Temperature-sensitive and oxygen-release dual-mode hydrogel cooperatively regulated and controlled by oxygen and microorganisms and application of hydrogel in aerobic composting

Abstract

The invention discloses temperature-sensitive-oxygen-release dual-mode hydrogel cooperatively regulated by oxygen and microorganisms and application of the temperature-sensitive-oxygen-release dual-mode hydrogel in aerobic composting, and belongs to the technical field of organic solid waste treatment and recycling. The technical problem that in the aerobic composting process, released oxygen is not matched with microbial metabolism requirements is solved. The temperature-sensitive-oxygen-release dual-mode hydrogel prepared by the invention is of a spherical structure and sequentially comprises a CaO2 core, an EC film for wrapping the CaO2 core, a temperature-sensitive hydrogel shell for wrapping the EC film and a compound microbial agent positioned on the temperature-sensitive hydrogel shell from inside to outside. The temperature-sensitive material responds to the temperature change of the pile body, when the pile temperature reaches 45 DEG C, the shell is triggered to shrink, the isolating layer is destroyed, oxygen is released and thermophilic bacteria are activated, on-demand oxygen supply and microbial agent controlled release are achieved, the problem of local oxygen deficit of the pile body can be effectively solved, the composting efficiency and quality are improved, and the method is suitable for treatment of organic solid waste such as agricultural waste and municipal sludge.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of organic solid waste treatment and resource utilization, and particularly relates to a temperature-sensitive-oxygen-releasing dual-mode hydrogel for oxygen and microbial synergistic regulation and application thereof in aerobic composting. BACKGROUND

[0002] Aerobic composting is one of the key biological technologies for realizing the resource utilization of organic solid waste, and its core relies on the efficient degradation and conversion of organic matter by aerobic microorganisms. In this process, oxygen is a key factor affecting microbial activity and metabolic pathways. Due to reasons such as material compaction, uneven water distribution, and excessive oxygen consumption rate of microbial respiration, local anaerobic (dissolved oxygen concentration < 5%) regions often occur in the composting body, triggering anaerobic fermentation, leading to incomplete decomposition of organic matter, slow humification process, and generation of harmful substances such as organic acids and ammonia gas, thereby reducing the composting quality and agricultural safety.

[0003] Currently, oxygen regulation in the composting process mainly relies on two types of means: physical aeration (such as turning and forced aeration) and chemical oxygen-releasing materials. CN222099826U discloses an automatic turning composting machine, which can automatically turn at a low speed and improve the air flow speed during turning, thereby accelerating the increase of oxygen content in the waste pile. However, turning and forced aeration can improve the oxygen distribution to a certain extent, but have high energy consumption and frequent operation, and it is difficult to achieve continuous oxygen supply in the deep layer of the composting body. In chemical oxygen-releasing materials, peroxide salts (such as CaO2 and MgO2) are widely studied due to their high oxygen content and slow-release potential. CN105925267A discloses a slow-release oxidant with calcium peroxide as the substrate and ethyl cellulose as the coating. The slow-release oxidant product has a release oxygen time of more than 100 days. This prior art realizes the slow release of active oxygen, but still has the following technical problems:

[0004] The release behavior lacks intelligent responsiveness, and the oxygen release rate does not match the actual oxygen demand dynamics of the composting body. The existing slow-release oxidant has the phenomenon of excessive oxygen release at the initial stage of composting (pile temperature < 45℃) and insufficient oxygen supply at the high-temperature stage (pile temperature ≥ 45℃). The hydrolysis byproducts (such as Ca(OH)2) will also cause a sharp increase in the pH of the composting body, which will destroy the microbial community structure (such as the method for mixed composting of livestock and poultry manure disclosed in CN112521202A). In addition, a single oxygen-releasing material cannot realize the on-demand release and spatial positioning of functional microorganisms, which limits the further improvement of composting efficiency.

[0005] Under this research background, developing an intelligent material system capable of responding to the temperature change of the reactor and realizing the coordinated release of oxygen and functional microorganisms is an important direction to break through the technical bottleneck of the existing technology. SUMMARY

[0006] One of the purposes of the present application is to provide an application of oxygen and microorganism synergistically regulated temperature-sensitive-oxygen-releasing bimodal hydrogel in aerobic composting, which solves the technical problem of mismatching between oxygen release and metabolic demand of microorganisms in the aerobic composting process. By constructing a temperature-sensitive-oxygen-releasing bimodal hydrogel with a core-shell structure, the shrinkage of the shell triggered by temperature is used to accurately control the start of the core CaO2 and the release of the bacterial agent, and through the "temperature-oxygen-bacterial agent" triple synergistic mechanism, it provides core technical support for realizing efficient, low-consumption and intelligent aerobic composting.

