Method for preparing fertilizer based on ultrafiltration pretreatment of proline fermentation liquor

Abstract

The invention discloses a method for preparing a fertilizer on the basis of ultrafiltration pretreatment of proline fermentation liquor, and relates to the technical field of fertilizer preparation, and the method comprises the steps of proline fermentation liquor pretreatment, nutrient substance blending, fermentation waste liquor pretreatment, liquid fertilizer preparation and quality detection. Various enzymes react with organic substances in the fermentation liquor, the cellulase can decompose polysaccharide substances such as cellulose in the fermentation liquor and convert the polysaccharide substances into micromolecular saccharides which are more easily absorbed by plants, and the protease can hydrolyze protein and release nutritional ingredients such as amino acid; the amylase can decompose carbohydrates such as starch into monosaccharides such as glucose, the above reactions can improve the nutrient content and the bioavailability of the fermentation liquor, and the three groups of filtering devices are used for filtering the proline fermentation liquor in sequence, so that impurities with different particle sizes can be effectively removed.

Description

Technical Field

[0001] The invention relates to the technical field of fertilizer preparation, in particular to a method for preparing fertilizer based on ultrafiltration pretreatment of proline fermentation liquid. Background Art

[0002] With the continuous advancement of agricultural modernization, the demand for efficient, environmentally friendly and nutritionally balanced fertilizers is increasing day by day. Proline, as an important amino acid, plays a key role in the growth and development of plants. Proline is a cyclic imino acid with a unique chemical structure and properties. Its content in plants is relatively high, especially when subjected to adverse stress. Plants will accumulate a large amount of proline. Proline can enhance the stress resistance of plants, such as drought resistance, salinity resistance, low temperature resistance, etc., and improve the survival ability of plants in harsh environments. This is because proline can regulate the osmotic pressure of cells, maintain the water balance of cells, and prevent cells from dying due to water loss. At the same time, proline can also participate in plant protein synthesis, energy metabolism and other physiological processes, and promote plant growth and development. Proline fermentation liquid is the product of proline produced by microbial fermentation. In addition to proline, the fermentation broth may also contain other metabolites, microbial cells, unutilized nutrients and some impurities. The traditional proline fermentation broth treatment method has many disadvantages. On the one hand, the traditional treatment method is inefficient and often cannot fully extract the effective ingredients in the fermentation broth, resulting in a waste of resources. On the other hand, the traditional method may introduce some impurities, affecting the quality and effect of the fertilizer. In addition, a large amount of waste may be generated during the traditional treatment process, causing serious pollution to the environment. The existing technology may be more complicated in the operation process and requires a higher cost investment. For example, some separation technologies require expensive equipment and a large amount of energy consumption, which increases the production cost of the fertilizer and is not conducive to large-scale promotion and application. To this end, we propose a method for preparing fertilizer based on ultrafiltration pretreatment of proline fermentation broth. Summary of the invention

[0003] The object of the present invention is to provide a method for preparing fertilizer based on ultrafiltration pretreatment of proline fermentation broth.

[0004] In order to solve the problems raised in the above background technology, the present invention provides the following technical solutions: a method for preparing fertilizer by ultrafiltration pretreatment of proline fermentation broth, comprising pretreatment of proline fermentation broth, blending of nutrients, pretreatment of fermentation waste liquid, preparation of liquid fertilizer and quality inspection, wherein the specific operation steps of preparing fertilizer by ultrafiltration pretreatment of proline fermentation broth are as follows: Step 1, collecting the proline fermentation broth, using three sets of filtering devices to filter the proline fermentation broth in sequence, adding a flocculant after the treatment, mixing and ultrasonic treatment, and collecting the supernatant after the proline fermentation broth is precipitated for later use; Step 2: transferring the supernatant into a corrosion-resistant glass container, placing it into a strong magnetic field for magnetization treatment, and filtering it for a second time after the treatment to remove impurities to obtain a pure fermentation liquid; Step 3, adding the composite microbial enzyme preparation to the pure fermentation broth, continuously stirring and mixing, and subjecting the mixture to ultrasonic treatment, to obtain a composite fermentation broth after the ultrasonic treatment is completed; Step 4: adding a nutrient regulator to the composite fermentation liquid, stirring and mixing, adjusting the pH value of the mixed solution, and subjecting the composite fermentation liquid to micro-nano bubble treatment during the adding process, and obtaining a liquid fertilizer after completion; Step 5, collecting the waste liquid produced in the above steps, taking the supernatant after precipitation, performing ion exchange treatment and reverse osmosis treatment and concentration, and after completion, mixing it with the proline fermentation liquid, repeating steps 1 to 4 to prepare liquid fertilizer; Step 6: Perform quality inspection on the prepared liquid fertilizer to ensure that all indicators meet the standards of liquid fertilizer, and fill the qualified liquid fertilizer. The filling conditions need to be kept sterile. After completion, the finished liquid fertilizer is obtained.

[0005] As a further solution of the present invention: in the step 1, the three groups of filtration are preliminary filtration, precision filtration and deep filtration, the preliminary filtration uses ordinary filter filtration, the filter pore size is 0.1um-0.3um, and the larger particles of impurities are filtered out; the precision filtration uses a microporous filter membrane, the filter pore size is 0.03um-0.05um, the operating pressure is controlled to be 0.05MPa-0.1MPa, the temperature is 20℃-25℃, and the fine particles of impurities are filtered out; the deep filtration uses an ultrafiltration filter membrane, the filter pore size is 0. 005um-0.01um, control the operating pressure to 0.3MPa-0.5MPa, the temperature to 20℃-25℃, after filtration, add polyaluminium chloride to the fermentation broth and perform ultrasonic treatment, the amount of polyaluminium chloride added is 0.5%-1% of the total weight of the proline fermentation broth, control the frequency of the ultrasonic device to 25kHz-30kHz, the ultrasonic power to 500W-800W, and perform ultrasonic treatment for 30min-60min under the above conditions. During this process, the reaction of polyaluminium chloride in water is as follows:

[0006] In the above equation, the positively charged aluminum hydroxide colloid produced by hydrolysis reacts with the negatively charged impurity particles in the fermentation broth to neutralize and adsorb and bridge the impurity particles, thereby condensing and precipitating the impurity particles.

