Method for preparing ammonium sulfate based on chicken manure fermentation

Abstract

The invention provides a method for preparing ammonium sulfate based on chicken manure fermentation, and belongs to the technical field of ammonium sulfate preparation, and the method comprises the following steps: S1, pretreating chicken manure to obtain pretreated chicken manure meeting fermentation requirements; s2, a functional acceleration component is added into the pretreated chicken manure, fermentation treatment is conducted after uniform mixing, a fermentation product and fermentation waste gas containing ammonia gas and sulfide are obtained, the functional acceleration component is attapulgite, and attapulgite is used after being roasted and smashed. The roasting temperature of the attapulgite is 300-500 DEG C, the crushing particle size is 100-200 meshes, the addition amount of the attapulgite is 0.5-5% of the dry weight of the pretreated chicken manure, specific aerobic fermentation control is matched, the fermentation period is shortened to 7-15 days and is shortened by 30% or above compared with a traditional process, the organic matter content of a fermentation product can be increased by 3-5% through the adsorption and flora enrichment effects of the attapulgite, and the production cost is reduced. The problems of long traditional fermentation period and fertility loss are effectively solved.

Description

Technical Field

[0001] This invention relates to the field of ammonium sulfate preparation and chemical fertilizer technology, specifically a method for preparing ammonium sulfate based on chicken manure fermentation. Background Technology

[0002] Chicken manure is a common waste product in the livestock industry, but it is also a high-quality fertilizer raw material rich in nutrients such as nitrogen, phosphorus, and potassium, and has important value in the field of agricultural recycling.

[0003] Traditional chicken manure fermentation typically involves piling up chicken manure and adding water periodically to keep the pile moist for fermentation. During fermentation, the pile needs to be turned every 3-5 days to accelerate the decomposition and fermentation of organic matter. Turning also ensures sufficient oxygen within the pile, thus achieving the desired fermentation effect. The main purpose of traditional chicken manure fermentation is to use the fermented chicken manure as fertilizer, without considering the ammonia and sulfide waste gases produced during fermentation. Traditional chicken manure fermentation has significant drawbacks: firstly, the natural fermentation cycle is generally long (20-30 days), resulting in low fermentation efficiency. Furthermore, uneven microbial activity during fermentation can lead to nutrient loss, making it difficult to guarantee the final fertilizer's fertility level. Secondly, chicken manure fermentation releases large amounts of ammonia and sulfide-containing waste gases. Direct emission of these gases not only causes air pollution and unpleasant odors but also wastes key nutrients such as nitrogen and sulfur, hindering efficient resource recovery.

[0004] In existing technologies, the treatment of waste gas from chicken manure fermentation often adopts a simple spray absorption method. This method can only solve the problem of the waste gas, but does not consider the recycling and utilization of the waste gas generated by chicken manure fermentation. Summary of the Invention

[0005] The purpose of this invention is to provide a method for preparing ammonium sulfate based on chicken manure fermentation, so as to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a method for preparing ammonium sulfate based on chicken manure fermentation, comprising the following steps: S1: Pre-treat chicken manure to obtain pre-treated chicken manure that meets fermentation requirements; S2: Add functional accelerating components to pretreated chicken manure, mix evenly, and then carry out fermentation treatment to obtain fermentation products and fermentation waste gas containing ammonia and sulfides; S3: Collect the fermentation waste gas and introduce it into the reaction device. Through acid absorption and oxidation reaction, the ammonia and sulfides in the waste gas are converted into ammonium sulfate precursor liquid. S4: Purify the ammonium sulfate precursor solution to obtain the ammonium sulfate product; S5: The fermentation products are granulated and coated sequentially. Bacillus subtilis is added during the coating process to obtain the finished organic fertilizer.

[0007] As a preferred embodiment of the present invention: the functional accelerating component is attapulgite, which is used after being roasted and crushed; the roasting temperature is 300-500℃, the roasting time is 2-4 hours, the particle size after crushing is 100-200 mesh, and the amount of the functional accelerating component added is 0.5%-5% of the dry weight of the pretreated chicken manure.

