfills and the like.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of environmental geotechnical engineering and solid waste landfill disposal technology, and particularly relates to a material and construction method for repairing internal fissures of a solid waste landfill slope by using a microbial-induced calcium carbonate precipitation technology. BACKGROUND

[0002] The long-term stability and impermeability of engineering slopes such as solid waste landfills and tailing ponds are directly related to the surrounding ecological environment and public safety. During the operation period and after the closure of such slopes, due to the physical and chemical effects of self-compression of the fill, chemical corrosion of leachate, dry-wet cycle, and freeze-thaw cycle, non-uniform fissure networks will gradually develop inside the slope, and a large number of shrinkage microcracks will occur on the surface. These fissures become preferential channels for leachate discharge and precipitation intrusion, not only exacerbating the risk of slope instability, but also possibly leading to serious soil and groundwater pollution.

[0003] At present, the repair and reinforcement of such slopes or foundations mainly rely on traditional cement-based materials:

[0004] Cement grouting technology: widely used for reinforcing deep soil. However, this technology has obvious limitations when used to treat solid waste landfill slopes: (1) poor permeability: the high viscosity and large particle size of cement slurry make it difficult to effectively penetrate and fill micron-sized fissures (usually less than 0.1 mm in width) in soil-rock mixtures, resulting in blind areas in repair and forming potential seepage paths. (2) poor environmental compatibility: the high alkalinity (pH>12) of cement can change the local geochemical environment of the site, and even have adverse reactions with leachate, posing a potential risk of pollution spread. (3) high carbon footprint: cement production is one of the world's major sources of carbon dioxide emissions, which is contrary to the current green, low-carbon environmental protection concept.

[0005] Cement mortar surface layer spraying: used for preventing surface erosion. However, the rigid coating has poor deformation coordination ability with flexible soil slopes, and is prone to brittle cracking and failure under the action of continuous uneven settlement, and also has the problems of high energy consumption and high emission.

[0006] In recent years, the emerging microbial induced carbonate precipitation (MICP) technology provides a new idea for soil reinforcement. This technology uses the enzymatic action of Klebsiella bacteria and other microorganisms to promote the hydrolysis of urea to generate carbonate ions, which combine with calcium ions in the environment to form calcium carbonate precipitation, thereby cementing soil particles and filling pores. The MICP technology has excellent slurry fluidity, can effectively penetrate into micro-fissures, and has mild reaction conditions and environmentally friendly products. However, the application of MICP technology alone to the repair of solid waste landfill slope still faces challenges: (1) surface layer vulnerability: the calcium carbonate cementation layer formed by MICP on the surface layer of the slope is relatively weak and can be easily eroded under direct exposure conditions such as rainwater erosion and solar weathering, making it difficult to maintain good impermeability for a long time. (2) repair depth and uniformity control: in unsaturated and heterogeneous landfill slopes, the migration and distribution of bacteria and cementing liquid are difficult to control accurately, which may result in uneven repair effect.

[0007] On the other hand, active magnesium oxide (MgO) carbonization solidification technology also shows potential as a low-carbon cementitious material. MgO reacts with water to form magnesium hydroxide, which then carbonizes with carbon dioxide to form magnesium carbonate compounds with high strength and good stability. This process can consume industrial carbon dioxide and achieve carbon sequestration. However, if this technology is used alone to treat loose and multi-fissured internal slopes, the slurry is difficult to penetrate over long distances, making it less economical. In addition, although the existing magnesium oxide carbonization shotcrete layer has a certain strength, it is relatively brittle and lacks the ability to coordinate deformation with the soil. Under the possible uneven settlement or dry-wet cycle of the slope, the shotcrete layer is still prone to shrinkage or stress cracks, affecting the stability of its long-term sealing effect. Therefore, there is an urgent need for a comprehensive repair method that can further improve the toughness and crack resistance of the surface sealing layer.

[0008] Therefore, the prior art lacks a comprehensive repair method that can efficiently fill internal micro-fissures and long-term durable seal the surface layer while meeting the requirements of environmental friendliness and low carbon emissions. The present invention is proposed in this context, aiming to overcome the limitations of the above-mentioned single MICP or MgO technology. SUMMARY

[0009] The present invention aims to provide a solid waste landfill fissure combined self-repairing material based on microbial mineralization, which fills internal fissures of the slope through the microbial induced carbonate precipitation (MICP) technology and seals the surface micro-fissures by combining the magnesium oxide (MgO) carbonization technology, forming a "internal-external coordination, double protection" repair system to achieve three-dimensional, green and long-term repair of the slope.