[0007] As a further solution of the present invention: in the step 2, the supernatant is transferred into a clean and dry glass container, a strong magnetic field generator is used, the magnetic field strength is set to 0.9T-1.2T, the flow rate of the fermentation liquid in the magnetic field is 10L / min-15L / min, and the fermentation liquid is treated for 20min-25min according to the above conditions. During the operation, stirring is continuously performed at a stirring rate of 20r / min-30r / min, and a pretreatment solution is obtained after the reaction is completed.

[0008] As a further scheme of the present invention: in the step 2, the pretreated solution is filtered in turn through an ultrafiltration device, the pore size of the ultrafiltration membrane is 0.01 mm, the operating pressure is set to 0.25 MPa, and the temperature is maintained at 24°C. During the filtration process, a cross-flow filtration method is used to control the filtration flow rate at 50 L / h-60 L / h, and a pure fermentation liquid is obtained after the filtration is completed.

[0009] As a further scheme of the present invention: in the step three, the added composite microbial enzyme preparation includes cellulase, protease, phytase, aldolase and chitinase, which are added at a ratio of 2%-4% of the total weight of the pure fermentation broth, and continuous stirring is performed during the addition process to control the enzyme preparation and the pure fermentation broth to be fully mixed, and stirring is performed at a stirring rate of 50r / min-80r / min for 2h-3h. After the stirring is completed, the mixed solution is ultrasonically treated with an ultrasonic device, and the ultrasonic frequency is set to 30kHz-40kHz, the power is set to 600W-900W, and the treatment time is set to 45min-60min. After the treatment is completed, a composite fermentation broth is obtained.

[0010] As a further solution of the present invention: In step 3, the reaction equation for cellulase-catalyzed cellulose hydrolysis is:

[0011] Cellulose is a polysaccharide composed of multiple glucose units connected by β-1,4-glycosidic bonds. Its general formula is , glucose is ; The reaction equation for protease-catalyzed protein hydrolysis is:

[0012] Proteins are composed of amino acids through peptide bonds The polymer compound formed by connecting amino acids, and its general formula is , Represents different side chain groups.

[0013] As a further scheme of the present invention: in the step 4, the nutrient regulator includes organic acid, amino acid and trace element, and the addition amount thereof is 1%-3%, 0.5%-1% and 0.1%-0.3% of the total weight of the composite fermentation liquid, respectively. After stirring and mixing with the composite fermentation liquid, the pH value of the mixed fermentation liquid is adjusted to 5.5-7.5 using a pH regulator. The pH meter is used for real-time monitoring during the addition process. After the pH value is adjusted to the target range, the addition of the pH regulator is stopped. During the addition of the nutrient regulator, a micro-nano bubble generator is used to inject oxygen into the composite fermentation liquid in the form of micro-nano bubbles. The diameter of the micro-nano bubbles is controlled to be 50nm-200nm, the gas-liquid ratio is 1:5-10, and the processing time is 1h-2h. After completion, liquid fertilizer is obtained.

[0014] As a further scheme of the present invention: in the step 5, the waste liquid generated by steps 1 to 4 is collected, precipitated for 12h-24h, and the supernatant is removed and ion exchange treatment is performed using a strong acid cation exchange resin, the waste liquid flow rate is controlled to be 15L / h-20L / h, the operating pressure of the reverse osmosis treatment concentration is controlled to be 1.5MPa-2.5MPa, the temperature is 30°C-40°C, and the waste liquid is concentrated to 20%-40% of the total volume of the treated solution, the concentrated waste liquid is mixed with the newly collected proline fermentation broth at a ratio of 1:3-5, and steps 1 to 4 are repeated to prepare liquid fertilizer.

[0015] As a further solution of the present invention: in step six, the prepared liquid fertilizer is subjected to comprehensive quality monitoring, including nutrient content determination, pH detection, heavy metal content detection and microbial index detection, and the fertilizer that passes the test is filled and stored in a dry and ventilated warehouse after completion.

