Preparation method of glutamic acid mycoprotein ecological fertilizer

Abstract

The invention discloses a preparation method of a glutamic acid mycoprotein ecological fertilizer, which comprises the following steps: firstly, adding polysilicate zinc into glutamic acid fermentation waste liquid, and filtering to obtain a mycoprotein-polysilicate zinc complex; zinc silicate and hydroxyapatite are added, and amino acid composite hydroxyapatite particles are formed under the action of citric acid; and spraying the urea-humic acid-dipotassium phosphate complex onto the amino acid composite hydroxyapatite particles to obtain the ecological fertilizer. According to the ecological fertilizer, mycoprotein in the glutamic acid fermentation waste liquid can be fully utilized, a good slow release effect of nitrogen, phosphorus and other elements can be achieved through the effects of the two complexes, and in addition, the addition of silicon and zinc elements can achieve a supplement effect on the growth of crops; therefore, the fertilizer provided by the invention has dual effects of environmental protection and long-acting slow release, and has a good promotion effect on the growth of crops.

Description

Technical field:

[0001] The invention relates to the field of ecological fertilizers, and more specifically to a method for preparing glutamic acid bacterial protein ecological fertilizers. Background technology:

[0002] Glutamic acid is an organic compound with the chemical name of α-aminoglutaric acid. It is a kind of amino acid and widely exists in nature. Glutamic acid is an important substance in protein metabolism and also one of the important neurotransmitters in the human body. In the food industry, sodium glutamate is used as a condiment to enhance the flavor of food, which is the main component of the commonly used condiment tasting essence in life.

[0003] The fermentation of glutamic acid by Corynebacterium glutamicum is a common method in the industry, but the wastewater discharged during the production of monosodium glutamate is a kind of industrial wastewater that is very difficult to treat. Due to the inability to effectively treat monosodium glutamate wastewater, many monosodium glutamate factories have been listed as key pollution sources in the country. The treatment of monosodium glutamate wastewater has become a major problem restricting the development of monosodium glutamate production enterprises.

[0004] Glutamic acid bacterial protein is the main by-product of MSG production. In order to save production costs and avoid waste of available resources, most MSG manufacturers currently choose to extract glutamate bacterial protein from wastewater and use it to produce feed or ecological fertilizer. Bacterial protein is a comprehensive utilization of waste resources, with relatively low cost and outstanding economic benefits. Therefore, the development and utilization of bacterial protein has broad prospects.

[0005] Patent CN110734331B discloses a compound fertilizer prepared from glutamate fermentation waste, which is prepared according to the following steps: step 1) preparing amino acid chelate particles; step 2) preparing urea-humic acid complex; step 3) preparing compound fertilizer. This method for preparing compound fertilizer has the following disadvantages: (1) the presence of a large amount of sulfates such as manganese sulfate and zinc sulfate in the amino acid metal chelate solution will still cause soil compaction to a certain extent; (2) directly collecting bacterial protein from glutamate fermentation liquid by centrifugation and then performing metal chelation cannot achieve complete resource utilization.

[0006] Therefore, it is particularly important to develop an ecological fertilizer that can both play a slow-release role and improve the utilization efficiency of bacterial protein. Summary of the invention:

[0007] The present invention provides a method for preparing a water-glutamate bacterial protein ecological fertilizer, aiming to develop an ecological fertilizer that can both play a slow-release role and improve the utilization efficiency of bacterial protein.

[0008] In order to achieve the technical purpose of the present invention, the present invention adopts the following technical scheme to prepare ecological fertilizer: first, polyzinc silicate is added to glutamate fermentation waste liquid, and bacterial protein-polyzinc silicate complex is obtained by filtering; zinc silicate and hydroxyapatite are added, and amino acid composite hydroxyapatite particles are formed through the action of citric acid; urea-humic acid-dipotassium hydrogen phosphate complex is sprayed on the amino acid composite hydroxyapatite particles to obtain ecological fertilizer.

