Method for promoting humification of kitchen waste compost

Abstract

The invention belongs to the technical field of vegetable fertilizers, and particularly relates to a method for promoting humification of kitchen waste compost. The method comprises the following steps: uniformly mixing kitchen waste serving as a composting raw material with a composting auxiliary material, and putting the mixture into a reactor for composting reaction; adjusting the initial carbon-nitrogen ratio of the mixed material to be 20-40 and the water content to be 50%-70%; the mass ratio of the compost raw material to the compost auxiliary material is 1: (2-4); in the mixing process of the compost raw material and the compost auxiliary material, adding charcoal into a reactor; adding mineral substances into the reactor when the reaction temperature is 50-60 DEG C; the addition amount of the mineral substances is 5%-15% of the total dry weight of the compost raw materials, the compost auxiliary materials and the biochar. The method for promoting humification of the kitchen waste compost provided by the invention can effectively solve the problems that the organic matters of the traditional kitchen waste compost are not stable enough and the humification efficiency is low.

Description

Technical Field

[0001] The invention belongs to the technical field of vegetable fertilizers, and in particular relates to a method for promoting the composting and humification of kitchen waste. Background Art

[0002] Kitchen waste contains high levels of nutrients such as carbohydrates, proteins, oils, and cellulose. The resource utilization of kitchen waste can not only reduce landfill and pollution, but also use these resources to improve soil quality and promote the development of renewable energy. For example, kitchen waste can be converted into biogas or turned into organic fertilizer through composting to reduce carbon emissions. Due to the high water content, high salt content, and high oil content of kitchen waste, which inhibit the growth of microorganisms, traditional kitchen waste composting has the problems of long processing cycle and low quality of compost products, which affects its resource utilization efficiency and economic benefits. Therefore, it is urgent to develop methods that can improve the efficiency and quality of kitchen waste composting.

[0003] Traditional kitchen waste composting has the problems of long composting cycle and poor product quality. The main reason is the low humification efficiency of composting. Traditional aerobic composting does not add any microbial agents, biochar, minerals and other additives, which will cause incomplete degradation of organic matter, insufficient treatment, and residues may cause pollution. Therefore, in order to improve the humification efficiency of kitchen waste composting, studies have shown that the composting process can be shortened by inoculating exogenous microorganisms, but there are problems such as unstable humification effect and insufficient duration of high temperature period of composting; studies have shown that precursor substances will have a certain impact on the relative molecular mass and structural complexity of humic acid. Through correlation analysis, it is found that phenols, carboxyls, amino acids, reducing sugars and humic acid show a significant negative correlation. Moderate regulation of humic acid precursors can also achieve the purpose of controlling the humification process, but there are problems such as high cost and difficulty in large-scale application.

[0004] In short, the traditional kitchen waste composting method has the problems of unstable compost organic matter and low humification efficiency. Summary of the invention

[0005] In order to solve the problems of unstable compost organic matter and low humification efficiency in the conventional kitchen waste composting method in the prior art, the present invention combines biochar and minerals and adds them to the kitchen waste composting process, extracts biochar and minerals in the composting process to promote compost humification and improve the quality of compost products, showing great advantages, and provides a new method for efficient humification of kitchen waste composting. To achieve the above purpose, the present invention adopts the following technical scheme.

[0006] The present invention provides a method for promoting composting and humification of kitchen waste, comprising the following steps:

[0007] Kitchen waste is used as a composting raw material, mixed evenly with composting auxiliary materials, and placed in a reactor for composting reaction; the initial carbon-nitrogen ratio of the mixed material is adjusted to 20-40 and the moisture content is 50%-70%; the mass ratio of the composting raw material to the composting auxiliary material is 1:2-4.

[0008] During the mixing process of the compost raw material and the compost auxiliary material, biochar is added into the reactor; the added amount of the biochar is 2% to 10% of the total dry weight of the compost raw material and the compost auxiliary material.

[0009] When the reaction temperature in the reactor is 50° C. to 60° C., minerals are added into the reactor; the added amount of the minerals is 5% to 15% of the total dry weight of the compost raw materials, the compost auxiliary materials and the biochar.

[0010] The composting reaction time is 20 to 60 days. During the composting reaction, the pile is turned over every 1 to 5 days. The method for promoting the humification of kitchen waste composting provided by the present invention adds biochar during the compost mixing process to adjust the compost pores and improve the microenvironment of the microbial community. At the same time, minerals are added during the high temperature period of the composting to promote microbial activity and accelerate the formation and accumulation of precursors. While promoting the humification effect of the composting, the stability of the organic matter content in the kitchen waste compost is ensured, so that the humification index of the final product is improved, the waste resources are more fully utilized, and the product quality is better. The method for promoting the humification of kitchen waste composting provided by the present invention can effectively solve the problems of insufficient stability of organic matter and low humification efficiency in traditional kitchen waste composting.

[0011] Preferably, during the composting reaction, an aeration system is synchronously provided for aeration; the aeration rate is set at 0.2L / min to 0.6L / min.

[0012] Preferably, the biochar is prepared using organic waste as raw material.

[0013] Biochar is a type of carbon-based material with extremely high carbon content, rich active functional groups, strong ion exchange capacity, high degree of aromatization and stable properties. Biochar-based materials have rich pore structures and surface oxygen-containing active groups, extremely high specific surface area, strong cation exchange capacity and stable chemical properties. They are multifunctional materials with strong adsorption capacity, which can change the charge and cation exchange capacity in compost and effectively fix nutrients such as N, P and K. The rich functional groups on the surface of biochar, such as carboxyl, hydroxyl, carbonyl and acyl, can be used as adsorption sites to adsorb humus to its surface and protect them from microbial decomposition to promote the humification process. Most of the humus in natural soil exists in the form of bound humus, that is, it combines with inorganic components of soil to form organic-inorganic complexes. The surface of clay minerals containing metal cations has a strong bridging effect and plays the most important role in the formation of clay mineral-humic acid complexes. Minerals act as catalysts and adsorbents to selectively preserve and protect organic matter through ligand exchange, hydrophobic interaction and cationic bridge bonds, Maillard reaction mechanism, and polyphenol theory. Studies have shown that metal oxides can be used as catalysts to promote the polycondensation reaction between phenols and amino acids during humification. Among them, the English abbreviation for cation exchange capacity is CEC.

[0014] Therefore, the present invention combines biochar and minerals and adds them to the kitchen waste composting process, extracting biochar and minerals in the compost to promote compost humification and improve the quality of compost products, showing great advantages, and provides a new method for efficient humification of kitchen waste composting.

[0015] The organic waste includes any one or more of biogas residue, distiller's grains, pig manure, kitchen waste and sludge. Biogas residue is a solid substance after anaerobic fermentation of organic matter. It is rich in organic matter, humic acid, and trace elements, and can improve the soil and provide the nutrients required for crop growth. Distiller's grains are a by-product of the winemaking process that contains rich crude protein, vitamins, trace elements, etc., which can improve soil structure and provide nutrients. Pig manure is rich in nutrients such as nitrogen, phosphorus, and potassium. Reasonable use can reduce the application of chemical fertilizers. Kitchen waste is perishable organic garbage generated by canteens, restaurants, etc., which can be applied to the field after composting to improve soil structure and promote crop growth. Sludge is rich in nitrogen, phosphorus, and potassium after aerobic fermentation, which can improve the water and fertilizer retention effect of the soil.

[0016] Preferably, the instrument conditions for preparing the biochar are as follows: a heating rate of 10°C / min to 15°C / min under nitrogen filling, a constant temperature of 480°C to 500°C, a constant temperature time of 2h to 3h, and a nitrogen flow rate of 90mL / min to 100mL / min.

[0017] Preferably, the mineral is any one or more of hematite, ferrihydrite, goethite, and metal manganese oxide, or any one of soil rich in iron or manganese and river silt that has been air-dried.