[0016] By adopting the above technical solution, compared with the prior art, the beneficial effects of the present invention are: 1. The present invention adds a composite microbial enzyme preparation to make various enzymes react with organic substances in the fermentation liquid. Cellulase can decompose polysaccharides such as cellulose in the fermentation liquid and convert them into small molecular sugars that are more easily absorbed by plants. Protease can hydrolyze protein to release nutrients such as amino acids. Amylase can decompose carbohydrates such as starch into monosaccharides such as glucose. The above reactions can improve the nutrient content and biological effectiveness of the fermentation liquid. The proline fermentation liquid is filtered in sequence by three groups of filtering devices, which can effectively remove impurities of particles of different sizes and provide a relatively pure fermentation liquid for subsequent processing steps. By performing secondary filtration on the fermentation liquid, new impurities that may be generated during the magnetization treatment are removed to obtain a pure fermentation liquid, which provides good conditions for the next step of adding the composite microbial enzyme preparation. The cross-flow filtration method and the precisely controlled filtration flow, operating pressure and temperature ensure the stability and reliability of the filtration effect, further improve the purity of the fermentation liquid, and transfer the supernatant into a corrosion-resistant glass container and perform a strong magnetic field magnetization treatment, which can change the structure and properties of the molecules in the fermentation liquid and improve the efficiency of subsequent reactions. 2. The present invention can effectively recover useful components in the waste liquid by precipitating, ion exchanging and concentrating the waste liquid generated in steps one to four, thereby reducing waste of resources and pollution to the environment. The precipitation treatment can remove some solid impurities in the waste liquid. By using a strong acid cation exchange resin for ion exchange treatment, harmful components such as heavy metal ions in the waste liquid can be removed, thereby improving the safety of the waste liquid. The reverse osmosis treatment and concentration can reduce the volume of the waste liquid and increase the concentration of the effective components. By adding a nutrient regulator, a fertilizer with more balanced nutrition can be formulated according to the needs of the plants. After stirring and mixing, the pH value of the mixed solution is adjusted to make it more suitable for plant growth and the stability of the nutrients in the fertilizer. During the addition process, a micro-nano bubble generator is used to inject oxygen into the composite fermentation liquid in the form of micro-nano bubbles, and the diameter and gas-liquid ratio of the micro-nano bubbles are controlled, which not only increases the dissolved oxygen content in the fermentation liquid and promotes the growth and metabolism of microorganisms, but also enables nutrients to be better dispersed and dissolved, thereby improving the quality and effect of the fertilizer. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 The figure is a schematic diagram of a specific process of preparing fertilizer from proline fermentation liquid in an embodiment of the present invention. DETAILED DESCRIPTION

[0018] 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.

[0019] The present invention discloses a method for preparing fertilizer by ultrafiltration pretreatment of proline fermentation broth, comprising pretreatment of proline fermentation broth, blending of nutrients, pretreatment of fermentation waste liquid, preparation of liquid fertilizer and quality inspection. The specific operation steps of preparing fertilizer by ultrafiltration pretreatment of proline fermentation broth are as follows: Step 1, collecting the proline fermentation broth, using three sets of filtering devices to filter the proline fermentation broth in sequence, adding a flocculant after the treatment, mixing and ultrasonic treatment, and collecting the supernatant after the proline fermentation broth is precipitated for later use; Step 2: transferring the supernatant into a corrosion-resistant glass container, placing it into a strong magnetic field for magnetization treatment, and filtering it for a second time after the treatment to remove impurities to obtain a pure fermentation liquid; Step 3, adding the composite microbial enzyme preparation to the pure fermentation broth, continuously stirring and mixing, and subjecting the mixture to ultrasonic treatment, to obtain a composite fermentation broth after the ultrasonic treatment is completed; Step 4: adding a nutrient regulator to the composite fermentation liquid, stirring and mixing, adjusting the pH value of the mixed solution, and subjecting the composite fermentation liquid to micro-nano bubble treatment during the adding process, and obtaining a liquid fertilizer after completion; Step 5, collecting the waste liquid produced in the above steps, taking the supernatant after precipitation, performing ion exchange treatment and reverse osmosis treatment and concentration, and after completion, mixing it with the proline fermentation liquid, repeating steps 1 to 4 to prepare liquid fertilizer; Step 6: Perform quality inspection on the prepared liquid fertilizer to ensure that all indicators meet the standards of liquid fertilizer, and fill the qualified liquid fertilizer. The filling conditions need to be kept sterile. After completion, the finished liquid fertilizer is obtained.

[0020] As a further solution of the present invention: in step 1, the three groups of filtration are preliminary filtration, precision filtration and deep filtration, the preliminary filtration uses ordinary filter filtration, the filter pore size is 0.1um-0.3um, and the larger particles of impurities are filtered out; the precision filtration uses a microporous filter membrane, the filter pore size is 0.03um-0.05um, the operating pressure is controlled to be 0.05MPa-0.1MPa, the temperature is 20℃-25℃, and the fine particles of impurities are filtered out; the deep filtration uses an ultrafiltration filter membrane, the filter pore size is 0. 005um-0.01um, control the operating pressure to 0.3MPa-0.5MPa, the temperature to 20℃-25℃, after filtration, add polyaluminium chloride to the fermentation broth and perform ultrasonic treatment, the amount of polyaluminium chloride added is 0.5%-1% of the total weight of the proline fermentation broth, control the frequency of the ultrasonic device to 25kHz-30kHz, the ultrasonic power to 500W-800W, and perform ultrasonic treatment for 30min-60min under the above conditions. During this process, the reaction of polyaluminium chloride in water is as follows:

[0021] In the above equation, the positively charged aluminum hydroxide colloid produced by hydrolysis reacts with the negatively charged impurity particles in the fermentation broth to neutralize and adsorb and bridge the impurity particles, thereby condensing and precipitating the impurity particles.

[0022] In one embodiment of the present invention: in step 2, the supernatant is transferred into a clean and dry glass container, a strong magnetic field generator is used, the magnetic field strength is set to 0.9T-1.2T, the flow rate of the fermentation liquid in the magnetic field is 10L / min-15L / min, and the fermentation liquid is treated according to the above conditions for 20min-25min. During the operation, stirring is continued at a stirring rate of 20r / min-30r / min, and a pretreatment solution is obtained after the reaction is completed.

[0023] In one embodiment of the present invention: in step 2, the pretreated solution is filtered in turn through an ultrafiltration device, the pore size of the ultrafiltration membrane is 0.01 mm, the operating pressure is set to 0.25 MPa, and the temperature is maintained at 24°C. During the filtration process, a cross-flow filtration method is used to control the filtration flow rate at 50L / h-60L / h, and a pure fermentation liquid is obtained after the filtration is completed.