[0009] The present invention provides a method for preparing a water-glutamic acid bacterial protein ecological fertilizer, and the preparation steps are as follows:

[0010] Step (1): adding polyzinc silicate to glutamate fermentation waste liquid, mixing for 1-2 hours, centrifuging and filtering, collecting the filtrate, drying and grinding the filtrate to obtain a bacterial protein-polyzinc silicate complex;

[0011] Step (2): preparing a zinc silicate aqueous solution, adding the bacterial protein-zinc polysilicate complex prepared in step (1) thereto; adding citric acid, adjusting the pH value to 6.0-7.0, stirring and reacting for 1-2 hours, adding hydroxyapatite, and supplementing citric acid at the same time, continuing to adjust the pH value to 6.0-7.0, continuing to stir and react for 1-2 hours, and centrifuging to obtain amino acid composite hydroxyapatite particles;

[0012] Step (3): preparing a urea-humic acid-dipotassium hydrogen phosphate complex;

[0013] Step (4): Spray the urea-humic acid-dipotassium hydrogen phosphate complex onto the amino acid composite hydroxyapatite particles, stir evenly, and dry at 40-60° C. to obtain ecological fertilizer.

[0014] Furthermore, the ratio of the amount of zinc polysilicate added in step (1) to the waste liquid is 1.5-3 g / 1L.

[0015] Furthermore, the concentration of the zinc silicate aqueous solution prepared in step (2) is 0.03-0.1 mol / L, and the ratio of the added amount of the complex to the zinc silicate aqueous solution is 30-100 g / L.

[0016] Furthermore, the amount of hydroxyapatite added in step (2) is 2-4 times that of the complex.

[0017] Furthermore, the specific preparation steps of the urea-humic acid-dipotassium hydrogen phosphate complex are: adding urea and water in a weight ratio of 1: (2-3) to a stirrer, heating to 30-35° C., stirring evenly, then adding humic acid and dipotassium hydrogen phosphate, raising the temperature to 70-90° C. for stirring reaction, and obtaining the urea-humic acid-dipotassium hydrogen phosphate complex.

[0018] Furthermore, the weight ratio of humic acid to urea is 1:(5-7); the weight ratio of dipotassium hydrogen phosphate to urea is 1:(6-10).

[0019] Furthermore, the mass ratio of the urea-humic acid-potassium dihydrogen phosphate complex to the amino acid chelate particles in step (4) is 1 L: (3-5) kg.

[0020] In the present invention, polysilicate zinc is added when extracting bacterial protein. On the one hand, polysilicate zinc can be added as a component as a non-toxic material, and polysilicate zinc itself can be used as a flocculant to utilize its flocculation function to extract as much bacterial protein as possible from the fermentation waste liquid, and then utilize the complexing function of zinc silicate itself and protein to form a complex, thereby improving the slow-release effect of the ecological fertilizer; thirdly, silicon and zinc are both high-quality trace elements in fertilizers, which can supplement the growth of crops.

[0021] The present invention uses urea, humic acid and dipotassium hydrogen phosphate to prepare a three-material synthetic complex, which can simultaneously supplement nitrogen, phosphorus and potassium elements to the soil and crops. At the same time, the complex formed by the three can also have a slow-release effect to a certain extent.

[0022] The present invention further adds zinc silicate to the bacterial protein-zinc polysilicate complex, and hydrolyzes the protein with citric acid to increase the complexing effect of amino acids and zinc silicate, and further adds hydroxyapatite, and adds citric acid again for treatment, so that the surface of hydroxyapatite has pores; the complexing effect of amino acids and hydroxyapatite is further increased, thereby improving the slow-release effect of ecological fertilizer. At the same time, by selecting hydroxyapatite as a carrier particle, the effect of continuously supplementing phosphorus elements for the soil can be achieved.

[0023] Compared with the prior art, the ecological fertilizer of the present invention can not only make full use of the bacterial protein in the glutamate fermentation waste liquid, but also play a good slow-release effect of elements such as nitrogen and phosphorus by the action of two complexes. In addition, the addition of silicon and zinc elements can supplement the growth of crops; thus, the fertilizer of the present invention has the dual effects of environmental protection and long-term slow release, and has a good promoting effect on the growth of crops. Specific implementation method:

[0024] In order to make the purpose, technical scheme and advantages of the present invention more clear, the technical scheme of the present invention is further described below through specific implementation methods. Those skilled in the art should know that the embodiments are only to help understand the technical content and technical effects of the present invention and should not be regarded as limiting the present invention.

[0025] The present invention includes 2 embodiments and 2 comparative examples.

