Method for producing compost from vegetable and food residues and compost produced by said method

Abstract

The present disclosure addresses the production of compost from raw materials including vegetable and food waste. [Solution] The present inventors have discovered and completed a new method for efficiently and stably producing compost useful for plant growth from plant residues and food residues. By carrying out the method disclosed herein, it is possible to produce compost that is less likely to cause reduction problems from raw materials that include plant residues (e.g., vegetable residues) and food residues (e.g., discarded prepared food waste and bread and dessert residues).

Description

[Technical field]

[0001] The present disclosure relates to a method for producing compost from feedstocks including plant and food residues and the compost produced thereby. [Background technology]

[0002] Vegetable waste generated on farmland and in homes, and food waste from food service factories, etc., are serious problems. One method for disposing of vegetable and food waste is composting, but stable composting is difficult because vegetable and food waste contain a lot of water and less nitrogen than livestock manure, which is generally used as a raw material for composting. Summary of the Invention [Means for solving the problem]

[0003] The present inventors have discovered a novel method for efficiently and stably producing compost useful for plant growth from vegetable and food wastes.

[0004] Thus, the present disclosure provides: (Item 1) A method for producing compost from raw materials including plant residues and food residues, comprising: 1) crushing and then dehydrating said vegetable residue; 2) mixing the dehydrated vegetable residue, the food residue and secondary materials to obtain an initial raw material; 3) transferring the initial raw material to a primary fermentation zone, aerating the initial raw material 24 hours a day for about 1 week to about 6 weeks, and carrying out primary fermentation at an average temperature of the initial raw material of about 60° C. to about 70° C. to obtain a primary fermentation product; 4) transferring the primary fermentation product to a secondary fermentation zone and carrying out secondary fermentation at about 45°C to about 60°C for about 1 week to about 8 weeks to obtain a secondary fermentation product; 5) transferring the secondary fermentation product to a tertiary fermentation zone and carrying out tertiary fermentation at about 45°C to about 55°C for about 4 weeks to about 12 weeks to obtain a tertiary fermentation product; 6) composting the tertiary fermentation product wherein the dehydrated vegetable residues and the dehydrated food residues comprise at least about 80% by weight of the raw material. Manufacturing method. (Item 2) The method for producing the present invention according to any one of the preceding items, further comprising aeration by stirring the primary fermentation product at a frequency of 2 times per day to 1 time per 4 days in the secondary fermentation step (4). (Item 3) The method for producing the present invention according to any one of the preceding items, further comprising aeration by turning the secondary fermentation product over at a frequency of 2 times per week to 1 time per 3 weeks in the tertiary fermentation step (5). (Item 4) The method according to any one of the preceding items, wherein the aeration in the primary fermentation is performed through an aeration tube. (Item 5) The method according to any of the preceding items, wherein the compost has a C / N ratio of less than 17. (Item 6) The process according to any of the preceding items, wherein the C / N ratio of the initial feedstock is at least 45. (Item 7) The method for producing the present invention according to any one of the preceding items, further comprising a step of pre-fermenting the initial raw material by forced aeration for about 1 day to about 2 weeks prior to the primary fermentation step of 3) above, thereby increasing the temperature of the initial raw material to about 50°C to about 70°C. (Item 8) The method for producing according to any of the preceding items, wherein the water content of the initial raw material is about 40 to about 80% (w / w). (Item 9) The method for producing a quaternary fermentation product according to any one of the preceding items, wherein the step 6) is a step of subjecting the tertiary fermentation product to quaternary fermentation at about 45° C. or higher for about 1 week to about 12 weeks to obtain a quaternary fermentation product, and composting the quaternary fermentation product. (Item 10) 6) The method for producing the fermented product according to any one of the preceding items, characterized in that no aeration is performed in the quaternary fermentation. (Item 11) The manufacturing method according to any one of the preceding items, wherein the secondary materials include rice husks and return compost. (Item 12) The manufacturing method according to any one of the preceding items, wherein the auxiliary material further comprises a waste mushroom bed. (Item 13) The method according to any one of the preceding items, wherein the return compost contains the tertiary fermentation product. (Item 14) Item 2. The method of any of the preceding items, wherein the weight of the dehydrated vegetable residue and food residue accounts for about 90% of the weight of the raw material. (Item 15) The method according to any of the preceding items, wherein the compost has a base exchange capacity (CEC) of at least 5. (Item 16) The method according to any of the preceding items, wherein the weight of ammonia nitrogen is at least about 25% and the weight of nitrate nitrogen is at least about 25% of the total weight of ammonia nitrogen and nitrate nitrogen in the compost. (Item 17) 2. Compost obtained by the method according to any one of the preceding items.

[0005] It is contemplated that the present disclosure may provide one or more of the above features in combinations other than those specifically described. Still further embodiments and advantages of the present disclosure will be recognized by those skilled in the art upon reading and understanding the following detailed description, if necessary. Effect of the Invention

[0006] The present disclosure makes it possible to efficiently and stably produce compost useful for plant cultivation from raw materials including vegetable waste and food waste. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 shows a flow diagram of the compost production method of the present disclosure. [Diagram 2] FIG. 2 shows the analysis results of the compost obtained by carrying out primary fermentation to quaternary fermentation. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] (Definition, etc.) For convenience, certain terms used in this disclosure are collected here. Unless otherwise specified, all technical and scientific terms used in this disclosure have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The singular forms "a," "an," and "the" include plural references unless the context clearly dictates otherwise.

[0009] The numerical ranges and parameters set forth in this disclosure are approximations. As used herein, the term "about" generally means 10% of a given value or range.

[0010] As used herein, "fermentation" refers to a phenomenon in which organic substances such as easily decomposable organic matter are decomposed by aerobic microorganisms into carbon dioxide and water.

