Process for preparing special compound fertilizer for tomatoes from amino acid fermentation wastewater

Abstract

The invention relates to the technical field of agricultural fertilizer preparation, in particular to a process for preparing a special compound fertilizer for tomatoes from amino acid fermentation wastewater, which comprises the following steps: concentrating the amino acid fermentation wastewater, compounding the concentrated amino acid fermentation wastewater with sodium humate, monopotassium phosphate and other raw materials, adding a trace element complexing agent, a bioactive aid and a microbial flora, and uniformly mixing to obtain the special compound fertilizer for tomatoes. The feed additive is prepared through fermentation regulation, vacuum drying and granulation processes. Organic matters in the amino acid fermentation wastewater can be effectively utilized, the raw material cost is reduced, and meanwhile, the nutrient release performance and the soil improvement capacity of the fertilizer are optimized. Through the synergistic effect of bacillus licheniformis and saccharomycetes, the growth promoting effect of the fertilizer is improved, the soil structure is improved, and the yield and quality of crops are improved. According to the process, resource utilization of wastewater is realized, environmental pollution is reduced, an environment-friendly input is provided for agriculture, and green transformation of the biological fermentation industry is promoted.

Description

Technical Field

[0001] This invention belongs to the field of agricultural fertilizer preparation technology, specifically a process for preparing tomato-specific compound fertilizer from amino acid fermentation wastewater. Background Technology

[0002] With increasing environmental awareness and the promotion of resource utilization concepts, the efficient treatment and resource utilization of amino acid fermentation wastewater has gradually become a research hotspot. Amino acid fermentation wastewater is a byproduct of the bio-fermentation industry, mainly containing high concentrations of organic matter, ammonia nitrogen, amino acids, sugars, and proteins. It is also characterized by strong acidity, high COD, high BOD, and high salinity. As a major global producer of amino acids, China generates a large amount of this type of wastewater annually. If not properly treated, the rich organic matter in this wastewater can pollute the environment and lead to resource waste. In recent years, how to transform this type of wastewater into high-value-added products has become an important direction for promoting the green transformation of the industry.

[0003] The development of specialized fertilizers plays a vital role in modern agriculture, especially for cash crops like tomatoes, whose nutrient requirements are characterized by stages, diversity, and specificity during their growth. Therefore, developing specialized fertilizers that meet the nutritional needs of tomatoes throughout their entire growth cycle is particularly important. However, existing related technologies still have limitations in terms of raw material sources, preparation processes, and functionality, affecting their application effectiveness in large-scale agricultural production.

[0004] A search revealed that patent CN104911129B relates to a microbial organic fertilizer based on Bacillus amyloliquefaciens T-5, which can inhibit the growth of tomato bacterial wilt pathogens through biocontrol mechanisms, while providing abundant organic matter, amino acids, and small molecule peptides to promote tomato growth. However, the organic fertilizer raw materials used in this technical solution are not clearly derived from waste resource utilization, which may lead to higher production costs. In addition, this organic fertilizer mainly focuses on the prevention and control of soil-borne diseases, and its coverage of the nutritional needs of tomatoes throughout their entire growth cycle is insufficient, making it difficult to fully meet the requirements of balanced nutrient supply for tomato cultivation.

[0005] A search revealed that patent CN104446907B provides a composite foliar fertilizer composed of nano-needle iron ore and amino acid hydrolysate. This fertilizer utilizes the adsorption properties of the nano-needle iron ore to prolong the retention time of the foliar fertilizer on the plant leaf surface, thereby improving fertilizer utilization and growth-promoting effects. However, this technology is primarily applied as a foliar spray, failing to fully utilize agricultural waste resources (such as amino acid fermentation wastewater). Furthermore, its preparation process is complex and production costs are high. In addition, this foliar fertilizer is only suitable for supplemental fertilization at specific growth stages and lacks systematic nutritional support for the entire tomato growth cycle.

