A method for quickly and efficiently ecological restoration of small agricultural pollution water body

Abstract

This invention provides a rapid and efficient method for the ecological restoration of polluted water bodies in small-scale agriculture, relating to the field of polluted water treatment. It employs a netting-based application method using *Isatis tinctoria* and composite algal agent microspheres. The composite algal agent microspheres are composed of a composite algal agent of *Chlorella proteoglycans* and *Cyclocarya meniensis*. The specific preparation method includes directional modification of algal cells, two-phase aqueous phase separation and embedding, core modification and regulation, in-situ preparation of the outer shell, and outer layer interface anchoring modification. This method, through the application of *Isatis tinctoria* and the composite algal agent, achieves deep removal of nitrogen and phosphorus, precise inhibition of cyanobacteria, and long-term ecological stability, providing an efficient, stable, safe, and low-cost ecological restoration solution for eutrophic water bodies in small-scale agriculture.

Description

Technical Field

[0001] This invention relates to the field of polluted water treatment technology, specifically to a method for rapid and efficient ecological restoration of polluted water bodies from small-scale agriculture. Background Technology

[0002] Small-scale agricultural water bodies are those distributed in farmland and rural areas for agricultural purposes such as irrigation, drainage, and drinking water for livestock and poultry. They are much smaller than large and medium-sized rivers, lakes, and reservoirs, and consist of ponds, ditches, canals, and pools with clearly defined functions of water collection, storage, and transportation. Common characteristics of small-scale agricultural water bodies include their numerous locations, wide distribution, long hydraulic retention time, weak self-purification capacity, and sensitivity to agricultural non-point source pollution. Currently, due to the discharge of fertilizers, pesticides, and livestock wastewater around these water bodies, pollution problems such as excessive nitrogen and phosphorus levels and algal blooms are widespread.

[0003] To address pollution in small-scale agricultural water bodies, current mainstream methods include adding chemical agents, aquatic plants, or microbial agents. While chemical agents can quickly improve the surface water quality of small-scale agricultural water bodies through flocculation and algae control, they are prone to secondary pollution and ecological damage, and cannot simultaneously remove nitrogen and phosphorus, posing risks to agricultural product safety, and their long-term effectiveness is poor. Adding microbial agents (such as Bacillus and photosynthetic bacteria) can degrade organic matter and reduce ammonia nitrogen in water bodies, but exogenous microbial agents have low survival rates in real farmland water bodies, are easily inhibited by competition from local microbial communities, and require specific environmental conditions. The responsiveness is poor, and the removal effect of bacterial agents is unstable (greatly affected by environmental factors such as temperature, dissolved oxygen, pH, and carbon source). They have a weak ability to remove total phosphorus, poor long-term effectiveness, and high cost. Adding aquatic plants (such as algae, calamus, and reeds) can absorb nitrogen and phosphorus in the water and inhibit the growth of algae in the water through growth competition among plants. However, aquatic plants occupy a large area, have low space utilization, and single plants are prone to overgrowth and damage the local ecological balance. In addition, the purification rate of aquatic plants is slow and the restoration efficiency is low, making it difficult to achieve significant improvement in water quality in the short term. Summary of the Invention

[0004] To address the problems existing in the prior art, the present invention aims to provide a method for rapid and efficient ecological restoration of polluted water bodies in small-scale agriculture. This method achieves effects such as deep removal of nitrogen and phosphorus, precise inhibition of cyanobacteria, rapid reduction of turbidity, and long-term ecological stability through the addition of *Isodon grandiflorus* and compound algae agents, providing an efficient, stable, safe, and low-cost ecological restoration solution for eutrophic water bodies in small-scale agriculture.

[0005] The objective of this invention is achieved through the following technical solution:

[0006] A rapid and efficient method for ecologically restoring polluted water bodies from small-scale agriculture employs a combination of netting and compound algae microsphere application (the compound algae microspheres are applied outside the netting). The compound algae microspheres are composed of a compound algae agent from *Chlorella vulgaris* and *Cyclocarya meniensis*, and their specific preparation method includes: Step S1, Targeted modification of algal cells: including passivation modification of Chlorella proteoglycans and silanization modification of Cyclocarya mennidae; Step S2, Aqueous Two-Phase Separation and Embedding: First, prepare the continuous outer phase of passivated and modified Chlorella pyrenoidosa and the dispersed inner phase of silanized and modified Cyclocarya mesniformis, and then perform aqueous two-phase mixing and microfluidic preparation to obtain the microsphere core. Step S3, Core Modification and Control: First, the core of the microspheres is modified. Then, the foaming precursor liquid and the modified microsphere core are used as the aqueous phase for secondary microfluidic embedding to obtain core-hollow microspheres. Step S4, In-situ preparation of the outer shell: First, prepare the outer shell precursor solution, and use the outer shell precursor solution and the core-hollow microspheres as the aqueous phase to perform three microfluidic embeddings to obtain tertiary structure microspheres; Step S5, Outer Interface Anchoring Modification: First, prepare a nanocrystalline cellulose suspension, then use the nanocrystalline cellulose suspension to perform interface anchoring modification on the tertiary structure microspheres, and finally passivate the medium to obtain composite algae microspheres.

[0007] Based on further optimization of the above scheme, the area of ​​the water hyacinth enclosure accounts for 20% to 50% of the area of ​​small-scale agricultural water bodies, the amount of water hyacinth added within the enclosure is 30 to 50 kg / mu (enclosure area), and the mass ratio of water hyacinth to compound algae microspheres within the enclosure is 1:0.06 to 0.1.

[0008] Based on further optimization of the above scheme, in step S1, the passivation modification of Chlorella proteoglycans specifically involves: First, placing 200 mL of Chlorella proteoglycans solution in a sterile storage tube, and concentrating and collecting algal cells using cross-flow microfiltration (at 4°C in the dark, using a 0.45 μm sterile PES microfiltration membrane, cross-flow velocity of 0.8 m / s, and transmembrane pressure of 0.02 MPa). The supernatant of the culture medium is filtered out to obtain a wet precipitate of algal cells. This precipitate is then washed twice with 80 mL of 0.05 mol / L MES (2-morpholinoethanesulfonic acid) buffer at pH 5.5. After each wash, the precipitate is filtered using gravity filtration (e.g., using a 0.45 μm sterile CN-CA filter membrane), and the filtered precipitate is resuspended in 100 mL of MES buffer to obtain... Algal cell suspension was prepared; then, 0.5 mL of a 10 mmol / L water-soluble biotin-N-succinimide ester solution was added to the algal cell suspension, and the mixture was stirred at 95–105 rpm for 28–32 min at 24–26 °C in the dark; subsequently, 0.5 g of methoxy polyethylene glycol amino (molecular weight 5000) was added, and the mixture was stirred at 95–105 rpm for 3.8–4.2 h at 24–26 °C in the dark; finally, the supernatant was removed by gravity filtration, and the mixture was washed three times with 80 mL of sterile ultrapure water each time. After each wash, the supernatant was removed by gravity filtration, and the filtered precipitate was resuspended in 20 mL of sterile ultrapure water to obtain the passivated and modified Chlorella proteoglycans solution.

[0009] Based on further optimization of the above scheme, in step S1, the silanization modification of *Cyclocarya melilotus* specifically involves: First, placing 200 mL of *Cyclocarya melilotus* solution in a sterile storage tube, and concentrating and collecting algal cells using cross-flow microfiltration (at 4°C in the dark, using a 0.45 μm sterile PES microfiltration membrane, cross-flow velocity of 0.8 m / s, and transmembrane pressure of 0.02 MPa). The supernatant is filtered off, and a wet precipitate of algal cells is obtained. The precipitate is then washed twice with 150 mL of 0.2 mol / L sterile isotonic trehalose solution (pH 7.2) and once with 150 mL of sterile ultrapure water. After each washing, gravity filtration is performed (e.g., using a 0.45 μm sterile CN-CA filter membrane). The algal cells were filtered and the precipitate was resuspended in 100 mL of 0.1 mol / L neutral Tris-HCl buffer (pH 7.5 ± 0.2) to obtain an algal cell suspension. Then, 2 mL of neutral amino-modified silica sol was added to the algal cell suspension, and the mixture was stirred at 95–105 rpm for 5.8–6.2 h at 24–26 °C in the dark. Finally, the supernatant was removed by gravity filtration, and the mixture was washed three times with 150 mL of sterile ultrapure water each time. After each wash, the supernatant was removed by gravity filtration, and the precipitate was resuspended in 20 mL of sterile ultrapure water to obtain the silanized modified *Cladosporium mesoni* solution.

[0010] Based on further optimization of the above scheme, in step S2, the continuous external phase of the passivated Chlorella proteoglycans includes methylcellulose (4000 mPa·s), sodium alginate (viscosity 100–200 mPa·s), anhydrous calcium chloride, D-gluconic acid lactone, passivated Chlorella proteoglycans solution, and sterile ultrapure water, with a mass ratio of 147–153:14.7–15.3:5.4–5.6:17.5–18.1:392.7–407.3:589.1–6 10.9; The preparation steps are as follows: Under the conditions of 24-26℃ and protection from light, add methylcellulose and sodium alginate to sterile ultrapure water in sequence, stir at 300-400 rpm for 10-15 min, degas under vacuum for 7-9 min (-0.08 MPa degassing), add passivated and modified Chlorella proteoglycans solution, stir at 50-80 rpm for 2-3 min, then add anhydrous calcium chloride and D-gluconolactone (5 min before microfluidic injection), and continue stirring for 1 min to obtain the final product; The internal dispersion of silanized *Cyclocarya melaniglita* comprises low-melting-point agarose, neutral amino-modified silica sol, silanized *Cyclocarya melaniglita* solution, and sterile ultrapure water in a mass ratio of 180–220:9–11:270–330:630–770. The preparation steps are as follows: Under light-protected conditions, add low-melting-point agarose to sterile ultrapure water and heat in a constant-temperature water bath at 63–67°C for 9–11 min. Then, allow it to stand in a constant-temperature water bath at 38–40°C for 7–9 min. Next, add neutral amino-modified silica sol and stir at 70–90 rpm for 2–4 min. Finally, add the silanized *Cyclocarya melaniglita* solution (3 min before microfluidic injection) and maintain stirring for 2–3 min to obtain the final product.

[0011] Based on further optimization of the above scheme, in step S2, the two-aqueous phase mixing is specifically as follows: at 24-26℃, the continuous external phase and the dispersed internal phase are mixed at a volume ratio of 3:1, stirred at a speed of 50-80 rpm for 1-3 minutes, and allowed to stand for 9-11 minutes to obtain the two-aqueous phase.

[0012] Based on further optimization of the above scheme, in step S2, the microfluidic preparation specifically involves: first, adding perfluoronaphthane to 0.48–0.52 wt% of tridecafluorooctyltriethoxysilane, and stirring at 300–400 rpm for 10–15 min at 24–26 °C under light-protected conditions to obtain a continuous oil phase; then, using a focusing microfluidic chip with a channel main size of 500 μm, the flow rate of the aqueous phase is 4.5–5.5 μL / min, and the oil phase is continuous. The flow rate of the phase was 18–22 μL / min. After the liquid stabilized, the monodisperse droplets at the outlet were collected into a sterile storage tube and allowed to stand at 24–26 °C for 9–11 min. Finally, the microspheres were washed three times with 5–10 times the volume of the microsphere cores in perfluorohexane for 5 min each time, and then washed three times with 5–10 times the volume of the microsphere cores in sterile ultrapure water. After each washing, the supernatant was removed by gravity filtration (using a 100 μm sterile nylon filter) to obtain the microsphere cores.

[0013] Based on further optimization of the above scheme, the modification of the microsphere core in step S3 is specifically as follows: Take 10 mmol / L, pH 8.3 sterile Tris-HCl buffer solution, and in a light-protected environment at 24-26℃, purge with nitrogen gas at a flow rate of 0.75-0.85 L / min for 9-11 min (to remove dissolved oxygen); then, add the microsphere core and the pretreated Tris-HCl buffer solution to a sterile reaction flask at a volume ratio of 0.9-1.1:8.1-9.9, and then add tannic acid to a final concentration of 0.8-1.2 g / L. In a light-protected environment at 24-26℃, stir at a speed of 95-105 rpm for 28-32 min, remove the supernatant by gravity filtration (using a 100 μm sterile nylon filter), and then wash three times with sterile ultrapure water, removing the supernatant by gravity filtration after each wash, to obtain the modified microsphere core.