[0011] As used herein, the term "plant residue" refers to residue that is 80% or more derived from plants. In a preferred embodiment, this may include, for example, vegetable residues, soybean residues, coffee grounds, tea leaves, etc.

[0012] As used herein, "food residues" refers to residues produced during the processing of human food.

[0013] As used herein, "secondary materials" refers to materials that are mixed into the raw material for composting to regulate the moisture content and ensure breathability of the raw material.

[0014] As used herein, "return compost" refers to compost with a low moisture content. Return compost is generally used as bedding or secondary material and contains many microorganisms that contribute to fermentation.

[0015] As used herein, "spent mushroom bed" refers to residues generated during mushroom cultivation production, typically including sawdust and mycelium.

[0016] As used in this specification, "turning" refers to transferring raw materials that have already begun fermentation during the fermentation process, and by turning, the raw materials located at the surface of the pile move to the center of the pile, and at the same time, air enters the raw materials, recreating a fluffy pile state with many voids, which activates decomposition and allows fermentation to occur uniformly.

[0017] As used herein, "cation exchange capacity (CEC)" is an index showing the ability of a fertilizer to adsorb and retain bases (cations). The higher the CEC value, the greater the capacity of the fertilizer to adsorb and retain Ca. 2+ , Mg 2+ , K + , NH4 + It is evaluated as having a high ability to adsorb and retain cations such as cations. It is also called the cation exchange capacity. The higher the CEC, the greater the compost's ability to retain fertilizer components.

[0018] As used in this specification, "C / N ratio" refers to the mass ratio of total carbon to total nitrogen (TC / TN) contained in a raw material or compost; the lower the C / N ratio value, the higher the nitrogen content relative to the carbon content, and the higher the value, the lower the nitrogen content relative to the carbon content.

[0019] As used herein, "ammonia nitrogen" refers to nitrogen components that are ammonium salts. Ammonia nitrogen is oxidized by nitrifying bacteria to nitrite nitrogen, and is further oxidized to nitrate nitrogen.

[0020] As used herein, "nitrate nitrogen" refers to nitrogen that exists in the form of nitrogen oxide, such as nitrate ions, among nitrogen components.

[0021] As used in this specification, "electrical conductivity" is a physical quantity that indicates the ease of electrical conduction in a substance, and is an indicator of the amount of water-soluble ions such as potassium and sodium in compost, and ultimately the salt concentration.

[0022] (Compost manufacturing method) In one aspect, the present disclosure provides a method for producing compost from a raw material including a plant residue and a food residue, the method comprising: 1) Crushing and then dehydrating the vegetable residue; 2) mixing the dehydrated vegetable residues, food residues and secondary materials to obtain the initial raw material; 3) transferring the initial raw material to a primary fermentation zone, aerating the initial raw material for at least 20 hours over a period of about 1 week to about 6 weeks, and carrying out primary fermentation at an average temperature of the initial raw material of about 60°C to about 70°C to obtain a primary fermentation product; 4) transferring the primary fermentation product to a secondary fermentation zone and carrying out secondary fermentation at about 45°C to about 60°C for about 1 week to about 8 weeks to obtain a secondary fermentation product; 5) transferring the secondary fermentation product to a tertiary fermentation zone and carrying out tertiary fermentation at about 45°C to about 55°C for about 4 weeks to about 12 weeks to obtain a tertiary fermentation product; 6) The process of composting the tertiary fermentation product wherein the dehydrated vegetable and food residues constitute at least about 80% by weight of the feedstock; A method of manufacture is provided.

[0023] (Preparation of raw materials) In a preferred embodiment, the vegetable residues may include vegetable scraps, agricultural plant waste, raw material waste from preparing side dishes, waste from side dishes, and residues from bread and desserts (cakes, castella, Japanese sweets, etc.).

[0024] In the present invention, the weight of the dehydrated vegetable residues and food residues may account for about 80% or more of the weight of the raw material. In a preferred embodiment, the weight of the dehydrated vegetable residues and food residues may account for about 90% or more of the weight of the raw material. In a typical embodiment of the present invention, the raw material for composting does not include livestock manure from birds or mammals. By not including livestock manure, the raw material can be composted without generating a foul odor. In a most preferred embodiment, the weight of the dehydrated vegetable residues and food residues may be 100%.

[0025] In one embodiment, the water content in the vegetable residue can be reduced by carrying out the steps of 1) crushing the vegetable residue and then dehydrating it. Since vegetable residue contains a large amount of water, it has been difficult to compost it, but the present inventors have found that it can be successfully composted by controlling the temperature zone and period in the fermentation stage. If the vegetable residue is not crushed, the cells in the vegetable residue will break down after about one week, causing moisture from the vegetable residue to seep into the raw material, making it difficult to maintain a high temperature during the fermentation of the raw material and to quickly increase the temperature in the early stage of fermentation. By crushing the vegetable residue before the fermentation of the raw material and then dehydrating it, it is possible to maintain a high temperature during the fermentation of the raw material. The dehydration of the vegetable residue can be carried out by various methods known in the art, such as belt press dehydration, centrifugal dehydration, and rotary pressure dehydration, but is preferably carried out by squeezing dehydration. Squeezing dehydration is preferable in that it can dehydrate a large amount of crushed vegetable residue to be composted using a simple device, with reduced labor and low energy. The dehydration of the vegetable residue can be performed until the moisture content is suitable for achieving the appropriate moisture content of the initial raw material described below, and in one embodiment, the dehydration step can remove about 30 to about 70% of the moisture in the vegetable residue. In a preferred embodiment, the dehydration step can remove about 30 to about 50% of the moisture in the vegetable residue. In a most preferred embodiment, the dehydration step can remove about 40% of the moisture in the vegetable residue. The time for dehydration can be appropriately determined by those skilled in the art depending on the target moisture content and the dehydration method, and in one embodiment, the dehydration can be performed for about 4 to 24 hours. In a preferred embodiment, the dehydration can be performed for about 12 to about 24 hours. In a most preferred embodiment, the dehydration can be performed for about 24 hours.

