Application of charcoal and / or ardealite in improvement of compost maturity degree and / or reduction of greenhouse gas emission in composting process

Abstract

The invention provides application of biochar and / or phosphogypsum in improvement of compost maturity degree and / or reduction of greenhouse gas emission in a composting process, and belongs to the technical field of agricultural waste treatment and fertilizer preparation. The charcoal and / or phosphogypsum are / is added in the composting process, so that compost maturity can be promoted, and emission of greenhouse gases in the composting process can be remarkably reduced. Results of the embodiment of the invention show that the charcoal or charcoal and phosphogypsum are added in the composting fermentation process of the vegetable wastes, so that the emission of CO2 and CH4 in the composting process can be obviously reduced, the color coefficient and E4 / E6 value of the compost obtained by fermentation are reduced, the composting maturity degree is improved, and the yield of the compost is increased. The compost obtained by fermentation can significantly improve the seed germination rate and germination index.

Description

Technical Field

[0001] The present invention belongs to the technical field of agricultural waste treatment and fertilizer preparation, and specifically relates to the application of biochar and / or phosphogypsum in improving the maturity of compost and / or reducing greenhouse gas emissions during the composting process. Background Art

[0002] With the acceleration of agricultural modernization, the amount of vegetable waste has skyrocketed. If directly discarded or simply piled up, this waste not only takes up a large amount of land resources, but also emits foul odors during natural decomposition, breeds mosquitoes and flies, and causes environmental pollution.

[0003] In the field of traditional vegetable composting and fermentation, there are many difficult problems to solve. From the perspective of composting effect, the long fermentation cycle is a major problem. It usually takes several months or even more than half a year to complete the composting process, which greatly limits the production efficiency of composting. Moreover, the quality of traditional compost products is uneven, and the nutrient content is unstable, which makes it difficult to meet the needs of crop growth, resulting in poor application effect in agricultural production. In terms of carbon emissions, the traditional composting process releases a large amount of greenhouse gases, such as carbon dioxide (CO2) and methane (CH4). According to research, for every ton of vegetable waste processed, the traditional composting method emits hundreds of kilograms of CO2 equivalent, which has a significant negative impact on global climate change.

[0004] Furthermore, current composting technologies struggle to balance multiple objectives. Simply pursuing rapid fermentation often results in insufficient compost maturity and poor product quality. Focusing on reducing greenhouse gas emissions can compromise compost efficiency and quality. Summary of the Invention

[0005] In response to the shortcomings of the prior art, the present invention aims to provide the use of biochar and / or phosphogypsum to improve compost maturity and / or reduce greenhouse gas emissions during the composting process. The biochar or biochar combined with phosphogypsum applied to vegetable waste compost can significantly improve compost maturity while significantly reducing greenhouse gas emissions during the composting process.

[0006] The purpose of the present invention is achieved through the following technical solutions:

[0007] The present invention provides the use of biochar and / or phosphogypsum in improved fermentation composting, wherein the improved fermentation composting includes increasing the maturity of the compost and / or reducing greenhouse gas emissions during the composting process.

[0008] In a preferred embodiment of the present invention, the compost fermentation substrate includes vegetable waste.

[0009] In a preferred embodiment of the present invention, the greenhouse gas includes CO2 and / or CH4.

[0010] The present invention also provides a composting method for improving the maturity of compost and / or reducing greenhouse gas emissions during the composting process, comprising:

[0011] The fermentation substrate is mixed with biochar and / or phosphogypsum to obtain a compost material, and the compost material is subjected to composting fermentation.

[0012] In a preferred embodiment of the present invention, when a mixture of fermentation substrate and biochar is used as the compost material, the added amount of the biochar is 3% to 10% of the mass of the compost material.

[0013] In a preferred embodiment of the present invention, when a mixture of fermentation substrate, biochar and phosphogypsum is used as the compost material, the added amount of the biochar is 3% to 10% of the mass of the compost material, and the added amount of the phosphogypsum is 3% to 10% of the mass of the compost material.

[0014] In a preferred embodiment of the present invention, the compost fermentation temperature is 55° C.; the ventilation rate during the compost fermentation process is 0.15 L / min; and the compost fermentation time is 30 to 35 days.

[0015] In a preferred embodiment of the present invention, before the composting fermentation is carried out, the carbon-nitrogen ratio of the compost material is adjusted to 25:1.

[0016] In a preferred embodiment of the present invention, the moisture content of the compost material is adjusted to 60% during composting fermentation.

[0017] In a preferred embodiment of the present invention, the fermentation substrate includes vegetable waste; the vegetable waste includes cabbage waste.

[0018] Beneficial effects of the present invention

[0019] The present invention provides the use of biochar and / or phosphogypsum in improving the maturity of compost and / or reducing greenhouse gas emissions during the composting process. The present invention can significantly promote the maturity of compost by adding biochar or adding biochar and phosphogypsum during the composting process, and can also significantly reduce the emission of greenhouse gases during the composting process. The present invention shows through the results of examples that adding biochar during the composting and fermentation process of vegetable waste can significantly reduce the emission rate of CO2 and CH4 during the composting process, reduce the cumulative emission of CO2 and CH4 during the composting process, improve the maturity of the compost, and the compost obtained by fermentation can increase the germination rate and germination index of radish seeds. Therefore, adding biochar to compost or vegetable waste compost can promote the maturity of compost, shorten the composting time, and at the same time reduce the emission of greenhouse gases such as CO2 and CH4 during the composting process. The present invention also demonstrates through examples that adding biochar and phosphogypsum to the vegetable waste composting process significantly reduces the emission rate and cumulative amount of CO2 and CH4 during the composting process, lowers the hue coefficient and E4 / E6 value of the resulting compost, and improves the germination rate and germination index of radish seeds in the compost obtained through seed fermentation. In summary, adding biochar, or both biochar and phosphogypsum, to vegetable waste composting can improve compost maturity and / or reduce greenhouse gas emissions during the composting process.

