A low-energy consumption, high-purity methionine fermentation waste liquid fertilizer preparation process

Abstract

The invention discloses a process for preparing fertilizer from high-purity methionine fermentation waste liquid with low energy consumption. The invention relates to the technical field of fertilizer preparation, and comprises pretreatment, synergistic extraction, ion exchange adsorption, microbial fermentation and nano-emulsification operation of methionine fermentation waste liquid. The invention has the advantages that serious pollution to the environment caused by direct discharge of waste liquid is effectively avoided by treating methionine fermentation waste liquid. The traditional chemical fertilizer production process has high energy consumption and potential harm to the environment. The methionine fermentation waste liquid contains rich organic and inorganic components. Discharging it without treatment will waste resources and pollute the environment. Air is introduced into the high-purity treated waste liquid through a gas distributor during the fermentation process, so that the air forms tiny bubbles in the waste liquid, thereby ensuring the aerobic respiration needs of microorganisms, avoiding shear damage to microorganisms caused by excessive ventilation, ensuring the normal progress of the fermentation process, and ensuring the quality and stability of the fermentation liquid.

Description

Technical Field

[0001] The invention relates to the technical field of fertilizer preparation, in particular to a process for preparing fertilizer from high-purity methionine fermentation waste liquid with low energy consumption. Background Art

[0002] With the development of global industrialization and agricultural modernization, the use of chemical fertilizers has increased dramatically. However, the production of traditional chemical fertilizers is often accompanied by high energy consumption and potential harm to the environment. At the same time, in many industrial fermentation processes, such as methionine fermentation, a large amount of waste liquid is generated. Taking methionine fermentation waste liquid as an example, these waste liquids contain rich organic and inorganic components. If they are directly discharged without proper treatment, it will not only cause a waste of resources, but also cause serious pollution to the environment. Under the current environmental situation, how to realize the resource utilization of industrial waste has become a research hotspot. For methionine fermentation waste liquid, developing a low-energy treatment method to convert it into valuable fertilizer has important economic and environmental significance. Traditional waste treatment methods often require a lot of energy consumption, and the treatment effect is not ideal. For methionine fermentation waste liquid, developing a low-energy treatment process is the key to reducing corporate production costs and reducing environmental impact. At the same time, with the increasing requirements for fertilizer quality in agricultural production, the market needs more environmentally friendly and efficient fertilizer products. If the goals of low energy consumption and high purity can be achieved by using methionine fermentation waste liquid to prepare fertilizer, it will bring a win-win situation for the agricultural and environmental protection fields. Methionine fermentation waste liquid actually contains many valuable components, which can be used as effective components of fertilizers. The waste liquid may contain residual amino acids, peptides and other organic and inorganic nutrients that are beneficial to plant growth. Converting these waste liquids into fertilizers can achieve resource recycling, reduce dependence on traditional fertilizer production raw materials (such as phosphate rock, potassium salt, etc.), improve resource utilization efficiency, and conform to the development concept of circular economy. To this end, we propose a low-energy and high-purity methionine fermentation waste liquid fertilizer preparation process. Summary of the invention

[0003] The purpose of the present invention is to provide a process for preparing fertilizer from high-purity methionine fermentation waste liquid with low energy consumption.

[0004] In order to solve the problems raised in the above background technology, the present invention provides the following technical solutions: a process for preparing fertilizer from high-purity methionine fermentation waste liquid with low energy consumption, comprising pretreatment of methionine fermentation waste liquid, synergistic extraction, ion exchange adsorption, microbial fermentation and nanoemulsification operation, wherein the specific operation steps of the process for preparing fertilizer from high-purity methionine fermentation waste liquid with low energy consumption are as follows: Step 1, collecting methionine fermentation waste liquid, performing vacuum low-temperature evaporation and concentration operation on it after three-layer filtration, and collecting the fermentation waste liquid concentrate; Step 2: placing the fermentation waste liquid concentrate in an ultrasonic-electric field synergistic extraction device for synergistic extraction, controlling the operating environment, and obtaining an ultrasonic-treated liquid after the synergistic extraction is completed; Step 3, selecting a composite ion exchange resin column, passing the ultrasonic treatment liquid through the composite ion exchange resin column under specific conditions to obtain a high-purity treatment waste liquid; Step 4: transfer the high-purity treated waste liquid to a fermentation tank, add a composite microbial flora consisting of three strains for fermentation, add enzyme preparations in stages after completion, stir and mix, and ferment to obtain a high-purity fermentation liquid; Step 5: Select a nano-emulsifier, add it and the high-purity fermentation liquid into a container in proportion, pressurize and stir to mix, add a stabilizer after mixing to obtain a liquid fertilizer product, and monitor the quality of the liquid fertilizer product.

[0005] As a further scheme of the present invention: in the step 1, under the temperature condition of 25°C-30°C, the collected methionine fermentation waste liquid is preliminarily filtered through a three-layer filter screen, the apertures of the three-layer filter screen are 100um, 50um and 20um from top to bottom, respectively. After the preliminary filtration, it is passed through a ceramic filter membrane, the aperture of the ceramic filter membrane is 20nm-30nm, and after the filtration is completed, it is transferred to a concentration device, and the waste liquid after the preliminary filtration is evaporated and concentrated at a low temperature, using a vacuum low-temperature evaporation technology, setting the evaporation temperature to 40°C-42°C, maintaining the vacuum degree between -0.08MPa--0.085MPa, setting the stirring speed to 60r / min-80r / min, and the fermentation waste liquid is evenly heated during the evaporation process. A condenser is provided on the top of the concentration device. During the evaporation process, the volume and concentration changes of the waste liquid are monitored in real time. When the volume of the waste liquid is reduced to 30%-40% of the original volume, the evaporation and concentration operation is completed, and the fermentation waste liquid concentrate is collected.

[0006] As a further scheme of the present invention: in the step 2, a new extractant prepared by mixing n-hexane, isopropanol and ethyl acetate in a ratio of 4:3:3 is added to the reactor of the extraction device, and the amount of the new extractant added is 120%-130% of the total volume of the fermentation waste liquid concentrate. The fermentation waste liquid concentrate is added to the reactor, and the ultrasonic generator and the electric field generator are started. Extraction begins under the synergistic action of ultrasound and the electric field. The diameter of tiny bubbles formed in the waste liquid by the cavitation effect generated by ultrasound is controlled between 1um and 5um. After the extraction is completed, the ultrasonic generator is turned off, and the electric field generator is kept running for 2min-5min. After completion, the electric field generator is stopped, and the reactor is left standing for 18min-20min. After the waste liquid and the extractant are separated into layers, the extraction phase of the lower layer is discharged and collected through the drainage port at the bottom, and the drainage speed is controlled at 30mL / min-35mL / min. The extraction phase of the upper layer is the ultrasonic treatment liquid.

[0007] As a further scheme of the present invention: in the step three, a composite ion exchange resin column is selected, the upper layer of which is a strongly acidic cation exchange resin, the middle layer is an adsorption layer made of a composite of nano metal-MOFs and functionalized graphene, the particle size of the nano MOFs is between 100nm-200nm, and the lower layer is a weakly alkaline anion exchange resin. When in use, the resin column is first rinsed with deionized water at a flow rate of 3BV / h for 45min-60min, the ultrasonic treatment liquid is introduced into the ion exchange resin column, the feed temperature is controlled to 28℃-35℃, the feed flow rate is set to 4mL / min-6mL / min, and the high-purity treated waste liquid treated by the composite ion exchange resin column is collected.

