A production and preparation method of a multi-source solid waste collaborative preparation liquid regenerated organic planting soil

Abstract

This invention relates to a method for producing liquid recycled organic planting soil by co-processing multiple sources of solid waste, belonging to the field of solid waste resource utilization and ecological environment restoration technology. Specifically, this invention provides a process for co-converting construction waste, demolition debris, engineering mud, coal gangue, and urban and rural organic solid waste to prepare liquid recycled planting soil suitable for ecological restoration. This technology can be applied to land reclamation in coal mining subsidence areas, restoration of degraded urban ecosystems, improvement of agricultural land quality, and treatment of saline-alkali land.

Description

Technical Field

[0001] This invention relates to a method for producing liquid recycled organic planting soil by co-processing multiple sources of solid waste, belonging to the field of solid waste resource utilization and ecological environment restoration technology. Specifically, this invention provides a process for co-converting construction waste, demolition debris, engineering mud, coal gangue, and urban organic solid waste to prepare liquid recycled planting soil suitable for ecological restoration. This technology can be applied to land reclamation in coal mining subsidence areas, restoration of degraded urban ecosystems, improvement of agricultural land quality, and treatment of saline-alkali land. Background Technology

[0002] The large-scale, high-value utilization of bulk solid wastes such as construction waste, coal gangue, and urban and rural organic solid waste is a serious challenge facing the transformation of ecological civilization. Existing technologies face the following prominent bottlenecks in treating these solid wastes, particularly in converting them into planting soil suitable for large-scale ecological restoration: The contradiction between single disposal pathways and high-value utilization: Current utilization of inorganic solid waste such as construction waste and coal gangue is mostly limited to low-value-added methods such as backfilling and road construction, failing to transform them into high-value soil amendment materials. Meanwhile, traditional disposal methods for organic solid waste such as kitchen waste and sewage sludge (such as incineration and landfill) are costly and have low resource utilization rates. The lack of technological pathways for the coordinated disposal of various types of solid waste leads to overall low resource utilization efficiency.

[0003] The form of soil products derived from solid waste is mismatched with the needs of large-scale applications: Existing technologies for preparing planting soil from solid waste generally produce solid or semi-solid products. These products have two inherent drawbacks: First, the production process involves energy-intensive drying and granulation steps, which increases costs; second, when applied to large-scale projects such as mine restoration and desertification control, the costs of loading, unloading, transportation, and on-site paving are extremely high, resulting in low construction efficiency and severely restricting their large-scale application.

[0004] The technological gap between raw material characteristics and product performance requirements: Raw materials such as construction waste and coal gangue often suffer from nutrient deficiency, poor physical structure, and even contain pollutants. Simple physical treatment cannot meet the standards for agricultural or ecological soil. On the other hand, there is a huge market demand for high-quality planting soil, but the traditional model of relying on the mining of natural peat, black soil, and other resources is not only unsustainable but also damages the ecological environment.

[0005] Therefore, the solid waste resource utilization industry urgently needs to break through existing technological paradigms and develop a new type of resource utilization product technology that can achieve multi-source solid waste co-processing, significantly reduce production and application costs, and produce stable performance products that are easy to scale up for construction. In particular, the development of a pumpable and sprayable liquid (or slurry) recycled planting soil is of urgent technological necessity and significant application value for establishing a circular chain of "solid waste disposal - soil remediation". Summary of the Invention

[0006] Technical problems to be solved This invention proposes a method for producing liquid recycled organic planting soil by synergistic preparation of multi-source solid waste. It aims to address the problems in existing technologies, such as low resource utilization rates and high disposal costs for bulk solid waste (especially construction waste, coal gangue, and urban and rural organic solid waste), and the difficulty in meeting the needs of large-scale, low-cost, and high-efficiency soil remediation projects with recycled products. Specifically, the following technical bottlenecks need to be overcome: 1. Multiple types of solid waste are difficult to convert in a coordinated and efficient manner, and single disposal routes are not economically viable; 2. Existing solid waste to soil conversion technologies mostly produce solid products, which have drawbacks such as high energy consumption, inconvenient application, and difficulty in large-scale mechanized construction; 3. The resulting planting substrates generally suffer from uneven nutrient distribution, poor structure, and limited functionality, which do not meet the precise needs of ecological restoration and agricultural improvement. Technical solution