[0020] This invention combines biochar and phosphogypsum in composting, creating a synergistic effect. The biochar's adsorption properties effectively absorb some harmful substances in the phosphogypsum, reducing its harmful effects on the compost. Phosphogypsum and biochar also work together to better promote the formation of humus. Adding biochar and phosphogypsum to the composting process optimizes the microbial environment and promotes compost maturity. It also significantly reduces greenhouse gas emissions such as CO2 and CH4 during the composting process. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is an experimental flow chart of adding biochar and phosphogypsum during the composting and fermentation process of vegetable waste in the embodiment;

[0022] Figure 2 Statistical results of CO2 emission rate when adding different amounts of biochar to vegetable waste compost;

[0023] Figure 3 Statistical results of cumulative CO2 emissions from vegetable waste compost with different amounts of biochar added;

[0024] Figure 4 Statistical results of CH4 emission rate when adding different amounts of biochar to vegetable waste compost;

[0025] Figure 5 Statistical results of CH4 cumulative emissions from vegetable waste compost with different amounts of biochar added;

[0026] Figure 6 The ΔlogK results of fermentation products when different amounts of biochar were added to vegetable waste compost;

[0027] Figure 7 The E4 / E6 value results of fermentation products with different amounts of biochar added to vegetable waste compost;

[0028] Figure 8 The GI value results of the fermentation products obtained by adding different amounts of biochar to vegetable waste compost;

[0029] Figure 9 The blank GI value results of the fermentation products obtained by adding different amounts of biochar to vegetable waste compost are used as a control;

[0030] Figure 10 Statistical results of CO2 emission rate when different amounts of phosphogypsum are added to vegetable waste compost;

[0031] Figure 11 Statistical results of cumulative CO2 emissions from vegetable waste compost with different amounts of phosphogypsum added;

[0032] Figure 12 Statistical results of CH4 emission rate when different amounts of phosphogypsum are added to vegetable waste compost;

[0033] Figure 13 Statistical results of CH4 cumulative emissions from vegetable waste compost with different amounts of phosphogypsum added;

[0034] Figure 14 The ΔlogK results of fermentation products when different amounts of phosphogypsum were added to vegetable waste compost;

[0035] Figure 15 The E4 / E6 value results of fermentation products with different amounts of phosphogypsum added to vegetable waste compost;

[0036] Figure 16 The graph shows the effects of the fermentation products of Examples 4 to 7 as fertilizers on seed germination. DETAILED DESCRIPTION

[0037] The present invention provides the use of biochar and / or phosphogypsum in improving the maturity of compost and / or reducing greenhouse gas emissions during the composting process.

[0038] As an optional embodiment of the present invention, the compost comprises vegetable waste fermentation compost. In one embodiment of the present invention, cabbage waste was used as the fermentation substrate for verification, but this alone cannot be considered the entire scope of protection of the present invention. As an optional embodiment of the invention, the greenhouse gas comprises CO2 and / or CH4.

[0039] By adding biochar to the composting and fermentation process of vegetable waste, the present invention significantly reduces the emission rate of CO2 and CH4 during the composting process, reduces the cumulative emissions of CO2 and CH4 during the composting process, improves the maturity of the compost, and the fermented compost can increase the germination rate and germination index of radish seeds. Therefore, adding biochar to compost or vegetable waste compost can promote compost maturity, shorten the composting time, and simultaneously reduce the emission of greenhouse gases such as CO2 and CH4 during the composting process.

[0040] The phosphogypsum described in the present invention is a by-product produced during the production of wet-process phosphoric acid. Due to its complex composition and the presence of harmful substances such as heavy metals and fluorides, phosphogypsum has high processing costs and is extremely difficult to dispose of. Long-term storage of phosphogypsum will gradually release pollutants into the surrounding soil and water bodies, leading to soil compaction, decreased fertility, and eutrophication of water bodies, posing a serious threat to ecological and environmental safety. Due to its inherent characteristics, phosphogypsum faces many challenges when directly applied to composting. In the prior art, phosphogypsum usually needs to be subjected to complex modification treatments before it can be used in composting, which undoubtedly increases processing costs and technical difficulties.

[0041] The present invention can significantly reduce the emission rate of CO2 and CH4 during the composting process by adding biochar and phosphogypsum during the composting fermentation process of vegetable waste, reduce the cumulative emissions of CO2 and CH4 during the composting process, reduce the hue coefficient and E4 / E6 value of the compost obtained by fermentation, and improve the compost obtained by seed fermentation to improve the germination rate and germination index of radish seeds. Therefore, adding biochar and phosphogypsum to compost or vegetable waste compost can promote compost maturity, shorten the composting time, and also reduce the emission of greenhouse gases such as CO2 and CH4 during the composting process. In summary, adding biochar or adding biochar and phosphogypsum during the composting process of vegetable waste can improve the degree of compost maturity and / or reduce greenhouse gas emissions during the composting process.

[0042] The present invention provides a composting method for improving the maturity of compost and / or reducing greenhouse gas emissions during the composting process, comprising:

[0043] Biochar and / or phosphogypsum are added to the fermentation substrate to obtain compost material, and the compost material is subjected to composting fermentation.

[0044] The present invention has no special limitation on the fermentation substrate, and any conventional composting fermentation substrate in the art can be used. As an optional embodiment of the present invention, the fermentation substrate includes vegetable waste. The present invention has no special limitation on the type of vegetable waste, and any conventional type of vegetable waste in the art can be used. As an optional embodiment of the present invention, the vegetable waste can be cabbage waste. After obtaining the fermentation substrate, the present invention washes the fermentation substrate and then dries and crushes it in sequence. The present invention has no special limitation on the washing method, and any conventional washing method in the art can be used. The present invention has no special limitation on the drying and crushing methods, and any conventional drying and crushing methods in the art can be used. As an optional embodiment of the present invention, the drying method can be natural sun drying in a ventilated place, and drying to a moisture content of ≤15%; the crushing is preferably crushed to a particle size of about 2 to 5 mm, which can be 2, 3, 4 or 5 mm.

[0045] The present invention preferably further includes adjusting the carbon-nitrogen ratio of the fermentation substrate before composting the fermentation substrate. The present invention does not specifically limit the raw materials used to adjust the carbon-nitrogen ratio of the fermentation substrate; any material with an appropriate carbon-nitrogen ratio content commonly used in the art may be used. As an optional embodiment of the present invention, when vegetable waste is used as the fermentation substrate, the raw materials used to adjust the carbon-nitrogen ratio of the fermentation substrate may be pine needles and / or glucose. The raw materials used to adjust the carbon-nitrogen ratio of the fermentation substrate in the present invention may also be cleaned, dried, and pulverized before composting. The present invention does not specifically limit the cleaning method; any cleaning method commonly used in the art may be used. The present invention does not specifically limit the drying and pulverizing methods; any drying and pulverizing methods commonly used in the art may be used. As an optional embodiment of the present invention, the drying method may be natural sun drying in a ventilated area to a moisture content of ≤15%. The pulverization preferably involves pulverizing to a particle size of approximately 2 to 5 mm, which may be 2, 3, 4, or 5 mm. As an optional embodiment of the present invention, the raw materials used to adjust the carbon-nitrogen ratio of the fermentation substrate may also be referred to as the fermentation substrate.

