Solid waste yellow sand system biological composite substrate and preparation method and application thereof

Abstract

This invention discloses a bio-composite matrix for solid waste and yellow sand systems, its preparation method, and its application. Belonging to the technical field of bio-composite organic matrices, this invention utilizes the significant complementarity of fly ash, drum slag, and biological organic matter in terms of physical structure, chemical composition, and biological activity. Through compounding, an ecological restoration matrix with aeration, water retention, and nutrient supply capabilities can be constructed. Fly ash improves the matrix's pore distribution, enhancing permeability and water retention capacity. Simultaneously, its rich content of minerals such as Si, Al, and Ca can regulate the matrix pH and provide nutrients to a certain extent. Drum slag acts as a skeletal support, improving the composite matrix's mechanical strength and compressive strength, preventing matrix compaction and sedimentation. Biological organic matter, rich in organic matter, humus, and residual mycelium, possesses excellent water retention and slow-release nutrient capacity, significantly enhancing matrix fertility and microbial activity, providing carbon sources and nutritional support for plant root growth.

Description

Technical Field

[0001] This invention belongs to the technical field of biological composite organic matrix, specifically relating to a biological composite matrix for solid waste yellow sand system, its preparation method and application. Background Technology

[0002] Currently, my country's steel smelting and coal-fired power generation industries are developing rapidly, leading to a continuous increase in the annual output of bulk industrial solid wastes such as steel slag and fly ash, both approaching 100 million tons annually. Long-term stockpiling of these solid wastes not only occupies vast amounts of land, but their heavy metal and alkaline components can also leach into surrounding soil and water bodies through rainwater, posing serious environmental risks. Regarding resource utilization, while steel slag can be used in building materials such as cement admixtures, concrete aggregates, and roadbed materials, its high free calcium oxide content and resulting poor stability severely limit its large-scale application. Although fly ash is consumed in large quantities in the building materials sector, its overall resource conversion rate is low. The dual pressure of solid waste treatment and efficient utilization is increasingly prominent, and how to achieve green and high-value utilization of solid wastes such as steel slag and fly ash has become an urgent problem to be solved by the industry.

[0003] Meanwhile, traditional turf substrates are mainly divided into two categories: soil substrates and sand substrates. Soil substrates rely on arable land soil as raw material, but the "Land Administration Law of the People's Republic of China" and the "Regulations on the Protection of Basic Farmland" clearly prohibit the destruction of the topsoil of arable land and prohibit the extraction of soil from basic farmland protection areas, making arable land soil unsuitable as the core raw material for turf substrates. Sand substrates, on the other hand, mostly use river sand and artificial sand, and large-scale application leads to high production costs, making it difficult to meet the large-scale needs of urban greening and ecological restoration. Therefore, developing a multi-solid-waste synergistic sand substrate that can replace arable land soil, reduce production costs, and is environmentally safe has become the core challenge and direction of current turf substrate research.

[0004] Existing research has confirmed that drum slag in steel slag has an ellipsoidal morphology, excellent uniformity and stability, and a high total phosphorus content, which can effectively improve matrix porosity. Simultaneously, steel slag is rich in beneficial elements for plant growth such as Si, P, and Mg, which can enhance root vitality in later stages. Fly ash, on the other hand, possesses a porous honeycomb structure, a large specific surface area, strong adsorption capacity, and abundant chemically active particles, which is conducive to microbial colonization and soil fertility improvement. Although drum slag and fly ash have potential applications in plant cultivation, a mature "fly ash-drum slag composite sand-like substrate" technology system has not yet been established. In particular, systematic research on the physicochemical properties, plant growth effects, and environmental safety of the substrate under different solid waste mixing ratios is lacking, thus failing to provide reliable technical support for the large-scale application of steel-coal solid waste in non-building material fields such as urban greening and mine restoration. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a biological composite matrix for solid waste and yellow sand system, its preparation method and application, so as to solve the problems mentioned in the background art or achieve better technical effects.

[0006] To solve the above-mentioned technical problems, the inventors, through practice and summarization, derived the technical solution of this invention. This invention discloses a biological composite matrix for solid waste and yellow sand systems, the components of which are as follows by weight:

[0007] 11-27 parts drum slag, 13-31 parts fly ash, 10-38 parts yellow sand and 32-38 parts biological organic matter;

[0008] The biological organic matter consists of peat, pine bark, acidic organic fertilizer, and coconut coir; wherein the mass percentage of peat is 40%, the mass percentage of pine bark is 20%, the mass percentage of acidic organic fertilizer is 20%, and the mass percentage of coconut coir is 20%.

