A method for mine ecological restoration based on modified acidic wastewater sludge loaded with microorganisms

Abstract

This invention discloses a method for mine ecological restoration based on modified acidic wastewater sludge loaded with microorganisms, belonging to the field of ecological restoration technology. The method includes: S1 dewatering the acidic wastewater sludge to achieve a preset moisture content; S2 mixing the dewatered acidic wastewater sludge with a geopolymer precursor, porous carbon material, and an alkaline activator to conduct a geopolymerization reaction, followed by curing to form a structured ecological substrate; S3 inoculating modular microbial communities (including alkali-tolerant pioneer bacteria, SRB, and PGPR) into the structured ecological substrate that has been naturally matured for more than 14 days (pH ≤ 8.5) at a rate of 5–8 mL / kg dry weight (bacterial concentration ≥ 1 × 10⁻⁶). 8 (CFU / mL). This invention constructs a synergistic remediation system through a layered design, encompassing pollutant stabilization and isolation, biotransformation, and vegetation reconstruction, thereby achieving the safe resource utilization of acidic wastewater sludge and the efficient and long-term restoration of mine ecosystems.

Description

Technical Field

[0001] This invention relates to the field of ecological restoration technology, and in particular to a method for mine ecological restoration based on modified acidic wastewater sludge loaded with microorganisms. Background Technology

[0002] In the field of mine ecological restoration, the resource utilization of sludge generated after the treatment of acidic wastewater is an important direction. A common approach in existing technologies is to stabilize and solidify the acidic wastewater sludge, reducing the risk of heavy metal leaching and improving its physical structure. This sludge is then used as a matrix material, simply mixed with commercial microbial agents and plant seeds to create remediation materials or directly applied as mine cover soil. This technological approach achieves the disposal and utilization of solid waste and provides the basic conditions for vegetation restoration, embodying the concept of treating waste with waste.

[0003] In the field of mine ecological restoration, sulfate-reducing bacteria are commonly used microorganisms in microbial remediation technologies. For example, our team's prior patent (Chinese Invention Patent CN104630097A, Patent Title: An Acidophilic Sulfate-Reducing Bacterium Strains and Their Applications, Strain Preservation Number CGMCC No. 10072) discloses an acidophilic sulfate-reducing bacterium strain FKB, which has been used for acidification control with good results.

[0004] However, when this strain or similar functional microorganisms are directly applied to the harsh environment of mining sites, the colonization rate and metabolic activity of the microorganisms are often difficult to maintain due to the lack of a carrier that can provide long-term protection. Current technologies mainly treat acidic wastewater sludge as a physical carrier or culture medium, with a relatively loose combination with functional microorganisms, amounting to a simple physical mixture. This composite approach is insufficient in protecting the introduced microorganisms in the harsh mining environment, making it difficult to guarantee long-term effective colonization, activity maintenance, and continuous and stable expression of function under harsh conditions. This is mainly because the materials fail to actively construct a sustainable, structured microenvironment for the microorganisms, integrating physical shelter, chemical buffering, and nutrient supply, thus challenging the durability of the remediation effect. How to modify materials to transform sludge from a passive carrier into an ecological engine capable of actively maintaining microbial functional activity is key to improving the effectiveness of remediation technologies.

[0005] Summary of the invention.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution: In a first aspect, the present invention provides a method for mine ecological restoration based on modified acidic wastewater sludge loaded with microorganisms, comprising: S1 dewatering the acidic wastewater sludge to bring its moisture content to a preset range; S2. The dehydrated acidic wastewater sludge is mixed with geopolymer precursors, porous carbon materials and alkaline activators. The high alkalinity provided by the alkaline activator and the exothermic reaction are used to overcome the adverse effects of high water content, promote the geopolymerization reaction, and form a structured ecological substrate after curing. S3. Inoculate modular microbial communities (including alkali-tolerant pioneer bacteria, SRB, and PGPR) into structured ecological substrates that have been naturally matured for more than 14 days (pH ≤ 8.5) at a rate of 5–8 mL / kg dry weight (bacterial concentration ≥ 1 × 10⁻⁶). 8 The active microbial remediation material (CFU / mL) was activated for 5–10 days under natural conditions (average daily temperature ≥15℃), during which time it was sprayed with 0.5%–1.5% molasses or 0.1%–0.5% amino acid aqueous solution to moisturize and provide nutrients, thus obtaining a low-cost, engineerable remediation material.