[0014] Based on further optimization of the above scheme, in step S3, the secondary microfluidic embedding specifically involves: first, adding ovalbumin and glycerol to sterile ultrapure water, with a mass-to-volume ratio of ovalbumin, glycerol, and sterile ultrapure water of 9.5–10.5 g: 1.9–2.1 g: 95–105 mL, stirring at 330–370 rpm for 9–11 min, and then vacuum degassing for 4–6 min (-0.08 MPa degassing) to obtain a foaming precursor solution; then, mixing the foaming precursor solution with the modified microsphere core suspension at a volume ratio of 9:1, stirring at 50–80 rpm for 1–3 min, and allowing it to stand for 9–11 min. n. A secondary microfluidic phase was obtained using a focusing microfluidic chip with a main channel size of 600 μm. The flow rate of the aqueous phase was 7.5–8.5 μL / min, and the flow rate of the continuous oil phase was 23.5–26.5 μL / min. After stabilizing the effluent, the monodisperse droplets at the outlet were collected in a sterile storage tube and allowed to stand at 24–26 °C for 14–16 min. Finally, the microspheres were washed three times with 5–10 times the volume of perfluorohexane and then three times with 5–10 times the volume of sterile ultrapure water. After each washing, the supernatant was removed by gravity filtration (using a 100 μm sterile nylon filter) to obtain the core-hollow microspheres.

[0015] Based on further optimization of the above scheme, the preparation step of the shell precursor liquid in step S4 is as follows: First, Mg(NO3)2·6H2O, Al(NO3)3·9H2O, and Fe(NO3)3·9H2O are dissolved in 100mL of ultrapure water at a molar ratio of 3:1:0.5 to obtain a salt solution. Under constant temperature stirring at 28-32℃ and stirring speed of 200-300rpm, the salt solution is added dropwise to a 1mol / L NaOH solution at a rate of 1-2mL / min. The volume of the NaOH solution is 115-120mL. After the addition is completed, stirring is continued for 28-32min. After hydrothermal reaction in a hydrothermal reactor at 118-122℃ for 5.8-6.2h, the mixture is naturally cooled to room temperature, washed with ultrapure water until neutral, and then vacuum dried at 58-62℃ for 11.5-12.5h to obtain ternary powder. Subsequently, the ternary powder was dispersed in anhydrous ethanol at a mass-to-volume ratio of 1 g:20 mL. The dispersion was ultrasonically controlled for 28–32 min at a frequency of 38–42 kHz, a power of 100–150 W, and a constant temperature water bath at 24–26 °C. Then, KH570 (3-(methacryloyloxy)propyltrimethoxysilane) was added at a mass ratio of 1.04–1.06:1. The pH of the system was adjusted to 4.4–4.6 using anhydrous citric acid. The mixture was stirred at 200–300 rpm for 3.8–4.2 h under a constant temperature water bath at 58–62 °C. After washing three times with anhydrous ethanol and vacuum drying, the modified powder was obtained. Then, β-cyclodextrin was dissolved in MES buffer with a concentration of 0.05 mol / L and a pH of 5.5. The mass-to-volume ratio of β-cyclodextrin to MES buffer was 1 g: 10 mL. Then, epichlorohydrin was added with a mass ratio of epichlorohydrin to β-cyclodextrin of 1:1. The mixture was stirred at 200-300 rpm for 3.8-4.2 h at 24-26 °C in the dark. After that, it was dialyzed for 24 h to obtain the β-cyclodextrin activated solution. Finally, chitosan was dissolved in a 1% (v / v) L-lactic acid solution and stirred until dissolved to obtain a chitosan matrix solution with a concentration of 20 g / L. Gallic acid was then added to the chitosan matrix solution at a mass ratio of 0.2:1, and stirred until dissolved. Next, β-cyclodextrin activating solution was added at a volume-to-mass ratio of 5 mL:1 g, and the mixture was stirred at 200–300 rpm for 1.8–2.2 h at 24–26 °C in the dark. Then, modified powder was added at a mass ratio of 0.3:1, and the mixture was stirred in a constant temperature water bath at 38–42 kHz, 100–150 W, and 24–26 °C. The mixture is ultrasonically dispersed for 9–11 min under the following conditions: tannic acid is then added at a mass ratio of 0.1:1 to chitosan, and stirred until dissolved. Then, a low-substituted water-soluble chitosan quaternary ammonium salt (substitution degree 3%–5%) is added at a mass ratio of 0.1:1 to chitosan. The mixture is stirred at 140–160 rpm for 4–6 min. The pH of the system is adjusted to 6.7–6.9 using a 1 mol / L NaOH solution. β-glycerophosphate disodium pentahydrate is added, with a final concentration of 0.09–0.11 mol / L. The mixture is then stirred at 140–160 rpm for 4–6 min to obtain the shell precursor solution.

[0016] Based on further optimization of the above scheme, in step S4, the three-stage microfluidic embedding specifically involves: first, mixing the outer shell precursor liquid and the core-hollow microsphere suspension at a volume ratio of 8:2, stirring at 50-80 rpm for 1-3 minutes, and allowing it to stand for 9-11 minutes to obtain a three-stage microfluidic aqueous phase; then, using a focusing microfluidic chip with a channel main size of 800 μm, the flow rate of the aqueous phase is 9.5-10.5 μL / min, and the flow rate of the oil continuous phase is... The flow rate was 28.5–31.5 μL / min. After stabilizing the output, the monodisperse droplets at the outlet were collected into a sterile storage tube and allowed to stand in the dark at 37–39°C for 9–11 min. Finally, the microspheres were washed three times with 5–10 times the volume of perfluorohexane and then three times with 5–10 times the volume of sterile ultrapure water. After each wash, the supernatant was removed by gravity filtration (using a 100 μm sterile nylon filter) to obtain the tertiary structure microspheres.

[0017] Based on further optimization of the above scheme, in step S5, the preparation of the nanocrystalline cellulose suspension is specifically as follows: cellulose is added to a 64wt% sulfuric acid solution, with a cellulose to sulfuric acid solution mass-to-volume ratio of 1g:100mL. The mixture is stirred in a water bath at 43–47℃ at a speed of 280–320rpm for 3.8–4.2h. Then, 10 times the volume of ultrapure water is added. The mixture is filtered and washed until neutral using natural gravity filtration (using a 0.22μm sterile filter membrane), and dialyzed for 3 days until the conductivity stabilizes. The solution is then subjected to a 38–42kHz frequency, 100–150W power, and 2 The cellulose suspension was ultrasonically dispersed for 28–32 min in a constant temperature water bath at 4–26℃ to obtain a cellulose suspension with a solid content of 1 wt%. Then, the cellulose suspension was added to a Tris-HCl buffer solution with a concentration of 0.1 mol / L and a pH of 8.5 at a volume ratio of 1–2:10. Epichlorohydrin was then added, with a mass ratio of epichlorohydrin to the solids in the cellulose suspension of 1:2. The mixture was stirred at 200–300 rpm for 11.5–12.5 h at 24–26℃ in the dark. The mixture was dialyzed for 3 days to remove unreacted reagents, resulting in a suspension with a solid content of 1 wt%.

[0018] Based on further optimization of the above scheme, in step S5, the interface anchoring modification is specifically as follows: First, the tertiary structure microsphere suspension is added to the nanocrystalline cellulose suspension at a volume ratio of 1:9. Under the conditions of 24-26℃ and protection from light, the mixture is stirred at a speed of 95-105 rpm for 3.8-4.2 hours to form a three-dimensional network anchoring layer of nanocellulose. Then, the microspheres are washed three times with 5-10 times the volume of sterile ultrapure water. After each wash, the supernatant is removed by natural gravity filtration (using a 100μm sterile nylon filter) to obtain the anchoring layer modified microspheres.

[0019] Based on further optimization of the above scheme, in step S5, the passivation layer medium is specifically as follows: the anchoring layer modified microsphere suspension is added to a Tris-HCl buffer solution with a concentration of 0.1 mol / L and a pH of 7.2, with a volume ratio of 1:9. Then, methoxy polyethylene glycol silane (molecular weight 2000) is added, and the final concentration of methoxy polyethylene glycol silane after addition is 4.8-5.2 g / L. The mixture is stirred at 150-200 rpm for 3.8-4.2 h at 24-26℃ in the dark. After the reaction is completed, the supernatant is removed by gravity filtration (using a 100 μm sterile nylon filter). The mixture is then washed 5 times with 5-10 times the volume of sterile ultrapure water to remove unreacted reagents and impurities. After each washing, the reagents are removed by gravity filtration (using a 100 μm sterile nylon filter). After the final filtration, the filtrate is discarded and allowed to drain naturally to obtain the composite algae microspheres.

[0020] The following are the effects of the technical solution of the present invention: This invention utilizes a bioremediation approach combining compound algae microspheres with *Isatis tinctoria* (a type of algae). It leverages the advantages of *Isatis tinctoria*, such as simple propagation, convenient application, wide adaptability, and the ability to adjust root length according to the nitrogen and phosphorus content of the water, to rapidly absorb nitrogen and phosphorus from the water. Simultaneously, it assists in inhibiting cyanobacteria through allelopathic effects, creating a favorable aquatic environment for the compound algae. Furthermore, it combines the efficient denitrification capacity of *Chlorella proteoglycans* and the phosphate removal capacity of *Cyclocarya meniensis* to achieve simultaneous degradation of nitrogen and phosphorus in polluted water bodies from small-scale agricultural operations. Through the synergistic effect of *Isatis tinctoria* and the compound algae, it not only rapidly degrades pollutants but also increases dissolved oxygen in the water through photosynthesis and promotes the recovery of native microbial communities. This effectively addresses problems such as weak phosphorus removal by traditional microbial agents, low purification efficiency of single plants, outbreaks of native algae in agricultural water bodies, low survival rates of microbial / algae agents, and unstable remediation effects.

[0021] Specifically, this invention uses passivation modification of Chlorella proteoglycans and silanization modification of Cyclocarya mennidae to not only passivate the proliferation rate of Chlorella and prevent it from over-reproducing and competing for nutrients and light, but also to provide Cyclocarya mennidae with a dedicated silicon source and enhance its environmental tolerance. This eliminates interspecific competition between Chlorella proteoglycans and Cyclocarya mennidae, and avoids the internal antagonism problem of rapid inactivation of diatoms after direct mixing of the two. Through spontaneous phase separation in a two-phase aqueous system and precise microfluidic preparation, Chlorella proteoglycans and Cyclocarya mennidae are physically isolated, further preventing diatoms from being squeezed out of their living space, and achieving the synergistic effect of simultaneous nitrogen and phosphorus removal by Chlorella proteoglycans and diatoms. Through core modification and regulation steps, not only is a bonding layer used to provide strong binding sites for subsequent foaming layers and shells, enhancing the interlayer bonding force of microspheres and preventing interlayer delamination, but the construction of a closed-cell controlled foaming layer also ensures that the microspheres are stably suspended in the water, preventing the algae agent from sinking to the bottom and becoming inactive due to lack of light, or floating on the surface and being killed by ultraviolet rays. This ensures that the composite algae agent quickly forms a dominant population and enhances population stability. Through the in-situ preparation step of the shell, gallic acid-grafted chitosan is used to endow the shell with targeted cyanobacterial inhibition capabilities, thereby inhibiting cyanobacterial blooms in the water and preventing cyanobacteria from competing with composite algae for nutrients. β-cyclodextrin-grafted chitosan is used to effectively adsorb and degrade allelopathic substances in the water, creating an undisturbed living environment for algal cells. Through the composite of ternary powders, dissolved algal organic matter in the water is efficiently captured and degraded, avoiding the inhibition of algal cells by dissolved algal organic matter and secondary pollution of the water. Simultaneously, the synergistic effect of the in-situ preparation of the outer shell, the modification and regulation of the core, and the two-phase aqueous phase separation and embedding steps forms a core-hollow-shell three-level structure, effectively ensuring the stability of the outer shell and core structure. Through outer interface anchoring modification, a three-dimensional network is formed using nanocrystalline cellulose, covalently bonded to the outer shell, further enhancing the overall structural integrity of the microspheres and preventing them from breaking down in water. A hydrophilic passivation layer is formed through passivation treatment, preventing non-specific adhesion of aquatic microorganisms, plankton, and plant roots, thus avoiding microsphere failure and secondary pollution. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the fencing installation in an embodiment of the present invention.

[0023] Figure 2 This is a schematic diagram of the water hyacinth to be released in an embodiment of the present invention.

[0024] Figure 3 This is a schematic diagram of the composite algae microspheres prepared in the embodiments of the present invention. Detailed Implementation

[0025] 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 described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0026] Example 1: A rapid and efficient method for ecologically restoring polluted water bodies from small-scale agriculture involves using large weed enclosure nets to add (e.g.) Figure 1 As shown, large watercress Figure 2 As shown, the method of adding compound algae microspheres is combined (compound algae microspheres are added outside the enclosure). The area of ​​the enclosure for water hyacinth accounts for 30% of the area of ​​the small agricultural water body. The amount of water hyacinth added inside the enclosure is 40 kg / mu (enclosure area). The mass ratio of water hyacinth inside the enclosure to compound algae microspheres is 1:0.08 (total addition ratio).

