A composite fertilizer containing seaweed extract and preparation method thereof

Abstract

The present invention relates to a composite fertilizer containing seaweed extract and a preparation method thereof, and belongs to the technical field of fertilizers. A preparation method of a composite fertilizer containing seaweed extract comprises mixing and leaching dried seaweed powder and ethanol aqueous solution, ultrasonic treatment under light-proof conditions, centrifugation to remove particles, rotary evaporation to remove the solvent, and vacuum drying to obtain seaweed extract; soaking rice husk carbon in sodium hydroxide aqueous solution, filtering, washing, drying, adding seaweed extract and base material to mix, spraying monomer solution, passing triethylamine gas under stirring conditions for constant temperature treatment, filtering, secondary washing, vacuum drying, and obtaining a preform; spraying syringaldehyde solution on the preform, stirring and mixing, filtering, washing, freeze-drying, and obtaining a composite fertilizer. The composite fertilizer prepared by the present invention can achieve slow release of fertilizer and greatly improve the utilization efficiency of fertilizer.

Description

Technical Field

[0001] The invention belongs to the technical field of fertilizers and relates to a composite fertilizer containing seaweed extract and a preparation method thereof. Background Art

[0002] Fertilizers play a key role in agricultural production and are of great significance for ensuring a good grain harvest and ensuring food security. Seaweed, as a marine spore plant that is visible to the naked eye, autotrophic, and has chloroplasts, mainly includes multicellular thallus, tubular, membranous or filamentous plants. There are currently two main types of seaweed fertilizer products on the market. One is a fertilizer prepared based on whole algae cells. Its advantage is that seaweed cells are alive and active; the other is a fertilizer prepared based on the extraction of seaweed active substances, which aims to discover ingredients with unique functions. Seaweed is rich in a large number of bioactive substances required for the growth of crops, including algae polysaccharides and their derivatives (oligosaccharides), a variety of monounsaturated fatty acids, long-chain polyunsaturated fatty acids, amino acids, small molecule peptides, natural pigments, minerals, plant hormones, trace elements, antibiotics, phenols, terpenes, etc.

[0003] Patent document No. CN101486619A discloses a method for preparing seaweed urea, which includes preparing concentrated seaweed extract by alkaline extraction, and then uniformly mixing the concentrated seaweed extract with molten urea solution in a urea granulation process, granulating in a granulation tower, and preparing a seaweed urea product. The combination of seaweed and urea can greatly improve the absorption and utilization rate of urea. However, the traditional fertilizer application method is affected by the environment (such as rain, temperature, microorganisms, etc.), and the utilization rate of traditional seaweed urea fertilizer is low, resulting in excessive use of seaweed urea fertilizer, which in turn has a serious impact on the ecological environment. Summary of the invention

[0004] The object of the present invention is to provide a composite fertilizer containing seaweed extract and a preparation method thereof. The composite fertilizer prepared by the present invention can achieve slow release of the fertilizer and greatly improve the utilization efficiency of the fertilizer.

[0005] The purpose of the present invention can be achieved through the following technical solutions:

[0006] A method for preparing a composite fertilizer containing seaweed extract, the preparation method comprising the following steps:

[0007] 1) Mixing and leaching the dried seaweed powder and ethanol aqueous solution, performing ultrasonic treatment under light-proof conditions, removing particles by centrifugation, removing the solvent by rotary evaporation, and vacuum drying to obtain the seaweed extract;

[0008] 2) soaking the rice husk carbon in a sodium hydroxide aqueous solution, filtering, washing, and drying, adding the seaweed extract and the base material to mix, spraying the monomer solution, passing triethylamine gas under stirring conditions for constant temperature treatment, filtering, secondary washing, and vacuum drying to obtain a preform;

[0009] 3) spraying the syringaldehyde solution onto the preform, stirring and mixing, filtering, washing, and freeze-drying to obtain a composite fertilizer.

[0010] As a preferred technical solution of the present invention, the present invention has the characteristics of simple operation and efficient reaction. The prepared composite fertilizer slow-release system can achieve the slow release of fertilizer, effectively reduce the fertilizer loss caused by leaching, decomposition, volatilization, etc., and greatly improve the fertilizer utilization rate.

