Ecological restoration material for mine water body treatment and preparation method thereof

Abstract

The invention provides an ecological restoration material for mine water treatment and a preparation method of the ecological restoration material, and belongs to the field of water pollution governing.The preparation method comprises the steps that a porous mineral base material and an alkaline slow-release component are evenly mixed and subjected to calcination treatment, and a composite base material is obtained; dipping the composite base material in a mixed solution of Fe (NO3) 3 and MnSO4 for a preset time, drying the composite base material, and carrying out ball-milling compounding on the composite base material and biological activated carbon to obtain an Fe-Mn oxide loaded activated carbon complex; mixing the activated carbon complex with an ecological restoration additive and diatomite, and performing extrusion granulation to obtain ecological composite particles; the ecological composite particles are soaked in a PLA solution for preset time, and the ecological restoration material for mine water body treatment is obtained after drying. Through cooperation of multiple components and improvement of a preparation process, multiple remediation mechanisms are integrated, heavy metal can be effectively adsorbed and converted, pH can be effectively adjusted, efficient, stable and lasting treatment on mine water pollution is achieved, and the method is an efficient and environment-friendly scheme for mine water treatment.

Description

Technical Field

[0001] The present invention relates to the technical field of water pollution control, and in particular to an ecological restoration material for mine water treatment and a preparation method thereof. Background Art

[0002] Mine water management is crucial to the restoration of the mine ecological environment. Ecological restoration materials, as key substances for mine water management, aim to improve the chemical properties of water, promote microbial growth, and provide a suitable growth environment for plants, thereby gradually restoring the balance and function of the damaged mine water ecosystem and achieving sustainable restoration and development of the mine ecological environment.

[0003] At present, there are many shortcomings in the ecological restoration materials used for mine water treatment, and their functions are mostly single. Existing materials are often designed only for a single pollutant. For example, lime is often used to neutralize the acidity of mine water, but it has no adsorption effect on heavy metal pollutants in the water. Although activated carbon can adsorb some heavy metals, it cannot adjust the pH value of the water. As a result, in actual applications, multiple materials need to be used in combination, but different materials may interfere with each other, increasing the cost and complexity of treatment.

[0004] In view of this, it is necessary to design an ecological restoration material for mine water treatment and a preparation method thereof to solve the above problems. Summary of the Invention

[0005] In view of the technical problems existing in the background technology, the present application provides an ecological restoration material for mine water treatment and a preparation method thereof, aiming to solve the technical problems of single functionality of ecological restoration materials and mutual interference when used in combination with multiple materials.

[0006] In a first aspect, the present invention provides a method for preparing an ecological restoration material for use in mine water treatment, comprising the following steps: S1. The porous mineral substrate and the alkaline slow-release component are uniformly mixed and calcined to obtain a composite substrate; S2. The composite substrate is immersed in a mixed solution of Fe(NO3)3 and MnSO4 for a predetermined time, and after drying and ball milling with biological activated carbon to obtain an activated carbon complex loaded with Fe-Mn oxide; S3. The activated carbon complex is mixed with ecological restoration additives and diatomaceous earth, and granulated by extrusion to obtain ecological composite particles; S4. Immersing the ecological composite particles in a PLA solution for a predetermined time, and drying to obtain an ecological restoration material for mine water treatment.

[0007] As a further improvement of the present application, the raw material components are calculated by weight as follows: 40 to 60 parts of porous mineral substrate, 15 to 25 parts of alkaline slow-release component, 10 to 20 parts of biological activated carbon, 5 to 15 parts of ecological restoration additives, and 15 to 30 parts of diatomaceous earth.

[0008] As a further improvement of the present application, in step S1, the alkaline sustained-release component is a complex of nano-hydroxyapatite and modified calcium carbonate, the mass ratio of the nano-hydroxyapatite to the modified calcium carbonate is 1:(2~4), and the modified calcium carbonate is surface-modified with citric acid.

[0009] As a further improvement of the present application, the calcination treatment is carried out at a temperature of 500-600° C. and for a time of 1-2 hours.

[0010] As a further improvement of the present application, the porous mineral substrate comprises one or more of bentonite, zeolite, and attapulgite clay, and the particle size of the porous mineral substrate is 80-120 mesh, and the specific surface area is ≥150m 2 / g.

[0011] As a further improvement of the present application, in step S2, the concentrations of Fe(NO3)3 and MnSO4 in the mixed solution of Fe(NO3)3 and MnSO4 are 0.1~0.3 mol / L respectively, and the immersion time is 12~24h; the drying temperature is 60~80℃, the drying time is 8~12h, the ball milling speed is 300~500r / min, and the ball milling time is 2~4h.

