Aluminum solid acid reduction additive and its preparation method and application

Abstract

The present invention discloses a solid aluminum acid reduction additive and its preparation method and application, relating to the technical field of soil improvement. The solid aluminum acid reduction additive includes biosilicon and amino acid in a mass ratio of 50-500:1, and the particle size of the biosilicon is 1-50 μm. The present invention selects low-priced biosilicon, utilizes its surface silanol and porous structure characteristics, and can adsorb active aluminum after being applied to acidic soil, and forms Si-O-Al bonds by reacting with surface silanol, thereby forming clay-like minerals, and finally effectively fixing the active aluminum in the clay-like mineral structure, which is difficult to release again; in addition, the charge imbalance of the clay-like minerals formed in the above process will also adsorb some hydrogen ions, thereby reducing soil acidity and achieving a long-term solid aluminum acid reduction effect. At the same time, utilizing the adsorption effect of amino acids on aluminum, the solid aluminum acid reduction effect of the additive can be made more obvious after loading amino acids.

Description

Technical Field

[0001] The present invention relates to the technical field of soil improvement, and in particular to an aluminum-fixing and acid-reducing additive, a preparation method thereof, and an application thereof. Background Art

[0002] The red soils of southern my country are subject to intense leaching, making soil minerals, especially silicates like clay, susceptible to chemical weathering. While silicon is lost with surface runoff, aluminum is retained in situ, primarily as 1:1 clay minerals (kaolinite) or as (hydro)aluminum oxide precipitation, resulting in a process of desiliconization and aluminum enrichment. This process leads to the continuous accumulation of aluminum in southern red soils. Furthermore, because this reactive aluminum is acidogenic and the aforementioned process forms some hydrogen ions, the acidification of red soils is becoming increasingly severe. Consequently, acidogenicity and aluminum toxicity reduce crop suitability and yield. Therefore, reducing aluminum activity and effectively inhibiting soil acidification has become an urgent issue.

[0003] Existing technologies usually use alkaline substances such as lime as the main raw materials, and use the alkalinity of raw / slaked lime to neutralize hydrogen ions and other substances in red soil. However, this method has the following problems: (1) Such alkaline substances have little direct effect on active aluminum, and it is difficult to control the acidity (potential acidity) caused by aluminum; (2) The released calcium ions can easily cause soil compaction, thereby reducing the soil's water and fertilizer supply capacity, thereby affecting crop yields. Therefore, the application of lime and other substances is difficult to solve the problem of soil acidification caused by the release of exchangeable aluminum, and it cannot be applied for a long time. Finding an effective method to control aluminum and inhibit acidity has become an urgent problem to be solved.

[0004] In view of this, the present invention is proposed. Summary of the Invention

[0005] The purpose of the present invention is to provide a solid aluminum acid reduction additive and a preparation method and application thereof.

[0006] The present invention is achieved in that:

[0007] In a first aspect, the present invention provides an aluminum-solidifying acid-reducing additive, comprising bio-silicon and amino acid in a mass ratio of 50-500:1, wherein the particle size of the bio-silicon is 1-50 μm.

[0008] In an optional embodiment, the mass ratio of the biosilicon to the amino acid is 80-120:1.

[0009] In an optional embodiment, the biosilica includes at least one of diatomaceous earth and deep-sea siliceous mud, wherein the deep-sea siliceous mud is a sediment containing at least one of diatom biosilica, sponge spicules, silicoflagellates and radiolarians.

[0010] In an alternative embodiment, the amino acid comprises at least one of glycine, serine, leucine, proline, tryptophan, phenylalanine, alanine, isoleucine, glutamic acid, aspartic acid, valine, lysine and arginine.

[0011] In an alternative embodiment, the amino acid comprises glycine.

[0012] In an optional embodiment, the biosilicon is obtained by ultrasonic pulverization or grinding.

[0013] In a second aspect, the present invention provides a method for preparing a solid aluminum acid reduction additive, comprising crushing biosilicon to a particle size of 1-50 μm, and then mixing the crushed biosilicon with amino acids at a mass ratio of 50-500:1.

[0014] In a third aspect, the use of the aluminum-fixing and acid-reducing additive as described in any of the aforementioned embodiments in improving acidified soil.

[0015] In an optional embodiment, the aluminum-fixing and acid-reducing additive is evenly applied to the acidic soil, and the addition amount of the aluminum-fixing and acid-reducing additive is 1-5 kg / mu.

