JP2000109386A - Composting method of organic waste and evaluation method of composted material thereby - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a composting method for producing compost from organic waste without generating any malodor and also to provide an evaluation method of a composted material by the composting method. SOLUTION: This composting method comprises subjecting organic waste to microbial decomposition in an anaerobic atmosphere and further subjecting the decomposed waste to microbial decomposition in an atmosphere in which facultative anaerobic bacteria and aerobic bacteria can be grown, wherein the organic waste is subjected to saccharification and fermentation and bacteria of the genus Bacillus, lactic acid bacteria and yeast are grown and further, aerobic decomposition of the organic waste by actinomycetes proceeds. The evaluation method comprises measuring a near-infrared spectrum of the composted material thus produced and on the basis of the measured near- infrared spectrum, determining the degree of ripening of the composted material, wherein the smaller the absorbance or the larger the amount of reflection in the near-infrared spectrum, the higher the degree of ripening of the composted material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for composting organic waste by fermenting organic waste to produce compost, and a method for evaluating compost to determine the progress of composting in the production of compost. More particularly, the present invention relates to a method for composting organic waste and a method for evaluating compost, which enable production of high-quality compost without causing environmental problems due to bad smell during fermentation of organic waste.

[0002]

2. Description of the Related Art In the past, in agriculture where the production unit was small, composting of organic waste such as garbage discharged from the processes of the agriculture and livestock industry and farmers through a long fermentation and decomposition period was carried out. It was used as a fertilizer for production. However, at present, pesticides and chemical fertilizers are used in order to expand and stabilize agricultural production, and organic waste is not composted.

However, in recent years, in the treatment of wastes including household garbage and industrial wastes, the problem of lack of landfills and incineration capacity has become apparent, and the waste disposal administration itself has felt a deadlock. Some kind of breakthrough is needed.

[0004] The use of compost has attracted attention because the discussion on the influence of synthetic chemical substances on the environment and living organisms has been vigorously conducted and interest in organic cultivation of agricultural products has been increasing.

[0005] Under such circumstances, household garbage and a large amount of organic waste discharged in the processing industries such as the agriculture and livestock industry, the food processing industry, the food service industry, and the sludge treatment have been produced in the past. Such treatment by composting is considered appropriate, and various attempts have been made.

[0006] For example, as a conventional method for producing compost, there is a method using an aerobic fermentation material as disclosed in Japanese Patent Application Laid-Open No. 52-112568. Since the method of producing compost by aerobic fermentation requires a long time for composting, attempts have been made to promote fermentation by air blowing or heating. In addition, we shorten time required for compost production,
For the purpose of preventing generation of offensive odor, a method for producing compost by anaerobic fermentation has been proposed in Japanese Patent Application Laid-Open No. H8-16789. According to this method, the water content of the organic waste is reduced to 3
An anaerobic fermentation is performed after adjusting to be 0 to 60%.

[0007]

However, the currently proposed method for producing compost from organic waste is incomplete, and the viewpoint is to reduce the time required for composting, with emphasis on treatment efficiency. Therefore, there is a problem that the compost produced has a bad smell or is of low quality unsuitable for agricultural production.

The present invention has been made to solve such problems of the prior art, and provides a method for composting an organic waste capable of providing a high-quality compost suitable for agricultural production without generating a bad odor. The purpose is to do.

Another object of the present invention is to provide a method for evaluating compost for detecting the progress of composting of organic waste.

[0010]

Means for Solving the Problems In order to achieve the above object, the present inventors have conducted intensive studies and as a result, have managed fermentation conditions so that microorganisms necessary for the progress of composting can be suitably propagated. By doing so, it has been found that it is possible to provide good compost while preventing generation of offensive odors and harmful substances, and has invented a method for composting organic waste according to the present invention.

In the composting of organic waste, the absorbance (or reflection) obtained by measuring the near-infrared reflection spectrum
Was found to be changed, and the method for evaluating compost according to the present invention was invented.

According to one aspect of the present invention, the method for composting organic waste according to the present invention includes a first step of saccharifying and fermenting the organic waste, and a method of adding Bacillus genus to the organic waste that has passed through the first step. And a second step of decomposing organic waste by breeding bacteria, lactic acid bacteria and yeast.

[0013] In the first step, filamentous fungi propagate.

[0014] The above composting method may further include a third step of propagating an actinomycete producing an antibiotic to the organic waste that has passed through the second step.

The method may further include a forming step of forming the organic waste having passed through the third step and drying the formed organic waste to a water content of at least 30 wt%.

Further, before the first step, a step of adjusting the C / N ratio of the organic waste to 25 to 40 and the water content to 45 to 70 wt% may be provided.

In the first step, the organic waste is maintained at 40 to 70 ° C. in an anaerobic atmosphere. In the second step, a first period during which Bacillus bacteria and lactic acid bacteria propagate and a second period during which yeast propagates The test is performed in an atmosphere in which facultative anaerobic bacteria and aerobic bacteria can proliferate.

In the first period of the second step, the temperature of the organic waste is maintained at 60 to 75 ° C. and bacteria of the genus Bacillus proliferate, and the temperature drops to 50 ° C. or less, and lactic acid bacteria proliferate.

Alternatively, according to another aspect of the present invention, the method for composting organic waste according to the present invention comprises a first step of microbial decomposition of organic waste in an anaerobic atmosphere; A second step of microbial decomposition of the organic waste that has passed through the process in an atmosphere in which anaerobic and aerobic bacteria can grow.

The anaerobic atmosphere in the first step has a carbon dioxide gas concentration of 10 to 35 vol%, an oxygen concentration of less than 5 vol%,
The humidity is 70 to 90%, and the atmosphere in the second step has an oxygen gas concentration of 5 to 40 vol% and a carbon dioxide gas concentration of 2 to 40 vol%.
vol% or less, humidity is 50 to 70%.