[0018] Among them, hematite is blue-gray in color and has a metallic luster. It can accelerate the degradation and humification of organic matter. Ferrihydrite is a reddish-brown spherical particle with a large specific surface area and high surface activity. It has a good adsorption and retention effect on soil organic matter during the composting process. Goethite is a common iron oxide mineral with good adsorption properties, which is mainly reflected in its adsorption capacity for organic matter and heavy metals. Metal manganese oxides are an important class of inorganic compounds that can improve the maturity of compost, reduce greenhouse gas emissions, and promote humification.

[0019] Preferably, the method for preparing the soil rich in iron or manganese comprises the following steps:

[0020] The collected soil containing the iron element or the manganese element is dried in the shade, the impurities are removed, the soil is ground, and the soil is passed through a sieve with an aperture of 1 mm to 4 mm to obtain the obtained soil.

[0021] Preferably, the method for preparing the air-dried river silt comprises the following steps:

[0022] Remove the impurities visible to the naked eye in the sludge, then dry the sludge in the shade, place it in a constant temperature environment of 48 to 52°C for drying, grind it, and pass it through a sieve with an aperture of 1mm to 4mm to obtain the product.

[0023] Preferably, the kitchen waste includes any one of kitchen waste from restaurants or canteens, leftover vegetables from farmers' markets, or household kitchen waste after garbage sorting. The present invention uses kitchen waste as compost raw material, fully utilizes kitchen waste, reduces environmental pollution, and promotes the recycling of organic matter.

[0024] Preferably, the composting auxiliary materials include any one or more of sawdust, straw, garden prunings, weeds, husks, cakes or other materials with low moisture content, looseness and high organic matter content. After being applied to the soil, the high organic matter content and looseness of the compost are conducive to increasing the water retention and aeration of the soil, reducing soil density, improving root penetration and plant growth conditions. Among them, the material with high organic matter content refers to the material with an organic matter content of ≥30%wt.

[0025] The present invention also provides a processing system for the method of promoting composting and humification of kitchen waste. The processing system comprises a reactor; a porous pad is placed in the bottom wall of the reactor, a water-absorbing material is arranged in the top wall of the reactor, and a sampling port is arranged in the side wall of the reactor.

[0026] The reactor is connected with a gas reaction bottle, a temperature sensor, a heater, a refrigerator, a leachate collection bottle, and an air intake fan. A gas flow meter is provided between the reactor and the air intake fan; the temperature sensor, the heater, the refrigerator, the gas flow meter, and the air intake fan are all electrically connected to the control center; the control center is arranged outside the reactor. When carrying out the composting reaction, the composting raw materials and the composting auxiliary materials are first placed in the reactor, a water-absorbing material is attached to the upper part of the reactor, a porous pad is placed at the bottom of the reactor, a sampling port is provided on the side wall, and condensed water, leachate and gas can be collected. The temperature sensor extends into the top of the box through the water-absorbing material and the reactor, and the gas flow meter is connected to the air intake port of the air intake fan. The temperature sensor and the gas flow meter are controlled by the control center.

[0027] The above-mentioned method provided by the present invention can be used for the composting reaction of kitchen waste. During the composting process, only the composting raw materials and composting auxiliary materials need to be placed in the reactor, and the temperature sensor 2 and the gas flow meter are controlled by the control center to ensure that the composting reaction process proceeds normally.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] The present invention provides a method for promoting the humification of kitchen waste composting. The present invention adds biochar during the compost mixing process to adjust the compost porosity and improve the microenvironment of the microbial community. At the same time, minerals are added during the high temperature period of the composting to promote microbial activity and accelerate the formation and accumulation of precursors. While promoting the humification effect of the composting, the stability of the organic matter content in the kitchen waste compost is ensured, so that the humification index of the final product is improved, the waste resources are more fully utilized, and the product quality is better. The method for promoting the humification of kitchen waste composting provided by the present invention can effectively solve the problems of insufficient stability of organic matter in traditional kitchen waste composting and low humification efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of the structure of the system for promoting the composting and humification treatment of kitchen waste in the present invention.

[0031] Explanation of the reference numerals: 1-gas reaction bottle, 2-temperature sensor, 3-water absorbing material, 4-control center, 5-sampling port, 6-leachate collecting bottle, 7-porous pad, 8-gas flow meter and 9-intake fan. DETAILED DESCRIPTION

[0032] The present invention is described in detail below in conjunction with the accompanying drawings and specific examples, but should not be construed as limiting the present invention. Unless otherwise specified, the technical means used in the following examples are conventional means well known to those skilled in the art, and the materials, reagents, etc. used in the following examples, unless otherwise specified, can be obtained from commercial sources.

[0033] Example 1

[0034] A method for promoting composting and humification of kitchen waste comprises the following steps:

[0035] (1) Biochar burning

[0036] The raw material of biochar is an organic waste: pig manure. The preparation method of biochar is: place the dried pig manure in a vacuum atmosphere furnace with a nitrogen flow rate of 100mL / min and pyrolyze it at 500℃ for 3h; the obtained pig manure-based biochar is called biochar. The prepared biochar is ground through a 2mm sieve and stored for later use.

[0037] The heating rate in the vacuum atmosphere furnace is 15°C / min.

[0038] Firing conditions: heating rate of 15°C / min, constant temperature of 500°C, and constant temperature time of 3h under nitrogen filling.

[0039] The basic properties of the prepared biochar are shown in Table 1.

[0040] Table 1 Basic properties of biochar

[0041]

[0042] Note: TC refers to total carbon; TN refers to total nitrogen; C / N refers to carbon-nitrogen ratio; EC refers to electrical conductivity.

[0043] (2) Preparation of minerals

[0044] The mineral is goethite, and its preparation method comprises the following steps:

[0045] 1 mol / L KOH solution and 1 mol / L Fe(NO3)3 solution were quickly mixed and stirred, and placed in a constant temperature furnace at 70°C for 60 hours. The obtained precipitate was centrifuged at 3500 rpm for 5 minutes, and the lower precipitate was collected; the collected precipitate was rinsed with pure water and dried to obtain goethite for later use.

[0046] (3) Aerobic composting operation

[0047] Kitchen waste is used as the composting raw material. After being crushed into 20 mm, it is evenly mixed with composting auxiliary materials and placed in a reactor for composting reaction; the initial C / N of the mixed material is adjusted to 22 and the moisture content is 55wt%; the aeration rate is set to 0.4L / min.

[0048] Among them, the mass ratio of composting raw materials to composting auxiliary materials is 1:3.

[0049] The kitchen waste is a mixture of rice, vegetables and meat residues, which comes from the canteen of Suzhou Organic Recycling Research Institute of China Agricultural University.

[0050] The composting auxiliary material is wood chips, the diameter of which is 20 mm and comes from Suzhou Timber Factory.

[0051] C / N is the carbon-nitrogen ratio.

[0052] During the mixing process of the compost raw materials and the compost auxiliary materials, the biochar prepared as above is added into the reactor; the amount of the biochar added is 4% of the total dry weight of the compost raw materials and the compost auxiliary materials.

[0053] When the reaction temperature is 60° C., the minerals prepared above are added into the reactor; the amount of the minerals added is 8% of the total dry weight of the compost raw materials, compost auxiliary materials and biochar.

[0054] The composting reaction time is 60 days. During the composting reaction period, the pile is turned over every 3 days.

[0055] The above composting reaction is carried out based on a system for promoting the composting and humification of kitchen waste. During the composting reaction, the composting raw materials and the composting auxiliary materials are placed in a reactor in the system for promoting the composting and humification of kitchen waste, and then other devices in the system for promoting the composting and humification of kitchen waste are used in coordination to jointly promote the normal progress of the composting reaction.

[0056] The system for promoting the composting and humification of kitchen waste includes a reactor; the reactor is a polyvinyl chloride reactor. A porous pad 7 is placed in the bottom wall of the reactor. The porous pad 7 is a flat material with evenly distributed pores, which play a role of air permeability to ensure the even distribution of oxygen. At the same time, the porous pad 7 separates the compost material from direct contact with the box. The porous pad 7 is a polypropylene PP perforated plate with a thickness of 3 mm, 40 cm*60 cm, and a pore size of 0.5 cm, purchased from Pingxiang Huanxing Chemical Packing Tower Internals Co., Ltd., Jiangxi Province.

