Improved matrix for in-situ ecological restoration of acidic mining wasteland as well as preparation method and application of improved matrix

Abstract

The invention relates to the technical field of ecological restoration, in particular to an improved matrix for in-situ ecological restoration of acidic mining wasteland and a preparation method and application of the improved matrix. The invention provides an improved matrix for in-situ ecological restoration of acidic mining wasteland. The improved matrix comprises the following components in parts by mass: 15-45 parts of fly ash, 15-45 parts of blast furnace slag, 15-45 parts of chicken manure and 15-45 parts of straw. The improved matrix disclosed by the invention can effectively improve the problems of soil acidification, soil depletion and the like; according to the method, the acid mine wasteland is subjected to ecological restoration by using the improved matrix in combination with a shrub and herbaceous plant mixed planting method, and the diversity of vegetation and microorganisms can be remarkably improved through the method; the remediation method can also effectively reduce the total amount of lead, cadmium, copper, arsenic and zinc in the soil.

Description

Technical Field

[0001] The present invention relates to the technical field of ecological restoration, and in particular to an improved matrix for in-situ ecological restoration of acid mine wasteland, and a preparation method and application thereof. Background Art

[0002] Mine ecological restoration is the key to alleviating the contradiction between mineral resource development and mine environmental protection. Vegetation reconstruction is the guarantee for the restoration and reconstruction of the mining area ecosystem, and soil habitat is the biggest limiting factor for vegetation growth in mining wasteland. Therefore, in the ecological restoration of mining wasteland, soil matrix improvement is the first problem to be solved and the core problem. At the same time, the accumulation of a large amount of solid waste not only occupies land, but also causes waste of resources. It is necessary to find a suitable way to utilize solid waste resources.

[0003] Based on this, the present invention is proposed. Summary of the invention

[0004] The purpose of the present invention is to provide an improved substrate that can effectively improve soil acidification, soil impoverishment and other problems, and also provide a restoration method that can increase vegetation and microbial diversity and reduce the total amount of lead, cadmium, copper, arsenic and zinc in the soil.

[0005] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0006] The present invention provides an improved matrix for in-situ ecological restoration of acid mine wasteland, comprising the following components in parts by weight: 15 to 45 parts of fly ash, 15 to 45 parts of blast furnace slag, 15 to 45 parts of chicken manure, and 15 to 45 parts of straw;

[0007] The present invention also provides a method for preparing the improved matrix, comprising the following steps: mixing fly ash, blast furnace slag, chicken manure and straw to prepare the improved matrix.

[0008] The present invention also provides application of the improved matrix in in-situ ecological restoration of acid mine wasteland.

[0009] The present invention also provides a method for in-situ ecological restoration of acid mine wasteland, comprising the following steps:

[0010] (1) Apply improved substrate and microbial agents to the acid mine wasteland, plow it and obtain the treated land;

[0011] (2) Planting shrubs and herbaceous plants on the treated land;

[0012] In step (1), the modified matrix is ​​the modified matrix described above.

[0013] Preferably, in step (1), the application rate of the improved substrate is 2.5 to 7.5 kg / m 2 The application rate of the microbial agent is 0.8-1.2 L / m 2 .

[0014] Preferably, in step (1), the microbial agent comprises a straw composting agent and water; the mass ratio of the straw composting agent to water is 1:90-110.

[0015] Preferably, in step (1), the tillage depth is 25 to 35 cm.

[0016] Preferably, in step (2), the shrubs include ramie and / or Amorpha fruticosa; the herbaceous plants include one or more of ryegrass, Setaria viridis, Cynodon dactylon, Medicago sativa, Solanum nigrum, Sedum sedum, Miscanthus sinensis, Tall Fescue, Bidens pilosa and Crotalaria foetida.

[0017] Preferably, in step (2), the planting amount of the shrubs is 4 to 6 trees / m 2 .

[0018] Preferably, in step (2), the planting amount of the herbaceous plants is 40 to 60 g / m 2 .

