Low-temperature curing preparation method of hierarchical pore structure bionic artificial fish reef based on biomineralization principle

Abstract

The invention relates to the technical field of artificial fish reef preparation and marine ecological restoration, and discloses a low-temperature curing preparation method of a bionic artificial fish reef with a hierarchical pore structure based on a biomineralization principle. The preparation method comprises the following steps: mixing silicon-calcium-based industrial solid waste, a marine biomass material, a biological template agent and an alkaline activator to prepare a biomimetic mineralization precursor; a hierarchical pore structure with macroscopic pores, mesoscopic pores and microcosmic pores in synergistic distribution is constructed through compression molding of a gradient pore distribution mold; carrying out biomineralization low-temperature curing under the conditions of controlled temperature, humidity and carbon dioxide atmosphere; and carrying out bionic surface treatment on the cured artificial fish reef. The prepared artificial fish reef has the advantages of being high in pore connectivity, good in mechanical property and high in surface biocompatibility, marine organism attachment and ecological succession are facilitated, the ecological adaptability of the artificial fish reef is improved while preparation energy consumption is reduced, and the artificial fish reef is suitable for the fields of marine ecological restoration and fishery resource protection.

Description

Technical Field

[0001] This invention relates to the field of artificial reef preparation and marine ecological restoration technology, specifically to a low-temperature solidification preparation method for a multi-level porous biomimetic artificial reef based on the principle of biomineralization, and the multi-level porous biomimetic artificial reef prepared by this method. Background Technology

[0002] With the increasing demand for marine ecological restoration and fishery resource protection, artificial reefs, as important engineering facilities for improving marine habitats and promoting the recovery of fishery resources, have been widely used in nearshore ecological restoration, stock enhancement and release, and marine ranching. Artificial reefs provide a three-dimensional spatial structure on the seabed, offering habitats, feeding grounds, and breeding grounds for fish and other marine life, thereby improving the local marine ecological environment.

[0003] Currently, the materials and structural forms used to prepare artificial reefs mainly include concrete reefs, reefs made from recycled waste materials, and reefs made from new composite materials.

[0004] Traditional concrete artificial reefs are typically made from ordinary silicate cement and natural aggregates, molded using molds and cured by steam or natural methods. While these reefs have advantages such as mature manufacturing processes and high mechanical properties, their production often requires significant energy, and the material system is highly alkaline, resulting in a high surface pH after molding. This can negatively impact attached organisms in the initial stages of marine deployment. Furthermore, the internal pore structure of traditional concrete reefs is relatively simple, consisting mainly of randomly distributed small pores with limited connectivity, making it difficult to simultaneously meet the diverse pore structure requirements of large fish for activity space and microorganisms and algae for attachment and growth.

[0005] To reduce costs and achieve resource reuse, some artificial reefs are made from recycled materials such as abandoned ships, used tires, or building components. While these reefs alleviate the pressure of solid waste disposal to some extent, their complex material composition, difficulty in controlling structural stability and durability, and the potential for environmental risks such as heavy metal leaching from some materials limit their long-term application in ecological restoration projects.

[0006] In recent years, with the development of ecological engineering concepts, some new artificial reefs have begun to incorporate porous ceramic materials, polymer composites, or bio-based materials to improve the pore structure and surface properties of the reefs. However, these technologies typically rely on high-temperature sintering or complex preparation processes, resulting in high production costs and energy consumption. Furthermore, they still fall short in achieving multi-scale synergistic pore distribution and long-term mechanical stability.

[0007] Furthermore, from an ecological adaptability perspective, existing artificial reefs primarily focus on macroscopic structural design, paying insufficient attention to the microscopic morphology of the reef surface and its impact on microbial film formation and colonization of attached organisms. Natural reef surfaces typically possess multi-scale rough structures and complex mineral compositions, which are conducive to the attachment and growth of microorganisms, algae, and invertebrates, while existing artificial reefs still lag significantly behind in terms of biomimicry of surface structures.

[0008] Therefore, existing artificial reef technologies generally face the following problems: First, the energy consumption during the preparation process is high, making it difficult to balance resource utilization and low-carbon preparation; second, the internal pore structure of the reef is of a single level or lacks connectivity, limiting its ecological function; and third, the surface structure and chemical properties of the reef do not match the needs of marine organism attachment, resulting in a slow process of biological attachment and ecological succession.

[0009] Based on the shortcomings of the existing technology, there is an urgent need to provide a method for preparing artificial reefs that can be solidified and molded at lower temperatures, while possessing a multi-level porous structure and good surface biomimetic properties. This method aims to improve the ecological adaptability and biological attachment capacity of artificial reefs while ensuring mechanical properties, thereby better meeting the practical needs of marine ecological restoration and fishery resource protection. Summary of the Invention

[0010] To address the problems existing in the background technology, this invention proposes a low-temperature solidification preparation method for a multi-level porous biomimetic artificial reef based on the principle of biomineralization, and the artificial reef prepared by this method. The technical solution of this invention will be further described below in conjunction with specific embodiments. This section provides a general description of possible embodiments of this invention based on the technical solution defined in the claims, to illustrate the core technical concept and its basic implementation.

[0011] It should be understood that the following embodiments are merely illustrative examples of the technical solutions of the present invention, intended to help those skilled in the art understand the technical concept of the present invention, and not to limit the scope of protection of the present invention in any way. The scope of protection of the present invention should be determined by the contents of the claims.

[0012] In one possible implementation, a low-temperature solidification method for preparing a multi-level porous biomimetic artificial reef based on the principle of biomineralization is provided, comprising the following steps: (1) Preparation of biomimetic mineralization precursor: Mix 40-65wt% of silicon-calcium based industrial solid waste, 15-30wt% of marine biomass material, 3-12wt% of biological template agent and 5-15wt% of alkaline activator, add water to adjust to water-solid ratio of 0.25-0.35, stir to form a uniform slurry and then let it stand for aging. (2) Multi-level pore structure forming: The slurry obtained in step (1) is injected into a mold with a gradient pore distribution and pressed under a pressure of 0.5-1.5MPa to form a reef blank with a biomimetic multi-level pore structure, wherein the pores include: macropores with a pore diameter of 5-15mm and a volume ratio of 30-40%; mesopores with a pore diameter of 1-5mm and a volume ratio of 40-50%; and micropores with a pore diameter of 0.01-1mm and a volume ratio of 15-25%. (3) Biomineralization low-temperature solidification: The molded blank is placed in an environment of 35-50℃ and relative humidity ≥85%, and a mixed gas containing 3-10% CO2 is introduced to carry out the mineralization reaction; (4) Bionic surface treatment: Laser micro-machining is performed on the solidified reef to construct a bionic texture structure with multi-scale features on the surface.

[0013] Furthermore, the silicon-calcium based industrial solid waste is at least one of fly ash, blast furnace slag, steel slag or silica fume, and its chemical composition satisfies: SiO2 35-55wt%, CaO 15-35wt%, Al2O3 10-25wt%.