[0006] The aforementioned problems indicate that existing related technical solutions still have room for improvement in terms of the environmental friendliness and economy of raw material sources, the comprehensiveness of fertilizer functions, and the optimization of preparation processes. Therefore, this invention proposes a process for preparing tomato-specific compound fertilizer from amino acid fermentation wastewater. The aim is to develop a low-cost, high-efficiency compound fertilizer by utilizing amino acid fermentation wastewater in accordance with the nutritional needs of tomatoes throughout their entire growth cycle, thereby meeting the demands of modern agriculture for environmentally friendly and efficient fertilizers. Summary of the Invention

[0007] The purpose of this invention is to overcome the shortcomings of the prior art and provide a process for preparing tomato-specific compound fertilizer based on amino acid fermentation wastewater. By making resource-efficient use of high-concentration organic wastewater and designing fertilizer formulas in combination with the nutritional needs of tomatoes throughout their entire growth cycle, a low-cost and high-efficiency fertilizer production system is formed, while simultaneously solving the problems of wastewater treatment and agricultural non-point source pollution.

[0008] This invention provides a process for preparing tomato-specific compound fertilizer from amino acid fermentation wastewater. The process includes the following steps: S1: By weight, take 300-400 parts of concentrated amino acid fermentation wastewater, 100-150 parts of sodium humate, 50-80 parts of potassium dihydrogen phosphate, 20-30 parts of magnesium sulfate, 10-15 parts of trace element compound agent, 5-8 parts of bioactive adjuvant, and 3-6 parts of microbial flora; wherein, the trace element compound agent is zinc sulfate, copper sulfate, and ammonium molybdate in a weight ratio of 3:2:1. The mixture comprises a mixture of chitosan and sodium alginate in a weight ratio of 2:1-1.5, wherein the bioactive adjuvant is a mixture of Bacillus licheniformis and yeast in a weight ratio of 1.5:1-2; S2: The amino acid fermentation wastewater is pretreated to reduce sugar content by secondary fermentation with halophilic lactic acid bacteria for 48-72 hours, with stirring every 8 hours at a speed of 80-120 rpm to reduce the sugar content in the wastewater, followed by extraction of wastewater through flocculation and sedimentation. Residual protein in the water is separated into a clear liquid using a membrane filtration device; S3: The pretreated amino acid fermentation wastewater clear liquid is mixed with sodium humate, potassium dihydrogen phosphate, and magnesium sulfate in a certain proportion, and trace element compound and bioactive adjuvant are added. The mixture is stirred at 120-180 rpm for 25-35 minutes to form a preliminary mixture; S4: Microbial flora is inoculated into the preliminary mixture at 0.3%-0.8% of the total weight of the mixture, and the mixture is subjected to constant temperature conditions of 28-32℃ and pH 6.0-7.0. Ferment for 36-60 hours; S5: The fermented mixture is dried for 4-6 hours at 60-80℃ using a vacuum drying device with a vacuum degree of -0.08 to -0.1MPa. Then, it is granulated by a granulator with a screen aperture of 2-4mm at a speed of 150-200rpm and a feeding speed of 10-15kg / min to obtain compound fertilizer granules with a particle size of 2-4mm; S6: After cooling the compound fertilizer granules to room temperature, they are packed into moisture-proof packaging bags for later use.

[0009] Further, in step S1, the ratio of zinc sulfate, copper sulfate and ammonium molybdate by weight is 3:2:1.

[0010] Further, in step S1, the ratio of chitosan to sodium alginate is 2:1-1.5 by weight.

[0011] Further, in step S1, the ratio of Bacillus licheniformis to yeast is 1.5:1-2 by weight.

[0012] Furthermore, in step S2, the fermentation time of the halophilic lactic acid bacteria is 48-72 hours, and the mixture is stirred once every 8 hours during the fermentation process at a speed of 80-120 rpm.

[0013] Furthermore, in step S3, the stirring speed is controlled at 120-180 rpm, and the stirring time is 25-35 minutes.

[0014] Furthermore, in step S4, the inoculation amount of the microbial community is 0.3%-0.8% of the total weight of the mixture.

[0015] Furthermore, in step S5, the vacuum degree of the vacuum drying equipment is -0.08 to -0.1 MPa, and the drying time is 4-6 hours.

