Process for preparing liquid fertilizer from lysine fermentation waste liquid

Abstract

The invention discloses a process for preparing a liquid fertilizer from a lysine fermentation waste liquid, and relates to the technical field of fertilizer preparation, and the process has the advantages that a specific metal organic framework (MOFs) derived porous carbon material is adopted as an adsorption material to realize efficient purification of lysine in the lysine fermentation waste liquid, the porous carbon material obtained after ZIF-8 is subjected to carbonization and other treatment has a high specific surface area and a rich pore structure, a large number of sites are provided for adsorption of lysine, amino is introduced through ammonia gas plasma treatment and can form hydrogen bonds or electrostatic interaction with carboxyl of lysine and the like, carboxyl is introduced through oxygen plasma treatment, and the adsorption efficiency of lysine is improved. By means of the precise design, lysine is effectively separated from other impurities, a high-purity lysine resource is obtained, the content and quality of effective components in subsequent liquid fertilizer can be improved, and meanwhile the comprehensive utilization efficiency and economic benefits of the resource are greatly improved.

Description

Technical Field

[0001] The invention relates to the technical field of fertilizer preparation, in particular to a process for preparing liquid fertilizer from lysine fermentation waste liquid. Background Art

[0002] With the development of the global economy and the growth of population, the demand for fertilizers in agricultural production continues to increase. At the same time, environmental protection and sustainable utilization of resources have also become important issues facing today's society. Under such a background, exploring innovative fertilizer preparation methods, especially using industrial waste for fertilizer production, has great practical significance. Lysine, as an important amino acid, has a wide range of applications in medicine, food, feed and other fields. The production of lysine is mainly carried out through fermentation technology, which produces a large amount of waste liquid. These waste liquids are rich in organic matter and nutrients. If they are discharged directly, it will not only cause a waste of resources, but also cause serious pollution to the environment. The existing technology has certain defects. First, the traditional adsorption materials have poor adsorption selectivity when treating lysine fermentation waste liquid, resulting in low lysine recovery rate and purity, and a large amount of valuable lysine resources are lost, which increases production costs and causes serious waste of resources. Secondly, the existing technology does not scientifically allocate nutrients after waste liquid treatment, lacks efficient nutrient carriers, resulting in a short duration of fertilizer effect, weak improvement effect on soil structure and fertility, and it is difficult to meet the growth needs of plants. Moreover, in the preparation of previous fertilizers, stability is difficult to guarantee, there is a lack of effective means of enhancing efficiency, and the soil microbial environment cannot be optimized, resulting in low fertilizer utilization, affected crop growth, and may also have adverse effects on the environment. For this reason, we propose a process for preparing liquid fertilizer from lysine fermentation waste liquid. Summary of the invention

[0003] The purpose of the present invention is to provide a process for preparing liquid fertilizer from lysine fermentation waste liquid.

[0004] In order to solve the problems raised in the above background technology, the present invention provides the following technical solution: a process for preparing liquid fertilizer from lysine fermentation waste liquid, the process for preparing liquid fertilizer specifically comprises the following steps: Step 1: prepare an adsorption material to purify lysine, select a metal organic framework (MOFs) derived porous carbon material as a basic carrier, and prepare it specifically in the following manner: dissolve zinc nitrate and 2-methylimidazole in a methanol solution respectively, then mix and stir the two solutions, then collect the product by centrifugation, wash the product with a washing liquid and dry it to obtain ZIF-8 crystals, place the ZIF-8 crystals in a tubular furnace for carbonization to obtain a MOFs derived porous carbon material, and then use ammonia plasma treatment technology and oxygen plasma treatment technology to treat the MOFs derived porous carbon material to introduce amino groups and carboxyl groups on its surface, and then pass the lysine fermentation waste liquid through an adsorption column equipped with the adsorption material for adsorption treatment, so that the lysine molecules in the waste liquid are adsorbed and other impurities flow out. After adsorption saturation, use a sodium carbonate solution to desorb lysine through the adsorption column to form a high-concentration lysine solution; Step 2: treating the remaining waste liquid after collecting lysine, adding sodium dihydrogen phosphate to the remaining waste liquid, and slowly dropping sodium hydroxide solution to adjust the pH value of the solution for reaction. During this process, the phosphate ions in the sodium dihydrogen phosphate combine with the calcium and magnesium ions in the waste liquid to form a calcium-magnesium phosphate phosphorus complex; Step 3, mixing the phosphorus-containing complex with the purified lysine solution, then adding a nitrogen source, a phosphorus source and an iron element to the mixed solution, then stirring the mixed solution evenly, and adjusting the nutrient ratio with other nutrients; Step 4: preparing nano-hydroxyapatite by a sol-gel method, dissolving calcium nitrate and diammonium hydrogen phosphate in deionized water respectively, then slowly dropping the diammonium hydrogen phosphate solution into the calcium nitrate solution, adding ammonia water to adjust the pH value, and then stirring evenly to obtain nano-hydroxyapatite inorganic nanoparticles, compounding polyacrylic acid and nano-hydroxyapatite inorganic nanoparticles by chemical cross-linking, and then stirring evenly to make the organic polymer wrap the inorganic nanoparticles to form a composite nanomaterial, and adding the composite nanomaterial to the mixed solution, stirring after adding to make it absorb nutrients; Step 5: Add sodium alginate as a stabilizer to the mixed solution, and add nitrogen-fixing bacteria, phosphate-solubilizing bacteria, and growth-promoting bacteria as synergists, followed by stirring, filtering, and sterilization, and mix them evenly. Subsequently, filter through a microporous filter membrane, and then sterilize through high temperature and high pressure to obtain liquid fertilizer.

