A kind of blue algae magnesium ammonium phosphate biological fertilizer and preparation method thereof

Abstract

The present invention provides a cyanobacteria magnesium ammonium phosphate biofertilizer and a preparation method thereof, and belongs to the technical field of fertilizer preparation. The present invention uses fresh cyanobacteria, agricultural grade monoammonium phosphate, and magnesium oxide powder as raw materials, and obtains primary cyanobacteria magnesium ammonium phosphate biofertilizer through a wall breaking and slurry mixing step, a magnesium oxide powder neutralization reaction step, a standing and maturation step, and a drying and crushing step, and then obtains the cyanobacteria magnesium ammonium phosphate biofertilizer through steps such as adding cyanobacteria for two times of mixing, drying and crushing again. The cyanobacteria magnesium ammonium phosphate biofertilizer prepared by the present invention not only has a cyanobacteria content of up to 20-25%, but also contains a large amount of magnesium ammonium phosphate fertilizer, which can be used as a slow-release fertilizer, so it can also provide a large amount of organic and inorganic nutrients for plants without any fermentation treatment. In addition, the direct, large-scale, low-energy, and efficient use of fresh cyanobacteria in the present invention also provides a new idea for the environmental protection treatment of fresh cyanobacteria.

Description

[0001] This application is a divisional application of a patent application entitled "A method for producing cyanobacteria-type magnesium ammonium phosphate slow-release fertilizer". The application date of the original application is January 5, 2022, and the application number is 202210003070.7. Technical Field

[0002] The invention belongs to the technical field of fertilizer preparation, and in particular relates to a cyanobacteria magnesium ammonium phosphate biofertilizer and a preparation method thereof. Background Art

[0003] How to deal with the blue algae in lakes that cause serious water pollution is a current problem. Although it is known that blue algae contain many beneficial ingredients and can be used as organic fertilizer, the blue algae in the lake contain a large amount of water, usually with a water content of about 90%. The blue algae treatment after salvage must first remove the water, and the blue algae has a large viscosity and a small dry specific surface area. Therefore, it is very difficult to treat the blue algae with such a large water content after salvage using existing technology. For example, drying blue algae with baking equipment is energy-consuming and cannot be processed in large quantities; drying blue algae with the sun not only takes up more land resources, but also takes a long time to dry; burying blue algae not only takes up land, but also is not conducive to the integrated utilization of resources; although adding a large amount of other dry materials to blue algae can reduce the water content of blue algae and ferment it to form organic fertilizer, the current dry materials, such as organic resources such as tobacco dust and sawdust, are limited in number, and the fermentation process is also very long, so it is not realistic. Therefore, the treatment of blue algae in lakes in various places is still in the research stage so far, and a new idea is urgently needed.

[0004] At the same time, in order to produce magnesium ammonium phosphate slow-release fertilizer, agricultural-grade monoammonium phosphate needs to be added with water to make a slurry so that it can react with magnesium oxide powder to form magnesium ammonium phosphate. However, the problem of water resource shortage is also imminent. Summary of the invention

[0005] In order to solve the above problems, the present invention provides a cyanobacteria magnesium ammonium phosphate bio-fertilizer and a preparation method thereof.

[0006] The invention uses fresh cyanobacteria, agricultural-grade monoammonium phosphate and magnesium oxide powder as raw materials, obtains primary cyanobacteria magnesium ammonium phosphate bio-fertilizer through the steps of wall breaking and slurry mixing, adding magnesium oxide powder for neutralization reaction, standing and aging, and drying and crushing, and then obtains the cyanobacteria magnesium ammonium phosphate bio-fertilizer through the steps of adding cyanobacteria for mixing twice, drying and crushing again.

[0007] The cyanobacteria magnesium ammonium phosphate biological fertilizer prepared by the invention not only has a cyanobacteria content as high as 20-25%, but also contains a large amount of magnesium ammonium phosphate fertilizer, which can be used as a slow-release fertilizer, so it can provide a large amount of organic and inorganic nutrients for plants without any fermentation treatment.