[0046] As an optional embodiment of the present invention, when biochar is added to the fermentation substrate, the amount of biochar added can be 3% to 10% of the mass of the compost material, or 3%, 4%, 5%, 6%, 7%, 8%, 9% or 10%. As an optional embodiment of the present invention, when biochar and phosphogypsum are added to the fermentation substrate, the amount of biochar added can be 3% to 10% of the mass of the compost material, or 3%, 4%, 5%, 6%, 7%, 8%, 9% or 10%; the amount of phosphogypsum added can be 3% to 10% of the mass of the compost material, or 3%, 4%, 5%, 6%, 7%, 8%, 9% or 10%.

[0047] The present invention adds biochar or biochar and phosphogypsum to the fermentation substrate to obtain a compost material. As an optional embodiment of the present invention, the carbon-nitrogen ratio of the compost material can be 25:1. Examples have shown that a carbon-nitrogen ratio of 25:1 has the best composting effect.

[0048] In an embodiment of the present invention, a composting method for improving the maturity of compost and / or reducing greenhouse gas emissions during the composting process is specifically described by fermenting vegetable waste. The vegetable waste used in the embodiment of the present invention is cabbage waste; when the cabbage waste is used as a fermentation substrate, the present invention uses pine needles and glucose to adjust the carbon-nitrogen ratio of the compost material. The present invention preferably sets the mass ratio of cabbage waste and pine needles to 1:1, and then adds biochar or adds biochar and phosphogypsum, and then calculates the amount of glucose added, adjusts the carbon-nitrogen ratio of the compost material to 25:1, and then carries out the subsequent composting process.

[0049] After obtaining the compost material, the present invention preferably mixes the compost material with an EM bacteria compost solution, adjusts the moisture content of the fermentation system to 60%, and then conducts compost fermentation. The present invention does not specifically limit the source of the EM bacteria compost solution; any conventional EM bacteria compost solution in the art can be used. As an optional embodiment of the present invention, the EM compost solution can be prepared by mixing EM bacteria with water and glucose, and then allowing the mixture to stand for 6-8 hours to obtain the EM compost solution. As an optional embodiment of the present invention, the EM bacteria include a bio-fertilizer fermentation agent purchased from Yijiayi Bioengineering Co., Ltd. As an optional embodiment of the present invention, the mass ratio of the EM bacteria, glucose, and water can be 1:5:100; the standing temperature can be room temperature (25°C); and the standing time can be 6-8 hours, or 6, 7, or 8 hours. The present invention does not specifically limit the mass ratio of the compost material and EM bacteria compost solution; any conventional mixing ratio in the art can be used.

[0050] After adjusting the moisture content of the fermentation system to 60%, the composting process is performed. As an optional embodiment of the present invention, the composting temperature can be 55°C; the ventilation rate during the composting process can be 0.15 L / min; and the composting time can be 30 to 35 days, or 30, 31, 32, 33, 34, or 35 days. After the composting is completed, compost is obtained.

[0051] In an embodiment of the present invention, the addition of biochar to cabbage waste compost can reduce greenhouse gas emissions such as CO2 and CH4. Adding 5% biochar is the most effective, as it can adsorb heavy metal (HM) ions such as As, Cd, and Hg, is non-toxic after decomposition, and promotes plant germination and growth. Adding phosphogypsum to vegetable waste compost with 5% biochar weakens the biochar's carbon sequestration, but enhances Cd adsorption, weakens Hg adsorption, and affects compost maturity. Adding 10% phosphogypsum to vegetable waste compost already containing 5% biochar results in a substantially mature and non-toxic fermentation product, achieving the best greenhouse gas reduction. The present invention, through the combined use of biochar and phosphogypsum, cleverly addresses the challenges of using phosphogypsum directly. The adsorption properties of biochar can effectively adsorb some of the harmful substances in phosphogypsum, reducing its harmful effects on the compost. Furthermore, the synergistic effect of the two in a specific ratio optimizes the compost's microbial environment and promotes compost maturity. When 10% phosphogypsum was added to vegetable waste compost already supplemented with 5% biochar, the fermentation product was essentially mature and non-toxic. This combined application emphasizes the importance of proportion. By precisely controlling the addition ratio of biochar and phosphogypsum, it simplifies the handling requirements for phosphogypsum, eliminating the need for complex pretreatment and allowing it to be directly used in vegetable compost. This significantly reduces processing costs and improves efficiency, providing a new, efficient and convenient approach for the coordinated treatment of agricultural and industrial waste.

[0052] In order to further illustrate the present invention, the technical solution provided by the present invention is described in detail below with reference to the accompanying drawings and embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0053] In the following technical scheme of the present invention, the source of vegetable waste is the vegetable fields near Kunming University of Science and Technology; the source of pine needles is the pine needle forest of Kunming University of Science and Technology; the biochar is obtained by burning corn straw; phosphogypsum is purchased from Jinning, Yunnan Province; the product name of EM bacteria: biological fertilizer composting fermentation agent, manufacturer: Puyang Yuyijiayi Biotechnology Co., Ltd.

[0054] The carbon-nitrogen ratios of the raw materials used in the following examples are shown in Table 1.

[0055] Table 1 Carbon-nitrogen ratio of different raw materials

[0056]

[0057]

[0058] The preparation method of the EM composting liquid used in the following composting fermentation is as follows: after mixing the EM bacterial agent, glucose and water in a mass ratio of 1:5:100, the mixture is allowed to stand at room temperature of 25°C for 6 to 8 hours to fully activate the microorganisms in the EM bacterial agent, thereby obtaining the EM composting liquid.

[0059] The experimental flow chart of adding biochar and phosphogypsum during the composting and fermentation process of vegetable waste in the following examples is as follows: Figure 1 shown.

