Preparation method and application of artificial soil prepared from coal gangue

Abstract

The invention discloses a preparation method and application of artificial soil prepared from coal gangue, 100 parts by weight of raw materials comprise: 1-10 parts by weight of a bacillus complex microbial inoculant, 5-10 parts by weight of natural soil, 5-10 parts by weight of aluminosilicate, 5-10 parts by weight of urea, 57-82 parts by weight of modified coal gangue, and 2-3 parts by weight of moss biological crust. The preparation method of the bacillus complex microbial inoculant comprises the step of adsorbing bacillus megatherium, bacillus subtilis and bacillus mucilaginosus into biomass microspheres, so as to obtain the bacillus complex microbial inoculant. The artificial soil prepared from the coal gangue is used as a matrix, and is compounded with the matrix under the action of microorganisms, so that nutrients in the coal gangue are released, the structure and water holding performance of the coal gangue are effectively improved, heavy metal pollution is reduced, the plant growth environment is improved, and the prepared artificial soil has the characteristics of high nutrients, water retention, air permeability and the like; the ecological restoration problem of the coal gangue mountain is effectively solved, and the method has large popularization conditions in the ecological restoration direction of the coal gangue mountain.

Description

Technical Field

[0001] The present application belongs to the technical field of soil conditioners and solid waste resource recycling, and in particular to a preparation method and application of artificial soil made from coal gangue. Background Art

[0002] Gangue is the solid waste discharged during coal mining and washing. Compared with ordinary coal, it has the characteristics of low carbon content, low calorific value and hard texture. Its main components are Al2O3 and SiO2. 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 the main solid waste generated during coal mining and washing, gangue has always brought serious burdens to the ecological environment. It not only occupies a large amount of land resources, but also may cause land impoverishment, salinization and desertification through improper landfill. At the same time, the spontaneous combustion of gangue will also produce toxic and harmful gases, further polluting the environment.

[0003] In the process of coal mining and processing, a large amount of coal gangue will inevitably be produced.

[0004] Backfilling and reclamation is the main way to utilize coal gangue. At present, more than 90% of coal gangue is directly landfilled, but this method is not only easy to cause soil and groundwater pollution, but also cause landslides, soil erosion and other disasters. Therefore, it is particularly important to explore new processes and technologies for the bulk utilization of coal gangue. In recent years, researchers have improved the activity of coal gangue through modification technology, making it an environmentally friendly material with various high added values. These modification methods include acid or alkali treatment, mechanochemical method, surface organic modification method, calcination modification method, hydrothermal modification method and composite modification method. Through these modification technologies, the adsorption performance, reaction activity and material properties of coal gangue can be significantly improved, but there are high costs, high energy consumption and high pollution. Therefore, it is urgent to find ways to utilize coal gangue resources.

[0005] The gangue mountains formed by direct landfill of coal gangue are difficult for plants to grow due to the lack of effective nutrients and poor water and fertilizer retention performance, which causes great difficulties for the ecological restoration of the gangue mountains. The fundamental problem that needs to be solved in the ecological restoration of the coal gangue mountains is to establish the site conditions required for vegetation growth.

[0006] The invention patent "Preparation and application of a microbial agent for an artificial ecological base of coal gangue" with application number "201911364735.1" discloses a composite microbial agent for an artificial ecological matrix of coal gangue, including 5 actinomycetes: thermophilic purple Streptomyces, thermophilic amylolytic Streptomyces, thermophilic carbon monoxide Streptomyces, micro-white yellow Streptomyces and thermo common Streptomyces, 1 bacterium: Pseudomonas, and 1 mold: Penicillium oxalicum; the invention application "Preparation method and application of a coal-based artificial soil" with application number "202410334575.0" discloses a method of mixing composted organic matter with soil, zeolite and preservatives. The auxiliary materials made by watering with water and mixed with coal gangue are then mixed for alfalfa planting; the invention patent "An artificial ecological matrix based on coal gangue and its preparation method", application number "201911367252.7" discloses an artificial ecological matrix and its preparation method, by adding microbial agents, composting with plant-derived organic matter, and preparing the artificial matrix after maturation; the invention patent "A method and system for preparing artificial soil from coal gangue and agricultural and animal husbandry waste", application number "201911367252.7" discloses a method for preparing artificial soil by mixing coal gangue with agricultural and animal husbandry waste, and quicklime needs to be added to adjust the pH. The invention patent "A method for preparing artificial soil using coal gangue", application number "202311847357.5" discloses a method for preparing artificial soil by mixing coal gangue with soil, biochar, bacterial agents, etc., which requires mixing a large amount of soil. The above-mentioned invention patent still has technical defects such as complex preparation method, wide variety of bacterial agents, and the need to mix in a large amount of natural soil, and has not effectively solved the existing problems of coal gangue mountains.