[0019] Beneficial effects of the present invention:

[0020] The invention provides an improved matrix for in-situ ecological restoration of acidic mine wastes. The invention takes full advantage of the raw materials available near the mining area as a starting point, and directly applies solid waste materials to the ecological restoration of the mining wastes. Therefore, the invention uses fly ash, blast furnace slag, chicken manure and straw as components of the soil improvement matrix to prepare the improved matrix, which can effectively improve the physical and chemical properties of the soil, so that all aspects of the soil reach the standard level of normal soil, and the soil fertility indicators such as available potassium and available phosphorus are higher than those of normal soil; the strong alkalinity of fly ash and blast furnace slag may cause soil salinization and lack of necessary nutrients for plant growth; and the use of chicken manure and straw may not be sufficient to fully alleviate the acidity of the soil, and excessive use of certain materials (such as chicken manure) may have an adverse effect on the soil microbial community and affect the ecological function of the soil. The decomposition process of straw is slow, which may lead to the inability to effectively increase soil organic matter in the short term; the present invention mixes fly ash, blast furnace slag, chicken manure and straw to solve the shortcomings of improving soil with a single solid waste material. The present invention makes full use of the four components of fly ash, blast furnace slag, chicken manure and straw to improve the soil in acidic mine wastelands. It is feasible and can effectively improve soil acidification, soil barrenness and other problems.

[0021] The present invention also uses a method of improving the acid mine wasteland by combining improved substrate with mixed planting of shrubs and herbaceous plants. After improvement by this method, a variety of plants grow well, significantly improving vegetation diversity, and also significantly improving soil microbial diversity and richness; the restoration method of the present invention can also effectively reduce the total amount of lead, cadmium, copper, arsenic and zinc in the soil. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is the growth conditions of ryegrass of groups of Examples 1 to 9, wherein H1 is group 1 of Example 1, H2 is group 2 of Example 2, H3 is group 3 of Example 3, H4 is group 4 of Example 4, H5 is group 5 of Example 5, H6 is group 6 of Example 6, H7 is group 7 of Example 7, H8 is group 8 of Example 8, and H9 is group 9 of Example 9;

[0023] Figure 2 This is the vegetation growth of unimproved soil, with the left picture showing 3 months and the right picture showing 6 months;

[0024] Figure 3 This is the growth of vegetation in the improved soil, with the left picture showing 3 months and the right picture showing 6 months;

[0025] Figure 4 It is an analysis of soil microbial community composition in soil after using different improvement methods. DETAILED DESCRIPTION

[0026] The present invention provides an improved matrix for in-situ ecological restoration of acid mine wasteland, comprising the following components in parts by weight:

[0027] 15 to 45 parts of fly ash, preferably 25 to 35 parts, more preferably 30 parts;

[0028] 15 to 45 parts of blast furnace slag, preferably 25 to 35 parts, more preferably 30 parts;

[0029] 15 to 45 parts of chicken manure, preferably 25 to 35 parts, more preferably 30 parts;

[0030] 15 to 45 parts of straw, preferably 25 to 35 parts, more preferably 30 parts.

[0031] The straw is rice straw.

[0032] The present invention also provides a method for preparing the improved matrix, comprising the following steps: mixing fly ash, blast furnace slag, chicken manure and straw to prepare the improved matrix.

[0033] In the present invention, the straw needs to be air-dried before mixing, and then crushed to a particle size of 1 to 3 mm;

[0034] The particle size is preferably 2 mm.

[0035] The present invention also provides application of the improved matrix in in-situ ecological restoration of acid mine wasteland.

[0036] The present invention also provides a method for in-situ ecological restoration of acid mine wasteland, comprising the following steps:

[0037] (1) Apply improved substrate and microbial agents to the acid mine wasteland, plow it and obtain the treated land;

[0038] (2) Planting shrubs and herbaceous plants on the treated land;

[0039] In step (1), the modified matrix is ​​the modified matrix described above.

[0040] In the present invention, in step (1), the application rate of the improved substrate is 2.5 to 7.5 kg / m 2 , preferably 4 to 6 kg / m 2 , more preferably 5kg / m 2 The application rate of the microbial agent is 0.8-1.2 L / m 2 , preferably 0.9 to 1.1 L / m 2 , more preferably 1L / m 2 .

