CN113735394A

CN113735394A - Preparation method of blue algae mud amino acid, product and application thereof

Info

Publication number: CN113735394A
Application number: CN202111097306.XA
Authority: CN
Inventors: 韩士群; 陈丙法; 巫佳杰
Original assignee: Jiangsu Academy of Agricultural Sciences
Current assignee: Jiangsu Academy of Agricultural Sciences
Priority date: 2021-09-18
Filing date: 2021-09-18
Publication date: 2021-12-03

Abstract

The invention discloses a preparation method of blue algae mud amino acid, a product and application thereof, and belongs to the technical field of algae mud treatment. The preparation method comprises the following steps: uniformly mixing the cyanobacteria mud, the animal protein, the ammonium salt, the phosphate, the potassium salt, the ferric salt, the zinc salt and the manganese salt with water, performing diaphragm filter pressing and dehydration, continuously using extruded water in the diaphragm filter pressing process as added water to perform diaphragm filter pressing, and circulating the process; filter pressing by a diaphragm to obtain a filter cake, and performing microwave acidolysis on the filter cake to obtain the cyanobacteria mud amino acid. The invention adopts a microwave acidolysis mode and reasonably designs an acidolysis formula, and utilizes the difficult-to-treat algae mud as a main protein resource library to produce amino acid, thereby realizing high-value resource utilization of the algae mud.

Description

Preparation method of blue algae mud amino acid, product and application thereof

Technical Field

The invention relates to the technical field of algae mud treatment, and particularly relates to a preparation method of blue algae mud amino acid, a product and application thereof.

Background

The blue algae fishing is an optimal way for emergently treating the blue algae bloom in the eutrophic lake and preventing the water quality from becoming odorous, and the product of the blue algae after the separation of the blue algae from the algae is algae mud. The algae mud brings great difficulty to harmless treatment and resource utilization due to high water content (about 90 percent) and algae toxin.

The blue algae is determined to be difficult to dewater by biological characteristics such as small particles, intracellular water and the like, and physicochemical characteristics such as high organic matter, large viscosity coefficient, low porosity and the like of the algae mud. Some discussion has also been made in the art regarding the dehydration of cyanobacteria or algal slimes: at present, the common method adopts flocculating agents such as polyaluminium chloride, ferric chloride, polyacrylamide and the like, and then utilizes equipment such as filter pressing and the like for dehydration, and the flocculating agents seriously influence resource utilization; some methods firstly adjust the blue algae to be acidic, then utilize oxidants such as hydrogen peroxide and the like to treat, and then carry out microwave radiation and filter pressing treatment. Although the method can effectively reduce the water content, a large amount of hydrochloric acid or sulfuric acid and a large amount of oxidant are required to be added, and the method is not suitable for large-scale treatment and utilization of blue algae; and a method of adding flocculating agents such as quicklime and the like and assisting conditioning agents such as sawdust and the like for filter pressing is also adopted, wherein the flocculating agents are up to 30 percent, and obviously the resource utilization is also influenced.

At present, regardless of a resource utilization mode or a harmless disposal mode, the technical route needs to further dehydrate algae mud (with water content of about 90%) obtained after algae-laden water separation to 50% -60%, and the existing deep dehydration of the algae mud needs to add a large amount of flocculating agents, so that the resource utilization is seriously influenced. The existing blue algae resource utilization approaches mainly comprise biogas production, organic fertilizer production, drying incineration, degradable biological plastics and the like. The technology for producing methane and organic fertilizer by using blue algae which can be treated in large scale has low added value of products and is not widely applied. Therefore, a new technology for dewatering the algae mud is explored, and a high-value resource utilization technology and a product of the algae mud are researched and developed, so that the facility construction cost and the operation cost are reduced, the economic benefit of the resource utilization of the algae mud is improved, and the algae mud treatment is guided to develop towards the industrialization direction, and the method is very urgent.

Disclosure of Invention

The invention aims to provide a preparation method of blue algae mud amino acid, a product and application thereof, and develops a novel process method for preparing amino acid by taking blue algae mud rich in protein as a raw material, thereby realizing high-value resource utilization of the algae mud.

