Soil conditioner for dry-hot valley region as well as preparation method and application of soil conditioner

Abstract

The invention relates to the technical field of solid waste treatment, in particular to a soil conditioner for a dry and hot valley region and a preparation method and application thereof.The preparation method comprises the following steps that S1, a complex microbial inoculant is prepared, strains are loaded to an immobilization carrier, and the immobilization carrier is porous activated carbon activated through acid pickling; s2, kitchen waste solid waste, landscaping solid waste and sewage plant sludge which are different in source are pretreated and then mixed, and a mixed material is obtained; s3, inoculating the mixed material obtained in the step S2 with the complex microbial inoculant obtained in the step S1, and then carrying out closed humidity-controlled fermentation, secondary decomposition and conditioning. According to the method, the process stability and the treatment efficiency are remarkably improved, the interference of a dry and hot environment on the fermentation process is effectively overcome, the continuous stability of the high-temperature fermentation period is ensured, the total fermentation period is shortened to 25-35 days, and the efficiency is remarkable.

Description

Technical Field

[0001] This invention relates to the field of solid waste treatment technology, specifically to a soil conditioner for hot and dry valley regions, its preparation method, and its application. Background Technology

[0002] In the operation system of hydropower stations, organic solid waste mainly comes from three types of scenarios: First, kitchen waste generated by staff canteens and ancillary facilities, characterized by high organic matter content (usually exceeding 60%), but also high moisture (70%-85%) and salt content (NaCl content of about 1%-3%), which is easy to decompose and ferment, releasing malodorous gases such as ammonia and hydrogen sulfide; Second, garden waste generated from the maintenance of landscaping in the station area, including pruned branches, fallen leaves, grass clippings, etc., with an annual output of about 15%-20% of the green area in the station area, mainly composed of cellulose, hemicellulose and lignin, with a resource utilization rate of less than 10% under traditional treatment methods; Third, residual sludge generated from the operation of supporting sewage treatment plants, which has a prominent risk of accumulation of organic matter content (30%-50%), microbial activity (flocs and pathogens) and heavy metals (such as Pb, Cd, Zn, etc.), and can easily cause secondary pollution if not properly disposed of.

[0003] Currently, although a certain system of treatment technologies for the above three types of organic solid waste has been formed, they all have significant limitations and are difficult to adapt to the resource utilization needs of the special environment of dry and hot river valleys. Traditional methods for treating kitchen waste mainly involve landfill or simple composting. While landfilling is simple to operate, its high water content easily leads to leachate seeping into and polluting groundwater. Furthermore, in hot and dry environments, the methane generation rate in landfills is accelerated (30%-50% higher than in humid areas), resulting in significant greenhouse gas emissions. Simple composting, on the other hand, is limited by the large fluctuations in microbial activity under hot and dry climates (high temperatures in summer inhibit mesophilic bacteria, and low temperatures in winter inhibit thermophilic bacteria). The composting cycle is long (usually 6-12 months), and the high salinity easily causes salinization of the compost pile (electrical conductivity EC > 8 dS / m). The final product has low fertilizer efficiency and weak soil improvement function.

[0004] The disposal of landscaping waste is becoming increasingly inefficient, with over 90% being directly transported to waste dumps or incinerated in the open. Waste dumping not only occupies a large amount of land (approximately 1.5 acres per 10,000 cubic meters of waste), but also releases methane due to the slow degradation of lignin (an average annual emission coefficient of approximately 0.1 t CH4 / 1,000 tons of waste). While incineration can reduce volume (weight reduction rate > 80%), the incineration temperature fluctuates easily in the dry and hot environment (often below 850℃), increasing the risk of persistent organic pollutants (POPs) such as dioxins. Furthermore, the incineration residue (accounting for approximately 10%-15%) still requires secondary treatment, resulting in significant resource waste.