[0008] As a further solution of the present invention: in the step three, the weakly alkaline anion exchange resin in the lower layer exchanges and adsorbs anionic impurities in the ultrasonic treatment liquid to remove anionic impurities, and the anionic impurity content in the treated waste liquid is controlled to be less than 10ppm. During the treatment process, the temperature of the composite ion exchange resin column is controlled between 26°C and 28°C.

[0009] As a further scheme of the present invention: in the step 4, before the high-purity treated waste liquid is transferred into the fermentation tank, the inside of the fermentation tank is first sprayed with a hydrogen peroxide solution with a mass fraction of 0.8% for disinfection, and after keeping it for 30 minutes, it is blown dry with air in a sterile environment, and then rinsed with sterile water for 3 times, and soaked in a peracetic acid solution with a mass fraction of 0.2% for 20 minutes. After completion, it is rinsed with sterile water until the pH value of the rinse liquid is neutral, and the high-purity treated waste liquid is transferred to the fermentation tank at a flow rate of 15L / min-20L / min, and then a composite microbial flora prepared by mixing Bacillus, Aspergillus and lactic acid bacteria in a ratio of 2:1:1 is inoculated into the fermentation tank, and the inoculation amount is 6% of the total volume of the high-purity treated waste liquid. After the inoculation is completed, it is stirred at a stirring rate of 40r / min-50r / min for 5 minutes to evenly disperse the microbial flora in the high-purity treated waste liquid.

[0010] As a further scheme of the present invention: in the step 4, during the fermentation process, air that has been sterilized by filtering through a 0.22 um microporous filter membrane is introduced into the fermenter at a ventilation volume of 0.8 vvm-1.0 vvm. The air enters the fermenter through a gas distributor. The air forms tiny bubbles with a diameter of 2 mm-3 mm in the high-purity treated waste liquid. Under this condition, fermentation is continued for 26 h-32 h. During the fermentation, samples are taken every 2 h, and the fermentation conditions are adjusted by monitoring the changes in the biomass of the microorganisms, metabolites, and nutrients in the waste liquid.

[0011] As a further scheme of the present invention: in the step 4, at the 12th hour after the start of fermentation, a protease is added to the fermenter, the enzyme activity of the protease is 1200U / g, and the addition amount is 0.15% of the total mass of the high-purity treated waste liquid; within 10 minutes after the addition of the protease, ozone is pulsed into the fermenter, the amount of each introduction is 0.1L, the interval time is 2min-3min, and a total of 3 times; at the 24th hour, cellulase and pectinase with an enzyme activity of 900U / g are added, and the addition amount is 0.1% of the mass of the waste liquid, respectively; after the addition is completed, the fermentation is continued for 20h-24h to fully transform the organic components in the high-purity treated waste liquid; when the fermentation achieves the expected effect, that is, the macromolecular organic matter in the waste liquid is fully decomposed and the microbial biomass no longer increases significantly, the fermentation is stopped to obtain a high-purity fermentation liquid; after the fermentation is completed, the high-purity fermentation liquid is rapidly cooled at a cooling rate of 5°C / min to reduce the temperature to below 10°C to inhibit the continued growth of microorganisms and the activity of enzymes.

[0012] As a further scheme of the present invention: in the step 5, a composite nanoemulsifier composed of polyoxyethylene sorbitan fatty acid ester, soybean lecithin and cetearyl alcohol polyether-20 in a ratio of 3:2:1 is selected, the three ingredients are first preheated at 40°C for 15 minutes, and then stirred and mixed in an environment with a vacuum degree of -0.09MPa for 20 minutes, and the stirring speed is 1000r / min1200r / min, and the high-purity fermentation liquid is added to the mixing container through the feed port at a flow rate of 10L / min, and at the same time, the prepared nanoemulsifier is added at a ratio of 6% of the volume of the high-purity fermentation liquid, and stirred at a stirring rate of 200r / min for 5 minutes to make the emulsifier preliminarily dispersed in the fermentation liquid to form a uniform mixed system. In this process, nitrogen with a purity of 99.9% is filled into the container from the nitrogen inlet to keep the pressure in the container at 0.02MPa to prevent air from entering, the nitrogen inlet is closed, and the high A pressure homogenizing nozzle and a jacket circulating water system are installed, and the temperature of the circulating water in the jacket is set to 30°C. The pressure in the container is gradually increased to 120MPa at a pressure increase rate of 10MPa / min. During the pressurization process, the stirring speed is simultaneously increased to 1500r / min and maintained for 25min-30min, so that the fermentation liquid forms a nanoemulsion under the action of high pressure and strong stirring. A mixed solution of 0.5% xanthan gum, 0.3% sodium carboxymethyl cellulose and 0.2% sodium alginate as a stabilizer is prepared, and the mixed solution is added into the nanoemulsion and stirred for 15min to evenly disperse the stabilizer in the emulsion. After the stabilizer is added, stirring is continued for 8min-15min, and the mixed solution is passed through the discharge port and the filter device at the bottom of the container into the temporary storage tank. In the temporary storage tank, the quality of the finished liquid fertilizer is tested, and the quality test includes the nutrient content, microbial indicators and pH value of the finished liquid fertilizer.

[0013] By adopting the above technical solution, compared with the prior art, the beneficial effects of the present invention are: 1. The present invention effectively avoids the serious environmental pollution caused by direct discharge of waste liquid by treating methionine fermentation waste liquid. The traditional chemical fertilizer production process is high in energy consumption and has potential harm to the environment. The methionine fermentation waste liquid contains rich organic and inorganic components. Discharging without treatment will waste resources and pollute the environment. During the fermentation process, air is introduced into the high-purity treated waste liquid using a gas distributor, so that the air forms tiny bubbles in the waste liquid, thereby ensuring the aerobic respiration needs of microorganisms, and avoiding shear damage to microorganisms caused by excessive ventilation, ensuring the normal fermentation process, and ensuring the quality and stability of the fermentation liquid. The methionine fermentation waste liquid is extracted under the synergistic action of an ultrasonic generator and an electric field generator. The tiny bubbles generated by ultrasound can induce a strong cavitation effect in the waste liquid, destroy the chemical bonds and intermolecular forces between the components, and cooperate with the electric field to significantly improve the extraction efficiency. After turning off the ultrasonic generator, the electric field generator is kept running to further ensure the extraction effect, so that the target component is fully transferred to the extractant phase. After standing and stratifying, the obtained ultrasonic-treated liquid is rich in high-purity effective components and has a low impurity content. 2. The present invention uses a special composite ion exchange resin column to efficiently remove various impurities in the ultrasonic treatment liquid, including heavy metal ions, complex organic impurities and anionic impurities, to provide high-quality, high-purity treated waste liquid for the fermentation step, to ensure the quality of the fertilizer, and to use a fermenter to pretreat the high-purity treated waste liquid, suitable inoculation operations and precisely controlled fermentation conditions, including ventilation volume, enzyme addition and fermentation time, etc., to ensure that the microbial fermentation process is stable and efficient, and fully decomposes macromolecular organic matter to increase the content of effective ingredients in the fertilizer. At the same time, the stability of the fermentation liquid is maintained by rapid cooling. During the microbial fermentation and enzymolysis process, macromolecular organic matter is fully decomposed into small molecular nutrients, and these small molecular components are more easily absorbed and utilized by plants, so that the finished liquid fertilizer can significantly improve the yield and quality of crops, bringing higher economic benefits to agricultural production. By converting methionine fermentation waste liquid into valuable fertilizer products, the dependence on traditional fertilizer production raw materials is reduced, and the preparation of liquid fertilizer finished products is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 The figure is a schematic diagram of the process of preparing liquid fertilizer from methionine fermentation broth 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 there is no conflict between them.

