Potassium fertilizer prepared from marine green plants

Abstract

The present application belongs to the technical field of fertilizer, and particularly relates to a green algae plant prepared enteromorpha potash fertilizer. The main component of enteromorpha polysaccharide is rhamnose, which is a cyclic molecular structure. The substituent group on the partial carbon position of rhamnose can react with potassium hydroxide to alkalinize rhamnose into alkalinized rhamnose. The alkalinized rhamnose reacts with chloroacetic acid to obtain potassium carboxymethyl rhamnose. When used as a fertilizer, the potassium element in the potassium carboxymethyl rhamnose is utilized by plants, and the potassium carboxymethyl rhamnose forms carboxymethyl rhamnose acid, which has strong water absorption and high water retention in soil, thereby avoiding soil compaction. The enteromorpha potash fertilizer prepared by the present application not only provides potassium element for plants, but also enhances the immunity, disease resistance and yield of plants due to the polysaccharide component of enteromorpha.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of fertilizers, and particularly relates to a Enteromorpha potash fertilizer prepared from marine green algae. BACKGROUND

[0002] Potassium is one of the indispensable elements for plant growth and plays an important role in the growth and development of plants. Currently, common potash fertilizers on the market mainly include potassium chloride, potassium sulfate, potassium dihydrogen phosphate, etc. Long-term application of the potash fertilizers is prone to cause soil compaction and salinization. The Enteromorpha potash fertilizer prepared from Enteromorpha not only has abundant raw materials, is natural and non-toxic, but also does not pollute the environment and soil, and can improve the water absorption and water retention of soil. However, there is no technology for preparing the potash fertilizer from Enteromorpha in the prior art. SUMMARY

[0003] To solve the problems in the prior art, the present application provides an Enteromorpha potash fertilizer prepared from marine green algae, which can avoid soil compaction and achieve the purposes of high water absorption and high water retention of soil.

[0004] To solve the above technical problems, the present application adopts the following technical solutions:

[0005] An Enteromorpha potash fertilizer prepared from marine green algae, and a preparation method of the Enteromorpha potash fertilizer.

[0006] S1, purification

[0007] The dried Enteromorpha is crushed to 300-500 mesh and added to deionized water, and then heated to 100-120 DEG C for 2-3 hours of extraction. After filtration, the filtrate is concentrated under reduced pressure to obtain an extract, and then added to an ethanol solution to obtain a precipitate A. The precipitate A is separated and dissolved in deionized water, and then subjected to dialysis and freeze-drying to obtain an Enteromorpha polysaccharide.

[0008] Preferably, the mass ratio of the dried Enteromorpha to the deionized water is 1:20-30.

[0009] Preferably, the mass of the extract is 50-60% of the mass of the filtrate.

[0010] Preferably, the mass ratio of the extract to the ethanol solution is 1:3-5, and the mass fraction of the ethanol solution is 92-97%.

[0011] Preferably, the molecular weight of the dialysis is 3500 Da, and the freeze-drying temperature is-15 to-10 DEG C, and the time is 12-18 hours.

[0012] The rhamnose accounts for more than 67% in the Enteromorpha polysaccharide, and the xylose accounts for more than 20%.

[0013] S2, alkalization

[0014] The Enteromorpha polysaccharide is dissolved in deionized water, and a potassium hydroxide solution is added to perform an alkalization reaction to obtain an alkalized Enteromorpha polysaccharide solution.

[0015] Preferably, the mass ratio of the Enteromorpha polysaccharide to the deionized water is 1:9-12.

[0016] Preferably, the amount of the potassium hydroxide solution added is 11-14% of the mass of the Enteromorpha polysaccharide in the potassium hydroxide solution.

[0017] Preferably, the alkalization reaction is performed at a temperature of 40-50 DEG C for 60-80 min.

