A biological composite organic flocculant, its preparation method and application

Abstract

The present invention relates to the field of water body ecological restoration, and specifically relates to a biological composite organic flocculant, a preparation method and an application thereof. Under the conditions of feeding various algae and fasting at low temperature, Daphnia magna are induced to produce Daphnia magna resting eggs containing unsaturated fatty acids and keratin proteins. The Daphnia magna resting eggs are grafted onto the organic flocculant to obtain a biological composite organic flocculant capable of maintaining the germination activity of the resting eggs and the flocculation effect of organic substances. By directly grafting the Daphnia magna resting eggs onto the organic flocculant, the organic flocculant can flocculate and settle to remove water body pollutants and improve water quality; the Daphnia magna resting eggs can germinate and release with the change of water quality, continuously remove water body particulate matters and improve transparency, thereby long-term improving the quality of the water ecosystem. The biological composite organic flocculant has no biological toxicity, good ecological safety, can continuously maintain the water body clear, and is used for controlling algal blooms, treating black and odorous water bodies and restoring eutrophic water bodies.

Description

Technical Field

[0001] The present invention relates to the field of water ecological restoration, and particularly to a biological composite organic flocculant, a preparation method thereof and an application thereof. Background Art

[0002] Eutrophic water bodies and black and odorous water bodies generally have poor water quality and low transparency. It is often necessary to add chemical agents such as flocculants to remove pollutants in the water and improve transparency, so as to improve the water habitat and provide conditions for the restoration of aquatic animals and plants. However, the use of a single flocculant often makes it difficult to maintain the water quality of the water body for a long time. After adding the flocculant to the water body, the agent quickly flocculates and precipitates into the bottom of the water body, with low utilization rate; or the agent quickly flows away during processes such as water flow and wind and waves. Therefore, it is necessary to repeatedly add chemical agents such as flocculants to maintain the water quality of the water body. However, some chemical flocculants are expensive, and the cost of repeated addition is high, and they have biological toxicity and pose an ecological risk. At present, although some relatively eco-friendly organic flocculants have begun to be widely used, after the repeatedly added organic flocculants are decomposed, on the one hand, they will increase the organic matter concentration in the water body, and on the other hand, they will cause an increase in suspended particulate matter, resulting in water quality deterioration. Even if the addition of the flocculant can keep the water body clear in the short term, the nutrients (nitrogen, phosphorus, etc.) in the water still exist, and the algae in the water will gradually increase, easily causing the water body to become turbid again, and aquatic animals and plants still cannot survive. Therefore, it is necessary to develop a new type of environmentally friendly composite organic flocculant that can quickly improve water quality and long-term maintain the quality of the water habitat with a single addition. Summary of the Invention

[0003] The purpose of the present invention is to provide a biological composite organic flocculant, a preparation method thereof and an application thereof. The biological dormant eggs are directly grafted onto the organic flocculant. The organic flocculant can flocculate and settle to remove water pollutants and improve water quality; the dormant eggs of Daphnia magna can germinate and release with the change of water quality, continuously remove water particulate matter and improve transparency, so as to long-term improve the quality of the water ecosystem. The composite organic flocculant has no biological toxicity, good ecological safety, can continuously maintain the water body clear, and is used for the removal of algal blooms, the treatment of black and odorous water bodies and the restoration of eutrophic water bodies.

[0004] In order to achieve the above purpose, the technical scheme adopted by the present invention is as follows:

[0005] In the first aspect, the present invention provides a preparation method of a biological composite organic flocculant. Under the conditions of feeding with various algae and fasting at low temperature, Daphnia magna is induced to produce dormant eggs of Daphnia magna containing unsaturated fatty acids and keratin proteins. The dormant eggs of Daphnia magna are grafted onto the organic flocculant to obtain a biological composite organic flocculant that can maintain the germination activity of the dormant eggs and the organic matter flocculation effect.

[0006] Further, the method for inducing resting eggs of Daphnia magna is as follows: Under the condition that the temperature is 15 - 25°C, Daphnia magna is fed with green algae and diatoms in a preset ratio, i.e., the weight ratio is 1:0.2 - 1, for ≥4 days, and then Daphnia magna is starved for ≥2 days under the condition that the temperature is ≤5°C, and resting eggs of Daphnia magna containing unsaturated fatty acids and keratin are collected.

[0007] Further, the raw materials for preparing the organic flocculant are acryloyl chloride and glycine, and the active enzyme is N-hydroxysuccinimide.

