Desertified soil strengthening slurry as well as preparation method and application thereof

Abstract

The invention provides sandy soil strengthening slurry as well as a preparation method and application thereof, and relates to the technical field of sandy soil improvement. The sandy soil strengthening slurry is prepared from the following raw materials in percentage by weight: 0.5 percent to 1 percent of xanthan gum, 0.05 percent to 0.2 percent of microcrystalline cellulose, 0.05 percent to 0.2 percent of chitosan, 0.02 percent to 0.05 percent (v / v) of triethanolamine, 0.1 percent to 0.5 percent (v / v) of glycerol and the balance of water. Through the synergistic effect of the natural bio-based materials, the compressive strength and shear strength of the sandy soil are remarkably improved while the problem of environmental pollution caused by polymer synthesis is solved. According to the method, sand stabilization and wind prevention can be achieved in a short time, the desertification land can be promoted to be converted into a sustainable ecological system, and an environment-friendly, efficient and low-cost solution is provided for desertification control.

Description

Technical Field

[0001] The present invention relates to the technical field of sandy soil improvement, and particularly to a reinforced slurry for desertified soil, a preparation method thereof, and an application thereof. Background Art

[0002] Due to the characteristics of loose, barren, and poor water and fertilizer retention capacity, desertified soil is extremely vulnerable to wind erosion, resulting in frequent sandstorms and a decline in land productivity.

[0003] In the early stage, wind prevention and sand fixation mainly relied on physical barriers (such as straw checkerboards and sand barriers) or single vegetation planting, but there were problems such as high cost, difficult maintenance, and poor ecological adaptability. For example, straw checkerboards are prone to aging and failure in extremely arid areas, and single-plant planting may lead to a decrease in biodiversity. Therefore, new sandy soil improvement technologies based on materials science and ecological engineering (such as biological crust induction, soil binders, and organic-inorganic composites) have gradually become research hotspots.

[0004] The invention patent with the publication number CN 103348838 A discloses a method for making modified sandy soil, which is formed by dissolving a water-soluble solid organic substance in water to form a solution with adhesiveness and adhesivity and then mixing it with sandy soil; after the water evaporates, the water-soluble solid organic substance therein can bond sandy soil particles and can dissolve in water again when encountering water to form a solution with adhesiveness and adhesivity to bond sandy soil particles. The present invention makes ordinary sandy soil "soil-like", fundamentally changes the interaction relationship between sandy soil particles, and constitutes a particle pore structure with binding force (cohesion); during use, the substance is difficult to lose due to its adhesiveness and adhesivity characteristics; it enables sandy soil to have the properties of stabilizing and storing water and nutrients like soil, can provide a solid growth condition for plants, and is an ideal measure for controlling sandy soil and deserts; at the same time, the modified sandy soil can also be used as a means to utilize sand resources such as beaches and sand dunes for plant planting.

[0005] The invention patent with the publication number CN 103348836 A discloses a method for controlling sand dunes using modified sandy soil, spreading the modified sandy soil on the surface of the desert to be controlled, and the modified sandy soil is formed by dissolving a water-soluble solid organic substance in water to form a solution with adhesiveness and adhesivity and then mixing it with sandy soil; after the water evaporates, the water-soluble solid organic substance therein can bond sandy soil particles and can dissolve in water again when encountering water to form a solution with adhesiveness and adhesivity to bond sandy soil particles, making ordinary sandy soil "soil-like", fundamentally changing the interaction relationship between sandy soil particles, and constituting a particle pore structure with binding force (cohesion); after repeated evaporation and wetting, the substance is difficult to lose due to its adhesiveness and adhesivity characteristics; it enables sandy soil to have the properties of stabilizing and storing water and nutrients like soil, and can provide a solid growth condition for plants, and is an ideal measure for controlling deserts.

[0006] Although the prior art improves the performance of sandy soil and realizes sandy soil treatment by mixing sandy soil with a solution, the modified products used include polymers such as polyvinyl alcohol, polyethylene oxide, polyethylene glycol, and sodium polyacrylate, which are likely to cause environmental pollution and are not conducive to ecological protection.