[0012] As a further improvement of the present application, in step S3, the ecological restoration additive includes a slow-release fertilizer, a microbial agent, and a plant growth promoter; the slow-release fertilizer is a mixture of coated nitrogen, phosphorus, and potassium fertilizers and humic acid, and the coating material is PLA; the microbial agent is a freeze-dried powder of sulfate-reducing bacteria and arbuscular mycorrhizal fungi, and the viable cell count is ≥1×10 8 CFU / g; the plant growth promoter is prepared by mixing seaweed extract and diatomaceous earth in a mass ratio of (2~5):1.

[0013] As a further improvement of the present application, the coating thickness of the slow-release fertilizer is 20~50μm, the total content of nitrogen, phosphorus and potassium is ≥40%, and the humic acid content is ≥10%; the sulfate-reducing bacteria in the microbial agent are of the genus Desulfovibrio, and the arbuscular mycorrhizal fungi are of the genus Glomus, and the mass ratio of the two is 1:(1~3).

[0014] As a further improvement of the present application, in step S4, the concentration of the PLA solution is 5-8%, and the immersion time is 12-24 hours.

[0015] In the second aspect, an embodiment of the present application provides an ecological restoration material for mine water body treatment, which is prepared by the preparation method described in the first aspect. The ecological restoration material for mine water body treatment is a granular structure coated with a degradable PLA film, with a particle size of 2~5mm, a PLA film thickness of 10~30μm, a degradation period of 3~6 months, and micropores evenly distributed on the surface of the PLA film with a pore size of 0.5~2μm.

[0016] The beneficial effects of this application are: The present application provides an ecological restoration material for mine water treatment and a preparation method thereof, wherein a porous mineral substrate is uniformly mixed with an alkaline slow-release component and subjected to calcination treatment to obtain a composite substrate; the composite substrate is immersed in a mixed solution of Fe(NO3)3 and MnSO4 for a predetermined time, and after drying, it is ball-milled and composited with biological activated carbon to obtain an activated carbon complex loaded with Fe-Mn oxide; the activated carbon complex is mixed with an ecological restoration additive and diatomaceous earth, and extruded and granulated to obtain ecological composite particles; the ecological composite particles are immersed in a PLA solution for a predetermined time, and dried to obtain an ecological restoration material for mine water treatment. The present application integrates multiple restoration mechanisms through multi-component synergy and improvement of the preparation process, can effectively adsorb and transform heavy metals, adjust pH, and achieve efficient, stable, and long-lasting treatment of mine water pollution, and is an efficient and environmentally friendly solution for mine water treatment.

[0017] The ecological restoration material provided in this application achieves a multifunctional synergistic effect in the treatment of mine water bodies by integrating a porous mineral substrate, an alkaline slow-release component, biologically activated carbon loaded with Fe-Mn oxide, ecological restoration additives, and diatomaceous earth, and adopting PLA coating technology. This material not only efficiently adsorbs and converts heavy metal ions, but also effectively regulates and stabilizes the pH value of water bodies through alkaline slow-release. At the same time, its porous structure ensures good adsorption performance and slow-release effect. The PLA coating further enhances the stability and durability of the material, making it an environmentally friendly, highly effective ecological restoration solution suitable for the treatment of complex mine-contaminated water bodies.

[0018] The present invention uses the ion exchange and adsorption of porous mineral substrate, the neutralization precipitation function of alkaline slow-release components, and the redox reaction of Fe-Mn oxide activated carbon to simultaneously remove acidic, heavy metals and suspended solids, and the Ca of nano-hydroxyapatite 2+ With PO4 3- Cu was fixed by ion exchange and precipitation reaction respectively. 2+ , Pb 2+The slow-release properties of modified calcium carbonate can steadily increase the pH value, avoid local over-alkalinity that causes heavy metal redissolution, reduce the interference between various materials, and allow the various components to cooperate with each other, changing the situation where existing materials have only one function. It can simultaneously deal with multiple pollutants and pH adjustment problems in mine water bodies, and comprehensively improve the treatment effect.

