A method for producing slow-release organic fertilizer by using cyanobacteria and papermaking sludge

Abstract

A method for producing slow-release organic fertilizer by cyanobacteria and papermaking sludge, comprising the following steps: 1. Slurry preparation: 1) preparing a phosphoric acid dilution solution; 2) preparing a potassium hydroxide dilution solution; 3) preparing a low-concentration potassium dihydrogen phosphate and dipotassium hydrogen phosphate mixed solution; 4) preparing an ammonium-containing low-concentration potassium dihydrogen phosphate solution; 5) preparing a complex electrolyte; 6) preparing micron magnesium potassium ammonium phosphorus particles; 2. Polycrystallization reaction: preparing large-particle magnesium potassium ammonium phosphorus polycrystals. Further preparing cyanobacterial magnesium potassium ammonium phosphorus polycrystals. Papermaking sludge, eucalyptus waste bark, magnesium potassium ammonium phosphorus polycrystal micropowder and composite bacterial agent are mixed by continuous drum to obtain an organic slow-release fertilizer raw material. The organic slow-release fertilizer raw material is composted and aerobically fermented, and the organic slow-release fertilizer is obtained by fermentation for 30 days. The organic fertilizer is prepared by fermentation treatment of cyanobacteria mud and papermaking sludge, which not only improves the fermentation efficiency, but also increases the nutrient content, and improves the utilization value of the fermented mud in the market.

Description

Technical Field

[0001] The invention relates to the technical field of solid waste treatment such as blue algae and papermaking sludge. Background Art

[0002] As an organic solid waste, the current treatment technologies for cyanobacteria mud mainly include incineration, landfill and traditional fermentation treatment followed by return to the field for use.

[0003] Incineration is a high-temperature heat treatment technology that oxidizes and decomposes sludge with excess air in an incinerator to destroy toxic and harmful substances in it, thereby achieving harmlessness, reduction and resource utilization of sludge. The volume of the residue after incineration is greatly reduced, and part of the heat energy can be recovered. However, there are problems such as high energy consumption and the waste gas and waste residue generated during the incineration process may cause secondary pollution to the environment.

[0004] Landfill is to directly bury the sludge in a designated site, and stabilize the sludge through natural decomposition and microbial action. The landfill method is simple and easy to operate, and the treatment cost is relatively low. However, there are problems such as occupying a large area of ​​land, causing the risk of secondary pollution, and difficult environmental management.

[0005] Traditional aerobic and anaerobic fermentation treatment is a common method for treating and recycling algae mud. This method aims to reduce the water content and harmful substance content of algae mud and improve the fertilizer efficiency of algae mud by composting and fermenting algae mud. The fermented algae mud can be applied to farmland as nutrient soil or organic fertilizer to realize the resource utilization of algae mud. However, due to the high water content of algae mud, its fermentation process is relatively slow and inefficient. This leads to a long processing cycle and occupies a large amount of land and resources. In addition, although the fermented algae mud can be used as fertilizer, its nutrient content is low and cannot meet the demand for high-efficiency fertilizers in modern agriculture. Due to the problems of low fermentation efficiency and low nutrient content, the utilization value of algae mud after traditional fermentation treatment is low in the market. Summary of the invention

[0006] In view of the above situation, in order to solve the problems existing in the above-mentioned technology, the present invention proposes a method for producing slow-release organic fertilizer by cyanobacteria and papermaking sludge. Organic fertilizer is prepared by fermentation treatment of cyanobacteria mud and papermaking sludge, which not only improves the fermentation efficiency, but also increases the nutrient content, thereby improving the utilization value of the fermented mud in the market.

[0007] A method for producing slow-release organic fertilizer by using cyanobacteria and papermaking sludge, comprising the following steps:

[0008] 1. Slurry preparation:

[0009] 1) Mix water and phosphoric acid and stir for 30 minutes to prepare a phosphoric acid dilution solution with a water content of 70%;

[0010] 2) Mixing water and potassium hydroxide and stirring for 30 minutes to prepare a potassium hydroxide dilute solution with a water content of 70%;

[0011] 3) Mixing 70% phosphoric acid dilution solution and 70% potassium hydroxide dilution solution to control the pH value to be between pH 4 and 7, stirring for 120 minutes at a temperature of 60° C., to prepare a low-concentration potassium dihydrogen phosphate and dipotassium hydrogen phosphate mixed solution;

[0012] 4) mixing a low-concentration potassium dihydrogen phosphate and dipotassium hydrogen phosphate mixed solution with liquid ammonia to control the pH value to be between pH 5 and 7, and stirring the mixture at a temperature of 25° C. for 30 minutes to prepare an ammonium-containing low-concentration potassium dihydrogen phosphate solution comprising water, ammonium ions, potassium dihydrogen phosphate / dipotassium hydrogen phosphate ions, potassium ions, unionized ammonia molecules, and hydrogen ions and hydroxide ions;

[0013] 5) mixing a low-concentration potassium dihydrogen phosphate solution containing ammonium and monoammonium phosphate, and stirring the mixture at 25° C. for 60 minutes to prepare a complex electrolyte;

[0014] 6) Mixing and stirring the complex electrolyte, cyanobacteria mud and wood fiber powder for 60 minutes to prepare micron magnesium potassium ammonium phosphate particles containing complex electrolyte, amino acids and ion-adsorbing wood fiber;

[0015] 2. Polycrystallization reaction:

[0016] The magnesium potassium ammonium phosphate particles and magnesium oxide are mixed and stirred for 10 minutes to prepare large-particle magnesium potassium ammonium phosphate polycrystals.

