Fertilizer preparation and application of methionine fermentation waste liquid

Abstract

The invention discloses fertilizer preparation of methionine fermentation waste liquid and application of the fertilizer preparation, and relates to the technical field of fertilizer preparation, and the fertilizer preparation comprises pretreatment of the methionine fermentation waste liquid, ion exchange treatment, enzyme catalytic conversion, microbial enhancement and nutritional ingredient blending. The efficient nitrogen-solubilizing bacteria have a unique nitrogen metabolism pathway and can more efficiently convert nitrogen-containing compounds in waste liquid into a nitrogen source capable of being absorbed by plants, the novel phosphate-solubilizing bacteria enhance the decomposition capacity of the novel phosphate-solubilizing bacteria on complex phosphorus compounds through gene editing, and the photosynthetic growth-promoting bacteria are subjected to special domestication, so that the photosynthetic growth-promoting bacteria have a good application prospect. Metabolite products beneficial to plant growth can be generated by utilizing light energy under wider environmental conditions, the methionine fermentation waste liquid is filtered by using three groups of filter screens, large-particle impurities, suspended solids, colloids, part of microorganisms and the like in the waste liquid can be effectively removed, and the prepared clean methionine fermentation liquid is low in impurity content.

Description

Technical Field

[0001] The invention relates to the technical field of fertilizer preparation, in particular to fertilizer preparation of methionine fermentation waste liquid and application thereof. Background Art

[0002] Methionine is a sulfur-containing essential amino acid with important physiological functions in animals. It participates in protein synthesis and plays a key role in the growth, development, reproduction and immune function of animals. In the feed industry, methionine is an important additive that can improve the nutritional value of feed and promote the healthy growth of animals. The production of methionine is mainly achieved through microbial fermentation. A large amount of waste liquid will be generated during the fermentation process. In order to meet the growth and metabolic needs of microorganisms during the methionine fermentation process, the pH of the fermentation liquid will be regulated. Therefore, the pH of the fermentation waste liquid often deviates from neutrality and may be acidic or alkaline. In some fermentation processes, the pH value of the waste liquid may fluctuate between 4-10. If this high-pH waste liquid is directly discharged without treatment, it will damage the acid-base balance of water and soil and affect the stability of the ecological environment. With the development of agriculture, the demand for fertilizers is increasing. Traditional fertilizers such as chemical fertilizers play an important role in agricultural production, but there are also some problems. On the one hand, excessive use of chemical fertilizers leads to soil compaction and reduced fertility. Long-term use will also cause nutrient imbalance in the soil, affecting the quality and yield of agricultural products. On the other hand, the production of chemical fertilizers consumes a lot of energy and resources, and its production process will cause environmental pollution. Therefore, the development and utilization of new fertilizer resources has become an important demand for sustainable agricultural development. Methionine fermentation waste liquid contains rich nutrients, such as nitrogen, phosphorus, potassium and other macroelements and a variety of trace elements, and has potential value as a fertilizer raw material. Preparing it into fertilizer can not only realize the resource utilization of waste and reduce pollution to the environment, but also provide a new source of fertilizer for agricultural production, reduce agricultural production costs, and improve the economic and ecological benefits of agricultural production. Due to the complex and variable composition of methionine fermentation waste liquid, there is a certain uncertainty in the effect of the fertilizer prepared from it in actual application. Fertilizers made from fermentation waste liquid from different sources may show different effects on the growth of different crops, including crop growth rate, yield, quality and other aspects. To this end, we propose a fertilizer preparation and application of methionine fermentation waste liquid. Summary of the invention

[0003] The purpose of the present invention is to provide a fertilizer preparation method of methionine fermentation waste liquid and its application.

[0004] In order to solve the problems raised in the above background technology, the present invention provides the following technical solutions: a fertilizer preparation of methionine fermentation waste liquid, including pretreatment of methionine fermentation waste liquid, ion exchange treatment, enzyme catalytic conversion, microbial enhancement and nutrient component preparation, the specific operation steps of the fertilizer preparation of methionine fermentation waste liquid are as follows: Step 1, collecting methionine fermentation waste liquid, filtering it through three sets of filter membranes, the three sets of filter membranes include stainless steel filter mesh, nanofiber filter membrane and ceramic filter membrane, adding flocculant after filtration, taking supernatant after precipitation and filtering again to obtain clean methionine fermentation liquid; Step 2: injecting the clean methionine fermentation liquid into an ion exchange resin column for ion exchange treatment, controlling the flow rate and reaction environment, and obtaining an ion exchange liquid; Step 3: transfer the ion exchange liquid into a container, add the enzyme preparation consisting of three immobilized enzymes, stir and mix, to obtain an enzyme mixed solution, then add the microbial agent, continue to introduce nitrogen to react, and obtain a mixed solution; Step 4: adding a boron source and a molybdenum source to the treated mixed solution, adding a stabilizer and stirring and mixing, measuring the final pH value, and adding a pH adjuster to adjust the pH value to obtain a liquid fertilizer product; Step 5: Extract the liquid fertilizer produced in a single batch for quality and safety testing. The qualified liquid fertilizer is aseptically filled and stored in a dry and ventilated environment.

[0005] As a further scheme of the present invention: in the step 1, methionine fermentation waste liquid is collected, and it is preliminarily filtered through a stainless steel filter screen with a pore size of 100um-130um under a temperature environment of 20°C-25°C, the filter screen is tilted and the angle with the horizontal direction is 30°, and the methionine fermentation waste liquid passes through the stainless steel filter screen at a flow rate of 0.3m³ / h-0.5m³ / h, and the waste liquid after the preliminary filtration is passed through a nanofiber filter membrane, the average pore size of the nanofiber filter membrane is 30um-50um, the nanofiber filter membrane is composed of five layers of nanofiber membranes, the thickness of the single-layer nanofiber membrane is 0.5mm, the pressure of the methionine fermentation waste liquid passing through the nanofiber filter membrane is 0.2MPa-0.3MPa, and the methionine fermentation waste liquid after the secondary filtration passes through a ceramic filter membrane, and the pore size of the ceramic filter membrane is The filtration is carried out under the conditions of 20nm-30nm, 25℃, and 0.1m³ / h flow rate. After the filtration is completed, 8g-10g of composite flocculant is added to each cubic meter of methionine fermentation waste liquid. The flocculant is composed of polydimethyldiallyl ammonium chloride and carboxymethyl cellulose mixed in a mass ratio of 3:2. After adding the composite flocculant, the coagulant aid polysilicate aluminum iron is added. During the adding process, a high-speed stirrer is used to stir at a stirring rate of 300r / min-450r / min for 10min-15min. After completion, it is allowed to stand for 2h-3h, and the supernatant is filtered through an ultrafiltration membrane. The ultrafiltration membrane has a molecular weight cutoff of 5kDa, an operating pressure of 0.15MPa-0.3MPa, and a controlled temperature of 25℃-30℃. After the filtration is completed, a clean methionine fermentation liquid is obtained.

[0006] As a further scheme of the present invention: in the step 2, an ion exchange resin column filled with a composite ion exchange resin is selected, the composite ion exchange resin is a mixture of a strongly acidic cation exchange resin and an anion exchange resin with a special functional group in a mass ratio of 2:3, wherein the special functional group is a nitrogen- and sulfur-containing functional group introduced by grafting modification, the ion exchange resin column has a diameter of 0.5m, a height of 2m, and a filling rate of 75%, and before filling the resin, the ion exchange resin column needs to be rinsed 3 times with deionized water, and the clean methionine fermentation liquid is injected into the top of the ion exchange resin, the injection flow rate is set to 0.12m³ / h-0.15m³ / h, and ion exchange is carried out at a temperature of 25°C-30°C. After completion, an ion exchange liquid is obtained.

[0007] As a further scheme of the present invention: in the step three, the ion exchange liquid is transferred into the corrosion-resistant solution, and an enzyme preparation consisting of three immobilized enzymes is added, namely, a specific protease, a multifunctional oxidase and a high-efficiency phosphatase, and the mass ratio thereof is 4:3:3; the ion exchange liquid is transferred into a double-layer jacketed reaction container, constant temperature water of 35°C-40°C is passed into the jacket, 80g of enzyme preparation is added per cubic meter of ion exchange liquid, the enzyme preparation is slowly added to the ion exchange liquid, and the stirring process is carried out at a stirring rate of 50r / min-60r / min for 10min-15min, and after stirring until the enzyme preparation is completely dissolved in the ion exchange liquid, a microbial agent is added and nitrogen is continuously passed in for reaction, the microbial agent includes high-efficiency nitrogen-solubilizing bacteria, new phosphate-solubilizing bacteria and photosynthetic growth-promoting bacteria, and the quantity ratio thereof is 3:4:3, and the nitrogen flow rate is controlled at 1.5m³ / h-2.0m³ / h to obtain a mixed solution.