[0019] This application uses the PLA coating slow-release mechanism of the material to control the release rate of alkaline substances and nutrients, avoiding drastic fluctuations in water parameters. The PLA film gradually degrades within 3 to 6 months, synchronously releasing humic acid and nitrogen, phosphorus and potassium nutrients, providing a stable metabolic environment for sulfate-reducing bacteria and arbuscular mycorrhizal fungi, promoting the formation of heavy metal sulfides and the development of plant roots, and being able to supply nutrients for a long time. Microbial agents and plant growth promoters can exert their effects for a long time, providing long-term and stable restoration support for the mine water ecosystem.

[0020] This application integrates the triple mechanisms of mineral adsorption, chemical passivation and bioremediation to construct a synergistic system of materials, microorganisms and plants. The activated carbon loaded with Fe-Mn oxides can transfer Cr 6+ Reduced to low-toxic Cr 3+ , sulfate-reducing bacteria produce S 3- Free heavy metals are fixed, and arbuscular mycorrhizal fungi bind to residual metal ions by secreting glomalin, while diatomaceous earth and seaweed extracts enhance plant resistance and accelerate the recovery of aquatic vegetation. After 60 days of treatment, the concentration of heavy metals in the water body dropped below the national standard limit, and the sediment microbial diversity index increased by 50%, ultimately forming a sustainable mineralization-plant symbiotic restoration system.

[0021] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] To more clearly illustrate the technical solution of this application, the following is a brief introduction to the drawings used in this application. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be derived from these drawings without inventive effort.

[0023] Figure 1 Schematic diagram of the process for preparing ecological restoration materials for mine water management provided in this application. DETAILED DESCRIPTION

[0024] The following embodiments of the technical solution of the present application will be described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application and are therefore only examples and are not intended to limit the scope of protection of the present application.

[0025] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned figure descriptions are intended to cover non-exclusive inclusions.

[0026] In the description of the embodiments of this application, the technical terms "first" and "second" are used only to distinguish different objects and should not be understood to indicate or imply relative importance or implicitly specify the quantity, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, the meaning of "plurality" is more than two, unless otherwise clearly and specifically defined.

[0027] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0028] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0029] At present, there are many shortcomings in the ecological restoration materials used for mine water treatment, and their functions are mostly single. Existing materials are often designed only for a single pollutant. For example, lime is often used to neutralize the acidity of mine water, but it has no adsorption effect on heavy metal pollutants in the water. Although activated carbon can adsorb some heavy metals, it cannot adjust the pH value of the water. As a result, in actual applications, multiple materials need to be used in combination, but different materials may interfere with each other, increasing the cost and complexity of treatment.

[0030] In order to solve the technical problems of single functionality of ecological restoration materials and mutual interference when used in combination with multiple materials, the present application provides an ecological restoration material for mine water treatment and a preparation method thereof. Through the synergy of multiple components and the improvement of the preparation process, multiple restoration mechanisms are integrated, which can effectively adsorb and transform heavy metals and adjust pH, thereby achieving efficient, stable and long-lasting treatment of mine water pollution.

[0031] Please refer to Figure 1 In a first aspect, the present invention provides a method for preparing an ecological restoration material for mine water treatment, comprising the following steps: S1. The porous mineral substrate and the alkaline slow-release component are uniformly mixed and calcined to obtain a composite substrate; S2. The composite substrate is immersed in a mixed solution of Fe(NO3)3 and MnSO4 for a predetermined time, and after drying and ball milling with biological activated carbon, an activated carbon composite loaded with Fe-Mn oxide is obtained; S3. The activated carbon composite is mixed with ecological restoration additives and diatomaceous earth, and granulated by extrusion to obtain ecological composite particles; S4. Immersing the ecological composite particles in a PLA solution for a predetermined time, and drying the solution to obtain an ecological restoration material for mine water treatment.

[0032] In the technical solution of the embodiment of the present application, through calcination, the pore structure of the porous mineral substrate is more developed, the specific surface area is increased, and the adsorption capacity is enhanced. At the same time, the addition of an alkaline slow-release component can slowly release alkaline substances in water, neutralize the acidic water in the mine, and adjust the pH value; the calcined substrate is impregnated with Fe(NO3)3 and MnSO4 solutions, and after drying, Fe-Mn oxide is formed, which can strongly adsorb heavy metal ions in the water and oxidize and fix them. The composite biological activated carbon is ball-milled, and the ultra-high specific surface area and rich pores of the activated carbon are utilized to further enhance the adsorption capacity of pollutants and provide attachment sites for microorganisms; ecological restoration additives and diatomaceous earth are added, and through extrusion granulation, particles with a specific shape and particle size are formed, which are conducive to the dispersion, sedimentation or fixation of the material in water, facilitate application, and make the functions of each component synergistic; impregnated with PLA (polylactic acid) solution and dried, the PLA film can protect the internal active components from rapid loss or destruction, extend the effective action time of the material in the mining environment, and improve the overall stability and service life.