[0016] Furthermore, in step S5, the screen aperture of the granulator is set to 2-4 mm, the granulator rotation speed is 150-200 rpm, and the feeding speed is 10-15 kg / min.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] (1) This invention forms a compound fertilizer raw material system with excellent nutrient release performance by combining amino acid fermentation wastewater with substances such as sodium humate and potassium dihydrogen phosphate. This system makes full use of the amino acids, ammonia nitrogen and other organic matter rich in wastewater, significantly improving the functionality of fertilizer while reducing raw material costs.

[0019] (2) This invention optimizes the physical properties and chemical stability of compound fertilizer by introducing a trace element complex, bioactive adjuvants, and microbial flora. The zinc sulfate, copper sulfate, and ammonium molybdate in the trace element complex work synergistically to enhance the fertilizer's ability to supply trace elements during the key stages of tomato growth; the chitosan and sodium alginate in the bioactive adjuvants effectively improve the slow-release performance of fertilizer granules; and the Bacillus licheniformis and yeast in the microbial flora further enhance the fertilizer's growth-promoting effect and soil-improving ability.

[0020] (3) This invention endows compound fertilizer with good plant growth-promoting properties by adding microbial communities and combining fermentation regulation technology. The synergistic effect of Bacillus licheniformis and yeast enables the fertilizer to quickly activate soil microbial activity after application, improve soil structure, and increase crop yield and quality.

[0021] (4) This invention ensures the uniformity and stability of compound fertilizer granules by combining vacuum drying and granulation processes. Vacuum drying reduces the moisture content of the raw materials to below 5%, improving the storage performance of the fertilizer; while the granulation process ensures the mechanical strength and ease of application of the fertilizer granules, facilitating subsequent field use.

[0022] (5) This invention achieves the resource utilization of amino acid fermentation wastewater through optimized process design, forming a closed-loop industrial chain. The organic matter in the wastewater is effectively converted into high-value-added compound fertilizer raw materials, reducing environmental pollution and providing environmentally friendly inputs for agriculture, thus promoting the green transformation of the bio-fermentation industry. Attached Figure Description

[0023] Figure 1 This is a process flow diagram for preparing tomato-specific compound fertilizer from amino acid fermentation wastewater according to the present invention. Detailed Implementation

[0024] like Figure 1 As shown in the figure, the present invention provides a process flow diagram for preparing tomato-specific compound fertilizer from amino acid fermentation wastewater. The technical solution of the present invention will be described in detail below with reference to specific embodiments.

[0025] Example 1

[0026] A process for preparing tomato-specific compound fertilizer from amino acid fermentation wastewater includes the following steps:

[0027] Raw material preparation (S1): By weight, take 350 parts of concentrated amino acid fermentation wastewater, 120 parts of sodium humate, 60 parts of potassium dihydrogen phosphate, 25 parts of magnesium sulfate, 12 parts of trace element compound agent, 6 parts of bioactive adjuvant, and 4 parts of microbial flora. Among them, the trace element compound agent is a mixture of zinc sulfate, copper sulfate and ammonium molybdate in a weight ratio of 3:2:1; the bioactive adjuvant is a mixture of chitosan and sodium alginate in a weight ratio of 2:1; and the microbial flora is a mixture of Bacillus licheniformis (ATCC14579) and yeast (ATCC 24168) in a weight ratio of 1.5:1.

[0028] Wastewater pretreatment (S2): Amino acid fermentation wastewater (COD = 60000 mg / L, salinity 6%) was placed in a fermenter and inoculated with halophilic lactic acid bacteria (commercially available strain). Fermentation lasted 60 hours, with stirring every 8 hours at a stirring speed of 100 rpm. After fermentation, 0.3-0.5 g / L sodium polyacrylate and 1-3 g / L polyferric sulfate were added for flocculation and precipitation. The pH was adjusted to 5.5-6.5. The clarified liquid was separated by membrane filtration. The membrane filtration device had a pore size of 0.1-0.5 μm and an operating pressure of 0.1-0.3 MPa.

[0029] Mixing and blending (S3): Mix the clear liquid with sodium humate, potassium dihydrogen phosphate, and magnesium sulfate, add trace element compound and bioactive adjuvant, stir at 150 rpm for 30 minutes to form a preliminary mixture.

[0030] Fermentation control (S4): Inoculate microbial flora at 0.5% of the weight of the mixture and ferment for 48 hours at 30℃ and pH 6.5.