[0024] In one embodiment of the present invention: in step three, the added composite microbial enzyme preparation includes cellulase, protease, phytase, aldolase and chitinase, which are added at a ratio of 2%-4% of the total weight of the pure fermentation broth, and continuous stirring is performed during the addition process to control the enzyme preparation and the pure fermentation broth to be fully mixed, and stirring is performed at a stirring rate of 50r / min-80r / min for 2h-3h. After stirring, the mixed solution is ultrasonically treated with an ultrasonic device, and the ultrasonic frequency is set to 30kHz-40kHz, the power is 600W-900W, and the treatment time is 45min-60min. After the treatment, a composite fermentation broth is obtained.

[0025] In one embodiment of the present invention: In step 3, the reaction equation for cellulase-catalyzed cellulose hydrolysis is:

[0026] Cellulose is a polysaccharide composed of multiple glucose units connected by β-1,4-glycosidic bonds. Its general formula is , glucose is ; The reaction equation for protease-catalyzed protein hydrolysis is:

[0027] Proteins are composed of amino acids through peptide bonds The polymer compound formed by connecting amino acids, and its general formula is , Represents different side chain groups.

[0028] In one embodiment of the present invention: in step 4, the nutrient regulator includes organic acid, amino acid and trace element, and the addition amount thereof is 1%-3%, 0.5%-1% and 0.1%-0.3% of the total weight of the composite fermentation liquid, respectively. After stirring and mixing with the composite fermentation liquid, the pH value of the mixed fermentation liquid is adjusted to 5.5-7.5 using a pH regulator. The pH meter is used for real-time monitoring during the addition process. After the pH value is adjusted to the target range, the addition of the pH regulator is stopped. During the addition of the nutrient regulator, a micro-nano bubble generator is used to inject oxygen into the composite fermentation liquid in the form of micro-nano bubbles. The diameter of the micro-nano bubbles is controlled at 50nm-200nm, the gas-liquid ratio is 1:5-10, and the processing time is 1h-2h. After completion, liquid fertilizer is obtained.

[0029] In one embodiment of the present invention: in step 5, the waste liquid generated in steps 1 to 4 is collected, precipitated for 12h-24h, and the supernatant is removed and ion exchange treatment is performed using a strong acid cation exchange resin, the waste liquid flow rate is controlled to be 15L / h-20L / h, the operating pressure of the reverse osmosis treatment concentration is controlled to be 1.5MPa-2.5MPa, the temperature is 30°C-40°C, and the waste liquid is concentrated to 20%-40% of the total volume of the treated solution, the concentrated waste liquid is mixed with the newly collected proline fermentation broth in a ratio of 1:3-5, and steps 1 to 4 are repeated to prepare liquid fertilizer.

[0030] In one embodiment of the present invention: in step six, the prepared liquid fertilizer is subjected to comprehensive quality monitoring, including nutrient content determination, pH detection, heavy metal content detection and microbial index detection, and the fertilizer that passes the test is filled and stored in a dry and ventilated warehouse after completion.

[0031] In one embodiment of the present invention: in step three, the added composite microbial enzyme preparation includes cellulase, protease, phytase, aldolase and chitinase. Phytase can decompose phytic acid in the fermentation broth to release phosphorus and inositol, etc. Phytic acid is the main storage form of phosphorus in plant seeds. A certain amount of phytic acid may exist in the fermentation broth. Phytase acts on phytic acid to hydrolyze it into inorganic phosphorus and inositol, etc., thereby increasing the content of effective phosphorus in the fermentation broth. Aldolase participates in the sugar metabolism process in the fermentation broth to decompose sucrose into glucose and fructose. These small molecular sugars are more easily absorbed and utilized by plants, thereby improving the fertilizer efficiency. Chitinase can decompose chitin in the fermentation broth. Chitin is one of the components of many fungal cell walls. In the fermentation broth, there are some fungal residues, which can be decomposed by chitinase to release nutrients therein, such as nitrogen, phosphorus, potassium, etc. At the same time, the decomposition product of chitin, chitosan oligosaccharide, has the effect of stimulating plant growth and enhancing plant immunity.

[0032] In one embodiment of the present invention: in step five, suitable strong acid cation exchange resin and strong basic anion exchange resin are selected, common strong acid cation exchange resins include sulfonic acid resins, etc., and strong basic anion exchange resins include quaternary ammonium resins, etc. The resins are pretreated to remove impurities and possible residues, and the resins are soaked in deionized water for 24 hours, and then the strong acid cation exchange resin and the strong basic anion exchange resin are alternately rinsed with 5% hydrochloric acid solution and 5% sodium hydroxide solution, respectively, each rinsing time is 2 hours, and finally rinsed with deionized water until neutral, the strong acid cation exchange resin and the strong basic anion exchange resin are mixed uniformly according to a certain proportion, and loaded into an ion exchange column to ensure that the resins are tightly filled without gaps and bubbles, and the two resins are mixed in a volume ratio of 1:1. The diameter and height of the ion exchange column are determined according to the waste liquid treatment capacity, and an ion exchange column with a diameter of 10cm-20cm and a height of 50cm-100cm is selected.

[0033] In one embodiment of the present invention: in step 5, the waste liquid is passed through the mixed ion exchange column at a certain flow rate, so that the ions in the waste liquid exchange reaction with the active groups on the resin, and the heavy metal ions and other harmful ions in the waste liquid are removed. The waste liquid flow rate is controlled to be 15L / h-20L / h. During the treatment process, the ion concentration change of the waste liquid is regularly monitored. When the exchange capacity of the ion exchange column decreases, the resin is regenerated or replaced in time. When the exchange capacity of the ion exchange column decreases to a certain extent, the resin needs to be regenerated. For strongly acidic cation exchange resin, regenerate with hydrochloric acid solution; for strongly basic anion exchange resin, regenerate with sodium hydroxide solution. Regenerate the strongly acidic cation exchange resin with 5% hydrochloric acid solution, the regeneration liquid flow rate is 5L / h-10L / h, the regeneration time is 2h-3h, regenerate the strongly basic anion exchange resin with 5% sodium hydroxide solution, the regeneration liquid flow rate is 5L / h-10L / h, the regeneration time is 2h-3h. After regeneration, rinse the resin with deionized water until it is neutral for next use.