[0007] To address the aforementioned technical problems, this invention provides a method for the synergistic preparation of liquid recycled organic planting soil from multiple solid waste sources. Its core lies in the coupling of three major process modules: "circular scrubbing and pulping," "multi-stage biological transformation and activation," and "liquidation and formulation," thereby achieving high-value conversion of solid waste and the functionalization and liquefaction of the product. The method includes the following steps:

[0008] Construction waste and / or coal gangue are fed into a water-jetting washing machine. The free-fall motion of materials of varying sizes under the water flow causes them to impact and rub against each other, resulting in a cyclical scrubbing process that crushes, washes, and disperses fine particles. Coarse and fine aggregates are separated by screening; larger particles on the screen are crushed and returned to the cyclic scrubbing process. The scrubbing wastewater is collected, concentrated, and precipitated. The frictional heat and mechanical force generated during this process promote particle surface modification, ultimately yielding a highly fluid slurry as a matrix. The slurry has a particle size of less than 0.15 mm, a moisture content of 50%–80%, and a pH value of 7.0–9.0.

[0009] Urban and rural organic solid wastes such as kitchen waste, municipal sludge, garden waste, and agricultural straw are crushed, sorted, and pre-treated before undergoing biological fermentation to obtain an organic slurry rich in organic matter, humic acid, and functional microorganisms. The biological fermentation process can employ one or more of the following methods: high-temperature aerobic fermentation, high-temperature anaerobic fermentation, subcritical water splitting, or enzymatic hydrolysis.

[0010] The highly fluid mud matrix obtained in step 1, the organic slurry obtained in step 2, and other functional additives are mixed in a preset ratio, and the moisture content and pH value of the system are adjusted to obtain a homogeneous, stable, and pumpable liquid regenerated planting soil. Specifically, this includes: 3.1 Compatibility: By dry weight percentage, the inorganic mud matrix (mainly from step 1) accounts for 40% to 70%, the organic matter conversion products (from step 2) account for 20% to 40%, and the functional auxiliary materials account for 0% to 15%.

[0011] 3.2 Activation and Modification: During the blending process, activated coal slurry may be selectively added. The activation treatment includes alkaline boiling to break the cell wall, steam heat treatment or microbial weathering; and functional microbial agents (such as phosphate-solubilizing bacteria, nitrogen-fixing bacteria, potassium-solubilizing bacteria, etc.) may be inoculated.

[0012] 3.3 Parameter Adjustment and Function Addition: The moisture content of the mixture should be adjusted to 50%–70%, and the pH value to 6.0–8.0. Depending on the target application scenario (such as saline-alkali land improvement, slope restoration, and farmland quality improvement), additional nutrients, soil structure improvers, water-retaining agents, or specific plant seeds can be added for customized modification.

[0013] The following provides an exemplary range of dry basis mass percentage ratios: Proportioning Instructions: The above proportions are dry basis percentages. Actual dosage should be adjusted based on the moisture content of each raw material. Activated coal slurry is an optional component; its addition can adjust the proportion of the inorganic slurry matrix accordingly. Beneficial effects

[0014] This invention has the following significant technical, economic and environmental benefits: 1. Collaborative treatment of multi-source solid waste to achieve high-value transformation of waste resources. For the first time, a collaborative conversion technology system for "coal slime-construction slag-urban and rural organic waste" has been established, which simultaneously disposes of more than ten types of bulk solid waste, including construction waste slag, engineering mud, coal gangue washing by-products (low-calorific-value coal slime), kitchen waste, urban sludge, agricultural waste, livestock manure, animal carcasses, garden waste, fly ash, and gypsum. This achieves "waste treatment with waste and synergistic efficiency enhancement", significantly reducing the risk of soil, water and air pollution caused by solid waste accumulation.

[0015] 2. It has achieved efficient and collaborative treatment and low-cost, high-value conversion of multi-source solid waste, solving the economic feasibility and scalability bottlenecks in the solid waste resource utilization industry.