[0005] Wastewater treatment sludge is primarily treated by dewatering and then sanitary landfilling. Some hydropower stations have experimented with drying and incineration processes, but these are costly (approximately 300-500 RMB / ton). Dewatered sludge typically still has a moisture content of 60%-80%, and direct landfilling can easily overload landfills (wet sludge has a volume approximately three times that of dry sludge). Furthermore, heavy metals (such as Pb, which can reach 200-500 mg / kg) are difficult to stabilize in a dry and hot environment due to the inhibition of microbial activity, posing a long-term pollution risk. Incineration, on the other hand, faces problems such as high energy consumption (requiring additional fuel to reach a calorific value >3500 kJ / kg) and low ash utilization value (heavy metal leaching toxicity limits its application in building materials).

[0006] Existing treatment technologies mostly target single types of solid waste, lacking a systematic approach to synergistic treatment. For example, the high nitrogen content (C / N ratio of approximately 15:1) of kitchen waste can complement the high carbon content (C / N ratio > 40:1) of garden waste, and composting the two can optimize the carbon-nitrogen balance. Microbial communities in sludge (such as Bacillus subtilis) can enhance the degradation efficiency of both kitchen and garden waste. Furthermore, the biogas residue produced from the co-digestion of these three wastes, after harmless treatment, can precisely meet the demand for "high organic matter, low salinity, and weakly alkaline" fertilizers for landscaping in arid and hot valley regions (the local soil pH is mostly between 7.5 and 8.5, requiring regulating organic fertilizers). However, existing technologies have not yet developed synergistic treatment processes tailored to the climatic characteristics of arid and hot valleys (such as high temperatures accelerating reactions, drought limiting water, and ultraviolet radiation inhibiting microorganisms), resulting in low resource utilization efficiency (comprehensive utilization rate < 20%) and continuously increasing environmental pressure.

[0007] Therefore, there are two unresolved technical bottlenecks in the promotion and application of existing organic solid waste composting technology in arid and hot valley regions: First, there is a conflict between maintaining moisture and high-temperature fermentation. Efficient aerobic fermentation relies on sustained temperatures above 55°C to ensure rapid degradation of organic matter and inactivation of pathogens. However, in hot, dry valleys, the combined effects of high temperatures and the heat generated during fermentation significantly accelerate the evaporation of moisture from the material. Once the moisture content of the material falls below the microbial activity threshold (typically 50%), the fermentation process is severely inhibited or even interrupted, resulting in incomplete composting.

[0008] Second, there is a contradiction between high-temperature fermentation and nitrogen retention. High temperature is a necessary condition for fermentation, but it also significantly promotes the conversion of organic nitrogen to ammonium nitrogen, and in a high pH environment, it exacerbates the volatilization loss of ammonium nitrogen in the form of ammonia (NH3). This results in low nitrogen nutrient content in the final product, seriously affecting its quality as a fertilizer or soil conditioner.

[0009] Therefore, developing a technical solution that can effectively coordinate high temperature, water retention, and nitrogen retention during the fermentation process in the harsh environment of arid and hot valleys has become an urgent technical challenge to be solved in this field. Summary of the Invention

[0010] The purpose of this invention is to provide a soil conditioner for hot and dry valley regions, its preparation method, and its application, thereby solving the technical problems of water evaporation and nitrogen volatilization during composting in hot and dry valley environments in the prior art.

[0011] This invention discloses a method for preparing a soil conditioner for hot and dry valley regions, comprising the following steps: S1. Prepare a composite bacterial agent and load the bacterial strain onto an immobilization carrier, wherein the immobilization carrier is porous activated carbon that has been acid-washed and activated; S2. Kitchen waste, landscaping waste, and sewage sludge from different sources are pretreated and then mixed to obtain a mixture. S3. The compound microbial agent in step S1 is inoculated into the mixture in step S2, and then subjected to closed-loop humidity-controlled fermentation and secondary composting and conditioning to obtain the final product.