[0014] Furthermore, the marine biomass material is at least one of shell powder, coral sand, or seaweed ash, with a CaCO3 content ≥80wt% and a particle size distribution of 1-100μm.

[0015] Furthermore, the biotemplative agent is at least one of chitosan, sodium alginate, or carrageenan, with a molecular weight of 100,000 to 1,000,000 Daltons.

[0016] Furthermore, the alkaline activator is a modified water glass solution with a modulus of 1.0-1.8 and a Na2O content of 8-12 wt%.

[0017] Preferably, the biomineralization low-temperature solidification process in step (3) is controlled in stages, including: the first stage, maintaining at 35-40℃ for 24 hours with a CO2 concentration of 3-5%; the second stage, maintaining at 40-45℃ for 36-48 hours with a CO2 concentration of 5-8%; the third stage, maintaining at 45-50℃ for 12-24 hours with a CO2 concentration of 8-10%; and the fourth stage, naturally cooling to room temperature.

[0018] Optionally, the biomimetic texture structure with multi-scale features described in step (4) includes: a trench network with a depth of 2-8 mm and a width of 5-15 mm at the macro scale; an undulating surface with a roughness Ra of 10-100 μm at the micro scale; and a bio-mineral protrusion structure with a size of 50-500 nm at the nanoscale.

[0019] Optionally, a bio-activation step may be included after step (4): the prepared artificial reef is immersed in an activation solution containing marine probiotics for 12-48 hours, said activation solution containing 10g of Bacillus sp. 5 -10 7 CFU / mL, Pseudoalteromonas sp. 10 4 -10 6 CFU / mL, and 0.1-1.0 mg / L each of Fe, Zn, and Mn ions.

[0020] Preferably, the settling and aging time in step (1) is 12-36 hours, and the mineralization reaction time in step (3) is 72-120 hours.

[0021] Alternatively, the mold described in step (2) is a 3D-printed biodegradable PLA mold with macroscopic pore channels that mimic the Voronoï structure of coral skeleton.

[0022] In one possible implementation, a multi-level porous biomimetic artificial reef prepared by the method described in any of the above embodiments is also provided, which has a compressive strength ≥25MPa, a pore connectivity ≥75%, a surface pH value of 7.5-8.5, and its bio-attachment promotion effect is 2-3 times higher than that of conventional concrete reefs.

[0023] Furthermore, the mineral composition of the biomimetic artificial reef with a multi-level porous structure includes: 15-30 wt% calcite-type CaCO3, 5-15 wt% aragonite-type CaCO3, 40-60 wt% hydrated calcium silicate gel, and 5-15 wt% unreacted raw materials.

[0024] Based on the above technical solutions, this invention proposes a low-temperature solidification preparation method for a multi-level porous biomimetic artificial reef based on the principle of biomineralization. This method uses silicon-calcium-based industrial solid waste and marine biomass materials as the main raw materials. By introducing biological template agents and alkaline activators, a biomimetic mineralization precursor system is constructed to induce the generation and deposition of calcium carbonate minerals under lower temperature conditions, thus distinguishing it from the traditional artificial reef preparation methods that rely on high-temperature hydration reactions or sintering processes.

[0025] Specifically, this invention controls the composition ratio and water-to-solid ratio of the precursor to effectively activate silicon-calcium-based industrial solid waste in an alkaline environment. At the same time, it utilizes the calcium carbonate component rich in marine biomass materials as the ion source for the mineralization reaction. Under the regulation of the biotemplate agent, it guides the orderly nucleation and growth of calcium carbonate, realizing a biomimetic biomineralization process. This results in a solidified structure with both mechanical properties and ecological adaptability at low temperatures, reducing energy consumption and carbon emissions during preparation.

[0026] In terms of structural construction, this invention utilizes a gradient pore distribution mold forming process to create a multi-level porous structure within the artificial reef, characterized by the coordinated distribution of macroscopic, mesoscopic, and microscopic pores. The macroscopic pores provide habitat and hiding spaces for fish and large marine organisms; the mesoscopic pores facilitate seawater circulation and nutrient exchange; and the microscopic pores provide an attachment interface for the early colonization of microbial membranes and attached organisms. The interconnectedness of these multi-level pores improves the overall mass transfer conditions and ecological functions within the artificial reef, achieving synergistic optimization of structural performance and ecological function.

[0027] In terms of curing process, this invention achieves low-temperature curing of biomineralization under controlled temperature, humidity and carbon dioxide concentration conditions, so that the calcium source in the precursor system reacts with carbon dioxide to generate calcium carbonate minerals, while promoting the structural stabilization of the silicon-calcium based system. Thus, the formation and curing of the reef can be completed without high-temperature curing or sintering, which not only ensures the mechanical strength of the material, but also avoids the adverse effects of high temperature conditions on the biomimetic structure and bio-friendly components.

[0028] Furthermore, this invention introduces a biomimetic surface treatment process after the artificial reef has solidified. Through laser micromachining, a biomimetic texture structure with macroscopic, microscopic, and nanoscale features is constructed on the reef surface, making its surface morphology more closely resemble the characteristics of a natural reef. This significantly improves surface roughness and interfacial properties, providing favorable conditions for the colonization of microorganisms, algae, and invertebrates. In some embodiments, further bioactivation treatment can be used to introduce beneficial microorganisms and trace elements onto the artificial reef surface, promoting the formation of microbial films and initiating ecological succession processes.

[0029] In summary, this invention combines the principles of biomineralization, hierarchical pore structure design, low-temperature curing process, and biomimetic surface construction to significantly improve the pore connectivity, surface biocompatibility, and ecological adaptability of artificial reefs while ensuring their mechanical properties. It overcomes the problems of high energy consumption, simple pore structure, and low bio-attachment efficiency in existing artificial reef preparation processes, and realizes an artificial reef preparation method that has the advantages of structural performance, ecological function, and resource utilization. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the overall process flow for the low-temperature solidification preparation method of the multi-level porous biomimetic artificial reef based on the principle of biomineralization of the present invention. Detailed Implementation

[0031] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described below are only used to explain the technical concept of the present invention, and not to limit the scope of protection of the present invention. Various equivalent substitutions, modifications, or improvements made by those skilled in the art to the technical solution described in this invention after reading this specification, without departing from the technical concept of the present invention, should fall within the scope of protection of the present invention.

[0032] In the following specific implementation, Figure 1 Based on the low-temperature curing preparation process shown, this invention describes the preparation method of the biomimetic artificial reef with a multi-level porous structure based on the principle of biomineralization and the resulting product. For ease of understanding, the preparation process is divided into several steps for description. However, it should be understood that the steps are not absolutely independent and can be reasonably adjusted or combined as needed in actual implementation. As long as they do not deviate from the technical concept of this invention, they all fall within the protection scope of this invention.