[0027] Among them, the composite algae microspheres are composed of a composite algae agent of Chlorella pyrenoidosa and Cyclocarya mennidae, and the specific preparation method includes: Step S1, Targeted modification of algal cells: including passivation modification of Chlorella proteoglycans and silanization modification of Cyclocarya mennidae; The passivation modification of Chlorella proteoglycans is as follows: First, 200 mL of Chlorella proteoglycan solution is placed in a sterile storage tube, and algal cells are concentrated and collected using cross-flow microfiltration (at 4℃ in the dark, using a 0.45 μm sterile PES microfiltration membrane, cross-flow velocity of 0.8 m / s, and transmembrane pressure of 0.02 MPa). The supernatant of the culture medium is filtered off, and a wet precipitate of algal cells is obtained (concentrated to a wet weight concentration of 200 ± 20 g / L). Then, the precipitate is washed twice with 80 mL of 0.05 mol / L MES (2-morpholinoethanesulfonic acid) buffer at pH 5.5. After each wash, the precipitate is filtered by gravity filtration (e.g., using a 0.45 μm sterile CN-CA filter membrane), and the filtered precipitate is resuspended in 100 mL of MES buffer. Algal cell suspension was obtained; then, 0.5 mL of a 10 mmol / L water-soluble biotin-N-succinimide ester (CAS: 35013-72-0) solution was added to the algal cell suspension, and the mixture was stirred at 95 rpm for 32 min at 24 °C in the dark; then, 0.5 g of methoxy polyethylene glycol amino (molecular weight 5000, CAS: 80506-64-5) was added, and the mixture was stirred at 95 rpm for 4.2 h at 24 °C in the dark; finally, the supernatant was removed by gravity filtration, and the mixture was washed three times with 80 mL of sterile ultrapure water each time. After each wash, the supernatant was removed by gravity filtration, and the filtered precipitate was resuspended in 20 mL of sterile ultrapure water to obtain the passivated and modified Chlorella proteoglycans solution.

[0028] The silanization modification of *Cyclocarya melilotus* was carried out as follows: First, 200 mL of *Cyclocarya melilotus* solution was placed in a sterile storage tube, and algal cells were concentrated and collected using cross-flow microfiltration (at 4℃ in the dark, using a 0.45 μm sterile PES microfiltration membrane, cross-flow velocity of 0.8 m / s, and transmembrane pressure of 0.02 MPa). The supernatant was filtered off, and the wet precipitate of algal cells was obtained (concentrated to a wet weight concentration of 150 ± 15 g / L). Then, the cells were washed twice with 150 mL of 0.2 mol / L sterile isotonic trehalose solution (pH 7.2) and once with 150 mL of sterile ultrapure water. After each washing, the cells were filtered using natural gravity filtration (e.g., using a 0.45 μm sterile CN-CA filter membrane). The filtered precipitate was resuspended in 100 mL of 0.1 mol / L neutral Tris-HCl buffer (pH 7.5 ± 0.2) to obtain an algal cell suspension. Then, 2 mL of neutral amino-modified silica sol (particle size 20 nm, solid content 10%, pH 7.2) was added to the algal cell suspension, and the mixture was stirred at 95 rpm for 6.2 h at 24 °C in the dark. Finally, the supernatant was filtered off by gravity filtration, and the mixture was washed three times with 150 mL of sterile ultrapure water each time. After each wash, the supernatant was removed by gravity filtration, and the filtered precipitate was resuspended in 20 mL of sterile ultrapure water to obtain the silanized modified *Cladophora menesiensis* solution.

[0029] Step S2, Aqueous Two-Phase Separation and Embedding: First, prepare the continuous external phase of passivated Chlorella proteoglycans and the dispersed internal phase of silanized Chlorella menei. The continuous external phase of passivated Chlorella proteoglycans includes methylcellulose (4000 mPa·s, weight-average molecular weight 20000–40000 Da), sodium alginate (viscosity 100–200 mPa·s, weight-average molecular weight 10000–20000 Da), anhydrous calcium chloride, ... D-gluconic acid lactone (CAS: 4253-68-3), passivated Chlorella vulgaris extract, and sterile ultrapure water were prepared in a mass ratio of 147:14.7:5.4:17.5:392.7:589.1. The preparation steps were as follows: Methylcellulose and sodium alginate were added sequentially to sterile ultrapure water at 24°C in the dark. The mixture was stirred at 300 rpm for 15 minutes, followed by vacuum degassing for 7 minutes (-0.08M). (Pa degassing), add passivated Chlorella proteoglycans solution, stir at 50 rpm for 3 min, then add anhydrous calcium chloride and D-gluconic acid lactone (5 min before microfluidic injection), and continue stirring for 1 min to obtain the final product; the dispersion internal phase of silanized modified Chlorella menei consists of low melting point agarose (melting point 38-42℃), neutral amino-modified silica sol, silanized modified Chlorella menei solution, and sterile ultrapure water, with a mass ratio of 180:9:270:630; the preparation steps are as follows: under light-protected conditions, add low melting point agarose to sterile ultrapure water, heat in a constant temperature water bath at 63℃ for 11 min, then let stand in a constant temperature water bath at 38℃ for 9 min, then add neutral amino-modified silica sol, stir at 70 rpm for 4 min, and finally add silanized modified Chlorella menei solution (3 min before microfluidic injection), and keep stirring for 3 min to obtain the final product.

[0030] Next, a two-phase aqueous mixing and microfluidic preparation were performed sequentially. Specifically, the two-phase aqueous mixture was prepared by mixing the continuous external phase and the dispersed internal phase at a volume ratio of 3:1 at 24°C, stirring at 50 rpm for 3 minutes, and then allowing it to stand for 9 minutes. The microfluidic preparation was as follows: First, perfluoronaphthane was added to 0.48 wt% of tridecafluorooctyltriethoxysilane (i.e., the volume ratio of tridecafluorooctyltriethoxysilane to perfluoronaphthane was 4.8:1000), and stirred at 300 rpm for 15 minutes at 24°C in the dark to obtain the continuous oil phase. Then, a focusing microfluidic chip with a main channel size of 500 μm (purchased from Suzhou Wenhao Microfluidics Technology Co., Ltd. or Dalian MicroNano Technology; channel depth 100 μm, focusing port width 100 μm, length 200 μm, main channel width 500 μm) was used. The microspheres were prepared by mixing microspheres with a diameter of 1.5 μm, a length of 20 mm, and an outlet channel width of 500 μm and a length of 10 mm. The flow rate of the aqueous phase was 4.5 μL / min, and the flow rate of the oil continuous phase was 18 μL / min. After stabilizing the effluent, the monodisperse droplets at the outlet were collected in a sterile storage tube and allowed to stand at 24 °C for 11 min. Finally, the microspheres were washed three times with 5 times the volume of perfluorohexane for 5 min each time, followed by three times with 5 times the volume of sterile ultrapure water. After each washing, the supernatant was removed by gravity filtration (using a 100 μm sterile nylon filter) to obtain the microsphere cores.

[0031] Step S3, Core Modification and Regulation: First, the microsphere core is modified as follows: Take 10 mmol / L, pH 8.3 sterile Tris-HCl buffer and purge nitrogen gas at a flow rate of 0.75 L / min for 11 min (to remove dissolved oxygen) in a 24℃ dark environment; then, add the microsphere core and the pretreated Tris-HCl buffer at a volume ratio of 0.9:8.1 to a sterile reaction flask, add tannic acid to a final concentration of 0.8 g / L, and stir at 95 rpm for 32 min in a 24℃ dark environment. Remove the supernatant by gravity filtration (using a 100 μm sterile nylon filter), and then wash three times with sterile ultrapure water. After each wash, remove the supernatant by gravity filtration to obtain the modified microsphere core.

[0032] A second microfluidic encapsulation process was then performed: first, ovalbumin (CAS: 9006-59-1) and glycerol were added to sterile ultrapure water at a mass-to-volume ratio of 9.5 g: 1.9 g: 95 mL. The mixture was stirred at 330 rpm for 11 min and then degassed under vacuum for 4 min (-0.08 MPa) to obtain a foaming precursor solution. Next, the foaming precursor solution was mixed with the modified microsphere core suspension at a volume ratio of 9:1, stirred at 50 rpm for 3 min, and allowed to stand for 11 min to obtain a secondary microfluidic phase. A focusing microfluidic chip with a main channel size of 600 μm (purchased from Suzhou Wenhao Microfluidic Technology Co., Ltd.) was used. Alternatively, Dalian Micro-Nano Technology; channel depth 150μm, focusing port width 120μm, length 240μm, main channel width 600μm, length 25mm, outlet channel width 600μm, length 12mm); the flow rate of the aqueous phase is 7.5μL / min, and the flow rate of the oil continuous phase is 23.5μL / min. After stabilizing the liquid output, collect the monodisperse droplets at the outlet into a sterile storage tube and let it stand at 24℃ for 16min; finally, wash three times with 5 times the volume of microspheres of perfluorohexane, and then wash three times with 5 times the volume of microspheres of sterile ultrapure water. After each washing, remove the supernatant by natural gravity filtration (using a 100μm sterile nylon filter) to obtain the core-hollow microspheres.

[0033] Step S4, In-situ Preparation of the Shell: First, prepare the shell precursor solution. Specifically, firstly, dissolve Mg(NO3)2·6H2O, Al(NO3)3·9H2O, and Fe(NO3)3·9H2O in 100mL of ultrapure water at a molar ratio of 3:1:0.5 to obtain a salt solution. Under constant temperature stirring at 28℃ and a stirring speed of 200rpm, add the salt solution dropwise at a rate of 1mL / min to a 1mol / L NaOH solution. The volume of the NaOH solution is 115mL (to maintain pH stability). After the addition is complete, continue stirring for 32min. After hydrothermal reaction in a hydrothermal reactor at 118℃ for 6.2h, allow it to cool naturally to room temperature, wash with ultrapure water until neutral, and then vacuum dry at 58℃. Ternary powder was obtained after 12.5 h. The ternary powder was then dispersed in anhydrous ethanol at a mass-to-volume ratio of 1 g:20 mL. The dispersion was ultrasonically controlled for 32 min at 38 kHz, 100 W, and 24°C. KH570 (3-(methacryloyloxy)propyltrimethoxysilane, CAS: 2530-85-0) was then added at a mass ratio of 1.04:1. The pH of the system was adjusted to 4.4 with anhydrous citric acid. The mixture was stirred at 200 rpm for 4.2 h in a 58°C water bath. After washing three times with anhydrous ethanol and vacuum drying (at the same temperature and time as described above), the modified powder was obtained. Next, β-cyclodextrin was dissolved in 0.05 mol / L MES buffer at pH 5.5, with a β-cyclodextrin to MES buffer mass-to-volume ratio of 1 g:10 mL. Then, epichlorohydrin was added, with a 1:1 mass ratio of epichlorohydrin to β-cyclodextrin. The mixture was stirred at 200 rpm for 4.2 h at 24 °C in the dark, followed by dialysis for 24 h (using a regenerated cellulose dialysis bag with a molecular weight cutoff of 2000 Da, with the ultrapure water dialysis fluid replaced every 6 h during dialysis) to obtain an activated β-cyclodextrin solution. Finally, chitosan was dissolved in 1% L-lactic acid solution (CAS: 79-33-4) and stirred until dissolved to obtain a chitosan-based solution with a concentration of 20 g / L. The chitosan matrix solution (degree of deacetylation 85%~95%, weight average molecular weight 100~200kDa) was prepared. Gallic acid (CAS: 149-91-7) was then added to the chitosan matrix solution at a mass ratio of 0.2:1, and stirred until dissolved. Next, β-cyclodextrin activation solution was added at a volume-to-mass ratio of 5mL:1g, and the mixture was stirred at 200rpm for 2.2h at 24℃ in the dark. Then, modified powder was added at a mass ratio of 0.3:1, and the mixture was ultrasonically dispersed for 11min at a frequency of 38kHz, a power of 100W, and a constant temperature water bath at 24℃. Finally, tannic acid was added at a mass ratio of 0.3:1 to chitosan.Mix the chitosan and glycerol in a 1:1 ratio until dissolved, then add a low-substituted water-soluble chitosan quaternary ammonium salt (substitution degree 3%–5%). The mass ratio of chitosan quaternary ammonium salt to chitosan is 0.1:1. Stir at 140 rpm for 6 minutes. Adjust the pH of the system to 6.7 using 1 mol / L NaOH solution. Add β-glycerophosphate disodium pentahydrate (CAS: 13408-09-8), bringing the final concentration of β-glycerophosphate disodium pentahydrate to 0.09 mol / L. Continue stirring at 140–160 rpm for 4–6 minutes to obtain the shell precursor solution.