[0007] In order to achieve the above purpose, the present application adopts the following technical scheme:

[0008] The application of oxygen and microorganism synergistically regulated temperature-sensitive-oxygen-releasing bimodal hydrogel in aerobic composting, the preparation method of the temperature-sensitive-oxygen-releasing bimodal hydrogel comprises the following steps:

[0009] a. Take CaO2 as the core, and use fluidized bed coating method to coat EC film on the periphery of CaO2 to obtain EC coated CaO2 microspheres;

[0010] b. Using suspension polymerization method, prepare temperature-sensitive hydrogel shell on the periphery of the EC coated CaO2 microspheres obtained in step a to obtain core-shell microspheres;

[0011] The specific method for preparing the core-shell microspheres is:

[0012] b1: prepare the oil phase;

[0013] b2, prepare the water phase, dissolve the reaction monomer and the crosslinking agent together in deionized water to obtain the water phase;

[0014] b3, place the EC coated CaO2 microspheres in the water phase and stir to disperse them, add the obtained water phase mixture into the oil phase, and add an initiator into the oil phase, the reaction temperature is 60-65℃, and the reaction time is 6-8 hours;

[0015] c. Load the bacterial agent on the surface of the core-shell microspheres by placing the core-shell microspheres in a composite microbial liquid, and dry to obtain a spherical structure of temperature-sensitive-oxygen-releasing bimodal hydrogel; the composite microbial liquid comprises thermophilic bacteria and / or thermophilic bacteria;

[0016] The application is to add temperature-sensitive hydrogel into fermentation raw materials to realize on-demand oxygen release:

[0017] The first stage is a starting and warming-up stage, at which the temperature of the pile body is less than 45 DEG C, the temperature-sensitive hydrogel shell is in a swelling state, the thermophilic bacteria loaded on the surface of the temperature-sensitive hydrogel shell are activated, and the thermophilic bacteria rapidly reproduce and release biological heat by using the easily degradable organic matter and oxygen, and the thermophilic bacteria loaded on the surface of the temperature-sensitive hydrogel shell are inoculated into the pile body and sleep for use; at this time, the temperature-sensitive hydrogel shell effectively isolates the EC-coated CaO2 microspheres and prevents the CaO2 microspheres from releasing oxygen; the second stage is intelligent triggering and oxygen release, on the basis of the first stage, the temperature of the pile body is increased, when the temperature of the pile body is greater than or equal to 45 DEG C, the temperature-sensitive hydrogel shell changes from the swelling state to the shrinking state, and the mechanical stress is generated inwardly to make the EC film rupture, the CaO2 is exposed to the external environment and starts to release oxygen; the thermophilic bacteria loaded on the surface of the temperature-sensitive hydrogel shell are activated and rapidly reproduce by using the easily degradable organic matter and oxygen.

[0018] The above technical solution directly brings the beneficial technical effects:

[0019] As a whole, the above method can solve the technical problem that the oxygen release and the metabolic demand of microorganisms do not match in the aerobic composting process, for example, when the temperature of the pile body is less than 45 DEG C, the swelling state of the temperature-sensitive hydrogel shell prevents the CaO2 from releasing oxygen, at this time, the bacteria agent is activated, and the easily degradable organic matter and oxygen are rapidly reproduced, which matches the metabolic demand of microorganisms and does not cause oxygen loss. With the increase of the temperature of the pile body, when the temperature of the pile body is greater than or equal to 45 DEG C, the mechanical stress generated by the swelling state of the temperature-sensitive hydrogel shell makes the EC film rupture, and the CaO2 starts to release oxygen, which is mainly CaO2 release in this stage. Therefore, the present application matches the oxygen release mode in the two stages according to the metabolic demand of microorganisms, which effectively solves the technical problem of local anaerobic composting, and improves the efficiency and quality of composting.

[0020] In the application of the oxygen and microorganism synergistically regulated temperature-sensitive-oxygen release dual-mode hydrogel in aerobic composting, the particle size of CaO2 in step a is 100-200 meshes.

[0021] In the application of the oxygen and microorganism synergistically regulated temperature-sensitive-oxygen release dual-mode hydrogel in aerobic composting, the concentration of the coating liquid in the fluidized bed coating method is 5-10% of EC ethanol solution, the inlet air temperature is 40-50 DEG C, the coating liquid is uniformly sprayed on the surface of CaO2 in a fluidized state after atomization, the ethanol is volatilized, the EC forms a continuous film on the periphery of CaO2 microspheres, and the EC-coated CaO2 microspheres are obtained after drying.