[0041] In the present invention, in step (1), the microbial agent comprises a straw composting agent and water; the mass ratio of the straw composting agent to water is 1:90 to 110, preferably 1:95 to 105, and more preferably 1:100.

[0042] The straw composting agent was purchased from Henan Yifuyuan Biotechnology Development Co., Ltd.

[0043] In the present invention, in step (1), the tillage depth is 25 to 35 cm, preferably 28 to 32 cm, and more preferably 30 cm;

[0044] During the tillage process, oversized stones are removed to prevent uneven vegetation growth and to improve the mixing of the substrate with the soil of the acid mine wasteland.

[0045] In the present invention, in step (2), the shrubs include ramie and / or Amorpha fruticosa, preferably ramie and Amorpha fruticosa;

[0046] The shrubs are planted by seedling transplanting;

[0047] In step (2), the herbaceous plants include one or more of ryegrass, Setaria viridis, Cynodon dactylon, alfalfa, Solanum nigrum, Sedum suspensa, Miscanthus sinensis, tall fescue, Bidens pilosa, and Croton rot, preferably one or more of ryegrass, Setaria viridis, Cynodon dactylon, alfalfa, Solanum nigrum, Bidens pilosa, and Croton rot, and further preferably ryegrass, Setaria viridis, Cynodon dactylon, alfalfa, Solanum nigrum, Bidens pilosa, and Croton rot.

[0048] In the present invention, in step (2), the planting amount of the shrubs is 4 to 6 trees / m 2 ;

[0049] When ramie and Amorpha fruticosa are planted together, the planting amount of ramie is 2 trees / m 2 The planting rate of Amorpha fruticosa is 3 trees / m 2 ;

[0050] The ramie is ramie root transplantation; the ramie root block height is 8 to 12 cm, preferably 9 to 11 cm, and more preferably 10 cm;

[0051] The Amorpha fruticosa is a transplanted seedling; the plant height of the Amorpha fruticosa is 25 to 35 cm, preferably 28 to 32 cm, and more preferably 30 cm.

[0052] In the present invention, in step (2), the planting amount of the herbaceous plants is 40 to 60 g / m 2 , preferably 45 to 55 g / m 2 , more preferably 50g / m 2 ;

[0053] When the herbaceous plants are ryegrass, Setaria viridis, Bermuda grass, alfalfa, Solanum nigrum, Bidens pilosa and Croton rot, the mass ratio of ryegrass, Setaria viridis, Bermuda grass, alfalfa, Solanum nigrum, Bidens pilosa and Croton rot is 25-30:5-10:5-10:15-20:15-20:20-25:10-15, preferably 27.5:7.5:7.5:17.5:17.5:27.5:12.5.

[0054] The herbaceous plant is planted by seed broadcasting.

[0055] In the present invention, in step (2), after the shrubs and herbaceous plants are planted on the treated land, watering is required, and the watering amount is 10 to 20 L / m 2 , preferably 13 to 17 L / m 2 , more preferably 15L / m 2 .

[0056] The technical solutions provided by the present invention are described in detail below in conjunction with the embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0057] Example 1 An improved matrix for in-situ ecological restoration of acid mine wastes

[0058] 0.15 kg of fly ash, 0.15 kg of blast furnace slag, 0.15 kg of chicken manure, and 0.15 kg of rice straw (the rice straw is air-dried and then ground into a particle size of 2 mm using a large mill) are mixed to prepare an improved matrix.

[0059] Example 2 An improved matrix for in-situ ecological restoration of acid mine wastes

[0060] 0.15 kg of fly ash, 0.30 kg of blast furnace slag, 0.45 kg of chicken manure, and 0.30 kg of rice straw (the rice straw is air-dried and then ground into a particle size of 2 mm using a large mill) are mixed to prepare an improved matrix.

[0061] Example 3 An improved matrix for in-situ ecological restoration of acid mine wastes

[0062] 0.15 kg of fly ash, 0.45 kg of blast furnace slag, 0.30 kg of chicken manure, and 0.45 kg of rice straw (the rice straw is air-dried and then ground into a particle size of 2 mm using a large mill) are mixed to prepare an improved matrix.