In order to achieve the purpose, the invention provides the following technical scheme:

one of the technical schemes of the invention is as follows: the preparation method of the cyanobacteria mud amino acid comprises the following steps:

uniformly mixing the cyanobacteria mud, the animal protein, the ammonium salt, the phosphate, the potassium salt, the ferric salt, the zinc salt and the manganese salt with water, performing diaphragm filter pressing and dehydration, continuously using extruded water in the diaphragm filter pressing process as added water to perform diaphragm filter pressing, and circulating the process; filter pressing is carried out by a diaphragm to obtain a filter cake, and the filter cake is subjected to microwave acidolysis to obtain amino acid;

the blue algae mud, the animal protein, the ammonium salt, the phosphate, the potassium salt and the water are as follows in parts by mass: 80-100 parts of cyanobacteria mud, 5-20 parts of animal protein, 3-8 parts of ammonium salt, 3-5 parts of phosphate, 1-5 parts of potassium salt, 1-2 parts of ferric salt, 0.5-0.8 part of zinc salt, 0.2-0.3 part of manganese salt and 20-25 parts of water.

The salt added in the invention can promote deep dehydration of the cyanobacteria mud in the early stage of filter pressing process and can catalyze the acidolysis of protein in the later stage.

Preferably, the source of the animal protein is animal hair; the ammonium salt is ammonium chloride and/or ammonium sulfate; the phosphate is calcium phosphate and/or calcium superphosphate; the potassium salt is potassium sulfate and/or potassium chloride; the ferric salt is ferric chloride and/or ferric sulfate; the zinc salt is zinc chloride and/or zinc sulfate; the manganese salt is manganese chloride and/or manganese sulfate.

Preferably, the aperture of the filter membrane used for filter pressing of the diaphragm is 0.1-0.3 μm.

Preferably, the circulation is terminated when the pressure filtration is cycled until the dry matter content in the extrusion water is > 10%.

Preferably, the water content of the filter cake is 50-60%.

Preferably, the microwave power of the filter cake for microwave acidolysis is 350-500W, the time is 0.5-4.5 h, the acid used is a hydrochloric acid solution, the concentration of the hydrochloric acid solution is 4-5 mol/L, and the mass-to-volume ratio of the filter cake to the hydrochloric acid solution is 1g (4-20) mL.

The second technical scheme of the invention is as follows: provides the cyanobacteria mud amino acid prepared by the preparation method of the cyanobacteria mud amino acid.

The third technical scheme of the invention provides an application of the cyanobacteria mud amino acid in a feed additive.

The fourth technical scheme of the invention provides a cyanobacteria mud amino acid foliar fertilizer, which comprises the following preparation steps: and (3) performing acidolysis on the extruded water obtained after the diaphragm is subjected to filter pressing to obtain the cyanobacteria mud amino acid foliar fertilizer.

The invention has the following beneficial technical effects:

the blue algae mud is rich in protein and is a good raw material for producing amino acid.

Compared with the traditional acidolysis method, the microwave acidolysis method provided by the invention can greatly reduce the acidolysis time, and the residual quantity of the amino acid phycotoxin and the heavy metal content obtained by acidolysis are extremely low, and meanwhile, the adverse effect on organisms is avoided.

In addition, the extruded water obtained in the preparation process of the cyanobacteria mud amino acid can be used as a direct raw material for preparing the amino acid foliar fertilizer, and the prepared amino acid foliar fertilizer has obvious yield increase effect.

Detailed Description

Reference will now be made in detail to various exemplary embodiments of the invention, the detailed description should not be construed as limiting the invention but as a more detailed description of certain aspects, features and embodiments of the invention. It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

Further, for numerical ranges in this disclosure, it is understood that each intervening value, between the upper and lower limit of that range, is also specifically disclosed. Every smaller range between any stated value or intervening value in a stated range and any other stated or intervening value in a stated range is encompassed within the invention. The upper and lower limits of these smaller ranges may independently be included or excluded in the range.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention.

As used herein, the terms "comprising," "including," "having," "containing," and the like are open-ended terms that mean including, but not limited to.

