Cyanobacterial bloom inhibitor and preparation method thereof

Abstract

The invention belongs to the technical field of water treatment, and particularly relates to a cyanobacterial bloom inhibitor and a preparation method thereof. The cyanobacterial bloom inhibitor is prepared from the following raw materials in parts by weight: 10 to 20 parts of sheareria nana extract, 3 to 5 parts of broussonetia papyrifera bark extract and 3 to 9 parts of fructus gardeniae extract. The novel cyanobacterial bloom inhibitor is developed, the photosynthesis capacity of cyanobacteria is reduced, the cell structure of cyanobacteria is destroyed, and the cyanobacterial bloom inhibitor has wide application prospects in the aspect of cyanobacterial bloom control. Moreover, the plant extract is adopted as the cyanobacterial bloom inhibitor, has the advantages of low cost, multiple types, high safety and the like, and can meet the requirements of different water areas and pollution degrees.

Description

Technical Field

[0001] This invention belongs to the field of water treatment technology, specifically relating to a cyanobacterial bloom inhibitor and its preparation method. Background Technology

[0002] In recent years, the continued exacerbation of eutrophication and global warming has led to the proliferation of certain harmful cyanobacteria, causing cyanobacterial blooms in marine and freshwater habitats. Faced with the increasing frequency and intensity of cyanobacterial blooms, their elimination and prevention have become a hot research topic in the field of water treatment technology. During cyanobacterial blooms, the massive proliferation and death of algae and other plankton cause the blooming algae to accumulate on the water surface, reducing water transparency and dissolved oxygen. They may even release secondary metabolites, such as highly toxic microcystins, severely damaging the aquatic environment, producing foul odors, and threatening the aquatic ecosystem upon which humans depend. Furthermore, if microcystins are ingested through drinking water, they can negatively impact human health.

[0003] There are many existing technologies for controlling algal blooms, mainly divided into physical, chemical, and biological methods. Physical methods primarily include mechanical removal, adsorption, wastewater diversion, filtration, and ultrasonic treatment. Mechanical removal is the most widely used, but it is less effective for large-scale algal blooms. Chemical methods often employ copper sulfate, hydrogen peroxide, chlorine, ozone, and diuron to control algal blooms. While these methods are fast-acting, they also have limitations. For example, some chemical algicides have limited persistence, and copper sulfate may pollute the environment and be toxic to aquatic organisms, thus it is mostly used for emergency algae control. Biological methods involve artificially planted submerged plants and the introduction of microbial reagents, but these methods are slow to take effect.

[0004] Therefore, there is an urgent need to develop an environmentally friendly inhibitor for cyanobacterial blooms with good control effects. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides a cyanobacterial bloom inhibitor and its preparation method. This invention develops an environmentally friendly cyanobacterial bloom inhibitor by inhibiting cyanobacterial photosynthesis and disrupting cyanobacterial cell structure, thereby reducing harmful effects on animals and humans. It has broad application prospects in controlling cyanobacterial blooms.

[0006] The primary objective of this invention is to provide a cyanobacterial bloom inhibitor that can effectively inhibit photosynthesis, destroy the cell structure of cyanobacteria, suppress the growth of cyanobacteria, and improve the effectiveness of preventing and controlling cyanobacterial blooms.

[0007] The second objective of this invention is to provide a method for preparing an inhibitor of cyanobacterial blooms.

[0008] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0009] A blue-green algal bloom inhibitor comprises the following raw materials in parts by weight: 10-20 parts of *Hemiberlesia javanica* extract, 3-5 parts of *Broussonetia papyrifera* bark extract, and 3-9 parts of *Gardenia jasminoides* extract.

[0010] Furthermore, the preparation process of the paper mulberry bark extract is as follows:

[0011] (1) After pre-treating the bark of the paper mulberry tree, chop it up, add a sodium hydroxide solution with a mass concentration of 10-15%, heat it, filter and wash it until it is neutral;

[0012] (2) Add a sodium hydroxide solution with a mass concentration of 3-5% and a hydrogen peroxide solution with a mass concentration of 5-10% to the product of step (1), heat it, filter and wash it until neutral, squeeze the product to make pulp, and collect the pulp to obtain the paper mulberry bark extract.

[0013] Further, in step (1), the mass ratio of the paper mulberry bark to the sodium hydroxide solution is (8-10):100; the temperature of the heat treatment is 95-100℃ and the time is 40-60min.