[0022] In the application of the oxygen and microorganism synergistically regulated temperature-sensitive-oxygen-releasing dual-mode hydrogel in aerobic composting, in step b1, the oil phase is liquid paraffin containing a stabilizer; in step b2, the reaction monomer is N-isopropyl acrylamide, and the crosslinking agent is N,N'-methylenebisacrylamide; in step b3, the initiator is ammonium persulfate.

[0023] In the application of the oxygen and microorganism synergistically regulated temperature-sensitive-oxygen-releasing dual-mode hydrogel in aerobic composting, in step b2, the water phase mixture is added to the oil phase with a temperature of 65 DEG C, and the water phase is dispersed into a plurality of small droplets in the oil phase, each of which contains at least one core particle; in step b3, nitrogen is introduced to remove oxygen during the reaction, the reaction monomer N-isopropyl acrylamide is polymerized and crosslinked in each droplet, and a core-shell microsphere structure is formed.

[0024] In the application of the oxygen and microorganism synergistically regulated temperature-sensitive-oxygen-releasing dual-mode hydrogel in aerobic composting, the thermophilic bacteria are Bacillus subtilis or Bacillus cereus, and the thermophilic bacteria are Bacillus stearothermophilus or Bacillus coagulans.

[0025] In the application of the oxygen and microorganism synergistically regulated temperature-sensitive-oxygen-releasing dual-mode hydrogel in aerobic composting, the bacteria loading temperature is 4-5 DEG C, and the loading time is 12-24 h.

[0026] In the application of the oxygen and microorganism synergistically regulated temperature-sensitive-oxygen-releasing dual-mode hydrogel in aerobic composting, the addition amount of the temperature-sensitive hydrogel is 10% of the total mass of the fermentation raw materials, the fermentation raw materials include agricultural waste and municipal sludge, the agricultural waste mainly includes livestock and poultry manure, and corn cob is used as auxiliary material, the initial water content of the pile is 55%-65%, and the initial C / N is 25-30.

[0027] Another object of the application is to provide an oxygen and microorganism synergistically regulated temperature-sensitive-oxygen-releasing dual-mode hydrogel, characterized in that it is a spherical structure, which sequentially comprises a CaO2 core, an EC film for wrapping the CaO2 core, a temperature-sensitive hydrogel shell for wrapping the EC film, and a composite microbial inoculum on the temperature-sensitive hydrogel shell; the particle size of the CaO2 core is 100-200 meshes.

[0028] Compared with the prior art, the application has the following beneficial technical effects:

[0029] (1) In the prior art, the CaO2 core coated by the EC film directly releases oxygen, and the related research is focused on improving the oxygen release time, and the application is focused on the technical problem that the oxygen release does not match the metabolic demand of microorganisms, which is based on the foresight judgment of the technical problem.

[0030] (2) The technical solution determined around the technical problem, by applying the temperature-sensitive material in the application, i.e. by the stress generated by the swelling state of the temperature-sensitive hydrogel shell to control whether the CaO2 core releases oxygen, the technical concept is rarely seen in the field of organic solid waste treatment and resource utilization, in addition, in the first stage, the mode of activating the inoculant, easily degradable organic matter and oxygen is mainly rapid reproduction, which is different from the mode of directly releasing oxygen in the prior art in this stage.

[0031] (3) The present application responds to the temperature change of the stack by using temperature-sensitive materials, which triggers the shell to shrink when the stack temperature reaches 45℃, destroys the isolation layer, releases oxygen and functional microorganisms, and realizes on-demand oxygen supply and inoculant controlled release. The hydrogel can effectively alleviate the local oxygen deficiency problem of the stack, promote the degradation and humification process of organic matter, improve the composting efficiency and quality, and is suitable for the treatment of agricultural waste and municipal sludge and other organic solid waste. The present application can simultaneously realize the release of oxygen and the coordinated regulation of functional microorganisms in the oxygen gel system, which has important research value and application prospect. BRIEF DESCRIPTION OF DRAWINGS

[0032] The present application will be further described below in conjunction with the drawings:

[0033] Figure 1 The temperature change graph of two treatment groups in Example 2 of the present application in the application of aerobic composting.

[0034] Figure 2 The oxygen concentration change graph of two treatment groups in Example 2 of the present application in the application of aerobic composting.

