Organic fertilizer bio-fermentation process suitable for mobile toilet fermentation bin

Abstract

The application discloses a kind of organic fertilizer biofermentation processes suitable for mobile toilet fermentation bin, belong to biofermentation technical field, including the following steps: preparation fermentation auxiliary material: fermentation auxiliary material includes base material, heat conducting material and heat preservation material;Preparation fermentation material: mixed base material, heat conducting material, heat preservation material and toilet fermenting agent, obtain fermentation material;Two-stage fermentation: first fermentation stage: mobile toilet fermentation bin starts to collect excrement within 48 hours, fermentation bin maintains the temperature in bin to 55~60 DEG C and is accompanied by intermittent stirring;Second fermentation stage: from the 48th hour that mobile toilet fermentation bin collects excrement to at least 24 hours after mobile toilet fermentation bin full bin, enter day and night steady-state fermentation;Mobile toilet fermentation bin starts to collect excrement to the whole fermentation period cumulative time of stopping fermentation after full bin is not less than 8 days;After fermentation, filter and recover heat conducting material, obtain organic fertilizer.The application solves the problem of uneven temperature distribution of fermentation system.

Description

Technical Field

[0001] This invention belongs to the field of bio-fermentation technology and relates to an organic fertilizer bio-fermentation process suitable for mobile toilet fermentation chambers. Background Technology

[0002] As an important component of public health facilities, the harmless treatment and resource utilization of excrement from portable toilets has always been a key focus of the industry. Converting excrement collected from portable toilets into organic fertilizer through biological fermentation not only solves the problem of excrement disposal but also achieves resource utilization of waste, resulting in significant environmental and economic benefits.

[0003] Existing mobile toilet excrement fermentation technology mainly faces the following problems: During the fermentation process, due to the poor heat conduction capacity of the fermentation material itself, heat is difficult to be evenly distributed in the fermentation system, which easily leads to uneven temperature field phenomenon with local overheating and local low temperature. Especially in winter when the ambient temperature is low or in outdoor conditions with large temperature differences between day and night, the heat loss of the fermentation system is fast, making it difficult to maintain the effective high temperature required for the harmlessness of excrement. Insufficient temperature and uneven distribution directly lead to incomplete fermentation and decomposition, which cannot effectively inactivate pathogenic organisms such as fecal coliforms and roundworm eggs, resulting in significant biosafety risks. Summary of the Invention

[0004] The purpose of this invention is to provide an organic fertilizer bio-fermentation process suitable for mobile toilet fermentation chambers, which solves the problem in existing mobile toilet excrement fermentation technology that the fermentation material itself has poor heat conduction capacity, making it difficult to evenly distribute heat in the fermentation system and the fermentation system loses heat quickly, making it difficult to maintain the effective high temperature required for the harmless treatment of excrement. This results in incomplete fermentation and decomposition, and the inability to effectively inactivate pathogenic organisms such as fecal coliforms and roundworm eggs, posing significant biosafety risks.

[0005] The technical solution adopted in this invention is as follows:

[0006] An organic fertilizer bio-fermentation process suitable for mobile toilet fermentation chambers includes the following steps:

[0007] S1. Preparation of fermentation adjuvants: The fermentation adjuvants include a base material, a heat-conducting material, and a heat-insulating material; the base material includes rice bran and sawdust; the heat-conducting material includes magnetized aluminum nitride modified by sodium lignosulfonate, hydroxypropyl cellulose, and agar; the heat-insulating material includes enzyme-triggered hydrophobic modified expanded perlite microspheres.

[0008] S2. Preparation of fermentation material: Mix base material, heat-conducting material, heat-insulating material and toilet fermentation agent to obtain fermentation material; wherein, the mass ratio of base material, heat-conducting material and heat-insulating material is (15~20):(6~10):(10~15); based on the excrement collected by 100kg of mobile toilet fermentation chamber, the amount of base material added is 5kg~6kg, and the amount of toilet fermentation agent inoculated accounts for 0.3kg~0.5kg of excrement collected by mobile toilet fermentation chamber;

[0009] S3, Two-stage fermentation:

[0010] S3.1 First fermentation stage: Within 48 hours from the start of the collection of excrement in the mobile toilet fermentation chamber, the temperature inside the fermentation chamber is maintained at 55~60℃ and accompanied by intermittent stirring;

[0011] S3.2, Second Fermentation Stage: From the 48th hour after the start of excrement collection in the mobile toilet fermentation chamber until the chamber is full, a steady-state fermentation process begins, lasting at least 24 hours. This steady-state fermentation includes the following stages:

[0012] S3.2.1, Low-temperature fermentation stage during the day: During the daytime period from 6:00 AM to 6:00 PM, the fermentation chamber is maintained at a temperature of 30-35°C with intermittent stirring.

[0013] S3.2.2, Nighttime high-temperature fermentation stage: During the nighttime period from 18:00 to 6:00 the next morning, the fermentation chamber is maintained at a temperature of 60~65℃ and intermittent stirring is carried out.

[0014] S4. In step S3, the total fermentation period of the mobile toilet fermentation chamber, from the start of collecting excrement to the cessation of fermentation after the chamber is full, shall not be less than 8 days. After fermentation, the heat-conducting material shall be filtered and recovered to obtain organic fertilizer.

[0015] Furthermore, the rice bran is modified rice bran, which is prepared by the following method: after supercritical CO2 extraction to remove fat, the rice bran is soaked in 1wt% NaOH solution at room temperature for 2 hours, washed with water until neutral, dried at 105℃, and then pulverized through a 40-mesh sieve to obtain modified rice bran.