In the first step, the temperature of the organic waste is maintained at 40 to 70 ° C., and in the second step, the period during which the temperature of the organic waste is maintained at 60 to 75 ° C. and the temperature are 50 ° C. C. or less.

The above composting method may further include a third step of propagating actinomycetes producing antibiotics to the organic waste that has passed through the second step.

The atmosphere in the third step has an oxygen gas concentration of 18 to 20%, a carbon dioxide gas concentration of 2% or less, and a humidity of 50%.
It is managed to be ~ 70%.

The above composting method may further include a forming step of forming the organic waste that has passed through the third step and drying the formed organic waste to a water content of at least 30 wt%.

In the above composting method, before the first step, the C / N ratio of the organic waste is 25 to 40 and the water content is 4%.
It may have a step of adjusting to 5 to 70 wt%, and it is possible to cope with organic wastes having different C / N ratios and water contents depending on the types.

The first step is carried out for 5 to 10 days,
Step is 14 to 30 days, and the third step is 30 to 90 days.
Done for days.

Further, according to the present invention, the volume of the organic waste is reduced by providing the organic waste to the first step.

Further, according to the present invention, the method for evaluating compost comprises measuring a near-infrared spectrum of the compost obtained by composting an organic substance, and based on the measured near-infrared spectrum, measuring the near-infrared spectrum of the compost. This is to determine the maturity.

In the above determination of the maturity, it is determined that the maturity is increased when the absorbance in the near infrared spectrum is small or when the reflection is large.

According to another aspect of the present invention, the method for evaluating compost according to the present invention includes a discriminant function for judging maturity from near-infrared spectrum data of a compost sample for calibration of maturity. The maturity of the compost is determined from the near-infrared spectrum data of the compost to be prepared and evaluated using the above discriminant function.

[0031]

BEST MODE FOR CARRYING OUT THE INVENTION Compost is a mixture containing metabolites obtained by decomposing organic substances by metabolism of microorganisms and microorganisms, and is useful for plants by applying compost to soil. The components are directly or indirectly incorporated into plants through microorganisms and small organisms in the soil to be assimilated. However, depending on the composting conditions, substances harmful to the plant may be generated in the compost or pathogenic bacteria that inhibit the growth of the plant or soil microorganisms may be generated. In other words, not all composts obtained by decomposing organic waste by microorganisms are suitable for growing plants, and in order to obtain an appropriate compost, it is extremely important to adjust the conditions while paying attention to the composting environment. In addition, since the ratio of components required for growth differs depending on the type of plant, a suitable compost may not be obtained depending on the plant to which the plant is applied. Further, there is often a problem that a bad odor due to putrefaction is released at the time of composting, which is an obstacle in performing composting as a treatment of organic waste.

[0032] Good quality compost is one that does not contain components and microorganisms that inhibit the growth of the plant, and that can properly provide nutrients necessary for the growth of the plant to the plant. Considering that plants can be ingested by humans via, it is a major premise that no harmful heavy metals or chemicals are mixed in the human body.

In order to obtain such a high quality compost by composting organic waste, trial and error were repeated.
It is necessary to prepare a composting environment so that rot does not predominantly progress and balance the microorganisms that propagate, and if the reproduction balance of the microorganisms is good, properly contain nutrients, enzymes, immune-enhancing substances, etc. It was found that good quality compost was obtained, and that no odor and no toxic substances were generated due to decay. In other words, in order to obtain a high-quality compost, it is important that the progress of putrefaction do not become dominant during the composting, and that non-degradable decomposition due to depolymerization such as fermentation of organic matter proceeds. This does not require an unnatural state in which specific microbial species are administered to organic waste and only propagates it, but is possible by properly managing the growth of soil microorganisms. . In short, fermentation / decomposition by complex bacteria is performed instead of fermentation by simple bacteria.

There are various types of microorganisms involved in the decomposition of organic substances, and the substances produced by the decomposition also vary widely. For example, filamentous fungi such as koji mold, yeast, lactic acid bacteria and the like used in the production of general fermented foods are known to produce useful substances such as sugars and alcohols. Produces toxic proteins (exotoxins) that cause diseases such as food poisoning and tetanus by the decomposition (rot) of proteins. There are also molds that produce antibiotics such as penicillin and molds that produce carcinogens such as aflatoxin. As described above, in the decomposition by microorganisms, harmful substances such as bad smells, pathogenic bacteria, and toxins may be produced, and useful substances may be produced.

To compost organic waste, starch,
It is necessary to decompose various organic substances such as sugars, fibers, fats and oils, hydrocarbons, proteins, and chitin, and this requires the propagation of various useful microorganisms. Moreover, if these various kinds of microorganisms cannot be propagated stepwise at appropriate timing, suitable composting with a good reproduction balance of the microorganisms does not proceed. In addition, it cannot be decomposed by fermentation with a simple microorganism.

As a result of investigating the process in which suitable composting proceeds, it was first found that the common process is common in that microorganisms having a saccharification action of organic substances propagate. Sugar, glucose, maltose, fructose, and other sugars are nutrients for various microorganisms such as filamentous fungi, lactic acid bacteria, yeasts, actinomycetes, and bacteria. Can be. Saccharification of organic matter, that is, sugar fermentation, is carried out by filamentous fungi such as Aspergillus (Aspergillus) and Rhizopus (Cryptobacterium), and such microorganisms propagate under anaerobic conditions. Many of the bacteria that cause spoilage are aerobic inactive under anaerobic conditions, so that they are easier to prevent spoilage under anaerobic conditions than under aerobic conditions, and that microorganisms that perform sugar fermentation preferentially propagate. As a result, propagation of other bacteria is suppressed, so that spoilage bacteria are also difficult to propagate.

