Preparation method for artificial soil made of coal gangue and use thereof
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- BCEG ENVIRONMENTAL REMEDIATION CO LTD
- Filing Date
- 2024-12-23
- Publication Date
- 2026-06-25
Smart Images
Figure CN2024141576_25062026_PF_FP_ABST
Abstract
Description
A method for preparing artificial soil from coal gangue and its application Technical Field
[0001] This application belongs to the technical field of soil conditioners and solid waste resource recycling, and particularly relates to a method for preparing and applying artificial soil made from coal gangue. Background Technology
[0002] Coal gangue is a solid waste generated during coal mining and washing. Compared to ordinary coal, it is characterized by low carbon content, low calorific value, and hard texture. Its main components are Al2O3 and SiO2, and it also contains varying amounts of Fe2O3, CaO, MgO, Na2O, K2O, P2O5, SO3, and trace rare elements such as gallium, vanadium, titanium, and cobalt. As a major solid waste generated during coal mining and washing, coal gangue has long placed a heavy burden on the ecological environment. It not only occupies a large amount of land resources but can also lead to land degradation, salinization, and desertification through improper landfilling. Furthermore, the spontaneous combustion of coal gangue can produce toxic and harmful gases, further polluting the environment.
[0003] China is a country rich in coal resources but relatively scarce in oil and gas resources, with coal dominating its energy structure. According to statistics, from 1989 to 2019, China consumed a total of 76.8 billion tons of standard coal equivalent, of which coal accounted for a staggering 69%. Inevitably, a large amount of coal gangue is generated during coal mining and processing. According to incomplete statistics, the cumulative amount of coal gangue piled up in my country has exceeded 7 billion tons, and it is estimated that approximately 300 to 500 million tons of coal gangue will still be generated annually until 2050. Such a massive amount of waste poses a significant threat to the ecological environment, urgently requiring solutions through resource utilization.
[0004] Backfilling and reclamation are the main ways to utilize coal gangue, with over 90% currently being directly landfilled. However, this method not only easily leads to soil and groundwater pollution but also causes disasters such as landslides and soil erosion. Therefore, exploring new processes and technologies for the large-scale utilization of coal gangue is particularly important. In recent years, researchers have improved the activity of coal gangue through modification techniques, transforming it into various high-value-added environmentally friendly materials. These modification methods include acid or alkali treatment, mechanochemical methods, surface organic modification, calcination modification, hydrothermal modification, and composite modification. These modification technologies have significantly improved the adsorption performance, reactivity, and material properties of coal gangue, but they also involve high costs, high energy consumption, and high pollution. Therefore, finding a way to utilize coal gangue resources is urgently needed.
[0005] Coal gangue mountains formed by direct landfilling of coal gangue are difficult to grow due to a lack of effective nutrients and poor water and fertilizer retention, which makes ecological restoration of coal gangue mountains extremely difficult. The fundamental problem to be solved in the ecological restoration of coal gangue mountains is to establish the site conditions required for vegetation growth.
[0006] The invention patent "Preparation and Application of a Composite Microbial Agent for Coal Gangue Artificial Ecological Substrate", application number "201911364735.1", discloses a composite microbial agent for coal gangue artificial ecological substrate, including five types of actinomycetes: *Streptomyces violaceum*, *Streptomyces thermophilum*, *Streptomyces thermophilum*, *Streptomyces microlepidocrocite*, and *Streptomyces thermophilum*, one type of bacterium: *Pseudomonas*, and one type of mold: *Penicillium oxalate*. The invention application "Preparation Method and Application of Coal-Based Artificial Soil", application number "202410334575.0", discloses the method of combining composted organic matter with soil, zeolite, and [other ingredients]. Aqueous agents prepared by mixing water with fertilizer are mixed with coal gangue for alfalfa planting; Patent No. 201911367252.7, entitled "An Artificial Ecological Substrate Based on Coal Gangue and Its Preparation Method," discloses an artificial ecological substrate and its preparation method, which involves adding microbial agents and composting plant-derived organic matter, followed by maturation to obtain the artificial substrate; Patent No. 201911367252.7, entitled "A Method and System for Preparing Artificial Soil from Coal Gangue and Agricultural and Livestock Waste," discloses a method for preparing artificial soil by mixing coal gangue and agricultural and livestock waste, which requires the addition of quicklime to adjust the pH; Patent No. 202311847357.5, entitled "A Method for Preparing Artificial Soil Using Coal Gangue," discloses a method for preparing artificial soil by mixing coal gangue with soil, biochar, and microbial agents, which requires mixing a large amount of soil. The aforementioned invention patents still have technical defects such as complex preparation methods, numerous types of microbial agents, and the need to mix in a large amount of natural soil, and have not effectively solved the existing problems of coal gangue piles.
[0007] Therefore, based on the above situation, there is an urgent need for an effective method to improve the existing problems of coal gangue piles, increase the nutrient content of coal gangue for utilization, and reduce the negative impacts of coal gangue. Summary of the Invention
[0008] The technical problem to be solved by this application is to overcome the shortcomings of existing technologies, such as the huge amount of coal gangue generated, improper landfill methods, lack of effective nutrients in coal gangue, heavy metal pollution of the environment, lack of means of resource utilization of coal gangue, and the need for pH adjustment, biological fermentation, and high cost and time due to the use of a high proportion of compound substrate (such as soil) in the soil utilization method. The application of this application is to provide a method for preparing artificial soil from coal gangue and its application.