[0016] Furthermore, the sawn wood surface is a modified sawn wood surface obtained by steam explosion pretreatment of broadleaf sawdust, followed by natural air drying and crushing through a 20-mesh sieve.

[0017] Furthermore, the mass ratio of rice bran to sawdust is 3:7.

[0018] Furthermore, the intermittent stirring method in steps S3.1, S3.2.1, and S3.2.2 is the same; the intermittent stirring method is as follows: each execution cycle is 2 hours, and one execution cycle consists of 10 minutes of forward rotation, followed by 5 minutes of rest, then 10 minutes of reverse rotation, followed by 95 minutes of rest. After the rest period, the next execution cycle begins; during both forward and reverse stirring within the intermittent stirring cycle, aeration is carried out simultaneously at a flow rate of 0.6 m³ / s. 3 / h.

[0019] Further, the thermally conductive material is prepared by the following method: AlN particles are immersed in 15 vol% dilute hydrochloric acid, ultrasonically treated, filtered, and washed with deionized water until neutral to obtain acid-treated AlN particles; FeCl2·4H2O and FeCl3·6H2O are dissolved in deoxygenated water at a molar ratio of 1:2 to obtain a mixed solution, then acid-treated AlN particles are added to the mixed solution, stirred evenly, and the system is heated to 60°C under nitrogen protection. Then, ammonia water is slowly added dropwise to adjust the pH to 9-10, and the reaction is carried out at 60°C for 1-1.5 hours. After the reaction is completed, the precipitate is separated by an external magnetic field, and the precipitate is repeatedly washed with deionized water until neutral and vacuum dried to obtain magnetized aluminum nitride.

[0020] Magnetized aluminum nitride was added to a 3 vol% GPTMS toluene solution, heated to react, filtered, washed, and vacuum dried to obtain modified magnetized aluminum nitride particles.

[0021] Sodium lignosulfonate was added to deionized water and heated and stirred until completely dissolved. Agar was then added, and the mixture was heated and stirred until completely dissolved. The temperature was then lowered to 60°C, and hydroxypropyl cellulose was added. The mixture was stirred at 60°C until a homogeneous colloid was obtained. The mass ratio of sodium lignosulfonate, agar, and hydroxypropyl cellulose was 3:4:40. Modified magnetized aluminum nitride particles were added to the colloid, with a mass ratio of modified magnetized aluminum nitride particles to hydroxypropyl cellulose of 5:2. The mixture was then reacted at 60°C and stirred at 150-200 rpm for 12 h. After the reaction was completed, the mixture was allowed to cool naturally to room temperature, filtered, washed, and vacuum dried to obtain the thermally conductive material.

[0022] Furthermore, the insulation material is prepared by the following method:

[0023] S7.1 Place expanded perlite microspheres in a vacuum impregnation tank, evacuate to -0.085 ~ -0.095 MPa and maintain for 30 min, inject a composite material at 70±5℃, the composite material being composed of stearic acid and expanded graphite in a mass ratio of 95:5, maintain vacuum impregnation for 2~4 h, restore normal pressure, continue impregnation for 30 min, remove and cool to obtain preliminarily modified microspheres;

[0024] S7.2. Prepare a spray by mixing hydrophobic silica aerogel powder with silica sol, spray it onto the surface of the pre-modified microspheres, and dry it to obtain intermediate modified microspheres.

[0025] S7.3. Immerse the intermediate modified microspheres in a chitosan solution containing acetic acid, soak at room temperature and then dry to obtain chitosan modified microspheres.

[0026] S7.4. Immerse the chitosan-modified microspheres in a gelatin aqueous solution, soak at 45°C, drain, and air dry with cold air to obtain gelatin / chitosan-modified microspheres.

[0027] S7.5. Spray the transglutaminase solution evenly onto the surface of the gelatin / chitosan modified microspheres and react at 40°C and 80%~90% relative humidity for 1~2 h. After the reaction is completed, dry at 40°C to constant weight to obtain the thermal insulation material.

[0028] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0029] 1. This invention provides an organic fertilizer bio-fermentation process suitable for mobile toilet fermentation chambers. The process incorporates heat-conducting and heat-insulating materials into the auxiliary materials, improving the heat conduction and insulation performance of the entire fermentation system and solving the problems of uneven temperature distribution and insufficient temperature in current fermentation systems. This invention uses magnetized aluminum nitride, synergistically modified from sodium lignosulfonate, agar, and hydroxypropyl cellulose, as the heat-conducting material. This avoids the hydrolysis of aluminum nitride and ensures its uniform distribution throughout the system, preventing it from settling at the bottom or floating at the top. The heat-insulating material in this invention... Within the first 48 hours of excrement collection, no insulation layer forms on top, and the exhaust channels are not blocked. This ensures successful startup of the fermentation system and prevents the insulation material from forming an insulation layer on top prematurely, which would inhibit the growth and reproduction of fermenting microorganisms in the fermentation system and cause the fermentation startup to fail. As fermentation progresses, the outer layer undergoes enzymatic hydrolysis, exposing the hydrophobic insulation material, which gradually floats on top of the fermented material, forming an insulation layer. With intermittent stirring and simultaneous aeration during stirring, the insulation layer achieves heat preservation and temperature stability without affecting the normal metabolic activities of the toilet fermentation agent in an aerobic / facultative anaerobic environment.