[0018] S3, etherification

[0019] The alkalized Enteromorpha polysaccharide solution is added with chloroacetic acid to perform an etherification reaction, and after the reaction is completed, anhydrous ethanol is added in batches until precipitation no longer occurs, to obtain a precipitate B, which is separated out and freeze-dried to obtain the Enteromorpha potassium fertilizer.

[0020] Preferably, the amount of the chloroacetic acid added is 17.5-21% of the mass of the Enteromorpha polysaccharide.

[0021] Preferably, the etherification reaction is performed at a temperature of 50-65 DEG C for 50-70 min.

[0022] Preferably, the freeze-drying is performed at a temperature of -15 to -10 DEG C for 12-18 h.

[0023] The main component of the Enteromorpha polysaccharide, rhamnose, is a cyclic molecular structure, and the substituents on the carbon positions of the rhamnose can undergo a substitution reaction with potassium hydroxide to alkalize the rhamnose into alkalized rhamnose, which is reacted with chloroacetic acid to obtain potassium carboxymethyl rhamnose. When used as a fertilizer, the potassium element in the potassium carboxymethyl rhamnose is utilized by plants, and the potassium carboxymethyl rhamnose loses potassium ions to form carboxymethyl rhamnose acid, which has strong water absorption and has a high water retention effect in the soil, thereby avoiding soil compaction.

[0024] Thanks to the above technical solutions, the present application achieves the following technical effects:

[0025] 1. The Enteromorpha potassium fertilizer prepared by the present application not only provides potassium elements for plants, but also enhances the immunity, disease resistance and yield of plants due to the polysaccharide component of Enteromorpha.

[0026] 2. After the potassium element in the Enteromorpha potassium fertilizer is absorbed by plants, the Enteromorpha potassium fertilizer releasing potassium can enhance the water retention of the soil, avoid soil compaction and improve the activity of the soil; at the same time, the frequency of watering during the planting of plants can be reduced, and water resources can be saved.

[0027] 3、The Enteromorpha potassium fertilizer prepared by the method has good slow-release effect on potassium elements, can greatly improve the utilization rate of the fertilizer, reduces the amount of fertilizer required in plant cultivation, and saves cost. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 is a reaction formula of rhamnose alkalization;

[0029] Figure 2 is a reaction formula of etherification of alkalized rhamnose;

[0030] Figure 3 is a schematic diagram of potassium carboxymethyl rhamnose losing potassium ions to form carboxymethyl rhamnose acid. DETAILED DESCRIPTION

[0031] The application will be further described below in combination with specific examples.

[0032] Example 1: An Enteromorpha potassium fertilizer prepared by using marine green algae plants, and a preparation method of the Enteromorpha potassium fertilizer, which comprises the following steps:

[0033] S1, purification

[0034] The dried Enteromorpha is crushed to 400 meshes, added to deionized water, heated to 110 DEG C for 3 hours of extraction, and then filtered. The filtrate is concentrated under reduced pressure to obtain an extract, and then added to an ethanol solution to obtain a precipitate A. The precipitate A is separated and dissolved in deionized water, and then subjected to dialysis and freeze-drying to obtain Enteromorpha polysaccharide.

[0035] The mass ratio of the dried Enteromorpha and the deionized water is 1:25.

[0036] The mass of the extract is 55% of the mass of the filtrate.

[0037] The mass ratio of the extract and the ethanol solution is 1:4, and the mass fraction of the ethanol solution is 95%.

[0038] The molecular weight of the dialysis is 3500 Da, the temperature of the freeze-drying is -12 DEG C, and the time is 16 hours.

[0039] The proportion of rhamnose in the Enteromorpha polysaccharide is 70.3%, and the proportion of xylose is 22.1%.

[0040] S2, alkalization

[0041] The Enteromorpha polysaccharide is dissolved in deionized water, and then a potassium hydroxide solution is added for alkalization reaction to obtain an alkalized Enteromorpha polysaccharide solution.

[0042] The mass ratio of the Enteromorpha polysaccharide and the deionized water is 1:10.