[0011] As a preferred technical solution of the present invention, in step 1), the extraction time is 24-30h; the ultrasonic treatment is at 35-40kHz and ultrasonic for 30-40min; the centrifugation is at 3000-3200r / min and centrifugation for 15-20min.

[0012] As a preferred technical solution of the present invention, in step 1), the usage ratio of the seaweed powder and the ethanol aqueous solution is 1 g: 10-10.5 mL; the mass fraction of the ethanol aqueous solution is 55-60%.

[0013] As a preferred technical solution of the present invention, in step 2), the soaking time is 30-45 minutes; the stirring and mixing is at 1200-1500r / min and stirring is 35-45 minutes; the washing is washing with deionized water until neutral; the secondary washing is washing with methanol; the vacuum drying temperature is 70°C; the constant temperature treatment is at 35-40°C and the treatment is 4-6h.

[0014] As a preferred technical solution of the present invention, in step 2), the mass ratio of the rice husk carbon, the sodium hydroxide solution, the seaweed extract, the base material and the monomer solution is 20-23:70-80:7.5-8.0:9-10:4.5-5.0.

[0015] As a preferred technical solution of the present invention, in step 2), the mass fraction of the sodium hydroxide aqueous solution is 18-20%; the base material is formed by mixing potassium sulfate, urea and calcium phosphate in a mass ratio of 10-12:30-35:8-10; and the monomer solution is formed by mixing mercaptoethylamine, p-aminothiophenol and methanol in a mass ratio of 0.3:1-1.2:2.5.

[0016] As a preferred technical solution of the present invention, mercaptoethylamine has a certain fluidity, and p-aminothiophenol contains a benzene ring structure and has good stability. By compounding the two and then reacting with unsaturated fatty acids, while ensuring excellent stability, the cross-linking density of the reaction is increased, so that a denser cross-linking structure is formed, which is beneficial to the uniformity of the subsequent coating.

[0017] As a preferred technical solution of the present invention, in step 3), the stirring and mixing is carried out at 300-400 r / min for 3-5 hours; and the washing is carried out by washing with anhydrous ethanol.

[0018] As a preferred technical solution of the present invention, in step 3), the mass ratio of the preform to the syringaldehyde solution is 12:2.0-2.3.

[0019] As a preferred technical solution of the present invention, the syringaldehyde solution is prepared by mixing syringaldehyde and anhydrous ethanol in a mass ratio of 1.0-1.4:3.

[0020] The invention discloses a composite fertilizer containing seaweed extract prepared by the preparation method.

[0021] As a preferred technical solution of the present invention, the seaweed powder is red algae powder of the Betaphycus gelatinae GEEL-20 variety, produced in Sanya, Hainan.

[0022] Beneficial effects of the present invention:

[0023] The present invention uses activated rice husk carbon to adsorb seaweed extract, base material, mercaptoethylamine and p-aminothiophenol through hydrogen bonding and electrostatic action to construct a continuous network penetrating structure with high strength and hydrophobicity. The stability of the compound fertilizer is improved and a denser coating structure is formed by the reaction of triethylamine and syringaldehyde, thereby achieving a significant slow-release effect. DETAILED DESCRIPTION

[0024] In order to further illustrate the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the specific implementation methods, structures, features and effects of the present invention are described in detail below in combination with the embodiments.

[0025] Example 1

[0026] A method for preparing a composite fertilizer containing seaweed extract comprises the following steps:

[0027] 1) Mixing and leaching the dried seaweed powder and ethanol aqueous solution, performing ultrasonic treatment under light-proof conditions, removing particles by centrifugation, removing the solvent by rotary evaporation, and vacuum drying to obtain the seaweed extract;

[0028] In step 1), the extraction time is 24 hours; the ultrasonic treatment is performed at 35 kHz for 30 minutes; the centrifugation is performed at 3000 r / min for 15 minutes;

[0029] In step 1), the ratio of the seaweed powder to the ethanol aqueous solution is 1 g: 10 mL; the mass fraction of the ethanol aqueous solution is 55%;

[0030] 2) soaking the rice husk carbon in a sodium hydroxide aqueous solution, filtering, washing, and drying, adding the seaweed extract and the base material to mix, spraying the monomer solution, passing triethylamine gas under stirring conditions for constant temperature treatment, filtering, secondary washing, and vacuum drying to obtain a preform;