[0009] This application adopts the following technical solution to solve the above-mentioned technical problems:
[0010] This application provides an artificial soil made from coal gangue, which, based on 100 parts by weight, comprises the following components: 1-10 parts of Bacillus compound inoculant, 5-10 parts of natural soil, 5-10 parts of aluminosilicate, 5-10 parts of urea, 57-82 parts of modified coal gangue, and 2-3 parts of moss biocrust.
[0011] The preparation method of the Bacillus compound agent includes the following steps: simultaneously adsorbing the Bacillus megaterium, Bacillus subtilis and Bacillus mucilaginosus onto biomass microspheres.
[0012] This study found that biomass microspheres, with their high permeability and large surface area, increase the number and survival rate of microbial agents compared to direct spraying onto coal gangue, thereby improving the efficiency of microbial activity. Bacillus megaterium enhances available phosphorus and nitrogen levels by releasing urease and phosphatase, Bacillus subtilis fixes nitrogen, and Bacillus mucilaginosus releases readily available potassium through silicate bacteria. By fully leveraging the synergistic effect of these three microorganisms, the release levels of nitrogen, phosphorus, and potassium in the soil are increased to achieve ideal levels.
[0013] In some embodiments, the Bacillus megaterium, Bacillus subtilis, and Bacillus mucilaginosus are all added in the form of bacterial solutions.
[0014] The viable count of the *Bacillus megaterium* bacterial solution was 10. 5 ~10 6 CFU / mL.
[0015] The viable count of the Bacillus subtilis bacterial solution was 10. 5 ~10 6 CFU / mL.
[0016] The viable count of the Bacillus mucilaginosus bacterial solution was 10. 5 ~10 6 CFU / mL.
[0017] The volume ratio of the Bacillus megaterium solution, the Bacillus subtilis solution, and the Bacillus mucilaginosus solution is 1:(1-2):(1-3), for example, 1:1:1, 1:2:1, 1:2:3, etc.
[0018] The Bacillus megaterium, Bacillus subtilis, and Bacillus mucilaginosus are further activated before adsorption.
[0019] Preferably, the activation method includes: preparing a mixture of one of the following strains, namely Bacillus megaterium, Bacillus subtilis, and Bacillus mucilaginosus, with brown sugar and water at a mass ratio of 1:(1-3):30, mixing well, and then performing the activation, for example, a mass ratio of 1:1.5:30, 1:2:30, etc.
[0020] More preferably, the activation operation is conventional in the art and is carried out in a shaker.
[0021] More preferably, the activation time is 12-24 hours (e.g., 14 hours, 16 hours, 18 hours, 20 hours, 22 hours, etc.), the activation speed is 160-180 rpm (e.g., 165 rpm, 170 rpm, 175 rpm, etc.), and the activation temperature is 28°C-30°C (e.g., 28.5°C, 29.5°C, etc.).
[0022] The preparation method of the biomass microspheres includes: dissolving biomass material in dilute acid, adding sodium cellulose and activated carbon and stirring evenly, adding alkaline solution dropwise to form gel microspheres, and then stirring, solidifying, washing, freezing and drying to obtain the biomass microspheres.
[0023] Preferably, the biomass material includes one or more of chitosan, wood chips, and straw.
[0024] Preferably, the biomass material is biomass material powder.
[0025] In this study, we found that when biomass materials are used as carriers, they can not only serve as carriers for microbial agents, but also provide exogenous organic matter. Furthermore, biomass materials have a larger surface area, possess certain water retention properties, and can provide abundant attachment sites for microorganisms, thereby further enhancing their potassium solubilization, phosphorus solubilization, and nitrogen fixation effects.
[0026] Preferably, the dilute acid includes glacial acetic acid.
[0027] The mass fraction of the dilute acid is 2%.
[0028] Preferably, the sodium cellulose comprises sodium carboxymethyl cellulose.
[0029] Preferably, the alkaline solution includes a NaOH solution or a KOH solution.
[0030] Preferably, the stirring and curing time is 0.5 h.
[0031] Preferably, the washing is performed with deionized water until the pH is neutral.
[0032] Preferably, the freezing time is 2 hours, until the gel microspheres are fixed.
[0033] Preferably, the freezing process further includes immersion in anhydrous ethanol, and more preferably, the immersion time is 2 hours.
[0034] Preferably, the drying is freeze drying.
[0035] Preferably, the mass-to-volume ratio of the biomass microspheres to the mixed bacterial solution of Bacillus megaterium, Bacillus subtilis, and Bacillus mucilaginosus is 1:(5-6) g / mL, for example, 1:5.2 g / mL, 1:5.4 g / mL, 1:5.6 g / mL, 1:5.8 g / mL, etc.
[0036] Preferably, the mass ratio of the biomass material, the sodium cellulose and the activated carbon is 3:(1-3):(1-3), for example 3:1:1, 3:2:1, 3:1:2, 3:2:2, etc.