[0043] The adding amount of the potassium hydroxide solution is 13% of the mass of Enteromorpha polysaccharide in the potassium hydroxide in the potassium hydroxide solution.

[0044] The temperature of the alkalization reaction is 45°C, and the time is 70 min.

[0045] S3, etherification

[0046] The etherification reaction is performed by adding chloroacetic acid to the alkalized Enteromorpha polysaccharide solution, and after the reaction is completed, anhydrous ethanol is added in batches until the precipitation no longer separates out, to obtain a precipitate B, which is separated out, and then freeze-dried to obtain the Enteromorpha potassium fertilizer.

[0047] The adding amount of the chloroacetic acid is 19% of the mass of Enteromorpha polysaccharide.

[0048] The temperature of the etherification reaction is 60°C, and the time is 60 min.

[0049] The temperature of the freeze-drying is -12°C, and the time is 16 h.

[0050] Example 2: An Enteromorpha potassium fertilizer prepared by using a marine green alga plant, and a preparation method of the Enteromorpha potassium fertilizer, comprising:

[0051] S1, purification

[0052] The dried Enteromorpha is crushed to 500 mesh and added to deionized water, heated to 100°C for 2 h, and then filtered, and the filtrate is concentrated under reduced pressure to obtain an extract, which is added to an ethanol solution to obtain a precipitate A, which is separated out and dissolved in deionized water, dialyzed, and then freeze-dried to obtain Enteromorpha polysaccharide.

[0053] The mass ratio of the dried Enteromorpha to the deionized water is 1:20.

[0054] The mass of the extract is 50% of the mass of the filtrate.

[0055] The mass ratio of the extract to the ethanol solution is 1:3, and the mass fraction of the ethanol solution is 92%.

[0056] The molecular weight of the dialysis is 3500 Da, and the temperature of the freeze-drying is -15°C, and the time is 12 h.

[0057] The mass fraction of rhamnose in the Enteromorpha polysaccharide is 67.6%, and the mass fraction of xylose is 21.5%.

[0058] S2, alkalization

[0059] The Enteromorpha polysaccharide is dissolved in deionized water, and then a potassium hydroxide solution is added to perform an alkalization reaction, to obtain an alkalized Enteromorpha polysaccharide solution.

[0060] The mass ratio of the Enteromorpha polysaccharide to the deionized water is 1:9.

[0061] The amount of potassium hydroxide solution added is 11% of the mass of Enteromorpha polysaccharide in the potassium hydroxide solution.

[0062] The temperature of the alkalization reaction is 40°C, and the time is 60 min.

[0063] S3, etherification

[0064] Chloroacetic acid is added to the alkalized Enteromorpha polysaccharide solution for etherification reaction. After the reaction is completed, anhydrous ethanol is added in portions until the precipitation no longer separates out, obtaining a precipitate B. The precipitate B is separated out, and after freeze-drying, an Enteromorpha potassium fertilizer is obtained.

[0065] The amount of chloroacetic acid added is 17.5% of the mass of Enteromorpha polysaccharide.

[0066] The temperature of the etherification reaction is 50°C, and the time is 50 min.

[0067] The temperature of the freeze-drying is -15°C, and the time is 12 h.

[0068] Example 3: An Enteromorpha potassium fertilizer prepared from a marine green alga plant, the preparation method of the Enteromorpha potassium fertilizer comprising:

[0069] S1, purification

[0070] The dried Enteromorpha is crushed to 300 mesh and added to deionized water. The temperature is raised to 120°C for 2 h of extraction. After filtration, the filtrate is concentrated under reduced pressure to an extract, and added to an ethanol solution to obtain a precipitate A. The precipitate A is separated out and dissolved in deionized water. After dialysis, freeze-drying is performed to obtain Enteromorpha polysaccharide.

[0071] The mass ratio of the dried Enteromorpha to deionized water is 1:30.

[0072] The mass of the extract is 60% of the mass of the filtrate.

[0073] The mass ratio of the extract to the ethanol solution is 1:5; and the mass fraction of the ethanol solution is 97%.

