Biological cushion material based on microalgae, preparation method of biological cushion material and application of biological cushion material in sandy soil improvement

Abstract

The invention discloses a biological cushion material based on microalgae, a preparation method of the biological cushion material and application of the biological cushion material in sandy soil improvement, and belongs to the technical field of agricultural ecological restoration. The preparation method of the biological cushion material comprises the following steps: (1) adding a microalgae suspension into a reaction kettle, adding glycerol according to the proportion, heating to 38-42 DEG C, stirring and dissolving, adding cationic starch, and stirring and mixing uniformly; and (2) adding polyurethane into the material prepared in the step (1), uniformly stirring, then adding sodium lignin sulfonate, reacting for 10-14 minutes at a constant temperature, and filtering the mixed liquid to obtain the biological cushion material. The microalgae is prepared from chlorella sorokiniana (Chlorella sorokiniana), Anabaena sp.) and Nodulcia cf.Harveyana (Nodulcia cf.Harveyana) according to a quantity ratio of 60: 20: 20, and the microalga is prepared from chlorella sorokiniana (Chlorella sorokiniana), Anabaena sp.) and Nodulcia cf.Harveyana (Nodulcia cf.Harveyana). The concentration of microalgae in the microalgae suspension is 1 * 10 < 6 >-1 * 10 < 7 > / mL; the addition amounts of the glycerol, the cationic starch, the sodium lignin sulfonate and the polyurethane are respectively 1 to 1.5 weight percent, 2 to 3 weight percent, 0.6 to 1 weight percent and 10 to 30 weight percent. The biological cushion material is wide in application range, and can be used as a soil conditioner, a coating agent of a slow / controlled-release fertilizer and a biological crust material for desertification control.

Description

Technical Field

[0001] This invention belongs to the field of agricultural ecological restoration technology, and in particular relates to a microalgae-based biological cushion material and its preparation method, as well as its application in sandy soil improvement. Background Technology

[0002] Microalgae, as highly efficient photosynthetic organisms, possess rapid growth, high biomass accumulation, and strong environmental adaptability, and have been widely used in wastewater treatment, biofuel production, and other fields. In recent years, the application of microalgae in agriculture has also gradually attracted attention, especially in soil improvement and desertification control. However, there is currently relatively little research and patent disclosure regarding the preparation of microalgae biomass mats and their application in sandy soils.

[0003] Microalgal biofilms are biofilm structures composed of microalgal cells and their secreted extracellular polymeric substances (EPS). They can fix carbon dioxide, absorb nutrients from the soil, and improve soil structure through photosynthesis. Studies have shown that microalgal biofilms can significantly improve soil water retention and nutrient utilization, while promoting the formation of soil microbial communities. Furthermore, the metabolic products of microalgae have a biostimulatory effect, enhancing plant resilience and growth. In desertification control, artificial algal crust technology has proven to be an effective method for sandy soil improvement. By inoculating microalgae onto the sandy surface to form a stable biofilm, wind and water erosion can be effectively reduced, and soil physicochemical properties can be improved.

[0004] Sandy soils, due to their large particles, high porosity, and poor water and fertilizer retention capacity, are often considered low-fertility soils and difficult to use directly for agricultural production. Traditional sand fixation methods such as chemical sand-fixing agents, mechanical mulching, and engineering sand fixation suffer from high costs, environmental risks, or poor sustainability. Therefore, developing an efficient, environmentally friendly, and sustainable sand improvement technology is of great significance. Summary of the Invention

[0005] This invention provides a method for preparing a microalgae-based bio-mat material, comprising the following steps: (1) Add the microalgae suspension to the reactor, add glycerol according to the ratio, heat to 38~42℃, stir to dissolve, and then add cationic starch and stir to mix evenly; (2) Add polyurethane to the material obtained in step (1) and stir evenly, then add sodium lignosulfonate and react at a constant temperature for 10-14 minutes. The mixed liquid is filtered to obtain the biological mat material. The microalgae are composed of Chlorella sorokinense ( Chlorella sorokiniana ), Anabaena ( Anabaena sp. ) and Haloxylon ammodendron ( Nodularia cf. Harveyana The microalgae are composed of microalgae in a ratio of 60:20:20; the concentration of microalgae in the microalgae suspension is 1×10⁻⁶.6 1 x 10 7 1~1.5wt%, 2~3wt%, 0.6~1wt%, 10~30wt%.