[0030] 2. The steady-state fermentation in this invention adopts a day-night reverse temperature control fermentation strategy of "low temperature during the day and high temperature at night", which is completely different from the conventional composting mode of "constant low temperature or constant high temperature". During the high temperature stage at night, efficient decomposition is achieved by active heating combined with the synergistic effect of heat-conducting material and heat-insulating material. During the low temperature stage during the day, the heat-insulating material is used to maintain a low fermentation temperature of 35°C, which can avoid the problem of odor during toilet use during the day and also avoid excessive energy consumption. Attached Figure Description

[0031] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly described 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 of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort, wherein:

[0032] Figure 1 This is a flowchart of an organic fertilizer bio-fermentation process suitable for mobile toilet fermentation chambers;

[0033] Figure 2 This is a photograph of the thermally conductive material of the present invention.

[0034] Figure 3 This is a physical image of the thermal insulation material of this invention. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only for explaining the invention and are not intended to limit the invention; that is, the described embodiments are merely some embodiments of the invention, and not all embodiments. The components of the embodiments of the invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0036] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0037] It should be noted that relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0038] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0039] like Figure 1 As shown, the present invention provides an organic fertilizer bio-fermentation process suitable for mobile toilet fermentation chambers, comprising the following steps:

[0040] S1. Preparation of fermentation adjuvants: The fermentation adjuvants include a base material, a heat-conducting material, and a heat-insulating material; the base material includes rice bran and sawdust; the heat-conducting material includes magnetized aluminum nitride modified by sodium lignosulfonate, hydroxypropyl cellulose, and agar; the heat-insulating material includes enzyme-triggered hydrophobic modified expanded perlite microspheres.

[0041] S2. Preparation of fermentation material: Mix base material, heat-conducting material, heat-insulating material and toilet fermentation agent to obtain fermentation material; wherein, the mass ratio of base material, heat-conducting material and heat-insulating material is (15~20):(6~10):(10~15); based on the excrement collected by 100kg of mobile toilet fermentation chamber, the amount of base material added is 5kg~6kg, and the amount of toilet fermentation agent inoculated accounts for 0.3kg~0.5kg of excrement collected by mobile toilet fermentation chamber; the toilet fermentation agent used in this application is commercially available Nanhua Qianmu organic material composting agent septic tank fermentation agent;

[0042] S3, Two-stage fermentation:

[0043] S3.1 First fermentation stage: Within 48 hours from the start of the collection of excrement in the mobile toilet fermentation chamber, the temperature inside the fermentation chamber is maintained at 55~60℃ and accompanied by intermittent stirring;

[0044] S3.2, Second Fermentation Stage: From the 48th hour after the start of excrement collection in the mobile toilet fermentation chamber until the chamber is full, a steady-state fermentation process begins, lasting at least 24 hours. This steady-state fermentation includes the following stages:

[0045] S3.2.1, Low-temperature fermentation stage during the day: During the daytime period from 6:00 AM to 6:00 PM, the fermentation chamber is maintained at a temperature of 30-35°C with intermittent stirring.

[0046] S3.2.2, Nighttime high-temperature fermentation stage: During the nighttime period from 18:00 to 6:00 the next morning, the fermentation chamber is maintained at a temperature of 60~65℃ and intermittent stirring is carried out.

[0047] S4. In step S3, the total fermentation period of the mobile toilet fermentation chamber, from the start of collecting excrement to the cessation of fermentation after the chamber is full, shall not be less than 8 days. After fermentation, the heat-conducting material shall be filtered and recovered to obtain organic fertilizer.

[0048] In the following embodiments, the rice bran is modified rice bran, which is prepared by the following method: rice bran is degreased by supercritical CO2 extraction, then soaked in 1wt% NaOH solution at room temperature for 2 hours, washed with water until neutral, dried at 105℃, and then pulverized through a 40-mesh sieve to obtain modified rice bran; wherein, the conditions for supercritical CO2 extraction degreasing are temperature 40℃, pressure 25MPa, and time 2 hours.

[0049] In the following embodiments, the sawn wood surface is obtained by pre-treating hardwood sawdust with steam explosion, air-drying it after steam explosion pre-treatment, and crushing it through a 20-mesh sieve; wherein, the conditions for steam explosion pre-treatment are: pressure of 2.5 MPa and pressure holding time of 3 min.

[0050] In the following examples, the mass ratio of rice bran to sawdust is 3:7.

[0051] In the following embodiments, the intermittent stirring method in steps S3.1, S3.2.1, and S3.2.2 is the same; the intermittent stirring method is as follows: each execution cycle is 2 hours. One execution cycle consists of 10 minutes of forward rotation (18~22 rpm), followed by 5 minutes of rest, then 10 minutes of reverse rotation (18~22 rpm), followed by 95 minutes of rest. After the rest period, the next execution cycle begins. During both forward and reverse rotation stirring within the intermittent stirring cycle, aeration is performed simultaneously at a flow rate of 0.6 m³ / s. 3 / h.

