A composite organic nutrient matrix of traditional Chinese medicine residue and tailings sand and soil and its preparation method

Abstract

This invention discloses a composite organic nutrient matrix of traditional Chinese medicine residue and tailings sand, and its preparation method, belonging to the field of solid waste resource utilization and soil improvement technology. The method first involves crushing the traditional Chinese medicine residue and uniformly controlling the carbon-nitrogen ratio, followed by inoculation, fermentation, and maturation to obtain homogeneous humus. Subsequently, this humus is mixed with alkali-treated bamboo fiber skeleton, kelp fragments, and dried cake, and granulated to form a porous network structure. Finally, it is compounded with tailings sand in a specific ratio and lightly compacted to obtain the finished matrix. This invention achieves unified and efficient resource utilization of traditional Chinese medicine residue from complex sources and effectively improves the infertile characteristics of tailings sand. The resulting matrix has high organic matter content, strong water and fertilizer retention capacity, and a stable structure that is not prone to stratification. It can significantly improve plant survival rates and reduce the maintenance costs of ecological restoration projects, demonstrating good economic and ecological benefits.

Description

Technical Field

[0001] This invention relates to the field of soil improvement and horticultural substrate preparation technology, and in particular to a composite organic nutrient substrate of traditional Chinese medicine residue and tailings sand and soil and its preparation method. Background Technology

[0002] China is the world's largest producer and consumer of traditional Chinese medicine (TCM) products, consuming vast quantities of processed TCM herbs and raw materials annually. Current TCM production processes, involving extraction of active ingredients through water and alcohol, generate substantial amounts of medicinal residue. This residue typically contains large quantities of underutilized plant structural carbon sources, including gelatinized starch, polysaccharides, cellulose, hemicellulose, and small amounts of residual protein and trace elements. Currently, this residue is primarily disposed of through landfilling, incineration, or low-value composting, resulting in resource waste and the risk of secondary pollution. Simultaneously, China's agricultural and forestry sectors, particularly in mine restoration, desertification control, and marginal land greening projects, have a significant demand for low-cost, high-organic-matter-content nutrient soil with good water retention and slow-release nutrient capabilities. On the other hand, large quantities of environmentally treated tailings sand (primarily composed of silica, with a content exceeding 60%) lack organic matter and have poor water retention, making it unsuitable for direct plant cultivation.

[0003] Therefore, how to achieve rapid homogenization and stable utilization of Chinese medicinal residues from complex sources, and how to form a composite organic nutrient matrix with tailings sand and soil that is structurally stable, not prone to stratification, and has functions similar to forest litter, has become an urgent technical problem to be solved. Summary of the Invention

[0004] The purpose of this invention is to provide a unified homogenization and fermentation technology system for Chinese herbal medicine residues from different sources that does not rely on the detection of the original components of the residues.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: a composite organic nutrient matrix of traditional Chinese medicine residue and tailings sand, which is composed of a structured organic composite and tailings sand in a mass ratio of 1:(1-3), wherein the structured organic composite is formed by mixing and granulating raw materials comprising the following mass parts: Fermented Chinese medicinal herb residue humus: 40-60 parts; Hydrophilic bamboo fiber skeleton: 10-20 parts; Shredded kelp: 5-10 portions; Dry cakes: 5-10 servings.

[0006] Furthermore, the fermented Chinese herbal medicine residue humus is obtained by crushing Chinese herbal medicine residue from different sources to a particle size of 5-15mm, uniformly adjusting the C / N ratio to 25-30:1, inoculating with compound microbial agents for aerobic fermentation and maturation.

[0007] Furthermore, the hydrophilic bamboo fiber skeleton is a porous hydrophilic fiber material obtained by cutting bamboo into 1-3cm segments and removing the surface wax by soaking in steam or alkaline solution.

[0008] Furthermore, the dried cake is at least one of rapeseed cake and peanut cake.

[0009] Furthermore, the main component of the tailings sand is silicon dioxide, with a content of not less than 60%.

[0010] Furthermore, the organic matter content of the composite organic nutrient substrate is not less than 28%, and the maximum water holding capacity is not less than 85%.

