Preparation method of straw-based red mud fermentation substrate soil and application thereof

Abstract

The present application provides a kind of straw-based red mud fermentation substrate soil, belong to industrial solid waste resource utilization and ecological restoration technical field.The substrate soil includes the following weight parts of raw materials: straw 3~5 parts, red mud 1~2 parts, livestock and poultry breeding wastewater 0.8~1.2 parts, yeast liquid concentration production nitrogen-containing wastewater 0.4~2.6 parts, protein powder production process nitrogen-containing wastewater 0.4~2.6 parts, SiC 0.1~0.6 parts, compound enzyme 0.04~0.06 parts, compound bacteria 0.04~0.06 parts, organic peat soil 2.4~2.6 parts and water 450~550 parts;The substrate soil of the present application meets the standard of GB / T 33891-2017 green land / forest land substrate, can be used for greening forest land planting, mine restoration and the like.

Description

Technical Field

[0001] This invention belongs to the field of industrial solid waste resource utilization and ecological restoration technology, and particularly relates to a method for preparing straw-based red mud fermentation substrate soil and its application. Background Technology

[0002] Red mud is a highly alkaline, bulk industrial solid waste generated during the alumina refining process from bauxite. Major red mud producing areas include Shandong, Shanxi, Henan, Guangxi Zhuang Autonomous Region, and Guizhou Province. Currently, the mainstream disposal methods for red mud fall into four categories: stockpiling, valuable metal recovery, building material utilization, and environmental remediation / ecological restoration. Stockpiling presents challenges such as large land occupation, high costs, and significant environmental risks. Valuable metal recovery and building material utilization generally face high energy consumption and costs, and their economic viability is sensitive to market fluctuations. They also have high requirements for red mud composition (e.g., high iron content, low alkali content) and struggle to simultaneously address the complex needs of dealkalization, fertilization, and heavy metal stabilization. In environmental remediation / ecological restoration, the preparation of mine remediation matrix soil from industrial solid waste is an emerging direction, but existing research largely focuses on the simple modification of single solid wastes (such as fly ash and tailings). For complex solid wastes like red mud, which are highly alkaline and have high heavy metal background values, current technologies have not yet offered solutions.

[0003] Guangxi Zhuang Autonomous Region is a major sugarcane producing province, and after the sugarcane harvest, a large amount of sugarcane stalks are generated and need to be disposed of as organic waste. Currently, apart from a small amount of stalks generated by mechanized harvesting that can be utilized for resource recovery, the vast majority of sugarcane stalks are still burned, resulting in a huge waste of biomass resources and serious air pollution.

[0004] Therefore, simultaneously realizing the resource utilization of red mud and straw is an urgent technical problem to be solved. Summary of the Invention

[0005] Therefore, the purpose of this invention is to provide a straw-based red mud fermentation substrate soil, which conforms to the GB / T 33891-2017 standard for substrates used in green spaces / forests and can be used for mine restoration.

[0006] To achieve the above-mentioned objectives, the present invention provides the following technical solution: This invention provides a straw-based red mud fermentation substrate, comprising the following raw materials in parts by weight: 3-5 parts straw, 1-2 parts red mud, 0.8-1.2 parts livestock and poultry breeding wastewater, 0.4-2.6 parts nitrogen-containing wastewater from yeast liquid concentration production, 0.4-2.6 parts nitrogen-containing wastewater from protein powder production, 0.1-0.6 parts SiC, 0.04-0.06 parts compound enzyme, 0.04-0.06 parts compound bacteria, 2.4-2.6 parts organic peat soil, and 450-550 parts water; The complex enzyme comprises the following raw materials in parts by weight: 15-35 parts cellulase, 20-25 parts hemicellulase, 5-20 parts ligninase, 10-20 parts protease and 10-20 parts lipase. The compound microbial strain comprises the following raw materials in parts by weight: 25-35 parts Trichoderma, 35-45 parts Bacillus subtilis, 5-15 parts Syzygium spp., 5-15 parts Lactic acid bacteria, and 5-15 parts Yeast.