[0008] Further, the method for preparing the organic flocculant is as follows: At room temperature, acryloyl chloride is dissolved in dichloromethane, glycine is added, and acryloylglycine, i.e., the organic flocculant, is formed under the catalysis of N-ethyldiisopropylamine.

[0009] Further, grafting the resting eggs of Daphnia magna onto the organic flocculant specifically means: Dissolving the acryloylglycine, i.e., the organic flocculant, in tetrahydrofuran, adding the active enzyme under the catalysis of dicyclohexylcarbodiimide to form an intermediate product, i.e., acryloylglycine-N-hydroxysuccinimide ester; then, under the conditions that the temperature is 25 - 40°C and the pH is 8.0 - 8.5, adding the resting eggs of Daphnia magna to the intermediate product, and the amino group of the keratin protein of the resting eggs of Daphnia magna substitutes the N-hydroxysuccinimide on the intermediate product, so that the resting eggs of Daphnia magna are grafted onto the organic flocculant to obtain a bio-composite organic flocculant.

[0010] In the second aspect, the present invention provides a bio-composite organic flocculant prepared by using the method for preparing the bio-composite organic flocculant of the present invention.

[0011] In the third aspect, the application of the bio-composite organic flocculant prepared by using the method for preparing the bio-composite organic flocculant of the present invention in controlling algal blooms, treating black and odorous water bodies, or repairing eutrophic water bodies

[0012] Further, the dosage of the bio-composite organic flocculant prepared by using the method for preparing the bio-composite organic flocculant is 0.1 - 0.5 g / L.

[0013] Further, the bio-composite organic flocculant is applicable to eutrophic water bodies and black and odorous water bodies that do not have the conditions of dredging, aeration, planting aquatic plants, adding flocculation aids, and stocking fish.

[0014] The beneficial effects of the present invention:

[0015] 1. This invention induces the synthesis of unsaturated fatty acids and keratin in dormant Daphnia magna eggs by feeding them a variety of algae and subjecting them to low-temperature fasting. Unsaturated fatty acids enhance the eggs' resistance to adverse environmental conditions, such as low temperature and hypoxia, increasing their germination rate and reducing their mortality after germination, thereby improving their purification efficiency. Keratin provides chemical functional amino groups and reaction sites for the condensation reaction between the eggs and the organic flocculant, ensuring direct grafting between the eggs and the organic flocculant molecules. The induced keratin is present only on the surface of the eggs. After germination, the shell ruptures and remains attached to the organic flocculant molecules, ensuring rapid separation of the germinating Daphnia magna from the organic flocculant molecules and eliminating the barrier that prevents the germinating Daphnia magna from escaping the organic flocculant layer and entering the water for filter feeding and purification.

[0016] 2. The present invention activates the protein groups of dormant Daphnia magna eggs and organic flocculants through active enzymes, causing a condensation reaction between the amino groups of the keratin proteins of the dormant Daphnia magna eggs and the carboxyl groups of the organic flocculant. This chemical reaction directly grafts the dormant Daphnia magna eggs onto the organic flocculant molecules, while maintaining high germination activity. This solution overcomes the problem of Daphnia magna eggs or dormant eggs being rapidly lost to the water after being directly added to the water body, thus failing to achieve a purification effect. Furthermore, the present invention addresses the problem that, when organic flocculants and dormant Daphnia magna eggs are added separately or mixed together, the dormant Daphnia magna eggs are rapidly intercepted, encapsulated, and precipitated by the organic flocculant molecules, preventing them from germinating or preventing adult Daphnia magna from swimming through the organic flocculant deposit layer and entering the water body after germination, resulting in low purification efficiency for dormant Daphnia magna eggs.

[0017] 3. The biocomposite organic flocculant prepared by the present invention not only performs its role as an organic flocculant in removing water pollutants, but also maintains the ability of dormant Daphnia magna eggs to germinate and continuously filter-feed to remove suspended particles from the water, thus resolving the problem of organic flocculants' limited functionality and short-lived purification effects. Organic molecules can flocculate and settle to remove water pollutants and improve water quality. However, upon addition to water, organic flocculants quickly settle to the bottom, resulting in a low utilization rate. The grafted dormant Daphnia magna eggs germinate and release in response to changes in water quality. As the germinating Daphnia magna larvae swim through the organic flocculant layer and enter the water, they stir up unreacted organic flocculant molecules at the bottom of the water, releasing them into the water and improving the removal efficiency of the organic flocculant. After germinating, Daphnia magna enter the water body and continuously remove suspended matter from the water, increasing transparency and further improving the state of the aquatic ecosystem.