[0017] According to the method of producing slow-release organic fertilizer by cyanobacteria and papermaking sludge of the present application, the large-particle magnesium potassium ammonium phosphate polycrystals are further crushed to obtain small-particle magnesium potassium ammonium phosphate polycrystals with a particle size ranging from 40 mesh to 12 mm in diameter.

[0018] According to a method for producing slow-release organic fertilizer by cyanobacteria and papermaking sludge of the present application, the small-particle magnesium potassium ammonium phosphate polycrystals and cyanobacteria mud containing 10% solids are further mixed in a mass ratio of 1:1 and then dried and stirred for 20 minutes to prepare cyanobacteria-type magnesium potassium ammonium phosphate polycrystals.

[0019] According to the method of producing slow-release organic fertilizer by cyanobacteria and papermaking sludge of the present application, the method further includes the following steps:

[0020] 1) crushing the cyanobacteria-type magnesium potassium ammonium phosphate polycrystal to obtain magnesium potassium ammonium phosphate polycrystal micropowder with a particle size of 200 to 500 meshes;

[0021] 2) papermaking sludge, eucalyptus waste bark, magnesium potassium ammonium phosphate polycrystalline micropowder and composite bacterial agent are mixed by continuous drum to obtain organic slow-release fertilizer raw material, wherein the amount of magnesium potassium ammonium phosphate polycrystalline micropowder is 20% of the total mass, and the mass ratio of papermaking sludge to eucalyptus waste bark is 1:0.33;

[0022] 3) The organic slow-release fertilizer raw materials are composted and aerobic fermented to obtain the organic slow-release fertilizer after fermentation for 30 days.

[0023] According to the method of producing slow-release organic fertilizer by cyanobacteria and papermaking sludge of the present application, the organic slow-release fertilizer is further mixed with magnesium potassium ammonium phosphate polycrystals and borax, calcium sulfate and zinc sulfate to obtain a compound slow-release organic fertilizer.

[0024] According to a method for producing slow-release organic fertilizer by using cyanobacteria and papermaking sludge in the present application, further, the composite bacterial agent is a composite bacterial agent including lactic acid bacteria, yeast, lignin bacteria, Bacillus subtilis, Bacillus megaterium, Bacillus gelatinus and / or Bacillus gelatinus.

[0025] According to the method of producing slow-release organic fertilizer by cyanobacteria and papermaking sludge of the present application, further, the wood fiber powder is powder particles prepared from papermaking sludge and / or eucalyptus waste bark.

[0026] After adopting the technology proposed in the present invention, the method for producing slow-release organic fertilizer by cooperating with papermaking sludge according to the embodiment of the present invention has the following beneficial effects.

[0027] 1) By combining the innovative magnesium potassium ammonium phosphate polycrystal process of "phosphoric acid + potassium hydroxide + cyanobacteria + papermaking sludge powder + industrial-grade ammonium phosphate + magnesium oxide + zinc sulfate + calcium sulfate + borax" with mature papermaking sludge, a "endophytic organic slow-release magnesium potassium ammonium phosphate polycrystal" with stable structure and low solubility was successfully constructed. This innovative substance, with its excellent specific surface area and precise release rate control characteristics, ensures that nutrients can be stably released at a scientifically set rate, providing continuous and balanced nutritional support for plant growth. At the same time, the unique advantages of waste resources such as cyanobacteria, papermaking sludge and eucalyptus bark are fully utilized. Through chemical and microbial transformation, the protein in cyanobacteria, wood fiber, bacterial metabolites and organic matter in papermaking sludge and eucalyptus waste bark are efficiently converted into various amino acids, organic matter and humic acid required by plants, providing a guarantee for plant growth. This innovation not only realizes the value-added utilization of cyanobacteria mud and papermaking sludge, but also improves the nutritional value of fertilizers and more effectively promotes the healthy growth of plants.

[0028] 2) Use wood fiber micropowder particles to guide solute molecules and ions to begin to aggregate and form small crystal nuclei, which gradually grow into crystals. Eventually, multiple crystals will be combined together through chemical bonding and physical adsorption to form a larger polycrystalline structure. This polycrystalline structure has stable physical and chemical properties and forms a polymer with a large specific surface area. It begins to dissolve nutrients when it encounters water and stops releasing nutrients when it is oversaturated with water, which greatly improves the utilization rate of fertilizers and fully protects the ecological environment.

[0029] 3) By using wood fiber micropowder particles to guide solute molecules and ions to begin to aggregate and form small crystal nuclei, and eventually form larger polycrystalline structures. The particles vary in size (generally 2mm to 12mm), and their stable structure can avoid the trouble of later granulation.