[0034] The shell precursor solution and the core-hollow microspheres were used as the aqueous phase for three-stage microfluidic encapsulation. Specifically, the shell precursor solution and the core-hollow microsphere suspension were first mixed at a volume ratio of 8:2, stirred at 50 rpm for 3 minutes, and allowed to stand for 11 minutes to obtain three microfluidic aqueous phases. Then, a focusing microfluidic chip with a main channel size of 800 μm (purchased from Suzhou Wenhao Microfluidic Technology Co., Ltd. or Dalian MicroNano Technology; channel depth 200 μm, focusing port width 160 μm, length 320 μm, main channel width 800 μm, length 320 μm) was used. The outlet channel width is 800 μm and the length is 15 mm. The flow rate of the aqueous phase is 9.5 μL / min and the flow rate of the oil continuous phase is 28.5 μL / min. After the liquid is stabilized, the monodisperse droplets at the outlet are collected in a sterile storage tube and allowed to stand at 37°C in the dark for 11 min. Finally, the microspheres are washed three times with 5 times the volume of perfluorohexane and then three times with 5 times the volume of sterile ultrapure water. After each washing, the supernatant is removed by gravity filtration (using a 100 μm sterile nylon filter) to obtain the tertiary structure microspheres.

[0035] Step S5, Outer Interface Anchoring Modification: First, prepare a nanocrystalline cellulose suspension. Specifically, add cellulose (such as cotton linter cellulose, degree of polymerization 800-1200) to a 64wt% sulfuric acid solution. The mass-to-volume ratio of cellulose to sulfuric acid solution is 1g:100mL. Stir at 280rpm for 4.2h in a 43℃ water bath. Then add 10 times the volume of ultrapure water. Filter and wash until neutral using gravity filtration (using a 0.22μm sterile filter membrane). Dialyze for 3 days until the conductivity stabilizes (using a regenerated cellulose dialysis bag with a molecular weight cutoff of 10000Da, dialysis every 12h). (The dialysis fluid was replaced with ultrapure water). The cellulose suspension was ultrasonically dispersed for 32 min at a frequency of 38 kHz, a power of 100 W, and a constant temperature water bath of 24 ℃ to obtain a cellulose suspension with a solid content of 1 wt%. Then, the cellulose suspension was added to a Tris-HCl buffer solution with a concentration of 0.1 mol / L and a pH of 8.5 at a volume ratio of 1:10. Epichlorohydrin was then added, with a mass ratio of epichlorohydrin to the solids in the cellulose suspension of 1:2. The mixture was stirred at 200 rpm for 12.5 h at 24 ℃ in the dark. After dialysis for 3 days to remove unreacted reagents, a suspension with a solid content of 1 wt% was obtained. Next, the tertiary structure microspheres were modified by interfacial anchoring using a nanocrystalline cellulose suspension. Specifically, the tertiary structure microsphere suspension was first added to the nanocrystalline cellulose suspension at a volume ratio of 1:9. The mixture was stirred at 95 rpm for 4.2 h at 24 °C in the dark to form a three-dimensional nanocrystalline cellulose network anchoring layer. The microspheres were then washed three times with 5 times the volume of sterile ultrapure water. After each wash, the supernatant was removed by gravity filtration (using a 100 μm sterile nylon filter) to obtain the anchoring layer modified microspheres. Finally, the passivation layer medium was prepared. Specifically, the anchoring layer modified microsphere suspension was added to a Tris-HCl buffer solution with a concentration of 0.1 mol / L and a pH of 7.2 at a volume ratio of 1:9. Then, methoxy polyethylene glycol silane (molecular weight 2000) was added, and the final concentration of methoxy polyethylene glycol silane after addition was 4.8 g / L. The mixture was stirred at 150 rpm for 4.2 h at 24 °C in the dark. After the reaction was completed, the supernatant was removed by gravity filtration (using a 100 μm sterile nylon filter). The mixture was then washed 5 times with 5 times the volume of sterile ultrapure water to remove unreacted reagents and impurities. After each washing, the reagents were removed by gravity filtration (using a 100 μm sterile nylon filter). After the final filtration, the filtrate was discarded and allowed to drain naturally to obtain the composite algae microspheres.

[0036] Example 2: A rapid and efficient method for ecologically restoring polluted water bodies from small-scale agriculture involves using large weed enclosure nets to add (e.g.) Figure 1 As shown, large watercress Figure 2 As shown, the method of adding compound algae microspheres is combined (compound algae microspheres are added outside the enclosure). The area of ​​the enclosure for water hyacinth accounts for 30% of the area of ​​the small agricultural water body. The amount of water hyacinth added inside the enclosure is 40 kg / mu (enclosure area). The mass ratio of water hyacinth inside the enclosure to compound algae microspheres is 1:0.08 (total addition ratio).

[0037] Among them, the composite algae microspheres are composed of a composite algae agent of Chlorella pyrenoidosa and Cyclocarya mennidae, and the specific preparation method includes: Step S1, Targeted modification of algal cells: including passivation modification of Chlorella proteoglycans and silanization modification of Cyclocarya mennidae; The passivation modification of Chlorella proteoglycans is as follows: First, 200 mL of Chlorella proteoglycan solution is placed in a sterile storage tube, and algal cells are concentrated and collected using cross-flow microfiltration (at 4℃ in the dark, using a 0.45 μm sterile PES microfiltration membrane, cross-flow velocity of 0.8 m / s, and transmembrane pressure of 0.02 MPa). The supernatant of the culture medium is filtered off, and a wet precipitate of algal cells is obtained (concentrated to a wet weight concentration of 200 ± 20 g / L). Then, the precipitate is washed twice with 80 mL of 0.05 mol / L MES (2-morpholinoethanesulfonic acid) buffer at pH 5.5. After each wash, the precipitate is filtered by gravity filtration (e.g., using a 0.45 μm sterile CN-CA filter membrane), and the filtered precipitate is resuspended in 100 mL of MES buffer. Algal cell suspension was obtained; then, 0.5 mL of a 10 mmol / L water-soluble biotin-N-succinimide ester (CAS: 35013-72-0) solution was added to the algal cell suspension, and the mixture was stirred at 100 rpm for 30 min at 25 °C in the dark; then, 0.5 g of methoxy polyethylene glycol amino (molecular weight 5000, CAS: 80506-64-5) was added, and the mixture was stirred at 100 rpm for 4 h at 25 °C in the dark; finally, the supernatant was removed by gravity filtration, and the mixture was washed three times with 80 mL of sterile ultrapure water each time. After each wash, the supernatant was removed by gravity filtration, and the filtered precipitate was resuspended in 20 mL of sterile ultrapure water to obtain the passivated and modified Chlorella proteoglycans solution.

[0038] The silanization modification of *Cyclocarya melilotus* was carried out as follows: First, 200 mL of *Cyclocarya melilotus* solution was placed in a sterile storage tube, and algal cells were concentrated and collected using cross-flow microfiltration (at 4℃ in the dark, using a 0.45 μm sterile PES microfiltration membrane, cross-flow velocity of 0.8 m / s, and transmembrane pressure of 0.02 MPa). The supernatant was filtered off, and the wet precipitate of algal cells was obtained (concentrated to a wet weight concentration of 150 ± 15 g / L). Then, the cells were washed twice with 150 mL of 0.2 mol / L sterile isotonic trehalose solution (pH 7.2) and once with 150 mL of sterile ultrapure water. After each washing, the cells were filtered using natural gravity filtration (e.g., using a 0.45 μm sterile CN-CA filter membrane). The filtered precipitate was resuspended in 100 mL of 0.1 mol / L neutral Tris-HCl buffer (pH 7.5 ± 0.2) to obtain an algal cell suspension. Then, 2 mL of neutral amino-modified silica sol (particle size 20 nm, solid content 10%, pH 7.2) was added to the algal cell suspension, and the mixture was stirred at 100 rpm for 6 h at 25 °C in the dark. Finally, the supernatant was filtered off by gravity filtration, and the mixture was washed three times with 150 mL of sterile ultrapure water each time. After each wash, the supernatant was removed by gravity filtration, and the filtered precipitate was resuspended in 20 mL of sterile ultrapure water to obtain the silanized modified Cladophora menesiensis solution.

[0039] Step S2, Aqueous Two-Phase Separation and Embedding: First, prepare the continuous external phase of passivated Chlorella proteoglycans and the dispersed internal phase of silanized Chlorella menei. The continuous external phase of passivated Chlorella proteoglycans includes methylcellulose (4000 mPa·s, weight-average molecular weight 20000–40000 Da), sodium alginate (viscosity 100–200 mPa·s, weight-average molecular weight 10000–20000 Da), anhydrous calcium chloride, and D... β-gluconolactone (CAS: 4253-68-3), passivated Chlorella vulgaris extract, and sterile ultrapure water were prepared in a mass ratio of 150:15:5.5:17.8:400:600. The preparation steps were as follows: methylcellulose and sodium alginate were added sequentially to sterile ultrapure water at 25°C and in the dark, stirred at 350 rpm for 12.5 min, and then degassed under vacuum for 8 min (-0.08 MPa). Add the passivated Chlorella proteoglycans solution and stir at 65 rpm for 2.5 min. Then add anhydrous calcium chloride and D-gluconic acid lactone (5 min before microfluidic injection) and continue stirring for 1 min to obtain the final product. The internal dispersion of silanized Chlorella melioides consists of low-melting-point agarose (melting point 38-42℃), neutral amino-modified silica sol, silanized Chlorella melioides solution, and sterile ultrapure water in a mass ratio of 200:10:300:700. The preparation steps are as follows: Under light-protected conditions, add low-melting-point agarose to sterile ultrapure water and heat in a constant temperature water bath at 65℃ for 10 min. Then, let it stand in a constant temperature water bath at 39℃ for 8 min. Next, add neutral amino-modified silica sol and stir at 80 rpm for 3 min. Finally, add silanized Chlorella melioides solution (3 min before microfluidic injection) and keep stirring for 2.5 min to obtain the final product.

[0040] Next, a two-phase aqueous mixing and microfluidic preparation were performed sequentially. Specifically, the two-phase aqueous mixture was prepared by mixing the continuous external phase and the dispersed internal phase at a volume ratio of 3:1 at 25°C, stirring at 65 rpm for 2 minutes, and then allowing it to stand for 10 minutes. The microfluidic preparation was as follows: First, perfluoronaphthane was added to 0.5 wt% of tridecafluorooctyltriethoxysilane (i.e., the volume ratio of tridecafluorooctyltriethoxysilane to perfluoronaphthane was 5:1000), and stirred at 350 rpm for 12.5 minutes at 25°C in the dark to obtain the continuous oil phase. Then, a focusing microfluidic chip with a main channel size of 500 μm (purchased from Suzhou Wenhao Microfluidics Technology Co., Ltd. or Dalian MicroNano Technology; channel depth 100 μm, focusing port width 100 μm, length 200 μm, main channel width 500 μm) was used. The microsphere cores were prepared by a process involving a 20mm long, 500μm wide, and 10mm long outlet channel. The flow rate of the aqueous phase was 5μL / min, and the flow rate of the continuous oil phase was 20μL / min. After stabilizing the outlet, the monodisperse droplets were collected in a sterile storage tube and allowed to stand at 25℃ for 10min. Finally, the microsphere cores were washed three times with 7.5 times the volume of the microsphere cores in perfluorohexane for 5min each time, followed by three times with 7.5 times the volume of the microsphere cores in sterile ultrapure water. After each wash, the supernatant was removed by gravity filtration (using a 100μm sterile nylon filter) to obtain the microsphere cores.

[0041] Step S3, Core Modification and Regulation: First, the microsphere core is modified as follows: Take 10 mmol / L, pH 8.3 sterile Tris-HCl buffer and purge nitrogen gas at a flow rate of 0.8 L / min for 10 min (to remove dissolved oxygen) in a light-protected environment at 25℃. Then, add the microsphere core and the pretreated Tris-HCl buffer at a volume ratio of 1:9 to a sterile reaction flask, and add tannic acid to a final concentration of 1.0 g / L. Stir at 100 rpm for 30 min in a light-protected environment at 25℃. Remove the supernatant by gravity filtration (using a 100 μm sterile nylon filter). Wash three times with sterile ultrapure water, removing the supernatant after each wash by gravity filtration to obtain the modified microsphere core.

[0042] A second microfluidic encapsulation process was then performed: first, ovalbumin (CAS: 9006-59-1) and glycerol were added to sterile ultrapure water at a mass-to-volume ratio of 10g:2g:100mL. The mixture was stirred at 350rpm for 10min and then degassed under vacuum for 5min (-0.08MPa) to obtain a foaming precursor solution. Next, the foaming precursor solution was mixed with the modified microsphere core suspension at a volume ratio of 9:1, stirred at 65rpm for 2min, and allowed to stand for 10min to obtain a secondary microfluidic phase. A focusing microfluidic chip with a main channel size of 600μm (purchased from Suzhou Wenhao Microfluidic Technology Co., Ltd.) was used. Dalian Micro-Nano Technology; channel depth 150μm, focusing port width 120μm, length 240μm, main channel width 600μm, length 25mm, outlet channel width 600μm, length 12mm); the flow rate of the aqueous phase is 8μL / min, and the flow rate of the oil continuous phase is 25μL / min. After stabilizing the liquid output, the monodisperse droplets at the outlet are collected in a sterile storage tube and allowed to stand at 25℃ for 15min. Finally, the microspheres are washed three times with 7.5 times the volume of perfluorohexane and then three times with 7.5 times the volume of sterile ultrapure water. After each washing, the supernatant is removed by gravity filtration (using a 100μm sterile nylon filter) to obtain the core-hollow microspheres.