[0034] In one embodiment of the present invention: the reaction process of the strongly acidic cation exchange resin is as follows:

[0035] in Represents the resin skeleton, represents metal ions; The reaction process of strong basic anion exchange resin is as follows:

[0036] in, It is a quaternary amino group in the strong basic anion exchange resin, which can react with , An exchange reaction occurs.

[0037] Embodiment 1 First, the proline fermentation liquid is collected and initially filtered using a common filter with a pore size of 0.2um. A microporous filter membrane is used for precision filtration with a pore size of 0.04um. The operating pressure is controlled to be 0.08MPa and the temperature is maintained at 22°C. An ultrafiltration filter membrane is used for deep filtration with a pore size of 0.008um. The operating pressure is 0.4MPa and the temperature is maintained at 23°C. After the filtration is completed, polyaluminium chloride accounting for 0.8% of the total weight of the proline fermentation liquid is added to the fermentation liquid, and ultrasonic treatment is performed. The frequency of the ultrasonic device is controlled to be 28kHz and the ultrasonic power is 700W. Under this condition, the ultrasonic treatment is performed for 45min to condense and precipitate the impurity particles. After precipitation, the supernatant is taken for standby use. Then, the supernatant was transferred into a clean and dry glass container, and a strong magnetic field generator was used, the magnetic field strength was set to 1.0T, and the fermentation liquid was treated in the magnetic field at a flow rate of 12L / min for 23min. During the operation, stirring was continued at a stirring rate of 25r / min. After the reaction was completed, a pre-treated solution was obtained. After that, the pre-treated solution was filtered through an ultrafiltration device, the pore size of the ultrafiltration membrane was 0.01mm, the operating pressure was set to 0.25MPa, and the temperature was maintained at 24°C. During the filtration process, a cross-flow filtration method was used to control the filtration flow rate at 55L / h. After the filtration was completed, a pure fermentation liquid was obtained; Next, a composite microbial enzyme preparation is added to the pure fermentation broth, wherein the composite microbial enzyme preparation includes cellulase, protease, phytase, aldolase and chitinase, and the composite microbial enzyme preparation is added at a ratio of 3% of the total weight of the pure fermentation broth. During the addition process, stirring is continued, and the stirring rate is controlled to be 70 r / min, and the stirring time is 2.5 h to ensure that the enzyme preparation and the pure fermentation broth are fully mixed. After the stirring is completed, the mixed liquid is ultrasonically treated with an ultrasonic device, and the ultrasonic frequency is set to 35 kHz, the power is set to 800 W, and the treatment time is set to 50 min. After the treatment is completed, a composite fermentation broth is obtained; Afterwards, a nutrient regulator is added to the composite fermentation broth, the nutrient regulator includes an organic acid, an amino acid and a trace element, and the addition amount thereof is 2%, 0.8% and 0.2% of the total weight of the composite fermentation broth, respectively. After the nutrient regulator is stirred and mixed with the composite fermentation broth, a pH regulator is used to adjust the pH of the mixed fermentation broth to 6.5. A pH meter is used for real-time monitoring during the addition process. After the pH value is adjusted to the target range, the addition of the pH regulator is stopped. During the addition of the nutrient regulator, a micro-nano bubble generator is used to inject oxygen into the composite fermentation broth in the form of micro-nano bubbles. The diameter of the micro-nano bubbles is controlled at 100 nm, the gas-liquid ratio is 1:8, and the processing time is 1.5 h. After completion, a liquid fertilizer is obtained; The waste liquid produced in the above steps was collected and processed. The waste liquid was first precipitated for 18 hours, and then the supernatant was taken for ion exchange treatment using a strong acid cation exchange resin. The waste liquid flow rate was controlled to 18 L / h, and then reverse osmosis treatment was performed for concentration. The operating pressure was controlled to 2.0 MPa and the temperature was controlled to 35°C. The waste liquid was concentrated to 30% of the total volume of the treated solution. The concentrated waste liquid was mixed with the newly collected proline fermentation broth in a ratio of 1:4, and the above steps were repeated to prepare liquid fertilizer.

[0038] Embodiment 2 After the proline fermentation liquid was collected, it was initially filtered with a common filter (pore size of 0.15um), followed by precision filtration with a microporous filter membrane (pore size of 0.035um, operating pressure of 0.07MPa, temperature of 21°C), and deep filtration with an ultrafiltration filter membrane (pore size of 0.007um, operating pressure of 0.35MPa, temperature of 22°C). After the filtration was completed, polyaluminium chloride accounting for 0.7% of the total weight was added to the fermentation liquid, the frequency of the ultrasonic device was controlled to 27kHz, the ultrasonic power was 650W, the ultrasonic treatment was performed for 40min, and the supernatant was taken after precipitation; The supernatant was transferred into a clean and dry glass container, and a strong magnetic field generator was used. The magnetic field strength was set to 0.95T, and the fermentation liquid was treated in the magnetic field at a flow rate of 11L / min for 22min. During the operation, the fermentation liquid was continuously stirred at a stirring rate of 24r / min, and then filtered twice through an ultrafiltration device (pore size of 0.01mm, operating pressure of 0.25MPa, temperature of 24℃, cross-flow filtration, flow rate of 52L / h) to obtain pure fermentation liquid; Adding 2.8% of the total weight of the composite microbial enzyme preparation to the pure fermentation broth, stirring for 2.4 hours at a stirring rate of 68 r / min to ensure that the enzyme preparation and the pure fermentation broth are fully mixed, and then treating with an ultrasonic device at a frequency of 34 kHz and a power of 750 W for 48 minutes to obtain a composite fermentation broth; Nutrition regulators were added to the composite fermentation broth, with the addition amounts of organic acid, amino acid and trace elements being 1.8%, 0.7% and 0.15% of the total weight of the composite fermentation broth respectively. After stirring and mixing, the pH value was adjusted to 6.2 with a pH regulator. During the adding process, a micro-nano bubble generator was used to inject oxygen into the composite fermentation broth in the form of micro-nano bubbles (with a diameter controlled at 80 nm and a gas-liquid ratio of 1:7). The nutrient regulators were treated for 1.8 hours to obtain liquid fertilizer.