[0008] In view of the fact that a large amount of water is required for slurrying of magnesium ammonium phosphate in the production process so that it can react with magnesium oxide powder to generate magnesium ammonium phosphate, the present invention utilizes water released by cyanobacteria wall breaking to slurry the magnesium ammonium phosphate, which not only saves water resources but also incidentally solves the problem that cyanobacteria are difficult to dry by a high-efficiency and low-cost method. At the same time, the produced cyanobacteria magnesium ammonium phosphate biofertilizer has superior performance and stable quality, is easily absorbed by crops, and does not compact the land or degrade the soil.

[0009] The present invention uses fresh blue algae directly, in large quantities, with low energy consumption and high efficiency, and also provides a new idea for the environmentally friendly treatment of fresh blue algae.

[0010] In order to achieve the above object, the present invention adopts the following technical solutions:

[0011] The present invention provides a method for preparing cyanobacteria magnesium ammonium phosphate biofertilizer, comprising the following steps:

[0012] Step 1: Primary preparation

[0013] (1) adding monoammonium phosphate to fresh cyanobacteria at a mass ratio of monoammonium phosphate: fresh cyanobacteria = 0.8-1.0:1.0, stirring for more than 30 minutes to fully break the cyanobacteria cells and release the water in the cyanobacteria cells, forming a slurry with a water content of 45-50%;

[0014] (2) adding magnesium oxide powder to the slurry obtained above at a molar ratio of effective P in the slurry: MgO in the magnesium oxide powder = 1:1.1-1.3, stirring and reacting for 10-15 minutes to obtain a reactant;

[0015] (3) leaving the above-obtained reactants to stand and mature for 20 to 30 days to obtain a semi-solidified mass;

[0016] (4) drying and crushing the obtained block to obtain primary cyanobacteria magnesium ammonium phosphate bio-fertilizer, wherein the cyanobacteria content in the primary cyanobacteria magnesium ammonium phosphate bio-fertilizer is 5-8%;

[0017] Step 2: Intermediate Preparation

[0018] The primary cyanobacteria magnesium ammonium phosphate bio-fertilizer obtained in step 1 is mixed evenly with fresh cyanobacteria in a mass ratio of 1:1, dried and crushed to obtain an intermediate cyanobacteria magnesium ammonium phosphate bio-fertilizer, wherein the cyanobacteria content in the intermediate cyanobacteria magnesium ammonium phosphate bio-fertilizer is 14-17%;

[0019] Step 3: Advanced preparation

[0020] The intermediate cyanobacteria magnesium ammonium phosphate bio-fertilizer obtained in step 2 is mixed evenly with fresh cyanobacteria in a ratio of 1:1, dried and crushed to obtain the cyanobacteria magnesium ammonium phosphate bio-fertilizer, wherein the cyanobacteria content in the cyanobacteria magnesium ammonium phosphate bio-fertilizer is 20-25%;

[0021] Repeat step 3 1 to 5 times to obtain cyanobacteria magnesium ammonium phosphate biofertilizer with higher cyanobacteria content;

[0022] The cyanobacteria magnesium ammonium phosphate biological fertilizer is a slow-release fertilizer, which can provide a large amount of organic and inorganic nutrients to plants without any fermentation treatment.

[0023] Preferably, the fresh blue algae in step (1) are newly salvaged blue algae with a water content of 89.0-91.0%.

[0024] Preferably, the monoammonium phosphate in step (1) is commercially available agricultural grade monoammonium phosphate.

[0025] Preferably, the magnesium oxide powder added in step (2) is light-burned magnesium oxide powder obtained by calcining magnesite and containing active magnesium oxide as a main component.

[0026] In the step (2) and (4) of the first step and the second and third steps, when the blue algae magnesium ammonium phosphate bio-fertilizer is mixed with fresh blue algae, the characteristics of magnesium ammonium phosphate being insoluble in water and having good material dispersibility are fully utilized, and the fresh blue algae with high viscosity and difficult to dry are dispersed into loose materials with large specific surface area and extremely easy to dry, and then the materials can be conventionally dried and crushed.

[0027] The present invention also provides a cyanobacteria magnesium ammonium phosphate bio-fertilizer prepared by the preparation method.