[0031] In step 2), the soaking time is 30 minutes; the stirring and mixing is at 1200 r / min and stirring for 35 minutes; the washing is washing with deionized water until neutral; the secondary washing is washing with methanol; the vacuum drying temperature is 70°C; the constant temperature treatment is at 35°C and the treatment is 4 hours;

[0032] In step 2), the mass ratio of the rice husk carbon, the sodium hydroxide solution, the seaweed extract, the base material and the monomer solution is 20:70:7.5:9:4.5;

[0033] In step 2), the mass fraction of the sodium hydroxide aqueous solution is 18%; the base material is formed by mixing potassium sulfate, urea and calcium phosphate in a mass ratio of 10:30:8; the monomer solution is formed by mixing mercaptoethylamine, p-aminothiophenol and methanol in a mass ratio of 0.3:1:2.5;

[0034] 3) spraying the syringaldehyde solution onto the preform, stirring and mixing, filtering, washing, and freeze-drying to obtain a composite fertilizer;

[0035] In step 3), the stirring and mixing is performed at 300 r / min for 3 hours; the washing is performed by washing with anhydrous ethanol;

[0036] In step 3), the mass ratio of the preform to the syringaldehyde solution is 12:2.0; the syringaldehyde solution is prepared by mixing syringaldehyde and anhydrous ethanol in a mass ratio of 1.0:3.

[0037] Example 2

[0038] A method for preparing a composite fertilizer containing seaweed extract comprises the following steps:

[0039] 1) Mixing and leaching the dried seaweed powder and ethanol aqueous solution, performing ultrasonic treatment under light-proof conditions, removing particles by centrifugation, removing the solvent by rotary evaporation, and vacuum drying to obtain the seaweed extract;

[0040] In step 1), the extraction time is 27 hours; the ultrasonic treatment is at 38 kHz for 35 minutes; the centrifugation is at 3100 r / min for 18 minutes;

[0041] In step 1), the ratio of the seaweed powder to the ethanol aqueous solution is 1 g: 10.2 mL; the mass fraction of the ethanol aqueous solution is 58%;

[0042] 2) soaking the rice husk carbon in a sodium hydroxide aqueous solution, filtering, washing, and drying, adding the seaweed extract and the base material to mix, spraying the monomer solution, passing triethylamine gas under stirring conditions for constant temperature treatment, filtering, secondary washing, and vacuum drying to obtain a preform;

[0043] In step 2), the soaking time is 38 minutes; the stirring and mixing is 1350r / min and stirring for 40 minutes; the washing is washing with deionized water until neutral; the secondary washing is washing with methanol; the vacuum drying temperature is 70°C; the constant temperature treatment is 38°C and the treatment is 5 hours;

[0044] In step 2), the mass ratio of the rice husk carbon, the sodium hydroxide solution, the seaweed extract, the base material and the monomer solution is 22:75:7.8:9.5:4.8;

[0045] In step 2), the mass fraction of the sodium hydroxide aqueous solution is 19%; the base material is prepared by mixing potassium sulfate, urea and calcium phosphate in a mass ratio of 11:32:9; the monomer solution is prepared by mixing mercaptoethylamine, p-aminothiophenol and methanol in a mass ratio of 0.3:1.1:2.5;

[0046] 3) spraying the syringaldehyde solution onto the preform, stirring and mixing, filtering, washing, and freeze-drying to obtain a composite fertilizer;

[0047] In step 3), the stirring and mixing is performed at 350 r / min for 4 hours; the washing is performed by washing with anhydrous ethanol;

[0048] In step 3), the mass ratio of the preform to the syringaldehyde solution is 12:2.2; the syringaldehyde solution is prepared by mixing syringaldehyde and anhydrous ethanol in a mass ratio of 1.2:3.