[0008] As a preferred embodiment of the present invention: the fermentation treatment in S2 is aerobic fermentation, the fermentation temperature is controlled at 55-65℃, and the fermentation cycle is 7-15 days; during the fermentation process, the fermentation is turned over and oxygen is replenished regularly to maintain the stable dissolved oxygen content of the fermentation system.

[0009] As a preferred embodiment of the present invention: the pretreatment in S1 includes impurity removal and moisture content adjustment; impurity removal adopts a combination of sieving and magnetic separation processes; the moisture content is adjusted to 50%-60%, and deionized water or fermentation product filtrate can be added during the adjustment process.

[0010] As a preferred embodiment of the present invention: the fermentation waste gas in S3 is collected through a negative pressure adsorption closed pipeline system, the waste gas collection efficiency of the collection system being ≥95%; the acid solution is a 10%-20% (w / w) dilute sulfuric acid solution, and the liquid-to-gas ratio of waste gas to acid solution is 1-3 L / m³. 3 .

[0011] As a preferred embodiment of the present invention: the oxidation reaction in S3 is achieved by adding an oxidant, wherein the oxidant is one or more of hydrogen peroxide, oxygen, and ozone; the amount of oxidant added is 1.2-2.0 times the molar amount of sulfides in the waste gas, the oxidation reaction temperature is 30-50℃, and the reaction time is 1-3 hours.

[0012] As a preferred embodiment of the present invention: the purification process in S4 includes the following steps in sequence: filtration, concentration, crystallization and drying; filtration adopts ceramic membrane filtration process; concentration is vacuum concentration, concentration temperature is 60-80℃, and concentration is carried out to a solution mass concentration of 30%-40%; crystallization is cooling crystallization, crystallization temperature is 0-10℃, and crystallization time is 8-12 hours; drying temperature is 80-100℃, and drying is carried out to a product moisture content ≤1%.

[0013] As a preferred embodiment of the present invention: granulation in step S5 is performed using disc granulation or extrusion granulation, resulting in granulated particles with a diameter of 2-5 mm; coating is performed using a coating solution, which is prepared by mixing a coating material with a Bacillus subtilis inoculant; the coating material is one or more of sodium carboxymethyl cellulose, starch, and sodium alginate, and the amount added is 1%-3% of the fermentation product mass; the effective viable count of the Bacillus subtilis inoculant is ≥10.9 The amount of CFU / g added is 0.1%-1.0% of the fermentation product mass; the coating process is controlled at a temperature of 30-40℃ and a humidity of 40%-50%.

[0014] As a preferred embodiment of the present invention: the organic matter content of the fermentation product in S2 increases by 3-5%, and the total nutrients (N+P2O5+K2O) ≥5%; the purity of the ammonium sulfate product in S4 is ≥98%; and the number of Bacillus subtilis viable in the finished organic fertilizer in S5 is ≥10. 6 CFU / g, particle compressive strength ≥15N, moisture content ≤15%.

[0015] As a preferred embodiment of the present invention: the ammonium sulfate product conforms to the GB 535-2020 standard, and the finished organic fertilizer conforms to the NY 884-2012 organic fertilizer standard; the pollutant emission reduction rate of the method is ≥90%, and the resource utilization rate is 40%-60% higher than that of conventional chicken manure treatment methods.