[0031] Drying and granulation (S5): Vacuum drying (vacuum degree -0.09MPa, temperature 70℃, time 5 hours), granulator screen aperture 3mm, rotation speed 180rpm, feed rate 12kg / min.

[0032] Example 2

[0033] Unlike Example 1, in this example, the amount of concentrated amino acid fermentation wastewater used is 300 parts, sodium humate 150 parts, potassium dihydrogen phosphate 50 parts, magnesium sulfate 30 parts, bioactive adjuvant 8 parts (the weight ratio of chitosan to sodium alginate is 2:1.5), and microbial flora 3 parts (the weight ratio of Bacillus licheniformis to yeast is 1.5:2).

[0034] The preparation steps are basically the same as in Example 1, except that:

[0035] - In step S2, the fermentation time is 48 hours and the stirring speed is 80 rpm.

[0036] - In step S4, the fermentation temperature is 28℃ and the pH is 6.0.

[0037] - In step S5, the vacuum drying temperature is 60℃ and the granulator speed is 150rpm.

[0038] Example 3

[0039] Unlike Example 1, in this example, the amount of concentrated amino acid fermentation wastewater used is 400 parts, sodium humate 100 parts, potassium dihydrogen phosphate 80 parts, magnesium sulfate 20 parts, trace element compound agent 15 parts, bioactive adjuvant 5 parts, and microbial flora 6 parts (the weight ratio of Bacillus licheniformis to yeast is 2:1).

[0040] The preparation steps are basically the same as in Example 1, except that:

[0041] - In step S2, the fermentation time is 72 hours and the stirring speed is 120 rpm.

[0042] - In step S4, the fermentation temperature is 32℃, pH 7.0, and the fermentation time is 36 hours.

[0043] - In step S5, the vacuum drying temperature is 80℃ and the granulator feed rate is 15kg / min.

[0044] Comparative Example 1

[0045] Unlike Example 1, this comparative example does not add microbial flora, but the amounts of other raw materials are the same as in Example 1, and the preparation method is also the same as in Example 1.

[0046] Comparative Example 2

[0047] Unlike Example 1, this comparative example does not contain a trace element complex agent, but the amounts of other raw materials are the same as in Example 1, and the preparation method is also the same as in Example 1.

[0048] Comparative Example 3

[0049] Unlike Example 1, this comparative example used commercially available tomato compound fertilizer (N-P2O5-K2O=15-15-15) and did not involve wastewater treatment.

[0050] The following experiments were conducted to verify the performance of the tomato-specific compound fertilizer of the present invention, based on the above embodiments:

[0051] I. Nutrient Content Test

[0052] Test method: The contents of N, P2O5, K2O and trace elements in compound fertilizer were determined according to the NY / T 2542-2014 standard.

[0053] The test results are shown in Table 1:

[0054] Table 1. Trace element content detection table for different samples

[0055] sample N(％) <![CDATA[P2O5(%)]]> <![CDATA[K2O(%)]]> Zn (mg / kg) Cu (mg / kg) Mo (mg / kg) Example 1 12.5 18.2 10.5 850 580 290 Example 2 11.8 19.0 11.2 820 550 280 Example 3 13.2 17.8 9.8 900 620 310 Comparative Example 1 12.3 18.0 10.3 840 570 285 Comparative Example 2 12.4 18.1 10.4 0 0 0 Comparative Example 3 15.0 15.0 15.0 200 150 50

[0056] Results Analysis: The N and P2O5 contents of Examples 1-3 were significantly higher than those of the commercially available compound fertilizer in Comparative Example 3, and they were also rich in trace elements such as Zn, Cu, and Mo. Comparative Example 1, which did not contain added microbial flora, had nutrient contents similar to Example 1, indicating that microorganisms primarily affect fertilizer release rather than basic nutrient content. Comparative Example 2, which did not contain a micronutrient compound (a mixture providing tomatoes with essential trace elements such as zinc, copper, and molybdenum), had zero Zn, Cu, and Mo content, verifying the necessity of adding trace elements.

