Mineral compound for reducing harm and increasing convergence of green tide and application of mineral compound

Abstract

The invention relates to the technical field of marine environment protection and carbon sink, in particular to a mineral compound for reducing harm and increasing sink of green tide and application of the mineral compound. And the mineral compound comprises the following components in percentage by mass: 75-85% of clay minerals, 19-29% of alkaline minerals and 0.1-1% of natural algicidal substances. The three components in the compound have a synergistic effect, the problems of seawater anoxia and acidification caused by green tide outbreak can be remarkably relieved, meanwhile, long-term burying of algae-derived organic carbon in the ocean is promoted, and the compound has a remarkable carbon gain effect. The method is environment-friendly, simple to operate and controllable in cost, and has the potential of large-scale application. The invention provides a safe and effective technical means for improving the carbon sequestration capacity of large-scale green tide and treating the offshore environment.

Description

Technical Field

[0001] This invention relates to the field of marine environmental protection and carbon sequestration technology, and in particular to a mineral complex for reducing pollution and increasing carbon sequestration during green tides and its applications. Background Technology

[0002] During their growth period, algal blooms accumulate in large quantities, not only blocking sunlight and hindering ocean air-water exchange, but also consuming dissolved oxygen in seawater, severely impacting the survival of aquatic organisms. Current methods for controlling algal blooms, such as physical removal and flocculation sedimentation, mostly aim to "promote their settling / decay," striving to eliminate the algae in a short time. However, these methods fail to systematically consider the secondary environmental problems caused by the subsequent degradation of the algae.

[0003] It is estimated that millions of tons of dying seaweed algae settle on the seabed at the end of each green tide, undergoing a drastic microbial mineralization process. This process not only causes ecological and environmental problems such as localized marine hypoxia and acidification, but also rapidly degrades the organic carbon fixed in the algae, releasing it back into the atmosphere as CO2, thus weakening its contribution as a potential carbon sink. Existing treatment methods, including physical salvage, composting and settling, and flocculation settling, can quickly remove the algae from the water, but cannot prevent them from accumulating on the seabed and entering the aerobic degradation stage. Some of the minerals used (such as modified clay) have limited environmental residual impact, but cannot alleviate the carbon re-release and localized ecological degradation caused by algal degradation. It is evident that existing technologies focus primarily on "how to remove the algae," while lacking effective solutions for the carbon fate and environmental effects "after their death."

[0004] Therefore, developing a synergistic technology that can both control the negative impacts of green tides and promote stable carbon sequestration by algae and enhance the actual carbon sink capacity of the ocean has become a key challenge that urgently needs to be addressed in this field, in order to address the environmental problems caused by the death of Ulva lactuca and such as carbon cycle imbalance, seawater hypoxia and acidification. Summary of the Invention

[0005] In response to the carbon sink loss and nearshore environmental degradation caused by the natural degradation of large-scale green tides of Ulva prolifera, this invention aims to provide a mineral complex for mitigating the harm and increasing carbon sinks caused by green tides in the nearshore environment.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A mineral complex for reducing pollution and increasing sequestration during green tides, comprising 75%-85% clay minerals, 19%-29% alkaline minerals, and 0.1%-1% natural algae-dissolving substances by mass percentage.

[0008] As shown in the preferred embodiment, the mineral complex comprises 75%-80% clay minerals, 19%-24% alkaline minerals, and 0.5%-1% natural algicidal substances by mass percentage.

[0009] The clay mineral is one or more of natural montmorillonite, kaolinite, and illite; its purity is higher than 80% to meet the requirements.

[0010] The alkaline mineral is one or more of natural limestone, calcite, and aragonite; its purity is higher than 80% to meet the requirements.

[0011] The natural algicidal substance is 3,3',5,5'-tetrabromo-2,2'-biphenyl; this algicidal substance can be generated by bacterial metabolism or chemically synthesized.

[0012] The complex is used as an active ingredient in the preparation of formulations, which are in the form of solid powder or aqueous suspension.

[0013] The application of a mineral complex for reducing pollution and increasing sedimentation during green tides, wherein the mineral complex is used as a treatment agent to alleviate seawater hypoxia and acidification in nearshore environments caused by dying algae during large-scale green tides.

[0014] The mineral complex is used in a treatment agent that effectively alleviates seawater hypoxia and acidification caused by the large-scale death of Ulva lactuca in green tides.

[0015] The mineral complex is used to promote the death of seaweed in marine environments and alleviate green tides.

[0016] The compound is used to promote the long-term burial of algal-derived organic carbon.

[0017] The mineral complex is added to the sea area to be treated, and the final concentration in the sea area does not exceed 0.05 g / L.