[0033] I. Overall Implementation Method Description In one embodiment of the present invention, the specific implementation is as follows: Figure 1 The low-temperature curing preparation process shown is used as a basis for explanation. Figure 1 As shown, the low-temperature solidification preparation method of the biomimetic artificial reef with a multi-level porous structure based on the principle of biomineralization of the present invention includes the following steps in sequence: preparation of biomimetic mineralization precursor, forming of multi-level porous structure, low-temperature solidification of biomineralization, biomimetic surface treatment, and in some embodiments, further including bioactivation treatment.

[0034] In the biomimetic mineralization precursor preparation step, silicon-calcium-based industrial solid waste, marine biomass materials, biological template agents, and alkaline activators are proportioned, mixed, and aged to form a precursor system suitable for subsequent biomineralization reactions. In the multi-level porous structure forming step, the precursor system is pressed and formed using a mold with a gradient pore distribution to construct the basic spatial structure of the artificial reef. In the low-temperature solidification step of biomineralization, the artificial reef achieves low-temperature solidification and structural stability by carrying out mineralization reactions under controlled temperature, humidity, and carbon dioxide atmosphere conditions. In the biomimetic surface treatment step, the surface of the artificial reef is microstructured to make its surface morphology more similar to that of natural reefs. In the optional bioactivation treatment step, beneficial microorganisms and trace elements are introduced to further improve the biocompatibility of the artificial reef.

[0035] The above steps are as follows Figure 1The steps are performed sequentially, with each step providing the necessary structural foundation or reaction conditions for the next. These steps are interconnected and synergistic, forming a complete low-temperature curing preparation process. This process allows for the fabrication of biomimetic artificial reefs with hierarchical porous structures and good ecological adaptability under relatively low energy consumption.

[0036] In the following specific implementation, the combination Figure 1 The process flow shown further explains the implementation methods and preferred solutions for each of the above steps.

[0037] II. Implementation Methods for Preparing Biomimetic Mineralization Precursors 2.1 Raw material selection and proportioning In one embodiment of the present invention, the biomimetic mineralization precursor is composed of silicon-calcium based industrial solid waste, marine biomass materials, biological template agents and alkaline activators in a predetermined ratio.

[0038] The silicon-calcium-based industrial solid waste can be selected from at least one of fly ash, blast furnace slag, steel slag, or silica fume. These materials are rich in silicon, calcium, and aluminum, and exhibit certain reactivity in alkaline environments, providing a basic inorganic framework for subsequent mineralization reactions and structural stability. By rationally utilizing silicon-calcium-based industrial solid waste, not only can preparation costs be reduced, but the resource utilization of solid waste can also be achieved.

[0039] The marine biomass material can be selected from at least one of shell powder, coral sand, or seaweed ash. This type of material usually contains a high proportion of calcium carbonate, which can serve as an important calcium source for biomineralization reactions. At the same time, its source is compatible with the marine ecological environment, which is conducive to improving the ecological adaptability of artificial reefs.

[0040] The biotemplate agent can be selected from at least one of chitosan, sodium alginate or carrageenan. In the precursor system, it mainly plays a role in regulating the nucleation and growth behavior of minerals. By providing organic templates or functional groups, it guides the formation mode and distribution state of calcium carbonate minerals, thereby creating conditions for the biomimetic mineralization process.

[0041] The alkaline activator is a modified water glass solution, whose main function is to provide an alkaline environment to activate the potential active components in silicon-calcium-based industrial solid waste, while promoting the dissolution and migration of ionic species in the precursor system, thus providing the necessary chemical conditions for subsequent mineralization reactions.

[0042] In this embodiment, the mass percentages of the above components are controlled as follows: 40–65 wt% silicon-calcium based industrial solid waste, 15–30 wt% marine biomass material, 3–12 wt% biological template agent, and 5–15 wt% alkaline activator. This formulation achieves a balance between mechanical properties, mineralization reactivity, and ecological compatibility in the precursor system.

[0043] 2.2 Slurry Preparation and Aging Process In one embodiment of the present invention, after completing the above-mentioned selection and proportioning of raw materials, silicon-calcium-based industrial solid waste, marine biomass materials, biological template agents and alkaline activators are mixed, and water is added to adjust the water-solid ratio of the system so that it is in a rheological state suitable for stirring and molding.

[0044] Controlling the water-to-solid ratio helps ensure that the slurry has good uniformity and formability, while avoiding the impact of excessive or insufficient water on subsequent structural forming and mineralization reactions.

[0045] During the mixing process, stirring ensures that the components are uniformly dispersed in the system, allowing the silicon-calcium based solid particles, marine biomass particles, biotemplates, and alkaline activators to come into full contact and form a homogeneous slurry. The stirring method is not specifically limited, as long as it achieves thorough mixing of the components.

[0046] After stirring, the resulting slurry is allowed to stand for aging. This aging process is not simply a matter of waiting; rather, it involves a series of physicochemical changes occurring in the slurry system under undisturbed conditions. On one hand, under the action of an alkaline activator, some active components in the silicon-calcium-based industrial solid waste are gradually activated, which is beneficial for the formation of a stable precursor structure. On the other hand, the biotemplate agent can interact with ionic species in the system during aging, providing an ordered environment for the subsequent nucleation and growth of calcium carbonate.

[0047] Through the above aging treatment, the precursor slurry achieves a relatively stable and balanced state in terms of component distribution, structural state and reactivity, thus laying the foundation for subsequent multi-level porous structure formation and low-temperature solidification of biomineralization.

[0048] III. Implementation Methods for Multi-level Pore Structure Forming 3.1 Gradient Pore Mold Forming Method In one embodiment of the present invention, after the preparation of the biomimetic mineralization precursor is completed and a stable precursor slurry is obtained, the precursor slurry is injected into a mold with a gradient pore distribution for molding.

[0049] The gradient pore distribution mold is used to pre-determine pore structures of different scales during the artificial reef forming process, so that the formed reef blank exhibits a pore distribution characteristic that gradually transitions from large to small in its overall spatial structure. Through this mold forming method, macroscopic pores, mesoscopic pores, and microscopic pores can be constructed simultaneously in a single forming step, providing a multi-layered internal spatial structure for the artificial reef.

[0050] During the molding process, external pressure is applied to the precursor slurry injected into the mold to compress it, causing the slurry to deform and gradually solidify under the constraint of the mold, thereby obtaining a reef-shaped preform with a predetermined shape and internal pore structure. This pressing process helps improve the overall density and structural stability of the preform, while ensuring the repeatability of the pore morphology and distribution.

[0051] By using the gradient pore mold forming method described above, the problems of random pore distribution and insufficient connectivity in traditional forming processes can be avoided, enabling artificial reefs to have clear and controllable multi-level pore structure characteristics during the forming stage.

[0052] 3.2 Formation and Synergistic Effect of Hierarchical Porous Structures In one embodiment of the present invention, the artificial reef blank formed by step S2 has a multi-level pore structure with macroscopic pores, mesoscopic pores and microscopic pores distributed in a coordinated manner.

