Enteromorpha prolifera potash fertilizer prepared from marine green algae plants

Abstract

The invention belongs to the technical field of fertilizers, and particularly relates to an enteromorpha potash fertilizer prepared from marine green algae plants. The main component rhamnose of the enteromorpha polysaccharide is of a cyclic molecular structure, substituent groups on partial carbon positions of the rhamnose can be subjected to substitution reaction with potassium hydroxide, the rhamnose is alkalized into alkalized rhamnose, and the alkalized rhamnose reacts with chloroacetic acid to obtain the potassium carboxymethyl rhamnoate. When the potassium carboxymethyl rhamnoate is used as a fertilizer, after potassium elements in the potassium carboxymethyl rhamnoate are utilized by plants, the potassium carboxymethyl rhamnoate forms carboxymethyl rhamnoic acid, and the carboxymethyl rhamnoic acid is high in water absorption and has a high water retention effect in soil, so that soil hardening is avoided. The enteromorpha potash fertilizer prepared by the invention not only can provide potassium element for plants, but also can enhance the immunity and disease resistance of the plants and increase the yield by the polysaccharide component of the enteromorpha.

Description

Technical Field

[0001] The invention belongs to the technical field of fertilizers, and in particular relates to a potassium fertilizer of Enteromorpha prepared by using marine green algae plants. Background Art

[0003] Potassium is one of the indispensable elements for plant growth and plays an important role in the growth and development of plants. Common potash fertilizers on the market include potassium chloride, potassium sulfate, potassium dihydrogen phosphate, etc. Long-term application can easily cause soil compaction and salinization. Using Enteromorpha to make Enteromorpha potassium fertilizer is not only rich in raw materials, natural and non-toxic, but also pollution-free to the environment and soil, and can also improve the water absorption and water retention rate of the soil. However, there is no technology for preparing potassium fertilizer using Enteromorpha in the prior art. Summary of the invention

[0004] In order to solve the problems existing in the prior art, the present invention provides a potassium fertilizer made from marine green algae to avoid soil compaction and achieve the invention purpose of high water absorption and high water retention in the soil.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions: A potassium fertilizer of Enteromorpha prepared by using marine green algae, wherein the preparation method of the potassium fertilizer of Enteromorpha comprises: S1. Purification The dried Enteromorpha was broken into 300-500 mesh, added into deionized water, heated to 100-120°C and extracted for 2-3 hours, filtered, the filtrate was concentrated under reduced pressure to obtain an extract, and added into an ethanol solution to obtain precipitate A, the precipitate A was separated and dissolved in deionized water, and Enteromorpha polysaccharide was obtained after dialysis and freeze-drying.

[0006] Preferably, the mass ratio of the dried enteromorpha to deionized water is 1:20-30.

[0007] Preferably, the mass of the extract is 50-60% of the mass of the filtrate.

[0008] Preferably, the mass ratio of the extract to the ethanol solution is 1:3-5; the mass fraction of the ethanol solution is 92-97%.

[0009] Preferably, the molecular weight of the dialysis is 3500Da; the temperature of the freeze-drying is -15 to -10°C, and the time is 12 to 18 hours.

[0010] The rhamnose content of the Enteromorpha polysaccharide is greater than 67%, and the xylose content is greater than 20%.

[0011] S2. Alkalization The enteromorpha polysaccharide is dissolved in deionized water, and then a potassium hydroxide solution is added to carry out an alkalization reaction to obtain an alkalized enteromorpha polysaccharide solution.

[0012] Preferably, the mass ratio of the enteromorpha polysaccharide to deionized water is 1:9-12.

[0013] Preferably, the amount of potassium hydroxide solution added is 11-14% of the mass of Enteromorpha polysaccharide in the potassium hydroxide solution.

[0014] Preferably, the alkalization reaction is carried out at a temperature of 40 to 50° C. and for a time of 60 to 80 minutes.

[0015] S3, etherification Chloroacetic acid is added to the alkalinized Enteromorpha polysaccharide solution to carry out etherification reaction. After the reaction is completed, anhydrous ethanol is added in portions until no more precipitate is precipitated to obtain precipitate B. The precipitate B is separated and freeze-dried to obtain Enteromorpha potassium fertilizer.

[0016] Preferably, the amount of chloroacetic acid added is 17.5-21% of the mass of Enteromorpha polysaccharide.

[0017] Preferably, the temperature of the etherification reaction is 50-65° C. and the time is 50-70 min.

[0018] Preferably, the freeze-drying temperature is -15 to -10°C and the time is 12 to 18 hours.