[0063] Example 4 An improved matrix for in-situ ecological restoration of acid mine wastes

[0064] 0.30 kg of fly ash, 0.15 kg of blast furnace slag, 0.45 kg of chicken manure, and 0.45 kg of rice straw (the rice straw is air-dried and then ground into a particle size of 2 mm using a large mill) are mixed to prepare an improved matrix.

[0065] Example 5 An improved matrix for in-situ ecological restoration of acid mine wastes

[0066] 0.30 kg of fly ash, 0.30 kg of blast furnace slag, 0.30 kg of chicken manure, and 0.15 kg of rice straw (the rice straw is air-dried and then ground into a particle size of 2 mm using a large mill) are mixed to prepare an improved matrix.

[0067] Example 6 An improved matrix for in-situ ecological restoration of acid mine wastes

[0068] 0.30 kg of fly ash, 0.45 kg of blast furnace slag, 0.15 kg of chicken manure, and 0.30 kg of rice straw (the rice straw is air-dried and then ground into a particle size of 2 mm using a large mill) are mixed to prepare an improved matrix.

[0069] Example 7 An improved matrix for in-situ ecological restoration of acid mine wasteland

[0070] 0.45 kg of fly ash, 0.15 kg of blast furnace slag, 0.45 kg of chicken manure, and 0.30 kg of straw (rice straw is air-dried and then ground into a particle size of 2 mm using a large mill) are mixed to prepare an improved matrix.

[0071] Example 8 An improved matrix for in-situ ecological restoration of acid mine wastes

[0072] 0.45 kg of fly ash, 0.30 kg of blast furnace slag, 0.15 kg of chicken manure, and 0.45 kg of straw (rice straw is air-dried and then ground into a particle size of 2 mm using a large mill) are mixed to prepare an improved matrix.

[0073] Example 9: An improved matrix for in-situ ecological restoration of acid mine wastes

[0074] 0.45 kg of fly ash, 0.45 kg of blast furnace slag, 0.45 kg of chicken manure, and 0.15 kg of straw (rice straw is air-dried and then ground into a particle size of 2 mm using a large mill) are mixed to prepare an improved matrix.

[0075] Comparative Example 1: An improved matrix for in-situ ecological restoration of acidic mine wasteland

[0076] Only 0.15 kg of fly ash was used as the modified substrate.

[0077] Comparative Example 2: An improved matrix for in-situ ecological restoration of acidic mine wasteland

[0078] Only 0.30 kg of fly ash was used as the modified matrix.

[0079] Comparative Example 3: An improved matrix for in-situ ecological restoration of acid mine wasteland

[0080] Only 0.45 kg of fly ash was used as the modified substrate.

[0081] Comparative Example 4: An improved matrix for in-situ ecological restoration of acidic mine wasteland

[0082] Only 0.15 kg of blast furnace slag was used as the modified matrix.

[0083] Comparative Example 5: An improved matrix for in-situ ecological restoration of acidic mine wasteland

[0084] Only 0.30 kg of blast furnace slag was used as the modified matrix.

[0085] Comparative Example 6: An improved matrix for in-situ ecological restoration of acidic mine wasteland

[0086] Only 0.45 kg of blast furnace slag was used as the modified matrix.

[0087] Comparative Example 7: An improved matrix for in-situ ecological restoration of acidic mine wasteland

[0088] Only 0.15 kg of chicken manure was used as the amended substrate.

[0089] Comparative Example 8: An improved matrix for in-situ ecological restoration of acid mine wasteland

[0090] Only 0.30 kg of chicken manure was used as the amended substrate.

[0091] Comparative Example 9: An improved matrix for in-situ ecological restoration of acidic mine wasteland

[0092] Only 0.45 kg of chicken manure was used as the amended substrate.

[0093] Comparative Example 10: An improved matrix for in-situ ecological restoration of acidic mine wasteland

[0094] Only 0.15 kg of rice straw (the rice straw was air-dried and then ground into a particle size of 2 mm using a large mill) was used as the modified substrate.