[0011] A method for preparing a composite organic nutrient matrix of traditional Chinese medicine residue and tailings sand includes the following steps: S1: Homogenization fermentation of Chinese herbal medicine residue: The Chinese herbal medicine residue with a moisture content of 50-75% is crushed to a particle size of 5-15mm, and its C / N ratio is adjusted to 25-30:1. Then, under aerobic conditions, it is inoculated with compound microbial agents and fermented at 45-65℃ for 7-15 days, followed by maturation for 15-30 days to obtain homogenized plant humus material. S2: Preparation of bamboo fiber skeleton: Cut bamboo material into 1-3cm segments, soak them in steam or alkaline aqueous solution, wash and dry them to obtain a hydrophilic porous bamboo fiber skeleton. S3: Preparation of the structured composite: The plant humus material obtained in step S1, the bamboo fiber skeleton obtained in step S2, kelp fragments and dried cake are mixed in a mass ratio of (40–60):(10–20):(5–10):(5–10), and the plant humus material is wrapped and embedded in the bamboo fiber skeleton by low-speed turning and agglomeration granulation to form a cotton ball-like or porous mesh structure. S4: Formation of composite nutrient matrix: The structured composite obtained in step S3 is mixed with tailings sand at a mass ratio of 1:(1–3), and after light compaction, a composite organic nutrient matrix with stable structure and not easy to separate into layers is obtained.

[0012] Further, in step S2, the alkaline aqueous solution is a NaOH solution with a mass concentration of 0.5–1%, and the soaking time is 2–4 hours.

[0013] Furthermore, the composite organic nutrient matrix produced by this method can be applied in forestry afforestation, ecological restoration of mining areas, greening of marginal land, or horticultural cultivation.

[0014] The beneficial effects of this invention compared with the prior art are: (1) This invention can process various kinds of medicinal residues without complicated testing by standard crushing and C / N ratio control, simplifying the process; (2) Deep fermentation transforms medicinal residues into stable humus, turning waste into treasure and realizing efficient recycling of organic matter; (3) The organic matter of medicinal residues and bamboo fiber work together to improve the structure of sandy soil, significantly enhancing its water holding capacity and improving the planting effect; (4) The substrate has excellent water and fertilizer retention and slow release functions, which can reduce the frequency and amount of artificial irrigation and topdressing in the later stage; (5) The unique structural design makes it difficult to separate into layers, and the particles are homogeneous, which is convenient for large-scale mechanized paving and construction operations. Attached Figure Description

[0015] Figure 1 This is a flowchart of the preparation method of the present invention.

[0016] Figure 2 This is a structural diagram of the product composition of the present invention.

[0017] Figure 3 This diagram illustrates the application areas of the product of this invention. Detailed Implementation

[0018] To enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below with reference to specific embodiments. The specific embodiments described herein are only for explaining the present invention and are not intended to limit the scope of protection of the present invention.

[0019] Example: Figures 1-3 The invention relates to a composite organic nutrient matrix of traditional Chinese medicine residue and tailings sand, and its preparation method, comprising the following preparation steps: S1: Homogenization and fermentation of Chinese herbal medicine residue: Chinese herbal medicine residue with a moisture content of 50–75% was crushed to a particle size of 5–15 mm, and its C / N ratio was adjusted to 25–30:1. Then, under aerobic conditions, a compound microbial agent was inoculated, and fermentation was carried out at 45–65℃ for 7–15 days, followed by maturation for 15–30 days to obtain homogenized plant humus material. A mixed residue (mainly containing root and rhizome residues such as Astragalus membranaceus, Glycyrrhiza uralensis, and Angelica sinensis) produced by a Chinese herbal medicine pharmaceutical company after water extraction was selected, with an initial moisture content of 65%. The residue was crushed to a particle size of approximately 10 mm using a twin-shaft shredder. 5% rapeseed cake (providing a slow-release nitrogen source), 3% shredded kelp (providing polysaccharides and trace elements), and 2% bamboo powder (providing a structural carbon source) were added to the crushed residue by mass fraction. After uniform mixing, the C / N ratio of the mixture was measured to be approximately 28:1. The mixture was piled into windrows and inoculated with a commercially available compound microbial agent containing *Trichoderma reesei* (a cellulose-decomposing bacterium) and *Bacillus subtilis* (a starch-decomposing bacterium) at a rate of 0.5‰ for aerobic fermentation. The fermentation temperature was controlled at 55±5℃, and the pile was turned every 3 days, with the main fermentation lasting 12 days. It was then transferred to a rain-sheltered shed for maturation for 20 days, during which time it was turned every 7 days, ultimately yielding a homogenized plant humus material that was dark brown in color, loose in texture, and odorless.