[0007] S4. At the mine site to be restored, different functional layers composed of the structured ecological substrate and / or the functional restoration material are laid sequentially from bottom to top to form a layered and progressive ecological restoration base. S5. Sow and plant pioneer plants on the surface layer of the layered and progressive ecological restoration base. S6. Perform initial maintenance on the completed repair system until the system develops self-sustaining capabilities.

[0008] This invention provides a method for mine ecological restoration based on modified acidic wastewater sludge loaded with microorganisms, which includes, in step S1, the dewatering treatment to make the sludge moisture content 40%-50%.

[0009] This invention provides a method for mine ecological restoration based on modified acidic wastewater sludge loaded with microorganisms, wherein, in step S2: The geopolymer precursors are metakaolin and mine tailings, and their addition amount is 10%-20% of the dry weight of dewatered sludge. The porous carbon material is biochar, and its addition amount is 3%-5% of the dry weight of dewatered sludge.

[0010] This invention provides a method for mine ecological restoration based on modified acidic wastewater sludge loaded with microorganisms, wherein step S2 specifically includes: S2.1. Dry mix the geopolymer precursor with the porous carbon material and dewatered sludge; S2.2 Add an alkaline activator to the dry mixture and stir to initiate a geopolymerization reaction; S2.3. The mixture is sealed and cured for 3-7 days under conditions of temperature above 20℃ and humidity above 90% to form the structured ecological substrate. The alkaline activator is a mixed solution of water glass and sodium hydroxide with a modulus (SiO2 / Na2O molar ratio) between 1.2 and 1.8.

[0011] This invention provides a method for mine ecological restoration based on modified acidic wastewater sludge loaded with microorganisms. In step S3, the pioneer colonizing bacteria are bacteria capable of secreting extracellular polymers and resistant to heavy metals. The core functional bacteria include at least one of sulfate-reducing bacteria and rhizosphere bacteria with plant growth-promoting functions. Specifically, the SRB is a sulfate-reducing bacterium described in the inventors' prior patent (Chinese Invention Patent CN104630097A), with the strain preservation number CGMCC No. 10072.

[0012] This invention provides a method for mine ecological restoration based on modified acidic wastewater sludge loaded with microorganisms. In step S3, the solid-state activation culture conditions are as follows: cultured for 5-10 days under natural on-site conditions, and sulfate-reducing bacteria and rhizosphere bacteria with plant growth-promoting functions are respectively inoculated onto a structured ecological substrate for culture to form functional restoration material A and functional restoration material B.

[0013] This invention provides a method for mine ecological restoration based on modified acidic wastewater sludge loaded with microorganisms, wherein the layered and progressive ecological restoration substrate in step S4 includes at least: The bottom barrier stabilizing layer is composed of the structured ecological substrate with a high content of geopolymers and is compacted. The middle layer of the bioreaction and nutrient layer is composed of the functional repair material A and is doped with a slow-release organic carbon source; The top layer of vegetation and rhizosphere is composed of the functional repair material B, topsoil, and water-retaining agent.

