Tomato waste film-covered aerobic composting method

Abstract

The application discloses a kind of solanaceous vegetables waste film-covered aerobic composting method, belong to agricultural waste resource utilization technical field.The method is aimed at the physicochemical characteristics of solanaceous vegetables waste, selects solanaceous vegetables waste as main material, livestock manure as auxiliary material, according to dry base mass ratio (2~10):1 Mixed, add microbial inoculum, adjust initial moisture content to 50%~70%, the mixture after pretreatment is loaded into film-covered aerobic composting device, under the control of aeration condition, aerobic composting treatment is carried out, and composting period is 20~35 days.The application solves the problem of insufficient adaptability of raw materials in the prior art by optimizing raw material combination and process parameters, promotes the rapid composting of the pile, reduces the phytotoxicity, the pH of the compost product is weakly alkaline, the carbon-nitrogen ratio is reasonable, the seed germination index is more than 70%, realizes the stable resource utilization of solanaceous vegetables waste, and has good popularization and application value.

Description

Technical Field

[0001] This invention belongs to the field of agricultural waste resource utilization technology, specifically relating to a film-covered aerobic composting method for solanaceous vegetable waste. Background Technology

[0002] In recent years, with population growth, intensive agricultural development, and changes in residents' consumption patterns, the area under vegetable cultivation has continued to expand, and vegetable production has increased significantly. During the production, distribution, and processing of vegetables, approximately 20% to 30% of vegetables are generated as waste in the form of vines, stems, leaves, and roots. If this vegetable waste is directly dumped or incinerated without effective treatment, it not only easily leads to land occupation, air pollution, and the spread of pathogens, but also results in the waste of organic resources and poses potential risks to the ecological environment. Therefore, developing efficient and stable technologies for the resource-based treatment of vegetable waste is of significant practical importance.

[0003] Membrane-covered aerobic composting is an improved aerobic composting method. It involves covering the top of the compost pile with a semi-permeable membrane that is waterproof, breathable, windproof, and heat-insulating, and using a bottom aeration device to create a relatively closed aerobic composting system. This method effectively prevents excessive moisture evaporation from the compost pile, reduces interference from external environmental conditions, and improves the uniformity of oxygen distribution within the pile, thereby promoting rapid heating and efficient degradation of organic matter. In practical applications, membrane-covered aerobic composting technology is mainly suitable for raw materials such as livestock and poultry manure and crop straw. Its operational effectiveness largely depends on the composition and physicochemical properties of the raw materials. However, solanaceous vegetable waste differs significantly from the aforementioned raw materials in terms of material characteristics. This type of waste typically has a high moisture content, a low carbon-to-nitrogen ratio, and a loose structure. Based on these characteristics, those skilled in the art often find it difficult to directly apply existing membrane-covered aerobic composting technology to solanaceous vegetable waste, and may even develop the technical misconception that this type of material is unsuitable for membrane-covered aerobic composting. Furthermore, different types of solanaceous vegetable waste vary in moisture content, carbon-to-nitrogen ratio, and structural characteristics, directly affecting the heating effect, maturation speed, and final product quality during composting. Current technologies primarily focus on optimizing ventilation conditions, without systematically analyzing and adapting processes to different types of solanaceous vegetable waste and their combinations with auxiliary materials. Therefore, it is difficult to clearly define the types of raw materials and corresponding process combinations suitable for membrane-covered aerobic composting.

[0004] Therefore, there is an urgent need in this field for a membrane-covered aerobic composting method for solanaceous vegetable waste to solve the problem of insufficient raw material compatibility in existing technologies. Summary of the Invention

[0005] To address the problems existing in the prior art, this invention provides a membrane-covered aerobic composting method suitable for solanaceous vegetable waste, so as to achieve stable composting utilization of vegetable waste and improve the quality of compost products.