[0012] After acid leaching and activation, the immobilized carrier has optimized specific surface area and surface functional groups, enabling it not only to provide physical attachment sites for microorganisms but also to adsorb and immobilize ammonium nitrogen (NH4+) produced during fermentation through ion exchange. 4+ ).

[0013] Furthermore, the strains are thermophilic Bacillus steatophilus and thermoactinomycetes.

[0014] Furthermore, the viable cell count in the bacterial suspension of the aforementioned strains was 1 x 10⁻⁶. 9 CFU / mL.

[0015] Furthermore, the ratio of viable bacteria in the thermophilic Bacillus stearothermophilus suspension to the thermoactinomycete suspension is 1-3:1.

[0016] Furthermore, the mass-to-volume ratio (kg:L) of the immobilized carrier to the bacterial suspension is 1:(1-3).

[0017] Furthermore, the initial carbon-to-nitrogen ratio (C / N) of the mixture in S2 is 25-35:1, and the initial moisture content is 60%-70%.

[0018] To obtain a material with physicochemical properties suitable for microbial fermentation.

[0019] Furthermore, the dry weight ratio of the kitchen waste, landscaping waste, and sewage sludge is 2-4:30-40:10-20.

[0020] Furthermore, the pretreatment includes conventional pretreatment steps such as crushing and dehydration.

[0021] Furthermore, the inoculation amount of the compound microbial agent is 0.1-0.3% of the dry weight of the material to be fermented.

[0022] Furthermore, the closed-loop humidity-controlled fermentation specifically involves placing the material in a closed-loop fermentation facility for high-temperature aerobic fermentation, maintaining the fermentation temperature at 55-70℃ for 10-15 days.

[0023] The closed environment aims to minimize the interference of the external environment (such as strong winds and low humidity) in the hot and dry valleys on the fermentation system, thereby reducing the disorderly loss of moisture from a macroscopic perspective.

[0024] Furthermore, during the closed-loop humidity-controlled fermentation, the overall moisture content of the material is maintained at no less than 55%.

[0025] Furthermore, the secondary composting and conditioning involves subjecting the material to a second fermentation after sealed and moisture-controlled fermentation for deep composting, followed by mixing it with coal ash to produce a soil conditioner.

[0026] Furthermore, the secondary fermentation cycle is 15-20 days; the mass mixing ratio of the decomposed product to the coal ash residue is 6-7:3-4.

[0027] A soil conditioner for hot and dry valley regions is prepared using the method described above.

[0028] Application of a soil conditioner for dry-hot valley regions in soil improvement or vegetation restoration projects in dry-hot valley regions.

[0029] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention significantly improves process stability and processing efficiency: This invention effectively overcomes the interference of dry and hot environment on the fermentation process, ensures the continuous stability of the high-temperature fermentation period, and shortens the total fermentation cycle to 25-35 days, with significant efficiency; 2. This invention significantly improves the resource retention rate: through the synergy of nitrogen fixation by activated carbon carrier and closed process, the nitrogen retention rate in the final product can reach more than 60%, which is much higher than that of conventional composting; at the same time, the amount of water replenishment per ton of material is greatly reduced, saving precious water resources. 3. This invention realizes the functionalization and high value of the product: the final product is compounded with coal ash and slag, and the resulting soil conditioner not only provides organic matter and nutrients, but also contains activated carbon particles and aluminosilicates that can effectively improve the soil's aggregate structure and water and fertilizer retention capacity, which is highly in line with the requirements of soil improvement for ecological restoration in arid and hot valley areas. Attached Figure Description