[0009] Furthermore, the components, by weight, are as follows:

[0010] 15 parts drum slag, 18 parts fly ash, 30 parts yellow sand and 37 parts biological organic matter.

[0011] Furthermore, the drum slag, by mass percentage, comprises 43.53% CaO, 24.25% Fe2O3, and 13.89% SiO2; the particle size of the drum slag is ≤1mm.

[0012] Furthermore, the fly ash comprises, by mass percentage, 47.46% SiO2 and 40.44% Al2O3, and the particle size of the fly ash is 400 mesh.

[0013] Furthermore, the SiO2 content in the yellow sand exceeds 90%; the particle size of the yellow sand is 0.1~2mm.

[0014] Furthermore, the preparation method of any of the above-mentioned solid waste-yellow sand system biocomposite matrix includes the following steps:

[0015] S1: Pre-treat peat, pine bark, acidic organic fertilizer and coconut coir separately;

[0016] S2: Add the pretreated biological organic matter from S1 to the mixing equipment, stir and adjust the moisture content to form a homogeneous substrate;

[0017] S3: Place the homogeneous substrate obtained in S2 under ventilated conditions for fermentation, and turn the pile appropriately during the process to promote material stability and microbial activation, so as to obtain biological organic matter;

[0018] S4: Mix fly ash, drum slag, yellow sand and biological organic matter, and stir evenly to obtain a solid waste yellow sand system biological composite matrix.

[0019] Furthermore, in S1, the pretreatment includes: appropriately crushing peat and coconut coir and adjusting the moisture content to 50-60%, crushing pine bark to a particle size of 3-5 mm, and sieving acidic organic fertilizer to remove impurities.

[0020] Furthermore, in step S2, the moisture content is adjusted to 55%.

[0021] Furthermore, in S3, the fermentation treatment time is 5 to 7 days.

[0022] Furthermore, the application of any of the above-mentioned solid waste yellow sand system biological composite substrates in the cultivation of ryegrass.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0024] (1) This invention utilizes the significant complementarity between fly ash, drum slag and biological organic matter in terms of physical structure, chemical composition and biological activity. Through compounding, an ecological restoration substrate with air permeability, water retention and nutrient supply capacity can be constructed.

[0025] (2) The fly ash of this invention is mainly composed of fine spherical particles, which have a large specific surface area and porous structure, improving the pore distribution of the matrix and enhancing its permeability and water retention capacity. At the same time, it is rich in mineral components such as Si, Al, and Ca, which can regulate the pH of the matrix and provide nutrients to a certain extent. The drum slag particles are relatively coarse and have a stable structure, playing a supporting role in the skeleton, which can improve the mechanical strength and compressive strength of the composite matrix and prevent the matrix from hardening and settling. The biological organic matter is rich in organic matter, humus and residual mycelium, and has good water retention and slow-release nutrient capacity, which can significantly improve the fertility of the matrix and the activity of microorganisms, providing carbon source and nutrient support for plant root growth.

[0026] (3) The fly ash and drum slag of the present invention jointly construct a stable multi-level porous structure. The large pores facilitate air exchange and root respiration, while the medium and small pores enhance the ability to retain water and nutrients. The biological organic matter filling the structure forms a "mineral-organic" composite interface, which improves the stability of the aggregates. The active organic components and microbial communities in the biological organic matter can promote the surface reaction of mineral particles, enhance ion exchange and nutrient adsorption and release processes, thereby forming a dynamic water and fertilizer regulation system. At the same time, the humic acid produced by the decomposition of organic matter can complex heavy metal ions, reducing potential ecological risks. At the plant-matrix interaction level, the reasonable pore structure is conducive to root extension and water-oxygen balance; the continuously released mineral and organic nutrients support chlorophyll synthesis and photosynthesis; and the active microbial community can enhance nutrient mineralization and root absorption efficiency. The three work synergistically, resulting in higher biomass accumulation, root development, and stress resistance in plants.

[0027] (4) This invention clarifies the effects of the fly ash-drum slag composite blending ratio on the physicochemical properties of the sand-like substrate, the growth performance of ryegrass and environmental safety, screens out the optimal ratio, and develops a multi-solid waste synergistic sand-like substrate that has cost advantages, cultivation effect and environmental safety, providing scientific basis and technical solutions for urban greening and mine ecological restoration. Attached Figure Description

[0028] Figure 1 This is a schematic diagram illustrating the mechanism of synergistic growth of ryegrass in the solid waste yellow sand system of this invention;

[0029] Figure 2 These are growth figures of ryegrass cultured in the biocomposite substrate prepared in Example 2, Comparative Example 1, and Comparative Example 2 of the present invention for 20 days and 50 days.