[0039] Embodiment 3 The proline fermentation broth was collected and initially filtered with a common filter (pore size of 0.18 um), then finely filtered with a microporous filter membrane (pore size of 0.042 um, operating pressure of 0.085 MPa, temperature of 23°C), and then deeply filtered with an ultrafiltration filter membrane (pore size of 0.009 um, operating pressure of 0.42 MPa, temperature of 24°C). After the filtration was completed, polyaluminium chloride accounting for 0.85% of the total weight was added to the fermentation broth, the frequency of the ultrasonic device was controlled to 29 kHz, the power was controlled to 780 W, the ultrasonic treatment was performed for 50 min, and the supernatant was taken after precipitation; The supernatant was transferred into a clean and dry glass container, and treated in a strong magnetic field with a magnetic field strength of 1.1T and a fermentation liquid flow rate of 13L / min for 24min, during which it was continuously stirred at a stirring rate of 26r / min, and then filtered twice through an ultrafiltration device (pore size of 0.01mm, operating pressure of 0.25MPa, temperature of 24°C, cross-flow filtration, flow rate of 58L / h) to obtain pure fermentation liquid; Adding 3.2% of the total weight of the composite microbial enzyme preparation to the pure fermentation broth, stirring for 2.6 hours at a stirring rate of 72 r / min, and then treating with an ultrasonic device at a frequency of 36 kHz and a power of 820 W for 52 minutes to obtain a composite fermentation broth; A nutrient regulator was added to the composite fermentation broth, with the addition amounts of organic acid, amino acid and trace element being 2.2%, 0.9% and 0.25% of the total weight of the composite fermentation broth respectively. After stirring and mixing, the pH value was adjusted to 6.8 with a pH regulator. During the adding process, a micro-nano bubble generator was used to inject oxygen into the composite fermentation broth in the form of micro-nano bubbles (with a diameter controlled at 120 nm and a gas-liquid ratio of 1:9). The nutrient regulator was treated for 1.6 hours to obtain a liquid fertilizer.

[0040] Embodiment 4: The proline fermentation broth was collected and initially filtered with a common filter (pore size of 0.22 um), then finely filtered with a microporous filter membrane (pore size of 0.045 um, operating pressure of 0.09 MPa, temperature of 24°C), and then deeply filtered with an ultrafiltration filter membrane (pore size of 0.01 um, operating pressure of 0.45 MPa, temperature of 25°C). After the filtration was completed, polyaluminium chloride accounting for 0.9% of the total weight was added to the fermentation broth, the frequency of the ultrasonic device was controlled to be 30 kHz, the power was 800 W, the ultrasonic treatment was performed for 55 min, and the supernatant was taken after precipitation; The supernatant was transferred into a clean and dry glass container, and treated in a strong magnetic field with a magnetic field strength of 1.15T and a fermentation liquid flow rate of 14L / min for 25min, during which the stirring was continuously carried out at a stirring rate of 28r / min, and then secondary filtration was performed through an ultrafiltration device (pore size of 0.01mm, operating pressure of 0.25MPa, temperature of 24°C, cross-flow filtration, flow rate of 60L / h) to obtain a pure fermentation liquid; Adding 3.5% of the total weight of the composite microbial enzyme preparation to the pure fermentation broth, stirring for 2.8 hours at a stirring rate of 75 r / min, and then treating with an ultrasonic device at a frequency of 38 kHz and a power of 850 W for 55 minutes to obtain a composite fermentation broth; A nutrient regulator was added to the composite fermentation broth, and the addition amounts of organic acid, amino acid and trace element were 2.5%, 1% and 0.3% of the total weight of the composite fermentation broth, respectively. After stirring and mixing, the pH value was adjusted to 7.0 with a pH regulator. During the adding process, a micro-nano bubble generator was used to inject oxygen into the composite fermentation broth in the form of micro-nano bubbles (the diameter was controlled at 150 nm, and the gas-liquid ratio was 1:10). The nutrient regulator was treated for 1.4 hours to obtain a liquid fertilizer.

