Earthworm biotransformation-based solid waste-lunar soil synergistic improvement and crop cultivation method

Abstract

The invention provides a solid waste-lunar soil synergistic improvement and crop cultivation method based on earthworm biotransformation, which comprises the following steps: drying, sterilizing and crushing organic solid wastes generated by a biological regenerative life support system (BLSS), mixing with water, performing ultrasonic extraction, and separating to obtain a nutrient solution and extraction residues; mixing the residues with lunar soil in proportion, inoculating earthworms, and performing aerobic co-fermentation to obtain biological improved lunar soil; finally, the lunar soil is directly used for crop cultivation, and the leach liquor is used as nutritional supplement. According to the method, the biotransformation effect of the earthworms is utilized, solid waste recycling and lunar soil structure function improvement are synchronously achieved, solid waste-lunar soil-crop closed-loop substance circulation is formed, and the method has the outstanding advantages that resource utilization in the system is efficient, the improvement effect is synergistic and lasting, and the extraterrestrial applicability is high.

Description

Technical Field

[0001] This invention relates to the field of in-situ utilization of extraterrestrial resources, and more specifically, to a method for the synergistic improvement of solid waste and lunar soil and crop cultivation based on earthworm biotransformation. Background Technology

[0002] With the ongoing advancement of manned lunar exploration and the construction of lunar bases, achieving long-term autonomous human survival on extraterrestrial bodies has become a key objective of deep space exploration. Against this backdrop, Bioregenerative Life Support Systems (BLSS) are considered a core technological approach to solving this problem. BLSS aims to regenerate essential life support substances such as oxygen, water, and food through the synergistic effects of biological components such as plants, animals, and microorganisms within the system, thereby constructing a relatively closed, self-sustaining life support environment.

[0003] However, BLSS inevitably generates a large amount of organic solid waste during operation, such as inedible parts of plants after harvest (e.g., straw, roots, old leaves) and human excrement from crew members. Directly discarding this organic solid waste or subjecting it to only simple fermentation not only occupies valuable cabin space but also leads to a significant waste of the organic matter, nitrogen, phosphorus, potassium, and other ash mineral nutrients it contains, severely restricting the material closure and operational efficiency of the BLSS system. Therefore, how to efficiently and thoroughly treat this solid waste generated within the system and achieve its resource reuse is one of the core challenges in improving the closure of the BLSS system.

[0004] On the other hand, lunar regolith, due to its unique formation environment and composition, generally suffers from a lack of organic matter, poor viscosity, compact structure, low porosity, and extremely poor water and fertilizer retention capacity, making it unsuitable for direct use as a substrate for crop cultivation. To achieve crop production on the moon, the physical and chemical properties of the lunar regolith must be improved. Traditional methods of lunar regolith improvement often rely on adding chemical binders, synthetic fertilizers, or other soil conditioners carried from Earth. This method not only increases the mass and cost of payloads launched from Earth, but also makes it difficult for these additives to regenerate in situ on the moon once consumed, failing to meet the needs of long-term, sustainable lunar stays and constituting another technological bottleneck for extraterrestrial agricultural development.

[0005] Earthworms, renowned "ecosystem engineers" in nature, play a crucial role in the material cycle and soil formation of terrestrial ecosystems. Through feeding and excretion, they significantly accelerate the degradation and transformation of organic matter; their secreted mucus and aggregated feces (earthworm castings) effectively improve soil aggregate structure and enhance substrate aeration, permeability, and water retention. Introducing this powerful biotransformation capacity of earthworms into the BLSS system to mediate the synergistic improvement of organic solid waste and lunar soil can theoretically achieve the dual goals of solid waste resource utilization and lunar soil maturation simultaneously. This represents a potential key technology for low-cost, sustainable improvement of BLSS system closure and agricultural output.

[0006] However, in existing BLSS (Biochemical Solid Waste Surgery) technology systems, lunar soil improvement and organic solid waste treatment are typically designed and operated as two separate processes, failing to fully explore and utilize the inherent synergistic and coupling effects of biotransformation. This technological fragmentation leads to low resource utilization efficiency, complex system configuration, and the failure to form a complete material cycle. Therefore, there is an urgent need in this field for an innovative technological solution that can organically integrate solid waste treatment, lunar soil improvement, and plant cultivation, fully utilizing the biological resources within the system to overcome the aforementioned technical obstacles. Summary of the Invention

[0007] In view of this, the present invention proposes a method for the synergistic improvement of solid waste and lunar soil and crop cultivation based on earthworm biotransformation, in order to solve the problems existing in the prior art. By utilizing organic solid waste, earthworms and standby equipment in the BLSS system, the method can synergistically achieve solid waste treatment and lunar soil improvement, increase crop yield and reduce extraterrestrial residence costs.