Next, the common feature is that after the sugar fermentation has progressed, other useful microorganisms are propagated using the produced sugar. Important at this stage is the growth of microorganisms that secrete degradative enzymes such as amylolytic enzymes, proteolytic enzymes, lipolytic enzymes, and the like. Such microorganisms include Bacillus bacteria such as Bacillus subtilis and Bacillus subtilis, and Bacillus subtilis has a high lipid and fiber decomposition activity,
Bacillus subtilis propagates while secreting amylase (amylolytic enzyme) and protease (proteolytic enzyme). Propagation of the protein progresses due to propagation of Bacillus subtilis to produce an amino compound. In the presence of air (oxygen), the amino compound is further oxidized from ammonia to nitrate by nitrosomonas (ammonia-oxidizing bacteria) and nitrobacter (nitrite-oxidizing bacteria), so that it can be absorbed by plants. At this time, the presence of carbon dioxide lowers the pH of the system and acts to suppress the emission of bad odors due to amino compounds and ammonia. Following the propagation of such microorganisms, lactic acid bacteria grow and produce lactic acid from saccharides to lower the pH of the system. Organic acids such as lactic acid suppress the emission of offensive odors due to ammonia and the like, and the low pH prevents the growth of putrefactive bacteria having low acid resistance. Therefore, the propagation of lactic acid bacteria is very effective in preventing putrefaction and offensive odor.

Thereafter, yeasts propagate, thereby producing vitamins, organic acids, amino acids and the like.

As described above, many kinds of microorganisms start to proliferate one after another by using the sugars produced by the filamentous fungi and the microorganisms proliferating subsequently as nutrients. Fading away. During this time, the temperature of the system rises due to the metabolism of microorganisms, which effectively acts to prevent the growth of putrefactive bacteria having low heat resistance. Therefore, by managing the organic waste to be composted to go through such a process, a suitable compost can be obtained.

The compost obtained through the above process is rich in nutrients and can be suitably used for growing plants. Further, when the compost is matured under conditions in which actinomycetes grow,
Actinomycetes, such as Streptomyces and Actinomyces, produced by components that improve plant resistance, such as antibiotics, proliferate, and their pH values rise to neutral or weak bases. When animals such as livestock are raised by using the plants grown using such aged compost as feed, there is also an effect that the immunity of the animals is improved.

The main point for promoting the propagation of microorganisms as described above is that the organic waste is firstly decomposed by microorganisms under anaerobic conditions, and then the organic waste is transferred to facultative anaerobic / aerobic coexisting conditions to decompose. It is to continue. In the initial anaerobic condition, saccharide fermentation (primary decomposition) by anaerobic filamentous fungi progresses, and thereafter the condition shifts to facultative anaerobic / aerobic coexistence conditions, thereby inhibiting the growth of obligate anaerobic bacteria. Facultative anaerobic bacteria and aerobic bacteria can be propagated, and degradation by Bacillus and lactic acid bacteria (secondary degradation), degradation by yeast (tertiary degradation), and degradation by aerobic bacteria actinomycetes (ripening) are possible. Then proceed.

The growth of microorganisms progresses in balance with the growth of other microorganisms, and it is difficult for one microorganism to grow with the growth of other microorganisms active. Therefore, preparing an environment so that fermentation easily proceeds in composting is effective for preventing spoilage. In the present invention, the propagation of useful microorganisms after the secondary decomposition is facilitated by the production of sugars in the primary decomposition, and the decay is easily suppressed by the propagation of the useful microorganisms prior to the propagation of the putrefactive bacteria. When composting is actually carried out in accordance with the present invention, if the primary decomposition has sufficiently proceeded, there is little contamination with putrefactive bacteria in the steps from secondary decomposition to ripening, and the management is relatively easy.

However, as is empirically known in the production of fermented foods, it is difficult to breed microorganisms that undergo the desired fermentation and decomposition once the microorganisms that cause spoilage once propagate, even if the environment is adjusted. In particular, the composting of the present invention ensures that the inherent functions of naturally occurring microorganisms are exerted in a specific direction in a specific direction, and is a limited process such as inoculating a specific pure culture microorganism in an aseptic state. It is not intended. Therefore, even if the environmental conditions are adjusted, there is no possibility that the reproduction balance of microorganisms will change due to any factor of equalization, and the growth of organic waste and microorganisms will be managed and composted until composting is completed. Need to be controlled.

The details of the organic waste composting process of the present invention, which is carried out in accordance with the above, including management and control, will be described below.

First, when foreign substances such as metals, plastics, and glass which cannot be decomposed by microorganisms are contained in the organic waste, it is preferable to remove these foreign substances from the organic waste in advance as a pretreatment. In particular, care must be taken for waste containing heavy metals such as dry batteries, batteries, and mercury thermometers. Plastic and glass may be removed after composting, but it is desirable to remove these foreign substances at the beginning in order to use the processing space volume efficiently.

The organic waste from which foreign matter has been removed has a C / N ratio (carbon / nitrogen ratio) of preferably about 25, depending on its content.
It is mixed and adjusted to be と 40, and the water content is preferably about 45 to 70 wt%, more preferably 60 to 65 wt%.
Drain or add water to a degree.

The reason for adjusting the C / N ratio of the organic waste to be composted is as follows.