[0016] The present invention discloses a process for preparing fertilizer from high-purity methionine fermentation waste liquid with low energy consumption, which comprises pretreatment of the methionine fermentation waste liquid, synergistic extraction, ion exchange adsorption, microbial fermentation and nanoemulsification operation. The specific operation steps of the process for preparing fertilizer from high-purity methionine fermentation waste liquid with low energy consumption are as follows: Step 1, collecting methionine fermentation waste liquid, performing vacuum low-temperature evaporation and concentration operation on it after three-layer filtration, and collecting the fermentation waste liquid concentrate; Step 2: placing the fermentation waste liquid concentrate in an ultrasonic-electric field synergistic extraction device for synergistic extraction, controlling the operating environment, and obtaining an ultrasonic-treated liquid after the synergistic extraction is completed; Step 3, selecting a composite ion exchange resin column, passing the ultrasonic treatment liquid through the composite ion exchange resin column under specific conditions to obtain a high-purity treatment waste liquid; Step 4: transfer the high-purity treated waste liquid to a fermentation tank, add a composite microbial flora consisting of three strains for fermentation, add enzyme preparations in stages after completion, stir and mix, and ferment to obtain a high-purity fermentation liquid; Step 5: Select a nano-emulsifier, add it and the high-purity fermentation liquid into a container in proportion, pressurize and stir to mix, add a stabilizer after mixing to obtain a liquid fertilizer product, and monitor the quality of the liquid fertilizer product.

[0017] In one embodiment of the present invention: in step 1, at a temperature of 25°C-30°C, the collected methionine fermentation waste liquid is preliminarily filtered through a three-layer filter screen, the pore sizes of the three-layer filter screen are 100um, 50um and 20um from top to bottom, respectively. After the preliminary filtration is completed, it is passed through a ceramic filter membrane, the pore size of the ceramic filter membrane is 20nm-30nm, and after the filtration is completed, it is transferred to a concentration device, and the waste liquid after the preliminary filtration is evaporated and concentrated at a low temperature, using a vacuum low-temperature evaporation technology, setting the evaporation temperature to 40°C-42°C, maintaining the vacuum degree between -0.08MPa--0.085MPa, setting the stirring speed to 60r / min-80r / min, and the fermentation waste liquid is evenly heated during the evaporation process. A condenser is provided on the top of the concentration device. During the evaporation process, the volume and concentration changes of the waste liquid are monitored in real time. When the volume of the waste liquid is reduced to 30%-40% of the original volume, the evaporation and concentration operation is completed, and the fermentation waste liquid concentrate is collected.

[0018] In one embodiment of the present invention: in step 2, a novel extractant prepared by mixing n-hexane, isopropanol and ethyl acetate in a ratio of 4:3:3 is added to the reactor of the extraction device, and the amount of the novel extractant added is 120%-130% of the total volume of the fermentation waste liquid concentrate. The fermentation waste liquid concentrate is added to the reactor, and an ultrasonic generator and an electric field generator are started. Extraction begins under the synergistic action of ultrasound and the electric field. The diameter of tiny bubbles formed in the waste liquid by the cavitation effect generated by ultrasound is controlled to be between 1um and 5um. After the extraction is completed, the ultrasonic generator is turned off, and the electric field generator is kept running for 2min-5min. After completion, the electric field generator is stopped, and the reactor is left standing for 18min-20min. After the waste liquid and the extractant are separated into layers, the extraction phase of the lower layer is discharged and collected through the drainage port at the bottom, and the drainage speed is controlled to be 30mL / min-35mL / min. The extraction phase of the upper layer is the ultrasonic treatment liquid.

[0019] In one embodiment of the present invention: in step three, a composite ion exchange resin column is selected, the upper layer of which is a strongly acidic cation exchange resin, the middle layer is an adsorption layer made of a composite of nano metal-MOFs and functionalized graphene, the particle size of the nano MOFs is between 100nm-200nm, and the lower layer is a weakly basic anion exchange resin. When in use, the resin column is first rinsed with deionized water at a flow rate of 3BV / h for 45min-60min, the ultrasonic treatment liquid is introduced into the ion exchange resin column, the feed temperature is controlled to 28°C-35°C, the feed flow rate is set to 4mL / min-6mL / min, and the high-purity treated waste liquid treated by the composite ion exchange resin column is collected.

[0020] In one embodiment of the present invention: in step three, the weakly alkaline anion exchange resin in the lower layer exchanges and adsorbs anionic impurities in the ultrasonic treatment liquid to remove anionic impurities, and the anionic impurity content in the treated waste liquid is controlled to be less than 10ppm. During the treatment process, the temperature of the composite ion exchange resin column is controlled between 26°C and 28°C.

[0021] In one embodiment of the present invention: in step 4, before the high-purity treated waste liquid is transferred into the fermentation tank, the inside of the fermentation tank is first sprayed with a 0.8% by mass hydrogen peroxide solution for disinfection, and after keeping for 30 minutes, it is blown dry with air in a sterile environment, and then rinsed with sterile water for 3 times, and soaked in a 0.2% by mass peracetic acid solution for 20 minutes. After completion, it is rinsed with sterile water until the pH of the rinse liquid is neutral, and the high-purity treated waste liquid is transferred to the fermentation tank at a flow rate of 15L / min-20L / min, and then a composite microbial flora prepared by mixing Bacillus, Aspergillus and lactic acid bacteria in a ratio of 2:1:1 is inoculated into the fermentation tank, and the inoculation amount is 6% of the total volume of the high-purity treated waste liquid. After the inoculation is completed, it is stirred at a stirring rate of 40r / min-50r / min for 5 minutes to evenly disperse the microbial flora in the high-purity treated waste liquid.

[0022] In one embodiment of the present invention: in step four, during the fermentation process, air that has been sterilized by filtering through a 0.22 um microporous filter membrane is introduced into the fermenter at a ventilation volume of 0.8 vvm-1.0 vvm. The air enters the fermenter through a gas distributor. The air forms tiny bubbles with a diameter of 2 mm-3 mm in the high-purity treated waste liquid. Under this condition, fermentation is continued for 26 h-32 h. During the fermentation, samples are taken every 2 h, and the fermentation conditions are adjusted by monitoring the changes in the biomass of the microorganisms, metabolites, and nutrients in the waste liquid.

[0023] In one embodiment of the present invention: in step 4, at the 12th hour after the start of fermentation, a protease is added to the fermenter, the enzyme activity of the protease is 1200U / g, and the addition amount is 0.15% of the total mass of the high-purity treated waste liquid. Within 10 minutes after the addition of the protease, ozone is pulsed into the fermenter, each time the amount is 0.1L, the interval time is 2min-3min, and a total of 3 times. At the 24th hour, cellulase and pectinase with an enzyme activity of 900U / g are added, and the addition amount is 0.1% of the mass of the waste liquid, respectively. After the addition is completed, the fermentation is continued for 20h-24h to fully transform the organic components in the high-purity treated waste liquid. When the fermentation achieves the expected effect, that is, the macromolecular organic matter in the waste liquid is fully decomposed and the microbial biomass no longer increases significantly, the fermentation is stopped to obtain a high-purity fermentation liquid. After the fermentation is completed, the high-purity fermentation liquid is rapidly cooled at a cooling rate of 5°C / min to reduce the temperature to below 10°C to inhibit the continued growth of microorganisms and the activity of enzymes.