[0014] This invention provides a method for mine ecological restoration based on modified acidic wastewater sludge loaded with microorganisms, wherein the thickness of the barrier stabilizing layer is 10-15 cm; The thickness of the bio-reaction and nutrient layer is 15-25cm. The slow-release organic carbon source is humic acid or crushed straw, and the amount added is 2%-5% of the weight of the functional repair material. At this thickness, the dissolved oxygen in the pore water is consumed by the high oxygen consumption metabolism of the slow-release organic carbon source. Combined with the coverage of the upper water body to block atmospheric reoxygenation, a local anaerobic microenvironment is formed inside the matrix. The thickness of the vegetation and rhizosphere layer is designed to be 5-10 cm, which is based on the synergistic control of the shallow root distribution characteristics of the target plant and the depth of the anaerobic layer. This thickness can meet the growth needs of plant roots in an aerobic environment, while effectively preventing roots from penetrating into the anaerobic layer below through physical isolation, thus avoiding interference with the anaerobic microbial habitat.

[0015] This invention provides a method for mine ecological restoration based on modified acidic wastewater sludge loaded with microorganisms, wherein, in step S5, nitrogen-fixing bacteria are simultaneously inoculated when sowing pioneer plants.

[0016] This invention provides a method for mine ecological restoration based on modified acidic wastewater sludge loaded with microorganisms, wherein, in step S3, the nutrient initiation solution contains 0.5%-1.5% molasses and 0.1%-0.5% amino acid aqueous solution by mass fraction.

[0017] The beneficial effects of this invention are as follows: S1 sludge dewatering, S2 sludge and geopolymer precursors mixed to form a structured ecological substrate, S3 modular microbial inoculation and activation to obtain functional remediation materials, S4 layered laying to construct a remediation base, S5 sowing pioneer plants, and S6 system maintenance, transforming sludge from waste into an ecological substrate with a specific physicochemical structure. Through pre-inoculation and activation of functional microorganisms, it becomes a living remediation material. Through layered design, a synergistic remediation system from pollutant stabilization and isolation, biotransformation to vegetation reconstruction is constructed, realizing the safe resource utilization of acidic wastewater sludge and the efficient and long-term restoration of mine ecology. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 The flowchart shows a mine ecological restoration method based on modified acidic wastewater sludge loaded with microorganisms. Figure 2 This is a diagram of a layered, progressive ecological restoration substrate structure. Detailed Implementation

[0020] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0021] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0022] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.

[0023] Example 1, referring to Figure 1 This is the first embodiment of the present invention, which provides a mine ecological restoration method based on modified acidic wastewater sludge loaded with microorganisms, applied to a copper mine spoil heap No. 1, including the following steps: S1, Acidic wastewater sludge pretreatment Sludge collected after neutralization and precipitation from an acidic wastewater treatment plant at a copper tailings dam was found to contain mainly Cu and Zn heavy metals. The sludge was then dewatered using plate and frame filter presses to reduce its moisture content to approximately 40%.

[0024] S2, Preparation of Structured Ecological Substrate Ingredients: Based on the dry weight of the dewatered sludge, weigh 10% metakaolin (geopolymer precursor) and 3% commercial biochar (porous carbon material).

[0025] Activator preparation: Mix water glass solution and sodium hydroxide solution in a certain proportion, adjust the SiO2 / Na2O molar ratio to 1.2, and cool to room temperature to prepare an alkaline activator.

[0026] Mixing and Reaction: Dry mix the dewatered sludge, metakaolin, and biochar in a forced mixer for 5 minutes. Then, slowly add the alkaline activator (25% of the total dry weight) and continue mixing for 15 minutes to ensure thorough mixing and initiate the geopolymerization reaction.

[0027] Curing: Place the evenly mixed materials in a container covered with plastic film and seal it for 5 days at room temperature (approximately 25°C) and high humidity to form a block-shaped structured ecological substrate with a certain initial strength. Sampling and testing showed that its heavy metal leaching concentration was lower than the "Identification Standard for Hazardous Waste".

[0028] S3. Pre-inoculation and activation of modular microbial communities Pioneer colonization flora: A strain of Sphingomonas sp. that can secrete large amounts of extracellular polymeric substances (EPS) and is tolerant to Cu and Zn was cultured in the laboratory.