Sawdust, chips, waste mushrooms grown in mushrooms,
Leaf litter, straw, rice husk, bark, etc. are organic wastes with a high C / N ratio, and those with such a high C / N ratio have a shortage of nitrogen for constituting microorganisms as the microbial decomposition progresses. As a result, the decomposition rate gradually decreases, and the decomposition is easily stopped.
For this reason, the time required for composting becomes long and it is difficult to decompose.
When applied to soil without sufficient composting, it slows crop growth by depriving the soil of nitrogen and thinning the soil. On the other hand, swarf, animal dung, rice bran, rice bran, okara, oil cake, bran, garbage, coffee cake, beer cake, sludge, etc. are organic wastes having a low C / N ratio, and are easily decomposed, but in the middle of composting. When it is applied to soil, it decomposes vigorously in the soil to generate ammonia, methane, carbon dioxide, etc., and causes root burning due to lack of oxygen or a large amount of ammonia, making root respiration difficult and killing the plant. Conversely, by utilizing such properties, for example, it is also possible to use a compost that is being prepared from an organic substance having a high C / N ratio in order to reduce the amount of nitrogen in soil where excess nitrogen has accumulated. However, in order to efficiently compost organic waste, it is preferable to adjust the C / N ratio so as to be in the appropriate range as described above so that the decomposition by microorganisms proceeds easily. In this regard,
Dairy waste, food processing waste, and the like have relatively clear contents, so it is not difficult to adjust the C / N ratio.

Although water is a necessary element for the growth of microorganisms, if the water content of the organic waste is excessive, air permeability is reduced, and the growth of microorganisms is suppressed. Accordingly, the water content of the organic waste is adjusted as described above according to the conditions required for the propagation of microorganisms while taking into consideration the air permeability. The rate of microbial degradation is affected by the water content,
It decomposes most when the amount is about 0 to 65% by weight, and when it is less than 40% by weight, the decomposition rate becomes extremely slow. Since excessive moisture easily causes putrefaction, if the water content is set to about 50% by weight before the start of decomposition and the primary decomposition is started and then water is adjusted to an appropriate amount, the putrefaction is easily prevented. However, since the temperature is easily lowered by the addition of water, the addition of water for adjusting the water content is desirably two or less, and in that case, it is necessary to pay attention to the temperature control.

The water added to adjust the water content of the organic waste is preferably natural water. Water that has been filtered and sterilized by adding calcium, such as tap water, is not suitable for composting, and water that can contain microorganisms and minerals, such as high-quality well water and Iwashimizu water, is preferable. It is also possible to use a culture solution obtained by culturing a soil microorganism or the above-mentioned useful microorganism. Regarding the adjustment of the water content, the use of secondary materials, that is, the mixing of multiple types of organic wastes is an effective means. For example, it is possible to properly adjust both the water content and the C / N ratio by mixing a material having a low water content and density such as peach grass and a material having a high water content and density such as animal dung. .

Further, it is preferable to add chitinous waste such as crab shells in advance, since it becomes possible to propagate Trichoderma (Thyroid mold) which degrades cellulose.

The organic waste whose water content and C / N ratio have been adjusted is subjected to primary decomposition to promote decomposition by microorganisms. Primary degradation is performed under anaerobic conditions for about 5 to 10 days, and saccharification progresses due to propagation of filamentous fungi. More specifically, the atmosphere during the primary decomposition is substantially free of oxygen gas (less than 5%), the carbon dioxide gas concentration is about 10 to 35 vol%, and the humidity is 7
Manage so as to be 0 to 90%. Since the amount of water in the atmosphere increases with the progress of decomposition, in order to maintain atmospheric conditions, it is preferable to circulate the decomposition atmosphere by taking it out of the system, adjusting the humidity by dehumidification, and then returning it to the system. The temperature is maintained at about 40-70 ° C. Under such conditions, the growth of anaerobic bacteria such as yeast, filamentous fungi and lactic acid bacteria, particularly filamentous fungi, progresses, and the growth of aerobic bacteria is suppressed.
When the primary decomposition proceeds suitably, aroma such as amazake is generated with the sugar fermentation. If the decomposition by microorganisms progresses locally, molds that cause decay due to local changes in the environment are likely to occur.Therefore, it is necessary to switch back in a timely manner so that the fermentation decomposition proceeds uniformly in the entire organic waste. desirable.

The organic waste that has undergone saccharification due to the primary decomposition is subjected to secondary decomposition for about 14 to 30 days under conditions of coexisting anaerobic / aerobic conditions, and is further decomposed by microorganisms. Specifically, the carbon dioxide concentration in the atmosphere during the secondary decomposition is about 2%.
Hereinafter, the oxygen concentration is about 5 to 40%, and the humidity is 50 to 70%.
It is managed to be on the order. When the protein decomposition by Bacillus subtilis progresses, the temperature rises. However, if the temperature is too high, the nitrogen content decreases sharply and hinders the growth of the microorganisms thereafter, so that the temperature is maintained at about 60 to 75 ° C. Switching is performed about four times a month. The temperature may be lowered by administration of water, also serving as hydration. If the secondary decomposition proceeds favorably, a scent similar to miso or soy sauce is generated at this point. If the secondary decomposition does not proceed properly due to insufficient growth of the filamentous fungi in the primary decomposition due to an error in the adjustment of the water content or the C / N ratio, the saccharide or organic carbon content and a trace amount of minerals are contained. Aqueous solution (for example, brown sugar water)
By replenishing the organic waste with a liquid in which lactic acid bacteria, Bacillus bacteria and the like have been grown, decomposition can proceed and odor can be prevented. When the decomposition by Bacillus subtilis passes the peak, the temperature of the organic waste decreases, and when the temperature falls below 50 ° C., lactic acid bacteria start to be activated, and the pH value of the organic waste decreases to become acidic. This kills harmful bacteria. If the lactic acid bacteria do not propagate and corrosion occurs, the pH value does not decrease and the lactic acid bacteria become basic instead, and begin to emit a bad smell such as an acid-stimulated odor. In this case, the secondary decomposition is performed again by adding the growth liquid of the microorganism described above.

When the lactic acid bacterium is turned over after its peak, the temperature of the organic waste rises again by about 5 ° C.
Then it drops again. In this period, about 90 days, yeast grows, white cells can be seen below the surface of organic matter, tertiary decomposition proceeds, and organic waste contains amino acids, proteins, alcohol, vitamins, etc. Become.

