Method for reducing nitrogen loss of aerobic composting of manure and improving quality of manure

Abstract

The invention discloses a method for reducing nitrogen loss of aerobic composting of excrement and improving the quality of the excrement. A water-retaining agent and hollow balls are added in the aerobic composting process of the excrement; adding water and covering powder or granules on the surface layer of the pile body for water retention and ammonia fixation after each time of turning in the early stage of fermentation, and stopping adding water and covering the materials after turning from 7-12 days of fermentation to the end of fermentation; from 12-17 days of fermentation to the end of fermentation, a method for increasing the turning frequency and forcibly ventilating during turning is adopted. According to the invention, the oxygen and moisture conditions of the fermentation material are improved, the microbial activity is improved, the turning frequency in the early stage of fermentation is reduced, the problem of ammonia gas and moisture release caused by turning in the early stage of fermentation is reduced, the environmental pollution in the aerobic fermentation process of excrement is reduced, and the temperature of the material is favorably maintained, so that disease eggs are effectively killed; therefore, nitrogen loss is reduced and manure quality is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of livestock and poultry manure treatment, and particularly relates to a method for reducing nitrogen loss in aerobic composting of manure and improving the quality of manure. Background Art

[0002] With the rapid development of the breeding industry to meet the social demand for meat, eggs and milk, improper disposal of livestock and poultry manure has also brought serious environmental problems. To reduce the environmental pollution caused by livestock and poultry manure, harmlessness and resource utilization have become the basic requirements for livestock and poultry manure disposal. Aerobic fermentation treatment of livestock and poultry manure can not only use high temperature to kill pathogenic microorganisms carried, reduce the spread of diseases, but also become high-quality fertilizer after composting, improve soil fertility, and replace chemical fertilizers to reduce the usage amount of chemical fertilizers. Aerobic fermentation of manure is a process in which aerobic microorganisms decompose and transform organic matter. In this process, oxygen and moisture are the key factors to maintain the activity of fermentation microorganisms. Lack of oxygen will cause the material to turn into anaerobic fermentation and produce macromolecular organic acids and other substances to form malodorous gases; lack of water will directly lead to a decrease in microbial activity, making the manure unable to be fully composted, but too much water will also occupy the material gaps and cause local hypoxia. Therefore, sufficient oxygen and appropriate moisture content are the basic conditions for full fermentation and composting of manure.

[0003] In the initial stage of livestock and poultry manure fermentation, due to high water content and relatively large density, the porosity of the material is small during the natural stacking process, and the oxygen-carrying capacity of the material during the stacking process is limited, which is the main reason for insufficient oxygen supply of the material.

[0004] During the aerobic fermentation process of manure, generally turning and direct ventilation are used to keep the material with sufficient oxygen supply. Due to the airflow being blocked by the material, the distribution uniformity of direct ventilation is poor, resulting in uneven composting, so it is generally used as an auxiliary means for aerobic fermentation and is rarely used alone; turning is to achieve contact with air by turning the material, which is simple, convenient and easy to operate, and is a commonly used process form in production. However, during the turning process of the material, ammonia gas generated by the decomposition of manure will accelerate overflow and diffuse into the environment, causing environmental pollution.

[0005] To sum up, in the prior art, there are problems of increased nitrogen loss and serious environmental pollution during the livestock and poultry manure fermentation process. If the number of turnings is reduced, it will lead to insufficient oxygen supply of the material. Summary of the Invention

[0006] The purpose of the present invention is to provide a method for reducing nitrogen loss in aerobic composting of manure and improving the quality of manure to solve the deficiencies of the prior art.

[0007] The purpose of the present invention is achieved by the following technical solutions:

[0008] A method for reducing nitrogen loss in aerobic composting of feces and improving the quality of manure, which comprises adding a water-retaining agent and hollow balls during the aerobic composting process of feces; adding water to the surface layer of the compost pile and covering it with powder or granular materials to retain water and fix ammonia after each turning in the early stage of fermentation, and stopping adding water and covering materials after turning from the 7th to the 12th day of fermentation until the end of fermentation; from the 12th to the 17th day of fermentation until the end of fermentation, increasing the turning frequency and performing forced ventilation during turning.