[0074] The molecular weight of the dialysis is 3500 Da; and the temperature of the freeze-drying is -10°C, and the time is 18 h.

[0075] The mass fraction of rhamnose in the Enteromorpha polysaccharide is 69.3%, and the mass fraction of xylose is 21.3%.

[0076] S2, alkalization

[0077] Enteromorpha polysaccharide is dissolved in deionized water, and a potassium hydroxide solution is added for alkalization reaction, obtaining an alkalized Enteromorpha polysaccharide solution.

[0078] The mass ratio of the Enteromorpha polysaccharide to deionized water is 1:12.

[0079] The adding amount of the potassium hydroxide solution is 14% of the mass of the potassium hydroxide in the potassium hydroxide solution relative to the mass of the Enteromorpha polysaccharide.

[0080] The temperature of the alkalization reaction is 50 DEG C, and the time is 80 min.

[0081] S3, etherification

[0082] The etherification reaction is performed by adding chloroacetic acid to the alkalized Enteromorpha polysaccharide solution, and after the reaction is completed, anhydrous ethanol is added in batches until precipitation no longer occurs, to obtain a precipitate B, which is separated out and freeze-dried to obtain the Enteromorpha potassium fertilizer.

[0083] The adding amount of the chloroacetic acid is 21% of the mass of the Enteromorpha polysaccharide.

[0084] The temperature of the etherification reaction is 65 DEG C, and the time is 70 min.

[0085] The temperature of the freeze-drying is -10 DEG C, and the time is 18 h.

[0086] Example 4: An Enteromorpha potassium fertilizer prepared from a marine green alga, wherein the preparation method of the Enteromorpha potassium fertilizer comprises:

[0087] S1, purification

[0088] The dried Enteromorpha is crushed to 500 mesh and added to deionized water, and heated to 100 DEG C for 3 h of extraction, and after filtration, the filtrate is concentrated under reduced pressure to an extract, which is added to an ethanol solution to obtain a precipitate A, which is separated out and dissolved in deionized water, and after dialysis and freeze-drying, the Enteromorpha polysaccharide is obtained.

[0089] The mass ratio of the dried Enteromorpha to deionized water is 1:22.

[0090] The mass of the extract is 53% of the mass of the filtrate.

[0091] The mass ratio of the extract to the ethanol solution is 1:3, and the mass fraction of the ethanol solution is 93%.

[0092] The molecular weight of the dialysis is 3500 Da, and the temperature of the freeze-drying is -14 DEG C, and the time is 13 h.

[0093] The mass fraction of rhamnose in the Enteromorpha polysaccharide is 68.4%, and the mass fraction of xylose is 22%.

[0094] S2, alkalization

[0095] The Enteromorpha polysaccharide is dissolved in deionized water, and a potassium hydroxide solution is added to perform an alkalization reaction, to obtain an alkalized Enteromorpha polysaccharide solution.

[0096] The mass ratio of the Enteromorpha polysaccharide to the deionized water is 1:10.

[0097] The adding amount of the potassium hydroxide solution is 12% of the mass of the Enteromorpha polysaccharide in the potassium hydroxide solution.

[0098] The temperature of the alkalization reaction is 40℃, and the time is 60 min.

[0099] S3, etherification

[0100] The etherification reaction is performed by adding chloroacetic acid to the alkalized Enteromorpha polysaccharide solution, and after the reaction is completed, anhydrous ethanol is added in batches until precipitation no longer occurs, to obtain a precipitate B, which is separated out and freeze-dried to obtain the Enteromorpha potassium fertilizer.

[0101] The adding amount of the chloroacetic acid is 19% of the mass of the Enteromorpha polysaccharide.

[0102] The temperature of the etherification reaction is 55℃, and the time is 55 min.

[0103] The temperature of the freeze-drying is -14℃, and the time is 13 h.