[0030] Figure 3 The images show the growth of ryegrass cultured in the biocomposite substrate prepared in Comparative Examples 3, 4 and 5 of this invention for 20 days and 50 days. Detailed Implementation

[0031] To make the above-mentioned objectives, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to specific examples.

[0032] Unless otherwise specified, all raw materials or reagents used in the following examples are commercially available products.

[0033] The main components of the drum slag are CaO (43.53%), Fe2O3 (24.25%) and SiO2 (13.89%), with a particle size range of ≤1mm.

[0034] The main components of fly ash are SiO2 (47.46%) and Al2O3 (40.44%), with a particle size of 400 mesh.

[0035] The main component of yellow sand is SiO2 (accounting for more than 90%), with a particle size range of 0.1~2mm.

[0036] In biological organic matter:

[0037] Peat: Particle size is 0.5~5mm, fiber length is 2~10mm, to ensure its water and fertilizer retention capacity and matrix pore structure, avoiding caking due to being too fine or insufficient water retention due to being too coarse.

[0038] Pine bark: Particle size is 3~15mm, decomposition degree ≥70%, which can improve the aeration of the substrate and the organic matter content, while slowly decomposing and releasing nutrients, avoiding the risk of seedling burn caused by undecomposed pine bark.

[0039] Acidic organic fertilizer: pH value 4.5~6.0, organic matter content ≥45%, total nitrogen, phosphorus and potassium nutrients ≥5%, can adjust the overall pH of the substrate and is suitable for the growth needs of plants such as ryegrass that prefer neutral to slightly acidic conditions.

[0040] Coconut coir: EC value ≤1.0mS / cm, particle size 1~8mm, expansion rate ≥500%, can improve the water retention capacity and buffering performance of the substrate, while avoiding damage to plant roots caused by high salt content.

[0041] A biological composite matrix for solid waste and yellow sand system, with the following components by weight:

[0042] 11-27 parts drum slag, 13-31 parts fly ash, 10-38 parts yellow sand, 32-38 parts biological organic matter;

[0043] The biological organic matter is composed of peat, pine bark, acidic organic fertilizer, and coconut coir; wherein, the mass percentage of peat is 40%, the mass percentage of pine bark is 20%, the mass percentage of acidic organic fertilizer is 20%, and the mass percentage of coconut coir is 20%.

[0044] The preparation method of the above-mentioned solid waste-sand system biocomposite matrix includes the following steps:

[0045] (1) Peat, pine bark, acidic organic fertilizer and coconut coir are pretreated separately. Peat and coconut coir are crushed appropriately and the moisture content is adjusted to 50-60%. Pine bark is crushed to a particle size of 3-5 mm. Acidic organic fertilizer is sieved to remove impurities.

[0046] (2) Add the pretreated biological organic matter from step (1) into the mixing equipment and stir evenly. Add water during stirring to adjust the moisture content of the entire system to 55% and mix thoroughly to form a homogeneous substrate.

[0047] (3) Place the homogeneous substrate obtained in step (2) under ventilation conditions for short-term stacking and fermentation treatment for 5-7 days. During this period, turn the stack appropriately to promote material stability and microbial activation, and finally obtain biological organic matter with loose structure, good water retention and air permeability, and suitable pH.

[0048] (4) Mix fly ash, drum slag, yellow sand and biological organic matter, and then stir with a mixer (2000 r / min, 3~10 min) to make the material uniform and obtain solid waste yellow sand system biological composite matrix.

[0049] Example 1

[0050] A biological composite matrix for solid waste and yellow sand system, with the following components by weight:

[0051] 11 parts drum slag, 13 parts fly ash, 38 parts yellow sand, and 38 parts biological organic matter;

[0052] The biological organic matter is composed of peat, pine bark, acidic organic fertilizer, and coconut coir; wherein, the mass percentage of peat is 40%, the mass percentage of pine bark is 20%, the mass percentage of acidic organic fertilizer is 20%, and the mass percentage of coconut coir is 20%.

[0053] The preparation method of the above-mentioned solid waste-sand system biocomposite matrix includes the following steps:

[0054] (1) Peat, pine bark, acidic organic fertilizer and coconut coir are pretreated separately. Peat and coconut coir are crushed appropriately and the moisture content is adjusted to 50%. Pine bark is crushed to a particle size of 3 mm. Acidic organic fertilizer is sieved to remove impurities.

[0055] (2) Add the pretreated biological organic matter from step (1) into the mixing equipment and stir evenly. Add water during stirring to adjust the moisture content of the entire system to 55% and mix thoroughly to form a homogeneous substrate.