[0007] Therefore, based on the above situation, an effective method is urgently needed to improve the existing problems of coal gangue mountains, increase the nutrient content of coal gangue for utilization, and reduce the negative impact of coal gangue. Summary of the invention

[0008] The technical problem to be solved by the present application is to overcome the defects of the prior art, such as huge amount of coal gangue produced, improper landfilling method of coal gangue, lack of effective nutrients in coal gangue, heavy metal pollution of the environment, lack of means for resource utilization of coal gangue, and the need for soil utilization means to adjust pH, biological fermentation, and use a high proportion of composite matrix (such as soil), resulting in high cost and long time, and to provide a preparation method and application of artificial soil made of coal gangue.

[0009] This application adopts the following technical solutions to solve the above technical problems:

[0010] The present application provides an artificial soil made of coal gangue, wherein the raw materials include the following components based on 100 parts by weight: 1 to 10 parts of Bacillus composite bacterial agent, 5 to 10 parts of natural soil, 5 to 10 parts of aluminosilicate, 5 to 10 parts of urea, 57 to 82 parts of modified coal gangue, and 2 to 3 parts of moss biological crust;

[0011] The preparation method of the Bacillus composite bacterial agent comprises the following steps: the Bacillus megaterium, the Bacillus subtilis and the Bacillus mucilaginosus are adsorbed on biomass microspheres at the same time.

[0012] The present application found in the research that biomass microspheres have the characteristics of high air permeability and surface area. Compared with direct spraying into coal gangue, biomass microspheres increase the number of microbial agent loads and survival, and improve the efficiency of microbial action. Bacillus megaterium increases the level of effective phosphorus and nitrogen by releasing urease and phosphatase, Bacillus subtilis plays a nitrogen fixation role, and Bacillus colloidalus releases fast-acting potassium through silicate bacteria, giving full play to the synergistic promotion of the three, thereby increasing the release level of nitrogen, phosphorus and potassium in the soil to an ideal level.

[0013] In some embodiments, the Bacillus megaterium, the Bacillus subtilis and the Bacillus mucilaginosus are all added in the form of bacterial liquid.

[0014] Wherein, the viable bacterial count of the Bacillus megaterium liquid is 10 5 ~10 6 CFU / mL.

[0015] Wherein, the viable bacterial count of the Bacillus subtilis liquid is 10 5 ~10 6 CFU / mL.

[0016] Wherein, the viable bacteria count of the Bacillus colloids liquid is 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 and the like.

[0018] Wherein, the Bacillus megaterium, the Bacillus subtilis and the Bacillus mucilaginosus also include an activation operation before adsorption.

[0019] Preferably, the activation method comprises: preparing one of the Bacillus megaterium, the Bacillus subtilis and the Bacillus mucilaginosus with brown sugar and water in a mass ratio of 1:(1-3):30, mixing and activating the mixture, the mass ratio being, for example, 1:1.5:30, 1:2:30, etc.

[0020] More preferably, the activation operation is conventional in the art and is performed in a shaker.

[0021] More preferably, the activation time is 12 to 24 h (e.g., 14 h, 16 h, 18 h, 20 h, 22 h, etc.), the activation speed is 160 to 180 rpm (e.g., 165 rpm, 170 rpm, 175 rpm, etc.), and the activation temperature is 28°C to 30°C (e.g., 28.5°C, 29.5°C, etc.).

[0022] The preparation method of the biomass microspheres comprises: dissolving the biomass material in dilute acid, adding sodium cellulose and activated carbon and stirring evenly, dropping alkaline solution to form gel beads, and obtaining the biomass microspheres after stirring, solidifying, washing, freezing and drying.

[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] During the research, the present applicant found that when biomass materials are selected as carriers, they can not only serve as bacterial agent carriers, but also provide exogenous organic matter. In addition, biomass materials have a larger surface area, certain water retention properties, and can provide abundant attachment sites for microorganisms, further improving the effects of potassium solubilization, phosphorus solubilization, and nitrogen fixation.

[0026] Preferably, the dilute acid comprises 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 NaOH solution or 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 beads are fixed.

[0033] Preferably, the freezing further includes immersing in anhydrous ethanol, and more preferably, the immersion time is 2 hours.

[0034] Preferably, the drying is freeze-drying.

[0035] Preferably, the mass volume ratio of the biomass microspheres to the mixed bacterial solution of the Bacillus megaterium, the Bacillus subtilis and the Bacillus mucilaginosus is 1:(5-6) g / mL, for example, the mass volume ratio is 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 1-4M, such as 2M, 3M, etc.

[0038] Preferably, the stirring operation is conventional in the art, and preferably the mixing is carried out under a magnetic stirrer. More preferably, the stirring time is 0.5 to 2 h, for example 0.8 h, 1 h, 1.2 h, 1.4 h, 1.6 h, 1.8 h, 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 liquid are conventional in the art, and the adsorption loading is carried out in a shaking table.

