A cyanobacterial bloom and algal toxin in-situ prevention and control method and device based on gas phase equilibrium regulation

Abstract

This invention relates to the field of water pollution control technology, and discloses a method and device for in-situ control of cyanobacterial blooms and algal toxins based on gas-phase equilibrium regulation. A microalgal physiological interference medium with high light transmittance and high airtightness is placed on the surface of the water body in the cyanobacterial aggregation area, creating a high-oxygen, low-carbon dioxide physiological stress environment at the air-water interface. This causes energy deficit and metabolic inactivation of pseudo-empty cell structures in the cyanobacteria, leading to non-lethal physiological in-situ sedimentation. This invention maintains the cell membrane integrity of *Microcystis aeruginosa* using non-lethal physical intervention, fundamentally solving the problem of short-term algal toxin outbreaks caused by cell lysis in traditional single algae-killing technologies, while simultaneously ensuring the photosynthesis of submerged plants at the bottom. It has advantages such as high ecological safety, synergistic algae suppression and toxin control, low carbon footprint, and low cost, and is suitable for emergency treatment of *Microcystis aeruginosa* outbreaks in various water bodies such as lakes and reservoirs.

Description

Technical Field

[0001] This invention relates to the field of water pollution control technology, and in particular to a method and apparatus for in-situ control of cyanobacterial blooms and algal toxins based on gas phase balance regulation. Background Technology

[0002] Cyanobacterial Harmful Algal Blooms (Cyanobacterial HABs), especially those of Microcystis aeruginosa ( Microcystis aeruginosa Cyanobacterial blooms, dominated by algae, pose a serious ecological challenge to eutrophic lakes and reservoirs worldwide. These blooms not only lead to decreased water transparency, depletion of dissolved oxygen, and a sharp decline in biodiversity, but their secondary metabolites—microcystins (MCs)—are also highly hepatotoxic and potentially carcinogenic, severely threatening drinking water safety. Currently, traditional control technologies for cyanobacterial blooms both domestically and internationally mainly include physical harvesting, chemical extermination (such as the addition of oxidants like hydrogen peroxide and copper sulfate), and biological inhibition. Long-term engineering practice has shown that while existing technologies can reduce cyanobacterial biomass, they generally have significant technical bottlenecks. For example, toxin-producing cyanobacteria, such as Microcystis aeruginosa, produce microcystin toxins that exist primarily as intracellular toxins within algal cells. Existing treatment technologies (such as those disclosed in CN111995014A, CN112919556B, and CN117142622A) often aim for high kill rates or instantaneous removal rates, frequently employing strong oxidation or high-energy-consuming physical methods. While these methods can quickly kill algae, they can easily cause algal cell rupture, leading to the release of large amounts of intracellular toxins and secondary pollution, making it difficult to achieve safe and efficient synergistic treatment of cyanobacterial blooms.

[0003] Light is fundamental for the survival of aquatic plants, and existing physical shading control schemes mostly employ black or opaque materials for physical shading. For example, technologies disclosed in CN107572664B, CN111825179A, and CN220704482U often use black shading nets or opaque materials. While such strong shading can completely stop cyanobacterial photosynthesis, it also simultaneously cuts off the light needed by submerged plants at the bottom (such as Vallisneria natans and Hydrilla verticillata). This one-size-fits-all intervention leads to the complete loss of primary productivity in the aquatic ecosystem (such as benthic photosynthetic organisms like diatoms and cryptophytes) and the loss of some decomposer functions (anaerobic photosynthetic bacteria), causing habitat degradation and weakening the water body's ability to self-repair and maintain ecological balance, thus violating the original intention of ecological restoration. It is particularly noteworthy that existing covering technologies (such as CN107572664B) usually have ventilation holes designed into the material or use suspended coverings to prevent water hypoxia, but this design only maintains gas exchange. In addition, existing selective transmission technologies (such as CN111847650 B) utilize the dependence of photosynthesis on specific spectra. By setting a green coating at the bottom of the device, the transmission of light in the 440-480 nm and 640-730 nm bands is limited. The core logic is still to suppress the proliferation of harmful algal blooms by physically blocking light energy. There is still a risk of accelerating algal cell lysis and causing a short-term rapid outbreak of toxins.