[0035] Figure 3 The seed germination index change graph of two treatment groups in Example 2 of the present application in the application of aerobic composting.

[0036] Figure 4 The humic acid content change graph of two treatment groups in Example 2 of the present application in the application of aerobic composting.

[0037] Figure 5 The structure decomposition graph of the temperature-sensitive-oxygen-releasing dual-mode hydrogel of the present application. DETAILED DESCRIPTION

[0038] The present application proposes a temperature-sensitive-oxygen-releasing dual-mode hydrogel for the coordinated regulation of oxygen and microorganisms and its application in aerobic composting. In order to make the advantages and technical solutions of the present application more clear and explicit, the present application will be further described below in conjunction with specific examples.

[0039] In the description of the present application, unless otherwise specified, " / " means "or", for example, A / B can mean A or B. "And / or" herein is only a description of the relationship between the associated objects, which means that there can be three relationships, for example, A and / or B, which can mean that A exists alone, A and B exist together, and B exists alone. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion.

[0040] The thermophilic bacteria referred to in the present application refers to microorganisms that can normally reproduce in room temperature 20-30℃ environment. The thermophilic bacteria refers to microorganisms that can grow and reproduce in an environment above 50℃.

[0041] The raw materials referred to in the present application can be purchased through commercial channels.

[0042] NIPAM referred to hereinafter is the abbreviation of N-isopropyl acrylamide, MBA is the abbreviation of N,N'-methylene bisacrylamide. EC is the abbreviation of ethyl cellulose. APS is the abbreviation of ammonium persulfate.

[0043] Example 1:

[0044] The specific preparation method of the oxygen and microorganism synergistically regulated temperature-sensitive-oxygen-releasing dual-mode hydrogel of the present application is:

[0045] First step, CaO2 is used as the core, and a fluidized bed coating method is used to coat EC film on the periphery to obtain EC-coated CaO2 microspheres.

[0046] The specific steps are as follows:

[0047] (1) Prepare the coating liquid solution: dissolve EC in anhydrous ethanol to prepare an EC ethanol solution with a concentration of 5-10% (w / v), and stir until completely clear. (2) Fluidized bed preheating: load CaO2 powder into the hopper of the fluidized bed coater, start the air inlet, and make the CaO2 particles in a stable fluidized state. Set the air inlet temperature to 40-50℃. (3) Spray coating: deliver the EC ethanol solution to the spray gun through a peristaltic pump, and uniformly spray it onto the surface of the CaO2 particles in a fluidized state after atomization. Ethanol is instantly volatilized in the hot air stream, and EC forms a dense and continuous film on the surface. (4) Post-treatment and drying: after coating, continue to dry for 10-15 minutes to ensure complete solvent evaporation. Collect the obtained microspheres, and sieve out the particles that may be adhered. (5) Intermediate product: obtain EC-coated CaO2 microspheres, and store them in a moisture-proof manner.

[0048] Second step, a suspension polymerization method is used to prepare a temperature-sensitive hydrogel shell on the periphery of the EC-coated CaO2 microspheres obtained in the first step to obtain core-shell microspheres.

[0049] The specific steps are as follows:

[0050] (1) Prepare the oil phase: add 150-200 mL of liquid paraffin and 0.5-1.0 g of sorbitan monooleate (Span-80) into a 250 mL three-necked flask, install a stirrer, a condenser tube, and a thermometer, start stirring at a speed of 200-400 rpm, and heat to 60-65°C. (2) Prepare the water phase: dissolve 10 g of NIPAM monomer and 0.5 g of MBA crosslinking agent in 30-50 mL of deionized water. Then add 10 g of EC-coated CaO2 microspheres, and gently stir to disperse them evenly to obtain a water phase mixture.

[0051] (4) Dissolve 0.1 g of APS initiator in a small amount (e.g., 5 mL) of deionized water to prepare an initiator solution. Under continuous stirring and nitrogen protection, slowly add the APS solution to the suspension system. React at 65°C for 6-8 hours under nitrogen protection.

[0052] (6.1) Preliminary washing and pretreatment:

[0053] a. Pour the entire mixture after polymerization into a large beaker, and let it stand for a while to allow the microspheres to settle at the bottom.

[0054] b. Carefully pour away the upper liquid paraffin oil phase. Add n-hexane to the beaker, stir well, then let it settle, and pour away the supernatant. Repeat this step 2-3 times to completely remove the residual oil and Span-80.

[0055] c. Use deionized water to wash in the same way, repeating 2-3 times to remove salts and any water-soluble impurities.