Example 1

Blue algae mud amino acid is prepared by taking blue algae mud as a main raw material:

taking 8kg of lake Taihu blue algae mud, 2kg of crushed poultry feather and pig hair, 300g of ammonium chloride, 500g of calcium phosphate and 500g of potassium sulfate, adding 2kg of water, stirring for 20 minutes, adding the mixture into a diaphragm plate and frame type filter press for filter pressing (with the aperture of a filter membrane being 0.2 mu m), pressing until the water content of a filter cake is 50-60%, using extruded water as added water for filter pressing again until the content of dry substances in the extruded water is more than 10%, and stopping the filter pressing to obtain the extruded water and the filter cake which are rich in protein, nitrogen, phosphorus, potassium and other nutrient substances.

Adding 1kg of the obtained filter cake into a reaction kettle, adding 10L of 5mol/L hydrochloric acid solution, stirring uniformly, carrying out acidolysis under 350W of microwave power, and determining the acidolysis condition of the cyanobacteria mud at different times by using an automatic amino acid analyzer, wherein the results are shown in Table 1.

The reaction kettle used for microwave acidolysis is an enamel reaction kettle, and microwaves are introduced into the reaction kettle through a conduit, because the conventional metal reaction kettle can shield the microwaves but cannot resist hydrochloric acid, and the cost is greatly increased if a polytetrafluoroethylene coating is used; the reaction kettle made of non-metallic materials can transmit microwaves, but is heat-resistant and pressure-resistant, so that the acid-resistant enamel reaction kettle is adopted in the invention.

TABLE 1 amino acid content (g/100g) of the cake acidolysis product at different times

Acidolysis time (h)	0.5	1	1.5	2	2.5	3	3.5	4	4.5
										Lysine Lys	2.45	2.68	2.74	2.85	3.02	2.99	2.96	2.84	2.74
Methionine Met	0.86	0.87	0.87	0.95	0.99	0.98	0.92	0.87	0.88
										Valine Val	2.01	2.38	2.60	2.79	3.12	2.96	3.12	3.16	3.14
Phenylalanine Phe	1.63	1.76	1.75	1.90	2.02	1.96	1.99	1.90	1.87
										Leucine Leu	3.78	4.14	4.38	4.58	5.00	4.84	4.85	4.78	4.55
Isoleucine lle	1.42	1.71	1.91	2.12	2.50	2.49	2.51	2.61	2.63
										Thr threonine	2.49	2.77	2.92	2.95	3.12	3.09	3.00	2.89	2.75
Arginine Arg	2.59	2.87	3.03	3.14	3.27	3.33	3.32	3.25	3.09
										Glycine Gly	2.51	2.61	2.69	2.74	2.96	2.85	2.78	2.74	2.61
Tyrosine Tyr	2.06	2.2	2.29	2.33	2.53	2.43	2.42	2.37	2.21
										Histidine His	0.59	0.64	0.65	0.70	0.73	0.71	0.72	0.69	0.67
Cysteine Cys	0.61	0.62	0.78	0.84	0.99	0.91	0.92	0.90	0.89
										Aspartic acid Asp	4.66	4.86	4.91	5.07	4.98	5.00	5.01	4.59	4.52
Glutamic acid Glu	5.79	6.34	6.64	6.77	6.82	6.77	6.76	6.44	6.38
										Serine Ser	2.86	3.03	3.10	3.13	3.24	3.21	3.09	2.94	2.86
Alanine Ala	4.40	4.64	4.71	4.83	5.07	5.01	4.87	4.73	4.53
										Proline Pro	1.90	2.01	2.09	2.11	2.27	2.19	2.10	2.06	1.95
Total essential amino acids	23.0	25.25	26.61	27.89	30.25	29.54	29.51	29.00	28.03
										Total amino acids	42.61	46.13	48.06	49.80	52.63	51.72	51.34	49.76	48.27

As can be seen from Table 1, by adopting the technical scheme of the invention, the acidolysis rate reaches the highest within 2.5h, and compared with the traditional acidolysis method which takes about 20h, the acidolysis efficiency is greatly improved.