[0019] Rhamnose, the main component of Enteromorpha polysaccharide, has a ring-shaped molecular structure. The substituents on some carbon positions of rhamnose can undergo substitution reactions with potassium hydroxide to alkalize rhamnose into alkaline rhamnose, which then reacts with chloroacetic acid to obtain potassium carboxymethyl rhamnolate. When used as a fertilizer, after the potassium element in potassium carboxymethyl rhamnolate is used by plants, potassium carboxymethyl rhamnolate loses potassium ions to form carboxymethyl rhamnoic acid. Carboxymethyl rhamnoic acid has strong water absorption and has a high water retention effect in the soil, thereby avoiding soil compaction.

[0020] Due to the adoption of the above technical solution, the technical effects achieved by the present invention are: 1. The enteromorpha potassium fertilizer prepared by the present invention can not only provide potassium elements for plants, but also the polysaccharide components of the enteromorpha can enhance the immunity, disease resistance and yield of plants.

[0021] 2. After the potassium element in the Enteromorpha potassium fertilizer of the present invention is absorbed by the plants, the Enteromorpha potassium fertilizer that releases potassium can also enhance the water retention of the soil, avoid soil compaction, and improve the activity of the soil; at the same time, it can reduce the number of watering times during plant planting and save water resources.

[0022] 3. The Enteromorpha potassium fertilizer prepared by the present invention has a good slow-release effect on potassium, which can greatly improve the utilization rate of fertilizers, reduce the amount of fertilizers required in plant cultivation, and save costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is the reaction formula for the alkalization of rhamnose; Figure 2 is the reaction formula for the etherification of alkalized rhamnose; Figure 3 Schematic diagram of potassium carboxymethylrhamnolate losing potassium ions to form carboxymethylrhamnoic acid. DETAILED DESCRIPTION

[0024] The present invention is further described below in conjunction with specific embodiments.

[0025] Example 1: A potassium fertilizer of Enteromorpha prepared by using marine green algae, wherein the preparation method of the potassium fertilizer of Enteromorpha comprises: S1. Purification The dried Enteromorpha was broken into 400 mesh, added into deionized water, heated to 110°C and extracted for 3 hours. After filtering, the filtrate was concentrated under reduced pressure to obtain an extract, and added into an ethanol solution to obtain precipitate A. The precipitate A was separated and dissolved in deionized water, and then dialyzed and freeze-dried to obtain Enteromorpha polysaccharide.

[0026] The mass ratio of the dried enteromorpha to deionized water is 1:25.

[0027] The mass of the extract is 55% of the mass of the filtrate.

[0028] The mass ratio of the extract to the ethanol solution is 1:4; the mass fraction of the ethanol solution is 95%.

[0029] The molecular weight of the dialysis was 3500Da; the temperature of the freeze-drying was -12°C and the time was 16h.

[0030] The rhamnose in the Enteromorpha polysaccharide accounts for 70.3%, and the xylose accounts for 22.1%.

[0031] S2. Alkalization The enteromorpha polysaccharide is dissolved in deionized water, and then a potassium hydroxide solution is added to carry out an alkalization reaction to obtain an alkalized enteromorpha polysaccharide solution.

[0032] The mass ratio of the Enteromorpha polysaccharide to deionized water is 1:10.

[0033] The amount of potassium hydroxide solution added is such that the potassium hydroxide in the potassium hydroxide solution accounts for 13% of the mass of Enteromorpha polysaccharide.

[0034] The alkalization reaction was carried out at a temperature of 45° C. and for 70 minutes.

[0035] S3, etherification Chloroacetic acid is added to the alkalinized Enteromorpha polysaccharide solution to carry out etherification reaction. After the reaction is completed, anhydrous ethanol is added in portions until no more precipitate is precipitated to obtain precipitate B. The precipitate B is separated and freeze-dried to obtain Enteromorpha potassium fertilizer.

[0036] The amount of chloroacetic acid added is 19% of the mass of Enteromorpha polysaccharide.

[0037] The temperature of the etherification reaction is 60° C. and the time is 60 min.

[0038] The freeze-drying temperature is -12°C and the time is 16 hours.

[0039] Example 2: A potassium fertilizer of Enteromorpha prepared by using marine green algae, wherein the preparation method of the potassium fertilizer of Enteromorpha comprises: S1. Purification The dried Enteromorpha was broken into 500 mesh, added into deionized water, heated to 100°C and extracted for 2 hours, filtered, the filtrate was concentrated under reduced pressure to obtain an extract, and added into an ethanol solution to obtain precipitate A, which was separated and dissolved in deionized water, dialyzed and freeze-dried to obtain Enteromorpha polysaccharide.