[0008] To achieve the above objectives, this invention proposes a method for the synergistic improvement of solid waste and lunar soil based on earthworm biotransformation and for crop cultivation, comprising the following steps: (1) Pretreatment: Acquire and pretreat organic solid waste, including drying, sterilization and pulverization; (2) Extraction: The pulverized solid waste obtained in step (1) is mixed with water and subjected to extraction treatment to separate the extract and the extraction residue. (3) Mixing and inoculation: Mix the extraction residue obtained in step (2) with lunar soil or simulated lunar soil in a certain proportion, add water to adjust the moisture, and inoculate earthworms to form a mixed substrate; (4) Co-fermentation: The mixed substrate obtained in step (3) is co-fermented under aerobic conditions. Through the synergistic effect of earthworms and microorganisms, biologically improved lunar soil is obtained. (5) Cultivation: The bio-modified lunar soil obtained in step (4) is used for crop cultivation, and the extract obtained in step (2) is used as a nutrient solution during the cultivation process.

[0009] Furthermore, the organic solid waste mentioned in step (1) originates from the Bioregenerative Life Support System (BLSS), which includes inedible plant parts and human excrement; the preparation ratio is as follows: water 50%-70%, inedible plant parts dry weight 25%-75%, and human excrement dry weight 0%-10%; the drying temperature in the pretreatment is 15°C to 120°C.

[0010] Furthermore, in step (2), the mass ratio of the pulverized solid waste to water is not higher than 1:8; the extraction treatment includes ultrasonic treatment.

[0011] Furthermore, in step (3), the dry mass mixing ratio of the extraction residue with lunar soil or simulated lunar soil is in the range of 1:10 to 1:100.

[0012] Furthermore, in step (3), a microbial agent is added during mixing, and the microbial agent comes from the solid waste fermentation treatment module of the BLSS system.

[0013] Furthermore, in step (3), the amount of earthworms added is 0.5%-5.0% of the total volume of the mixture; the moisture content of the mixture after adding water and conditioning is 55%-80%.

[0014] Furthermore, in step (4), the co-fermentation temperature is 15℃-30℃, and the duration is 5 days-200 days; the earthworm is Eisenia fetida (Eisenia fetida). Eisenia fetida ).

[0015] Furthermore, in step (3), if the mixed substrate shows toxicity to earthworms, the substrate in the cultivation trough is divided into heterogeneous zones, namely a mixed substrate zone and a pure lunar soil zone, to provide refuge for earthworms.

[0016] The present invention also provides a biologically improved lunar soil prepared by the method described above, which contains earthworms, earthworm castings, biotransformed organic matter and lunar soil, and has improved granular structure and nutrient content, and can be directly used for crop cultivation.

[0017] The present invention also provides a system for implementing the method described above, the system being integrated within a bioregenerative life support system, comprising sequentially connected components: The solid waste treatment module is used to receive and pre-treat organic solid waste; The extraction module is used for extraction and solid-liquid separation of pretreated solid waste; The mixing and conditioning module is used to mix leaching residue, lunar soil or simulated lunar soil, water, and optional microbial agents; A co-fermentation module is used to contain the mixed substrate and inoculate earthworms for aerobic co-fermentation. The plant cultivation module is used to receive the co-fermented bio-modified lunar soil and cultivate crops. The extract produced by the extraction module is transported to the plant cultivation module as a nutrient solution.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention achieves highly efficient synergy between solid waste resource utilization and lunar soil improvement through earthworm-mediated biotransformation. The entire scheme relies on the circulating resources within the BLSS system to transform organic solid waste such as plant straw and human excrement into high-value products, significantly reducing the dependence of extraterrestrial stays on Earth's resupply and significantly improving the system's material closure.

[0019] Earthworms, acting as the core biological engine, simultaneously stabilize solid waste and improve lunar soil structure during their feeding and excretion processes. The earthworm castings they produce naturally bind lunar soil particles, effectively reducing bulk density, increasing porosity, and enhancing water and fertilizer retention capacity, forming an ideal cultivation substrate that combines physical structure and nutrient supply.

[0020] The unique ultrasonic extraction pretreatment achieves the best results while avoiding the worst, efficiently extracting plant nutrient solution while removing harmful salts and microorganisms from earthworms, creating a safe environment for subsequent biotransformation. Optimized parameter ranges and heterogeneous partitioning design further enhance the system's adaptability and robustness in the face of extraterrestrial environmental fluctuations, ensuring the stable operation of the lunar farm. Attached Figure Description

[0021] Figure 1 This is a process flow diagram of the solid waste-lunar soil synergistic improvement and crop cultivation method based on earthworm biotransformation of the present invention. Detailed Implementation

[0022] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0023] All raw materials used in this invention are not particularly limited in their source; they can be purchased from the market or prepared using conventional methods known to those skilled in the art.

