Microbial solidification sand barrier and preparation method thereof

Abstract

The invention provides a microbial solidified sand barrier and a preparation method thereof, a cementing liquid and a microbial liquid are respectively added into aeolian sandy soil, the aeolian sandy soil is treated by a microbial induced calcium carbonate precipitation technology, and then the aeolian sandy soil is dried and solidified at a high temperature to obtain the microbial solidified sand barrier. The aeolian sandy soil is a basic material, the microbial liquid contains active microorganisms capable of inducing calcium carbonate precipitation, and the cementing liquid provides a calcium source and promotes a precipitation reaction. The cementing liquid comprises a soluble calcium source and urea, the microbial liquid is bacillus pasteurii liquid, calcium carbonate precipitation is induced in the aeolian sandy soil by means of metabolic activity of specific microorganisms, so that sandy soil is solidified, a firm sand barrier is formed, more efficient and environment-friendly wind and sand control is achieved, the wind erosion resistance of the aeolian sandy soil can be remarkably improved, and the service life of the aeolian sandy soil is prolonged. A new solution is provided for wind and sand disaster prevention and control in arid and semi-arid areas, and the defects of an existing sand stabilization technology are effectively overcome.

Description

Technical Field

[0001] The invention belongs to the technical field of windbreak and sand fixation, and relates to a microbial sand fixation barrier and a preparation method thereof. Background Art

[0002] Aeolian sandy soil is mainly distributed in arid and semi-arid areas. Due to its loose structure, large pores, dry climate and wind action, it is very easy to cause natural disasters such as wind erosion and sandstorms. These disasters not only damage the local ecological environment, but also seriously affect the production and life of surrounding areas. At present, commonly used sand fixation technologies include physical barriers (such as grass grids, nylon nets, vegetation coverage, etc.), chemical solidification (using adhesives) and biological measures (planting vegetation). However, these methods have certain limitations. For example, although the cost of physical sand fixation methods is relatively low, they are easily damaged by wind erosion and sandstorms and require frequent maintenance and replacement. Chemical sand fixation methods, chemical curing agents may pollute the environment, and the cost is high, and the durability of the curing effect remains to be verified. Biological sand fixation methods rely on the growth of plants, but this method has limited effect in arid and nutrient-poor soils, and the growth cycle is long, so it is difficult to see results in the short term. In recent years, with the development of microbial technology, microbial induced calcium carbonate precipitation (MICP) has attracted attention as a new sand fixation technology. MICP technology induces the precipitation of minerals such as calcium carbonate in sandy soil through the metabolic activities of specific microorganisms, thereby enhancing the stability of sandy soil. This technology has the advantages of being environmentally friendly, low-cost, and easy to operate, and provides a new idea for the solidification of aeolian sandy soil. Although MICP technology has shown good results under laboratory conditions, it still faces many challenges in practical applications, such as the stability of the solidification effect, the feasibility of large-scale application, and adaptability under different environmental conditions. In addition, how to combine MICP technology with existing sand fixation measures to improve the sand fixation effect while reducing the impact on the environment is also a hot issue in current research. Summary of the invention

[0003] In response to the problems existing in the prior art, the present invention provides a microbial sand barrier and a preparation method thereof to achieve more efficient and environmentally friendly sand control, which can significantly improve the wind erosion resistance of sandy soil, provide a new solution for the prevention and control of sand disasters in arid and semi-arid areas, and effectively solve the shortcomings of existing sand fixation technology.

[0004] The present invention is achieved through the following technical solutions: A method for preparing a microbial solidified sand barrier, comprising: A binder and a microbial liquid are added to the sandy soil respectively, and after being treated by microbial induced calcium carbonate precipitation technology, the sand barrier is obtained by drying and solidifying at high temperature. The cementing liquid includes a soluble calcium source and urea, and the microbial bacterial liquid is a Bacillus pasteurianus bacterial liquid; the concentration of the cementing liquid is 1.5-2.0 mol / L; The Bacillus pasteurianus bacterial liquid is obtained by culturing in CASO AGAR medium at a constant temperature of 30° C. and 200 rpm for 48 hours; Each liter of CASO AGAR medium contains 20 g urea, 15 g casein peptone, 5 g soy peptone, 5 g NaCl, 20 g agar, and the rest is H 2 O.