[0026] Embodiment 1:

[0027] Step (1): adding polyzinc silicate to glutamate fermentation waste liquid, mixing for 2 hours, centrifuging and filtering, collecting the filtrate, drying and grinding the filtrate to obtain a bacterial protein-polyzinc silicate complex; wherein 2 g of polysilicate silicate is added to every 1 L of fermentation waste liquid;

[0028] Step (2): preparing a 0.05 mol / L aqueous zinc silicate solution, adding the bacterial protein-polyzinc silicate complex prepared in step (1) thereto, wherein the ratio of the complex added to the aqueous zinc silicate solution is 50 g / L; adding citric acid, adjusting the pH value to 6.0, stirring and reacting for 1 hour, adding hydroxyapatite 3 times the mass of the complex, supplementing citric acid, continuing to adjust the pH value to 6.0, continuing to stir and react for 1 hour, and centrifuging to obtain amino acid composite hydroxyapatite particles;

[0029] Step (3): adding urea, humic acid and dipotassium hydrogen phosphate to prepare a urea-humic acid-dipotassium hydrogen phosphate complex; the specific preparation steps are: adding 1 part by mass of urea and 2 parts by mass of water into a stirrer, heating to 30° C., stirring evenly, then adding humic acid and dipotassium hydrogen phosphate, raising the temperature to 80° C. for stirring reaction, and obtaining a urea-humic acid-dipotassium hydrogen phosphate complex; wherein the weight ratio of humic acid to urea is 1:6; the weight ratio of dipotassium hydrogen phosphate to urea is 1:8.

[0030] Step (4): Spray 1L of urea-humic acid-dipotassium hydrogen phosphate complex onto 4Kg of amino acid composite hydroxyapatite particles, stir evenly, and dry at 40°C to obtain ecological fertilizer.

[0031] Embodiment 2:

[0032] Step (1): adding polyzinc silicate to glutamate fermentation waste liquid, mixing for 2 hours, centrifuging and filtering, collecting the filtrate, drying and grinding the filtrate to obtain a bacterial protein-polyzinc silicate complex; wherein 2.5 g of polysilicate silicate is added to every 1 L of fermentation waste liquid;

[0033] Step (2): preparing a 0.05 mol / L aqueous zinc silicate solution, adding the bacterial protein-polyzinc silicate complex prepared in step (1) thereto, wherein the ratio of the complex added to the aqueous zinc silicate solution is 80 g / L; adding citric acid, adjusting the pH value to 7.0, stirring and reacting for 1 hour, adding hydroxyapatite 3 times the mass of the complex, supplementing citric acid, continuing to adjust the pH value to 7.0, continuing to stir and react for 1 hour, and centrifuging to obtain amino acid composite hydroxyapatite particles;

[0034] Step (3): adding urea, humic acid and dipotassium hydrogen phosphate to prepare a urea-humic acid-dipotassium hydrogen phosphate complex; the specific preparation steps are: adding 1 part by mass of urea and 2 parts by mass of water into a stirrer, heating to 30° C., stirring evenly, then adding humic acid and dipotassium hydrogen phosphate, raising the temperature to 80° C. for stirring reaction, and obtaining a urea-humic acid-dipotassium hydrogen phosphate complex; wherein the weight ratio of humic acid to urea is 1:6; the weight ratio of dipotassium hydrogen phosphate to urea is 1:8.

[0035] Step (4): Spray 1L of urea-humic acid-dipotassium hydrogen phosphate complex onto 4Kg of amino acid composite hydroxyapatite particles, stir evenly, and dry at 50°C to obtain ecological fertilizer.

[0036] Comparative Example 1:

[0037] Step (1): centrifugally filter the glutamate fermentation waste liquid, collect the filtrate, dry and grind the filtrate to obtain bacterial protein.

[0038] Step (2): prepare a 0.05 mol / L zinc silicate aqueous solution, add the bacterial protein prepared in step (1) thereto, wherein the ratio of the bacterial protein added to the zinc silicate aqueous solution is 50 g / L; add citric acid, adjust the pH value to 6.0, stir and react for 1 hour, add hydroxyapatite 3 times the mass of the complex, supplement citric acid, continue to adjust the pH value to 6.0, continue to stir and react for 1 hour, and then centrifuge to obtain amino acid composite hydroxyapatite particles.

[0039] Step (3): adding urea, humic acid and dipotassium hydrogen phosphate to prepare a urea-humic acid-dipotassium hydrogen phosphate complex; the specific preparation steps are: adding 1 part by mass of urea and 2 parts by mass of water into a stirrer, heating to 30° C., stirring evenly, then adding humic acid and dipotassium hydrogen phosphate, raising the temperature to 80° C. for stirring reaction, and obtaining a urea-humic acid-dipotassium hydrogen phosphate complex; wherein the weight ratio of humic acid to urea is 1:6; and the weight ratio of dipotassium hydrogen phosphate to urea is 1:8.