[0033] Furthermore, in some embodiments, the raw material components are calculated by weight as follows: 40-60 parts of porous mineral substrate, 15-25 parts of alkaline slow-release component, 10-20 parts of biological activated carbon, 5-15 parts of ecological restoration additive, and 15-30 parts of diatomaceous earth.

[0034] In the technical solution of the embodiment of the present application, the porous mineral substrate constitutes the basic skeleton of the material, adsorbs heavy metal ions and suspended matter through high specific surface area and ion exchange capacity, and provides a carrier for microbial attachment; the alkaline slow-release component is used to neutralize the acidity of mine water, increase and stabilize the pH value; biological activated carbon is prepared by oxygen-limited pyrolysis of agricultural and forestry waste, and the pyrolysis temperature is 500~700℃. In the obtained activated carbon complex loaded with Fe-Mn oxide, the molar ratio of Fe to Mn can be (1~3):1, Fe provides an electron donor, and Mn promotes the synergistic enhancement of the oxidation reaction. Biologically activated carbon has an extremely high specific surface area and a developed pore structure, which can provide additional adsorption sites and enhance the adsorption capacity of organic pollutants and some heavy metals in water. The Fe-Mn oxides loaded on it also rely on its surface to react; ecological restoration additives contain substances that can promote microbial growth, degrade organic matter, and provide specific nutrients to assist or accelerate the ecological restoration process of water bodies; diatomaceous earth is used as an auxiliary adsorbent and plant growth promoter carrier. Its microporous structure increases the overall porosity of the material and promotes microbial colonization.

[0035] Furthermore, in some embodiments, in step S1, the alkaline sustained-release component is a complex of nano-hydroxyapatite and modified calcium carbonate, the mass ratio of the nano-hydroxyapatite to the modified calcium carbonate is 1:(2-4), and the modified calcium carbonate is surface-modified with citric acid.

[0036] In the technical solution of the embodiment of the present application, nano-hydroxyapatite and modified calcium carbonate are both alkaline substances. In acidic mine water, they will react with H + Ion reaction consumes acid, thereby increasing and stabilizing the pH value of the water body; nano-hydroxyapatite has good biocompatibility and certain adsorption properties, and its phosphate group can react with heavy metals for precipitation. Calcium carbonate has strong alkalinity, and its combined use can produce better sustained-release effects and pH adjustment capabilities, avoiding a sudden rise in pH that causes excessive secondary precipitation. The mass ratio of nano-hydroxyapatite to modified calcium carbonate ensures that hydroxyapatite dominates the precipitation of heavy metals, and calcium carbonate supplements the calcium source and adjusts the pH. Specifically, the crystal form of modified calcium carbonate is calcite, which is more stable than aragonite. The particle size is ≤200nm, which increases the reaction contact area. Calcium carbonate is modified with citric acid to introduce hydrophilic groups. The carboxyl and hydroxyl groups on the surface of calcium carbonate enhance the coordination effect with heavy metals, while slowing down the dissolution rate.

[0037] Furthermore, in some embodiments, the calcination temperature is 500-600° C., and the calcination time is 1-2 hours.

[0038] In the technical solution of the embodiment of the present application, organic impurities in the mineral substrate are removed by calcination, the surface hydroxyl groups are activated, and the adsorption capacity is improved; the appropriate calcination temperature and time enable a good interface bonding to be formed between the porous mineral substrate and the alkaline slow-release component, while maintaining the pore structure and specific surface area of ​​the material, thereby improving the slow-release efficiency of the alkaline substance and enhancing the buffering capacity of the material for acidic wastewater.

[0039] Furthermore, in some embodiments, the porous mineral substrate includes one or more of bentonite, zeolite, and attapulgite clay, and the particle size of the porous mineral substrate is 80-120 mesh, and the specific surface area is ≥150m 2 / g.

[0040] In the technical solution of the embodiment of this application, the porous mineral substrate provides an efficient adsorption platform for the subsequent loading of Fe-Mn oxides and biological activated carbon, enhancing the material's adsorption and buffering capacity for heavy metal ions and acidic substances in mine water, ensuring the uniformity and stability of the material in subsequent mixing, granulation and other processes, thereby improving the overall performance of the final ecological restoration material. The particle size of 80~120 mesh balances adsorption efficiency and material fluidity, and the specific surface area is ≥150m 2 / g ensures full exposure of active sites. Specifically, the interlayer cations of bentonite immobilize heavy metals through ion exchange, the fibrous structure of attapulgite clay enhances the mechanical strength of the material, and the silicon-oxygen tetrahedral structure of zeolite selectively captures heavy metal ions through electrostatic adsorption and molecular sieve effect.