[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 rotation 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, such as 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 absorb the surrounding gangue matrix to form agglomerates, improve the permeability and water retention of the gangue matrix, help regulate water, fertilizer, gas, heat, etc. in the gangue matrix, and provide a good living environment for plant growth.

[0046] In some embodiments, the preparation method of the modified coal gangue includes: crushing the coal gangue, screening it, adding gypsum and then grinding it to obtain the modified coal gangue.

[0047] The particle size after sieving is 0.15-2 mm, such as 0.16 mm, 0.17 mm, 0.18 mm, 0.19 mm, etc., preferably 2 mm.

[0048] The present application obtains fine particles of coal gangue by crushing, which reduces the pores on the one hand and reduces the oxygen content inside the coal gangue on the other hand to avoid spontaneous combustion reaction.

[0049] Wherein, the mass ratio of the gypsum to the coal gangue is 1:(5-30), for example, 1:10, 1:15, 1:20, 1:25, etc.

[0050] Wherein, the gypsum includes phosphogypsum.

[0051] During the research, the present applicant found that the use of phosphogypsum can provide a phosphorus source on the one hand, and can also neutralize the pH value of coal gangue on the other hand, thereby achieving the purpose of treating waste with waste.

[0052] Wherein, the grinding includes ball milling or grinding. After grinding, modified coal gangue with soil texture is prepared.

[0053] In some embodiments, the preparation method of the moss biological crust includes: obtaining moss outdoors, spreading it flat on kraft paper, and naturally drying it in a drying room. After drying, using tweezers to pick out stones, plant residues and other non-crusting components, remove impurities, and crush it with a plant crusher.

[0054] Among them, the moss biocrust is 1-2 kg / m 2 Spread, for example 1.5g / m 2 , 1.8kg / m 2 wait.

[0055] The present application also provides a method for preparing artificial soil made from coal gangue, which comprises: mixing the Bacillus composite bacterial agent, natural soil, aluminosilicate, urea and modified coal gangue evenly according to the above proportions, and evenly spreading the moss biological crust after mixing.

[0056] The present application also provides an application of artificial soil made from coal gangue in any of increasing the available phosphorus in coal gangue soil, increasing the available potassium in coal gangue soil, increasing the cation exchange capacity in coal gangue soil, and adsorbing heavy metals in coal gangue.

[0057] This application combines the effects of microorganisms, matrix compounding, and biological crust. On the one hand, a microbial agent carrier is prepared using biomass materials, and activated microorganisms are attached to the microbial agent carrier to form a slow-release microbial agent, which is applied to coal gangue to release nitrogen, phosphorus, and potassium in the coal gangue to meet 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; at the same time, the biological crust technology is used to adsorb and enrich heavy metals in the coal gangue.

[0058] On the basis of being in accordance with the common sense in the art, the above-mentioned preferred conditions can be arbitrarily combined to obtain the preferred embodiments of the present application.

[0059] The reagents and raw materials used in this application are commercially available.

[0060] The positive effects of this application are:

[0061] (1) The Bacillus composite bacterial agent used in the present application does not require fermentation culture. It can act on the bacterial agent carrier through simple activation with brown sugar, thereby achieving the effect of releasing nutrients from coal gangue and realizing the resource application of coal gangue. At the same time, it is adsorbed on the prepared biomass material and used as a carrier in the form of microspheres, so that it has porous adsorption channels and can load a large amount of microbial agents, so that the microbial agents can be slowly released in the coal gangue and play a role. Natural soil is added to provide organic matter and improve the pore structure of the coal gangue matrix. By adding minerals such as zeolite, the air permeability and water retention of the artificial soil made from coal gangue are improved. At the same time, moss biological crust is used to act on the coal gangue, and the heavy metals in the coal gangue are enriched by gene adsorption of bacterial decomposition metabolism in the moss. The biological crust is innovatively used to reduce the heavy metal content in the coal gangue and reduce the environmental risks during the resource utilization of coal gangue.

[0062] (2) The mechanically modified gangue artificial soil used in this application, by adding phosphogypsum to the crushed gangue, combined with the action of microorganisms, matrix compounding and biological crusting, not only releases nutrients in the gangue, effectively improves the structure and water holding capacity of the 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 can also increase the pH of the artificial soil matrix, making the artificial soil matrix more suitable for plant growth conditions and improving the plant growth environment. In addition, the preparation method is simple and the preparation process is easy to operate. It is suitable for application in the resource soilization of gangue heaps, improves the utilization efficiency of gangue, and can effectively realize the ecological restoration of gangue heaps. It has great promotion conditions in the direction of ecological restoration of gangue heaps. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] Figure 1The growth diagram of tall fescue after 10 days of cultivation in the artificial soil made of coal gangue prepared in the embodiment and the comparative example;

[0064] Figure 2 The graphs show the growth of tall fescue after 20 and 30 days of cultivation in the artificial soil made of coal gangue prepared in the examples and comparative examples. DETAILED DESCRIPTION

[0065] The present application is further described below by way of examples, but the present application is not limited to the scope of the examples. The experimental methods in the following examples without specifying specific conditions are selected according to conventional methods and conditions, or according to the product instructions.