[0024] There are no particular restrictions on the purity of any of the raw materials used in this invention. However, this invention preferably uses raw materials of analytical grade or purity commonly used in the field of chemical synthesis.

[0025] This invention provides several specific implementation scenarios for a method of co-improving solid waste and lunar soil based on earthworm biotransformation and crop cultivation. The overall process of the method can be found in [reference needed]. Figure 1 As shown, it systematically demonstrates the entire process from solid waste pretreatment, extraction, mixing, inoculation with earthworms for co-fermentation to final crop cultivation.

[0026] Example 1: Earthworm-mediated solid waste-lunar soil improvement (basic case study) This embodiment was conducted in a simulated "Lunar Palace 1" BLSS system environment. Wheat was grown within the system to provide food, while simultaneously generating large quantities of inedible plant parts (such as straw and roots) and human excrement. The goal of this embodiment is to treat these organic solid wastes and utilize them to prepare an improved lunar soil substrate suitable for plant cultivation.

[0027] Raw materials and equipment: Lunar soil: The lunar soil was simulated using JSC-1A, and its basic physical and chemical properties are close to those of real lunar basalt weathered soil.

[0028] Organic solid waste: a mixture of wheat straw and human excrement from the BLSS system, in a semi-composted state, produced by aerobic fermentation.

[0029] Earthworms: "Jinong No. 6" Eisenia fetida (…) Eisenia fetida This variety is highly adaptable to temperature (15℃-25℃) and has been sterilized before inoculation to ensure it is free of pathogenic microorganisms.

[0030] Equipment: Co-fermentation tank (50 L capacity, with temperature control, aeration and spraying functions) of the BLSS system solid waste treatment module, mixer (50 r / min speed), electronic scale (0.1 kg accuracy), ultrasonic vibrator, and moisture analyzer.

[0031] Specific steps: 1. Solid Waste Pretreatment and Extraction: First, the collected organic solid waste is subjected to dry heat sterilization at 160℃ for 30 minutes to kill potential pathogens. After cooling, it is pulverized using a pulverizer to pass through a 2mm sieve. 100 g of the treated solid waste powder is weighed and added to 800 g of deionized water at a mass ratio of 1:8. The mixture is then placed in an ultrasonic vibrator and ultrasonically treated at 40kHz and 300W for 2 hours to fully extract soluble nutrients from the solid waste. Subsequently, the mixture is centrifuged (3000 rpm, 10 min) to obtain the supernatant as the extraction nutrient solution. The precipitate is the extraction residue, which is dried at 80℃ to constant weight.

[0032] 2. Material Mixing: Weigh 1.4 kg of lunar soil and 30 g of the extracted solid waste residue obtained in the above steps (i.e., the mass ratio of lunar soil to solid waste residue is approximately 47:1) based on dry weight. Put both into a mixer and mix at 50 r / min for 15 minutes until they are uniformly mixed to obtain preliminary dry material.

[0033] 3. Earthworm Inoculation and Moisture Conditioning: Inoculate 10 healthy and active Eisenia fetidae earthworms into the uniformly mixed dry material. Simultaneously start the spraying equipment to spray deionized water, and ensure the moisture is evenly distributed while the mixer is running continuously (50 r / min, 10 minutes). The final moisture content of the material is precisely controlled to 75% using a moisture meter.

[0034] 4. Aerobic Co-fermentation: The inoculated and humidified mixture is transferred to a co-fermentation chamber and subjected to aerobic co-fermentation for 10 days at a constant temperature of 20±2℃. During this period, the oxygen concentration in the substrate is maintained through an aeration system to simulate the synergistic effect between earthworms and microorganisms.

[0035] 5. Crop Cultivation Verification: After co-fermentation, without removing the earthworms, this bio-modified lunar soil was directly used as a substrate and placed into the crop cultivation trough. Wheat seeds were sown on its surface, and during cultivation, the extracted nutrient solution prepared in step 1 (diluted 5 times) was regularly irrigated. The soil was exposed to 12 hours of light per day, and the temperature was maintained at 22±2℃.

[0036] Effect verification: Physical properties: The bulk density of the improved lunar soil increased from the original 1.62 g / cm³. 3 Reduced to 0.85 g / cm³ 3 (47.5% reduction); the proportion of water-stable aggregate structure (particle size 0.25 mm - 2 mm) increased to 52% (original simulated lunar soil <10%); saturated water content increased from 20% to 35% (75% increase).