[0010] Another object of the present invention is to provide the application of the above-mentioned solid waste landfill fissure combined self-repairing material.

[0011] In order to achieve the above-mentioned object of the present application, the present application is based on a microbial mineralization solid waste landfill fissure combined self-repairing material, which is characterized by comprising a microbial repairing material and a surface sealing material:

[0012] The microbial repairing material comprises a bacterial solution and a cementing solution: Klebsiella is used as a bacterial strain, and is cultured in a calcification experimental medium in a constant-temperature oscillation incubator at 25-35°C and 200-330 rpm for 36-75 hours to obtain a high-activity bacterial solution; meanwhile, the cementing solution is prepared by mixing calcium chloride and urea at a molar ratio of 1:(0.8-1.2) to obtain a cementing solution with a mass concentration of 0.8%-3.0%.

[0013] The surface sealing material is prepared by using on-site soil as a main raw material, drying, crushing, and then passing through a 5-10 mm sieve to obtain a dry on-site soil; drying active magnesium oxide, passing through a 5-8 mm sieve, and then mixing and stirring the sieve underpart with the dry on-site soil, chopped fibers and water in a proportion to prepare a fiber-reinforced magnesium oxide carbonization grouting liquid; the mass ratio of magnesium oxide dry powder, water and dry on-site soil is (20-25):(25-30):100, and the content of the chopped fibers is 0.2%-0.5% of the mass of the dry on-site soil.

[0014] Preferably, the length of the chopped fibers is 8-15 mm to ensure that the repair range covers the potential sliding surface.

[0015] Preferably, Klebsiella is used as a bacterial strain, and is cultured in a calcification experimental medium in a constant-temperature oscillation incubator at 28-32°C and 220-320 rpm for 48-72 hours to obtain a high-activity bacterial solution; meanwhile, the cementing solution is prepared by mixing calcium chloride and urea at a molar ratio of 1:1 to obtain a cementing solution with a mass concentration of 2.0%.

[0016] Preferably, the culture solution of the calcification experimental medium comprises 17.0-18.5 g / L calcium acetate, 3.8-4.3 g / L yeast powder, and pH=7.

[0017] Further, the culture solution of the calcification experimental medium comprises 17.5 g / L calcium acetate, 4 g / L yeast powder, and pH=7.

[0018] The application of the microbial mineralization solid waste landfill fissure combined self-repairing material is implemented by the following steps:

[0019] 1) Grouting network layout: grouting holes are laid out on the slope surface of the main body of the solid waste landfill slope to be repaired according to the designed grid spacing, and grouting pipes are embedded in the grouting holes to form an internal grouting pipe network.

[0020] 2) Microbial grouting: adopt the grouting strategy of "bacteria first, glue second, batch standing", inject bacteria liquid and cementing liquid into the interior of the main body of the solid waste landfill site slope through the grouting pipe in turn, carry out a repair cycle, the repair cycle includes injecting bacteria liquid, standing, injecting cementing liquid again, and standing again; after the repair cycle, repeat the repair cycle 2-5 times again after 24-48 hours, and finally form a microbial mineralization filling area.

[0021] 3) Repair effect test: take the permeability coefficient as the core acceptance index, the permeability coefficient δ1 of the soil sample in the interior of the main body of the solid waste landfill site slope after microbial grouting repair needs to be reduced to 10 -7 cm / s or less to ensure that the anti-permeability ability is significantly improved; if δ1 > 1×10 -7 cm / s, return to step 2) to re-supplement microbial grouting repair.

[0022] 4) Surface fissure sealing repair: use a shotcreting device to uniformly spray the fiber-reinforced magnesium oxide carbonization shotcreting liquid on the slope surface of the main body of the solid waste landfill site slope to form a sprayed layer; then cover a gas-impermeable sealing film and insert a carbon dioxide aeration pipe, and introduce carbon dioxide gas into the sealing film to carry out carbonization reaction for 24-48 hours, and finally form a magnesium oxide carbonization shotcreting sealing layer; under this condition, magnesium hydroxide in the slurry reacts with carbon dioxide to generate magnesium carbonate crystals with strong cementation ability, further reducing the surface porosity and blocking the rainfall infiltration path.