The decomposed product dried at the time of completion of the tertiary decomposition can be sufficiently used as compost, but it becomes more effective compost by further aging. Aging of the organic waste after the completion of the tertiary decomposition is performed under aerobic conditions for about 30 to 90 days. The atmosphere during ripening preferably has a carbon dioxide concentration of about 2% or less, an oxygen concentration of about 18-20%, and a humidity of 50%.
It is managed to be about 70%. In this state, actinomycetes such as Streptomyces, Actinomyces, and Flavobacterium multiply to produce antibiotics, which increase the pH value and stabilize the neutral to weakly alkaline range. If organic waste contains chitin, Trichoderma will also propagate. Propagation of bacteria that produce antibiotics requires air permeability, so it is preferable to turn them back once or twice a month to prevent spoilage. During ripening, the water content is likely to be insufficient, so the water content is adjusted. It is preferable to use a culture solution of a microorganism. Usually, after aging for about one month, a compost having gray spots caused by actinomycetes is obtained. If rocks such as granite and basalt are crushed and introduced as much as possible during maturation, a compost rich in minerals necessary for soil and microorganisms can be obtained. Minerals can enhance the activity of microorganisms and promote plant activity. When rock is added to the compost, after application to the soil, it promotes germination and rooting of the plant, increases the respiratory action of the root, increases the amount of protein in the plant, prevents continuous cropping failure, adjusts the balance of soil components, In this method, effects such as imparting resistance to stress such as drought, improving clay soil, retaining water-soluble inorganic fertilizer, and absorbing unnecessary substances to plant roots can be obtained.

When the process from primary decomposition to ripening takes about 3 to 6 months, the organic waste becomes good compost. The compost that has matured is subjected to shape processing such as granulation as necessary,
By drying so that the water content does not become 30% or less, a compost product that does not cause odor or harm is obtained. If overdried, actinomycetes in the compost will be inactivated.

In the above-mentioned primary decomposition, secondary decomposition, tertiary decomposition and ripening, the introduction of negative ions into the atmosphere improves the activity of microorganisms, especially anaerobic microorganisms. For anaerobic microorganisms, oxygen, particularly O ₂ ⁺ , inhibits the vital mechanism, but reduced O ₂ ^- is harmless, so it converts oxygen in the atmosphere to reduced form or converts negative ions into negative ions. By supplying, the vitality of anaerobic microorganisms can be improved. Also, aerobic microorganisms have ion exchange incorporated into their biological mechanisms, the quality of oxygen supplied is important, and the supply of negative ions has an effect on activation. The supply of negative ions is described in, for example,
It can be performed safely using the negative ion generator described in Japanese Patent No. 74946.

In at least one of the above-described primary decomposition, secondary decomposition, tertiary decomposition and ripening, an elastic wave having an appropriate wavelength and waveform such as music may be supplied to promote the decomposition.

Compared with the case of industrial production, in a process using microorganisms, even if the control is performed sufficiently, there is a greater risk of unexpected accidents such as propagation of harmful bacteria. Therefore, to minimize the damage caused by such accidents,
It is better to divide organic waste into relatively small batches and use separate containers for fermentation / decomposition so that rot does not spread throughout the waste, and to proceed while checking the progress of decomposition for each container. preferable. Since the volume of organic waste rapidly decreases with the progress of composting, especially from the primary decomposition to the secondary decomposition, the container capacity during decomposition, the capacity of the entire system, the distribution of containers, etc. are designed taking this into account. Is preferred.
Waste, such as garbage, undergoes primary decomposition, reducing its capacity by a factor of about 25. For this reason, the primary decomposition step of the composting method of the present invention can be suitably used as a method for reducing the volume of organic waste.

The above-mentioned method for composting organic waste can be carried out, for example, using a compost production system 1 as shown in FIG. This compost production system 1 has a building 5 equipped with a conveyor 3 and the inside of the building 5
It is partitioned into a decomposition chamber 7, a second decomposition chamber 9, and an aging chamber 11. Furthermore, warehouse 13, deodorization room 15, temporary storage space 1
7. Water treatment / coolant device 19, pre-decomposition chamber 21A, 2
1B, an office 61, a quality control room 63, and a shipping room 65 are attached, and organic waste is a vegetable residue (garbage),
They are separated into animal residues, animal droppings, fish and shellfish waste, etc., stored in containers, and placed in the temporary storage space 17. In the first decomposition chamber 7, the second decomposition chamber 9 and the aging chamber 11,
A carbon dioxide gas concentration meter, an oxygen concentration meter, a thermometer, a hygrometer, a thermothermometer, and an ammonia concentration meter are additionally provided to control the composition and temperature of the atmosphere. Further, in order to promote the growth and decomposition of microorganisms, a negative ion generator and a speaker for supplying music may be provided.

Information on organic waste is stored in the quality control room 6
The organic waste of the container is accumulated and managed in the management system of No. 3 and the pre-decomposition chamber 21A or 2B is transferred through the carry-in conveyor with hopper 23A or 23B based on the information of the management system.
1B and mixed to prepare an organic waste having an appropriate C / N ratio. Here, drainage for moisture adjustment is also performed. The organic waste in the pre-decomposition chambers 21A and 21B is supplied to the transport conveyor 3 by the conveyors 25A and 25B and stored in the pallet P. At this time, the generation of odor is prevented by spraying a microorganism culture solution such as lactic acid bacteria on the organic waste on the pallet P.

The take-out conveyor 2 for supplying the pallets P of the conveyor 3 to the first disassembling chamber 7 and the passage 31
7 and 33 are provided, and the passage 31 communicates with the second decomposition chamber 9 and the aging chamber 11. Shutters 29, 35, 37, which can be opened and closed to shut off the atmosphere of each room from the conveyor 3
39 and 41 are provided. In the middle of the conveyor 3, reversing and turning devices 43 and 45 and a shaker 47 are additionally provided.