[0057] II. Comparative Experiment on Tomato Cultivation

[0058] Experimental Design: The experiment was conducted in Hohhot, Inner Mongolia Autonomous Region, specifically within a facility agriculture base dedicated to tomato cultivation. The tomato variety used in this experiment was Pink Tomato No. 1. During the experiment, Examples 1 to 3 and Comparative Examples 1 to 3 were implemented according to the established experimental protocol. Each treatment was replicated three times to ensure the accuracy and reliability of the data. All tomato plants received routine management practices during the experiment, including irrigation, fertilization, and pest and disease control.

[0059] To comprehensively evaluate the experimental results, the following indicators were measured: emergence rate, fruit set rate, yield, and vitamin C content. Emergence rate reflects seed germination and initial growth; fruit set rate is directly related to the reproductive growth and final yield of tomatoes; yield is an important indicator for measuring the economic benefits of tomato cultivation; and vitamin C content is a key indicator for evaluating the nutritional value of tomatoes.

[0060] The experimental results are shown in Table 2:

[0061] Table 2. Indicator detection table for different samples used in tomato cultivation

[0062]

[0063] Results Analysis: The emergence rate, fruit setting rate, yield, and vitamin C content of Examples 1-3 were significantly higher than those of the commercially available compound fertilizer in Comparative Example 3, indicating that the specialized compound fertilizer better meets the nutritional needs of tomatoes. Comparative Example 1, without added microbial flora, saw a decrease in yield and quality indicators of approximately 8-10%, demonstrating the importance of microbial flora in promoting growth. Comparative Example 2, lacking micronutrients, experienced a decrease in tomato yield and vitamin C content of approximately 6-8%, indicating that micronutrients are crucial for tomato quality formation.

[0064] III. Fertilizer Degradation Experiment

[0065] Test method: The compound fertilizer granules were buried in farmland soil (moisture content 25%, temperature 25℃), and the residue rate was measured periodically.

[0066] The test results are shown in Table 3:

[0067] Table 3. Fertilizer degradation residue rate detection table for different samples

[0068] sample 30-day residue rate (%) 60-day residue rate (%) 90-day residue rate (%) Example 1 65.2 32.5 10.8 Example 2 68.3 35.7 12.5 Example 3 62.8 30.2 9.6 Comparative Example 1 66.5 34.2 11.5 Comparative Example 3 85.6 68.3 45.2

[0069] Results analysis: The 90-day residue rates of Examples 1-3 were all below 13%, significantly lower than the 45.2% of the commercially available compound fertilizer in Comparative Example 3, indicating that the compound fertilizer prepared by this process has good biodegradability. The addition of microbial flora (Examples 1-3) further improved the degradation rate compared to Comparative Example 1, reducing the 90-day residue rate by approximately 5-8%.

[0070] IV. Economic Benefit Analysis

[0071] Taking Example 1 as an example, treating 1 ton of amino acid fermentation wastewater can produce approximately 0.5 tons of compound fertilizer, with a raw material cost of about 80 yuan and a market price of about 1200 yuan / ton. The net profit per ton of wastewater treated is about 520 yuan. Based on an annual wastewater treatment capacity of 330,000 tons, the annual profit would be approximately 172 million yuan, while simultaneously reducing wastewater treatment costs by approximately 20 million yuan per year.

[0072] In summary, through comparative experiments using examples and comparative examples, the process for preparing tomato-specific compound fertilizer from amino acid fermentation wastewater provided by this invention has the following advantages:

[0073] 1. Resource utilization of wastewater reduces production costs while simultaneously addressing environmental pollution issues.

[0074] 2. The formula is highly targeted, meeting the nutritional needs of tomatoes throughout their entire growth cycle and significantly improving yield and quality.

[0075] 3. The addition of microbial flora and bioactive adjuvants (functional substances that enhance the slow-release properties of fertilizers and promote nutrient absorption) enhances the fertilizer's growth-promoting effect and soil improvement capacity.

[0076] 4. It has good process stability, is suitable for large-scale industrial application, and has significant economic and social benefits.

[0077] The above embodiments are merely one of the preferred embodiments of the present invention and should not be used to limit the scope of protection of the present invention. Any modifications or refinements made to the main design concept and spirit of the present invention that are not of substantial significance, but solve the same technical problem as the present invention, should be included within the scope of protection of the present invention.