[0023] 5) Surface repair effect test: sample the formed magnesium oxide carbonization shotcreting sealing layer, measure the soil sample permeability coefficient δ2, if δ2 > 1×10 -7 cm / s, return to step 4) to re-perform surface fissure sealing repair; if δ2 ≤ 1×10 -7 cm / s, the surface fissure sealing repair is completed.

[0024] Preferably, the grouting holes are arranged in multiple rows parallel to the slope top of the main body of the solid waste landfill site, the row spacing is 5-7 meters, the spacing between the grouting holes in the same row is 2-3 meters, and the depth of the grouting hole is 6-10 meters.

[0025] Preferably, the sealing film is a black plastic film, and the mass concentration of carbon dioxide gas introduced into the sealing film is ≥99%.

[0026] Compared with the prior art, the crack combination self-repairing material based on microbial mineralization of the solid waste landfill site and the application adopt the technical scheme, through internal MICP solidification and surface fiber reinforced magnesium oxide carbonization sealing combination, a synergistic protection system of "internal strength and external toughness" is constructed, which improves the impermeability and stability of the slope, significantly enhances the toughness, crack resistance and long-term durability of the surface sealing layer, and is especially suitable for the engineering slope treatment of solid waste landfill site and other high impermeability requirements. Specific positive effects are as follows:

[0027] (1) Strong pertinence: the characteristics of good flowability and small particle size of microbial mineralization products are used to accurately repair micron-sized cracks that cement slurry cannot reach.

[0028] (2) Green and low carbon: the microbial mineralization process has mild conditions, and the magnesium oxide carbonization process can actively consume industrial CO2, realizing the carbon solidification effect of consuming industrial carbon dioxide, and having significant environmental benefits.

[0029] (3) Synergistic effect: internal microbial solidification and surface magnesium oxide carbonization sealing combination form a three-dimensional protection system from macro to micro and from inside to surface, which significantly improves the long-term stability and impermeability of the slope.

[0030] (4) Toughness and durability improvement: by adding PP fiber to the magnesium oxide spraying liquid, the bridging and crack resistance of the fiber are used to significantly improve the tensile strength and toughness of the surface sealing layer, so that it can better adapt to the small deformation of the slope without cracking, thereby ensuring the stability of the long-term impermeability effect, and forming a synergistic protection system of rigidity and flexibility with internal MICP repair. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 It is the internal grouting area of the solid waste landfill site slope repair structure schematic diagram in the application.

[0032] Figure 2 It is the surface sealing layer of the solid waste landfill site slope repair structure schematic diagram in the application.

[0033] The figure mark is: 1-solid waste landfill site slope main body; 2-internal grouting pipe network; 3-microbial mineralization filling area (internal repair area); 4-magnesium oxide carbonization spraying sealing layer (surface repair area); 5-sealing film; 6-carbon dioxide vent pipe. DETAILED DESCRIPTION

[0034] The application of the microbial mineralization-based solid waste landfill fissure combined self-repairing material will be further described in detail below in combination with the drawings and examples. However, the protection scope of the present application is not limited thereto. Those skilled in the art will understand that the following examples are only used for illustrating the present application and should not be regarded as limiting the scope of the present application. The specific conditions and parameters not mentioned in the examples are carried out according to the conventional conditions or the conditions suggested by the actual operators on site. The reagents, instruments and equipment used are all commercially available goods in the market.

[0035] This example takes a high slope repair project of a solid waste landfill in Anhui Province as the application scenario. The slope is mainly composed of miscellaneous fill, construction waste and silty clay mixed and stacked, with a height of about 20 meters, internal fissures development, and a large number of microcracks on the surface under the action of dry-wet cycle, with the risk of leachate leakage and stability.

[0036] The microbial mineralization-based solid waste landfill fissure combined self-repairing material of the present application comprises a microbial repair material and a surface sealing material.