[0052] In the following embodiments, the thermally conductive material was prepared by the following method: AlN particles were immersed in 15 vol% dilute hydrochloric acid, ultrasonically treated at 40°C for 15 min, then filtered and washed with deionized water until neutral to obtain acid-treated AlN particles; 0.05 mol FeCl2·4H2O and 0.1 mol FeCl3·6H2O were dissolved in 200 mL deoxygenated water to obtain a mixed solution, and then acid-treated AlN particles were added to the mixed solution at a solid-liquid ratio of 1 g:10 mL. After stirring evenly, the system was heated to 60°C under nitrogen protection, and then ammonia water was slowly added dropwise to adjust the pH to 9-10. The reaction was then carried out at 60°C for 1 hour. After the reaction was completed, the precipitate was separated by an external magnetic field (0.5 T), and the precipitate was repeatedly washed with deionized water until neutral. It was then vacuum dried (60°C, -0.09 MPa) for 4 hours to obtain magnetized aluminum nitride; magnetized aluminum nitride was added to 3 vol% dilute hydrochloric acid at a solid-liquid ratio of 1 g:10 mL. In a GPTMS toluene solution, the mixture was reacted at 80°C for 6 hours, filtered, washed, and vacuum dried to obtain modified magnetized aluminum nitride particles. 3g of sodium lignosulfonate was added to 1000mL of deionized water and stirred at 50°C until completely dissolved. Then, 4g of agar was added, the temperature was raised to 90°C and stirred until completely dissolved, then cooled to 60°C, and 40g of hydroxypropyl cellulose (molecular weight 200,000) was added. The mixture was stirred at 60°C for 30 minutes until a homogeneous colloid was formed. 100g of modified magnetized aluminum nitride particles were added to the colloid, and the mixture was then reacted at 60°C and 150-200 rpm for 12 hours. After the reaction, the mixture was allowed to cool naturally to room temperature, filtered, washed, and vacuum dried to obtain a thermally conductive material. (See attached image). Figure 2 As shown.

[0053] In the following embodiments, the thermal insulation material is prepared by the following method:

[0054] S7.1. Stearic acid and expanded graphite were placed in a stainless steel container at a mass ratio of 95:5 and heated to 70±5℃. The mixture was mechanically stirred at 200 rpm for 30 min to obtain a composite material. 100 g of expanded perlite microspheres were placed in a vacuum impregnation tank and sealed. The vacuum was evacuated to -0.085 ~ -0.095 MPa and maintained for 30 min. The composite material at 70±5℃ was drawn in through the impregnation valve. The impregnation liquid level of the composite material was 2~3 cm higher than the top surface of the expanded perlite microspheres. The vacuum degree was maintained above -0.08 MPa. Impregnation was continued for 2~4 h. Then, the pressure was slowly restored to normal (pressure relief rate ≤0.01 MPa / min). Impregnation was continued for 30 min under normal pressure. After impregnation, the microspheres were removed, drained, and cooled in a water bath to obtain the preliminarily modified microspheres.

[0055] S7.2. Mix 12 g of hydrophobic silica aerogel powder with 30 g of 30 wt% silica sol and stir at 200 rpm for 15 min to prepare a uniform spray material. Place the pre-modified microspheres in a rotating roller bed and spray the spray material evenly onto the surface of the pre-modified microspheres with a spray gun. Dry with hot air at 60~80℃ for 2 h. Repeat the spraying and drying process (if a single batch of spray material is insufficient, replenish the spray material in the same proportion and continue to use) until the coating thickness on the surface of the pre-modified microspheres reaches 0.6 mm to obtain intermediate modified microspheres.

[0056] S7.3 Dissolve 2.0 g of chitosan in 200 mL of 1 vol% acetic acid aqueous solution (containing 2.0 mL of glacial acetic acid), stir at 200 rpm for 2 h at room temperature (25℃) until completely dissolved to prepare a chitosan solution; according to the solid-liquid ratio of 1 g: 12 mL, take intermediate modified microspheres and immerse them in the chitosan solution, stir slowly at 50 rpm for 15 min at room temperature (25℃), remove the microspheres, place them on a 20-mesh sieve and drain for 5 min; dry with hot air at 40℃ for 1 h to obtain chitosan modified microspheres;

[0057] S7.4 Dissolve 10.0 g of gelatin in 200 mL of deionized water, stir at 200 rpm for 30 min in a 45 ℃ water bath until completely dissolved, to prepare a 5 wt% gelatin solution; according to the solid-liquid ratio of 1 g: 10 mL, take chitosan modified microspheres and immerse them in the 45 ℃ gelatin solution, maintain 45 ℃ and stir at 50 rpm for 15 min, then filter and dry with cold air to obtain gelatin / chitosan modified microspheres;

[0058] S7.5. Dissolve transglutaminase in deionized water at a ratio of 0.5g TG enzyme to 20mL deionized water to prepare an enzyme solution. Place gelatin / chitosan modified microspheres in a rotating roller bed or drum and turn on the rotation (20~30 rpm). Atomize the enzyme solution and spray it evenly onto the surface of the rotating gelatin / chitosan modified microspheres using a spray gun, ensuring the transglutaminase (TG enzyme) accounts for 0.5% of the mass of the gelatin / chitosan modified microspheres. After spraying, transfer the gelatin / chitosan modified microspheres to a sealed container and allow them to react at 40℃ and 80%~90% relative humidity for 1.5 h. After the reaction, dry with hot air at 40℃ for 2 h until constant weight is achieved to obtain the insulation material. (See attached image). Figure 3 As shown. (The ingredients for each step can be independently and reasonably adjusted according to the actual proportions of the corresponding step).