[0053] Among them, macroscopic pores have a diameter on the millimeter scale and are mainly used to provide activity, habitat and hiding space for fish and larger marine organisms; mesoscopic pores have a diameter on the sub-millimeter to millimeter scale, which is conducive to the flow of seawater inside the reef and promotes the exchange of nutrients and dissolved oxygen; microscopic pores have a diameter on the micrometer scale and provide attachment interfaces and growth space for the early colonization of microorganisms, algae and attached organisms.

[0054] The pores of different scales mentioned above do not exist in isolation, but rather form an interconnected pore network structure under the shaping effect of a gradient pore mold. Through the interconnection between multi-level pores, continuous mass transfer channels can be formed inside the artificial reef, allowing seawater, nutrients, and organisms to freely exchange between spaces of different scales, thereby improving the ecological environment conditions inside the artificial reef.

[0055] Furthermore, the synergistic distribution of the hierarchical pore structure helps to improve the pore connectivity and space utilization efficiency of artificial reefs while ensuring overall mechanical properties, providing favorable spatial conditions for mineral deposition and structural stability during subsequent low-temperature solidification of biomineralization.

[0056] 3.3 Impact of the forming stage on subsequent mineralization and solidification In one embodiment of the present invention, the multi-level porous reef preform obtained by step S2 provides the necessary structural basis for the subsequent biomineralization low-temperature solidification step.

[0057] On the one hand, the hierarchical pore structure facilitates the transport of carbon dioxide and moisture within the green body, enabling the mineralization reaction to proceed relatively uniformly within the green body; on the other hand, the pore wall surface provides abundant interfaces for the subsequent deposition and growth of calcium carbonate minerals, which helps to form a stable mineralization structure.

[0058] Therefore, by introducing a gradient pore distribution design in the molding stage, not only was the biomimetic construction of the artificial reef spatial structure realized, but also favorable conditions were created for the smooth progress of the subsequent low-temperature mineralization and solidification process and the final realization of the artificial reef's performance.

[0059] IV. Implementation Methods of Low-Temperature Solidification for Biomineralization 4.1 Setting up a low-temperature mineralization and solidification environment In one embodiment of the present invention, after the multi-level porous structure is formed and the reef blank is obtained, the reef blank is placed in a controlled mineralization solidification environment for biomineralization low-temperature solidification treatment.

[0060] The mineralization and solidification environment is one in which temperature, humidity, and gas composition are controlled. The temperature is maintained within the range of 35–50°C, and the relative humidity is kept at a high level to prevent the green body from losing water too quickly during the solidification process, which would affect the mineralization reaction. At the same time, a mixed gas containing carbon dioxide is introduced into this environment to place the reef green body in a carbon dioxide-rich atmosphere.

[0061] The aforementioned environmental setup allows carbon dioxide to diffuse fully within the hierarchical porous structure and react with the moisture and calcium source inside the green body, creating conditions for the subsequent formation of calcium carbonate. Compared to traditional solidification methods that rely on high-temperature hydration reactions or sintering processes, this low-temperature environment reduces energy consumption while avoiding adverse effects on the biomimetic structure and bio-friendly components.

[0062] 4.2 Biomineralization reaction process and solidification mechanism In one embodiment of the present invention, under a low-temperature mineralization and solidification environment, a biomineralization reaction process mainly involving the formation of calcium carbonate occurs inside the reef blank.

[0063] Specifically, under the action of an alkaline activator, the calcium source in the precursor system is gradually released and reacts with the introduced carbon dioxide in an aqueous environment to generate calcium carbonate minerals. At the same time, the biotemplator introduced in the precursor system regulates the nucleation and growth process of calcium carbonate through the functional groups in its molecular structure, so that the generated minerals are gradually deposited on the surface of the pore walls and interconnected with each other.

[0064] As the mineralization reaction proceeds, calcium carbonate minerals gradually form a continuous mineralized structure on the pore walls and at the pore boundaries of the hierarchical porous structure, thereby achieving solidification and structural stability of the reef preform. This solidification process is mainly driven by mineral deposition and structural reorganization, rather than the high-temperature hydration or sintering reaction in traditional cement systems, and therefore can be completed at lower temperature conditions.

[0065] In addition, the hierarchical porous structure provides abundant reaction interfaces and mass transfer channels for the mineralization reaction, which is conducive to the migration of carbon dioxide, water and ions inside the green body, enabling the mineralization reaction to proceed more uniformly inside the reef, thereby improving the consistency and stability of the solidified structure.

[0066] 4.3 Preferred Implementation Method of Segmented Controlled Mineralization and Solidification In a preferred embodiment of the present invention, the biomineralization low-temperature solidification process is carried out in a segmented control manner.

[0067] In the initial stage, mineralization is carried out under low temperature and low carbon dioxide concentration conditions to ensure a smooth start to the mineralization reaction and prevent minerals from depositing too quickly on the surface of the green body, which would affect the internal structure. In the intermediate stage, the temperature and carbon dioxide concentration are appropriately increased to promote the continuous mineralization reaction inside the green body and to make the mineral deposition more complete. In the subsequent stage, the mineralization reaction is gradually completed by further adjusting the mineralization conditions and the structure tends to stabilize. Finally, the solidification process ends by natural cooling.

[0068] By controlling the mineralization and solidification conditions in stages, the mineralization reaction rate and mineral deposition behavior can be effectively adjusted, which is conducive to forming a uniform, dense mineralization and solidification structure that matches the multi-level pore structure. This ensures the integrity and connectivity of the internal pore structure of the artificial reef while maintaining its mechanical properties.

[0069] 4.4 Effect of Low-Temperature Mineralization and Solidification on Finished Product Performance In one embodiment of the present invention, through the above-mentioned biomineralization low-temperature solidification treatment, the artificial reef can still maintain its multi-level porous structure characteristics and surface structure basic while completing the solidification.

[0070] Low-temperature mineralization and solidification avoids problems such as material shrinkage, pore collapse, or structural damage under high-temperature conditions, which helps maintain the pore connectivity of artificial reefs. At the same time, the calcium carbonate minerals generated by mineralization interact with the silicon-calcium-based system, giving the overall structure of the reef good mechanical stability and durability, providing a reliable foundation for subsequent biomimetic surface treatment and long-term service in the marine environment.

[0071] V. Implementation Methods of Bionic Surface Treatment 5.1 Purpose of implementing biomimetic surface treatment In one embodiment of the present invention, after completing the low-temperature solidification of biomineralization and obtaining a structurally stable artificial reef, the artificial reef is subjected to biomimetic surface treatment.

[0072] The ecological function of artificial reefs in the marine environment depends not only on their overall structure and internal porosity, but also on their surface morphology and interfacial properties. Natural reef surfaces typically have multi-scale undulating structures and complex microscopic morphologies, which are conducive to the attachment and growth of microorganisms, algae, and invertebrates. In contrast, artificial components made by conventional molding processes have relatively flat surfaces, which are difficult to meet the surface structure requirements of attached organisms.

[0073] Therefore, by performing biomimetic treatment on the surface of artificial reefs and constructing multi-scale structural features on their surface, making them more similar in morphology to natural reefs, it is beneficial to improve the surface biocompatibility of artificial reefs and provide favorable conditions for subsequent attachment of marine organisms and ecological succession.

