Organic silicon acidic soil conditioner and preparation method thereof

Abstract

The invention relates to the technical field of soil remediation, and provides an organic silicon acidic soil conditioner and a preparation method thereof. The organic silicon acidic soil conditioner is prepared from the following components: 4 to 6 parts of organic silicon, 30 to 40 parts of alkaline blast furnace slag, 10 to 15 parts of red mud, 8 to 12 parts of dolomite, 15 to 20 parts of aminated composite charcoal and 18 to 24 parts of bio-based functional additive, the aminated composite biochar is obtained by carrying out surface amination on composite biochar; the composite biochar is obtained by modifying biochar with rectorite. By means of the technical scheme, the problem that in the prior art, an acid soil conditioner is difficult to reduce the content of exchanged aluminum in acid soil is solved.

Description

Technical Field

[0001] This invention relates to the field of soil remediation technology, specifically to an organosilicon acid soil conditioner and its preparation method. Background Technology

[0002] Soil acidification is one of the major challenges facing global agricultural production and the ecological environment, and its causes involve the dual impacts of natural processes and human activities. Under natural conditions, soil weathering and leaching, the accumulation of carbonic acid produced by biological respiration, and the leaching of base ions by rainfall gradually lower the soil pH value. In modern agricultural production, long-term excessive application of chemical nitrogen fertilizers (such as ammonium nitrogen fertilizers), continuous cropping leading to soil nutrient imbalance, and industrial acid rain deposition are all human factors that further accelerate the soil acidification process, especially in tropical and subtropical regions and in greenhouse cultivation soils, where the acidification problem is more prominent.

[0003] Currently, acidic soil conditioning mainly relies on traditional alkaline conditioners such as lime and carbonates. While these conditioners can quickly neutralize soil acidity and raise pH levels, they have significant limitations. They lack the ability to specifically immobilize heavy metal ions in the soil and are unable to effectively reduce the content of toxic ions such as exchangeable aluminum, thus failing to fundamentally solve the problem of crop root poisoning. Therefore, there is an urgent need for an acidic soil conditioner that can powerfully reduce the content of exchangeable aluminum in acidic soils. Summary of the Invention

[0004] This invention proposes an organosilicon acidic soil conditioner and its preparation method, which solves the problem in related technologies that acidic soil conditioners are difficult to reduce the exchangeable aluminum content in acidic soils.

[0005] The technical solution of the present invention is as follows: This invention proposes an organosilicon acidic soil conditioner, comprising the following components: 4-6 parts organosilicon, 30-40 parts alkaline blast furnace slag, 10-15 parts red mud, 8-12 parts dolomite, 15-20 parts aminated composite biochar, and 18-24 parts bio-based functional additives. The aminated composite biochar is obtained by surface amination of composite biochar. The composite biochar is obtained by modifying biochar with attapulgite.

[0006] As a further technical solution, the preparation method of the composite biochar includes the following steps: A1. After the straw is crushed and carbonized, biochar is obtained; the biochar is mixed with attapulgite, calcined, cooled, baked, ground and sieved to obtain composite biochar; A2. Disperse the composite biochar in water, add diethylenetriamine and epichlorohydrin, stir to react, filter, wash, and sieve to obtain aminated composite biochar.

[0007] As a further technical solution, the carbonization is carried out in an inert gas atmosphere; The carbonization temperature is 500~600℃.

[0008] As a further technical solution, the mass ratio of biochar to attapulgite is 5~8:1; The calcination temperature is 600~620℃, and the calcination time is 2~2.5h.

[0009] As a further technical solution, the volume ratio of diethylenetriamine to epichlorohydrin is 1:1.8~2; The mass-to-volume ratio of the composite biochar to epichlorohydrin is 2g:1.8~2mL; The temperature of the stirring reaction is 85~90℃, and the stirring reaction time is 2h.

[0010] As a further technical solution, the bio-based functional additive is polyglutamic acid and / or betaine.

[0011] Preferably, the bio-based functional additives are polyglutamic acid and betaine.