[0026] In one embodiment, the initial raw material with an adjusted moisture content can be obtained by carrying out step 2) of mixing the dehydrated plant residue, food residue, and secondary materials to obtain the initial raw material. In a preferred embodiment, the secondary materials include rice husks, straw, sawdust, wood chips, waste mushroom beds, return compost, coffee grounds, tea leaves, fruit juice residue, beer lees, etc.

[0027] In one embodiment, the moisture content of the initial raw material may be about 40 to about 80% (w / w). In a preferred embodiment, the moisture content of the initial raw material may be about 50 to about 80% (w / w). In a most preferred embodiment, the moisture content of the initial raw material may be about 65 to about 75% (w / w). In one embodiment, the plant residue contained in the initial raw material may include vegetable residue. In one embodiment, the food residue contained in the initial raw material may include residue discharged from a food factory (for example, residue from a prepared food factory (raw material waste during the preparation of prepared food, waste garbage from prepared food) and bread / dessert (residues of cake, castella, Japanese confectionery, etc.). Vegetable residues and residues discharged from food factories are raw materials that can be consumed by humans if they are fresh, so a safe initial raw material can be obtained by using vegetable residues as the plant residue and residues discharged from food factories as the food residue. In one embodiment, In some embodiments, the vegetable residue may be about 20% to about 60% (e.g., about 20%, about 30%, about 40%, about 50%, about 60%) of the total initial raw materials. In a preferred embodiment, the vegetable residue may be about 30% to about 50% of the total initial raw materials. In a most preferred embodiment, the vegetable residue may be about 30% to about 40% of the total initial raw materials. In one embodiment, the food residue may include egg shells, which may result in a higher calcium concentration in the final product than normal.

[0028] In one embodiment, the secondary materials may include rice hulls and / or back compost.

[0029] In one embodiment, the volume ratio of the raw materials to the secondary materials may be raw materials:secondary materials=1:1-4. In a preferred embodiment, the volume ratio of the raw materials to the secondary materials may be raw materials:secondary materials=1:1-2. In one embodiment, coffee grounds may be used as the secondary materials. In one embodiment, the return compost may contain tertiary fermentation products, which will be described later. By adding the return compost to the raw materials as a secondary material, it becomes possible to efficiently transfer microorganisms involved in composting to the raw materials, resulting in a shortened composting period and a shortened time required for the temperature of the raw materials to rise.

[0030] In one embodiment, the secondary material may include a waste mushroom bed. The waste mushroom bed contains sawdust and mushroom hyphae, so by adding the waste mushroom bed to the raw material, the sawdust fiber part and some of the mushroom components remain in the final product. This has a positive effect when the final product is used to grow plants. This is because one of the roles of compost in plant growth is soil creation, and by adding the waste mushroom bed, the final product contains cellulose, lignin, and hemicellulose, which improves the physical properties of the soil to which the final product is added, making it fluffy and soft. In addition, although the sawdust contained in the waste mushroom bed also contains phenolic substances, these are decomposed during composting. Compost made from waste mushroom beds contains high concentrations of antagonistic bacteria such as Streptomyces and Bacillus.

[0031] (Pre-fermentation) In one embodiment, the production method of the present invention may include a pre-fermentation step before the primary fermentation. The pre-fermentation step may be provided to reduce the moisture content in the raw material and improve the rise of fermentation in the primary fermentation (to increase the initial speed of fermentation).

[0032] In the pre-fermentation step, rice husks may be spread on the floor and walls of the place where pre-fermentation is performed. Rice husks create voids, which can contribute to the discharge of moisture and efficient ventilation. Furthermore, by spreading rice husks, it is possible to prevent clogging of the nozzle for ventilation. In one embodiment, rice husks are mixed into the pre-fermentation product after the pre-fermentation treatment. In one embodiment, instead of rice husks, fibrous plant waste (e.g., rice straw) can be used. In one embodiment, rice husks may be spread to a height of about 5 to about 70 cm, preferably about 5 to 60 cm, and most preferably about 5 cm, on the place where pre-fermentation is performed. In this way, efficient ventilation can be achieved while allowing moisture to escape.

[0033] The pre-fermentation step is carried out before the primary fermentation step 3), and the initial raw material is pre-fermented by forced aeration for about 1 day to about 2 weeks to raise the temperature of the initial raw material to about 50°C to about 70°C. In a preferred embodiment, the initial raw material can be pre-fermented by forced aeration for about 3 days to about 10 days before the primary fermentation step 3). In a most preferred embodiment, the initial raw material can be pre-fermented by forced aeration for about 1 week before the primary fermentation step 3). In one embodiment, the pretreatment step can be carried out in a location separate from the primary fermentation area. In another embodiment, the pretreatment step can be carried out in the same location as the primary fermentation area, in a state where the raw material being pretreated is not mixed with the raw material being treated after the primary fermentation. By carrying out the pretreatment step in a location separate from the primary fermentation area, or in a state where the raw material being treated after the primary fermentation is not mixed with the raw material being treated after the primary fermentation, harmful microorganisms contained in the raw material being pretreated can be prevented from being transferred to the raw material being treated after the primary fermentation. The temperature of the raw material during pretreatment can reach the 40°C range 1-2 days after the start of pretreatment, and the 50°C range 3-4 days after the start of pretreatment. In a preferred embodiment, a mechanism is provided to drain water leaking from the raw material during pretreatment and primary fermentation so that the water does not accumulate in the pretreatment area and primary fermentation area, thereby reducing the risk of harmful microorganisms contained in the initial raw material being mixed into the primary fermentation and preventing the generation of unpleasant odors during fermentation.