[0037] Chemical characteristics: Total nitrogen content increased significantly from 0.02% to 0.22%; available phosphorus content increased from <5 mg / kg to 25 mg / kg; humic acid content increased from undetectable to 6.8%.

[0038] Plant cultivation results: Wheat planted with the improved lunar soil as a substrate achieved a germination rate of 98% after 5 days (compared to only 72% in the original simulated lunar soil); the average seedling length at the 10-day stage was 11.3 cm (compared to 7.2 cm in the original lunar soil); and after 20 days of growth, the average plant height reached 35 cm (compared to only 18 cm in the original lunar soil). These results fully verify the excellent feasibility of using the bio-improved lunar soil prepared by this method as a plant cultivation substrate.

[0039] Comparative Example 1 This comparative example aims to illustrate that, without earthworm biotransformation, simply mixing organic solid waste with lunar soil has extremely limited improvement effects.

[0040] Procedure: Except for not inoculating with earthworms, the other steps are exactly the same as in Example 1. After mixing and conditioning the materials, let them stand for 10 days under the same conditions.

[0041] Results: After 10 days, the matrix structure was loose, with no obvious granular structure forming. The bulk density was 1.45 g / cm³. 3 The soil structure decreased by only 10.5%; the proportion of granular structure was 15%; and the saturated moisture content was 25%. After planting wheat, the germination rate was 78% after 5 days and the plant height was 22 cm after 20 days. All indicators were significantly lower than those in Example 1, proving that the biological role of earthworms is the key to achieving significant improvement in lunar soil structure and fertility.

[0042] Example 2: Changing the ratio of lunar soil to solid waste and the fermentation time This embodiment explores the effects of the ratio of lunar soil to solid waste and the co-fermentation time on the improvement effect.

[0043] Operation: The basic steps are the same as in Example 1, but the dry weight ratio of lunar soil to the extracted solid waste residue is adjusted to 20:1 (i.e., 1.0 kg of lunar soil to 50 g of solid waste residue). Simultaneously, the aerobic co-fermentation stage is extended to 30 days. The earthworm inoculation amount and moisture content remain unchanged.

[0044] Results: Compared with Example 1 (10-day fermentation), extending the fermentation time further increased the humic acid content of the improved lunar soil to 8.5%, and the proportion of granular structure reached 58%. When planting lettuce, the leaves were thicker, and the biomass (fresh weight) was about 15% higher than that of lettuce harvested at the same time in Example 1. This indicates that, under appropriate ratios, appropriately extending the co-fermentation time with earthworms helps to further mature the substrate and improve its fertility.

[0045] Comparative Example 2 This comparative example illustrates the potential problems that may arise from the direct use of organic solid waste without prior leaching or extraction pretreatment.

[0046] Operation: The basic steps are the same as in Example 1, but the "solid waste extraction" step is omitted. The sterilized and pulverized solid waste is directly mixed with lunar soil in the same proportion and inoculated with earthworms.

[0047] Results: During co-fermentation, reduced earthworm activity was observed, and some earthworms attempted to escape the mixed substrate. After fermentation, the substrate electrical conductivity (EC value) was found to be high, reaching 3.5 mS / cm, indicating salt accumulation. When wheat was subsequently planted, the seedlings exhibited mild salt stress symptoms and grew at a slower rate than in Example 1. This comparative example demonstrates that ultrasonic extraction pretreatment can effectively remove some soluble salts that are detrimental to earthworms and crops, and is a crucial step in ensuring successful biotransformation and healthy crop growth.

[0048] Example 3: Using different earthworm species This embodiment verifies the effectiveness of other applicable earthworm varieties.

[0049] Operation: The basic steps are the same as in Example 1, but the earthworm species is changed to "Daping No. 2" Eisenia fetida. All material ratios and environmental parameters remain the same.

[0050] Results: The bulk density of the improved lunar soil decreased to 0.88 g / cm³. 3 The granular structure accounted for 50%, the wheat germination rate was 96%, and the plant height after 20 days was 34 cm. Its improvement effect was comparable to that of "Jinong No. 6," indicating that the method described in this invention is universally applicable to the adaptable Eisenia fetida species, which is commonly used in organic waste treatment.

[0051] Example 4: Continuous Production Mode Integrated into BLSS This embodiment simulates the continuous and modular operation of this method in a real lunar base BLSS.