[0007] Therefore, it is necessary to provide a sandy soil improvement product that does not use polymers, so as to improve sandy soil and enhance its wind erosion resistance on the premise of reducing the risk of environmental pollution, and realize desertification reversal and ecological restoration. Summary of the Invention

[0008] In view of this, the present invention provides a reinforced slurry for sandy soil, its preparation method and application. Through the synergistic effect of natural biobased materials (such as xanthan gum, chitosan, microcrystalline cellulose), the present invention not only solves the environmental pollution problem of synthetic polymers, but also significantly improves the compressive strength and shear strength of sandy soil. The present invention can not only fix sand and prevent wind in the short term, but also promote the transformation of sandy land into a sustainable ecosystem, providing an environmentally friendly, efficient and low-cost solution for desertification control.

[0009] The first aspect of the present invention is to provide a reinforced slurry for sandy soil, comprising the following raw materials:

[0010] Xanthan gum 0.5 wt.% - 1 wt.%, microcrystalline cellulose 0.05 wt.% - 0.2 wt.%, chitosan 0.05 wt.% - 0.2 wt.%, triethanolamine 0.2‰ - 0.5‰ (v / v), glycerol 1‰ - 5‰ (v / v), and the balance is water.

[0011] Preferably, the mass ratio of the microcrystalline cellulose to the xanthan gum is 1:(5 - 10), and more preferably, the mass ratio of the microcrystalline cellulose to the xanthan gum is 1:10.

[0012] Preferably, the mass ratio of the chitosan to the xanthan gum is 1:(5 - 10), and more preferably, the mass ratio of the chitosan to the xanthan gum is 1:10.

[0013] Preferably, the reinforced slurry for sandy soil comprises the following raw materials:

[0014] Xanthan gum 1 wt.%, microcrystalline cellulose 0.1 wt.%, chitosan 0.1 wt.%, triethanolamine 0.5‰ (v / v), glycerol 5‰ (v / v), and the balance is water.

[0015] The second aspect of the present invention is to provide a preparation method of a reinforced slurry for sandy soil, specifically comprising the following steps:

[0016] S1. Dissolve xanthan gum in water, heat and stir for a period of time to obtain solution A;

[0017] S2. Sequentially add triethanolamine and microcrystalline cellulose into Solution A, heat and stir for a period of time to obtain Solution B;

[0018] S3. Add chitosan and glycerol into Solution B, heat and stir for a period of time and then cool to obtain the strengthened slurry for desertified soil;

[0019] Preferably, the heating temperature in Step S1 is 20°C - 60°C, the stirring speed is 600 - 1200 rpm, and the stirring time is 2 - 4 h. More preferably, the heating temperature in Step S1 is 40°C, the stirring speed is 1200 rpm, and the stirring time is 2 h.

[0020] Preferably, the heating temperature in Step S2 is 40°C - 70°C, the stirring speed is 600 - 1200 rpm, and the stirring time is 0.5 - 3 h. More preferably, the heating temperature in Step S2 is 50°C, the stirring speed is 1200 rpm, and the stirring time is 0.5 h.

[0021] Preferably, the heating temperature in Step S3 is 50°C, the stirring speed is 300 - 800 rpm, and the stirring time is 0.5 - 3 h. More preferably, the heating temperature in Step S3 is 50°C, the stirring speed is 500 rpm, and the stirring time is 0.5 h.

[0022] The third aspect of the present invention is to provide an application of the strengthened slurry for desertified soil in strengthening desertified soil, and the strengthened slurry for desertified soil is the strengthened slurry for desertified soil described in the above technical solution.

[0023] Preferably, the application method of the strengthened slurry for desertified soil is as follows:

[0024] Mix the strengthened slurry for desertified soil and desertified soil evenly to obtain strengthened desertified soil, thereby achieving the treatment of desertified soil.

[0025] Preferably, the volume ratio of the strengthened slurry for desertified soil to desertified soil is 1:(5 - 8).