[0024] In one embodiment of the present invention: in step five, a composite nanoemulsifier composed of polyoxyethylene sorbitan fatty acid ester, soybean lecithin and cetearyl alcohol polyether-20 in a ratio of 3:2:1 is selected, the three ingredients are first preheated at 40°C for 15min, and then stirred and mixed for 20 minutes in an environment with a vacuum degree of -0.09MPa, and the stirring speed is 1000r / min1200r / min, and the high-purity fermentation broth is added to the mixing container through the feed port at a flow rate of 10L / min, and at the same time, the prepared nanoemulsifier is added at a ratio of 6% of the volume of the high-purity fermentation broth, and stirred at a stirring rate of 200r / min for 5min to make the emulsifier preliminarily dispersed in the fermentation broth to form a uniform mixed system. In this process, nitrogen with a purity of 99.9% is filled into the container from the nitrogen inlet to keep the pressure in the container at 0.02MPa to prevent air from entering, and the nitrogen inlet is closed, and the high A pressure homogenizing nozzle and a jacket circulating water system are installed, and the temperature of the circulating water in the jacket is set to 30°C. The pressure in the container is gradually increased to 120MPa at a pressure increase rate of 10MPa / min. During the pressurization process, the stirring speed is simultaneously increased to 1500r / min and maintained for 25min-30min, so that the fermentation liquid forms a nanoemulsion under the action of high pressure and strong stirring. A mixed solution of 0.5% xanthan gum, 0.3% sodium carboxymethyl cellulose and 0.2% sodium alginate as a stabilizer is prepared, and the mixed solution is added into the nanoemulsion and stirred for 15min to evenly disperse the stabilizer in the emulsion. After the stabilizer is added, stirring is continued for 8min-15min, and the mixed solution is passed through the discharge port and the filter device at the bottom of the container into the temporary storage tank. In the temporary storage tank, the quality of the finished liquid fertilizer is tested, and the quality test includes the nutrient content, microbial indicators and pH value of the finished liquid fertilizer.

[0025] In one embodiment of the present invention: the upper layer of strongly acidic cation exchange resin is passed through the resin column with a hydrochloric acid solution with a concentration of 2.5 mol / L at a flow rate of 1.5 BV / h, and the treatment volume is 2.5 BV to activate the cation exchange function of the resin. For the middle layer of composite adsorption layer, it is first rinsed with a mixed solution of 0.5% by mass polyethylene glycol and 0.1% by mass ethylenediaminetetraacetic acid (EDTA) at a flow rate of 2 BV / h and a rinsing time of 30 min to fully expose and activate the active sites of the adsorption layer. Finally, for the lower layer of weakly basic anion exchange resin, a sodium hydroxide solution with a concentration of 2 mol / L is used at a flow rate of 1.5 BV / h to treat a volume of 2 BV for regeneration.

[0026] In one embodiment of the present invention: the waste liquid treated by the composite ion exchange resin column is a high-purity treatment waste liquid, which is collected in a storage container, and the inner wall of the container is coated with a layer of polyethylene terephthalate coating with corrosion and oxidation resistance. During the collection process, nitrogen with a purity of 99.99% is filled into the top of the storage container to prevent the components in the waste liquid from being oxidized or reacting with carbon dioxide in the air. After the collection is completed, a small amount of antioxidant and complexing agent mixture is added thereto, the antioxidant is ascorbic palmitate, and the complexing agent is sodium citrate, which can capture free radicals in the high-purity treatment waste liquid, prevent the oxidation of organic components in the high-purity treatment waste liquid, and complex the residual trace metal ions to improve the purity and stability of the high-purity treatment waste liquid.

[0027] In one embodiment of the present invention: when adding enzyme preparations in stages, the protease is first dissolved in a sterile buffer solution filtered through a 0.45um filter membrane to prepare an enzyme solution with a concentration of 10 mg / mL, and then slowly injected into the fermentation tank at a speed of 5 mL / min through a peristaltic pump, while increasing the stirring speed to 90 r / min, and stirring is continued for 12 min-15 min to evenly distribute the protease in the waste liquid to promote the decomposition of proteins and polypeptides.

[0028] In one embodiment of the present invention: when adding cellulase and pectinase, the enzyme solution is first prepared into an enzyme solution with a concentration of 8 mg / L in a sterile buffer solution, and then injected into the fermentation tank at a speed of 4 mL / min through a peristaltic pump. After adding, the stirring speed is maintained at 90 r / min, and the stirring time is 10 minutes to evenly distribute the cellulase and pectinase in the waste liquid.

[0029] Embodiment 1 Under the temperature condition of 25°C, the collected methionine fermentation waste liquid is preliminarily filtered through three layers of filter screens (the pore sizes are 100um, 50um, and 20um from top to bottom). After the preliminary filtration is completed, it is passed through a ceramic filter membrane with a pore size of 20nm, and then transferred to a concentration device. The vacuum low-temperature evaporation technology is used, the evaporation temperature is set to 40°C, the vacuum degree is maintained at -0.08MPa, the stirring speed is 60r / min, and a condenser is set on the top of the concentration device to monitor the waste liquid volume and concentration changes in real time. When the waste liquid volume is reduced to 30% of the original volume, the evaporation concentration operation is completed, and the fermentation waste liquid concentrate is collected; A new extractant prepared by mixing n-hexane, isopropanol and ethyl acetate in a ratio of 4:3:3 is added to the reactor of the extraction device, and the amount of the new extractant added is 120% of the total volume of the fermentation waste liquid concentrate. The fermentation waste liquid concentrate is added to the reactor, and an ultrasonic generator and an electric field generator are started. The diameter of tiny bubbles formed in the waste liquid by the cavitation effect generated by ultrasound is controlled to be 1 um. After the extraction is completed, the ultrasonic generator is turned off, and the electric field generator is kept running for 2 minutes, and then the electric field generator is stopped, and the reactor is left standing for 18 minutes. After the waste liquid and the extractant are separated into layers, the extraction phase of the lower layer is discharged through the bottom drainage port at a drainage rate of 30 mL / min and collected, and the extraction phase of the upper layer is the ultrasonic treatment liquid; A composite ion exchange resin column was selected, and the resin column was first rinsed with deionized water at a flow rate of 3 BV / h for 45 min, and the ultrasonic treatment liquid was introduced into the ion exchange resin column, and the feed temperature was controlled to be 28°C, and the feed flow rate was set to 4 mL / min. During the treatment process, the temperature of the composite ion exchange resin column was controlled at 26°C, and the high-purity treatment waste liquid treated by the composite ion exchange resin column was collected to ensure that the anion impurity content in the treated waste liquid was less than 10 ppm; Before transferring the high-purity treated waste liquid into the fermentation tank, the inside of the fermentation tank was sprayed with a 0.8% mass fraction hydrogen peroxide solution for disinfection. After keeping it for 30 minutes, it was blown dry with air in a sterile environment, rinsed with sterile water three times, and soaked in a 0.2% mass fraction peracetic acid solution for 20 minutes, and then rinsed with sterile water until the pH of the rinse liquid was neutral. The high-purity treated waste liquid was transferred to the fermentation tank at a flow rate of 15L / min, and then a composite microbial flora prepared by mixing Bacillus, Aspergillus and lactic acid bacteria in a ratio of 2:1:1 was inoculated, and the inoculation amount was 6% of the total volume of the high-purity treated waste liquid. After the inoculation was completed, it was incubated at 40r / min stirring rate for 5min, during the fermentation process, air sterilized by 0.22um microporous filter membrane was introduced into the fermenter, the ventilation volume was 0.8vvm, the air formed tiny bubbles with a diameter of 2mm in the waste liquid through the gas distributor, and the fermentation was continued for 26h, during which sampling was performed every 2h, at 12h after the start of fermentation, protease (enzyme activity of 1200U / g) was added to the fermenter, the addition amount was 0.15% of the total mass of the high-purity treated waste liquid, within 10min after the addition of protease, ozone was pulsed into the fermenter, each time the amount was 0.1L, the interval time was 2min, and it was introduced 3 times in total; A composite nanoemulsifier consisting of polyoxyethylene sorbitan fatty acid ester, soybean lecithin and cetearyl alcohol polyether-20 in a ratio of 3:2:1 was selected, the three components were first preheated at 40°C for 15 minutes, and then stirred at a stirring speed of 1000r / min for 20 minutes in an environment with a vacuum degree of -0.09MPa, and the high-purity fermentation broth was added to the mixing container through the feed port at a flow rate of 10L / min, and the prepared nanoemulsifier was added at a ratio of 6% of the volume of the high-purity fermentation broth, and stirred at a stirring rate of 200r / min for 5 minutes. During this process, nitrogen with a purity of 99.9% was filled into the container from the nitrogen inlet. Nitrogen is added to keep the pressure in the container at 0.02MPa, the nitrogen inlet is closed, the high-pressure homogenizing nozzle and the jacket circulating water system (water temperature is 30℃) are started, and the pressure is increased to 120MPa at a rate of 10MPa / min. During the pressurization process, the stirring speed is increased to 1500r / min and maintained for 25min. Then, a mixed solution of 0.5% xanthan gum, 0.3% sodium carboxymethyl cellulose and 0.2% sodium alginate as a stabilizer is prepared, added into the nanoemulsion and stirred for 15min, and then continued to stir for 8min. The mixed solution is passed through the discharge port and the filtration device at the bottom of the container to obtain a liquid fertilizer product.