[0016] Compared with the prior art, the beneficial effects of the present invention are: 1) This invention introduces roasted and pulverized attapulgite into the chicken manure fermentation process. The attapulgite is roasted at 300-500℃ and pulverized to a particle size of 100-200 mesh. The amount added is 0.5%-5% of the dry weight of the pretreated chicken manure. Combined with specific aerobic fermentation control, the fermentation cycle is shortened to 7-15 days, which is more than 30% shorter than the traditional process. Furthermore, through the adsorption and microbial enrichment effect of attapulgite, the organic matter content of the fermentation product is increased by 3-5%, and the total nutrients (N+P2O5+K2O) are ≥5%. This effectively solves the problems of long fermentation cycle and fertility loss in traditional processes. At the same time, relying on the negative pressure adsorption closed pipeline system and the synergistic oxidation reaction of the oxidant, ammonia and sulfides in the waste gas can be efficiently converted into ammonium sulfate precursor liquid. After purification, ammonium sulfate product with a purity of ≥98% is obtained, realizing zero pollution emission of waste gas and resource utilization of nitrogen and sulfur resources. This solves the defects of low efficiency and resource waste in traditional waste gas treatment. 2) This invention, through specific granulation and coating process design, uses disc granulation or extrusion granulation to prepare uniform granules of 2-5mm, combined with materials such as sodium carboxymethyl cellulose and Bacillus subtilis inoculant, achieving an effective viable bacteria count ≥10. 9 The coating solution, composed of CFU / g, is applied at 30-40℃ and 40%-50% humidity. This not only improves the compressive strength of the finished organic fertilizer granules to ≥15N and the moisture content to ≤15%, significantly enhancing the product's appearance, but also, through the protective effect of the coating material, ensures that the survival rate of Bacillus subtilis is ≥10. 6The CFU / g method effectively solves the problems of uneven adhesion of microbial agents and easy inactivation in traditional processes. The resulting ammonium sulfate product meets the GB 535-2020 standard, and the finished organic fertilizer meets the NY 884-2012 standard. The pollutant emission reduction rate is ≥90%, and the resource utilization rate is increased by 40%-60%, comprehensively taking into account environmental benefits, economic benefits and agricultural application value. Attached Figure Description

[0017] Figure 1 This is a schematic flowchart of the method for preparing ammonium sulfate based on chicken manure fermentation according to the present invention. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] Please see Figure 1 A method for preparing ammonium sulfate based on chicken manure fermentation includes the following steps: S1: Pre-treat chicken manure to obtain pre-treated chicken manure that meets fermentation requirements; S2: Add functional accelerating components to pretreated chicken manure, mix evenly, and then carry out fermentation treatment to obtain fermentation products and fermentation waste gas containing ammonia and sulfides; S3: Collect the fermentation waste gas and introduce it into the reaction device. Through acid absorption and oxidation reaction, the ammonia and sulfides in the waste gas are converted into ammonium sulfate precursor liquid. S4: Purify the ammonium sulfate precursor solution to obtain the ammonium sulfate product; S5: The fermentation products are granulated and coated sequentially. Bacillus subtilis is added during the coating process to obtain the finished organic fertilizer.

[0020] Specifically, in the resource utilization of chicken manure in farms, fresh chicken manure is first pretreated through S1 to remove impurities and adjust the moisture content, providing qualified raw materials for subsequent fermentation. Then, functional accelerating components are added to the pretreated chicken manure through S2, and fermentation is started after mixing. This shortens the fermentation cycle and ensures the fertility of the fermentation products. At the same time, waste gas containing ammonia and sulfides is generated. Subsequently, S3 introduces the waste gas into the reaction device through a collection system. The pollutants are converted into ammonium sulfate precursor liquid by acid absorption and oxidation reaction, avoiding waste gas pollution. Then, S4 filters, concentrates, crystallizes and dries the precursor liquid to obtain high-purity ammonium sulfate. Finally, S5 granulates and coats the fermentation products and adds Bacillus subtilis to produce organic fertilizer with good appearance and high bacterial activity. The whole process is closely connected, realizing the dual resource utilization of chicken manure: "waste gas recovery to produce ammonium sulfate and fermentation products to produce organic fertilizer".

[0021] In this embodiment: the functional accelerating component is attapulgite, which is used after being roasted and crushed; the roasting temperature is 300-500℃, the roasting time is 2-4 hours, the particle size after crushing is 100-200 mesh, and the amount of the functional accelerating component added is 0.5%-5% of the dry weight of the pretreated chicken manure.