[0005] The specific culture process of Bacillus pasteurianus liquid is as follows: Before culturing, the CASO AGAR medium was sterilized at 121°C for 20 minutes, and then inoculated with the CASO AGAR medium after cooling. The inoculated CASO AGAR medium was shaken and cultured in a constant temperature shaker at 30°C and 200 rpm for 48 hours; During the culture period, the OD of the bacterial solution in the culture medium was measured every two hours. 600 value and pH value to monitor the growth of Bacillus pasteurianus; After the culture is completed, if the culture medium changes from transparent to turbid and there are no foreign bacteria, it indicates that the bacteria are successfully activated and the Bacillus pasteurianus bacterial solution is obtained, which is refrigerated at 4°C for later use.

[0006] Preferably, the specific preparation process of the microbial solidified sand barrier is: The collected sandy soil was sieved to remove impurities, filled into the solidification model, and non-woven fabric was laid on the surface; then the microbial liquid was added by spraying, and the liquid at the bottom of the solidification model was released after standing for 2 hours; then the cementing liquid was added, and the liquid at the bottom of the solidification model was solidified after standing for 2 hours, and the obtained solidified sample was placed for 48 hours and naturally air-dried to obtain the microbial solidified sand barrier; The capacity of the solidification model is 0.012 cubic meters, the amount of microbial liquid added is 4.8 L, and the amount of cementing liquid added is 4.8 L.

[0007] Preferably, the five sides of the curing model are closed, the top is open and the bottom is perforated; before curing, the small holes are sealed with sealing plugs, and non-woven fabric is laid on the bottom of the curing model.

[0008] Preferably, the soluble calcium source is calcium chloride.

[0009] Preferably, the surface of the microbial solidified sand barrier is provided with a rough surface or a groove; the microbial solidified sand barrier is in the shape of a long strip or a grid.

[0010] Preferably, the wax sealing method is used to measure the dry density of the microbial solidified sand barrier.

[0011] Preferably, the microbial solidified sand barriers are arranged at intervals of 3-5m.

[0012] A microbial solidified sand barrier is prepared based on the preparation method of the microbial solidified sand barrier.

[0013] Compared with the prior art, the present invention has the following beneficial technical effects: The present invention discloses a microbial sand barrier solidified by microbial induced calcium carbonate precipitation (MICP) technology and a preparation method thereof. A binder and a microbial culture solution are added to the sandy soil respectively, and after being treated by the microbial induced calcium carbonate precipitation technology, the sand barrier solidified by microbial solidification is obtained after being dried and solidified at high temperature. The sandy soil is the basic material, the microbial culture solution contains active microorganisms that can induce calcium carbonate precipitation, and the binder provides a calcium source and promotes the precipitation reaction. The metabolic activities of specific microorganisms are used to induce calcium carbonate precipitation in the sandy soil, thereby solidifying the sand and forming a solid sand barrier to improve its wind erosion resistance. This is the first attempt to apply the microbial induced calcium carbonate precipitation (MICP) technology in the field of sand fixation. Compared with traditional methods, the microbial sand barrier solidification has absolute advantages in environmental friendliness, cost-effectiveness, rapid results, and enhanced stability.

[0014] Furthermore, the microorganisms and chemicals used in the present invention are environmentally friendly and will not have a negative impact on the surrounding ecosystem. Compared with traditional chemical sand fixation methods, the risk of chemical pollution is avoided.

[0015] Furthermore, the present invention utilizes MICP technology to directly induce the precipitation of calcium carbonate in aeolian sandy soil without the need to add a large amount of chemical curing agents or frequently replace physical barrier materials, thereby reducing material and maintenance costs.

[0016] Furthermore, the sand barrier solidified by the present invention has a higher dry density and calcium carbonate content, which significantly improves the stability and wind erosion resistance of the sand barrier, and provides a more lasting sand fixation effect compared to physical barriers and biological measures.

[0017] Furthermore, the preparation method of the present invention is simple and easy to implement on a large scale. Through the optimized strains and curing formula, a solid sand barrier can be quickly formed in the sandy soil.

[0018] Furthermore, the microbial sand-fixing barrier of the present invention is suitable for various environmental conditions, especially in arid and semi-arid areas, and can maintain a good sand-fixing effect even under extreme climatic conditions.