[0034] (Primary fermentation process) In the production method of the present invention, the primary fermentation is carried out by maintaining the temperature at 50°C or higher to reduce harmful microorganisms to a substantially harmless level. In one embodiment, the primary fermentation can be carried out at an average temperature of the initial raw material of about 50°C to about 70°C. By maintaining an appropriate temperature for about 2 to 3 months between the primary fermentation and the tertiary fermentation, harmful microorganisms (e.g., Salmonella, Escherichia coli, Campylobacter, etc.) contained in the raw material can be sterilized and substances harmful to crop growth (e.g., phenolic compounds, lower fatty acids, etc.) can be decomposed (by maintaining the temperature for about 2 to 3 months, the number of harmful microorganisms contained in the initial raw material can be reduced by 10 orders of magnitude from the initial number of bacteria, and they can be killed to a level that is practically problem-free). In one embodiment, the primary fermentation can be carried out at an average temperature of the initial raw material of about 70°C or lower. By maintaining the temperature at about 70°C or lower, the risk of death of microorganisms useful for composting (e.g., Bacillus bacteria, actinomycetes, nitrifying bacteria (ammonia oxidizing bacteria, nitrite-producing bacteria)) can be reduced. Water may be added to the initial feedstock to keep the average temperature of the initial feedstock during primary fermentation below about 70°C.

[0035] In one embodiment, in the step of 3) obtaining a primary fermentation product, aeration can be performed continuously or intermittently. In one embodiment, in the step of obtaining a primary fermentation product, aeration can be performed for about 1 week to about 6 weeks, for example, about 1 week to about 4 weeks, about 2 weeks to about 6 weeks, or about 3 weeks to about 6 weeks, at a time and aeration amount that can prevent the fermentation target from becoming anaerobic. In a preferred embodiment, in the step of obtaining a primary fermentation product, aeration can be performed daily for about 2 to about 5 weeks. In a most preferred embodiment, aeration can be performed daily for about 3 to about 5 weeks, for example, about 4 weeks, in the step of obtaining a primary fermentation product. By aerating the fermentation target every day, the oxygen demand of the aerobic microorganisms that decompose the fermentation target can be met. Daily aeration in primary fermentation can be constant aeration for 24 hours. If the above-mentioned oxygen demand can be met, the aeration time may be shortened. In addition, by aerating the fermentation target for a long period of time every day, for example, for 24 hours, it is possible to prevent the fermentation target from becoming anaerobic, and aerobic fermentation can be promoted. This makes the fermentation target aerobic, preventing the denitrification reaction of denitrifying bacteria that are more active under anaerobic conditions, and also makes it possible to prevent denitrification of nitrate nitrogen in the fermentation target, which leads to an increase in the amount of nitrogen in the produced compost. Furthermore, by aerating for a long period of time, for example 24 hours, it is also possible to prevent the nozzle of the equipment used for aeration from clogging.

[0036] In one embodiment, the primary fermentation treatment can be carried out at separate locations for each fermentation stage. In a preferred embodiment, the primary fermentation treatment can be carried out in separate locations for each week after the start of fermentation (e.g., the first week of fermentation, the second week of fermentation, the third week of fermentation, etc.). By carrying out the primary fermentation at separate locations for each fermentation stage, such as by moving the location for each fermentation stage, it is possible to prevent heat accumulation in the fermentation target, and also to prevent the temperature from rising to 70°C or higher and the death of nitrifying bacteria and the like.

[0037] In one embodiment, aeration in the primary fermentation may be from an aeration tube. In one embodiment, the aeration tube may be an aeration tube laid on the floor of the primary fermentation area, or may be a rod-shaped aeration tube that can be inserted into the raw material or the fermentation product. 3 To advance 1% of the flow rate, it takes about 3 to 7 L / m 3 The required air volume is 6 to 14 L / m2 when piling up the raw material at 2 m3. 2 Therefore, in one embodiment, the amount of air supplied from the air diffuser is about 3 to 32 L / m 2 / min or more. In a preferred embodiment, the flow rate is about 5 to 17 L / m 2 / min or more. In the most preferred embodiment, the air supply from the air diffuser is 6 to 14 L / m 2 / min or even more.

[0038] (Secondary fermentation process) In the present invention, the secondary fermentation step is aimed at reducing harmful microorganisms to a substantially harmless level by maintaining the temperature during fermentation at about 45°C or higher while performing aeration at a frequency less than that of the primary fermentation step. In one embodiment, in the secondary fermentation step 4), aeration by stirring the primary fermentation product can be performed twice a day to once a day. In a preferred embodiment, aeration by stirring the primary fermentation product can be performed once a day to once a day. In the most preferred embodiment, aeration by stirring can be performed once every two days, four times. By performing agitation, the primary fermentation product can be homogenized and further, the anaerobic nature of the primary fermentation product can be prevented. In one embodiment, the agitation can be performed using a rotary agitator. In one embodiment, the secondary fermentation is maintained at a temperature of the upper 40s to the lower 50s (45°C to 54°C). By maintaining such a temperature, microorganisms performing aerobic fermentation are activated and nitrifying bacteria are also activated. In one embodiment, the secondary fermentation can be carried out at a temperature not exceeding 70° C. to prevent the death of the nitrifying bacteria.