[0037] (1) Preparation of microbial repair material

[0038] The microbial repair material comprises a bacterial solution and a cementing solution.

[0039] Preparation of bacterial solution: The calcification experiment culture solution recommended by the American Type Culture Collection (ATCC) is used, and the specific composition is: 17.5 g / L calcium acetate, 4 g / L yeast powder, pH = 7. The prepared culture solution is sterilized at 121℃ for 20 minutes, and then placed on an ultra-clean bench to cool to room temperature for standby.

[0040] Take 500 mL of sterile culture solution and place it in a 1 L conical flask. Use a sterile pipette to add 5 mL of Klebsiella original bacterial solution (volume ratio 1:100) in the ultra-clean bench. Then put the conical flask into a constant temperature shaking incubator and shake at 30℃ and 250 rpm for 60 hours to obtain a high-activity Klebsiella bacterial solution.

[0041] Preparation of cementing solution: Take analytical pure calcium chloride (CaCl2) and urea (CO(NH2)2) and weigh them according to a molar ratio of 1:1, dissolve them in deionized water, and fully stir until completely dissolved to prepare a mixed cementing solution with a total mass concentration of 2.0% of CaCl2 and urea.

[0042] (2) Preparation of surface sealing material

[0043] Take soil from the site to be repaired, remove the surface weeds and stones, dry, crush and pass through a 5mm sieve to obtain the dry soil under the sieve.

[0044] Industrial-grade active magnesium oxide (MgO) was dried in an oven at 105°C for 2 hours, and then passed through a 5 mm sieve to obtain magnesium oxide dry powder.

[0045] Preparation of fiber-reinforced magnesium oxide carbonization grouting liquid: the raw materials were prepared according to the mass ratio of magnesium oxide dry powder: water: field dry soil = 20:25:100. At the same time, 0.3% of short polypropylene (PP) fibers by mass of the field dry soil were added, and the fiber length was 12 mm.

[0046] Mixing process: first, the magnesium oxide dry powder, field dry soil and short polypropylene (PP) fibers were dry-mixed in a blender for 3 minutes to ensure that the fibers were evenly dispersed in the dry material without clumping. Then, the specified amount of water was slowly added and wet-mixed for 5 minutes until a fiber-reinforced magnesium oxide carbonization grouting liquid with uniform color and good workability was formed.

[0047] Combining Figure 1 The internal grouting area and the surface sealing layer of the solid waste landfill slope repair structure schematic diagram of the application are shown in the figure. Figure 2 The application of the solid waste landfill fissure combined self-repairing material based on microbial mineralization is characterized by the following steps:

[0048] 1) Grouting network layout: a rectangular grid of grouting holes is laid out on the slope surface of the solid waste landfill slope main body 1 to be repaired, and grouting pipes are embedded in the grouting holes to form an internal grouting pipe network 2. The grouting holes are arranged in multiple rows parallel to the slope top of the solid waste landfill slope main body 1, with a row spacing of 5-7 meters and a hole spacing of 2-3 meters in the same row. The grouting hole depth is 6-10 meters. In the industrial test site, 5 rows of grouting holes (N=5) were arranged with a row spacing of 5 meters, and 6 grouting holes (M=6) were arranged in each row with a hole spacing of 2 meters. The grouting hole depth is 8 meters. After the hole is formed by a drilling machine, a special grouting pipe is immediately embedded and the hole is sealed.

[0049] 2) Microbial grouting: using the "bacteria first, glue second, batch standing" grouting strategy, the bacteria solution and the cementing liquid are injected into the interior of the solid waste landfill slope main body 1 through the grouting pipe to carry out a repair cycle. The repair cycle includes injecting bacteria solution, standing, injecting cementing liquid again, and standing again. After the first repair cycle, the repair cycle is repeated 2-5 times with an interval of 24-48 hours, and finally a microbial mineralization filling area 3 is formed.

[0050] In the industrial application site, define a one-time repair cycle as follows: first, inject microbial liquid into all 30 (M x N = 30) grouting pipes at the same time, about 26.7 liters (about 800 liters in total) per grouting hole, and then stand for 4 hours; then, inject a cementing liquid with the same volume as the microbial liquid into all the grouting pipes (26.7 liters per hole, a total of 800 liters), and stand for another 4 hours.