[0030] 4) Through the synergistic cooperation of cyanobacteria mud and papermaking sludge, cyanobacteria provide amino acids and part of organic matter, and papermaking sludge provides part of organic matter and humic acid, and fermentation treatment is carried out to prepare organic fertilizer, thereby increasing the nutrient content of the final product; at the same time, since papermaking sludge contains a large amount of fiber and is relatively fluffy, it is conducive to fermentation. Compared with the traditional fermentation method of cyanobacteria mud, the fermentation efficiency is greatly improved.

[0031] 5) The method proposed in this application not only treats various wastes such as cyanobacteria mud and papermaking sludge, saving a lot of disposal costs for governments and enterprises; it can also improve the fermentation efficiency while providing plants with more sufficient organic nutrients, greatly enhancing the utilization value of organic fertilizer products after waste fermentation treatment in the market. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It shows a test design processing table in a fertilizer efficiency comparison test according to an embodiment of the present invention;

[0033] Figure 2 A comparative table showing the growth of trees with different base fertilizers over 1.2 years in a fertilizer efficiency comparison test according to an embodiment of the present invention is shown;

[0034] Figure 3 A graph showing the growth comparison of trees after applying different base fertilizers in a fertilizer efficiency comparison test according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0035] The various preferred embodiments of the present invention will be described below with reference to the accompanying drawings. The following description with reference to the accompanying drawings is provided to assist in the understanding of the exemplary embodiments of the present invention as defined by the claims and their equivalents. It includes various specific details to assist in understanding, but they are to be viewed as exemplary only. Therefore, those skilled in the art will recognize that various changes and modifications may be made to the embodiments described herein without departing from the scope and spirit of the present invention. Moreover, in order to make the specification more clear and concise, detailed descriptions of functions and configurations well known in the art will be omitted.

[0036] The limiting terms such as high-concentration organic slow-release fertilizers and high-organic organic slow-release fertilizers described in the embodiments of the present application are limited to the distinction between products prepared at different stages in the technical solution of the present application. The purpose is to distinguish products at different stages, and it is not a comparison or limitation with other existing fertilizers. The organic slow-release fertilizers, organic slow-release fertilizer raw materials, organic slow-release fertilizers, and compound slow-release organic fertilizers described in the present application have different names corresponding to the distinction between products prepared at different stages in the technical solution of the present application. The purpose is to distinguish products at different stages, and it is not a comparison or limitation with other existing fertilizers. The definition of complex electrolytes described in the present application is also similar. The specific circumstances of complex electrolytes are also explained in the specific embodiments, and the term complex electrolytes is only used to simplify the expression.

[0037] The preparation process of the embodiment of the present application is as follows:

[0038] 1. Preparation of magnesium potassium ammonium phosphate polycrystals:

[0039] In the process of chemical crystallization, the following stages are experienced:

[0040] 1. Slurry preparation:

[0041] 1) mixing water and 85% phosphoric acid with a high-speed stirrer for 30 minutes to prepare a phosphoric acid dilution solution with a water content of 70%;

[0042] The mass ratio of water to phosphoric acid is 1.83:1, and the phosphoric acid dilution solution is prepared by changing the total mass.

[0043] 2) mixing water and 90% potassium hydroxide with a high-speed stirrer for 30 minutes to prepare a potassium hydroxide dilution solution with a water content of 70%;

[0044] The mass ratio of water to potassium hydroxide is 2.3:1, and the potassium hydroxide dilute solution is prepared by changing the total mass.

[0045] 3) Mixing 70% phosphoric acid dilution solution and 70% potassium hydroxide dilution solution to control the pH value to be between pH 4 and 7, and stirring the mixture in a high-speed stirrer at a temperature of 60° C. for 120 min to prepare a low-concentration potassium dihydrogen phosphate and dipotassium hydrogen phosphate mixed solution;

[0046] The mass ratio of the 70% phosphoric acid dilution solution to the 70% potassium hydroxide dilution solution is 1.8-2.0:0.9-1. The prepared low-concentration mixed solution of potassium dihydrogen phosphate and dipotassium hydrogen phosphate is mainly potassium dihydrogen phosphate and contains a small amount of dipotassium hydrogen phosphate.

[0047] 4) mixing a low-concentration potassium dihydrogen phosphate and dipotassium hydrogen phosphate mixed solution with 99.9% liquid ammonia to control the pH value to be between pH 5 and pH 7, and mixing and stirring in a mixer at a temperature of 25° C. for 30 minutes to prepare an ammonium-containing low-concentration potassium dihydrogen phosphate solution comprising water, ammonium ions, potassium dihydrogen phosphate / dipotassium hydrogen phosphate ions, potassium ions, unionized ammonia molecules, and a small amount of hydrogen ions and hydroxide ions;

[0048] The mass ratio of the low-concentration potassium dihydrogen phosphate and dipotassium hydrogen phosphate mixed solution to liquid ammonia is 3.3-3.6:0.9-1.