[0037] Preferably, the concentration of the alkaline solution is 1 to 4 M, for example 2 M, 3 M, etc.
[0038] Preferably, the stirring operation is conventional in the art, preferably the mixing is carried out under a magnetic stirrer, more preferably, the stirring time is 0.5 to 2 hours, for example 0.8 hours, 1 hour, 1.2 hours, 1.4 hours, 1.6 hours, 1.8 hours, etc.; more preferably, the stirring speed is 100 to 300 rpm, for example 150 rpm, 200 rpm, 250 rpm, etc.
[0039] The biomass microspheres adsorbing bacterial solution are conventional in the art, and the adsorption loading is carried out in a shaker.
[0040] Preferably, the adsorption time is 2 to 4 hours, for example, 2.2 hours, 2.4 hours, 2.6 hours, 2.8 hours, 3 hours, etc.
[0041] Preferably, the rotational speed of the shaking table is 160-180 rpm, such as 165 rpm, 170 rpm, 175 rpm, etc.
[0042] Preferably, the adsorption temperature is 20-30°C, for example 22°C, 24°C, 26°C, 28°C, etc.
[0043] In some embodiments, the natural soil is local natural soil.
[0044] In some embodiments, the aluminosilicate includes one of zeolite, illite, and bentonite.
[0045] The aluminosilicate can adsorb the surrounding coal gangue matrix to form aggregates, improve the permeability and water retention of the coal gangue matrix, and help regulate water, fertilizer, air and heat in the coal gangue matrix, providing a good living environment for plant growth.
[0046] In some embodiments, the method for preparing the modified coal gangue includes: crushing the coal gangue, sieving it, adding gypsum, and grinding it to obtain the modified coal gangue.
[0047] The particle size after sieving is 0.15 to 2 mm, for example, 0.16 mm, 0.17 mm, 0.18 mm, 0.19 mm, etc., preferably 2 mm.
[0048] This application obtains fine-particle coal gangue after crushing, which reduces porosity and lowers the oxygen content inside the coal gangue, thus preventing spontaneous combustion.
[0049] The mass ratio of gypsum to coal gangue is 1:(5-30), for example, 1:10, 1:15, 1:20, 1:25, etc.
[0050] The gypsum includes phosphogypsum.
[0051] The study found that using phosphogypsum can provide a phosphorus source and neutralize the acidity and alkalinity of coal gangue, thus achieving the goal of treating waste with waste.
[0052] The grinding process includes ball milling or rolling. After grinding, modified coal gangue with a soil-like texture is prepared.
[0053] In some embodiments, the method for preparing the moss biocrust includes: obtaining moss outdoors, spreading it flat on kraft paper, air-drying it naturally in a drying room, removing non-crust components such as stones and plant residues with tweezers after air-drying, removing impurities, and then crushing it with a plant pulverizer.
[0054] Among them, moss biocrusts are formed at a rate of 1-2 kg / m². 2 Spread the seeds, for example, at a concentration of 1.5 g / m³. 2 1.8kg / m 2 wait.
[0055] This application also provides a method for preparing artificial soil made from coal gangue, the method comprising: mixing Bacillus compound inoculant, natural soil, aluminosilicate, urea and modified coal gangue evenly according to the above proportions, and then uniformly spreading moss biocrusts after mixing.
[0056] This application also provides an application of coal gangue-based artificial soil in increasing the available phosphorus, available potassium, cation exchange capacity, and adsorbing heavy metals from coal gangue.
[0057] This application combines the effects of microorganisms, matrix compounding, and biocrust formation. On the one hand, a microbial agent carrier is prepared using biomass materials, and activated microorganisms are attached to the carrier to form a slow-release microbial agent. This agent is then applied to coal gangue to release nitrogen, phosphorus, and potassium from the gangue, meeting the needs of crop growth. On the other hand, modified artificial soil is formed by adding phosphogypsum and coal gangue to provide a phosphorus source, enhance the nutrients in the coal gangue, neutralize the pH, and achieve waste treatment. Simultaneously, biocrust technology is used to adsorb and enrich heavy metals in the coal gangue.
[0058] Based on common knowledge in the field, the above-mentioned preferred conditions can be combined arbitrarily to obtain various preferred embodiments of this application.
[0059] All reagents and raw materials used in this application are commercially available.
[0060] The positive and progressive effects of this application are as follows:
[0061] (1) The Bacillus compound microbial agent used in this application does not require fermentation and cultivation. It can be activated by simple brown sugar and act on the microbial agent carrier to achieve the effect of releasing nutrients from coal gangue and realize the resource utilization of coal gangue. At the same time, it is adsorbed on the biomass material to be produced, and the microspheres are used as the carrier to make it have porous adsorption channels, which can carry a large number of microbial agents, so that the microbial agents are slowly released in the coal gangue and play a role. It adds natural soil, provides organic matter, and improves the pore structure of coal gangue matrix. By adding minerals such as zeolite, it improves the air permeability and water retention of artificial soil made from coal gangue. At the same time, by using the biocrust of moss on the coal gangue, the genes of bacterial decomposition and metabolism in the moss adsorb and enrich the heavy metals in the coal gangue. The biocrust effect is innovatively used to reduce the heavy metal content in the coal gangue and reduce the environmental risks when utilizing coal gangue resources.