[0014] Further, in step (2), the mass ratio of the product of step (1), sodium hydroxide solution and hydrogen peroxide solution is 1:(20-30):(35-45); the temperature of the heat treatment is 70-80℃ and the time is 40-60min.

[0015] Furthermore, the preparation process of the *Symplocos edulis* extract is as follows: crush *Symplocos edulis*, add 8-10 times the amount of water of *Symplocos edulis*, soak and then heat and reflux 3 times, each time for 80-120 minutes. Combine the filtrates obtained from the 3 refluxes, concentrate under reduced pressure and then dry to obtain *Symplocos edulis* extract.

[0016] Furthermore, the soaking treatment time is 5-8 hours.

[0017] Furthermore, the preparation process of the gardenia extract is as follows: Gardenia is crushed, and water of 3-5 times the weight of the gardenia is added. After soaking, the mixture is heated and refluxed 3 times, each time for 40-60 minutes. The filtrates obtained from the 3 refluxes are combined, concentrated under reduced pressure, and then dried to obtain the gardenia extract.

[0018] Furthermore, the soaking treatment time is 4-6 hours.

[0019] A method for preparing a cyanobacterial bloom inhibitor includes the following steps:

[0020] The extract is obtained by mixing the extracts of Shrimp Beard Grass Extract, Paper Mulberry Bark Extract, and Gardenia Extract.

[0021] The beneficial technical effects of this invention are as follows:

[0022] (1) The present invention develops a novel cyanobacterial bloom inhibitor that reduces the photosynthetic capacity of cyanobacteria and destroys the cyanobacterial cell structure, and has broad application prospects in controlling cyanobacterial blooms.

[0023] (2) The present invention uses plant extracts as inhibitors of cyanobacterial blooms, which have the advantages of low cost, many types and high safety, and can meet the needs of different water areas and pollution levels. Attached Figure Description

[0024] Figure 1 The graph shows the inhibition rate of the cyanobacterial bloom inhibitor of this invention against Microcystis aeruginosa.

[0025] Figure 2 This is a graph showing the effect of the cyanobacterial bloom inhibitor of the present invention on the chlorophyll a content of Microcystis aeruginosa.

[0026] Figure 3 The figure shows the effect of the cyanobacterial bloom inhibitor of the present invention on the MDA content of Microcystis aeruginosa. Detailed Implementation

[0027] The present invention will now be described in detail with reference to embodiments thereof. These examples are provided by way of explanation and not by way of limitation. In fact, those skilled in the art will recognize that modifications and variations can be made to the present invention without departing from its scope or spirit. For example, a feature shown or described as part of one embodiment may be used in another embodiment to produce yet another embodiment. Therefore, it is desirable that the present invention encompass such modifications and variations that fall within the scope of the appended claims and their equivalents.

[0028] Unless otherwise specified, the experimental methods used in the embodiments and comparative examples of this invention are conventional methods, and the materials and reagents used are commercially available unless otherwise specified.

[0029] Example 1

[0030] A blue-green algal bloom inhibitor comprises the following raw materials in parts by weight: 15 parts of *Hemiberlesia lingua* extract, 4 parts of *Broussonetia papyrifera* bark extract, and 6 parts of *Gardenia jasminoides* extract.

[0031] The preparation process of the paper mulberry bark extract is as follows:

[0032] (1) Rinse the paper mulberry bark with clean water, remove surface impurities, cut into small pieces of 4-6 mm, add to sodium hydroxide solution A with a mass concentration of 12% and the mass ratio of paper mulberry bark to sodium hydroxide solution A is 9:100, then heat at 98℃ for 50 min, remove sodium hydroxide solution and wash with water until neutral;

[0033] (2) Add 4% sodium hydroxide solution B and 8% hydrogen peroxide solution to the product of step (1), wherein the mass ratio of the product of step (1), sodium hydroxide solution B and hydrogen peroxide solution is 1:25:40. Heat the product at 75°C for 50 minutes, remove the solution and wash until neutral. Squeeze the product into a pulp and collect the pulp to obtain the paper mulberry bark extract.

[0034] The preparation process of *Hemiberlesia lingua* extract is as follows: *Hemiberlesia lingua* is crushed, and water with a mass of 9 times that of *Hemiberlesia lingua* is added. The soaking time is 7 hours. Then, it is heated and refluxed 3 times, with each reflux time being 100 minutes. Then, it is filtered, and the filtrate is collected. Finally, the filtrates obtained from the 3 refluxes are combined, concentrated under reduced pressure, and dried in an electric thermostatic drying oven at 80℃ to obtain *Hemiberlesia lingua* extract.