[0028] One of the technical problems to be solved by the present invention is: how to handle up to 90% of the moisture in fresh blue algae in time. Because if the moisture in the blue algae is not handled in time and effectively, the blue algae fished up will easily rot due to the high water content, and then cause huge secondary pollution to the environment, and also lose a large amount of organic fertilizer resources in the blue algae. For this reason, the present invention utilizes the water released by the fresh blue algae wall breaking to solve the problem of needing to use water for slurry mixing in the production process of magnesium ammonium phosphate slow-release fertilizer, because, first, in the process of producing magnesium ammonium phosphate slow-release fertilizer, it is necessary to use a large amount of water to adjust monoammonium phosphate into slurry, second, water is also needed to form the internal crystal water of magnesium ammonium phosphate in the magnesium ammonium phosphate slaking process, and third, because the magnesium ammonium phosphate produced is insoluble in water and has good dispersibility, when the magnesium ammonium phosphate is formed, the blue algae will adhere to the small particles of magnesium ammonium phosphate with good dispersibility, thereby expanding the specific surface area of ​​the blue algae, such blue algae type magnesium ammonium phosphate material is easy to be dried with existing drying equipment, or directly dried by the sun, so it can also fundamentally solve the problem that the prior art cannot handle blue algae.

[0029] The second technical problem to be solved by the present invention is: how to improve the cyanobacteria treatment efficiency and reduce the processing cost of cyanobacteria. For this reason, the present invention utilizes cyanobacteria to produce cyanobacteria magnesium ammonium phosphate biofertilizer, wherein although primary treatment can make full use of the water contained in cyanobacteria, one ton of magnesium ammonium phosphate can only be consumed for each production of one ton of magnesium ammonium phosphate, and the content of cyanobacteria in the product is relatively low, not higher than 8%. To solve this difficulty, the present invention makes full use of the characteristics of low solubility and good dispersibility of magnesium ammonium phosphate, first produces low-level cyanobacteria type magnesium ammonium phosphate with cyanobacteria, then mixes with cyanobacteria to form a loose material with a relatively large specific surface area and very easy to dry, then dries the material, obtains intermediate cyanobacteria type magnesium ammonium phosphate, then mixes with cyanobacteria, until obtaining a cyanobacteria content higher, a cyanobacteria type magnesium ammonium phosphate slow-release fertilizer with better fertilizer quality, and after each ton of low-level cyanobacteria type magnesium ammonium phosphate is mixed with fresh cyanobacteria, at least 8 tons of fresh cyanobacteria can be consumed, therefore, the method of the present invention can not only significantly reduce the cost of processing cyanobacteria, but also obtain a cyanobacteria magnesium ammonium phosphate biofertilizer with a higher organic matter content.

[0030] The present invention has the following advantages and effects:

[0031] 1. Water saving: The process water required in the production of magnesium ammonium phosphate comes from fresh blue algae to be processed, without consuming other water resources;

[0032] 2. Blue algae can be efficiently recycled: Blue algae have a high water content and are easy to corrupt. If the water content of blue algae cannot be reduced in time and effectively to prevent blue algae from corrupting, it will cause serious pollution to the environment and the organic fertilizer in the blue algae cannot be recycled. The blue algae-type magnesium ammonium phosphate material formed by the present invention has good dispersibility, large specific surface area, and is very easy to dry. It can be dried by ordinary drying equipment or by natural solar airing. The dried blue algae is a very good organic fertilizer.

[0033] 3. Excellent fertilizer performance: Blue algae is a very good organic fertilizer with a high organic nitrogen content, while magnesium ammonium phosphate is a very good slow-release inorganic fertilizer. The combination of the two has excellent fertilizer effect and is particularly suitable for use as base fertilizer. Fruits such as apples, strawberries, and peaches grown with this fertilizer have good flavor.

[0034] 4. Low production cost and significant economic benefits: After being mixed and dispersed with magnesium ammonium phosphate, cyanobacteria will form a loose material with a large specific surface area and is extremely easy to dry. It can be dried by natural airing with extremely low drying costs; even if traditional coal-fired drying is used, the drying energy consumption cost is lower than the value of the recovered cyanobacteria (the energy consumption cost of drying one ton of fresh cyanobacteria is about 120 yuan, and 0.1 ton of dry cyanobacteria can be obtained, with a fertilizer value of 160 yuan).