[0041] Embodiment 5 The proline fermentation broth was collected and initially filtered with a common filter (pore size of 0.16um), then finely filtered with a microporous filter membrane (pore size of 0.038um, operating pressure of 0.075MPa, temperature of 22°C), and then deeply filtered with an ultrafiltration filter membrane (pore size of 0.008um, operating pressure of 0.4MPa, temperature of 23°C). After the filtration was completed, polyaluminium chloride accounting for 0.75% of the total weight was added to the fermentation broth, the frequency of the ultrasonic device was controlled to 28kHz, the power was controlled to 720W, the ultrasonic treatment was performed for 45min, and the supernatant was taken after precipitation; The supernatant was transferred into a clean and dry glass container, and treated in a strong magnetic field with a magnetic field strength of 1.02T and a fermentation liquid flow rate of 12L / min for 23min, during which it was continuously stirred at a stirring rate of 25r / min, and then filtered twice through an ultrafiltration device (pore size of 0.01mm, operating pressure of 0.25MPa, temperature of 24°C, cross-flow filtration, flow rate of 54L / h) to obtain a pure fermentation liquid; Adding 3% of the total weight of the composite microbial enzyme preparation to the pure fermentation broth, stirring for 2.5 hours at a stirring rate of 70 r / min, and then treating with an ultrasonic device at a frequency of 35 kHz and a power of 800 W for 50 minutes to obtain a composite fermentation broth; A nutrient regulator was added to the composite fermentation broth, with the addition amounts of organic acid, amino acid and trace element being 2%, 0.8% and 0.2% of the total weight of the composite fermentation broth respectively. After stirring and mixing, the pH value was adjusted to 6.6 with a pH regulator. During the adding process, a micro-nano bubble generator was used to inject oxygen into the composite fermentation broth in the form of micro-nano bubbles (with a diameter controlled at 110 nm and a gas-liquid ratio of 1:8). The nutrient regulator was treated for 1.7 hours to obtain a liquid fertilizer.

[0042] The amino acid fertilizers prepared in the above five groups of embodiments were tested, and the specific testing steps were as follows: Determination of nutrient content, Determination of the content of major nutrient elements such as nitrogen, phosphorus and potassium: the nitrogen content was determined by Kjeldahl method, the phosphorus content was determined by molybdenum antimony colorimetry, and the potassium content was determined by flame photometry; Determination of amino acid content: Use an amino acid analyzer to quantitatively analyze various amino acids in liquid fertilizer; Determination of trace element content: The content of trace elements such as iron, zinc, and copper is determined by atomic absorption spectrometry and other methods.

[0043] pH testing, Use a pH meter to directly measure the pH of liquid fertilizers.

[0044] Heavy metal content detection, Atomic absorption spectrometry, inductively coupled plasma mass spectrometry and other methods are used to detect the content of heavy metal elements such as lead, cadmium, mercury, chromium, and arsenic.

[0045] Microbiological index detection, The plate counting method is used to detect microbial indicators such as the total number of bacteria and total number of fungi in liquid fertilizers.

[0046] The test data of the finished fertilizer products in the five groups of embodiments are calculated as follows: Embodiment 1

[0047] Nitrogen content: 2.0%; Phosphorus content: 2.5%; Potassium content: 2.2%; Total amino acid content: 0.8%; pH: 6.5.

[0048] Embodiment 2 Nitrogen content: 1.8%; Phosphorus content: 2.3%; Potassium content: 2.0%; Total amino acids: 0.7%; pH: 6.2.

[0049] Embodiment 3 Nitrogen content: 2.1%; Phosphorus content: 2.6%; Potassium content: 2.3%; Total amino acids: 0.9%; pH value: 6.8.

[0050] Embodiment 4: Nitrogen content: 2.2%; Phosphorus content: 2.7%; Potassium content: 2.4%; Total amino acids: 1.0%; pH: 7.0.

[0051] Embodiment 5 Nitrogen content: 1.9%; Phosphorus content: 2.4%; Potassium content: 2.1% Total amino acid content: 0.8%; pH: 6.6.

[0052] The heavy metal contents in the above five groups of embodiments all meet the following standards: Lead content: ≤50mg / kg; Cadmium content: ≤3mg / kg; Mercury content: ≤2mg / kg; Chromium content: ≤150mg / kg; Arsenic content: ≤10mg / kg.

[0053] The trace elements in the five groups of examples meet the requirements of relevant standards.

[0054] Microbiological indicators, Total bacterial count ≤1000 CFU / mL; The total fungal count was ≤100 CFU / mL.

[0055] In summary, the feasibility and effectiveness of preparing fertilizers by ultrafiltration pretreatment of fermentation broth in Fu'an City according to the five groups of embodiments of the present invention have important practical significance and application value.

[0056] 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.

[0057] 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.

[0058] 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.

[0059] 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 method for preparing fertilizer by ultrafiltration pretreatment of proline fermentation broth, comprising pretreatment of proline fermentation broth, blending of nutrients, pretreatment of fermentation waste liquid, preparation of liquid fertilizer and quality inspection, characterized in that: The specific operation steps of preparing fertilizer based on ultrafiltration pretreatment of proline fermentation broth are as follows: Step 1, collecting the proline fermentation broth, filtering it using three sets of filtering devices, adding a flocculant for ultrasonic treatment, and taking the supernatant for standby use after the proline fermentation broth is precipitated; Step 2: Transfer the supernatant into a glass container, and magnetize it in a strong magnetic field. After the treatment, filter it twice to remove impurities and obtain pure fermentation liquid; Step 3, adding the composite microbial enzyme preparation to the pure fermentation broth, continuously stirring and mixing, and subjecting the mixture to ultrasonic treatment to obtain a composite fermentation broth; Step 4: adding a nutrient regulator to the composite fermentation liquid, stirring and mixing, adjusting the pH value of the mixed solution, and subjecting the composite fermentation liquid to micro-nano bubble treatment during the adding process, and obtaining a liquid fertilizer after completion; Step 5, collecting the waste liquid produced in the above steps, taking the supernatant after precipitation, performing ion exchange treatment and reverse osmosis treatment and concentration, and after completion, mixing it with the proline fermentation liquid, repeating steps 1 to 4 to prepare liquid fertilizer; Step 6: Perform quality inspection on the prepared liquid fertilizer to ensure that all indicators meet the standards of liquid fertilizer, and fill the qualified liquid fertilizer to obtain finished liquid fertilizer.