[0012] In this invention, an organosilicon acidic soil conditioner was prepared by using polyglutamic acid and betaine as a bio-based functional additive, which reduced the content of exchangeable aluminum in acidic soils. Polyglutamic acid contains a large number of carboxyl groups, which can react with Al... 3+ Forms stable chelates; betaine is an amphoteric electrolyte, and its quaternary ammonium group can bind to H in the soil. + It helps to raise and stabilize the soil pH. Meanwhile, the cations released from betaine can react with Al... 3+ Competition for soil colloid exchange sites reduces Al 3+ It is adsorbed by colloids, which reduces the proportion of exchangeable aluminum in acidic soils.

[0013] As a further technical solution, when the bio-based functional additive is polyglutamic acid and betaine, the mass ratio of polyglutamic acid to betaine is 2~3:1.

[0014] As a further technical solution, the red mud is Bayer process red mud.

[0015] As a further technical solution, the organosilicon includes silicone oil.

[0016] The present invention also proposes a method for preparing an organosilicic acid soil conditioner, comprising the following steps: mixing the components of the organosilicic acid soil conditioner evenly, granulating, and obtaining the organosilicic acid soil conditioner.

[0017] The working principle and beneficial effects of this invention are as follows: In this invention, an organosilicon acidic soil conditioner prepared by adding aminated composite biochar can reduce the content of exchangeable aluminum in acidic soils. Firstly, the biochar is modified with attapulgite to obtain a composite biochar with a larger specific surface area and richer pore structure. Its pores can physically adsorb Al from the soil. 3+ Reduce Al 3+ It binds to the exchange sites of soil colloids; subsequent amination modification introduces amino-containing functional groups onto the surface of the composite biochar. These functional groups are strong coordinating groups, facilitating the chemical complexation of Al. 3+ It provides active sites, thereby reducing the content of exchangeable aluminum in acidic soils through the combined action of physical and chemical adsorption. Detailed Implementation

[0018] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0019] In the following examples and comparative examples, the silicone oil is dimethyl silicone oil, type 201; the average particle size of attapulgite is 100 mesh; and the number average molecular weight of polyglutamic acid is 100,000.

[0020] Example 1 An organosilicon acidic soil conditioner comprises the following components: 4 parts silicone oil, 30 parts alkaline blast furnace slag, 10 parts Bayer red mud, 8 parts dolomite, 15 parts aminated composite biochar, and 18 parts polyglutamic acid. The preparation method of aminated composite biochar includes the following steps: A1. After the straw is crushed to a particle size of 1.6 mm, it is carbonized at 500 °C in a nitrogen atmosphere to obtain biochar; the biochar and attapulgite are mixed at a mass ratio of 5:1, calcined at 600 °C for 2.5 h, cooled, baked at 60 °C, and ground through a 100-mesh sieve to obtain composite biochar. A2. Disperse the composite biochar in 3 times its mass of water, add diethylenetriamine and epichlorohydrin, with a mass-volume ratio of 2g:1mL:1.8mL for the composite biochar, diethylenetriamine and epichlorohydrin. Stir and react at 85℃ for 2h, filter, wash and pass through a 100-mesh sieve to obtain aminated composite biochar. A method for preparing an organosilicon acidic soil conditioner includes the following steps: The components of the organosilicic acid soil conditioner are mixed evenly according to the above weight parts, and then granulated to obtain the organosilicic acid soil conditioner.

[0021] Example 2 An organosilicon acidic soil conditioner comprises the following components: 6 parts silicone oil, 40 parts alkaline blast furnace slag, 15 parts Bayer red mud, 12 parts dolomite, 20 parts aminated composite biochar, and 24 parts polyglutamic acid. The preparation method of aminated composite biochar includes the following steps: A1. After the straw is crushed to a particle size of 1.6 mm, it is carbonized at 600℃ in a nitrogen atmosphere to obtain biochar; the biochar and attapulgite are mixed at a mass ratio of 8:1, calcined at 620℃ for 2 hours, cooled, baked at 60℃, and ground through a 100-mesh sieve to obtain composite biochar. A2. Disperse the composite biochar in 3 times its mass of water, add diethylenetriamine and epichlorohydrin, with a mass-volume ratio of 2g:1mL:2mL for the composite biochar, diethylenetriamine and epichlorohydrin. Stir and react at 90℃ for 2h, filter, wash and pass through a 100-mesh sieve to obtain aminated composite biochar. A method for preparing an organosilicon acidic soil conditioner includes the following steps: The components of the organosilicic acid soil conditioner are mixed evenly according to the above weight parts, and then granulated to obtain the organosilicic acid soil conditioner.