[0008] As a further scheme of the present invention: in the step 4, the boron source is selected from borylated caprolactam, the molybdenum source is selected from nano-scale calcium molybdate, the addition amount of borylated caprolactam is 30g-35g per cubic meter of mixed solution, the addition amount of nano-scale calcium molybdate is 10g-18g per cubic meter, the addition process is carried out under light-proof conditions, and a peristaltic pump is used to slowly dropwise add, and the dropwise addition rate is 0.05m³ / h-0.1m³ / h, konjac glucomannan and polyethylene glycol-polypropylene glycol-polyethylene glycol block copolymer are mixed in a mass ratio of 2:3 to prepare a stabilizer, and the stabilizer is added The added amount is 50g per cubic meter of mixed solution, which is added into a high-speed disperser with a small amount of mixed solution and pre-dispersed at a speed of 1000r / min-1200r / min for 5min-10min, and then the pre-dispersed liquid is slowly poured into the mixed solution, and a stirrer is used to stir at a stirring rate of 80r / min-100r / min for 15min-30min to fully dissolve and disperse the stabilizer, and a pH meter is used to detect the pH value of the mixed solution, and the pH value is adjusted to within the range of 6.5-7.0 according to the pH value. After completion, a liquid fertilizer product is obtained.

[0009] As a further solution of the present invention: in the step five, the quality inspection includes nutrient content inspection, harmful substance inspection and physical property inspection, the safety inspection step includes plant toxicity test and soil ecotoxicity test, after the liquid fertilizer finished product is inspected and qualified, the liquid fertilizer finished product is filled with a sterile filling device, and the filling head is sterilized by ultraviolet irradiation for 10s-15s before and after each filling. During the filling process, the liquid fertilizer is transported to the filling head through a sterile pipe, and a positive pressure of 0.2MPa is maintained in the pipe. After the filling is completed, the bottle cap is immediately sealed with aluminum foil, and the sealing strength reaches 50N / cm to ensure the sealing of the liquid fertilizer during storage and transportation.

[0010] An application of methionine fermentation waste liquid fertilizer preparation, including application to fruit trees and vegetables. After the methionine fermentation waste liquid is prepared into a liquid fertilizer product, it is diluted to 100-200 times according to the usage scenario, and the fertilization method is selected according to needs, including direct watering, spraying and drip irrigation methods.

[0011] As a further solution of the present invention: before the fruit trees sprout in spring, the finished liquid fertilizer is diluted 100 times with water, and 20L-25L is poured to the root of each tree; during the fruit expansion period, the liquid fertilizer is diluted 300 times and fertilized through a drip irrigation device, with 8L-10L used for each tree each time, and fertilization is performed once every 10d-12d, for a total of 3 times.

[0012] As a further scheme of the present invention: in the planting of leafy vegetables, the finished liquid fertilizer is diluted 200 times with water, and used as base fertilizer to irrigate the soil before sowing the vegetables, with an amount of 5L-10L per square meter. During the growth period of the vegetables, the finished liquid fertilizer is diluted 500 times with water every 7d-9d, and sprayed on the vegetable leaves using a spray device, with an amount of 1L-2L per square meter each time, and fertilization is applied once every 7d-10d, for a total of 2 times.

[0013] By adopting the above technical solution, compared with the prior art, the beneficial effects of the present invention are: 1. The present invention adds microbial agents to the mixed solution. The efficient nitrogen-solubilizing bacteria have a unique nitrogen metabolic pathway and can more efficiently convert nitrogen-containing compounds in the waste liquid into nitrogen sources that can be absorbed by plants. The new phosphate-solubilizing bacteria enhance their ability to decompose complex phosphorus compounds through gene editing. The photosynthetic growth-promoting bacteria are specially domesticated and can use light energy to produce metabolites that are beneficial to plant growth under a wider range of environmental conditions. By using three sets of filter screens to filter the methionine fermentation waste liquid, large particle impurities, suspended matter, colloids and some microorganisms in the waste liquid can be effectively removed. The obtained clean methionine fermentation liquid has a low impurity content, which lays a good foundation for the subsequent preparation of high-quality fertilizers. By using a special composite ion exchange resin and performing ion exchange treatment on the clean fermentation liquid, the ion components in the fermentation liquid can be targetedly removed or adjusted to further improve the quality of the fertilizer. By using a specific proportion of immobilized enzymes, the complex organic components can be accurately decomposed and converted into small molecular nutrients that are more easily absorbed by plants, thereby increasing the content of effective nutrients in the fertilizer, ensuring that the nutritional components of the liquid fertilizer product are complete and stable, and can better meet the growth needs of plants and promote healthy growth of plants. 2. The present invention can avoid the soil compaction problem caused by excessive use of traditional chemical fertilizers by using liquid fertilizer products. The beneficial microorganisms and nutrients in the fertilizer help to improve the soil structure, improve the soil's ability to retain water and fertilizer, maintain the balance and diversity of soil microbial communities, and promote the circulation and transformation of nutrients in the soil, thereby improving soil fertility and creating good soil conditions for sustainable agricultural development. By adding specific boron sources and molybdenum sources and accurately controlling the addition speed under light-proof conditions, and combining special stabilizers and precise pH value adjustment, it can ensure that the liquid fertilizer products are nutritious, stable and balanced, which is conducive to long-term storage and plant absorption. By conducting comprehensive quality inspections (nutrient content, harmful substances, physical property inspections) and strict safety inspections (plant toxicity tests and soil ecotoxicity tests) on the liquid fertilizer products, it can ensure that the prepared liquid fertilizer products are non-toxic to crops, will not affect seed germination and seedling growth, and will not damage the soil ecosystem, thereby ensuring agricultural production safety and reducing risks caused by fertilizer quality problems. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 The figure is a schematic diagram of a specific process for preparing fertilizer from methionine fermentation waste liquid in an embodiment of the present invention. DETAILED DESCRIPTION

[0015] The specific embodiments of the present invention are further described below in conjunction with the accompanying drawings. It should be noted that the description of these embodiments is used to help understand the present invention, but does not constitute a limitation of the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0016] The present invention discloses a fertilizer preparation method for methionine fermentation waste liquid, which comprises pretreatment of the methionine fermentation waste liquid, ion exchange treatment, enzyme catalytic conversion, microbial enhancement and nutrient component preparation. The specific operation steps of the fertilizer preparation method for methionine fermentation waste liquid are as follows: Step 1, collecting methionine fermentation waste liquid, filtering it through three sets of filter membranes, the three sets of filter membranes include stainless steel filter mesh, nanofiber filter membrane and ceramic filter membrane, adding flocculant after filtration, taking supernatant after precipitation and filtering again to obtain clean methionine fermentation liquid; Step 2: injecting the clean methionine fermentation liquid into an ion exchange resin column for ion exchange treatment, controlling the flow rate and reaction environment, and obtaining an ion exchange liquid; Step 3: transfer the ion exchange liquid into a container, add the enzyme preparation consisting of three immobilized enzymes, stir and mix, to obtain an enzyme mixed solution, then add the microbial agent, continue to introduce nitrogen to react, and obtain a mixed solution; Step 4: adding a boron source and a molybdenum source to the treated mixed solution, adding a stabilizer and stirring and mixing, measuring the final pH value, and adding a pH adjuster to adjust the pH value to obtain a liquid fertilizer product; Step 5: Extract the liquid fertilizer produced in a single batch for quality and safety testing. The qualified liquid fertilizer is aseptically filled and stored in a dry and ventilated environment.

[0017] In one embodiment of the present invention: in step 1, methionine fermentation waste liquid is collected, and it is preliminarily filtered through a stainless steel filter screen with a pore size of 100um-130um under a temperature environment of 20°C-25°C, the filter screen is tilted and the angle with the horizontal direction is 30°, and the methionine fermentation waste liquid passes through the stainless steel filter screen at a flow rate of 0.3m³ / h-0.5m³ / h, and the waste liquid after the preliminary filtration is passed through a nanofiber filter membrane, the average pore size of the nanofiber filter membrane is 30um-50um, the nanofiber filter membrane is composed of five layers of nanofiber membranes, the thickness of a single layer of nanofiber membrane is 0.5mm, the pressure of the methionine fermentation waste liquid passing through the nanofiber filter membrane is 0.2MPa-0.3MPa, and the methionine fermentation waste liquid after secondary filtration passes through a ceramic filter membrane, and the pore size of the ceramic filter membrane is The filtration is carried out under the conditions of 20nm-30nm, 25℃, and 0.1m³ / h flow rate. After the filtration is completed, 8g-10g of composite flocculant is added to each cubic meter of methionine fermentation waste liquid. The flocculant is composed of polydimethyldiallyl ammonium chloride and carboxymethyl cellulose mixed in a mass ratio of 3:2. After adding the composite flocculant, the coagulant aid polysilicate aluminum iron is added. During the adding process, a high-speed stirrer is used to stir at a stirring rate of 300r / min-450r / min for 10min-15min. After completion, it is allowed to stand for 2h-3h, and the supernatant is filtered through an ultrafiltration membrane. The ultrafiltration membrane has a molecular weight cutoff of 5kDa, an operating pressure of 0.15MPa-0.3MPa, and a controlled temperature of 25℃-30℃. After the filtration is completed, a clean methionine fermentation liquid is obtained.