[0059] Based on the above, the specific implementation of the present invention is as follows:

[0060] Example 1

[0061] Based on the above, a preferred embodiment of the present invention provides an organic fertilizer bio-fermentation process suitable for mobile toilet fermentation chambers, comprising the following steps:

[0062] S1. Preparation of fermentation auxiliary materials: The fermentation auxiliary materials include a base material, a heat-conducting material, and a heat-insulating material; the base material includes rice bran and sawdust, with a mass ratio of rice bran to sawdust of 3:7; the heat-conducting material includes magnetized aluminum nitride modified by sodium lignosulfonate, hydroxypropyl cellulose, and agar; the heat-insulating material includes enzyme-triggered hydrophobically modified expanded perlite microspheres; the specific preparation methods of rice bran, sawdust, heat-conducting material, and heat-insulating material are specifically disclosed in the above content, and will not be elaborated further here;

[0063] S2. Preparation of fermentation material: Mix base material, heat-conducting material, heat-insulating material and toilet fermentation agent to obtain fermentation material; wherein, the mass ratio of base material, heat-conducting material and heat-insulating material is 17.5:8:12.5; based on the excrement collected by 100kg of mobile toilet fermentation chamber, the amount of base material added is 5.5kg, and the amount of toilet fermentation agent inoculated accounts for 0.4kg of excrement collected by mobile toilet fermentation chamber;

[0064] S3, Two-stage fermentation:

[0065] S3.1, First Fermentation Stage: Within 48 hours of the mobile toilet's fermentation chamber beginning to collect excrement, the temperature inside the chamber is maintained at 60℃ with intermittent stirring. The intermittent stirring method is as follows: each cycle lasts 2 hours. One cycle consists of 10 minutes of forward rotation (20 rpm), followed by 5 minutes of resting, then 10 minutes of reverse rotation (20 rpm), followed by 95 minutes of resting. After the resting period, the next cycle begins. During both forward and reverse rotations within the intermittent stirring cycle, aeration is performed simultaneously at a rate of 0.6 m³ / h. 3 / h;

[0066] S3.2, Second Fermentation Stage: From the 48th hour after the start of excrement collection in the mobile toilet fermentation chamber until the chamber is full, a steady-state fermentation process begins, lasting at least 24 hours. This steady-state fermentation includes the following stages:

[0067] S3.2.1, Daytime Low-Temperature Fermentation Stage: During the daytime period from 6:00 AM to 6:00 PM, the fermentation chamber temperature is maintained at 35°C with intermittent stirring. The intermittent stirring method is as follows: each cycle lasts 2 hours. One cycle consists of 10 minutes of forward rotation (20 rpm), followed by 5 minutes of rest, then 10 minutes of reverse rotation (20 rpm), followed by 95 minutes of rest. After the rest period, the next cycle begins. During both forward and reverse rotations within the intermittent stirring cycle, aeration is performed simultaneously at a rate of 0.6 m³ / s. 3 / h;

[0068] S3.2.2, Nighttime High-Temperature Fermentation Stage: During the nighttime period from 18:00 to 6:00 the next morning, the fermentation chamber temperature is maintained at 65℃ with intermittent stirring. The intermittent stirring method is as follows: each cycle lasts 2 hours. One cycle consists of 10 minutes of forward rotation (20 rpm), followed by 5 minutes of rest, then 10 minutes of reverse rotation (20 rpm), followed by 95 minutes of rest. After the rest period, the next cycle begins. During both forward and reverse rotations within the intermittent stirring cycle, aeration is performed simultaneously at a rate of 0.6 m³ / s. 3 / h;

[0069] S4. In step S3, the total fermentation period of the mobile toilet fermentation chamber, from the start of collecting excrement to the cessation of fermentation after the chamber is full, shall not be less than 8 days. After the mobile toilet fermentation chamber is full of fermentation, the heat-conducting material shall be filtered and recovered to obtain organic fertilizer.

[0070] The mobile toilet fermentation chamber collects mainly feces, urine, and toilet flushing water. The entire fermentation period, from the start of waste collection to cessation of fermentation when the chamber is full, is no less than 8 days. If the time to full is ≥7 days, fermentation ends 24 hours after full capacity, yielding organic fertilizer. If the time to full is <7 days, steady-state fermentation continues after full capacity, ensuring a total fermentation period of 8-10 days to obtain organic fertilizer. In summary, if the total fermentation period at full capacity is less than 8 days, the diurnal steady-state fermentation is extended until the total fermentation period is complete. The fermentation period is 8-10 days. If the total fermentation period is 8 days or more when the warehouse is full, continue steady-state fermentation for 24 hours after the warehouse is full, and then stop fermentation. After fermentation, the organic fertilizer is handled as follows: Place the organic fertilizer in a normal temperature environment (25℃, relative humidity 50%, aerobic environment, no need to seal) and let it stand for about 2 days. After stirring evenly, it can be directly diluted and used according to the actual situation. Alternatively, after standing, it can be granulated and dried to obtain solid organic fertilizer. This application mainly processes it into solid organic fertilizer.

[0071] Example 2

[0072] This embodiment is based on Embodiment 1, except that the mass ratio of the base material, thermally conductive material, and thermal insulation material in this embodiment is 15:6:10, while the rest is the same as in Embodiment 1.

[0073] Example 3

[0074] This embodiment is based on Embodiment 1, except that the mass ratio of the base material, thermally conductive material, and thermal insulation material in this embodiment is 20:10:15, while the rest is the same as in Embodiment 1.

[0075] Comparative Example 1

[0076] Based on Example 1, the difference between this comparative example and Example 1 is that the fermentation auxiliary material in this comparative example does not include heat-conducting material, and the fermentation material preparation process does not include heat-conducting material, while the rest is the same as Example 1.

[0077] Comparative Example 2

[0078] Based on Example 1, the difference between this comparative example and Example 1 is that the fermentation auxiliary material in this comparative example does not include heat-insulating material, and the fermentation material preparation process does not include heat-insulating material, while the rest is the same as Example 1.

[0079] Comparative Example 3

[0080] Based on Example 1, the difference between this comparative example and Example 1 is that the insulation material in this comparative example is intermediate modified microspheres, and steps S7.3 to S7.5 are not performed; the rest is the same as in Example 1.