[0043] Step S4, In-situ Preparation of the Shell: First, prepare the shell precursor solution. Specifically, firstly, dissolve Mg(NO3)2·6H2O, Al(NO3)3·9H2O, and Fe(NO3)3·9H2O in 100mL of ultrapure water at a molar ratio of 3:1:0.5 to obtain a salt solution. Under constant temperature stirring at 28℃ and a stirring speed of 250rpm, add the salt solution dropwise to a 1mol / L NaOH solution at a concentration of 1.5mL / min. The volume of the NaOH solution is 117mL (to maintain pH stability). After the addition is complete, continue stirring for 30min. After hydrothermal reaction in a hydrothermal reactor at 120℃ for 6h, allow it to cool naturally to room temperature, wash with ultrapure water until neutral, and then vacuum at 60℃. After drying for 12 hours, ternary powder was obtained. Then, the ternary powder was dispersed in anhydrous ethanol at a mass-to-volume ratio of 1 g:20 mL. The dispersion was ultrasonically controlled for 30 minutes at a frequency of 40 kHz, a power of 125 W, and a constant temperature water bath at 25 °C. KH570 (3-(methacryloyloxy)propyltrimethoxysilane, CAS: 2530-85-0) was then added at a mass ratio of 1.05:1 to the ternary powder. The pH of the system was adjusted to 4.5 with anhydrous citric acid. The mixture was stirred at 250 rpm for 4 hours in a constant temperature water bath at 60 °C. After washing three times with anhydrous ethanol and vacuum drying (at the same temperature and time as described above), modified powder was obtained. Next, β-cyclodextrin was dissolved in 0.05 mol / L MES buffer at pH 5.5, with a β-cyclodextrin to MES buffer mass-to-volume ratio of 1 g:10 mL. Then, epichlorohydrin was added, with a 1:1 mass ratio of epichlorohydrin to β-cyclodextrin. The mixture was stirred at 250 rpm for 4 h at 25°C in the dark, followed by dialysis for 24 h (using a regenerated cellulose dialysis bag with a molecular weight cutoff of 2000 Da, with the ultrapure water dialysis fluid replaced every 6 h during dialysis) to obtain an activated β-cyclodextrin solution. Finally, chitosan was dissolved in 1% L-lactic acid solution (CAS: 79-33-4) and stirred until dissolved to obtain a chitosan matrix with a concentration of 20 g / L. The chitosan matrix solution (degree of deacetylation 85%~95%, weight average molecular weight 100~200kDa) was prepared. Gallic acid (CAS: 149-91-7) was then added to the chitosan matrix solution at a mass ratio of 0.2:1, and stirred until dissolved. Next, β-cyclodextrin activating solution was added at a volume-to-mass ratio of 5mL:1g, and stirred at 250rpm for 2h at 25℃ in the dark. Then, modified powder was added at a mass ratio of 0.3:1, and ultrasonically dispersed for 10min at a frequency of 40kHz, a power of 1250W, and a constant temperature water bath at 25℃. Finally, tannic acid was added at a mass ratio of 0.3:1 to chitosan.Mix the chitosan and glycerol in a 1:1 ratio until dissolved, then add a low-substituted water-soluble chitosan quaternary ammonium salt (substitution degree 3%–5%). The mass ratio of chitosan quaternary ammonium salt to chitosan is 0.1:1. Stir at 150 rpm for 5 minutes. Adjust the pH of the system to 6.8 using 1 mol / L NaOH solution. Add β-glycerophosphate disodium pentahydrate (CAS: 13408-09-8), bringing the final concentration of β-glycerophosphate disodium pentahydrate to 0.1 mol / L. Continue stirring at 150 rpm for 5 minutes to obtain the shell precursor solution.

[0044] The shell precursor solution and the core-hollow microspheres were used as the aqueous phase for three-stage microfluidic encapsulation. Specifically, the shell precursor solution and the core-hollow microsphere suspension were first mixed at a volume ratio of 8:2, stirred at 65 rpm for 2 minutes, and allowed to stand for 10 minutes to obtain three microfluidic aqueous phases. Then, a focusing microfluidic chip with a main channel size of 800 μm (purchased from Suzhou Wenhao Microfluidic Technology Co., Ltd. or Dalian MicroNano Technology; channel depth 200 μm, focusing port width 160 μm, length 320 μm, main channel width 800 μm, length 320 μm) was used. The outlet channel is 800 μm wide and 15 mm long. The flow rate of the aqueous phase is 10 μL / min and the flow rate of the continuous oil phase is 30 μL / min. After the liquid is stabilized, the monodisperse droplets at the outlet are collected in a sterile storage tube and allowed to stand at 38°C in the dark for 10 min. Finally, the microspheres are washed three times with 7.5 times the volume of perfluorohexane and then three times with 7.5 times the volume of sterile ultrapure water. After each washing, the supernatant is removed by gravity filtration (using a 100 μm sterile nylon filter) to obtain the tertiary structure microspheres.

[0045] Step S5, Outer Interface Anchoring Modification: First, prepare a nanocrystalline cellulose suspension. Specifically, add cellulose (such as cotton linter cellulose, degree of polymerization 800-1200) to a 64wt% sulfuric acid solution. The mass-to-volume ratio of cellulose to sulfuric acid solution is 1g:100mL. Stir at 300rpm for 4 hours in a 45℃ water bath. Then add 10 times the volume of ultrapure water. Filter and wash until neutral using gravity filtration (using a 0.22μm sterile filter membrane). Dialyze for 3 days until the conductivity stabilizes (using a regenerated cellulose dialysis bag with a molecular weight cutoff of 10000Da, changing the bag every 12 hours during dialysis). A cellulose suspension with a solid content of 1 wt% was obtained by ultrasonic dispersion of an ultrapure water dialysate (external solution) at a frequency of 40 kHz, a power of 125 W, and a constant temperature water bath at 25 ℃ for 30 min. Then, the cellulose suspension was added to a Tris-HCl buffer solution with a concentration of 0.1 mol / L and a pH of 8.5 at a volume ratio of 1.5:10. Epichlorohydrin was then added, with a mass ratio of epichlorohydrin to the solids in the cellulose suspension of 1:2. The mixture was stirred at 250 rpm for 12 h at 25 ℃ in the dark. After dialyzing for 3 days to remove unreacted reagents, a suspension with a solid content of 1 wt% was obtained.

[0046] The tertiary structure microspheres were then modified by interfacial anchoring using a nanocrystalline cellulose suspension. Specifically, the tertiary structure microsphere suspension was added to the nanocrystalline cellulose suspension at a volume ratio of 1:9. The mixture was stirred at 100 rpm for 4 hours at 25°C in the dark to form a three-dimensional nanocrystalline cellulose network anchoring layer. The microspheres were then washed three times with 7.5 times the volume of sterile ultrapure water. After each wash, the supernatant was removed by gravity filtration (using a 100 μm sterile nylon filter) to obtain the anchoring layer modified microspheres.

[0047] Finally, the passivation layer medium was prepared. Specifically, the anchoring layer modified microsphere suspension was added to a Tris-HCl buffer solution with a concentration of 0.1 mol / L and a pH of 7.2 at a volume ratio of 1:9. Then, methoxy polyethylene glycol silane (molecular weight 2000) was added to a final concentration of 5 g / L. The mixture was stirred at 175 rpm for 4 hours at 25°C in the dark. After the reaction was completed, the supernatant was removed by gravity filtration (using a 100 μm sterile nylon filter). The mixture was then washed 5 times with 7.5 times its volume of sterile ultrapure water to remove unreacted reagents and impurities. After each wash, the reagents were removed by gravity filtration (using a 100 μm sterile nylon filter). After the final filtration, the filtrate was discarded and allowed to drain naturally to obtain the composite algae microspheres.

[0048] Example 3: A rapid and efficient method for ecologically restoring polluted water bodies from small-scale agriculture involves using large weed enclosure nets to add (e.g.) Figure 1 As shown, large watercress Figure 2 As shown, the method of adding compound algae microspheres is combined (compound algae microspheres are added outside the enclosure). The area of ​​the enclosure for water hyacinth accounts for 30% of the area of ​​the small agricultural water body. The amount of water hyacinth added inside the enclosure is 40 kg / mu (enclosure area). The mass ratio of water hyacinth inside the enclosure to compound algae microspheres is 1:0.08 (total addition ratio).

[0049] Among them, the composite algae microspheres are composed of a composite algae agent of Chlorella pyrenoidosa and Cyclocarya mennidae, and the specific preparation method includes: Step S1, Targeted modification of algal cells: including passivation modification of Chlorella proteoglycans and silanization modification of Cyclocarya mennidae; The passivation modification of Chlorella proteoglycans is as follows: First, 200 mL of Chlorella proteoglycan solution is placed in a sterile storage tube, and algal cells are concentrated and collected using cross-flow microfiltration (at 4℃ in the dark, using a 0.45 μm sterile PES microfiltration membrane, cross-flow velocity of 0.8 m / s, and transmembrane pressure of 0.02 MPa). The supernatant of the culture medium is filtered off to obtain a wet precipitate of algal cells (concentrated to a wet weight concentration of 200 ± 20 g / L). Then, the cells are washed twice with 80 mL of 0.05 mol / L MES (2-morpholinoethanesulfonic acid) buffer at pH 5.5. After each wash, the cells are filtered using natural gravity filtration (e.g., using a 0.45 μm sterile CN-CA filter membrane), and the filtered precipitate is resuspended in 100 mL of MES buffer to obtain an algal cell suspension (concentrated to a wet weight concentration of 200 ± 20 g / L). The cell wet weight concentration was 150±15 g / L. Then, 0.5 mL of a 10 mmol / L water-soluble biotin-N-succinimide ester (CAS: 35013-72-0) solution was added to the algal cell suspension, and the mixture was stirred at 105 rpm for 28 min at 26℃ in the dark. After that, 0.5 g of methoxy polyethylene glycol amino (molecular weight 5000, CAS: 80506-64-5) was added, and the mixture was stirred at 105 rpm for 3.8 h at 26℃ in the dark. Finally, the supernatant was removed by gravity filtration, and the mixture was washed three times with 80 mL of sterile ultrapure water each time. After each wash, the supernatant was removed by gravity filtration, and the filtered precipitate was resuspended in 20 mL of sterile ultrapure water to obtain the passivated and modified Chlorella proteoglycans solution.

[0050] The silanization modification of *Cyclocarya melilotus* is as follows: First, 200 mL of *Cyclocarya melilotus* solution was placed in a sterile storage tube, and algal cells were concentrated and collected using cross-flow microfiltration (at 4℃ in the dark, using a 0.45 μm sterile PES microfiltration membrane, cross-flow velocity of 0.8 m / s, and transmembrane pressure of 0.02 MPa). The supernatant was filtered off to obtain a wet precipitate of algal cells. The precipitate was then washed twice with 150 mL of 0.2 mol / L sterile isotonic trehalose solution (pH 7.2) and once with 150 mL of sterile ultrapure water. After each washing, the precipitate was filtered using gravity filtration (e.g., using a 0.45 μm sterile CN-CA membrane), and the filtered precipitate was resuspended in 1 mL of water. Algal cell suspension was obtained by adding 2 mL of neutral amino-modified silica sol (particle size 20 nm, solid content 10%, pH 7.2) to the algal cell suspension and stirring at 105 rpm for 5.8 h at 26 °C in the dark. Finally, the supernatant was filtered off by gravity filtration and washed three times with sterile ultrapure water, 150 mL each time. After each wash, the supernatant was removed by gravity filtration and the filtered precipitate was resuspended in 20 mL of sterile ultrapure water to obtain the silanized modified Cladophora menesiensis solution.

[0051] Step S2, Aqueous Two-Phase Separation and Embedding: First, prepare the continuous external phase of passivated Chlorella proteoglycans and the dispersed internal phase of silanized Chlorella menei. The continuous external phase of passivated Chlorella proteoglycans includes methylcellulose (4000 mPa·s, weight-average molecular weight 20000–40000 Da), sodium alginate (viscosity 100–200 mPa·s, weight-average molecular weight 10000–20000 Da), anhydrous calcium chloride, ... D-gluconic acid lactone (CAS: 4253-68-3), passivated Chlorella vulgaris extract, and sterile ultrapure water were prepared in a mass ratio of 153:15.3:5.6:18.1:407.3:610.9. The preparation steps were as follows: Methylcellulose and sodium alginate were added sequentially to sterile ultrapure water at 26°C in the dark. The mixture was stirred at 400 rpm for 10 minutes, followed by vacuum degassing for 9 minutes (-0.08M). (Pa degassing), add passivated Chlorella proteoglycans solution, stir at 80 rpm for 2 min, then add anhydrous calcium chloride and D-gluconic acid lactone (5 min before microfluidic injection), and continue stirring for 1 min to obtain the final product; the dispersion internal phase of silanized modified Chlorella menei consists of low melting point agarose (melting point 38-42℃), neutral amino-modified silica sol, silanized modified Chlorella menei solution, and sterile ultrapure water, with a mass ratio of 220:11:330:770; the preparation steps are as follows: under light-protected conditions, add low melting point agarose to sterile ultrapure water, heat in a constant temperature water bath at 67℃ for 9 min, then let stand in a constant temperature water bath at 40℃ for 7 min, then add neutral amino-modified silica sol, stir at 90 rpm for 2 min, and finally add silanized modified Chlorella menei solution (3 min before microfluidic injection), and keep stirring for 2 min to obtain the final product.