[0005] As a further scheme of the present invention: in the step 1, the volume ratio of the zinc nitrate solution and the 2-methylimidazole solution is 1-2:0.8-1.3, the concentration of zinc nitrate is 0.2mol / L-0.4mol / L, and the concentration of 2-methylimidazole is 0.4 / L-0.8mol / L, and the two solutions are mixed and stirred at room temperature for reaction for 16h-20h.

[0006] As a further scheme of the present invention: in the step 1, the washing liquid is a methanol solution, and the centrifuged product is washed 3-5 times with the methanol solution, the amount of methanol used for each washing is 2-4 times the mass of the product, and the ZIF-8 crystals are obtained by drying at 60°C-80°C for 16h-20h.

[0007] As a further scheme of the present invention: in the step 1, the ZIF-8 crystal is heated to 800°C-1000°C at a heating rate of 6°C / min-10°C / min in a tubular furnace under a nitrogen atmosphere, and then kept warm for 2h-4h for carbonization to obtain a MOFs-derived porous carbon material, and then treated for 15min-25min using an ammonia plasma treatment technology at a power of 150W-250W to introduce amino groups on the surface of the material, and then treated for 10min-20min using an oxygen plasma treatment technology at a power of 100W-200W to introduce carboxyl groups on the surface of the material, and then the lysine fermentation waste liquid is adsorbed at a flow rate of 30ml / min-50ml / min and a temperature of 25°C-35°C through an adsorption column equipped with the adsorption material. After saturated adsorption, lysine is desorbed through the adsorption column using a sodium carbonate solution with a concentration of 0.4mol / L-0.6mol / L at a flow rate of 20ml / min-40ml / min.

[0008] As a further solution of the present invention: in the step 2, the amount of sodium dihydrogen phosphate added is 0.2 mol-0.4 mol per liter of residual waste liquid, sodium hydroxide solution is added dropwise to adjust the pH value of the solution to 5-7, and the reaction is stirred at 35°C-45°C for 1.5h-2.5h.

[0009] As a further scheme of the present invention: in the step three, the volume ratio of the phosphorus-containing complex and the purified lysine solution is 1-2:3-4, the added nitrogen source is ammonium nitrate, and ammonium nitrate is added until the mass percentage of nitrogen in the final fertilizer reaches 12%-18%, the added nitrogen and phosphorus source is potassium dihydrogen phosphate, and potassium dihydrogen phosphate is added until the mass percentage of phosphorus in the final fertilizer reaches 8%-12%, and the added iron element is ferrous sulfate, and ferrous sulfate is added until the mass concentration of iron in the final fertilizer is 0.2g / L-0.4g / L.

[0010] As a further solution of the present invention: in the step 4, the concentration of calcium nitrate is 0.1 mol / L-0.3 mol / L, the concentration of diammonium hydrogen phosphate is 0.06 mol / L-0.18 mol / L, ammonia water is added to adjust the pH value to 9-11, and the reaction is stirred at a temperature of 40°C-60°C for 2h-4h.

[0011] As a further scheme of the present invention: in the step 4, polyacrylic acid and nano-hydroxyapatite inorganic nanoparticles are chemically cross-linked and composited at a mass ratio of 1.0-1.3:0.8-1.8, the stirring temperature is 60°C-80°C, the stirring time is 1.5h-2.5h, the composite nanomaterial is added to the mixed solution, the reaction temperature is controlled to 25°C-35°C, the stirring time is 30min-60min, and the nutrients include lysine, potassium dihydrogen phosphate, ammonium nitrate and ferrous sulfate.

[0012] As a further solution of the present invention: in the step 5, the amount of sodium alginate added is 1%-2% of the mass of the mixed solution, and the effective viable count of each bacterial agent of nitrogen-fixing bacteria, phosphate-solubilizing bacteria and growth-promoting bacteria is 3.0×10 7 -8.0×10 7 The solution is stirred at a speed of 150r / min-250r / min for 30min-60min at a temperature of 35℃-45℃, the pore size of the microporous filter membrane is 0.2μ-0.4μm, and the high temperature and high pressure sterilization is sterilized at 120℃-130℃ for 15min-25min.