[0007] Preferably, the straw includes sugarcane straw.

[0008] Preferably, the red mud has a pH value of 9.5 to 13.0 and its composition includes: 20% to 60% Fe2O3, 10% to 20% Al2O3, 5% to 20% SiO2, 1% to 20% CaO, 2% to 10% TiO2 and 2% to 10% Na2O.

[0009] Preferably, the total nitrogen of the livestock and poultry breeding wastewater is ≥1000 mg / L, CODcr is ≥10000 mg / L, and pH value is 6~9; The total nitrogen content of the concentrated yeast liquid produced from nitrogen-containing wastewater is ≥3000 mg / L, ammonia nitrogen is ≥2000 mg / L, CODcr is ≥12000 mg / L, and pH value is 6~9. The total nitrogen content of the nitrogen-containing wastewater from the protein powder production process is ≥3000 mg / L, CODcr is ≥15000 mg / L, and pH value is 4~10.

[0010] Preferably, the carbon-nitrogen ratio of the matrix soil is 20:1 to 30:1.

[0011] This invention provides a method for preparing the above-mentioned matrix soil, comprising the following steps: The straw, red mud, SiC, compound enzyme, compound bacteria and organic peat soil are mixed evenly, and the livestock and poultry breeding wastewater, nitrogen-containing wastewater from yeast liquid concentration production, nitrogen-containing wastewater from protein powder production process and water are added to obtain fermentation mixture; Ferment the mixture at 40-70℃ and 45-60% humidity, cover and ferment for 28-32 days, then cover and let it stand for aging for 20-50 days.

[0012] Preferably, during the covered fermentation, the first turning of the pile is carried out on the 6th to 8th day of fermentation. If the core temperature of the pile is higher than 60°C, water is added during the turning process to maintain a moisture content of 45% to 65%. If the core temperature of the pile is lower than 60°C, the first nutrient solution is added to maintain a moisture content of 45% to 65%. On days 14-16 of fermentation, the pile is turned a second time. If the core temperature is above 60℃, water is added during the turning process to maintain a moisture content of 45%-65%. If the core temperature is below 60℃, the first nutrient solution is added to maintain a moisture content of 45%-65%. The third turning of the pile should be carried out on the 28th to 30th day of fermentation. During the turning process, water should be added to maintain the moisture content of 45% to 65%.

[0013] Preferably, the method for preparing the first nutrient solution includes: mixing the mixture with water at a volume ratio of 1:9 to 11; The preparation method of the second nutrient solution includes: mixing the mixture with water at a volume ratio of 1:19~21; The mixture is a mixture of livestock and poultry breeding wastewater, nitrogen-containing wastewater from yeast liquid concentration production, and nitrogen-containing wastewater from protein powder production in equal volume ratios.

[0014] This invention provides the application of the above-mentioned matrix soil or the matrix soil prepared by the above-mentioned method in mine restoration.

[0015] Preferably, the substrate soil is used as mine cover soil or slope revegetation substrate.

[0016] Compared with the prior art, the present invention has the following beneficial effects: This invention provides a straw-based red mud fermentation substrate soil, which comprises the following raw materials in parts by weight: 3-5 parts straw, 1-2 parts red mud, 0.8-1.2 parts livestock and poultry breeding wastewater, 0.4-2.6 parts nitrogen-containing wastewater from yeast liquid concentration production, 0.4-2.6 parts nitrogen-containing wastewater from protein powder production, 0.1-0.6 parts SiC, 0.04-0.06 parts compound enzyme, 0.04-0.06 parts compound bacteria, 2.4-2.6 parts organic peat soil, and 450-550 parts water. The substrate soil of this invention conforms to the GB / T 33891-2017 standard for substrates used in green spaces / forests and can be used for mine restoration. Detailed Implementation

