WO2023045591A1

WO2023045591A1 - Algae inhibition material and application thereof in agricultural greenhouse films

Info

Publication number: WO2023045591A1
Application number: PCT/CN2022/110463
Authority: WO
Inventors: 杨其长; 杨晓; 郭俊凌; 何云翔; 王晓玲; 胡江涛; 王明耀
Original assignee: 中国农业科学院都市农业研究所; 四川大学
Priority date: 2021-09-27
Filing date: 2022-08-05
Publication date: 2023-03-30
Also published as: CN113736298A; CN113736298B

Abstract

The present invention relates to the technical field of algae inhibition. Disclosed are an algae inhibition material and an application thereof in agricultural greenhouse films. Raw ingredients of the algae inhibition material comprise a plant polyphenol, metal ions, a biomass material, and an additive. The polyphenol-metal complexation enables the metal ions to be stabilized on the surface of an agricultural film and play a synergistic role with the plant polyphenol in inhibiting algae. The contact of polyphenol-metal complexes with algal substances can cause oxidative damage to algal cell membranes, interfering with the normal metabolism of algae and causing apoptosis of algae cells, thereby inhibiting or killing algae. A sprayed nano-coating will not affect the light transmittance of currently used agricultural films, thus the utilization of light by plants can be ensured; the spraying method is simple and quick, efficient and energy-saving, and low in cost, and meets conditions for large-scale use.

Description

Algae-inhibiting materials and their application in agricultural greenhouse films

technical field

The invention belongs to the technical field of algae inhibition, and in particular relates to an algae inhibition material and its application in agricultural greenhouse films.

Background technique

Agricultural greenhouse film is one of the important facilities in modern agricultural production technology. It provides more suitable growth conditions for crops, and can realize functions such as heat preservation and frost resistance, moisture retention and fertilizer preservation, which can greatly increase crop yields, and changes the high dependence of different crops on natural conditions in traditional agriculture. At the same time, the emergence of functional agricultural greenhouse films has enriched and expanded its application range, such as high transparency films, light conversion films, etc., which increase the utilization rate of sunlight for plants; liquid agricultural greenhouse films and degradable agricultural greenhouse films reduce the The pressure of waste agricultural film materials on environmental pollution, the products after decomposition can increase soil fertility; the modified agricultural greenhouse film increases the mechanical strength, provides a more efficient heat preservation function, and can also greatly improve the ability to resist natural disasters.

In the world, my country is the largest country in the production and use of agricultural greenhouse film. Facing the pressure of crop production and the huge demand for agricultural film, the currently used agricultural greenhouse film has the problem of recycling after being discarded and the potential risk of causing pollution. The most widely used agricultural films are polyolefin (PO) film, polyethylene (PE) film, ethylene-vinyl acetate copolymer (EVA) film, etc. The service life of these membranes ranges from about 8 to 24 months, and can be extended to 3 to 4 years after functionalization. Among them, the deposition of dust, algae and ultraviolet aging are the main reasons for the limited life of this type of agricultural greenhouse film. The deposition of dust and algae seriously affects the light transmittance of the agricultural greenhouse film and affects the growth of plants. The replaced abandoned greenhouse film cannot be degraded, and the cost of recycling is very high. Therefore, there are abandoned agricultural greenhouse films that pollute the land, cause salinization, hinder the transformation of light, heat, and fertilizer in the land, and cause large-scale production reduction. How to improve the utilization efficiency of agricultural film and prolong the service life of agricultural film in today's sustainable development is a key technical problem to be solved urgently in the process of promoting the construction of agricultural ecological civilization under the trend of agricultural clean production.