[0049] 5) mixing the ammonium-containing low-concentration potassium dihydrogen phosphate solution and monoammonium phosphate, and stirring the mixture in a high-speed stirrer at 25° C. for 60 minutes to prepare a complex electrolyte;

[0050] The mass ratio of the ammonium-containing low-concentration potassium dihydrogen phosphate solution to monoammonium phosphate is 5.5-6:1-1.2. The prepared complex electrolyte contains multiple ions such as K+, NH4, H+, OH-, HPO42-, and H2PO4-.

[0051] 6) Mixing the complex electrolyte, the cyanobacteria mud and the wood fiber powder, and mixing and stirring for 60 minutes with a low-speed mixer to prepare micron magnesium potassium ammonium phosphate particles containing the complex electrolyte, amino acids and ion-adsorbing wood fiber;

[0052] The mass ratio of the complex electrolyte: cyanobacteria mud: wood fiber powder is 5.5-6.0: 1-1.5: 3.5-4.

[0053] The wood fiber powder is powder particles prepared from papermaking sludge and / or eucalyptus waste bark.

[0054] 2. Polycrystalline reaction

[0055] 1) mixing magnesium potassium ammonium phosphate particles and magnesium oxide, and stirring for 10 minutes by a vertical shaft stirrer to prepare large-particle magnesium potassium ammonium phosphate polycrystals;

[0056] The mass ratio of the magnesium potassium ammonium phosphate particles to magnesium oxide is 7.5-7.5:1-1.5, and the prepared large-particle magnesium potassium ammonium phosphate polycrystal is a high-concentration organic slow-release fertilizer containing organic matter 12-15, N10-12, P20-24, K9-11, and Mg8-10.

[0057] 2) crushing the large-particle magnesium potassium ammonium phosphate polycrystals through a bipolar crusher to obtain small-particle magnesium potassium ammonium phosphate polycrystals ranging from 40 mesh to 12 mm, and producing them as needed;

[0058] 3) mixing the small-particle magnesium potassium ammonium phosphate polycrystals and the cyanobacteria mud containing 10% solids in a mass ratio of 1:1, drying the mixture, and then stirring the mixture with a vertical shaft mixer for 20 minutes to prepare cyanobacteria-type magnesium potassium ammonium phosphate polycrystals;

[0059] The small-particle magnesium potassium ammonium phosphate polycrystal and the blue algae mud containing 10% solids are mixed in a mass ratio of 1:1 and then dried at a drying temperature of 200° C. for 5 cycles. The prepared organic slow-release fertilizer is a high-organic organic slow-release fertilizer containing organic matter 30-35, N7-8, P12-14, K5-7, and Mg5-6.

[0060] The high-concentration organic slow-release fertilizers described in this application, i.e., large-particle magnesium potassium ammonium phosphate polycrystals and small-particle magnesium potassium ammonium phosphate polycrystals, and high-organic organic slow-release fertilizers, i.e., cyanobacteria-type magnesium potassium ammonium phosphate polycrystals, can be summarized as "endoplasmic slow-release magnesium potassium ammonium phosphate polycrystals", and their formation process is a reaction process combining chemical reaction and physical change, which includes elements such as magnesium (Mg), potassium (K), ammonium (NH4+), phosphorus (P), amino acids, and organic matter. These elements can be summarized as "solution generates compounds, compounds and residual ions of the solution coordinate to form complexes, compounds and complexes aggregate with wood fiber micropowder to form polymers" during the reaction process, which is a complex product combining chemical reaction, complexation, and polymerization.

[0061] Compared with the prior art, the embodiments of the present invention have the following beneficial effects:

[0062] 1. The primary product of the present invention, i.e., high-concentration organic slow-release fertilizer, is a high-concentration ternary slow-release compound fertilizer with a small amount of plant-usable organic matter and protein; the advanced product of the present invention, i.e., high-organic matter organic slow-release fertilizer, is a ternary medium-concentration organic fertilizer with a large amount of organic matter and protein. The fertilizer can meet the growth needs of plants and improve the soil.

[0063] 2. By using wood fiber micropowder particles to guide solute molecules and ions to begin to aggregate and form small crystal nuclei, these crystal nuclei are the starting point of crystal growth. Once the crystal nuclei are formed, the solute molecules or ions in the solution will continue to diffuse and deposit on the surface of the crystal nuclei, causing the crystal nuclei to gradually grow into crystals. Eventually, multiple crystals will be combined together through chemical bonding and physical adsorption to form a larger polycrystalline structure. This polycrystalline structure has stable physical and chemical properties and forms a polymer with a large specific surface area. Nutrients begin to dissolve when in contact with water, and stop releasing nutrients when the water is oversaturated. This invention greatly improves the utilization rate of fertilizers and fully protects the ecological environment.

[0064] 3. By using wood fiber micropowder particles to guide solute molecules and ions to begin to aggregate and form small crystal nuclei, and eventually form a larger polycrystalline structure. The particles vary in size (generally 2mm to 12mm), and their stable structure can avoid the trouble of granulation in the later stage.

[0065] 4. Utilize the high organic matter and high protein content of cyanobacteria to provide various rare amino acids for fertilizers, and at the same time, dispose of cyanobacteria to contribute to environmental protection.