[0017] This invention provides a straw-based red mud fermentation substrate, comprising the following raw materials in parts by weight: 3-5 parts straw, 1-2 parts red mud, 0.8-1.2 parts livestock and poultry breeding wastewater, 0.4-2.6 parts nitrogen-containing wastewater from yeast liquid concentration production, 0.4-2.6 parts nitrogen-containing wastewater from protein powder production, 0.1-0.6 parts SiC, 0.04-0.06 parts compound enzyme, 0.04-0.06 parts compound bacteria, 2.4-2.6 parts organic peat soil, and 450-550 parts water; The complex enzyme comprises the following raw materials in parts by weight: 15-35 parts cellulase, 20-25 parts hemicellulase, 5-20 parts ligninase, 10-20 parts protease and 10-20 parts lipase. The compound microbial strain comprises the following raw materials in parts by weight: 25-35 parts Trichoderma, 35-45 parts Bacillus subtilis, 5-15 parts Syzygium spp., 5-15 parts Lactic acid bacteria, and 5-15 parts Yeast.

[0018] In this invention, the substrate soil comprises the following raw materials in parts by weight: 3-5 parts straw, 1-2 parts red mud, 0.8-1.2 parts livestock and poultry breeding wastewater, 0.4-2.6 parts nitrogen-containing wastewater from yeast liquid concentration production, 0.4-2.6 parts nitrogen-containing wastewater from protein powder production, 0.1-0.6 parts SiC, 0.04-0.06 parts compound enzyme, 0.04-0.06 parts compound bacteria, 2.4-2.6 parts organic peat soil, and 450-550 parts water. Preferably, the composition is 3.5-4.5 parts straw, 1.3-1.7 parts red mud, 0.9-1.1 parts livestock and poultry breeding wastewater, 0.6-2.4 parts nitrogen-containing wastewater from yeast liquid concentration production, 0.6-2.4 parts nitrogen-containing wastewater from protein powder production, and SiC. The substrate soil comprises the following raw materials in parts by weight: 0.2-0.4 parts straw, 0.05-0.06 parts red mud, 0.05-0.06 parts compound bacteria, 2.5-2.6 parts organic peat soil, and 470-530 parts water; In one embodiment of the present invention, the substrate soil comprises the following raw materials in parts by weight: 4 parts straw, 1 part red mud, 0.1 parts SiC, 0.05 parts compound enzyme, 0.05 parts compound bacteria, 2.5 parts organic peat soil, 1 part livestock and poultry breeding wastewater, 0.5 parts nitrogen-containing wastewater from yeast liquid concentration production, 0.5 parts nitrogen-containing wastewater from protein powder production process, and 500 parts water; In another embodiment of the present invention, the substrate soil comprises the following raw materials in parts by weight: 4 parts straw, 1 part red mud, 0.05-0.06 parts compound bacteria, 2.5-2.6 parts organic peat soil, and 470-530 parts water. 0.6 parts, compound enzyme 0.05 parts, compound bacteria 0.05 parts, organic peat soil 2.5 parts, livestock and poultry breeding wastewater 1 part, nitrogen-containing wastewater from yeast liquid concentration production 2.5 parts, nitrogen-containing wastewater from protein powder production process 2.5 parts, and 500 parts water.The compound enzyme comprises the following raw materials in parts by weight: 15-35 parts cellulase, 20-25 parts hemicellulase, 5-20 parts ligninase, 10-20 parts protease, and 10-20 parts lipase; the compound bacteria comprises the following raw materials in parts by weight: 25-35 parts Trichoderma, 35-45 parts Bacillus subtilis, 5-15 parts Syzygium aromaticum, 5-15 parts lactic acid bacteria, and 5-15 parts yeast, preferably 27-32 parts Trichoderma, 37-42 parts Bacillus subtilis, 7-12 parts Syzygium aromaticum, 7-12 parts lactic acid bacteria, and 7-12 parts yeast, more preferably 30 parts Trichoderma, 40 parts Bacillus subtilis, 10 parts Syzygium aromaticum, 10 parts lactic acid bacteria, and 10 parts yeast; the straw includes sugarcane straw; the red mud has a pH of 9.5-13.0 and its composition includes: 20%-60% Fe2O3, 10%-20%... The substrate consists of Al2O3, 5%~20% SiO2, 1%~20% CaO, 2%~10% TiO2, and 2%~10% Na2O; the total nitrogen content of the livestock and poultry breeding wastewater is ≥1000 mg / L, CODcr is ≥10000 mg / L, and pH is 6~9; the total nitrogen content of the nitrogen-containing wastewater from the yeast liquid concentration production process is ≥3000 mg / L, ammonia nitrogen is ≥2000 mg / L, CODcr is ≥12000 mg / L, and pH is 6~9; the total nitrogen content of the nitrogen-containing wastewater from the protein powder production process is ≥3000 mg / L, CODcr is ≥15000 mg / L, and pH is 4~10; the carbon-nitrogen ratio of the substrate soil is 20:1~30:1, such as 20:1, 21:1, 22:1, 23:1, 24:1, 25:1, 26:1, 27:1, 28:1, 29:1, or 30:1.