[0004] Unlike existing technologies such as CN111995014A, CN112919556B and CN117142622A, where green or blue films only serve to passively block light or assist chemical reactions, this method has a key drawback: it cannot fundamentally eliminate the harm of toxins, and may instead lead to the rapid death of cyanobacteria cells after treatment, accelerating the release of algal toxins, odor substances and other substances into the extracellular space, and there is an ecological risk of heavy metal accumulation or strong oxidants accidentally harming non-target organisms.

[0005] To address the above technical problems, this invention is proposed. Summary of the Invention

[0006] The purpose of this invention is to provide a method and device for in-situ control of cyanobacterial blooms and algal toxins based on gas-phase equilibrium regulation, aiming to overcome the secondary pollution risks caused by existing treatment technologies that kill algae first and then cause poisoning. By constructing a gas-phase barrier interface and utilizing a high light pressure and low carbon physiological stress pathway, non-lethal in-situ sedimentation of cyanobacteria is induced without lysing algal cells, and toxins are weakened from the genetic source.

[0007] To achieve the above objectives, in a first aspect, the present invention provides a method for in-situ control of cyanobacterial blooms and algal toxins based on gas phase equilibrium regulation. A microalgal physiological interference medium with high light transmittance and high airtightness is set on the surface of the water body in the cyanobacterial aggregation area. A physiological stress environment with high oxygen and low carbon dioxide is constructed at the air-water interface, causing energy deficit and metabolic inactivation of pseudo-empty cell structure in cyanobacteria, resulting in non-lethal physiological in-situ sedimentation of cyanobacteria. The microalgal physiological interference medium has a carbon dioxide permeability coefficient of less than 500 cm⁻¹. 3 ·mm / (m 2 (24h·0.1MPa), the average transmittance of the microalgal physiological interference medium to visible light is greater than 80%.

[0008] Furthermore, the microalgae physiological interference medium is a transparent high-barrier membrane or a red high-barrier membrane; The transparent high-barrier membrane has a carbon dioxide permeability coefficient of less than 500 cm⁻¹. 3 ·mm / (m 2 (24h, 0.1MPa), with an average transmittance of over 85% for visible light in the 400nm-700nm range; The red high-barrier membrane has a carbon dioxide permeability coefficient of less than 500 cm⁻¹. 3 ·mm / (m 2 (24h·0.1MPa), the average absorbance of visible light in the 500nm-560nm range is greater than 1.0, and the average transmittance of visible light in the 650nm-750nm range is greater than 80%.

[0009] Furthermore, the transparent high-barrier film or the red high-barrier film is selected from vinyl chloride film, polyvinylidene chloride film, or composite film containing an inorganic barrier layer; the inorganic barrier layer is selected from one or more of silicon oxide (SiOx), aluminum oxide (AlOx), or magnesium oxide (MgOx).

[0010] Furthermore, the high-oxygen, low-carbon dioxide physiological stress environment delayed the entry of cyanobacterial blooms into the logarithmic growth phase by 3-7 days compared to the control group without microalgal physiological interference media; wherein the high-oxygen, low-carbon dioxide physiological stress environment is at the air-water interface, with a dissolved oxygen concentration greater than 8 mg / L and a carbon dioxide concentration less than 0.5 mg / L.

[0011] Furthermore, the high-oxygen, low-carbon dioxide physiological stress environment induces the metabolic inactivation of cyanobacterial pseudovacuoles. Within 3-14 days of being covered by the microalgal physiological interference medium, the algal cells settle in situ and maintain the integrity of the algal cell membrane to prevent the release of intracellular toxins into the water.

[0012] Furthermore, the surface of the microalgae physiological interference medium is treated with anti-bioattachment.

[0013] Furthermore, the cyanobacteria are microalgae with pseudo-empty cell structures that release harmful substances when subjected to stress and lysis, including the genera *Microcystis*, *Anabaena*, *Hylocereus*, *Arthrophyllus*, *Phyllostachys*, and *Phyllostachys*.