[0026] Compared with the prior art, the beneficial technical effects of the present invention:

[0027] The present invention uses natural bio-based materials such as xanthan gum (microbial polysaccharide), chitosan (chitin derivative), and microcrystalline cellulose (plant fiber extract) to prepare the strengthened slurry for desertified soil, ensuring that the product is biodegradable and will not produce persistent pollution after decomposition in the environment, and has higher ecological compatibility.

[0028] The polymer binders in the prior art mainly form cohesion by physically wrapping sand particles, but are prone to aging and failure under the long-term influence of ultraviolet rays, dry-wet cycles, etc. In the present invention, the network structure of xanthan gum combines with the cationic properties of chitosan, which can combine with the negative charges on the sand particle surface to form stable chemical bonds; microcrystalline cellulose enhances the cross-linking between particles through hydrogen bonds. The synergistic effect of the three significantly improves the compressive strength and shear strength of sandy soil, and is more suitable for complex stress environments.

[0029] The water absorbency of xanthan gum and chitosan in the present invention can adjust the humidity of sandy soil, maintain the bonding effect through repeated dissolution-curing in the dry-wet cycle, extend the sand fixation time limit, and can also improve the water retention capacity of sandy soil and reduce water evaporation. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The present invention will be further described below in conjunction with the drawings.

[0031] Figure 1 It is a physical diagram of the sample in Test Example 1. Among them, the left side is the control group sample, and the right side is the experimental group sample;

[0032] Figure 2 It is the test result of the compressive strength of the sample in Test Example 1;

[0033] Figure 3 It is the test result of the strain shear force instrument of the sandy soil strengthened by the sandification soil strengthening slurry in Example 1 in Test Example 2;

[0034] Figure 4 It is the test result of the strain shear force instrument of the sandy soil strengthened by the sandification soil strengthening slurry in Comparative Example 1 in Test Example 2; DETAILED DESCRIPTION OF THE INVENTION

[0036] The technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0037] To further illustrate the present invention, the following detailed description is provided through the following examples. All the raw materials used in the following examples of the present invention are commercially available.

[0038] The first aspect of the present invention is to provide a sandification soil strengthening slurry, which comprises the following raw materials:

[0039] Xanthan gum 0.5 wt.% - 1 wt.%, microcrystalline cellulose 0.05 wt.% - 0.2 wt.%, chitosan 0.05 wt.% - 0.2 wt.%, triethanolamine 0.2‰ - 0.5‰ (v / v), glycerol 1‰ - 5‰ (v / v), the balance being water.

[0040] In some specific embodiments of the present invention, the mass ratio of the microcrystalline cellulose to the xanthan gum is 1:(5 - 10), preferably 1:10; the mass ratio of the chitosan to the xanthan gum is 1:(5 - 10), preferably 1:10.

[0041] In some preferred embodiments of the present invention, the sandy soil strengthening slurry comprises the following raw materials:

[0042] Xanthan gum 1 wt.%, microcrystalline cellulose 0.1 wt.%, chitosan 0.1 wt.%, triethanolamine 0.5‰ (v / v), glycerol 5‰ (v / v), the balance being water.

[0043] The second aspect of the present invention is to provide a preparation method of a sandy soil strengthening slurry, which specifically comprises the following steps:

[0044] S1. Dissolve xanthan gum in water, heat and stir for a period of time to obtain solution A;

[0045] S2. Sequentially add triethanolamine and microcrystalline cellulose to solution A, heat and stir for a period of time to obtain solution B;

[0046] In this step, triethanolamine can activate microcrystalline cellulose, and then promote the mixing and crosslinking of microcrystalline cellulose and xanthan gum to form an interpenetrating network;

[0047] S3. Add chitosan and glycerol to solution B, heat and stir for a period of time and then cool to obtain the sandy soil strengthening slurry;

[0048] In this step, glycerol can adjust the fluidity of the slurry, and chitosan can reinforce the interpenetrating network formed by xanthan gum and microcrystalline cellulose.