[0074] 5.2 Laser Micromachining Bionic Surface Treatment Method In one embodiment of the present invention, the biomimetic surface treatment is performed by laser micromachining.

[0075] Laser micromachining enables precise processing of artificial reef surfaces without contact with the material itself, facilitating the formation of stable and controllable microstructures while maintaining the overall structural integrity. By adjusting laser processing parameters, structural features of different scales can be formed on the artificial reef surface, thereby achieving the construction of biomimetic surface morphologies.

[0076] During the process, the artificial reef, which has undergone low-temperature mineralization and solidification, is placed in a laser processing area. Its outer surface is scanned and processed, causing localized melting, reconstruction, or roughening, thereby forming an undulating structure at the macroscopic, microscopic, and nanoscale. This processing mainly affects the surface layer of the artificial reef and does not adversely affect its internal hierarchical porous structure or overall mechanical properties.

[0077] 5.3 Formation of Multi-Scale Biomimetic Texture Structures In one embodiment of the present invention, a biomimetic texture structure with multi-scale features is formed on the surface of an artificial reef through the above-mentioned laser micromachining process.

[0078] Specifically, on a macroscopic scale, the surface of artificial reefs forms grooves or depressions with a certain depth and width. These structures increase the surface undulation and provide shelter for attached organisms. On a microscopic scale, the surface of artificial reefs forms undulating structures with a certain roughness, which helps to increase the surface specific surface area and improve the attachment probability of microorganisms and algae. On a nanoscale, the surface of artificial reefs further forms fine protrusions or mineral-like structures, which helps to improve the surface energy state and enhance the adsorption capacity of biomolecules and microorganisms.

[0079] The superposition of these different scales of surface structures gives the artificial reef surface a multi-layered, multi-scale biomimetic morphological feature, making it more closely resemble the surface state of a natural reef as a whole.

[0080] 5.4 The Role of Biomimetic Surface Treatment in Ecological Adaptability In one embodiment of the present invention, through the biomimetic surface treatment in step S4, the artificial reef significantly improves its surface interface characteristics while maintaining its hierarchical porous structure and mechanical properties.

[0081] Multi-scale biomimetic surface structures can provide favorable attachment conditions for the formation of microbial films, promoting the initial colonization of microorganisms on the surface of artificial reefs. As the microbial film forms and develops, it can further attract algae, invertebrates and other attached organisms to colonize, thereby accelerating the ecological succession process on the surface of artificial reefs.

[0082] Therefore, by using biomimetic surface treatment, artificial reefs can more quickly form a positive interaction with the surrounding ecosystem after being deployed in the marine environment, thereby improving the ecological adaptability and effectiveness of artificial reefs.

[0083] VI. Optional Implementation Methods for Bio-activation Treatment 6.1 Purpose of setting up biological activation treatment In an optional embodiment of the present invention, after completing the biomimetic surface treatment, the artificial reef is further subjected to a bio-activation treatment.

[0084] After structural shaping, mineralization, and biomimetic surface treatment, artificial reefs possess a good foundation in spatial structure and surface morphology. However, in the marine environment, the rapid colonization of attached organisms and the initiation of ecological succession are often closely related to whether a stable microbial film can form on the surface of the artificial reef. Therefore, by introducing bioactivation treatment, initial conditions conducive to microbial colonization can be provided on the surface of the artificial reef before it is put into use, thereby accelerating the realization of the ecological functions of artificial reefs in the marine environment.

[0085] 6.2 Biological activation treatment method In this optional embodiment, the bio-activation treatment is achieved by immersing the artificial reef, which has undergone biomimetic surface treatment, in an activation solution.

[0086] The activation solution contains marine probiotics and trace elements. The marine probiotics may include Bacillus sp. and Pseudoalteromonas sp., and the trace elements may include iron, zinc, and manganese ions. By controlling the concentration of microorganisms in the activation solution and the activation time, the surface of the artificial reef can be initially colonized by probiotic microorganisms.

[0087] During the soaking process, probiotics can attach to the multi-scale biomimetic texture structure on the surface of the artificial reef and gradually form an initial microbial film. At the same time, trace elements provide the necessary nutritional conditions for the growth and metabolism of microorganisms, which is conducive to improving the survival rate and stability of microorganisms on the surface of the artificial reef.

[0088] 6.3 Effects of biological activation treatment In an optional embodiment of the present invention, through the above-mentioned biological activation treatment, the artificial reef can possess a certain degree of biological activity before being deployed into the marine environment.

[0089] The microbial film formed on the surface of artificial reefs can serve as a basis for the subsequent colonization of algae, invertebrates, and other marine organisms, which is conducive to accelerating the ecological succession process on the surface of artificial reefs. At the same time, probiotics and their metabolites can also improve the microenvironment on the surface of artificial reefs, further enhancing the biocompatibility of artificial reefs.

[0090] It should be noted that the biological activation treatment is an optional step in this invention. Whether or not it is implemented does not affect the basic structural formation and low-temperature mineralization and solidification process of the artificial reef. However, implementing this step can further improve the ecological adaptability and application effect of the artificial reef.

[0091] VII. Implementation Methods of Artificial Reef Products 7.1 Structural Status of Artificial Reef Products In one embodiment of the present invention, a biomimetic artificial reef with a multi-level porous structure is prepared by means of the aforementioned steps of preparing biomimetic mineralization precursor, forming a multi-level porous structure, low-temperature solidification of biomineralization, and biomimetic surface treatment.

[0092] The artificial reef has a blocky or component-like structure with a multi-level pore structure in which macroscopic, mesoscopic, and microscopic pores are distributed in a coordinated manner. Among them, the pores at each level are spatially interconnected to form a continuous pore network, which gives the artificial reef good spatial permeability and mass transfer conditions.

[0093] Through the above-mentioned multi-level porous structure design, artificial reefs provide suitable living spaces for marine organisms of different scales while maintaining overall structural stability: macroscopic pores are conducive to the habitat and refuge of fish and larger marine organisms, mesoscopic pores are conducive to seawater circulation and nutrient exchange, and microscopic pores provide rich attachment interfaces for microorganisms and attached organisms, thus enabling artificial reefs to have good ecological adaptability.

[0094] 7.2 Mechanical and Surface Properties of Artificial Reef Products In one embodiment of the present invention, the artificial reef, through biomineralization and low-temperature solidification treatment, maintains the integrity of its multi-level porous structure while exhibiting good overall mechanical properties.

[0095] Specifically, the artificial reef possesses compressive strength sufficient for long-term service in marine environments, and its high porosity facilitates seawater flow and exchange within the reef. Furthermore, because the biomineralization and solidification process avoids high-temperature sintering or strongly alkaline hydration reactions, the surface pH of the artificial reef remains within a relatively mild range, making it more suitable for the attachment and growth of marine organisms.