[0056] (3) The homogeneous substrate obtained in step (2) is placed under ventilation conditions for short-term stacking and fermentation treatment for 7 days. During this period, the substrate is turned over appropriately to promote material stability and microbial activation, and finally, a loose structure, good water retention and air permeability, and suitable pH biological organic matter is obtained.

[0057] (4) Mix fly ash, drum slag, yellow sand and biological organic matter, and then stir with a mixer (2000 r / min, 4 min) to make the material uniform and obtain fly ash-drum slag biomass organic composite matrix.

[0058] Example 2

[0059] A biological composite matrix for solid waste and yellow sand system, with the following components by weight:

[0060] 15 parts drum slag, 18 parts fly ash, 30 parts yellow sand, and 37 parts biological organic matter;

[0061] The biological organic matter is composed of peat, pine bark, acidic organic fertilizer, and coconut coir; wherein, the mass percentage of peat is 40%, the mass percentage of pine bark is 20%, the mass percentage of acidic organic fertilizer is 20%, and the mass percentage of coconut coir is 20%.

[0062] The preparation method of the above-mentioned solid waste yellow sand system biological composite matrix is ​​the same as that in Example 1.

[0063] Example 3

[0064] A biological composite matrix for solid waste and yellow sand system, with the following components by weight:

[0065] 20 parts drum slag, 23 parts fly ash, 23 parts yellow sand, 34 parts biological organic matter;

[0066] The biological organic matter is composed of peat, pine bark, acidic organic fertilizer, and coconut coir; wherein, the mass percentage of peat is 40%, the mass percentage of pine bark is 20%, the mass percentage of acidic organic fertilizer is 20%, and the mass percentage of coconut coir is 20%.

[0067] The preparation method of the above-mentioned solid waste yellow sand system biological composite matrix is ​​the same as that in Example 1.

[0068] Example 4

[0069] A biological composite matrix for solid waste and yellow sand system, with the following components by weight:

[0070] 23 parts drum slag, 27 parts fly ash, 17 parts yellow sand, and 33 parts biological organic matter;

[0071] The biological organic matter is composed of peat, pine bark, acidic organic fertilizer, and coconut coir; wherein, the mass percentage of peat is 40%, the mass percentage of pine bark is 20%, the mass percentage of acidic organic fertilizer is 20%, and the mass percentage of coconut coir is 20%.

[0072] The preparation method of the above-mentioned solid waste yellow sand system biological composite matrix is ​​the same as that in Example 1.

[0073] Example 5

[0074] A biological composite matrix for solid waste and yellow sand system, with the following components by weight:

[0075] 27 parts drum slag, 31 parts fly ash, 10 parts yellow sand, and 32 parts biological organic matter;

[0076] The biological organic matter is composed of peat, pine bark, acidic organic fertilizer, and coconut coir; wherein, the mass percentage of peat is 40%, the mass percentage of pine bark is 20%, the mass percentage of acidic organic fertilizer is 20%, and the mass percentage of coconut coir is 20%.

[0077] The preparation method of the above-mentioned solid waste yellow sand system biological composite matrix is ​​the same as that in Example 1.

[0078] Comparative Example 1

[0079] A biological composite matrix, comprising the following components by weight:

[0080] 52 samples of yellow sand and 48 samples of biological organic matter;

[0081] The biological organic matter is composed of peat, pine bark, acidic organic fertilizer, and coconut coir; wherein, the mass percentage of peat is 40%, the mass percentage of pine bark is 20%, the mass percentage of acidic organic fertilizer is 20%, and the mass percentage of coconut coir is 20%.

[0082] The preparation method of the above-mentioned bio-composite matrix includes the following steps:

[0083] (1) Peat, pine bark, acidic organic fertilizer and coconut coir are pretreated separately. Peat and coconut coir are crushed appropriately and the moisture content is adjusted to 50%. Pine bark is crushed to a particle size of 3 mm. Acidic organic fertilizer is sieved to remove impurities.

[0084] (2) Add the pretreated biological organic matter from step (1) into the mixing equipment and stir evenly. Add water during stirring to adjust the moisture content of the entire system to 55% and mix thoroughly to form a homogeneous substrate.

[0085] (3) The homogeneous substrate obtained in step (2) is placed under ventilation conditions for short-term stacking and fermentation treatment for 7 days. During this period, the substrate is turned over appropriately to promote material stability and microbial activation, and finally, a loose structure, good water retention and air permeability, and suitable pH biological organic matter is obtained.

[0086] (4) Mix yellow sand with biological organic matter, and then stir it with a mixer (2000r / min, 6min) to make the material uniform and obtain fly ash-drum slag biomass organic composite matrix.