[0057] The top wall of the reactor is provided with a water-absorbing material 3, which is mainly used to maintain the appropriate humidity inside the compost. These materials can absorb excess water and maintain the ventilation inside the compost. Its structure is porous and uses a 1 cm thick PVA water-absorbing sponge sheet. The water-absorbing sponge is purchased from Shenzhen Xingya Sponge Products Co., Ltd.

[0058] The side wall of the reactor is provided with a sampling port 5, which is used to extract sample structure from the compost in the reactor so as to monitor and analyze the maturity and composition changes of the compost. The sampling port 5 is located on both sides of the reactor. The reactor wall is made of stainless steel with good sealing properties to adapt to the moisture and microbial erosion in the composting environment.

[0059] The reactor is connected with a gas reaction bottle 1, a temperature sensor 2, a leachate collection bottle 6, and an air intake fan 9.

[0060] The gas reaction bottle 1 is a container for collecting gas generated during the composting process. The material is made of translucent glass with the characteristics of corrosion resistance and sealing. The connection interface is connected to the inside of the compost box.

[0061] The temperature sensor 2 uses Pt100 as the temperature measuring element, with a 316 stainless steel probe rod encapsulated externally, and the conductor is filled with heat-conducting and insulating materials, and is controlled by the control center 4. The temperature sensor 2 extends into the top of the box through the water-absorbing material 3 and the reactor.

[0062] The leachate collecting bottle 6 is made of translucent glass, has good sealing performance, is connected to the bottom of the box body, and has corrosion resistance. The leachate collecting bottle 6 is used to collect the leachate generated by the reaction in the reactor.

[0063] The air inlet fan 9 is used to transport gas into the reactor.

[0064] Furthermore, a gas flow meter 8 is provided between the reactor and the air intake fan 9, and the gas flow meter 8 is connected to the air intake port of the air intake fan 9. The gas flow meter 8 uses an ultrasonic flow meter to measure the air intake volume of the air intake fan. The amount and rate of gas delivered by the air intake fan 9 to the reactor are adjusted in time according to the gas flow in the reactor displayed by the gas flow meter 8.

[0065] The temperature sensor 2 and the air intake fan 9 are electrically connected to the control center 4. The control center 4 is also electrically connected to a heater and a refrigerator. The heater and the refrigerator can be conventional heaters and refrigerators used in bioreactors.

[0066] The control center 4 is arranged on the outer wall of the reactor. The control center 4 is a controller, which adopts an STM32 single chip microcomputer. The controller is provided with switches for controlling the temperature sensor 2, the heater and the refrigerator, and the gas flow meter 8 respectively. The temperature sensor 2 senses the temperature in the reactor at any time and transmits the signal to the controller. If the temperature changes, the controller controls the heater and the refrigerator to start working, so that the temperature in the reactor is always at a temperature suitable for the normal composting reaction.

[0067] When composting, the compost raw materials and compost auxiliary materials are placed on the porous pad 7 at the bottom of the reactor. During the composting process, the excess water generated is absorbed by the water-absorbing material 3 attached to the upper part of the reactor, which can ensure that the compost in the reactor is maintained at a humidity suitable for the reaction to a certain extent. At the same time, the temperature sensor 2 senses the temperature in the reactor at any time and transmits the signal to the controller. If the temperature changes, the controller controls the heater and the refrigerator to start working, so that the temperature in the reactor is always at a temperature suitable for the normal composting reaction.

[0068] The gas flow meter 8 displays the gas flow in the reactor at any time. When the gas flow meter 8 displays that the gas flow in the reactor exceeds the upper limit, the controller controls the air intake fan 9 to reduce the gas flow and speed delivered to the reactor.

[0069] The leachate or condensed water generated during the reaction is collected by the leachate collecting bottle 6 .

[0070] The sample produced by the reaction can be taken out from the sampling port 5, thereby facilitating the monitoring and analysis of the maturity and composition changes of the compost.

[0071] The gas delivered into the reactor by the air inlet blower 9 is air.

[0072] Example 2

[0073] A method for promoting composting and humification of kitchen waste comprises the following steps:

[0074] (1) Biochar burning

[0075] The raw material of biochar is an organic waste: pig manure. The preparation method of biochar is the same as that of Example 1.

[0076] (2) Preparation of minerals

[0077] The mineral is ferrihydrite, and its preparation method comprises the following steps:

[0078] 1 mol·L -1 Adjust the pH of Fe(NO3)3·9H2O to 7 with NaOH; shake at 200 rpm for 24 hours and centrifuge at 3200 rpm for 5 minutes. Wash the solid with ionized water and add pure water to make ferrihydrite. The ferrite suspension sample was stored in a refrigerator at 4℃ and used within 2 days after synthesis.

[0079] (3) Aerobic composting operation

[0080] Kitchen waste was used as the compost raw material, crushed to 20 mm, mixed evenly with compost auxiliary materials, and placed in a reactor for composting reaction; the initial C / N of the mixed material was adjusted to 23 and the moisture content was 57%; the mass ratio of the compost raw material to the compost auxiliary material was 1:3. The aeration rate was set to 0.4 L / min.

[0081] The kitchen waste is mixed food residues of rice, vegetables and meat, and its source is the same as that in Example 1.

[0082] The composting auxiliary materials are the same as those in Example 1.

[0083] During the mixing process of the compost raw materials and the compost auxiliary materials, the biochar prepared as above is added into the reactor; the amount of biochar added is 6% of the total dry weight of the compost raw materials and the compost auxiliary materials.

[0084] When the reaction temperature is 60° C., the minerals prepared above are added into the reactor; the amount of the minerals added is 10% of the total dry weight of the compost raw materials, the compost auxiliary materials and the biochar.

[0085] The composting reaction time is 60 days. During the composting reaction period, the pile is turned over every 3 days.

[0086] The above composting reaction is carried out based on a system for promoting the composting and humification of kitchen waste, wherein the system for promoting the composting and humification of kitchen waste and its working principle are the same as those in Example 1.

[0087] Example 3

[0088] A method for promoting composting and humification of kitchen waste comprises the following steps:

[0089] (1) Biochar burning

[0090] The raw material of biochar is an organic waste: pig manure. The preparation method of biochar is the same as that of Example 1.

[0091] (2) Preparation of minerals

[0092] The mineral is hematite, and its preparation method comprises the following steps:

[0093] First, ferrous chloride, sodium nitrite and hexamethylenetetramine were used to prepare the scaly marble sample according to the following steps: 20g FeCl2·4H2O, 28g (CH2)6N4 and 7g NaNO2 were dissolved in 400mL, 80mL and 80mL distilled water respectively; the three solutions were fully mixed to form a blue-green precipitate; the precipitate was left in the solution, aged at 65°C for 3h, then centrifuged, washed three times with 95% alcohol by volume and three times with distilled water to remove anions and organic impurities; the precipitate was dried at 65°C for 48h to become a dehydrated gel, which was ground into -FeOOH; then the -FeOOH sample was sintered at 420°C for 2h. The final product is hematite. Among them, the chemical name of scaly marble is FeOOH. The chemical name of ferrous chloride is FeCl2·4H2O. The chemical name of sodium nitrite is NaNO 2) The chemical name of hexamethylenetetramine is (CH2)6N4.

[0094] (3) Aerobic composting operation

[0095] Kitchen waste was used as the compost raw material, crushed to 20 mm, mixed evenly with compost auxiliary materials, and placed in a reactor for composting reaction; the initial C / N of the mixed material was adjusted to 24 and the moisture content was 59%; the mass ratio of the compost raw material to the compost auxiliary material was 1:3. The aeration rate was set to 0.4 L / min.

[0096] The kitchen waste is mixed food residues of rice, vegetables and meat, and its source is the same as that in Example 1.

[0097] The composting auxiliary materials are the same as those in Example 1.

[0098] During the mixing process of the compost raw materials and the compost auxiliary materials, the biochar prepared as above is added into the reactor; the amount of biochar added is 8% of the total dry weight of the compost raw materials and the compost auxiliary materials.