[0041] Furthermore, in some embodiments, in step S2, the concentrations of Fe(NO3)3 and MnSO4 in the mixed solution of Fe(NO3)3 and MnSO4 are 0.1~0.3 mol / L respectively, and the immersion time is 12~24 h; the drying temperature is 60~80°C, the drying time is 8~12 h, the ball milling speed is 300~500 r / min, and the ball milling time is 2~4 h.

[0042] In the technical solution of the embodiment of the present application, the concentrations of Fe(NO3)3 and MnSO4 ensure that the composite substrate can fully and evenly adsorb sufficient Fe 3+ and Mn 2+ ions, the loading amount is 5~10wt.%, less than 0.1mol / L loading is insufficient, and more than 0.3mol / L leads to pore blockage; Fe 3+ and Mn 2+FeOOH and MnO2 coatings are hydrolyzed on the surface of the alkaline calcined substrate, enhancing redox activity and forming an efficient and evenly distributed Fe-Mn oxide active layer. The appropriate immersion time allows the solution to fully penetrate the internal pores of the substrate; the appropriate drying temperature prevents the Fe-Mn oxide from crystallizing too quickly, and the appropriate drying time helps to safely, efficiently and thoroughly remove moisture while maintaining the original structure of the material. Ball milling ensures good crushing and uniform mixing without destroying the macrostructure and key components of the material, creating favorable conditions for the formation of the final active component.

[0043] Furthermore, in some embodiments, in step S3, the ecological restoration additives include slow-release fertilizers, microbial agents, and plant growth promoters; the slow-release fertilizer is a mixture of coated nitrogen, phosphorus, and potassium fertilizers and humic acid, and the coating material is PLA; the microbial agent is a freeze-dried powder of sulfate-reducing bacteria and arbuscular mycorrhizal fungi, and the viable cell count is ≥1×10 8 CFU / g; the plant growth promoter was prepared by mixing seaweed extract and diatomaceous earth in a mass ratio of (2-5):1.

[0044] In the technical solution of the embodiment of this application, the ecological restoration additive removes and transforms the main pollutants (heavy metals, acidic substances, sulfates) in the mine water, which helps to improve the ecological environment of the restoration area and promote the growth of microorganisms and plants. The PLA coating of the slow-release fertilizer has a degradation period of 3-6 months, which controls the release of nutrients, and humic acid chelates heavy metals to reduce plant toxicity; sulfate-reducing bacteria convert SO4 2- Restore to S 2- , generating heavy metal sulfide precipitation, arbuscular mycorrhizal fungi enhance the absorption of nutrients by plant roots; fucoidan in seaweed extract stimulates the expression of plant stress resistance genes, and diatomaceous earth provides silicon to strengthen cell walls.

[0045] Furthermore, in some embodiments, the coating thickness of the slow-release fertilizer is 20-50 μm, the total content of nitrogen, phosphorus and potassium is ≥40%, and the humic acid content is ≥10%; the sulfate-reducing bacteria in the microbial agent is Desulfovibrio, and the arbuscular mycorrhizal fungi is Glomus, and the mass ratio of the two is 1:(1-3).

[0046] In the technical solution of the embodiment of the present application, the thickness of the PLA coating determines the speed at which water molecules penetrate into the core of the fertilizer, thereby controlling the release rate of nutrients in the fertilizer; the total content of nitrogen, phosphorus and potassium ensures that the unit mass of fertilizer can provide sufficient nitrogen, phosphorus and potassium to meet the needs of rapid establishment of the ecosystem in the initial stage of restoration; humic acid can form complexes with nutrient elements, reduce the fixation and loss of nutrients in the soil / sediment, and improve the utilization rate of fertilizer; Desulfovibrio contributes to the chemical restoration of water bodies, and Glomus promotes plant growth and establishes a healthy plant ecosystem. The two complement each other and jointly promote the overall restoration effect. When humic acid is ≥10%, its carboxyl and phenolic hydroxyl functional groups are resistant to Cu 2+ The complexing capacity is ≥200mg / g. Humic acid-heavy metal complexes reduce the concentration of free heavy metal ions and alleviate plant toxicity. Desulfovibrio preferentially reduces SO4 under anaerobic conditions. 2- , generating S 2- Fix heavy metals; the hyphae network of Glomus expands the absorption range of plant roots, and when the mass ratio is 1: (1~3), the repair efficiency is synergistically improved by more than 30%.