[0022] Specifically, when accelerating chicken manure fermentation, the functional accelerating component attapulgite needs to be roasted at 300-500℃ for 2-4 hours to remove internal impurities and expand the specific surface area. Then, it is crushed to 100-200 mesh to ensure full contact with the pretreated chicken manure. After being added at a ratio of 0.5%-5% of the dry weight of the pretreated chicken manure, its porous structure can quickly enrich the microorganisms required for fermentation, accelerate the decomposition and metabolism of organic matter in the chicken manure, and at the same time adsorb nutrients such as nitrogen and phosphorus released during fermentation, reduce nutrient loss, and achieve the synergistic effect of "shortening the fermentation cycle and improving fertilizer fertility", solving the problems of low efficiency and easy loss of fertilizer in traditional fermentation.

[0023] In this embodiment: the fermentation treatment in S2 is aerobic fermentation, the fermentation temperature is controlled at 55-65℃, and the fermentation cycle is 7-15 days; during the fermentation process, the fermentation is turned over and oxygen is replenished regularly to maintain the stable dissolved oxygen content of the fermentation system.

[0024] Specifically, during the aerobic fermentation control of chicken manure, chicken manure mixed with functional accelerating components is placed in the fermentation device, and the fermentation temperature is controlled at 55-65℃. The appropriate temperature range can maximize the activity of fermenting microorganisms and accelerate the decomposition of organic matter. The fermentation cycle is set to 7-15 days to ensure that the chicken manure is fully decomposed. During the process, the manure is turned over every 24-48 hours, and oxygen is supplemented to maintain a stable dissolved oxygen content in the fermentation system and avoid local anaerobic environments that may lead to incomplete fermentation or the production of odors. When the temperature is lower than 55℃ or the dissolved oxygen is lower than the set value, the system automatically starts the heating or blowing module to further ensure the stability of the fermentation process, and finally obtains fermented products with high decomposition and fertility standards.

[0025] In this embodiment: the pretreatment in S1 includes impurity removal and moisture content adjustment; impurity removal adopts a combination of screening and magnetic separation processes; the moisture content is adjusted to 50%-60%, and deionized water or fermentation product filtrate can be added during the adjustment process. Pretreated chicken manure that meets the fermentation requirements refers to chicken manure with impurities removed and a moisture content of 50%-60%.

[0026] Specifically, during the pretreatment of chicken manure, for freshly collected chicken manure containing impurities, a combination of screening and magnetic separation is first used. Screening removes solid impurities such as stones and plastics, while magnetic separation separates mixed metal fragments, preventing impurities from affecting subsequent fermentation or damaging the equipment. Then, the moisture content of the chicken manure is adjusted to 50%-60%. If the moisture content is too high, fermentation product filtrate is added to absorb excess water; if it is too low, deionized water is added. This moisture content range provides a suitable water environment for fermentation microorganisms, preventing insufficient moisture from reducing microbial activity and avoiding excessive moisture from causing poor aeration, thus laying the foundation for the efficient fermentation of S2.

[0027] In this embodiment: the fermentation waste gas in S3 is collected through a negative pressure adsorption closed pipeline system, and the waste gas collection efficiency of the collection system is ≥95%; the acid solution is a 10%-20% (w / w) dilute sulfuric acid solution, and the liquid-to-gas ratio of waste gas to acid solution is 1-3 L / m³. 3 The specific structure of the negative pressure adsorption closed pipeline system does not constitute a limitation of this application and will not be described in detail here.