[0030] Embodiment 2 Under the temperature condition of 27°C, the collected methionine fermentation waste liquid is preliminarily filtered through three layers of filter screens (the pore sizes are 100um, 50um, and 20um from top to bottom). After the preliminary filtration is completed, it is passed through a ceramic filter membrane with a pore size of 25nm, and then transferred to a concentration device. The vacuum low-temperature evaporation technology is used, the evaporation temperature is set to 41°C, the vacuum degree is maintained at -0.082MPa, the stirring speed is 70r / min, and a condenser is set on the top of the concentration device to monitor the waste liquid volume and concentration changes in real time. When the waste liquid volume is reduced to 35% of the original volume, the evaporation concentration operation is completed, and the fermentation waste liquid concentrate is collected; A new extractant prepared by mixing n-hexane, isopropanol and ethyl acetate in a ratio of 4:3:3 is added to the reactor of the extraction device, and the amount of the new extractant added is 125% of the total volume of the fermentation waste liquid concentrate. The fermentation waste liquid concentrate is added to the reactor, and an ultrasonic generator and an electric field generator are started. The diameter of microbubbles formed in the waste liquid by the cavitation effect generated by ultrasound is controlled to be 3 um. After the extraction is completed, the ultrasonic generator is turned off, and the electric field generator is kept running for 3 minutes, and then the electric field generator is stopped, and the reactor is left standing for 19 minutes. After the waste liquid and the extractant are separated into layers, the extraction phase of the lower layer is discharged and collected through the bottom drainage port at a drainage rate of 32 mL / min, and the extraction phase of the upper layer is the ultrasonic treatment liquid; A composite ion exchange resin column was selected, and the resin column was first rinsed with deionized water at a flow rate of 3 BV / h for 50 min, and the ultrasonic treatment liquid was introduced into the ion exchange resin column, and the feed temperature was controlled to be 30°C, and the feed flow rate was set to 5 mL / min. During the treatment process, the temperature of the composite ion exchange resin column was controlled at 27°C, and the high-purity treatment waste liquid treated by the composite ion exchange resin column was collected to ensure that the anion impurity content in the treated waste liquid was less than 10 ppm; Before transferring the high-purity treated waste liquid into the fermentation tank, the inside of the fermentation tank was sprayed with a 0.8% hydrogen peroxide solution for disinfection. After keeping it for 30 minutes, it was blown dry with air in a sterile environment, rinsed with sterile water three times, and soaked in a 0.2% peracetic acid solution for 20 minutes, and then rinsed with sterile water until the pH of the rinse liquid was neutral. The high-purity treated waste liquid was transferred to the fermentation tank at a flow rate of 18L / min, and then a composite microbial flora prepared by mixing Bacillus, Aspergillus and lactic acid bacteria in a ratio of 2:1:1 was inoculated. The inoculation amount was 6% of the total volume of the high-purity treated waste liquid. After the inoculation was completed, the mixture was incubated at 45r / m in stirring rate for 5 min. During the fermentation process, air that had been sterilized by filtering with a 0.22 um microporous filter membrane was introduced into the fermenter at a ventilation volume of 0.9 vvm. The air formed tiny bubbles with a diameter of 2.5 mm in the waste liquid through a gas distributor. The fermentation was continued for 29 h, during which samples were taken every 2 h. At the 12th hour after the start of fermentation, protease (enzyme activity of 1200 U / g) was added to the fermenter at a rate of 0.15% of the total mass of the high-purity treated waste liquid. Within 10 min after the addition of protease, ozone was pulsed into the fermenter at a rate of 0.1 L each time at an interval of 2.5 min, for a total of 3 times. A composite nanoemulsifier consisting of polyoxyethylene sorbitan fatty acid ester, soybean lecithin and cetearyl alcohol polyether-20 in a ratio of 3:2:1 was selected, the three components were first preheated at 40°C for 15 minutes, and then stirred at a stirring speed of 1100r / min for 20 minutes in an environment with a vacuum degree of -0.09MPa, and the high-purity fermentation broth was added to the mixing container through the feed port at a flow rate of 10L / min, and the prepared nanoemulsifier was added at a ratio of 6% of the volume of the high-purity fermentation broth, and stirred at a stirring rate of 200r / min for 5 minutes. During this process, nitrogen with a purity of 99.9% was filled into the container from the nitrogen inlet to make The pressure in the container is maintained at 0.02MPa, the nitrogen inlet is closed, the high-pressure homogenizing nozzle and the jacket circulating water system (water temperature is 30°C) are started, and the pressure is increased to 120MPa at a rate of 10MPa / min. During the pressurization process, the stirring speed is simultaneously increased to 1500r / min and maintained for 28min. Then, a mixed solution of 0.5% xanthan gum, 0.3% sodium carboxymethyl cellulose and 0.2% sodium alginate as a stabilizer is prepared, added into the nanoemulsion and stirred for 15min, and then continued to stir for 10min. The mixed solution enters the temporary storage tank through the discharge port and the filter device at the bottom of the container to obtain a liquid fertilizer product.

