Double-layer microalgae hydrogel for removing two drugs as well as preparation method and application of double-layer microalgae hydrogel

Abstract

The invention discloses double-layer microalgae hydrogel for removing two drugs as well as a preparation method and application of the double-layer microalgae hydrogel, and belongs to the technical field of microorganism application. The invention provides a strain of chlorella sp. Ch-SI50, and the preservation number of the chlorella sp. Ch-SI50 is CCTCC (China Center For Type Culture Collection) NO: M2024223. The double-layer microalgae hydrogel is prepared from the chlorella and hydrogel. The method has the beneficial effects that the microalgae-hydrogel can prevent microalgae from overflowing and polluting the original water environment while removing pollutants, and the method is a sewage purification scheme integrating physical adsorption and microalgae degradation. Therefore, the microalgae-hydrogel can be applied to typical polluted water containing drug wastewater to remove drug pollutants, protect water quality and maintain ecological balance.

Description

Technical Field

[0001] The present invention belongs to the technical field of microbiology, and particularly relates to a strain of Chlorella sp. Ch-SI50, a double-layer microalgae hydrogel for removing two drugs, and a preparation method and application thereof. Background Art

[0002] With the rapid increase in population and the growing demand for production and living, the use of organic substances has increased, and the resulting organic pollution problems have become increasingly serious. Organic pollutants detected in sewage treatment plants include pesticides, antibiotics, personal care products, and so on. A large number of scientific studies have focused on using physical and chemical methods to solve organic pollution problems. Although these methods show excellent treatment efficiency under low-interference simulation conditions, the high treatment cost and interference of the actual environment have become the key factors restricting their application.

[0003] At present, the main sewage treatment method in sewage treatment plants is the activated sludge method, which uses complex microbial aggregates in activated sludge for biodegradation. This method has excellent removal effects on conventional pollutants (such as nitrogen, phosphorus, etc.), but poor removal effects on new organic pollutants. Therefore, exploring engineering removal solutions for new organic pollutants is a hot topic in current research.

[0004] Currently, the organic pollutants that people pay more attention to are various pesticides and antibiotics, which have been detected in agricultural wastewater and aquaculture wastewater respectively. However, with the widespread spread of global epidemics, drugs have been gradually widely used. They are not completely used in the body and are then excreted. Due to their excellent water solubility, they will flow into sewage with the ecological cycle and deposit in sewage, becoming organic pollutants in sewage. With the rapid increase in usage, drug pollution has gradually attracted more attention and become a new research hotspot.

[0005] The pain reliever acetaminophen (ACE): It is a commonly used pain reliever with an annual usage of 145,000 tons and has been detected in up to 95% of the influent samples. Its concentration in manufacturing wastewater is 0.3 - 461.0 μg / L -1 which is 10 - 1000 times higher than the value in surface water. During use, about 60% - 70% of the ingested ACE is not metabolized and excreted. Long-term exposure to high concentrations of acetaminophen may cause neurotoxicity and oxidative stress to aquatic organisms (such as fish and algae), leading to long-term environmental pollution and health risks for organisms and humans, and affecting the stable operation of the ecosystem.

[0006] Antiviral drug ribavirin (RBV): It is often detected in medical wastewater. As a broad-spectrum antiviral drug, clinical trials have been conducted on virus patients to control the spread of the epidemic virus. Due to the limited metabolic capacity of the human body, about 60% of orally administered ribavirin flows into wastewater treatment plants and natural water bodies, leading to wastewater-based epidemics. The concentration in wastewater treatment plants (including metabolites) is as high as 7402 ng / L, and the detected concentration in rivers is 52.2 ng / L. Long-term exposure to excessive ribavirin can cause serious hazards, such as hindering the photosynthesis of algae and causing zebrafish dysfunction by hindering heart differentiation and inducing oxidative stress in plankton. Therefore, the study of ribavirin removal is a research hotspot.