[0099] When the reaction temperature is 60° C., the minerals prepared above are added into the reactor; the amount of the minerals added is 12% of the total dry weight of the compost raw materials, the compost auxiliary materials and the biochar.

[0100] The composting reaction time is 60 days. During the composting reaction period, the pile is turned over every 3 days.

[0101] The above composting reaction is carried out based on a system for promoting the composting and humification of kitchen waste, wherein the system for promoting the composting and humification of kitchen waste and its working principle are the same as those in Example 1.

[0102] Example 4

[0103] A method for promoting composting and humification of kitchen waste comprises the following steps:

[0104] (4) Biochar burning

[0105] The raw material of biochar is an organic waste: pig manure. The preparation method of biochar is the same as that of Example 1.

[0106] (1) Preparation of minerals

[0107] The mineral is manganese dioxide, and its preparation method comprises the following steps:

[0108] MnO2 was ground into powder by ball mill for 6 hours for later use.

[0109] (2) Aerobic composting operation

[0110] Kitchen waste was used as the compost raw material, crushed to 40 mm, mixed evenly with compost auxiliary materials, and placed in a reactor for composting reaction; the initial C / N of the mixed material was adjusted to 25 and the moisture content was 61%; the mass ratio of the compost raw material to the compost auxiliary material was 1:3. The aeration rate was set to 0.4 L / min.

[0111] The kitchen waste is mixed food residues of rice, vegetables and meat, and its source is the same as that in Example 1.

[0112] The composting auxiliary materials are the same as those in Example 1.

[0113] During the mixing process of the compost raw materials and the compost auxiliary materials, the biochar prepared as above is added into the reactor; the amount of biochar added is 10% of the total dry weight of the compost raw materials and the compost auxiliary materials.

[0114] When the reaction temperature is 60° C., the minerals prepared above are added into the reactor; the amount of the minerals added is 5% of the total dry weight of the compost raw materials, compost auxiliary materials and the biochar.

[0115] The composting reaction time is 60 days. During the composting reaction period, the pile is turned over every 3 days.

[0116] The above composting reaction is carried out based on a system for promoting the composting and humification of kitchen waste, wherein the system for promoting the composting and humification of kitchen waste and its working principle are the same as those in Example 1.

[0117] Example 5

[0118] A method for promoting composting and humification of kitchen waste comprises the following steps:

[0119] (1) Biochar burning

[0120] The raw material of biochar is an organic waste: biogas residue. The preparation method of biochar is as follows: the dried biogas residue is placed in a vacuum atmosphere furnace with a nitrogen flow rate of 100 mL / min and pyrolyzed at 500°C for 3 hours; the obtained biogas residue-based biochar is ground through a 2 mm sieve and stored for later use.

[0121] The heating rate in the vacuum atmosphere furnace is 15°C / min.

[0122] Firing conditions: heating rate under nitrogen is 15°C / min, constant temperature is 500°C, constant temperature time is 3h, and nitrogen flow rate is 100mL / min.

[0123] The basic properties of the prepared biochar are shown in Table 1.

[0124] (2) Preparation of minerals

[0125] The mineral is goethite, and its preparation method is shown in Example 1.

[0126] (3) Aerobic composting operation

[0127] Kitchen waste was used as the compost raw material, crushed to 20 mm, mixed evenly with compost auxiliary materials, and placed in a reactor for composting reaction; the initial C / N of the mixed material was adjusted to 22 and the moisture content was 63%; the mass ratio of the compost raw material to the compost auxiliary material was 1:3. The aeration rate was set to 0.4 L / min.

[0128] Among them, the kitchen waste and composting auxiliary materials are the same as those in Example 1.

[0129] During the mixing process of the compost raw materials and the compost auxiliary materials, the biochar prepared as above is added into the reactor; the amount of biochar added is 4% of the total dry weight of the compost raw materials and the compost auxiliary materials.

[0130] When the reaction temperature is 60° C., the minerals prepared above are added into the reactor; the amount of the minerals added is 8% of the total dry weight of the compost raw materials, compost auxiliary materials and the biochar.

[0131] The composting reaction time is 60 days. During the composting reaction period, the pile is turned over every 3 days.

[0132] The above composting reaction is carried out based on a system for promoting the composting and humification of kitchen waste. During the composting reaction, the composting raw materials and the composting auxiliary materials are placed in a reactor in the system for promoting the composting and humification of kitchen waste, and then other devices in the system for promoting the composting and humification of kitchen waste are used in combination to jointly promote the normal progress of the composting reaction. The system for promoting the composting and humification of kitchen waste is the same as that in Example 1.

[0133] Example 6

[0134] A method for promoting composting and humification of kitchen waste comprises the following steps:

[0135] (2) Biochar burning

[0136] The raw material of biochar is a kind of organic waste: biogas residue. The preparation method of biochar is the same as that of Example 5.

[0137] (2) Preparation of minerals

[0138] The mineral is ferrihydrite, and its preparation method is shown in Example 2.

[0139] (3) Aerobic composting operation

[0140] Kitchen waste was used as the compost raw material, crushed to 20 mm, mixed evenly with compost auxiliary materials, and placed in a reactor for composting reaction; the initial C / N of the mixed material was adjusted to 23 and the moisture content was 55%; the mass ratio of the compost raw material to the compost auxiliary material was 1:3. The aeration rate was set to 0.4 L / min.

[0141] Among them, the kitchen waste and composting auxiliary materials are the same as those in Example 1.

[0142] During the mixing process of the compost raw materials and the compost auxiliary materials, the biochar prepared as above is added into the reactor; the amount of biochar added is 6% of the total dry weight of the compost raw materials and the compost auxiliary materials.

[0143] When the reaction temperature is 60° C., the minerals prepared above are added into the reactor; the amount of the minerals added is 10% of the total dry weight of the compost raw materials, the compost auxiliary materials and the biochar.

[0144] The composting reaction time is 60 days. During the composting reaction period, the pile is turned over every 3 days.

[0145] The above composting reaction is carried out based on a system for promoting the composting and humification of kitchen waste, wherein the system for promoting the composting and humification of kitchen waste and its working principle are the same as those in Example 1.

[0146] Example 7

[0147] A method for promoting composting and humification of kitchen waste comprises the following steps:

[0148] (1) Biochar burning

[0149] The raw material of biochar is a kind of organic waste: biogas residue. The preparation method of biochar is the same as that of Example 5.

[0150] (2) Preparation of minerals

[0151] The mineral is hematite, and its preparation method is shown in Example 3.

[0152] (3) Aerobic composting operation

[0153] Kitchen waste was used as the compost raw material, crushed to 20 mm, mixed evenly with compost auxiliary materials, and placed in a reactor for composting reaction; the initial C / N of the mixed material was adjusted to 24 and the moisture content was 57%; the mass ratio of the compost raw material to the compost auxiliary material was 1:3. The aeration rate was set to 0.4 L / min.

[0154] Among them, the kitchen waste and composting auxiliary materials are the same as those in Example 1.

[0155] During the mixing process of the compost raw materials and the compost auxiliary materials, the biochar prepared as above is added into the reactor; the amount of biochar added is 8% of the total dry weight of the compost raw materials and the compost auxiliary materials.

[0156] When the reaction temperature is 60° C., the minerals prepared above are added into the reactor; the amount of the minerals added is 12% of the total dry weight of the compost raw materials, the compost auxiliary materials and the biochar.

[0157] The composting reaction time is 60 days. During the composting reaction period, the pile is turned over every 3 days.

[0158] The above composting reaction is carried out based on a system for promoting the composting and humification of kitchen waste, wherein the system for promoting the composting and humification of kitchen waste and its working principle are the same as those in Example 1.

[0159] Example 8

[0160] A method for promoting composting and humification of kitchen waste comprises the following steps:

[0161] (1) Biochar burning

[0162] The raw material of biochar is a kind of organic waste: biogas residue. The preparation method of biochar is the same as that of Example 5.