[0040] Step (4): Spray 1L of urea-humic acid-dipotassium hydrogen phosphate complex onto 4Kg of amino acid composite hydroxyapatite particles, stir evenly, and dry at 40°C to obtain ecological fertilizer.

[0041] Comparative Example 2:

[0042] Step (1): adding polyzinc silicate to glutamate fermentation waste liquid, mixing for 2 hours, centrifuging and filtering, collecting the filtrate, drying and grinding the filtrate to obtain a bacterial protein-polyzinc silicate complex; wherein 2 g of polysilicate silicate is added to every 1 L of fermentation waste liquid;

[0043] Step (2): prepare a 0.05 mol / L zinc silicate aqueous solution, add the bacterial protein-polyzinc silicate complex prepared in step (1) thereto, and the ratio of the added complex to the zinc silicate aqueous solution is 50 g / L; add citric acid, adjust the pH value to 6.0, stir and react for 1 hour, add hydroxyapatite 3 times the mass of the complex, continue to stir and react for 1 hour, and then centrifuge and filter to obtain amino acid composite hydroxyapatite particles.

[0044] Step (3): adding urea, humic acid and potassium dihydrogen phosphate to prepare a urea-humic acid complex; the specific preparation steps are: adding 1 part by mass of urea and 2 parts by mass of water into a stirrer, heating to 30° C., stirring evenly, then adding humic acid and potassium dihydrogen phosphate, raising the temperature to 80° C. for stirring reaction, and obtaining a urea-humic acid-potassium dihydrogen phosphate complex; wherein the weight ratio of humic acid to urea is 1:6; the weight ratio of potassium dihydrogen phosphate to urea is 1:8.

[0045] Step (4): Spray 1L of urea-humic acid-potassium dihydrogen phosphate complex onto 4Kg of amino acid composite hydroxyapatite particles, stir evenly, and dry at 40°C to obtain ecological fertilizer.

[0046] Release rate determination: The intermittent extraction method recommended by the chemical industry standard for the determination of nutrient release rate of slow-release fertilizers (NY / T3040-2016) was used to determine the 24-hour release rate, 7-day release rate, 14-day release rate, 28-day release rate, and 56-day release rate of the fertilizer. Nitrogen and phosphorus were used as detection indicators to determine their release rates, which are listed in Tables 1 and 2.

[0047] Table 1: Nitrogen release rates of Examples and Comparative Examples

[0048] serial number 24h release rate 7-day release rate 14-day release rate 28-day release rate 56-day release rate Example 1 3.71 5.48 15.27 34.52 72.97 Example 2 4.25 5.93 16.81 37.38 78.26 Comparative Example 1 4.78 11.69 26.57 58.14 94.81 Comparative Example 2 3.96 9.82 24.36 49.86 89.27

[0049] Table 2: Phosphorus release rates of Examples and Comparative Examples

[0050] serial number 24h release rate 7-day release rate 14-day release rate 28-day release rate 56-day release rate Example 1 6.57 13.24 25.71 42.56 60.95 Example 2 6.29 13.59 26.15 44.19 59.64 Comparative Example 1 6.18 12.95 25.90 43.07 58.71 Comparative Example 2 7.94 17.83 34.15 52.74 69.53

[0051] From the comparison of the nitrogen release rates of the embodiment in Table 1 and the comparative example 1, it can be seen that by adding zinc polysilicate to the fermentation waste liquid, the extraction efficiency of bacterial protein can be effectively improved, and a good sustained release effect can be achieved. From the comparison of the nitrogen release rates of the embodiment in Table 1 and the comparative example 2, it can be seen that by treating hydroxyapatite with citric acid, amino acids can be better combined with hydroxyapatite, so that the nitrogen element has a good sustained release effect.

[0052] From the comparison of the phosphorus release rates of Example 2 and Comparative Example 2, it can be seen that by treating hydroxyapatite with citric acid, the amino acid can be better combined with hydroxyapatite, so that the phosphorus element in hydroxyapatite has a better sustained release effect. At the same time, compared with potassium dihydrogen phosphate and urea, dipotassium hydrogen phosphate has a better complexing effect with urea, so that the phosphorus element of dipotassium hydrogen phosphate has a good sustained release effect.

[0053] The performance test of the compound fertilizer of the present invention is carried out by taking Chinese cabbage as an example. Four test cases (1)-(4) are set, and 10 pots are set in each group. The design principle is as follows: the soil is all local brown soil; the following fertilizers are applied as base fertilizer before planting cabbage, and all 40 pots of cabbage are randomly arranged.