Example 2

taking 8kg of lake Taihu blue algae mud, 1.8kg of crushed poultry feather and pig hair, 300g of ammonium chloride, 500g of calcium phosphate and 500g of potassium sulfate, adding 2kg of water, stirring for 20 minutes, adding the mixture into a diaphragm plate and frame type filter press for filter pressing (with the aperture of a filter membrane being 0.2 mu m), pressing until the water content of a filter cake is 50-60%, using extrusion water as added water for filter pressing again until the content of dry substances in the extrusion water is more than 10%, and stopping the filter pressing to obtain the extrusion water and the filter cake which are rich in protein, nitrogen, phosphorus, potassium and other nutrient substances.

Adding 1kg of the obtained filter cake into a reaction kettle, adding 4.5mol/L hydrochloric acid solutions with different volumes, stirring uniformly, carrying out acidolysis for 1.5h under 350W of microwave power, and measuring the amino acid content of acidolysis products of the filter cake with different acid-material ratios by using an amino acid automatic analyzer, wherein the results are shown in Table 2.

TABLE 2 amino acid content (g/100g) of filter cake acidolysis products for different acid-to-feed ratios

As can be seen from Table 2, the total amount of amino acids, the content of lysine, arginine, threonine and the degree of acid hydrolysis tended to increase first and then decrease with increasing acid-to-feed ratio, and the total amount of amino acids, threonine and the degree of acid hydrolysis reached maximum values at 12:1, which were 47.53g/100g, 2.89g/100g and 79.94% respectively. The content of lysine and arginine reaches the maximum value at 14:1, and respectively reaches 2.44g/100g and 3.39g/100 g. When the acid-material ratio is more than 4:1, the content of the methionine is basically unchanged and is maintained at about 0.80g/100 g.

Example 3

taking 10kg of lake Taihu blue algae mud, 0.5kg of crushed poultry feather and pig hair, 500g of ammonium chloride, 400g of calcium phosphate and 300g of potassium sulfate, adding 2.5kg of water, stirring for 20 minutes, adding the mixture into a diaphragm plate-and-frame filter press for filter pressing (with the aperture of a filter membrane being 0.2 mu m), pressing until the water content of a filter cake is 50-60%, using extrusion water as the added water for filter pressing again until the content of dry substances in the extrusion water is more than 10%, and stopping the filter pressing to obtain the extrusion water and the filter cake which are rich in nutrients such as protein, nitrogen, phosphorus, potassium and the like.

Adding 1kg of the obtained filter cake into a reaction kettle, adding 10L of 4mol/L hydrochloric acid solution, stirring uniformly, carrying out acidolysis under 500W of microwave power for 2.5h, and measuring the total amino acid content of the microwave acidolysis to be 52.63g/100 g.

Example 4

taking 9kg of lake Taihu blue algae mud, 1kg of crushed poultry feather and pig hair, 800g of ammonium chloride, 300g of calcium phosphate and 100g of potassium sulfate, adding 2kg of water, stirring for 30 minutes, adding the mixture into a diaphragm plate and frame type filter press for filter pressing (with the aperture of a filter membrane being 0.2 mu m), pressing until the water content of a filter cake is 50-60%, using extruded water as added water for filter pressing again until the content of dry substances in the extruded water is more than 10%, and stopping the filter pressing to obtain the extruded water and the filter cake which are rich in protein, nitrogen, phosphorus, potassium and other nutrient substances.

Adding 1kg of the obtained filter cake into a reaction kettle, adding 10L of 4.5mol/L hydrochloric acid solution, stirring uniformly, carrying out acidolysis under the microwave power of 400W, wherein the acidolysis time is 2.5h, and the total amino acid content obtained by microwave acidolysis is 52.66g/100 g.

Security evaluation

(1) Algal toxin content of microwave acidolysis product

It was found that the content of microcystin-RR (MC-RR) and microcystin-RR (MC-LR) in the Taihu blue algae sludge before the acid hydrolysis in example 1 was 50810. mu.g/kg and 32300. mu.g/kg, respectively. The micro-capsule algae toxin can be strongly degraded by microwave acidolysis, and the longer the acidolysis time is, the lower the residual quantity of the algae toxin is. When the acidolysis is carried out for 2 hours, the MC-RR and MC-LR are respectively 0.90 mug/kg and 0.94 mug/kg, the removal rate reaches 99.99 percent, and the MC-RR and MC-LR contents in different acidolysis times are shown in a table 3.