[0013] By adopting the above technical solution, compared with the prior art, the beneficial effects of the present invention are: 1. The present invention realizes the efficient purification of lysine in lysine fermentation waste liquid by using a specific metal organic framework (MOFs) derived porous carbon material as an adsorption material. Among them, the porous carbon material obtained after ZIF-8 is treated by carbonization has a high specific surface area and a rich pore structure, which provides a large number of sites for the adsorption of lysine. The amine group introduced by ammonia plasma treatment can form hydrogen bonds or electrostatic interactions with the carboxyl group of lysine, and the carboxyl group introduced by oxygen plasma treatment can further enhance the affinity with lysine. This precise design allows lysine to be effectively separated from other impurities to obtain high-purity lysine resources, which can not only improve the content and quality of effective ingredients in subsequent liquid fertilizers, but also greatly improve the comprehensive utilization efficiency and economic benefits of resources; 2. The present invention generates a phosphorus-containing complex by treating the remaining waste liquid, thereby adding phosphorus nutrition to the fertilizer, rationally adjusting the ratio of nutrients such as nitrogen, phosphorus, and potassium, and using nano-hydroxyapatite composite nanomaterials to adsorb multiple nutrients. Nano-hydroxyapatite has good biocompatibility and adsorption performance, can effectively load nutrients, and can slowly release nutrients in the soil to meet the long-term growth needs of plants. At the same time, the addition of composite nanomaterials can also improve the physical and chemical properties of the soil, improve soil fertility and water and fertilizer retention capabilities, promote plant root growth and nutrient absorption, thereby improving the yield and quality of crops, and realizing the transformation of waste liquid resources into high-efficiency liquid fertilizers; 3. The present invention ensures the stability, safety and effectiveness of the liquid fertilizer by adding sodium alginate as a stabilizer and microbial agents such as nitrogen-fixing bacteria, phosphate-solubilizing bacteria and growth-promoting bacteria as synergists, and through process steps such as stirring, filtering and sterilization. Sodium alginate stabilizes the system of the fertilizer solution to prevent the precipitation and deterioration of nutrients. The microbial agent can improve the soil microbial environment. The nitrogen-fixing bacteria can convert nitrogen in the air into a nitrogen source that can be used by plants. The phosphate-solubilizing bacteria can decompose the insoluble phosphorus in the soil. The growth-promoting bacteria promotes plant growth and development, improves the fertilizer utilization rate and plant stress resistance, and the liquid fertilizer finally obtained has balanced nutrition, lasting fertilizer effect and is environmentally friendly. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 A schematic diagram of the process steps in an embodiment of the present invention; Figure 2 Schematic diagram of performance comparison of embodiments of the present invention. DETAILED DESCRIPTION

[0015] The specific embodiments of the present invention will be 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.

[0016] 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.

[0017] Please see attached Figure 1 -Attached Figure 2 The present invention provides a process for preparing liquid fertilizer from lysine fermentation waste liquid, and the process for preparing liquid fertilizer specifically comprises the following steps: Step 1: prepare an adsorption material to purify lysine, select a metal organic framework (MOFs) derived porous carbon material as a basic carrier, and prepare it specifically in the following manner: dissolve zinc nitrate and 2-methylimidazole in a methanol solution respectively, then mix and stir the two solutions, then collect the product by centrifugation, wash the product with a washing liquid and dry it to obtain ZIF-8 crystals, place the ZIF-8 crystals in a tubular furnace for carbonization to obtain a MOFs derived porous carbon material, and then use ammonia plasma treatment technology and oxygen plasma treatment technology to treat the MOFs derived porous carbon material to introduce amino groups and carboxyl groups on its surface, and then pass the lysine fermentation waste liquid through an adsorption column equipped with the adsorption material for adsorption treatment, so that the lysine molecules in the waste liquid are adsorbed and other impurities flow out. After adsorption saturation, use a sodium carbonate solution to desorb lysine through the adsorption column to form a high-concentration lysine solution; Step 2: treating the remaining waste liquid after collecting lysine, adding sodium dihydrogen phosphate to the remaining waste liquid, and slowly dropping sodium hydroxide solution to adjust the pH value of the solution for reaction. During this process, the phosphate ions in the sodium dihydrogen phosphate combine with the calcium and magnesium ions in the waste liquid to form a calcium-magnesium phosphate phosphorus complex; Step 3, mixing the phosphorus-containing complex with the purified lysine solution, then adding a nitrogen source, a phosphorus source and an iron element to the mixed solution, then stirring the mixed solution evenly, and adjusting the nutrient ratio with other nutrients; Step 4: preparing nano-hydroxyapatite by a sol-gel method, dissolving calcium nitrate and diammonium hydrogen phosphate in deionized water respectively, then slowly dropping the diammonium hydrogen phosphate solution into the calcium nitrate solution, adding ammonia water to adjust the pH value, and then stirring evenly to obtain nano-hydroxyapatite inorganic nanoparticles, compounding polyacrylic acid and nano-hydroxyapatite inorganic nanoparticles by chemical cross-linking, and then stirring evenly to make the organic polymer wrap the inorganic nanoparticles to form a composite nanomaterial, and adding the composite nanomaterial to the mixed solution, stirring after adding to make it absorb nutrients; Step 5: Add sodium alginate as a stabilizer to the mixed solution, and add nitrogen-fixing bacteria, phosphate-solubilizing bacteria, and growth-promoting bacteria as synergists, followed by stirring, filtering, and sterilization, and mix them evenly. Subsequently, filter through a microporous filter membrane, and then sterilize through high temperature and high pressure to obtain liquid fertilizer.

[0018] In one embodiment of the present invention: in step 1, the volume ratio of zinc nitrate solution and 2-methylimidazole solution added is 1-2:0.8-1.3, the concentration of zinc nitrate is 0.2mol / L-0.4mol / L, the concentration of 2-methylimidazole is 0.4 / L-0.8mol / L, and the two solutions are mixed and stirred at room temperature for reaction for 16h-20h.

[0019] In one embodiment of the present invention: in step 1, the washing liquid is a methanol solution, and the centrifuged product is washed 3-5 times with a methanol solution, the amount of methanol used for each washing is 2-4 times the mass of the product, and the ZIF-8 crystals are obtained by drying at 60°C-80°C for 16h-20h.