[0062] (2) The mechanically modified coal gangue artificial soil used in this application, by adding phosphogypsum to the crushed coal gangue, combined with microbial action, matrix compounding and biological crusting, not only releases nutrients in the coal gangue, effectively improves the structure and water retention of the coal gangue, and reduces heavy metal pollution, but also improves the permeability of the matrix, increases the effective nitrogen, phosphorus and potassium content in the matrix, and increases the pH of the artificial soil matrix, making the artificial soil matrix more suitable for plant growth conditions and improving the plant growth environment. Moreover, the preparation method is simple and the preparation process is easy to operate, making it suitable for the resource soilization of coal gangue mountains, improving the utilization efficiency of coal gangue, and effectively solving the ecological restoration problem of coal gangue mountains. It has great potential for promotion in the ecological restoration of coal gangue mountains. Attached Figure Description
[0063] Figure 1 shows the growth of tall fescue after 10 days of cultivation in artificial soil made from coal gangue prepared using the examples and comparative examples.
[0064] Figure 2 shows the growth of tall fescue after 20 and 30 days of cultivation in artificial soil made from coal gangue prepared in the examples and comparative examples. Detailed Implementation
[0065] The present application is further illustrated below by way of embodiments, but these embodiments are not intended to limit the scope of the present application. Experimental methods not specifically described in the following embodiments are performed according to conventional methods and conditions, or as selected in accordance with the product instructions.
[0066] Unless otherwise specified, the experimental methods used in the following examples are conventional methods.
[0067] The Bacillus megaterium used in the following examples and comparative examples was purchased from Guangxi Nongbao Bioengineering Co., Ltd.
[0068] The Bacillus subtilis described in the following examples and comparative examples was purchased from Guangxi Nongbao Biotechnology Co., Ltd.
[0069] The Bacillus mucilaginosus in the following examples and comparative examples was purchased from Guangxi Nongbao Bioengineering Co., Ltd.
[0070] All other raw materials used in the following examples and comparative examples are commercially available.
[0071] Example 1
[0072] An artificial soil made from coal gangue, comprising 100 parts by weight of the following components: 1 part of Bacillus compound inoculant, 5 parts of local natural soil, 5 parts of zeolite, 5 parts of urea, 82 parts of modified coal gangue, and 2 parts of moss biocrust.
[0073] An artificial soil made from coal gangue, the preparation method includes the following steps:
[0074] (1) The preparation method of Bacillus compound inoculum includes:
[0075] 1) Activation: Bacillus megaterium, Bacillus subtilis, and Bacillus mucilage were activated separately with brown sugar at a mass ratio of bacterial solution:brown sugar:water = 1:1:30. After mixing in an Erlenmeyer flask, the mixture was placed in a shaker and activated for 20 hours at a speed of 170 rpm and a temperature of 29°C. After activation, the viable count of Bacillus megaterium was 10. 6 CFU / mL yielded a viable count of 10 Bacillus subtilis. 6 CFU / mL, yielding a viable count of 10cFU / mL in the *Bacillus mucilaginosus* bacterial suspension. 6 CFU / mL, for later use;
[0076] 2) Preparation of chitosan gel microspheres: Dissolve 3g of chitosan powder in 2% glacial acetic acid solution and stir magnetically until completely dissolved. Add 1g of sodium carboxymethyl cellulose and dissolve. Then add 1g of activated carbon and stir until well mixed. Use a dropper to evenly add the above mixture to 2M NaOH solution to form chitosan gel microspheres. Continue stirring for 0.5 hours. After the chitosan gel microspheres are completely solidified, wash repeatedly with deionized water and filter until the pH of the liquid is neutral. Discard the deionized water, spread the chitosan gel microspheres evenly in a petri dish, freeze in a refrigerator for 2 hours to fix the shape of the microspheres, then immerse in anhydrous ethanol for 2 hours. Discard the liquid and freeze-dry to obtain chitosan gel microspheres for later use.
[0077] 3) Weigh 2 mL of Bacillus megaterium culture, 2 mL of Bacillus subtilis culture, and 2 mL of Bacillus mucilaginosus culture, add 1 g of chitosan gel microspheres, control the shaking speed at 170 rpm, set the temperature at 28℃, and place it in the shaking incubator for 3 hours to complete the preparation.
[0078] (2) Methods for preparing modified coal gangue include:
[0079] The coal gangue is crushed and passed through a 2mm sieve. 10% phosphogypsum is added to the sieved coal gangue, and after 36 hours of grinding, modified coal gangue with soil texture is formed.
[0080] (3) Mix the Bacillus compound agent, local natural soil, zeolite, urea and modified coal gangue in the above proportions, stir thoroughly under a stirrer, and let it stand at room temperature for later use.
[0081] (4) Spread the collected moss on kraft paper and air dry it in a drying room. After air drying, use tweezers to remove stones, plant residues and other non-skin-forming components, and crush them with a plant crusher to make moss biological skin.
[0082] (5) Spread the prepared sample from (3) evenly in the tray container to a thickness of 3 cm, and evenly spread moss biocrusts on the sample surface at a rate of 1 kg / m². 2 Water it twice a day.