[0014] Secondly, the present invention provides an apparatus for implementing the above-mentioned method for in-situ control of cyanobacterial blooms and algal toxins based on gas phase balance regulation. The apparatus includes a microalgal physiological interference medium, a flexible floating frame, and anchors. The microalgal physiological interference medium is a transparent high-barrier membrane or a red high-barrier membrane, which is tightly attached to the water surface. The flexible floating frame is disposed on the side of the transparent high-barrier membrane or the red high-barrier membrane. The upper end of the anchor is connected to the flexible floating frame and hangs into the water, so that the transparent high-barrier membrane or the red high-barrier membrane forms an airtight seal with the water surface.

[0015] Thirdly, this invention provides the application of the above-mentioned method for in-situ control of cyanobacterial blooms and algal toxins based on gas phase equilibrium regulation in water pollution prevention and control, for the prevention and control of cyanobacterial blooms in water bodies.

[0016] Furthermore, it is used to prevent and control Microcystis aeruginosa blooms in water bodies.

[0017] Furthermore, by constructing an extreme high-oxygen, low-carbon environment, the gene encoding a key enzyme in the Calvin cycle was inhibited. rbcS Gene expression enables Rubisco enzymes to activate oxygenase activity, physically blocking the targeted remodeling of cyanobacterial carbon metabolism pathways and preventing Microcystis aeruginosa blooms in water bodies.

[0018] The core of this invention is to tightly cover the water surface with a transparent, high-barrier material (carbon dioxide permeability coefficient less than 500 cm⁻¹). 3 ·mm / (m 2 A physical sealing method was used to block cyanobacteria at an interface (24h, 0.1MPa). This method utilizes the negative feedback mechanism of energy and buoyancy regulation in cyanobacterial physiological metabolism to achieve precise physiological inhibition of cyanobacteria through metabolic reversal. Under strong light irradiation, the cyanobacteria under the membrane maintained oxygen production activity. Due to the extremely low permeability of the high-barrier membrane material to gases, the dissolved oxygen in the water layer under the membrane rapidly reached a supersaturated state (>8.0mg / L), while exogenous carbon dioxide could not be replenished. This high-oxygen, low-carbon environment forced Rubisco enzymes to activate oxygenase activity (photorespiration), causing the cyanobacteria to shift from carbon accumulation to carbon consumption, resulting in an energy deficit. Due to the energy deficit, the cells could not maintain the metabolic repair and synthesis of pseudo-empty cell structures. Combined with fluctuations in intracellular osmotic pressure, this induced physiological inactivation or collapse of the pseudo-empty cells. The cyanobacteria then lost buoyancy and naturally sank to the bottom low-light zone while maintaining cell membrane integrity, avoiding the release of intracellular algal toxins caused by cell rupture.

[0019] The advantages and positive effects of the in-situ control method and device for cyanobacterial blooms and algal toxins based on gas-phase equilibrium regulation described in this invention are as follows: 1. Avoiding Toxin Outbursts: By constructing a non-lethal physiological stress environment, the integrity of the cell membrane structure is ensured throughout the entire process of inhibiting cyanobacterial growth, thus avoiding the instantaneous toxin outbreaks caused by cell lysis in traditional algae-killing techniques. Simultaneously, this method can significantly downregulate key gene clusters for algal toxin synthesis at the molecular level (…). mcy The transcriptional expression of the gene achieves dual safety assurance through inhibition of toxin synthesis and control of release.

[0020] 2. Algae suppression and grass protection: The high-barrier materials used have excellent spectral characteristics, avoiding habitat degradation caused by traditional shading solutions and maintaining the self-purification capacity and primary productivity of the aquatic ecosystem.

[0021] 3. Low carbon and high efficiency: No chemicals are required. In-situ treatment is achieved by utilizing natural light energy and the physical properties of materials. It has outstanding advantages such as low cost, simple operation and no risk of secondary pollution.

