Membrane type aerobic compost rapid decomposition method

Abstract

The invention discloses a method for quickly decomposing membrane type aerobic compost, and relates to the technical field of resources and environment. Comprising the following steps: monitoring the oxygen content and nitrous oxide content of membrane aerobic compost through an automatic compost monitoring system; and adding a microbial agent into the membrane type aerobic compost. The stack body automatic monitoring system comprises a plug-in oxygen content sensor, a plug-in nitrous oxide sensor, an in-membrane gas oxygen content sensor, an in-membrane gas nitrous oxide sensor and a plug-in temperature sensor. The microbial agent comprises bacillus velezensis CICC 24433, bacillus coagulans CICC 21735, lactobacillus plantarum CICC 20322 and trichoderma viride CICC 13038, and the effective viable count of the microbial agent is greater than or equal to 10 billion / mL. According to the method, microorganisms such as cellulose, protein and starch can be rapidly multiplied and degraded, the nitrogen conversion process is accelerated, the overall efficiency of membrane type composting is improved, the decomposition process is accelerated, the decomposition effect and the product quality are improved, and efficient treatment of solid waste through membrane type aerobic composting is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of resources and environment, and in particular to a method for rapid decomposition of membrane aerobic composting. Background Art

[0002] Membrane aerobic composting is a technology that uses a semipermeable membrane with selective permeability to cover the pre-mixed materials, lays aeration pipes at the bottom of the materials to provide oxygen to the pile, and seals the pile on all sides, aiming to achieve harmless and resourceful treatment of organic waste. This technology has been widely used in recent years due to its advantages such as less odor emission and low operating costs. However, compared with traditional aerobic composting methods, such as trough turning process and reactor process, no stirring is performed during membrane composting, and fermentation can only be completed under static conditions. During this process, the air provided by the bottom aeration passes through the pile, through the "cavity" between the pile and the membrane, and is finally discharged through micron to nanometer pores. This mode of operation raises the following two key issues:

[0003] First, due to the lack of turning operations during the composting process, it is easy to cause uneven mixing of local materials. At this time, relying solely on traditional methods to determine the oxygen content in the pile may not accurately reflect the oxygen supply effect of the composting. Therefore, it is difficult to effectively monitor the short-range denitrification of nitrogen caused by hypoxia through monitoring data, and it is difficult to accurately control the progress of composting.

[0004] Secondly, if the oxygen supply is not timely, the system may become hypoxic or even enter an anaerobic state, which will inhibit the metabolic activity of indigenous microorganisms, causing the pile temperature to drop, making it difficult to achieve rapid and sufficient decomposition of the pile. Summary of the invention

[0005] The object of the present invention is to provide a method for rapid maturation of membrane aerobic composting, which can accelerate the maturation process, improve the maturation effect and product quality, and realize efficient treatment of solid waste by membrane aerobic composting.

[0006] To achieve the above-mentioned purpose, the technical solution of the present application is: a method for rapid maturation of membrane aerobic composting, comprising monitoring the oxygen content and nitrous oxide content of the membrane aerobic composting through an automatic pile monitoring system; and adding microbial agents into the membrane aerobic composting.

[0007] As a preferred solution of the present invention, the stack automatic monitoring system includes an inserted oxygen content sensor, an inserted nitrous oxide sensor, an intra-membrane gas oxygen content sensor, an intra-membrane gas nitrous oxide sensor, and an inserted temperature sensor.

[0008] As a preferred embodiment of the present invention, the microbial agent includes Bacillus velezensis CICC 24433, Bacillus coagulans CICC 21735, Lactiplantibacillus plantarum CICC 20322 and Trichoderma viride CICC13038, and the effective viable count is ≥1 billion / mL.

[0009] As a preferred embodiment of the present invention, the mixing ratio of Bacillus velez CICC 24433, Bacillus coagulans CICC 21735, Bacillus plantarum CICC 20322 and Trichoderma viride CICC 13038 is 1:0.5:2:1.

[0010] As a preferred embodiment of the present invention, in the Bacillus Velezii CICC 24433, Bacillus coagulans CICC21735, Bacillus plantarum CICC 20322 and Trichoderma viride CICC 13038, the cellulose and protease activities are ≥200U / mL, the nitrification and denitrification enzyme activities are ≥50U / mL, and the lactate dehydrogenase activity is ≥300U / mL.

[0011] As a preferred embodiment of the present invention, the dosage of the microbial agent is 0.1 to 0.5‰ of the dry weight of the membrane aerobic composting material.

[0012] As a preferred solution of the present invention, the intra-membrane gas oxygen content sensor and the intra-membrane gas nitrous oxide sensor are located between the compost film and the surface layer of the compost pile.

[0013] As a preferred solution of the present invention, the insertable oxygen content sensor, the insertable nitrous oxide sensor, and the insertable temperature sensor are inserted into the membrane aerobic compost.