[0066] Unless otherwise specified, the experimental methods used in the following examples are conventional methods.

[0067] The Bacillus megaterium in the following examples and comparative examples was purchased from Guangxi Nongbao Bioengineering Co., Ltd.

[0068] The Bacillus subtilis in the following examples and comparative examples was purchased from Guangxi Nongbao Bioengineering Co., Ltd.

[0069] The Bacillus subtilis in the following examples and comparative examples was purchased from Guangxi Nongbao Bioengineering Co., Ltd.

[0070] Other raw materials in the following examples and comparative examples are all commercially available.

[0071] Example 1

[0072] An artificial soil made of coal gangue comprises the following components based on 100 parts by mass: 1 part of a Bacillus composite bacterial agent, 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 biological crust.

[0073] An artificial soil made of coal gangue, the preparation method comprising the following steps:

[0074] (1) The preparation method of the Bacillus composite bacterial agent comprises:

[0075] 1) Activation: Bacillus megaterium, Bacillus subtilis, and Bacillus mucilaginosus were activated with brown sugar respectively, and the mixture was mixed in a conical flask and placed in a shaker for activation for 20 hours. The shaker speed was controlled at 170 rpm and the temperature was set at 29°C. After the activation was completed, the number of viable bacteria of Bacillus megaterium was 10 6 CFU / mL, the viable count of Bacillus subtilis was 10 6 CFU / mL, the viable count of the Bacillus colloids liquid was 10 6 CFU / mL, reserve;

[0076] 2) Preparation of chitosan gel microspheres: 3 g of chitosan powder was dissolved in 2% glacial acetic acid solution, and magnetic stirring was applied until completely dissolved. 1 g of sodium carboxymethyl cellulose was added, and after dissolution, 1 g of activated carbon was added, and the mixture was evenly added dropwise to a 2M NaOH solution using a rubber-tipped dropper to form chitosan gel microspheres. The mixture was stirred continuously for 0.5 hours. After the chitosan gel microspheres were completely solidified, they were repeatedly washed with deionized water and filtered until the pH of the liquid was neutral. The deionized water was discarded, and the chitosan gel microspheres were spread flat on a culture dish and frozen in a refrigerator for 2 hours to fix the shape of the microspheres. The microspheres were then immersed in anhydrous ethanol for 2 hours, and the liquid was discarded. The chitosan gel microspheres were obtained after freeze-drying and stored for later use.

[0077] 3) Weigh 2 mL of Bacillus megaterium liquid, 2 mL of Bacillus subtilis liquid, and 2 mL of Bacillus mucilaginosus liquid, add 1 g of chitosan gel microspheres, control the shaker speed at 170 rpm, set the temperature to 28°C, and place in the shaker for adsorption for 3 hours to complete the preparation.

[0078] (2) The preparation method of modified coal gangue includes:

[0079] The gangue is crushed and passed through a 2 mm sieve. 10% phosphogypsum is added to the sieved gangue and ground for 36 hours to form modified gangue with soil texture.

[0080] (3) After mixing the Bacillus composite bacterial agent, local natural soil, zeolite, urea and modified coal gangue according to the above proportions, stir them thoroughly under a stirrer and place them at room temperature for later use.

[0081] (4) Spread the collected moss flat on kraft paper and air-dry it in a drying room. After air-drying, use tweezers to pick out stones, plant residues and other non-crusting components, and crush them with a plant crusher to make a moss biological crust.

[0082] (5) Spread the sample prepared in (3) onto a tray container with a thickness of 3 cm, and evenly spread the moss biocrust on the surface of the sample at a rate of 1 kg / m 2 , water twice a day.

[0083] Example 2

[0084] An artificial soil made of coal gangue comprises the following components based on 100 parts by mass: 5 parts of Bacillus composite bacterial agent, 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 biological crust.

[0085] An artificial soil made of coal gangue, the preparation method comprising the following steps:

[0086] (1) The preparation method of the Bacillus composite bacterial agent comprises:

[0087] 1) Activation: Bacillus megaterium, Bacillus subtilis, and Bacillus mucilaginosus were activated with brown sugar respectively, and the mixture was mixed in a conical flask and placed in a shaker for activation for 20 hours. The shaker speed was controlled at 170 rpm and the temperature was set at 29°C. After the activation was completed, the number of viable bacteria of Bacillus megaterium was 10 6 CFU / mL, the viable count of Bacillus subtilis was 10 6 CFU / mL, the viable count of the Bacillus colloids liquid was 10 6 CFU / mL, reserve;