[0022] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0023] Figure 1 This is a comparison chart of the expression levels of genes related to algal toxin synthesis in Example 1 of the present invention; Figure 2 This is a comparison chart of the content of extracellular and intracellular microcystin in the water bodies of each group at the end of the experiment in Example 1 of the present invention; Figure 3 This is a bar chart showing the change in dissolved oxygen content difference between different experimental groups and the control group over time in Example 2 of the present invention; Figure 4 The graphs show the visible light absorption characteristics of the films in different experimental groups in Example 2 of this invention. Figure 5 This is a diagram showing the effects of different experimental group film treatments on the expression of core genes related to photosynthetic electron transport, carbon fixation, and energy metabolism in Microcystis aeruginosa in Example 2 of the present invention, and the metabolic mechanism. In this diagram, A is the relative expression level of key functional genes of photosynthetic electron transport, carbon fixation, and energy metabolism in Microcystis aeruginosa, and B is the functional node diagram of key genes of photosynthetic electron transport, carbon fixation, and energy metabolism in related metabolic pathways in Microcystis aeruginosa. Figure 6 The growth curves of Microcystis aeruginosa in different experimental and control groups in Example 3 of this invention are shown. Figure 7 This is a growth curve diagram of *Synthetium lappa* PCC6803 in different experimental and control groups in Example 3 of the present invention; Figure 8This is a schematic diagram of the on-site deployment of the present invention in a large body of water.

[0024] Figure Labels 1. Transparent high-barrier membrane; 2. Flexible floating frame; 3. Anchors. Detailed Implementation

[0025] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0026] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.

[0027] Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this invention. Experimental methods in the following embodiments that do not specify specific conditions are generally determined according to national standards. Experimental instruments, equipment, and reagents in the following embodiments that do not specify their sources are all commercially available materials.

[0028] Unless otherwise defined or stated, all technical and scientific terms used in this invention have the same meaning as those skilled in the art. Furthermore, any methods and materials similar to or equivalent to those described herein may be applied to the methods of this invention.

[0029] Microcystis aeruginosa ( Microcystis aeruginosa FACHB-905 was purchased from the Freshwater Algae Bank (FACHB) of the Institute of Hydrobiology, Chinese Academy of Sciences. (Syntropha cylindrica) Synechocystis The strain sp. PCC 6803 was obtained from the Pasteur Culture Collection of Cyanobacteria (PCC) and was donated by the Peter Nixon Laboratory at Imperial College London.

[0030] This invention constructs a gas-phase barrier interface and utilizes a high light pressure and low carbon physiological stress pathway to induce non-lethal in-situ sedimentation of cyanobacteria without lysing algal cells, thereby weakening toxins at the genetic level.

[0031] Unlike traditional methods that target light energy through shielding and blocking, this invention uses a transparent or red high-barrier membrane to induce non-lethal in-situ sedimentation of cyanobacteria while ensuring a normal energy supply for photosynthesis, and weakens algal toxin synthesis at the source of gene expression. This invention, centered on gas-phase balance regulation, innovatively maintains the integrity of algal cell membranes while reducing the release of microcystins into the extracellular space at the molecular level. It effectively regulates cyanobacterial biomass, induces physiological in-situ sedimentation, and blocks the rapid release of toxins at the source.

[0032] Furthermore, the transparent high-barrier membrane of this invention has an average transmittance of greater than 85% for visible light (400-700 nm); or a red high-barrier membrane can be used, with an absorbance greater than 1.0 in the 500-560 nm wavelength band and a transmittance greater than 80% in the 650-750 nm wavelength band. Algae suppression is achieved by creating a high-oxygen, low-carbon environment through high airtightness. Its core algae suppression mechanism still relies on gas phase balance regulation rather than light energy cutoff. This is combined with an airtight sealing design that closely adheres to the interface (carbon dioxide permeability <500 cm⁻¹). 3 ·mm / (m 2 By applying a 24-hour, 0.1 MPa pressure, the oxygen generated in situ is "locked" below the interface to create a supersaturated dissolved oxygen environment (>8.0 mg / L), thereby forcibly inducing cyanobacteria to initiate a high-energy-consuming photorespiratory metabolic mode. This design forces cyanobacteria to shift from normal carbon assimilation to metabolic imbalance and energy deficit, ultimately inducing non-lethal physiological in-situ sedimentation while maintaining the integrity of the algal cell membrane. This fundamentally solves the problem of rapid toxin release due to cell lysis in traditional technologies.