[0087] Comparative Example 2

[0088] A biological composite matrix, comprising the following components by weight:

[0089] 29 parts fly ash, 32 parts yellow sand, and 39 parts biological organic matter;

[0090] The biological organic matter is composed of peat, pine bark, acidic organic fertilizer, and coconut coir; wherein, the mass percentage of peat is 40%, the mass percentage of pine bark is 20%, the mass percentage of acidic organic fertilizer is 20%, and the mass percentage of coconut coir is 20%.

[0091] The preparation method of the above-mentioned biocomposite matrix is ​​the same as that in Example 1.

[0092] Comparative Example 3

[0093] A biological composite matrix, comprising the following components by weight:

[0094] 50 parts drum slag, 32 parts yellow sand, and 18 parts biological organic matter;

[0095] The biological organic matter is composed of peat, pine bark, acidic organic fertilizer, and coconut coir; wherein, the mass percentage of peat is 40%, the mass percentage of pine bark is 20%, the mass percentage of acidic organic fertilizer is 20%, and the mass percentage of coconut coir is 20%.

[0096] The preparation method of the above-mentioned biocomposite matrix is ​​the same as that in Example 1.

[0097] Comparative Example 4

[0098] Unlike Example 2, only the formulation of the biological organic matter was changed, as follows:

[0099] In the biological organic matter, peat accounts for 40% by mass, pine bark accounts for 15% by mass, acidic organic fertilizer accounts for 30% by mass, and coconut coir accounts for 15% by mass; the other components remain unchanged.

[0100] Comparative Example 5

[0101] Unlike Example 2, only the formulation of the biological organic matter was changed, as follows:

[0102] In the biological organic matter, peat accounts for 40% by mass, pine bark accounts for 25% by mass, acidic organic fertilizer accounts for 10% by mass, and coconut coir accounts for 25% by mass; the other components remain unchanged.

[0103] The bio-organic turf substrates prepared in Examples 1-5 and Comparative Examples 1-5 were subjected to physicochemical property tests (the measured physicochemical property indicators included: pH, electrical conductivity, bulk density, total porosity, aeration porosity and water-holding porosity), and the test results are shown in Table 1 below.

[0104] Table 1. Preparations obtained in Examples 1-5 and Comparative Examples 1-5

[0105] Physicochemical properties of biological organic turf substrate

[0106]

[0107] As shown in Table 1, a comparison of Examples 1-5 reveals that as the ratio of alkaline components to light organic matter in the formulation was gradually adjusted, the pH value of the matrix continuously increased from 9.44 to 11.12, indicating a gradual increase in overall alkalinity. This reflects a continuous increase in the proportion of strongly alkaline raw materials added to the formulation, resulting in a gradient change in the acid-base environment of the matrix. Simultaneously, the conductivity increased from 434 μS·cm. -1 Steadily rising to 921 μS·cm -1 The soluble salt content increased with increasing alkaline components, and the overall values ​​remained within the safe range for turfgrass growth, indicating no risk of salt damage. This suggests that the elemental solubility was normal after the metallurgical solid waste and biological organic matter were combined, and the matrix was safe. The bulk density showed a continuous decreasing trend, from 0.99 g·cm³. -3 Reduced to 0.88 g·cm⁻¹ -3The substrate compaction decreases, and the structure becomes looser, which is beneficial for root penetration and respiration. Total porosity initially fluctuates slightly before decreasing significantly, while aeration porosity continuously increases and water-holding porosity continuously decreases. The substrate's water-air balance tilts towards aeration, with aeration gradually improving while water-holding capacity gradually weakens, resulting in a significant remodeling of the pore structure. Example 2 achieves the best balance among various physicochemical indicators, with a moderate pH, low electrical conductivity, low bulk density, and coordinated aeration and water-holding porosity performance. Its pore structure is adapted to the water and air requirements of turf root growth, making it the optimal implementation case of this invention.