[0056] (6.2) Wet sieving - separation by size

[0057] a. Redisperse the "crude product" wet cake with deionized water to form a dilute suspension.

[0058] b. Assemble a set of upper 100-mesh and lower 200-mesh sieves in the order from top to bottom.

[0059] c. Pour the sample suspension into the top sieve (100 mesh), rinse gently and shake the sieve with a slow water stream (or directly in a water basin);

[0060] d. Collect the sample in the "100-200 mesh" interval, and store it as a suspension in deionized water for the next step.

[0061] (6.3) Differential centrifugation - separation by density

[0062] a. Dispense the sieved sample suspension into centrifuge tubes;

[0063] b. Try 1000-1500 rpm in a table centrifuge for 1-3 minutes;

[0064] c. Carefully pour the supernatant into another container. The precipitate is the ideal core-shell microsphere after preliminary purification;

[0065] d. Purification: Redispersed the precipitate with deionized water, repeat the above centrifugation process 1-2 times. Discard the supernatant after each centrifugation.

[0066] (6.4) Washing and drying

[0067] a. Washing: Wash the final precipitate obtained by centrifugation once with deionized water or anhydrous ethanol to remove any residual trace impurities.

[0068] b. Drying:

[0069] (1) Transfer the washed microsphere product to a petri dish or surface dish;

[0070] (2) Place it in a vacuum drying oven for drying at room temperature or 30°C;

[0071] (3) Dry to a water content of less than 10% (which can be monitored by weight method) to obtain EC-CaO2@PNIPAM core-shell microspheres.

[0072] Third step, loading of microbial inoculant

[0073] Place the core-shell microspheres in the composite microbial inoculant solution for loading of the microbial inoculant, and load the surface of the core-shell microspheres, and dry to obtain a spherical structure of temperature-sensitive-oxygen-releasing dual-mode hydrogel, as shown in Figure 5 .

[0074] The specific steps are as follows:

[0075] (1) Preparation of composite bacterial solution: After expanding culture of mesophilic bacteria (such as Bacillus subtilis) and thermophilic bacteria (such as Geobacillus stearothermophilus), centrifugal collection of bacterial bodies, resuspension with physiological saline, and mixing, a high-concentration (5×10 9 ~ 1×1010 a complex bacteria suspension (CFU / mL).

[0076] (2) Loading process (low-temperature swelling adsorption method):

[0077] (2.1) Submerge the EC-CaO2@PNIPAM core-shell microspheres in the complex bacteria solution;

[0078] (2.2) Place the whole system in a 4-5°C refrigerator and stand for 12-24 hours.

[0079] (2.3) After loading is completed, filter out the microspheres.

[0080] (2.4) Drying and storage: dry the bacteria-loaded wet microspheres under mild conditions (such as 30°C cold wind) until the water content is less than 10%. The dried product is the final temperature-sensitive oxygen-releasing type complex microbial inoculant, which should be sealed, protected from light, and stored at 4°C for standby.

[0081] (2.5) Loading rate calculation

[0082] (1);

[0083] In formula (1):

[0084] C1 - initial bacteria solution concentration, CFU / mL;

[0085] V1 - initial bacteria solution volume, mL;

[0086] C2 - residual bacteria solution concentration, CFU / mL;

[0087] V2 - residual bacteria solution volume, mL.

[0088] Example 2:

[0089] This example is based on the aerobic composting process, and the composting experiment is carried out in a rectangular aerobic composting reaction bin (internal size: 1 m x 1 m x 1.5 m). The fermentation raw material is mainly pig manure, and corn cob is used as auxiliary material. The initial corn cob length is about 10 cm, which is reduced to about 3 cm after crushing pretreatment. Three treatment groups are set: one is the treatment group added with the temperature-sensitive-oxygen-releasing dual-mode hydrogel of the application (TSOR), and the addition amount is 10% of the total dry mass of the fermentation raw material; the second is the treatment group added with CaO2 (CP), and the addition amount is 10% of the total dry mass of the fermentation raw material; the last group is the blank control group (CK), which does not add any functional material or exogenous microorganism, but only mixes pig manure and corn cob in the same proportion. The initial moisture content of the three groups of piles is adjusted to 60%, and the initial carbon-nitrogen ratio (C / N) is set to 25. Oxygen is supplied by regular turning during the composting process. After mixing, the fermentation is carried out according to the standard operation of aerobic composting process, and the experimental results are combinedFigures 1-4 As shown.