[0019] This invention provides a method for preparing the above-mentioned matrix soil, comprising the following steps: The straw, red mud, SiC, compound enzyme, compound bacteria and organic peat soil are mixed evenly, and the livestock and poultry breeding wastewater, nitrogen-containing wastewater from yeast liquid concentration production, nitrogen-containing wastewater from protein powder production process and water are added to obtain fermentation mixture; Ferment the mixture at 40-70℃ and 45-60% humidity, cover and ferment for 28-32 days, then cover and let it stand for aging for 20-50 days.

[0020] In this invention, during the covered fermentation process, the first turning of the pile is performed on days 6-8. If the core temperature is above 60°C, water is added during the turning process to maintain a moisture content of 45%-65%. If the core temperature is below 60°C, the first nutrient solution is added to maintain a moisture content of 45%-65%. A second turning is performed on days 14-16. If the core temperature is above 60°C, water is added during the turning process to maintain a moisture content of 45%-65%. If the core temperature is below 60°C, the first nutrient solution is added to maintain a moisture content of 45%-65%. The moisture content is maintained at 45%~65%; a third turning is performed on the 28th~30th day of fermentation, during which water is added to maintain the moisture content at 45%~65%; the preparation method of the first nutrient solution includes: mixing the mixed liquid with water at a volume ratio of 1:9~11; the volume ratio of the mixed liquid to water is 1:9~11, such as 1:9, 1:10, 1:11; the mixed liquid is a mixture of the livestock and poultry breeding wastewater, the nitrogen-containing wastewater from the concentrated yeast liquid production process, and the nitrogen-containing wastewater from the protein powder production process in equal volume ratios. The preparation method of the second nutrient solution includes: mixing the mixed liquid with water at a volume ratio of 1:19~21; the volume ratio of the mixed liquid to water is 1:19~21, such as 1:19, 1:20, 1:21; the mixed liquid is a mixture of the livestock and poultry breeding wastewater, the nitrogen-containing wastewater from the concentrated yeast liquid production process, and the nitrogen-containing wastewater from the protein powder production process in equal volume ratios.

[0021] This invention provides the application of the above-mentioned matrix soil or the matrix soil prepared by the above-mentioned method in mine restoration.

[0022] In this invention, the substrate soil is used as mine cover soil or slope revegetation substrate.