[0020] In one embodiment of the present invention: in step one, the ZIF-8 crystal is heated to 800°C-1000°C at a heating rate of 6°C / min-10°C / min in a tubular furnace under a nitrogen atmosphere, and then kept warm for 2h-4h for carbonization to obtain a MOFs-derived porous carbon material, and then treated with an ammonia plasma treatment technology at a power of 150W-250W for 15min-25min to introduce amine groups on the surface of the material, and then treated with an oxygen plasma treatment technology at a power of 100W-200W for 10min-20min to introduce carboxyl groups on the surface of the material, and then the lysine fermentation waste liquid is adsorbed at a flow rate of 30ml / min-50ml / min and a temperature of 25°C-35°C through an adsorption column equipped with the adsorption material. After saturated adsorption, a sodium carbonate solution with a concentration of 0.4mol / L-0.6mol / L is used to desorb lysine through the adsorption column at a flow rate of 20ml / min-40ml / min.

[0021] In one embodiment of the present invention: in step 2, the amount of sodium dihydrogen phosphate added is 0.2 mol-0.4 mol per liter of residual waste liquid, sodium hydroxide solution is added dropwise to adjust the pH value of the solution to 5-7, and the reaction is stirred at 35°C-45°C for 1.5h-2.5h.

[0022] In one embodiment of the present invention: in step three, the volume ratio of the phosphorus-containing complex and the purified lysine solution is 1-2:3-4, the added nitrogen source is ammonium nitrate, and ammonium nitrate is added until the mass percentage of nitrogen in the final fertilizer reaches 12%-18%, the added nitrogen and phosphorus source is potassium dihydrogen phosphate, and potassium dihydrogen phosphate is added until the mass percentage of phosphorus in the final fertilizer reaches 8%-12%, and the added iron element is ferrous sulfate, and ferrous sulfate is added until the mass concentration of iron in the final fertilizer is 0.2g / L-0.4g / L.

[0023] In one embodiment of the present invention: in step 4, the concentration of calcium nitrate is 0.1 mol / L-0.3 mol / L, the concentration of diammonium hydrogen phosphate is 0.06 mol / L-0.18 mol / L, ammonia water is added to adjust the pH value to 9-11, and the reaction is stirred at a temperature of 40°C-60°C for 2h-4h.

[0024] In one embodiment of the present invention: in step 4, polyacrylic acid and nano-hydroxyapatite inorganic nanoparticles are chemically cross-linked and composited at a mass ratio of 1.0-1.3:0.8-1.8, the stirring temperature is 60°C-80°C, the stirring time is 1.5h-2.5h, the composite nanomaterial is added to the mixed solution, the reaction temperature is controlled to 25°C-35°C, the stirring time is 30min-60min, and the nutrients include lysine, potassium dihydrogen phosphate, ammonium nitrate and ferrous sulfate.

[0025] In one embodiment of the present invention, in step 5, the amount of sodium alginate added is 1%-2% of the mass of the mixed solution, and the effective viable count of each bacterial agent of nitrogen-fixing bacteria, phosphate-solubilizing bacteria, and growth-promoting bacteria is 3.0×10 per milliliter. 7 -8.0×10 7 The solution is stirred at a speed of 150r / min-250r / min for 30min-60min at a temperature of 35℃-45℃, the pore size of the microporous filter membrane is 0.2μ-0.4μm, and the high temperature and high pressure sterilization is sterilized at 120℃-130℃ for 15min-25min.

[0026] In one embodiment of the present invention, during the mixing and stirring of zinc nitrate and 2-methylimidazole, 0.1%-0.3% of polyvinyl pyrrolidone (PVP) is added as a dispersant accounting for the total mass of the solution, and the average molecular weight of PVP is 10000-30000. The dispersant can make the generated ZIF-8 crystal particles more uniform and reduce agglomeration, so that the subsequently obtained MOFs-derived porous carbon material has a more uniform pore structure and improves the adsorption performance of lysine; In one embodiment of the present invention: when polyacrylic acid and nano-hydroxyapatite inorganic nanoparticles are chemically cross-linked and composited, a silane coupling agent accounting for 0.5%-1.5% of the mass of the nano-hydroxyapatite inorganic nanoparticles is added, and the silane coupling agent is γ-aminopropyltriethoxysilane. The silane coupling agent can enhance the chemical bonding between nano-hydroxyapatite and polyacrylic acid, improve the stability of the composite nanomaterial, and further enhance the composite nanomaterial's ability to adsorb and sustainably release nutrients.

[0027] In one embodiment of the present invention: after adding nitrogen-fixing bacteria, phosphate-solubilizing bacteria and growth-promoting bacteria, chitosan is added in an amount of 0.05%-0.15% by mass of the mixed solution. Chitosan can form a protective film on the surface of the bacterial agent, thereby improving the survival rate of the bacterial agent during storage and use of the fertilizer. In addition, chitosan itself has certain biological activity and can cooperate with the bacterial agent to further promote plant growth.