[0104] Example 5: An Enteromorpha potassium fertilizer prepared by using a marine green alga plant, wherein the preparation method of the Enteromorpha potassium fertilizer comprises:

[0105] S1, purification

[0106] The air-dried Enteromorpha is crushed to 300 mesh and added to deionized water, and heated to 120℃ for 2.5 h of extraction, and after filtration, the filtrate is concentrated under reduced pressure to an extract, and added to an ethanol solution to obtain a precipitate A, which is separated out and dissolved in deionized water, and after dialysis, freeze-drying is performed to obtain the Enteromorpha polysaccharide.

[0107] The mass ratio of the air-dried Enteromorpha to the deionized water is 1:28.

[0108] The mass of the extract is 57% of the mass of the filtrate.

[0109] The mass ratio of the extract to the ethanol solution is 1:5, and the mass fraction of the ethanol solution is 96%.

[0110] The molecular weight of the dialysis is 3500 Da, and the temperature of the freeze-drying is -13℃, and the time is 15 h.

[0111] The mass fraction of rhamnose in the Enteromorpha polysaccharide is 69.6%, and the mass fraction of xylose is 21.7%.

[0112] S2, alkalization

[0113] The Enteromorpha polysaccharide is dissolved in deionized water, and then a potassium hydroxide solution is added to perform an alkalization reaction, to obtain an alkalized Enteromorpha polysaccharide solution.

[0114] The mass ratio of the Enteromorpha polysaccharide to the deionized water is 1:11.

[0115] The potassium hydroxide solution is added in an amount of 13% of the mass of the Enteromorpha polysaccharide in the potassium hydroxide solution.

[0116] The alkalization reaction is performed at a temperature of 45℃ for 70 minutes.

[0117] S3, etherification

[0118] The alkalized Enteromorpha polysaccharide solution is added with chloroacetic acid to perform an etherification reaction, and after the reaction is completed, anhydrous ethanol is added in portions until precipitation no longer occurs, to obtain a precipitate B, which is separated out, and then freeze-dried to obtain the Enteromorpha potassium fertilizer.

[0119] The chloroacetic acid is added in an amount of 20% of the mass of the Enteromorpha polysaccharide.

[0120] The etherification reaction is performed at a temperature of 60℃ for 65 minutes.

[0121] The freeze-drying is performed at a temperature of -13℃ for 15 hours.

[0122] The Enteromorpha potassium fertilizer prepared in Examples 1-5 is mixed with urea and diammonium phosphate to form a new type of compound fertilizer, in which the proportions of nitrogen, phosphorus and potassium are 1:1:1; commercially available potassium chloride fertilizer, urea and diammonium phosphate are mixed to form a conventional compound fertilizer, in which the proportions of nitrogen, phosphorus and potassium are 1:1:1. The new type of compound fertilizer formed by mixing the Enteromorpha potassium fertilizer prepared in Examples 1-5 is applied to test fields 1-5 respectively, and the application amount is 75 Kg / mu; the conventional compound fertilizer is applied to test field 6, and the application amount is 108 Kg / mu. The crops planted in the test fields are Chinese cabbage, and the planting amount is 400 per test field, and the areas of the test fields 1-6 are all 100 m 2 , and the maturation period of the crops is 80 days. After the crops are matured, the yield, water amount and soil hardening degree are recorded, and the specific results are shown in Table 1.

[0123] Table 1

[0124] Test item Yield (Kg) Watering amount (m3) Total soil porosity reduction rate (%) Soil aeration porosity reduction rate (%) Soil bulk density improvement rate (%) Example 1 3321 90 2.4 1.5 0.08 Example 2 3204 90 4.6 3.7 0.13 Example 3 3275 90 3.9 3.1 0.1 Example 4 3253 90 3.5 3.3 0.12 Example 5 3292 90 2.9 2.8 0.1 Conventional compound fertilizer 2887 135 23 18 21

[0125] As can be seen from Table 1, the test fields applied with Examples 1-5 have high yield, low water and fertilizer consumption, and low soil hardening degree, indicating that the polysaccharide component in the Enteromorpha potassium fertilizer can improve the yield of crops and improve the water retention effect of soil, and avoid soil hardening. At the same time, the disease phenomenon of test fields 1-5 is obviously less than that of test field 6, indicating that the polysaccharide component in the Enteromorpha potassium fertilizer can improve the disease resistance of crops.