Claims

1. A process for preparing tomato-specific compound fertilizer from amino acid fermentation wastewater, characterized in that, The process Includes the following steps: S1: By weight, take 300-400 parts of concentrated amino acid fermentation wastewater, 100-150 parts of sodium humate, 50-80 parts of potassium dihydrogen phosphate, 20-30 parts of magnesium sulfate, 10-15 parts of trace element compound agent, 5-8 parts of bioactive adjuvant, and 3-6 parts of microbial flora. The trace element compound is a mixture of zinc sulfate, copper sulfate and ammonium molybdate in a weight ratio of 3:2:1; the bioactive adjuvant is a mixture of chitosan and sodium alginate in a weight ratio of 2:1-1.5; and the microbial community is a mixture of Bacillus licheniformis and yeast in a weight ratio of 1.5:1-2. S2: The amino acid fermentation wastewater is pretreated to reduce sugar content by secondary fermentation with halophilic lactic acid bacteria for 48-72 hours. During the fermentation process, the mixture is stirred once every 8 hours at a speed of 80-120 rpm to reduce the sugar content in the wastewater. Then, residual protein in the wastewater is extracted by flocculation and sedimentation, and the clear liquid is separated by membrane filtration. S3: Mix the pretreated amino acid fermentation wastewater with sodium humate, potassium dihydrogen phosphate and magnesium sulfate in a certain proportion, add trace element compound and bioactive additive, and stir at 120-180 rpm for 25-35 minutes to form a preliminary mixture. S4: Inoculate the preliminary mixture with microbial flora at a rate of 0.3%-0.8% of the total weight of the mixture, and ferment for 36-60 hours under constant temperature conditions of 28-32℃ and pH value of 6.0-7.0; S5: The fermented mixture is dried in a vacuum drying device with a vacuum degree of -0.08 to -0.1 MPa at a temperature of 60-80℃ for 4-6 hours. Then it is granulated by a granulator with a screen aperture of 2-4 mm. The granulator speed is 150-200 rpm and the feeding speed is 10-15 kg / min to obtain compound fertilizer granules with a particle size of 2-4 mm. S6: After cooling the compound fertilizer granules to room temperature, pack them into moisture-proof packaging bags for later use.

2. The process for preparing tomato-specific compound fertilizer from amino acid fermentation wastewater according to claim 1, characterized in that: In step S1, the ratio of zinc sulfate, copper sulfate and ammonium molybdate by weight is 3:2:

1.

3. The process for preparing tomato-specific compound fertilizer from amino acid fermentation wastewater according to claim 1, characterized in that: In step S1, the ratio of chitosan to sodium alginate is 2:1-1.5 by weight.

4. The process for preparing tomato-specific compound fertilizer from amino acid fermentation wastewater according to claim 1, characterized in that: In step S1, the ratio of Bacillus licheniformis to yeast is 1.5:1-2 by weight.

5. The process for preparing tomato-specific compound fertilizer from amino acid fermentation wastewater according to claim 1, characterized in that: In step S2, the fermentation time of the halophilic lactic acid bacteria is 48-72 hours, and the mixture is stirred once every 8 hours during the fermentation process at a speed of 80-120 rpm.

6. The process for preparing tomato-specific compound fertilizer from amino acid fermentation wastewater according to claim 1, characterized in that: In step S3, the stirring speed is controlled at 120-180 rpm, and the stirring time is 25-35 minutes.

7. The process for preparing tomato-specific compound fertilizer from amino acid fermentation wastewater according to claim 1, characterized in that: In step S4, the inoculation amount of the microbial community is 0.3%-0.8% of the total weight of the mixture.

8. The process for preparing tomato-specific compound fertilizer from amino acid fermentation wastewater according to claim 1, characterized in that: In step S5, the vacuum degree of the vacuum drying equipment is -0.08 to -0.1 MPa, and the drying time is 4-6 hours.

9. The process for preparing tomato-specific compound fertilizer from amino acid fermentation wastewater according to claim 1, characterized in that: In step S5, the screen aperture of the granulator is set to 2-4mm, the granulator speed is 150-200rpm, and the feeding speed is 10-15kg / min.

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