[0088] 2) Preparation of chitosan gel microspheres: 3 g of chitosan powder was dissolved in 2% glacial acetic acid solution, and magnetic stirring was applied until completely dissolved. 1 g of sodium carboxymethyl cellulose was added, and after dissolution, 1 g of activated carbon was added, and the mixture was evenly added dropwise to a 2M NaOH solution using a rubber-tipped dropper to form chitosan gel microspheres. The mixture was stirred continuously for 0.5 hours. After the chitosan gel microspheres were completely solidified, they were repeatedly washed with deionized water and filtered until the pH of the liquid was neutral. The deionized water was discarded, and the chitosan gel microspheres were spread flat on a culture dish and frozen in a refrigerator for 2 hours to fix the shape of the microspheres. The microspheres were then immersed in anhydrous ethanol for 2 hours, and the liquid was discarded. The chitosan gel microspheres were obtained after freeze-drying and stored for later use.

[0089] 3) Weigh 2 mL of Bacillus megaterium liquid, 2 mL of Bacillus subtilis liquid, and 2 mL of Bacillus mucilaginosus liquid, add 1 g of chitosan gel microspheres, control the shaker speed at 170 rpm, set the temperature to 28°C, and place in the shaker for adsorption for 3 hours to complete the preparation.

[0090] (2) The preparation method of modified coal gangue includes:

[0091] The coal gangue is crushed and passed through a 2 mm sieve. 10% phosphogypsum is added to the sieved coal gangue and ball-milled for 36 hours to form modified coal gangue with soil texture.

[0092] (3) After mixing the Bacillus composite bacterial agent, local natural soil, zeolite, urea and modified coal gangue according to the above proportions, stir them thoroughly under a stirrer and place them at room temperature for later use.

[0093] (4) Spread the collected moss flat on kraft paper and air-dry it in a drying room. After air-drying, use tweezers to pick out stones, plant residues and other non-crusting components, and crush them with a plant crusher to make a moss biological crust.

[0094] (5) Spread the sample prepared in (3) onto a tray container with a thickness of 3 cm, and evenly spread the moss biocrust on the surface of the sample at a rate of 1.5 kg / m 2 , water twice a day.

[0095] Example 3

[0096] An artificial soil made of coal gangue comprises the following components based on 100 parts by mass: 10 parts of Bacillus composite bacterial agent, 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 biological crust.

[0097] An artificial soil made of coal gangue, the preparation method comprising the following steps:

[0098] (1) The preparation method of the Bacillus composite bacterial agent comprises:

[0099] 1) Activation: Bacillus megaterium, Bacillus subtilis, and Bacillus mucilaginosus were activated with brown sugar respectively, and the mixture was mixed in a conical flask and placed in a shaker for activation for 20 hours. The shaker speed was controlled at 170 rpm and the temperature was set at 29°C. After the activation was completed, the number of viable bacteria of Bacillus megaterium was 10 6 CFU / mL, the viable count of Bacillus subtilis was 10 6 CFU / mL, the viable count of the Bacillus colloids liquid was 10 6 CFU / mL, reserve;

[0100] 2) Preparation of chitosan gel microspheres: 3 g of chitosan powder was dissolved in 2% glacial acetic acid solution, and magnetic stirring was applied until completely dissolved. 1 g of sodium carboxymethyl cellulose was added, and after dissolution, 1 g of activated carbon was added, and the mixture was evenly added dropwise to a 2M NaOH solution using a rubber-tipped dropper to form chitosan gel microspheres. The mixture was stirred continuously for 0.5 hours. After the chitosan gel microspheres were completely solidified, they were repeatedly washed with deionized water and filtered until the pH of the liquid was neutral. The deionized water was discarded, and the chitosan gel microspheres were spread flat on a culture dish and frozen in a refrigerator for 2 hours to fix the shape of the microspheres. The microspheres were then immersed in anhydrous ethanol for 2 hours, and the liquid was discarded. The chitosan gel microspheres were obtained after freeze-drying and stored for later use.

[0101] 3) Weigh 2 mL of Bacillus megaterium liquid, 2 mL of Bacillus subtilis liquid, and 2 mL of Bacillus mucilaginosus liquid, add 1 g of chitosan gel microspheres, control the shaker speed at 170 rpm, set the temperature to 28°C, and place in the shaker for adsorption for 3 hours to complete the preparation.

[0102] (2) The preparation method of modified coal gangue includes:

[0103] The coal gangue is crushed and passed through a 2 mm sieve. 10% phosphogypsum is added to the sieved coal gangue and ball-milled for 36 hours to form modified coal gangue with soil texture.

[0104] (3) After mixing the Bacillus composite bacterial agent, local natural soil, zeolite, urea and modified coal gangue according to the above proportions, stir them thoroughly under a stirrer and place them at room temperature for later use.