[0020] S2: Preparation of bamboo fiber skeleton: Bamboo material is cut into 1-3cm segments, soaked in steam or alkaline aqueous solution, washed and dried to obtain a hydrophilic porous bamboo fiber skeleton; bamboo processing scraps are processed into bamboo fiber sheets with an average length of 2cm and a width of 2-3mm using a special cutting machine. The bamboo fiber sheets are placed in a 0.8% sodium hydroxide aqueous solution and soaked at normal pressure and 85℃ for 3 hours to fully remove the wax on the surface of the bamboo. Then, they are repeatedly rinsed with clean water until neutral, drained, and naturally air-dried until the moisture content is below 15%, resulting in a rough, porous, hydrophilic bamboo fiber skeleton.

[0021] S3: Preparation of the structured composite: The plant humus material obtained in step S1, the bamboo fiber skeleton obtained in step S2, kelp fragments and rapeseed cake are mixed in a mass ratio of (40–60):(10–20):(5–10):(5–10). The mixture is then granulated by low-speed turning and agglomeration, so that the plant humus material is wrapped and embedded in the bamboo fiber skeleton to form a cotton ball-like or porous mesh structure. Take 50 parts by weight of the plant humus material prepared in S1, 15 parts by weight of the bamboo fiber skeleton prepared in S2, 8 parts by weight of the dried and crushed kelp fragments, and 8 parts by weight of the crushed rapeseed cake, and put them into a low-speed double helix mixer and mix for 15 minutes. It is then transferred to a disc granulator, rotated at a low speed (15 rpm), and intermittently sprayed with a small amount of atomized water (moisture content controlled within 3%). Through the agglomeration and granulation action, the viscous humus material is evenly wrapped and tightly embedded in the mesh skeleton made of bamboo fiber, forming a cotton-like porous structure with a certain degree of elasticity, about 5-10 mm in diameter.

[0022] S4: Formation of the composite nutrient matrix: The structured composite obtained in step S3 is mixed with tailings sand at a mass ratio of 1:(1–3), and lightly compacted to obtain a structurally stable composite organic nutrient matrix that is not prone to segregation. The structured composite prepared in step S3 is mixed with iron tailings sand (main component: SiO2>60%, particle size 0.05-1mm) that has undergone environmental protection treatment (washing, desulfurization) at a mass ratio of 1:2. A loader is used to perform three mixing operations to ensure uniform mixing. The mixed material is then placed into woven bags with ventilation holes at the bottom and lightly compacted manually or mechanically (bulk density controlled at 0.8-1.0 g / cm³). 3 After sealing, the finished composite organic nutrient matrix is ​​obtained. Testing showed that the matrix did not exhibit significant stratification or segregation during a transport vibration simulation experiment.

[0023] In step S1, the organic regulating materials used to adjust the C / N ratio include one or more of the following: dried cake, shredded kelp, and / or bamboo fiber materials. Dried cake, as a core nitrogen source supplement, is rich in organic nitrogen (protein content can reach 40-50%) and elements such as phosphorus and potassium. It not only rapidly adjusts the C / N ratio to the target range (25-30:1) but also provides a continuous, slow-release nitrogen nutrient during fermentation. Shredded kelp, as a functional regulator, uses natural alginate (such as sodium alginate) to enhance the water-holding capacity and microbial activity of the fermentation system, while supplementing trace elements such as iodine, zinc, and magnesium, improving the nutritional balance of the final product. Bamboo fiber materials, as a structural carbon source, have a high cellulose / lignin content that optimizes the pore structure of the fermented material, providing a physical support foundation for the subsequent formation of a stable matrix framework while adjusting the C / N ratio. Through a synergistic mechanism of "nutrient supply—functional enhancement—structural construction," these three types of materials achieve standardized control of the C / N ratio and fermentation characteristics of any source of medicinal residue.

[0024] In step S1, the composite microbial agent comprises cellulose-decomposing bacteria, starch-decomposing bacteria, and lignin-degrading bacteria. To efficiently degrade the complex plant components in medicinal herb residues, the composite microbial agent is a specifically formulated combination of functional microbial communities. Its core components include at least: cellulose-decomposing bacteria for decomposing cellulose, starch-decomposing bacteria for degrading residual starch, and lignin-degrading bacteria for breaking down lignin structures. These three types of bacteria work synergistically to ensure that medicinal herb residues from different sources can undergo sufficient and stable biotransformation.