[0066] 5. According to the process requirements, wood fiber powder can be used to adjust the water content of the solution, which is conducive to the smooth progress of the next step. At the same time, wood fiber powder is used as the core of the polycrystalline, and the porous structure of wood fiber is used to further increase the specific surface area, provide a channel for water absorption, guide water directly to the interior of the polycrystalline, and fully dissolve the nutrients in the small crystals. This measure not only realizes the importance of the function of wood fiber powder, but also provides organic matter and utilizes waste resources.

[0067] 2. Magnesium potassium ammonium phosphate polycrystals (nutrients) are used for fermentation:

[0068] 1) grinding the cyanobacteria type magnesium potassium ammonium phosphate polycrystals by Raymond mill to obtain 200-500 mesh magnesium potassium ammonium phosphate polycrystal powder;

[0069] 2) papermaking sludge, eucalyptus waste bark, magnesium potassium ammonium phosphate polycrystalline micropowder and composite bacterial agent are mixed by continuous drum to obtain organic slow-release fertilizer raw material, wherein the amount of magnesium potassium ammonium phosphate polycrystalline micropowder is 20% of the total mass, and the mass ratio of papermaking sludge to eucalyptus waste bark is 1:0.33;

[0070] 3) composting the organic slow-release fertilizer raw materials and aerobic fermenting them for 30 days to obtain the organic slow-release fertilizer;

[0071] 4) Mix organic slow-release fertilizer, magnesium potassium ammonium phosphate polycrystal, borax, calcium sulfate and zinc sulfate as needed to obtain various types of compound slow-release organic fertilizers. (If necessary)

[0072] In order to improve the fertilizer utilization rate and plant growth effect, the embodiment of the present application adds a nutrient agent, namely the endoplasmic slow-release magnesium potassium ammonium phosphorus polycrystal, and a variety of composite bacterial agents such as lactic acid bacteria, yeast, lignin bacteria, Bacillus subtilis, Bacillus megaterium, jelly-like Bacillus, and colloid Bacillus to a mixture of papermaking sludge and eucalyptus waste bark, and the mixture is fermented. The fermentation process mainly relies on the "endoplasmic slow-release magnesium potassium ammonium phosphorus polycrystal" to continuously provide phosphorus sources and nitrogen sources and a large amount of carbon sources from sludge and bark to form a fermentation reaction, while various composite bacterial agents such as lactic acid bacteria, yeast, lignin bacteria, Bacillus subtilis, Bacillus megaterium, jelly-like Bacillus, and colloid Bacillus work together to complete various enzymolysis and bacterial hydrolysis reactions. The protein in cyanobacteria, wood fiber, bacterial metabolites and organic matter in papermaking sludge and eucalyptus waste bark are efficiently converted into various amino acids, organic matter and humic acid required by plants. The fertilizer after decomposition is rich in organic matter, humic acid, amino acids, nitrogen, phosphorus, potassium and trace elements, becoming a high-quality slow-release fertilizer that integrates various biological bacteria, amino acids, nitrogen, phosphorus, potassium and trace elements. The overall utilization rate of this fertilizer is as high as over 95%. Its mechanism is mainly that after the conversion of slightly soluble nutrients, the insoluble nitrogen, phosphorus, potassium and trace elements are decomposed and transformed in a targeted, selective, organized and orderly manner by Bacillus megaterium, Bacillus gelatinus and Bacillus gelatinus, thereby providing additional nutrients to achieve the design goals. Its process characteristics are: using "endosomitic slow-release magnesium, potassium, ammonium and phosphorus polycrystals" as a fermentation nutrient, continuously providing phosphorus and nitrogen sources to form fermentation reactions with the carbon sources of sludge and bark, and quickly and thoroughly decomposing organic matter to achieve the purpose of fermentation.

[0073] Compared with the prior art, the embodiments of the present invention have the following beneficial effects:

[0074] 1. Using "endosolic slow-release magnesium potassium ammonium phosphate polycrystals" as fermentation nutrients (dosage 20% to 40%) for fermentation can continuously provide phosphorus and nitrogen sources to organic matter, and can form fermentation reactions with various organic carbon sources. There is no shortage of phosphorus and nitrogen sources during the entire fermentation period, which greatly increases the fermentation efficiency and quickly and thoroughly decomposes organic matter.

[0075] 2. Since the "endoplasmic slow-release magnesium potassium ammonium phosphate polycrystal" contains a large amount of amino acids, it can naturally chelate some metal elements in the material during the fermentation process, making them small molecules and polypeptide trace elements that can be absorbed by plants. This process is cost-effective. It not only provides a large amount of amino acids for plants, but also uses the amino acids of cyanobacteria to ferment and chelate some metal residues. It also disposes of a large amount of cyanobacteria mud and papermaking sludge in an environmentally friendly manner, and increases the value of waste bark.