[0105] (4) Spread the collected moss flat on kraft paper and air-dry it in a drying room. After air-drying, use tweezers to pick out stones, plant residues and other non-crusting components, and crush them with a plant crusher to make a moss biological crust.

[0106] (5) Spread the sample prepared in (3) onto a tray container with a thickness of 3 cm, and evenly spread the moss biocrust on the surface of the sample at a rate of 2 kg / m 2 , water twice a day.

[0107] Comparative Example 1

[0108] Compared with Example 1, the difference is that the artificial soil made of coal gangue does not contain the Bacillus composite bacterial agent.

[0109] An artificial soil made of coal gangue comprises the following components based on 100 parts by mass: 5 parts of local natural soil, 5 parts of zeolite, 5 parts of urea, 83 parts of modified coal gangue, and 2 parts of moss biological crust.

[0110] An artificial soil made of coal gangue, the preparation method comprising the following steps:

[0111] (1) The preparation method of modified coal gangue includes:

[0112] The coal gangue is crushed and passed through a 2 mm sieve. 10% phosphogypsum is added to the sieved coal gangue and ball-milled for 36 hours to form modified coal gangue with soil texture.

[0113] (2) Mix local natural soil, zeolite, urea and modified coal gangue according to the above proportions, stir them thoroughly under a stirrer, and place them at room temperature for later use.

[0114] (3) Spread the collected moss on kraft paper and air dry it in a drying room. After air drying, use tweezers to pick out stones, plant residues and other non-crusting components, and crush them with a plant crusher to make moss biocrust.

[0115] (4) Spread the sample prepared in (2) onto a tray container with a thickness of 3 cm, and evenly spread the moss biocrust on the surface of the sample at a rate of 1 kg / m 2 , water twice a day.

[0116] Comparative Example 2

[0117] Compared with Example 2, the difference is that the Bacillus composite agent is not added to the artificial soil made from coal gangue, and the amount of moss biological crust seed source spread from coal gangue to the surface of artificial soil is reduced to 1 kg / m 2 .

[0118] An artificial soil made of coal gangue comprises the following components based on 100 parts by mass: 10 parts of local natural soil, 5 parts of zeolite, 5 parts of urea, 78 parts of modified coal gangue and 2 parts of moss biological crust.

[0119] An artificial soil made of coal gangue, the preparation method comprising the following steps:

[0120] (1) The preparation method of modified coal gangue includes:

[0121] The coal gangue is crushed and passed through a 2 mm sieve. 10% phosphogypsum is added to the sieved coal gangue and ball-milled for 36 hours to form modified coal gangue with soil texture.

[0122] (2) Mix local natural soil, zeolite, urea and modified coal gangue according to the above proportions, stir them thoroughly under a stirrer, and place them at room temperature for later use.

[0123] (3) Spread the collected moss flat on kraft paper and air-dry it in a drying room. After air-drying, use tweezers to pick out stones, plant residues and other non-crusting components, and crush them with a plant crusher to make a moss biological crust.

[0124] (4) Spread the sample prepared in (2) onto a tray container with a thickness of 3 cm, and evenly spread the moss biocrust on the surface of the sample at a rate of 1 kg / m 2 , water twice a day.

[0125] Comparative Example 3

[0126] Compared with Example 3, the difference is that the Bacillus composite agent is not added to the artificial soil made from coal gangue, and the amount of moss biological crust seed source sown on the surface of coal gangue to artificial soil is reduced to 1 kg / m 2 .

[0127] An artificial soil made of coal gangue comprises the following components based on 100 parts by mass: 5 parts of local natural soil, 10 parts of zeolite, 5 parts of urea, 78 parts of modified coal gangue and 2 parts of moss biological crust.

[0128] An artificial soil made of coal gangue, the preparation method comprising the following steps:

[0129] (1) The preparation method of modified coal gangue includes:

[0130] The coal gangue is crushed and passed through a 2 mm sieve. 10% phosphogypsum is added to the sieved coal gangue and ball-milled for 36 hours to form modified coal gangue with soil texture.

[0131] (2) Mix local natural soil, zeolite, urea and modified coal gangue according to the above proportions, stir them thoroughly under a stirrer, and place them at room temperature for later use.

[0132] (3) Spread the collected moss flat on kraft paper and air-dry it in a drying room. After air-drying, use tweezers to pick out stones, plant residues and other non-crusting components, and crush them with a plant crusher to make a moss biological crust.

[0133] (4) Spread the sample prepared in (2) onto a tray container with a thickness of 3 cm, and evenly spread the moss biocrust on the surface of the sample at a rate of 1 kg / m 2 , water twice a day.

[0134] Effect Example 1

[0135] An appropriate amount of the artificial soil made of coal gangue prepared in Examples 1 to 3 and Comparative Examples 1 to 3 was applied to a flower pot for planting tall fescue. 50 plants were set in each group, planted at room temperature, watered daily, and irradiated with a plant fill light for 10 hours a day. After 10 days, the germination rate, plant height, and biomass of the tall fescue were recorded. The results are shown in Table 1.