[0028] Specifically, when chicken manure fermentation produces waste gas containing ammonia and sulfides, a negative pressure adsorption closed pipeline system is activated. This system efficiently collects the waste gas using a negative pressure of -0.02 to 0.04 MPa, achieving a collection efficiency of ≥95%. This prevents waste gas leakage that could cause air pollution or odor diffusion. After the waste gas is introduced into the reaction device, a 10%-20% (by mass) dilute sulfuric acid solution is introduced, controlling the liquid-to-gas ratio of waste gas to acid at 1-3 L / m³. 3 This concentration and liquid-to-gas ratio ensure that dilute sulfuric acid fully absorbs ammonia in the waste gas to generate ammonium sulfate as a primary product, while providing a suitable reaction environment for subsequent sulfide oxidation, thus achieving the initial conversion of waste gas.

[0029] In this embodiment: the oxidation reaction in S3 is achieved by adding an oxidant, which is one or a mixture of hydrogen peroxide, oxygen, and ozone; the amount of oxidant added is 1.2-2.0 times the molar amount of sulfides in the waste gas, the oxidation reaction temperature is 30-50℃, and the reaction time is 1-3 hours.

[0030] Specifically, for sulfide-containing waste gas that has been absorbed by dilute sulfuric acid, one or more mixed oxidants, such as hydrogen peroxide, oxygen, or ozone, are added. The amount of oxidant added is 1.2-2.0 times the molar amount of sulfides in the waste gas to ensure that the sulfides are completely oxidized. The reaction temperature is controlled at 30-50℃ and the reaction time is 1-3 hours. These temperature and time conditions can promote the reaction between the oxidant and the sulfides, converting the sulfides into sulfate ions. The sulfate ions combine with the ammonium ions generated by the previous reaction of ammonia and dilute sulfuric acid to form a pure ammonium sulfate precursor liquid, avoiding the impact of sulfide residue on the purity of ammonium sulfate, and realizing the simultaneous resource conversion of the two pollutants in the waste gas.

[0031] In this embodiment: the purification process in S4 includes filtration, concentration, crystallization and drying steps in sequence; filtration adopts ceramic membrane filtration process; concentration is vacuum concentration, concentration temperature is 60-80℃, and concentration is carried out to a solution mass concentration of 30%-40%; crystallization is cooling crystallization, crystallization temperature is 0-10℃, and crystallization time is 8-12 hours; drying temperature is 80-100℃, and drying is carried out to a product moisture content ≤1%.

[0032] Specifically, in the refining of ammonium sulfate, the ammonium sulfate precursor solution is first filtered using a ceramic membrane to remove suspended impurities and ensure its purity. Then, it undergoes vacuum concentration, with the concentration temperature controlled at 60-80℃. The precursor solution is concentrated to a mass concentration of 30%-40% at this relatively low temperature to avoid damaging the ammonium sulfate structure. Subsequently, it is cooled to 0-10℃ and crystallized at this constant temperature for 8-12 hours, allowing the ammonium sulfate to precipitate in crystalline form and ensuring uniform crystal particle size. Finally, it is dried at 80-100℃, controlling the moisture content of the crystals to ≤1% to prevent the ammonium sulfate from absorbing moisture and clumping. The final product is ammonium sulfate with a purity ≥98%, meeting the purity requirements for industrial or agricultural ammonium sulfate.

[0033] In this embodiment: granulation in step S5 employs disc granulation or extrusion granulation processes, resulting in granulated particles with a diameter of 2-5 mm; coating is performed using a coating solution, which is prepared by mixing a coating material with Bacillus subtilis inoculant; the coating material is one or more of sodium carboxymethyl cellulose, starch, and sodium alginate, added at 1%-3% of the fermentation product mass; the effective viable count of the Bacillus subtilis inoculant is ≥10. 9 The amount of CFU / g added is 0.1%-1.0% of the fermentation product mass; the coating process is controlled at a temperature of 30-40℃ and a humidity of 40%-50%.