[0049] Example 3

[0050] A method for preparing a composite fertilizer containing seaweed extract comprises the following steps:

[0051] 1) Mixing and leaching the dried seaweed powder and ethanol aqueous solution, performing ultrasonic treatment under light-proof conditions, removing particles by centrifugation, removing the solvent by rotary evaporation, and vacuum drying to obtain the seaweed extract;

[0052] In step 1), the extraction time is 30 hours; the ultrasonic treatment is performed at 40 kHz for 40 minutes; the centrifugation is performed at 3200 r / min for 20 minutes;

[0053] In step 1), the ratio of the seaweed powder to the ethanol aqueous solution is 1 g: 10.5 mL; the mass fraction of the ethanol aqueous solution is 60%;

[0054] 2) soaking the rice husk carbon in a sodium hydroxide aqueous solution, filtering, washing, and drying, adding the seaweed extract and the base material to mix, spraying the monomer solution, passing triethylamine gas under stirring conditions for constant temperature treatment, filtering, secondary washing, and vacuum drying to obtain a preform;

[0055] In step 2), the soaking time is 45 minutes; the stirring and mixing is at 1500r / min and stirring for 45 minutes; the washing is washing with deionized water until neutral; the secondary washing is washing with methanol; the vacuum drying temperature is 70°C; the constant temperature treatment is at 40°C and the treatment is 6 hours;

[0056] In step 2), the mass ratio of the rice husk carbon, the sodium hydroxide solution, the seaweed extract, the base material and the monomer solution is 23:80:8.0:10:5.0;

[0057] In step 2), the mass fraction of the sodium hydroxide aqueous solution is 20%; the base material is formed by mixing potassium sulfate, urea and calcium phosphate in a mass ratio of 12:35:10; the monomer solution is formed by mixing mercaptoethylamine, p-aminothiophenol and methanol in a mass ratio of 0.3:1.2:2.5;

[0058] 3) spraying the syringaldehyde solution onto the preform, stirring and mixing, filtering, washing, and freeze-drying to obtain a composite fertilizer;

[0059] In step 3), the stirring and mixing is performed at 400 r / min for 5 hours; the washing is performed by washing with anhydrous ethanol;

[0060] In step 3), the mass ratio of the preform to the syringaldehyde solution is 12:2.3; the syringaldehyde solution is prepared by mixing syringaldehyde and anhydrous ethanol in a mass ratio of 1.4:3.

[0061] Comparative Example 1

[0062] Compared with Example 2, the difference in Comparative Example 1 is step 2);

[0063] Step 2) adding rice husk carbon to the seaweed extract and the base material, spraying the monomer solution, introducing triethylamine gas under stirring conditions for constant temperature treatment, filtering, secondary washing, and vacuum drying to obtain a preform;

[0064] The remaining components, preparation steps and parameters were the same.

[0065] Comparative Example 2

[0066] Compared with Example 2, the difference of Comparative Example 2 is that mercaptoethylamine and p-aminothiophenol are not used in Comparative Example 2, and the other components, preparation steps and parameters are the same.

[0067] Comparative Example 3

[0068] Compared with Example 2, the difference in Comparative Example 3 is that mercaptoethylamine is used in Comparative Example 3 instead of p-aminothiophenol, and the other components, preparation steps and parameters are the same.

[0069] Comparative Example 4

[0070] Compared with Example 2, Comparative Example 4 is different in that p-aminothiophenol is used instead of mercaptoethylamine, and the other components, preparation steps and parameters are the same.

[0071] Comparative Example 5

[0072] Compared with Example 2, the difference in Comparative Example 5 is that no syringaldehyde is used in Comparative Example 5, and the other components, preparation steps and parameters are the same.

[0073] Comparative Example 6

[0074] Compared with Example 2, the difference in Comparative Example 6 is that no rice husk carbon is used in Comparative Example 6, and the other components, preparation steps and parameters are the same.

[0075] The amino acid fertilizers prepared in Examples 1-3 and Comparative Examples 1-6 were tested as follows, and the test results are shown in Table 1.

[0076] Slow-release experiment of fertilizer: According to the national standard of slow-release fertilizer in my country (GB / T23348-2009), the water dissolution rate method was used for determination. 10g of compound fertilizer was weighed, each was soaked in 250g of clean water and placed in a constant temperature box at 25℃, and the urea dissolution rate was measured after 1 day, 14 days, 28 days and 35 days;

[0077] Table 1

[0078] 1 day 14 days 28 days 35 days Example 1 0.5 7.36 16.43 33.54 Example 2 0.8 7.65 16.55 33.72 Example 3 0.6 7.33 16.28 33.03 Comparative Example 1 1.4 16.84 26.29 41.68 Comparative Example 2 5.1 24.57 34.23 64.25 Comparative Example 3 4.3 22.50 31.61 60.84 Comparative Example 4 4.0 21.64 30.21 58.89 Comparative Example 5 3.5 20.58 29.79 57.78 Comparative Example 6 1.8 18.12 27.20 43.38

[0079] From the test results in Table 1, it can be seen that compared with Comparative Examples 1-6, the compound fertilizer prepared in Examples 1-3 of the present invention has excellent slow-release effect.