[0009] Preferably, the water-retaining agent is a high-molecular resin water-retaining agent, and the addition amount is 0.3-0.5% of the feces quality or 150-300 g of water-retaining agent per cubic meter of 3 feces.

[0010] Preferably, the hollow ball has a hollow structure, and the shell is provided with hollow grooves and / or irregular small holes. The diameter of the hollow ball is 3-5 cm, and the addition amount is not less than 50 per cubic meter;

[0011] The hollow ball can withstand the mass of the feces in the compost pile without collapsing.

[0012] Preferably, the moisture content of the feces material is adjusted to 60-70% and the C / N ratio is 25-30 at the beginning of fermentation;

[0013] When the moisture content of the feces material is high, dehydration or recycling of fully decomposed materials is used to adjust the moisture content.

[0014] Preferably, the amount of water added to the surface layer is 300-800 mL per square meter of the material, so that the wetting depth of the surface layer material is 1-2 cm.

[0015] Preferably, the powder and / or granular material is crushed straw, the particle size of the crushed straw is not more than 2 cm, and the dosage is 100-500 g per square meter of the material.

[0016] Preferably, turning is carried out once every 1-2 days in the early stage of fermentation;

[0017] From the 12th to the 17th day of fermentation until the end of fermentation, turning is carried out 2-3 times a day;

[0018] When the temperature of the fermentation pile is too high, greater than 65 °C, turning is carried out 2-3 times a day.

[0019] Preferably, continuous fermentation mode is adopted for fermentation;

[0020] For the materials in the front section of the fermentation tank in continuous fermentation, that is, the materials from the start of fermentation to 12-17 days before, turning is carried out once a day; when the temperature of the pile is too high, greater than 65 °C, turning is carried out 2-3 times a day;

[0021] The material in the latter stage of the fermentation tank for continuous fermentation, that is, the material from 12 to 17 days of fermentation until the end of fermentation, is turned and tossed 2 to 3 times a day, and forced ventilation is carried out during the turning and tossing process.

[0022] Preferably, the temperature of the fermented material remains above 55 °C for 3 to 5 days during the backward movement process. A part of this section of the material is returned to the feeding place and mixed with the newly added material, and the recycling amount is 10 to 15% of the daily added material amount.

[0023] Preferably, batch fermentation mode is adopted for fermentation;

[0024] In the early stage of fermentation, it is turned and tossed once every 2 days. When the temperature of the pile body is too high, greater than 65 °C, it is turned and tossed 2 to 3 times a day;

[0025] From 12 to 17 days of fermentation until the end of fermentation, the number of times of turning and tossing per day is adjusted to 2 to 3 times, and forced ventilation is carried out during the turning and tossing process.

[0026] In the present invention, by adding a water retention agent, hollow balls during the aerobic fermentation process of feces, covering the material surface with materials and spraying water in the early stage of fermentation, increasing the turning and tossing frequency in the later stage of fermentation and carrying out forced ventilation during turning and tossing, the oxygen and moisture conditions of the fermented material are improved, the microbial activity is enhanced, the number of times of turning and tossing in the early stage of fermentation is reduced, the problems of ammonia and moisture release caused by turning and tossing in the early stage of fermentation are reduced, the environmental pollution during the aerobic fermentation process of feces is reduced, it helps to maintain the material temperature so as to effectively kill pest eggs, and thus reduce nitrogen loss and improve the quality of manure. Description of the Drawings

[0027] Figure 1 It is a process flow chart of the continuous fermentation mode adopted by the present invention. Detailed Embodiments

[0028] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application will be described in detail below with reference to the drawings and specific embodiments.

[0029] The present application provides a method for reducing nitrogen loss in aerobic composting of feces and improving the quality of manure, by adding a water retention agent and hollow balls during the aerobic composting process of feces. The feces can be livestock and poultry feces, human feces, etc.