[0034] Specifically, in the post-processing of fermentation products, the fermentation products are first pulverized and then granulated using disc granulation or extrusion granulation processes to produce uniform particles with a diameter of 2-5 mm, ensuring particle shape and stability. Next, a coating solution is prepared, using 1%-3% of the fermentation product mass of sodium carboxymethyl cellulose, starch, or sodium alginate as the coating material, along with an effective viable bacteria count ≥10⁻⁶.9 A mixture of CFU / g Bacillus subtilis inoculant was added at a rate of 0.1%-1.0% of the fermentation product mass. The granules were then coated at 30-40℃ and 40%-50% humidity. The coating material ensured that Bacillus subtilis was evenly adhered to the granule surface and formed a protective film, reducing the damage to the inoculant's activity from the external environment and improving the granules' appearance. The final product had a compressive strength ≥15N, a moisture content ≤15%, and an inoculant survival rate ≥10. 6 Finished organic fertilizer with CFU / g.

[0035] In this embodiment: the organic matter content of the fermentation product in S2 increases by 3-5%, and the total nutrients (N+P2O5+K2O) ≥5%; the purity of the ammonium sulfate product in S4 is ≥98%; and the number of Bacillus subtilis viable in the finished organic fertilizer in S5 is ≥10. 6 CFU / g, particle compressive strength ≥15N, moisture content ≤15%.

[0036] Specifically, through the combination of functional accelerating components and fermentation parameters in S2, the organic matter content of the fermentation product increases by 3-5%, and the total nutrients (N+P2O5+K2O) ≥5%, meeting the fertility requirements of organic fertilizer. In S4, through refined processing of filtration, concentration, crystallization, and drying, impurities in the precursor liquid are removed and moisture is controlled to ensure the purity of the ammonium sulfate product is ≥98%. In S5, through standardized granulation parameters and coating processes, the finished organic fertilizer granules achieve a compressive strength ≥15N and a moisture content ≤15%. At the same time, the coating material protects the activity of Bacillus subtilis, ensuring a survival count ≥10. 6 CFU / g, with each step working together, ensures that both products meet the preset quality standards, thereby enhancing their market application value.

[0037] In this embodiment: the ammonium sulfate product complies with GB 535-2020 standard, and the finished organic fertilizer complies with NY 884-2012 organic fertilizer standard; the pollutant emission reduction rate of the method is ≥90%, and the resource utilization rate is 40%-60% higher than that of conventional chicken manure treatment methods.

[0038] Specifically, in industrial chicken manure treatment applications, the S3-S4 waste gas treatment and ammonium sulfate preparation processes ensure that the ammonium sulfate product meets the GB 535-2020 standard and can be directly used for agricultural fertilization or industrial production. The S5 fermentation product post-treatment process ensures that the organic fertilizer meets the NY 884-2012 standard, satisfying the needs of organic agriculture. At the same time, the entire method achieves a pollutant emission reduction rate of ≥90% through closed-loop waste gas collection and pollutant conversion and utilization, avoiding the pollution problems of traditional chicken manure treatment. Furthermore, the dual-product output mode of "ammonium sulfate and organic fertilizer" improves resource utilization by 40%-60% compared to conventional chicken manure treatment methods, taking into account environmental benefits, economic benefits, and agricultural application value.

[0039] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0040] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for preparing ammonium sulfate based on chicken manure fermentation, characterized in that, Includes the following steps: S1: Pre-treat chicken manure to obtain pre-treated chicken manure that meets fermentation requirements; S2: Add functional accelerating components to pretreated chicken manure, mix evenly, and then carry out fermentation treatment to obtain fermentation products and fermentation waste gas containing ammonia and sulfides; S3: Collect the fermentation waste gas and introduce it into the reaction device. Through acid absorption and oxidation reaction, the ammonia and sulfides in the waste gas are converted into ammonium sulfate precursor liquid. S4: Purify the ammonium sulfate precursor solution to obtain the ammonium sulfate product; S5: The fermentation products are granulated and coated sequentially. Bacillus subtilis is added during the coating process to obtain the finished organic fertilizer.