With the prolongation of the outdoor use time of the agricultural greenhouse film, pollutants (mainly dust and algae) are easy to deposit and grow on the outer surface of the agricultural film. Provides an environment for breeding. Therefore, the synergistic adhesion of algae and dust reduces the light transmittance of the agricultural greenhouse film, which affects the growth of plants and reduces production. Although there are many membrane technologies to improve the dust resistance of the agricultural film, the main method is to make the outer surface of the agricultural film smooth and smooth to prevent the deposition and growth of dust and algae. On the other hand, the main measure is to regularly clean the agricultural film to reduce the adhesion of pollutants. Due to the light and thin nature of the agricultural film itself, if it is mechanically cleaned (such as wiping, scraping), it is easy to cause damage to the agricultural film, or residual scratches will destroy its original hydrophobicity. If you use cleaning agents at will, and most of these cleaning agents contain surfactants and other additives, if they enter the land, they will cause problems such as land deterioration, water environment deterioration, algae growth, and competition with plants for nutrients. Therefore, outdoors where the natural conditions are changeable and uncontrollable, pollutants are quickly deposited on the outer surface of the agricultural film. Due to the mixing and connection of algae and dust, it increases the difficulty of artificial cleaning and increases the cost of agricultural film maintenance. This has also led to the low cleaning rate and high replacement rate of the current agricultural greenhouse film. The replaced agricultural film will cause potential land pollution because it cannot be recycled and degraded. Therefore, algae breed in the dust deposited on the agricultural film, and grow and adhere to the surface of the agricultural film, which is the main reason for reducing the light transmittance of the agricultural film, and inhibiting the growth of algae on the agricultural film is the key to improving the use efficiency of the agricultural film. An important key point. However, there is currently no specific cleaning technology developed for the algae deposited on the agricultural greenhouse film. Therefore, it is very important to develop a green and sustainable agricultural greenhouse film anti-algae technology.

Contents of the invention

In order to solve the problems in the background technology, the present invention provides an algae-inhibiting material, which can obviously inhibit the growth of algae when used in an agricultural greenhouse film.

In order to achieve the above object, in the first aspect, the present invention provides an algae-inhibiting material, the raw materials of which include plant polyphenols, metal ions, biomass materials and additives.

Further, the concentration ratio of the plant polyphenols to metal ions is 2:1-10:1.

Further, the plant polyphenols include but not limited to any one or more of myricetin and wattle bark tannin.

Further, the metal ion is any multiple of Cu ²⁺ , Sm ³⁺ and Fe ³⁺ .

Further, the biomass material contains any one or more of alginic acid, sodium alginate, calcium alginate, and magnesium alginate; the biomass material is configured as a solution with a mass percent concentration of 0.1-2.9%.

Further, the auxiliary agent includes but is not limited to tris-hydrochloric acid mixed solution, hydrogen phosphate di-salt-dihydrogen phosphate mixed solution, any one of bicarbonate, carbonate, hydroxide salt or Various.

Further, the pH value of the auxiliary agent is 6.5-9.0.

Further, the dibasic hydrogen phosphate-dihydrogen phosphate mixed solution is a mixed solution of dipotassium hydrogen phosphate-potassium dihydrogen phosphate, or a mixed solution of disodium hydrogen phosphate-sodium dihydrogen phosphate; the bicarbonate is bicarbonate Potassium or sodium bicarbonate; The carbonate is potassium carbonate or sodium carbonate; The hydroxide salt is potassium hydroxide or sodium hydroxide.

Further, the algae inhibiting algae include but not limited to Chlorella vulgaris and/or Microcystis aeruginosa.

In the second aspect, the present invention also provides the application of the algae-inhibiting material in the agricultural greenhouse film. The algae-inhibiting material is covered on the agricultural greenhouse film to form a nanometer layer.

Further, the raw materials of the algae-inhibiting material include plant polyphenols, metal ions, biomass materials and auxiliary agents.

Further, the specific method for covering the algae-inhibiting material on the agricultural greenhouse film includes:

First add plant polyphenols and metal ions into water and mix evenly, spray on the agricultural greenhouse film; then spray biomass material solution and additives in sequence.

Further, the metal ion is any multiple of Cu ²⁺ , Sm ³⁺ and Fe ³⁺ .

Further, the pH value of the auxiliary agent is 6.5-9.0.

Compared with the prior art, the present invention has the following beneficial effects:

The plant polyphenols used in the present invention have good biocompatibility, are secondary metabolites of plants, are rich in sources, low in cost, and have multiple reactivity, including coordination and complexation with various metal ions, Combine with biomass macromolecules to form stable complexes. Since there are hydrophilic phenolic hydroxyl groups and hydrophobic benzene rings in the structure of plant polyphenols, plant polyphenols have various interaction forces, such as hydrogen bonds, hydrophobic interactions, π-π interactions, and dipole interactions, with different characteristic surfaces. affinity and adhesion. The addition of biomass materials increases the hydrophilicity of the surface of the agricultural greenhouse film, improves the anti-fouling performance, and prevents the deposition of algae on the agricultural film. Due to the polyphenol-metal complexation, the metal ions can be stabilized on the surface of the agricultural film, and together with the plant polyphenols, they can synergistically inhibit algae. The contact of polyphenol-metal complexes with algae substances will cause oxidative damage to the algae cell membrane, interfere with the normal metabolism of algae, cause apoptosis of algae cells, thereby inhibiting or killing algae. The sprayed nano-coating will not affect the light transmittance of the currently used agricultural film, and can ensure the utilization of light by plants. The spraying method is simple and quick, highly efficient, energy-saving, and low in cost, and meets the conditions for large-scale use. In addition, additives are added to the formula so that the pH value of the solution is within the range of weak acid-neutral-weak base, which not only ensures the stability of the complexation of polyphenols and metal ions, but also makes the solution easy to use without causing pollution and dangerous.