[0023] In this invention, experiments show that the substrate soil obtained in Example 1 of this application has an organic matter content of 25.2%, total nutrients of 2.0%, pH value of 7.10, total arsenic of 30.4 mg / kg, total cadmium of 5.0 mg / kg, and a seed germination index of 95.5%, all of which fully comply with the GB / T 33891-2017 standard for substrates used in green spaces / forests; the substrate soil obtained in Example 2 of this application has an organic matter content of 28.1%, total nutrients of 2.5%, pH value of 7.52, total arsenic of 35.0 mg / kg, total cadmium of 4.8 mg / kg, and a seed germination index of 85.2%, all of which fully comply with the GB / T 33891-2017 standard for substrates used in green spaces / forests.

[0024] In this invention, unless otherwise specified, all raw material components are commercially available products well known to those skilled in the art.

[0025] The technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0026] In the following examples, cellulase (Shandong Longket Enzyme Preparation Co., Ltd., catalog number 2403250132), hemicellulase (Shandong Longket Enzyme Preparation Co., Ltd., catalog number 250102), ligninase (Shandong Longket Enzyme Preparation Co., Ltd., catalog number 240215), protease (Shandong Longket Enzyme Preparation Co., Ltd., catalog number 231201), lipase (Shandong Longket Enzyme Preparation Co., Ltd., catalog number 240902), Trichoderma (Hengfeng Biotechnology Co., Ltd., catalog number 230125), Bacillus subtilis (Hunan Qinong Biotechnology Co., Ltd., catalog number 2022031618), white mold (Shandong Tainuo Pharmaceutical Co., Ltd., catalog number 20241004), lactic acid bacteria (Shaanxi Huashi Biotechnology Co., Ltd., catalog number 20240325), and yeast (Nanjing Zhenghe Biotechnology Co., Ltd., catalog number 20221125) were used. The pH value of red mud is 9.5~13.0, and its composition includes: 20%~60% Fe2O3, 10%~20% Al2O3, 5%~20% SiO2, 1%~20% CaO, 2%~10% TiO2 and 2%~10% Na2O; Organic peat soil: Woody peat (Nanning Shunfeng Organic Fertilizer Raw Material Factory, organic matter content 40%~60%) is dried by low-temperature hot air at 60℃ and then mixed with perlite. The mass ratio of woody peat to perlite is 5%~10%. Livestock and poultry breeding wastewater (wastewater collected after removing pig manure from pig farms after water-washing and dry-wet separation, and then naturally fermented in an anaerobic tank for 30 days): total nitrogen ≥1000 mg / L, CODcr ≥10000 mg / L, pH value 6~9; The process involves the production of nitrogen-containing wastewater from concentrated yeast broth (centrifugation of yeast fermentation broth yields a precipitate and a supernatant, the precipitate being yeast milk (concentrated yeast phase), and the supernatant being the first mother liquor; the yeast milk is washed with water, centrifuged, and the supernatant is the second mother liquor; the first and second mother liquors are mixed, evaporated, and condensed to form concentrated nitrogen-containing wastewater from concentrated yeast broth): total nitrogen content ≥3000 mg / L, ammonia nitrogen ≥2000 mg / L, CODcr ≥12000 mg / L, pH value 6~9; Nitrogenous wastewater from protein powder production (wastewater from the protein washing process in soybean meal production, which is neutralized and blended to obtain nitrogenous wastewater): total nitrogen content ≥3000mg / L, CODcr ≥15000mg / L, pH value 4~10.

[0027] Example 1 A method for preparing red mud and straw substrate soil, comprising the following steps: (1) Mix 4 kg of fresh sugarcane straw, 1 kg of red mud, 0.1 kg of SiC, 0.05 kg of compound enzyme, 0.05 kg of compound bacteria, and 2.5 kg of organic peat soil evenly. Add 1 kg of livestock and poultry breeding wastewater, 0.5 kg of concentrated nitrogen-containing wastewater from yeast liquid production, and 0.5 kg of nitrogen-containing wastewater from protein powder production process. Add 500 mL of water to adjust the initial material moisture content to 45%~65% to obtain fermentation raw materials.

[0028] The compound enzyme consists of 15g cellulase, 25g hemicellulase, 25g ligninase, 10g protease, and 15g lipase.