[0029] Core functional microbial community: Sulfate-reducing bacteria, used after laboratory amplification; a resistant rhizosphere growth-promoting bacterium (PGPR) with IAA-producing ability, obtained through commercially available inoculants. The SRB used in this embodiment is based on the prior patent of the inventors' team (Chinese Invention Patent CN104630097A, Patent Title: An Acidophilic Sulfate-Reducing Bacterium Strains and Their Applications), deposited at the China General Microbiological Culture Collection Center (CGMCC), with accession number CGMCC No. 10072.

[0030] Pre-inoculation and activation: The structured ecological substrate obtained in step S2, after natural air drying, forms porous blocks. It already possesses a suitable pore structure and particle size distribution (most particles are 1–5 cm), requiring no additional mechanical crushing. If some blocks are too large (>5 cm), they can be lightly broken down to ≤4 cm to facilitate bacterial penetration and uniform inoculation. The pioneer colonizing bacteria (Sphingomonas), SRB patented bacterial agent, and PGPR are respectively formulated to a concentration of not less than 1×10⁻⁶. 8 A bacterial suspension of CFU / mL was prepared. Sulfate-reducing bacteria and rhizosphere bacteria with plant growth-promoting functions were inoculated onto structured ecological substrates and cultured to form functional remediation material A and functional remediation material B, respectively. Based on the dry weight of the ecological substrate, the inoculation amount of each type of bacterial suspension was 5–8 mL / kg (i.e., 5–8 mL of bacterial suspension sprayed per kg of substrate), ensuring the total moisture content was controlled at 40%–50% to maintain microbial activity and prevent leaching loss. The inoculated materials were piled in a shaded, rainproof open-air area, covered with breathable non-woven fabric to reduce moisture evaporation and prevent contamination by other microorganisms. Activation culture was carried out at room temperature for 5–10 days, relying on the natural ambient temperature (daily average temperature ≥15℃). During this period, low-concentration nutrient solution (such as 0.5% molasses or 0.1% amino acid aqueous solution) was sprayed as needed, depending on the weather, to keep the material moist but not waterlogged. Through this process, functional microorganisms can colonize in the pores of the substrate and form a biofilm, with a viable count reaching 10^6. 7 -10 8 CFU / g, meeting the requirements for field applications.

[0031] S4. On-site construction of a layered and progressive ecological restoration base. Laying the base layer (barrier stabilization layer): Take a similar ecological substrate with 20% geopolymer content that has not been inoculated with microorganisms (permeability coefficient <10 after compaction). -7 The speed is 1 cm / s, the thickness is 10 cm, and it is moderately compacted with a light roller.

[0032] Laying the intermediate layer (bioreaction and nutrient layer): The functional repair material A prepared in step S3 is laid in the intermediate layer to a thickness of 25cm. During laying, 5% (by weight) of humic acid powder is evenly mixed in as a slow-release organic carbon source. This layer is kept loose.

[0033] Laying the top layer (vegetation and rhizosphere layer): Mix functional remediation material B, local sandy loam soil, and water-retaining agent (polyacrylamide) in a volume ratio of 3:6:1, and lay the mixture to a thickness of 10cm. Evenly sow the mixed seeds of tolerant pioneer plants (tall fescue, alfalfa, and bermudagrass) in this layer, and simultaneously inoculate with commercially available arbuscular mycorrhizal fungi (AMF) inoculum.

[0034] S5. Vegetation Restoration and Maintenance After sowing, cover with non-woven fabric. In the initial stage (first 60 days), sprinkler irrigation should be carried out according to the weather conditions to keep the topsoil moist. After 60 days, the repaired base has been initially stabilized and the vegetation coverage has reached more than 50%, at which point natural maintenance can be switched to.