Description of drawings

Fig. 1 is the ultraviolet-visible absorption spectrum of the 0th day and the 7th day of the greenhouse film that is coated with biomass-based polyphenol-metal nanocoating in embodiment 1 of the present invention;

Fig. 2 is the fluorescent picture of the inhibition of Chlorella vulgaris by nano-coating on the greenhouse film in Example 1 of the present invention;

Fig. 3 is the fluorescent picture of the inhibition of Microcystis aeruginosa by nano-coating on the greenhouse film in Example 1 of the present invention;

Fig. 4 is the fluorescent picture of the suppression of Chlorella vulgaris and Microcystis aeruginosa in culture medium by nano-coating in Example 2 of the present invention;

Fig. 5 is the result of the fluorescent quantification test of the inhibition of Chlorella vulgaris and Microcystis aeruginosa in culture medium by nano-coating in Example 2 of the present invention;

Fig. 6 is the light transmittance statistics in the coating-cleaning cycle test of the greenhouse film coated with the nano-coating and the blank greenhouse film in Example 3 of the present invention.

Detailed ways

The present invention is specifically described below by means of the accompanying drawings and examples. It is necessary to point out that the following examples are only used to further illustrate the present invention, and should not be construed as limiting the protection scope of the present invention. Those skilled in the art can make some non-essential improvements and adjustments to the present invention based on the contents of the present invention described above.

One embodiment of the present invention provides an algae-inhibiting material, which can inhibit the growth of Chlorella vulgaris, Microcystis aeruginosa and the like. The algae-inhibiting material raw material contains plant polyphenols, metal ions, biomass materials and additives.

The plant polyphenols used in the present invention have good biocompatibility, are secondary metabolites of plants, are rich in sources, low in cost, and have multiple reactivity, including coordination and complexation with various metal ions, Combine with biomass macromolecules to form stable complexes. The contact of polyphenol-metal complexes with algae substances will cause oxidative damage to the algae cell membrane, interfere with the normal metabolism of algae, cause apoptosis of algae cells, thereby inhibiting or killing algae. The addition of biomass materials increases the hydrophilicity of the surface of the agricultural greenhouse film, improves the anti-fouling performance, and prevents the deposition of algae on the agricultural film.

The plant polyphenols, metal ions, biomass materials and additives are all in solution form, and the concentration ratio of the plant polyphenols to metal ions is 2:1˜10:1.

In an optional embodiment, the plant polyphenols include but not limited to any one or more of myrica tannins and vitex bark tannins; the metal ions are Cu ²⁺ , Sm ³⁺ and Fe ³⁺ Any multiple of them; the biomass material includes any one or more of alginic acid, sodium alginate, calcium alginate, and magnesium alginate; the auxiliary agent includes but is not limited to tris-hydrochloric acid mixed Any one or more of liquid, hydrogen phosphate di-salt-dihydrogen phosphate mixed liquid, bicarbonate, carbonate, hydroxide salt.

The biomass material is configured as a solution with a mass percentage concentration of 0.1-2.9%; the pH value of the auxiliary agent is 6.5-9.0.

In a specific embodiment, the dibasic hydrogen phosphate-dihydrogen phosphate mixed solution is dipotassium hydrogen phosphate-potassium dihydrogen phosphate mixed solution, or disodium hydrogen phosphate-sodium dihydrogen phosphate mixed solution; the bicarbonate The salt is potassium bicarbonate or sodium bicarbonate; the carbonate is potassium carbonate or sodium carbonate; the hydroxide salt is potassium hydroxide or sodium hydroxide.

Another embodiment of the present invention provides an application of an algae-inhibiting material in an agricultural greenhouse film. The algae-inhibiting material is covered on the agricultural greenhouse film to form a nanometer layer.