[0052] Next, a two-phase aqueous mixing and microfluidic preparation were performed sequentially. Specifically, the two-phase aqueous mixture was prepared by mixing the continuous external phase and the dispersed internal phase at a volume ratio of 3:1 at 26°C, stirring at 80 rpm for 1 min, and then allowing it to stand for 11 min. The microfluidic preparation was as follows: First, perfluoronaphthane was added to 0.52 wt% of tridecafluorooctyltriethoxysilane (i.e., the volume ratio of tridecafluorooctyltriethoxysilane to perfluoronaphthane was 5.2:1000), and stirred at 400 rpm for 10 min at 26°C in the dark to obtain the continuous oil phase. Then, a focusing microfluidic chip with a main channel size of 500 μm (purchased from Suzhou Wenhao Microfluidics Technology Co., Ltd. or Dalian MicroNano Technology; channel depth 100 μm, focusing port width 100 μm, length 200 μm, main channel width 500 μm) was used. The microsphere cores were prepared by mixing microspheres with a diameter of 1.5 μm (20 mm in length and 500 μm in width and 10 mm in length) and an outlet channel (500 μm in width and 10 mm in length). The flow rate of the aqueous phase was 5.5 μL / min and the flow rate of the oil continuous phase was 22 μL / min. After stabilizing the outlet, the monodisperse droplets were collected in a sterile storage tube and allowed to stand at 26 °C for 9 min. Finally, the microsphere cores were washed three times with 10 times the volume of perfluorohexane for 5 min each time, followed by three times with 10 times the volume of sterile ultrapure water. After each wash, the supernatant was removed by gravity filtration (using a 100 μm sterile nylon filter) to obtain the microsphere cores.

[0053] Step S3, Core Modification and Regulation: First, the microsphere core is modified as follows: Take 10 mmol / L, pH 8.3 sterile Tris-HCl buffer and purge nitrogen gas at a flow rate of 0.85 L / min for 9 min (to remove dissolved oxygen) in a 26℃ dark environment; then, add the microsphere core and the pretreated Tris-HCl buffer at a volume ratio of 1.1:9.9 to a sterile reaction flask, add tannic acid to a final concentration of 1.2 g / L, and stir at 105 rpm for 28 min in a 26℃ dark environment. Remove the supernatant by gravity filtration (using a 100 μm sterile nylon filter), and then wash three times with sterile ultrapure water. After each wash, remove the supernatant by gravity filtration to obtain the modified microsphere core.

[0054] A second microfluidic encapsulation process was then performed: first, ovalbumin (CAS: 9006-59-1) and glycerol were added to sterile ultrapure water at a mass-to-volume ratio of 10.5 g: 2.1 g: 105 mL. The mixture was stirred at 370 rpm for 9 min and then degassed under vacuum for 6 min (-0.08 MPa) to obtain a foaming precursor solution. Next, the foaming precursor solution was mixed with the modified microsphere core suspension at a volume ratio of 9:1, stirred at 80 rpm for 1 min, and allowed to stand for 9 min to obtain a secondary microfluidic phase. A focusing microfluidic chip with a main channel size of 600 μm (purchased from Suzhou Wenhao Microfluidics Technology Co., Ltd.) was used. Dalian Micro-Nano Technology; channel depth 150μm, focusing port width 120μm, length 240μm, main channel width 600μm, length 25mm, outlet channel width 600μm, length 12mm); the flow rate of the aqueous phase is 8.5μL / min, and the flow rate of the oil continuous phase is 26.5μL / min. After stabilizing the liquid output, the monodisperse droplets at the outlet are collected in a sterile storage tube and allowed to stand at 26℃ for 14min. Finally, the microspheres are washed three times with 10 times the volume of perfluorohexane and then three times with 10 times the volume of sterile ultrapure water. After each washing, the supernatant is removed by gravity filtration (using a 100μm sterile nylon filter) to obtain the core-hollow microspheres.

[0055] Step S4, In-situ Preparation of the Shell: First, prepare the shell precursor solution. Specifically, firstly, dissolve Mg(NO3)2·6H2O, Al(NO3)3·9H2O, and Fe(NO3)3·9H2O in 100mL of ultrapure water at a molar ratio of 3:1:0.5 to obtain a salt solution. Under constant temperature stirring at 28℃ and a stirring speed of 300rpm, add the salt solution dropwise to a 1mol / L NaOH solution at a concentration of 120mL (to maintain pH stability). After the addition is complete, continue stirring for 28min. After hydrothermal reaction in a hydrothermal reactor at 122℃ for 5.8h, allow it to cool naturally to room temperature, wash with ultrapure water until neutral, and then vacuum dry at 62℃. After 11.5 hours, ternary powder was obtained. Then, the ternary powder was dispersed in anhydrous ethanol at a mass-to-volume ratio of 1 g:20 mL. The dispersion was ultrasonically controlled for 28 minutes at a frequency of 42 kHz, a power of 150 W, and a constant temperature water bath at 26 °C. KH570 (3-(methacryloyloxy)propyltrimethoxysilane, CAS: 2530-85-0) was then added at a mass ratio of 1.06:1 to the ternary powder. The pH of the system was adjusted to 4.6 with anhydrous citric acid. The mixture was stirred at 300 rpm for 3.8 hours in a constant temperature water bath at 62 °C. After washing three times with anhydrous ethanol and vacuum drying (at the same temperature and time as described above), the modified powder was obtained. Then, β-cyclodextrin was dissolved in 0.05 mol / L MES buffer at pH 5.5, with a mass-to-volume ratio of β-cyclodextrin to MES buffer of 1 g:10 mL. Epichlorohydrin was then added, with a mass ratio of epichlorohydrin to β-cyclodextrin of 1:1. The mixture was stirred at 300 rpm for 3.8 h at 26 °C in the dark, followed by dialysis for 24 h (using a regenerated cellulose dialysis bag with a molecular weight cutoff of 2000 Da, replacing the ultrapure water dialysis fluid every 6 h) to obtain an activated β-cyclodextrin solution. Finally, chitosan was dissolved in 1% L-lactic acid solution (CAS: 79-33-4) and stirred until dissolved to obtain a chitosan-based solution with a concentration of 20 g / L. The chitosan matrix solution (degree of deacetylation 85%~95%, weight average molecular weight 100~200kDa) was prepared. Gallic acid (CAS: 149-91-7) was then added to the chitosan matrix solution at a mass ratio of 0.2:1, and stirred until dissolved. Next, β-cyclodextrin activation solution was added at a volume-to-mass ratio of 5 mL:1 g, and the mixture was stirred at 300 rpm for 1.8 h at 26°C in the dark. Then, modified powder was added at a mass ratio of 0.3:1, and the mixture was ultrasonically dispersed for 9 min at a frequency of 42 kHz, a power of 150 W, and a constant temperature water bath at 26°C. Finally, tannic acid was added at a mass ratio of 0.3:1 to chitosan.Mix the chitosan and glycerol in a 1:1 ratio until dissolved, then add a low-substituted water-soluble chitosan quaternary ammonium salt (substitution degree 3%–5%). The mass ratio of chitosan quaternary ammonium salt to chitosan is 0.1:1. Stir at 160 rpm for 4 minutes. Adjust the pH of the system to 6.9 using 1 mol / L NaOH solution. Add β-glycerophosphate disodium pentahydrate (CAS: 13408-09-8), bringing the final concentration of β-glycerophosphate disodium pentahydrate to 0.11 mol / L. Continue stirring at 160 rpm for 4 minutes to obtain the shell precursor solution.

[0056] The shell precursor solution and the core-hollow microspheres were used as the aqueous phase for three-stage microfluidic encapsulation. Specifically, the shell precursor solution and the core-hollow microsphere suspension were first mixed at a volume ratio of 8:2, stirred at 80 rpm for 1 min, and allowed to stand for 9 min to obtain three microfluidic aqueous phases. Then, a focusing microfluidic chip with a main channel size of 800 μm (purchased from Suzhou Wenhao Microfluidic Technology Co., Ltd. or Dalian MicroNano Technology; channel depth 200 μm, focusing port width 160 μm, length 320 μm, main channel width 800 μm, length 30 μm) was used. The outlet channel is 800 μm wide and 15 mm long. The flow rate of the aqueous phase is 10.5 μL / min and the flow rate of the oil continuous phase is 31.5 μL / min. After the liquid is stabilized, the monodisperse droplets at the outlet are collected in a sterile storage tube and allowed to stand at 39 °C in the dark for 9 min. Finally, the microspheres are washed three times with 10 times the volume of perfluorohexane and then three times with 10 times the volume of sterile ultrapure water. After each washing, the supernatant is removed by gravity filtration (using a 100 μm sterile nylon filter) to obtain the tertiary structure microspheres.

[0057] Step S5, Outer Interface Anchoring Modification: First, prepare a nanocrystalline cellulose suspension. Specifically, add cellulose (such as cotton linter cellulose, degree of polymerization 800-1200) to a 64wt% sulfuric acid solution. The mass-to-volume ratio of cellulose to sulfuric acid solution is 1g:100mL. Stir at 320rpm for 3.8h in a 47℃ water bath. Then add 10 times the volume of ultrapure water. Filter and wash until neutral using gravity filtration (using a 0.22μm sterile filter membrane). Dialyze for 3 days until conductivity stabilizes (using a regenerated cellulose dialysis bag with a molecular weight cutoff of 10000Da, with adjustments made every 12h during dialysis). (The dialysis fluid was changed once with ultrapure water). The cellulose suspension was ultrasonically dispersed for 28 min at a frequency of 42 kHz, a power of 150 W, and a constant temperature water bath of 26 ℃ to obtain a cellulose suspension with a solid content of 1 wt%. Then, the cellulose suspension was added to a Tris-HCl buffer solution with a concentration of 0.1 mol / L and a pH of 8.5 at a volume ratio of 2:10. Epichlorohydrin was then added, with a mass ratio of epichlorohydrin to the solid content of the cellulose suspension of 1:2. The mixture was stirred at 300 rpm for 11.5 h at 26 ℃ in the dark. After dialysis for 3 days to remove unreacted reagents, a suspension with a solid content of 1 wt% was obtained.

[0058] The tertiary structure microspheres were then modified by interfacial anchoring using a nanocrystalline cellulose suspension. Specifically, the tertiary structure microsphere suspension was added to the nanocrystalline cellulose suspension at a volume ratio of 1:9. The mixture was stirred at 105 rpm for 3.8 h at 26 °C in the dark to form a three-dimensional nanocrystalline cellulose network anchoring layer. The microspheres were then washed three times with 10 times the volume of sterile ultrapure water. After each wash, the supernatant was removed by gravity filtration (using a 100 μm sterile nylon filter) to obtain the anchoring layer modified microspheres.

[0059] Finally, the passivation layer medium was prepared. Specifically, the anchoring layer modified microsphere suspension was added to a Tris-HCl buffer solution with a concentration of 0.1 mol / L and a pH of 7.2 at a volume ratio of 1:9. Then, methoxy polyethylene glycol silane (molecular weight 2000) was added, and the final concentration of methoxy polyethylene glycol silane after addition was 5.2 g / L. The mixture was stirred at 200 rpm for 3.8 h at 26 °C in the dark. After the reaction was completed, the supernatant was removed by gravity filtration (using a 100 μm sterile nylon filter). The mixture was then washed 5 times with 10 times its volume of sterile ultrapure water to remove unreacted reagents and impurities. After each wash, the reagents were removed by gravity filtration (using a 100 μm sterile nylon filter). After the final filtration, the filtrate was discarded and allowed to drain naturally to obtain the composite algae microspheres.

[0060] Example 4: As another preferred embodiment of the present invention, based on any one of Embodiments 1 to 3, the Chlorella proteoglycans solution and Cyclocarya meniensis solution in step S1 are both purchased from the Freshwater Algae Culture Bank of the Chinese Academy of Sciences (Chlorella proteoglycans number FACHB-5, Cyclocarya meniensis number FACHB-1955) and subjected to standardized large-scale culture, specifically as follows: Chlorella proteoglycans were cultured on sterile BG11 medium (BG11 medium is a widely used basic medium for microalgae culture, and its formula includes ferric ammonium citrate, vitamin B6 solution, etc.); Cyclocarya meni was cultured on standard BG11 medium with the addition of 100 mg / L Na2SiO3·9H2O and the pH adjusted to 7.1–7.3.