[0136] Table 1 Germination rate, plant height and biomass of tall fescue 10 days after planting

[0137] Group Germination rate (%) Plant height (cm) Biomass (g) Example 1 70 7.5 4.85 Example 2 71 9.7 6.57 Example 3 77 15.1 8.80 Comparative Example 1 33 5.5 2.22 Comparative Example 2 40 7.2 4.57 Comparative Example 3 46 8.7 3.65

[0138] The results show that in terms of germination rate, the germination rate of Examples 1 to 3 is significantly higher than that of Comparative Examples 1 to 3, and the germination rate of Examples 1 to 3 is more than twice that of Comparative Examples 1 to 3; in terms of plant height, the plant height of Examples 1 to 3 is significantly higher than that of Comparative Examples 1 to 3; in terms of biomass, the biomass of Examples 1 to 3 is significantly higher than that of Comparative Examples 1 to 3, and the biomass of Examples 1 to 3 is 43%-141% greater than that of Comparative Examples 1 to 3. It can be seen that in terms of germination rate, plant height and biomass, the results of Examples 1 to 3 are all significantly higher than those of Comparative Examples 1 to 3.

[0139] Depend on Figure 1 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 artificial soil made of coal gangue prepared in Examples 1 to 3 is sufficient to meet the germination and growth of tall fescue plants, which not only meets the needs, but also significantly increases the water holding capacity and enhances the air permeability, promotes the rapid growth of tall fescue, and has a low preparation cost and is suitable for large-scale use.

[0140] Effect Example 2

[0141] Nutrient content detection method: pH uses the "Potentiometric Method for Determination of Soil pH" (HJ962-2018); organic matter uses the "Determination of Ignition Loss of Organic Matter in Solid Waste" (HJ761-2015); total nitrogen uses the "Kjeldahl Method for Determination of Total Nitrogen in Soil Quality" (HJ717-2014); available phosphorus uses the "Determination of Available Phosphorus in Soil by Sodium Bicarbonate Extraction-Molybdenum Antimony Antiphorus Spectrophotometry" (HJ 704-2014); cation exchange capacity uses the "Determination of Cation Exchange Capacity of Soil by Hexaamminecobalt Trichloride Extraction-Spectrophotometry" (HJ 889-2017); available potassium uses the "Determination of Potassium in Forest Soils" (LY / T 1234-2015).

[0142] The nutrient content of the artificial soil made of coal gangue in Examples 1 to 3 and Comparative Examples 1 to 3 was tested after 10 days. The results are shown in Table 2.

[0143] Table 2 Nutrient content of artificial soil made from coal gangue 10 days after preparation

[0144]

[0145] The results show that with the increase of time, the composite Bacillus plays a greater role in the decomposition and release of nutrients in coal gangue. From the changes in the initial nutrient content of Examples 1 to 3 to the nutrient content after 10 days, it can be seen that the overall nutrient content of the artificial soil made from coal gangue increased. Compared with the control group, the total nitrogen in Example 1 increased from 2301 mg / kg to 3565 mg / kg, the effective phosphorus in Example 2 increased from 45 mg / kg to 55.8 mg / kg, and the cation exchange capacity in Example 3 increased from 6.3 to 15.1. It can be seen that the artificial soil made from coal gangue prepared by Examples 1 to 3 has a good promoting effect on the release of nutrients and can meet the growth needs of plants; while Comparative Examples 1-3 are relatively lacking in total nitrogen, effective phosphorus, cation exchange capacity and available potassium nutrients.

[0146] Depend on Figure 2 It can be seen that after the aboveground biomass was cut after 30 days, the artificial soil still maintained a high fertilizer efficiency, the leaves of the regenerated tall fescue became wider and taller, and the growth of the tall fescue in Examples 1 to 3 was still better than that in Comparative Examples 1 to 3.

[0147] Effect Example 3

[0148] Heavy metal determination method: "Determination of Metal Elements in Solid Waste by Inductively Coupled Plasma Mass Spectrometry" (HJ766-2015).

[0149] The heavy metals in the artificial soil made from coal gangue after 120 days of reaction in Examples 1-3 and Comparative Examples 1-3 were detected. The results are shown in Table 3.

[0150] Table 3 Heavy metal content in coal gangue after 120 days of moss biocrusting

[0151] serial number Nickel (mg / kg) Zinc (mg / kg) Manganese (mg / kg) Chromium (mg / kg) Example 1 21.56 66.58 228.41 65.34 Example 2 19.10 61.58 227.47 60.26 Example 3 16.14 55.06 211.90 48.13 Comparative Example 1 22.81 68.41 235.95 66.06 Comparative Example 2 24.76 77.35 250.02 80.15 Comparative Example 3 24.56 72.75 242.32 67.11

[0152] The results show that compared with comparative example 1, the content of heavy metals such as nickel and zinc in Example 1 changes little, and the heavy metal content of the products obtained in comparative example 2 and example 3 and Examples 2 to 3 is significantly reduced. Among them, the content of nickel, zinc, manganese and chromium is reduced by 30 to 52%, 26 to 32%, 10 to 14% and 33 to 39% respectively.