[0060] Example 1

[0061] A method for composting vegetable waste comprises the following steps:

[0062] (1) Cabbage leaf waste and pine needles were collected, impurities were removed, and after washing with clean water, the cabbage waste and pine needles were placed in a well-ventilated place to dry naturally, thereby obtaining dried cabbage waste and dried pine needles. The dried cabbage waste and dried pine needles were crushed by a grinder to a particle size of about 2 to 5 mm, and 10 g of cabbage waste and 10 g of pine needles were mixed evenly at a mass ratio of 1:1 to form a fermentation substrate.

[0063] (2) Add biochar accounting for 3% of the total mass of the fermentation substrate (10 g of cabbage waste and 10 g of pine needles), set up two parallel samples, and fully stir and mix the biochar and fermentation substrate.

[0064] (3) The amount of glucose to be added was calculated based on the carbon-nitrogen ratio of each raw material (cabbage waste, pine needles, and biochar). The amount of glucose added is shown in Table 2. The carbon-nitrogen ratio in the fermentation system was adjusted to approximately 25:1. EM bacteria compost liquid was added to adjust the moisture content of the system to 60%. During the addition process, the EM bacteria compost liquid was evenly sprayed onto the compost raw materials layer by layer (spraying a layer of EM bacteria compost liquid on each layer of compost raw materials). A fermentation system was obtained.

[0065] (4) The fermentation system was placed in a fermentation container and placed in a constant temperature incubator at 55°C with a ventilation rate maintained at 0.15 L / min for composting fermentation, referred to as fermentation, for 35 days.

[0066] Example 2

[0067] A method for composting vegetable waste, comprising the same steps as in Example 1, with the only difference being that in step (2), biochar was added at a level of 5% of the total mass of the fermentation substrate (10 g of cabbage waste and 10 g of pine needles). The amounts of glucose and water added in step (3) are detailed in Table 2.

[0068] Example 3

[0069] A method for composting vegetable waste, comprising the same steps as in Example 1, with the only difference being that in step (2), biochar was added at a level of 10% of the total mass of the fermentation substrate (10 g of cabbage waste and 10 g of pine needles). The amounts of glucose and water added in step (3) are detailed in Table 2.

[0070] Comparative Example 1

[0071] A method for composting vegetable waste, comprising the same steps as in Example 1, with the only difference being that no biochar is added in step (2). The amounts of glucose and water added in step (3) are detailed in Table 2.

[0072] The addition amounts of biochar, glucose, and water in Examples 1 to 3 and Comparative Example 1 are shown in Table 2.

[0073] Table 2 Addition amount of biochar, glucose and water in Examples 1 to 3 and Comparative Example 1

[0074] Examples Processing abbreviation Biochar addition amount (g) Amount of glucose added (g) Water addition amount (g) Comparative Example 1 T0(ac) - 9.57 12.00 Example 1 T1(bc) 0.6 9.24 12.36 Example 2 T2(dc) 1.0 9.01 12.60 Example 3 T3(gc) 2.0 8.70 13.20

[0075] Application Example 1

[0076] 1. Monitoring greenhouse gas (GHG) emissions during the fermentation process of Examples 1 to 3 and Comparative Example 1

[0077] GHG emissions during the fermentation process were measured using a gas chromatograph. The results are shown in Tables 3 to 6 and Figures 2 to 5 shown. Figure 2 Statistical results of CO2 emission rate when adding different amounts of biochar to vegetable waste compost; Figure 3 Statistical results of cumulative CO2 emissions from vegetable waste compost with different amounts of biochar added; Figure 4 Statistical results of CH4 emission rate when adding different amounts of biochar to vegetable waste compost; Figure 5 Statistical results of cumulative CH4 emissions from vegetable waste compost with different amounts of biochar added.

[0078] Table 3 CO2 emission rate (mg.g) of vegetable waste compost with different amounts of biochar added -1 Cd -1 )

[0079] Fermentation time (d) 1 3 5 9 12 15 18 25 30 35 T0 34.269 29.666 36.985 20.633 6.919 5.367 2.693 3.925 4.084 3.719 T0” 35.967 33.526 32.935 19.654 8.028 7.364 3.827 4.205 4.303 3.844 T0 mean 35.118 31.596 34.960 20.143 7.474 6.365 3.260 4.065 4.194 3.781 T0STD 1.201 2.730 2.864 0.692 0.784 1.412 0.802 0.197 0.155 0.089 T1 16.785 9.486 9.135 8.438 8.190 8.510 3.393 4.103 3.871 3.818 T1” 25.853 24.974 9.054 8.013 8.606 7.288 2.943 3.705 3.990 3.635 T1 mean 21.319 17.230 9.095 8.226 8.398 7.899 3.168 3.904 3.931 3.727 T-1STD 6.413 10.952 0.057 0.300 0.294 0.864 0.318 0.282 0.084 0.129 T2 14.679 12.187 9.113 7.819 0.958 1.402 0.908 1.330 1.442 1.288 T2” 12.466 12.584 10.099 8.513 1.577 0.921 0.955 1.542 1.328 1.425 T2 mean 13.573 12.386 9.606 8.166 1.267 1.161 0.931 1.436 1.385 1.356 T2STD 1.565 0.281 0.697 0.491 0.438 0.340 0.034 0.150 0.081 0.097 T3 13.578 10.272 12.445 9.694 1.067 0.750 0.526 0.808 0.886 0.830 T3” 10.169 11.664 10.554 8.848 1.026 1.368 0.647 1.084 0.803 0.785 T3 mean 11.873 10.968 11.499 9.271 1.046 1.059 0.587 0.946 0.845 0.808 T3STD 2.410 0.985 1.337 0.598 0.029 0.438 0.086 0.195 0.059 0.032

[0080] Note: In the table, T0 is the T0(ac) treatment group, and T0” corresponds to the T0 parallel experimental group; T1 is the T1(bc) treatment group, and T1” corresponds to the T1 parallel experimental group; T2 is the T2(dc) treatment group, and T2” corresponds to the T2 parallel experimental group; T3 is the T3(gc) treatment group, and T3” corresponds to the T3 parallel experimental group; STD is standard deviation, the same below.