[0081] The intermediate modified microspheres were prepared by the following method:

[0082] S7.1. Stearic acid and expanded graphite were placed in a stainless steel container at a mass ratio of 95:5 and heated to 70±5℃. The mixture was mechanically stirred at 200 rpm for 30 min to obtain a composite material. 100 g of expanded perlite microspheres were placed in a vacuum impregnation tank and sealed. The vacuum was evacuated to -0.085 ~ -0.095 MPa and maintained for 30 min. The composite material at 70±5℃ was drawn in through the impregnation valve. The impregnation liquid level of the composite material was 2~3 cm higher than the top surface of the expanded perlite microspheres. The vacuum degree was maintained above -0.08 MPa. Impregnation was continued for 2~4 h. Then, the pressure was slowly restored to normal (pressure relief rate ≤0.01 MPa / min). Impregnation was continued for 30 min under normal pressure. After impregnation, the microspheres were removed, drained, and cooled in a water bath to obtain the preliminarily modified microspheres.

[0083] S7.2. Mix 12 g of hydrophobic silica aerogel powder with 30 g of silica sol (30 wt%) and stir at 200 rpm for 15 min to prepare a uniform spray material. Place the pre-modified microspheres in a rotating roller bed and spray the spray material evenly onto the surface of the pre-modified microspheres with a spray gun. Dry with hot air at 60~80℃ for 2 h. Repeat the spraying and drying process (if a single batch of spray material is insufficient, replenish the spray material in the same proportion and continue to use) until the coating thickness on the surface of the pre-modified microspheres reaches 0.6 mm to obtain intermediate modified microspheres, which serve as the thermal insulation material for this comparative example.

[0084] Comparative Example 4

[0085] Based on Example 1, the difference between this comparative example and Example 1 is as follows: The thermal conductive material of this comparative example was prepared by the following method: AlN particles were immersed in 15 vol% dilute hydrochloric acid and ultrasonically treated at 40°C for 15 min. Then, the mixture was filtered and washed with deionized water until neutral to obtain acid-treated AlN particles. 0.05 mol FeCl2·4H2O and 0.1 mol FeCl3·6H2O were dissolved in 200 mL of deoxygenated water to obtain a mixed solution. Then, acid-treated AlN particles were added to the mixed solution at a solid-liquid ratio of 1 g: 10 mL. After stirring evenly, the system was heated to 60°C under nitrogen protection. Then, ammonia water was slowly added dropwise to adjust the pH to 9-10. The mixture was then reacted at 60°C for 1 hour. After the reaction was completed, the precipitate was separated by an external magnetic field (0.5 T). The precipitate was repeatedly washed with deionized water until neutral and then vacuum dried (60°C, -0.09 MPa) for 4 hours to obtain magnetized aluminum nitride. No further modification was performed, and the precipitate was directly used as the thermal conductive material of this comparative example. Everything else is the same as in Example 1.

[0086] Comparative Example 5

[0087] Based on Example 1, the difference from Example 1 is that the fermentation auxiliary material in this comparative example only includes the base material and does not include the heat-conducting material and the heat-insulating material; the base material includes rice bran and sawdust, and both rice bran and sawdust are the above-mentioned modified rice bran and modified sawdust; the mass ratio of rice bran to sawdust is 3:7; the rest is the same as in Example 1.

[0088] Comparative Example 6

[0089] Based on Example 1, the difference from Example 1 is that the fermentation auxiliary material in this comparative example only includes the base material and does not include the heat-conducting material and the heat-insulating material; the base material includes conventional rice bran and conventional sawdust, with a mass ratio of conventional rice bran to conventional sawdust of 3:7; the rest is the same as in Example 1; the modified rice bran and modified sawdust mentioned above are not used; the conventional rice bran is rice bran before being degreased by the above-mentioned supercritical CO2 extraction; the conventional sawdust is the hardwood sawdust before being pretreated by steam explosion.

[0090] Comparative Example 7

[0091] Based on Example 1, but differing from Example 1, this comparative example uses a fermentation temperature of 35°C combined with the intermittent stirring process of Example 1 instead of the two-stage fermentation of Example 1. The fermentation cycle is 24 hours from the start of excrement collection to full capacity. Everything else is the same as in Example 1.

[0092] Comparative Example 8

[0093] Based on Example 1, but differing from Example 1, this comparative example uses a fermentation temperature of 65°C combined with the intermittent stirring process of Example 1 instead of the two-stage fermentation of Example 1. The fermentation cycle is 24 hours from the start of excrement collection to full capacity. Everything else is the same as in Example 1.

[0094] Experimental Example 1

[0095] Temperature uniformity test of the fermentation system: 10 kg of fresh excrement collected from the fermentation chamber of the mobile toilet was taken for each experimental sample; experimental fermentation materials were prepared according to the fermentation material formulas of Examples 1-3 and Comparative Examples 1-6 respectively (calculated based on 10 kg of excrement collected from the mobile toilet fermentation chamber, the amount of base material added was 0.55 kg, and the amount of toilet fermentation agent inoculated was 0.04 kg of excrement collected from the mobile toilet fermentation chamber); the fresh excrement was mixed evenly with the fermentation material of the corresponding experimental group to form a pile, which was then placed into cylindrical test containers of the same specifications. Thermocouple temperature probes were arranged at the following positions: center measuring point; geometric center of the pile; radial measuring point: any point at 1 / 2 radius from the center; axial measuring point: upper axial measuring point at 1 / 2 radius upward from the center, and lower axial measuring point at 1 / 2 radius downward from the center; test method: the heating power supply at the bottom of the container was turned on, and the temperature at the center point was heated to 65℃, and then the power supply was turned off. At the same time, the temperature of each measuring point was recorded, and the results were calculated.