[0028] Example 1, please refer to the attached Figure 1 -Attached Figure 2First, prepare the adsorption material to purify lysine, dissolve zinc nitrate and 2-methylimidazole in methanol solution, the concentration of zinc nitrate is 0.4 mol / L, the concentration of 2-methylimidazole is 0.8 mol / L, the volume ratio of zinc nitrate solution and 2-methylimidazole solution is 1:1.3, mix and stir at room temperature for 20 hours, collect the product by centrifugation, wash the product with methanol solution 5 times, the amount of methanol used for each washing is 3 times the mass of the product, and then dry it at 80°C for 20 hours to obtain ZIF-8 crystals, then place the ZIF-8 crystals in a tubular furnace and heat them to 1000°C at a heating rate of 6°C / min under a nitrogen atmosphere, then keep them warm for 4 hours for carbonization to obtain MOFs-derived porous carbon materials, and then Ammonia plasma treatment technology was used for 25 minutes at a power of 250W to introduce amine groups on the surface of the material, and then oxygen plasma treatment technology was used for 20 minutes at a power of 200W. Lysine fermentation waste liquid was adsorbed at a flow rate of 30ml / min and a temperature of 35°C through an adsorption column equipped with the adsorption material. After saturated adsorption, lysine was desorbed through the adsorption column with a sodium carbonate solution with a concentration of 0.6mol / L at a flow rate of 40ml / min to form a high-concentration lysine solution. Then, the remaining waste liquid after collecting lysine was treated, and sodium dihydrogen phosphate was added to the remaining waste liquid in an amount of 0.4mol per liter of the remaining waste liquid, and sodium hydroxide solution was slowly added dropwise to adjust The pH value of the solution was increased to 7, and then the reaction was stirred at 45°C for 2.5 hours to generate a calcium magnesium phosphate phosphorus complex, and then the phosphorus complex was mixed with the purified lysine solution in a volume ratio of 1:3, and ammonium nitrate (until the mass percentage of nitrogen in the final fertilizer reached 16%), potassium dihydrogen phosphate (until the mass percentage of phosphorus in the final fertilizer reached 12%), and ferrous sulfate (until the mass concentration of iron in the final fertilizer was 0.4 g / L) were added and stirred evenly, and then nano hydroxyapatite was prepared by a sol-gel method, 0.3 mol / L calcium nitrate and 0.18 mol / L diammonium hydrogen phosphate were respectively dissolved in deionized water, and the diammonium hydrogen phosphate solution was slowly added dropwise to the calcium nitrate solution, and then the mixture was stirred evenly. Ammonia water was added to adjust the pH value to 10, and the nano-hydroxyapatite inorganic nanoparticles were prepared after stirring at 60°C for 4 hours. Polyacrylic acid and nano-hydroxyapatite inorganic nanoparticles were then chemically cross-linked and composited at a mass ratio of 1.3:0.8 (stirring temperature was 60°C, stirring time was 2.5 hours), and the composite nanomaterial was added to the mixed solution (the reaction temperature was controlled at 35°C, and the stirring time was 60 minutes) to absorb nutrients, which included lysine, potassium dihydrogen phosphate, ammonium nitrate and ferrous sulfate. Finally, sodium alginate was added to the mixed solution, and the amount of sodium alginate added was 2% of the mass of the mixed solution. In addition, nitrogen-fixing bacteria, phosphate-solubilizing bacteria, and growth-promoting bacteria were also included. The effective viable count of each bacterial agent was 8.0×10 per milliliter. 7The mixture was then stirred at 250 r / min for 60 min at 35°C, filtered through a microporous filter membrane with a pore size of 0.4 μm, and then sterilized at 130°C for 25 min to obtain a liquid fertilizer.

[0029] Example 2, please refer to the attached Figure 1 -Attached Figure 2First, prepare the adsorption material to purify lysine, dissolve cobalt chloride and 4-methylimidazole in ethanol solution, the concentration of cobalt chloride is 0.4 mol / L, the concentration of 4-methylimidazole is 0.8 mol / L, the volume ratio of cobalt chloride solution and 4-methylimidazole solution is 1:1.3, mix and stir at room temperature for 20 hours, collect the product by centrifugation, wash the product with ethanol solution 5 times, the amount of ethanol used for each washing is 3 times the mass of the product, and then dry it at 80°C for 20 hours to obtain crystals, then place the Co-MI crystals in a tubular furnace and heat them to 1000°C at a heating rate of 6°C / min under a nitrogen atmosphere, and then keep them warm for 4 hours for carbonization to obtain C o-MOFs derived porous carbon material, then treated with ammonia plasma treatment technology at a power of 250W for 25min to introduce amine groups on the surface of the material, and then treated with oxygen plasma treatment technology at a power of 200W for 20min, the lysine fermentation waste liquid was adsorbed at a flow rate of 30ml / min and a temperature of 35°C through an adsorption column equipped with the adsorption material. After saturated adsorption, lysine was desorbed through the adsorption column with a sodium carbonate solution with a concentration of 0.6mol / L at a flow rate of 40ml / min to form a high-concentration lysine solution, and then the remaining waste liquid after collecting lysine was treated, and diphosphate was added to the remaining waste liquid. Sodium hydrogen is added in an amount of 0.4 mol per liter of the remaining waste liquid, and sodium hydroxide solution is slowly added dropwise to adjust the pH value of the solution to 7, and then the reaction is stirred at a temperature of 45°C for 2.5 hours to generate a calcium magnesium phosphate phosphorus complex, and then the phosphorus complex is mixed with the purified lysine solution in a volume ratio of 1:3, and ammonium nitrate (until the mass percentage of nitrogen in the final fertilizer reaches 16%), potassium dihydrogen phosphate (until the mass percentage of phosphorus in the final fertilizer reaches 12%), and ferrous sulfate (until the mass concentration of iron in the final fertilizer is 0.4 g / L) are added and stirred evenly, and then the nanomaterial is prepared by a sol-gel method, and 0.3 mol / L of titanium Tetrabutyl ester of acid was mixed with an appropriate amount of ethanol, water and hydrochloric acid, and stirred under certain conditions to react to form nano titanium dioxide, which was chemically cross-linked with polyacrylic acid at a mass ratio of 1.3:0.8 (stirring temperature was 60°C, stirring time was 2.5h), and the composite nanomaterial was added to the mixed solution (the reaction temperature was controlled to be 35°C, and the stirring time was 60min) to absorb nutrients, including lysine, potassium dihydrogen phosphate, ammonium nitrate and ferrous sulfate. Finally, sodium alginate was added to the mixed solution, and the amount of sodium alginate added was 2% of the mass of the mixed solution. In addition, nitrogen-fixing bacteria, phosphate-solubilizing bacteria and growth-promoting bacteria were also included, and the effective viable bacteria count of each bacterial agent was 8.0×10 per milliliter. 7 The mixture was then stirred at 250 r / min for 60 min at 35°C, filtered through a microporous filter membrane with a pore size of 0.4 μm, and then sterilized at 130°C for 25 min to obtain a liquid fertilizer.