[0018] 4. The biocomposite organic flocculant prepared in this invention can rapidly improve water quality through organic flocculation. The grafted dormant eggs of Daphnia magna can maintain water clarity over the long term. Using pure natural materials, it is pollution-free, simple to implement, and requires minimal effort. A single application can achieve a long-lasting purification effect. Description of the Drawings

[0019] Figure 1 This is a flowchart of the preparation method of the biological composite organic flocculant described in the present invention.

[0020] Figure 2 This is the condensation reaction of the dormant eggs of Daphnia magna activated by NHS active ester and the carboxyl group of organic matter described in the present invention. Detailed Embodiments

[0021] The following will describe the embodiments of the present invention with reference to the drawings and preferred embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be understood that the preferred embodiments are only for explaining the present invention and not for limiting the protection scope of the present invention.

[0022] It should be noted that the diagrams provided in the following embodiments only illustrate the basic concept of the present invention in a schematic manner. The diagrams only show the components related to the present invention and are not drawn according to the number, shape, and size of the components in actual implementation. The type, quantity, and ratio of each component in actual implementation can be arbitrarily changed, and the component layout type may also be more complex.

[0023] Example 1, see Figure 1 , the preparation method of the biological composite organic flocculant shown includes the following steps:

[0024] Step 1, Cultivation of Daphnia magna and Collection of Daphnia magna Dormant Eggs. Under the conditions of feeding with various algae and fasting at low temperature, Daphnia magna is induced to produce dormant eggs containing unsaturated fatty acids and keratin proteins, and the dormant eggs of Daphnia magna are collected.

[0025] Daphnia magna is fed with a mixed solution of Chlorella vulgaris and Cyclotella sp. Feeding starts from the juvenile stage of Daphnia magna. The feeding conditions are as follows: the density of Daphnia magna is 40 - 50 individuals / L, the density of Chlorella vulgaris is 10 6 individuals / mL, the density of Cyclotella sp. is 10 5 individuals / mL, the weight ratio of Chlorella vulgaris to Cyclotella sp. is about 1:0.5, the temperature is set at 21°C, the light duration is set at 14 h / day, the dissolved oxygen is set at 5.5 - 7.5 mg / L, and the pH is set at 8.5 - 9.0.

[0026] After feeding Daphnia magna with the algae mixed solution for 5 days, the incubation temperature is reduced to 4°C and feeding is stopped; after fasting for 3 days, Daphnia magna produces dormant eggs, and the dormant eggs of Daphnia magna are collected for standby.

[0027] Step 2: Graft the resting eggs of Daphnia magna onto the organic flocculant to obtain a bio - composite organic flocculant.

[0028] The raw materials for preparing the organic flocculant are acryloyl chloride and glycine, and the active enzyme is N - hydroxysuccinimide, i.e., NHS. See Figure 2 , at an indoor temperature of 22 °C, dissolve 5 g of acryloyl chloride in 50 ml of dichloromethane, i.e., DCM, add 5 g of glycine, and then add 0.01 g of N - ethyldiisopropylamine, i.e., DiPEA. Under the catalysis of N - ethyldiisopropylamine, i.e., DiPEA, acryloyl glycine is formed. The mixture of acryloyl glycine formed is removed of the remaining solvent and the solid is collected through a rotary evaporator at a water bath temperature of 60 °C and a rotation speed of 5 r / min to obtain 6.5 g of acryloyl glycine powder.

[0029] Dissolve the obtained 6.5 g of acryloyl glycine powder in 50 ml of tetrahydrofuran, i.e., THF, add 0.1 g of N - hydroxysuccinimide, i.e., NHS under the catalysis of 0.02 g of dicyclohexylcarbodiimide, i.e., DCC to form an intermediate product, i.e., acryloyl glycine - N - hydroxysuccinimide ester.

[0030] Under the conditions of a temperature of 25 °C and a pH of 8.5, add 0.5 g (about 500 pieces) of the resting eggs of Daphnia magna to the intermediate product. Under the conditions of a water bath temperature of 66 °C and a rotation speed of 5 r / min, the amino group of the keratin protein of the resting eggs of Daphnia magna replaces the N - hydroxysuccinimide on the intermediate product, grafting the resting eggs of Daphnia magna onto the organic flocculant. Remove the remaining solvent and collect the solid through a rotary evaporator to obtain 5.2 g of bio - composite organic flocculant.