[0096] The absolute values ​​of the temperature difference between the radial measuring point and the center measuring point ΔT1, the absolute values ​​of the temperature difference between the upper axial measuring point and the center measuring point ΔT2, and the absolute values ​​of the temperature difference between the lower axial measuring point and the center measuring point ΔT3; the values ​​of three parallel samples were integrated for each test group, and the results are shown in Table 1.

[0097] ΔT1 = |Radial measuring point temperature - Center measuring point temperature|;

[0098] ΔT2 = |Temperature at upper axial measuring point - Temperature at center measuring point|;

[0099] ΔT3 = |Temperature at the lower axial measuring point - Temperature at the center measuring point|.

[0100] Table 1 Results of temperature uniformity test in fermentation system

[0101] Example 1 2.2~2.5 1.4~1.6 1.8~2.3 Example 2 2.8~3.0 2.0~2.5 2.2~2.4 Example 3 2.3~2.7 1.3~1.8 1.8~2.4 Comparative Example 1 8.5~9.5 6.3~7.2 6.5~6.7 Comparative Example 2 3.0~3.8 4.5~6.5 2.8~3.4 Comparative Example 3 2.8~3.5 4.0~6.0 2.5~2.9 Comparative Example 4 7.2~7.5 5.7~6.3 5.1~6.0 Comparative Example 5 11.0~12.5 9.0~10.3 9.4~9.8 Comparative Example 6 13.9~14.6 11.2~11.5 11.0~11.4

[0102] Experimental Example 2

[0103] A mobile toilet fermentation chamber collecting 100 kg of excrement was used as the sample chamber. The fermentation process was carried out according to Examples 1-3 and Comparative Examples 1-8, with a total fermentation cycle of 10 days. After fermentation, the organic fertilizer was placed in a natural indoor environment with aerobic conditions at 25°C and 50% relative humidity for 2 days without sealing. After standing, the mixture was stirred evenly, granulated, and dried to obtain solid organic fertilizer. Based on the standard "NY / T 525-2021 Organic Fertilizer", samples were taken to test the organic matter mass fraction (dry basis), total nutrient (N+P2O5+K2O) mass fraction (dry basis), seed germination index (GI), and pathogenic organism content (fecal coliform count) and (Ascaris egg mortality rate) of the solid organic fertilizer. The values ​​of three parallel samples were combined for each experiment, and the results are shown in Table 2.

[0104] Table 2 Results of Organic Fertilizer Quality Testing

[0105] Example 1 50.5 ~ 52.3 6.8~7.2 88~93 15~20 ≥99.0% Example 2 48.7~49.0 6.4~6.7 84~87 18~25 ≥99.0% Example 3 50.2~51.5 6.5~6.9 87~91 15~22 ≥99.0% Comparative Example 1 31.7~32.2 5.3~5.5 64~68 Substandard Substandard Comparative Example 2 34.5~35.5 5.5~5.9 70~78 Substandard Substandard Comparative Example 3 25.0~25.7 4.2~4.6 50~55 Substandard Substandard Comparative Example 4 32.5~33.4 5.3~5.8 73~75 Substandard Substandard Comparative Example 5 28.6~29.2 4.8~5.2 59~64 Substandard Substandard Comparative Example 6 27.0~27.8 4.5~4.9 57~60 Substandard Substandard Comparative Example 7 24.5~25.3 4.0~4.5 48~52 Substandard Substandard Comparative Example 8 45.2~46.0 6.1~6.5 80~82 16~19 ≥99.0%

[0106] Note: Records of fecal coliform count and ascarid egg mortality rates that do not meet the standards of "NY / T 525-2021 Organic Fertilizer" in actual testing are considered substandard and specific data will not be provided.

[0107] As shown in Tables 1 and 2, this application reduced the temperature distribution difference in the fermentation system. In addition to meeting the requirements of standards NY / T 525-2021 and NY / T 525-2026 for the test items listed in Table 2, the organic fertilizer prepared in this application also meets the requirements of standards NY / T 525-2021 and NY / T 525-2026 for heavy metal content and other indicators. Since NY / T 525-2026 will replace NY / T 525-2021 on October 1, 2026, this application temporarily adopts NY / T 525-2021 for organic fertilizer.

[0108] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, and improvements made by those skilled in the art within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An organic fertilizer bio-fermentation process suitable for mobile toilet fermentation chambers, characterized in that: Includes the following steps: S1. Preparation of fermentation adjuvants: The fermentation adjuvants include a base material, a heat-conducting material, and a heat-insulating material; the base material includes rice bran and sawdust; the heat-conducting material includes magnetized aluminum nitride modified by sodium lignosulfonate, hydroxypropyl cellulose, and agar; the heat-insulating material includes enzyme-triggered hydrophobic modified expanded perlite microspheres. S2. Preparation of fermentation material: Mix base material, heat-conducting material, heat-insulating material and toilet fermentation agent to obtain fermentation material; wherein, the mass ratio of base material, heat-conducting material and heat-insulating material is (15~20):(6~10):(10~15); based on the excrement collected by 100kg of mobile toilet fermentation chamber, the amount of base material added is 5kg~6kg, and the amount of toilet fermentation agent inoculated accounts for 0.3kg~0.5kg of excrement collected by mobile toilet fermentation chamber; S3, Two-stage fermentation: S3.1 First fermentation stage: Within 48 hours from the start of the collection of excrement in the mobile toilet fermentation chamber, the temperature inside the fermentation chamber is maintained at 55~60℃ and accompanied by intermittent stirring; S3.2, Second Fermentation Stage: From the 48th hour after the start of excrement collection in the mobile toilet fermentation chamber until the chamber is full, a steady-state fermentation process begins, lasting at least 24 hours. This steady-state fermentation includes the following stages: S3.2.1, Low-temperature fermentation stage during the day: During the daytime period from 6:00 AM to 6:00 PM, the fermentation chamber is maintained at a temperature of 30-35°C with intermittent stirring. S3.2.2, Nighttime High-Temperature Fermentation Stage: During the nighttime period from 18:00 to 6:00 the next morning, the fermentation chamber is maintained at a temperature of 60~65℃ with intermittent stirring. S4. In step S3, the total fermentation period of the mobile toilet fermentation chamber, from the start of collecting excrement to the cessation of fermentation after the chamber is full, shall not be less than 8 days. After fermentation, the heat-conducting material shall be filtered and recovered to obtain organic fertilizer.