[0035] The preparation process of gardenia extract is as follows: Gardenia is crushed, and water with a mass of 4 times that of gardenia is added. The soaking time is 5 hours. Then, the mixture is heated and refluxed 3 times, with each reflux time being 50 minutes. The mixture is then filtered, and the filtrate is collected. The filtrates obtained from the 3 refluxes are combined, concentrated under reduced pressure, and dried in an electric thermostatic drying oven at 80℃ to obtain gardenia extract.

[0036] This embodiment also provides a method for preparing the above-mentioned cyanobacterial bloom inhibitor, including the following steps:

[0037] The extract is obtained by mixing the extracts of Shrimp Beard Grass Extract, Paper Mulberry Bark Extract, and Gardenia Extract.

[0038] Example 2

[0039] A blue-green algal bloom inhibitor comprises the following raw materials in parts by weight: 1 part of *Hemiberlesia lingua* extract, 3 parts of *Broussonetia papyrifera* bark extract, and 3 parts of *Gardenia jasminoides* extract.

[0040] The preparation process of the paper mulberry bark extract is as follows:

[0041] (1) Rinse the paper mulberry bark with clean water, remove surface impurities, cut into small pieces of 4-6 mm, add to sodium hydroxide solution A with a mass concentration of 10%, the mass ratio of paper mulberry bark to sodium hydroxide solution A is 8:100, then heat at 95℃ for 60 min, remove sodium hydroxide solution and wash with water until neutral;

[0042] (2) Add 3% sodium hydroxide solution B and 5% hydrogen peroxide solution to the product of step (1), wherein the mass ratio of the product of step (1), sodium hydroxide solution B and hydrogen peroxide solution is 1:20:35. Heat the product at 70°C for 60 min, remove the solution and wash until neutral. Squeeze the product into a pulp and collect the pulp to obtain the paper mulberry bark extract.

[0043] The preparation process of *Hemiberlesia lingua* extract is as follows: *Hemiberlesia lingua* is crushed, and water with a mass of 8 times that of *Hemiberlesia lingua* is added. The soaking time is 5 hours. Then, it is heated and refluxed 3 times, with each reflux time being 80 minutes. Then, it is filtered, and the filtrate is collected. Finally, the filtrates obtained from the 3 refluxes are combined, concentrated under reduced pressure, and dried in an electric thermostatic drying oven at 75℃ to obtain *Hemiberlesia lingua* extract.

[0044] The preparation process of gardenia extract is as follows: Gardenia is crushed, and water with a mass of 3 times that of gardenia is added. The soaking time is 4 hours. Then, the mixture is heated and refluxed 3 times, with each reflux time being 40 minutes. The mixture is then filtered, and the filtrate is collected. The filtrates obtained from the 3 refluxes are combined, concentrated under reduced pressure, and dried in a 75℃ electric thermostatic drying oven to obtain gardenia extract.

[0045] This embodiment also provides a method for preparing the above-mentioned cyanobacterial bloom inhibitor, and the preparation steps are the same as in Example 1.

[0046] Example 3

[0047] A blue-green algal bloom inhibitor comprises the following raw materials in parts by weight: 20 parts of *Hemiberlesia lingua* extract, 5 parts of *Broussonetia papyrifera* bark extract, and 9 parts of *Gardenia jasminoides* extract.

[0048] The preparation process of the paper mulberry bark extract is as follows:

[0049] (1) Rinse the paper mulberry bark with clean water, remove surface impurities, cut into small pieces of 4-6 mm, add to sodium hydroxide solution A with a mass concentration of 15%, the mass ratio of paper mulberry bark to sodium hydroxide solution A is 10:100, then heat at 100℃ for 40 min, remove sodium hydroxide solution and wash with water until neutral;

[0050] (2) Add 5% sodium hydroxide solution B and 10% hydrogen peroxide solution to the product of step (1), wherein the mass ratio of the product of step (1), sodium hydroxide solution B and hydrogen peroxide solution is 1:30:45. Heat the product at 70°C for 40 minutes, remove the solution and wash until neutral. Squeeze the product into a pulp and collect the pulp to obtain the paper mulberry bark extract.

[0051] The preparation process of *Hemiberlesia lingua* extract is as follows: *Hemiberlesia lingua* is crushed, and water with a mass of 10 times that of *Hemiberlesia lingua* is added. The soaking time is 8 hours. Then, it is heated and refluxed 3 times, with each reflux time being 120 minutes. Then, it is filtered, and the filtrate is collected. Finally, the filtrates obtained from the 3 refluxes are combined, concentrated under reduced pressure, and dried in an electric thermostatic drying oven at 85℃ to obtain *Hemiberlesia lingua* extract.