[0061] Culture conditions: constant temperature and light shaking incubator, temperature 24-26℃, light intensity 1950-2050 lux, light duration 12h / day, shaking speed 145-155rpm, aseptic culture environment.

[0062] During mid-logarithmic growth, the OD of Chlorella proteoglycans... 680 =1.2±0.1, cell density ≥5×10 6 cells / mL; OD of *Ménidella* 680 =0.8±0.1, cell density ≥2×10 6 When the number of cells / mL reaches a certain level, harvesting can begin.

[0063] Comparative Example 1: A method for remediating polluted water bodies in small-scale agriculture involves combining the application of *Potentilla chinensis* (a type of weed) through a net enclosure with the addition of compound algae microspheres (the compound algae microspheres are added outside the net enclosure). The net enclosure covers 30% of the area of ​​the small-scale agricultural water body, and the application rate of *Potentilla chinensis* within the net enclosure is 40 kg / mu (net area). The mass ratio of *Potentilla chinensis* to compound algae microspheres within the net enclosure is 1:0.08.

[0064] Among them, the composite algae microspheres are composed of a composite algae agent of Chlorella pyrenoidosa and Cyclocarya mennidae, and the specific preparation method includes: Step S1, Aqueous Two-Phase Separation and Embedding: First, prepare the continuous external phase of *Chlorella proteoglycans* and the dispersed internal phase of *Cladosporium mennidense*. The continuous external phase of *Chlorella proteoglycans* includes methylcellulose (4000 mPa·s), sodium alginate (viscosity 100-200 mPa·s), anhydrous calcium chloride, D-gluconic acid lactone (CAS: 4253-68-3), *Chlorella proteoglycans* solution, and sterile ultrapure water in a mass ratio of 150:15:5.5:17.8:400:600. The preparation steps are as follows: Under light-protected conditions at 25℃, methylcellulose and sodium alginate are added sequentially to sterile ultrapure water, stirred at 350 rpm for 12.5 min, and then degassed under vacuum for 8 min (-0.08 MPa). Then, the passivated *Chlorella proteoglycans* solution is added, and the mixture is stirred at 65 rpm for 2.5 min. Add paraffin-embedded calcium chloride microspheres (5 min before microfluidic injection) and continue stirring for 1 min to obtain the final product. The internal dispersion of *Cyclocarya melilotes* consists of low-melting-point agarose, neutral amino-modified silica sol (particle size 20 nm, solid content 10%, pH 7.2), silanized *Cyclocarya melilotes* solution, and sterile ultrapure water in a mass ratio of 200:10:300:700. The preparation steps are as follows: Under light-protected conditions, add low-melting-point agarose to sterile ultrapure water and heat in a constant temperature water bath at 65°C for 10 min. Then, let it stand in a constant temperature water bath at 39°C for 8 min. Next, add neutral amino-modified silica sol and stir at 80 rpm for 3 min. Finally, add silanized *Cyclocarya melilotes* solution (3 min before microfluidic injection) and keep stirring for 2.5 min to obtain the final product.

[0065] Then, the two-phase aqueous mixing and microfluidic preparation are carried out in sequence, with the specific steps being the same as step S2 in Example 2, to obtain the microsphere core.

[0066] Step S2, kernel modification and regulation: consistent with step S3 in Example 2.

[0067] Step S3, In-situ preparation of the outer shell: Same as step S4 in Example 2.

[0068] Step S4, Outer Interface Anchoring Modification: Same as Step S5 in Example 2.

[0069] Comparative Example 2: A method for remediating polluted water bodies in small-scale agriculture involves combining the application of *Potentilla chinensis* (a type of weed) through a net enclosure with the addition of compound algae microspheres (the compound algae microspheres are added outside the net enclosure). The net enclosure covers 30% of the area of ​​the small-scale agricultural water body, and the application rate of *Potentilla chinensis* within the net enclosure is 40 kg / mu (net area). The mass ratio of *Potentilla chinensis* to compound algae microspheres within the net enclosure is 1:0.08.

[0070] Among them, the composite algae microspheres are composed of a composite algae agent of Chlorella pyrenoidosa and Cyclocarya mennidae, and the specific preparation method includes: Step S1, Algal Cell Directed Modification: Same as Step S1 in Example 2.

[0071] Step S2, Aqueous Two-Phase Separation and Embedding: Aqueous two-phase mixing and microfluidic preparation are performed sequentially. The aqueous two-phase mixing is specifically as follows: at 25°C, the passivated and modified Chlorella proteoglycans solution and the silanized and modified Cyclocarya melitica are mixed at a volume ratio of 3:1, stirred at 65 rpm for 2 min, and allowed to stand for 10 min to obtain the aqueous two-phase mixture.

[0072] The microfluidic control equipment is consistent with step S2 in Example 2.

[0073] Step S3, Kernel Modification and Regulation: Consistent with step S3 in Example 2.

[0074] Step S4, In-situ Preparation of the Outer Shell: Same as Step S4 in Example 2.

[0075] Step S5, outer interface anchoring modification: consistent with step S5 in Example 2.

[0076] Comparative Example 3: A method for remediating polluted water bodies in small-scale agriculture involves combining the application of *Potentilla chinensis* (a type of weed) through a net enclosure with the addition of compound algae microspheres (the compound algae microspheres are added outside the net enclosure). The net enclosure covers 30% of the area of ​​the small-scale agricultural water body, and the application rate of *Potentilla chinensis* within the net enclosure is 40 kg / mu (net area). The mass ratio of *Potentilla chinensis* to compound algae microspheres within the net enclosure is 1:0.08.

[0077] Among them, the composite algae microspheres are composed of a composite algae agent of Chlorella pyrenoidosa and Cyclocarya mennidae, and the specific preparation method includes: Step S1, Algal Cell Directed Modification: Same as Step S1 in Example 2.

[0078] Step S2, two-phase aqueous phase separation and embedding: consistent with step S2 in Example 2.

[0079] Step S3, Core Modification and Control: Secondary microfluidic embedding is performed, specifically: the foaming precursor solution and the microsphere core suspension are mixed at a volume ratio of 9:1, stirred at 65 rpm for 2 minutes, and allowed to stand for 10 minutes to obtain a secondary microfluidic aqueous phase. The foaming precursor solution is the same as in step S3 of Example 2. A focusing microfluidic chip with a main channel size of 600 μm (purchased from Suzhou Wenhao Microfluidics Technology Co., Ltd. or Dalian MicroNano Technology) is used to control the flow of the aqueous phase. The flow rate was 8 μL / min, and the flow rate of the oil phase continuous phase was 25 μL / min. After the liquid stabilized, the monodisperse droplets at the outlet were collected into a sterile storage tube and allowed to stand at 25°C for 15 min. Finally, the microspheres were washed three times with 7.5 times the volume of perfluorohexane and then three times with 7.5 times the volume of sterile ultrapure water. After each washing, the supernatant was removed by gravity filtration (using a 100 μm sterile nylon filter) to obtain the core-hollow microspheres.

[0080] Step S4, In-situ Preparation of the Outer Shell: Same as Step S4 in Example 2.

[0081] Step S5, outer interface anchoring modification: consistent with step S5 in Example 2.

[0082] Comparative Example 4: A method for remediating polluted water bodies in small-scale agriculture involves combining the application of *Potentilla chinensis* (a type of weed) through a net enclosure with the addition of compound algae microspheres (the compound algae microspheres are added outside the net enclosure). The net enclosure covers 30% of the area of ​​the small-scale agricultural water body, and the application rate of *Potentilla chinensis* within the net enclosure is 40 kg / mu (net area). The mass ratio of *Potentilla chinensis* to compound algae microspheres within the net enclosure is 1:0.08.

[0083] Among them, the composite algae microspheres are composed of a composite algae agent of Chlorella pyrenoidosa and Cyclocarya mennidae, and the specific preparation method includes: Step S1, Algal Cell Directed Modification: Same as Step S1 in Example 2.

[0084] Step S2, two-phase aqueous phase separation and embedding: consistent with step S2 in Example 2.

[0085] Step S3, Kernel Modification and Regulation: Consistent with step S3 in Example 2.

[0086] Step S4, In-situ Preparation of the Outer Shell: Same as Step S4 in Example 2.

[0087] Step S5, Outer Interface Anchoring Modification: First, prepare a nanocrystalline cellulose suspension, specifically in the same manner as step S5 in Example 2. Then, perform interface anchoring modification on the tertiary structure microspheres using the nanocrystalline cellulose suspension, specifically in the same manner as step S5 in Example 2; after a final filtration, discard the filtrate and allow it to drain naturally to obtain the composite algae microspheres.

[0088] Comparative Example 5: A method for remediating polluted water bodies in small-scale agriculture involves combining the application of *Potentilla chinensis* (a type of weed) through a net enclosure with the addition of compound algae microspheres (the compound algae microspheres are added outside the net enclosure). The net enclosure covers 30% of the area of ​​the small-scale agricultural water body, and the application rate of *Potentilla chinensis* within the net enclosure is 40 kg / mu (net area). The mass ratio of *Potentilla chinensis* to compound algae microspheres within the net enclosure is 1:0.08.

[0089] Among them, the composite algae microspheres are composed of a composite algae agent of Chlorella pyrenoidosa and Cyclocarya mennidae, and the specific preparation method includes: Step S1, Algal Cell Directed Modification: Same as Step S1 in Example 2.

[0090] Step S2, two-phase aqueous phase separation and embedding: consistent with step S2 in Example 2.

[0091] Step S3, Kernel Modification and Regulation: Consistent with step S3 in Example 2.

[0092] Step S4, In-situ Preparation of the Outer Shell: Same as Step S4 in Example 2.

[0093] Step S5, Outer Interface Passivation: The tertiary structure microsphere suspension was added to a Tris-HCl buffer solution with a concentration of 0.1 mol / L and a pH of 7.2 at a volume ratio of 1:9. Then, methoxy polyethylene glycol silane (molecular weight 2000) was added to a final concentration of 5 g / L. The mixture was stirred at 175 rpm for 4 hours at 25°C in the dark. After the reaction was completed, the supernatant was removed by gravity filtration (using a 100 μm sterile nylon filter). The mixture was then washed 5 times with 7.5 times its volume of sterile ultrapure water to remove unreacted reagents and impurities. After each wash, the reagents were removed by gravity filtration (using a 100 μm sterile nylon filter). After the final filtration, the filtrate was discarded and allowed to drain naturally to obtain the composite algae microspheres.

[0094] Experimental testing: A small-scale simulated agricultural pollution water body was constructed, with an area of ​​8 mu (approximately 0.53 hectares) and a water depth of 300 cm. The total nitrogen was 4.2 mg / L, the total phosphorus was 1.1 mg / L, and the cyanobacterial biomass was 1.2 × 10⁻⁶. 7 The cells / L were divided into eight equal-area zones using a geomembrane partition. In each zone, combinations of *Isatis tinctoria* and composite algae microspheres from Examples 1-3 and Comparative Examples 1-5 were applied using a perimeter fence. Total nitrogen, total phosphorus, and cyanobacterial biomass were tested. The results are shown in the table below.