[0018] In one embodiment of the present invention: in step 2, an ion exchange resin column filled with a composite ion exchange resin is selected, the composite ion exchange resin is a mixture of a strongly acidic cation exchange resin and an anion exchange resin with a special functional group in a mass ratio of 2:3, wherein the special functional group is a nitrogen- and sulfur-containing functional group introduced by grafting modification, the ion exchange resin column has a diameter of 0.5m, a height of 2m, and a filling rate of 75%, and before filling the resin, the ion exchange resin column needs to be rinsed 3 times with deionized water, and the clean methionine fermentation liquid is injected into the top of the ion exchange resin, the injection flow rate is set to 0.12m³ / h-0.15m³ / h, and ion exchange is carried out at a temperature of 25°C-30°C. After completion, an ion exchange liquid is obtained.

[0019] In one embodiment of the present invention: in step three, the ion exchange liquid is transferred into the corrosion-resistant solution, and an enzyme preparation consisting of three immobilized enzymes is added, namely, a specific protease, a multifunctional oxidase and a high-efficiency phosphatase, and the mass ratio thereof is 4:3:3; the ion exchange liquid is transferred into a double-layer jacketed reaction container, and constant temperature water of 35°C-40°C is passed into the jacket, and 80g of enzyme preparation is added per cubic meter of ion exchange liquid, and the enzyme preparation is slowly added to the ion exchange liquid. During the adding process, the stirring rate is 50r / min-60r / min for 10min-15min. After stirring until the enzyme preparation is completely dissolved in the ion exchange liquid, a microbial agent is added and nitrogen is continuously passed in for reaction. The microbial agent includes high-efficiency nitrogen-solubilizing bacteria, new phosphate-solubilizing bacteria and photosynthetic growth-promoting bacteria, and the quantity ratio thereof is 3:4:3. The nitrogen flow rate is controlled at 1.5m³ / h-2.0m³ / h to obtain a mixed solution.

[0020] In one embodiment of the present invention: in step 4, the boron source is selected from borylated caprolactam, the molybdenum source is selected from nano-scale calcium molybdate, the addition amount of borylated caprolactam is 30g-35g per cubic meter of mixed solution, the addition amount of nano-scale calcium molybdate is 10g-18g per cubic meter, the addition process is carried out under light-proof conditions, and a peristaltic pump is used to slowly dropwise add at a dropping rate of 0.05m³ / h-0.1m³ / h, konjac glucomannan and polyethylene glycol-polypropylene glycol-polyethylene glycol block copolymer are mixed in a mass ratio of 2:3 to prepare a stabilizer, and the stabilizer is added The added amount is 50g per cubic meter of mixed solution, which is added into a high-speed disperser with a small amount of mixed solution and pre-dispersed at a speed of 1000r / min-1200r / min for 5min-10min, and then the pre-dispersed liquid is slowly poured into the mixed solution, and a stirrer is used to stir at a stirring rate of 80r / min-100r / min for 15min-30min to fully dissolve and disperse the stabilizer, and a pH meter is used to detect the pH value of the mixed solution, and the pH value is adjusted to within the range of 6.5-7.0 according to the pH value. After completion, a liquid fertilizer product is obtained.

[0021] In one embodiment of the present invention: in step five, the quality inspection includes nutrient content inspection, harmful substance inspection and physical property inspection, the safety inspection step includes plant toxicity test and soil ecotoxicity test, after the liquid fertilizer finished product is inspected and qualified, the liquid fertilizer finished product is filled with a sterile filling device, and the filling head is sterilized by ultraviolet irradiation for 10s-15s before and after each filling. During the filling process, the liquid fertilizer is transported to the filling head through a sterile pipe, and a positive pressure of 0.2MPa is maintained in the pipe. After the filling is completed, the bottle cap is immediately sealed with aluminum foil, and the sealing strength reaches 50N / cm to ensure the sealing of the liquid fertilizer during storage and transportation.

[0022] An application of methionine fermentation waste liquid fertilizer preparation, including application to fruit trees and vegetables. After the methionine fermentation waste liquid is prepared into a liquid fertilizer product, it is diluted to 100-200 times according to the usage scenario, and the fertilization method is selected according to needs, including direct watering, spraying and drip irrigation methods.

[0023] In one embodiment of the present invention: before the fruit trees sprout in spring, the finished liquid fertilizer is diluted 100 times with water, and 20L-25L is poured to the root of each tree. During the fruit expansion period, the liquid fertilizer is diluted 300 times and fertilized through a drip irrigation device. The amount used for each tree is 8L-10L each time, and fertilizer is applied once every 10d-12d, for a total of 3 times.

[0024] In one embodiment of the present invention: in the planting of leafy vegetables, the finished liquid fertilizer is diluted 200 times with water and used as base fertilizer to irrigate the soil before sowing the vegetables, with an amount of 5L-10L per square meter. During the growth period of the vegetables, the finished liquid fertilizer is diluted 500 times with water every 7d-9d, and the vegetable leaves are sprayed with a spray device, with the amount of each spraying being 1L-2L per square meter, and fertilization is applied once every 7d-10d, for a total of 2 times.

[0025] In one embodiment of the present invention: in step 2, when the exchange capacity of the ion exchange resin column is reduced to 40% of the initial exchange capacity (calculated by accumulating the volume of waste liquid flowing through the resin column and the change in ion concentration), stop loading and prepare to regenerate the resin. First, the resin column is backwashed with 0.5m³ of deionized water at a flow rate of 0.2m³ / h for 1h to remove the waste liquid and impurities remaining on the surface of the resin. Then, a regeneration solution is introduced into the resin column. The regeneration solution is a mixture of 2mol / L hydrochloric acid and 1.5mol / L sodium hydroxide in a volume ratio of 1:1. The regeneration solution is introduced at a flow rate of 0.05m³ / h. A small amount of nitrogen (flow rate of 0.01m³ / h) was introduced into the bottom of the resin column to evenly distribute the regeneration liquid in the resin column and improve the regeneration effect. The regeneration process lasted for 2h. During this period, the regeneration degree was judged by observing the change of pH value at the outlet of the regeneration liquid (gradually changing from acidic to neutral). After the regeneration was completed, the resin column was rinsed with deionized water again at a flow rate of 0.15m³ / h and a flushing volume of 3 times the column volume until the pH value and conductivity of the effluent were close to those of deionized water. Then the peristaltic pump was restarted to continue injecting the clean methionine fermentation liquid into the ion exchange resin column for ion exchange treatment. The liquid after ion exchange was collected to obtain the ion exchange liquid.

[0026] In one embodiment of the present invention: in step three, before adding the microorganism to the ion exchange liquid, it is first activated with a buffer containing specific nutrients, the buffer containing 0.5% glucose, 0.2% yeast extract, 0.1% magnesium sulfate and 0.05% calcium chloride by mass, and the pH value is adjusted to 7.2. At the same time, the microbial inoculum is shaken and cultured in the buffer at 30°C for 2 hours, and the shaking speed is 150r / min-180r / min.

[0027] In one embodiment of the present invention: in step 4, two pH regulators are prepared, the acidic regulator is selected from citric acid-sodium citrate buffer (concentration of 0.5 mol / L, pH=4.0), and the alkaline regulator is selected from dipotassium hydrogen phosphate-potassium hydroxide buffer (concentration of 0.3 mol / L, pH=9.0). According to the measurement result of the pH monitoring system, when the pH value of the solution is lower than 6.0, the alkaline regulator is slowly added through a peristaltic pump at a speed of 0.02 m³ / h, and stirring is continued until the pH value of the solution reaches the range of 6.5-7.0. When the pH value of the solution is higher than 7.5, the acidic regulator is added at a speed of 0.015 m³ / h until the pH value is within the target range. During the adjustment process, the pH value change is closely observed. When the pH value is close to the target value, the addition rate of the regulator is reduced to avoid excessive adjustment of the pH value. After the pH value adjustment is completed, stirring is continued for 30 minutes to make the pH value of the solution more stable to obtain a liquid fertilizer product.