[0031] Example 2: Use of the bio - composite organic flocculant prepared in Example 1. Add the organic flocculant grafted with the resting eggs of Daphnia magna to the water body with low transparency to make the suspended particles in the water settle. After the resting eggs germinate, continuously remove the particles in the water.

[0032] Weigh 0.2 g of the synthesized bio - composite organic flocculant and add it to 1 L of water with a turbidity of 80 NTU, a hardness (calculated as CaCO3) of 180 mg / L, a dissolved oxygen of 6 mg / L, a pH of 7.5, and an ammonia nitrogen of 0.05 mg / L. After 2 h, the NTU value in the water drops to 8. As the transparency of the water increases, light can project onto the surface of the dormant eggs in the flocculant. After 2 days of dosing, large - scale Daphnia begin to hatch successively. After treating the low - transparency eutrophic water body with the composite organic flocculant loaded with large - scale Daphnia dormant eggs, the water body can become clear. The large - scale Daphnia dormant eggs on the surface of the organic flocculant germinate to form large - scale Daphnia. The population of large - scale Daphnia dormant eggs can continuously capture suspended particles and algae in the water body, maintain the water transparency, and improve the water quality. The long - term maintenance of water transparency will contribute to the restoration of submerged plants and benthic animal communities, thereby enhancing the self - purification and maintenance ability of the water ecosystem.

[0033] The above embodiments are merely preferred embodiments cited to fully illustrate the present invention, and the protection scope of the present invention is not limited thereto. Equivalent substitutions or transformations made by those skilled in the art on the basis of the present invention are all within the protection scope of the present invention.

Claims

1. A preparation method of a biological composite organic flocculant, characterized in that: Under the conditions of feeding with various algae and fasting at low temperature, Daphnia magna resting eggs containing unsaturated fatty acids and keratin proteins are induced. Specifically, the method for inducing Daphnia magna resting eggs is as follows: Under the condition of a temperature of 15 - 25 °C, Daphnia magna is fed with a mixture of green algae and diatoms in a preset ratio for ≥ 4 days, and then Daphnia magna is fasted for ≥ 2 days under the condition of a temperature ≤ 5 °C, and Daphnia magna resting eggs containing unsaturated fatty acids and keratin proteins are collected; The Daphnia magna resting eggs are grafted onto an organic flocculant to obtain a bio - composite organic flocculant that can maintain the germination activity of the resting eggs and the flocculation effect of organic matter.

2. The preparation method of the biological composite organic flocculant according to claim 1, characterized in that: The raw materials for preparing the organic flocculant are acryloyl chloride and glycine.

3. The preparation method of the bio-composite organic flocculant according to claim 2, characterized in that, The preparation method of the organic flocculant is: At room temperature, acryloyl chloride is dissolved in dichloromethane, glycine is added, and acryloyl glycine, that is, the organic flocculant, is generated under the catalysis of N - ethyldiisopropylamine.

4. The preparation method of the bio-composite organic flocculant according to claim 3, wherein The grafting of Daphnia magna resting eggs onto the organic flocculant is specifically as follows: The acryloyl glycine, that is, the organic flocculant, is dissolved in tetrahydrofuran, N - hydroxysuccinimide, that is, the active enzyme, is added under the catalysis of dicyclohexylcarbodiimide to generate an intermediate product, that is, acryloyl glycine - N - hydroxysuccinimide ester; Then, under the conditions of a temperature of 25 - 40 °C and a pH of 8.0 - 8.5, Daphnia magna resting eggs are added, and the amino group of the keratin protein of the Daphnia magna resting eggs replaces the N - hydroxysuccinimide on the intermediate product, so that the Daphnia magna resting eggs are grafted onto the organic flocculant to prepare the bio - composite organic flocculant.

5. A biological composite organic flocculant, characterized in that, Prepared by using the preparation method of the bio - composite organic flocculant according to any one of claims 1 to 4.

6. Application of the bio - composite organic flocculant prepared by using the preparation method of the bio - composite organic flocculant according to any one of claims 1 to 4 in controlling algal blooms, treating black and odorous water bodies, or repairing eutrophic water bodies.

7. The application according to claim 6, characterized in that: The dosage of the bio - composite organic flocculant prepared by using the preparation method of the bio - composite organic flocculant according to any one of claims 1 to 4 is 0.1 - 0.5 g / L.

8. The application according to claim 7, wherein: The bio - composite organic flocculant is applicable to eutrophic water bodies and black and odorous water bodies that do not have the conditions of dredging, aeration, planting aquatic plants, adding flocculation aids, and stocking fish.

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