[0049] In some specific embodiments of the present invention, the heating temperature in step S1 is 20°C - 60°C, preferably 40°C, the stirring speed is 600 - 1200 rpm, preferably 1200 rpm, and the stirring time is 2 - 4 h; the heating temperature in step S2 is 40°C - 70°C, preferably 50°C, the stirring speed is 600 - 1200 rpm, preferably 1200 rpm, and the stirring time is 0.5 - 3 h; the heating temperature in step S3 is 50°C, the stirring speed is 300 - 800 rpm, preferably 500 rpm, and the stirring time is 0.5 - 3 h.

[0050] The third aspect of the present invention is to provide an application of a desertified soil strengthening slurry in strengthening desertified soil, and the desertified soil strengthening slurry is the desertified soil strengthening slurry described in the above technical solution.

[0051] In some specific embodiments of the present invention, the application method of the desertified soil strengthening slurry is as follows:

[0052] Mix the desertified soil strengthening slurry and the desertified soil evenly to obtain strengthened desertified soil, thereby realizing the treatment of desertified soil;

[0053] The volume ratio of the desertified soil strengthening slurry to the desertified soil is 1:(5 - 8).

[0054] Hereinafter, the technical solutions in the embodiments of the present application will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present application, not all embodiments. Based on the embodiments in the present application, other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the scope of protection of the invention. In the following embodiments, all raw materials are commercially available.

[0055] Unless otherwise specified, all experiments are repeated 3 times, and the results are expressed as averages.

[0056] Example 1 A desertified soil strengthening slurry is composed of the following raw materials:

[0057] Xanthan gum 1 wt.%, microcrystalline cellulose 0.1 wt.%, chitosan 0.1 wt.%, triethanolamine 0.5‰ (v / v), glycerol 5‰ (v / v), and the balance is water.

[0058] The preparation method of the desertified soil strengthening slurry is as follows:

[0059] S1. Weigh the raw materials according to the ratio, then dissolve xanthan gum in water, and stir at a speed of 1200 rpm at 40°C for 2 h to obtain solution A;

[0060] S2. Add triethanolamine and microcrystalline cellulose to solution A in sequence, and stir at a speed of 1200 rpm at 50°C for 0.5 h to obtain solution B;

[0061] S3. Add chitosan and glycerol to solution B, stir at a speed of 500 rpm at 50°C for 0.5 h and then cool to obtain the desertified soil strengthening slurry.

[0062] Test Example 1

[0063] Mix the desertified soil strengthening slurry prepared in Example 1 and the desertified soil evenly at a volume ratio of 1:8 as the experimental group, and replace the desertified soil strengthening slurry with an equal amount of pure water as the control. Place the samples of the experimental group and the control group in a mold of 70 cm × 70 cm × 70 cm, take them out after compaction under the same conditions, air-dry them at room temperature for 7 days, and then test the compressive strength of the soil blocks on an unconfined compressive strength tester. The test results are as Figure 1 , Figure 2 shown.

[0064] The results show that the samples of the control group could not form stable soil blocks after air-drying, so they had no bearing capacity, while the strengthened desertified soil samples of the experimental group could withstand a pressure of 588.5 kPa.

[0065] Comparative Example 1

[0066] The difference from Example 1 is that microcrystalline cellulose and chitosan were not used.

[0067] The cohesive force of the sandy soil strengthened by the soil strengthening slurry in Example 1 was 170.5 kPa, and the internal friction angle was 25.3°. The cohesive force of the sandy soil strengthened by the soil strengthening slurry in Comparative Example 1 was 20.0 kPa, and the internal friction angle was 37.7°.

[0068] It can be seen that in the soil strengthening slurry of the present invention, although the amount of microcrystalline cellulose and chitosan is very small, they have an important influence on improving the strengthening effect of sandy soil.

[0069] Comparative Example 2

[0070] The difference from Example 1 is that triethanolamine was not used.

[0071] Comparative Example 3

[0072] The difference from Example 1 is that glycerol was not used.