[0096] After biomimetic surface treatment, the artificial reef surface develops a biomimetic texture structure with multi-scale characteristics, significantly improving surface roughness and interfacial properties, thus providing favorable conditions for the formation of microbial films and the colonization of attached organisms. In some embodiments, after bio-activation treatment, the artificial reef exhibits high bio-attachment activity in the initial stage of its deployment in the marine environment.

[0097] 7.3 Mineral Composition Characteristics of Artificial Reef Products In one embodiment of the present invention, the mineral composition of the artificial reef mainly comes from the mineral phases formed during the low-temperature solidification process of biomineralization and the incompletely reacted inorganic components.

[0098] Specifically, artificial reefs contain a certain proportion of calcite-type calcium carbonate and aragonite-type calcium carbonate. These calcium carbonate minerals are generated through biomineralization reactions and deposited on the pore walls and interfaces of the hierarchical porous structure, playing an important role in the structural stability and mechanical properties of the artificial reef. Simultaneously, artificial reefs also contain hydrated calcium silicate gel, which, as part of the inorganic framework, interweaves with the calcium carbonate minerals, further enhancing the overall structural stability.

[0099] In addition, there may be a small amount of unreacted raw material components in artificial reefs. These components serve as structural fillers or potential reactants and do not adversely affect the overall performance of the artificial reefs.

[0100] The aforementioned mineral composition characteristics enable artificial reefs to achieve synergistic effects in terms of structure, performance, and ecological adaptability, making them suitable for long-term use in marine environments.

[0101] 7.4 Description of the application effects of artificial reef products In one embodiment of the present invention, the multi-level porous biomimetic artificial reef prepared by the above method can form a microbial film in a short time after being put into the marine environment, and gradually attract algae, invertebrates and fish to gather.

[0102] Due to the synergistic effect of its internal multi-level porous structure and surface biomimetic texture structure, artificial reefs can effectively improve the habitat conditions of local sea areas, increase the efficiency of biological attachment and the speed of ecological succession, thus playing a positive role in marine ecological restoration and fishery resource protection.

[0103] Application Examples Example 1: Standard Parameter Example This embodiment provides a low-temperature solidification preparation method for a multi-level porous biomimetic artificial reef based on the principle of biomineralization. The method follows... Figure 1 The process flow shown is carried out sequentially, including preparation of biomimetic mineralization precursor, formation of multi-level porous structure, low-temperature solidification of biomineralization, biomimetic surface treatment, and optional bioactivation treatment.

[0104] (I) Preparation of biomimetic mineralization precursors Silicon-calcium based industrial solid waste, marine biomass materials, biological template agents, and alkaline activators were selected as raw materials, among which: The silicon-calcium based industrial solid waste is a mixture of fly ash and blast furnace slag, accounting for 52 wt% of the total precursor mass; The marine biomass material is shell powder, accounting for 22 wt% of the total precursor mass; The biotemplative agent is chitosan, accounting for 8 wt% of the total precursor mass; The alkaline activator is a modified water glass solution, accounting for 10 wt% of the total mass of the precursor.

[0105] After mixing the above components, water was added to adjust the water-to-solid ratio of the system to 0.30. The components were then stirred to ensure uniform dispersion, forming a homogeneous slurry. The resulting slurry was then allowed to stand and age for 24 hours to obtain a stable biomimetic mineralization precursor system.

[0106] (II) Forming of multi-level porous structures The aging precursor slurry is injected into a mold with a gradient pore distribution and pressed under a pressure of 1.0 MPa to obtain a reef blank with a predetermined shape and internal pore structure.

[0107] The artificial reef blank has a multi-level porous structure inside, wherein: The macroscopic pores have a diameter of 10 mm and account for approximately 35% of the volume. The mesopores have a pore size of 3 mm and account for approximately 45% of the volume. The pore size of the micropores is 0.5 mm, accounting for approximately 20% of the volume.

[0108] The pores at each level are interconnected, forming a continuous pore network structure.

[0109] (III) Low-temperature solidification of biomineralization The artificial reef preform was placed in a biomineralization low-temperature curing environment for curing. The temperature of the curing environment was controlled at 42°C, the relative humidity was maintained above 85%, and a mixture of carbon dioxide and air with a volume fraction of 6% was introduced.

[0110] The mineralization and solidification process adopts a segmented control method, specifically as follows: Phase 1: Maintain at 38℃ and 4% CO2 concentration for 24 hours; Second stage: Maintain at 42℃ and 6% CO2 concentration for 48 hours; Third stage: Maintain at 48℃ and CO2 concentration of 9% for 24 hours; Fourth stage: Allow the temperature to cool naturally to room temperature.

[0111] Through the above-mentioned low-temperature solidification treatment of biomineralization, the reef blank is solidified and obtains a stable structure.

[0112] (iv) Bionic Surface Treatment Artificial reefs that have undergone low-temperature mineralization and solidification are subjected to laser micromachining to construct multi-scale biomimetic texture structures on their surface. After processing, the surface of the artificial reef forms a composite surface morphology with macroscopic grooves, microscopic rough structures, and nanoscale protrusions, thereby improving the biocompatibility of the artificial reef surface.

[0113] (v) Bioactivation treatment (optional) In this embodiment, the artificial reef with the biomimetic surface treatment is further subjected to bio-activation treatment. The artificial reef is immersed in an activation solution for 24 hours, the activation solution containing: Bacillus sp., at a concentration of 1×10 6 CFU / mL; Pseudoalteromonas sp., at a concentration of 5 × 10⁻⁶ 5 CFU / mL; Fe, Zn, and Mn ions, 0.5 mg / L each.

[0114] (vi) Performance of the artificial reef obtained in Example 1 The biomimetic artificial reef with a hierarchical porous structure prepared by the above method has the following properties after testing: The compressive strength is 28 MPa; The pore connectivity rate is 78%; The surface pH value is 8.0; In a simulated seawater environment, its bio-attachment effect is about twice as good as that of conventional concrete artificial reefs.

[0115] This demonstrates that the method described in this embodiment can stably prepare biomimetic artificial reefs with a multi-level porous structure and good ecological adaptability under low-temperature conditions.

[0116] Example 2: Parameter Upper Limit / Optimized Example This embodiment optimizes and adjusts the raw material ratio, hierarchical pore structure parameters, and low-temperature solidification conditions for biomineralization based on Embodiment 1. The remaining process flow is the same as in Embodiment 1. Figure 1 The process flow shown is consistent, still including the preparation of biomimetic mineralization precursors, the formation of multi-level porous structures, low-temperature solidification of biomineralization, biomimetic surface treatment, and bioactivation treatment in sequence.

[0117] (I) Preparation of biomimetic mineralization precursors (parameter optimization) Silicon-calcium based industrial solid waste, marine biomass materials, biological template agents, and alkaline activators were selected as raw materials, among which: The silicon-calcium based industrial solid waste is a mixture of fly ash and blast furnace slag, accounting for 62 wt% of the total precursor mass; The marine biomass material is shell powder, accounting for 28 wt% of the total precursor mass; The biological template agent is chitosan, accounting for 10 wt% of the total mass of the precursor; The alkaline activator is a modified water glass solution, accounting for 14 wt% of the total mass of the precursor.