[0007] There are about hundreds of thousands of species of algae on Earth, widely distributed in various extreme environments and environmental elements, so they have strong adaptability to various environmental stresses. In recent years, microalgae have been found to have the application potential for removing conventional and emerging pollutants in wastewater treatment. At the same time, as a biomass resource, microalgae can accumulate high-value-added products (such as proteins, oils, and pigments, etc.) while removing pollutants, with extremely high economic value. In addition, compared with physical and chemical methods, algae have inherent advantages such as less secondary pollution, green degradation, low cost, and wide distribution in removing pollutants. Due to the unique advantages shown by microalgae, they are regarded as a sewage treatment method with great application value and have gradually become a very promising research object in sewage treatment experiments and engineering applications.

[0008] Although there are many studies on the treatment of organic pollutants in the water environment by microalgae, it is still challenging to maintain their catalytic efficacy in dynamic flowing water and prevent bacteria from spreading into the water. Due to their high biocompatibility and nutritional potential, hydrogels have become a potential solution in environmental research. They provide a sustainable environment for preserving the viability, functionality, and safety of encapsulated living cells. At the same time, the current hydrogel encapsulation system faces major problems, such as low mechanical strength and reduced biocatalytic activity.

[0009] The Chinese patent application document with the publication number CN116099038A discloses a bioactive hydrogel and its preparation method. The preparation method includes the following steps: preparing thiolated carboxymethyl chitosan, mixing it with tetra-arm polyvinyl alcohol norbornene, adding a photoinitiator and deionized water to the mixture, mixing evenly to obtain a hydrogel precursor solution, irradiating the hydrogel precursor solution with ultraviolet light to obtain a hydrogel matrix, and loading the hydrogel matrix with drugs to obtain a bioactive hydrogel. This hydrogel is formed by photopolymerization, which has the advantages of being fast and convenient; the prepared hydrogel has good biocompatibility and is safe to use, and this hydrogel has a certain mechanical strength. When acting on a wound, it has moderate viscosity and will not cause secondary damage to the wound when replaced and torn. Moreover, this hydrogel has the functions of hemostasis, antibacterial, promoting cell proliferation and tissue regeneration, and can accelerate the healing of the wound. However, the performance of the hydrogel in this patent is still poor. Therefore, it still needs to be further improved. Summary of the Invention

[0010] The technical problem to be solved by the present invention is how to solve the problems of low mechanical strength and poor biological activity of the existing hydrogels.

[0011] The present invention solves the above technical problems by the following technical means:

[0012] In the first aspect of the present invention, a strain of Chlorella sp. Ch-SI50 is proposed, and the preservation number is CCTCC NO: M2024223.

[0013] In the second aspect of the present invention, a cultivation method of the above-mentioned Chlorella sp. Ch-SI50 is proposed. The Chlorella is inoculated into BG-11 medium and cultured at a temperature of 25 ± 1 °C. The light intensity during the cultivation process is 30 - 50 μmol / m 2 / s, and the light-dark ratio during the cultivation process is 12h:12h.

[0014] Preferably, the light intensity is 40 μmol / m 2 / s.

[0015] In the third aspect of the present invention, a preparation method of a microalgae hydrogel is proposed, including the following steps:

[0016] (1) Mix and stir sodium alginate with Chlorella sp. Ch-SI50, then add a calcium chloride solidification solution. After molding, wash to obtain sodium alginate microspheres containing Chlorella.

[0017] (2) Mix agarose with water, heat to completely dissolve agarose, and then add acrylamide, N,N'-methylenebisacrylamide, 2,2-azobis(2-methyl-N-(2-hydroxyethyl)propionamide), and mix.

[0018] (3) Transfer the mixed solution obtained in (2) to a sterile mold, and add the sodium alginate microspheres obtained in (1) to the mixed solution before the agarose gelation, and make the sodium alginate microspheres completely wrapped by the mixed solution;

[0019] (4) Irradiate with blue light (to initiate the polymerization of acrylamide) to obtain a transparent hydrogel framework with sodium alginate microspheres and hollow bubbles inside (i.e., the microalgae hydrogel is obtained).

[0020] Preferably, in (2), the dosage ratio of agarose, water, acrylamide, N,N'-methylenebisacrylamide, 2,2-azobis(2-methyl-N-(2-hydroxyethyl)propionamide) is 1-5 g: 80-100 mL: 3-8 g: 0.02-0.07 g: 0.5-3 g. Further preferably, it is 2 g: 91.5 mL: 5 g: 0.05 g: 1.5 g.