[0016] In an optional embodiment, the addition amount of the aluminum-fixing and acid-reducing additive is 3-5 kg / mu.

[0017] The present invention has the following beneficial effects:

[0018] The solid aluminum acid reduction additive provided by the present invention is prepared by mixing crushed bio-silicon and amino acids in a specific ratio. At this time, the amino acids can be loaded on the porous structure of the bio-silicon to form an inorganic-organic complex. The fixation of aluminum is completed by the reaction of low-cost bio-silicon with aluminum. At the same time, the amino acids are loaded on the bio-silicon by utilizing the adsorption effect of the amino acids on aluminum, so that the acid-inhibiting and aluminum-reducing effects of the additive can be made more obvious. By applying the solid aluminum acid reduction additive to acidic soil, the solid aluminum acid reduction additive can adsorb active aluminum and combine with it through reaction to form Si-O-Al bonds, thereby forming clay-like minerals, etc., fixing the active aluminum in the clay-like mineral structure, which is difficult to release again. In addition, the charge imbalance of the clay-like minerals formed in the above process will also adsorb some hydrogen ions, thereby reducing the acidity of the soil and achieving a long-lasting solid aluminum acid reduction effect. The preparation method of the solid aluminum acid reduction additive of the present invention has the characteristics of high efficiency, ease of implementation, and low cost, and is easy to promote. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0020] Figure 1 TEM-EDS images of the biological diatom shells (a) before the aluminum-fixing and acid-reducing additive provided in Example 1 of the present invention was applied to red soil and (b) after the biological diatom shells were applied to red soil. DETAILED DESCRIPTION

[0021] To make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are described clearly and completely below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer are used. Where the manufacturer of the reagents or instruments is not specified, all are conventional products that can be purchased commercially.

[0022] The present invention provides an aluminum-solidifying acid-reducing additive, which comprises biosilicon and amino acid in a mass ratio of 50-500:1, and the particle size of the biosilicon is 1-50 μm.

[0023] Among them, porous biosilica is a biologically formed siliceous shell with silanol groups on its surface and a porous structure. It has high adsorption and stable loading capacity for elements. In particular, biosilica has a unique preference for the adsorption of aluminum. More importantly, biosilica can combine with aluminum through hydroxyl groups to form authigenic minerals similar to clay minerals at room temperature, thereby stably storing aluminum in the mineral lattice. Therefore, with the help of the effect of biosilica on aluminum, its activity can be effectively inhibited, its acidogenicity and aluminum toxicity can be reduced. In addition, due to the limited number of silanol groups on the surface of biosilica, its direct use effect is not good; at the same time, biosilica has a small specific surface area and a limited enrichment effect on aluminum. Therefore, biosilica needs to be treated to increase its specific surface area and surface activity.

[0024] In this regard, in the present invention, biosilicon is mixed with amino acids and modified by amino acids. Since both biosilicon and aluminum are easy to adsorb organic matter, the biosilicon loaded with amino acids has a more obvious enrichment effect on aluminum.

[0025] Specifically, in the present invention, the mass ratio of biosilicon to amino acids is 50-120:1. Research by the present invention has found that within this mass ratio range, the adsorption of aluminum in the soil is more effective, while also having a better acid-reducing effect. For example, the mass ratio can be any one of 50:1, 60:1, 70:1, 80:1, 85:1, 90:1, 95:1, 100:1, 105:1, 110:1, 115:1, and 120:1, or a range between any two of these, with a more preferred range of 80-120:1.

[0026] The biosilica comprises at least one of diatomaceous earth and deep-sea siliceous mud, wherein the deep-sea siliceous mud is a sediment containing at least one of diatomaceous biosilica, sponge spicules, silicoflagellates, and radiolarians. The biosilica raw material has a large particle size, making it difficult to adsorb. In the present invention, the biosilica is ultrasonically crushed or ground to obtain a powder with a particle size of 1-50 μm, which makes subsequent uniform loading and spreading easier.

[0027] Amino acids are a significant component of soil organic nitrogen and a crucial nutrient source for soil microorganisms. During their metabolic processes, soil microorganisms can use amino acids as precursors to biosynthesize plant growth regulators through biological pathways, stimulating plant growth and regulating plant physiological processes. However, amino acids alone are ineffective at aluminum adsorption and acid reduction. In the present invention, combining biosilicon with amino acids significantly enhances the aluminum-binding and acid-reducing properties of biosilicon. These amino acids include, but are not limited to, glycine (Gly), serine (Ser), leucine (Leu), proline (Pro), tryptophan (Trp), phenylalanine (Phe), alanine (Ala), isoleucine (Ile), glutamic acid (Glu), aspartic acid (Asp), valine (Val), lysine (Lys), and arginine (Arg). Preferably, the amino acid used in the present invention is glycine. Glycine is a commercially available chemical reagent and is added in a solvent or powder form.