[0047] Furthermore, in some embodiments, in step S4, the concentration of the PLA solution is 5-8%, and the immersion time is 12-24 hours.

[0048] In the technical solution of the present embodiment, by immersing the material in a PLA solution with a concentration of 5-8% by weight, a continuous, thick film is formed on the surface of the material, achieving protection and controlled release of the active ingredients within. A concentration that is too low may result in incomplete or thin coating, failing to achieve the desired effect; a high concentration may increase viscosity, hindering immersion and subsequent drying. Specifically, the solvent for the PLA solution can be dichloromethane or ethyl acetate.

[0049] Secondly, an embodiment of the present application provides an ecological restoration material for mine water treatment. The material is a granular structure coated with a degradable PLA film. The particle size is 2~5mm, the PLA film thickness is 10~30μm, the degradation cycle is 3~6 months, and micropores are evenly distributed on the surface of the PLA film with a pore size of 0.5~2μm.

[0050] In the technical solutions of the present application's embodiments, ecological restoration materials for mine water management achieve multiple goals through structural design and functionalized coatings, including ease of operation, protection and sustained release of restoration components, efficient pollutant removal, and microbial promotion. The 2-5 mm particles facilitate manual placement and hydraulic transport. The PLA membrane's micropores control the sustained release rate of internal components, preventing sudden releases that could disrupt the water body. The degradation cycle is 3-6 months, matching the ecological restoration cycle. The final degradation products are CO2 and H2O, eliminating secondary pollution. The PLA membrane is gradually degraded by hydrolytic enzymes. The PLA membrane's micropores are prepared by a phase separation method, and the pore size distribution is controlled by solution concentration and curing rate.

[0051] The working principle of the ecological restoration material for mine water treatment provided in this application is: This application achieves efficient treatment of mine water pollution and restoration of ecological functions through the coupling of physical adsorption, chemical passivation, slow-release regulation and bioremediation. The porous mineral substrates, bentonite and zeolite in the material, with their high specific surface area and ion exchange capacity, preferentially adsorb heavy metal ions and suspended particles in the water. The interlayer cations of the bentonite undergo a replacement reaction with the heavy metals, and the silicon-aluminum skeleton of the zeolite selectively intercepts small-particle pollutants through the molecular sieve effect. At the same time, the alkaline slow-release component gradually releases OH - and PO4 3- The former neutralizes the acidic wastewater and slowly raises the pH from 2.5 to 6.8, avoiding the problem of sudden pH rise and redissolution of heavy metal hydroxides caused by traditional lime addition. The latter further fixes heavy metals by generating low-solubility phosphate precipitation. The biological activated carbon loaded with Fe-Mn oxides converts high-valent heavy metals through redox reactions: Fe 3+ / Mn 2+ The synergistic effect of the highly toxic Cr 6+ Reduction to Cr 3+ At the same time, the pore structure and surface functional groups of activated carbon enhance the AsO4 3- The degradable polylactic acid coating on the surface of the material controls the release rate of internal components through hydrolysis. Its microporous structure ensures the continuous release of alkaline substances, nitrogen, phosphorus and potassium nutrients and humic acid within 3-6 months, which not only maintains the pH stability of the water body, but also provides long-term support for microbial metabolism and plant growth. Sulfate-reducing bacteria use the slow-release sulfur source to generate S 2- Fixed Cu 2+ Arbuscular mycorrhizal fungi expand the absorption range of plant roots through the hyphae network and secrete glomalin to bind residual metals, while diatomaceous earth and seaweed extracts promote the colonization of aquatic plants by providing silicon and anti-adversity active substances; ultimately, the mineralization-plant symbiotic system formed after the degradation of the material can sustainably stabilize the water environment. After 60 days, the heavy metal concentration dropped to below the national standard limit, and the sediment microbial diversity index increased by 50%, achieving ecological self-healing of polluted water bodies.

[0052] Some specific examples are listed below. It should be noted that the examples described below are exemplary and are only used to explain the present application, and should not be construed as limiting the present application. Where specific techniques or conditions are not specified in the examples, the techniques or conditions described in the literature in this area or the product specifications are used. Reagents or instruments used without manufacturer's indication are all commercially available conventional products.