[0126] Note: soil total porosity reduction rate = (soil initial total porosity - soil total porosity after period) / soil initial total porosity x 100%;

[0127] soil aeration porosity reduction rate = (soil initial aeration porosity - soil total porosity after period) / soil initial aeration porosity x 100%;

[0128] soil bulk density improvement rate = (soil bulk density after period - soil initial bulk density) / soil initial bulk density x 100%.

[0129] Unless otherwise specified, the proportions described in the present application are mass proportions, and the percentages are mass percentages; the raw materials are commercially available.

[0130] Finally, it should be noted that the above description is only the preferred embodiments of the present application, and is not intended to limit the present application, although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacements for part of the technical features. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A kind of enteromorpha potash fertilizer prepared by marine green plants, it is characterized in that, The preparation method of the Enteromorpha potassium fertilizer comprises purification, alkalization and etherification. The purification is that the dried Enteromorpha is crushed to 300-500 meshes, added into deionized water, heated to 100-120 DEG C for 2-3 hours, filtered, and then the filtrate is concentrated under reduced pressure to obtain an extract, and the extract is added into an ethanol solution to obtain precipitate A, and the precipitate A is separated and dissolved in deionized water, dialyzed, and freeze-dried to obtain Enteromorpha polysaccharide. The alkalization is that the Enteromorpha polysaccharide is dissolved in deionized water, and a potassium hydroxide solution is added for alkalization reaction to obtain an alkalized Enteromorpha polysaccharide solution. The etherification is that chloroacetic acid is added into the alkalized Enteromorpha polysaccharide solution for etherification reaction, and then anhydrous ethanol is added in batches until no precipitate is formed, to obtain precipitate B, and the precipitate B is separated and freeze-dried to obtain the Enteromorpha potassium fertilizer.

2. The Enteromorpha potash fertilizer according to claim 1, wherein the Enteromorpha is a marine green alga. The mass ratio of the dried Enteromorpha and the deionized water is 1:20-30. ​ The mass of the extract is 50-60% of the mass of the filtrate. The mass ratio of the extract and the ethanol solution is 1:3-5, and the mass fraction of the ethanol solution is 92-97%.

3. The Enteromorpha potash fertilizer according to claim 1, wherein the Enteromorpha is a marine green alga. The molecular weight of the dialysis is 3500 Da, the freeze-drying temperature is-15 to-10 DEG C, and the freeze-drying time is 12-18 hours. The rhamnose accounts for more than 67% of the Enteromorpha polysaccharide, and the xylose accounts for more than 20%.

4. The Enteromorpha potash fertilizer according to claim 1, wherein the Enteromorpha is a marine green alga. The mass ratio of the Enteromorpha polysaccharide and the deionized water is 1:9-12. The added amount of the potassium hydroxide solution is 11-14% of the mass of the Enteromorpha polysaccharide in the potassium hydroxide solution.

5. The Enteromorpha potash fertilizer according to claim 1, wherein the Enteromorpha is a marine green alga. The alkalization reaction temperature is 40-50 DEG C, and the alkalization reaction time is 60-80 min.

6. The Enteromorpha potash fertilizer according to claim 1, wherein the Enteromorpha is a marine green alga. The added amount of the chloroacetic acid is 17.5-21% of the mass of the Enteromorpha polysaccharide. The etherification reaction temperature is 50-65 DEG C, and the etherification reaction time is 50-70 min.

7. The Enteromorpha potash fertilizer according to claim 1, wherein the Enteromorpha is a marine green alga. The freeze-drying temperature is-15 to-10 DEG C, and the freeze-drying time is 12-18 hours.

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