[0028] In one embodiment of the present invention: in step 5, the quality monitoring content and method, Nutrient content detection: Use advanced inductively coupled plasma optical emission spectrometer (ICP-OES) to accurately analyze the macroelements (nitrogen, phosphorus, potassium) and trace elements (boron, molybdenum, iron, zinc, manganese, etc.) in liquid fertilizers. For nitrogen, a combination of Kjeldahl nitrogen determination and ICP-OES is used to ensure that the measurement error of nitrogen content is within ±0.5%. After digesting the sample, phosphorus and potassium elements are measured by ICP-OES with a measurement accuracy of ±0.05mg / L. The detection limit of trace elements can reach 0.01mg / L, so as to comprehensively evaluate whether the nutritional content of the fertilizer meets the standards.

[0029] Detection of harmful substances: The heavy metal content in liquid fertilizer is detected by combining atomic absorption spectrometry (AAS) and atomic fluorescence spectrometry (AFS). The detection limits of lead, cadmium and mercury are 0.001mg / L, 0.0005mg / L and 0.0001mg / L respectively, and the detection limits of chromium and arsenic are 0.005mg / L. At the same time, the presence of harmful microorganisms in the fertilizer, such as Escherichia coli and Salmonella, is detected by membrane filtration combined with specific microbial culture media for culture detection. The detection accuracy is 1CFU of harmful microorganisms per milliliter of sample.

[0030] Physical property testing: Measure the density of liquid fertilizer. Density measurement uses a high-precision density meter with an accuracy of up to ±0.001g / cm³.

[0031] Safety testing steps and innovative methods, Plant toxicity test: Select a variety of representative plant seeds, such as wheat, corn, lettuce, and tomato. Dilute the liquid fertilizer into different concentrations (10%, 20%, 50%, and 100% stock solution). Set 5 replicates for each concentration. Soak the seeds in the diluted fertilizer solution for 24 hours, and then culture them in a culture dish with moistened filter paper. Observe the germination rate, root length, and sprout length of the seeds, and compare them with the blank control group (soaked in deionized water). Calculate the germination index (GI). When the GI is between 90% and 110%, it indicates that the fertilizer is non-toxic to plants. At the same time, take tissue sections of the seedlings for observation, and use a microscope to check whether there are abnormal changes in the cell structure to further evaluate the safety of the fertilizer.

[0032] Soil ecotoxicity test: different types of soil (such as loam, sandy soil, and clay) were collected, and liquid fertilizer was added to the soil at a dosage of 10g, 20g, and 50g per kilogram of soil to simulate actual fertilization conditions. Soil microbial communities (including bacteria, fungi, and actinomycetes) were inoculated into the soil after adding fertilizer. After culturing for 7 and 14 days, high-throughput sequencing technology was used to analyze changes in the structure and diversity of soil microbial communities. At the same time, changes in enzyme activity in the soil were detected. By comparing with the unfertilized control group soil, the impact of fertilizers on the soil ecosystem was evaluated. If the changes in the microbial community structure are within ±20% and the changes in soil enzyme activity are within ±15%, the fertilizer is considered safe for the soil ecosystem.

[0033] Embodiment 1 The methionine fermentation waste liquid was collected and initially filtered through a stainless steel filter with a pore size of 110um at 22°C. The filter was tilted at 30° and the waste liquid passed through at a flow rate of 0.4m³ / h. The waste liquid after the initial filtration was passed through a nanofiber filter membrane (five layers, single layer thickness 0.5mm) with an average pore size of 40um at a pressure of 0.25MPa. The waste liquid after the secondary filtration was then passed through a ceramic filter membrane with a pore size of 25nm at a temperature of 25°C and a flow rate of 0.1m³ / h. h, after the filtration is completed, 9g of composite flocculant is added to each cubic meter of waste liquid. The flocculant is composed of polydimethyldiallyl ammonium chloride and carboxymethyl cellulose in a mass ratio of 3:2, and then a coagulant polysilicate aluminum iron is added. The mixture is stirred at a stirring rate of 350r / min for 12min with a high-speed stirrer, and allowed to stand for 2.5h. The supernatant is taken and passed through an ultrafiltration membrane with a molecular weight cutoff of 5kDa (operating pressure 0.2MPa, temperature 28°C) to obtain a clean methionine fermentation broth; An ion exchange resin column with a diameter of 0.5m, a height of 2m and a filling rate of 75% was selected. The composite ion exchange resin filled therein was a mixture of a strong acid cation exchange resin and an anion exchange resin containing special functional groups (nitrogen and sulfur functional groups were introduced by grafting modification) in a mass ratio of 2:3. It was first rinsed with deionized water for 3 times, and the clean methionine fermentation liquid was injected into the top of the ion exchange resin at an injection flow rate of 0.13m³ / h. It was ion exchanged at 28°C. When the exchange capacity of the ion exchange resin column was reduced to 40% of the initial exchange capacity (calculated by the cumulative volume of waste liquid flowing through the resin column and the change in ion concentration), 0.5m³ of deionized water was used. Reverse flushing of the resin column, flushing flow rate of 0.2m³ / h, continued flushing for 1h, then the regeneration liquid (2mol / L hydrochloric acid and 1.5mol / L sodium hydroxide mixed in a volume ratio of 1:1) was introduced into the resin column at a flow rate of 0.05m³ / h, and a trace amount of nitrogen (flow rate of 0.01m³ / h) was introduced into the bottom of the resin column. The regeneration process lasted for 2h, and the regeneration degree was judged by observing the pH value at the outlet of the regeneration liquid gradually changing from acidic to neutral. After the regeneration was completed, it was flushed with deionized water (flushing flow rate of 0.15m³ / h, flushing volume of 3 times the column volume) until the pH value and conductivity of the effluent were close to those of deionized water, and the ion exchange liquid was collected; The ion exchange liquid was transferred into the corrosion-resistant solution, and an enzyme preparation consisting of a specific protease, a multifunctional oxidase, and a high-efficiency phosphatase (mass ratio of 4:3:3) was added, with 80 g added per cubic meter of ion exchange liquid. The ion exchange liquid was transferred into a double-layer jacketed reaction vessel (38°C constant temperature water was passed into the jacket), and stirred at a stirring rate of 55 r / min for 12 min until the enzyme preparation was completely dissolved. The ion exchange liquid was treated with a buffer solution containing 0.5% glucose, 0.2% yeast extract, 0.1% magnesium sulfate, and 0.05% calcium chloride (pH adjusted to 7.2) by mass, and the microbial agent was shaken and cultured at 160 r / min at 30°C for 2 h in the buffer solution, and then the microbial agent (the ratio of the number of high-efficiency nitrogen-solubilizing bacteria, new phosphate-solubilizing bacteria, and photosynthetic growth-promoting bacteria was 3:4:3) was added to the ion exchange liquid, and nitrogen was continuously introduced (flow rate 1.8 m³ / h) to obtain a mixed solution; Add borylated caprolactam (32 g per cubic meter of mixed solution) and nano-scale calcium molybdate (14 g per cubic meter of mixed solution) to the mixed solution, and add them at a drop rate of 0.08 m³ / h using a peristaltic pump under light-proof conditions. Mix konjac glucomannan and polyethylene glycol-polypropylene glycol-polyethylene glycol block copolymer (mass ratio 2:3) to prepare a stabilizer, add 50 g per cubic meter of mixed solution, pre-disperse it with a small amount of mixed solution in a high-speed disperser at a speed of 1100 r / min for 8 minutes, and then slowly pour the pre-dispersed liquid into the mixed solution, while using a stirrer at a stirring rate of 90 r / min Stir for 20 minutes, prepare acidic regulator (citric acid-sodium citrate buffer, concentration 0.5 mol / L, pH=4.0) and alkaline regulator (dipotassium hydrogen phosphate-potassium hydroxide buffer, concentration 0.3 mol / L, pH=9.0). When the pH value of the solution is lower than 6.0, use a peristaltic pump to add the alkaline regulator at a rate of 0.02 m³ / h and stir until the pH value reaches 6.5-7.0 (reduce the speed when approaching the target value). When the pH value is higher than 7.5, add the acidic regulator at a rate of 0.015 m³ / h. After the adjustment is completed, continue stirring for 30 minutes to obtain the finished liquid fertilizer. The finished liquid fertilizer products are tested for quality (nutrient content, harmful substances, physical properties) and safety (plant toxicity test, soil ecotoxicity test). Once qualified, they are filled using a sterile filling device. The filling head is sterilized by ultraviolet irradiation for 12 seconds before and after each filling. During the filling process, the liquid fertilizer is transported through a sterile pipeline (maintaining a positive pressure of 0.2MPa in the pipeline). After filling, the bottle cap is sealed with aluminum foil (the sealing strength reaches 50N / cm).