[0081] Table 4 Cumulative CO2 emissions from vegetable waste compost with different amounts of biochar added (mg / g)

[0082]

[0083] Table 5 CH4 emission rates (mg.g) when different amounts of biochar were added to vegetable waste compost -1 Cd -1 )

[0084]

[0085]

[0086] Table 6 Cumulative CH4 emissions from vegetable waste compost with different amounts of biochar added (mg / g)

[0087] Fermentation time (d) 1 3 5 9 12 15 18 25 30 35 T0 0.068 0.117 0.150 0.205 0.263 0.328 0.405 0.443 0.476 0.505 T0” 0.063 0.108 0.120 0.178 0.255 0.294 0.379 0.413 0.451 0.485 T0 mean 0.065 0.112 0.135 0.192 0.259 0.311 0.392 0.428 0.463 0.495 T0STD 0.004 0.007 0.021 0.019 0.006 0.024 0.019 0.021 0.017 0.014 T1 0.050 0.100 0.169 0.244 0.392 0.408 0.456 0.518 0.567 0.609 T1” 0.063 0.116 0.176 0.249 0.329 0.365 0.423 0.471 0.516 0.555 T1 mean 0.057 0.108 0.173 0.247 0.361 0.387 0.440 0.494 0.542 0.582 T1STD 0.009 0.011 0.005 0.003 0.045 0.030 0.023 0.033 0.036 0.039 T2 0.053 0.105 0.176 0.232 0.294 0.358 0.441 0.497 0.535 0.569 T2” 0.050 0.076 0.134 0.196 0.281 0.342 0.420 0.482 0.524 0.557 T2 mean 0.052 0.091 0.155 0.214 0.287 0.350 0.430 0.490 0.530 0.563 T2STD 0.002 0.020 0.030 0.025 0.009 0.011 0.015 0.010 0.008 0.009 T3 0.034 0.090 0.155 0.198 0.234 0.269 0.302 0.343 0.380 0.405 T3” 0.047 0.101 0.162 0.203 0.243 0.294 0.334 0.405 0.450 0.480 T3 mean 0.040 0.096 0.159 0.200 0.239 0.281 0.318 0.374 0.415 0.442 T3STD 0.009 0.008 0.006 0.004 0.007 0.018 0.023 0.043 0.050 0.053

[0088] From Tables 3 to 6 and Figures 2 to 5 The results show that CO2 emission rates for the control and three composting treatments all showed a gradual weakening trend with increasing composting time. In the early stages of composting, CO2 emission rates for all three treatments were lower than those for the control. In the middle stages of composting, T1(bc) gradually reached a similar CO2 emission rate to that of the control (T0(ac). Among the four treatments, T3(gc) showed the greatest reduction, while no significant difference was observed between T2(dc) and T3(gc). Cumulative CO2 emissions for the control and three composting treatments increased with increasing composting time. CO2 emissions were significantly reduced when biochar addition exceeded 3%. T2(dc) had the lowest cumulative CO2 emissions of the four treatments, with CO2 emissions 66.35% lower than that of the control by day 35. This suggests that the addition of 5% biochar is the most effective carbon emission control measure for vegetable composting. Considering both CO2 emission rate and cumulative emissions, the addition of 5% biochar demonstrates a strong CO2 emission reduction capability for natural vegetable composting. The addition of biochar does not necessarily suppress CH4 emissions during composting. For example, the emission rate of T1(bc) during the initial composting phase was significantly higher than that of the control group, T0(ac). The overall emission rate of T3(gc) was at its lowest, indicating that CH4 emissions were effectively suppressed. A biochar addition of >5% significantly reduced cumulative CH4 emissions, with a maximum reduction of approximately 10.7%. Currently, adding 10% biochar is the optimal option for reducing CO2 and CH4 emissions during aerobic composting. CH4 is produced under anaerobic conditions. Since anaerobic treatment is not performed during composting, the CH4 emission rate does not accurately reflect whether CH4 emissions are suppressed during biochar addition.

[0089] 2. After fermentation, the hue coefficient (A600 / C) and optical density (E4 / E6) of the fermentation products of Examples 1 to 3 and Comparative Example 1 were measured by spectrophotometer. The results are shown in Figures 7 to 8 and Figures 6-7 . Figure 6 ΔlogK of fermentation products when different amounts of biochar were added to vegetable waste compost; Figure 7 E4 / E6 values of fermentation products with different amounts of biochar added to vegetable waste compost.

[0090] Table 7 ΔlogK of fermentation products of vegetable waste compost with different amounts of biochar added

[0091] Grouping Hue coefficient (ΔlogK) Standard deviation T0(ac) 0.34 0.02 T1(bc) 0.52 0.03 T2(dc) 0.53 0.00 T3(gc) 0.47 0.01

[0092] Table 8 E4 / E6 values of fermentation products of vegetable waste compost with different amounts of biochar added

[0093]

[0094] From Tables 7 to 8 and Figures 6-7 The hue coefficient of the compost extract increased after biochar addition, and the hue coefficient gradually increased with increasing biochar addition. The hue coefficient was highest at T2(dc), but there was no significant difference between T1(bc) and T2(dc). When biochar addition was >5%, the hue coefficient of the T3(gc) group began to decrease, but remained greater than that of the control group (T0(ac). This suggests that biochar addition promotes compost maturity, with the best composting effect occurring when 3-5% biochar was added. With increasing biochar addition, the optical density first increased, reaching a maximum at T2(dc), but there was no significant difference between T1(bc) and T2(dc). When biochar addition was >5%, the optical density of the T3(gc) group decreased and remained lower than that of the control group (T0(ac). Optical density values indicate that the compost structure was most complex when 10% biochar was added, while the structure of the compost with 3% and 5% biochar became simpler than that of the control group. Organic carbon (OC) is the carbon element present in living organisms in the form of organic matter. It is produced through biodegradation in compost. Composting cow dung with straw and biochar can effectively increase soil organic carbon content. Soil organic carbon is closely related to soil fertility. Table 4 shows that the organic carbon content of compost products increased after adding biochar, with the highest T2(dc) organic carbon content, indicating the best biodegradation performance. This indicates that adding biochar accelerates biodegradation in compost, with the best composting performance achieved when adding 5% biochar.

[0095] 3. After fermentation, the total organic carbon (TOC) in the fermentation products of Examples 1 to 3 and Comparative Example 1 was measured using an elemental analyzer. The results are shown in Table 9.

[0096] Table 9 Total organic carbon in the fermentation products of Examples 1 to 3 and Comparative Example 1 (mean ± standard deviation)

[0097] Grouping T0(ac) T1(bc) T2(dc) T3(gc) Total organic carbon NPOC (mg) 2.8594±0.085d 4.8095±0.043b 5.9303±0.26a 3.8392±0.025c

[0098] Table 9 shows that soil organic carbon is closely related to soil fertility. The organic carbon content of compost products increased after adding biochar, with the highest organic carbon content in T2(dc), indicating the best compost biodegradation. This indicates that adding biochar accelerates biodegradation in compost, with the best composting performance achieved when adding 5%.