[0051] In this embodiment, the above repair cycle is performed every 36 hours, a total of 3 times, to accumulate a sufficient amount of calcium carbonate precipitation in the internal cracks of the slope.

[0052] 3) Repair effect test: take the permeability coefficient as the core acceptance index, the permeability coefficient δ1 of the soil sample after microbial grouting repair in the main body 1 of the solid waste landfill slope needs to be reduced to 10 -7 cm / s; if δ1 > 1 x 10 -7 cm / s, return to step 2) and re-supplement microbial grouting repair.

[0053] In this embodiment, 7 days after the end of microbial mineralization filling, a thin-walled soil sampler is used to drill and sample in the repair area, the obtained soil sample is marked as "crack solidified soil sample", and immediately sealed with plastic wrap and adhesive tape and taken back to the laboratory.

[0054] According to the variable water head permeability test method in the "Standard for Soil Test Methods" (GB / T 50123-2019), the average permeability coefficient δ1 of the soil sample is measured to be 5.6 x 10 -8 cm / s, the order of magnitude is less than 10 -7 cm / s, which meets the internal repair requirements and can proceed to the next step of surface repair.

[0055] 4) Surface crack sealing repair: use a hydraulic mortar sprayer to uniformly and layer-by-layer spray the fiber-reinforced magnesium oxide carbonized mortar to the slope surface of the solid waste landfill slope main body 1, uniformly covering the entire surface of the slope, and control the total thickness of the sprayed layer to be 3-5 cm; then cover the non-airtight sealing film 5 to tightly cover the entire surface of the slope, and press the film around with soil and rock.

[0056] Then, several carbon dioxide gas pipes 6 are inserted into the sealing film 5, a carbon dioxide (CO2) cylinder is connected to the carbon dioxide gas pipes 6, and carbon dioxide gas with a mass concentration of ≥99% is introduced into the sealing film 5 for carbonation reaction for 36 hours to form a magnesium oxide carbonized mortar sealing layer 4, and the sealing film 5 is a black plastic film.

[0057] 5) Surface repair effect test: sample the formed magnesium oxide carbonized mortar sealing layer 4, measure the permeability coefficient δ2 of the soil sample, and if δ2 > 1 x 10 -7cm / s, return to step 4) to re-perform surface fissure sealing and repairing; if δ2≤1×10 -7 cm / s, surface fissure sealing and repairing is completed.

[0058] The average permeability coefficient δ2 of the surface soil sample measured in the field is 3.2×10 -8 cm / s, and the order of magnitude is less than 10 -7 cm / s. At the same time, field observation shows that a dense, continuous, and hard shell without visible cracks is formed on the surface.

[0059] After the treatment by the method, the internal fissures and surface micro-cracks of the solid waste landfill slope are effectively repaired. The final test results show that the permeability coefficients of the internal and surface are reduced to below 10 -7 cm / s, reaching an excellent impermeability level. In addition, the surface sealing layer with PP fibers shows good integrity and does not appear any cracking in the subsequent three-month rainy season observation, proving its excellent toughness and durability. The invention successfully realizes the stereoscopic, green, and long-acting repair of the solid waste landfill slope.

Claims

1. A microbial-mineralization-based solid waste landfill fissure assembly self- healing material, characterized in that The application relates to a microbial repair material and a surface sealing material. The microbial repair material comprises bacteria liquid and cementing liquid; Klebsiella is used as a bacterial strain, the bacteria liquid with high activity is obtained by culturing the Klebsiella in a calcification experimental culture medium in a constant-temperature oscillation incubator at 25-35 DEG C and 200-330 rpm for 36-75 hours, and meanwhile, the cementing liquid with a mass concentration of 0.8%-3.0% and composed of calcium chloride and urea in a molar ratio of 1:(0.8-1.2) is prepared. The surface sealing material is prepared by using on-site soil as a main raw material, drying, crushing and then screening through a 5-10mm sieve, so that the screened part is on-site dry soil; the active magnesium oxide is dried, screened through a 5-8mm sieve, and then mixed with the on-site dry soil, chopped fibers and water in a certain proportion to prepare a fiber-reinforced magnesium oxide carbonization shotcreting liquid; the mass ratio of the magnesium oxide dry powder, water and on-site dry soil is (20-25):(25-30):100, and the content of the chopped fibers is 0.2%-0.5% of the on-site dry soil.