[0163] (2) Preparation of minerals

[0164] The mineral is manganese dioxide, and its preparation method is shown in Example 4.

[0165] (3) Aerobic composting operation

[0166] Kitchen waste was used as the compost raw material, crushed to 20 mm, mixed evenly with compost auxiliary materials, and placed in a reactor for composting reaction; the initial C / N of the mixed material was adjusted to 25 and the moisture content was 59%; the mass ratio of the compost raw material to the compost auxiliary material was 1:3. The aeration rate was set to 0.4 L / min.

[0167] Among them, the kitchen waste and composting auxiliary materials are the same as those in Example 1.

[0168] During the mixing process of the compost raw materials and the compost auxiliary materials, the biochar prepared as above is added into the reactor; the amount of biochar added is 10% of the total dry weight of the compost raw materials and the compost auxiliary materials.

[0169] When the reaction temperature is 60° C., the minerals prepared above are added into the reactor; the amount of the minerals added is 5% of the total dry weight of the compost raw materials, compost auxiliary materials and the biochar.

[0170] The composting reaction time is 60 days. During the composting reaction period, the pile is turned over every 3 days.

[0171] The above composting reaction is carried out based on a system for promoting the composting and humification of kitchen waste, wherein the system for promoting the composting and humification of kitchen waste and its working principle are the same as those in Example 1.

[0172] Example 9

[0173] A method for promoting composting and humification of kitchen waste comprises the following steps:

[0174] (1) Biochar burning

[0175] The raw material of biochar is an organic waste: wine lees. The preparation method of biochar is as follows: the dried wine lees are placed in a vacuum atmosphere furnace with a nitrogen flow rate of 100 mL / min and pyrolyzed at 500°C for 3 hours; the obtained wine lees-based biochar is ground through a 2 mm sieve and stored for later use.

[0176] The heating rate in the vacuum atmosphere furnace is 15°C / min.

[0177] Firing conditions: heating rate under nitrogen is 15°C / min, constant temperature is 500°C, constant temperature time is 3h, and nitrogen flow rate is 100mL / min.

[0178] The basic properties of the prepared biochar are shown in Table 1.

[0179] (2) Preparation of minerals

[0180] The mineral is goethite, and its preparation method is shown in Example 1.

[0181] (3) Aerobic composting operation

[0182] Kitchen waste was used as the compost raw material, crushed to 40 mm, mixed evenly with compost auxiliary materials, and placed in a reactor for composting reaction; the initial C / N of the mixed material was adjusted to 22 and the moisture content was 61%; the mass ratio of the compost raw material to the compost auxiliary material was 1:3. The aeration rate was set to 0.4 L / min.

[0183] Among them, the kitchen waste and composting auxiliary materials are the same as those in Example 1.

[0184] During the mixing process of the compost raw materials and the compost auxiliary materials, the biochar prepared as above is added into the reactor; the amount of biochar added is 4% of the total dry weight of the compost raw materials and the compost auxiliary materials.

[0185] When the reaction temperature is 60° C., the minerals prepared above are added into the reactor; the amount of the minerals added is 8% of the total dry weight of the compost raw materials, compost auxiliary materials and the biochar.

[0186] The composting reaction time is 60 days. During the composting reaction period, the pile is turned over every 3 days.

[0187] The above composting reaction is carried out based on a system for promoting the composting and humification of kitchen waste, wherein the system for promoting the composting and humification of kitchen waste and its working principle are the same as those in Example 1.

[0188] Example 10

[0189] A method for promoting composting and humification of kitchen waste comprises the following steps:

[0190] (1) Biochar burning

[0191] The raw material of biochar is an organic waste: wine lees. The preparation method of biochar is the same as that of Example 9.

[0192] (2) Preparation of minerals

[0193] The mineral is ferrihydrite, and its preparation method is shown in Example 2.

[0194] (3) Aerobic composting operation

[0195] Kitchen waste was used as the compost raw material, crushed to 20 mm, mixed evenly with compost auxiliary materials, and placed in a reactor for composting reaction; the initial C / N of the mixed material was adjusted to 23 and the moisture content was 63%; the mass ratio of the compost raw material to the compost auxiliary material was 1:3. The aeration rate was set to 0.4 L / min.

[0196] Among them, the kitchen waste and composting auxiliary materials are the same as those in Example 1.

[0197] During the mixing process of the compost raw materials and the compost auxiliary materials, the biochar prepared as above is added into the reactor; the amount of biochar added is 6% of the total dry weight of the compost raw materials and the compost auxiliary materials.

[0198] When the reaction temperature is 60° C., the minerals prepared above are added into the reactor; the amount of the minerals added is 10% of the total dry weight of the compost raw materials, the compost auxiliary materials and the biochar.

[0199] The composting reaction time is 60 days. During the composting reaction period, the pile is turned over every 3 days.

[0200] The above composting reaction is carried out based on a system for promoting the composting and humification of kitchen waste, wherein the system for promoting the composting and humification of kitchen waste and its working principle are the same as those in Example 1.

[0201] Embodiment 11

[0202] A method for promoting composting and humification of kitchen waste comprises the following steps:

[0203] (1) Biochar burning

[0204] The raw material of biochar is an organic waste: wine lees. The preparation method of biochar is the same as that of Example 9.

[0205] (2) Preparation of minerals

[0206] The mineral is hematite, and its preparation method is shown in Example 3.

[0207] (3) Aerobic composting operation

[0208] Kitchen waste was used as the compost raw material, crushed to 20 mm, mixed evenly with compost auxiliary materials, and placed in a reactor for composting reaction; the initial C / N of the mixed material was adjusted to 24 and the moisture content was 55%; the mass ratio of the compost raw material to the compost auxiliary material was 1:3. The aeration rate was set to 0.4 L / min.

[0209] Among them, the kitchen waste and composting auxiliary materials are the same as those in Example 1.

[0210] During the mixing process of the compost raw materials and the compost auxiliary materials, the biochar prepared as above is added into the reactor; the amount of biochar added is 8% of the total dry weight of the compost raw materials and the compost auxiliary materials.

[0211] When the reaction temperature is 60° C., the minerals prepared above are added into the reactor; the amount of the minerals added is 12% of the total dry weight of the compost raw materials, compost auxiliary materials and the biochar.

[0212] The composting reaction time is 60 days. During the composting reaction period, the pile is turned over every 3 days.

[0213] The above composting reaction is carried out based on a system for promoting the composting and humification of kitchen waste, wherein the system for promoting the composting and humification of kitchen waste and its working principle are the same as those in Example 1.

[0214] Example 12

[0215] A method for promoting composting and humification of kitchen waste comprises the following steps:

[0216] (1) Biochar burning

[0217] The raw material of biochar is an organic waste: wine lees. The preparation method of biochar is the same as that of Example 9.

[0218] (2) Preparation of minerals

[0219] The mineral is manganese dioxide, and its preparation method is shown in Example 4.

[0220] (3) Aerobic composting operation

[0221] Kitchen waste was used as the compost raw material, crushed to 20 mm, mixed evenly with compost auxiliary materials, and placed in a reactor for composting reaction; the initial C / N of the mixed material was adjusted to 25 and the moisture content was 57%; the mass ratio of the compost raw material to the compost auxiliary material was 1:3. The aeration rate was set to 0.4 L / min.

[0222] Among them, the kitchen waste and composting auxiliary materials are the same as those in Example 1.

[0223] During the mixing process of the compost raw materials and the compost auxiliary materials, the biochar prepared as above is added into the reactor; the amount of biochar added is 10% of the total dry weight of the compost raw materials and the compost auxiliary materials.

[0224] When the reaction temperature is 60° C., the minerals prepared above are added into the reactor; the amount of the minerals added is 5% of the total dry weight of the compost raw materials, compost auxiliary materials and the biochar.

[0225] The composting reaction time is 60 days. During the composting reaction period, the pile is turned over every 3 days.

[0226] The above composting reaction is carried out based on a system for promoting the composting and humification of kitchen waste, wherein the system for promoting the composting and humification of kitchen waste and its working principle are the same as those in Example 1.