[0006] On the one hand, the present invention provides a method for aerobic composting of solanaceous vegetable waste using a membrane-covered composting device, comprising the following steps: selecting solanaceous vegetable waste as the main material and livestock and poultry manure as the auxiliary material, mixing them and adding microbial agents, adjusting the initial moisture content and carbon-nitrogen ratio, and loading them into a membrane-covered aerobic composting device for intermittent aeration composting.

[0007] Specifically, the waste from solanaceous vegetables is selected from any one or more of tomato stalks, chili stalks, or eggplant vines, and the livestock and poultry manure is cow manure or pig manure.

[0008] Specifically, the mixing ratio of the main material and the auxiliary material is a dry basis mass ratio of (2-10):1, preferably a dry basis mass ratio of (4-6):1.

[0009] Specifically, the microbial agent is composed of *Tricholoma harzianum*, *Bacillus subtilis*, *Saccharomyces cerevisiae*, and *Metarhizium anisopliae*, and is commercially available. Specifically, its addition amount is 0.2% to 0.5% of the total mass of the mixture, preferably 0.3% to 0.4% of the total mass of the mixture.

[0010] Specifically, the initial moisture content is adjusted to 50%–70%, and the initial carbon-nitrogen ratio is controlled to 10–25. Preferably, the initial moisture content is adjusted to 55%–65%, and the initial carbon-nitrogen ratio is controlled to 12–19.

[0011] Specifically, the main ingredient is chopped to 5-50 mm before mixing, preferably 10-20 mm.

[0012] Specifically, the membrane-covered aerobic composting device includes a semi-permeable membrane covering structure, an aeration system, and a parameter monitoring and control system, with an effective volume of not less than 30L, preferably not less than 36L.

[0013] Specifically, the intermittent aeration mode is to ventilate for 10-50 minutes and stop for 10-50 minutes, with a ventilation rate of 0.5-1.5 L / min. Preferably, the intermittent aeration mode is to ventilate for 25-35 minutes and stop for 25-35 minutes, with a ventilation rate of 0.8-1.0 L / min.

[0014] Specifically, no turning is performed during the composting process, and the composting cycle is 20 to 35 days, preferably 25 to 30 days.

[0015] On the other hand, the present invention provides a well-rotted compost prepared by the method described above.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] (1) This invention targets the physical and chemical properties of solanaceous vegetable waste, adopts a membrane-covered aerobic composting system, and with optimized raw material combination and process parameters, significantly improves composting efficiency, allows the compost to smoothly go through the complete stages such as the thermophilic period and the heat philic period, and the maximum temperature can reach above 65℃, effectively kill pathogenic microorganisms, and shorten the composting cycle to 25 days.

[0018] (2) The present invention effectively controls the moisture content of the compost pile to decrease to 50% to 55%, ensuring efficient degradation of organic matter, excellent degradation effect of volatile solids, continuous reduction of carbon-nitrogen ratio, significant improvement of humification degree, stable physical and chemical properties of compost products, weakly alkaline pH, which meets the standards for mature compost.

[0019] (3) The method of the present invention is applicable to different types of solanaceous vegetable waste and their combination with auxiliary materials. It has good raw material compatibility, does not require turning over, simplifies the process flow, and reduces energy consumption.

[0020] (4) The germination index of the compost product seeds produced by the method of the present invention eventually exceeds 70%, completely eliminating plant toxicity, realizing the transformation of vegetable waste from pollutants to high-quality organic fertilizer, avoiding resource waste and environmental pollution, and having economic, ecological and social benefits, with broad prospects for promotion. Attached Figure Description

[0021] Figure 1 This refers to the temperature changes during the membrane-covered aerobic composting process of this invention.

[0022] Figure 2 This refers to the change in moisture content during the membrane-covered aerobic composting process of this invention.

[0023] Figure 3 This invention relates to pH changes during the membrane-covered aerobic composting process.

[0024] Figure 4 This refers to the changes in volatile solids during the membrane-covered aerobic composting process of the present invention.