[0083] Example 2
[0084] An artificial soil made from coal gangue, comprising 100 parts by weight of the following components: 5 parts of Bacillus compound inoculant, 10 parts of local natural soil, 5 parts of zeolite, 5 parts of urea, 72.5 parts of modified coal gangue, and 2.5 parts of moss biocrust.
[0085] An artificial soil made from coal gangue, the preparation method includes the following steps:
[0086] (1) The preparation method of Bacillus compound inoculum includes:
[0087] 1) Activation: Bacillus megaterium, Bacillus subtilis, and Bacillus mucilage were activated separately with brown sugar at a mass ratio of bacterial solution:brown sugar:water = 1:1:30. After mixing in an Erlenmeyer flask, the mixture was placed in a shaker and activated for 20 hours at a speed of 170 rpm and a temperature of 29°C. After activation, the viable count of Bacillus megaterium was 10. 6 CFU / mL yielded a viable count of 10 Bacillus subtilis. 6 CFU / mL, yielding a viable count of 10cFU / mL in the *Bacillus mucilaginosus* bacterial suspension. 6 CFU / mL, for later use;
[0088] 2) Preparation of chitosan gel microspheres: Dissolve 3g of chitosan powder in 2% glacial acetic acid solution and stir magnetically until completely dissolved. Add 1g of sodium carboxymethyl cellulose and dissolve. Then add 1g of activated carbon and stir until well mixed. Use a dropper to evenly add the above mixture to 2M NaOH solution to form chitosan gel microspheres. Continue stirring for 0.5 hours. After the chitosan gel microspheres are completely solidified, wash repeatedly with deionized water and filter until the pH of the liquid is neutral. Discard the deionized water, spread the chitosan gel microspheres evenly in a petri dish, freeze in a refrigerator for 2 hours to fix the shape of the microspheres, then immerse in anhydrous ethanol for 2 hours. Discard the liquid and freeze-dry to obtain chitosan gel microspheres for later use.
[0089] 3) Weigh 2 mL of Bacillus megaterium culture, 2 mL of Bacillus subtilis culture, and 2 mL of Bacillus mucilaginosus culture, add 1 g of chitosan gel microspheres, control the shaking speed at 170 rpm, set the temperature at 28℃, and place it in the shaking incubator for 3 hours to complete the preparation.
[0090] (2) Methods for preparing modified coal gangue include:
[0091] The coal gangue was crushed and passed through a 2mm sieve. 10% phosphogypsum was added to the sieved coal gangue, and the mixture was ball-milled for 36 hours to form modified coal gangue with soil texture.
[0092] (3) Mix the Bacillus compound agent, local natural soil, zeolite, urea and modified coal gangue in the above proportions, stir thoroughly under a stirrer, and let it stand at room temperature for later use.
[0093] (4) Spread the collected moss on kraft paper and air dry it in a drying room. After air drying, use tweezers to remove stones, plant residues and other non-skin-forming components, and crush them with a plant crusher to make moss biological skin.
[0094] (5) Spread the prepared sample from (3) evenly in the tray container to a thickness of 3 cm, and evenly spread moss biocrusts on the sample surface at a rate of 1.5 kg / m². 2 Water it twice a day.
[0095] Example 3
[0096] An artificial soil made from coal gangue, comprising the following components in 100 parts by weight: 10 parts of Bacillus compound inoculant, 5 parts of local natural soil, 10 parts of zeolite, 5 parts of urea, 67 parts of modified coal gangue, and 3 parts of moss biocrust.
[0097] An artificial soil made from coal gangue, the preparation method includes the following steps:
[0098] (1) The preparation method of Bacillus compound inoculum includes:
[0099] 1) Activation: Bacillus megaterium, Bacillus subtilis, and Bacillus mucilage were activated separately with brown sugar at a mass ratio of bacterial solution:brown sugar:water = 1:1:30. After mixing in an Erlenmeyer flask, the mixture was placed in a shaker and activated for 20 hours at a speed of 170 rpm and a temperature of 29°C. After activation, the viable count of Bacillus megaterium was 10. 6 CFU / mL yielded a viable count of 10 Bacillus subtilis. 6 CFU / mL, yielding a viable count of 10cFU / mL in the *Bacillus mucilaginosus* bacterial suspension. 6 CFU / mL, for later use;
[0100] 2) Preparation of chitosan gel microspheres: Dissolve 3g of chitosan powder in 2% glacial acetic acid solution and stir magnetically until completely dissolved. Add 1g of sodium carboxymethyl cellulose and dissolve. Then add 1g of activated carbon and stir until well mixed. Use a dropper to evenly add the above mixture to 2M NaOH solution to form chitosan gel microspheres. Continue stirring for 0.5 hours. After the chitosan gel microspheres are completely solidified, wash repeatedly with deionized water and filter until the pH of the liquid is neutral. Discard the deionized water, spread the chitosan gel microspheres evenly in a petri dish, freeze in a refrigerator for 2 hours to fix the shape of the microspheres, then immerse in anhydrous ethanol for 2 hours. Discard the liquid and freeze-dry to obtain chitosan gel microspheres for later use.