[0035] 5. Significant social benefits: The use of the present invention to recycle cyanobacteria can not only avoid the secondary environmental pollution caused by landfilling cyanobacteria, but also recycle a large amount of valuable cyanobacteria organic fertilizer resources, providing a high-quality, inexpensive, high-quality organic and inorganic slow-release fertilizer for the development of high-quality specialty crops, which has no environmental nitrogen and phosphorus surface source pollution problems after use. DETAILED DESCRIPTION

[0036] The present invention will be further described below in conjunction with embodiments.

[0037] Example 1

[0038] A. Take 1000g of fresh blue algae just salvaged from the Longmen Algae Station of Dianchi Lake (including: water content 91.0%, organic matter 62.6%, nitrogen 4.4%, P2O5 0.6%), add 900g of agricultural grade monoammonium phosphate (including: N10.1%, P2O5 46.2%, MgO 0.9%), the ratio of agricultural grade monoammonium phosphate to blue algae is 0.9:1, stir for 35 minutes to form a slurry with a water content of 48.0%;

[0039] B. Add 390 g of light-burned magnesium oxide powder to the slurry obtained in step A at a molar ratio of effective P in the slurry: MgO in light-burned magnesium oxide powder (wherein: MgO content is 70.5%) = 1:1.2, and stir to react for 10 minutes to obtain a reaction mass;

[0040] C. The reaction material obtained in step B is allowed to stand and mature for 20 days to obtain a semi-solidified block;

[0041] D. Dry and crush the block obtained in step C to obtain 1533 grams of primary cyanobacteria magnesium ammonium phosphate bio-fertilizer, including 5.9% cyanobacteria, 3.7% organic matter, 5.9% N, 27.1 P2O5: 18.4% MgO;

[0042] E. Take 1500 grams of the primary cyanobacteria magnesium ammonium phosphate bio-fertilizer obtained in step D, mix it with 1500 grams of fresh cyanobacteria obtained in step A at a ratio of 1:1 to obtain 3000 grams of the mixed material, dry it in the sun, and crush it to obtain 1658 grams of intermediate cyanobacteria magnesium ammonium phosphate bio-fertilizer, wherein: cyanobacteria 13.5%, organic matter 8.4%, N 5.7%, P2O5 24.6%; MgO 16.4%;

[0043] F. Take 1600 grams of the intermediate cyanobacteria magnesium ammonium phosphate bio-fertilizer obtained in step E, mix it with the same fresh cyanobacteria as in step A at a ratio of 1:1, and obtain 3200 grams of the mixed material. After drying and crushing, 1751 grams of cyanobacteria magnesium ammonium phosphate bio-fertilizer is obtained, wherein: cyanobacteria 20.6%, organic matter 12.9%, N 5.6%, P2O5 22.5%, and MgO 15.0%.

[0044] Example 2

[0045] A. Take 1000g of fresh blue algae just salvaged from the Longmen Algae Station of Dianchi Lake (including: water content 89.0%, dry nitrogen content 4.3%, dry organic matter 62.9%, dry P2O5 0.6%), add 800g of agricultural grade monoammonium phosphate (including: N10.1%, P2O546.2%, MgO0.9%), the ratio of agricultural grade monoammonium phosphate to blue algae is 0.8:1.0, stir for 35 minutes, make the two form slurry, the slurry water content is 49.4%;

[0046] B. Add 320 g of light-burned magnesium oxide powder to the slurry obtained in step A at a molar ratio of effective P in the slurry: MgO in light-burned magnesium oxide powder (wherein: MgO content is 70.5%) = 1:1.1, and stir to react for 15 minutes to obtain a reaction mass;

[0047] C. The reaction material obtained in step B is allowed to stand and mature for 30 days to obtain a semi-solidified block;

[0048] D. After drying and crushing the blocks obtained in step C, 1401 grams of primary cyanobacteria magnesium ammonium phosphate bio-fertilizer was obtained, including: cyanobacteria 7.9%, organic matter 4.9%, N 5.7%, P2O5 26.5%, and MgO 16.2%;

[0049] E. Take 1400 grams of the primary cyanobacteria magnesium ammonium phosphate bio-fertilizer obtained in step D, mix it with 1400 grams of fresh cyanobacteria obtained in step A at a ratio of 1:1 to obtain 2800 grams of mixed material, and dry and crush it to obtain 1573 grams of intermediate cyanobacteria magnesium ammonium phosphate bio-fertilizer, wherein: cyanobacteria 16.8%, organic matter 10.5%, N 5.5%, P2O5 23.7% MgO 14.4%;