[0031] Embodiment 3 Under the temperature condition of 29°C, the collected methionine fermentation waste liquid is preliminarily filtered through three layers of filter screens (the pore sizes are 100um, 50um, and 20um from top to bottom). After the preliminary filtration is completed, it is passed through a ceramic filter membrane with a pore size of 28nm, and then transferred to a concentration device. The vacuum low-temperature evaporation technology is used, the evaporation temperature is set to 42°C, the vacuum degree is maintained at -0.084MPa, the stirring speed is 75r / min, and a condenser is set on the top of the concentration device to monitor the waste liquid volume and concentration changes in real time. When the waste liquid volume is reduced to 38% of the original volume, the evaporation concentration operation is completed, and the fermentation waste liquid concentrate is collected; A new extractant prepared by mixing n-hexane, isopropanol and ethyl acetate in a ratio of 4:3:3 is added to the reactor of the extraction device, and the amount of the new extractant added is 128% of the total volume of the fermentation waste liquid concentrate. The fermentation waste liquid concentrate is added to the reactor, and an ultrasonic generator and an electric field generator are started. The diameter of microbubbles formed in the waste liquid by the cavitation effect generated by ultrasound is controlled to be 4 um. After the extraction is completed, the ultrasonic generator is turned off, and the electric field generator is kept running for 4 minutes, and then the electric field generator is stopped, and the reactor is left standing for 20 minutes. After the waste liquid and the extractant are separated into layers, the extraction phase of the lower layer is discharged through the bottom drainage port at a drainage rate of 34 mL / min and collected, and the extraction phase of the upper layer is the ultrasonic treatment liquid; A composite ion exchange resin column was selected, and the resin column was first rinsed with deionized water at a flow rate of 3 BV / h for 55 min, and the ultrasonic treatment liquid was introduced into the ion exchange resin column, and the feed temperature was controlled to be 32°C, and the feed flow rate was set to 5.5 mL / min. During the treatment process, the temperature of the composite ion exchange resin column was controlled at 27.5°C, and the high-purity treatment waste liquid treated by the composite ion exchange resin column was collected to ensure that the anion impurity content in the treated waste liquid was less than 10 ppm; Before transferring the high-purity treated waste liquid into the fermentation tank, the inside of the fermentation tank was sprayed with a 0.8% hydrogen peroxide solution for disinfection. After keeping it for 30 minutes, it was blown dry with air in a sterile environment, rinsed with sterile water three times, and soaked in a 0.2% peracetic acid solution for 20 minutes. Then, it was rinsed with sterile water until the pH of the rinse liquid was neutral. The high-purity treated waste liquid was transferred to the fermentation tank at a flow rate of 19L / min, and then a composite microbial flora prepared by mixing Bacillus, Aspergillus and lactic acid bacteria in a ratio of 2:1:1 was inoculated. The inoculation amount was 6% of the total volume of the high-purity treated waste liquid. After the inoculation was completed, the mixture was incubated at 48r / m in stirring rate for 5 min. During the fermentation process, air that had been sterilized by filtering with a 0.22 um microporous filter membrane was introduced into the fermenter at a ventilation volume of 0.95 vvm. The air formed tiny bubbles with a diameter of 2.8 mm in the waste liquid through a gas distributor. The fermentation was continued for 30 h, during which samples were taken every 2 h. At the 12th hour after the start of fermentation, protease (enzyme activity of 1200 U / g) was added to the fermenter at a rate of 0.15% of the total mass of the high-purity treated waste liquid. Within 10 min after the addition of protease, ozone was pulsed into the fermenter at a rate of 0.1 L each time at an interval of 2.8 min, for a total of 3 times. A composite nanoemulsifier consisting of polyoxyethylene sorbitan fatty acid ester, soybean lecithin and cetearyl alcohol polyether-20 in a ratio of 3:2:1 was selected, the three components were first preheated at 40°C for 15 minutes, and then stirred at a stirring speed of 1150r / min for 20 minutes in an environment with a vacuum degree of -0.09MPa, and the high-purity fermentation broth was added to the mixing container through the feed port at a flow rate of 10L / min, and the prepared nanoemulsifier was added at a ratio of 6% of the volume of the high-purity fermentation broth, and stirred at a stirring rate of 200r / min for 5 minutes. During this process, nitrogen with a purity of 99.9% was filled into the container from the nitrogen inlet to make The pressure in the container was maintained at 0.02MPa, the nitrogen inlet was closed, the high-pressure homogenizing nozzle and the jacket circulating water system (water temperature 30°C) were started, and the pressure was increased to 120MPa at a rate of 10MPa / min. During the pressurization process, the stirring speed was increased to 1500r / min and maintained for 29min. A mixed solution of 0.5% xanthan gum, 0.3% sodium carboxymethyl cellulose and 0.2% sodium alginate as a stabilizer was prepared, added into the nanoemulsion and stirred for 15min, and then continued to stir for 12min. The mixed solution passed through the discharge port and the filter device at the bottom of the container and entered the temporary storage tank to obtain a liquid fertilizer product.

[0032] Embodiment 4: Under the temperature condition of 30°C, the collected methionine fermentation waste liquid is preliminarily filtered through three layers of filter screens (the pore sizes are 100um, 50um, and 20um from top to bottom). After the preliminary filtration is completed, it is passed through a ceramic filter membrane with a pore size of 30nm, and then transferred to a concentration device. The vacuum low-temperature evaporation technology is used, the evaporation temperature is set to 42°C, the vacuum degree is maintained at -0.085MPa, the stirring speed is 80r / min, and a condenser is set on the top of the concentration device to monitor the waste liquid volume and concentration changes in real time. When the waste liquid volume is reduced to 40% of the original volume, the evaporation concentration operation is completed, and the fermentation waste liquid concentrate is collected; A new extractant prepared by mixing n-hexane, isopropanol and ethyl acetate in a ratio of 4:3:3 is added to the reactor of the extraction device, and the amount of the new extractant added is 130% of the total volume of the fermentation waste liquid concentrate. The fermentation waste liquid concentrate is added to the reactor, and an ultrasonic generator and an electric field generator are started. The diameter of microbubbles formed in the waste liquid by the cavitation effect generated by ultrasound is controlled to be 5 um. After the extraction is completed, the ultrasonic generator is turned off, and the electric field generator is kept running for 5 minutes, and then the electric field generator is stopped, and the reactor is left standing for 20 minutes. After the waste liquid and the extractant are separated into layers, the extraction phase of the lower layer is discharged through the bottom drainage port at a drainage rate of 35 mL / min and collected, and the extraction phase of the upper layer is the ultrasonic treatment liquid; A composite ion exchange resin column was selected, and the resin column was first rinsed with deionized water at a flow rate of 3BV / h for 60 minutes, and the ultrasonic treatment liquid was introduced into the ion exchange resin column, and the feed temperature was controlled to be 35°C, and the feed flow rate was set to 6mL / min. During the treatment process, the temperature of the composite ion exchange resin column was controlled at 28°C, and the high-purity treatment waste liquid treated by the composite ion exchange resin column was collected to ensure that the anion impurity content in the treated waste liquid was less than 10ppm; Before transferring the high-purity treated waste liquid into the fermentation tank, the inside of the fermentation tank was sprayed with a 0.8% hydrogen peroxide solution for disinfection. After keeping it for 30 minutes, it was blown dry with air in a sterile environment, rinsed with sterile water three times, and soaked in a 0.2% peracetic acid solution for 20 minutes, and then rinsed with sterile water until the pH of the rinse liquid was neutral. The high-purity treated waste liquid was transferred to the fermentation tank at a flow rate of 20L / min, and then a composite microbial flora prepared by mixing Bacillus, Aspergillus and lactic acid bacteria in a ratio of 2:1:1 was inoculated, and the inoculation amount was 6% of the total volume of the high-purity treated waste liquid. After the inoculation was completed, it was incubated at 50r / min stirring rate for 5min, during the fermentation process, air sterilized by 0.22um microporous filter membrane was introduced into the fermenter, the ventilation volume was 1.0vvm, the air formed tiny bubbles with a diameter of 3mm in the waste liquid through the gas distributor, the fermentation was continued for 32h, during which sampling was performed every 2h, at 12h after the start of fermentation, protease (enzyme activity of 1200U / g) was added to the fermenter, the addition amount was 0.15% of the total mass of the high-purity treated waste liquid, within 10min after the addition of protease, ozone was pulsed into the fermenter, the amount of each injection was 0.1L, the interval time was 3min, and it was injected 3 times in total; A composite nanoemulsifier consisting of polyoxyethylene sorbitan fatty acid ester, soybean lecithin and cetearyl alcohol polyether-20 in a ratio of 3:2:1 was selected, the three components were first preheated at 40°C for 15 minutes, and then stirred at a stirring speed of 1200r / min for 20 minutes in an environment with a vacuum degree of -0.09MPa, and the high-purity fermentation broth was added to the mixing container through the feed port at a flow rate of 10L / min, and the prepared nanoemulsifier was added at a ratio of 6% of the volume of the high-purity fermentation broth, and stirred at a stirring rate of 200r / min for 5 minutes. During this process, nitrogen with a purity of 99.9% was filled into the container from the nitrogen inlet to make The pressure in the container is maintained at 0.02MPa, the nitrogen inlet is closed, the high-pressure homogenizing nozzle and the jacket circulating water system (water temperature is 30°C) are started, and the pressure is increased to 120MPa at a rate of 10MPa / min. During the pressurization process, the stirring speed is simultaneously increased to 1500r / min and maintained for 30min. Then, a mixed solution of 0.5% xanthan gum, 0.3% sodium carboxymethyl cellulose and 0.2% sodium alginate as a stabilizer is prepared, added into the nanoemulsion and stirred for 15min, and then continued to stir for 15min. The mixed solution enters the temporary storage tank through the discharge port and the filter device at the bottom of the container to obtain a liquid fertilizer product.