[0040] The mass ratio of the dried enteromorpha to deionized water is 1:20.

[0041] The mass of the extract is 50% of the mass of the filtrate.

[0042] The mass ratio of the extract to the ethanol solution is 1:3; the mass fraction of the ethanol solution is 92%.

[0043] The molecular weight of the dialysis was 3500Da; the temperature of the freeze-drying was -15°C and the time was 12h.

[0044] The rhamnose in the Enteromorpha polysaccharide accounts for 67.6%, and the xylose accounts for 21.5%.

[0045] S2. Alkalization The enteromorpha polysaccharide is dissolved in deionized water, and then a potassium hydroxide solution is added to carry out an alkalization reaction to obtain an alkalized enteromorpha polysaccharide solution.

[0046] The mass ratio of the Enteromorpha polysaccharide to deionized water is 1:9.

[0047] The amount of potassium hydroxide solution added is such that the potassium hydroxide in the potassium hydroxide solution accounts for 11% of the mass of Enteromorpha polysaccharide.

[0048] The temperature of the alkalization reaction is 40° C. and the time is 60 min.

[0049] S3, etherification Chloroacetic acid is added to the alkalinized Enteromorpha polysaccharide solution to carry out etherification reaction. After the reaction is completed, anhydrous ethanol is added in portions until no more precipitate is precipitated to obtain precipitate B. The precipitate B is separated and freeze-dried to obtain Enteromorpha potassium fertilizer.

[0050] The amount of chloroacetic acid added is 17.5% of the mass of Enteromorpha polysaccharide.

[0051] The temperature of the etherification reaction is 50° C. and the time is 50 min.

[0052] The freeze-drying temperature is -15°C and the time is 12 hours.

[0053] Example 3: A potassium fertilizer of Enteromorpha prepared by using marine green algae, wherein the preparation method of the potassium fertilizer of Enteromorpha comprises: S1. Purification The dried Enteromorpha was broken into 300 mesh, added into deionized water, heated to 120°C and extracted for 2 hours. After filtering, the filtrate was concentrated under reduced pressure to obtain an extract, and added into an ethanol solution to obtain precipitate A. The precipitate A was separated and dissolved in deionized water, and Enteromorpha polysaccharide was obtained after dialysis and freeze-drying.

[0054] The mass ratio of the dried enteromorpha to deionized water is 1:30.

[0055] The mass of the extract is 60% of the mass of the filtrate.

[0056] The mass ratio of the extract to the ethanol solution is 1:5; the mass fraction of the ethanol solution is 97%.

[0057] The molecular weight of the dialysis was 3500Da; the temperature of the freeze-drying was -10°C and the time was 18h.

[0058] In the Enteromorpha polysaccharide, rhamnose accounts for 69.3% and xylose accounts for 21.3%.

[0059] S2. Alkalization The enteromorpha polysaccharide is dissolved in deionized water, and then a potassium hydroxide solution is added to carry out an alkalization reaction to obtain an alkalized enteromorpha polysaccharide solution.

[0060] The mass ratio of the Enteromorpha polysaccharide to deionized water is 1:12.

[0061] The amount of potassium hydroxide solution added is such that the potassium hydroxide in the potassium hydroxide solution accounts for 14% of the mass of Enteromorpha polysaccharide.

[0062] The temperature of the alkalization reaction is 50° C. and the time is 80 min.

[0063] S3, etherification Chloroacetic acid is added to the alkalinized Enteromorpha polysaccharide solution to carry out etherification reaction. After the reaction is completed, anhydrous ethanol is added in portions until no more precipitate is precipitated to obtain precipitate B. The precipitate B is separated and freeze-dried to obtain Enteromorpha potassium fertilizer.

[0064] The amount of chloroacetic acid added is 21% of the mass of Enteromorpha polysaccharide.

[0065] The temperature of the etherification reaction is 65° C. and the time is 70 min.

[0066] The freeze-drying temperature is -10°C and the time is 18 hours.

[0067] Example 4: A potassium fertilizer of Enteromorpha prepared by using marine green algae, wherein the preparation method of the potassium fertilizer of Enteromorpha comprises: S1. Purification The dried Enteromorpha was broken into 500 mesh, added into deionized water, heated to 100°C and extracted for 3 hours. After filtering, the filtrate was concentrated under reduced pressure to obtain an extract, and added into an ethanol solution to obtain precipitate A. The precipitate A was separated and dissolved in deionized water, and then dialyzed and freeze-dried to obtain Enteromorpha polysaccharide.