[0101] 3) Weigh 2 mL of Bacillus megaterium culture, 2 mL of Bacillus subtilis culture, and 2 mL of Bacillus mucilaginosus culture, add 1 g of chitosan gel microspheres, control the shaking speed at 170 rpm, set the temperature at 28℃, and place it in the shaking incubator for 3 hours to complete the preparation.
[0102] (2) Methods for preparing modified coal gangue include:
[0103] The coal gangue was crushed and passed through a 2mm sieve. 10% phosphogypsum was added to the sieved coal gangue, and the mixture was ball-milled for 36 hours to form modified coal gangue with soil texture.
[0104] (3) Mix the Bacillus compound agent, local natural soil, zeolite, urea and modified coal gangue in the above proportions, stir thoroughly under a stirrer, and let it stand at room temperature for later use.
[0105] (4) Spread the collected moss on kraft paper and air dry it in a drying room. After air drying, use tweezers to remove stones, plant residues and other non-skin-forming components, and crush them with a plant crusher to make moss biological skin.
[0106] (5) Spread the prepared sample from (3) evenly in the tray container to a thickness of 3 cm, and evenly spread moss biocrusts on the sample surface at a rate of 2 kg / m². 2 Water it twice a day.
[0107] Comparative Example 1
[0108] Compared with Example 1, the difference is that the artificial soil made from coal gangue did not contain Bacillus compound inoculant. The artificial soil made from coal gangue, based on 100 parts by weight, includes the following components: 5 parts local natural soil, 5 parts zeolite, 5 parts urea, 83 parts modified coal gangue, and 2 parts moss biocrust.
[0109] An artificial soil made from coal gangue, the preparation method includes the following steps:
[0110] (1) Methods for preparing modified coal gangue include:
[0111] The coal gangue was crushed and passed through a 2mm sieve. 10% phosphogypsum was added to the sieved coal gangue, and the mixture was ball-milled for 36 hours to form modified coal gangue with soil texture.
[0112] (2) Mix the local natural soil, zeolite, urea and modified coal gangue in the above proportions, stir thoroughly under a mixer and let stand at room temperature for later use.
[0113] (3) Spread the collected moss on kraft paper and air dry it naturally in a drying room. After air drying, use tweezers to remove stones, plant residues and other non-skin-forming components, and crush them with a plant pulverizer to make moss bio-skin.
[0114] (4) Spread the prepared sample from (2) evenly in the tray container to a thickness of 3 cm, and evenly spread moss biocrusts on the sample surface at a rate of 1 kg / m². 2 Water it twice a day.
[0115] Comparative Example 2
[0116] Compared with Example 2, the difference lies in the fact that no Bacillus compound inoculant was added to the artificial soil made from coal gangue, and the amount of moss biocrust seed source sown on the surface of the artificial soil from coal gangue was reduced to 1 kg / m². 2 .
[0117] An artificial soil made from coal gangue, comprising the following components in 100 parts by weight: 10 parts local natural soil, 5 parts zeolite, 5 parts urea, 78 parts modified coal gangue, and 2 parts moss biocrust.
[0118] An artificial soil made from coal gangue, the preparation method includes the following steps:
[0119] (1) Methods for preparing modified coal gangue include:
[0120] The coal gangue was crushed and passed through a 2mm sieve. 10% phosphogypsum was added to the sieved coal gangue, and the mixture was ball-milled for 36 hours to form modified coal gangue with soil texture.
[0121] (2) Mix the local natural soil, zeolite, urea and modified coal gangue in the above proportions, stir thoroughly under a mixer and let stand at room temperature for later use.
[0122] (3) Spread the collected moss on kraft paper and air dry it in a drying room. After air drying, use tweezers to pick out non-skinned components such as stones and plant residues, and crush them with a plant crusher to make moss biological skin.
[0123] (4) Spread the prepared sample from (2) evenly in the tray container to a thickness of 3 cm, and evenly spread moss biocrusts on the sample surface at a rate of 1 kg / m². 2 Water it twice a day.
[0124] Comparative Example 3
[0125] Compared with Example 3, the difference lies in the fact that no Bacillus compound inoculant was added to the artificial soil made from coal gangue, and the amount of moss biocrust seed source sown on the surface of the artificial soil from coal gangue was reduced to 1 kg / m². 2 .
[0126] An artificial soil made from coal gangue, comprising 100 parts by weight of the following components: 5 parts local natural soil, 10 parts zeolite, 5 parts urea, 78 parts modified coal gangue, and 2 parts moss biocrust.
[0127] An artificial soil made from coal gangue, the preparation method includes the following steps:
[0128] (1) Methods for preparing modified coal gangue include:
[0129] The coal gangue was crushed and passed through a 2mm sieve. 10% phosphogypsum was added to the sieved coal gangue, and the mixture was ball-milled for 36 hours to form modified coal gangue with soil texture.
[0130] (2) Mix the local natural soil, zeolite, urea and modified coal gangue in the above proportions, stir thoroughly under a mixer and let stand at room temperature for later use.
[0131] (3) Spread the collected moss on kraft paper and air dry it in a drying room. After air drying, use tweezers to pick out non-skinned components such as stones and plant residues, and crush them with a plant crusher to make moss biological skin.