[0022] Example 3 An organosilicon acidic soil conditioner comprises the following components: 5 parts silicone oil, 35 parts alkaline blast furnace slag, 12 parts Bayer red mud, 10 parts dolomite, 18 parts aminated composite biochar, and 22 parts polyglutamic acid. The preparation method of aminated composite biochar includes the following steps: A1. After the straw is crushed to a particle size of 1.6 mm, it is carbonized at 550℃ in a nitrogen atmosphere to obtain biochar; the biochar and attapulgite are mixed at a mass ratio of 6:1, calcined at 620℃ for 2 hours, cooled, baked at 60℃, and ground through a 100-mesh sieve to obtain composite biochar. A2. Disperse the composite biochar in 3 times its mass of water, add diethylenetriamine and epichlorohydrin, with a mass-volume ratio of 2g:1mL:2mL for the composite biochar, diethylenetriamine and epichlorohydrin. Stir and react at 90℃ for 2h, filter, wash and pass through a 100-mesh sieve to obtain aminated composite biochar. A method for preparing an organosilicon acidic soil conditioner includes the following steps: The components of the organosilicic acid soil conditioner are mixed evenly according to the above weight parts, and then granulated to obtain the organosilicic acid soil conditioner.

[0023] Example 4 The only difference between this embodiment and Example 1 is that polyglutamic acid is replaced with an equal amount of betaine.

[0024] Example 5 The only difference between this embodiment and Embodiment 1 is that 18 parts of polyglutamic acid are replaced with 12 parts of polyglutamic acid and 6 parts of betaine.

[0025] Example 6 The only difference between this embodiment and Example 1 is that 18 parts of polyglutamic acid are replaced with 13.5 parts of polyglutamic acid and 4.5 parts of betaine.

[0026] Example 7 The only difference between this embodiment and Embodiment 1 is that 18 parts of polyglutamic acid are replaced with 9 parts of polyglutamic acid and 9 parts of betaine.

[0027] Example 8 The only difference between this embodiment and Example 1 is that 18 parts of polyglutamic acid are replaced with 14.4 parts of polyglutamic acid and 3.6 parts of betaine.

[0028] Comparative Example 1 The only difference between this comparative example and Example 1 is that the aminated composite biochar is replaced with an equal amount of composite biochar; the preparation method of the composite biochar includes the following steps: After the straw is crushed to a particle size of 1.6 mm, it is carbonized at 500 °C in a nitrogen atmosphere to obtain biochar. The biochar and attapulgite are mixed at a mass ratio of 5:1, calcined at 600 °C for 2.5 h, cooled, baked at 60 °C, and ground through a 100-mesh sieve to obtain composite biochar.

[0029] Comparative Example 2 The only difference between this comparative example and Example 1 is that the aminated composite biochar is replaced with an equal amount of aminated biochar; the preparation method of the aminated biochar includes the following steps: A1. After the straw is crushed to a particle size of 1.6 mm, it is carbonized at 500℃ in a nitrogen atmosphere to obtain biochar. A2. Disperse biochar in 3 times its mass of water, add diethylenetriamine and epichlorohydrin, with a mass-to-volume ratio of 2g:1mL:1.8mL for biochar, diethylenetriamine and epichlorohydrin, and stir at 85℃ for 2 hours. Filter, wash and pass through a 100-mesh sieve to obtain aminated biochar.

[0030] Comparative Example 3 The only difference between this comparative example and Example 1 is that the aminated composite biochar is replaced with an equal amount of biochar; the method for preparing the biochar includes the following steps: After the straw is crushed to a particle size of 1.6 mm, it is carbonized at 500 °C in a nitrogen atmosphere to obtain biochar.

[0031] Experimental Example 1 The performance of the organosilicon acidic soil conditioners prepared in Examples 1-8 and Comparative Examples 1-3 was tested: The organosilicon acidic soil conditioners prepared in Examples 1-8 and Comparative Examples 1-3 were added to the experimental soil. The pH of the experimental soil was 4.1, the exchangeable aluminum content was 385 mg / kg, and the dosage of the organosilicon acidic soil conditioner was 2200 kg / hm². 2 The physicochemical properties of the soil were measured after 10 days. The exchangeable aluminum content of the experimental soils treated with the organosilicon acid soil conditioners prepared in Examples 1-8 and Comparative Examples 1-3 was tested, and the results are shown in Table 1. Table 1. Test results of exchangeable aluminum in the experimental soil after application.