[0033] The following examples provide a detailed explanation.

[0034] Example 1 like Figure 1 As shown, *Microcystis aeruginosa* was cultured for 14 consecutive days. Three groups were set up: a control group (no membrane), a transparent membrane group, and a red membrane group. In the transparent membrane and red membrane groups, the corresponding filter membranes completely covered the water surface of the culture system, with a coverage area of ​​100% of the water surface. The membrane treatment was implemented continuously for 14 days from the start to the end of the culture. After 14 days of culture, metagenomic sequencing technology was used to analyze the key gene clusters for microcystin synthesis in *Microcystis aeruginosa* of each group at the gene transcription level. mcy The expression levels of gene clusters were detected and analyzed.

[0035] The results showed that under the high-oxygen, low-carbon stress environment constructed using transparent and red films, *Microcystis aeruginosa*... mcyA and mcyD The transcriptional levels of key genes involved in toxin synthesis were significantly downregulated compared to the control group. For example... Figure 2 The biochemical test results further verified that the intracellular and extracellular microcystin content in the water of the transparent film group and the red film group (experimental group) was significantly lower than that of the control group.

[0036] Example 2 like Figure 3As shown, under the conditions of covering with transparent and red films, the dissolved oxygen content in the water not only did not decrease, but was significantly higher than that of the control group. This result indicates that *Microcystis aeruginosa* can continuously perform photosynthesis and produce oxygen using the suitable spectrum transmitted through the film. The mechanism is as follows: the film adheres tightly to the water surface, forming an airtight barrier layer. On the one hand, this physically inhibits the diffusion and loss of photosynthetically produced oxygen into the atmosphere, effectively retaining oxygen in the water and avoiding the hypoxia problem easily caused by conventional shading methods. On the other hand, this barrier structure limits the replenishment of atmospheric CO2 into the water, thus creating a high-oxygen, low-carbon microenvironment. In contrast, the dissolved oxygen level in the blue film group was significantly lower than that in the red and transparent film groups. This result indirectly reflects the differential regulation of the photosynthetic oxygen production capacity of *Microcystis aeruginosa* under different light quality conditions, further verifying the auxiliary role of spectral adaptability in maintaining photosynthetic oxygen production efficiency and ensuring the construction of a high-oxygen environment. In summary, by selecting thin film materials with suitable spectral transmittance characteristics, the carbon-oxygen balance can be effectively regulated while maintaining the dissolved oxygen level in the water, providing a feasible technical approach for achieving physiological regulation of cyanobacteria (such as inducing photorespiration).

[0037] To verify the precise control of light quality by the thin film described in this invention, a full-band spectral scan (380 nm to 750 nm) was performed on the thin films of each experimental group using a UV-Vis spectrophotometer. The results are as follows: Figure 4 As shown in the figure, the horizontal axis represents wavelength (nm), and the vertical axis represents absorbance. The transparent high-barrier membrane of this invention has an average transmittance of greater than 85% for visible light (400-700 nm); the red high-barrier membrane has an absorbance greater than 1.0 in the 500-560 nm wavelength range and a transmittance greater than 80% in the 650-750 nm wavelength range. These spectral characteristics provide a material basis for constructing a high-oxygen, low-carbon microenvironment and regulating the physiological responses of cyanobacteria.

[0038] like Figure 5 As shown in Figure 1 and Table 1, based on the differences in gene expression in photosynthetic metabolic pathways regulated by different spectra, this invention reveals the molecular basis of light quality-specific regulation of photosynthetic electron transport, carbon fixation, and energy metabolism by comparing and analyzing the differences in transcriptional levels of key functional genes under transparent membrane, red membrane, and blue membrane treatments, combined with the physiological stress mechanism regulated by gas phase balance.