[0076] The magnesium potassium ammonium phosphate polycrystal of the present invention can provide "high-concentration organic slow-release fertilizer (organic matter 12-15, N10-12, P20-24, K9-11, Mg8-10)" and "high organic slow-release fertilizer (organic matter 30-35, N7-8, P12-14, K5-7, Mg5-6)". After grinding the magnesium potassium ammonium phosphate polycrystal, it is used in aerobic fermentation to produce high-organic advanced organic slow-release fertilizer with a total nutrient content of 20% to 30% (list: organic matter 31%, N5.19%, P9.1%, K5.15%, Mg3.57%), while the total nutrient content of existing organic fertilizers is usually ≤10%; the present invention has achieved significant technical effects. Because of their unique nutrient release mechanism, the three fertilizers do not burn seedlings and can be applied along the root system, providing nutrients to plants in the most direct way.

[0077] According to 10 sets of data from the BET method experiment, the specific surface area of ​​the "endosomal sustained-release magnesium potassium ammonium phosphate polycrystal" described in this application is 0.187 m 2 / g~0.265m 2 / g, with an average value of 0.236m 2 / g. Specific gravity 0.68, it is a porous granular material. Based on 2000g of fertilizer, specific surface area = 0.236m 2 / g×2000g=472m 2 , the total surface area of ​​2000 grams of fertilizer is 472 square meters.

[0078] According to the magnesium potassium ammonium phosphate polycrystals of the present application, the release rate is controllable, and the specific data are as follows:

[0079] (1) Nutrient release rate of magnesium potassium ammonium phosphate polycrystals:

[0080] Each supersaturation dissolution of nutrients is 0.02%.

[0081] (2) Specific ingredients of fertilizer:

[0082] 2000g of 100 mesh ~ 2mm granular fertilizer, containing 31% organic matter, 5.19% N, 9.1% P, 5.15% K, and 3.57% Mg.

[0083] (3) Field test data:

[0084] Eucalyptus trees planted with this fertilizer showed no symptoms of fertilizer deficiency within 36 months.

[0085] Total nutrients dissolved in a single time:

[0086] To calculate the total nutrients released in a single batch, we need to know the amount of each nutrient in the fertilizer and assume that they are all released at the same rate.

[0087] Total nutrient content (by weight percentage) = 31% (organic matter, usually not included in nutrient calculations) + 5.19% N + 9.1% P + 5.15% K + 3.57% Mg = 23.01% (only N, P, K, and Mg are calculated).

[0088] Total nutrients dissolved in a single time = 2000g × 23.01% × 0.02% = 0.09204g.

[0089] This means that the fertilizer will dissolve about 0.09204 grams of nutrients each time it is supersaturated.

[0090] Increasing particle size prolongs nutrient release time:

[0091] An increase in particle size will slow down the release rate of nutrients because larger particles mean a smaller specific surface area, thereby reducing the contact area with the soil and the dissolution rate.

[0092] The specific relationship between the increase in particle size of slow-release fertilizers and the extension of release time:

[0093] ①Qualitative relationship:

[0094] Particle size increases → surface area decreases → dissolution rate slows down → release time is prolonged.

[0095] ②Quantitative trend:

[0096] Within a certain range, as the particle size increases, the release time tends to be prolonged.

[0097] However, it should be noted that when the particle size increases to a certain extent, its effect on the release time may gradually weaken, because the dissolution rate of the fertilizer has become very slow at this time. Further increasing the particle size requires increasing the usage and increasing the surface area to meet the plant's nutrient needs.

[0098] ③Example description

[0099] Taking 500-mesh magnesium potassium ammonium phosphate polycrystals as an example, the N, P, and K nutrients contained in it can last up to 12 months in an over-watered environment; while the magnesium potassium ammonium phosphate polycrystals with larger grains (1mm) lose 30% of the total nutrients in 12 months in an over-watered environment, and the particle size becomes smaller. This fully illustrates the effect of particle size on the release time of polycrystals.

[0100] In summary, by controlling the amount of fertilizer used and the particle size used, we can control the release rate of nutrients, achieve a continuous and stable supply of nutrients, and meet the long-term growth needs of crops. In this example, 2000 grams of magnesium potassium ammonium phosphate polycrystalline fertilizer with a particle size of 1mm provided sufficient nutrients for eucalyptus trees for 36 months without any symptoms of fertilizer deficiency.

[0101] Fertilizer efficiency comparison test:

[0102] The test site is located at the core base of Poliantang Company in Wenlang Village, Weiyuan Town, Jinggu County. The test site has a typical southern subtropical monsoon climate, with an average altitude of 1,600m, an average annual rainfall of 1,250mm, and the rainy season is mainly concentrated from late May to late October. The annual average temperature is 20.5℃, the coldest month is January, and the hottest month is June. The soil is red soil, with high humus content, deep soil layer, and high nutrient content of topsoil.

[0103] 1. Experimental fertilizer

[0104] The fertilizers in this test project include: organic slow-release fertilizers made according to the embodiments of the present invention, and the control group fertilizers are other fertilizers available on the market, including control group A, control group B, control group C, control group D, control group E, control group F, control group G, control group H, control group I, and control group J. A total of 11 different fertilizers participated in this test project.

[0105] 2. Experimental Design

[0106] The experiment adopted a randomized block design method, with each plot being a treatment level, and each plot covering an area of ​​4 mu, without replication. The eucalyptus afforestation density was based on the planting standard of 111 plants / mu of forest land, and the afforestation seedlings were JL107 asexual tissue culture seedlings. The plots were separated by marker poles. Because the organic slow-release fertilizer (cyanobacteria fertilizer) produced according to the embodiment of the present invention has an effective period of 3 years, topdressing is not required, and the base fertilizer is applied once and for all. See the attached for details. Figure 1 Experimental design treatment table.