[0090] Comparison of experimental results:

[0091] Depend on Figure 1 Analysis of temperature data from the patent embodiments reveals that the TSOR group, with the addition of the thermosensitive-oxygen-releasing dual-mode hydrogel prepared in this invention, exhibits significant advantages during aerobic composting. It shows the fastest heating rate, exceeding 45°C on day 3 and reaching a peak of 67.54°C on day 7, approximately 13°C and 10°C higher than the CK group (54.14°C) and CP group (57.02°C), respectively. More importantly, the TSOR group maintained a temperature above 55°C for 10 days (days 5 to 14), far exceeding the CK group (approximately 4 days) and CP group (approximately 6 days). This is attributed to the thermosensitive outer shell triggering contraction above 45°C, rupturing the EC membrane to release CaO2 oxygen and functional microorganisms, providing continuous and sufficient oxygen and inoculant support for the thermophilic microbial community, thus greatly maintaining the high metabolic activity of the microorganisms. Although the CP group experienced a slightly faster temperature rise than the TSOR group in the early stages (before day 5) due to CaO2 oxygen release, the lack of intelligent regulation resulted in excessively rapid oxygen release that could not match the needs of microorganisms. This led to insufficient high-temperature maintenance and a faster temperature drop in the later stages. During the cooling period, the TSOR group showed a more gradual and stable temperature decrease, ultimately achieving an average temperature similar to the CK and CP groups (approximately 25°C). This indicates that the organic matter degradation was more thorough and the composting process was more stable and complete, fully demonstrating the optimizing effect of intelligent materials on on-demand oxygen supply and microbial control in the composting temperature process.

[0092] Depend on Figure 2 Analysis of oxygen concentration data shows that the TSOR group exhibits a significant advantage in its intelligent oxygen release mechanism, with the highest and most stable overall oxygen concentration. During the initial composting phase (days 1-5), the oxygen concentrations of the three groups were similar. At this time, the compost temperature had not yet reached the trigger temperature, and the TSOR group's outer shell remained intact, relying primarily on surface microbial activity and physical aeration for oxygen supply. Entering the high-temperature period (after day 5), the differences widened dramatically: the TSOR group's concentration peaked at 16.17% on day 10 and remained above 14.71% throughout. This was due to the contraction and rupture of its temperature-sensitive outer shell after the reactor temperature exceeded 45°C, triggering the continuous release of oxygen from the CaO2 core, precisely matching the intense oxygen demand of the high-temperature microorganisms. In contrast, the CP group, lacking intelligent regulation, experienced premature and rapid decomposition of CaO2 in the early stages, leading to a decline in oxygen release capacity in the later stages (after day 15), with its concentration plummeting below 13.64%, even falling below that of the CK group on day 35. This indicates a severe mismatch between its oxygen release behavior and the actual oxygen demand dynamics of the reactor. The CK group, relying solely on physical aeration, experienced oxygen consumption far exceeding replenishment, resulting in a continuous decrease in concentration to 8.21% (day 15), remaining in a state of oxygen deficiency. The TSOR group, through temperature-triggered on-demand oxygen supply, effectively avoided localized anaerobic environments, providing a core guarantee for efficient aerobic degradation.

[0093] Depend on Figure 3 It can be seen that the seed germination index (GI) is a key indicator for evaluating compost maturity and phytotoxicity. Data analysis shows that the TSOR group exhibited the fastest, most stable, and most thorough maturity process. Its GI value rapidly jumped to a peak of 155.49% on day 7, far exceeding the CP group (123.24%) and the CK group (84.44%), and remained stable above 100% thereafter (fluctuating around 128% throughout the later period). This indicates that the compost product detoxified phytotoxicity and reached complete maturity very early. Although the CP group showed a relatively high peak (137.44%) in the early stage (day 5) due to the oxygen release of CaO2 promoting degradation, its oxygen release behavior was uncontrollable and lacked continuous support from functional microorganisms. Consequently, the GI value fluctuated significantly and decreased in the later period (from 104.8% on day 21 to 86.77% on day 35), indicating that the maturity process was unstable and repetitive, and the degradation of organic matter was incomplete. The GI value of the CK group remained the lowest and increased extremely slowly, peaking at only 88.61% (day 9). It fluctuated multiple times throughout the process and ultimately failed to break through 75%, indicating that the compost consistently exhibited significant phytotoxicity and poor maturity. The superior performance of the TSOR group was attributed to its temperature-sensitive intelligent release mechanism: precisely releasing oxygen and compound microbial agents during high-temperature periods ensured the thorough and stable degradation of organic matter, greatly reducing the accumulation of intermediate toxic and harmful substances (such as organic acids and ammonia), thereby significantly shortening the maturity cycle and producing high-quality, non-toxic compost products.