[0029] The compound bacteria consist of: 30g Trichoderma, 40g Bacillus subtilis, 10g Syzygium spp., 10g Lactic acid bacteria, and 10g yeast.

[0030] (2) Cover the fermentation raw materials with polyethylene film and ferment them at a temperature of 40℃ and a humidity of 50%. Turn the compost pile once on the 7th day of fermentation. During the turning process, add 1000mL of water to maintain a humidity of 45%~65% and monitor the temperature at the center of the compost. If the temperature at the center of the compost is 55℃, add water to maintain a humidity of 45%~65% (if the temperature at the center of the compost is higher than or equal to 60℃, only water needs to be added and no nitrogen source needs to be added; if the temperature at the center of the compost is lower than 55℃, add 1000mL of the first nutrient solution; the first nutrient solution is a mixture of livestock and poultry breeding wastewater, nitrogen-containing wastewater from yeast liquid concentration production and nitrogen-containing wastewater from protein powder production in equal volume ratios, and the volume ratio of the mixture to water is 1:10). On the 15th day of fermentation, turn the compost pile once more, adding water during the turning process to maintain a humidity of 45%, and monitoring the center temperature of the compost at 60℃. If the temperature is 60℃ or higher, add water to maintain a humidity of 45-65% (if the center temperature of the compost is higher than or equal to 60℃, only water needs to be added, not nitrogen; if the center temperature of the compost is lower than 60℃, add 1000mL of the second nutrient solution; the second nutrient solution is prepared by mixing livestock and poultry breeding wastewater, nitrogen-containing wastewater from yeast liquid concentration production, and nitrogen-containing wastewater from protein powder production in equal volume ratios, with a volume ratio of 1:20 between the mixture and water). On the 30th day of fermentation, water was added during the turning process to maintain a humidity of 50%. The mixture was then covered with a film and left to age for 40 days without turning, resulting in red mud straw substrate soil.

[0031] Example 2 A method for preparing red mud and straw substrate soil, comprising the following steps: (1) Mix 4 kg of fresh straw, 1 kg of red mud, 0.6 kg of SiC, 0.05 kg of compound enzyme, 0.05 kg of compound bacteria, and 2.5 kg of organic peat soil. Add 1 kg of livestock and poultry breeding wastewater, 2.5 kg of nitrogen-containing wastewater from yeast liquid concentration production, and 2.5 kg of nitrogen-containing wastewater from protein powder production process. Add 500 mL of water to adjust the initial material moisture content to 45-65% to obtain fermentation raw materials.

[0032] (2) Cover the fermentation raw materials with polyethylene film and ferment at a temperature of 40℃ and a humidity of 55%. Turn the compost pile once on the 7th day of fermentation. During the turning process, add 1000mL of water to maintain a humidity of 45~65% and monitor the temperature at the center of the compost. If the temperature at the center of the compost is 55℃, add water to maintain a humidity of 45~65% (if the temperature at the center of the compost is higher than or equal to 60℃, only water needs to be added and no nitrogen source needs to be added; if the temperature at the center of the compost is lower than 55℃, add 1000mL of the first nutrient solution; the first nutrient solution is a mixture of livestock and poultry breeding wastewater, nitrogen-containing wastewater from yeast liquid concentration production and nitrogen-containing wastewater from protein powder production in equal volume ratios, and the volume ratio of the mixture to water is 1:10). On the 15th day of fermentation, turn the compost pile once more. During the turning process, add 1000mL of water to maintain a humidity of 50%, and monitor the compost center temperature. If it reaches 60℃, add water to maintain a humidity of 45-65%. (If the compost center temperature is higher than or equal to 60℃, only water needs to be added, not nitrogen source; if the compost center temperature is lower than 60℃, add 1000mL of the second nutrient solution. The second nutrient solution is prepared by mixing livestock and poultry breeding wastewater, nitrogen-containing wastewater from yeast liquid concentration production, and nitrogen-containing wastewater from protein powder production in equal volume ratios, with a water volume ratio of 1:20.) On the 30th day of fermentation, 1000mL of water was added during the turning process to maintain a humidity of 50%. The mixture was then covered with a film and left to age for 50 days without turning, resulting in red mud straw substrate soil.