[0227] Embodiment 13

[0228] A method for promoting composting and humification of kitchen waste comprises the following steps:

[0229] (1) Biochar burning

[0230] The raw material for biochar is an organic waste: sludge.

[0231] Preparation of sludge: First, remove the visible impurities in the sludge, then dry the sludge in the shade indoors, place it in a constant temperature environment of 50℃, and grind the air-dried sludge so that it can all pass through a 2mm aperture sieve.

[0232] The preparation method of biochar is as follows: the dried sludge is placed in a vacuum atmosphere furnace with a nitrogen flow rate of 100 mL / min and pyrolyzed at 500°C for 3 h; the obtained sludge-based biochar is ground through a 2 mm sieve and stored for later use.

[0233] The heating rate in the vacuum atmosphere furnace is 15°C / min.

[0234] Firing conditions: heating rate under nitrogen is 15°C / min, constant temperature is 500°C, constant temperature time is 3h, and nitrogen flow rate is 100mL / min.

[0235] The basic properties of the prepared biochar are shown in Table 1.

[0236] (2) Preparation of minerals

[0237] The mineral is goethite, and its preparation method is shown in Example 1.

[0238] (3) Aerobic composting operation

[0239] Kitchen waste was used as the compost raw material, crushed to 20 mm, mixed evenly with compost auxiliary materials, and placed in a reactor for composting reaction; the initial C / N of the mixed material was adjusted to 22 and the moisture content was 59%; the mass ratio of the compost raw material to the compost auxiliary material was 1:3. The aeration rate was set to 0.4 L / min.

[0240] Among them, the kitchen waste and composting auxiliary materials are sawdust as in Example 1.

[0241] During the mixing process of the compost raw materials and the compost auxiliary materials, the biochar prepared as above is added into the reactor; the amount of biochar added is 4% of the total dry weight of the compost raw materials and the compost auxiliary materials.

[0242] When the reaction temperature is 60° C., the minerals prepared above are added into the reactor; the amount of the minerals added is 8% of the total dry weight of the compost raw materials, compost auxiliary materials and the biochar.

[0243] The composting reaction time is 60 days. During the composting reaction period, the pile is turned over every 3 days.

[0244] The above composting reaction is carried out based on a system for promoting the composting and humification of kitchen waste, wherein the system for promoting the composting and humification of kitchen waste and its working principle are the same as those in Example 1.

[0245] Embodiment 14

[0246] A method for promoting composting and humification of kitchen waste comprises the following steps:

[0247] (1) Biochar burning

[0248] The raw material for biochar is an organic waste: sludge.

[0249] Preparation of sludge: same as Example 13.

[0250] The preparation method of biochar is the same as that in Example 13.

[0251] (2) Preparation of minerals

[0252] The mineral is ferrihydrite, and its preparation method is shown in Example 2.

[0253] (3) Aerobic composting operation

[0254] Kitchen waste was used as the compost raw material, crushed to 20 mm, mixed evenly with compost auxiliary materials, and placed in a reactor for composting reaction; the initial C / N of the mixed material was adjusted to 23 and the moisture content was 61%; the mass ratio of the compost raw material to the compost auxiliary material was 1:3. The aeration rate was set to 0.4 L / min.

[0255] Among them, the kitchen waste and composting auxiliary materials are the same as those in Example 1.

[0256] During the mixing process of the compost raw materials and the compost auxiliary materials, the biochar prepared as above is added into the reactor; the amount of biochar added is 6% of the total dry weight of the compost raw materials and the compost auxiliary materials.

[0257] When the reaction temperature is 60° C., the minerals prepared above are added into the reactor; the amount of the minerals added is 10% of the total dry weight of the compost raw materials, the compost auxiliary materials and the biochar.

[0258] The composting reaction time is 60 days. During the composting reaction period, the pile is turned over every 3 days.

[0259] The above composting reaction is carried out based on a system for promoting the composting and humification of kitchen waste, wherein the system for promoting the composting and humification of kitchen waste and its working principle are the same as those in Example 1.

[0260] Embodiment 15

[0261] A method for promoting composting and humification of kitchen waste comprises the following steps:

[0262] (1) Biochar burning

[0263] The raw material for biochar is an organic waste: sludge.

[0264] Preparation of sludge: same as Example 13.

[0265] The preparation method of biochar is the same as that in Example 13.

[0266] (2) Preparation of minerals

[0267] The mineral is hematite, and its preparation method is shown in Example 3.

[0268] (3) Aerobic composting operation

[0269] Kitchen waste was used as the compost raw material, crushed to 20 mm, mixed evenly with compost auxiliary materials, and placed in a reactor for composting reaction; the initial C / N of the mixed material was adjusted to 24 and the moisture content was 63%; the mass ratio of the compost raw material to the compost auxiliary material was 1:3. The aeration rate was set to 0.4 L / min.

[0270] Among them, the kitchen waste and composting auxiliary materials are the same as those in Example 13.

[0271] During the mixing process of the compost raw materials and the compost auxiliary materials, the biochar prepared as above is added into the reactor; the amount of biochar added is 8% of the total dry weight of the compost raw materials and the compost auxiliary materials.

[0272] When the reaction temperature is 60° C., the minerals prepared above are added into the reactor; the amount of the minerals added is 12% of the total dry weight of the compost raw materials, compost auxiliary materials and the biochar.

[0273] The composting reaction time is 60 days. During the composting reaction period, the pile is turned over every 3 days.

[0274] The above composting reaction is carried out based on a system for promoting the composting and humification of kitchen waste, wherein the system for promoting the composting and humification of kitchen waste and its working principle are the same as those in Example 1.

[0275] Example 16

[0276] A method for promoting composting and humification of kitchen waste comprises the following steps:

[0277] (1) Biochar burning

[0278] The raw material for biochar is an organic waste: sludge.

[0279] Preparation of sludge: same as Example 13.

[0280] The preparation method of biochar is the same as that in Example 13.

[0281] (2) Preparation of minerals

[0282] The mineral is manganese dioxide, and its preparation method is shown in Example 4.

[0283] (3) Aerobic composting operation

[0284] Kitchen waste was used as the compost raw material, crushed to 20 mm, mixed evenly with compost auxiliary materials, and placed in a reactor for composting reaction; the initial C / N of the mixed material was adjusted to 25 and the moisture content was 55%; the mass ratio of the compost raw material to the compost auxiliary material was 1:3. The aeration rate was set to 0.4 L / min.

[0285] Among them, the kitchen waste and composting auxiliary materials are the same as those in Example 1.

[0286] During the mixing process of the compost raw materials and the compost auxiliary materials, the biochar prepared as above is added into the reactor; the amount of biochar added is 10% of the total dry weight of the compost raw materials and the compost auxiliary materials.

[0287] When the reaction temperature is 60° C., the minerals prepared above are added into the reactor; the amount of the minerals added is 5% of the total dry weight of the compost raw materials, compost auxiliary materials and the biochar.

[0288] The composting reaction time is 60 days. During the composting reaction period, the pile is turned over every 3 days.

[0289] The above composting reaction is carried out based on a system for promoting the composting and humification of kitchen waste, wherein the system for promoting the composting and humification of kitchen waste and its working principle are the same as those in Example 1.

[0290] Embodiment 17

[0291] A method for promoting composting and humification of kitchen waste comprises the following steps:

[0292] (1) Biochar burning

[0293] The raw material for biochar is a type of organic waste: food waste.

[0294] Preparation of food waste: remove bones, plastic waste, and shell impurities that are difficult to compost in food waste, and then dry the food waste in a constant temperature environment of 50°C. The food waste comes from the canteen of Suzhou Organic Recycling Research Institute of China Agricultural University.

[0295] The preparation method of biochar is as follows: the dried food waste is placed in a vacuum atmosphere furnace with a nitrogen flow rate of 100 mL / min and pyrolyzed at 500°C for 3 hours; the obtained food waste-based biochar is ground through a 2 mm sieve and stored for later use.

[0296] The heating rate in the vacuum atmosphere furnace is 15°C / min.