[0006] In one embodiment of the present application, the temperature in step (1) is raised to 40℃.

[0007] In one embodiment of the present application, the reaction in step (2) is carried out at a constant temperature for 12 minutes.

[0008] In one embodiment of the present application, the amount of glycerol added is 1.2wt%, 1.3wt% or 1.4wt%.

[0009] In one embodiment of the present application, the amount of cationic starch added is 2.3wt%, 2.5wt% or 2.8wt%.

[0010] In one embodiment of the present application, the amount of sodium lignosulfonate added is 0.7wt%, 0.8wt% or 0.9wt%.

[0011] In one embodiment of the present application, the amount of polyurethane added is 15wt%, 20wt% or 25wt%.

[0012] The present application also provides a biological mat material prepared by the above preparation method.

[0013] The present application also provides the use of the above biological mat material in sand soil improvement, comprising the following steps: spraying the biological mat material on the surface of the sand soil at a dosage of 2 L / m2 to 5 L / m2.

[0014] Compared with the prior art, the present application has the following beneficial effects: (1) The microalgae biological mat material provided by the present application is safe and environmentally friendly, biodegradable, non-toxic and odorless, and has safety guarantee for agricultural production; (2) The microalgae biological mat material of the present application has a wide range of applications and can be used as a soil conditioner, a coating agent for slow-release fertilizers and a biological crust material for desertification control; (3) The microalgae biological mat material of the present application has obvious use effect, and contains various mineral and biological components, which can provide special nutrients required for crop growth, improve the conversion and utilization of nutrient components by crops, and improve the physical and chemical properties of soil; (4) The use method is simple and easy to operate, and is suitable for large-scale production and application. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1Figure for the detection results of the soil pH in different layers of the biological mat in Example 1.

[0016] Figure 2 Figure for the detection results of the soil ammonia nitrogen content in different layers of the biological mat in Example 1.

[0017] Figure 3 Figure for the detection results of the soil electrical conductivity in different layers of the biological mat in Example 1.

[0018] Figure 4 Figure for the detection results of the soil soluble salt content in different layers of the biological mat in Example 1.

[0019] Figure 5 Figure for the detection results of the soil available potassium content in different layers of the biological mat in Example 1.

[0020] Figure 6 Figure for the detection results of the soil available phosphorus content in different layers of the biological mat in Example 1.

[0021] Figure 7 Figure for the detection results of the soil microbial species diversity in different layers of the biological mat in Example 1.

[0022] Figure 8 Figure for the relative abundance column chart of the soil microbial diversity in different layers of the biological mat in Example 1.

[0023] Figure 9 Figure for the difference in the number of soil microbial species in different layers of the biological mat in Example 1.

[0024] Figures 7-9 In the above table, S1 corresponds to 0L / m 2 , i.e. the negative control group of only spraying water; S2, S3 and S4 correspond to the top layer, middle layer and lower layer of Example 1 respectively, 12L / m 2 ; S5, S6 and S7 correspond to the top layer, middle upper layer and middle lower layer of Example 1 respectively, 4L / m 2 . DETAILED DESCRIPTION

[0025] The cationic starch used in the following examples is a quaternary ammonium starch ether, and the microalgae are composed of Chlorella sorokiniana ( Chlorella sorokiniana ), Lyngbya sp. ( Anabaena sp. ) and Galdieria sp. ( Nodularia cf. Harveyana ) in a quantity ratio of 60:20:20.