The pallet P transported from the transport conveyor 3 to the first decomposition chamber 7 is stored on a shelf 69 by the robot 71, and the primary decomposition of the organic waste is performed. The organic waste in each pallet P is timely analyzed to check the progress of fermentation,
The pallet P that has been determined to have completed the primary disassembly is transported to the passage 31 by the transport conveyor 3 and the take-out conveyor 33, and is moved by the robot 79 to the shelf 7 in the second disassembly chamber 9.
3 for secondary decomposition and tertiary decomposition. The pallet P determined to have undergone the tertiary decomposition of the organic waste by the analysis is transferred to the shelf 75 of the maturing room 11 by the robot 79.
Is stored and aged to produce compost. The aged pallet P is further stored in the warehouse 13 by the robot 79.
Is stored on the shelf 77.

The shipping room 65 is provided with a granulating device 49, a bag filling device 51, a take-out conveyor 53 and a supply conveyor 57, and shutters 55, 59 which can be opened and closed to shut off the conveyors 53, 57 and the warehouse 13. Is provided. The pallet P conveyed from the aging room 11 to the warehouse 13 is carried into the shipping room 65 by the conveyor 53, and performs sampling and analysis for a final product check.
If there is insufficient composting, it is returned to the ripening room 11 for ripening again. The completed compost is subjected to a shaking sorter 47 to remove foreign substances and sorted by particle size. Coarse particle size
It is added to the organic waste for adjusting the water content of the organic waste or as a seed fungus. The compost having a fine particle size is subjected to granulation using a granulation device 49 and packaging by a bag packing device 51 as necessary. The packed products are packed in pallets by the palletizing robot 67 and stored on the shelves 77 of the warehouse 13 by the conveyor 47. Products that are not bagged are also stored in the warehouse 13 on pallets.

The decomposition and composting of organic matter by microorganisms is called "ripening" and is distinguished from "rot". Conventionally, the degree of maturity of organic matter and the degree of “maturity” have been determined by a combustion method, a germination test, a decay test, and the like described below. Recently, a GPC method has been generally used as a quantitative determination method. It is getting. The GPC method is a method in which components are fractionated according to molecular weight using GPC (gel permeation chromatography), and a ratio (GPC ratio) of a component having a predetermined low molecular weight in all components is determined, thereby determining a degree of maturity. is there. As ripening progresses, the carbon content decreases due to the disappearance of decomposition of carbohydrates and the like.
The / N ratio also decreases. As the C / N ratio decreases, GPC
The degree of maturity is determined using the correlation that the rate also decreases. According to the GPC method, a molecular weight of about 1500
The amount of fractions detected and fractionated below (280 nm
(Detection by absorption of ultraviolet light characteristic of substances such as proteins and nucleic acids) in the total components (G
PC ratio), in the composting according to the present invention, this value is 10% or more in the “immature” state during the primary decomposition (saccharification and fermentation), and in the “mature” state during the secondary decomposition. Two
10%, 0.5-2% in "mature" state during tertiary degradation,
In the “ripe” state during ripening, the GPC rate is 0.5% or less. In the “immature” state, readily degradable proteins and saccharides are undegraded, phenolic acid, tannic acid and fat remain, and pathogenic bacteria and weed seeds are not killed. In the "medium-ripened" state, easily degradable proteins and saccharides are degraded by about half, and pathogenic bacteria and weed seeds are killed by the rise in temperature due to the degradation. In the "ripe" state, most organic substances including phenolic acid and tannic acid are decomposed and the microflora is stabilized. Both types of compost are decomposed by microorganisms in the soil when applied to the soil, and become fertilizers for plants.Immature compost is decomposed in the soil when carbon dioxide, hydrogen sulfide, methane, organic acids, ammonia Etc., which interfere with the normal growth of plant roots and cause disease, and also cause odor and groundwater contamination, and also cause the quality of agricultural products to be reduced by pests and become a source of infection. . As the compost matures, such harms are reduced and immunity-enhancing substances are generated to promote plant growth.

In the composting of organic waste according to the present invention, in order to properly perform the composting, the transition time of each decomposition stage,
In particular, a criterion for determining when to shift from the primary decomposition to the secondary decomposition is required. Although it is of course possible to make a perceptual judgment based on the appearance or smell or the like by a method described later, a device analysis method is required for making a more accurate and efficient judgment in a short time. In this regard, the above-described GPC method requires time for measurement, and thus is not suitable for frequently inspecting the decomposition state, and is also disadvantageous in improving the efficiency of a plant and inspecting the quality of products. The inventor of the present application has found a method capable of accurately and efficiently detecting the maturity of an organic waste to be composted in a short time, and presents the method here. The method presented by the inventor of the present application is a method of determining the maturity based on the measurement of the near-infrared reflection spectrum.

FIG. 2 is a spectrum chart showing a near-infrared reflection spectrum of the organic waste subjected to composting. The degree of maturity of the compost sample was determined by the GPC method, the primary decomposition was completed, and the tertiary decomposition was completed. It summarizes the results of measuring the near-infrared reflection spectrum of five samples for each of the sample and the matured sample. Sign A
The hatched area indicated by the symbol indicates the area in which the spectrum of the one after completion of the primary decomposition is distributed, the vertical line area indicated by the symbol B indicates the area in which the spectrum after the completion of the third decomposition is distributed, and the horizontal line area indicated by the symbol C indicates the area after the ripening is completed. This is the area where the spectrum of compost is distributed. As is clear from FIG. 2, in the near-infrared reflection spectrum, the spectrum shape and the absorbance (or reflection) change in the entire wavenumber range depending on the maturity of the compost, and the absorbance decreases as the maturity increases. About 4200-5000cm ^-1
And remarkable difference in absorbance at about 5400~7000cm ^-1, specificity is seen in the spectral shape in the vicinity especially 4500cm ^-1. It is clear from this that the maturity can be determined by near-infrared spectral analysis of the compost. For example, the areas A, B, and C in FIG. 2 are used to manage the composting process as a boundary between an immature state and a mature state, a boundary between a mature state and a mature state, and a boundary between a mature state and a mature state. be able to. If the wavelength (or wave number) at which the absorbance is measured is specified to be one or several, and the judging material is limited so as to judge the maturity from the change in the absorbance measured at this wavelength, the judgment time can be reduced. .