[0033] Comparative Example 1 The difference between this comparative example and Example 1 is that the amount of organic peat soil in step (1) of this comparative example is 1 kg, while the other steps are the same as in Example 1.

[0034] Comparative Example 2 The difference between this comparative example and Example 1 is that in step (1) of this comparative example, the amount of organic peat soil is 1 kg and the amount of water is 5000 mL, while the other steps are the same as in Example 1.

[0035] Comparative Example 3 The difference between this comparative example and Example 1 is that in step (1) of this comparative example, the amount of organic peat soil is 1 kg and the amount of water is 50000 mL, while the other steps are the same as in Example 1.

[0036] Comparative Example 4 The difference between this comparative example and Example 1 is that in step (1) of this comparative example, there are 8 kg of fresh straw, 4 kg of red mud, and 1 kg of organic peat soil. The remaining steps are the same as in Example 1.

[0037] Comparative Example 5 The difference between this comparative example and Example 1 is that in step (1) of this comparative example, there are 8 kg of fresh straw, 8 kg of red mud, and 1 kg of organic peat soil. The remaining steps are the same as in Example 1.

[0038] Comparative Example 6 The difference between this comparative example and Example 2 is that in step (1) of this comparative example, SiC 0.1kg, compound enzyme 0.01kg, and compound bacteria 0.01kg are used, while the other steps are the same as in Example 1.

[0039] Comparative Example 7 The difference between this comparative example and Example 2 is that in step (1) of this comparative example, SiC 0.1kg, compound enzyme 0.01kg, compound bacteria 0.01kg, and organic peat soil 0.1kg are used. The remaining steps are the same as in Example 1.

[0040] Comparative Example 8 The difference between this comparative example and Example 2 is that in step (1) of this comparative example, SiC 0.1kg, compound enzyme 0.01kg, compound bacteria 0.01kg, and organic peat soil 10kg are used. The remaining steps are the same as in Example 1.

[0041] Example 2: Testing of Red Mud and Straw Matrix Soil Untreated red mud was used as a control group, and tests were conducted according to the methods in Table 1. Standards for each item are found in the national standard GB / T33891-2017 "Standards for Organic Substrates for Green Space / Forest Land Use". Test results are shown in Table 2.

[0042] Table 1 Sample Testing Items and Methods

[0043] Table 2 Detection Results

[0044] Table 2 shows that the substrate soil obtained in Example 1 of this application has an organic matter content of 25.2%, total nutrients of 2.0%, pH value of 7.10, total arsenic of 30.4 mg / kg, total cadmium of 5.0 mg / kg, and a seed germination index of 95.5%, all of which fully comply with the GB / T 33891-2017 standard for substrates used in green spaces / forests; the substrate soil obtained in Example 2 of this application has an organic matter content of 28.1%, total nutrients of 2.5%, pH value of 7.52, total arsenic of 35.0 mg / kg, total cadmium of 4.8 mg / kg, and a seed germination index of 85.2%, all of which fully comply with the GB / T33891-2017 standard for substrates used in green spaces / forests.

[0045] In summary, the substrate soil prepared by the method of this application meets the GB / T 33891-2017 standard for substrates used in green spaces / forests and can be used for planting in green spaces / forests and for mine restoration.