[0108] A comparison of Example 2 with Comparative Examples 1-3 reveals that Example 2 is significantly superior to the comparative examples in key indicators such as pH value, electrical conductivity, bulk density, and pore structure. Example 2's pH value falls within a reasonable range of 8.12-12.2, exhibiting moderate alkalinity without excessive alkalinity; its electrical conductivity is far lower than that of Comparative Example 2, falling within the safe range for turfgrass growth; its soluble salt content is low, eliminating the risk of salt damage; and its bulk density ranges from 0.96 to 1.18 g·cm³. -3 The total porosity and aeration porosity of Comparative Example 1 were significantly lower than those of Comparative Examples 2 and 3, which had excessively high bulk density. The loose matrix structure was conducive to root growth. The total porosity and aeration porosity were significantly higher than those of Comparative Examples 2 and 3, which had deteriorated pore structure. The water-holding porosity was also much better than that of Comparative Example 3, which had pore imbalance. The water-air coordination ability was outstanding. Although Comparative Example 1 had a better pore structure, its pH was low and its electrical conductivity was insufficient, resulting in weak nutrient and ion release capacity. Comparative Example 2 had excessive bulk density, excessive aeration porosity, and severely insufficient water-holding porosity, resulting in a serious imbalance of water and air. Comparative Example 3 had excessive alkalinity, excessive electrical conductivity, and a significant decrease in water-holding porosity, which could easily lead to salt damage and excessive aeration, resulting in insufficient water retention. The preferred embodiment of the present invention achieves synergistic optimization of pH, electrical conductivity, bulk density and pore structure through formula optimization. It avoids the defects of insufficient nutrients in Comparative Example 1, compact structure in Comparative Example 2, and salt damage and pore imbalance in Comparative Example 3. It also takes into account suitable alkalinity, low salt damage, loose bulk density and coordinated water and air pore structure. The overall physicochemical properties are more suitable for the growth needs of turf.

[0109] A comparison of Example 2 and Comparative Example 4 reveals that adjusting the proportion of acidic organic fertilizer in the bio-organic matter (increasing it from 20% to 30%) lowered the pH of the substrate from 9.45 to 8.65, increasing its acidity, which aligns with the formulation characteristics of acidic organic fertilizer addition; the electrical conductivity was 495 μS·cm. -1 Slightly higher than in Example 2, with a slight increase in soluble salt content; bulk density was 0.91 g·cm³. -3The substrate compactness was higher than in Example 2; the total porosity was 47.2%, slightly better than in Example 2; the aeration porosity was 6.2%, significantly lower than in Example 2, indicating a decrease in aeration performance; and the water-holding porosity was 41.0%, basically the same as in Example 2. After the formula adjustment, the overall water-air balance of the substrate shifted towards the water-retention side, resulting in insufficient aeration and failing to meet the high aeration requirements of turfgrass roots. This is a direct result of the increased proportion of acidic organic fertilizer and the reduction of lightweight organic fillers, leading to pore structure reconstruction.

[0110] Comparing Example 2 with Comparative Example 5, it can be seen that the proportion of acidic organic fertilizer decreased from 20% to 10%, the substrate pH value increased from 9.45 to 9.85, and the alkalinity further increased; the electrical conductivity was 655 μS·cm. -1 The soluble salt content was higher than in Example 2; the bulk density was 0.85 ± 0.01 g·cm³. -3 Consistent with Example 2, the substrate looseness was similar; the total porosity was 45.3±0.10, lower than Example 2; the aeration porosity was 8.5±0.01, slightly higher than Example 2, indicating a slight improvement in aeration performance; the water-holding porosity was 36.8±0.11, significantly lower than Example 2, indicating a significant decrease in water-holding capacity. After the formula adjustment, the substrate water-air balance shifted towards the aeration side, resulting in insufficient water retention and a tendency for substrate drought. This failed to balance the water retention and aeration required for turf growth, reflecting the negative impact of reduced acidic organic fertilizer content and increased lightweight organic filler on the pore structure.

[0111] The bio-organic turf substrates prepared in Examples 1-5 and Comparative Examples 1-5 were potted and sown with ryegrass. Light and watering were provided during a 50-day growth cycle, without the application of any fertilizer. Finally, the optimal substrate ratio was selected through comprehensive measurement and analysis of the substrate's physicochemical properties, environmental safety, and the growth and physiological indicators of the above-ground and underground parts of the ryegrass. The results are shown in Table 2 below.

[0112] Table 2. Preparations of Examples 1-5 and Comparative Examples 1-5

[0113] Results of cultivating ryegrass plants in a biological organic turf substrate

[0114]

[0115] From Table 2 and Figures 2-3As can be seen from the comparison of Examples 1-5, with the gradual adjustment of the ratio of alkaline components to light organic matter in the formula, the physicochemical properties of the substrate undergo a gradient change, and the growth indicators of ryegrass plants show significant differences. In Example 1, the leaf dry weight was 0.63g and the root length was 5.46cm, while in Example 5, the leaf dry weight decreased to 0.29g and the root length was only 1.78cm, indicating a gradual weakening of growth vigor. At the same time, the turf morphology indicators, leaf area, plant height, and germination rate, also continued to decrease with the adjustment of the formula. In Example 1, the leaf area was 3.30cm². 2 The germination rate was 45%, while the leaf area in Example 5 was 1.05 cm². 2 The germination rate was only 23%. Overall, this indicates that while increasing the proportion of alkaline components and adjusting the proportion of light organic matter improved substrate aeration, excessive adjustments led to an imbalance in substrate water and air, and an imbalance in nutrient supply, inhibiting ryegrass seed germination and plant growth. Example 2 achieved the best balance in growth indicators and is the optimal embodiment of this invention.