2. The microbially-mineralization based solid waste landfill fissure pack combined self-healing material according to claim 1, characterized in that: The length of the chopped fibers is 8-15mm.

3. The microbially-mineralized-based self-healing material for solid waste landfill fissure assembly according to claim 1, characterized in that: The bacteria liquid with high activity is obtained by culturing Klebsiella in a calcification experimental culture medium in a constant-temperature oscillation incubator at 28-32 DEG C and 220-320 rpm for 48-72 hours, and meanwhile, the cementing liquid with a mass concentration of 2.0% and composed of calcium chloride and urea in a molar ratio of 1:1 is prepared.

4. The microbially-mineralized-based solid waste landfill fissure pack combined self- repair material of claim 1, wherein: The culture solution of the calcification experimental culture medium comprises 17.0-18.5g / L calcium acetate and 3.8-4.3g / L yeast powder, and the pH value is 7.

5. The microbially-mineralized-based solid waste landfill fissure pack combined self- repair material of claim 1, wherein The culture solution of the calcification experimental culture medium comprises 17.5g / L calcium acetate and 4g / L yeast powder, and the pH value is 7.

6. Use of a microbially mineralized-based self-healing material for solid waste landfill fissures according to claim 1, 2, 3, 4 or 5, characterized in that The following steps are adopted: 1) grouting network layout: grouting holes are laid on the slope surface of the solid waste landfill slope main body (1) according to the designed grid spacing, and grouting pipes are embedded in the grouting holes to form an internal grouting pipe network (2); 2) microbial grouting: a "bacteria first and then cement, batch standing" grouting strategy is adopted, the bacteria liquid and the cementing liquid are injected into the internal part of the solid waste landfill slope main body (1) through the grouting pipes in sequence to carry out a repair cycle, the repair cycle comprises injecting the bacteria liquid, standing, injecting the cementing liquid again, and standing again; after the repair cycle, 24-48 hours are waited, and the repair cycle is repeated 2-5 times, and finally a microbial mineralization filling area (3) is formed; 3) Repair effect test: take the permeability coefficient as the core acceptance index, the permeability coefficient δ1 of the soil sample in the main body (1) of the solid waste landfill site after microbial grouting repair needs to be reduced to 10 -7 cm / s or less; if δ1 > 1×10 -7 cm / s, return to step 2) to re-supplement microbial grouting repair; 4) surface fissure sealing repair: the fiber-reinforced magnesium oxide carbonization shotcreting liquid is uniformly sprayed on the slope surface of the solid waste landfill slope main body (1) by using a shotcreting device to form a sprayed layer; then, a gas-impermeable sealing film (5) is covered and a carbon dioxide aeration pipe (6) is inserted, and carbon dioxide gas is introduced into the sealing film (5) to carry out a carbonization reaction for 24-48 hours, and finally a magnesium oxide carbonization shotcreting sealing layer (4) is formed; 5) Surface repair effect test: sample the formed magnesium oxide carbonized sprayed sealing layer (4), measure the soil sample permeability coefficient δ2, if δ2 > 1×10 -7 cm / s, return to step 4) to re-perform surface fissure sealing repair; if δ2 ≤ 1×10 -7 cm / s, the surface fissure sealing repair is completed.

7. Use of a microbial-mineralization-based fissure-packaged self-healing material for solid waste landfills according to claim 6, characterized in that: The grouting holes are arranged in multiple rows in the direction parallel to the slope top of the solid waste landfill slope main body (1), the row spacing is 5-7m, the spacing between the grouting holes in the same row is 2-3m, and the depth of the grouting holes is 6-10m.

8. Use of a microbial-mineralization-based fissure-packaged self-healing material for solid waste landfills according to claim 7, characterized in that: The sealing film (5) is a black plastic film, and carbon dioxide gas with a mass concentration of greater than or equal to 99% is introduced into the sealing film (5).

9. Use of a microbial-mineralization-based fissure-packaged self-healing material for solid waste landfills according to claim 8, characterized in that: In step 4), the thickness of the sprayed layer is controlled to be 3-5 cm.

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