[0080] The invention uses activated rice husk carbon to mutually adsorb seaweed extract, base material, mercaptoethylamine and p-aminothiophenol through hydrogen bonding and electrostatic action, and a continuous network penetrating structure is formed inside the compound fertilizer, and the structure has high strength and excellent hydrophobicity. Among them, trace metal elements further react with amino acids, -COOH, -OH, -NH2 and the like of mercaptoethylamine and p-aminothiophenol in the compound fertilizer and gradually form a layer of dense hydrophobic cross-linked network structure, and then cross-linking occurs between triethylamine and unsaturated fatty acids, thereby avoiding the problem of element loss caused by degradation of carbon-carbon double bonds under environmental influences, and improving the slow-release effect by increasing the stability of the compound fertilizer. Finally, the aldehyde group on syringaldehyde can react not only with p-aminothiophenol and mercaptoethylamine, but also with amino acids in the seaweed extract, thereby forming a denser coating structure, thereby achieving a significant slow-release effect.

[0081] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technical personnel in this field can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A method for preparing a compound fertilizer containing seaweed extract, It is characterized in that The preparation method comprises the following steps: 1) Mixing and leaching dried seaweed powder and ethanol aqueous solution, ultrasonically treating under light-proof conditions, removing particles by centrifugation, removing the solvent by rotary evaporation, and vacuum drying to obtain a seaweed extract; the amount ratio of the seaweed powder to the ethanol aqueous solution is 1g:10-10.5mL; the mass fraction of the ethanol aqueous solution is 55-60%; 2) After soaking the rice husk carbon in a sodium hydroxide aqueous solution, filtering, washing, and drying, adding seaweed extract and base material to mix, spraying the monomer solution, passing triethylamine gas under stirring conditions for constant temperature treatment, filtering, secondary washing, and vacuum drying to obtain a preform; the mass ratio of the rice husk carbon, sodium hydroxide solution, seaweed extract, base material and monomer solution is 20-23:70-80:7.5-8.0:9-10:4.5-5.0; the mass fraction of the sodium hydroxide aqueous solution is 18-20%; the base material is a mixture of potassium sulfate, urea and calcium phosphate in a mass ratio of 10-12:30-35:8-10; the monomer solution is a mixture of mercaptoethylamine, p-aminothiophenol and methanol in a mass ratio of 0.3:1-1.2:2.5; 3) spraying the syringaldehyde solution onto the preform, stirring and mixing, filtering, washing, and freeze-drying to obtain a composite fertilizer; the mass ratio of the preform to the syringaldehyde solution is 12:2.0-2.3; the syringaldehyde solution is prepared by mixing syringaldehyde and anhydrous ethanol in a mass ratio of 1.0-1.4:

3.

2. A method for preparing a composite fertilizer containing seaweed extract according to claim 1, Features: In step 1), the extraction time is 24-30 hours; the ultrasonic treatment is performed at 35-40 kHz for 30-40 minutes; and the centrifugation is performed at 3000-3200 r / min for 15-20 minutes.

3. The method for preparing a composite fertilizer containing seaweed extract according to claim 1, Features: In step 2), the soaking time is 30-45 minutes; the stirring and mixing is 1200-1500 r / min, stirring for 35-45 minutes; the washing is washing with deionized water until neutral; The secondary washing adopts methanol washing; the temperature of the vacuum drying is 70°C; the constant temperature treatment is at 35-40°C for 4-6h.

4. The method for preparing a composite fertilizer containing seaweed extract according to claim 1, Features: In step 3), the stirring and mixing is carried out at 300-400 r / min for 3-5 hours; and the washing is carried out using anhydrous ethanol.

5. A compound fertilizer containing seaweed extract prepared by the preparation method according to any one of claims 1 to 4.