As described above, the degree of maturity can be determined by measuring the near-infrared spectra of the standard compost sample and the compost to be evaluated and visually comparing the obtained spectrum charts. If the degree of maturity can be determined by data processing, it is effective for automatic control and quality control of the process. An example of judging the maturity by data processing from the measurement of the near-infrared reflection spectrum will be described below. Of course, other generally known data processing methods may be used, and an appropriate data processing method may be used as needed.

First, the measurement data of the calibration sample measured in the near-infrared region as shown in FIG. 2 is subjected to Fourier transform, and then stored as spectral data of wave number and absorbance (or transmittance, reflection). If necessary, the spectrum is converted (transmittance-absorbance-reflection). The absorbance (or transmittance, reflection) at each wave number is developed in a multidimensional space, and principal component analysis is performed. In the case of PLS regression analysis, the principal component analysis is performed by similarly developing the absorbance (or transmittance, reflection) in a multidimensional space using the hand analysis value as a variable in addition to the wave number.

A new principal component axis (first
After determining the axis and the second axis ---), it is determined how each sample is positioned in the principal component space (calculation of principal component scores), and a discriminant model and a discriminant model are calculated from each sample point according to discriminant analysis. A discriminant function for judging the maturity is created.

The unknown sample to be evaluated is measured, the position in the principal component space is determined from the obtained spectral data according to the same processing as described above, and the Mahalanobis general distance is determined by the discriminant function. Whether it belongs to the classification (maturity) is quantitatively determined, and the maturity is determined.

The measurement of the near-infrared spectrum of the compost can be carried out by using a commonly used measuring device, but a probe type equipped with a detector which can be directly inserted into a sample and measured. The use of the measuring device is particularly effective for improving the efficiency of process control and quality control.

In order to confirm the judgment result based on the near-infrared reflection spectrum as described above, the above-described GPC method and other methods for judging the degree of junk can be used together. For example, there are a combustion method, a germination test, a putrefaction test, an earthworm evaluation method, and the like. The details of these evaluation methods are as follows.

(Combustion Method) Compost placed on a metal foil or spoon is fired, and the degree of maturity is determined based on the odor. If the compost is immature, an unpleasant odor such as ammonia odor or acid odor is felt. When ripe, there is no odor, and in some cases it has a wine-like aroma.

(Germination test) The degree of maturity is determined by examining the germination rate and growth amount of seeds such as radish, komatsuna and Chinese cabbage. If the germination rate is 80% or more and there is no growth inhibition or abnormal roots, it is judged to be ripe. There are a planter method using soil and a petri dish method using no soil. Germination when no compost is used is also performed as a control test.

(Rot test) Water is added to the compost to create a state in which microorganisms can proliferate, and the state is left at 20 to 30 ° C. for 3 to 7 days to observe the state. When an unpleasant odor (ammonia odor, rancid odor) is generated aside from the gas, it indicates that a readily decomposable organic substance is contained, and thus it is judged to be immature.

(Evaluation method of earthworms) By utilizing the property of earthworms that prefers soil with a lot of organic matter due to ripening and performs skin respiration,
The maturity is determined by observing the behavior and skin condition of the earthworm placed on the compost. Compost moisture content is 60 ~ 7
After adjusting to 0%, place the earthworm on the compost, observe the state immediately after that, leave it for 1 day in the shade, and observe again. If immature, the earthworms will bend as soon as they come into contact with the compost and try to escape, almost dead in a day. In the case of juku juku, she dislikes touching the compost, and one day later, her skin discolors and her movement slows down. In the case of ripeness, it begins to dive as soon as it is placed on compost, and there is no change in skin color or behavior after one day.

[0078]

Hereinafter, the present invention will be described in more detail based on experimental results.

(Example) 375 liters of fir (C)
/ N ratio = 70-80), 375 liters of rice bran (C /
N ratio = about 15), 300 liters of okara (C / N ratio =
8-12), 75 liters of chicken manure and 1125 liters of red clay are mixed in a decomposition tank to obtain a C / N ratio of 3
0, an organic waste having a water content of 60% by weight was prepared. The decomposition tank is isolated from the outside air, and the oxygen content of the atmosphere is 5 vol% or less.
The atmosphere was adjusted to a primary decomposition atmosphere such that the concentration of carbon dioxide gas became 15 vol% and the humidity became 80% or less, and the mixture was allowed to stand still, and cut back once a week. During this time, the temperature rose rapidly and was stable at 40-60 ° C. The water content of the organic waste was maintained at 50-60%. Seven days later, a smell like amazake was generated from the organic waste, and the near-infrared reflection spectrum was measured. The reflection at 5200 cm ^-1 was 0.09, and it was determined that the primary decomposition was completed.