[0095] The table clearly shows that: because the two algae in the compound algae microspheres in Comparative Example 1 were not modified, the algal cells experienced intense interspecies competition and poor antagonism, resulting in rapid inactivation after encapsulation; after 10 days of application, while the *Ipomoea aquatica* exerted its basic nitrogen and phosphorus absorption and allelopathic algal inhibition effects, the algal cells in the microspheres began to show interspecies competition and decreased activity; after 20 to 30 days of application, due to interspecies competition and lack of stress-resistant modification, a large number of algal cells died, the microspheres lost their nitrogen and phosphorus removal functions, and the cyanobacterial biomass rebounded; after 60 days of application, the *Ipomoea aquatica* entered a growth plateau period, the basic remediation effect weakened, and the compound algae released nitrogen and phosphorus pollution sources upon death, resulting in poor long-term remediation capabilities. Because Comparative Example 2 lacked a two-phase aqueous matrix phase separation, the two algae were in the same space, resulting in intense competition between algal cell species. After 10 days of release, *Isodon grandiflorus* exerted basic nitrogen and phosphorus absorption and allelopathic algal inhibition effects, and the algal cells completed directional modification and possessed basic stress resistance. After 20 days of release, the faster-growing *Chlorella proteoglycans* squeezed out the space and nutrients of *Cyclocarya meniensis*, and diatoms were significantly inhibited. After 30 to 60 days of release, the competition between algal species became unbalanced, and the excessive proliferation of *Chlorella* led to the disruption of the microsphere's internal environment, resulting in the inactivation of a large number of diatoms, the cessation of nitrogen and phosphorus removal functions, and a significant rebound in cyanobacterial biomass. Because the core microspheres in Comparative Example 3 were not modified with an adhesive layer, there was no bonding force between the core and the foaming layer. After secondary encapsulation, interlayer delamination occurred, causing the microsphere density to run out of control and sink to the bottom. After 10 days of deployment, the microsphere structure was not completely destroyed and remained suspended in the light layer, possessing basic functions. After 20 days of deployment, large-scale interlayer delamination occurred, water entered the hollow structure, the microspheres sank to the bottom, and the activity of the algal cells inside decreased rapidly due to insufficient light. After 30 to 60 days of deployment, the microspheres completely sank to the bottom, a large number of algal cells died, the denitrification and phosphorus removal functions were lost, the cyanobacterial biomass returned, and only the basic remediation effect of *Ipomoea aquatica* was observed. Because Comparative Example 4 lacked outer interface passivation, its long-term stability decreased. After 10-20 days of application, the microsphere structure became relatively intact, enabling it to inhibit cyanobacteria growth and remove nitrogen and phosphorus. After 30 days, due to the lack of passivation, the composite algae microspheres were non-specifically adhered to by aquatic microorganisms, organic matter, and plant roots, clogging surface pores and hindering light and material exchange in the internal algal cells, leading to a rapid decline in activity and a slight rebound in cyanobacteria. After 30 days, the microspheres were completely adhered and encapsulated, algal cells were inactivated, and only a basic repair effect on *Isodon stenoptera* remained. Because Comparative Example 5 lacked an anchoring layer, the microsphere structure lacked strength and was easily broken. After 10 days, the microsphere function returned to normal, and the overall effect was normal. After 20 days, the passivation layer detached, the anti-adhesion effect was lost, and interlayer breakage and algal cell leakage occurred. After 30-60 days, the microsphere structure was completely damaged, a large number of algal cells were lost, and the function was lost.

Claims

1. A method for fast and efficient ecological remediation of small agricultural contaminated water bodies, characterized in that: The method of adding algae microspheres using a combination of netting and compound algae preparation is adopted. The compound algae microspheres are composed of a compound algae preparation of *Chlorella proteoglycans* and *Cyclocarya meniensis*. The specific preparation method includes: Step S1, Targeted modification of algal cells: including passivation modification of Chlorella proteoglycans and silanization modification of Cyclocarya mennidae; Step S2, Aqueous Two-Phase Separation and Embedding: First, prepare the continuous outer phase of passivated and modified Chlorella pyrenoidosa and the dispersed inner phase of silanized and modified Cyclocarya mesniformis, and then perform aqueous two-phase mixing and microfluidic preparation to obtain the microsphere core. Step S3, Core Modification and Control: First, the core of the microspheres is modified. Then, the foaming precursor liquid and the modified microsphere core are used as the aqueous phase for secondary microfluidic embedding to obtain core-hollow microspheres. Step S4, In-situ preparation of the outer shell: First, prepare the outer shell precursor solution, and use the outer shell precursor solution and the core-hollow microspheres as the aqueous phase to perform three microfluidic embeddings to obtain tertiary structure microspheres; Step S5, Outer Interface Anchoring Modification: First, prepare a nanocrystalline cellulose suspension, then use the nanocrystalline cellulose suspension to perform interface anchoring modification on the tertiary structure microspheres, and finally passivate the medium to obtain composite algae microspheres.

2. The method for fast and efficient ecological restoration of small agricultural contaminated water bodies according to claim 1, characterized in that: The area of ​​the weed enclosure accounts for 20% to 50% of the area of ​​the small-scale agricultural water body. The amount of weed added to the enclosure is 30 to 50 kg / mu, and the mass ratio of weed to compound algae microspheres in the enclosure is 1:0.06 to 0.

1.

3. The method for fast and efficient ecological restoration of small agricultural contaminated water bodies according to claim 1 or 2, characterized in that: In step S1, the passivation modification of Chlorella proteoglycans specifically involves the following steps: First, 200 mL of Chlorella proteoglycan solution is placed in a sterile storage tube, and algal cells are collected by cross-flow microfiltration. The supernatant of the culture medium is filtered out to obtain a wet precipitate of algal cells. The precipitate is then washed twice with 80 mL of 0.05 mol / L MES buffer at pH 5.

5. After each wash, the precipitate is filtered by gravity, and then resuspended in 100 mL of MES buffer to obtain an algal cell suspension. Next, 0.5 mL of 10 mmol / L water-soluble biological agent is added to the algal cell suspension. The N-succinimide ester solution was stirred at 95–105 rpm for 28–32 min at 24–26 °C in the dark. Then, 0.5 g of methoxy polyethylene glycol amino was added, and the mixture was stirred at 95–105 rpm for 3.8–4.2 h at 24–26 °C in the dark. Finally, the supernatant was removed by gravity filtration, and the mixture was washed three times with 80 mL of sterile ultrapure water each time. After each wash, the supernatant was removed by gravity filtration, and the filtered precipitate was resuspended in 20 mL of sterile ultrapure water to obtain the passivated Chlorella proteoglycans solution.

4. The method for fast and efficient ecological restoration of small agricultural contaminated water bodies according to claim 2 or 3, characterized in that: In step S1, the silanization modification of *Cyclocarya melaniglita* specifically involves: First, placing 200 mL of *Cyclocarya melaniglita* solution in a sterile storage tube, concentrating and collecting algal cells using cross-flow microfiltration, filtering out the supernatant to obtain a wet precipitate of algal cells, then washing twice with 150 mL of 0.2 mol / L sterile isotonic trehalose solution and once with 150 mL of sterile ultrapure water. After each washing, filtering is performed using gravity filtration, and the filtered precipitate is resuspended in 100 mL of 0.1 mol / L neutral Tris-HCl. Algal cell suspension was obtained in buffer solution; then, 2 mL of neutral amino-modified silica sol was added to the algal cell suspension, and the mixture was stirred at 95–105 rpm for 5.8–6.2 h at 24–26 °C in the dark; finally, the supernatant was removed by gravity filtration, and the mixture was washed three times with 150 mL of sterile ultrapure water each time. After each wash, the supernatant was removed by gravity filtration, and the filtered precipitate was resuspended in 20 mL of sterile ultrapure water to obtain the silanized modified Cladophora menesiensis solution.

5. The method for fast and efficient ecological restoration of small agricultural contaminated water bodies according to claim 4, characterized in that: In step S2, the continuous external phase of the passivated Chlorella proteoglycans comprises methylcellulose, sodium alginate, anhydrous calcium chloride, D-gluconic acid lactone, passivated Chlorella proteoglycans solution, and sterile ultrapure water, with a mass ratio of 147–153:14.7–15.3:5.4–5.6:17.5–18.1:392.7–407.3:589.1–610.

9. The preparation steps are as follows: under light-protected conditions at 24–26°C, methylcellulose and sodium alginate are added sequentially to sterile ultrapure water, stirred at 300–400 rpm for 10–15 min, vacuum degassing for 7–9 min, then the passivated Chlorella proteoglycans solution is added, stirred at 50–80 rpm for 2–3 min, then anhydrous calcium chloride and D-gluconic acid lactone are added, and stirring is continued for 1 min to obtain the final product. The internal dispersion of silanized *Cyclocarya melaniglita* comprises low-melting-point agarose, neutral amino-modified silica sol, silanized *Cyclocarya melaniglita* solution, and sterile ultrapure water in a mass ratio of 180–220:9–11:270–330:630–770. The preparation steps are as follows: Under light-protected conditions, low-melting-point agarose is added to sterile ultrapure water and heated in a constant-temperature water bath at 63–67°C for 9–11 minutes. Then, it is allowed to stand in a constant-temperature water bath at 38–40°C for 7–9 minutes. Next, neutral amino-modified silica sol is added, and the mixture is stirred at 70–90 rpm for 2–4 minutes. Finally, the silanized *Cyclocarya melaniglita* solution is added, and stirring is maintained for 2–3 minutes to obtain the final product.

6. The method for rapid and efficient ecological restoration of polluted water bodies from small-scale agriculture according to claim 5, characterized in that: In step S2, the aqueous two-phase mixing is specifically performed as follows: at 24-26°C, the continuous external phase and the dispersed internal phase are mixed at a volume ratio of 3:1, stirred at a speed of 50-80 rpm for 1-3 minutes, and allowed to stand for 9-11 minutes to obtain the aqueous two-phase mixture.

7. A method for rapid and efficient ecological restoration of polluted water bodies from small-scale agriculture according to claim 6, characterized in that: In step S2, the microfluidic preparation is as follows: First, perfluoronaphthane is added to 0.48–0.52 wt% of tridecafluorooctyltriethoxysilane, and stirred at 300–400 rpm for 10–15 min at 24–26 °C in the dark to obtain the continuous oil phase. Then, using a focusing microfluidic chip with a channel main size of 500 μm, the flow rate of the aqueous phase is 4.5–5.5 μL / min and the flow rate of the continuous oil phase is 18–22 μL / min. After stabilizing the liquid output, the monodisperse droplets at the outlet are collected in a sterile storage tube and allowed to stand at 24–26 °C for 9–11 min. Finally, the microspheres are washed three times with 5–10 times the volume of perfluorohexane for 5 min each time, and then washed three times with 5–10 times the volume of sterile ultrapure water. After each washing, the supernatant is removed by gravity filtration to obtain the microsphere cores.

8. The method for rapid and efficient ecological restoration of polluted water bodies from small-scale agriculture according to claim 7, characterized in that: In step S3, the secondary microfluidic embedding specifically involves: first, adding ovalbumin and glycerol to sterile ultrapure water, with a mass-to-volume ratio of ovalbumin, glycerol, and sterile ultrapure water of 9.5–10.5 g: 1.9–2.1 g: 95–105 mL, stirring at 330–370 rpm for 9–11 min, and then vacuum degassing for 4–6 min to obtain a foaming precursor solution; then, mixing the foaming precursor solution with the modified microsphere core suspension at a volume ratio of 9:1, stirring at 50–80 rpm for 1–3 min, and allowing to stand for 9–11 min to obtain the secondary microsphere core embedding. The sub-microfluidic aqueous phase was obtained using a focusing microfluidic chip with a main channel size of 600 μm. The flow rate of the aqueous phase was 7.5–8.5 μL / min, and the flow rate of the continuous oil phase was 23.5–26.5 μL / min. After stabilizing the liquid output, the monodisperse droplets at the outlet were collected in a sterile storage tube and allowed to stand at 24–26 °C for 14–16 min. Finally, the microspheres were washed three times with 5–10 times the volume of perfluorohexane and then three times with 5–10 times the volume of sterile ultrapure water. After each washing, the supernatant was removed by gravity filtration to obtain the core-hollow microspheres.

9. A method for rapid and efficient ecological restoration of polluted water bodies from small-scale agriculture according to claim 8, characterized in that: In step S4, the three-stage microfluidic embedding is specifically as follows: First, the shell precursor liquid and the core-hollow microsphere suspension are mixed at a volume ratio of 8:2, stirred at 50-80 rpm for 1-3 min, and allowed to stand for 9-11 min to obtain three microfluidic aqueous phases; then, using a focusing microfluidic chip with a channel main size of 800 μm, the flow rate of the aqueous phase is 9.5-10.5 μL / min, and the flow rate of the oil continuous phase is 28.5-31.5 μL / min. After stabilizing the liquid output, the monodisperse droplets at the outlet are collected in a sterile storage tube and allowed to stand at 37-39℃ in the dark for 9-11 min; finally, the microspheres are washed three times with 5-10 times the volume of perfluorohexane and then three times with 5-10 times the volume of sterile ultrapure water. After each washing, the supernatant is removed by gravity filtration to obtain the tertiary structure microspheres.

10. A method for rapid and efficient ecological restoration of polluted water bodies from small-scale agriculture according to claim 9, characterized in that: In step S5, the preparation of the nanocrystalline cellulose suspension specifically involves: adding cellulose to a 64wt% sulfuric acid solution, with a cellulose to sulfuric acid solution mass-to-volume ratio of 1g:100mL; stirring at 280-320rpm for 3.8-4.2h in a water bath at 43-47℃; then adding 10 times the volume of ultrapure water; filtering and washing until neutral using gravity filtration; dialyzing for 3 days until conductivity stabilizes; and then superabsorbing the nanocrystalline cellulose in a constant temperature water bath at 38-42kHz, 100-150W, and 24-26℃. The cellulose suspension was dispersed acoustically for 28–32 min to obtain a cellulose suspension with a solid content of 1 wt%. Then, the cellulose suspension was added to a Tris-HCl buffer solution with a concentration of 0.1 mol / L and a pH of 8.5 at a volume ratio of 1–2:

10. Epichlorohydrin was then added, with a mass ratio of epichlorohydrin to the solids in the cellulose suspension of 1:

2. The mixture was stirred at 200–300 rpm for 11.5–12.5 h at 24–26 °C in the dark. The mixture was dialyzed for 3 days to remove unreacted reagents, resulting in a suspension with a solid content of 1 wt%.

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