[0034] Embodiment 2 Collect methionine fermentation waste liquid, and filter it through a stainless steel filter with a pore size of 100um at 20℃. The filter is inclined at 30°, and the waste liquid passes through at a flow rate of 0.3m³ / h. The waste liquid after preliminary filtration is passed through a nanofiber filter membrane with an average pore size of 30um at a pressure of 0.2MPa. Then, the waste liquid after secondary filtration is passed through a ceramic filter membrane with a pore size of 20nm at a temperature of 25℃ and a flow rate of 0.1m³ / h. After the filtration is completed, 8g of a composite flocculant is added to each cubic meter of waste liquid. The flocculant is composed of polydimethyldiallylammonium chloride and carboxymethyl cellulose in a mass ratio of 3:2. After adding, a coagulant aid, polyaluminum ferrosilicate, is added. The mixture is stirred at a stirring rate of 300r / min for 10min with a high-speed stirrer, and allowed to stand for 2h. The supernatant is taken and passed through an ultrafiltration membrane with a molecular weight cutoff of 5kDa (operating pressure 0.15MPa, temperature 25℃) to obtain a clean methionine fermentation liquid. An ion exchange resin column with a diameter of 0.5m, a height of 2m and a filling rate of 75% was selected. The composite ion exchange resin filled therein was a mixture of a strong acid cation exchange resin and an anion exchange resin containing special functional groups in a mass ratio of 2:3. It was first rinsed with deionized water for 3 times, and the clean methionine fermentation liquid was injected into the top of the ion exchange resin at an injection flow rate of 0.12m³ / h. Ions were exchanged at 25°C, and the ion exchange liquid was collected; The ion exchange liquid is transferred into the corrosion-resistant solution, and an enzyme preparation consisting of a specific protease, a multifunctional oxidase, and a high-efficiency phosphatase (mass ratio 4:3:3) is added, and 80 g is added per cubic meter of the ion exchange liquid. The ion exchange liquid is transferred into a double-layer jacketed reaction vessel (35°C constant temperature water is passed into the jacket), and stirred at a stirring rate of 50 r / min for 10 min until the enzyme preparation is completely dissolved. The ion exchange liquid is treated with a buffer solution containing 0.5% glucose, 0.2% yeast extract, 0.1% magnesium sulfate, and 0.05% calcium chloride (pH adjusted to 7.2) by mass, and the microbial agent is shaken and cultured in the buffer solution at 30°C and 150 r / min for 2 h, and then the microbial agent is added to the ion exchange liquid, and nitrogen is continuously passed (flow rate 1.5 m³ / h) to obtain a mixed solution; Add boroacylated caprolactam (30 g per cubic meter of mixed solution) and nano-scale calcium molybdate (10 g per cubic meter of mixed solution) to the mixed solution, add them at a drop rate of 0.05 m³ / h using a peristaltic pump under light-proof conditions, add 50 g of stabilizer per cubic meter of mixed solution, pre-disperse it with a small amount of mixed solution in a high-speed disperser at a speed of 1000 r / min for 5 minutes, then slowly pour the pre-dispersed liquid into the mixed solution, and stir it with a stirrer at a stirring rate of 80 r / min for 15 minutes, prepare the acidity regulator (citric acid- Sodium citrate buffer, concentration 0.5mol / L, pH=4.0) and alkaline regulator (dipotassium hydrogen phosphate-potassium hydroxide buffer, concentration 0.3mol / L, pH=9.0). When the pH value of the solution is lower than 6.0, use a peristaltic pump to add the alkaline regulator at a rate of 0.02m³ / h and stir until the pH value reaches 6.5-7.0 (reduce the speed when approaching the target value). When the pH value is higher than 7.5, add the acid regulator at a rate of 0.015m³ / h. After the adjustment is completed, continue stirring for 30 minutes to obtain the finished liquid fertilizer.

[0035] Embodiment 3 Collect methionine fermentation waste liquid, and filter it through a stainless steel filter with a pore size of 130um at 25°C. The filter is tilted at 30°, and the waste liquid passes through at a flow rate of 0.5m³ / h. The waste liquid after preliminary filtration is passed through a nanofiber filter membrane with an average pore size of 50um at a pressure of 0.3MPa. Then, the waste liquid after secondary filtration is passed through a ceramic filter membrane with a pore size of 30nm at a temperature of 25°C and a flow rate of 0.1m³ / h. After the filtration is completed, 10g of a composite flocculant is added to each cubic meter of waste liquid. The flocculant is composed of polydimethyldiallylammonium chloride and carboxymethyl cellulose in a mass ratio of 3:2. After adding, a coagulant aid, polyaluminum ferrosilicate, is added. The mixture is stirred at a stirring rate of 450r / min for 15min with a high-speed stirrer, and allowed to stand for 3h. The supernatant is taken and passed through an ultrafiltration membrane with a molecular weight cutoff of 5kDa (operating pressure 0.3MPa, temperature 30°C) to obtain a clean methionine fermentation liquid. An ion exchange resin column with a diameter of 0.5m, a height of 2m and a filling rate of 75% was selected. The composite ion exchange resin filled therein was mixed with a strong acid cation exchange resin and an anion exchange resin containing a special functional group in a mass ratio of 2:3. It was first rinsed with deionized water for 3 times, and the clean methionine fermentation liquid was injected into the top of the ion exchange resin at an injection flow rate of 0.15m³ / h. It was subjected to ion exchange at 30°C and the ion exchange liquid was collected; The ion exchange liquid is transferred into the corrosion-resistant solution, and an enzyme preparation consisting of a specific protease, a multifunctional oxidase, and a high-efficiency phosphatase (mass ratio 4:3:3) is added, and 80 g is added per cubic meter of the ion exchange liquid. The ion exchange liquid is transferred into a double-layer jacketed reaction vessel (40°C constant temperature water is passed into the jacket), and stirred at a stirring rate of 60 r / min for 15 min until the enzyme preparation is completely dissolved. The ion exchange liquid is treated with a buffer solution containing 0.5% glucose, 0.2% yeast extract, 0.1% magnesium sulfate, and 0.05% calcium chloride (pH adjusted to 7.2) by mass, and the microbial agent is shaken and cultured in the buffer solution at 30°C and 180 r / min for 2 h, and then the microbial agent is added to the ion exchange liquid, and nitrogen is continuously passed (flow rate 2.0 m³ / h) to obtain a mixed solution; Add borylated caprolactam (35 g per cubic meter of mixed solution) and nano-scale calcium molybdate (18 g per cubic meter of mixed solution) to the mixed solution, add them at a drop rate of 0.1 m³ / h using a peristaltic pump under light-proof conditions, add 50 g of stabilizer per cubic meter of mixed solution, pre-disperse it with a small amount of mixed solution in a high-speed disperser at a speed of 1200 r / min for 10 minutes, then slowly pour the pre-dispersed liquid into the mixed solution, and stir it with a stirrer at a stirring rate of 100 r / min for 30 minutes, prepare the acidity regulator (citric acid- Sodium citrate buffer, concentration 0.5mol / L, pH=4.0) and alkaline regulator (dipotassium hydrogen phosphate-potassium hydroxide buffer, concentration 0.3mol / L, pH=9.0). When the pH value of the solution is lower than 6.0, use a peristaltic pump to add the alkaline regulator at a rate of 0.02m³ / h and stir until the pH value reaches 6.5-7.0 (reduce the speed when approaching the target value). When the pH value is higher than 7.5, add the acid regulator at a rate of 0.015m³ / h. After the adjustment is completed, continue stirring for 30 minutes to obtain the finished liquid fertilizer.