2. The organic fertilizer bio-fermentation process for a mobile toilet fermentation chamber according to claim 1, characterized in that: The rice bran is modified rice bran, which is prepared by the following method: after degreasing by supercritical CO2 extraction, the rice bran is soaked in 1wt% NaOH solution at room temperature for 2 hours, washed with water until neutral, dried at 105℃, and then pulverized through a 40-mesh sieve to obtain modified rice bran.

3. The organic fertilizer bio-fermentation process suitable for mobile toilet fermentation chambers according to claim 1, characterized in that: The sawn wood surface is obtained by pre-treating broadleaf sawdust with steam explosion, air-drying it after steam explosion pre-treatment, and then crushing it through a 20-mesh sieve.

4. The organic fertilizer bio-fermentation process suitable for mobile toilet fermentation chambers according to claim 1, characterized in that: The mass ratio of rice bran to sawdust is 3:

7.

5. The organic fertilizer bio-fermentation process suitable for mobile toilet fermentation chambers according to claim 1, characterized in that: The intermittent stirring method is the same in steps S3.1, S3.2.1, and S3.2.2; the intermittent stirring method is as follows: each execution cycle is 2 hours, and one execution cycle consists of 10 minutes of forward rotation, followed by 5 minutes of rest, then 10 minutes of reverse rotation, followed by 95 minutes of rest. After the rest period, the next execution cycle begins; during both forward and reverse stirring within the intermittent stirring cycle, aeration is carried out simultaneously at a flow rate of 0.6 m³ / s. 3 / h.

6. The organic fertilizer bio-fermentation process suitable for mobile toilet fermentation chambers according to claim 1, characterized in that: The thermally conductive material was prepared by the following method: AlN particles were immersed in 15 vol% dilute hydrochloric acid, ultrasonically treated, filtered, and washed with deionized water until neutral to obtain acid-treated AlN particles; FeCl2·4H2O and FeCl3·6H2O were dissolved in deoxygenated water at a molar ratio of 1:2 to obtain a mixed solution; then the acid-treated AlN particles were added to the mixed solution, stirred evenly, and the system was heated to 60°C under nitrogen protection; then ammonia was slowly added dropwise to adjust the pH to 9-10, and the reaction was carried out at 60°C for 1-1.5 hours; after the reaction was completed, the precipitate was separated by an external magnetic field, and the precipitate was repeatedly washed with deionized water until neutral and vacuum dried to obtain magnetized aluminum nitride; Magnetized aluminum nitride was added to a 3 vol% GPTMS toluene solution, heated to react, filtered, washed, and vacuum dried to obtain modified magnetized aluminum nitride particles. Sodium lignosulfonate was added to deionized water and heated and stirred until completely dissolved. Agar was then added, and the mixture was heated and stirred until completely dissolved. The temperature was then lowered to 60°C, and hydroxypropyl cellulose was added. The mixture was stirred at 60°C until a homogeneous colloid was obtained. The mass ratio of sodium lignosulfonate, agar, and hydroxypropyl cellulose was 3:4:

40. Modified magnetized aluminum nitride particles were added to the colloid, with a mass ratio of modified magnetized aluminum nitride particles to hydroxypropyl cellulose of 5:

2. The mixture was then reacted at 60°C and stirred at 150-200 rpm for 12 h. After the reaction was completed, the mixture was allowed to cool naturally to room temperature, filtered, washed, and vacuum dried to obtain the thermally conductive material.

7. The organic fertilizer bio-fermentation process suitable for mobile toilet fermentation chambers according to claim 1, characterized in that: The thermal insulation material is prepared by the following method: S7.1 Place expanded perlite microspheres in a vacuum impregnation tank, evacuate to -0.085 ~ -0.095 MPa and maintain for 30 min, inject a composite material at 70±5℃, the composite material being composed of stearic acid and expanded graphite in a mass ratio of 95:5, maintain vacuum impregnation for 2~4 h, restore normal pressure, continue impregnation for 30 min, remove and cool to obtain preliminarily modified microspheres; S7.

2. Prepare a spray by mixing hydrophobic silica aerogel powder with silica sol, spray it onto the surface of the pre-modified microspheres, and dry it to obtain intermediate modified microspheres. S7.

3. Immerse the intermediate modified microspheres in a chitosan solution containing acetic acid, soak at room temperature and then dry to obtain chitosan modified microspheres. S7.

4. Immerse the chitosan-modified microspheres in a gelatin aqueous solution, soak at 45°C, drain, and air dry with cold air to obtain gelatin / chitosan-modified microspheres. S7.

5. Spray the transglutaminase solution evenly onto the surface of the gelatin / chitosan modified microspheres and react at 40°C and 80%~90% relative humidity for 1~2 h. After the reaction is completed, dry at 40°C to constant weight to obtain the thermal insulation material.

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