[0030] Adding hollow balls to the material can improve the spatial distribution of the pile body material, increase the porosity, enhance the exchange ability of the material with oxygen, effectively increase the turning and tossing time interval, and reduce the odor diffusion and moisture loss caused by turning and tossing. At the same time, aiming at the problem that the high temperature generated during the material fermentation process causes the rapid evaporation of the material moisture, adding a water retention material can slow down the moisture loss rate, maintain the moisture content in the material gap, improve the ammonia dissolution and adsorption ability, and reduce ammonia volatilization.

[0031] Therefore, adding water-retaining agents and hollow balls during the manure composting process can improve the moisture and oxygen conditions of the pile, provide a suitable environment for aerobic microorganisms, increase the time interval between turning over the materials in the early stage of fermentation, reduce the number of turning overs, and reduce ammonia volatilization, moisture and heat loss caused by turning over.

[0032] At the same time, at the beginning of fermentation, water is added to the surface of the pile and powder and / or granular material is covered to retain water and fix ammonia; the order of watering and covering straw can be changed without restriction.

[0033] During the fermentation process, the materials are continuously turned over for ventilation and oxygen supply; in the early stage of fermentation, water is added to the surface of the pile and powder and / or granular materials are covered after each turning. Ammonia generation is mainly concentrated in the early stage of fermentation. In the later stage of fermentation, the metabolism is basically stable and the amount of ammonia released is small. Therefore, after the pile has been fermented for 7 to 12 days, stop adding water to the surface and covering with powder and / or granular materials after turning.

[0034] Powder and / or granules can be made of materials with abundant voids and large specific surface areas, such as activated carbon, attapulgite and straw, which can absorb water and adsorb and fix ammonia. Preferably, straw, which is widely available and inexpensive, is used. On the one hand, straw powder and / or granules can be mixed with feces for fermentation and effectively degraded. At the same time, straw has a large specific surface area and high adsorption performance, and can adsorb and fix ammonia. On the other hand, straw forms a high moisture layer on the surface by absorbing water, which is easier to bind volatile ammonia and reduce ammonia escape.

[0035] In the later stage of fermentation, the material is basically decomposed and the amount of ammonia released is small. The main function of this stage is to dehydrate and reduce the water content of the manure. Therefore, no more water is added and straw is covered, otherwise the water content of the manure will increase and the straw will not be fully decomposed.

[0036] Therefore, adding water to the pile surface and covering materials in the early stage of fermentation can maintain the surface materials in suitable moisture conditions, while also absorbing ammonia and reducing the amount of ammonia volatilization.

[0037] In the late fermentation period, specifically from 12 to 17 days to the end of fermentation, since the fermentation material of this application contains a water retaining agent, the moisture content of the material is higher than that of conventional fermentation. For this reason, this application adopts the method of increasing the frequency of turning over and performing forced ventilation during turning over to accelerate the diffusion of moisture in the material, quickly reduce the moisture and temperature of the material, reduce the conversion of ammonia nitrogen in feces, reduce ammonia loss, increase the nitrogen content in the manure, and improve the quality of the manure. The turning over frequency can be increased by 1 to 2 times per day compared with the early stage of fermentation.

[0038] Therefore, in the aerobic fermentation process of feces, the present invention improves the oxygen and moisture conditions of the fermentation materials, enhances the microbial activity, reduces the number of turning operations in the early stage of fermentation, reduces the problems of ammonia and moisture release caused by turning in the early stage of fermentation, reduces environmental pollution during the aerobic fermentation process of feces, helps to maintain the material temperature so as to effectively kill pest eggs, and thus reduces nitrogen loss and improves the quality of manure by adding a water-retaining agent, hollow spheres, covering the material surface with materials and sprinkling water in the early stage of fermentation, increasing the turning frequency in the later stage of fermentation, and performing forced ventilation during turning.

[0039] Preferably, the water-retaining agent is a water-retaining agent of high molecular resin type, preferably granular water-retaining agent, and the addition amount is 0.3-0.5% of the feces quality, or 150-300 g is added per cubic meter of feces material.