[0021] In the fourth aspect of the present invention, the microalgae hydrogel prepared by the above preparation method is proposed.

[0022] In the fifth aspect of the present invention, the application of the above-mentioned Chlorella sp. Ch-SI50 or microalgae hydrogel in purifying drug-containing wastewater is proposed.

[0023] Preferably, the drug includes acetaminophen (ACE) and / or ribavirin (RBV).

[0024] The beneficial effects of the present invention are as follows:

[0025] 1. This patent proposes a viscous hydrogel framework for bacterial immobilization. The framework consists of Ca2+-alginate microspheres encapsulated with bacteria, which are located inside a double-network (DN) framework made of agarose and acrylamide to enhance its mechanical strength. The photoinitiator VA-086 and a blue light source are selected to ensure the initialization of polymerization and generate bubbles without sacrificing the viability of microorganisms. The hydrophilic functional groups attached to the polymer backbone enable the hydrogel to rapidly absorb water and environmental organic pollutants therein.

[0026] 2. After the strain of Chlorella is expanded and cultured to the logarithmic phase in the present invention, it is respectively added to two organic pollutants with a certain concentration, and the tolerance of Chlorella to the pollutants and the effect of removing the two drugs are observed. Subsequently, a new double-layer hydrogel structure encapsulating the microalgae balls of this strain is further designed to accelerate the removal of pollutants. The microalgae-hydrogel can prevent the microalgae from overflowing and polluting the original water environment while achieving the removal of pollutants, and it is a sewage purification solution integrating physical adsorption and microalgae degradation. Therefore, the microalgae-hydrogel can be applied to the polluted water of typical drug-containing wastewater to remove drug pollutants, protect the water quality of the water body, and maintain the ecological balance. Brief Description of the Drawings

[0027] Figure 1 This is the microalgae pigment level diagram in Example 1 of the present invention. Among them, a is the chlorophyll level diagram of microalgae removing paracetamol, b is the chlorophyll level diagram of microalgae removing ribavirin, and c is the carotenoid level diagram of microalgae removing paracetamol and ribavirin;

[0028] Figure 2 This is the schematic diagram of the production process of the microalgae hydrogel in Example 1 of the present invention;

[0029] Figure 3 This is the comparison diagram of the removal effects of paracetamol (a) and ribavirin (b) by the microalgae hydrogel in Example 1 of the present invention;

[0030] Figure 4 This is the compression modulus diagram of the microalgae hydrogel in Example 1 of the present invention;

[0031] Figure 5 This is the OD in the culture medium during the treatment process of the hydrogel in Example 1 of the present invention 680 and the schematic diagram of the hydrogel;

[0032] Figure 6 This is the chemical bond change diagram before and after the action of the microalgae hydrogel in Example 1 of the present invention;

[0033] Figure 7 This is the morphological feature diagram of the microalgae hydrogel in Example 1 of the present invention. Among them, a is the physical diagram of the microalgae hydrogel, b is the action mechanism diagram of the microalgae hydrogel, c is the composition display diagram of the microalgae hydrogel, d is the scanning electron microscope image of the cross-section of the alginate microsphere, e is the cutting diagram of the outer hydrogel structure, and f is the microalgae diagram of the cross-section of the inner hydrogel. Detailed Embodiments

[0034] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0035] The test materials and reagents used in the following embodiments, unless otherwise specified, can all be obtained from commercial channels.

[0036] For those not specifying specific technologies or conditions in the embodiments, they can all be carried out according to the technologies or conditions described in the literature in this field or according to the product instructions. Unless otherwise specified, the quantitative tests in the following embodiments are all set with more than three repeated experiments, and the results are averaged.