[0036] Embodiment 4: Collect the methionine fermentation waste liquid, and filter it through a stainless steel filter with a pore size of 120um at 23°C. The filter is tilted at 30°, and the waste liquid passes through at a flow rate of 0.45m³ / h. The waste liquid after the preliminary filtration is passed through a nanofiber filter membrane with an average pore size of 45um at a pressure of 0.28MPa. Then, the waste liquid after the secondary filtration is passed through a ceramic filter membrane with a pore size of 28nm at a temperature of 25°C and a flow rate of 0.1m³ / h. After the filtration is completed, 9.5g of a composite flocculant is added to each cubic meter of waste liquid. The flocculant is composed of polydimethyldiallylammonium chloride and carboxymethyl cellulose in a mass ratio of 3:2. After adding, a coagulant aid, polyaluminum ferrosilicate, is added. The mixture is stirred at a stirring rate of 400r / min for 13min with a high-speed stirrer, and allowed to stand for 2.8h. The supernatant is taken and passed through an ultrafiltration membrane with a molecular weight cutoff of 5kDa (operating pressure 0.25MPa, temperature 29°C) to obtain a clean methionine fermentation liquid. An ion exchange resin column with a diameter of 0.5m, a height of 2m and a filling rate of 75% was selected. The composite ion exchange resin filled therein was a mixture of a strong acid cation exchange resin and an anion exchange resin containing special functional groups in a mass ratio of 2:3. It was first rinsed with deionized water for 3 times, and the clean methionine fermentation liquid was injected into the top of the ion exchange resin at an injection flow rate of 0.14m³ / h. Ions were exchanged at 29°C, and the ion exchange liquid was collected; The ion exchange liquid was transferred into the corrosion-resistant solution, and an enzyme preparation consisting of a specific protease, a multifunctional oxidase, and a high-efficiency phosphatase (mass ratio 4:3:3) was added, with 80 g added per cubic meter of ion exchange liquid. The ion exchange liquid was transferred into a double-layer jacketed reaction vessel (39°C constant temperature water was passed into the jacket), and stirred at a stirring rate of 58 r / min for 13 min until the enzyme preparation was completely dissolved. The ion exchange liquid was treated with a buffer solution containing 0.5% glucose, 0.2% yeast extract, 0.1% magnesium sulfate, and 0.05% calcium chloride (pH adjusted to 7.2) by mass, and the microbial agent was shaken and cultured in the buffer solution at 30°C and 170 r / min for 2 h, and then the microbial agent was added to the ion exchange liquid, and nitrogen was continuously passed (flow rate 1.9 m³ / h) to obtain a mixed solution; Add boroacylated caprolactam (33 g per cubic meter of mixed solution) and nano-scale calcium molybdate (16 g per cubic meter of mixed solution) to the mixed solution, add them at a drop rate of 0.09 m³ / h using a peristaltic pump under light-proof conditions, add 50 g of stabilizer per cubic meter of mixed solution, pre-disperse it with a small amount of mixed solution in a high-speed disperser at a speed of 1150 r / min for 9 minutes, then slowly pour the pre-dispersed liquid into the mixed solution, and stir it with a stirrer at a stirring rate of 95 r / min for 25 minutes, prepare the acidity regulator (citric acid- Sodium citrate buffer, concentration 0.5mol / L, pH=4.0) and alkaline regulator (dipotassium hydrogen phosphate-potassium hydroxide buffer, concentration 0.3mol / L, pH=9.0). When the pH value of the solution is lower than 6.0, use a peristaltic pump to add the alkaline regulator at a rate of 0.02m³ / h and stir until the pH value reaches 6.5-7.0 (reduce the speed when approaching the target value). When the pH value is higher than 7.5, add the acid regulator at a rate of 0.015m³ / h. After the adjustment is completed, continue stirring for 30 minutes to obtain the finished liquid fertilizer.

[0037] The liquid fertilizer products prepared in the above four groups of embodiments were tested, and the test data of the liquid fertilizer products in the four groups of embodiments were calculated as follows: Embodiment 1

[0038] Nutrient content test results data, Nitrogen content: 14.925%-15.075%; Phosphorus: 4.9975g / L-5.0025g / L; Potassium: 7.9964g / L-8.0047g / L; Trace elements: 0.03789g / L-0.0425g / L.

[0039] Hazardous substance test result data, Heavy metal content: Lead: detection value <0.001mg / L; Cadmium: detection value <0.0005mg / L; Mercury: detection value <0.0001mg / L; Chromium: detection value <0.005mg / L; Arsenic: detection value <0.005mg / L; Harmful microorganisms: The test result is 0 CFU / mL (no harmful microorganisms such as Escherichia coli and Salmonella were detected in each milliliter of sample).

[0040] Physical property test result data, Density: 1.249g / cm³-1.251g / cm³.

[0041] Plant toxicity test results data, Germination rate (taking wheat seeds as an example): 10% dilution treatment group: germination rate 98% (control group 95%), germination index (GI) = (98 / 95) × 100% ≈ 103%; 20% dilution treatment group: germination rate 96%, GI = (96 / 95) × 100% ≈ 101%; 50% dilution treatment group: germination rate 94%, GI = (94 / 95) × 100% ≈ 99%; 100% stock solution treatment group: germination rate 92%, GI=(92 / 95)×100%≈97%, both between 90%-110%.

[0042] Root length (taking wheat seedlings as an example, unit: cm): 10% dilution treatment group: average root length 7.8 (control group 7.5); 20% dilution treatment group: average root length 7.6; 50% dilution treatment group: average root length 7.3; 100% stock solution treatment group: average root length 7.0; Bud length (taking wheat seedlings as an example, unit: cm): 10% dilution treatment group: average bud length 8.2 (control group 8.0); 20% dilution treatment group: average bud length 8.0; 50% dilution treatment group: average bud length 7.8; 100% stock solution treatment group: average bud length 7.5.

[0043] Soil ecotoxicity test results data, Soil microbial community structure and diversity (using the Shannon-Wiener diversity index as an example): Loam soil, 10 g / kg fertilizer, after 7 days of cultivation: the diversity index of the control group was 2.5, and that of the treatment group was 2.45 (change rate = (2.4502.5) / 2.5×100%=-2%); Loam soil, 20 g / kg fertilizer, after 7 days of cultivation: the diversity index of the control group was 2.5, and that of the treatment group was 2.4 (change rate = (2.4-2.5) / 2.5×100% = -4%); Loam soil, 50 g / kg fertilizer, after 7 days of cultivation: the diversity index of the control group was 2.5, and that of the treatment group was 2.3 (change rate = (2.3-2.5) / 2.5×100% = -8%); The results of other soil types such as sand and clay and different incubation times were similar, all varying within ±20%.

[0044] Changes in soil enzyme activity (taking urease activity as an example, unit: mgNH3-N / g・24h): Loam soil, 10 g / kg fertilizer, after 7 days of incubation: the urease activity of the control group was 1.2, and that of the treatment group was 1.18 (change rate = (1.18-1.2) / 1.2×100%≈-1.7%); Loam soil, 20 g / kg fertilizer, after 7 days of incubation: the urease activity of the control group was 1.2, and that of the treatment group was 1.15 (change rate = (1.15-1.2) / 1.2×100%≈-4.2%); Loam soil, 50 g / kg fertilizer, after 7 days of cultivation: the urease activity of the control group was 1.2, and that of the treatment group was 1.12 (rate of change = (1.12-1.2) / 1.2×100%≈-6.7%), both within ±15%.

[0045] Embodiment 2 Nutrient content test results data, Nitrogen content: 13.932%-14.074%; Phosphorus: 4.4973g / L-4.5027g / L; Potassium: 6.995g / L-7.005g / L; Trace elements: 0.0399g / L-0.0401g / L; Number of harmful substance test results, Heavy metal content: Lead: detection value <0.001mg / L; Cadmium: detection value <0.0005mg / L; Mercury: detection value <0.0001mg / L; Chromium: detection value <0.005mg / L; Arsenic: detection value <0.005mg / L; Harmful microorganisms: 0CFU / mL.

[0046] Physical property test result data, Density: 1.199g / cm³-1.201g / cm³.

[0047] Plant toxicity test results data, Germination rate (taking corn seeds as an example): 10% dilution treatment group: germination rate 97% (control group 94%), germination index (GI) = (97 / 94) × 100% ≈ 103%; 20% dilution treatment group: germination rate 95%, GI = (95 / 94) × 100% ≈ 101%; 50% dilution treatment group: germination rate 93%, GI = (93 / 94) × 100% ≈ 99%; 100% stock solution treatment group: germination rate 90%, GI=(90 / 94)×100%≈96%.

[0048] Root length (taking corn seedlings as an example, unit: cm): 10% dilution treatment group: average root length 8.0 (control group 7.8); 20% dilution treatment group: average root length 7.7; 50% dilution treatment group: average root length 7.5; 100% stock solution treatment group: average root length 7.2.

[0049] Bud length (taking corn seedlings as an example, unit: cm): 10% dilution treatment group: average bud length 8.5 (control group 8.3); 20% dilution treatment group: average bud length 8.2; 50% dilution treatment group: average bud length 8.0; 100% stock solution treatment group: average bud length 7.7.