[0099] 4. The heavy metal (HM) content in the fermentation products of Examples 1 to 3 and Comparative Example 1 was determined using an atomic absorption spectrometer. The results are shown in Table 10.

[0100] Table 10 Heavy metal (HM) content in the fermentation products of Examples 1 to 3 and Comparative Example 1

[0101]

[0102] Table 10 shows that the nutrients required for plant growth include C, H, O, N, K, Ca, P, and other trace elements. Biochar has adsorptive properties and absorbs trace heavy metals such as As and Cd during the composting process. The addition of biochar to compost reduced Cd content by at least 63.3% and as much as 75.5%. Compared to the other treatments, T2(dc) had the lowest Hg content and the highest levels of other trace elements essential for plant growth, such as Mn and Zn. Combined with the GI values of each treatment, it can be seen that adding 5% biochar to natural composting resulted in a non-toxic compost and a superior heavy metal adsorption effect.

[0103] 5. Observe the effect of the fermentation products of Examples 1 to 3 and Comparative Example 1 as fertilizers on seed germination, and record the germination rate and germinated root length.

[0104] The seeds used were radish seeds from Beijing Aohua Agricultural Technology Co., Ltd. 10.0 g of the compost samples (fermentation products) of Examples 1 to 3 and Comparative Example 1 were weighed and placed in a 250 mL conical flask. 100 mL of deionized water or distilled water was added at a solid-liquid ratio (mass-to-volume ratio) of 1 g:10 mL. The bottle cap was tightened and fixed vertically on an oscillator. The oscillation frequency was adjusted to not less than 100 times / min and the amplitude was not less than 40 mm. The mixture was extracted by reciprocating horizontal oscillation at room temperature for 1 h. After being removed and allowed to stand for 0.5 h, the supernatant was filtered on a filter device pre-installed with filter paper. The filtered extract was collected and shaken for testing. Ten plump, roughly uniform radish seeds were placed evenly in a 9 cm Petri dish lined with two sheets of filter paper. First, 10 mL of distilled water was added, followed by 5 mL of each compost extract. The dish was covered and incubated in a climate chamber at 15-20°C and 60% humidity under constant light intensity for 96 hours. Root length and the number of radish seeds that sprouted from each compost extract were measured, and the germination rate was calculated. The test was repeated three times for each sample, with deionized water or distilled water used as a control. The number of seeds that germinated and root length were measured.

[0105] The effects of the fermentation products of Examples 1 to 3 and Comparative Example 1 on seed germination as fertilizers are shown in Tables 11 and Figures 8-9 shown. Figure 8 GI values with different amounts of biochar added.

[0106] Table 11 Effect of the fermentation products of Examples 1 to 3 and Comparative Example 1 as fertilizers on seed germination

[0107]

[0108] From Table 11 and Figures 8-9 The experimental results showed that the GI values of all treatments were significantly greater than 80% and significantly higher than the control. The GI value of T2(dc) was the highest, approximately twice that of the control. This indicates that adding biochar to the composted vegetable product is non-toxic and can significantly promote plant germination and growth.

[0109] Example 4

[0110] A method for composting vegetable waste, comprising the same steps as in Example 1, except that in step (2), biochar is added at a level of 5% of the total mass of the fermentation substrate (10 g of cabbage waste and 10 g of pine needles), and phosphogypsum is added at a level of 3% of the total mass of the fermentation substrate (10 g of cabbage waste and 10 g of pine needles). The amounts of glucose and water added in step (3) are detailed in Table 12.

[0111] Example 5

[0112] A method for composting vegetable waste, comprising the same steps as in Example 1, except that in step (2), biochar is added at a level of 5% of the total mass of the fermentation substrate (10 g of cabbage waste and 10 g of pine needles), and phosphogypsum is added at a level of 5% of the total mass of the fermentation substrate (10 g of cabbage waste and 10 g of pine needles). The amounts of glucose and water added in step (3) are detailed in Table 12.

[0113] Example 6

[0114] A method for composting vegetable waste, comprising the same steps as in Example 1, except that in step (2), biochar is added at a level of 5% of the total mass of the fermentation substrate (10 g of cabbage waste and 10 g of pine needles), and phosphogypsum is added at a level of 10% of the total mass of the fermentation substrate (10 g of cabbage waste and 10 g of pine needles). The amounts of glucose and water added in step (3) are detailed in Table 12.

[0115] Example 7

[0116] A method for composting vegetable waste, comprising the same steps as in Example 1, except that in step (2), biochar was added at a level of 5% of the total mass of the fermentation substrate (10 g of cabbage waste and 10 g of pine needles). The amounts of glucose and water added in step (3) are detailed in Table 12.

[0117] The addition amounts of phosphogypsum, glucose and water in Examples 4 to 7 are shown in Table 12.

[0118] Table 12 Addition amount of phosphogypsum, glucose and water in Examples 4 to 7

[0119]

[0120] Application Example 2

[0121] 1. Monitoring greenhouse gas (GHG) emissions during the fermentation process of Examples 4 to 7

[0122] Greenhouse gas (GHG) emissions were monitored using a gas chromatograph during the fermentation process. The results are shown in Tables 13 to 16 and Figures 10-13 shown. Figure 10 Statistical results of CO2 emission rate when different amounts of phosphogypsum are added to vegetable waste compost; Figure 11 Statistical results of cumulative CO2 emissions from vegetable waste compost with different amounts of phosphogypsum added; Figure 12 Statistical results of CH4 emission rate when different amounts of phosphogypsum are added to vegetable waste compost; Figure 13 Statistical results of cumulative CH4 emissions from vegetable waste compost with different amounts of phosphogypsum added.