[0040] Preferably, the hollow sphere is of a hollow structure, with hollow slots and / or irregular small holes provided on the shell, the diameter of the hollow sphere is 3-5 cm, and the addition amount is not less than 50 per cubic meter; further preferably, the width of the hollow slot is 2-4 mm, and the diameter of the small hole is 3-4 mm, which can effectively permeate air and prevent feces materials from entering the hollow sphere at the same time.

[0041] The hollow sphere is preferably a plastic ball that is corrosion-resistant and has good strength and toughness, and can withstand the mass of feces in the stack without collapsing.

[0042] Preferably, the moisture content of the material is moderately increased at the initial stage of fermentation, and the moisture content of the feces material is adjusted to 60-70%. And the C / N ratio is adjusted to 25-30 according to the characteristics of feces to facilitate fermentation.

[0043] The moisture content of conventional fermentation materials is generally controlled at about 60%. If the moisture content is too high, acidification will occur due to small porosity between materials and poor ventilation, resulting in insufficient oxygen supply. If the moisture content is too low, the biological activity of the materials will be restricted. The moisture content after feces solid-liquid separation (pressurized dehydration) is generally 70%. Therefore, during conventional fermentation, it is generally necessary to slightly adjust the moisture content of feces, such as leaving it to dry for a period of time to volatilize the excess moisture.

[0044] However, in the present application, due to the strong water absorption capacity of the water-retaining agent, the excess moisture in feces will be absorbed by the water-retaining agent. At the same time, due to the addition of hollow spheres, the porosity in the materials is increased and the oxygen content between the materials is increased. Therefore, the requirement for the moisture content of feces materials is no longer strict. When the moisture content in feces is greater than 60% and less than 70%, there is no need to adjust the moisture content of feces materials anymore, and there will be no problem of excessive moisture during the fermentation process. At the same time, it can also keep the moisture during fermentation from dehydrating too quickly and affecting the microbial activity, significantly reducing the workload.

[0045] When the moisture content of the fecal material is too high, dehydration methods can be used to remove free water. Dehydration can be achieved using solid-liquid separation equipment such as centrifuges and extrusion devices. When using the continuous fermentation mode, the method of recycling fully decomposed materials can be adopted to adjust the moisture content.

[0046] Preferably, the water addition on the surface layer is 300 - 800 mL per square meter of material, so that the wetting depth of the surface layer material is 1 - 2 cm.

[0047] Preferably, the powder and / or granular material is crushed straw, and the particle size of the crushed straw is not greater than 2 cm, with a dosage of 100 - 500 g per square meter of material.

[0048] Preferably, in the early stage of fermentation, turning and tossing is carried out once every 1 - 2 days to reduce ammonia loss; starting from 12 - 17 days of fermentation until the end of fermentation, the frequency of turning and tossing is increased, and turning and tossing is carried out 2 - 3 times a day.

[0049] When the temperature of the pile body is too high, greater than 65 °C, to prevent abnormal fermentation, turning and tossing is carried out 2 - 3 times a day to reduce the temperature of the pile body.

[0050] In the early stage of fermentation, when the temperature of the material rises slowly, the frequency of turning and tossing can be appropriately increased to improve the ventilation volume.

[0051] Fermentation can adopt the continuous fermentation mode or the batch fermentation mode.

[0052] When using the continuous fermentation mode; in the normal continuous fermentation mode, feeding is carried out at the front end of the fermentation tank every day. After feeding, a turning machine is used to turn and toss backward, so that the material moves backward under the action of turning and tossing. When it moves to the end, the fermentation is completed. The time for the material to move from the front end to the end in the fermentation tank is generally 20 - 25 days, that is, the fermentation cycle of continuous fermentation is generally 20 - 25 days. Therefore, the fermentation stages of the fermentation materials at different positions in the fermentation tank for continuous fermentation are different. The materials in the front section are in the early stage of fermentation, and the materials in the rear section are in the late stage of fermentation.

[0053] Preferably, for the materials in the front section of the fermentation tank, that is, the materials from the start of fermentation to 12 - 17 days before the end of fermentation, turning and tossing is carried out once a day; when the temperature of the pile body is too high, greater than 65 °C, turning and tossing is carried out 2 - 3 times a day;

[0054] For the materials in the rear section of the fermentation tank, that is, the materials from 12 - 17 days of fermentation to the end of fermentation, turning and tossing is carried out 2 - 3 times a day; and forced ventilation is carried out during the turning and tossing process.