[0025] In step S2, the alkaline aqueous solution is a 0.5–1% (w / w) NaOH solution, and the soaking time is 2–4 hours. This process parameter system is based on a comprehensive balance of fiber modification, production efficiency, and energy consumption control. This concentration range is sufficient to effectively hydrolyze the silica wax layer and part of the hemicellulose on the bamboo surface, exposing the fiber microtubule structure and forming abundant micropores, thereby significantly improving its water absorption and adhesion to subsequent humic materials. Simultaneously, strictly limiting the soaking time to 2–4 hours is to precisely control the degree of lignin dissolution while achieving ideal hydrophilic modification, avoiding severe loss of the mechanical strength of the fiber skeleton due to over-treatment, thus preventing the loss of its key function as a three-dimensional network support structure. This optimized mild alkaline treatment condition is the core technical step in transforming bamboo fiber from a hydrophobic waste material into a high-performance hydrophilic structural skeleton.

[0026] The organic nutrient substrate produced by this method has an organic matter content of no less than 28% and a maximum water holding capacity of no less than 85%. This value is significantly higher than that of conventional horticultural substrates and ordinary compost products. It mainly originates from stable humus substances formed through deep fermentation and transformation of organic matter such as medicinal residue, cake fertilizer, and kelp fragments. Simultaneously, its maximum water holding capacity of no less than 85% is attributed to the synergistic effect between the macroporous structure constructed by the bamboo fiber framework and the microporous water-retaining network formed by humus and kelp colloids. These two core indicators together ensure that the substrate possesses excellent slow-release fertilization capacity and water retention function, providing reliable performance assurance for its application in water-saving afforestation, ecological restoration, and other fields.

[0027] The composite organic nutrient substrate produced by this method has applications in forestry afforestation, mining area ecological restoration, marginal land greening, and horticulture. Due to its unique high organic matter content, excellent structural stability, and outstanding water and fertilizer retention capacity, it shows broad and efficient application prospects in many fields with urgent needs for soil improvement. Specifically, it is mainly applied in the following scenarios.

[0028] Forestry planting: It can be used as topsoil or base fertilizer in afforestation projects in difficult sites (such as arid areas and gravelly land), effectively improving the survival rate and growth vigor of seedlings in the early stage of planting, and significantly reducing the need for irrigation and maintenance.

[0029] Ecological restoration of mining areas: It can be directly used to cover or improve the surface of barren substrates such as tailings ponds and spoil heaps that have undergone engineering treatment, quickly build a plant growth layer with preliminary fertility and water retention functions, and promote pioneer plant settlement and ecological succession.

[0030] Marginal land greening: applicable to soil improvement and vegetation establishment of marginal lands such as sandy land and saline-alkali land (requires salt leaching measures), to enhance land productivity and ecological function.

[0031] Horticultural cultivation: It can be used as a cultivation substrate for potted plants, rooftop greening, and container seedling production, or mixed with traditional garden soil to improve soil physical and chemical properties. It is suitable for home gardening, municipal greening, and professional planting. The application of this substrate can achieve the ecological cycle goal of "treating waste with waste and turning waste into treasure", while significantly reducing the long-term maintenance costs of related projects.

[0032] To compare the performance of different matrix ratios, a control experiment was conducted.

[0033] To investigate the effect of the proportions of key components on matrix performance, examples (E1-E4) and comparative examples (C1, pure tailings sand; C2, commercially available ordinary garden compost) with different proportions were set up. The preparation was carried out according to the basic process described above, and the specific proportions and performance test results are as follows: Table 1 Physicochemical properties of different matrix formulations (formulations for each group are by weight parts)

[0034] Test results show that the organic matter content, water retention capacity, and pore structure of the substrates in each embodiment of the present invention are significantly superior to those of pure tailings sand (C1) and ordinary compost (C2). A comparison of E1-E3 with C1-C2 reveals that the amount of bamboo fiber skeleton significantly affects the water retention rate and porosity of the substrate; the resulting network structure is key to constructing a highly water-retaining, highly porous "cotton-like" substrate. The overall performance of embodiments E1-E4 is far superior to that of C1-C2.

[0035] Verification of the plant cultivation effect of the composite substrate: To verify the practical application effect of this composite substrate, a pot experiment was conducted using Caragana korshinskii, a common shrub species used for vegetation restoration in mining areas. The substrate prepared in Example 1 (test group) was compared with comparative examples C1 (tailings sand control group) and C2 (ordinary compost control group). Ten replicates were set for each group. After planting, the substrates were managed under the same greenhouse environment (25±3℃, natural light). Water management was carried out by weighing; when the substrate moisture content dropped to 30% of its maximum water holding capacity, the substrate was watered uniformly until saturation. No additional fertilizer was applied.