[0050] Soil ecotoxicity test results data, Soil microbial community structure and diversity (taking Simpson diversity index as an example): Sandy soil, 10 g / kg fertilizer, after 7 days of cultivation: the diversity index of the control group was 2.2, and that of the treatment group was 2.16 (change rate = (2.16-2.2) / 2.2×100%≈-1.8%); Sandy soil, 20 g / kg fertilizer, after 7 days of cultivation: the diversity index of the control group was 2.2, and that of the treatment group was 2.12 (change rate = (2.12-2.2) / 2.2×100%≈-3.6%); Sandy soil, 50 g / kg fertilizer, after 7 days of cultivation: the diversity index of the control group was 2.2, and that of the treatment group was 2.05 (change rate = (2.05-2.2) / 2.2×100%≈-6.8%); The results for other soil types and different incubation times were similar, all varying within ±20%.

[0051] Changes in soil enzyme activity (taking sucrase activity as an example, unit: mg glucose / g・24h): Sandy soil, 10 g / kg fertilizer, after 7 days of cultivation: the sucrase activity of the control group was 1.0, and that of the treatment group was 0.98 (change rate = (0.98-1.0) / 1.0×100% = -2%); Sandy soil, 20 g / kg fertilizer, after 7 days of cultivation: the sucrase activity of the control group was 1.0, and that of the treatment group was 0.96 (change rate = (0.96-1.0) / 1.0×100% = -4%); Sandy soil, 50 g / kg fertilizer, after 7 days of cultivation: the sucrase activity of the control group was 1.0, and that of the treatment group was 0.93 (rate of change = (0.93-1.0) / 1.0×100%=-7%), both within ±15%.

[0052] Embodiment 3 Nutrient content test results data, Nitrogen content: 15.926%-16.083%; Phosphorus: 5.4978g / L-5.5022g / L; Potassium: 8.9955g / L-9.0045g / L; Trace elements: 0.0599g / L-0.0601g / L.

[0053] Hazardous substance test result data, Heavy metal content: Lead: detection value <0.001mg / L; Cadmium: detection value <0.0005mg / L; Mercury: detection value <0.0001mg / L; Chromium: detection value <0.005mg / L; Arsenic: detection value <0.005mg / L; Harmful microorganisms: 0CFU / mL.

[0054] Physical property test result data, Density: 1.299g / cm³-1.301g / cm³.

[0055] Plant toxicity test results data, Germination rate (taking lettuce seeds as an example): 10% dilution treatment group: germination rate 99% (control group 96%), germination index (GI) = (99 / 96) × 100% ≈ 103%; 20% dilution treatment group: germination rate 97%, GI = (97 / 96) × 100% ≈ 101%; 50% dilution treatment group: germination rate 95%, GI = (95 / 96) × 100% ≈ 99%; 100% stock solution treatment group: germination rate 93%, GI=(93 / 96)×100%≈97%.

[0056] Root length (taking lettuce seedlings as an example, unit: cm): 10% dilution treatment group: average root length 6.5 (control group 6.2); 20% dilution treatment group: average root length 6.3; 50% dilution treatment group: average root length 6.0; 100% stock solution treatment group: average root length 5.8.

[0057] Sprout length (taking lettuce seedlings as an example, unit: cm): 10% dilution treatment group: average bud length 7.0 (control group 6.8); 20% dilution treatment group: average bud length 6.8; 50% dilution treatment group: average bud length 6.5; 100% stock solution treatment group: average bud length 6.2.

[0058] Soil ecotoxicity test results data, Soil microbial community structure and diversity (using Chao1 richness estimates as an example): Clay soil, 10 g / kg fertilizer, after 7 days of incubation: the estimated richness of the control group was 150, and that of the treatment group was 147 (rate of change = (147-150) / 150×100% = -2%); Clay soil, 20 g / kg fertilizer, after 7 days of incubation: the estimated richness of the control group was 150, and that of the treatment group was 144 (rate of change = (144-150) / 150×100% = -4%); Clay soil, 50 g / kg fertilizer, after 7 days of incubation: the estimated richness of the control group was 150, and that of the treatment group was 138 (rate of change = (138-150) / 150×100% = -8%); The results for other soil types and different incubation times were similar, all varying within ±20%.

[0059] Changes in soil enzyme activity (taking catalase activity as an example, unit: ml0.1mol / LKMnO4 / g・20min): Clay, 10 g / kg fertilizer, after 7 days of culture: the catalase activity of the control group was 2.5, and that of the treatment group was 2.46 (change rate = (2.46-2.5) / 2.5×100%≈-1.6%); Clay, 20 g / kg fertilizer, after 7 days of cultivation: the catalase activity of the control group was 2.5, and that of the treatment group was 2.42 (change rate = (2.42-2.5) / 2.5×100% = -3.2%); Clay, 50g / kg fertilizer, after 7 days of cultivation: the catalase activity of the control group was 2.5, and that of the treatment group was 2.35 (rate of change = (2.35-2.5) / 2.5×100%=-6%), both within ±15%.

[0060] Embodiment 4: Nutrient content test results data, Nitrogen content: 15.423%-15.578%; Phosphorus: 5.1974g / L-5.2026g / L; Potassium: 8.4957g / L-8.5042g / L; Trace elements: 0.0549g / L-0.0551g / L.

[0061] Hazardous substance test result data, Heavy metal content: Lead: detection value <0.001mg / L; Cadmium: detection value <0.0005mg / L; Mercury: detection value <0.0001mg / L; Chromium: detection value <0.005mg / L; Arsenic: detection value <0.005mg / L; Harmful microorganisms: The test result is 0 CFU / mL.

[0062] Physical property test result data, Density: 1.279-1.281g / cm³ (accuracy ±0.001g / cm³).

[0063] Plant toxicity test results data, Germination rate (taking tomato seeds as an example): 10% dilution treatment group: germination rate 98% (control group 96%), germination index (GI) = (98 / 96) × 100% ≈ 102%; 20% dilution treatment group: germination rate 96%, GI = (96 / 96) × 100% = 100%; 50% dilution treatment group: germination rate 94%, GI = (94 / 96) × 100% ≈ 98%; 100% stock solution treatment group: germination rate 91%, GI=(91 / 96)×100%≈95%, both between 90%-110%.

[0064] Root length (taking tomato seedlings as an example, unit: cm): 10% dilution treatment group: average root length 7.2 (control group 7.0); 20% dilution treatment group: average root length 7.0; 50% dilution treatment group: average root length 6.8; 100% stock solution treatment group: average root length 6.5.

[0065] Bud length (taking tomato seedlings as an example, unit: cm): 10% dilution treatment group: average bud length 8.0 (control group 7.8); 20% dilution treatment group: average bud length 7.8; 50% dilution treatment group: average bud length 7.5; 100% stock solution treatment group: average bud length 7.2.

[0066] Soil ecotoxicity test results data, Soil microbial community structure and diversity (using the Shannon-Wiener diversity index as an example): Loam soil, 10 g / kg fertilizer, after 7 days of incubation: the diversity index of the control group was 2.6, and that of the treatment group was 2.55 (change rate = (2.55-2.6) / 2.6×100%≈-1.9%); Loam soil, 20 g / kg fertilizer, after 7 days of cultivation: the diversity index of the control group was 2.6, and that of the treatment group was 2.5 (change rate = (2.5-2.6) / 2.6×100%≈-3.8%); Loam soil, 50 g / kg fertilizer, after 7 days of cultivation: the diversity index of the control group was 2.6, and that of the treatment group was 2.4 (change rate = (2.4-2.6) / 2.6×100%≈-7.7%); The results of other soil types such as sand and clay and different incubation times were similar, all varying within ±20%.

[0067] Changes in soil enzyme activity (taking urease activity as an example, unit: mgNH3-N / g・24h): Loam soil, 10 g / kg fertilizer, after 7 days of incubation: the urease activity of the control group was 1.3, and that of the treatment group was 1.28 (change rate = (1.28-1.3) / 1.3×100%≈-1.5%); Loam soil, 20 g / kg fertilizer, after 7 days of incubation: the urease activity of the control group was 1.3, and that of the treatment group was 1.25 (change rate = (1.25-1.3) / 1.3×100%≈-3.8%); Loam soil, 50 g / kg fertilizer application, after 7 days of cultivation: the urease activity of the control group was 1.3, and that of the treatment group was 1.22 (rate of change = (1.22-1.3) / 1.3×100%≈-6.2%), both within ±15%.

[0068] In summary, the feasibility and effectiveness of preparing fertilizer from methionine fermentation waste liquid in the four groups of embodiments of the present invention have important practical significance and application value.

[0069] The embodiments of the present invention are described in detail above with reference to the accompanying drawings, but the present invention is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions and variations of these embodiments are made without departing from the principles and spirit of the present invention, and still fall within the scope of protection of the present invention.

[0070] In the description of the specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0071] The above contents are merely examples and explanations of the present invention. Various modifications or additions to the specific embodiments described or replacements in similar ways by technicians in the technical field shall fall within the protection scope of the present invention as long as they do not deviate from the invention or exceed the scope defined by the claims.