[0055] During the process of the fermented materials moving backward, the temperature above 55°C lasts for 3 to 5 days. This section of materials is semi-composted materials with a high microbial content and the highest activity. Part of this section of materials is returned to the feeding place and mixed with the newly added materials, and then the dominant microbial flora is introduced. The recycling amount is 10 - 15% of the daily added material amount. At the same time, the water content of this section of materials (generally about 45 - 50%) is lower than that of the initial fermented feces, and the water content of the initial fecal materials can also be adjusted.

[0056] When the batch fermentation mode is adopted;

[0057] In the early stage of fermentation, it is turned and tossed once every 2 days. When the temperature of the compost pile is too high, greater than 65°C, it is turned and tossed 2 - 3 times a day;

[0058] From the 12th to 17th day of fermentation until the end of fermentation, the number of times of turning and tossing per day is adjusted to 2 - 3 times, and forced ventilation is carried out during the turning and tossing process.

[0059] When the materials are completely composted, the hollow balls are separated from the manure through equipment such as a drum sieve, and the hollow balls are recovered for reuse.

[0060] When this method is used for aerobic fermentation of other organic wastes, it also falls within the protection scope of the present invention.

[0061] Example 1

[0062] This example adopts a continuous fermentation mode as shown in Figure 1 (the vertical coordinate is the position of the fermentation tank) for aerobic composting fermentation. It is a tank-type fermentation, and a turning machine is used for mechanical turning. The width of the fermentation tank is 6m, the height is 1.4m, the loading depth is 1m, and the length is 40m. The fermentation raw material is cow dung. The water-retaining agent used is a potassium salt type, and the main component is potassium polyacrylate, with an addition amount of 300g / m 3 , the hollow balls are made of hard plastic, with a diameter of 40mm, the surface is hollowed out, the groove width is 2mm, and 80 are added per cubic meter of feces. The specific steps are as follows:

[0063] Fermentation preparation and startup:

[0064] The fecal sewage in the sewage collection tank is separated by a screw extrusion type solid-liquid separator, and the separated solid feces (with a water content of 70%) are transported to the fermentation tank. 5 tons of cow dung after solid-liquid separation are processed daily. The decomposed fermentation inoculant is added at 0.1% of the weight of the cow dung. At the same time, hollow balls and water-retaining agents are added and mixed evenly. After continuous feeding for 10 days, the front end of the fermentation tank enters the stable fermentation stage.

[0065] Start fermentation:

[0066] Starting from the 11th day, feed the materials once a day, and add the decomposed bacterial agent, the water retention agent and the hollow balls in the above proportions. Then use a turning machine to turn the materials backward to evenly mix the water retention agent, the hollow balls and the materials. Subsequently, sprinkle water on the surface layer of the materials in the front section of the fermentation tank (from the head end of the fermentation tank to the 15m position), with the water sprinkling amount being about 300 milliliters per square meter. After sprinkling water, sprinkle crushed straw on the surface layer, with the dosage being about 300 grams per square meter. Subsequently, feed the materials according to the above procedure every day. After feeding, turn the materials backward. After turning, sprinkle water on the surface layer of the materials in the front section of the fermentation tank and cover with straw. After 10 consecutive days, the fermentation tank is filled with materials and enters the normal ammonia-reducing fermentation mode. When the fecal materials move to the rear section of the fermentation tank (from 25m to the end of the fermentation tank), the materials in the rear section are turned one more time a day, and forced ventilation is carried out using a blower during turning.

[0067] During the fermentation process, continuously monitor the temperature of the fermented materials. When the material temperature is too high (such as during summer fermentation) and greater than 65°C, appropriately increase the turning frequency to ventilate and cool down.