[0016] This invention is the first to construct a three-in-one synergistic conversion technology system integrating "construction waste / sludge-coal slime-urban and rural organic solid waste," which can simultaneously process multiple types of bulk solid waste, transforming traditionally costly waste disposal into core raw materials. Through process integration and "waste-to-waste treatment," the overall cost of raw materials can be reduced by 60% to 100% (i.e., achieving "negative cost" raw materials), fundamentally solving the industry pain points of limited single solid waste disposal pathways and poor economic efficiency, and providing an economically feasible foundation for the large-scale industrialization of solid waste resource utilization.

[0017] This technology reduces landfill space and secondary pollution risks at the source through the co-processing of solid waste. The produced liquid planting soil can directly replace the mining of scarce natural resources such as peat and black soil, avoiding ecological damage. At the same time, by returning organic matter to the field, it can effectively enhance soil carbon sequestration, improve degraded arable land, and has significant carbon sequestration and emission reduction benefits, forming a green cycle of "treating waste with waste, nourishing soil with waste, and increasing efficiency through carbon sequestration".

[0018] 4. Overcome key technological bottlenecks and significantly reduce costs. By using a pre-processed solid waste recycled aggregate production line, not only are stones and other impurities removed, but most insect eggs and bacteria are also eliminated through intense friction and impact, ultimately yielding a pure and highly fluid slurry. Furthermore, from an economic perspective, the upstream recycled aggregate products can cover all operating costs, significantly reducing the cost of slurry preparation and thus enabling negative cost raw materials for recycled soil production.

[0019] 5. The product has superior performance and is suitable for large-scale mechanized soil remediation. Attached Figure Description Figure 1 This is a process flow diagram of a method for preparing liquid recycled organic planting soil by synergistic preparation of multi-source solid waste according to the present invention. Detailed Implementation

[0020] Example 1: Preparation of liquid recycled planting soil for reclamation of coal mining subsidence areas Raw material ratio (dry basis): 50% construction waste slurry, 25% low-calorific-value coal slime, 25% urban organic solid waste (dewatered sludge: kitchen waste: garden waste = 2:3:5); Coal slime alkali boiling and cell wall breaking: 2% dilute alkali solution was prepared from industrial waste alkali, with a liquid-to-solid ratio of 3:1. The solution was boiled at 90℃ for 3 hours. After neutralization, the pH was 7.8, and the organic matter dissolution rate was 42%. High-temperature anaerobic fermentation: The pretreated organic solid waste is mixed according to the designed ratio, and the moisture content of the mixture is adjusted to 58% and the C / N ratio to 28:1. It is placed in a biogas digester and fermented at 60℃ for 12 days.

[0021] Liquid preparation: After mixing biogas slurry, mud, other solid waste, microbial inoculants, and seeds, the moisture content is adjusted to 65% and the pH to 7.0. Phosphate-solubilizing bacteria and nitrogen-fixing bacteria are added to make liquid planting soil.

[0022] Ambient temperature aerobic natural maturation: The uniformly mixed material is pumped or transported by tanker truck and directly applied to the plot to be remediated, where it matures naturally at ambient temperature and aerobic conditions. Product specifications: 18% organic matter (dry basis), 10% total humic acid (dry basis), 95% seed germination index, pH 7.0, meets GB 15618-2018 heavy metal risk screening values, reduces production costs by 30%, and increases construction efficiency by 60%.

[0023] Example 2: Preparation of Liquid Regenerated Planting Soil for Ecological Restoration of Urban Slopes High-temperature aerobic fermentation: Urban and rural organic solid waste with a moisture content of 56% and a C / N ratio of 26:1 is fed into a biogas digester and fermented at 58℃ for 11 days. Coal slime alkali boiling and cell wall breaking: 1.5% dilute alkali solution was prepared from industrial waste alkali, with a liquid-to-solid ratio of 3:1. The solution was boiled at 85℃ for 2.5 hours. After neutralization, the pH was 7.6, and the organic matter dissolution rate was 40%. Raw material ratio (dry basis): 55% construction waste slurry, 20% low-calorific-value coal slime, and 25% urban and rural organic solid waste (kitchen waste: garden waste = 4:6); Liquid preparation: After mixing biogas slurry, mud, other solid waste, microbial inoculants, and seeds, the moisture content is adjusted to 58% and the pH to 6.8. Bermuda grass, Amorpha fruticosa seeds, and water-retaining agents are added to make a liquid planting soil that can be sprayed.