In a specific embodiment, the specific method of covering the algae-inhibiting material on the agricultural greenhouse film comprises:

Plant polyphenols have the effect of interacting with different interfaces and adhesion, but the complexation of polyphenols and metals may reduce the adhesion between polyphenols and agricultural greenhouse films. In order to strengthen the plant polyphenol-metal complex The adhesion of the nano-coating, while adding biomass materials, assists the adhesion of plant polyphenols-metal ions in the greenhouse film, and at the same time increases the hydrophilicity of the nano-coating and enhances its anti-fouling performance. Finally, the auxiliary agent is sprayed to increase the stability of the polyphenol-metal nanoparticles, and also to make the film-forming substances adhere to the film quickly. After the algae-inhibiting material of the present invention is sprayed on the agricultural greenhouse film, the nano-coating formed will not affect the light transmittance of the currently used agricultural film, can ensure the utilization of light by plants, and effectively inhibit the growth of algae.

In order to better understand the technical solution provided by the present invention, the following uses a number of specific examples to illustrate the algae-inhibiting material, application method and performance test provided by the above-mentioned embodiments of the present invention.

Example 1

This embodiment provides the application method and performance test of the algae-inhibiting material on the agricultural greenhouse film:

The polyphenol used in this example is bayberry tannin (BT), and the details of plant polyphenols, metal ions, biomass materials and auxiliary agents are shown in Table 1.

Table 1

First add plant polyphenols and metal ions into water and mix evenly, spray on the agricultural greenhouse film; then spray biomass material solution and additives in sequence. The inhibitory properties of the agricultural greenhouse films sprayed with algae-inhibiting materials obtained in this example on Microcystis aeruginosa (MA) and Chlorella vulgaris (CH) were tested respectively.

The test method is as follows: the experimental group is set as an agricultural greenhouse film coated with an algae-inhibiting material, and the control group is a blank agricultural greenhouse film not coated with an algae-inhibiting material. The algae fluids of Microcystis aeruginosa and Chlorella vulgaris were deposited on the greenhouse membranes of the experimental group and the control group by mechanical centrifugation, and placed in the algal incubator for 24 hours, and the fluorescence of the experimental group and the control group were compared for 3 days strength. Fig. 2 is the fluorescence effect diagram of algae-inhibiting material to Chlorella vulgaris, Fig. 3 is the fluorescence effect diagram of algae-inhibiting material to Microcystis aeruginosa. Algae and Chlorella vulgaris growth inhibitory effect.

For the above-mentioned agricultural greenhouse films of the experimental group and the control group, the ultraviolet absorption was tested on the 0th day and 7th day after coating respectively, and the obtained ultraviolet-visible absorption spectra are shown in Figure 1 . It can be seen from Figure 1 that the agricultural greenhouse film coated with algae-inhibiting material in the experimental group has the characteristic absorption peak of tannin at 275nm on the 0th day and 7th day, indicating the stability of the nano-coating.

Example 2

This example is used to illustrate the performance test of polyphenol-metal nanoparticles formed by the same polyphenol and various metal ions to inhibit Microcystis aeruginosa and Chlorella:

In this example, the polyphenol is bayberry tannin (BT), and the remaining ingredients are shown in Table 2.

Table 2

For the algae-inhibiting material prepared above, a solid medium was used to replace the agricultural greenhouse film, and the algae-inhibiting material was coated on the medium containing Chlorella vulgaris and Microcystis aeruginosa respectively, and its effects on Chlorella vulgaris and Microcystis aeruginosa were determined respectively. Inhibitory performance of Microcystis; set the experimental group as the medium coated with algae-inhibiting material, and the control group as the medium without coating the algae-inhibiting material, and place the samples of the experimental group and the control group in a white light box at 25°C for cultivation 3 days, the photos after 3 days of culture are shown in Fig. 4 . It can be seen from Figure 4 that the same polyphenol-metal nanoparticle algae inhibitory material has obvious inhibitory effects on Microcystis aeruginosa and Chlorella vulgaris, and the inhibitory properties of different algae are slightly different. Figure 5 is the data after the fluorescence detection of the solution after washing the culture medium with water. From the fluorescence data, the algae-inhibiting material has an inhibitory effect on the growth of algae, and the growth of Chlorella vulgaris is inhibited by 86%. Algae growth was inhibited by 71%.