When the oxygen gas concentration in the atmosphere in the decomposition tank is 20
%, The concentration of carbon dioxide gas was about 2% or less, and the humidity was adjusted to about 60%. The atmosphere was adjusted to a secondary decomposition atmosphere, allowed to stand, and cut back once a week. During this time the temperature rose and was in the range 55-75 ° C. The organic waste began to emit soy sauce-like aroma, and after 14 days of secondary decomposition, the temperature dropped to around 45 ° C. When the near-infrared reflection spectrum was measured, the reflection at 5200 cm ⁻¹ was found. It was determined that the secondary decomposition was completed at 0.18. Further, 90 days after the switching, the near-infrared reflection spectrum was measured. The reflection at 5200 cm ^-1 was 0.30, indicating that the tertiary decomposition was completed. Also, pH
When the value was measured, it was 5.5-6.0 and showed weak acidity.

The atmosphere in the decomposition tank was adjusted to an oxygen gas concentration of 20.
%, A carbon dioxide gas concentration of about 2% or less and a humidity of about 60% were adjusted to an aging atmosphere and allowed to stand, and then cut back once a month. After 60 days, many gray spots were formed on the surface of the organic waste, and the near-infrared reflection spectrum was measured. The reflection at 5200 cm ^-1 was 0.35, indicating that the tertiary decomposition was completed. When the pH value was measured, it was almost neutral.

When the organic waste in the decomposition tank was taken out and put into a 1-liter beaker, an earthworm was placed on the upper surface and left in a dark place for one day, and the earthworm died in the organic waste.
No abnormalities were seen.

[0083]

As described above, according to the present invention,
An excellent compost can be obtained from an organic waste without emitting a bad smell, and its industrial value is extremely large. In addition, the compost obtained by the present invention is rich in components that promote the growth of plants, so that high-quality compost suitable for agricultural production and horticulture can be supplied.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a compost production system that performs a composting method according to the present invention.

FIG. 2 is a spectrum chart showing a near-infrared reflection spectrum of an organic waste subjected to composting.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Compost manufacturing system 3 Conveyor 7 First decomposition room 9 Second decomposition room 11 Aging room 13 Warehouse 15 Deodorization room 19 Water treatment / coolant device 21A, 21B Pre-decomposition room

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C05F 9/02 G01N 21/35 Z G01N 21/35 B09B 3/00 ZABA

Claims (18)

[Claims] A first step of saccharifying and fermenting the organic waste; and a second step of decomposing the organic waste by propagating Bacillus bacteria, lactic acid bacteria, and yeast on the organic waste that has passed through the first step. A method for composting organic waste, comprising: 2. The method according to claim 1, wherein filamentous fungi propagate in the first step. 3. The composting method according to claim 1, further comprising a third step of breeding actinomycetes producing antibiotics on the organic waste that has passed through the second step. 4. The method for composting according to claim 3, further comprising a forming step of forming the organic waste that has passed through the third step and drying the formed organic waste to a water content of 30% by weight or more. 5. The method according to claim 1, further comprising the step of adjusting the C / N ratio of the organic waste to 25 to 40 and the water content to 45 to 70 wt% before the first step. The composting method as described. 6. In the first step, the organic waste is maintained at 40 to 70 ° C. in an anaerobic atmosphere, and in the second step, a first period during which Bacillus bacteria and lactic acid bacteria grow and a yeast grows. The composting method according to any one of claims 1 to 5, wherein the method is performed in an atmosphere in which facultative anaerobic bacteria and aerobic bacteria can proliferate, including a second period. 7. In the first period of the second step, the temperature of the organic waste is maintained at 60 to 75 ° C. and bacteria of the genus Bacillus proliferate, and the temperature falls to 50 ° C. or lower, and lactic acid bacteria proliferate. The method for composting according to claim 6. 8. A first step of microbial decomposition of organic waste in an anaerobic atmosphere, and in an atmosphere in which organic anaerobic bacteria and aerobic bacteria that have passed through the first step can propagate. And a second step of microbial decomposition. 9. The anaerobic atmosphere in the first step has a carbon dioxide gas concentration of 10 to 35 vol%, an oxygen concentration of less than 5 vol%, and a humidity of 70 to 90%. The composting method according to claim 8, wherein the oxygen gas concentration is 5 to 40 vol%, the carbon dioxide gas concentration is 2 vol% or less, and the humidity is 50 to 70%. 10. In the first step, the temperature of the organic waste is maintained at 40 to 70 ° C., and in the second step,
The composting method according to claim 8 or 9, wherein the method has a period in which the temperature of the organic waste is maintained at 60 to 75 ° C and a period in which the temperature is 50 ° C or lower. 11. The composting method according to claim 8, further comprising a third step of breeding actinomycetes producing antibiotics in the organic waste that has passed through the second step. 12. The atmosphere in the third step is controlled so that the oxygen gas concentration is 18 to 20%, the carbon dioxide gas concentration is 2% or less, and the humidity is 50 to 70%. Item 13. The composting method according to Item 11. 13. The method according to claim 11, further comprising a forming step of forming the organic waste having passed through the third step and drying the formed organic waste to a water content of 30% by weight or more.
The composting method as described. 14. The method according to claim 8, further comprising a step of adjusting the C / N ratio of the organic waste to 25 to 40 and the water content to 45 to 70 wt% before the first step. The composting method as described. 15. The first step is 5-10 days, the second step is 14-30 days, and the third step is 30-30 days.
The method according to any of claims 11 to 14, wherein the method is performed for 90 days. 16. A method of measuring the near-infrared spectrum of a compost obtained by composting an organic matter, and judging the maturity of the compost based on the measured near-infrared spectrum. Evaluation method. 17. The evaluation method according to claim 16, wherein in the determination of the maturity, the maturity is determined to be high when the absorbance in the near-infrared spectrum is small or when the reflection is large. 18. A discriminant function for judging the degree of maturity from near-infrared spectrum data of a compost sample for calibration of maturity is prepared by discriminant analysis, and the discrimination function is determined from near-infrared spectrum data of the compost to be evaluated. A method for evaluating compost, comprising determining the maturity of the compost using a function.