[0035] Example 2, refer to Figure 1 This is the second embodiment of the present invention. This embodiment provides a mine ecological restoration method based on modified acidic wastewater sludge loaded with microorganisms, applied to the No. 2 spoil heap of a copper mine, including the following steps: This embodiment is basically the same as Embodiment 1, with the main difference being: In step S2: the geopolymer precursor is mine tailings, and the addition amount is 20% of the dry weight of dewatered sludge; the porous carbon material is commercial biochar, and the addition amount is 5%.

[0036] In step S4: the barrier stabilization layer is 15cm thick, the bioreaction and nutrient layer is 15cm thick, and the vegetation and rhizosphere layer is 5cm thick. The slow-release organic carbon source incorporated into the bioreaction and nutrient layer is crushed corn stalks, with an incorporation amount of 5%. The low-concentration nutrient solution is 1.5% molasses or 0.5% amino acid aqueous solution.

[0037] Example 3, referring to Figure 1 This is the first embodiment of the present invention, which provides a mine ecological restoration method based on modified acidic wastewater sludge loaded with microorganisms, applied to the slope #3 of a copper mine pit, including the following steps: This embodiment is basically the same as Embodiment 1, with the main difference being: After being dewatered by plate and frame filter press, the moisture content of the sludge is reduced to about 50%.

[0038] In step S2: the geopolymer precursor is a complex of metakaolin and mine tailings (mass ratio 1:1), with a total addition amount of 20%. The modulus of the alkaline activator is 1.8.

[0039] In step S4: Simultaneously sow a mixture of seeds from tolerant pioneer shrubs (ramie, cassia, and sumac).

[0040] Comparative Example 1 This comparative model simulates a conventional sludge-microorganism hybrid remediation method.

[0041] S1: Same as in Example 1, dewater the acidic wastewater sludge to a moisture content of 40%.

[0042] S2: No modification with geopolymers and biochar is performed. The dewatered sludge is directly mixed with 10% quicklime and 5% clay, stirred evenly, to form a simple solidified sludge.

[0043] S3: The same pioneer colonizing bacteria and core functional bacteria used in Example 1 are directly prepared into a mixed bacterial solution for later use without pre-inoculation and activation.

[0044] S4: On-site, the solidified sludge is simply mixed with bacterial solution and a small amount of compound fertilizer, and then spread directly on the surface of the spoil heap to form a covering layer of about 45cm thick.

[0045] S5: Sow and maintain the plants as in Example 1.

[0046] This comparative example lacks the steps of constructing a "structured ecological substrate" and "pre-inoculation activation," resulting in weak binding between microorganisms and the carrier and a simple system structure.

[0047] Comparative Example 2 This comparative study aims to investigate the effects of omitting the steps of "porous carbon materials" and "modular microbial pre-inoculation activation".

[0048] S1, S2: In step S2 of Example 1, no biochar is added. Only metakaolin (10%) and alkaline activator are mixed with sludge and cured to form a substrate.

[0049] S3: No specific modular microbial pre-inoculation activation step is performed. The functional bacterial culture solution from Example 1 is directly sprayed onto the surface after the substrate is laid on site.

[0050] S4, S5: Perform layered laying and vegetation reconstruction as in Example 1.

[0051] In this comparative example, the microbial habitat of the substrate was deteriorated, and the microorganisms had not adapted and colonized beforehand.

[0052] Comparative Example 3 This comparative example aims to explore the effects of using a homogeneous structure instead of a "layered progressive" structure.

[0053] S1, S2, S3: The same functional repair materials were prepared exactly as in Example 1.

[0054] S4: No layering is performed. All the functional repair materials obtained in step S3 are mixed with a small amount of water-retaining agent and then evenly laid on the surface of the tailings dam in one go, with a total thickness of 45cm (similar to the total thickness in Example 1).

[0055] S5: Plants are directly sown on the surface of the homogeneous layer and maintained in the same manner as in Example 1.