[0095] Comparative Example 11: An improved matrix for in-situ ecological restoration of acidic mine wasteland

[0096] Only 0.30 kg of rice straw (the rice straw was air-dried and then ground into a particle size of 2 mm using a large mill) was used as the modified substrate.

[0097] Comparative Example 12: An improved matrix for in-situ ecological restoration of acidic mine wasteland

[0098] Only 0.45 kg of rice straw (the rice straw was air-dried and then ground into a particle size of 2 mm using a large mill) was used as the modified substrate.

[0099] Experimental Example 1

[0100] The selected study area is the Nanling mountainous area in northern Guangdong.

[0101] 10 kg of the soil from the study area (test soil) and the improved matrix prepared in Examples 1 to 9 and Comparative Examples 1 to 12 were mixed and placed in flower pots (bottom diameter 10 cm, inner diameter 13.7 cm, pot height 15.7 cm). The soil from the study area without the improved matrix was used as the blank control group (CK). Then 200 mL of water was added to each flower pot. After being placed in a greenhouse for 7 days to allow it to reach a naturally stable state, 0.16 g of ryegrass was sown in each pot (unit optimal sowing amount). Two identical parallel experiments were set up for each group of experiments. After ryegrass had grown for 60 days, the soil physical and chemical properties and ryegrass growth were measured to analyze the soil improvement effect. The physical and chemical properties of each group of soil were measured according to the following method as shown in Tables 1 to 2. The growth of ryegrass was measured as shown in Tables 3 and Figure 1shown.

[0102] (1) Physical properties

[0103] Determination methods of bulk density, porosity, saturated water content and field water holding capacity: refer to the "Soil Physical Properties Determination Method" compiled by Nanjing Institute of Soil Science, Chinese Academy of Sciences;

[0104] Clay content: The soil particle size is measured by dry method using a laser particle size analyzer; the content of soil clay (clay particle size is <0.002mm, powder particle size is 0.05-0.002mm, sand particle size is 2-0.05mm) is tested;

[0105] (2) Chemical properties

[0106] Soil pH value: Soil pH was measured according to the potentiometric method (HJ 962-2018);

[0107] Soil organic matter, cation exchange capacity (CEC), alkaline nitrogen, available phosphorus, and available potassium content: completed by Nanjing Cavens Testing Company, using potassium dichromate oxidation-external heating method to determine soil organic matter content; alkaline diffusion method to measure alkaline nitrogen content; sodium bicarbonate solution extraction, molybdenum antimony colorimetric method to determine available phosphorus content; ammonium acetate extraction-flame photometer, EDTA-ammonium acetate exchange method to determine available potassium content;

[0108] Table 1 Physical properties of soils in each group

[0109] Experimental Group <![CDATA[Bulk density (g / cm 3 )]]> Porosity(%) Saturated water content (%) Field water holding capacity (%) Clay percentage (%) CK 1.38±0.01 42.43±0.98 33.63±2.36 26.45±1.74 27.88±3.21 Example 1 1.31±0.07 46.13±0.21 35.32±2.08 27.87±1.26 25.37±2.86 Example 2 1.16±0.05 47.27±0.72 40.68±2.46 27.96±0.96 24.14±3.31 Example 3 1.06±0.06 48.73±1.5 45.84±2.13 28.69±1.53 24.39±3.10 Example 4 1.04±0.05 50.87±3.97 48.97±3.06 29.04±1.14 26.15±2.64 Example 5 1.13±0.02 47.8±0.79 42.16±2.67 28.36±1.17 27.21±2.71 Example 6 1.18±0.04 47.97±2.1 40.8±2.24 28.94±1.38 24.44±3.18 Example 7 1.12±0.05 51.53±1.88 46.26±2.83 28.69±1.24 23.26±3.22 Example 8 1.14±0.02 50.93±2.66 44.68±3.12 28.12±1.33 25.77±1.93 Example 9 1.23±0.04 48.5±3.21 39.35±2.51 27.31±1.21 27.69±2.86 Comparative Example 1 1.36±0.12 48.21±0.83 35.57±1.84 26.73±2.38 23.25±2.63 Comparative Example 2 1.33±0.17 49.12±1.68 35.88±1.53 27.96±2.32 23.57±2.63 Comparative Example 3 1.32±0.08 49.85±0.19 36.44±2.28 29.22±0.07 25.88±1.96 Comparative Example 4 1.39±0.22 45.42±0.33 33.06±1.31 25.02±0.68 26.97±2.28 Comparative Example 5 1.43±0.18 44.61±2.74 31.82±1.59 26.56±0.72 26.33±2.43 Comparative Example 6 1.47±0.11 43.51±1.05 30.92±1.69 24.63±2.63 27.81±1.42 Comparative Example 7 1.35±0.16 47.15±2.81 34.66±1.77 26.36±1.08 23.53±2.59 Comparative Example 8 1.32±0.13 48.42±1.81 36.06±2.69 28.19±1.85 24.93±1.44 Comparative Example 9 1.27±0.21 48.15±1.42 37.69±2.71 31.26±0.47 23.99±2.08 Comparative Example 10 1.25±0.13 49.25±0.53 37.02±3.33 31.65±2.36 20.89±1.86 Comparative Example 11 1.16±0.12 52.17±1.03 46.58±2.74 33.45±2.18 22.81±1.31 Comparative Example 12 1.08±0.15 54.46±2.41 54.29±3.86 35.62±1.11 21.43±2.32