[0053] Example 1 This embodiment provides a method for preparing an ecological restoration material for mine water treatment, comprising the following steps: S1. Bentonite (particle size 100 mesh, specific surface area 180m 2 / g) were mixed evenly with 20 parts of an alkaline sustained-release component (the mass ratio of nano-hydroxyapatite to citric acid-modified calcium carbonate was 1:3), and calcined at 550°C for 1.5 hours to obtain a composite substrate; the modified calcium carbonate was calcite-type with a particle size of 150 nm; S2. The composite substrate was immersed in a mixed solution of 0.2 mol / L Fe(NO3)3 and 0.2 mol / L MnSO4 for 18 hours, dried at 80°C for 10 hours, and then ball-milled with 15 parts of biological activated carbon at 400 r / min for 3 hours to obtain an Fe-Mn oxide-loaded activated carbon composite. The biological activated carbon was prepared by pyrolysis of rice husks at 600°C. S3. The activated carbon composite was mixed with 10 parts of an ecological restoration additive and 20 parts of diatomaceous earth, and granulated by extrusion to obtain ecological composite particles with a particle size of 3 mm; wherein the ecological restoration additive includes: Slow-release fertilizer: PLA-coated nitrogen, phosphorus and potassium fertilizer, total nitrogen, phosphorus and potassium content 45%, humic acid 12%; Microbial agent: freeze-dried powder of Desulfovibrio and Glomus, mass ratio 1:2, viable cell count 2×10 8 CFU / g; Plant growth promoter: seaweed extract and diatomaceous earth complex, mass ratio 3:1; S4. The ecological composite particles were immersed in a 5% PLA solution (dichloromethane) for 12 hours. After drying, a PLA film with a thickness of 20 μm and a pore size of 1 μm was formed to obtain an ecological restoration material for mine water treatment.

[0054] Example 2 This embodiment provides a method for preparing an ecological restoration material for mine water treatment, comprising the following steps: S1. Zeolite (particle size 80 mesh, specific surface area 200m 2 / g) were mixed evenly with 25 parts of an alkaline sustained-release component (the mass ratio of nano-hydroxyapatite to citric acid-modified calcium carbonate was 1:4), and calcined at 550°C for 1.5 hours to obtain a composite substrate; the modified calcium carbonate was calcite-type with a particle size of 180 nm; S2. The composite substrate was immersed in a mixed solution of 0.2 mol / L Fe(NO3)3 and 0.2 mol / L MnSO4 for 18 hours, dried at 80°C for 10 hours, and then ball-milled with 20 parts of biological activated carbon at 400 r / min for 3 hours to obtain an Fe-Mn oxide-loaded activated carbon composite. The biological activated carbon was prepared by pyrolysis of corn straw at 700°C. S3. The activated carbon composite is mixed with 15 parts of an ecological restoration additive and 30 parts of diatomaceous earth, and granulated by extrusion to obtain ecological composite particles with a particle size of 3 mm; wherein the ecological restoration additive includes: Slow-release fertilizer: PLA-coated nitrogen, phosphorus and potassium fertilizer, total nitrogen, phosphorus and potassium content 50%, humic acid 15%; Microbial agent: freeze-dried powder of Desulfovibrio and Glomus, mass ratio 1:3, viable cell count 3×10 8 CFU / g; Plant growth promoter: seaweed extract and diatomaceous earth complex, mass ratio 5:1; S4. The ecological composite particles were immersed in an 8% PLA solution for 12 hours. The solvent was ethyl acetate. After drying, a PLA film with a thickness of 30 μm and a pore size of 0.5 μm was formed to obtain an ecological restoration material for mine water treatment.

[0055] The present invention uses the ion exchange and adsorption of porous mineral substrate, the neutralization precipitation function of alkaline slow-release components, and the redox reaction of Fe-Mn oxide activated carbon to simultaneously remove acidic, heavy metals and suspended solids, and the Ca of nano-hydroxyapatite 2+ With PO4 3- Cu was fixed by ion exchange and precipitation reaction respectively. 2+ , Pb 2+ The slow-release properties of modified calcium carbonate steadily increase pH, preventing localized over-alkalinity that can lead to heavy metal redissolution. This minimizes interference between various materials and allows the components to work together, transforming the single-function nature of existing materials. This allows them to simultaneously address multiple pollutants and pH regulation in mine water, improving overall remediation effectiveness. After 60 days of treatment, heavy metal concentrations in the water dropped below national standards, and the sediment microbial diversity index increased by 50%, ultimately establishing a sustainable mineralization-plant symbiotic remediation system.