[0068] The mass ratio of the dried enteromorpha to deionized water is 1:22.

[0069] The mass of the extract is 53% of the mass of the filtrate.

[0070] The mass ratio of the extract to the ethanol solution is 1:3; the mass fraction of the ethanol solution is 93%.

[0071] The molecular weight of the dialysis was 3500Da; the temperature of the freeze-drying was -14°C and the time was 13h.

[0072] The rhamnose in the Enteromorpha polysaccharide accounts for 68.4% and the xylose accounts for 22%.

[0073] S2. Alkalization The enteromorpha polysaccharide is dissolved in deionized water, and then a potassium hydroxide solution is added to carry out an alkalization reaction to obtain an alkalized enteromorpha polysaccharide solution.

[0074] The mass ratio of the Enteromorpha polysaccharide to deionized water is 1:10.

[0075] The amount of potassium hydroxide solution added is 12% of the mass of Enteromorpha polysaccharide in the potassium hydroxide solution.

[0076] The temperature of the alkalization reaction is 40° C. and the time is 60 min.

[0077] S3, etherification Chloroacetic acid is added to the alkalinized Enteromorpha polysaccharide solution to carry out etherification reaction. After the reaction is completed, anhydrous ethanol is added in portions until no more precipitate is precipitated to obtain precipitate B. The precipitate B is separated and freeze-dried to obtain Enteromorpha potassium fertilizer.

[0078] The amount of chloroacetic acid added is 19% of the mass of Enteromorpha polysaccharide.

[0079] The temperature of the etherification reaction was 55° C. and the time was 55 min.

[0080] The freeze-drying temperature is -14°C and the time is 13 hours.

[0081] Example 5: A potassium fertilizer of Enteromorpha prepared by using marine green algae, wherein the preparation method of the potassium fertilizer of Enteromorpha comprises: S1. Purification The dried Enteromorpha was broken into 300 mesh, added into deionized water, heated to 120°C and extracted for 2.5 hours. After filtering, the filtrate was concentrated under reduced pressure to obtain an extract, and added into an ethanol solution to obtain precipitate A. The precipitate A was separated and dissolved in deionized water, and then dialyzed and freeze-dried to obtain Enteromorpha polysaccharide.

[0082] The mass ratio of the dried enteromorpha to deionized water is 1:28.

[0083] The mass of the extract is 57% of the mass of the filtrate.

[0084] The mass ratio of the extract to the ethanol solution is 1:5; the mass fraction of the ethanol solution is 96%.

[0085] The molecular weight of the dialysis was 3500Da; the temperature of the freeze-drying was -13°C and the time was 15h.

[0086] The rhamnose in the Enteromorpha polysaccharide accounts for 69.6%, and the xylose accounts for 21.7%.

[0087] S2. Alkalization The enteromorpha polysaccharide is dissolved in deionized water, and then a potassium hydroxide solution is added to carry out an alkalization reaction to obtain an alkalized enteromorpha polysaccharide solution.

[0088] The mass ratio of the Enteromorpha polysaccharide to deionized water is 1:11.

[0089] The amount of potassium hydroxide solution added is such that the potassium hydroxide in the potassium hydroxide solution accounts for 13% of the mass of Enteromorpha polysaccharide.

[0090] The alkalization reaction was carried out at a temperature of 45° C. and for 70 minutes.

[0091] S3, etherification Chloroacetic acid is added to the alkalinized Enteromorpha polysaccharide solution to carry out etherification reaction. After the reaction is completed, anhydrous ethanol is added in portions until no more precipitate is precipitated to obtain precipitate B. The precipitate B is separated and freeze-dried to obtain Enteromorpha potassium fertilizer.

[0092] The amount of chloroacetic acid added is 20% of the mass of Enteromorpha polysaccharide.

[0093] The temperature of the etherification reaction is 60° C. and the time is 65 min.

[0094] The freeze drying temperature is -13°C and the time is 15h.

[0095] The potassium enteromorpha fertilizer prepared in Examples 1-5 was mixed with urea and diammonium phosphate to form a new type of compound fertilizer, wherein the ratio of nitrogen, phosphorus and potassium was 1:1:1; commercially available potassium chloride fertilizer, urea and diammonium phosphate were mixed to form a conventional compound fertilizer, wherein the ratio of nitrogen, phosphorus and potassium was 1:1:1. The new compound fertilizer prepared by mixing the potassium enteromorpha fertilizer prepared in Examples 1-5 was applied to test fields 1-5 at an application rate of 75 kg / mu; the conventional compound fertilizer was applied to test field 6 at an application rate of 108 kg / mu. The crops planted in the test fields were cabbages, with a planting amount of 400 per test field. The area of ​​test fields 1-6 was 100 m 2 The crop maturity period is 80 days. After the crops mature, the yield, watering amount and soil compaction degree are recorded. The specific results are shown in Table 1.