TABLE 3 content of microcystins in the microwave acidolysis products at different acidolysis times

Acidolysis time (h)	0	0.5	1	1.5	2	2.5	3
								MC-RR(μg/kg)	50810	3.45	1.33	0.98	0.90	0.90	0.88
MC-LR(μg/kg)	32300	2.89	1.99	1.0	0.94	0.88	0.83

(2) Heavy metal content of microwave acidolysis product

The contents of heavy metals As, Pb, Hg and Cr in the microwave acid hydrolysis product of example 1, which had an acid hydrolysis time of 2.5 hours, were measured and compared with the national feed hygiene standards, and the results are shown in Table 4.

TABLE 4

(3) The effect of the microwave acid hydrolysis product of example 1, which had an acid hydrolysis time of 2.5h, on the micronucleus occurrence rate and PCE/RBC ratio of mouse bone marrow cells was determined, wherein the negative control was sterile water and the positive control was cyclophosphamide (at a dose of 40mg/kg · bw), and the results of the determination are shown in Table 5.

TABLE 5

Note: "x" compared to negative control P < 0.01; the micronucleus rate (‰) of the pleochromocyte is equal to the number of the pleochromocyte containing micronucleus/the total number of the pleochromocyte multiplied by 100.

As can be seen from Table 5, the micronucleus rates of normal mature erythrocytes of the blue algae mud microwave acidolysis products of the dosage groups are not significantly different from those of the negative control group (P >0.05), and the dosage groups do not show a good dosage-response relationship (P > 0.05). The difference of micronucleus rates of female and male is not significant under the same dosage (P > 0.05). The results show that the micro-nucleation forming rate of mouse marrow pleochromocyte is not obviously increased by the blue algae mud microwave acidolysis product under the tested concentration. The micronucleus test result shows negative, namely the microwave acidolysis product of the blue algae mud does not have influence on the formation of mouse marrow pleochromocyte micronucleus and the PCE/RBC ratio.

(4) Teratogenicity of the microwave acid hydrolysis product with 2.5h acid hydrolysis time on the mouse sperm in example 1 was determined, wherein the negative control was sterile water, the positive control was cyclophosphamide (dose 40mg/kg · bw), and the results of the determination are shown in table 6.

TABLE 6

Note: in table 6, the same lower case letters represent no significant difference, the different lower case letters represent significant difference, and the different upper case letters represent significant difference. The number of detected sperms is 5000.

As can be seen from Table 6, the results of feeding mice with various doses of cyanobacteria mud microwave acidolysis products show that the difference between the sperm teratogenesis rates of the mice of different dose groups and the negative control is not significant, and the difference between the sperm teratogenesis rates of the mice and the cyclophosphamide group reaches a very significant level, which indicates that the cyanobacteria acidolysis products have no teratogenic influence on the sperm of the mice. In the mouse sperms of 3 dose groups, the proportion of various malformation types is very close to that of the negative control, and the amorphous type and the unhooked type account for most of the proportion; but is much different from cyclophosphamide. The total sperm aberration rate of each dose group is not significantly different from that of a negative control group (P is more than 0.05); the dosage of blue algae mud microwave acidolysis products is increased, and the difference of the total sperm abnormal rate among dosage groups is not significant (P > 0.05); the sperm aberration rate of the positive control group is very significant (P <0.01) compared with the sperm aberration rate of each dose group and the sperm aberration rate of the negative control group. The result of the teratospermia test shows that the result is negative, which indicates that the microwave acidolysis product of the cyanobacteria mud does not influence the sperm teratospermia rate of the mice.

Example 5

The preparation method of the cyanobacteria mud amino acid foliar fertilizer comprises the following steps:

using the extruded water rich in nutrients such as protein, nitrogen, phosphorus, potassium and the like in the example 1 as a raw material, carrying out acidolysis by using a 5mol/L hydrochloric acid solution, and adjusting the content of amino acid in the acidolysis solution to be more than or equal to 10.0% by using water; the total amount of microelements such as iron, manganese, copper, zinc and the like is more than or equal to 2.0 percent; water insoluble matter is less than or equal to 5.0 percent; the pH value is more than or equal to 3.0; and preparing the cyanobacteria mud amino acid foliar fertilizer.