[0039] In one embodiment, the secondary fermentation step 4) may be carried out for about 1 week to about 12 weeks. In a preferred embodiment, the secondary fermentation step 4) may be carried out for about 1 week to about 8 weeks, about 1 week to about 4 weeks, about 2 weeks to about 12 weeks, about 3 weeks to about 8 weeks, about 3 weeks to about 12 weeks, about 4 weeks to about 8 weeks, or about 4 weeks to about 12 weeks. In a most preferred embodiment, the secondary fermentation step 4) may be carried out for about 2 weeks to about 8 weeks, for example, about 6 weeks. By carrying out the secondary fermentation for the above period, it is possible to reduce the amount of easily decomposable organic matter.

[0040] In one embodiment, the secondary fermentation step 4) may be carried out at about 45°C to about 75°C. In a preferred embodiment, the secondary fermentation step 4) may be carried out at about 45°C to about 65°C. In a most preferred embodiment, the secondary fermentation step 4) may be carried out at about 45°C to about 60°C.

[0041] (Tertiary fermentation process) In the present invention, the tertiary fermentation step maintains the temperature during fermentation at about 45° C. or higher while performing aeration at a frequency lower than that of the secondary fermentation step, and maintains fermentation. In one embodiment, in the tertiary fermentation step 5), aeration by turning and stirring the secondary fermentation product can be performed twice a week to once a week. In a preferred embodiment, in the tertiary fermentation step 5), aeration by turning and stirring the secondary fermentation product can be performed once a week to once a week. In the most preferred embodiment, in the tertiary fermentation step 5), aeration by turning and stirring the secondary fermentation product can be performed once a week to once a week. The reason for reducing the aeration frequency in the tertiary fermentation compared to the secondary fermentation is that the amount of easily decomposable organic matter contained in the target of tertiary fermentation is less than the amount of easily decomposable organic matter contained in the target of secondary fermentation, and the temperature of the target of tertiary fermentation is less likely to rise, so the aeration frequency accompanied by heat radiation is reduced to maintain the temperature of the target of tertiary fermentation.

[0042] In one embodiment, the tertiary fermentation step 5) may be carried out for about 2 weeks to about 12 weeks. In a preferred embodiment, the tertiary fermentation step 5) may be carried out for about 4 weeks to about 10 weeks. In a most preferred embodiment, the tertiary fermentation step 5) may be carried out for about 8 weeks.

[0043] In one embodiment, the tertiary fermentation step 5) may be carried out at about 45° C. to about 75° C. In a preferred embodiment, the tertiary fermentation step 5) may be carried out at about 45° C. to about 65° C. In a most preferred embodiment, the tertiary fermentation step 5) may be carried out at about 45° C. to about 55° C. The tertiary fermentation product may be made into the above-mentioned return compost.

[0044] (Quaternary fermentation) In the present invention, a quaternary fermentation step may be provided. The quaternary fermentation step may be performed without aeration, to reduce easily decomposable organic matter, so as to prevent the rapid proliferation of microorganisms in soil when used as compost, which would cause reduction damage to the soil to become anaerobic. In one embodiment, the step 6) of converting the tertiary fermentation product into compost may include a step of subjecting the tertiary fermentation product to quaternary fermentation at about 45°C to about 55°C for about 1 week to about 12 weeks to obtain a quaternary fermentation product, and converting the quaternary fermentation product into compost. In a preferred embodiment, the step 6) of converting the tertiary fermentation product into compost may include a step of subjecting the tertiary fermentation product to quaternary fermentation for about 3 weeks to about 8 weeks to obtain a quaternary fermentation product, and converting the quaternary fermentation product into compost. In a most preferred embodiment, the step 6) of converting the tertiary fermentation product into compost may include a step of subjecting the tertiary fermentation product to quaternary fermentation for about 4 weeks to obtain a quaternary fermentation product, and converting the quaternary fermentation product into compost. In one embodiment, aeration is not performed in the quaternary fermentation. In one embodiment, the quaternary fermentation process may be performed for a predetermined period of time, or may be terminated when the temperature falls below a certain level without a set period of time, while checking the temperature, etc. In a preferred embodiment, the quaternary fermentation process is terminated when the temperature falls below a certain level without a set period of time, while checking the temperature, etc. In one embodiment, the quaternary fermentation is performed in a container such as a flexible container, and is terminated when the container is opened after the temperature has dropped and the temperature does not increase even when the container is turned over. By fermenting the compost until the temperature does not increase even when the compost is turned over, the amount of easily decomposable organic matter in the compost can be sufficiently reduced. This prevents reduction disorders in which microorganisms rapidly grow and the soil becomes anaerobic when the compost is used as compost. In one embodiment, sieving may be performed after the end of the process.

[0045] (Properties of compost) In one embodiment, the compost may have a pH of about 7 and an electrical conductivity (EC) of 10 mS / cm or less. In a preferred embodiment, the compost may have an electrical conductivity (EC) of 8 mS / cm or less. In a most preferred embodiment, the compost may have an electrical conductivity (EC) of 6 mS / cm or less. If the electrical conductivity of the compost is within the above range, the salt concentration in the compost is not high, and therefore, when the compost is used in soil as compost, growth disorders (salt concentration disorders), such as crop roots being unable to absorb water, are unlikely to occur.

[0046] In one embodiment, the compost of the present disclosure contains waste mushroom bed as a raw material, and therefore may contain a large amount of Streptomyces and Bacillus, which have disease suppression effects.