[0030] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 This is a flowchart of the present invention. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0033] Example 1 This embodiment discloses a soil conditioner for hot and dry valley regions, its preparation method, and its application, such as... Figure 1 As shown, it includes the following steps: 1. Preparation of compound microbial agents 10 kg of coconut shell activated carbon with a particle size of 0.5-1.0 mm was soaked in a 1.0 mol / L hydrochloric acid solution for 2 hours for activation. It was then repeatedly washed with deionized water until neutral and dried at 105 °C for later use. Preserved *Bacillus steatophilus* (CGMCC No. 1.1866) and *Thermoplastic actinomycetes* (CICC No. 10672) were separately activated and cultured to prepare bacterial suspensions with a viable count of 1 x 10⁹ CFU / mL. 15 L of *Bacillus steatophilus* suspension and 5 L of *Thermoplastic actinomycetes* suspension (viable count ratio 3:1) were mixed with the treated activated carbon and vacuum adsorbed under sterile conditions for 2 hours. The mixture was then dried at 30 °C to obtain the composite microbial agent described in this invention.

[0034] 2. Raw material pretreatment and co-processing Kitchen waste was collected, crushed and dewatered, with a moisture content of 65% and a dry weight of 30 kg; landscaping waste was collected, pulverized, with a moisture content of 40% and a dry weight of 350 kg; sewage sludge was collected, filtered and dewatered, with a moisture content of 62% and a dry weight of 150 kg. The three were mixed in a dry weight ratio of 30:350:150, or 3:35:15. After calculation and adjustment with a small amount of urea, the initial carbon-to-nitrogen ratio (C / N) of the mixture was 30:1, and the initial moisture content was 65%.

[0035] 3. Inoculate with core microbial agent Place approximately 1000 kg of the mixture (dry weight approximately 530 kg) in a closed fermentation chamber. Take 1.1 kg of the compound microbial agent prepared in step 1 (inoculation amount approximately 0.2% of the dry weight of the material), sprinkle it evenly into the material, and mix thoroughly.

[0036] 4. Sealed and humidity-controlled fermentation The fermentation chamber is closed, and the forced ventilation system is activated. The fermentation temperature is controlled between 60-65°C using temperature sensors and a heating system (which can utilize waste heat from a hydroelectric power station at night). The material moisture content is monitored in real-time using a humidity sensor; when the measured value drops below 58%, the atomizing spray system on the top of the chamber automatically activates to replenish moisture. This stage involves high-temperature aerobic primary fermentation, with a cycle of 12 days.

[0037] 5. Secondary fermentation and conditioning After the primary fermentation is completed, the material is removed and stacked in the aging workshop for secondary fermentation (post-fermentation), which takes 18 days. After the fermentation is completed, 700 kg of the fermented product is mixed evenly with 300 kg of coal ash from a hydroelectric power station boiler (mass ratio 7:3) in a horizontal mixer to obtain the final product, a drought-resistant and water-retaining soil conditioner specifically for ecological restoration in arid and hot river valleys.

[0038] Example 2 (Lower Limit) A method for the co-treatment of organic solid waste from a large hydropower station in a dry-hot valley region includes the following steps: 1. Preparation of compound microbial agents Take 10 kg of bamboo-made activated carbon with a particle size of 0.5-1.0 mm, soak it in 0.5 mol / L hydrochloric acid solution for 3 hours to activate it, wash and dry it for later use. Prepare 1 x 10⁻⁶ viable bacteria. 9 A CFU / mL suspension of *Bacillus stearothermophilus* and a suspension of *Pseudomonas aeruginosa* were prepared. 5 L of *Bacillus stearothermophilus* suspension and 5 L of *Pseudomonas aeruginosa* suspension (viable cell ratio 1:1) were mixed with treated activated carbon (mass-volume ratio 1:1), and the mixture was vacuum adsorbed for 2.5 hours under aseptic conditions, followed by low-temperature drying to obtain a composite microbial agent.

[0039] 2. Raw material pretreatment and co-processing (step a) Kitchen waste (20 kg dry weight), landscaping waste (300 kg dry weight), and sewage sludge (100 kg dry weight) were collected and mixed in a dry weight ratio of 20:300:100, or 2:30:10. After adjustment, the initial carbon-to-nitrogen ratio (C / N) of the mixture was 25:1, and the initial moisture content was 60%.