[0118] After mixing the above components, water is added to adjust the water-to-solid ratio of the system to 0.27. The system is stirred to form a uniform slurry, and the resulting slurry is allowed to stand and age for 36 hours to further enhance the reactivity and structural uniformity of the precursor system.

[0119] (II) Forming of multi-level porous structures (optimization of structural parameters) The aged precursor slurry is injected into a mold with a gradient pore distribution and pressed under a pressure of 1.4 MPa to obtain the reef blank.

[0120] The artificial reef blank has a multi-level porous structure inside, wherein: The macroscopic pores have a diameter of 14 mm and account for approximately 38% of the volume. The mesopores have a pore size of 4 mm and account for approximately 48% of the volume. The pore size of the micropores is 0.8 mm, accounting for approximately 22% of the volume.

[0121] By combining the above parameters, the internal pore structure of the artificial reef is made more unobstructed, while maintaining a high overall structural stability.

[0122] (III) Low-temperature solidification of biomineralization (optimized mineralization conditions) The artificial reef preform was placed in a biomineralization low-temperature solidification environment for solidification treatment. The environmental conditions were set as follows: Curing temperature 48℃; Relative humidity should be maintained above 90%; A mixture of carbon dioxide and air with a volume fraction of 9% is introduced.

[0123] The mineralization and solidification process also adopts a segmented control method, specifically as follows: Phase 1: Maintain at 40℃ and 5% CO2 concentration for 24 hours; Second stage: Maintain at 45℃ and 7% CO2 concentration for 48 hours; Third stage: Maintain at 50℃ and CO2 concentration of 10% for 24 hours; Fourth stage: Allow the temperature to cool naturally to room temperature.

[0124] The optimized mineralization and solidification conditions described above promote the more complete and uniform generation and deposition of calcium carbonate minerals within the hierarchical porous structure.

[0125] (iv) Bionic Surface Treatment The artificial reef that has completed low-temperature mineralization and solidification was subjected to laser micromachining to construct a multi-scale biomimetic texture structure on its surface. The resulting surface morphology was consistent with that in Example 1, but the surface structure stability was further enhanced due to the increased internal mineralization.

[0126] (v) Biological activation treatment The biomimetic surface-treated artificial reef was immersed in an activation solution for 36 hours, wherein the activation solution contained: The concentration of Bacillus sp. was 5 × 10⁻⁶. 6 CFU / mL; The concentration of *Pseudoalteromonas* sp. was 1 × 10⁻⁶. 6 CFU / mL; The concentrations of Fe, Zn, and Mn ions are all 0.8 mg / L.

[0127] (vi) Performance of the artificial reef obtained in Example 2 The multi-level porous biomimetic artificial reef prepared using the above optimized parameters exhibits the following performance after testing: The compressive strength is 34 MPa; The pore connectivity rate is 82%; The surface pH value is 7.8; In a simulated seawater environment, its bio-attachment effect is about 3 times better than that of conventional concrete artificial reefs.

[0128] Compared with Example 1, Example 2 further improves mechanical properties and ecological adhesion performance while maintaining the integrity of the multi-level porous structure.

[0129] Comparative Example 1: Method for preparing artificial reefs without biological template agents This comparative example provides a method for preparing artificial reefs. The overall process flow is basically the same as that of Example 1, including the preparation of biomimetic mineralization precursors, the formation of multi-level porous structures, low-temperature curing treatment and surface treatment steps. The difference is that no biological template agent is added to the precursor system.

[0130] (a) Precursor preparation (without biological template agent) Silicon-calcium based industrial solid waste, marine biomass materials, and alkaline activators were selected as raw materials, among which: The silicon-calcium based industrial solid waste is a mixture of fly ash and blast furnace slag, accounting for 60 wt% of the total precursor mass. The marine biomass material is shell powder, accounting for 25 wt% of the total precursor mass; The alkaline activator is a modified water glass solution, accounting for 15 wt% of the total precursor mass; No biological template agent was added in this comparative example.

[0131] After mixing the above components, add water to adjust the water-to-solid ratio to 0.30, stir to form a uniform slurry, and let it stand for 24 hours to age.

[0132] (II) Multi-level porous structure forming and curing treatment The obtained slurry is injected into a mold with a gradient pore distribution and pressed into shape under a pressure of 1.0 MPa to obtain a reef blank.

[0133] Subsequently, the artificial reef blank was placed in the same low-temperature mineralization and curing environment as in Example 1 for curing treatment, and the cured artificial reef was subjected to the same surface treatment.

[0134] (III) Performance of the artificial reef obtained in Comparative Example 1 The artificial reefs prepared using the above method have the following properties after testing: The compressive strength is 22 MPa; The pore connectivity rate is 65%; The surface pH value is 8.6; In simulated seawater environments, its bio-attachment effect is only slightly higher than that of conventional concrete artificial reefs.

[0135] Compared with Example 1, due to the lack of introduction of biological template agents, the nucleation and growth of calcium carbonate minerals lacked effective regulation, the mineralization structure was unevenly distributed, resulting in a significant decrease in both mechanical properties and bio-attachment properties.

[0136] Comparative Example 2: Method for preparing artificial reefs in a CO2-free mineralization environment This comparative example provides another method for preparing artificial reefs, which differs from Example 1 in that a mineralizing gas environment containing CO2 is not introduced during the solidification stage.

[0137] (I) Precursor preparation and molding The raw material composition, ratio, water-to-solid ratio, stirring method, and aging time of the precursor were the same as those in Example 1.

[0138] The aged slurry is injected into a gradient pore distribution mold and pressed into shape under a pressure of 1.0 MPa to obtain a reef blank.

[0139] (ii) Solidification treatment (CO2-free mineralization environment) The artificial reef blank was placed in an environment with a temperature of 42°C and a relative humidity of not less than 85% for curing treatment. However, CO2 gas was not introduced during the curing process, and the curing was carried out only in a normal air environment. The curing time was the same as in Example 1.

[0140] Subsequently, the solidified artificial reef underwent the same biomimetic surface treatment.

[0141] (iii) Performance of artificial reefs obtained in Comparative Example 2 The artificial reefs prepared using the above method have the following properties after testing: The compressive strength is 24 MPa; The pore connectivity rate is 70%; The surface pH value is 8.4; The bio-attachment effect was significantly lower than that in Example 1.

[0142] Compared with Example 1, due to the lack of a CO2 mineralization environment during the solidification process, the amount of calcium carbonate minerals generated was insufficient, and the biomineralization reaction was inadequate, which adversely affected both structural stability and ecological adhesion performance.

[0143] By comparing and analyzing Examples 1 and 2 with Comparative Examples 1 and 2, it can be seen that in the technical solution adopted by the present invention, each key technical feature has a clear and synergistic technical role in the formation and performance realization of the artificial reef.