[0037] Example 1:

[0038] 1. Obtaining of Chlorella

[0039] (1) Preparation of BG-11 medium

[0040] ① NaNO3 solution: 75.0000 g of NaNO3 is dissolved in water and made up to 500 mL;

[0041] ② CaCl2 solution: 2.7180 g is dissolved in water and made up to 100 mL;

[0042] ③ K2HPO4 solution: 4.0000 g of K2HPO4·3H2O is dissolved in water and made up to 100 mL;

[0043] ④ MgSO4 solution: 7.5000 g of MgSO4·7H2O is dissolved in water and made up to 100 mL;

[0044] ⑤ Ferric ammonium citrate: 0.6000 g of ferric ammonium citrate is dissolved in water and made up to 100 mL;

[0045] ⑥ Citric acid solution: 0.6000 g of citric acid is dissolved in water and made up to 100 mL;

[0046] ⑦ NaCO3 solution: 2.0000 g of NaCO3 is dissolved in water and made up to 100 mL;

[0047] ⑧ EDTANa2 solution: 0.1000 g of EDTA-Na2 is dissolved in water and made up to 100 mL;

[0048] ⑨ Trace elements: 0.2860 g of H3BO3, 0.1860 g of MnCl2·4H2O, 0.0220 g of ZnSO4·7H2O, 0.0390 g of Na2MoO4·2H2O, 0.0080 g of CuSO4·5H2O, 0.0050 g of Co(NO3)2·6H2O are successively dissolved in water and made up to 100 mL;

[0049] Take 10 mL of NaNO3 solution, 1 mL each of components (2)-(9), adjust the pH to 7 with 400 μL of NaOH solution, and make up to 1.0 L to obtain the BG-11 medium.

[0050] (2) Sampling the wastewater from the Eco-Environment Bureau of the High-Tech Development Zone (Ma'anshan, Anhui). On the sterile operating table, use a sterile pipette to suck the influent water and activated sludge water samples and drop them on the sterilized BG-11 solid medium for inoculation. Drop 2-3 drops on each petri dish, then seal the petri dish with a sealing film, invert it and place it at a culture temperature of 25 ± 1 °C and a light intensity of 40 μmol / m2 / s, cultured in a light incubator with a light-dark ratio of 12 h∶12 h. After 7 - 10 days, a mixed microalgae community was obtained. Observe the microalgae community and perform multiple repeated streak plate inoculation cultures until a purified single colony is obtained. A total of 10 species of microalgae were obtained after isolation and purification. Select one of the microalgae and observe its morphology under a microscope. Combine "Freshwater Algae in China - Systematics, Taxonomy and Ecology" to conduct a preliminary classification and identification of the microalgae. The identification is carried out through colony morphology, biochemistry and 18S rDNA sequencing analysis. Specifically: After the genomic DNA of the sample to be tested is roughly extracted, select the corresponding primers to amplify the specific fragment, use the TSINGKE DNA Gel Extraction Kit (Code No.GE0101) to cut the gel and recover the target fragment, and perform sequencing with the corresponding primers. The primers used for amplifying 18s rDNA are:

[0051] HET-F: 5′-ACCTGGTTGATCCTGCCAGTAGTCATAC-3′; (SEQ ID No.1)

[0052] HET-R: 5′-GGTTCACCTACGGAAACCTTGTTACGACTTCA-3′. (SEQ ID No.2)

[0053] The amplified sequence was compared with the NCBI database. The comparison results showed that this strain of microalgae is Chlorella sp., and it was named Chlorella sp.Ch-SI50.

[0054] 2. Cultivation of Chlorella

[0055] Transfer the isolated and purified Chlorella sp.Ch-SI50 strain to a 150 mL sterile conical flask filled with sterilized BG-11 liquid medium for preservation culture. After the algal cells grow to the logarithmic growth phase, transfer part of the algal solution to a 1.0 L sterile conical flask for scale-up culture. The culture temperature in the light incubator is set at 25±1 °C, and the light intensity is 40 μmol / m 2 / s, with a light-dark ratio of 12 h∶12 h. Solid plate and liquid cultures are carried out simultaneously to ensure the pure preservation and culture of microalgae.