[0047] In one embodiment, the C / N ratio of the initial feedstock may be at least 30. In a preferred embodiment, the C / N ratio of the initial feedstock may be at least 40. In a most preferred embodiment, the C / N ratio of the initial feedstock may be at least 45. In one embodiment, the C / N ratio of the compost produced by the method of the present disclosure may be less than 20 (e.g., less than 20, less than 19, less than 18, less than 17, less than 16). In a preferred embodiment, the C / N ratio of the compost produced by the method of the present disclosure may be less than 19. In a most preferred embodiment, the C / N ratio of the compost produced by the method of the present disclosure may be less than 17. A compost with a low C / N ratio is a compost that does not contain any easily decomposable organic matter, and is a compost that is less likely to cause reduction disorders in which microorganisms rapidly grow in soil and the soil becomes anaerobic when used as a compost.

[0048] In one embodiment, the compost may contain more ammonia nitrogen than nitrate nitrogen. This is because ammonia nitrogen is a cation, and therefore has the advantage of being easily adsorbed and retained in soil, and is easily used as a fertilizer component when put into a field. In another embodiment, the compost may contain more nitrate nitrogen than ammonia nitrogen. This is because nitrate nitrogen is less likely to cause a foul odor than ammonia nitrogen. In one embodiment, the ratio of nitrate nitrogen to ammonia nitrogen may be about 1:about 2 to about 2:about 1. This is because the inclusion of ammonia nitrogen has the advantage of being easily adsorbed and retained in soil, and is easily used as a fertilizer component when put into a field, and since there is also nitrate nitrogen, it is less likely to cause a foul odor compared to when there is a lot of ammonia nitrogen. In one embodiment, the weight ratio of ammonia nitrogen to nitrate nitrogen is 2:1 to 1:3. In a preferred embodiment, the weight ratio of ammonia nitrogen to nitrate nitrogen is 1:1 to 1:3. In one embodiment, the weight of ammonia nitrogen may be at least 25% and the weight of nitrate nitrogen may be at least 25% of the total weight of ammonia nitrogen and nitrate nitrogen in the compost of the present disclosure. In a preferred embodiment, the weight of ammonia nitrogen may be at least 30% and the weight of nitrate nitrogen may be at least 30% of the total weight of ammonia nitrogen and nitrate nitrogen in the compost of the present disclosure. In the most preferred embodiment, the weight of ammonia nitrogen may be at least 40% and the weight of nitrate nitrogen may be at least 40% of the total weight of ammonia nitrogen and nitrate nitrogen in the compost of the present disclosure. Ammonia nitrogen is a neutral to weakly alkaline nitrogen with a pH of 7.6 to 8, and volatilizes as ammonia, which causes a bad odor and causes nitrogen loss, but it has the advantage of being easily adsorbed and retained in the soil because it is a cation, and there is no waste as a fertilizer component when it is put into a field. Nitrate nitrogen is NO3 -Therefore, it is difficult to be adsorbed by soil and washed away by rain, which may lead to environmental pollution such as groundwater, but has the advantage of being less likely to cause odor problems. In one embodiment, the total amount of ammonia nitrogen and nitrate nitrogen may be about 10 to about 20% of the total nitrogen amount, and organic nitrogen may be about 80 to about 90% of the total nitrogen amount. Organic nitrogen becomes ammonia nitrogen as organic matter containing microbial cells is decomposed, and is discharged from the organic matter, and then becomes nitrate nitrogen, which allows for sustained nitrogen release.

[0049] In one embodiment, the compost made from plant residues and food residues contains appropriate amounts of nitrogen, phosphorus, and potassium, and is also rich in fiber, making it good for soil building. When excessive amounts of phosphorus and potassium are present, the soil's salt concentration increases, which can cause growth disorders (salt concentration disorders) such as crop roots being unable to absorb water, while phosphorus promotes flowering and fruiting, and potassium works to grow roots and increase resistance to temperature or pests, so that even if the amount of phosphorus and potassium is low, it can have a negative effect on plant growth. In addition, the high fiber content improves the physical properties of the soil, making it possible to make it into a so-called soft soil.

[0050] In one embodiment, the base exchange capacity (CEC, unit: meq / 100 g or cmol(+) kg -1 ) may be at least 5 (e.g., 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40). In a preferred embodiment, the base exchange capacity (CEC) of the compost may be at least 8. In a most preferred embodiment, the base exchange capacity (CEC) of the compost may be at least 10. The higher the CEC, the higher the ability to adsorb and retain cations, and therefore the higher the amount of nutrients retained by the compost.

[0051] The present disclosure has been described above by showing preferred embodiments for ease of understanding. The present disclosure will be described below based on examples, but the above description and the following examples are provided for illustrative purposes only and are not provided for the purpose of limiting the present disclosure. Therefore, the scope of the present disclosure is not limited to the embodiments or examples specifically described in this specification, but is limited only by the scope of the claims. EXAMPLES

[0052] (Example 1-1: Preparation of raw materials) Vegetable scraps as plant residues and food waste discharged from food factories and food processing factories (e.g., cut vegetable scraps, side dish scraps, noodle factory scraps, mentaiko factory scraps, bread factory scraps, and confectionery factory scraps) as food scraps were loaded separately onto trucks, covered with sheets, and transported to the factory where fermentation took place. The transported vegetable scraps and food waste were unloaded in a fresh state at separate locations. Waste mushroom beds were laid in advance at the unloading area as a moisture absorbent. The unloaded vegetable scraps (approximately 2 tonnes) were crushed in a biaxial crusher, and the crushed material was placed in a container and left for 24 hours until the moisture content reached approximately 60%.

[0053] The vegetable waste with reduced moisture content was mixed with food waste in a ratio of about 1:1 (4t in total). Then, secondary materials including rice husks, waste mushroom beds, and return compost were further mixed with the mixture of vegetable waste and food waste in a ratio of about 2:1 to obtain 7t of raw material. The moisture content of the raw material was about 80%, and the C / N ratio was about 60.