[0019] Furthermore, the solidified sand barriers provide a good foundation for the restoration of vegetation, which helps to further fix sand through biological measures and achieve ecological restoration and sustainable development. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 The present invention is a flow chart for preparing the microbial solidified sand barrier; Figure 2 Schematic diagram of the test device of Example 1; Figure 3 This is a diagram of the compressive strength test process of Example 1; Figure 4 OD of the bacterial solution within 48 h in Example 2 600 and pH value changes; Figure 5 Schematic diagram of PVC board curing in Example 2, FIG. (a) is a PVC board curing model, and FIG. (b) is a sandy soil filling curing model; Figure 6 is the X-ray diffraction analysis diagram of Example 2; Figure 7 These are optical microscopic images of the samples of Example 2, where (a) is the original aeolian sandy soil, (b) is the microbial solidified sand barrier prepared with 1.5 mol / L cementing fluid, and (c) is the microbial solidified sand barrier prepared with 2.0 mol / L cementing fluid; Figure 8 The dry density difference diagram of the samples solidified by different cementing liquid concentrations in Example 2, Figure (a) is the microbial solidified sand barrier prepared by 1.5 mol / L cementing liquid, Figure (b) is the microbial solidified sand barrier prepared by 2.0 mol / L cementing liquid, and Figure (c) is a combined comparison diagram; Fig. 9 This is a graph showing the difference in calcium carbonate content in samples solidified with different binder concentrations in Example 2. Figure (a) shows the microbial solidified sand barrier prepared with 1.5 mol / L binder, Figure (b) shows the microbial solidified sand barrier prepared with 2.0 mol / L binder, and Figure (c) is a combined comparison graph. DETAILED DESCRIPTION

[0021] The present invention is further described in detail below in conjunction with specific embodiments, which are intended to explain the present invention rather than to limit it.

[0022] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0023] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0024] The present invention provides a microbial solidified sand barrier and a preparation method thereof, so as to achieve more efficient and environmentally friendly wind and sand control. By optimizing the selection of bacterial strains, solidification formula and process flow, the present invention can significantly improve the wind erosion resistance of wind-blown sandy soil, and provide a new solution for the prevention and control of wind-blown sand disasters in arid and semi-arid areas. The present invention relates to the technical field of soil and water conservation and desertification control, and in particular to a method for solidifying wind-blown sandy soil using microbial induced calcium carbonate precipitation technology to form a sand barrier with excellent wind erosion resistance and a preparation method thereof. The technology aims to provide a new material and method for wind erosion control with low cost, high efficiency and environmental friendliness, such as Figure 1 shown.

[0025] Example 1 The shape of the microbial sand barrier: The sand barrier can be in various shapes, such as long strips, grids or other shapes that are conducive to fixing sand. The specific shape depends on the actual application scenario and the needs of wind and sand fixation.

[0026] One of the preferred specific implementations: Assuming that in a wide sandy terrain, the wind blows from a single direction, a series of long strips of microbial sand barriers can be designed parallel to the wind direction. These sand barriers can extend for several meters in length, with a width of about 40 cm and a height of about 30 cm to adapt to the wind direction and reduce wind erosion. The sand barriers can be arranged at a certain interval, such as setting a sand barrier every 3-5 m, to allow sufficient space for air circulation, reduce the direct impact of wind on the sand barriers, and promote the growth of vegetation behind the sand barriers. This long strip sand barrier design can effectively fix the sand and prevent the sand from being blown away by the wind. By using MICP technology inside the sand barrier, the stability and compressive strength of the sand barrier can be increased, enabling it to withstand stronger winds. In addition, the surface of the solidified sand barrier can be designed to be rough or grooved to further improve its blocking effect on wind and sand. This design not only helps to fix the flowing sand, but also serves as a basis for planting vegetation. Over time, the growth of vegetation will further enhance the sand fixation effect of the sand barrier and improve the local ecological environment.

[0027] Microbial culture: The microorganism used in this test is Bacillus pasteurianus ( Sporosarcina pasteurii), from the Central Collection of Microbial Cultures, number ATCC 11859. CASO AGAR medium (20 g urea, 15 g casein peptone, 5 g soy peptone, 5 g NaCl, 20 g agar, and the rest H 2 O) and cultured in a constant temperature shaker at 30°C and 200 rpm for 48 h to obtain a highly active bacterial solution.