[0024] Ambient temperature aerobic natural maturation: The uniformly mixed material is pumped or transported by tanker truck and directly applied to the plot to be remediated, where it matures naturally at ambient temperature and aerobic conditions. Product specifications: 16% organic matter (dry basis), 9% total humic acid (dry basis), 92% seed germination index, can be high-pressure sprayed on steep slopes, water retention is 30% higher than traditional topsoil, production costs are reduced by 50%, and construction efficiency is increased by 40%.

Claims

1. A production and preparation method of multi-source solid waste synergistically preparing liquid regenerated organic planting soil, characterized in that, Includes the following steps: a. Preparation of high-flowability mud matrix: Heavy solid waste such as construction waste and / or coal gangue of mixed particle sizes is fed into a water mill washing equipment. The free fall motion of the materials of different particle sizes under the water flow causes them to impact and rub against each other, which is used to achieve material crushing, washing and dispersion of mud particles. After rinsing and screening to separate coarse and fine aggregates, the large particles on the screen are crushed and returned to the circulating washing process. Finally, the washing wastewater is concentrated and precipitated. The frictional heat and mechanical force generated in the process promote the surface modification of particles to obtain high-flowability mud as a matrix for liquid recycled organic planting soil. b. Organic matter conversion: After treating urban and rural organic solid waste, organic slurry or powder is obtained, which serves as a microbial carrier, carbon source and loose framework material for liquid regenerated organic planting soil. c. Liquid formulation: Mix the mud matrix obtained in step (1), the organic matter obtained in step (2), and other functional additives, adjust the moisture content to a pumpable state, and obtain a liquid multi-source solid waste recycled organic planting soil product.

2. The method of claim 1, wherein: The high-flowability mud obtained in step (1) has a particle size of less than 0.15 mm, a water content of 50%–80%, and a pH value of 7.0–9.

0.

3. The method according to claim 1 or 2, characterized in that, Step (1) further includes: activating the coal slime, wherein the activation treatment includes one or more of mechanical grinding, alkaline boiling to break the cell wall, steam heat treatment, and microbial weathering.

4. The method according to claim 1, characterized in that, The bio-fermentation process in step (2) adopts one or a combination of the following methods: a. High-temperature aerobic fermentation: Adjust the moisture content of organic solid waste to 50%-65%, inoculate with compound microbial agents, and ferment at 50℃-70℃ for 7-20 days; b. High-temperature anaerobic fermentation: Organic solid waste is put into an anaerobic reactor and fermented at 50℃-65℃ for 10-20 days to produce biogas slurry and stabilized organic matter; c. Subcritical water splitting or enzymatic hydrolysis.

5. The method according to claim 1, characterized in that, The functional auxiliary materials in step (3) include one or more of the following: fly ash, gypsum, phosphogypsum, dried sludge, water-retaining agent, nutrients, and plant seeds.

6. The method according to claim 1, characterized in that, In step (3), the components are as follows by dry weight percentage: inorganic mud matrix: 40%-70%, organic matter conversion products: 20%-40%, functional additives: 0%-15%.

7. The method according to claim 1, characterized in that, Step (3) also includes inoculating with functional microbial agents, which include one or more of phosphate-solubilizing bacteria, nitrogen-fixing bacteria, potassium-solubilizing bacteria, lignin-decomposing bacteria, and plant rhizosphere growth-promoting bacteria.

8. A liquid regenerated planting soil prepared by the method according to any one of claims 1-7, characterized in that, It is a homogeneous slurry with a moisture content of 50%–70%, and can be directly pumped for application.

9. The liquid recycled planting soil according to claim 8, characterized in that, The following technical indicators must be met: organic matter content (dry basis) ≥12%, total humic acid content (dry basis) ≥5%, seed germination index ≥80%, pH value 6.0-8.0, and heavy metal content must meet the risk screening value requirements of GB 15618-2018.

10. The liquid recycled planting soil according to claim 8 or 9, characterized in that, It is transported by tanker trucks or pumping systems and applied by spraying, trenching or hydroseeding.

11. The application of liquid regenerated planting soil according to any one of claims 8 to 10 in the field of soil remediation.

12. The application according to claim 11, characterized in that, The application scenarios include rooftop planting, reclamation of coal mining subsidence areas, ecological restoration of slopes, improvement of degraded farmland, treatment of saline-alkali land, and landscaping or facility agriculture substrates.

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