[0054] (Example 1-2: Pre-fermentation) (Days 1-2) In the area where the aeration system (Easy Jet by Miraie Co., Ltd.) was installed on the floor for pre-fermentation, rice husks were laid about 5 cm thick, and the raw materials were piled up to a height of about 2 m on top of that. The aeration volume of the aeration system on the first day was 2.44 L / m 3 / min, and the aeration system airflow on the second day was 2.44 L / m 3 The aeration rate was set at 100 / min for 24 hours. The material harvested that day was added daily for a week.

[0055] (Day 3) Set the ventilation volume to 6.1 L / m 3 / min for 24 hours. The temperature of the raw material was in the 50°C range.

[0056] (7th day) The raw materials were left in the pre-fermentation area for one week without stirring such as turning over, and then mixed with rice husks laid on the floor. The temperature of the raw materials was in the 50°C range.

[0057] (Example 1-3: Primary fermentation) The raw material that had undergone pre-fermentation was placed in the primary fermentation area, with walls lined with rice husks, at a height of about 2 m. The aeration system had an aeration rate of 6.1 L / m 3 The flow rate was set to 1 / min. Every week, the raw materials were moved to another location in the primary fermentation area, where rice husks were laid out about 5cm thick. When moving, the rice husks laid on the floor were mixed with the raw materials. Primary fermentation was carried out for three weeks, with the fermentation location being moved every week. Water leaking from the raw materials during pretreatment and primary fermentation was moved to tanks located at the bottom of the pretreatment and primary fermentation areas, so as not to accumulate in the pretreatment and primary fermentation areas. During primary fermentation, the temperature was maintained at around 60-70°C, except immediately after stirring.

[0058] (Example 1-4: Secondary fermentation) The raw materials that had undergone primary fermentation were transferred to the secondary fermentation area and placed at a height of about 1m. In the secondary fermentation area, a rotary mixer (6m wide x 1m high x 80m) was used to mix the materials once every two days, with four mixes per time. After mixing, the temperature of the raw materials dropped to the 50 degree range within half a day. The secondary fermentation was continued for about six weeks, with the temperature maintained at around 60-70 degrees, except immediately after mixing.

[0059] (Example 1-5: Tertiary fermentation) The raw materials that had undergone secondary fermentation were transferred to the tertiary fermentation area and placed at a height of about 2m. In the tertiary fermentation area, the mixture was stirred by turning it over about once a week. Except for the time immediately after turning, the temperature was maintained at about 60 to 70 degrees, and the tertiary fermentation took place over a period of about 8 weeks.

[0060] (Example 1-6: Quaternary fermentation) The raw materials that had undergone tertiary fermentation were transferred to a flexible container (quaternary fermentation area). In the quaternary fermentation area, no stirring was performed and quaternary fermentation took place for approximately one month to obtain compost. After one month, it was confirmed that the temperature had dropped to below outside temperature +10°C, and that there was no increase in temperature even after turning over. After confirming that there was no increase in temperature, the pH and electrical conductivity of the compost were measured and it was confirmed that the pH was around 7 (pH7.7) and the electrical conductivity was 8ms / cm or less (7.8). After confirmation, the compost was sieved using a rotary sieve with 4mm mesh and packed into 16L bags.

[0061] The compost was submitted to the Toyo Environmental Analysis Center for analytical testing. The results of the compost analysis are shown in Figure 2. The base exchange capacity was high at 10.3, indicating that the compost had the capacity to retain a large amount of nutrients. The C / N ratio was also sufficiently low at 15, indicating that the compost had undergone sufficient fermentation, contained no easily decomposable organic matter, and was unlikely to cause reduction problems. In addition, the ammonia nitrogen concentration was 0.16%, the nitrate nitrogen concentration was 0.09%, and the total nitrogen content was 1.5%, indicating that the organic nitrogen was approximately 83%, indicating that nitrogen could be supplied continuously. Furthermore, the electrical conductivity was 7.8ms / cm, indicating that the salt concentration was not high, indicating that the compost was unlikely to cause crop growth problems. In addition, since waste mushroom beds are used as secondary materials, the compost contains cellulose, lignin, and hemicellulose, and contains high concentrations of antagonistic bacteria such as Streptomyces and Bacillus, so when the compost is used, it can improve the physical properties of the soil and make it possible to grow crops that are resistant to diseases.In addition, because it is rich in total silica, it is highly effective in preventing rice from falling over.

[0062] (Example 2: Compost production without tertiary and quaternary fermentation) Compost was produced under the same conditions as in Example 1, except that tertiary and quaternary fermentation were not performed. As a result, compost could be obtained, but the fermentation state of the compost was uneven compared to Example 1, and the C / N ratio was high. This is thought to be because there was a larger amount of easily decomposable organic matter remaining compared to the compost of Example 1. Although not intending to be bound by theory, it is thought that the fermentation period of Example 1 was more preferable.

[0063] (Example 3: Compost production without pre-fermentation treatment) Compost was produced under the same conditions as in Example 1, except that pre-fermentation was not performed in a separate location prior to the primary fermentation. As a result, compared to Example 1, harmful microorganisms such as E. coli were sometimes detected in the compost. Although compost was successfully produced, it was found that because pre-fermentation was not performed in a separate location from the primary fermentation, harmful microorganisms in the raw materials may have been mixed into the raw materials for primary fermentation, and therefore it was found that it would be better to carry out pre-fermentation in separate locations from the primary fermentation.