[0030] Example 3, please refer to the attached Figure 1 -Attached Figure 2First, prepare the adsorption material to purify lysine, dissolve zinc nitrate and 2-methylimidazole in methanol solution, respectively, the concentration of zinc nitrate is 0.2 mol / L, the concentration of 2-methylimidazole is 0.4 mol / L, the volume ratio of zinc nitrate solution and 2-methylimidazole solution added is 2:1.3, mix and stir at room temperature for 16 hours, collect the product by centrifugation, wash the product with methanol solution 5 times, the amount of methanol used for each washing is 3 times the mass of the product, and then dry it at 80°C for 20 hours to obtain ZIF-8 crystals, and then place the ZIF-8 crystals in a tubular furnace and heat them to 1000°C at a heating rate of 6°C / min under a nitrogen atmosphere, and then keep them warm for 4 hours for carbonization to obtain MOFs-derived porous carbon materials, and then Ammonia plasma treatment technology was used for 25 minutes at a power of 250W to introduce amine groups on the surface of the material, and then oxygen plasma treatment technology was used for 20 minutes at a power of 200W. Lysine fermentation waste liquid was adsorbed at a flow rate of 50ml / min and a temperature of 25°C through an adsorption column equipped with the adsorption material. After saturated adsorption, lysine was desorbed through the adsorption column with a sodium carbonate solution with a concentration of 0.4mol / L at a flow rate of 40ml / min to form a high-concentration lysine solution. Then, the remaining waste liquid after collecting lysine was treated, and sodium dihydrogen phosphate was added to the remaining waste liquid in an amount of 0.2mol per liter of the remaining waste liquid, and sodium hydroxide solution was slowly added dropwise to adjust The solution pH value is increased to 5, and then the reaction is stirred at a temperature of 40°C for 2.0h to generate a calcium magnesium phosphate phosphorus complex, and then the phosphorus complex is mixed with the purified lysine solution in a volume ratio of 2:3, and ammonium nitrate (until the mass percentage of nitrogen in the final fertilizer reaches 12%), potassium dihydrogen phosphate (until the mass percentage of phosphorus in the final fertilizer reaches 8%), and ferrous sulfate (until the mass concentration of iron in the final fertilizer is 0.24g / L) are added and stirred evenly, and then nano hydroxyapatite is prepared by a sol-gel method, 0.3mol / L calcium nitrate and 0.18mol / L diammonium hydrogen phosphate are respectively dissolved in deionized water, and the diammonium hydrogen phosphate solution is slowly added dropwise to the calcium nitrate solution, and the mixture is stirred at the same time. Ammonia water was added to adjust the pH value to 10, and the nano-hydroxyapatite inorganic nanoparticles were prepared after stirring at 60°C for 4 hours. Polyacrylic acid and nano-hydroxyapatite inorganic nanoparticles were then chemically cross-linked and composited at a mass ratio of 1.3:0.8 (stirring temperature was 60°C, stirring time was 2.5 hours), and the composite nanomaterial was added to the mixed solution (the reaction temperature was controlled at 35°C, and the stirring time was 60 minutes) to absorb nutrients, which included lysine, potassium dihydrogen phosphate, ammonium nitrate and ferrous sulfate. Finally, sodium alginate was added to the mixed solution, and the amount of sodium alginate added was 2% of the mass of the mixed solution. In addition, nitrogen-fixing bacteria, phosphate-solubilizing bacteria, and growth-promoting bacteria were also included. The effective viable count of each bacterial agent was 3.0×10 per milliliter. 7The mixture was then stirred at 45°C at a speed of 250 r / min for 60 min, filtered through a microporous filter membrane with a pore size of 0.2 μm, and then sterilized at a temperature of 130°C for 25 min to obtain a liquid fertilizer.