[0054] (1) Ecological fertilizer prepared in Example 1: 20 g per pot;

[0055] (2) Ecological fertilizer prepared in Comparative Example 1: 20 g per pot;

[0056] (3) Ecological fertilizer prepared in Comparative Example 2: 20 g per pot;

[0057] (4) Control group: no fertilizer was applied.

[0058] The relevant results were measured 90 days after planting, and the average of each group was taken, as shown in Table 3.

[0059] Table 3: Test case results

[0060] Test Case Ball height / cm Ball weight / KG Number of leaves / piece Net material rate / % (1) 48.9 4.71 57.3 86.5 (2) 44.2 4.34 54.2 81.4 (3) 42.7 4.29 51.9 80.7 (4) 40.3 3.68 44.8 73.6

[0061] It can be seen from Table 3 that the cabbage head height, head weight, number of head leaves and net material rate of the cabbage treated with the ecological fertilizer prepared in the embodiment of the present invention are significantly improved compared with the cabbage treated with the compound fertilizer of Comparative Examples 1-2. This is mainly due to the obvious slow-release effect of the ecological fertilizer of the present invention on important elements such as nitrogen and phosphorus, which has a significant promoting effect on the growth of Chinese cabbage.

[0062] It should be noted that the present application is not limited to the above-mentioned embodiments. The above-mentioned embodiments are only examples, and the embodiments having the same structure as the technical idea and exerting the same effect within the scope of the technical solution of the present application are all included in the technical scope of the present application. In addition, without departing from the scope of the main purpose of the present application, various modifications that can be thought of by those skilled in the art to the embodiments and other methods of combining some of the constituent elements in the embodiments are also included in the scope of the present application.

Claims

1. A method for preparing a water-glutamic acid bacterial protein ecological fertilizer, characterized in that: The method comprises the following preparation steps: Step (1): adding polyzinc silicate to glutamate fermentation waste liquid, mixing for 1-2 hours, centrifuging and filtering, collecting the filtrate, drying and grinding the filtrate to obtain a bacterial protein-polyzinc silicate complex; Step (2): preparing a zinc silicate aqueous solution, adding the bacterial protein-zinc polysilicate complex prepared in step (1) thereto; adding citric acid, adjusting the pH value to 6.0-7.0, stirring and reacting for 1-2 hours, adding hydroxyapatite and biomass charcoal composite, and supplementing citric acid at the same time, continuing to adjust the pH value to 6.0-7.0, continuing to stir and react for 1-2 hours, and centrifuging to obtain amino acid composite hydroxyapatite particles; Step (3): preparing a urea-humic acid-dipotassium hydrogen phosphate complex; Step (4): Spray the urea-humic acid-dipotassium hydrogen phosphate complex onto the amino acid composite hydroxyapatite particles, stir evenly, and dry at 40-60° C. to obtain ecological fertilizer.

2. The preparation method according to claim 1, characterized in that: The ratio of the amount of zinc polysilicate added in step (1) to the waste liquid is 1.5-3 g / 1L.

3. The preparation method according to claim 1, characterized in that: The concentration of the zinc silicate aqueous solution prepared in step (2) is 0.03-0.1 mol / L, and the ratio of the added amount of the complex to the zinc silicate aqueous solution is 30-100 g / L.

4. The preparation method according to claim 1, characterized in that: The amount of hydroxyapatite added in step (2) is 2-4 times that of the complex.

5. The preparation method according to claim 1, characterized in that: The specific preparation steps of the urea-humic acid-dipotassium hydrogen phosphate complex in step (3) are as follows: urea and water are added to a stirrer in a weight ratio of 1:(2-3), the temperature is raised to 30-35° C., and the mixture is stirred evenly; then humic acid and dipotassium hydrogen phosphate are added, the temperature is raised to 70-90° C., and the mixture is stirred for reaction to obtain the urea-humic acid-dipotassium hydrogen phosphate complex.

6. The preparation method according to claim 5, characterized in that: The weight ratio of humic acid to urea is 1:(5-7); the weight ratio of dipotassium hydrogen phosphate to urea is 1:(6-10).

7. The preparation method according to claim 1, characterized in that: In step (4), the mass ratio of the urea-humic acid-potassium dihydrogen phosphate complex to the amino acid chelate particles is 1L:(3-5)kg.