[0052] Operation: such as Figure 1 As shown, the system includes a solid waste treatment module, a mixing and conditioning module, an earthworm co-fermentation module, and a plant cultivation module. Inedible plant parts and human excrement continuously enter the solid waste treatment module for aerobic fermentation until semi-decomposed. A portion of the semi-decomposed solid waste is dried, crushed, and ultrasonically extracted; the residue is then mixed with fresh lunar soil in a specific ratio in the mixing and conditioning module. Another portion of the semi-decomposed solid waste can be directly added to the mixing module as a microbial inoculant. After the mixture is moistened, it enters the earthworm co-fermentation module for continuous improvement. The improved substrate is transported in batches to the plant cultivation module for crop production. The inedible parts produced after crop harvest return to the solid waste treatment module, forming a complete closed-loop material cycle of "solid waste-lunar soil-crop-solid waste".

[0053] Results: After 60 days of operation, the total amount of lunar soil improvement substrate in the system steadily increased, crop yield tended to stabilize, and dependence on external fertilizer input decreased by more than 70%. This proves that the present invention is not only an effective improvement method, but also a highly closed resource recycling system solution suitable for long-term extraterrestrial residence.

[0054] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A method for co-improvement of solid waste and lunar soil and crop cultivation based on earthworm biotransformation, characterized in that, Includes the following steps: (1) Pretreatment: Acquire and pretreat organic solid waste, including drying, sterilization and pulverization; (2) Extraction: The pulverized solid waste obtained in step (1) is mixed with water and subjected to extraction treatment to separate the extract and the extraction residue. (3) Mixing and inoculation: Mix the extraction residue obtained in step (2) with lunar soil or simulated lunar soil in a certain proportion, add water to adjust the moisture, and inoculate earthworms to form a mixed substrate; (4) Co-fermentation: The mixed substrate obtained in step (3) is co-fermented under aerobic conditions. Through the synergistic effect of earthworms and microorganisms, biologically improved lunar soil is obtained. (5) Cultivation: The bio-modified lunar soil obtained in step (4) is used for crop cultivation, and the extract obtained in step (2) is used as a nutrient solution during the cultivation process.

2. The method as described in claim 1, characterized in that, The organic solid waste mentioned in step (1) originates from the Bioregenerative Life Support System (BLSS), including inedible plant parts and human excrement; The preparation ratio is as follows (by weight): water 50%-70%, inedible plant parts dry weight 25%-75%, and human excrement dry weight 0%-10%; the drying temperature in the pretreatment is 15℃ to 120℃.

3. The method as described in claim 1, characterized in that, In step (2), the mass ratio of the pulverized solid waste to water is not higher than 1:8; the extraction treatment includes ultrasonic treatment.

4. The method as described in claim 1, characterized in that, In step (3), the dry mass mixing ratio of the extraction residue with lunar soil or simulated lunar soil is in the range of 1:10 to 1:

100.

5. The method as described in claim 1, characterized in that, In step (3), a microbial agent is added during mixing. The microbial agent comes from the solid waste fermentation treatment module of the BLSS system.

6. The method as described in claim 1, characterized in that, In step (3), the amount of earthworms added is 0.5%-5.0% of the total volume of the mixture; the moisture content of the mixture after adding water and conditioning is 55%-80%.

7. The method as described in claim 1, characterized in that, In step (4), the co-fermentation temperature is 15℃-30℃, and the duration is 5 days-200 days; the earthworm is Eisenia fetida (Eisenia fetida). Eisenia fetida ).

8. The method as described in claim 1, characterized in that, In step (3), if the mixed substrate shows toxicity to earthworms, the substrate in the cultivation trough is divided into heterogeneous zones, namely a mixed substrate zone and a pure lunar soil zone, to provide refuge for earthworms.

9. A bio-modified lunar soil prepared by the method described in any one of claims 1-8, characterized in that, It contains earthworms, earthworm castings, biotransformed organic matter, and lunar soil, and has improved granular structure and nutrient content, making it suitable for direct use in crop cultivation.

10. A system for implementing the method according to any one of claims 1-8, characterized in that, The system is integrated within a bioregenerative life support system and includes sequentially connected components: The solid waste treatment module is used to receive and pre-treat organic solid waste; The extraction module is used for extraction and solid-liquid separation of pretreated solid waste; The mixing and conditioning module is used to mix leaching residue, lunar soil or simulated lunar soil, water, and optional microbial agents; A co-fermentation module is used to contain the mixed substrate and inoculate earthworms for aerobic co-fermentation. The plant cultivation module is used to receive the co-fermented bio-modified lunar soil and cultivate crops. The extract produced by the extraction module is transported to the plant cultivation module as a nutrient solution.

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