[0096] Table 1 Test items Output (Kg) Watering volume (m3) Total soil porosity reduction rate (%) Soil ventilation porosity reduction rate (%) Soil bulk density increase 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 As can be seen from Table 1, the test fields applied in Examples 1-5 had high yields, less water and fertilizer, and low soil compaction, indicating that the polysaccharide components in the Enteromorpha potassium fertilizer can increase crop yields, improve soil water retention, and avoid soil compaction. At the same time, the disease phenomenon in Test Fields 1-5 was significantly less than that in Test Field 6, indicating that the polysaccharide components in the Enteromorpha potassium fertilizer can improve the disease resistance of crops.

[0097] Note: Soil total porosity reduction rate = (soil initial total porosity - soil total porosity after cycle) / soil initial total porosity × 100%; Soil ventilation porosity reduction rate = (soil initial ventilation porosity - soil total porosity after cycle) / soil initial ventilation porosity × 100%; Soil bulk density increase rate = (soil bulk density after cycle - soil initial bulk density) / soil initial bulk density × 100%.

[0098] Unless otherwise specified, the ratios and percentages described in the present invention are all weight ratios and weight percentages; and the raw materials are all commercially available.

[0099] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention is described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A potassium fertilizer prepared from marine green algae, characterized in that: The preparation method of the enteromorpha potassium fertilizer comprises purification, alkalization and etherification.

2. The enteromorpha potassium fertilizer prepared by using marine green algae according to claim 1, characterized in that: The purification process comprises the following steps: breaking the dried Enteromorpha into 300-500 meshes, adding the mixture into deionized water, heating the mixture to 100-120° C. and extracting the mixture for 2-3 hours, filtering the mixture, concentrating the filtrate under reduced pressure into an extract, and adding the extract into an ethanol solution to obtain a precipitate A, separating the precipitate A, dissolving the precipitate in deionized water, and obtaining Enteromorpha polysaccharide after dialysis and freeze-drying.

3. The enteromorpha potassium fertilizer prepared by using marine green algae according to claim 2, characterized in that: The mass ratio of the dried enteromorpha to 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 to the ethanol solution is 1:3-5; the mass fraction of the ethanol solution is 92-97%.

4. The enteromorpha potassium fertilizer prepared by using marine green algae according to claim 2, characterized in that: The molecular weight of the dialysis is 3500Da; the temperature of the freeze-drying is -15 to -10°C, and the time is 12 to 18 hours; The rhamnose content of the Enteromorpha polysaccharide is greater than 67%, and the xylose content is greater than 20%.

5. The enteromorpha potassium fertilizer prepared by using marine green algae according to claim 1, characterized in that: The alkalization step is to dissolve the Enteromorpha polysaccharide in deionized water, and then add potassium hydroxide solution to carry out an alkalization reaction to obtain an alkalized Enteromorpha polysaccharide solution.

6. The enteromorpha potassium fertilizer prepared by using marine green algae according to claim 5, characterized in that: The mass ratio of the enteromorpha polysaccharide to deionized water is 1:9-12; The amount of potassium hydroxide solution added is 11-14% of the mass of Enteromorpha polysaccharide in the potassium hydroxide solution.

7. The enteromorpha potassium fertilizer prepared by using marine green algae according to claim 5, characterized in that: The temperature of the alkalization reaction is 40-50° C. and the time is 60-80 minutes.

8. The enteromorpha potassium fertilizer prepared by using marine green algae according to claim 1, characterized in that: The etherification comprises adding chloroacetic acid to the alkaline Enteromorpha polysaccharide solution to carry out etherification reaction, adding anhydrous ethanol in portions after the reaction is completed until no more precipitate is precipitated to obtain precipitate B, separating precipitate B, and freeze-drying to obtain Enteromorpha potassium fertilizer.

9. The enteromorpha potassium fertilizer prepared by using marine green algae according to claim 8, characterized in that: The amount of chloroacetic acid added is 17.5-21% of the mass of Enteromorpha polysaccharide; The temperature of the etherification reaction is 50-65° C., and the time is 50-70 minutes.

10. The enteromorpha potassium fertilizer prepared by using marine green algae according to claim 8, characterized in that: The freeze drying temperature is -15 to -10°C and the time is 12 to 18 hours.

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