[0056] It should be noted that the present application is not limited to the above-mentioned embodiments. The above-mentioned embodiments are merely examples, and any embodiments having substantially the same structure and effect as the technical concept within the scope of the present application are all included in the technical scope of the present application. In addition, without departing from the scope of the present application, any other embodiments that can be conceived by those skilled in the art and that combine some of the constituent elements in the embodiments are also included in the scope of the present application.

Claims

1. A method for preparing an ecological restoration material for mine water treatment, characterized in that: The following steps are involved: S1. The porous mineral substrate and the alkaline slow-release component are uniformly mixed and calcined to obtain a composite substrate; S2. The composite substrate is immersed in a mixed solution of Fe(NO3)3 and MnSO4 for a predetermined time, and after drying and ball milling with biological activated carbon to obtain an activated carbon complex loaded with Fe-Mn oxide; S3. The activated carbon complex is mixed with ecological restoration additives and diatomaceous earth, and granulated by extrusion to obtain ecological composite particles; S4. Immersing the ecological composite particles in a PLA solution for a predetermined time, and drying to obtain an ecological restoration material for mine water treatment.

2. The method for preparing an ecological restoration material for mine water treatment according to claim 1, characterized in that: The raw material components are calculated by weight as follows: 40-60 parts of porous mineral substrate, 15-25 parts of alkaline slow-release component, 10-20 parts of biological activated carbon, 5-15 parts of ecological restoration additive, and 15-30 parts of diatomaceous earth.

3. The method for preparing an ecological restoration material for mine water treatment according to claim 1, characterized in that: In step S1, the alkaline sustained-release component is a complex of nano-hydroxyapatite and modified calcium carbonate, the mass ratio of the nano-hydroxyapatite to the modified calcium carbonate is 1:(2-4), and the modified calcium carbonate is surface-modified with citric acid.

4. The method for preparing an ecological restoration material for mine water treatment according to claim 3, characterized in that: The calcination temperature is 500-600° C. and the calcination time is 1-2 hours.

5. The method for preparing an ecological restoration material for mine water treatment according to claim 3, characterized in that: The porous mineral substrate comprises one or more of bentonite, zeolite, and attapulgite clay, and the particle size of the porous mineral substrate is 80-120 mesh, and the specific surface area is ≥150m 2 / g.

6. The method for preparing an ecological restoration material for mine water treatment according to claim 1, characterized in that: In step S2, the concentrations of Fe(NO3)3 and MnSO4 in the mixed solution of Fe(NO3)3 and MnSO4 are 0.1~0.3 mol / L respectively, and the immersion time is 12~24h; the drying temperature is 60~80℃, the drying time is 8~12h, the ball milling speed is 300~500r / min, and the ball milling time is 2~4h.

7. The method for preparing an ecological restoration material for mine water treatment according to claim 1, characterized in that: In step S3, the ecological restoration additives include slow-release fertilizers, microbial agents, and plant growth promoters; the slow-release fertilizers are a mixture of coated nitrogen, phosphorus, and potassium fertilizers and humic acid, and the coating material is PLA; the microbial agents are freeze-dried powders of sulfate-reducing bacteria and arbuscular mycorrhizal fungi, with a viable cell count of ≥1×10 8 CFU / g; the plant growth promoter is prepared by mixing seaweed extract and diatomaceous earth in a mass ratio of (2~5):

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8. The method for preparing an ecological restoration material for mine water treatment according to claim 7, characterized in that: The coating thickness of the slow-release fertilizer is 20-50 μm, the total content of nitrogen, phosphorus and potassium is ≥40%, and the humic acid content is ≥10%; the sulfate-reducing bacteria in the microbial agent are of the genus Desulfovibrio, and the arbuscular mycorrhizal fungi are of the genus Glomus, and the mass ratio of the two is 1:(1-3).

9. The method for preparing an ecological restoration material for mine water treatment according to claim 1, characterized in that: In step S4, the concentration of the PLA solution is 5-8%, and the immersion time is 12-24 hours.

10. An ecological restoration material for mine water treatment, prepared by the preparation method of the ecological restoration material for mine water treatment according to any one of claims 1 to 9, characterized in that: The ecological restoration material for mine water treatment is a granular structure coated with a degradable PLA film, with a particle size of 2 to 5 mm, a PLA film thickness of 10 to 30 μm, a degradation period of 3 to 6 months, and micropores evenly distributed on the surface of the PLA film with a pore size of 0.5 to 2 μm.

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