[0052] The preparation process of gardenia extract is as follows: Gardenia is crushed, and water with a mass of 5 times that of gardenia is added. The soaking time is 6 hours. Then, the mixture is heated and refluxed 3 times, with each reflux time being 60 minutes. The mixture is then filtered, and the filtrate is collected. The filtrates obtained from the 3 refluxes are combined, concentrated under reduced pressure, and dried in an electric thermostatic drying oven at 85℃ to obtain gardenia extract.

[0053] This embodiment also provides a method for preparing the above-mentioned cyanobacterial bloom inhibitor, and the preparation steps are the same as in Example 1.

[0054] Comparative Example 1

[0055] Comparative Example 1 is basically the same as Example 1, except that the extract of *Heliotropium indicum* is omitted.

[0056] Comparative Example 2

[0057] Comparative Example 2 is basically the same as Example 1, except that the paper mulberry bark extract is omitted.

[0058] Comparative Example 3

[0059] Comparative Example 3 is basically the same as Example 1, except that the extracts of *Heliotropium indicum* and *Broussonetia papyrifera* bark are replaced with *Gardenia jasminoides* extract.

[0060] Experimental Example 1

[0061] 1.1 Culture of Microcystis aeruginosa: Microcystis aeruginosa was added to BG-11 medium, the formulation of which is shown in Tables 1 and 2. The light intensity was set at 2000 lx, the temperature at 25 ± 1℃, and the light and dark cycles were repeated for 12 h. The culture medium was shaken three times a day until algal cells in the logarithmic growth phase were obtained.

[0062] Table 1. BG-11 Culture Medium Formulation

[0063] Components Content of each component in 1L BG-11 medium <![CDATA[K2HPO4·3H2O]]> 0.04g <![CDATA[MgSO4·7H2O]]> 0.075g <![CDATA[CaCl2·2H2O]]> 0.036g Citric acid 0.006g Ferric ammonium citrate 0.006g EDTA 0.1g <![CDATA[Na2CO3]]> 0.02g <![CDATA[NaNO3]]> 1.5g <![CDATA[A5]]> 0.1mL

[0064] Table 2A5 Solution Formulation

[0065] Components <![CDATA[Concentration (g / L H2O)]]> <![CDATA[H3BO3]]> 2.86 <![CDATA[MnCl2·4H2O]]> 1.81 <![CDATA[ZnSO4·7H2O]]> 0.22 <![CDATA[Na2MoO4·2H2O]]> 0.39 <![CDATA[CuSO4·5H2O,]]> 0.08 <![CDATA[Co(NO3)2·6H2O]]> 0.01

[0066] 1.2 Algal cells in the logarithmic growth phase were divided into groups of 1.5 × 10⁻⁶. 6An inoculation density of 1 cell / mL was added to 100mL of BG-11 medium, followed by the addition of the inhibitor obtained in Example 1, controlling the inhibitor concentration in the medium to 5g / L. Then, Examples 2-3 and Comparative Examples 1-3 were set up with the same amount of inhibitor added, following the same method. Each group was set up in triplicate, with the culture conditions being the same as in step 1.1. Cell counts of *Microcystis aeruginosa* were performed on days 1, 3, 5, and 7 to determine the inhibition rate of each inhibitor on the algae. The results are as follows: Figure 1 As shown.

[0067] Depend on Figure 1 The results showed that the inhibitors in Examples 1-3 had a higher inhibition rate on algal cells than those in Comparative Examples 1-3, and the inhibition rate of the cyanobacterial bloom inhibitors on algal cells increased with increasing culture time.

[0068] 1.3 After 7 days of inhibitor treatment, the algal solution was collected, centrifuged at 6000 rpm for 5 min, the supernatant was discarded, and the precipitate (the lower layer of cyanobacterial cells) was collected. Methanol was added to the precipitate, and the mixture was extracted in the dark in a refrigerator until the precipitate turned white. The mixture was then centrifuged at 8000 rpm for 10 min, the supernatant was collected, and the absorbance was measured at 665 nm and 720 nm to calculate the chlorophyll a content. The results are as follows: Figure 2 As shown.