[0039] Table 1. Effects of different experimental groups of membrane treatment on the expression of genes related to photosynthetic electron transport, carbon fixation, and energy metabolism in Microcystis aeruginosa.

[0040] Specifically, both transparent membrane and red membrane treatments significantly upregulated genes related to photosynthetic electron transport ( petE , petB , chlHThe expression of ) maintains the high light energy capture and continuous oxygen production activity of sub-membrane cyanobacteria, thereby rapidly constructing a hyperoxic environment with dissolved oxygen supersaturation (>8.0 mg / L) under airtight interfaces; at the same time, both significantly inhibit the expression of genes encoding key enzymes of the Calvin cycle ( rbcS The expression of ) reduces CO2 assimilation efficiency, confirming that the CO2 permeability coefficient is less than 500 cm⁻¹. 3 ·mm / (m 2 The barrier effect of 0.1 MPa (24h) leads to carbon source depletion (<0.5 mg / L), forcing Rubisco enzymes to activate oxygenase activity, causing cyanobacteria to shift from carbon accumulation to photorespiration carbon consumption mode. Furthermore, the transparent membrane fully activates genes involved in the glycolysis pathway (…). pyk , pckA ), while the erythrocyte selectively upregulates pyk Genes, and both significantly enhanced genes at all key nodes of the tricarboxylic acid cycle (TCA cycle). sdhA , mdh , prpc The expression of α-elements indicates that cyanobacteria are forced to enhance respiratory metabolism to maintain photorespiration and pseudocell repair under energy deficit conditions, ultimately leading to pseudocell metabolic inactivation due to energy deficiency. In contrast, although blue membrane treatment can upregulate photosystem genes, it has no significant effect on the expression of genes related to carbon fixation, glycolysis, and respiration, and cannot construct an effective physiological stress environment, thus its algal suppression effect is not significant.

[0041] The above results indicate that the transparent membrane and the red membrane, based on gas-phase equilibrium regulation, synergistically upregulate the expression of key genes involved in photosynthetic electron transport and respiration, and downregulate the expression of carbon fixation genes, thereby directionally reshaping the energy metabolism network of cyanobacteria and inducing non-lethal physiological in-situ sedimentation of cells. Specifically, the transparent membrane achieves broad-spectrum metabolic regulation through its high full-spectrum transmittance (>85%), while the red membrane enhances electron transport efficiency through selective red light transmittance (650-750nm transmittance >80%). Both effectively induce algal cell sedimentation and inhibit intracellular toxin release within 3-14 days, providing direct gene expression regulatory targets and molecular mechanism validation for in-situ control of cyanobacterial blooms based on gas-phase equilibrium regulation.

[0042] Example 3 To verify the universality of the gas-phase balance regulation method described in this invention in inhibiting different species of cyanobacteria, this embodiment uses Microcystis aeruginosa (… Microcystisaeruginosa FACHB-905), Synechocystis ( Synechocystis The experiment was conducted using *Microcystis aeruginosa* sp. PCC6803 as the research object. The dominant algae species in algal blooms, *Microcystis aeruginosa*, was used as a typical test species. The growth curve under film covering conditions was measured, and the results are as follows: Figure 6As shown, this invention can delay the logarithmic growth phase of *Microcystis aeruginosa* by 3-7 days, and film covering has a significant inhibitory effect on the growth of *Microcystis aeruginosa*. Additionally, the model unicellular cyanobacterium *Synthia spp.* was selected as the experimental subject, and the experimental results are as follows... Figure 7 As shown, the experiment still included a control group, a transparent membrane group, and a red membrane group. The membrane was placed tightly against the water surface to achieve 100% coverage. The covering method was the same as in Example 1. The results showed that within 5 days of coverage treatment, the growth of *Microcystis aeruginosa* in both the transparent membrane and red membrane groups was significantly inhibited. The above experiments demonstrate that the high-oxygen, low-carbon physiological stress environment constructed in this invention is not only effective against *Microcystis aeruginosa*, but also has a significant physiological inhibitory effect on single-celled cyanobacteria (such as *Microcystis aeruginosa*) by interfering with cyanobacterial photosynthesis and core metabolic processes. This indicates that the gas-phase balance regulation method has broad applicability and engineering application value in the management of multi-species complex cyanobacterial blooms.