[0107] 3. Survey Results and Analysis

[0108] The diameter at breast height, tree height and trunk shape of the test forest were measured. This test report uses the measured data of 1.2 years for analysis, and the test data are analyzed using Excel software.

[0109] The timber volume is calculated according to the eucalyptus tree volume calculation formula provided by the Leizhou Forestry Bureau.

[0110] V=0.0000628767×H 0.96436 ×D 1.821621

[0111] Where: V represents timber volume, D represents breast diameter, and H represents tree height.

[0112] The survey results show that the treatment with the highest growth rate in 1.2 years of forest trees is the organic slow-release fertilizer of the present invention, with an average tree height of 7.66m, an average breast diameter of 7.16cm, and an annual stock volume of 1.68m per mu. 3The yield per mu increased by 22.63% compared with the control group; the second place was the control group H, with an average tree height of 7.22m, an average breast diameter of 6.63cm, and a yield per mu of 1.37m 3 The lowest per-acre yield was in the control group D, which was only 0.62 m 3 . See attached for details. Figure 2 Comparison table of 1.2-year growth of trees with different basal fertilizers.

[0113] According to the method of producing slow-release organic fertilizer by cyanobacteria and papermaking sludge, the utilization value of algae mud after fermentation treatment in the market is improved. The organic fertilizer is prepared by fermentation treatment of cyanobacteria and papermaking sludge, which not only improves the fermentation efficiency but also increases the nutrient content.

[0114] According to a method of producing slow-release organic fertilizer by cyanobacteria and papermaking sludge of the present invention, a specially prepared endoplasmic slow-release magnesium potassium ammonium phosphorus polycrystal is used as a nutrient agent. The nutrient agent is made of cyanobacteria, papermaking sludge / waste bark powder and a variety of chemical raw materials, and is rich in humic acid, organic matter, amino acids, nitrogen, phosphorus and potassium, and can provide slow-release phosphorus and nitrogen sources for subsequent fermentation processes. Potassium salt only oozes out very little inorganic salt due to its low solubility and will not affect the flora. Papermaking sludge is rich in lignin, wood fiber, protein, humic acid and organic matter, and is a qualified raw material for organic fertilizer. Eucalyptus waste bark is rich in lignin, wood fiber and organic matter, and can integrate moisture when mixed with papermaking sludge, which is conducive to fermentation.

[0115] According to a method of producing slow-release organic fertilizer by cyanobacteria and papermaking sludge of the present invention, by combining the innovative magnesium potassium ammonium phosphate polycrystal process of "phosphoric acid + potassium hydroxide + cyanobacteria + papermaking sludge powder + industrial-grade ammonium phosphate + magnesium oxide + zinc sulfate + calcium sulfate + borax" with decomposed papermaking sludge, a "endophytic organic slow-release magnesium potassium ammonium phosphate polycrystal" with stable structure and low solubility is successfully constructed. This innovative substance, with its excellent specific surface area and precise release rate control characteristics, ensures that nutrients can be stably released at a scientifically set rate, providing continuous and balanced nutritional support for plant growth. At the same time, the unique advantages of waste resources such as cyanobacteria, papermaking sludge and eucalyptus bark are fully utilized, and through chemical and microbial transformation, the protein in cyanobacteria, the wood fiber, bacterial metabolites and organic matter in papermaking sludge and eucalyptus waste bark are efficiently converted into various amino acids, organic matter and humic acid required by plants, providing a guarantee for plant growth. This innovation not only achieves the added value of cyanobacteria mud and papermaking sludge, but also improves the nutritional value of fertilizers and more effectively promotes the healthy growth of plants.

[0116] Wood fiber micropowder particles are used to guide solute molecules and ions to begin to aggregate and form small crystal nuclei, which gradually grow into crystals. Eventually, multiple crystals will be combined together through chemical bonding and physical adsorption to form a larger polycrystalline structure. This polycrystalline structure has stable physical and chemical properties and forms a polymer with a large specific surface area. It begins to dissolve nutrients when it encounters water and stops releasing nutrients when it is oversaturated with water, which greatly improves the utilization rate of fertilizers and fully protects the ecological environment.

[0117] By using wood fiber micropowder particles to guide solute molecules and ions to begin to aggregate and form small crystal nuclei, and eventually form larger polycrystalline structures. The particles vary in size (usually 2mm to 12mm), and their stable structure can avoid the trouble of later granulation.

[0118] Through the synergistic cooperation of cyanobacteria mud and papermaking sludge, cyanobacteria provide amino acids and part of organic matter, and papermaking sludge provides part of organic matter and humic acid, and fermentation treatment is carried out to prepare organic fertilizer, thereby increasing the nutrient content of the final product; at the same time, because papermaking sludge contains a large amount of fiber and is relatively fluffy, it is conducive to fermentation. Compared with the traditional fermentation method of cyanobacteria mud, the fermentation efficiency is greatly improved.