[0018] Advantages of this invention:

[0019] This invention relates to a mineral complex composed of natural clay minerals, alkaline minerals, and natural algicidal substances. The clay minerals effectively slow down the decomposition rate of organic matter by microorganisms through adsorption and the formation of a physical coating layer on the algal surface. The alkaline minerals continuously release carbonate / bicarbonate ions, neutralizing acidic substances produced during degradation and maintaining the pH balance of the water body. The natural algicidal substances accelerate the death of *Ulva prolifera* by targeting and lysing algal cells. These three components are not simply additive but work synergistically: after the algal cells rupture due to the natural algicidal substances, the clay minerals can more fully adsorb and encapsulate the released organic matter, forming a stable "algal-mineral" complex. The alkaline minerals, while mitigating acidification, also provide a more stable interfacial environment for the clay minerals, enhancing their carbon fixation capacity. This synergistic effect of the three components can significantly alleviate seawater hypoxia and acidification problems caused by green tide outbreaks, while simultaneously promoting the long-term burial of algal-derived organic carbon in the ocean, resulting in a significant carbon gain effect. This invention is environmentally friendly, simple to operate, and cost-effective, possessing the potential for large-scale application. This invention provides a safe and effective technical means for enhancing the carbon sequestration capacity of large-scale green tides and for nearshore environmental governance. Attached Figure Description

[0020] Figure 1 This diagram illustrates the effect of algicidal substances on the growth status of *Ulva prolifera* in an embodiment of the present invention.

[0021] Figure 2 The graph shows the effect of adding mineral complexes on pH during the degradation of Ulva prolifera in an embodiment of the present invention.

[0022] Figure 3 The graph shows the effect of adding mineral complexes to the degradation of Ulva prolifera in this embodiment of the invention on dissolved oxygen (DO).

[0023] Figure 4 The figure shows the effect of adding mineral complexes on CO2 release during the degradation of Ulva prolifera in this embodiment of the invention.

[0024] Figure 5 The graph shows the effect of adding mineral complexes on the dissolved organic carbon (DOC) content during the degradation of Ulva prolifera in this embodiment of the invention. Detailed Implementation

[0025] The following examples further illustrate specific embodiments of the present invention. It should be noted that the specific embodiments described herein are merely for illustration and explanation and are not intended to limit the scope of the present invention.

[0026] Example 1

[0027] Fresh *Ulva prolifera* plants selected during the green tide outbreak were used as experimental subjects. They were placed in sterilized seawater culture medium containing a low dose of algicidal substances (the main active ingredient being 3,3',5,5'-tetrabromo-2,2'-biphenyl hydroquinone) and cultured at 20°C, under a light intensity of 3000 lux and a light-dark cycle of 12 h:12 h. Sterile seawater culture medium without added algicidal substances served as the control group (see [link to study]). Figure 1 The sterilized seawater culture medium containing a low dose of algicidal substances (the main active ingredient being 3,3',5,5'-tetrabromo-2,2'-biphenyl) is designated 2216E. The specific preparation method is as follows: Accurately weigh 5.0 g of peptone, 1.0 g of yeast extract, 0.1 g of ferric citrate, and various inorganic salts (including 19.45 g of sodium chloride and 5.98 g of magnesium chloride, etc.), and dissolve them sequentially in 800 mL of pure water, bringing the volume to 1 L. After aliquoting the culture medium, autoclave at 121℃ for 20 minutes.

[0028] The results showed that in the control group without the added algicidal substance, the *Ulva prolifera* maintained normal growth, with intact algae and a bright green color. However, after 24 hours of treatment with the added algicidal substance, the *Ulva prolifera* significantly lost its activity, exhibiting yellowing, sedimentation, shrinkage, and decomposition. These experimental results demonstrate that the algicidal substance can cause rapid death of algae within a short period, highlighting its important application value in algal bloom control and aquatic ecological environment protection.

[0029] Example 2

[0030] In July 2024, fresh, decaying *Ulva prolifera* was collected from the site of a green tide outbreak in Qingdao, Shandong Province. Impurities were removed, and the algae were repeatedly rinsed with sterilized seawater. Simultaneously, surrounding seawater was collected and filtered through a 3-micron filter membrane. The *Ulva prolifera* was mixed with fresh seawater in an acid-washed glass container, followed by the addition of a mineral complex and thorough mixing. The *Ulva prolifera* density was set at 5 g / L, and the mineral complex concentration at 0.05 g / L (the mineral complex contained 0.25 g of clay minerals, 0.08 g of algicidal minerals, and 0.002 g of algae-dissolving substances, respectively). Control groups (seawater + macroalgae) without mineral complex and control groups (seawater + mineral complex) without *Ulva prolifera* were established, along with a blank control group (seawater) without either *Ulva prolifera* or mineral complex. A 90-day *Ulva prolifera* degradation experiment was conducted under constant temperature and darkness conditions. Seawater samples were collected from the *Ulva prolifera* degradation system on days 0, 1, 3, 5, 10, 30, 60, 90, 120, and 150, and pH, DO, and CO2 partial pressure were monitored. p Dynamic changes in CO2 (see [reference]) Figure 2-4 ).