[0040] 3. Inoculate with the core bacterial agent (step b) Place approximately 1050 kg of the mixture (dry weight approximately 420 kg) in a closed fermentation chamber. Take 0.42 kg of the compound microbial agent prepared in step 1 (inoculation amount is 0.1% of the dry weight of the material), sprinkle it evenly into the material and mix thoroughly.

[0041] 4. Sealed and humidity-controlled fermentation (step c) Close the fermentation chamber and activate the forced ventilation system. Control the fermentation temperature between 55-60℃. Monitor the humidity in real time using a humidity sensor and automatically replenish water to maintain the material moisture content at no less than 55%. This high-temperature aerobic main fermentation cycle lasts 15 days.

[0042] 5. Secondary fermentation and conditioning (step d) After the primary fermentation is completed, a secondary fermentation is carried out, which takes 20 days. After the decomposition is completed, 600 kg of the decomposed product is mixed evenly with 400 kg of coal ash (mass ratio 6:4) to obtain a drought-resistant and water-retaining soil conditioner.

[0043] Example 3: (Upper Range) A method for the co-treatment of organic solid waste from a large hydropower station in a dry-hot valley region includes the following steps: 1. Preparation of compound microbial agents Take 10 kg of coconut shell activated carbon with a particle size of 0.5-1.0 mm, soak it in 1.5 mol / L hydrochloric acid solution for 1.5 hours to activate it, wash and dry it for later use. Prepare 1 x 10⁻⁶ viable bacteria. 9 CFU / mL bacterial suspension. 22.5 L of thermophilic Bacillus steatosis bacterial suspension and 7.5 L of common thermoactinomycete bacterial suspension (viable cell ratio 3:1) were mixed with treated activated carbon (mass-volume ratio 1:3), vacuum adsorption was performed for 1.5 hours, and then dried at low temperature to obtain a composite microbial agent.

[0044] 2. Raw material pretreatment and co-processing (step a) Kitchen waste (40 kg dry weight), landscaping waste (400 kg dry weight), and sewage sludge (200 kg dry weight) were collected and mixed in a dry weight ratio of 40:400:200, or 4:40:20. After adjustment, the initial carbon-to-nitrogen ratio (C / N) of the mixture was 35:1, and the initial moisture content was 70%.

[0045] 3. Inoculate with the core bacterial agent (step b) The above-mentioned mixture of approximately 2133 kg (dry weight approximately 640 kg) was placed in a closed fermentation chamber. 1.92 kg of the compound microbial agent prepared in step 1 (inoculation amount of 0.3% of the dry weight of the material) was evenly sprinkled into the material and mixed thoroughly.

[0046] 4. Sealed and humidity-controlled fermentation (step c) Close the fermentation chamber and activate the forced ventilation system. Maintain the fermentation temperature between 65-70℃. When the nighttime temperature drops below the set value, introduce waste heat from the hydroelectric power station for auxiliary heating. Maintain material moisture content at no less than 55% through automatic spraying. This high-temperature aerobic main fermentation cycle lasts 10 days.

[0047] 5. Secondary fermentation and conditioning (step d) After the primary fermentation is completed, a secondary fermentation is carried out, which takes 15 days. After the decomposition is completed, 700 kg of the decomposed product is mixed evenly with 300 kg of coal ash (mass ratio 7:3) to obtain a drought-resistant and water-retaining soil conditioner.

[0048] Example 2 Performance: The effective number of days during the high temperature period (55 ℃) is 13 days, the total fermentation cycle is 35 days, the nitrogen retention rate is 58.5%, the total water replenishment per ton of dry material is 145 kg, and the seed germination index is 90.2%.