2. A method for preparing fertilizer based on ultrafiltration pretreatment of proline fermentation broth according to claim 1, characterized in that: In the step 1, the three groups of filtration are preliminary filtration, precision filtration and deep filtration, the preliminary filtration adopts ordinary filter filtration, the filter pore size is 0.1um-0.3um, and the larger particles of impurities are filtered out. The precision filtration adopts a microporous filter membrane, the filter pore size is 0.03um-0.05um, the operating pressure is controlled to be 0.05MPa-0.1MPa, the temperature is 20℃-25℃, and the fine particles of impurities are filtered out. The deep filtration adopts an ultrafiltration filter membrane, the filter pore size is 0.005um-0.01um, the operating pressure is controlled to be 0.3MPa-0.5MPa, and the temperature is 20℃-25℃. After the filtration is completed, polyaluminum chloride is added to the fermentation liquid and ultrasonic treatment is performed. The amount of polyaluminum chloride added is 0.5%-1% of the total weight of the proline fermentation liquid, the frequency of the ultrasonic device is controlled to be 25kHz-30kHz, and the ultrasonic power is 500W-800W. Under the above conditions, the ultrasonic treatment is performed for 30min-60min. In this process, the polyaluminum chloride reacts in water as follows: ； In the above equation, the positively charged aluminum hydroxide colloid produced by hydrolysis reacts with the negatively charged impurity particles in the fermentation broth to neutralize and adsorb and bridge the impurity particles, thereby condensing and precipitating the impurity particles.

3. The method for preparing fertilizer by ultrafiltration pretreatment of proline fermentation broth according to claim 1, characterized in that: In the step 2, the supernatant is transferred into a clean and dry glass container, a strong magnetic field generator is used, the magnetic field strength is set to 0.9T-1.2T, the flow rate of the fermentation liquid in the magnetic field is 10L / min-15L / min, and the fermentation liquid is treated for 20min-25min according to the above conditions. During the operation, stirring is continued at a stirring rate of 20r / min-30r / min, and a pretreatment solution is obtained after the reaction is completed.

4. The method for preparing fertilizer by ultrafiltration pretreatment of proline fermentation broth according to claim 1, characterized in that: In the step 2, the pretreated solution is filtered through an ultrafiltration device in sequence, the pore size of the ultrafiltration membrane is 0.01 mm, the operating pressure is set to 0.25 MPa, and the temperature is maintained at 24°C. During the filtration process, a cross-flow filtration method is used to control the filtration flow rate at 50 L / h-60 L / h. After the filtration is completed, a pure fermentation liquid is obtained.

5. The method for preparing fertilizer by ultrafiltration pretreatment of proline fermentation broth according to claim 1, characterized in that: In the step three, the added composite microbial enzyme preparation includes cellulase, protease, phytase, aldolase and chitinase, which are added at a ratio of 2%-4% of the total weight of the pure fermentation liquid, and continuous stirring is performed during the addition process to control the enzyme preparation and the pure fermentation liquid to be fully mixed, and stirring is performed at a stirring rate of 50r / min-80r / min for 2h-3h. After stirring, the mixed liquid is ultrasonically treated with an ultrasonic device, and the ultrasonic frequency is set to 30kHz-40kHz, the power is set to 600W-900W, and the treatment time is set to 45min-60min. After the treatment, a composite fermentation liquid is obtained.

6. The method for preparing fertilizer by ultrafiltration pretreatment of proline fermentation broth according to claim 1, characterized in that: In the step 3, the reaction equation for cellulase-catalyzed cellulose hydrolysis is: ； Cellulose is a polysaccharide composed of multiple glucose units connected by β-1,4-glycosidic bonds. Its general formula is , glucose is ; The reaction equation for protease-catalyzed protein hydrolysis is: ； Proteins are composed of amino acids through peptide bonds The polymer compound formed by connecting amino acids, and its general formula is , Represents different side chain groups.

7. The method for preparing fertilizer by ultrafiltration pretreatment of proline fermentation broth according to claim 1, characterized in that: In the step 4, the nutrient regulator includes organic acid, amino acid and trace elements, and the addition amount thereof is 1%-3%, 0.5%-1% and 0.1%-0.3% of the total weight of the composite fermentation liquid, respectively. After stirring and mixing with the composite fermentation liquid, the pH value of the mixed fermentation liquid is adjusted to 5.5-7.5 using a pH regulator. The pH meter is used for real-time monitoring during the addition process. After the pH value is adjusted to the target range, the addition of the pH regulator is stopped. During the addition of the nutrient regulator, a micro-nano bubble generator is used to inject oxygen into the composite fermentation liquid in the form of micro-nano bubbles. The diameter of the micro-nano bubbles is controlled to be 50nm-200nm, the gas-liquid ratio is 1:5-10, and the processing time is 1h-2h. After completion, liquid fertilizer is obtained.

8. The method for preparing fertilizer by ultrafiltration pretreatment of proline fermentation broth according to claim 1, characterized in that: In the step 5, the waste liquid generated in steps 1 to 4 is collected, precipitated for 12h-24h, and the supernatant is removed and ion exchange treatment is performed using a strong acid cation exchange resin, the waste liquid flow rate is controlled to be 15L / h-20L / h, the operating pressure of the reverse osmosis treatment concentration is controlled to be 1.5MPa-2.5MPa, the temperature is 30°C-40°C, and the waste liquid is concentrated to 20%-40% of the total volume of the treated solution, the concentrated waste liquid is mixed with the newly collected proline fermentation broth at a ratio of 1:3-5, and steps 1 to 4 are repeated to prepare liquid fertilizer.

9. The method for preparing fertilizer by ultrafiltration pretreatment of proline fermentation broth according to claim 1, characterized in that: In step six, the prepared liquid fertilizer is subjected to comprehensive quality monitoring, including nutrient content determination, pH detection, heavy metal content detection and microbial index detection. The qualified fertilizer is bottled and stored in a dry and ventilated warehouse after completion.

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