[0028] Furthermore, the preparation method of the above-mentioned solid aluminum acid reduction additive is simple. It only requires crushing the biosilicon to a particle size of 1-50 μm, and then mixing the crushed biosilicon with amino acids in a mass ratio of 50-500:1. The mixing in the present invention can adopt various conventional methods as long as the uniform mixing of biosilicon and amino acids can be achieved.

[0029] The present invention also provides the use of the aforementioned aluminum-solidifying and acid-reducing additive in improving acidified soil. Specifically, the present invention provides a method for improving acidified soil, comprising uniformly applying the aforementioned aluminum-solidifying and acid-reducing additive to acidic soil. The amount of the aluminum-solidifying and acid-reducing additive added is 1-5 kg / mu, preferably 3-5 kg / mu. Acidic soils include, but are not limited to, red soil.

[0030] The features and performance of the present invention are further described in detail below with reference to the embodiments.

[0031] The diatomite used in the following examples and comparative examples was collected from the Changbai diatomite mine in Jilin Province. It has a round sieve-like structure and an initial particle size of 2-5 mm. The deep-sea siliceous mud was collected from the Mariana Trench and has an initial particle size of ≥5 mm. The acidic soil used in the following examples and comparative examples is the red soil from Yingtan, Jiangxi Province.

[0032] Example 1

[0033] This embodiment provides a method for improving acidified soil, which includes uniformly applying an aluminum-fixing and acid-reducing additive to red soil at an application rate of 1 kg / mu, wherein the aluminum-fixing and acid-reducing additive includes ground diatomaceous earth (particle size of 2-50 μm) and glycine in a mass ratio of 500:1.

[0034] Example 2

[0035] This embodiment provides a method for improving acidified soil, which includes uniformly applying an aluminum-fixing and acid-reducing additive to red soil at an application rate of 5 kg / mu, wherein the aluminum-fixing and acid-reducing additive includes ground diatomaceous earth (particle size of 2-50 μm) and glycine, with a mass ratio of 500:1.

[0036] Example 3

[0037] This embodiment provides a method for improving acidified soil, which includes uniformly applying an aluminum-fixing and acid-reducing additive to red soil at an application rate of 5 kg / mu, wherein the aluminum-fixing and acid-reducing additive includes ground diatomaceous earth (particle size of 2-50 μm) and glycine in a mass ratio of 100:1.

[0038] Example 4

[0039] This embodiment provides a method for improving acidified soil, which includes uniformly applying an aluminum-fixing and acid-reducing additive to red soil at an application rate of 5 kg / mu, wherein the aluminum-fixing and acid-reducing additive includes ground diatomaceous earth (particle size of 2-50 μm) and glycine in a mass ratio of 50:1.

[0040] Example 5

[0041] This embodiment provides a method for improving acidified soil, which includes uniformly applying an aluminum-fixing and acid-reducing additive to red soil at an application rate of 5 kg / mu, wherein the aluminum-fixing and acid-reducing additive includes ground deep-sea siliceous mud (particle size of 1-50 μm) and glycine, with a mass ratio of 100:1.

[0042] Example 6

[0043] This embodiment provides a method for improving acidified soil, which includes uniformly applying an aluminum-fixing and acid-reducing additive to red soil at an application rate of 5 kg / mu, wherein the aluminum-fixing and acid-reducing additive includes ultrasonically crushed diatomaceous earth (particle size of 2-50 μm) and glycine, with a mass ratio of 100:1.

[0044] Example 7

[0045] This embodiment provides a method for improving acidified soil, which includes uniformly applying an aluminum-fixing and acid-reducing additive to red soil at an application rate of 5 kg / mu, wherein the aluminum-fixing and acid-reducing additive includes ground diatomaceous earth (particle size of 2-50 μm) and serine, with a mass ratio of 100:1.

[0046] Comparative Example 1

[0047] This comparative example provides a method for improving acidified soil, which comprises uniformly applying an aluminum-fixing and acid-reducing additive to red soil at an application rate of 1 kg / mu, wherein the aluminum-fixing and acid-reducing additive is unground diatomaceous earth with a particle size of 2-5 mm.