[0033] The liquid fertilizers prepared in the above four groups of embodiments were tested for quality, and the testing method was as follows: Nutritional testing, Sample pretreatment: Measure 10 mL of the liquid fertilizer to be tested, filter it through a 0.45 um filter membrane, set the mobile phase to a methanol-water system for gradient elution, select a C18 column and set parameters such as column temperature and flow rate, determine the detection wavelength based on the characteristics of the detected components, prepare a standard solution to draw a standard curve, and calculate the nutrient content.

[0034] Microbiological index detection, Prepare the corresponding culture medium and sterilize it, spread the sample on the culture medium plate after gradient dilution, and count after culturing under appropriate conditions.

[0035] pH value detection, Use a pH meter that has been calibrated at three points with a standard pH buffer solution (such as pH 4.00, pH 6.86, and pH 9.18), insert the electrode into the liquid fertilizer sample to be tested, gently stir it to make it uniform, and record the value after the reading stabilizes. Repeat the measurement 3 times for each sample and take the average value.

[0036] The calculation results are as follows: Embodiment 1

[0037] Nutritional test results, Amino acid content: 15g / L; Peptide content: 8g / L; Nitrogen content (in N): 20g / L; Phosphorus content (as P2O5): 10g / L; Potassium content (expressed as K2O): 12g / L.

[0038] Microbiological index test results, Total bacterial count: 100 CFU / mL; Total mold and yeast count: 10 CFU / mL; No harmful pathogens were detected.

[0039] pH test result: 6.5.

[0040] Embodiment 2 Nutritional test results, Amino acid content: 16g / L; Peptide content: 9g / L; Nitrogen content (in terms of N): 22g / L; Phosphorus content (in terms of P2O5): 12 g / L; Potassium content (expressed as K2O): 13g / L.

[0041] Microbiological index test results, Total bacterial count: 80CFU / mL; Total mold and yeast count: 8 CFU / mL; No harmful pathogens were detected.

[0042] pH test result: 6.8.

[0043] Embodiment 3 Nutritional test results, Amino acid content: 17g / L; Peptide content: 10g / L; Nitrogen content (in terms of N): 23 g / L; Phosphorus content (as P2O5): 13g / L; Potassium content (expressed as K2O): 14g / L.

[0044] Microbiological index test results, Total bacterial count: 70 CFU / mL; Total mold and yeast count: 5 CFU / mL; No harmful pathogens were detected.

[0045] pH test result: 7.0.

[0046] Embodiment 4: Nutritional test results, Amino acid content: 18g / L; Peptide content: 11g / L; Nitrogen content (in terms of N): 25g / L; Phosphorus content (as P2O5): 14 g / L; Potassium content (as K2O): 15g / L.

[0047] Microbiological index test results, Total bacterial count: 60CFU / mL; Total mold and yeast count: 3CFU / mL; No harmful pathogens were detected.

[0048] pH test result: 7.2.

[0049] In summary, the feasibility and effectiveness of preparing fertilizers from high-purity methionine fermentation broth in the four groups of embodiments of the present invention have important practical significance and application value.

[0050] The embodiments of the present invention are described in detail above in conjunction with 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 are made to these embodiments without departing from the principle and spirit of the present invention, and they still fall within the protection scope of the present invention.

[0051] 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 expressions of the above terms do not necessarily refer to the same embodiment or example, and the specific features, structures, materials or characteristics described may be combined in an appropriate manner in any one or more embodiments or examples.

[0052] 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.

[0053] 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 process for preparing fertilizer from high-purity methionine fermentation waste liquid with low energy consumption, comprising pretreatment of methionine fermentation waste liquid, synergistic extraction, ion exchange adsorption, microbial fermentation and nanoemulsification operation, characterized in that: The specific operation steps of the process for preparing fertilizer from high-purity methionine fermentation waste liquid with low energy consumption are as follows: Step 1, collecting methionine fermentation waste liquid, performing vacuum low-temperature evaporation and concentration operation on it after three-layer filtration, and collecting the fermentation waste liquid concentrate; Step 2: placing the fermentation waste liquid concentrate in an ultrasonic-electric field synergistic extraction device for synergistic extraction, and obtaining an ultrasonic-treated liquid after completion; Step 3, selecting a composite ion exchange resin column, passing the ultrasonic treatment liquid through the composite ion exchange resin column under specific conditions to obtain a high-purity treatment waste liquid; Step 4: transfer the high-purity treated waste liquid to a fermentation tank, add a composite microbial flora for fermentation, add enzyme preparations in stages after completion, stir and mix, and ferment to obtain a high-purity fermentation liquid; Step 5: Select a nano-emulsifier, add it and the high-purity fermentation liquid into a container in proportion, pressurize and stir to mix, and add a stabilizer after mixing to obtain a liquid fertilizer product.

2. The process for preparing fertilizer from high-purity methionine fermentation waste liquid with low energy consumption according to claim 1, characterized in that: In the step 1, at a temperature of 25°C-30°C, the collected methionine fermentation waste liquid is preliminarily filtered through a three-layer filter screen, the apertures of the three-layer filter screen are 100um, 50um and 20um from top to bottom, respectively. After the preliminary filtration is completed, it is passed through a ceramic filter membrane, the aperture of the ceramic filter membrane is 20nm-30nm, and after the filtration is completed, it is transferred to a concentration device, and the waste liquid after the preliminary filtration is evaporated and concentrated at a low temperature. The vacuum low-temperature evaporation technology is used, the evaporation temperature is set to 40°C-42°C, the vacuum degree is maintained between -0.08MPa--0.085MPa, the stirring speed is set to 60r / min-80r / min, the fermentation waste liquid is evenly heated during the evaporation process, a condenser is provided on the top of the concentration device, and during the evaporation process, the volume and concentration changes of the waste liquid are monitored in real time. When the volume of the waste liquid is reduced to 30%-40% of the original volume, the evaporation and concentration operation is completed, and the fermentation waste liquid concentrate is collected.