[0014] As a preferred solution of the present invention, the inserted oxygen content sensor and the inserted nitrous oxide sensor are located 40-60% of the pile height from the bottom of the membrane aerobic composting; the inserted temperature sensor is located 50-70% of the pile height from the bottom of the membrane aerobic composting.

[0015] As a preferred solution of the present invention, every 100-300m 3 A set of automatic monitoring system for the composting pile is installed in the membrane aerobic composting capacity.

[0016] By adopting the above technical scheme, the present invention can achieve the following technical effects: the oxygen content of the pile in the present invention can be accurately controlled, the composting time is shortened by 30% to 50%, the cellulose biomass decomposition efficiency is greater than 65%, the protein decomposition efficiency is greater than 95%, the nitrogen loss rate is less than 15%, the humus content is greater than 25%, and rapid maturity of membrane aerobic composting is achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0018] Figure 1 This is a schematic diagram of the structure of the pile automatic monitoring system;

[0019] Explanation of the serial numbers in the figure: 1. Insertion type oxygen content sensor, 2. In-membrane gas oxygen content sensor, 3. Insertion type nitrous oxide sensor, 4. In-membrane gas nitrous oxide sensor, 5. Insertion type temperature sensor, 6. Compost film, 7. Compost surface interface. DETAILED DESCRIPTION

[0020] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0021] Example 1: Membrane aerobic composting was used to treat chicken manure from a breeding farm in Dalian. The length, width and height of the composting tank were 10×6×1.5m, and the full volume was about 110m 3 In the compost film production process, insertion holes for the plug-in oxygen content sensor, the plug-in nitrous oxide sensor, the in-film gas oxygen content sensor, the in-film gas nitrous oxide sensor, and the plug-in temperature sensor are reserved.

[0022] The auxiliary material is corn stalks, the total weight of a single feed is 65 tons, the dry weight is 22.5 tons, and the microbial agent is added according to 0.2% of the dry weight. The microbial agent includes Bacillus velezensis CICC 24433, Bacillus coagulans CICC 21735, Lactiplantibacillus plantarum CICC 20322 and Trichoderma viride CICC 13038, the mixing ratio is 1:0.5:2:1, the total dosage is 4.5L, the effective viable bacteria count is ≥1 billion / mL, the cellulose and protease activities are ≥200U / mL, the nitrification and denitrification enzyme activities are ≥50U / mL, and the lactate dehydrogenase activity is ≥300U / mL. The stock solution is diluted 5 times to 22.5L and sprayed evenly during the raw material mixing process.

[0023] The mixed compost raw materials are added into the composting tank, covered with a semi-permeable membrane, and then the sensors are inserted into the reserved jacks. The oxygen content sensor and nitrous oxide sensor are located between the composting film and the surface of the pile (hereinafter referred to as "cavity sensor"). The outer part of the membrane is fixed with a prefabricated angle steel frame. In addition, the inserted oxygen content sensor and the inserted nitrous oxide sensor are 0.8 meters above the bottom of the membrane aerobic compost. The inserted temperature sensor is 0.8 meters above the bottom of the membrane aerobic compost. Turn on the aeration oxygen supply fan and start composting. The specific control logic is as follows.

[0024] (1) Temperature is the first priority control parameter. When the temperature is greater than 70°C, the PLC system does not use the oxygen content and nitrous oxide content data, and directly controls the fan aeration to reduce the pile temperature to 50°C. When the temperature is less than 40°C, the PLC system does not collect the oxygen content and nitrous oxide content data, and directly controls the fan aeration volume to 35% of the normal setting.

[0025] (2) When the sensor in the pile detects that the oxygen content is less than 0.5%, the fan is controlled to start aeration until the oxygen content is greater than 20%. At this time, if the cavity nitrous oxide content is greater than 0.4mmol / (kg·TS·min), the PLC controls the aeration fan to continue aeration for 60 minutes. After 10 to 15 cycles, if the cavity nitrous oxide content continues to exceed 0.4mmol / kg·TS, it proves that there is a serious oxygen-deficient area in the pile and the pile needs to be turned over.

[0026] (3) When the nitrous oxide content in the pile is greater than 10mmol / L, if the cavity oxygen content is less than 10% and the pile oxygen content is less than 5%, adjust the fan aeration volume to 150% of the normal setting; if this state continues for 10 to 15 cycles without change, replace the sensor position and measure again; if the nitrous oxide content in the pile is still greater than 10mmol / L, it proves that there is a serious oxygen-deficient area in the pile and the pile needs to be inverted.

[0027] According to this method, the activities of various target enzymes in the composting process were measured. Samples were taken from three points (one of which was around the sensor) at a distance of about 0.5m from the bottom of the compost, and the enzyme activities were measured and the average value was calculated.