[0048] Comparative Example 2

[0049] This comparative example provides a method for improving acidified soil, which comprises uniformly applying an aluminum-fixing and acid-reducing additive to red soil at an application rate of 5 kg / mu, wherein the aluminum-fixing and acid-reducing additive is unground diatomaceous earth with a particle size of 2-5 mm.

[0050] Comparative Example 3

[0051] This comparative example provides a method for acidifying soil, which comprises uniformly applying an aluminum-fixing and acid-reducing additive to red soil at an application rate of 1 kg / mu, wherein the aluminum-fixing and acid-reducing additive is ground diatomaceous earth with a particle size of 2-50 μm.

[0052] Comparative Example 4

[0053] This comparative example provides a method for acidifying soil, which comprises uniformly applying an aluminum-fixing and acid-reducing additive to red soil at an application rate of 5 kg / mu, wherein the aluminum-fixing and acid-reducing additive is ground diatomaceous earth with a particle size of 2-50 μm.

[0054] Comparative Example 5

[0055] This comparative example provides a method for improving acidified soil, which comprises uniformly applying an aluminum-fixing and acid-reducing additive to red soil at an application rate of 5 kg / mu, wherein the aluminum-fixing and acid-reducing additive is ultrasonically crushed diatomaceous earth with a particle size of 1-30 μm.

[0056] Comparative Example 6

[0057] This comparative example provides a method for improving acidified soil, which comprises uniformly applying an aluminum-fixing and acid-reducing additive to red soil at an application rate of 5 kg / mu, wherein the aluminum-fixing and acid-reducing additive is unground deep-sea siliceous mud with a particle size of ≥5 mm.

[0058] Comparative Example 7

[0059] This comparative example provides a method for improving acidified soil, which comprises uniformly applying an aluminum-fixing and acid-reducing additive to red soil at an application rate of 5 kg / mu, wherein the aluminum-fixing and acid-reducing additive is ground deep-sea siliceous mud with a particle size of ≤50 μm.

[0060] Comparative Example 8

[0061] This comparative example provides a method for improving acidified soil, which comprises uniformly applying an aluminum-fixing and acid-reducing additive to red soil at an application rate of 5 kg / mu, wherein the aluminum-fixing and acid-reducing additive is glycine with a particle size of 2-50 μm.

[0062] Comparative Example 9

[0063] This comparative example provides a method for improving acidified soil, which comprises uniformly applying an aluminum-fixing and acid-reducing additive to red soil at an application rate of 5 kg / mu, wherein the aluminum-fixing and acid-reducing additive is unground diatomaceous earth (2-5 mm) and glycine, with a mass ratio of 100:1.

[0064] Experimental example

[0065] After applying the aluminum-solidifying and acid-reducing additives provided in the above examples and comparative examples to red soil, the soil was incubated for 60 days. During the incubation process, water was regularly added to maintain 80% of the field water holding capacity. After the incubation period, some red soil samples were taken for index testing to detect the pH and active aluminum content of the red soil before and after the application of the aluminum-solidifying and acid-reducing additives. The pH value was determined by potentiometric method at a soil-water ratio of 1:1, and the active aluminum content was determined by potassium chloride exchange method. The pH of the red soil before the application of the aluminum-solidifying and acid-reducing additives was 4.23, and the active aluminum content was 3.77 cmol / kg. For the test results of the red soil after the application of the aluminum-solidifying and acid-reducing additives, please refer to Table 1.

[0066] Table 1. Statistical table of red soil pH and active aluminum content in different examples

[0067]

[0068] The biodiatom shells of the aluminum-fixing and acid-reducing additive provided in Example 1 were tested before and after application to red soil. Figure 1 In (a), before soil culture, the initial biological diatom shell has a typical smooth round sieve structure, and no aluminum element signal is detected in the structure; the sample after the culture of Example 1 is observed under a transmission electron microscope. Figure 1 As can be seen in (b), after 60 days of cultivation with red soil, the surface of the biological diatom shell structure is rich in nano-sized substances, and obvious aluminum element signals are detected, indicating that the silanol groups on the surface of the biological diatom shell are closely related to the active Al in the soil. 3+ Combined to form clay-like minerals.