[0025] Figure 5 This invention relates to the change in the carbon-nitrogen ratio during the membrane-covered aerobic composting process.

[0026] Figure 6 This refers to the changes in seed germination index during the film-covered aerobic composting process of this invention. Detailed Implementation

[0027] The present invention will be further described below with reference to specific embodiments, and the advantages and features of the present invention will become clearer as a result of the description. However, these embodiments are merely illustrative and do not constitute any limitation on the scope of protection defined by the claims of the present invention.

[0028] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that the upper and lower limits of the range and each intermediate value between them are specifically disclosed. Any stated value or intermediate value within a stated range, as well as each smaller range between any other stated value or intermediate value within said range, are also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0029] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0030] Example 1

[0031] Tomato straw was selected as the main material and cow manure as the auxiliary material, mixed at a dry weight ratio of 5:1. 0.3% of the total mass of the mixture was added with a microbial inoculant (organic material composting agent (including straw-specific type) from Zhongnong Lvkang (Beijing) Biotechnology Co., Ltd., containing *Heterobacter harzianum*, *Bacillus subtilis*, *Saccharomyces cerevisiae*, and *Metarhizium anisopliae*). The initial carbon-to-nitrogen ratio was 12.6, and the initial moisture content of the mixture was adjusted to 63.48%. The tomato straw was chopped to 10-20 mm before mixing, and the cow manure was fresh. The mixture was loaded into the material hopper of a self-developed membrane-covered aerobic composting equipment with an effective volume of 36 L without turning the compost. Aeration was carried out at a ventilation rate of 0.84 L / min, using an intermittent aeration mode of 30 min ventilation followed by 30 min cessation. The composting cycle was 25 days, and this treatment was designated T1.

[0032] Example 2

[0033] Tomato straw was selected as the main material, and pig manure as the auxiliary material, mixed at a dry weight ratio of 5:1. 0.3% of the total mass of the mixture was added as a microbial inoculant, resulting in an initial carbon-to-nitrogen ratio of 13.86. The initial moisture content of the mixture was adjusted to 61.57%. The tomato straw was chopped to 10-20 mm before mixing, and the pig manure was fresh. The mixture was loaded into the material hopper of a membrane-covered aerobic composting equipment and composted without turning the compost. The effective volume of the membrane-covered aerobic composting equipment was 36 L. Aeration conditions were set at a ventilation rate of 0.84 L / min, using an intermittent aeration mode of 30 min ventilation followed by 30 min cessation. The composting cycle was 25 days, and this treatment was designated T2.

[0034] Example 3

[0035] Chili stalks were selected as the main material, and cow dung as the auxiliary material. They were mixed at a dry weight ratio of 5:1. 0.3% of a commercial microbial inoculant (organic material composting agent (including straw-specific type) from Zhongnong Lvkang (Beijing) Biotechnology Co., Ltd.) was added to the total mass of the mixture. The initial carbon-to-nitrogen ratio was 18.85, and the initial moisture content of the mixture was adjusted to 61.70%. The chili stalks were chopped to 10-20 mm before mixing, and the cow dung was fresh. The mixture was loaded into the material hopper of a film-covered aerobic composting equipment and composted without turning the compost. The effective volume of the film-covered aerobic composting equipment was 36 L. Aeration conditions were set at a ventilation rate of 0.84 L / min, using an intermittent aeration mode of 30 min ventilation followed by 30 min cessation. The composting cycle was 25 days, and this treatment was designated T3.