[0069] Chlorophyll is a type of green pigment found in the vast majority of algae and all other photosynthetic organisms. Its concentration is commonly used as an important indicator of algal biomass in water. Higher chlorophyll a content generally indicates a larger algal biomass. Figure 2 The results showed that the chlorophyll a content in Examples 1-3 was lower than that in Comparative Examples 1-3. This indicates that the chlorophyll a content in Examples 1-3 was inhibited, and the inhibitor of the present invention can inhibit algal photosynthesis and prevent eutrophication of water bodies. Although the chlorophyll a content in Comparative Examples 1-3 also showed varying degrees of reduction, the effect was poor.

[0070] 1.4 After 7 days of inhibitor treatment, algal culture was collected, and algal cells were disrupted using a cell disruptor. Then, the MDA content was determined according to the instructions of the malondialdehyde (MDA) detection kit. The results are as follows: Figure 3 As shown.

[0071] The excessive accumulation of MDA in plants leads to toxic reactions in the cell membrane system, causing cell membrane degradation, loss of normal physiological function, and alterations in chloroplast microstructure, thereby reducing photosynthesis in algal cells. Changes in malondialdehyde (MDA) levels reflect the damage caused by inhibitors to algal cells; higher levels indicate greater cell damage. Figure 3It can be seen that on the 7th day, the algal cell content of the Example 1-3 group was significantly higher than that of the Comparative Example 1-3, indicating that the cyanobacterial bloom inhibitor of the present invention caused lipid peroxidation of the cell membrane of algal cells, which aggravated the degree of oxidative damage to algal cells.

[0072] The foregoing has described and evaluated some embodiments of the present invention. It should be understood that the present invention is not limited to the specific embodiments described above. Any person skilled in the art can make many possible variations and modifications to the technical solutions of the present invention, or modify them into equivalent embodiments, without departing from the scope of the present invention. This does not affect the essential content of the present invention. Therefore, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention, without departing from the content of the present invention, still fall within the protection scope of the present invention.

Claims

1. A cyanobacterial bloom inhibitor, characterized in that, The ingredients include the following parts by weight: 10-20 parts of Shrimp Beard Grass Extract, 3-5 parts of Paper Mulberry Bark Extract, and 3-9 parts of Gardenia Extract.

2. The cyanobacterial bloom inhibitor according to claim 1, characterized in that, The preparation process of the paper mulberry bark extract is as follows: (1) After pre-treating the bark of the paper mulberry tree, chop it up, add a sodium hydroxide solution with a mass concentration of 10-15%, heat it, filter and wash it until it is neutral; (2) Add a sodium hydroxide solution with a mass concentration of 3-5% and a hydrogen peroxide solution with a mass concentration of 5-10% to the product of step (1), heat it, filter and wash it until neutral, squeeze the product to make pulp, and collect the pulp to obtain the paper mulberry bark extract.

3. The cyanobacterial bloom inhibitor according to claim 2, characterized in that, In step (1), the mass ratio of the paper mulberry bark to the sodium hydroxide solution is (8-10):100; the temperature of the heat treatment is 95-100℃ and the time is 40-60min.

4. The cyanobacterial bloom inhibitor according to claim 2, characterized in that, In step (2), the mass ratio of the product from step (1), sodium hydroxide solution, and hydrogen peroxide solution is 1:(20-30):(35-45); the temperature of the heat treatment is 70-80℃ and the time is 40-60min.

5. The cyanobacterial bloom inhibitor according to claim 1, characterized in that, The preparation process of the shrimp whisker grass extract is as follows: take shrimp whisker grass and crush it, add water with 8-10 times the weight of shrimp whisker grass, soak it, heat and reflux it 3 times, each time for 80-120 minutes, combine the filtrates obtained from the 3 refluxes, concentrate under reduced pressure and dry to obtain shrimp whisker grass extract.

6. The cyanobacterial bloom inhibitor according to claim 5, characterized in that, The soaking treatment time is 5-8 hours.

7. The cyanobacterial bloom inhibitor according to claim 1, characterized in that, The preparation process of the gardenia extract is as follows: Gardenia is crushed, and water with a weight of 3-5 times that of the gardenia is added. After soaking, the mixture is heated and refluxed 3 times, each time for 40-60 minutes. The filtrates obtained from the 3 refluxes are combined, concentrated under reduced pressure, and then dried to obtain the gardenia extract.

8. The cyanobacterial bloom inhibitor according to claim 7, characterized in that, The soaking treatment time is 4-6 hours.

9. The method for preparing the cyanobacterial bloom inhibitor according to any one of claims 1-8, characterized in that, The process includes the following steps: mixing shrimp whisker grass extract, paper mulberry bark extract, and gardenia extract.

Images