[0049] Example 3 Performance: The effective number of days during the high temperature period (55 ℃) was 9 days, the total fermentation cycle was 25 days and it was not fully decomposed, the nitrogen retention rate was 62.1%, the total water replenishment per ton of dry material was 170 kg, and the seed germination index was 93.1%.

[0050] Examples 2 and 3 respectively used low-value and high-value parameter combinations within the protection range, both of which showed good performance, proving the stability and reliability of the method of the present invention.

[0051] Comparative Example 1: Using conventional open composting methods The material ratio was the same as in Example 1. Equal amounts of *Bacillus steatophilus* and *Actinomyces commensalense* powder (not fixed with activated carbon carrier) were inoculated. The mixture was placed outdoors to form windrows, which were mechanically turned over once daily. Due to the strong winds and intense sunlight in the dry, hot valley, the surface of the windrows needed to be sprayed with water daily to try to maintain humidity.

[0052] Comparative Example 2: Closed fermentation but without using the compound microbial agent of this invention. Except for the fact that the inoculated bacterial agent is one of two bacterial powders with the same number of viable bacteria without activated carbon carrier, all other conditions and steps are the same as in Example 1.

[0053] Comparative Example 3: Using the compound microbial agent of the present invention but employing open fermentation. The same compound microbial inoculant as in Example 1 was used, but the fermentation process was carried out in an open windrow, and the management method was the same as in Comparative Example 1.

[0054] Comparative Example 4 Except for the initial material ratio, all other conditions and steps (including the type of microbial agent, inoculum size, and closed fermentation) are the same as in Example 1. In this comparative example, by increasing the proportion of kitchen waste and decreasing the proportion of landscaping waste, the carbon-to-nitrogen ratio (C / N) of the initial mixture was adjusted to 24:1, and the initial moisture content was adjusted to 55%. Both of these parameters are lower than the range defined in claim 1 of this invention (C / N 25-35:1, moisture content 60%-70%).

[0055] Comparative Example 4 Performance: Effective days during the high temperature period (55 ℃) were 3 days, the total fermentation cycle was 60 days before complete decomposition, the nitrogen retention rate was 21.5%, the total water replenishment per ton of dry material was 130 kg, and the seed germination index was 58.3%.

[0056] In Comparative Example 4, the initial C / N ratio was too low, leading to a relative excess of nitrogen. Although the temperature rose rapidly in the early stages of fermentation, it quickly cooled down due to insufficient carbon source, resulting in a very short high-temperature period of only 3 days. Simultaneously, a large amount of nitrogen evaporated as ammonia, resulting in an extremely low nitrogen retention rate (21.5%), far lower than in Example 1. Furthermore, the low initial moisture content (less than 60%) directly inhibited the initial activity and reproduction of microorganisms, leading to a slow fermentation start-up and overall stagnation. The fermentation cycle exceeded 60 days without complete decomposition, manifested by a low seed germination index, indicating that the product may have phytotoxicity and cannot be used as a qualified soil conditioner. The low total water replenishment was not due to water conservation, but rather to low fermentation intensity, low heat production, and low water evaporation.

[0057] Performance Testing and Results Analysis The key parameters and final product performance of Example 1 and Comparative Examples 1-3 during the fermentation process were tested, and the results are shown in Table 1.

[0058] Table 1 Performance Comparison of Different Processing Methods

[0059] The following conclusions can be drawn from the data in Table 1: Comparative analysis of Example 1 and Comparative Example 1: All indicators of Example 1 are significantly better than those of Comparative Example 1 which uses conventional technology, proving that the overall technical solution of the present invention has outstanding substantive features and significant progress compared with the prior art.

[0060] Comparative analysis of Example 1 with Comparative Examples 2 and 3: This set of comparisons aims to analyze the function of each technical feature within the present invention.

[0061] Comparing Example 1 and Comparative Example 2 (both using a closed process), the former, due to the use of the compound microbial agent of the present invention, still has significant advantages in nitrogen retention rate and fermentation cycle. This directly confirms that the water retention and nitrogen fixation function of activated carbon carrier at the microscopic level is one of the key technical elements for achieving the excellent effect of the present invention.