[0094] Depend on Figure 4It can be seen that humic acid is the core index for evaluating the degree of humification and quality of compost. The data show that the TSOR group exhibits the best humus retention and conversion capacity. Its initial humic acid content is the highest (234.12 mg / kg), which is significantly higher than that of the CP group (215.93 mg / kg) and the CK group (163.32 mg / kg), and this advantage is maintained throughout the composting process. Although the humic acid content of the three groups decreases due to microbial degradation and utilization, the TSOR group has the most gentle decline, and the final content (162.34 mg / kg) is much higher than that of the CP group (149.78 mg / kg) and the CK group (95.91 mg / kg). This shows that the intelligent oxygen release and bacteria release mechanism of the TSOR group creates a more stable and efficient aerobic environment for microorganisms, not only promoting the complete decomposition of easily degradable organic matter, but more importantly, optimizing the humification process: on the one hand, it reduces the loss of stable organic matter as a carbon source for microbial degradation, and on the other hand, it may promote the conversion and synthesis of intermediate products to humic acid by regulating microbial metabolic pathways. Looking at the CP group, due to its non-intelligent explosive oxygen release, it accelerates the decomposition of organic matter (including humus) in the early stage, resulting in a faster decrease in its content; while the CK group has a sustained anaerobic environment, which may accelerate the dissimilation of humus, resulting in the lowest content and the greatest loss. The TSOR technology effectively balances degradation and synthesis, maximizes the retention of stable organic matter rich in fertilizer efficiency, and improves the humification level and agricultural value of the compost product.

[0095] The thermophilic bacteria used in the present application are Bacillus subtilis or Bacillus cereus, and the thermophilic bacteria are Bacillus stearothermophilus or Bacillus coagulans. Under the guidance of the present application, those skilled in the art can also select other types of thermophilic bacteria and thermophilic bacteria according to actual needs.

[0096] The parts not mentioned in the present application can be realized by referring to the prior art.

[0097] Those skilled in the art should recognize that the above embodiments are only used to illustrate the present application, and are not used as a limitation on the present application. Any appropriate changes and variations to the above embodiments within the spirit and scope of the present application are within the scope of the present application.

Claims

1. Application of oxygen and microorganism synergistically regulated temperature-sensitive-oxygen-releasing dual-mode hydrogel in aerobic composting, characterized in that, The preparation method of the temperature-sensitive-oxygen-releasing dual-mode hydrogel comprises the following steps: a. taking CaO2 as the core, and coating the EC film on the periphery of the core by fluidized bed coating method to obtain the EC-coated CaO2 microspheres; b. preparing the temperature-sensitive hydrogel shell on the periphery of the EC-coated CaO2 microspheres obtained in step a. by suspension polymerization method to obtain the core-shell microspheres; The specific method for preparing the core-shell microspheres is as follows: b1: preparing the oil phase; b2. preparing the water phase by dissolving the reaction monomer and the crosslinking agent in deionized water to obtain the water phase; b3. placing the EC-coated CaO2 microspheres in the water phase and stirring to disperse them, adding the obtained water phase mixture into the oil phase, and adding the initiator into the oil phase, and the reaction temperature is 60-65°C, and the reaction time is 6-8 hours; c. placing the core-shell microspheres in the composite microbial liquid to load the microbial agent on the surface of the core-shell microspheres, and drying to obtain the temperature-sensitive-oxygen-releasing dual-mode hydrogel with a spherical structure; the composite microbial liquid comprises thermophilic bacteria and / or thermophilic bacteria; The application is to add the temperature-sensitive hydrogel into the fermentation raw material to realize oxygen release on demand: The first stage: starting and warming-up stage, at this time, the temperature of the heap < 45°C, the temperature-sensitive hydrogel shell is in the swelling state, the thermophilic bacteria loaded on the surface of the temperature-sensitive hydrogel shell are activated, and the easily degradable organic matter and oxygen are used to reproduce and release biological heat quickly, and the thermophilic bacteria loaded on the surface of the temperature-sensitive hydrogel shell are inoculated into the heap and dormant; at this time, the temperature-sensitive hydrogel shell effectively isolates the EC-coated CaO2 microspheres, and prevents the CaO2 microspheres from releasing oxygen; the second stage: intelligent triggering and oxygen release, on the basis of the first stage, the temperature of the heap is increased, when the temperature of the heap ≥ 45°C, the temperature-sensitive hydrogel shell changes from the swelling state to the shrinking state, and the mechanical stress is generated inward to make the EC film break, and the CaO2 is exposed to the external environment and starts to release oxygen; the thermophilic bacteria loaded on the surface of the temperature-sensitive hydrogel shell are activated, and the easily degradable organic matter and oxygen are used to reproduce quickly.