[0026] The addition ratios of the humectants, auxiliary materials, emulsifiers and film-forming aids in the following examples are calculated based on the microalgae suspension.

[0027] Example 1 A microalgae-based biological cushion material, which is composed of: Microalgae suspension (obtained by liquid medium culture): 1×10 7 Individuals / mL, 100 parts; Humectant: glycerol, 1.5wt%; Auxiliary material: cationic starch, 3wt%; Emulsifier: sodium lignosulfonate, 1wt%; Film forming aid: polyurethane, 10wt%.

[0028] The preparation method of the biological cushion material comprises the following steps: (1) Add the microalgae suspension into the reaction kettle, add glycerol according to the proportion, heat to 40℃, stir and dissolve, then add cationic starch and stir to mix uniformly; (2) According to the proportion, add biological aids to the material prepared in step (1) and stir uniformly, add emulsifier (the emulsifier needs to be pre-dissolved with a small amount of water, the same below), and then heat for 15 minutes, then pass the mixed liquid through a filter into a finished product reaction kettle, and after cooling, perform finished product filling to obtain the functional microalgae biological cushion material.

[0029] Example 2 A microalgae-based biological cushion material, which is composed of: Microalgae suspension: 1×10 7 Individuals / mL, 150 parts; Humectant: glycerol, 1.2wt%; Auxiliary material: cationic starch, 2.5wt%; Emulsifier: sodium lignosulfonate, 0.8wt%; Film forming aid: polyurethane, 20wt%.

[0030] The preparation method of the biological cushion material comprises the following steps: (1) Add the microalgae suspension into the reaction kettle, add glycerol according to the proportion, heat to 40℃, stir and dissolve, then add cationic starch and stir to mix uniformly; (2) According to the proportion, add biological aids to the material prepared in step (1) and stir uniformly, add emulsifier, and then heat for 12 minutes, then pass the mixed liquid through a filter into a finished product reaction kettle, and after cooling, perform finished product filling to obtain the functional microalgae biological cushion material.

[0031] Example 3 A microalgae-based biological cushion material, which is composed of: Microalgae suspension: 1×10 7 Individuals / mL, 200 parts; Moisturizer: glycerol, 1wt%; Auxiliary materials: cationic starch, 2wt%; Emulsifier: sodium lignosulfonate, 0.6wt%; Film forming aid: polyurethane, 30wt%.

[0032] The preparation method of the biological cushion material comprises the following steps: (1) The microalgae suspension is added to the reaction kettle, glycerol is added according to the proportion, heated to 40℃, stirred and dissolved, and then cationic starch is added and stirred to mix uniformly; (2) According to the proportion, the biological auxiliary agent is added to the material prepared in step (1) and stirred uniformly, the emulsifier is added, and the mixture is reacted at constant temperature for 10 minutes. Then the mixed liquid is added to the finished product reaction kettle through the filter, and after cooling, the finished product is filled to obtain the functional microalgae biological cushion material.

[0033] Example 4 A microalgae-based biological cushion material, which comprises: Microalgae suspension: 1×10 7 Individuals / mL, 120 parts; Moisturizer: glycerol, 1.3wt%; Auxiliary materials: cationic starch, 2.8wt%; Emulsifier: sodium lignosulfonate, 0.9wt%; Film forming aid: polyurethane, 15wt%.

[0034] The preparation method of the biological cushion material comprises the following steps: (1) The microalgae suspension is added to the reaction kettle, glycerol is added according to the proportion, heated to 40℃, stirred and dissolved, and then cationic starch is added and stirred to mix uniformly; (2) According to the proportion, the biological auxiliary agent is added to the material prepared in step (1) and stirred uniformly, the emulsifier is added, and the mixture is reacted at constant temperature for 10 minutes. Then the mixed liquid is added to the finished product reaction kettle through the filter, and after cooling, the finished product is filled to obtain the functional microalgae biological cushion material.