The yield increasing effect of the cyanobacteria mud amino acid foliar fertilizer prepared in the example 5 is considered: the cyanobacteria mud amino acid foliar fertilizer prepared in example 5 is diluted 10 times by clear water, and foliar spraying is carried out on pakchoi, compared with non-spraying and spraying of equal volume of clear water. The results show that the yield of the pakchoi per mu is increased by 95.6kg and the yield is increased by 7.3% compared with the mode that the pakchoi is not sprayed on the leaf surfaces, and the yield of the pakchoi per mu is increased by 81.9kg and the yield is increased by 6.2% compared with the mode that the pakchoi is sprayed with clear water.

The above-described embodiments are merely illustrative of the preferred embodiments of the present invention, and do not limit the scope of the present invention, and various modifications and improvements of the technical solutions of the present invention can be made by those skilled in the art without departing from the spirit of the present invention, and the technical solutions of the present invention are within the scope of the present invention defined by the claims.

Claims

1. The preparation method of the cyanobacteria mud amino acid is characterized by comprising the following steps:

uniformly mixing the cyanobacteria mud, the animal protein, the ammonium salt, the phosphate, the potassium salt, the ferric salt, the zinc salt and the manganese salt with water, performing diaphragm filter pressing and dehydration, continuously using extruded water in the diaphragm filter pressing process as added water to perform diaphragm filter pressing, and circulating the process; filter pressing is carried out by a diaphragm to obtain a filter cake, and microwave acidolysis is carried out on the filter cake to obtain the cyanobacteria mud amino acid;

the blue algae mud, the animal protein, the ammonium salt, the phosphate, the potassium salt, the ferric salt, the zinc salt, the manganese salt and the water are as follows in parts by mass: 80-100 parts of cyanobacteria mud, 5-20 parts of animal protein, 3-8 parts of ammonium salt, 3-5 parts of phosphate, 1-5 parts of potassium salt, 1-2 parts of ferric salt, 0.5-0.8 part of zinc salt, 0.2-0.3 part of manganese salt and 20-25 parts of water.

2. The method for preparing the cyanobacteria mud amino acid as claimed in claim 1, wherein the source of the animal protein is animal hair; the ammonium salt is ammonium chloride and/or ammonium sulfate; the phosphate is calcium phosphate and/or calcium superphosphate; the potassium salt is potassium sulfate and/or potassium chloride; the ferric salt is ferric chloride and/or ferric sulfate; the zinc salt is zinc chloride and/or zinc sulfate; the manganese salt is manganese chloride and/or manganese sulfate.

3. The method for preparing the cyanobacteria mud amino acid as claimed in claim 1, wherein the aperture of the filter membrane used for filter pressing of the diaphragm is 0.1-0.3 μm.

4. The method for preparing the amino acid from the cyanobacteria mud as claimed in claim 1, wherein the circulation is terminated when the content of dry substances in the extrusion water is more than 10% by circulating pressure filtration.

5. The preparation method of the cyanobacteria mud amino acid as claimed in claim 1, wherein the water content of the filter cake is 50-60%.

6. The preparation method of the cyanobacteria mud amino acid as claimed in claim 1, wherein the microwave power for performing microwave acidolysis on the filter cake is 350-500W, the time is 0.5-4.5 h, the acid used is hydrochloric acid solution, the concentration of the hydrochloric acid solution is 4-5 mol/L, and the mass-to-volume ratio of the filter cake to the hydrochloric acid solution is 1g (4-20) mL.

7. The cyanobacteria sludge amino acid prepared by the method for preparing the cyanobacteria sludge amino acid according to any one of claims 1 to 6.

8. Use of the cyanobacteria puree amino acid of claim 7 in a feed additive.

9. The cyanobacteria mud amino acid foliar fertilizer is characterized by comprising the following preparation steps: the extruded water obtained after the filter pressing of the diaphragm in the claim 1 is used as a raw material to prepare the cyanobacteria mud amino acid foliar fertilizer after acidolysis.