[0153] Finally, it should be noted that in this application, the terms "comprises", "includes" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or apparatus that includes a series of elements includes not only those elements, but also other elements that are not explicitly listed, or also includes elements that are inherent to such process, method, article or apparatus.

[0154] Although the present application has been disclosed above through the description of the specific embodiments of the present application, it should be understood that those skilled in the art can design various modifications, improvements or equivalents to the present application within the spirit and scope of the attached scheme. These modifications, improvements or equivalents should also be considered to be included in the scope of protection claimed in the present application.

Claims

1. An artificial soil made of coal gangue, characterized in that: Based on 100 parts by weight, the raw materials include the following components: 1 to 10 parts of Bacillus composite bacterial agent, 5 to 10 parts of natural soil, 5 to 10 parts of aluminosilicate, 5 to 10 parts of urea, 57 to 82 parts of modified coal gangue, and 2 to 3 parts of moss biological crust; The preparation method of the Bacillus composite bacterial agent comprises: adsorbing Bacillus megaterium, Bacillus subtilis and Bacillus mucilaginosus into biomass microspheres.

2. The artificial soil made of coal gangue according to claim 1, characterized in that: The preparation method of the Bacillus composite bacterial agent meets at least one of the following conditions: The Bacillus megaterium, the Bacillus subtilis and the Bacillus mucilaginosus are all added in the form of bacterial liquid; The Bacillus megaterium, the Bacillus subtilis and the Bacillus mucilaginosus also include an activation operation before adsorption.

3. The artificial soil made of coal gangue according to claim 2, characterized in that: The preparation method of the Bacillus composite bacterial agent meets at least one of the following conditions: The viable bacterial count of the Bacillus megaterium liquid is 10 5 ~10 6 CFU / mL; The viable count of the Bacillus subtilis liquid is 10 5 ~10 6 CFU / mL; The viable count of the Bacillus subtilis liquid is 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 comprises: dissolving the biomass material in dilute acid, adding sodium cellulose and activated carbon and stirring evenly, dropping an alkali solution to form gel beads, and stirring and solidifying, washing, freezing, and drying to obtain the biomass microspheres; The activation method comprises: preparing a bacterial solution of one of the Bacillus megaterium, the Bacillus subtilis and the Bacillus mucilaginosus, brown sugar and water in a mass ratio of 1:(1-3):30, mixing and then performing the activation.

4. The artificial soil made of coal gangue according to claim 3, characterized in that: The method for preparing 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 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 0.5h; The washing is performed with deionized water until the pH is neutral; The freezing time is 2h; After freezing, the step of immersing in anhydrous ethanol is also included, and the immersion time is 2 hours; The drying is freeze drying.

5. The artificial soil made of coal gangue according to claim 3, characterized in that: The method for preparing the biomass microspheres satisfies at least one of the following conditions: The mass volume ratio of the biomass microspheres to the mixed bacterial liquid of the Bacillus megaterium, the Bacillus subtilis and the Bacillus mucilaginosus is 1: (5-6) g / mL. The usage 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 to 4 M; The stirring is carried out under a magnetic stirrer, The adsorption time is 2 to 4 hours; The activation was carried out on a shaker.

6. The artificial soil made of coal gangue according to 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 to 24 hours; The activation speed is 160-180 rpm; The activation temperature is 28-30°C.

7. The artificial soil made of coal gangue according to claim 1, characterized in that: The method for preparing the biomass microspheres satisfies at least one of the following conditions: The natural soil is the local natural soil; The aluminosilicate includes one of zeolite, illite and bentonite; The preparation method of the modified coal gangue comprises: crushing the coal gangue, screening it, adding gypsum and grinding it to obtain the modified coal gangue; The preparation method of the moss biological crust comprises: collecting moss outdoors, spreading it flat on kraft paper, air-drying it, removing impurities, and crushing it.

8. The artificial soil made of coal gangue according to 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 to 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 made of coal gangue as claimed in claim 1, characterized in that: The method for preparing artificial soil made of coal gangue comprises: mixing a bacillus composite bacterial agent, natural soil, aluminosilicate, urea and modified coal gangue evenly, and evenly spreading moss biological crust after mixing.

10. Use of artificial soil made of coal gangue in any one of increasing the available phosphorus in the artificial soil of coal gangue, increasing the available potassium in the artificial soil of coal gangue, increasing the cation exchange capacity in the artificial soil of coal gangue, and absorbing and enriching heavy metals in the artificial soil of coal gangue.

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