[0056] This comparative model lacks functional zoning, and all materials have uniform properties.

[0057] Table 1. Heavy metal leaching of sludge before and after modification under different remediation treatments (unit: mg / L)

[0058] Table 2. Changes in soil remediation indices over time under different remediation treatments.

[0059] Table 3. Changes in vegetation growth indicators over time under different restoration treatments.

[0060] All embodiments (1-3) of this invention exhibit excellent comprehensive remediation effects: pH remains stable near neutral, plants grow well, microbial activity is high and stable, heavy metals are effectively fixed, and the system structure is stable. This is attributed to the stable microenvironment provided by the "structured ecological substrate" for microorganisms, the highly active bacterial community ensured by "pre-inoculation activation," and the functional zoning and synergy achieved by the "layered progressive structure."

[0061] Comparative Example 1 (conventional mixing method) showed the worst results, proving that simple mixing cannot build a long-term stable repair system.

[0062] Comparative Example 2 (without biochar, without pre-activation) shows that the lack of porous carbon material and pre-inoculation activation step significantly reduces the microbial capacity and community activity of the substrate, resulting in reduced remediation efficiency.

[0063] Comparative Example 3 (homogeneous structure) shows that, despite the use of the substrate and microbial agent of the present invention, the lack of a layered design leads to mixed internal functions. The activity of microorganisms in the lower layer decreases due to limited conditions such as nutrition and oxygen, while the upper layer suffers from long-term stability issues due to factors such as disturbance of plant roots. The overall effect is inferior to that of a layered design.

[0064] In summary, this invention transforms sludge from waste into an ecological substrate with a specific physicochemical structure through a multi-material process: S1 sludge dewatering; S2 mixing sludge with geopolymer precursors and other materials to form a structured ecological substrate; S3 modular microbial inoculation and activation to obtain functional remediation materials; S4 layered laying to construct a remediation base; S5 sowing pioneer plants; and S6 system maintenance. By pre-inoculating and activating functional microorganisms, it becomes a living remediation material. Furthermore, through layered design, a synergistic remediation system is constructed, encompassing pollutant stabilization and isolation, biotransformation, and vegetation reconstruction. This achieves the safe resource utilization of acidic wastewater sludge and the efficient and long-term remediation of mine ecology.

[0065] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for mine ecological restoration based on modified acidic wastewater sludge loaded with microorganisms, characterized in that: include, S1 dewaters acidic wastewater sludge to bring its moisture content to a preset range; S2. The dehydrated acidic wastewater sludge is mixed with geopolymer precursors, porous carbon materials and alkaline activators. The high alkalinity provided by the alkaline activator and the exothermic reaction are used to overcome the adverse effects of high water content, promote the geopolymerization reaction, and form a structured ecological substrate after curing. S3. Inoculate modular microbial communities (including alkali-tolerant pioneer bacteria, sulfate-reducing bacteria (SRB), and rhizosphere growth-promoting bacteria (PGPR)) into structured ecological substrates that have been naturally matured for more than 14 days (pH ≤ 8.5) at a rate of 5–8 mL / kg dry weight (bacterial concentration ≥ 1 × 10⁻⁶). 8 CFU / mL), activated for 5–10 days in a natural environment (average daily temperature ≥15℃), during which a nutrient-initiating solution is sprayed to moisturize and provide nutrients, to obtain a low-cost, engineerable loaded active microbial remediation material; S4. At the mine site to be restored, different functional layers composed of the structured ecological substrate and the functional restoration material are laid sequentially from bottom to top to form a layered and progressive ecological restoration base. S5. Sow and plant pioneer plants on the surface layer of the layered and progressive ecological restoration base. S6. Perform initial maintenance on the completed repair system until the system develops self-sustaining capabilities.

2. The mine ecological restoration method based on modified acidic wastewater sludge loaded with microorganisms as described in claim 1, characterized in that: In step S1, the dewatering treatment reduces the sludge moisture content to 40%-50%.