[0032] By comparing the data of Examples 1-3 and Comparative Examples 1-3, the organosilicon acidic soil conditioner containing aminated composite biochar prepared by Examples 1-3, after being applied to the experimental acidic soil, had a lower exchangeable aluminum content than that of Comparative Examples 1-3. This indicates that the exchangeable aluminum content of acidic soil can be reduced by adding aminated composite biochar.

[0033] By comparing the data from Examples 1 and 4-8, the organic silicate acidic soil conditioner containing aminated composite biochar prepared in Examples 5-8 by adding polyglutamic acid and betaine showed that the exchangeable aluminum content of the soil was lower than that in Examples 1 and 4 after application to the experimental acidic soil. This indicates that the exchangeable aluminum content of acidic soil can be reduced by adding polyglutamic acid and betaine. By comparing the data from Examples 5-8, Examples 5-6 further reduced the exchangeable aluminum content of acidic soil by adjusting the mass ratio of polyglutamic acid to betaine to 2-3:1.

[0034] Experimental Example 2 The pH of the experimental soils treated with the organosilicon acidic soil conditioners prepared in Examples 1-3 was tested, and the results are shown in Table 2. Table 2. Test results of pH of the experimental soil after application.

[0035] According to the data in Table 2, the organosilicon acidic soil conditioner prepared by this invention, after being applied to the experimental acidic soil, increased the pH value of the acidic soil to 6.8 or above.

[0036] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An organosilicon acidic soil conditioner, characterized in that, It includes the following components: 4-6 parts organosilicon, 30-40 parts alkaline blast furnace slag, 10-15 parts red mud, 8-12 parts dolomite, 15-20 parts aminated composite biochar, and 18-24 parts bio-based functional additives. The aminated composite biochar is obtained by surface amination of composite biochar. The composite biochar is obtained by modifying biochar with attapulgite.

2. The organosilicon acidic soil conditioner according to claim 1, characterized in that, The method for preparing the composite biochar includes the following steps: A1. After the straw is crushed and carbonized, biochar is obtained; the biochar is mixed with attapulgite, calcined, cooled, baked, ground and sieved to obtain composite biochar; A2. Disperse the composite biochar in water, add diethylenetriamine and epichlorohydrin, stir to react, filter, wash, and sieve to obtain aminated composite biochar.

3. The organosilicon acidic soil conditioner according to claim 2, characterized in that, The carbonization is carried out in an inert gas atmosphere; The carbonization temperature is 500~600℃.

4. The organosilicon acidic soil conditioner according to claim 2, characterized in that, The mass ratio of biochar to attapulgite is 5~8:1; The calcination temperature is 600~620℃, and the calcination time is 2~2.5h.

5. The organosilicon acidic soil conditioner according to claim 2, characterized in that, The volume ratio of diethylenetriamine to epichlorohydrin is 1:1.8~2; The mass-to-volume ratio of the composite biochar to epichlorohydrin is 2g:1.8~2mL; The temperature of the stirring reaction is 85~90℃, and the stirring reaction time is 2h.

6. The organosilicon acidic soil conditioner according to claim 1, characterized in that, The bio-based functional additive is polyglutamic acid and / or betaine.

7. The organosilicon acidic soil conditioner according to claim 6, characterized in that, When the bio-based functional additive is polyglutamic acid and betaine, the mass ratio of polyglutamic acid to betaine is 2~3:

1.

8. The organosilicon acidic soil conditioner according to claim 1, characterized in that, The red mud mentioned is Bayer process red mud.

9. The organosilicon acidic soil conditioner according to claim 1, characterized in that, The organosilicon includes silicone oil.

10. A method for preparing an organosilicon acidic soil conditioner, used to prepare the organosilicon acidic soil conditioner according to any one of claims 1 to 9, characterized in that, Includes the following steps: The components of the organosilicic acid soil conditioner are mixed evenly and granulated to obtain the organosilicic acid soil conditioner.

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