[0132] (4) Spread the prepared sample from (2) evenly in the tray container to a thickness of 3 cm, and evenly spread moss biocrusts on the sample surface at a rate of 1 kg / m². 2 Water it twice a day.
[0133] Example 1
[0134] Appropriate amounts of the coal gangue-based artificial soil prepared in Examples 1-3 and Comparative Examples 1-3 were applied to flowerpots for planting tall fescue. Each group consisted of 50 plants, planted at room temperature, watered daily, and irradiated with plant grow lights for 10 hours per day. After 10 days, the germination rate, plant height, and biomass of the tall fescue were recorded, and the results are shown in Table 1.
[0135] Table 1 Germination rate, plant height, and biomass of tall fescue 10 days after planting.
[0136] The results showed that, in terms of germination rate, the germination rates of Examples 1-3 were significantly higher than those of Comparative Examples 1-3, with a difference of more than two times. Regarding plant height, the plant height of Examples 1-3 was significantly higher than that of Comparative Examples 1-3. In terms of biomass, the biomass of Examples 1-3 was significantly higher than that of Comparative Examples 1-3, with a biomass of 43%-141% greater. Therefore, in terms of germination rate, plant height, and biomass, the results of Examples 1-3 were significantly higher than those of Comparative Examples 1-3.
[0137] As shown in Figure 1, and through the growth status of tall fescue, it can be seen that the leaves of tall fescue are relatively green during the growth process. It can be seen that the nutrient content of the coal gangue artificial soil prepared in Examples 1 to 3 is sufficient to meet the germination and growth of tall fescue plants. It not only meets the requirements, but also significantly increases the water holding capacity and enhances the air permeability, promoting the rapid growth of tall fescue. Moreover, the preparation cost is low, making it suitable for large-scale use.
[0138] Example 2
[0139] Nutrient content detection methods: pH was determined using the potentiometric method for soil pH (HJ962-2018); organic matter was determined using the loss on ignition method for organic matter in solid waste (HJ761-2015); total nitrogen was determined using the Kjeldahl method for soil quality total nitrogen (HJ717-2014); available phosphorus was determined using the sodium bicarbonate extraction-molybdenum antimony spectrophotometric method for soil available phosphorus (HJ 704-2014); cation exchange capacity was determined using the hexaamminecobalt trichloride extraction-spectrophotometric method for soil cation exchange capacity (HJ 889-2017); and available potassium was determined using the method for forest soil potassium (LY / T 1234-2015).
[0140] The nutrient content of the coal gangue-based artificial soils in Examples 1-3 and Comparative Examples 1-3 was tested after 10 days, and the results are detailed in Table 2.
[0141] Table 2 Nutrient content of artificial soil made from coal gangue 10 days after preparation
[0142] The results showed that the compound Bacillus played a significant role in the decomposition and release of nutrients from coal gangue over time. Changes in nutrient content after 10 days in the initial nutrient contents of Examples 1-3 showed that the overall nutrient content of the coal gangue-based artificial soil increased. Compared to the control group, total nitrogen in Example 1 increased from 2301 mg / kg to 3565 mg / kg, available phosphorus in Example 2 increased from 45 mg / kg to 55.8 mg / kg, and cation exchange capacity in Example 3 increased from 6.3 to 15.1. This indicates that the coal gangue-based artificial soil prepared in Examples 1-3 effectively promoted nutrient release and met the growth requirements of plants; while Comparative Examples 1-3 were deficient in total nitrogen, available phosphorus, cation exchange capacity, and available potassium.
[0143] As shown in Figure 2, after 30 days of aboveground biomass pruning, the artificial soil still maintained a high fertility, and the regenerated tall fescue leaves were wider and more upright. Moreover, the tall fescue in Examples 1-3 was still better than that in Comparative Examples 1-3.
[0144] Example 3
[0145] Heavy metal determination method: "Determination of metallic elements in solid waste by inductively coupled plasma mass spectrometry" (HJ766-2015).
[0146] Heavy metals in the coal gangue-based artificial soils from Examples 1-3 and Comparative Examples 1-3 after 120 days of reaction were tested, and the results are detailed in Table 3.
[0147] Table 3. Heavy metal content of coal gangue after 120 days due to moss biocrust formation.
[0148] The results showed that, compared with Comparative Example 1, the content of heavy metals such as nickel and zinc in Example 1 changed less. In Comparative Examples 2 and 3, the heavy metal content of the products obtained in Examples 2 and 3 was significantly reduced. Specifically, the contents of nickel, zinc, manganese, and chromium decreased by 30-52%, 26-32%, 10-14%, and 33-39%, respectively.
[0149] Finally, it should be noted that the terms “comprising,” “including,” or any other variations thereof in this application are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.
[0150] Although this application has been disclosed above through the description of specific embodiments, it should be understood that those skilled in the art can devise various modifications, improvements, or equivalents to this application within the spirit and scope of the appended solutions. Such modifications, improvements, or equivalents should also be considered to be included within the scope of protection claimed in this application.