[0068] Normal fermentation:

[0069] After entering normal fermentation, feed the materials once a day using the above method. During feeding, no decomposed bacterial agent is added. The method of material recycling is used to supplement microorganisms, and at the same time, the water retention agent and the hollow balls in the above proportions are added. Use a turning machine to turn the materials backward to evenly mix the water retention agent, the hollow balls and the materials. Subsequently, sprinkle water on the surface layer of the materials in the front section of the fermentation tank (from the head end of the fermentation tank to the 15m position), with the water sprinkling amount being about 300 milliliters per square meter. After sprinkling water, sprinkle crushed straw on the surface layer, with the dosage being about 300 grams per square meter. The materials in the rear section of the fermentation tank (from 25m to the end) are turned one more time a day, and forced ventilation is carried out using a blower during turning.

[0070] During the fermentation process, continuously monitor the temperature of the fermented materials. When the material temperature is too high (such as during summer fermentation) and greater than 65°C, appropriately increase the turning frequency to ventilate and cool down.

[0071] The newly added materials move to the end of the fermentation tank in about 20 days.

[0072] Material recycling is carried out before turning. The specific measures are as follows:

[0073] After adding new materials, use an excavator to shovel the materials at about 10m in the fermentation tank onto the newly added materials and evenly mix them with 7 tons of newly added materials. Subsequently, based on the mass of the newly added materials, add the water retention agent and the hollow balls in proportion, and no decomposed bacterial agent is added. The amount of material taken is about 1 ton, and at the same time, fill the material-taking area with the surrounding materials.

[0074] Comparative example 1

[0075] Continuous fermentation was carried out using the same fermentation tank as in Example 1. The water content of the fecal material used was about 65%. Bacterial agents were added during feeding, while water-retaining agents and hollow balls were not added, and straw was not covered nor was surface watering performed.

[0076] New material was added once a day, and turning was carried out once after adding the material. When the material temperature was too high, greater than 65 °C, the turning frequency was appropriately increased.

[0077] During the normal fermentation processes of Example 1 and Comparative Example 1, the temperature, moisture content of the materials at different positions in the fermentation tank, and the evolution of volatile ammonia on the surface are shown in Tables 1, 2, and 3. It can be seen from Tables 1 - 3 that the temperature and water content of the materials treated in Example 1 were higher than those in Comparative Example 1 in the early stage of fermentation, while the decreasing rates of temperature and water content were faster than those in Comparative Example 1 in the later stage of fermentation. The ammonia volatilization amount in Example 1 was lower than that in Comparative Example 1 throughout the fermentation stage.

[0078] Ball / fertilizer separation:

[0079] The completely decomposed materials were sorted using a cylindrical screen with a screen hole diameter of 30 mm; after separating the plastic balls, the plastic balls were inspected, and the broken balls were removed and reused.

[0080] Table 1 Temperature distribution of materials at different positions in the fermentation tank (°C)

[0081] Fermentation tank location 2m 5m 10m 15m 20m 25m 30m 35m Comparative Example 1 23 50 55 62 53 49 45 42 Example 1 22 50 58 65 56 52 42 40

[0082] Table 2 Average moisture content distribution of materials at different positions in the fermentation tank (%)

[0083] Fermentation tank location 2m 5m 10m 15m 20m 25m 30m 35m Comparative Example 1 65 60 58 53 49 46 41 37 Example 1 68 63 62 56 51 45 39 38

[0084] Table 3 Daily average cumulative ammonia volatilization amount at different positions in the fermentation tank [mg / (㎡·d)]

[0085] Fermentation tank location 2m 5m 10m 15m 20m 25m 30m 33m Total Comparative Example 1 1.18 8.17 6.16 3.24 2.13 1.22 0.63 0.21 22.94 Example 1 1.21 7.57 5.42 2.81 2.11 1.13 0.59 0.19 21.03

[0086] Example 2

[0087] In this example, aerobic composting fermentation was carried out in a batch fermentation mode, using a tank fermentation method with mechanical turning. The fermentation tank had a width of 6 m, a height of 1.4 m (loading depth 1 m), and a length of 40 m. The fermentation raw material was cow dung. The water-retaining agent used was a potassium salt type, with the main component being potassium polyacrylate, and the addition amount was 300 g / m 3 , the hollow balls were made of hard plastic, with a diameter of 40 mm, a surface with hollow holes, and a groove width of 2 mm, and the addition amount was 80 pieces / m 3 .