Example 3

This example is used to illustrate the influence of algae-inhibiting materials on the light transmittance of agricultural film:

Add bayberry tannin (BT) and Cu ²⁺ solution into water according to the concentration ratio of 4:1 and mix evenly, spray on the agricultural greenhouse film, then spray sodium alginate solution with a concentration of 1.5%, and finally spray phosphoric acid with pH=7.4 A mixture of sodium dihydrogen and disodium hydrogen phosphate dodecahydrate to obtain an anti-algae nano-coating adhered on the agricultural film.

Light transmittance test method: The light transmittance test was carried out on the agricultural greenhouse film coated with algae-inhibiting material obtained in this example. The light transmittance test uses a UV-Vis-NIR spectrometer (Perkin Elmer PE1050) to test the transmittance in the wavelength range of 250-2500nm, and the test performance is shown in Figure 6. Figure 6 is the transmission spectrum (250-2500nm) of the agricultural greenhouse film when coated with the algae-inhibiting material and after repeated coating-cleaning cycles ten times, showing that the light transmittance of the two samples has exceeded 85%. It shows that the nano-coating will not affect the high light transmittance of the greenhouse film itself, and the light transmittance changes little after repeated coating-cleaning cycles.

It can be seen from the above examples and accompanying drawings that the nano-coating algae-inhibiting material of the present invention can stably adhere to the surface of the agricultural greenhouse film without affecting the normal use of the agricultural greenhouse.

It should be noted that at last: above each embodiment is only in order to illustrate technical scheme of the present invention, and is not intended to limit; Although the present invention has been described in detail with reference to foregoing each embodiment, those of ordinary skill in the art should understand that: It is still possible to modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the technical solutions of the various embodiments of the present invention. range.

Claims

The algae-inhibiting material is characterized in that the raw materials include plant polyphenols, metal ions, biomass materials and additives.
The algae-inhibiting material according to claim 1, characterized in that the concentration ratio of the plant polyphenols to the metal ions is 2:1-10:1; the pH value of the additive is 6.5-9.0.
The algae-inhibiting material according to claim 1 or 2, wherein the plant polyphenols include but not limited to any one or more of myrica tannin and Vitex bark tannin; the metal ion is Cu 2 Any multiple of + , Sm 3+ and Fe 3+ ; wherein, the algae inhibiting algae include but not limited to Chlorella vulgaris and/or Microcystis aeruginosa.
The algae-inhibiting material according to claim 1, wherein the biomass material comprises any one or more of alginic acid, sodium alginate, calcium alginate, and magnesium alginate; the biomass material is configured as A solution with a mass percentage concentration of 0.1-2.9%.
The algae-inhibiting material according to claim 1 or 2, wherein the additives include but are not limited to Tris-hydrochloric acid mixed solution, hydrogen phosphate di-salt-dihydrogen phosphate mixed solution, bicarbonate Any one or more of salt, carbonate, hydroxide salt.
The application of the algae-inhibiting material in the agricultural greenhouse film is characterized in that the algae-inhibiting material is covered on the agricultural greenhouse film to form a nano-layer; the raw materials of the algae-inhibiting material include plant polyphenols, metal ions, biomass materials and additives.
The application of algae-inhibiting material in agricultural greenhouse film as claimed in claim 6, is characterized in that, the concentration ratio of described plant polyphenol and metal ion is 2:1～10:1; The pH value of described auxiliary agent is 6.5～9.0.
The application of algae-inhibiting material in agricultural greenhouse film as claimed in claim 6 or 7, is characterized in that, described plant polyphenol comprises but not limited to any one or more in bayberry tannin, Vitex bark tannin; The metal ion is any multiple of Cu 2+ , Sm 3+ and Fe 3+ ; the algae inhibiting algae include but not limited to Chlorella vulgaris and/or Microcystis aeruginosa.
The application of algae-inhibiting material in agricultural greenhouse film as claimed in claim 6, is characterized in that, described biomass material comprises any one or more in alginic acid, sodium alginate, calcium alginate, magnesium alginate; The biomass material is configured as a solution with a mass percentage concentration of 0.1-2.9%.
The application of the algae-inhibiting material in agricultural greenhouse film as claimed in claim 6 or 7, characterized in that, the auxiliary agent includes but not limited to tris-hydrochloric acid mixture, hydrogen phosphate di-salt-phosphoric acid di Any one or more of hydrogen salt mixture, bicarbonate, carbonate, hydroxide salt.