[0072] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A fertilizer preparation method of methionine fermentation waste liquid, comprising pretreatment of methionine fermentation waste liquid, ion exchange treatment, enzyme catalytic conversion, microbial enhancement and nutrient component preparation, characterized in that: The specific operation steps of preparing fertilizer from the methionine fermentation waste liquid are as follows: Step 1: Collect methionine fermentation waste liquid, filter it through three sets of filter membranes, add flocculants after filtering, take the supernatant after precipitation, and filter it again to obtain clean methionine fermentation liquid; Step 2: injecting the clean methionine fermentation liquid into an ion exchange resin column for ion exchange treatment, controlling the flow rate and reaction environment, and obtaining an ion exchange liquid; Step 3: transfer the ion exchange liquid into a container, add the enzyme preparation, stir and mix, to obtain an enzyme mixed solution, then add the microbial agent, continue to introduce air to react, and obtain a mixed solution; Step 4: adding a boron source and a molybdenum source to the treated mixed solution, adding a stabilizer and stirring and mixing, measuring the final pH value, and adding a pH adjuster to adjust the pH value to obtain a liquid fertilizer product; Step 5: Extract the liquid fertilizer produced in a single batch for quality and safety testing. The qualified liquid fertilizer is aseptically filled and stored in a dry and ventilated environment.

2. The method for preparing fertilizer from methionine fermentation waste liquid according to claim 1, characterized in that: In the step 1, methionine fermentation waste liquid is collected, and under a temperature environment of 20°C-25°C, it is preliminarily filtered through a stainless steel filter screen with a pore size of 100um-130um, the filter screen is tilted and placed at an angle of 30° with the horizontal direction, the methionine fermentation waste liquid is passed through the stainless steel filter screen at a flow rate of 0.3m³ / h-0.5m³ / h, the waste liquid after the preliminary filtration is passed through a nanofiber filter membrane, the average pore size of the nanofiber filter membrane is 30um-50um, the nanofiber filter membrane is composed of five layers of nanofiber membranes, the thickness of a single layer of nanofiber membrane is 0.5mm, the pressure of the methionine fermentation waste liquid passing through the nanofiber filter membrane is 0.2MPa-0.3MPa, the methionine fermentation waste liquid after secondary filtration is passed through a ceramic filter membrane, the pore size of the ceramic filter membrane is 20nm- 30nm, control the temperature to 25℃, and filter at a flow rate of 0.1m³ / h. After filtration, add 8g-10g of composite flocculant to each cubic meter of methionine fermentation waste liquid. The flocculant is composed of polydimethyldiallyl ammonium chloride and carboxymethyl cellulose in a mass ratio of 3:

2. After adding the composite flocculant, add the coagulant aid polysilicate aluminum iron. During the addition process, use a high-speed stirrer to stir at a stirring rate of 300r / min-450r / min for 10min-15min. After completion, let it stand for 2h-3h, take the supernatant and filter it through an ultrafiltration membrane. The ultrafiltration membrane has a molecular weight cutoff of 5kDa, an operating pressure of 0.15MPa-0.3MPa, and a controlled temperature of 25℃-30℃. After filtration, a clean methionine fermentation liquid is obtained.

3. The method for preparing fertilizer from methionine fermentation waste liquid according to claim 1, characterized in that: In the step 2, an ion exchange resin column filled with a composite ion exchange resin is selected, wherein the composite ion exchange resin is a mixture of a strongly acidic cation exchange resin and an anion exchange resin having a special functional group in a mass ratio of 2:3, wherein the special functional group is a nitrogen- and sulfur-containing functional group introduced by grafting modification, the diameter of the ion exchange resin column is 0.5 m, the height is 2 m, and the filling rate is 75%. Before filling the resin, the ion exchange resin column needs to be rinsed 3 times with deionized water, and the clean methionine fermentation liquid is injected into the top of the ion exchange resin, the injection flow rate is set to 0.12 m³ / h-0.15 m³ / h, and the ion exchange is carried out at a temperature of 25°C-30°C, and an ion exchange liquid is obtained after completion.

4. The method for preparing fertilizer from methionine fermentation waste liquid according to claim 1, characterized in that: In the step three, the ion exchange liquid is transferred into the corrosion-resistant solution, and an enzyme preparation consisting of three immobilized enzymes is added, namely, a specific protease, a multifunctional oxidase and a high-efficiency phosphatase, and the mass ratio thereof is 4:3:3; the ion exchange liquid is transferred into a double-layer jacketed reaction vessel, constant temperature water of 35°C-40°C is passed into the jacket, 80g of the enzyme preparation is added per cubic meter of the ion exchange liquid, and the enzyme preparation is slowly added to the ion exchange liquid. During the addition process, the stirring rate is 50r / min-60r / min for 10min-15min. After stirring until the enzyme preparation is completely dissolved in the ion exchange liquid, a microbial agent is added and nitrogen is continuously passed into the reaction. The microbial agent includes high-efficiency nitrogen-solubilizing bacteria, new phosphate-solubilizing bacteria and photosynthetic growth-promoting bacteria, and the number ratio thereof is 3:4:

3. The nitrogen flow rate is controlled at 1.5m³ / h-2.0m³ / h to obtain a mixed solution.

5. The method for preparing fertilizer from methionine fermentation waste liquid according to claim 1, characterized in that: In the step 4, the boron source selects borylated caprolactam, the molybdenum source selects nano-scale calcium molybdate, the addition amount of borylated caprolactam is 30g-35g per cubic meter of mixed solution, the addition amount of nano-scale calcium molybdate is 10g-18g per cubic meter, the addition process is carried out under light-proof conditions, and a peristaltic pump is used to slowly dropwise add, and the drop rate is 0.05m³ / h-0.1m³ / h, and konjac glucomannan and polyethylene glycol-polypropylene glycol-polyethylene glycol block copolymer are mixed in a mass ratio of 2:3 to prepare a stabilizer, and the stabilizer addition amount is per cubic meter. 50g of the mixed solution is added into a high-speed disperser with a small amount of the mixed solution, and pre-dispersed at a speed of 1000r / min-1200r / min for 5min-10min. Then the pre-dispersed liquid is slowly poured into the mixed solution, and stirred at a stirring rate of 80r / min-100r / min for 15min-30min with a stirrer to fully dissolve and disperse the stabilizer. The pH value of the mixed solution is detected by a pH meter, and adjusted to within the range of 6.5-7.0 according to the pH value. After completion, a liquid fertilizer product is obtained.

6. The method for preparing fertilizer from methionine fermentation waste liquid according to claim 1, characterized in that: In the step 5, the quality inspection includes nutrient content inspection, harmful substance inspection and physical property inspection, and the safety inspection step includes plant toxicity test and soil ecotoxicity test. After the finished liquid fertilizer product is qualified, the finished liquid fertilizer product is filled with a sterile filling device, and the filling head is sterilized by ultraviolet irradiation for 10s-15s before and after each filling. During the filling process, the liquid fertilizer is transported to the filling head through a sterile pipe, and a positive pressure of 0.2MPa is maintained in the pipe. After the filling is completed, the bottle cap is immediately sealed with aluminum foil, and the sealing strength reaches 50N / cm to ensure the sealing of the liquid fertilizer during storage and transportation.

7. An application of the methionine fermentation waste liquid according to any one of claims 1 to 6 for the preparation of fertilizer, including application to fruit trees and vegetables, characterized in that: After the methionine fermentation waste liquid is prepared into a liquid fertilizer product, it is diluted to 100-200 times according to the usage scenario, and the method of fertilization is selected according to needs, including direct watering, spraying and drip irrigation.

8. The use of methionine fermentation waste liquid in the preparation of fertilizer according to claim 7, characterized in that: Before the fruit trees sprout in spring, dilute the liquid fertilizer 100 times with water and water the roots of each tree with 20L-25L. During the fruit expansion period, dilute the liquid fertilizer 300 times and apply fertilizer through a drip irrigation device. The amount used for each tree is 8L-10L each time, and apply fertilizer once every 10d-12d, for a total of 3 times.

9. The use of methionine fermentation waste liquid in the preparation of fertilizer according to claim 7, characterized in that: In the cultivation of leafy vegetables, dilute the finished liquid fertilizer 200 times with water and use it as base fertilizer to irrigate the soil before sowing the vegetables. The amount per square meter is 5L-10L. During the growth period of vegetables, dilute the finished liquid fertilizer 500 times with water every 7d-9d, and use a spray device to spray the vegetable leaves. The amount of each spraying is 1L-2L per square meter. Fertilize once every 7d-10d, for a total of 2 times.

Images