[0050] F. Take 1500 grams of the intermediate cyanobacteria magnesium ammonium phosphate bio-fertilizer obtained in step E, mix it with 1500 grams of fresh cyanobacteria obtained in step A at a ratio of 1:1 to obtain 3000 grams of mixed material, and obtain 1673 grams of new cyanobacteria magnesium ammonium phosphate bio-fertilizer after drying and crushing, wherein: cyanobacteria 24.9%, organic matter 15.6%, N 5.4%, P2O5 21.2%, MgO 12.9%.

[0051] The novel cyanobacteria magnesium ammonium phosphate biofertilizer prepared in the above two embodiments not only has a cyanobacteria content of up to 20-25%, but also contains a large amount of magnesium ammonium phosphate fertilizer, which can be used as a slow-release fertilizer, so it can provide a large amount of organic and inorganic nutrients for plants without any fermentation treatment. At the same time, the large amount of water in the fresh cyanobacteria also effectively solves the water demand problem in the production process of magnesium ammonium phosphate fertilizer, saving a large amount of water resources. In addition, the direct, large-scale, low-energy and efficient use of fresh cyanobacteria in the present invention also provides a new idea for the environmentally friendly treatment of fresh cyanobacteria.

Claims

1. A method for preparing cyanobacteria magnesium ammonium phosphate biofertilizer, characterized in that: The following steps are involved: Step 1: Primary preparation (1) adding monoammonium phosphate to fresh cyanobacteria at a mass ratio of monoammonium phosphate: fresh cyanobacteria = 0.8-1.0:1.0, stirring for more than 30 minutes to fully break the cyanobacteria cells and release the water in the cyanobacteria cells, forming a slurry with a water content of 45-50%; (2) Add magnesium oxide powder to the slurry obtained above at a molar ratio of effective P in the slurry: MgO in the magnesium oxide powder = 1:1.1-1.3, and stir to react for 10-15 minutes to obtain the reactant: (3) leaving the above-obtained reactants to stand and mature for 20 to 30 days to obtain a semi-solidified mass; (4) drying and crushing the obtained block to obtain primary cyanobacteria magnesium ammonium phosphate bio-fertilizer, wherein the cyanobacteria content in the primary cyanobacteria magnesium ammonium phosphate bio-fertilizer is 5-8%; Step 2: Intermediate Preparation The primary cyanobacteria magnesium ammonium phosphate bio-fertilizer obtained in step 1 is mixed evenly with fresh cyanobacteria in a mass ratio of 1:1, dried and crushed to obtain an intermediate cyanobacteria magnesium ammonium phosphate bio-fertilizer, wherein the cyanobacteria content in the intermediate cyanobacteria magnesium ammonium phosphate bio-fertilizer is 14-17%; Step 3: Advanced preparation The intermediate cyanobacteria magnesium ammonium phosphate bio-fertilizer obtained in step 2 is mixed evenly with fresh cyanobacteria in a ratio of 1:1, dried and crushed to obtain the cyanobacteria magnesium ammonium phosphate bio-fertilizer, wherein the cyanobacteria content in the cyanobacteria magnesium ammonium phosphate bio-fertilizer is 20-25%; Repeat step 3 1 to 5 times to obtain the cyanobacteria magnesium ammonium phosphate biofertilizer with a higher cyanobacteria content; The cyanobacteria magnesium ammonium phosphate biological fertilizer is a slow-release fertilizer.

2. The preparation method according to claim 1, characterized in that The fresh blue algae in step (1) are blue algae newly salvaged from shore and having a water content of 89.0-91.0%.

3. The preparation method according to claim 2, characterized in that: The monoammonium phosphate in step (1) is commercially available agricultural grade monoammonium phosphate.

4. The preparation method according to claim 3, characterized in that: The magnesium oxide powder added in the step (2) is light-burned magnesium oxide powder obtained by calcining magnesite and containing active magnesium oxide as a main component.

5. A cyanobacteria magnesium ammonium phosphate biofertilizer prepared by the preparation method according to any one of claims 1 to 4.