[0110] Table 2 Chemical properties of soils in each group

[0111]

[0112]

[0113] Table 3 Growth of ryegrass in each group

[0114]

[0115]

[0116] As can be seen from Tables 1 to 2, compared with the CK group, after using the improved matrix described in Examples 1 to 9, the physical and chemical properties of the soil have been greatly improved, and all aspects have reached the standard level of normal soil, and the soil fertility indicators such as available potassium and available phosphorus are higher than normal soil; the shortcomings of improving the soil with a single solid waste material have been solved, and it is feasible to use a mixture of fly ash, blast furnace slag, chicken manure and straw to improve the soil in the abandoned mining area, which can effectively improve the problems of soil acidification and soil barrenness.

[0117] From Table 3 and Figure 1 It can be seen that the plant height, root length, biomass, germination rate and other indicators of ryegrass after using the improved substrate described in Examples 1 to 9 are higher than those of the CK group. The plant germination rate is greatly affected by fly ash and blast furnace slag, and the dosage of the two should not be too high. The dosage of chicken manure and straw is the key variable affecting the growth of ryegrass, and the root length and plant height are greatly affected by them.

[0118] Among them, the addition of fly ash has a significant improvement effect on the test soil, which can reduce soil bulk density, increase soil pores, adjust pH, increase soil fertility, and also significantly promote the growth of ryegrass;

[0119] The improvement effect of blast furnace slag on the test soil is mainly reflected in the regulation of acidic soil by its alkalinity effect. 2+ It can significantly reduce the toxicity of heavy metals in the soil and promote the germination and growth of ryegrass, but its shortcomings are also obvious. The addition of blast furnace slag has a negative impact on soil bulk density, water content, alkaline nitrogen content, cation exchange capacity, etc. The amount of blast furnace slag added to the soil should be controlled and should not exceed 3% to prevent negative impact on the soil.

[0120] The addition of chicken manure has the most obvious effect on improving soil fertility. Chicken manure and residues from farms contain a large amount of nutrients, which can significantly increase the nutrient content of the soil, especially the content of alkaline nitrogen, quick-acting potassium, and effective phosphorus. Its rich nitrogen, phosphorus, and potassium content provide the necessary nutrients for plant growth. Therefore, the ryegrass plant grown in chicken manure has the best growth, and its plant height, root length, and biomass are significantly higher than those of other improved substrates.

[0121] The improvement of straw has a significant effect on the physical properties of the soil. After adding straw with a large mass and volume to the soil, the soil bulk density is significantly reduced and the soil water holding capacity is significantly enhanced. At the same time, the soil organic matter content is increased and the soil fertility is increased. Due to the long decomposition cycle of straw, the effect of increasing the content of alkaline nitrogen, quick-acting potassium and available phosphorus is not obvious.