Claims
1. An artificial soil made from coal gangue, characterized in that, Based on 100 parts by weight, the raw materials include the following components: 1-10 parts of Bacillus compound inoculant, 5-10 parts of natural soil, 5-10 parts of aluminosilicate, 5-10 parts of urea, 57-82 parts of modified coal gangue, and 2-3 parts of moss biocrust. The preparation method of the Bacillus compound agent includes: adsorbing Bacillus megaterium, Bacillus subtilis and Bacillus mucilaginosus into biomass microspheres.
2. The artificial soil made from coal gangue as described in claim 1, characterized in that, The preparation method of the Bacillus compound inoculant meets at least one of the following conditions: The Bacillus megaterium, Bacillus subtilis and Bacillus mucilaginosus were all added in the form of bacterial solution; The *Bacillus megaterium*, *Bacillus subtilis*, and *Bacillus mucilaginosus* are further activated before adsorption.
3. The artificial soil made from coal gangue as described in claim 2, characterized in that, The preparation method of the Bacillus compound inoculant satisfies at least one of the following conditions: The viable count of the Bacillus megaterium culture was 10. 5 ~10 6 CFU / mL; The viable count of the Bacillus subtilis culture was 10. 5 ~10 6 CFU / mL; The viable count of the Bacillus mucilaginosus bacterial solution was 10. 5 ~10 6 CFU / mL; The volume ratio of the Bacillus megaterium solution, the Bacillus subtilis solution, and the Bacillus mucilaginosus solution is 1:(1-2):(1-3), for example, 1:1:1; The preparation method of the biomass microspheres includes: dissolving biomass material in dilute acid, adding sodium cellulose and activated carbon and stirring evenly, adding alkaline solution dropwise to form gel microspheres, and obtaining the biomass microspheres after stirring, solidification, washing, freezing and drying. The activation method includes: preparing a bacterial solution of one of the Bacillus megaterium, Bacillus subtilis and Bacillus mucilaginosus with brown sugar and water at a mass ratio of 1:(1-3):30, mixing it well and then performing the activation.
4. The artificial soil made from coal gangue as described in claim 3, characterized in that, The preparation method of the biomass microspheres satisfies at least one of the following conditions: The biomass material includes one or more of chitosan, wood chips, and straw; The biomass material is a biomass material powder; The dilute acid includes glacial acetic acid; The mass fraction of the dilute acid is 2%; The sodium cellulose includes sodium carboxymethyl cellulose; The alkaline solution includes NaOH solution or KOH solution; The stirring and curing time is 0.5 hours; The washing process involves using deionized water until the pH reaches neutral. The freezing time is 2 hours; The freezing process also includes immersion in anhydrous ethanol for 2 hours. The drying process is freeze-drying.
5. The artificial soil made from coal gangue as described in claim 3, characterized in that, The preparation method of the biomass microspheres satisfies at least one of the following conditions: The mass-to-volume ratio of the biomass microspheres to the mixed bacterial solution of Bacillus megaterium, Bacillus subtilis, and Bacillus mucilaginosus is 1:(5-6)g / mL. The ratio of the biomass material, the sodium cellulose, and the activated carbon is 3:(1-3):(1-3). The concentration of the alkaline solution is 1–4 M; The stirring is performed using a magnetic stirrer. The adsorption time is 2 to 4 hours; The activation is performed in a shaker.
6. The artificial soil made from coal gangue as described in claim 5, characterized in that, The method for preparing the biomass microspheres satisfies at least one of the following conditions: The mass ratio of the biomass material, the sodium cellulose, and the activated carbon is 3:1:1; The concentration of the alkaline solution is 2M; The stirring time is 0.5 to 2 hours, for example, 0.5 hours; The stirring speed is 100-300 rpm, for example 150 rpm; The activation time is 12–24 hours; The activation rotation speed is 160-180 rpm; The activation temperature is 28–30°C.
7. The artificial soil made from coal gangue as described in claim 1, characterized in that, The method for preparing the biomass microspheres satisfies at least one of the following conditions: The natural soil in question is the local natural soil. The aluminosilicate includes one of zeolite, illite, and bentonite; The method for preparing the modified coal gangue includes: crushing the coal gangue, sieving it, adding gypsum, and grinding it to obtain the modified coal gangue. The method for preparing the moss biocrust includes: collecting moss outdoors, spreading it flat on kraft paper, air-drying it, removing impurities, and then crushing it.
8. The artificial soil made from coal gangue as described in claim 7, characterized in that, The method for preparing the biomass microspheres satisfies at least one of the following conditions: The particle size after sieving is 0.15–2 mm, for example, 2 mm; The mass ratio of the gypsum to the coal gangue is 1:(5-30), for example, 1:10; The gypsum includes phosphogypsum.
9. A method for preparing artificial soil from coal gangue as described in claim 1, characterized in that, The method for preparing artificial soil from coal gangue includes: mixing Bacillus compound inoculant, natural soil, aluminosilicate, urea, and modified coal gangue evenly, and then uniformly spreading moss biocrusts after mixing.
10. The application of a coal gangue-based artificial soil in any one of the following aspects: increasing available phosphorus in coal gangue artificial soil, increasing available potassium in coal gangue soil, increasing cation exchange capacity in coal gangue soil, and adsorbing and enriching heavy metals in coal gangue.