[0036] Table 2 Comparison of growth indicators of Caragana seedlings after 60 days

[0037] The root development index was a comprehensive evaluation based on root length, root volume, and root dry weight, standardized with C1 group as 1.0. The experimental results showed that the test group using the composite substrate of this invention exhibited significantly better survival rate, growth, biomass accumulation, and root development compared to the two control groups (p<0.01). Particularly noteworthy is that the average irrigation interval in the test group reached 10.3 days, approximately 194% longer than the tailings sand control group (C1) and approximately 72% longer than the ordinary compost control group (C2), fully demonstrating the superior water and fertilizer retention capacity and slow-release nutrient characteristics of the substrate of this invention, which can significantly reduce maintenance costs.

[0038] This invention constructs a systematic technical path for the co-utilization of traditional Chinese medicine residue and tailings sand, possessing significant ecological, economic, and industrial value. Through a specific process of "homogenized fermentation-structure construction-encapsulation and mixing," this invention successfully transforms two solid wastes—traditional Chinese medicine residue and tailings sand—into a high-performance composite organic nutrient matrix. This matrix not only achieves high-value resource utilization of waste but also exhibits significant advantages in physical structure, nutrient supply, and water retention, making it particularly suitable for ecological restoration and greening projects with stringent soil requirements.

Claims

1. A composite organic nutrient matrix of traditional Chinese medicine residue and tailings sand, characterized in that, It is composed of a structured organic composite and tailings sand at a mass ratio of 1:(1-3), wherein the structured organic composite is formed by mixing and granulating raw materials comprising the following mass parts: Fermented Chinese medicinal herb residue humus: 40-60 parts; Hydrophilic bamboo fiber skeleton: 10-20 parts; Shredded kelp: 5-10 portions; Dry cakes: 5-10 servings.

2. The composite organic nutrient matrix of traditional Chinese medicine residue and tailings sand according to claim 1, characterized in that, The fermented Chinese herbal medicine residue humus is obtained by crushing Chinese herbal medicine residue from different sources to a particle size of 5-15mm, uniformly adjusting the C / N ratio to 25-30:1, inoculating with compound microbial agents for aerobic fermentation and maturation.

3. The composite organic nutrient matrix of traditional Chinese medicine residue and tailings sand according to claim 1, characterized in that, The hydrophilic bamboo fiber skeleton is a porous hydrophilic fiber material obtained by cutting bamboo into 1-3cm segments and removing the surface wax by soaking in steam or alkaline solution.

4. The composite organic nutrient matrix of traditional Chinese medicine residue and tailings sand according to claim 1, characterized in that, The dried cake is at least one of rapeseed cake and peanut cake.

5. The composite organic nutrient matrix of traditional Chinese medicine residue and tailings sand according to claim 1, characterized in that, The main component of the tailings sand is silicon dioxide, with a content of not less than 60%.

6. The composite organic nutrient matrix of traditional Chinese medicine residue and tailings sand according to claim 1, characterized in that, The organic matter content of the composite organic nutrient substrate is not less than 28%, and the maximum water holding capacity is not less than 85%.

7. A method for preparing a composite organic nutrient matrix of traditional Chinese medicine residue and tailings sand, characterized in that, Includes the following steps: S1: Homogenization fermentation of Chinese herbal medicine residue: The Chinese herbal medicine residue with a moisture content of 50-75% is crushed to a particle size of 5-15mm, and its C / N ratio is adjusted to 25-30:

1. Then, under aerobic conditions, it is inoculated with compound microbial agents and fermented at 45-65℃ for 7-15 days, followed by maturation for 15-30 days to obtain homogenized plant humus material. S2: Preparation of bamboo fiber skeleton: Cut bamboo material into 1-3cm segments, soak them in steam or alkaline aqueous solution, wash and dry them to obtain a hydrophilic porous bamboo fiber skeleton. S3: Preparation of the structured composite: The plant humus material obtained in step S1, the bamboo fiber skeleton obtained in step S2, kelp fragments and dried cake are mixed in a mass ratio of (40–60):(10–20):(5–10):(5–10), and the plant humus material is wrapped and embedded in the bamboo fiber skeleton by low-speed turning and agglomeration granulation to form a cotton ball-like or porous mesh structure. S4: Formation of composite nutrient matrix: The structured composite obtained in step S3 is mixed with tailings sand at a mass ratio of 1:(1–3), and after light compaction, a composite organic nutrient matrix with stable structure and not easy to separate into layers is obtained.

8. The method for preparing a composite organic nutrient matrix of traditional Chinese medicine residue and tailings sand according to claim 7, characterized in that, In step S2, the alkaline aqueous solution is a NaOH solution with a mass concentration of 0.5–1%, and the soaking time is 2–4 hours.

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