[0122] Example 10 A method for in-situ ecological restoration of acid mine wasteland

[0123] (1) The improved substrate and microbial agent described in Example 7 [straw composting agent (purchased from Henan Yifuyuan Biotechnology Development Co., Ltd.)] were spread on the acidic mine wasteland, wherein the application rate of the improved substrate was 5.625 kg / m 2 The application rate of microbial agents is 1L / m 2 , plow 30cm, remove oversized rocks to prevent uneven vegetation growth, and get the treated land;

[0124] (2) Ramie roots were transplanted to the treatment site, with 2 plants planted per square meter, and each root block had an average height of 10 cm. Amorpha fruticosa seedlings were transplanted to the treatment site, with 3 plants planted per square meter, with an average plant height of 30 cm. Herbaceous plants such as ryegrass, foxtail grass, bermudagrass, alfalfa, nightshade, Bidens pilosa, and Crotalaria japonica were mixed and sown in the treatment site at a mass ratio of 25:10:5:15:15:20:10, with a sowing rate of 50 g / cm 2 ; Then water 15L of water per square meter and no further maintenance is required.

[0125] Comparative Example 13

[0126] The herbal plants ryegrass, foxtail grass, bermudagrass, alfalfa, nightshade, bidens pilosa and crotalaria were mixed and sown in the acid mine wasteland with a mass ratio of 25:10:5:15:15:20:10, and the sowing amount was 50g / cm 2 , irrigate with 15L of water per square meter, and no further maintenance will be required thereafter.

[0127] Comparative Example 14

[0128] The difference from Example 10 is that ramie and Amorpha fruticosa are not planted, and the other steps are the same as Example 10.

[0129] Comparative Example 15

[0130] The difference from Example 10 is that the herbaceous plants are not spread, and the other steps are the same as Example 10.

[0131] Experimental Example 2

[0132] The method described in Example 10 was used to repair the abandoned land in the Dabaoshan mining area. After 60 days of planting shrubs and herbaceous plants, the improved soil was collected using the ring knife sampling method. The bulk density, pH, organic matter, CEC, alkaline nitrogen, available potassium, and available phosphorus content of the soil before and after improvement were determined according to the method described in Experimental Example 1. The moisture content, total nitrogen, total phosphorus, and total potassium of the soil before and after improvement were determined according to the following method. The measurement results are shown in Table 4;

[0133] The growth of shrubs and herbaceous plants was observed after 3 and 6 months of planting, with no improvement as the control. The results are as follows Figures 2-3 As shown;

[0134] Soil moisture content: Determined by drying method, in an oven at 105°C, dry the soil sample in the ring knife and the aluminum box to constant weight, weigh the weight of the ring knife and the aluminum box before and after drying, and then calculate the soil moisture content, soil moisture content (%) = weight of the ring knife and the aluminum box after drying / weight of the ring knife and the aluminum box before drying × 100%;

[0135] Total nitrogen, total phosphorus, and total potassium: Use sulfuric acid-accelerator digestion and Kjeldahl method to determine the total nitrogen content of the soil. Use NaOH alkali fusion and molybdenum antimony anti-spectrophotometry to determine the total phosphorus content of the soil. Use NaOH alkali fusion and flame photometer to determine the total potassium content of the soil.

[0136] Table 4 Physical and chemical properties of soil before and after improvement

[0137]

[0138] As can be seen from Table 4, the method described in Example 10 was used to repair the abandoned land in the Dabaoshan mining area, which effectively improved the acidic environment of the soil in the mining area, increased the soil pH value to 6.57, and significantly improved soil fertility indicators such as organic matter, cation exchange capacity, and alkaline nitrogen. All soil indicators reached the greening planting soil standard.

[0139] Experimental Example 3

[0140] The soil matrix of the abandoned land in the Dabaoshan mining area was improved by the methods described in Example 10 (C3), Comparative Example 13 (CK), Comparative Example 14 (C1), and Comparative Example 15 (C2); 60 days after the shrubs and herbaceous plants were planted, the improved soil was collected by the ring knife sampling method, and the BCR detection method was used to determine the content of each form (residual state, oxidizable state, reducible state, and weak acid extractable state) of heavy metals (lead, cadmium, copper, arsenic, and zinc) in the improved soil, as shown in Table 5; Shanghai Meiji Biotechnology Co., Ltd. was commissioned to detect the soil microorganisms of the improved soil and analyze the composition of the soil microbial community. The results are as follows Figure 4 shown.