3. The process for preparing fertilizer from high-purity methionine fermentation waste liquid with low energy consumption according to claim 1, characterized in that: In the step 2, a new extractant prepared by mixing n-hexane, isopropanol and ethyl acetate in a ratio of 4:3:3 is added to the reactor of the extraction device, and the amount of the new extractant added is 120%-130% of the total volume of the fermentation waste liquid concentrate. The fermentation waste liquid concentrate is added to the reactor, and an ultrasonic generator and an electric field generator are started. Extraction begins under the synergistic action of ultrasound and the electric field. The diameter of tiny bubbles formed in the waste liquid by the cavitation effect generated by ultrasound is controlled to be between 1um and 5um. After the extraction is completed, the ultrasonic generator is turned off, and the electric field generator is kept running for 2min-5min. After completion, the electric field generator is stopped, and the reactor is allowed to stand for 18min-20min. After the waste liquid and the extractant are separated, the extraction phase of the lower layer is discharged and collected through the drainage port at the bottom, and the drainage speed is controlled to be 30mL / min-35mL / min. The extraction phase of the upper layer is the ultrasonic treatment liquid.

4. The process for preparing fertilizer from high-purity methionine fermentation waste liquid with low energy consumption according to claim 1, characterized in that: In the step three, a composite ion exchange resin column is selected, wherein the upper layer is a strongly acidic cation exchange resin, the middle layer is an adsorption layer made of a composite of nano-metal-MOFs and functionalized graphene, the particle size of the nano-MOFs is between 100nm and 200nm, and the lower layer is a weakly alkaline anion exchange resin. When in use, the resin column is first rinsed with deionized water at a flow rate of 3BV / h for 45min-60min, the ultrasonic treatment liquid is introduced into the ion exchange resin column, the feed temperature is controlled to 28°C-35°C, the feed flow rate is set to 4mL / min-6mL / min, and the high-purity treated waste liquid treated by the composite ion exchange resin column is collected.

5. The process for preparing fertilizer from high-purity methionine fermentation waste liquid with low energy consumption according to claim 1, characterized in that: In the step three, the weakly alkaline anion exchange resin in the lower layer exchanges and adsorbs anionic impurities in the ultrasonic treatment liquid to remove anionic impurities, and the anionic impurity content in the treated waste liquid is controlled to be less than 10 ppm. During the treatment process, the temperature of the composite ion exchange resin column is controlled between 26° C. and 28° C.

6. The process for preparing fertilizer from high-purity methionine fermentation waste liquid with low energy consumption according to claim 1, characterized in that: In the step 4, before the high-purity treated waste liquid is transferred to the fermentation tank, the inside of the fermentation tank is first sprayed with a hydrogen peroxide solution with a mass fraction of 0.8% for disinfection. After keeping it for 30 minutes, it is blown dry with air in a sterile environment, and then rinsed with sterile water for 3 times, and soaked in a peracetic acid solution with a mass fraction of 0.2% for 20 minutes. After completion, it is rinsed with sterile water until the pH of the rinse liquid is neutral, and the high-purity treated waste liquid is transferred to the fermentation tank at a flow rate of 15L / min-20L / min, and then a composite microbial flora prepared by mixing Bacillus, Aspergillus and lactic acid bacteria in a ratio of 2:1:1 is inoculated into the fermentation tank, and the inoculation amount is 6% of the total volume of the high-purity treated waste liquid. After the inoculation is completed, it is stirred at a stirring rate of 40r / min-50r / min for 5min to evenly disperse the microbial flora in the high-purity treated waste liquid.

7. The process for preparing fertilizer from high-purity methionine fermentation waste liquid with low energy consumption according to claim 1, characterized in that: In the step 4, during the fermentation process, air that has been sterilized by filtering through a 0.22 um microporous filter membrane is introduced into the fermenter at a ventilation volume of 0.8 vvm-1.0 vvm. The air enters the fermenter through a gas distributor. The air forms tiny bubbles with a diameter of 2 mm-3 mm in the high-purity treated waste liquid. Under this condition, fermentation is continued for 26 h-32 h. During the fermentation period, samples are taken every 2 h, and the fermentation conditions are adjusted by monitoring the changes in the biomass of the microorganisms, metabolites, and nutrients in the waste liquid.

8. The process for preparing fertilizer from high-purity methionine fermentation waste liquid with low energy consumption according to claim 1, characterized in that: In the step 4, at the 12th hour after the start of fermentation, a protease is added to the fermenter, the enzyme activity of the protease is 1200U / g, and the addition amount is 0.15% of the total mass of the high-purity treated waste liquid. Within 10 minutes after the addition of the protease, ozone is pulsed into the fermenter, the amount of each introduction is 0.1L, the interval time is 2min-3min, and a total of 3 times. At the 24th hour, cellulase and pectinase with an enzyme activity of 900U / g are added, and the addition amount is 0.1% of the mass of the waste liquid, respectively. After the addition is completed, the fermentation is continued for 20h-24h to fully transform the organic components in the high-purity treated waste liquid. When the fermentation achieves the expected effect, that is, the macromolecular organic matter in the waste liquid is fully decomposed and the microbial biomass no longer increases significantly, the fermentation is stopped to obtain a high-purity fermentation liquid. After the fermentation is completed, the high-purity fermentation liquid is rapidly cooled at a cooling rate of 5°C / min to reduce the temperature to below 10°C to inhibit the continued growth of microorganisms and the activity of enzymes.

9. The process for preparing fertilizer from high-purity methionine fermentation waste liquid with low energy consumption according to claim 1, characterized in that: In the step 5, a composite nanoemulsifier consisting of polyoxyethylene sorbitan fatty acid ester, soybean lecithin and cetearyl alcohol polyether-20 in a ratio of 3:2:1 is selected, the three ingredients are first preheated at 40°C for 15min, and then stirred and mixed for 20 minutes in an environment with a vacuum degree of -0.09MPa, and the stirring speed is 1000r / min1200r / min, and the high-purity fermentation broth is added to the mixing container through the feed port at a flow rate of 10L / min, and at the same time, the prepared nanoemulsifier is added at a ratio of 6% of the volume of the high-purity fermentation broth, and stirred at a stirring rate of 200r / min for 5min to make the emulsifier preliminarily dispersed in the fermentation broth to form a uniform mixed system. In this process, nitrogen with a purity of 99.9% is filled into the container from the nitrogen inlet to keep the pressure in the container at 0.02MPa to prevent air from entering, the nitrogen inlet is closed, and the high-pressure homogenizing nozzle and The jacket circulating water system sets the circulating water temperature in the jacket to 30°C, gradually increases the pressure in the container to 120MPa, and the pressure increase rate is 10MPa / min. During the pressurization process, the stirring speed is increased to 1500r / min and maintained for 25min-30min, so that the fermentation liquid forms a nanoemulsion under the action of high pressure and strong stirring, and then prepares a mixed solution of 0.5% xanthan gum, 0.3% sodium carboxymethyl cellulose and 0.2% sodium alginate as a stabilizer, adds it to the nanoemulsion and stirs for 15min to evenly disperse the stabilizer in the emulsion. After the stabilizer is added, continue stirring for 8min-15min, and pass the mixed solution through the discharge port and filter device at the bottom of the container into the temporary storage tank. In the temporary storage tank, the liquid fertilizer product is quality tested, and the quality test includes the nutrient content, microbial indicators and pH value of the liquid fertilizer product.

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