[0069] As can be seen from the above table, the present invention uses bio-silicon of a specific particle size to compound with amino acids, which can achieve a better pH-raising effect and is more conducive to reducing the active aluminum content. As can be seen from Examples 2-4, ground diatomaceous earth and glycine have better effects within the preferred ratio range of the present invention. Although ground diatomaceous earth and glycine also have better effects at 50:1 in Example 4, the amount of glycine used in Example 4 is greater, its cost is greater, and the advantage of pH raising compared to Example 2 is not obvious, and it is reduced compared to Example 3. Therefore, a ratio of 100:1 is preferred. As can be seen from Comparative Examples 1-2, the unground diatomaceous earth has a large particle size and poor adsorption effect on aluminum in red soil. Even if the amount applied is increased, its effect is still significantly worse than that of Example 1. In Comparative Examples 3 and 4, ground diatomaceous earth is applied alone, which has a certain effect on the pH raising amount and active aluminum content of red soil, but its effect is still worse than the combination of ground diatomaceous earth and glycine. In Comparative Example 5, ultrasonically crushed diatomaceous earth was applied alone, which was slightly better than ground diatomaceous earth, fully proving that the effect of ultrasound is better than that of grinding. However, considering that the cost of ultrasound is greater than that of grinding, the use of ground diatomaceous earth can still achieve the desired effect. As can be seen from Comparative Examples 6 and 7, the effect of ground deep-sea siliceous mud is also better than that of unground deep-sea siliceous mud, but its effect when applied alone is still poor. At the same time, in Comparative Example 8, the application of glycine alone actually reduced the pH of the red soil to a certain extent, and at the same time did not have the effect of adsorbing active aluminum. By comparing the effects of Example 3, Comparative Example 4 and Comparative Example 8 above, it can be seen that the combination of ground diatomaceous earth and glycine has a synergistic effect. As can be seen from Comparative Example 9, even when unground diatomaceous earth and glycine are compounded, a good effect of increasing pH and reducing active aluminum content cannot be obtained, which fully demonstrates the importance of diatomaceous earth particle size selection.

[0070] In summary, the solid aluminum acid reduction additive provided by the present invention is obtained by mixing the crushed bio-silicon and amino acids in a specific ratio. At this time, the amino acids can be loaded into the porous structure of the bio-silicon to form an inorganic-organic complex, and the fixation of aluminum is completed by the reaction of the cheap bio-silicon with aluminum. At the same time, the adsorption effect of the amino acids on aluminum is utilized, and the amino acids are loaded on the bio-silicon, which can make the fixation effect of the solid aluminum acid reduction additive on aluminum more obvious. By applying the solid aluminum acid reduction additive to acidic soil, the solid aluminum acid reduction additive can adsorb active aluminum and combine with it through reaction, thereby forming a Si-O-Al bond, and then forming a clay-like mineral, etc., fixing the active aluminum in the clay-like mineral structure, which is difficult to release again. At the same time, the charge imbalance of the clay-like mineral formed in the process will also adsorb some hydrogen ions, thereby reducing the acidity of the soil and achieving a long-term solid aluminum acid reduction effect. The preparation method of the solid aluminum acid reduction additive of the present invention has the characteristics of high efficiency, ease of implementation, and low cost, and is easy to promote.

[0071] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A solid aluminum acid reduction additive, characterized in that: It consists of bio-silicon and amino acids in a mass ratio of 80-120:1, and the particle size of the bio-silicon is 1-50 μm; The biosilica comprises at least one of diatomaceous earth and deep-sea siliceous mud, wherein the deep-sea siliceous mud is a sediment containing at least one of diatom biosilica, sponge spicules, siliceous flagellates and radiolarians; The amino acids include at least one of glycine, serine, leucine, proline, tryptophan, phenylalanine, alanine, isoleucine, glutamic acid, aspartic acid, valine, lysine and arginine.

2. The aluminum solid acid reduction additive according to claim 1, characterized in that The amino acids include glycine.

3. The aluminum solid acid reduction additive according to claim 1, characterized in that The biosilicon is obtained by ultrasonic crushing or grinding.

4. A method for preparing the solid aluminum acid reduction additive according to any one of claims 1 to 3, characterized in that: The biosilicon is crushed into a particle size of 1-50 μm, and then the crushed biosilicon is mixed with amino acids at a mass ratio of 80-120:

1.

5. Use of the aluminum-fixing and acid-reducing additive according to any one of claims 1 to 3 in improving acidified soil.

6. The use according to claim 5, characterized in that The aluminum-fixing and acid-reducing additive is evenly applied to the acidic soil, and the addition amount of the aluminum-fixing and acid-reducing additive is 1-5 kg / mu.

7. The use according to claim 5, characterized in that The addition amount of the aluminum-fixing and acid-reducing additive is 3-5 kg / mu.

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