[0043] Example 4 A device for in-situ control of cyanobacterial blooms and toxins based on gas phase equilibrium regulation includes a microalgae physiological interference medium, a flexible floating frame 2, and an anchor 3. The microalgae physiological interference medium is a transparent high-barrier membrane 1 or a red high-barrier membrane, which is tightly attached to the water surface. The flexible floating frame 2 can be filled with HDPE pipe and foam and is set on the side of the transparent high-barrier membrane 1 or the red high-barrier membrane. The upper end of the anchor 3 is connected to the flexible floating frame 2 and hangs into the water, so that the transparent high-barrier membrane 1 or the red high-barrier membrane forms an airtight seal with the water surface.

[0044] pass Figure 8 The on-site deployment diagram (taking a transparent high-barrier membrane as an example) intuitively demonstrates the actual application scenario of the treatment device described in this invention in a natural water area with a cyanobacterial bloom. Figure 8 The main body of the device consists of a transparent high-barrier membrane 1, a flexible floating frame 2, and anchors 3. The transparent high-barrier membrane 1 adopts a multi-layer composite structure, and its carbon dioxide permeability coefficient is less than 500 cm³. 3 ·mm / (m 2With a visible light transmittance greater than 85% (24h·0.1MPa), it can form an airtight barrier interface tightly attached to the water surface when covering areas where cyanobacteria accumulate. The flexible floating frame 2 is designed as a sealed hollow cuboid structure, filled with lightweight foam material, which allows the device to float stably on the water surface and has good resistance to wave disturbance. The anchor 3 is fixed to the edge of the frame by underwater weights or pile foundations to achieve device positioning and prevent drifting, while maintaining tight adhesion and sealing between the membrane and the water surface. The above arrangement can effectively block the mass transfer process of atmospheric carbon dioxide to the water body and retain the oxygen produced by cyanobacteria photosynthesis in the water body below the membrane, creating a high-oxygen, low-carbon physiological stress environment in situ below the interface. This invention does not cause algal cell membrane rupture during the inhibition of cyanobacteria, and achieves cyanobacteria control through non-lethal sedimentation. It fundamentally avoids the secondary pollution risks of algal cell lysis and large-scale release of algal toxins that are easily caused by traditional algae-killing technologies, and is suitable for safe and in-situ treatment of cyanobacterial blooms in natural waters.

[0045] Therefore, this invention employs the aforementioned method and device for in-situ control of cyanobacterial blooms and toxins based on gas-phase equilibrium regulation. By using non-lethal physical intervention, it maintains the cell membrane integrity of *Microcystis aeruginosa*, fundamentally solving the problem of short-term outbreaks of algal toxins caused by cell lysis in traditional single-method algae control techniques, while simultaneously ensuring the photosynthesis of submerged plants at the bottom. It boasts advantages such as high ecological safety, synergistic algae suppression and toxin control, low carbon footprint, environmental friendliness, and low cost, making it suitable for emergency response to *Microcystis aeruginosa* outbreaks in various water bodies such as lakes and reservoirs.

[0046] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for in-situ control of cyanobacterial blooms and algal toxins based on gas-phase equilibrium regulation, characterized in that: A microalgal physiological interference medium with high light transmittance and high airtightness is set on the surface of the water body in the cyanobacteria aggregation area. A physiological stress environment with high oxygen and low carbon dioxide is constructed at the air-water interface, causing energy deficiency and metabolic inactivation of pseudo-empty cell structure in cyanobacteria, resulting in non-lethal physiological in-situ sedimentation of cyanobacteria. The surface of the microalgal physiological interference medium is treated with anti-bioadhesion, and the permeability of the microalgal physiological interference medium to carbon dioxide is less than 500 cm⁻¹. 3 ·mm / (m 2 (24h·0.1MPa), the average transmittance of the microalgal physiological interference medium to visible light is greater than 80%.