2. The method for preparing ammonium sulfate based on chicken manure fermentation according to claim 1, characterized in that, The functional accelerating component is attapulgite, which is used after being roasted and crushed. The roasting temperature is 300-500℃, the roasting time is 2-4 hours, and the particle size after crushing is 100-200 mesh. The amount of the functional accelerating component added is 0.5%-5% of the dry weight of the pretreated chicken manure.

3. A method for preparing ammonium sulfate based on chicken manure fermentation according to claim 1 or 2, characterized in that, The fermentation process in S2 is aerobic fermentation, with the fermentation temperature controlled at 55-65℃ and the fermentation cycle at 7-15 days. During the fermentation process, the mixture is turned over regularly and oxygen is replenished to maintain a stable dissolved oxygen content in the fermentation system.

4. The method for preparing ammonium sulfate based on chicken manure fermentation according to claim 1, characterized in that, The pretreatment in S1 includes impurity removal and moisture content adjustment; impurity removal adopts a combination of sieving and magnetic separation processes; the moisture content is adjusted to 50%-60%, during which deionized water or fermentation product filtrate can be added.

5. The method for preparing ammonium sulfate based on chicken manure fermentation according to claim 1, characterized in that, In S3, the fermentation waste gas is collected through a negative pressure adsorption closed pipeline system, with a waste gas collection efficiency of ≥95%. The acid solution is a 10%-20% (w / w) dilute sulfuric acid solution, and the liquid-to-gas ratio of waste gas to acid solution is 1-3 L / m³. 3 .

6. A method for preparing ammonium sulfate based on chicken manure fermentation according to claim 1 or 5, characterized in that, The oxidation reaction in S3 is achieved by adding an oxidant, which is one or a mixture of hydrogen peroxide, oxygen, and ozone. The amount of oxidant added is 1.2-2.0 times the molar amount of sulfides in the exhaust gas. The oxidation reaction temperature is 30-50℃, and the reaction time is 1-3 hours.

7. The method for preparing ammonium sulfate based on chicken manure fermentation according to claim 1, characterized in that, The purification process in S4 includes filtration, concentration, crystallization, and drying steps in sequence; filtration is carried out using ceramic membrane filtration technology; concentration is performed by vacuum concentration at a temperature of 60-80℃, until the solution mass concentration is 30%-40%; Crystallization is carried out by cooling, with a crystallization temperature of 0-10℃ and a crystallization time of 8-12 hours; drying temperature is 80-100℃, and drying is carried out until the product moisture content is ≤1%.

8. The method for preparing ammonium sulfate based on chicken manure fermentation according to claim 1, characterized in that, In S5, granulation is performed using disc granulation or extrusion granulation processes, resulting in granulated particles with a diameter of 2-5 mm. Coating is carried out using a coating solution, which is prepared by mixing a coating material with a Bacillus subtilis inoculum. The coating material is one or more of sodium carboxymethyl cellulose, starch, and sodium alginate, added at 1%-3% of the fermentation product mass. The effective viable count of the Bacillus subtilis inoculum is ≥10. 9 The amount of CFU / g added is 0.1%-1.0% of the fermentation product mass; the coating process is controlled at a temperature of 30-40℃ and a humidity of 40%-50%.

9. The method for preparing ammonium sulfate based on chicken manure fermentation according to claim 1, characterized in that, In S2, the organic matter content of the fermentation products increases by 3-5%, and the total nutrients are ≥5%; in S4, the purity of the ammonium sulfate product is ≥98%; and in S5, the Bacillus subtilis viable count in the finished organic fertilizer is ≥10. 6 CFU / g, particle compressive strength ≥15N, moisture content ≤15%.

10. A method for preparing ammonium sulfate based on chicken manure fermentation according to any one of claims 1-9, characterized in that, The ammonium sulfate product conforms to GB 535-2020 standard, and the finished organic fertilizer conforms to NY 884-2012 organic fertilizer standard; the pollutant emission reduction rate of the method is ≥90%, and the resource utilization rate is 40%-60% higher than that of conventional chicken manure treatment methods.

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