[0031] Designing the Experiment Experimental materials: lysine fermentation wastewater; Chemical reagents: zinc nitrate, 2-methylimidazole, methanol, sodium carbonate, sodium dihydrogen phosphate, sodium hydroxide, ammonium nitrate, potassium dihydrogen phosphate, ferrous sulfate, cobalt chloride, 4-methylimidazole, ethanol, tetrabutyl titanate, hydrochloric acid, polyacrylic acid, sodium alginate, nitrogen-fixing bacteria agent, phosphate-dissolving bacteria agent, growth-promoting bacteria agent, etc.; Test plants and soil: The test plants were selected from Chinese cabbage seeds, which were of good quality and from the same source. The experimental soil was collected from the same farmland area, and after removing stones, grass roots and other debris, it was sieved through a 2mm sieve and fully mixed for later use; Experimental equipment: centrifuge, drying oven, tubular furnace, plasma treatment equipment, adsorption column, stirrer, constant temperature water bath, pH meter, electronic balance, atomic absorption spectrometer, element analyzer, UV-visible spectrophotometer, soil compaction meter, soil porosity meter, plant growth incubator; According to the preparation methods of Example 1, Example 2 and Example 3, three parallel samples were prepared, and they were marked as A1-A3 (Example 1), B1-B3 (Example 2), and C1-C3 (Example 3). In the process of adsorption and desorption of lysine, the waste liquid before adsorption, the waste liquid after adsorption and the desorption liquid are accurately collected; Performance Testing Lysine recovery rate determination: accurate sampling before adsorption, after adsorption and after desorption; An amino acid analyzer was used to determine the lysine content in samples from each stage; According to the formula: Lysine recovery rate = (mass of lysine in desorption solution ÷ mass of lysine in waste solution before adsorption) × 100%, the average lysine recovery rate was calculated; Fertilizer nutrient content determination Nitrogen content determination: The nitrogen content in the liquid fertilizer prepared in each embodiment was determined using an element analyzer, and the cumulative release rate of nitrogen element was determined over 28 days; Take a certain amount of liquid fertilizer and place it in a dialysis bag, put it in a container filled with deionized water, and place it at 25°C for 28 days; Dialysate was taken regularly (every 2 days) and the nitrogen content in the dialysate was determined by an element analyzer. The cumulative release rate of nitrogen in 28 days was calculated according to the formula: cumulative release rate = (mass of released nitrogen ÷ mass of total nitrogen in fertilizer) × 100%; Determination of nitrogen content change rate in 28 days: Liquid fertilizer was placed at room temperature for 28 days, and samples were taken on the first day and 28 days; The nitrogen content was measured by an elemental analyzer, and the nitrogen content change rate in 28 days was calculated according to the formula: nitrogen content change rate = (nitrogen content on day 28 - nitrogen content on day 0) ÷ nitrogen content on day 0 × 100%; Soil improvement effect determination Soil porosity change determination: Prepare soils of the same mass and initial porosity, add equal amounts of liquid fertilizers from each embodiment, and mix well; Before adding fertilizer and after a certain period of plant growth (30 days), soil porosity was measured using a soil porosity meter, and the change in soil porosity was calculated; Plant growth promotion effect determination Potted plant experiment: Prepare flower pots of the same specifications, fill them with the same amount of unfertilized soil, and add the same amount of liquid fertilizers of each embodiment; The same number and variety of seeds (Brachys pakchoi) were sown in each pot and cultivated under the same conditions of light, temperature and humidity; Fresh weight determination After the plants have grown for a certain period (30 days), carefully remove the plants, rinse the roots with clean water, dry the surface water, weigh them with an electronic balance, and record the fresh weight; Root surface area determination Use a root scanner to scan plant roots and use professional software to analyze the root surface area As attached Figure 2 As shown, in terms of lysine recovery rate, Example 1, Example 2 and Example 3 have the strongest ability to recover lysine from waste liquid, and Example 1 is also ahead in nitrogen content, indicating that the fertilizer has richer initial nutrition. The cumulative release rate of nitrogen elements in 28 days reflects the long-term fertilizer supply capacity, and Example 1 performs better. The 28-day nitrogen content change rate reflects stability, and Example 1 has the smallest change rate and better stability. The change in soil porosity shows the degree of improvement in the physical structure of the soil, and Example 1 is the most significant. The fresh weight and root surface area intuitively reflect the effect of promoting plant growth. The advantages of Example 1 are obvious. Overall, Example 1 is superior to other examples in multiple core indicators.

[0032] Although the present invention is disclosed as above in terms of preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications without departing from the spirit and scope of the present invention. Therefore, any modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the scope of protection defined by the claims of the present invention.

Claims

1. A process for preparing liquid fertilizer from lysine fermentation waste liquid, characterized in that: The process for preparing liquid fertilizer specifically comprises the following steps: Step 1: prepare an adsorption material to purify lysine, select a metal organic framework (MOFs) derived porous carbon material as a basic carrier, and prepare it specifically in the following manner: dissolve zinc nitrate and 2-methylimidazole in a methanol solution respectively, then mix and stir the two solutions, then collect the product by centrifugation, wash the product with a washing liquid and dry it to obtain ZIF-8 crystals, place the ZIF-8 crystals in a tubular furnace for carbonization to obtain a MOFs derived porous carbon material, and then use ammonia plasma treatment technology and oxygen plasma treatment technology to treat the MOFs derived porous carbon material to introduce amino groups and carboxyl groups on its surface, and then pass the lysine fermentation waste liquid through an adsorption column equipped with the adsorption material for adsorption treatment. After adsorption saturation, use sodium carbonate solution to desorb lysine through the adsorption column to form a high-concentration lysine solution; Step 2: treating the remaining waste liquid after collecting lysine, adding sodium dihydrogen phosphate to the remaining waste liquid, and slowly adding sodium hydroxide solution to adjust the pH value of the solution for reaction to generate a calcium magnesium phosphate phosphorus complex; Step 3, mixing the phosphorus-containing complex with the purified lysine solution, then adding a nitrogen source, a phosphorus source and an iron element to the mixed solution, and then stirring the mixed solution evenly; Step 4: preparing nano-hydroxyapatite by a sol-gel method, dissolving calcium nitrate and diammonium hydrogen phosphate in deionized water respectively, then slowly dropping the diammonium hydrogen phosphate solution into the calcium nitrate solution, adding ammonia water to adjust the pH value, and then stirring evenly to obtain nano-hydroxyapatite inorganic nanoparticles, compounding polyacrylic acid and nano-hydroxyapatite inorganic nanoparticles by chemical cross-linking, and then stirring evenly to make the organic polymer wrap the inorganic nanoparticles to form a composite nanomaterial, and adding the composite nanomaterial to the mixed solution, stirring after adding to make it absorb nutrients; Step 5: Add sodium alginate as a stabilizer to the mixed solution, and add nitrogen-fixing bacteria, phosphate-solubilizing bacteria, and growth-promoting bacteria as synergists, followed by stirring, filtering, and sterilization, and mix them evenly. Subsequently, filter through a microporous filter membrane, and then sterilize through high temperature and high pressure to obtain liquid fertilizer.