[0028] Mixing of bacterial solution and sandy soil: First, place a layer of pebbles in a rectangular plastic box, place a layer of non-woven fabric on the stones, and place 8 cm of desert sandy soil on the non-woven fabric. Use spraying to add 400 mL of cementing liquid (containing soluble calcium source and urea, as substrates for microbial metabolism to promote the precipitation of calcium carbonate) and 400 mL of bacterial solution to the sandy soil. The sample preparation container is as follows: Figure 2 shown.

[0029] Curing effect test: (1) After the solidification of the aeolian sandy soil, it was dried at 105°C for 24 hours and the dry density was measured by the wax sealing method. The test results showed that the dry density of the solidified aeolian sandy soil was significantly increased compared with the original aeolian sandy soil (1.61 g / cm³), reaching a maximum of 1.98 g / cm³. This indicates that the formation of calcium carbonate crystals effectively increased the density of the aeolian sandy soil.

[0030] (2) The solidified sandy soil samples treated with microbial induced calcium carbonate precipitation (MICP) showed strong compressive strength, up to 3.20 MPa. Figure 3 This is because the cementing fluid promotes the formation of more calcium carbonate crystals, thereby increasing the density and strength of the specimen.

[0031] (3) By testing the permeability coefficient of the solidified sandy soil, it was found that the permeability coefficient of the solidified sandy soil decreased with the addition of the cementing fluid. MCIP generated calcium carbonate crystals on the surface and pores of the sandy soil particles, which reduced the porosity of the sandy soil and caused the permeability to decrease.

[0032] After curing is completed, the microbial cured sand barrier needs to be air-dried in a natural environment to further improve its stability and strength.

[0033] Example 2 Preparation of bacterial culture: To prepare the Bacillus pasteurianus culture, first prepare the liquid culture medium and sterilize it at 121°C for 20 minutes. After sterilization, cool the culture medium and inoculate it on a sterile operating table. The inoculated culture medium is shaken and cultured in a constant temperature shaker at 30°C and 200 rpm for 48 hours. During the culture period, measure the OD of the bacterial culture every two hours. 600The value and pH value were used to monitor the growth of Bacillus pasteurianus. After the culture was completed, if the culture medium changed from transparent to turbid and there were no foreign bacteria, it indicated that Bacillus pasteurianus was successfully activated. The pH of the bacterial solution was stable at 9.18, and the OD 600 The value reaches 2.145, indicating that bacteria multiply in large numbers, such as Figure 4 After completion, the bacterial solution was stored in a 4°C refrigerator for later use.

[0034] Preparation of microbial sand barrier: To prepare the microbial sand barrier, the collected sand was first sieved through a 1 mm sieve to remove impurities. Then, a PVC board was used to make a solidification model with a size of 40 cm long, 10 cm wide, and 30 cm high. The model was closed on five sides, with an open top and holes at the bottom. Figure 5 As shown; Before solidification, seal the small hole with a sealing plug and lay a non-woven fabric at the bottom. Fill the soil sample into the model according to the natural density of the aeolian sand, and lay a layer of non-woven fabric on the surface to protect the soil sample. Subsequently, pour 4.8 L of bacterial solution into the model, let it stand for 2 hours, and then release the bottom liquid. Next, pour 4.8 L of 1.5 mol / L cementing solution, let it stand for 2 hours, and then release it. After the solidified sample is left to dry naturally for 48 hours, a microbial solidified sand barrier is obtained; The same method was used to prepare microbial solidified sand barriers with a binder concentration of 2.0 mol / L.

[0035] Composition analysis of microbial solidified sand barriers: In order to analyze the composition of the aeolian sand samples and the solidified microbial sand barriers, X-ray diffraction (XRD) analysis was performed, such as Figure 6 As shown. XRD analysis confirmed the formation of calcite calcium carbonate by comparing the diffraction pattern of the sample under X-ray irradiation with the standard pattern. The results showed that the solidified sample showed specific diffraction peaks of calcite compared with the original aeolian sand, confirming the formation of calcium carbonate. In addition, the position of the diffraction peaks matched the characteristics of quartz crystals, confirming that the crystal form of the sand particles was quartz.