[0031] The results showed that the dissolved oxygen (DO) in the untreated *Ulva prolifera* degradation group (seawater + macroalgae) decreased sharply within 30 days, exhibiting a severe hypoxic state; while the DO in the mineral complex-added group (seawater + macroalgae + mineral complex) decreased more slowly and to a smaller extent, and showed a faster recovery trend in the later stages. Figure 2 In the experimental group without added mineral compounds, the pH value of the water continuously decreased from an initial 8.0 to around 6.8, indicating significant acidification; while under the influence of mineral compounds, the rate of pH decrease slowed significantly, remaining at a relatively high level throughout the process. Figure 3 By monitoring the partial pressure of CO2 ( p CO2) was found in the mineral complex addition group p The peak CO2 level was significantly reduced by approximately 58% compared to the group degraded by *Ulva prolifera*, demonstrating its effectiveness in reducing CO2 release. Figure 4 This indicates that the addition of mineral complexes slows down the degradation of dying algae, significantly reduces CO2 release, and increases seawater pH, effectively alleviating water acidification and hypoxia caused by the degradation of Ulva prolifera.

[0032] In addition to pH, DO, and CO2, the release dynamics of DOC during the degradation of dying *Ulva prolifera* were also studied. Based on the dynamic changes in DOC, it was found that after the addition of the mineral complex, the release rate of DOC from dying *Ulva prolifera* was slow and the concentration was significantly lower in the early stage of degradation. Figure 5 Furthermore, after long-term degradation, 30% (relative to the initial biomass of *Ulva prolifera*) of the carbon from the dying *Ulva prolifera* thallus was retained in different carbon forms (mainly DIC, DOC, POC, and detrital carbon); while under the long-term action of minerals, approximately 45% of the carbon from the thallus remained, increasing the total carbon sequestration by 50%. This indicates that the use of mineral complexes not only inhibits thallus decomposition and reduces CO2 release, but also increases the amount of carbon buried in the thallus, enabling it to have the ability to sequester carbon for a long time.

Claims

1. A mineral complex for reducing pollution and increasing sequestration during green tides, characterized in that, The mineral complex consists of 75%-85% clay minerals, 19%-29% alkaline minerals, and 0.1%-1% natural algaecides by mass percentage.

2. The mineral complex for reducing pollution and increasing carbon sequestration during green tides according to claim 1, characterized in that, The mineral complex consists of 75%-80% clay minerals, 19%-24% alkaline minerals, and 0.5%-1% natural algaecides by mass percentage.

3. The mineral complex for reducing pollution and increasing sequestration during green tides according to claim 1 or 2, characterized in that, The clay mineral is one or more of natural montmorillonite, kaolinite, and illite.

4. The mineral complex for reducing pollution and increasing sequestration during green tides according to claim 1 or 2, characterized in that, The alkaline mineral is one or more of natural limestone, calcite, and aragonite.

5. The mineral complex for reducing pollution and increasing sequestration during green tides according to claim 1 or 2, characterized in that, The natural algicidal substance is 3,3',5,5'-tetrabromo-2,2'-biphenyldiphenol.

6. The mineral complex for reducing pollution and increasing carbon sequestration during green tides according to claim 1 or 2, characterized in that, The mineral complex is used as the active ingredient in the preparation of the formulation, which is in the form of a solid powder or an aqueous suspension.

7. The application of the mineral complex according to claim 1 for reducing pollution and increasing sequestration during green tides, characterized in that, The mineral complex is used as a treatment agent to alleviate seawater hypoxia and acidification in nearshore environments caused by dying algae during large-scale green tides.

8. The application of the mineral complex for reducing pollution and increasing sequestration during green tides according to claim 7, characterized in that, The mineral complex is used in a treatment agent that effectively alleviates seawater hypoxia and acidification caused by the large-scale death of Ulva lactuca in green tides.

9. The application of the mineral complex for reducing pollution and increasing sequestration during green tides according to claim 7, characterized in that, The mineral complex is used to promote the death of seaweed in marine environments and alleviate green tides.

10. The application of the mineral complex for reducing pollution and increasing sequestration during green tides according to claim 7, characterized in that, The mineral complex is used to promote the long-term burial of algal-derived organic carbon.

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