[0123] Table 13 CO2 emission rate (mg.g) when different amounts of phosphogypsum were added to vegetable waste compost -1Cd -1 )

[0124] Fermentation time (d) 1 2 5 8 14 21 31 T-0 1.520 22.334 20.064 11.400 2.572 5.555 2.305 T-0” 2.204 13.638 19.331 10.939 9.706 6.496 3.561 T-0AVER 1.862 17.986 19.698 11.169 6.139 6.025 2.933 T-0STD 0.484 6.149 0.518 0.326 5.045 0.665 0.888 T-1 1.073 11.237 22.840 14.594 6.220 4.334 2.127 T-1” 1.184 2.888 23.995 23.115 8.646 7.017 5.751 T-1AVER 1.128 7.062 23.417 18.855 7.433 5.676 3.939 T-1STD 0.079 5.903 0.817 6.025 1.716 1.898 2.563 T-2 1.684 4.101 11.331 13.903 7.979 5.948 4.256 T-2” 1.953 5.936 16.674 26.211 13.594 10.680 4.376 T-2AVER 1.818 5.019 14.003 20.057 10.787 8.314 4.316 T-2STD 0.190 1.298 3.778 8.704 3.970 3.346 0.085 T-3 1.696 8.287 20.454 19.259 9.260 5.644 2.172 T-3” 2.179 5.665 12.290 22.636 12.765 10.181 3.885 T-3AVER 1.937 6.976 16.372 20.948 11.013 7.912 3.029 T-3STD 0.341 1.854 5.772 2.388 2.478 3.208 1.211

[0125] Note: In the table, T-0 refers to the T0(ck) treatment group, and T-0” corresponds to the T-0 parallel experimental group; T-1 refers to the T1(cp) treatment group, and T-1” corresponds to the T-1 parallel experimental group; T-2 refers to the T2(ch) treatment group, and T-2” corresponds to the T-2 parallel experimental group; T-3 refers to the T3(ct) treatment group, and T-3” corresponds to the T-3 parallel experimental group; STD is the standard deviation; AVER is the mean, the same below.

[0126] Table 14 Cumulative CO2 emissions from vegetable waste compost with different amounts of phosphogypsum added (mg / g)

[0127]

[0128]

[0129] Table 15 CH4 emission rate (mg.g) when different amounts of phosphogypsum were added to vegetable waste compost -1 Cd -1 )

[0130] Fermentation time (d) 1 2 5 8 14 21 31 T-0 0.014 0.009 0.000 0.000 0.014 0.000 0.000 T-0” 0.012 0.010 0.000 0.000 0.000 0.000 0.000 T-0AVER 0.013 0.009 0.000 0.000 0.007 0.000 0.000 T-0STD 0.002 0.001 0.000 0.000 0.010 0.000 0.000 T-1 0.012 0.010 0.000 0.000 0.000 0.000 0.000 T-1” 0.011 0.010 0.000 0.000 0.000 0.000 0.000 T-1AVER 0.011 0.010 0.000 0.000 0.000 0.000 0.000 T-1STD 0.001 0.000 0.000 0.000 0.000 0.000 0.000 T-2 0.021 0.013 0.000 0.000 0.000 0.000 0.000 T-2” 0.010 0.013 0.000 0.000 0.000 0.000 0.000 T-2AVER 0.015 0.013 0.000 0.000 0.000 0.000 0.000 T-2STD 0.008 0.000 0.000 0.000 0.000 0.000 0.000 T-3 0.008 0.009 0.014 0.007 0.000 0.000 0.000 T-3” 0.000 0.011 0.015 0.006 0.000 0.000 0.000 T-3AVER 0.004 0.010 0.014 0.006 0.000 0.000 0.000 T-3STD 0.006 0.001 0.000 0.000 0.000 0.000 0.000

[0131] Table 16 Cumulative CH4 emissions from vegetable waste compost with different amounts of phosphogypsum added (mg / g)

[0132]

[0133]

[0134] From Tables 13 to 16 and Figures 10-13Therefore, it cannot be concluded that the addition of phosphogypsum inhibits CO2 emission rates. For example, after the fifth day, CO2 emission rates after adding different amounts of phosphogypsum were higher than those in the control group without phosphogypsum. After adding phosphogypsum, CO2 emission rates initially increased, then decreased, and then stabilized. After treatment with different amounts of phosphogypsum, CO2 emission rates in the T1(cp) group were consistently higher than those in the control group at T0(ck). The final cumulative CO2 emissions in each treatment group after adding phosphogypsum were higher than those in the control group at T0(ck). Cumulative CO2 emissions increased significantly after adding phosphogypsum, and with the increase in phosphogypsum, cumulative CO2 emissions also increased, indicating that the addition of phosphogypsum reduced the carbon sequestration effect of biochar during the composting process. CH4 emission rates initially increased, then decreased, and finally stabilized with increasing composting days. The addition of phosphogypsum does not necessarily inhibit CH4 emission rates. CH4 emission rates decreased significantly after the fifth day, with almost no CH4 emissions in the middle and later stages. In the middle and late stages of composting, the cumulative CH4 emissions remained basically unchanged. The cumulative CH4 emissions in the T3(ct) group were higher than those in the control group T0(ck), while the cumulative CH4 emissions when 3% and 5% phosphogypsum were added were less than those in the control group, indicating that the addition of 10% phosphogypsum would increase CH4 emissions during composting.

[0135] 2. After fermentation, the hue coefficient (A600 / C) and optical density (E4 / E6) of the fermentation products of Examples 4 to 7 were measured by spectrophotometer.

[0136] Table 17 ΔlogK of fermentation products with different amounts of phosphogypsum added to vegetable waste compost

[0137] Processing abbreviation Grouping Hue coefficient (ΔlogK) Standard deviation T0(ck) D+5%C 0.53 0.00 T1(cp) D+5%C+3%P 0.38 0.01 T2(ch) D+5%C+5%P 0.34 0.02 T3 (ct) D+5%C+10%P 0.35 0.02

[0138] Table 18 E4 / E6 values of fermentation products of vegetable waste compost with different amounts of phosphogypsum added

[0139]

[0140]

[0141] From Tables 17 to 18 and Figures 14-15 The results show that the hue index decreased after adding phosphogypsum. With increasing phosphogypsum addition, the hue index initially decreased and then increased, with significant differences between treatments, indicating that the addition of phosphogypsum reduced compost maturity. The optical density initially decreased and then increased with the addition of phosphogypsum. The optical density values (E4 / E6) were all above 15, indicating that the addition of phosphogypsum significantly affected the compost maturity, reducing it.

[0142] 3. After fermentation, the total organic carbon (TOC) in the fermentation products of Examples 4 to 7 was determined using an elemental analyzer.