[0116] Comparison of Example 2 with Comparative Examples 1-3: In terms of above-ground growth indicators, the leaf dry weight of Example 2 reached 0.56g, an increase of approximately 27.3% compared to Comparative Example 1 (0.44g), approximately 366.7% compared to Comparative Example 2 (0.12g), and approximately 460.0% compared to Comparative Example 3 (0.10g); the leaf area was 3.61cm². 2 Compared with Comparative Example 1 (1.03cm) 2 The improvement was approximately 250.5%, compared to control sample 2 (0.82cm). 2 The improvement was approximately 340.2%, compared to control sample 3 (0.65cm). 2 The growth rate was approximately 455.4%; the plant height was 11.89 cm, an increase of approximately 44.1% compared to Comparative Example 1 (8.25 cm), approximately 94.9% compared to Comparative Example 2 (6.10 cm), and approximately 128.7% compared to Comparative Example 3 (5.20 cm). These data clearly demonstrate that the substrate formulation of Example 2 can significantly promote the accumulation of aboveground biomass and the expansion of photosynthetic area in ryegrass, resulting in more vigorous plant growth and laying a solid foundation for subsequent turf establishment and landscaping effects.

[0117] In terms of root growth indicators, the root length of Example 2 reached 10.47 cm, an increase of approximately 48.3% compared to Comparative Example 1 (7.06 cm), approximately 926.5% compared to Comparative Example 2 (1.02 cm), and approximately 1131.8% compared to Comparative Example 3 (0.85 cm). The root dry weight was 0.27 g, slightly lower than Comparative Example 1 (0.95 g), but significantly higher than Comparative Example 2 (0.05 g) and Comparative Example 3 (0.04 g), representing increases of approximately 440.0% and 575.0%, respectively. The longer root system and better root dry weight distribution mean that the substrate of Example 2 is more conducive to the root development and nutrient absorption of ryegrass, which can enhance the plant's stability and resistance, and avoid problems such as lodging and premature aging caused by weak root systems.

[0118] In terms of germination rate, the germination rate of Example 2 was 47%, which was basically the same as that of Comparative Example 1 (48%), and significantly higher than that of Comparative Example 2 (30%) and Comparative Example 3 (25%). This indicates that the formula ensures the germination rate while taking into account the subsequent growth potential of the plants, thus avoiding the defects of low germination rate and difficulty in seedling formation in Comparative Examples 2 and 3.

[0119] A comparison of the best embodiment and Comparative Example 4 reveals that in the composite substrate system, increasing the proportion of acidic organic fertilizer from 20% to 30% resulted in a comprehensive decrease in plant growth indicators. Leaf dry weight was 0.40g, root length was 6.20cm, and germination rate was 35%, significantly lower than the 0.56g, 10.47cm, and 47% of Example 2. While increasing the proportion of acidic organic fertilizer slightly adjusted the substrate pH, the decrease in the proportion of pine bark and coconut coir led to a reduction in substrate aeration and nutrient slow-release capacity. This resulted in an imbalance in the supply of water, air, and nutrients required for seed germination and seedling growth, significantly weakening plant growth and failing to achieve the lawn establishment effect of Best Example 2.

[0120] A comparison of the preferred embodiment and Comparative Example 5 reveals that when the proportion of acidic organic fertilizer decreased from 20% to 10%, all growth indicators significantly decreased: leaf dry weight was 0.33g, root length was 2.80cm, germination rate was only 20%, and leaf area was 1.20cm². 2 The plant height of 7.20cm was far lower than that of Example 2. Although the increased proportion of pine bark and coconut coir improved the aeration of the substrate, the insufficient proportion of acidic organic fertilizer led to insufficient nutrient supply and reduced water retention capacity. Seed germination and seedling growth were severely inhibited, and root development and above-ground growth were also hindered. The overall growth performance was far lower than that of the best Example 2, and it could not meet the technical requirements for high-quality and rapid establishment of lawns.

[0121] This invention utilizes the significant complementarity between fly ash, drum slag, and biological organic matter in terms of physical structure, chemical composition, and biological activity. Through compounding, an ecological restoration substrate with a combination of aeration, water retention, and nutrient supply capabilities can be constructed. Its synergistic mechanism is as follows: Figure 1As shown, this is particularly evident in three aspects: structural optimization, water and fertilizer regulation, and biological promotion.