[0297] Firing conditions: heating rate under nitrogen is 15°C / min, constant temperature is 500°C, constant temperature time is 3h, and nitrogen flow rate is 100mL / min.

[0298] The basic properties of the prepared biochar are shown in Table 1.

[0299] (2) Preparation of minerals

[0300] The mineral is goethite, and its preparation method is shown in Example 1.

[0301] (3) Aerobic composting operation

[0302] Kitchen waste was used as the compost raw material, crushed to 20 mm, mixed evenly with compost auxiliary materials, and placed in a reactor for composting reaction; the initial C / N of the mixed material was adjusted to 22 and the moisture content was 57%; the mass ratio of the compost raw material to the compost auxiliary material was 1:3. The aeration rate was set to 0.4 L / min.

[0303] Among them, the kitchen waste and composting auxiliary materials are the same as those in Example 1.

[0304] During the mixing process of the compost raw materials and the compost auxiliary materials, the biochar prepared as above is added into the reactor; the amount of biochar added is 4% of the total dry weight of the compost raw materials and the compost auxiliary materials.

[0305] When the reaction temperature is 60° C., the minerals prepared above are added into the reactor; the amount of the minerals added is 8% of the total dry weight of the compost raw materials, compost auxiliary materials and the biochar.

[0306] The composting reaction time is 60 days. During the composting reaction period, the pile is turned over every 3 days.

[0307] The above composting reaction is carried out based on a system for promoting the composting and humification of kitchen waste, wherein the system for promoting the composting and humification of kitchen waste and its working principle are the same as those in Example 1.

[0308] Embodiment 18

[0309] A method for promoting composting and humification of kitchen waste comprises the following steps:

[0310] (1) Biochar burning

[0311] The raw material for biochar is a type of organic waste: food waste.

[0312] The preparation method of biochar is the same as Example 17.

[0313] (2) Preparation of minerals

[0314] The mineral is ferrihydrite, and its preparation method is shown in Example 2.

[0315] (3) Aerobic composting operation

[0316] Kitchen waste was used as the compost raw material, crushed to 20 mm, mixed evenly with compost auxiliary materials, and placed in a reactor for composting reaction; the initial C / N of the mixed material was adjusted to 23 and the moisture content was 59%; the mass ratio of the compost raw material to the compost auxiliary material was 1:3. The aeration rate was set to 0.4 L / min.

[0317] Among them, the kitchen waste and composting auxiliary materials are the same as those in Example 1.

[0318] During the mixing process of the compost raw materials and the compost auxiliary materials, the biochar prepared as above is added into the reactor; the amount of biochar added is 6% of the total dry weight of the compost raw materials and the compost auxiliary materials.

[0319] When the reaction temperature is 60° C., the minerals prepared above are added into the reactor; the amount of the minerals added is 10% of the total dry weight of the compost raw materials, the compost auxiliary materials and the biochar.

[0320] The composting reaction time is 60 days. During the composting reaction period, the pile is turned over every 3 days.

[0321] The above composting reaction is carried out based on a system for promoting the composting and humification of kitchen waste, wherein the system for promoting the composting and humification of kitchen waste and its working principle are the same as those in Example 1.

[0322] Embodiment 19

[0323] A method for promoting composting and humification of kitchen waste comprises the following steps:

[0324] (1) Biochar burning

[0325] The raw material for biochar is a type of organic waste: food waste.

[0326] The preparation method of biochar is the same as Example 17.

[0327] (2) Preparation of minerals

[0328] The mineral is hematite, and its preparation method is shown in Example 3.

[0329] (3) Aerobic composting operation

[0330] Kitchen waste was used as the compost raw material, crushed to 20 mm, mixed evenly with compost auxiliary materials, and placed in a reactor for composting reaction; the initial C / N of the mixed material was adjusted to 24 and the moisture content was 61%; the mass ratio of the compost raw material to the compost auxiliary material was 1:3. The aeration rate was set to 0.4 L / min.

[0331] Among them, the kitchen waste and composting auxiliary materials are the same as those in Example 1.

[0332] During the mixing process of the compost raw materials and the compost auxiliary materials, the biochar prepared as above is added into the reactor; the amount of biochar added is 8% of the total dry weight of the compost raw materials and the compost auxiliary materials.

[0333] When the reaction temperature is 60° C., the minerals prepared above are added into the reactor; the amount of the minerals added is 12% of the total dry weight of the compost raw materials, compost auxiliary materials and the biochar.

[0334] The composting reaction time is 60 days. During the composting reaction period, the pile is turned over every 3 days.

[0335] The above composting reaction is carried out based on a system for promoting the composting and humification of kitchen waste, wherein the system for promoting the composting and humification of kitchen waste and its working principle are the same as those in Example 1.

[0336] Embodiment 20

[0337] A method for promoting composting and humification of kitchen waste comprises the following steps:

[0338] (1) Biochar burning

[0339] The raw material for biochar is a type of organic waste: food waste.

[0340] The preparation method of biochar is the same as Example 17.

[0341] (2) Preparation of minerals

[0342] The mineral is manganese dioxide, and its preparation method is shown in Example 4.

[0343] (3) Aerobic composting operation

[0344] Kitchen waste was used as the compost raw material, crushed to 20 mm, mixed evenly with compost auxiliary materials, and placed in a reactor for composting reaction; the initial C / N of the mixed material was adjusted to 25 and the moisture content was 63%; the mass ratio of the compost raw material to the compost auxiliary material was 1:3. The aeration rate was set to 0.4 L / min.

[0345] Among them, the kitchen waste and composting auxiliary materials are the same as those in Example 1.

[0346] During the mixing process of the compost raw materials and the compost auxiliary materials, the biochar prepared as above is added into the reactor; the amount of biochar added is 10% of the total dry weight of the compost raw materials and the compost auxiliary materials.

[0347] When the reaction temperature is 60° C., the minerals prepared above are added into the reactor; the amount of the minerals added is 5% of the total dry weight of the compost raw materials, compost auxiliary materials and the biochar.

[0348] The composting reaction time is 60 days. During the composting reaction period, the pile is turned over every 3 days.

[0349] The above composting reaction is carried out based on a system for promoting the composting and humification of kitchen waste, wherein the system for promoting the composting and humification of kitchen waste and its working principle are the same as those in Example 1.

[0350] In order to illustrate the effect of the method for composting and humifying kitchen waste provided in the above-mentioned Examples 1 to 20 of the present invention, the following comparative example is set up.

[0351] Among them, Comparative Example 1 is kitchen waste composting without adding minerals and biochar, and the composting method refers to Example 1.

[0352] Comparative Examples 2 to 6 are kitchen waste composts with only biochar added without adding minerals, and the composting methods refer to Example 1, Example 5, Example 9, Example 13, and Example 17, respectively.

[0353] Comparative Examples 7 to 10 are kitchen waste composts with only minerals added without adding biochar, and the composting methods refer to Examples 1 to 4, respectively.

[0354] The experimental designs of the above-mentioned Comparative Examples 1 to 10 and Examples 1 to 20 are shown in Table 2.

[0355] Table 2 Experimental design table

[0356]

[0357]

[0358] In order to illustrate the effect of the method for promoting composting and humification of kitchen waste provided by the present invention, the following research was conducted:

[0359] The present invention adopts a humic acid extraction method to measure humic acid, humic acid, fulvic acid, TOC, humification index, humification rate and polymerization degree of the air-dried compost sample after decomposition, and the specific steps are as follows:

[0360] The screened 2 mm air-dried compost sample was mixed with deionized water at a w / v ratio of 1:10 and shaken at 70°C for 1 hour. The water-soluble organic matter was removed by passing through a 0.45 μm filter membrane. The precipitate was thoroughly mixed with 0.1 M Na4P2O7-10H2O and NaOH at a w:v ratio of 1:10 at 70°C for 1 hour. After centrifugation at 3500 rpm and filtration through a 0.45 μm filter membrane, the supernatant was used to obtain HS solution. The HS solution was acidified to pH = 1 with 1 M H2SO4, and then the suspension was allowed to stand for 12 hours. After centrifugation at 3500 rpm, the supernatant and precipitate were HA and FA, respectively. The precipitate HA was treated with 0.05 M NaOH. The contents of HA, FA and HS were tested by an organic carbon analyzer.