[0143] Table 19 Total organic carbon in the fermentation products of Examples 4 to 7 (mean ± standard deviation)

[0144] Grouping T0(ck) T1(cp) T2(ch) T3 (ct) Total organic carbon NPOC (mg) 8.4543±0.34a 3.2193±0.0091d 6.3886±0.62b 5.319±0.0068c

[0145] As can be seen from Table 19, the NPOC values in the compost products decreased after adding phosphogypsum, which also shows that the addition of phosphogypsum will affect the biological decomposition in the compost, thereby affecting the maturity of the compost and reducing the maturity of the compost.

[0146] 4. The heavy metal (HM) content in the fermentation products of Examples 4 to 7 was determined using an atomic absorption spectrometer.

[0147] Table 20 Heavy metal (HM) content in the fermentation products of Examples 4 to 7 (mg / g)

[0148] name T0(ck) T1(cp) T2(ch) T3 (ct) Arsenic AS 113.79±2.11 105.65±3.39 106.80±2.19 109.12±4.51 Bismuth Bi 95.96±1.75 122.48±8.58 56.55±1.73 258.48±6.44 CadmiumCd 0.27±0.02 0.25±0.04 0.22±0.02 0.24±0.03 Chromium Cr 5.64±0.28 12.82±1.38 3.27±0.12 5.27±0.21 Copper 64.52±2.27 32.03±0.07 36.43±0.42 44.10±0.19 Iron 16.40±0.04 4.37±0.33 3.29±0.20 0.65±0.02 Mercury 56.82±0.47 74.39±2.03 104.60±3.72 108.48±1.72 Manganese Mn 11.23±0.96 4.60±0.29 11.22±0.19 16.47±0.74 NickelNi 8.66±0.12 5.50±0.19 8.85±0.11 8.57±0.33 Lead 36.47±2.27 35.24±1.24 28.89±0.77 20.93±0.76 Zinc 9.69±0.07 7.67±0.17 6.34±0.17 5.61±0.16

[0149] As shown in Table 20, phosphogypsum may contain toxic metals such as cadmium, arsenic, chromium, lead and mercury, as well as radioactive elements such as uranium and radium, depending on the region. The presence of these impurities can have adverse effects on the environment [8]. Sugarcane bagasse biochar at lower temperatures can be applied to metal co-contaminated soils to reduce the combined effects of metal stress on microbial and biochemical functions. The experiment measured the addition of different amounts of phosphogypsum to biochar vegetable natural compost products. As the amount of phosphogypsum added increased, it was found that the content of elements such as Bi, Hg, and Ni increased; after the addition of phosphogypsum, the content of elements such as Cd, Cr, Fe, and Zn decreased. Excessive Fe can affect plant germination and growth. Excessive Fe may cause soil acidification and inhibit plant germination and growth. When 3% and 5% phosphogypsum were added, the Fe content was not much different from that of the control group. However, when 10% phosphogypsum was added, the Fe content decreased significantly, about 5 times less than that of the control group.

[0150] 5. Observe the effect of the fermentation products of Examples 4 to 7 as fertilizers on seed germination, and record the germination rate and germinated root length using the same method as in Application Example 1.

[0151] Table 21 Effect of the fermentation products of Examples 4 to 7 as fertilizers on seed germination

[0152] Processing abbreviation Grouping Average germination rate (100%) Root mean square length (mm) GI value (100%) T0(ck) T0(D+5%C) 60.00％ 22.52 61.74％ T1(cp) T1(D+5%C+3%P) 55.00％ 25.60 64.32％ T2(ch) T2(D+5%C+5%P) 51.67％ 16.97 40.05％ T3 (ct) T3(D+5%C+10%P) 65.00％ 29.92 88.87％ comparison water 76.67％ 28.55 100.00％

[0153] The effects of the fermentation products of Examples 4 to 7 as fertilizers on seed germination are shown in Tables 21 and Figure 16As shown, the addition of phosphogypsum significantly affects the GI (Glycerin Index) of biochar vegetable compost. It is generally believed that a GI greater than 50% indicates compost maturity, and a GI above 85% indicates compost is completely non-toxic to plants. When 3% and 5% phosphogypsum were added to the biochar vegetable compost, the GI values were less than 50%, indicating that the addition of phosphogypsum reduced compost maturity. However, when 10% phosphogypsum was added, the GI value reached 95%, indicating that the compost was fully mature and non-toxic to plants. The GI value indicates that the addition of 10% phosphogypsum to the compost was fully mature and essentially non-toxic to plants.

[0154] Although the above embodiment provides a detailed description of the present invention, it is only a part of the embodiments of the present invention, not all of the embodiments. People can also obtain other embodiments based on this embodiment without creativity, and these embodiments all fall within the scope of protection of the present invention.

Claims

1. Application of biochar and / or phosphogypsum in improved fermentation composting, characterized in that: The improved fermentation composting includes increasing the maturity of the compost and / or reducing greenhouse gas emissions during the composting process.

2. The application according to claim 1, characterized in that The fermentation substrate of the compost comprises vegetable waste.

3. The application according to claim 1, characterized in that The greenhouse gases include CO2 and / or CH4.

4. A composting method for improving compost maturity and / or reducing greenhouse gas emissions during composting, characterized in that: include: The fermentation substrate is mixed with biochar and / or phosphogypsum to obtain a compost material, and the compost material is subjected to composting fermentation.

5. The composting method according to claim 4, characterized in that: When a mixture of fermentation substrate and biochar is used as the compost material, the added amount of the biochar is 3% to 10% of the mass of the compost material.

6. The composting method according to claim 4, characterized in that: When a mixture of fermentation substrate, biochar and phosphogypsum is used as the compost material, the added amount of the biochar is 3% to 10% of the mass of the compost material, and the added amount of the phosphogypsum is 3% to 10% of the mass of the compost material.

7. The composting method according to claim 4, characterized in that: The composting fermentation temperature is 55° C.; the ventilation rate during the composting fermentation process is 0.15 L / min; and the composting fermentation time is 30 to 35 days.

8. The composting method according to claim 4, characterized in that: Before the composting fermentation is carried out, the carbon-nitrogen ratio of the compost material is adjusted to 25:

1.

9. The composting method according to claim 4, characterized in that: During composting fermentation, the moisture content of the compost material is adjusted to 60%.

10. The composting method according to claim 4, characterized in that: The fermentation substrate includes vegetable waste; the vegetable waste includes cabbage waste.

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