[0036] Microstructure analysis after solidification: The original sand samples and the microbial solidified sand barrier samples solidified with 1.5 mol / L and 2.0 mol / L cementing fluids were observed using optical and electron microscopes. Figure 7 As shown, the results show that the original sand is composed of smooth sand particles, while there are white calcium carbonate precipitates between the sand particles in the solidified samples. These precipitates make the sand particles bond together to form a solidified whole with compressive strength, which is suitable for use as a microbial solidification sand barrier material.

[0037] Solidification effect of microbial solidified sand barrier: In this experiment, a ring knife was used to take samples from the solidified microbial sand barrier at different depths (surface layer 2 cm, 0-10 cm, 10-20 cm, 20-30 cm and bottom layer 2 cm), such as Figure 8As shown. After the sample was dried at 105°C, its dry density was calculated. The results showed that compared with the original sand (1.61 g / cm³), the dry density of the sand barrier cured with 1.5 mol / L binder increased from 0.32 to 0.54 g / cm³, with a growth rate of 20.25% to 34.00%. The dry density of the sand barrier cured with 2.0 mol / L binder increased from 0.37 to 0.82 g / cm³, with a growth rate of 23.25% to 51.13%. At both concentrations, the coefficient of variation of the dry density was less than 0.1, indicating that the curing effect was uniform. As can be seen from the figure, the dry density of the cured samples is generally higher than that of the original sand, and the dry density of the samples cured with 1.5 mol / L binder is slightly lower than that of 2.0 mol / L. Under 1.5 mol / L cementing solution, the maximum dry density occurs at a depth of 20-30 cm (2.15 g / cm³), while under 2.0 mol / L cementing solution, the maximum dry density occurs at a depth of 20-30 cm (2.43 g / cm³), and the dry density decreases at the bottom 2 cm.

[0038] The experiment further showed that after the PVC board solidification method was used to treat the wind-blown sand, the calcium carbonate content in the microbial solidified sand barrier increased significantly, such as Fig. 9 As shown in the figure, at a concentration of 1.5 mol / L cementing fluid, the calcium carbonate content ranged from 1.61% to 4.37%, showing a trend of first increasing and then decreasing. At a concentration of 2.0 mol / L, the content ranged from 1.97% to 4.47%, also increasing first and then decreasing. The calcium carbonate content did not differ much between the depths of 0-10 cm and 10-20 cm, but was significantly different compared with other layers. At both concentrations, the coefficient of variation of the calcium carbonate content indicated that the curing effect was relatively uniform.

[0039] The present invention uses microbial induced calcium carbonate precipitation (MICP) technology to solidify wind-blown sand soil and prepares a microbial solidified sand barrier with excellent wind erosion resistance. Compared with the existing technology, it has the following significant advantages: Environmental friendliness: The microorganisms and chemicals used in the present invention are environmentally friendly and will not have a negative impact on the surrounding ecosystem. Compared with traditional chemical sand fixation methods, the risk of chemical pollution is avoided.

[0040] Cost-effectiveness: MICP technology can directly induce the precipitation of calcium carbonate in aeolian sandy soil without the need to add large amounts of chemical curing agents or frequently replace physical barrier materials, thereby reducing material and maintenance costs.

[0041] Durability and stability: The sand barrier solidified by the present invention has a higher dry density and calcium carbonate content, which significantly improves the stability and wind erosion resistance of the sand barrier, and provides a more durable sand fixation effect compared to physical barriers and biological measures.

[0042] Easy to operate: The preparation method of the present invention is simple and easy to implement on a large scale. Through the optimized strains and curing formula, a solid sand barrier can be quickly formed in the sandy soil.

[0043] Strong adaptability: The microbial sand-fixing barrier of the present invention is suitable for various environmental conditions, especially in arid and semi-arid areas, and can maintain a good sand-fixing effect even under extreme climatic conditions.

[0044] Promote vegetation recovery: The solidified sand barrier provides a good foundation for the recovery of vegetation, which helps to further fix sand through biological measures to achieve ecological restoration and sustainable development.

[0045] Scientific verification: The wind tunnel test and field test verified the anti-wind erosion performance of the microbial solidified sand barrier, and scientific data supported the actual effect and application value of the invention.