[0056] 3. Removal of drugs by Chlorella sp.Ch-SI50

[0057] After the Chlorella sp.Ch-SI50 strain is scale-up cultured to the logarithmic phase, take an appropriate amount of the algal solution and dilute it with sterilized BG-11 medium to OD 680≈1.0, then take 10 mL of the diluted algal solution and place it in a 250 mL sterile conical flask. Then, separately add the stock solutions (200 mg / L) of paracetamol and ribavirin (≥98.0%, Henan Institute for the Control of Standard Substances, China) to the algal solution so that the total volume of the final liquid in the conical flask is 200 mL. The concentration of ribavirin pollutant in the algal solution is 5 mg / L, and 3 replicates are set for each group. Plug the conical flask with a cotton plug, seal it with kraft paper, and place it in a light incubator at a temperature of 25 ± 1 °C, a light-dark ratio of 12 h:12 h, and a light intensity of 120 μmol / m 2 / s for 18 days. Then, study and analyze the physicochemical properties of this strain of Chlorella and the removal effect of Chlorella on ribavirin. This part aims to explore the effect of Chlorella sp. Ch-SI50 on the removal of representative organic pollutants in medical wastewater.

[0058] 4. Microalgae-Hydrogel Construction and Drug Removal

[0059] Dissolve 1 g of sodium alginate in 49 mL of BG-11 medium containing Chlorella sp. Ch-SI50 respectively. Stir the mixture overnight, and then drop it into a sterilized 2 wt% calcium chloride solidification solution with a 1 ml pipette tip. After molding, collect the beads and wash them several times with deionized water to obtain alginate microspheres encapsulating bacteria with a diameter of 2 mm. Further, dissolve 2 g of agarose in 91.5 mL of deionized water and heat the mixture to 90 °C until completely dissolved. Then, slowly cool the solution to 45 °C. At this temperature, add 5 g of acrylamide, 0.05 g of N,N'-methylenebisacrylamide (1 wt% Am), and 1.5 g of 2,2'-azobis(2-methyl-N-(2-hydroxyethyl)propionamide) (VA-086) to the agarose syrup. Once the solution temperature reaches 35 °C, transfer the solution to a sterile mold, and add a certain amount of bacteria-encapsulating alginate microspheres to the solution before the agarose gelation. Initiate the polymerization of acrylamide by irradiating with blue light (385 nm) for 5 minutes. Obtain a transparent hydrogel framework with alginate microspheres and air bubbles in the middle inside.

[0060] Hydrogel cubes (5 × 1 × 1 cm), uniformly made, are used to treat 50 mL of standardized wastewater. Add the hydrogels encapsulating microalgae to the water contaminated with drugs, and study the removal of pollutants and the physical properties of the hydrogels.

[0061] 5. Related Measurement Methods

[0062] (1) Pigment levels of microalgae: Chlorella vulgaris cultured with different drugs was used as the test sample. Samples were taken every 3 days, 5 mL of algal solution each time. The solution was centrifuged at 8000 rpm for 5 minutes, and the supernatant was discarded. The precipitate was resuspended in 5 mL of 90% methanol, water-bathed at 60 °C for 10 minutes in the dark, and centrifuged again for 5 minutes. Then, the absorbance of the supernatant was measured at 665, 652, and 470 nm using a UV spectrophotometer, and the total chlorophyll and carotenoid contents were calculated using the following equations:

[0063] C a (mg / L) = 16.82A 665 - 9.28A 652

[0064] C b (mg / L) = 36.92A 652 - 16.54A 665

[0065] C car (mg / L) = (1000A 470 - 1.91C a - 95.15C b ) / 225

[0066] C 总 (mg / L) = C a + C b

[0067] In the equations, C a represents the chlorophyll a content (mg / L); C b represents the chlorophyll b content (mg / L); C car represents the carotenoid content (mg / L), and C 总 represents the total chlorophyll content (mg / L).

[0068] (2) Determination of drug concentration: To verify whether this strain of Chlorella vulgaris has a removal effect on pollutants, samples were taken every 3 days to measure the change in the ribavirin content in the algal solution. Specifically: 2 mL of the algal solution was filtered through a 0.22 μm organic filter membrane and analyzed by high-performance liquid chromatography (HPLC, Wanyi Technology). The mobile phase was 0.1% formic acid in water (V / V), the flow rate was set at 0.6 mL / min, the column temperature was set at 35 °C, and the injection volume was 10 μL. Then, the change in the pollutant content was calculated as the removal rate.