[0073] Comparative Example 4

[0074] The difference from Example 1 is that microcrystalline cellulose was replaced with an equal amount of ordinary cellulose.

[0075] Comparative Example 5

[0076] The difference from Example 1 is that

[0077] (1) The mass ratio of microcrystalline cellulose to xanthan gum is 1:1;

[0078] (2) The mass ratio of microcrystalline cellulose to xanthan gum is 1:15;

[0079] Comparative Example 6

[0080] The difference from Example 1 is that

[0081] (1) The mass ratio of chitosan to xanthan gum is 1:1;

[0082] (2) The mass ratio of chitosan to xanthan gum is 1:15.

[0083] Test Example 2

[0084] The desertified soil strengthening slurry prepared in Example 1 and Comparative Examples 1-6 was mixed with desertified soil at a volume ratio of 1:5, then placed in a soil core sampler and compacted. After being air-dried at room temperature for 7 days, the shear strength of the soil block was tested in a strain shear meter. Some results are as Figure 3 、 Figure 4 shown.

[0085] By fitting the test results of the sand soil by the strain shear meter and the test results of the strain shear meter, the cohesion and internal friction angle of the sand soil were calculated through Coulomb's law. The results are shown in Table 1.

[0086] Table 1 Performance Test Results

[0087]

[0088] The above embodiments only represent several implementation manners of the present invention. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention patent shall be subject to the appended claims.

Claims

1. A reinforced slurry for desertified soil, characterized in that, It includes the following raw materials: Xanthan gum 0.5 wt.% - 1 wt.%, microcrystalline cellulose 0.05 wt.% - 0.2 wt.%, chitosan 0.05 wt.% - 0.2 wt.%, triethanolamine 0.2‰ - 0.5‰ (v / v), glycerol 1‰ - 5‰ (v / v), and the balance is water.

2. The enhanced slurry for desertified soil according to claim 1, characterized in that The mass ratio of the microcrystalline cellulose to the xanthan gum is 1:(5 - 10).

3. The reinforced slurry for desertified soil according to claim 1, characterized in that, The mass ratio of the chitosan to the xanthan gum is 1:(5 - 10).

4. A reinforced slurry for desertified soil according to claim 1, characterized in that The sandy soil strengthening slurry includes the following raw materials: Xanthan gum 1 wt.%, microcrystalline cellulose 0.1 wt.%, chitosan 0.1 wt.%, triethanolamine 0.5‰ (v / v), glycerol 5‰ (v / v), and the balance is water.

5. The preparation method of the desertified soil strengthening slurry according to any one of claims 1-4, characterized in that, It includes the following steps: S1. Dissolve xanthan gum in water, heat and stir for a period of time to obtain solution A; S2. Sequentially add triethanolamine and microcrystalline cellulose to solution A, heat and stir for a period of time to obtain solution B; S3. Add chitosan and glycerol to solution B, heat and stir for a period of time and then cool to obtain the sandy soil strengthening slurry.

6. The preparation method according to claim 5, characterized in that, The heating temperature in step S1 is 40°C, the stirring speed is 600 - 1200 rpm, and the stirring time is 2 h.

7. The preparation method according to claim 5, characterized in that, The heating temperature in step S2 is 50°C, the stirring speed is 600 - 1200 rpm, and the stirring time is 0.5 h.

8. The preparation method according to claim 5, wherein The heating temperature in step S3 is 50°C, the stirring speed is 300 - 800 rpm, and the stirring time is 0.5 h.

9. Application of a strengthened slurry for desertified soil in strengthening desertified soil, characterized in that, The sandy soil strengthening slurry is the sandy soil strengthening slurry described in any one of claims 1 - 4 or the sandy soil strengthening slurry prepared by the preparation method described in any one of claims 5 - 8.

10. The application according to claim 9, characterized in that, The method is as follows: Mix the sandy soil strengthening slurry with the sandy soil evenly to obtain the strengthened sandy soil, and achieve the treatment of the sandy soil.

Images