[0046] In summary, the present invention provides a new method of sand fixation that is efficient, environmentally friendly, economical and durable through innovative microbial technology, which effectively overcomes the limitations of the existing technology and provides a new solution for the prevention and control of wind and sand disasters.

[0047] To sum up, the above are only preferred embodiments of the present invention and are not intended to limit the present invention in any form. Any ordinary technician in the industry can smoothly implement the present invention as shown in the drawings and described above. However, any equivalent changes, modifications and evolutions made by technicians familiar with the profession without departing from the scope of the technical solution of the present invention using the technical content disclosed above are all equivalent embodiments of the present invention. At the same time, any equivalent changes, modifications and evolutions made to the above embodiments based on the essential technology of the present invention are still within the protection scope of the technical solution of the present invention.

Claims

1. A method for preparing a microbial solidified sand barrier, characterized in that: include, A binder and a microbial liquid are added to the sandy soil respectively, and after being treated by microbial induced calcium carbonate precipitation technology, the sand barrier is obtained by drying and solidifying at high temperature. The cementing liquid includes a soluble calcium source and urea, and the microbial bacterial liquid is a Bacillus pasteurianus bacterial liquid; the concentration of the cementing liquid is 1.5-2.0 mol / L; The Bacillus pasteurianus bacterial liquid is obtained by culturing in CASO AGAR medium at a constant temperature of 30° C. and 200 rpm for 48 hours; Each liter of CASO AGAR medium includes 20 g urea, 15 g casein peptone, 5 g soy peptone, 5 g NaCl, 20 g agar and the rest is H2O.

2. The method for preparing a microbial solidified sand barrier according to claim 1, characterized in that: The specific culture process of the Bacillus pasteurianus liquid is as follows: Before culturing, the CASO AGAR medium was sterilized at 121°C for 20 minutes, and then inoculated with the CASO AGAR medium after cooling. The inoculated CASO AGAR medium was shaken and cultured in a constant temperature shaker at 30°C and 200 rpm for 48 hours; During the culture period, the OD of the bacterial solution in the culture medium was measured every two hours. 600 value and pH value to monitor the growth of Bacillus pasteurianus; After the culture is completed, if the culture medium changes from transparent to turbid and there are no foreign bacteria, it indicates that the bacteria are successfully activated and the Bacillus pasteurianus bacterial solution is obtained, which is refrigerated at 4°C for later use.

3. The method for preparing a microbial solidified sand barrier according to claim 1, characterized in that: The specific preparation process of microbial solidification sand barrier is as follows: The collected aeolian sand was sieved to remove impurities, filled into the solidification model, and non-woven fabric was laid on the surface; then the microbial liquid was added by spraying, and the liquid at the bottom of the solidified model was released after standing for 2 hours; then the binder liquid was added, and the liquid at the bottom of the solidified model was solidified after standing for 2 hours. The obtained solidified sample was placed for 48 hours and then naturally air-dried to obtain a microbial solidified sand barrier.

4. The method for preparing a microbial solidified sand barrier according to claim 3, characterized in that: The capacity of the solidification model is 0.012 cubic meters, the amount of microbial liquid added is 4.8 L, and the amount of cementing liquid added is 4.8 L.

5. The method for preparing a microbial solidified sand barrier according to claim 3, characterized in that: The five sides of the curing model are closed, the top is open and the bottom is perforated; before curing, the small holes are sealed with sealing plugs, and non-woven fabric is laid on the bottom of the curing model.

6. The method for preparing a microbial solidified sand barrier according to claim 1, characterized in that: The soluble calcium source is calcium chloride.

7. The method for preparing a microbial solidified sand barrier according to claim 1, characterized in that: The surface of the microbial solidified sand barrier is provided with a rough surface or a groove; the microbial solidified sand barrier is in a strip shape or a grid shape.

8. The method for preparing a microbial solidified sand barrier according to claim 1, characterized in that: The wax sealing method was used to measure the dry density of microbial solidified sand barriers.

9. The method for preparing a microbial solidified sand barrier according to claim 1, characterized in that: The microbial solidified sand barriers are arranged at intervals of 3-5m.

10. A microbial solidified sand barrier, prepared based on the preparation method of the microbial solidified sand barrier according to any one of claims 1 to 9.

Images