3. The mine ecological restoration method based on modified acidic wastewater sludge loaded with microorganisms as described in claim 1, characterized in that: In step S2: The geopolymer precursor is metakaolin and / or mine tailings, and its addition amount is 10%-20% of the dry weight of dewatered sludge; The porous carbon material is biochar, and its addition amount is 3%-5% of the dry weight of dewatered sludge.

4. The mine ecological restoration method based on modified acidic wastewater sludge loaded with microorganisms as described in claim 3, characterized in that: Step S2 specifically includes: S2.

1. Dry mix the geopolymer precursor with the porous carbon material and dewatered sludge; S2.2 Add an alkaline activator to the dry mixture and stir to initiate a geopolymerization reaction; S2.

3. The mixture is sealed and cured for 3-7 days under conditions of temperature above 20℃ and humidity above 90% to form the structured ecological substrate. The alkaline activator is a mixed solution of water glass and sodium hydroxide with a modulus (SiO2 / Na2O molar ratio) between 1.2 and 1.

8.

5. The mine ecological restoration method based on modified acidic wastewater sludge loaded with microorganisms as described in claim 1, characterized in that: In step S3, the pioneer colonizing bacteria are bacteria that can secrete extracellular polymers and are resistant to heavy metals; the core functional bacteria include sulfate-reducing bacteria and rhizosphere bacteria with plant growth-promoting functions.

6. The mine ecological restoration method based on modified acidic wastewater sludge loaded with microorganisms as described in claim 1, characterized in that: The solid-state activation culture conditions described in step S3 are as follows: culture for 5-10 days under natural on-site conditions, and inoculate sulfate-reducing bacteria and rhizosphere bacteria with plant growth-promoting functions onto the structured ecological substrate for culture, forming functional repair material A and functional repair material B.

7. The mine ecological restoration method based on modified acidic wastewater sludge loaded with microorganisms as described in claim 1, characterized in that: In step S3, the nutrient starting solution contains 0.5%-1.5% molasses and 0.1%-0.5% amino acid aqueous solution by mass.

8. The mine ecological restoration method based on modified acidic wastewater sludge loaded with microorganisms as described in claim 1, characterized in that: The layered and progressive ecological restoration substrate mentioned in step S4 includes at least: The bottom barrier stabilizing layer is composed of the structured ecological substrate with a high content of geopolymers and is compacted. The middle layer of the bioreaction and nutrient layer is composed of the functional repair material A and is doped with a slow-release organic carbon source; The top layer of vegetation and rhizosphere is composed of the functional repair material B, topsoil, and water-retaining agent.

9. The mine ecological restoration method based on modified acidic wastewater sludge loaded with microorganisms as described in claim 7, characterized in that: The thickness of the barrier stabilizing layer is 10-15 cm; The thickness of the bio-reaction and nutrient layer is 15-25cm. The slow-release organic carbon source is humic acid or crushed straw, and the amount added is 2%-5% of the weight of the functional repair material. At this thickness, the dissolved oxygen in the pore water is consumed by the high oxygen consumption metabolism of the slow-release organic carbon source. Combined with the coverage of the upper water body to block atmospheric reoxygenation, a local anaerobic microenvironment is formed inside the matrix. The thickness of the vegetation and rhizosphere layer is designed to be 5-10 cm, which is based on the synergistic control of the shallow root distribution characteristics of the target plant and the depth of the anaerobic layer. This thickness can meet the growth needs of plant roots in an aerobic environment, while effectively preventing roots from penetrating into the anaerobic layer below through physical isolation, thus avoiding interference with the anaerobic microbial habitat.

10. The mine ecological restoration method based on modified acidic wastewater sludge loaded with microorganisms as described in claim 1, characterized in that: In step S5, nitrogen-fixing bacteria are simultaneously inoculated when the pioneer plants are sown.

Images