[0036] Example 4

[0037] Eggplant vines were selected as the main material, and cow manure as the auxiliary material. They were mixed at a dry weight ratio of 5:1. 0.3% of a commercial microbial inoculant (organic material composting agent (including straw-specific type) from Zhongnong Lvkang (Beijing) Biotechnology Co., Ltd.) was added to the total mass of the mixture. The initial carbon-to-nitrogen ratio was 17.4, and the initial moisture content of the mixture was adjusted to 62.09%. The eggplant vines were chopped to 10-20 mm before mixing, and the cow manure was fresh. The mixture was loaded into the material hopper of a film-covered aerobic composting equipment and composted without turning the compost. The effective volume of the film-covered aerobic composting equipment was 36 L. Aeration conditions were set at a ventilation rate of 0.84 L / min, using an intermittent aeration mode of 30 min ventilation followed by 30 min cessation. The composting cycle was 25 days, and this treatment was designated T4.

[0038] Example 5

[0039] During the composting process of Examples 1-4, samples were taken from the compost pile on days 0, 3, 6, 9, 12, 15, 20, and 25. Five sampling points were randomly selected each time, and the samples were mixed evenly and stored at −20°C for subsequent physicochemical property analysis.

[0040] (1) Measurement of reactor temperature

[0041] During the composting process, temperature sensors are installed in the upper, middle, and lower layers of the compost pile to monitor temperature changes and simultaneously record the ambient temperature.

[0042] (2) Moisture content determination

[0043] The moisture content was determined using the 105℃ drying method. An appropriate amount of compost sample was placed in a constant-weight weighing dish, and the initial mass was recorded. The sample was then dried at 105℃ to constant weight, and the moisture content was calculated based on the difference in mass before and after drying.

[0044] (3) pH value measurement

[0045] Take an appropriate amount of sample and mix it with deionized water. After thorough shaking, prepare an extract. Then, use a pH meter to measure the pH value of the extract.

[0046] (4) Determination of volatile solids

[0047] After drying and pulverizing the sample, it was ignited at 575°C to constant weight to calculate the volatile solids content.

[0048] (5) Carbon-to-nitrogen ratio

[0049] The total carbon and total nitrogen content of the sample was determined using an elemental analyzer, and the carbon-nitrogen ratio was calculated accordingly.

[0050] (6) Seed germination index

[0051] The phytotoxicity of compost was assessed using the seed germination index. Seed germination rate and root length were measured in both compost extract and deionized water, and the germination index was calculated using the following formula:

[0052]

[0053] In the formula:

[0054] GI—Seed Germination Index, expressed as a percentage (%);

[0055] A1—Germination rate of seeds cultured in compost extract, expressed as a percentage (%);

[0056] A2—Root length of seeds cultured in compost extract, in centimeters (cm);

[0057] B1—germination rate of seeds cultured in deionized water, expressed as a percentage (%);

[0058] B2—Root length of seeds cultured in deionized water, in centimeters (cm).

[0059] (7) Results and Analysis

[0060] Temperature changes during the membrane-covered aerobic composting process in each treatment (T1-T4) of Examples 1-4 are as follows: Figure 1 As shown, the membrane-covered aerobic composting process sequentially went through a thermophilic period, a heat-loving period, a cooling period, and a maturation period, indicating that each embodiment could complete the aerobic composting process under the process conditions of the present invention. Among them, Example 1 achieved the highest temperature during the thermophilic period, exceeding 65°C.

[0061] The changes in moisture content during the membrane-covered aerobic composting process in each treatment (T1-T4) of Examples 1-4 are as follows: Figure 2 As shown, the moisture content gradually decreased throughout the composting process. The initial moisture content of each embodiment was 60%–65%, and after membrane-covered aerobic composting treatment, the moisture content dropped to 50%–55% at the end of composting.

[0062] The pH changes during the membrane-covered aerobic composting process in each treatment (T1-T4) of Examples 1-4 are as follows: Figure 3 As shown, the pH value of the compost pile increased in the early stage of composting, then gradually stabilized, and decreased slightly in the later stage of composting. At the end of composting, the pH value of the compost products in each example was weakly alkaline, which is consistent with the physicochemical characteristics of mature compost.