[0046] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A straw-based red mud fermentation substrate soil, characterized in that, The raw materials include the following parts by weight: 3-5 parts straw, 1-2 parts red mud, 0.8-1.2 parts livestock and poultry breeding wastewater, 0.4-2.6 parts nitrogen-containing wastewater from yeast liquid concentration production, 0.4-2.6 parts nitrogen-containing wastewater from protein powder production, 0.1-0.6 parts SiC, 0.04-0.06 parts compound enzyme, 0.04-0.06 parts compound bacteria, 2.4-2.6 parts organic peat soil, and 450-550 parts water; The compound enzyme comprises the following raw materials in parts by weight: 15-35 parts cellulase, 20-25 parts hemicellulase, 5-20 parts ligninase, 10-20 parts protease and 10-20 parts lipase. The compound microbial strain comprises the following raw materials in parts by weight: 25-35 parts Trichoderma, 35-45 parts Bacillus subtilis, 5-15 parts Syzygium spp., 5-15 parts Lactic acid bacteria, and 5-15 parts Yeast.

2. The substrate soil according to claim 1, characterized in that, The straw includes sugarcane straw.

3. The substrate soil according to claim 1, characterized in that, The red mud has a pH value of 9.5 to 13.0 and its composition includes: 20% to 60% Fe2O3, 10% to 20% Al2O3, 5% to 20% SiO2, 1% to 20% CaO, 2% to 10% TiO2 and 2% to 10% Na2O.

4. The substrate soil according to claim 1, characterized in that, The total nitrogen in the livestock and poultry breeding wastewater is ≥1000 mg / L, CODcr is ≥10000 mg / L, and pH value is 6~9; The total nitrogen content of the concentrated yeast liquid produced from nitrogen-containing wastewater is ≥3000 mg / L, ammonia nitrogen is ≥2000 mg / L, CODcr is ≥12000 mg / L, and pH value is 6~9; The total nitrogen content of the nitrogen-containing wastewater from the protein powder production process is ≥3000 mg / L, CODcr is ≥15000 mg / L, and pH value is 4~10.

5. A substrate soil according to any one of claims 1 to 4, characterized in that, The carbon-nitrogen ratio of the substrate soil is 20:1 to 30:

1.

6. A method for preparing the matrix soil according to any one of claims 1 to 5, characterized in that, Includes the following steps: The straw, red mud, SiC, compound enzyme, compound bacteria and organic peat soil are mixed evenly, and the livestock and poultry breeding wastewater, nitrogen-containing wastewater from yeast liquid concentration production, nitrogen-containing wastewater from protein powder production process and water are added to obtain fermentation mixture; Ferment the mixture at 40-70℃ and 45-60% humidity, cover and ferment for 28-32 days, then cover and let it stand for aging for 20-50 days.

7. The preparation method according to claim 6, characterized in that, During covered fermentation, the first turning of the pile should be carried out on the 6th to 8th day of fermentation. If the core temperature of the pile is higher than 60℃, water should be added during the turning process to maintain a moisture content of 45% to 65%. If the core temperature of the pile is lower than 60℃, the first nutrient solution should be added to maintain a moisture content of 45% to 65%. On days 14-16 of fermentation, the pile is turned a second time. If the core temperature is above 60℃, water is added during the turning process to maintain a moisture content of 45%-65%. If the core temperature is below 60℃, the first nutrient solution is added to maintain a moisture content of 45%-65%. The third turning of the pile should be carried out on the 28th to 30th day of fermentation. During the turning process, water should be added to maintain the moisture content of 45% to 65%.

8. The method according to claim 6, characterized in that, The preparation method of the first nutrient solution includes: mixing the mixture with water at a volume ratio of 1:9~11; The preparation method of the second nutrient solution includes: mixing the mixture with water at a volume ratio of 1:19~21; The mixture is a mixture of livestock and poultry breeding wastewater, nitrogen-containing wastewater from yeast liquid concentration production, and nitrogen-containing wastewater from protein powder production in equal volume ratios.

9. The application of the matrix soil according to any one of claims 1 to 5 or the matrix soil prepared by the preparation method according to any one of claims 6 to 8 in mine restoration.

10. The application according to claim 9, characterized in that, The substrate soil is used as mine cover soil or slope revegetation substrate.

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