2. The use of the oxygen and microbe synergistically regulated temperature-sensitive oxygen-releasing dual-mode hydrogel according to claim 1 in aerobic composting, characterized in that: In step a, the particle size of CaO2 is 100-200 mesh.

3. The use of the oxygen and microbe synergistically regulated temperature-sensitive oxygen-releasing dual-mode hydrogel according to claim 1 in aerobic composting, characterized in that: In step a, the concentration of the coating liquid in the fluidized bed coating method is 5-10% of the EC ethanol solution, the inlet air temperature is 40-50°C, the coating liquid is uniformly sprayed on the surface of CaO2 in the fluidized state after being atomized, the ethanol is volatilized, the EC forms a continuous film on the periphery of CaO2 microspheres, and after drying, the EC-coated CaO2 microspheres are obtained.

4. The use of the oxygen and microbe synergistically regulated temperature-sensitive oxygen-releasing dual-mode hydrogel according to claim 1 in aerobic composting, characterized in that: In step b1, the oil phase is liquid paraffin containing a stabilizer; in step b2, the reaction monomer is N-isopropyl acrylamide, and the crosslinking agent is N,N'-methylene bisacrylamide; in step b3, the initiator is ammonium persulfate.

5. The use of the oxygen and microbe synergistically regulated temperature-sensitive oxygen-releasing dual-mode hydrogel according to claim 4 in aerobic composting, characterized in that: In step b2, the water phase mixture is added to the oil phase with a temperature of 65°C, and the water phase is dispersed into several small droplets in the oil phase, and each droplet contains at least one core particle; In step b3, nitrogen is introduced to remove oxygen during the reaction, the reaction monomer N-isopropyl acrylamide polymerizes and crosslinks in each droplet, and a core-shell microsphere structure is formed.

6. The use of the oxygen and microbe synergistically regulated temperature-sensitive oxygen-releasing dual-mode hydrogel according to claim 1 in aerobic composting, characterized in that: The thermophilic bacteria are Bacillus subtilis or Bacillus cereus; the thermophilic bacteria are Bacillus stearothermophilus or Bacillus coagulans.

7. The use of the oxygen and microbe synergistically regulated temperature-sensitive-oxygen-releasing dual-mode hydrogel according to claim 1 in aerobic composting, characterized in that: The loading temperature of the microbial agent is 4-5 DEG C, and the loading time is 12-24 hours.

8. The use of the oxygen and microbe synergistically regulated temperature-sensitive-oxygen-releasing dual-mode hydrogel according to claim 7 in aerobic composting, characterized in that: The added amount of the temperature-sensitive hydrogel is 10% of the total mass of the fermentation raw materials, the fermentation raw materials include agricultural waste and municipal sludge, the agricultural waste mainly includes livestock and poultry manure and corn cob as auxiliary materials, the initial water content of the heap is 55%-65%, and the initial C / N is 25-30.

9. A synergistically oxygen and microbe regulated temperature-sensitive-oxygen releasing dual-mode hydrogel, characterized in that: It is a spherical structure, which sequentially comprises a CaO2 core, an EC film for wrapping the CaO2 core, a temperature-sensitive hydrogel shell for wrapping the EC film, and a composite microbial agent on the temperature-sensitive hydrogel shell; the particle size of the CaO2 core is 100-200 meshes. The thermophilic bacteria are Bacillus subtilis or Bacillus cereus; the thermophilic bacteria are Bacillus stearothermophilus or Bacillus coagulans. The loading temperature of the microbial agent is 4-5 DEG C, and the loading time is 12-24 hours. The added amount of the temperature-sensitive hydrogel is 10% of the total mass of the fermentation raw materials, the fermentation raw materials include agricultural waste and municipal sludge, the agricultural waste mainly includes livestock and poultry manure and corn cob as auxiliary materials, the initial water content of the heap is 55%-65%, and the initial C / N is 25-30. It is a spherical structure, which sequentially comprises a CaO2 core, an EC film for wrapping the CaO2 core, a temperature-sensitive hydrogel shell for wrapping the EC film, and a composite microbial agent on the temperature-sensitive hydrogel shell; the particle size of the CaO2 core is 100-200 meshes.

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