[0088] The fermentation tank was divided into 4 sections, each 10 meters long, and was sequentially marked as the 1st section, the 2nd section, the 3rd section, and the 4th section from one end. Among them, the 2nd section was used as the test section, the 3rd section was used as the control section, and the 1st and 4th sections were used as the material preparation sections.

[0089] Stockpiling: Every day, the cow dung after solid-liquid separation (with 65% water content) is transported to the fermentation tank. Half of it is naturally stacked in the first section with a stacking height of 1.2 m, and the other half is naturally stacked in the fourth section with a stacking height of 1.2 m. Stockpiling is carried out continuously for 10 days.

[0090] Feeding: After the stockpiling is completed, the materials in the first section are transferred to the second section by a forklift, and the materials are mixed during the transfer process. After the transfer is completed, they are turned over once by a turning machine, and then decomposed fermentation bacteria agents, water retaining agents and hollow balls are added. The addition amount of the decomposed bacteria agent is 60 g / m 3 , the addition amount of the water retaining agent is 300 g / m 3 , the addition amount of the hollow balls is 80 pieces / m 3 , after turning over again, water is sprinkled on the surface. The water sprinkling amount is about 300 milliliters per square meter. After sprinkling water, straw powder is scattered. The dosage of the straw powder is about 300 grams per square meter, and it enters the fermentation stage. Similarly, the materials in the fourth section are transferred to the third section and evenly mixed, and then 60 g / m 3 of decomposed bacteria agent is added, and after turning over, it enters the fermentation stage.

[0091] Operation: After the experimental group operates normally, turning over is carried out once every 2 days. Starting from the 3rd day, after each turning over, first evenly scatter straw powder on the surface layer of the materials, with a dosage of 250 - 300 g / m 2 , and then water is sprinkled. The water sprinkling amount is 300 mL / m 2 . When fermenting for 10 days until the fermentation ends, no straw powder and water are scattered during turning over. Starting from the 15th day, turning over is carried out 2 times a day, and forced ventilation is carried out by a blower during turning over. The fermentation ends after 25 days.

[0092] The control group carries out turning over once every 2 days after operating normally, and it ends after 25 days.

[0093] Testing: The temperature and moisture changes of the materials 40 cm below the surface layer are shown in Table 4 and Table 5, and the ammonia emissions from the surface layer of the materials are shown in Table 6. It can be seen from Tables 4 - 6 that the temperature and moisture content of the materials treated in Example 2 are slightly higher than those of the control group. For batch fermentation compared with continuous fermentation, the number of turning over times in the early stage of fermentation is reduced. In the fecal materials of this application, water retaining agents and hollow balls are added. The water retaining agent can lock part of the free water, so the moisture content is relatively higher than that of the control group. At the same time, due to the hollow balls increasing the porosity of the pile body, the relative air volume of the pile body increases, the microbial activity increases, and the temperature is also slightly higher than that of the control group. The ammonia volatilization amount in Example 2 is lower than that of the control group during the whole fermentation stage.

[0094] Table 4 Variation of material temperature with time (℃)

[0095] Time 1 3 5 7 9 11 13 15 17 19 21 23 25 Control 38 47 52 55 58 57 53 49 48 46 43 43 41 Example 2 38 48 55 58 61 61 55 51 50 48 47 46 42

[0096] Table 5 Variation of material moisture content with time (%)

[0097] Time 1 3 5 7 9 11 13 15 17 19 21 23 25 Control 64 64 61 57 53 50 48 47 46 44 43 42 38 Example 2 64 63 62 60 56 53 51 50 47 45 44 43 40

[0098] Table 6 Average daily cumulative ammonia volatilization of materials [mg / (㎡·d)]

[0099]

[0100] Although the preferred embodiments of the present invention have been described, those skilled in the art can make additional changes and modifications once they learn the basic creative concept. Therefore, the appended claims are intended to be construed to include the preferred embodiments as well as all changes and modifications that fall within the scope of the present invention. Obviously, those skilled in the art can make various changes and variations to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention is also intended to include these modifications and variations.