[0064] (Example 4: Compost production without moving between fermentation stages in the primary fermentation process) Compost was produced under the same conditions as in Example 1, except that the location of fermentation was not moved every week in the primary fermentation treatment stage. As a result, the compost had less nitrate nitrogen and more ammonia nitrogen than in Example 1. Although compost was successfully produced, not moving the location may have caused the fermentation target to accumulate excess heat, which may have led to poor activity of nitrifying bacteria, which are sensitive to high temperatures of 70 degrees or more. As in Example 1, it was found that it is better to move the location periodically in primary fermentation.

[0065] (Example 5: Compost production without rice husks in pre-fermentation treatment) Compost was produced under the same conditions as in Example 1, except that rice husks were not laid in the pre-fermentation treatment stage. As a result, the moisture content of the fermentation target was higher and the C / N ratio was higher compared to Example 1. Compost was successfully produced, but not laying rice husks may have lowered the oxygen concentration and prevented sufficient fermentation. It is preferable to perform the pre-fermentation treatment by laying rice husks as in Example 1.

[0066] (Example 6: Temperature during primary fermentation treatment) Compost was produced under the same conditions as in Example 1, except that the temperature of the primary fermentation treatment exceeded 70°C. As a result, the amount of nitrate nitrogen was reduced compared to the compost produced in Example 1. Although the compost was successfully produced, it is possible that the fermentation temperature was too high, which reduced the activity of nitrifying bacteria, which are sensitive to high temperatures of 70°C or higher.

[0067] (Example 7: Temperature during secondary fermentation treatment) Compost was produced under the same conditions as in Example 1, except that the temperature of the secondary fermentation treatment exceeded 70°C. As a result, the amount of nitrate nitrogen was reduced compared to the compost produced in Example 1. Although the compost was successfully produced, it is possible that the fermentation temperature was too high, which reduced the activity of nitrifying bacteria, which are sensitive to high temperatures of 70°C or higher.

[0068] (Example 8: Temperature during tertiary fermentation treatment) Compost was produced under the same conditions as in Example 1, except that the temperature of the tertiary fermentation treatment exceeded 70°C. As a result, the amount of nitrate nitrogen was reduced compared to the compost produced in Example 1. Although the compost was successfully produced, it is possible that the fermentation temperature was too high, which reduced the activity of nitrifying bacteria, which are sensitive to high temperatures of 70°C or higher.

[0069] (Note) Although the present disclosure has been illustrated using the preferred embodiments thereof, it is understood that the present disclosure should be interpreted in scope only by the claims. It is understood that the patents, patent applications, and other documents cited in this specification are incorporated by reference into this specification in the same manner as if the contents themselves were specifically set forth herein. [Industrial Applicability]

[0070] Compost produced by the compost production method provided in the present disclosure is less likely to cause reduction problems and is therefore believed to have great commercial value.

Claims

1. A method for producing compost from raw materials including plant residues and food residues, comprising: 1) crushing and then dehydrating said vegetable residue; 2) mixing the dehydrated vegetable residue, the food residue and secondary materials to obtain an initial raw material; 3) transferring the initial raw material to a primary fermentation zone, aerating the initial raw material 24 hours a day for 1 to 6 weeks, and carrying out primary fermentation of the initial raw material at 60°C to 70°C to obtain a primary fermentation product; 4) transferring the primary fermentation product to a secondary fermentation zone and carrying out secondary fermentation at 45°C to 60°C for 1 week to 8 weeks to obtain a secondary fermentation product; 5) transferring the secondary fermentation product to a tertiary fermentation zone and carrying out tertiary fermentation at 45°C to 55°C for 4 to 12 weeks to obtain a tertiary fermentation product; 6) Composting the tertiary fermentation product wherein the dehydrated vegetable residues and the food residues constitute at least 80% by weight of the raw material; below a) in the primary fermentation step 3), the primary fermentation is carried out in a different location every week; b) in the secondary fermentation step of 4), aeration by stirring the primary fermentation product at a frequency of 2 times / day to 1 time / 4 days; and c) In the tertiary fermentation step of 5), aeration is performed by turning the secondary fermentation product over at a frequency of 2 times / week to 1 time / 3 weeks; [0033] Manufacturing method.

2. The method according to claim 1 , wherein the aeration in the primary fermentation is performed through an aeration tube.

3. The method of claim 1 , wherein the compost has a C / N ratio of less than 17.

4. 2. The process of claim 1, wherein the C / N ratio of the initial feedstock is at least 45.

5. The method according to claim 1, further comprising a step of pre-fermenting the initial raw material by forced aeration for 1 day to 2 weeks prior to the primary fermentation step 3) to raise the temperature of the initial raw material to 50°C to 70°C.

6. The method according to claim 1, wherein the moisture content of the initial raw material is 40-80% (w / w).

7. The manufacturing method according to claim 1, wherein the step 6) is a step of subjecting the tertiary fermentation product to quaternary fermentation at 45° C. or higher for 1 to 12 weeks to obtain a quaternary fermentation product, and composting the quaternary fermentation product.

8. The method according to claim 7, wherein aeration is not performed in the quaternary fermentation of the step 6).

9. The method according to claim 1 , wherein the secondary materials include rice husks and return compost.

10. The method according to claim 9 , wherein the auxiliary material further comprises a waste mushroom bed.

11. The method of claim 9 , wherein the return compost comprises the tertiary fermentation product.

12. 2. The method of claim 1, wherein the weight of the dehydrated vegetable residues and food residues accounts for 90% of the weight of the raw material.

13. The method according to any one of claims 1 to 12, wherein the compost has a base exchange capacity (CEC) of at least 5.

14. The method according to claim 13, wherein the weight of ammonia nitrogen is at least 25% and the weight of nitrate nitrogen is at least 25% of the total weight of ammonia nitrogen and nitrate nitrogen in the compost.

15. Compost obtained by the method according to claim 1.

Images