[0144] First, in Comparative Example 1, although the composition of other raw materials and process conditions were basically the same as in Example 1 without the introduction of a biotemplate, the resulting artificial reef was significantly inferior to that of Example 1 in terms of mechanical properties, pore connectivity, and bio-attachment effect. This indicates that the biotemplate is not simply an auxiliary component in the precursor system, but plays a key regulatory role in the nucleation and growth behavior of calcium carbonate minerals during biomineralization. The introduction of a biotemplate allows for a more uniform distribution of mineralization products within the hierarchical porous structure, thereby improving the overall structural stability and uniformity, and providing more suitable microscopic interface conditions for attached organisms.

[0145] Secondly, in Comparative Example 2, no CO2 mineralization environment was introduced during the solidification process. Although it used the same precursor system and molding process as Example 1, the lack of an effective source of carbon dioxide made it difficult for the mineralization reaction to proceed fully under low-temperature conditions, resulting in insufficient formation of calcium carbonate minerals. This, in turn, affected the structural stability and ecological compatibility of the artificial reef. This demonstrates that a CO2 mineralization environment is a necessary condition for achieving effective biomineralization solidification under low-temperature conditions, and it plays a crucial role in providing mineralization reactants and promoting mineral deposition in this invention.

[0146] Further combining Examples 1 and 2, it can be seen that when a biotemplative agent is introduced and low-temperature solidification is carried out in a CO2 mineralization environment, by optimizing and controlling the raw material ratio, pore structure parameters and mineralization conditions, the mechanical properties and biological attachment properties of the artificial reef can be further improved while maintaining the integrity of the multi-level pore structure. This demonstrates the synergistic advantages of the technical solution of the present invention in terms of structural performance and ecological function.

[0147] In summary, only by simultaneously introducing a bio-templating agent and implementing low-temperature solidification treatment under CO2 mineralization conditions can stable formation of artificial reefs be achieved with lower energy consumption, while significantly improving their ecological adhesion and adaptability while ensuring mechanical properties. This invention, through the organic combination of the above-mentioned key technical features, overcomes the problems of high energy consumption, low mineralization efficiency, and insufficient bio-attachment effects in existing artificial reef preparation technologies, demonstrating significant technological progress.

[0148] In summary, this invention introduces the principle of biomineralization into the preparation process of artificial reefs, combining multi-level porous structure forming, low-temperature mineralization solidification, and biomimetic surface treatment techniques to achieve stable forming and performance improvement of artificial reefs under low energy consumption conditions. The prepared artificial reefs not only possess excellent mechanical properties and pore connectivity, but their surface structure and chemical characteristics are also more conducive to the attachment of marine organisms and ecological succession, effectively improving the ecological adaptability and application effects of artificial reefs. This invention provides a feasible technical approach for the low-carbonization, resource utilization, and ecological function enhancement of artificial reefs, and has good engineering application prospects and promotional value.

[0149] It should be noted that the above specific embodiments are only used to illustrate the technical solution of the present invention, and are not intended to limit the scope of protection of the present invention. Any equivalent substitutions, modifications, or improvements made by those skilled in the art to the technical solution described in the present invention without departing from the technical concept of the present invention shall fall within the scope of protection of the present invention. The scope of protection of the present invention is defined by the appended claims.

Claims

1. A low-temperature solidification preparation method for a multi-level porous biomimetic artificial reef based on the principle of biomineralization, characterized in that, Includes the following steps: (1) Preparation of biomimetic mineralization precursor: Mix 40-65wt% of silicon-calcium based industrial solid waste, 15-30wt% of marine biomass material, 3-12wt% of biological template agent and 5-15wt% of alkaline activator, add water to adjust to water-solid ratio of 0.25-0.35, stir to form a uniform slurry and then let it stand for aging. (2) Multi-level pore structure forming: The slurry obtained in step (1) is injected into a mold with a gradient pore distribution and pressed under a pressure of 0.5-1.5 MPa to form a reef blank with a biomimetic multi-level pore structure, wherein the pores include: Macroscopic porosity: pore size 5-15mm, volume percentage 30-40%; Mesopores: pore size 1-5mm, volume percentage 40-50%; Microscopic pores: pore size 0.01-1mm, volume percentage 15-25%; (3) Biomineralization low-temperature solidification: The molded blank is placed in an environment of 35-50℃ and relative humidity ≥85%, and a mixed gas containing 3-10% CO2 is introduced to carry out the mineralization reaction; (4) Bionic surface treatment: Laser micro-machining is performed on the solidified reef to construct a bionic texture structure with multi-scale features on the surface.

2. The method according to claim 1, characterized in that, The silicon-calcium based industrial solid waste is at least one of fly ash, blast furnace slag, steel slag or silica fume, and its chemical composition satisfies: SiO2 35-55wt%, CaO 15-35wt%, Al2O3 10-25wt%.

3. The method according to claim 1, characterized in that, The marine biomass material is at least one of shell powder, coral sand or seaweed ash, with a CaCO3 content ≥80wt% and a particle size distribution of 1-100μm.

4. The method according to claim 1, characterized in that, The biotemplate agent is at least one of chitosan, sodium alginate, or carrageenan, with a molecular weight of 100,000 to 1,000,000 Daltons.

5. The method according to claim 1, characterized in that, The alkaline activator is a modified water glass solution with a modulus of 1.0-1.8 and a Na2O content of 8-12 wt%.

6. The method according to claim 1, characterized in that, The biomineralization low-temperature solidification process described in step (3) is controlled in stages: Phase 1: Maintain 35-40℃ for 24 hours, CO2 concentration 3-5%; Phase 2: Maintain at 40-45℃ for 36-48 hours, with a CO2 concentration of 5-8%; Phase 3: Maintain at 45-50℃ for 12-24 hours, with a CO2 concentration of 8-10%; Fourth stage: Allow the temperature to cool naturally to room temperature.

7. The method according to claim 1, characterized in that, The biomimetic texture structure with multi-scale features mentioned in step (4) includes: Macroscale: a trench network with a depth of 2-8 mm and a width of 5-15 mm; Microscale: Uneven surfaces with a roughness Ra of 10-100 μm; Nanoscale: Biomorphic mineral protrusions with a diameter of 50-500 nm.

8. The method according to claim 1, characterized in that, Following step (4) is step (5) bio-activation treatment: the prepared artificial reef is immersed in an activation solution containing marine probiotics for 12-48 hours, wherein the activation solution contains 10g of Bacillus sp. 5 -10 7 CFU / mL, Pseudoalteromonas sp. 10 4 -10 6 CFU / mL, and 0.1-1.0 mg / L each of Fe, Zn, and Mn ions.

9. The method according to any one of claims 1-8, characterized in that, The settling and aging time in step (1) is 12-36 hours, and the mineralization reaction time in step (3) is 72-120 hours.

10. The method according to claim 1, characterized in that, The mold mentioned in step (2) is a 3D printed biodegradable PLA mold, whose macroscopic pore channels are Voronoï structures that mimic coral skeletons.

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