[0028] Table 1 Changes in enzyme activity during composting process (U / mL)

[0029]

[0030] In the composting process of the embodiment, there was no unnecessary turning of the pile due to insufficient oxygen supply. After the composting was completed, samples were taken back to the laboratory for testing. The cellulose degradation efficiency reached 83.01%, the protein decomposition efficiency reached 96.72%, the system nitrogen loss rate reached 14.32%, and the humus content reached 28.15%. After 30 days of composting, the total nutrients (8.7%) and seed germination index (91%) reached the organic fertilizer (NY525-2021) standard, achieving rapid maturity of membrane aerobic composting.

[0031] Comparative Example 1:

[0032] Membrane aerobic composting was used to treat chicken manure in a breeding farm in Dalian. The length, width and height of the composting tank were 10×6×1.5m, and the full volume was about 110m 3 The auxiliary material is corn stalks, with a total weight of 68.5 tons per charge and a dry weight of 23.7 tons.

[0033] Without adding exogenous bacterial agents, the traditional method is adopted to control the operation of the aeration oxygen supply fan through the insertion oxygen content sensor and the insertion temperature sensor. The insertion height is about 0.5m from the bottom of the pile. The specific control logic is as follows.

[0034] (1) Temperature is the first priority control parameter. When the temperature is greater than 70°C, the fan speed is 0.2 m / s. 3 / (m 3 ·min) to aerate the pile and supply oxygen; stop when the temperature is <50℃.

[0035] (2) When the oxygen content of the pile is less than 0.5%, the aeration fan starts to work and stops when the oxygen content is greater than 20%.

[0036] According to this method, the activities of various target enzymes in the composting process were measured. Samples were taken from three points (one of which was around the sensor) at a distance of about 0.5m from the bottom of the compost, and the enzyme activities were measured and the average value was calculated.

[0037] Table 2 Changes in enzyme activity during composting process (U / mL)

[0038]

[0039]

[0040] The comparative composting was turned over once after 20 days. After the composting was completed, samples were taken back to the laboratory for testing. The cellulose degradation efficiency was 43.25%, the protein decomposition efficiency reached 79.21%, the system nitrogen loss rate was 26.89%, and the humus content was 17.24%. After 40 days of composting, the total nutrients (4.7%) and seed germination index (76%) all reached the organic fertilizer (NY525-2021) standard.

[0041] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for rapid decomposition of membrane aerobic composting, characterized in that: The method includes monitoring the oxygen content and nitrous oxide content of the membrane aerobic composting through an automatic pile monitoring system; and adding microbial agents into the membrane aerobic composting.

2. The method for rapid decomposition of membrane aerobic composting according to claim 1, characterized in that: The stack automatic monitoring system comprises an inserted oxygen content sensor, an inserted nitrous oxide sensor, an intra-membrane gas oxygen content sensor, an intra-membrane gas nitrous oxide sensor, and an inserted temperature sensor.

3. The method for rapid decomposition of membrane aerobic composting according to claim 1, characterized in that: The microbial agent comprises Bacillus velez CICC 24433, Bacillus coagulans CICC 21735, Bacillus plantarum CICC20322 and Trichoderma viride CICC 13038, and the effective live bacteria count is ≥1 billion / mL.

4. The method for rapid decomposition of membrane aerobic composting according to claim 3, characterized in that: The mixing ratio of the Bacillus Velezii CICC 24433, the Bacillus coagulans CICC 21735, the Bacillus plantarum CICC 20322 and the Trichoderma viride CICC 13038 is 1:0.5:2:

1.

5. The method for rapid decomposition of membrane aerobic composting according to claim 3, characterized in that: In the Bacillus Velezii CICC 24433, Bacillus coagulans CICC 21735, Bacillus plantarum CICC 20322 and Trichoderma viride CICC 13038, the cellulose and protease activities are ≥200 U / mL, the nitrification and denitrification enzyme activities are ≥50 U / mL, and the lactate dehydrogenase activity is ≥300 U / mL.

6. The method for rapid decomposition of membrane aerobic composting according to claim 1, characterized in that: The dosage of the microbial agent is 0.1-0.5% of the dry weight of the membrane aerobic composting material.

7. The method for rapid decomposition of membrane aerobic composting according to claim 2, characterized in that: The oxygen content sensor of the gas in the film and the nitrous oxide sensor of the gas in the film are located between the compost film and the surface layer of the compost body.

8. The method for rapid decomposition of membrane aerobic composting according to claim 2, characterized in that: The insertable oxygen content sensor, the insertable nitrous oxide sensor and the insertable temperature sensor are inserted into the membrane aerobic compost.

9. The method for rapid decomposition of membrane aerobic composting according to claim 8, characterized in that: The insertion type oxygen content sensor and the insertion type nitrous oxide sensor are located at 40-60% of the pile height from the bottom of the membrane aerobic composting; the insertion type temperature sensor is located at 50-70% of the pile height from the bottom of the membrane aerobic composting.

10. The method for rapid decomposition of membrane aerobic composting according to claim 1, characterized in that: Every 100-300m 3 A set of automatic monitoring system for the composting pile is installed in the membrane aerobic composting capacity.

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