[0119] The method proposed in this application not only treats various wastes such as cyanobacteria mud and papermaking sludge, saving a lot of disposal costs for governments and enterprises; it can also improve fermentation efficiency while providing plants with more sufficient organic nutrients, greatly enhancing the utilization value of organic fertilizer products after waste fermentation treatment in the market.

[0120] The present invention has been introduced in detail above. Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

[0121] Through the description of the above embodiments, those skilled in the art can clearly understand that the present invention can be implemented. Of course, the above listed situations are only examples, and the present invention is not limited thereto. Those skilled in the art should understand that other variations or simplifications according to the technical solution of the present invention can be appropriately applied to the present invention and should be included in the scope of the present invention.

Claims

1. A method for producing slow-release organic fertilizer by using cyanobacteria and papermaking sludge, characterized in that: The following steps are involved: A. Slurry preparation: 1) Mix water and phosphoric acid and stir for 30 minutes to prepare a phosphoric acid dilution solution with a water content of 70%; 2) Mixing water and potassium hydroxide and stirring for 30 minutes to prepare a potassium hydroxide dilute solution with a water content of 70%; 3) Mixing 70% phosphoric acid dilution solution and 70% potassium hydroxide dilution solution to control the pH value to be between pH 4 and 7, stirring for 120 minutes at a temperature of 60° C., to prepare a low-concentration potassium dihydrogen phosphate and dipotassium hydrogen phosphate mixed solution; 4) mixing a low-concentration potassium dihydrogen phosphate and dipotassium hydrogen phosphate mixed solution with liquid ammonia to control the pH value to be between pH 5 and 7, and stirring the mixture at a temperature of 25° C. for 30 minutes to prepare an ammonium-containing low-concentration potassium dihydrogen phosphate solution comprising water, ammonium ions, potassium dihydrogen phosphate / dipotassium hydrogen phosphate ions, potassium ions, unionized ammonia molecules, and hydrogen ions and hydroxide ions; 5) mixing a low-concentration potassium dihydrogen phosphate solution containing ammonium and monoammonium phosphate, and stirring the mixture at 25° C. for 60 minutes to prepare a complex electrolyte; 6) Mixing and stirring the complex electrolyte, cyanobacteria mud and wood fiber powder for 60 minutes to prepare micron magnesium potassium ammonium phosphate particles containing complex electrolyte, amino acids and ion-adsorbing wood fiber; B. Polycrystalline reaction: The magnesium potassium ammonium phosphate particles and magnesium oxide are mixed and stirred for 10 minutes to prepare large-particle magnesium potassium ammonium phosphate polycrystals.

2. The method for producing slow-release organic fertilizer by using cyanobacteria and papermaking sludge according to claim 1, characterized in that: The large-particle magnesium potassium ammonium phosphate polycrystals are crushed to obtain small-particle magnesium potassium ammonium phosphate polycrystals with a particle size ranging from 40 mesh to a diameter of 12 mm.

3. The method for producing slow-release organic fertilizer by using cyanobacteria and papermaking sludge according to claim 1, characterized in that: The small-particle magnesium potassium ammonium phosphate polycrystals and cyanobacteria mud containing 10% solids are mixed in a mass ratio of 1:1, dried, and stirred for 20 minutes to prepare cyanobacteria-type magnesium potassium ammonium phosphate polycrystals.

4. The method for producing slow-release organic fertilizer by using cyanobacteria and papermaking sludge according to claim 3, characterized in that: The following steps are also included: 1) crushing the cyanobacteria-type magnesium potassium ammonium phosphate polycrystal to obtain magnesium potassium ammonium phosphate polycrystal micropowder with a particle size of 200 to 500 meshes; 2) papermaking sludge, eucalyptus waste bark, magnesium potassium ammonium phosphate polycrystalline micropowder and composite bacterial agent are mixed by continuous drum to obtain organic slow-release fertilizer raw material, wherein the amount of magnesium potassium ammonium phosphate polycrystalline micropowder is 20% of the total mass, and the mass ratio of papermaking sludge to eucalyptus waste bark is 1:0.33; 3) The organic slow-release fertilizer raw materials are composted and aerobic fermented to obtain the organic slow-release fertilizer after fermentation for 30 days.

5. The method for producing slow-release organic fertilizer by using cyanobacteria and papermaking sludge according to claim 4, characterized in that: The organic slow-release fertilizer is mixed with magnesium potassium ammonium phosphate polycrystals, borax, calcium sulfate and zinc sulfate to obtain a compound slow-release organic fertilizer.

6. The method for producing slow-release organic fertilizer by using cyanobacteria and papermaking sludge according to claim 4, characterized in that: The composite bacterial agent is a composite bacterial agent including lactic acid bacteria, yeast, lignin bacteria, Bacillus subtilis, Bacillus megaterium, Bacillus gelatinus and / or Bacillus gelatinus.

7. The method for producing slow-release organic fertilizer by using cyanobacteria and papermaking sludge according to claim 1, characterized in that: The wood fiber powder is powder particles prepared from papermaking sludge and / or eucalyptus waste bark.

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