2. A process for preparing liquid fertilizer from lysine fermentation waste liquid according to claim 1, characterized in that: In the step 1, the volume ratio of the zinc nitrate solution and the 2-methylimidazole solution is 1-2:0.8-1.3, the concentration of the zinc nitrate is 0.2mol / L-0.4mol / L, and the concentration of the 2-methylimidazole is 0.4 / L-0.8mol / L, and the two solutions are mixed and stirred at room temperature for reaction for 16h-20h.

3. The process for preparing liquid fertilizer from lysine fermentation waste liquid according to claim 1, characterized in that: In the step 1, the washing liquid is a methanol solution, and the centrifuged product is washed 3-5 times with the methanol solution, the amount of methanol used for each washing is 2-4 times the mass of the product, and the ZIF-8 crystals are obtained by drying at 60° C.-80° C. for 16 h-20 h.

4. The process for preparing liquid fertilizer from lysine fermentation waste liquid according to claim 1, characterized in that: In the step 1, the ZIF-8 crystal is heated to 800°C-1000°C at a heating rate of 6°C / min-10°C / min in a tubular furnace under a nitrogen atmosphere, and then kept warm for 2h-4h for carbonization to obtain a MOFs-derived porous carbon material, and then treated with an ammonia plasma treatment technology for 15min-25min at a power of 150W-250W to introduce amine groups on the surface of the material, and then treated with an oxygen plasma treatment technology for 10min-20min at a power of 100W-200W to introduce carboxyl groups on the surface of the material, and then lysine fermentation waste liquid is adsorbed at a flow rate of 30ml / min-50ml / min and a temperature of 25°C-35°C through an adsorption column equipped with the adsorption material. After saturated adsorption, lysine is desorbed through the adsorption column using a sodium carbonate solution with a concentration of 0.4mol / L-0.6mol / L at a flow rate of 20ml / min-40ml / min.

5. The process for preparing liquid fertilizer from lysine fermentation waste liquid according to claim 1, characterized in that: In the step 2, the amount of sodium dihydrogen phosphate added is 0.2 mol-0.4 mol per liter of the remaining waste liquid, sodium hydroxide solution is added dropwise to adjust the pH value of the solution to 5-7, and the reaction is stirred at 35° C.-45° C. for 1.5 h-2.5 h.

6. The process for preparing liquid fertilizer from lysine fermentation waste liquid according to claim 1, characterized in that: In the step 3, the volume ratio of the phosphorus-containing complex and the purified lysine solution is 1-2:3-4, the added nitrogen source is ammonium nitrate, and ammonium nitrate is added until the mass percentage of nitrogen in the final fertilizer reaches 12%-18%, the added nitrogen and phosphorus source is potassium dihydrogen phosphate, and potassium dihydrogen phosphate is added until the mass percentage of phosphorus in the final fertilizer reaches 8%-12%, and the added iron element is ferrous sulfate, and ferrous sulfate is added until the mass concentration of iron in the final fertilizer is 0.2g / L-0.4g / L.

7. The process for preparing liquid fertilizer from lysine fermentation waste liquid according to claim 1, characterized in that: In the step 4, the concentration of calcium nitrate is 0.1 mol / L-0.3 mol / L, the concentration of diammonium hydrogen phosphate is 0.06 mol / L-0.18 mol / L, ammonia water is added to adjust the pH value to 9-11, and the reaction is stirred at a temperature of 40° C.-60° C. for 2 h-4 h.

8. The process for preparing liquid fertilizer from lysine fermentation waste liquid according to claim 1, characterized in that: In the step 4, polyacrylic acid and nano-hydroxyapatite inorganic nanoparticles are chemically cross-linked and composited at a mass ratio of 1.0-1.3:0.8-1.8, the stirring temperature is 60°C-80°C, the stirring time is 1.5h-2.5h, the composite nanomaterial is added to the mixed solution, the reaction temperature is controlled to be 25°C-35°C, the stirring time is 30min-60min, and the nutrients include lysine, potassium dihydrogen phosphate, ammonium nitrate and ferrous sulfate.

9. The process for preparing liquid fertilizer from lysine fermentation waste liquid according to claim 1, characterized in that: In step 5, the amount of sodium alginate added is 1%-2% of the mass of the mixed solution, and the effective viable count of each bacterial agent of nitrogen-fixing bacteria, phosphate-solubilizing bacteria, and growth-promoting bacteria is 3.0×10 per milliliter. 7 -8.0×10 7 The solution is stirred at a speed of 150r / min-250r / min for 30min-60min at a temperature of 35℃-45℃, the pore size of the microporous filter membrane is 0.2μ-0.4μm, and the high temperature and high pressure sterilization is sterilized at 120℃-130℃ for 15min-25min.

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