2. The method for in-situ control of cyanobacterial blooms and toxins based on gas-phase equilibrium regulation according to claim 1, characterized in that: The microalgae physiological interference medium is a transparent high-barrier membrane or a red high-barrier membrane. The transparent high-barrier membrane has a carbon dioxide permeability coefficient of less than 500 cm⁻¹. 3 ·mm / (m 2 (24h, 0.1MPa), with an average transmittance of over 85% for visible light in the 400nm-700nm range; The red high-barrier membrane has a carbon dioxide permeability coefficient of less than 500 cm⁻¹. 3 ·mm / (m 2 (24h·0.1MPa), the average absorbance of visible light in the 500nm-560nm range is greater than 1.0, and the average transmittance of visible light in the 650nm-750nm range is greater than 80%.

3. The method for in-situ control of cyanobacterial blooms and toxins based on gas-phase equilibrium regulation according to claim 2, characterized in that: The transparent high-barrier film or the red high-barrier film is selected from vinyl chloride film, polyvinylidene chloride film, or composite film containing an inorganic barrier layer; the inorganic barrier layer is selected from one or more of silicon oxide (SiOx), aluminum oxide (AlOx), or magnesium oxide (MgOx).

4. The method for in-situ control of cyanobacterial blooms and algal toxins based on gas-phase equilibrium regulation according to claim 1, characterized in that: The high-oxygen, low-carbon dioxide physiological stress environment delayed the entry of cyanobacterial blooms into the logarithmic growth phase by 3-7 days compared to the control group without microalgal physiological interference media. The high-oxygen, low-carbon dioxide physiological stress environment was defined as an air-water interface with a dissolved oxygen concentration greater than 8 mg / L and a carbon dioxide concentration less than 0.5 mg / L.

5. The method for in-situ control of cyanobacterial blooms and algal toxins based on gas-phase equilibrium regulation according to claim 1, characterized in that: The high-oxygen, low-carbon dioxide physiological stress environment induces the metabolic inactivation of cyanobacterial pseudo-empty cells. Within 3-14 days of being covered by the microalgal physiological interference medium, the algal cells settle in situ and maintain the integrity of the algal cell membrane to prevent the release of intracellular toxins into the water.

6. The method for in-situ control of cyanobacterial blooms and algal toxins based on gas-phase equilibrium regulation according to claim 1, characterized in that: The cyanobacteria are microalgae with pseudo-empty cell structures that release harmful substances when subjected to stress and lysis, including the genera *Microcystis*, *Anabaena*, *Syngonium*, *Arthrophyllus*, and *Pterocytospora*.

7. The method according to claim 1, characterized in that: The physiological stress environment significantly downregulated the transcription levels of key gene clusters mcyA and mcyD in cyanobacterial microcystin synthesis compared to the control group not covered by the transparent high-barrier membrane or the red high-barrier membrane.

8. An apparatus for implementing the in-situ control method for cyanobacterial blooms and algal toxins based on gas-phase equilibrium regulation as described in any one of claims 1-7, characterized in that: The device includes a microalgae physiological interference medium, a flexible floating frame, and anchors; The microalgae physiological interference medium is a transparent high-barrier membrane or a red high-barrier membrane, which is closely attached to the water surface; a flexible floating frame is set on the side of the transparent high-barrier membrane or the red high-barrier membrane; the upper end of the anchor is connected to the flexible floating frame and hangs into the water, so that the transparent high-barrier membrane or the red high-barrier membrane forms an airtight seal with the water surface.

9. The application of the in-situ control method for cyanobacterial blooms and algal toxins based on gas-phase equilibrium regulation as described in any one of claims 1-7 in water pollution control, characterized in that: Used to prevent and control cyanobacterial blooms in water bodies.

10. The application according to claim 9, characterized in that: The cyanobacterium is *Microcystis aeruginosa*, and the high-oxygen, low-carbon dioxide physiological stress environment inhibits the encoding gene of the key enzyme in the Calvin cycle of *Microcystis aeruginosa*. rbcS Gene expression enables Rubisco enzymes to activate oxygenase activity, thereby achieving targeted remodeling of cyanobacterial carbon metabolism pathways.

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