[0062] Comparing Example 1 and Comparative Example 3 (both using the microbial agent of the present invention), the former, due to its matching closed humidity control process, is far superior to the latter in terms of water saving effect, fermentation efficiency and nitrogen retention. This confirms that macroscopic process control is a necessary condition for maximizing the performance of compound microbial agents.

[0063] In summary, the two core technical features of the present invention, namely the compound microbial agent and the closed-loop humidity-controlled fermentation process, are not simply superpositions of technologies, but rather an organic combination and mutual support. Together, they solve the core technical contradictions of water retention and high temperature, and nitrogen retention and high efficiency in aerobic fermentation in a hot and dry valley environment, achieving unexpected synergistic effects.

[0064] The above are the embodiments listed in this example. However, this example is not limited to the optional embodiments described above. Those skilled in the art can arbitrarily combine the above methods to obtain other various embodiments. Anyone can derive other various forms of embodiments based on the inspiration of this example. The above specific embodiments should not be construed as limiting the scope of protection of this example. The scope of protection of this example should be determined by the claims, and the specification can be used to interpret the claims.

Claims

1. A method of preparing a soil amendment for dry-hot valley regions, characterized by: Comprising the following steps: S1. Preparing a composite microbial inoculant and loading the strains to an immobilized carrier, which is a porous activated carbon activated by acid pickling; S2. Mixing pretreated kitchen solid waste, landscaping solid waste and sewage sludge from different sources to obtain a mixture; S3. Inoculating the composite microbial inoculant in step S1 into the mixture in step S2, then performing closed and moisture-controlled fermentation and secondary decomposition and conditioning to obtain the product.

2. A method of preparing a soil amendment for dry hot valley regions according to claim 1, characterised in that: The strains are Geobacillus stearothermophilus and Thermomicrobium.

3. A method of preparing a soil amendment for dry hot valley regions as claimed in claim 1, wherein: The viable cell count of the bacterial suspension of the strain was 1 x 10 9 CFU / mL.

4. A method of preparing a soil amendment for dry hot valley regions according to claim 2, characterised in that: The ratio of viable bacterial count of Geobacillus stearothermophilus and Thermomicrobium is 1-3:

1.

5. The method of claim 1, wherein the soil amendment for dry valley regions is prepared by: The initial carbon-nitrogen ratio (C / N) of the mixture in S2 is 25-35:1, and the initial moisture content is 60%-70%.

6. A method of preparing a soil amendment for dry hot valley regions as claimed in claim 1, wherein: The dry weight ratio of kitchen solid waste, landscaping solid waste and sewage sludge is 2-4:30-40:10-20. The closed and moisture-controlled fermentation is specifically high-temperature aerobic fermentation of the material in a closed fermentation facility, with the fermentation temperature maintained at 55-70℃ and the fermentation time being 10-15 days. The secondary decomposition and conditioning is secondary fermentation of the material after closed and moisture-controlled fermentation to achieve deep decomposition, followed by mixing with coal ash to produce a soil conditioner.

7. A method of preparing a soil amendment for dry hot valley regions according to claim 6, characterised in that: The period of secondary fermentation is 15-20 days, and the mass mixing ratio of the decomposition product to coal ash is 6-7:3-4.

8. A method of preparing a soil amendment for dry hot valley regions as claimed in claim 1, wherein: The whole moisture content of the material during closed and moisture-controlled fermentation is maintained at no less than 55%.

9. A soil amendment for dry-hot valley regions, characterized by: The soil conditioner for dry-hot valley regions is prepared by using the method of any one of claims 1-8.

10. The use of the soil conditioner for dry-hot valley regions according to claim 9 in the improvement of infertile soil or vegetation restoration engineering in a dry-hot valley region.

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