[0122] Fly ash, primarily composed of fine spherical particles, possesses a large specific surface area and porous structure, improving matrix pore distribution and enhancing air permeability and water retention capacity. It is also rich in minerals such as Si, Al, and Ca, which can regulate matrix pH and provide nutrients to some extent. Drum slag, with its coarser particles and stable structure, acts as a skeletal support, improving the mechanical strength and compressive resistance of the composite matrix and preventing matrix compaction and settling. Biological organic matter, rich in organic matter, humus, and residual mycelium, has excellent water retention and slow-release nutrient capacity, significantly enhancing matrix fertility and microbial activity, providing carbon sources and nutritional support for plant root growth.

[0123] Fly ash and drum slag together construct a stable multi-level porous structure. Large pores facilitate air exchange and root respiration, while small and medium pores enhance water and nutrient retention. Biological organic matter fills this structure, forming a "mineral-organic" composite interface and improving aggregate stability. The active organic components and microbial communities in the biological organic matter promote surface reactions of mineral particles, enhancing ion exchange and nutrient adsorption and release processes, thus forming a dynamic water and fertilizer regulation system. Simultaneously, the humic acid produced by organic matter decomposition can complex heavy metal ions, reducing potential ecological risks. At the plant-matrix interaction level, a well-designed porous structure promotes root extension and water-oxygen balance; continuously released mineral and organic nutrients support chlorophyll synthesis and photosynthesis; and an active microbial community enhances nutrient mineralization and root absorption efficiency. Through the synergistic effect of these three factors, plants exhibit higher biomass accumulation, root development, and stress resistance.

Claims

1. A biological composite matrix for a solid waste-sand system, characterized in that, The components, by weight, are as follows: 11-27 parts drum slag, 13-31 parts fly ash, 10-38 parts yellow sand and 32-38 parts biological organic matter; The biological organic matter consists of peat, pine bark, acidic organic fertilizer, and coconut coir; wherein the mass percentage of peat is 40%, the mass percentage of pine bark is 20%, the mass percentage of acidic organic fertilizer is 20%, and the mass percentage of coconut coir is 20%.

2. The biological composite matrix of the solid waste-yellow sand system according to claim 1, characterized in that, The components, by weight, are as follows: 15 parts drum slag, 18 parts fly ash, 30 parts yellow sand and 37 parts biological organic matter.

3. The biological composite matrix of the solid waste-yellow sand system according to claim 1, characterized in that, The drum slag, by mass percentage, comprises 43.53% CaO, 24.25% Fe2O3, and 13.89% SiO2; the particle size of the drum slag is ≤1mm.

4. The biological composite matrix of the solid waste-yellow sand system according to claim 1, characterized in that, The fly ash comprises 47.46% SiO2 and 40.44% Al2O3 by mass, and the particle size of the fly ash is 400 mesh.

5. The biological composite matrix of the solid waste-yellow sand system according to claim 1, characterized in that, The SiO2 content in the yellow sand exceeds 90%; the particle size of the yellow sand is 0.1~2mm.

6. A method for preparing a biological composite matrix for a solid waste-sand system as described in any one of claims 1 to 5, characterized in that, The steps are as follows: S1: Pre-treat peat, pine bark, acidic organic fertilizer and coconut coir separately; S2: Add the pretreated biological organic matter from S1 to the mixing equipment, stir and adjust the moisture content to form a homogeneous substrate; S3: Place the homogeneous substrate obtained in S2 under ventilated conditions for fermentation, and turn the pile appropriately during the process to promote material stability and microbial activation, so as to obtain biological organic matter; S4: Mix fly ash, drum slag, yellow sand and biological organic matter, and stir evenly to obtain a solid waste yellow sand system biological composite matrix.

7. The method for preparing the biological composite matrix of the solid waste yellow sand system according to claim 6, characterized in that, In S1, the pretreatment includes: appropriately crushing peat and coconut coir and adjusting the moisture content to 50-60%, crushing pine bark to a particle size of 3-5 mm, and sieving acidic organic fertilizer to remove impurities.

8. The method for preparing the biological composite matrix of the solid waste yellow sand system according to claim 6, characterized in that, In step S2, the moisture content is adjusted to 55%.

9. The method for preparing the biological composite matrix of the solid waste-yellow sand system according to claim 6, characterized in that, In S3, the fermentation process takes 5 to 7 days.

10. The application of the solid waste yellow sand system biological composite substrate according to any one of claims 1 to 5 in the cultivation of ryegrass.

Images