[0141] Table 5 Heavy metal content in different test treatment sites

[0142]

[0143] The soil habitat of the unimproved Dabaoshan mining area wasteland is extremely poor, and vegetation is difficult to survive under natural conditions. After improvement using the method described in Example 10, a variety of plants grow well and plant diversity increases significantly. Under different restoration methods, Bidens pilosa and Ramie have the highest importance values ​​and are the dominant plants for vegetation reconstruction in the mining area.

[0144] As can be seen from Table 5, after using the restoration method described in Example 10, the total amounts of lead, cadmium, copper, arsenic and zinc in the abandoned land of Dabaoshan mining area decreased to varying degrees, and the maximum reduction rates of lead, cadmium, copper, arsenic and zinc reached 21.52%, 34.82%, 17.14%, 7.59% and 39.46% respectively; except for zinc and cadmium, the proportions of oxidizable states, reducible states and weakly acid extractable states of other heavy metal elements decreased, and the heavy metal solidification effect was good.

[0145] from Figure 3 It can be seen that compared with Comparative Example 13, after improvement using the method described in Example 10 and Comparative Examples 14-15, the diversity and richness of soil microorganisms increased significantly. After improvement using the method described in Example 10, the microbial diversity and richness of the soil were the highest.

[0146] It can be seen from the above embodiments that the present invention provides an improved substrate for in-situ ecological restoration of acidic mine wastes, and its preparation method and application. The improved substrate of the present invention can effectively improve soil acidification, soil impoverishment and other problems; after the acidic mine wastes are improved by the restoration method of the present invention, a variety of plants grow well, the vegetation diversity is significantly improved, and the soil microbial diversity and richness are also significantly improved; the restoration method of the present invention can also effectively reduce the total amount of lead, cadmium, copper, arsenic and zinc in the soil.

[0147] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. An improved matrix for in-situ ecological restoration of acid mine wastes, characterized in that: The invention comprises the following components in parts by weight: 15 to 45 parts of fly ash, 15 to 45 parts of blast furnace slag, 15 to 45 parts of chicken manure and 15 to 45 parts of straw.

2. The method for preparing the improved matrix according to claim 1, characterized in that: The method comprises the following steps: mixing fly ash, blast furnace slag, chicken manure and straw to prepare an improved matrix.

3. Use of the improved matrix according to claim 1 in in-situ ecological restoration of acid mine wastes.

4. A method for in-situ ecological restoration of acid mine wasteland, characterized in that: The steps include: (1) Apply improved substrate and microbial agents to the acid mine wasteland, plow it and obtain the treated land; (2) Planting shrubs and herbaceous plants on the treated land; In step (1), the improved matrix is ​​the improved matrix according to claim 1.

5. The method according to claim 4, characterized in that In step (1), the application rate of the improved substrate is 2.5 to 7.5 kg / m 2 The application rate of the microbial agent is 0.8-1.2 L / m 2 .

6. The method according to claim 5, characterized in that In step (1), the microbial agent includes a straw composting agent and water; the mass ratio of the straw composting agent to water is 1:90-110.

7. The method according to claim 6, characterized in that In step (1), the tillage depth is 25 to 35 cm.

8. The method according to claim 7, characterized in that In step (2), the shrubs include ramie and / or Amorpha fruticosa; the herbaceous plants include one or more of ryegrass, Setaria viridis, Cynodon dactylon, Medicago sativa, Solanum nigrum, Sedum sulphureum, Miscanthus sinensis, Tall Fescue, Bidens pilosa, Lespedeza bicolor and Croton rotundus.

9. The method according to claim 8, characterized in that In step (2), the planting amount of the shrubs is 4 to 6 trees / m 2 .

10. The method according to claim 9, characterized in that In step (2), the planting amount of the herbaceous plants is 40-60 g / m 2 .

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