[0063] The changes in volatile solids during the membrane-covered aerobic composting process in each treatment (T1-T4) of Examples 1-4 are as follows: Figure 4 As shown, the degradation rate of volatile solids was relatively fast in the early stage of composting, gradually decreasing after entering the thermophilic stage, indicating that the organic matter was effectively degraded during composting. The degree of volatile solids degradation varied among different raw material combinations, with the treatment group using tomato straw as the main material exhibiting a higher level of organic matter degradation.

[0064] The changes in carbon-nitrogen ratio during the membrane-covered aerobic composting process in each treatment (T1-T4) of Examples 1-4 are as follows: Figure 5 As shown, the carbon-to-nitrogen ratio decreases during composting, indicating that the degree of humification in composting deepens.

[0065] The changes in seed germination index during the film-covered aerobic composting process in each treatment (T1-T4) of Examples 1-4 are as follows: Figure 6As shown, the initial seed germination indices of T1 to T4 differed, with some treatments having an initial seed germination index below 70%. As the film-covered aerobic composting process progressed, the seed germination index of each treatment gradually increased, exceeding 70% at the end of composting. This indicates that the film-covered aerobic composting method described in this invention can effectively reduce the phytotoxicity of solanaceous vegetable waste and obtain well-rotted compost products.

[0066] This invention proposes a membrane-covered aerobic composting method for solanaceous vegetable waste. The main composting materials are tomato stalks, chili stalks, and eggplant vines, with cow manure or pig manure as auxiliary materials. After being mixed in a certain proportion, the compost can be obtained through membrane-covered aerobic fermentation.

[0067] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A method for aerobic composting of solanaceous vegetable waste using a membrane-covered system, characterized in that, The process includes the following steps: selecting waste from solanaceous vegetables as the main material and livestock and poultry manure as the auxiliary material, mixing them, adding microbial agents, adjusting the initial moisture content and carbon-nitrogen ratio, and loading them into a membrane-covered aerobic composting device for intermittent aeration composting.

2. The method according to claim 1, characterized in that, The waste from solanaceous vegetables is selected from any one or more of tomato stalks, chili stalks, or eggplant vines, and the livestock and poultry manure is cow manure or pig manure.

3. The method according to claim 1, characterized in that, The mixing ratio of the main material and the auxiliary material is a dry basis mass ratio of (2-10):1, preferably a dry basis mass ratio of (4-6):

1.

4. The method according to claim 1, characterized in that, The microbial agent is composed of *Tricholoma harzianum*, *Bacillus subtilis*, *Saccharomyces cerevisiae*, and *Metarhizium anisopliae*, and its addition amount is 0.2% to 0.5% of the total mass of the mixture, preferably 0.3% to 0.4% of the total mass of the mixture.

5. The method according to claim 1, characterized in that, The initial moisture content is adjusted to 50%–70%, and the initial carbon-nitrogen ratio is controlled to 10–25. Preferably, the initial moisture content is adjusted to 55%–65%, and the initial carbon-nitrogen ratio is controlled to 12–19.

6. The method according to claim 1, characterized in that, The main ingredients are chopped to 5-50 mm before mixing, preferably 10-20 mm.

7. The method according to claim 1, characterized in that, The membrane-covered aerobic composting device includes a semi-permeable membrane covering structure, an aeration system, and a parameter monitoring and control system, with an effective volume of not less than 30L, preferably not less than 36L.

8. The method according to claim 1, characterized in that, The intermittent aeration mode is ventilating for 10-50 minutes and stopping for 10-50 minutes, with a ventilation rate of 0.5-1.5 L / min. Preferably, the intermittent aeration mode is ventilating for 25-35 minutes and stopping for 25-35 minutes, with a ventilation rate of 0.8-1.0 L / min.

9. The method according to claim 1, characterized in that, No turning is performed during the composting process, and the composting cycle is 20 to 35 days, preferably 25 to 30 days.

10. The compost prepared by the method according to any one of claims 1-9.

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