[0035] Example 5 A microalgae-based biological cushion material, which comprises: Microalgae suspension: 1×10 7 Individuals / mL, 180 parts; Moisturizer: glycerol, 1.4wt%; Auxiliary materials: cationic starch, 2.3wt%; Emulsifier: sodium lignosulfonate, 0.7wt%; Film forming aid: polyurethane, 25wt%.

[0036] The preparation method of the biological cushion material comprises the following steps: (1) A microalgae suspension is added into a reaction kettle, glycerol is added according to a proportion, the temperature is raised to 40 DEG C, and stirring and dissolution are carried out, and then cationic starch is added and stirred and mixed uniformly; (2) The material prepared in step (1) is added into a biological additive according to a proportion, and stirring, emulsifier and constant temperature reaction are carried out for 14 minutes, then the mixed liquid is added into a finished product reaction kettle through a filter, and after cooling, finished product filling is carried out, so that the functional microalgae biological cushion material is obtained.

[0037] In the sand improvement application experiment of the application, the functional microalgae biological cushion material prepared according to the formula of examples 1-5 is used, and the spraying treatment is carried out at a concentration of 2 L / square meter, 3 L / square meter, 4 L / square meter and 5 L / square meter, and a negative control group with a spraying amount of 0 L / square meter is set, and the spraying amount is 2 L / square meter according to the formula of example 1. The test cycle is 2 months.

[0038] In the sand improvement experiment of the application, the microalgae biological cushion layer has a significant influence on the physical and chemical properties of the soil. Specifically, the soil pH value changes little under different treatment doses, and is maintained between 7.7 and 8.3, which shows that the microalgae biological cushion layer has a stabilizing effect on the soil acidity and alkalinity. The conductivity and soluble salt content increase with the increase of the treatment dose, especially in the top layer of soil, the conductivity reaches 0.49 ms / cm and the soluble salt content reaches 0.19 g / L under the treatment of 4 L / m 2 The treatment dose, which shows that the microalgae biological cushion layer significantly improves the soluble ion concentration in the soil. The ammonium nitrogen content in different soil layers shows a first increase and then a decrease trend, among which the top layer of soil reaches a peak value of 38.45 mg / kg under the treatment of 3 L / m 2 The treatment dose, which shows that the microalgae biological cushion layer significantly improves the soluble ion concentration in the soil. The ammonium nitrogen content in different soil layers shows a first increase and then a decrease trend, among which the top layer of soil reaches a peak value of 38.45 mg / kg under the treatment of 3 L / m 2 The treatment dose, which shows that the microalgae biological cushion layer significantly improves the soluble ion concentration in the soil. The ammonium nitrogen content in different soil layers shows a first increase and then a decrease trend, among which the top layer of soil reaches a peak value of 38.45 mg / kg under the treatment of 3 L / m 2 The treatment dose, which shows that the microalgae biological cushion layer significantly improves the soluble ion concentration in the soil. The ammonium nitrogen content in different soil layers shows a first increase and then a decrease trend, among which the top layer of soil reaches a peak value of 38.45 mg / kg under the treatment of 3 L / m 2 The treatment dose, which shows that the microalgae biological cushion layer significantly improves the soluble ion concentration in the soil. The ammonium nitrogen content in different soil layers shows a first increase and then a decrease trend, among which the top layer of soil reaches a peak value of 38.45 mg / kg under the treatment of 3 L / m 2 The treatment dose, which shows that the microalgae biological cushion layer significantly improves the soluble ion concentration in the soil. The ammonium nitrogen content in different soil layers shows a first increase and then a decrease trend, among which the top layer of soil reaches a peak value of 38.45 mg / kg under the treatment of 3 L / m 2The processing time was 6.03 mg / kg. These results show that the microalgae biological mat can effectively regulate the nutrient content and ion concentration in the soil, but excessive dosage may lead to the loss or fixation of certain nutrients, affecting their effectiveness. Figures 1-6 The detection results of the biological mat prepared in Example 1.