Claims

1. A method for reducing nitrogen loss in aerobic composting of feces and improving the quality of manure, characterized in that, Add a water retaining agent and hollow balls during the aerobic composting process of feces; add water to the surface layer of the compost pile after each turning in the early stage of fermentation and cover it with powder or granular materials to retain water and fix ammonia. From the 7th to the 12th day of fermentation until the end of fermentation, stop adding water and covering materials after turning; from the 12th to the 17th day of fermentation until the end of fermentation, adopt the method of increasing the turning frequency and forced ventilation during turning.

2. The method for reducing nitrogen loss in aerobic composting of feces and improving the quality of manure as claimed in claim 1, wherein The water retaining agent is a water retaining agent of the polymer resin type, and the addition amount is 0.3-0.5% of the feces mass or 150-300 g of the water retaining agent per m 3 of feces.

3. The method for reducing nitrogen loss in aerobic composting of feces and improving the quality of manure as claimed in claim 1, wherein The hollow ball has a hollow structure, with hollow grooves and / or irregular small holes on the shell. The diameter of the hollow ball is 3 - 5 cm, and the addition amount is not less than 50 per cubic meter; The hollow ball can withstand the quality of the feces in the compost pile without collapsing.

4. The method for reducing nitrogen loss in aerobic composting of feces and improving the quality of manure as claimed in claim 1, wherein Adjust the moisture content by mass percentage of the feces material to 60 - 70% and the C / N ratio to 25 - 30 at the initial stage of fermentation; When the moisture content of the feces material is relatively high, dehydration or the reuse of fully decomposed materials is adopted to adjust the moisture content.

5. The method for reducing nitrogen loss in aerobic composting of feces and improving the quality of manure as claimed in claim 1, wherein The amount of water added to the surface layer is 300 - 800 mL per square meter of the material, so that the wetting depth of the surface layer material is 1 - 2 cm.

6. The method for reducing nitrogen loss in aerobic composting of feces and improving the quality of manure as claimed in claim 1, wherein The powder and / or granular materials are crushed straws. The particle size of the crushed straws is not more than 2 cm, and the dosage is 100 - 500 g per square meter of the material.

7. The method for reducing nitrogen loss in aerobic composting of feces and improving the quality of manure as claimed in claim 1, wherein Turn the compost once every 1 - 2 days in the early stage of fermentation; From the 12th to the 17th day of fermentation until the end of fermentation, turn the compost 2 - 3 times a day; When the temperature of the fermentation compost pile is too high, greater than 65 °C, turn the compost 2 - 3 times a day.

8. The method for reducing nitrogen loss in aerobic composting of feces and improving the quality of manure as claimed in claim 1, wherein The fermentation adopts a continuous fermentation mode; For the materials in the front section of the fermentation tank in continuous fermentation, that is, the materials from the start of fermentation to 12 - 17 days before, turn the compost once a day; when the temperature of the compost pile is too high, greater than 65 °C, turn the compost 2 - 3 times a day; For the materials in the rear section of the fermentation tank in continuous fermentation, that is, the materials from 12 - 17 days of fermentation until the end of fermentation, turn the compost 2 - 3 times a day, and conduct forced ventilation during the turning process.

9. The method for reducing nitrogen loss in aerobic composting of feces and improving the quality of manure as claimed in claim 8, wherein The temperature of the fermented materials above 55 °C lasts for 3 - 5 days during the backward movement process. Part of this section of materials is returned to the feeding place and mixed with the newly added materials. The reuse amount is 10 - 15% of the daily added material amount.

10. The method for reducing nitrogen loss in aerobic composting of feces and improving the quality of manure as claimed in claim 1, wherein The fermentation adopts a batch fermentation mode; In the early stage of fermentation, turn and toss once every two days. When the temperature of the compost pile is too high, greater than 65 °C, turn and toss 2 - 3 times a day; From the 12th to the 17th day of fermentation until the end of fermentation, adjust the number of times of turning and tossing per day to 2 - 3 times, and conduct forced ventilation during the turning and tossing process.

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