[0069] (3) Hydrogel performance testing:

[0070] Compressive stress: The compressive modulus was determined by fitting the data from the initial linear part before the plateau or the change point. The hydrogel was tested using a universal mechanical testing instrument (KZ-SSBC-500, China). The hydrogel sample was cut into cubes with dimensions of 20×20×10 mm. A constant compression rate of 2 mm / min was applied until a significant change in the plateau or slope was observed, at which point data collection was stopped. The compressive modulus was determined by fitting the data from the steady segment or the initial linear part before the change point.

[0071] Morphological characteristics: Morphological images were obtained using a scanning electron microscope and an optical microscope. The hydrogel and microspheres were freeze-dried and cut into 1-mm-thick slices for observation. Images were obtained using a Schottky Field emission scanning electron microscope at 3 kV. The optical microscope was used to describe the morphological images of microalgae and the hydrogel.

[0072] Leakage prevention function: The leakage prevention function of the hydrogel was determined by measuring the absorbance of the solution at 680 nm (UV spectrophotometer).

[0073] Fourier transform infrared spectroscopy (FT-IR): Fourier transform infrared spectroscopy was used to detect changes in chemical bonds in the hydrogel before and after the action of the hydrogel.

[0074] Results:

[0075] Chlorophyll is the main indicator of photosynthetic electron transfer activity and is closely related to all aspects of photosynthesis, including light capture, energy transfer, and light energy conversion. As shown in Figures a and b in Figure 1 , the chlorophyll levels (including chlorophyll a and b) of Chlorella sp. Ch-SI50 continuously increased with the culture time, indicating that it showed good tolerance to both organic pollutants and maintained a good growth state. Chlorophyll a mainly converts light energy into chemical energy by absorbing red light. Chlorophyll b assists chlorophyll a and enhances the efficiency of photosynthesis in green plants. Therefore, the chlorophyll a level in microalgae in both pollutants was significantly higher than that of chlorophyll b. Carotenoids play an important role in light capture. It has antioxidant properties and can protect cells by quenching free radicals such as singlet oxygen generated intracellularly, preventing lipid peroxidation, and thus providing a defense system for the photosynthesis process. The carotenoid levels in microalgae in the sewage of both pollutants also gradually increased, indicating that the self-protection system of microalgae gradually came into play to resist external adverse factors.

[0076] Since directly introducing microalgae into sewage will cause exogenous chlorophyll pollution in the sewage and organic matter pollution caused by chlorophyll corruption, fixing or encapsulating microalgae is the key to its application in actual scenarios. The present invention proposes a new type of double-layer encapsulation method, encapsulating microalgae into hydrogels, which can prevent microalgae from spilling while achieving pollutant removal. The schematic diagram of the production process of microalgae hydrogels is as shown in Figure 2 shown. Microalgae and sodium alginate are mixed to construct the first-layer hydrogel system, and the outer layer is encapsulated with the second-layer agarose hydrogel to further protect and prevent microalgae from spilling. Hydrogel is a material with extremely strong water compatibility, rich in voids and chemical bond structures inside, and is a good coating material. Applying it to the purification of sewage containing pharmaceutical pollutants is a novel application idea.

[0077] As shown in Figure 3 shown, after preliminary screening, Chlorella sp. Ch-SI50 itself has a certain degree of biological removal of acetaminophen and ribavirin. Microalgae regard organic pollutants as nutrients such as their own carbon and nitrogen sources, so they can degrade organic pollutants in sewage. Further, microalgae hydrogels are used to remove these two drugs, and the results show that microalgae hydrogels significantly improve the removal efficiency of the two pollutants. This indicates that the chemical bonds on the surface of the hydrogel provide action sites for these two organic substances, facilitating the formation of interactions and being suitable for the removal of these two pollutants. The role of microalgae hydrogels is an integrated solution that combines chemical bond adsorption and further degradation by microalgae, which can solve the complex problems such as a large number of secondary pollutants in the later stage of sewage treatment plants and the need for further treatment of products.

[0078] Furthermore, as shown in Figure 4 shown, the microalgae hydrogel maintains a good compressive modulus for 18 days, about 0.4 - 0.5 Mpa. According to previous studies, this compressive modulus can withstand the water pressure impact at a depth of 12 meters underwater, indicating that the microalgae hydrogel maintains excellent physical strength. By measuring the OD 680 value in the microalgae hydrogel, the leakage situation of the hydrogel can be judged.