[0361] Among them, the Chinese name of HA is humic acid, and the Chinese name of FA is fulvic acid.

[0362] Organic carbon analyzer: TOC-L CPH, Shimadzu, Japan.

[0363] The humification index is calculated as follows:

[0364] Humic index = CHA / TOC×100.

[0365] Humation rate = CHS / TOC×100.

[0366] Degree of polymerization = CHA / CFA.

[0367] In the above formula, TOC refers to total organic carbon; the English abbreviation of humic index is HI; CHA refers to humic acid concentration; the English abbreviation of humification rate is HR; CHS refers to humic acid concentration; the English abbreviation of degree of polymerization is DP; CFA refers to fulvic acid concentration.

[0368] At the same time, the present invention adopts the standard method in the agricultural industry standard "NY525-2021 Organic Fertilizer" to determine the seed germination rate, and the specific steps are as follows:

[0369] Weigh 10.00g of the sample and place it in a 250mL conical flask. After converting the sample's moisture content, add the corresponding mass of water at a solid-liquid ratio of 1:10, and shake the machine at a frequency of 100 times / min, with an amplitude of not less than 40mm. Oscillate and extract at 25°C for 1h, and let it stand for 0.5h. Collect the filtered extract, shake it well, and use it for analysis. The sample is a fresh sample.

[0370] The solid-to-liquid ratio refers to mass / volume.

[0371] Place 1 or 2 pieces of qualitative filter paper in a 9 cm culture dish and put 10 plump cucumber seeds of basically the same size. Add 10 mL of extract, cover the culture dish, and culture in a 25°C incubator away from light for 48 hours. Count the number of germinated seeds and measure the length of the main root one by one with a vernier caliper. Use water as a control for a blank test.

[0372] The results are shown in Table 2.

[0373] Table 2 Test results

[0374]

[0375]

[0376] From the results in Table 2, it can be seen that the product humic acid content is the highest when sludge biochar is added by 4%wt and goethite is added by 8%wt; the TOC and humic acid contents are the highest when pig manure biochar is added by 8%wt and hematite is added by 12%wt, and the humification degree is the best. The average humic acid content of the embodiment is 57% higher than that of the comparative example, the average humic acid content of the embodiment is 49% higher than that of the comparative example, the average fulvic acid content of the embodiment is higher than that of the comparative example, the average TOC content of the embodiment is 59% higher than that of the comparative example, the average humification index of the embodiment is 19% higher than that of the comparative example, and the average seed germination rate of the embodiment is 27% higher than that of the comparative example, which are all significantly higher than the comparative example, indicating that adding biochar and minerals in the composting process can effectively improve the compost humification effect and promote the stability of organic matter.

[0377] Biochar itself is partially oxidized and degraded to release soluble organic compounds and aromatic compounds that are incorporated into humus-like substances, promoting the formation and stability of HA. The high specific surface area of ​​biochar can provide a suitable habitat for the growth and reproduction of microorganisms in compost. The rich pore structure can accelerate the rapid circulation of oxygen and energy transfer in the composting system, promote the aerobic metabolism of microorganisms, and add minerals to accelerate the formation and accumulation of precursors, thereby promoting the humification of compost. Minerals and humic acid interact through various adsorption mechanisms to form organic-inorganic complexes, ensuring the stable formation of humic acid in compost. Biochar and minerals promote the degradation of organic matter in compost, accelerate the composting process, promote the increase of humic acid and fulvic acid content, promote the improvement of compost polymerization degree, and enhance the transformation of organic matter in compost into stable humic acid.

[0378] In summary, the present invention provides a method for promoting the composting and humification of kitchen waste. The addition of different types of biochar and minerals can greatly improve the humification degree of the compost, and the organic fertilizer product can promote seed germination.

[0379] It should be noted that when the present invention involves a numerical range, it should be understood that the two endpoints of each numerical range and any numerical value between the two endpoints can be selected. In order to avoid redundancy, the present invention describes a preferred embodiment.

[0380] Although preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once the basic inventive concepts are known, and all such changes and modifications fall within the scope of the present invention.

Claims

1. A method for promoting composting and humification of kitchen waste, characterized in that: The steps include: Kitchen waste is used as a composting raw material, mixed evenly with a composting auxiliary material, and placed in a reactor for composting reaction; the initial carbon-nitrogen ratio of the mixed material is adjusted to 20-40 and the moisture content is 50%-70%; the mass ratio of the composting raw material to the composting auxiliary material is 1:2-4; During the mixing process of the compost raw material and the compost auxiliary material, biochar is added to the reactor; the amount of the biochar added is 2% to 10% of the total dry weight of the compost raw material and the compost auxiliary material; When the temperature in the reactor is 50° C. to 60° C., adding minerals into the reactor; the amount of the minerals added is 5% to 15% of the total dry weight of the compost raw materials, the compost auxiliary materials and the biochar; The composting reaction time is 20 to 60 days. During the composting reaction, the compost is turned once every 1 to 5 days.

2. A method for promoting composting and humification of kitchen waste according to claim 1, characterized in that: During the composting reaction, an aeration system is synchronously provided for aeration; the aeration rate is set at 0.2L / min to 0.6L / min.

3. A method for promoting composting and humification of kitchen waste according to claim 1, characterized in that: The biochar is prepared using organic waste as raw material; The organic waste includes any one or more of biogas residue, distiller's grains, pig manure, kitchen waste and sludge.

4. A method for promoting composting and humification of kitchen waste according to claim 3, characterized in that: The instrument conditions for preparing the biochar are as follows: a heating rate of 10°C / min to 15°C / min under nitrogen filling, a constant temperature of 480°C to 500°C, a constant temperature time of 2h to 3h, and a nitrogen flow rate of 90mL / min to 100mL / min.

5. The method for promoting composting and humification of kitchen waste according to claim 1, characterized in that: The mineral is any one or more of hematite, ferrihydrite, goethite and metal manganese oxide, or any one of soil rich in iron or manganese and river silt that has been air-dried.

6. A method for promoting composting and humification of kitchen waste according to claim 5, characterized in that: The method for preparing the soil rich in iron or manganese comprises the following steps: The collected soil containing iron or manganese elements is dried in the shade, impurities are removed, ground, and passed through a sieve with a pore size of 1mm to 4mm to obtain the obtained soil.

7. A method for promoting composting and humification of kitchen waste according to claim 5, characterized in that: The method for preparing the air-dried river silt comprises the following steps: Remove the impurities visible to the naked eye in the sludge, then dry the sludge in the shade, place it in a constant temperature environment of 48℃ ~ 52℃ for drying, grind it, and pass it through a sieve with an aperture of 1mm ~ 4mm to obtain the sludge.

8. The method for promoting composting and humification of kitchen waste according to claim 1, characterized in that: The kitchen waste includes any one of kitchen waste from restaurants or canteens, leftover vegetables from farmers' markets, or household kitchen waste after garbage sorting.

9. The method for promoting composting and humification of kitchen waste according to claim 1, characterized in that: The composting auxiliary materials include any one or more of wood chips, straw, garden prunings, weeds, shell bran, and cake meal.

10. A processing system for the method for promoting composting and humification of kitchen waste according to claim 1, characterized in that: The treatment system comprises a reactor; a porous pad (7) is placed in the bottom wall of the reactor, a water-absorbing material (3) is arranged in the top wall of the reactor, and a sampling port (5) is arranged in the side wall of the reactor; The reactor is connected to a gas reaction bottle (1), a temperature sensor (2), a heater, a refrigerator, a leachate collection bottle (6), and an air intake fan (9); a gas flow meter (8) is provided between the reactor and the air intake fan (9); the temperature sensor (2), the heater, the refrigerator, the gas flow meter (8), and the air intake fan (9) are all electrically connected to a control center (4); and the control center (4) is arranged outside the reactor.

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