[0039] In the sand improvement experiment of the present application, the microalgae biological mat has a significant impact on the physical and chemical properties of the soil. Specifically: (1) The species richness difference between each treatment group is obvious, and the 2L / m 2 The number of each interface, class, order, family, genus and species classification element in the bottom layer is generally less, and the biological diversity is lower, while the 4L / m 2 The upper layer, the middle layer and the bottom layer have higher soil biodiversity, and from the negative control group to the 2L / m 2 , 4L / m 2 The number of species at each classification element shows an upward trend. Among the various classification elements, the number of domains is the smallest and relatively stable; the number of classes, orders, families and genera fluctuates greatly between samples; the number of species fluctuates relatively small Figure 7 ).

[0040] (2) Compared with the negative control group, in the experimental group, the genera of luteimonas, alternaria, rhodobacter, sphingobium, paracoccus, lysobacter, IMCC26256, raoultella, chloroplast, lithobacter, gilt-gs-136, sphingomonas, micromonas, sericytochromatia, bacillus, nocardoides, devosia, pseudomonas, microbacterium, methylobacterium, rhizobium-neorhizobium-pararhizobium-rhizobium all have an upward trend Figure 8 ).

[0041] (3) The negative control group and the experimental group have 113 species of bacteria, of which 4L / m 2 , the specific bacteria of the middle layer soil are 531 species, the most, followed by 4L / m 2 , the specific bacteria of the upper layer soil are 491 species Figure 9 ).

[0042] The above examples only describe the preferred mode of the present application, and do not limit the scope of the present application. Without departing from the design spirit of the present application, various modifications and improvements to the technical solutions of the present application made by those skilled in the art shall fall within the protection scope determined by the claims of the present application.

Claims

1. A method for preparing a microalgae-based bio-matting material, characterized in that, Includes the following steps: (1) Add the microalgae suspension to the reactor, add glycerol according to the ratio, heat to 38~42℃, stir to dissolve, and then add cationic starch and stir to mix evenly; (2) Add polyurethane to the material obtained in step (1) and stir evenly, then add sodium lignosulfonate and react at a constant temperature for 10-14 minutes. The mixed liquid is filtered to obtain the biological mat material. The microalgae are composed of Chlorella sorokinense ( Chlorella sorokiniana ), Anabaena ( Anabaena sp. ) and Haloxylon ammodendron ( Nodularia cf. Harveyana The microalgae are composed of microalgae in a ratio of 60:20:20; the concentration of microalgae in the microalgae suspension is 1×10⁻⁶. 6 ~1×10 7 The amounts of glycerol, cationic starch, sodium lignosulfonate, and polyurethane added are 1~1.5wt%, 2~3wt%, 0.6~1wt%, and 10~30wt%, respectively.

2. The preparation method according to claim 1, characterized in that, In step (1), the temperature is raised to 40°C.

3. The preparation method according to claim 2, characterized in that, In step (2), the reaction is carried out at a constant temperature for 12 minutes.

4. The preparation method according to claim 3, characterized in that, The amount of glycerol added is 1.2 wt%, 1.3 wt%, or 1.4 wt%.

5. The preparation method according to claim 4, characterized in that, The cationic starch is added at a rate of 2.3 wt%, 2.5 wt%, or 2.8 wt%.

6. The preparation method according to claim 5, characterized in that, The amount of sodium lignosulfonate added is 0.7wt%, 0.8wt%, or 0.9wt%.

7. The preparation method according to claim 6, characterized in that, The amount of polyurethane added is 15wt%, 20wt%, or 25wt%.

8. A biological cushion material prepared by the preparation method according to any one of claims 1 to 7.

9. The application of the biological cushion material according to claim 8 in sandy soil improvement, characterized in that, Includes the following steps: Apply the biological cushion material to the surface of the sandy soil at a dosage of 2 L / m² to 5 L / m².

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