[0079] As shown in Figure 5 shown, the OD 680 outside the hydrogel remains at an extremely low level, close to the blank OD value of pure water, indicating that no microalgae leakage has occurred in the microalgae hydrogel, achieving the anti-leakage purpose of the invention.

[0080] As shown in Figure 6 shows the chemical bond changes before and after the action of the hydrogel. It can be seen that the hydrogel is rich in a large number of chemical bond sites, which can provide a large number of attachment sites for pharmaceutical pollutants. Before and after the action, the chemical bonds at these action sites vibrate and shift, indicating that new substances are attached to the surface of the hydrogel. At the same time, the overall types of chemical bonds do not change significantly, indicating that the hydrogel has a stable chemical bond structure.

[0081] Finally, the morphological characteristics of the hydrogel are shown in Figure 7 . Figure 7a is a picture of the microalgae hydrogel. Figure 7b shows the mechanism of action of the microalgae hydrogel. The hydrogel adsorbs organic pollutants and is further degraded by microalgae within the hydrogel. Figure 7c shows the composition of the microalgae hydrogel. The inner microalgae sodium alginate beads and the outer agarose hydrogel form a double-layer hydrogel network, ensuring the anti-leakage function of the microalgae hydrogel. Figures 7d and 7e show that both layers of the hydrogel contain a large number of void structures, ensuring that sewage and pollutants can penetrate into the interior of the hydrogel. Figure 7f shows that Chlorella sp. Ch-SI50 is abundantly present on the surface of the hydrogel beads, demonstrating the contact interface and contact mode between microalgae and the hydrogel.

[0082] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments or perform equivalent replacements for some of the technical features. However, such modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A strain of Chlorella sp. Ch-SI50, characterized in that, The preservation number is CCTCC NO: M2024223.

2. The cultivation method of Chlorella sp. Ch-SI50 according to claim 1, characterized in that, Chlorella was inoculated into BG 11 medium and cultured at a temperature of 25 ± 1 °C, and the light intensity during the culture process was 30 - 50 μmol / m 2 / s.

3. The culturing method according to claim 2, wherein The light intensity is 40 μmol / m 2 / s.

4. The cultivation method according to claim 2, characterized in that, The light-dark ratio during the cultivation process is 12 h:12 h.

5. A method for preparing a microalgae hydrogel, characterized in that, It includes the following steps: (1) Mix sodium alginate with the Chlorella sp. Ch-SI50 described in claim 1 by stirring, then add a calcium chloride solidification solution. After forming, wash to obtain sodium alginate microspheres containing Chlorella. (2) Mix agarose with water, heat to completely dissolve the agarose, and then add acrylamide, N,N'-methylenebisacrylamide, 2,2'-azobis(2-methyl-N-(2-hydroxyethyl)propionamide), and mix. (3) Transfer the mixed solution obtained in (2) to a sterile mold, and add the sodium alginate microspheres obtained in (1) to the mixed solution before the agarose gelation, and make the sodium alginate microspheres completely wrapped by the mixed solution. (4) Irradiate with blue light to obtain the product.

6. The preparation method according to claim 5, wherein (2) In this step, the dosage ratio of agarose, water, acrylamide, N,N'-methylenebisacrylamide, 2,2'-azobis(2-methyl-N-(2-hydroxyethyl)propionamide) is 1-5 g:80-100 mL:3-8 g:0.02-0.07 g:0.5-3 g.

7. The preparation method according to claim 6, wherein (2) In this step, the dosage ratio of agarose, water, acrylamide, N,N'-methylenebisacrylamide, 2,2'-azobis(2-methyl-N-(2-hydroxyethyl)propionamide) is 2 g:91.5 mL:5 g:0.05 g:1.5 g.

8. The microalgae hydrogel prepared by the preparation method according to any one of claims 5 to 7.

9. The application of the Chlorella sp. Ch-SI50 described in claim 1 or the microalgae hydrogel described in claim 8 in purifying drug-containing wastewater.

10. The application according to claim 9, characterized in that The drug includes acetaminophen (ACE) and / or ribavirin (RBV).

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