WO2008059749A1

WO2008059749A1 - Composting treatment method and compost produced by using the same

Info

Publication number: WO2008059749A1
Application number: PCT/JP2007/071712
Authority: WO
Inventors: Yutaka Matano; Toshimasa Sugie; Naoki Kato; Chikako Nakamura
Original assignee: Menicon Co., Ltd.
Priority date: 2006-11-15
Filing date: 2007-11-08
Publication date: 2008-05-22

Abstract

It is intended to provide a composting treatment method for converting an organic waste into a compost through a fermentation treatment, whereby the amount of a water-absorbing polymer remaining after the composting treatment can be reduced and moisture control and composting can be carried out within a short period of time, and a compost produced by using the same. In a composting method for converting a compost material (for example, livestock feces and urine) into a compost with the use of an aerobic microorganism, a polysaccharide digesting enzyme such as cellulase and a water-absorbing polymer comprising a polysaccharide such as cellulose or its derivative are added to the compost material as described above followed by the composting treatment.

Description

Specification

Composting method and compost manufactured using the method

Technical field

[0001] The present invention relates to a composting method and compost produced using the composting method. More specifically, the present invention promotes composting by reducing the moisture content of the compost raw material itself while preventing the increase in the bulk of the compost raw material by blending the water absorbent polymer, and is derived from the water absorbent polymer in the compost. The present invention relates to a composting method that suppresses residual impurities and compost produced using the method.

Background art

In general, biomass, for example, livestock excrement, sewage surplus sludge, and food waste are known as materials composed of organic resources derived from biological sources. Sewage surplus sludge is sludge obtained by biological treatment of organic waste containing nitrogen discharged from households as sewage. Biomass is attracting attention because it contains elements such as nitrogen, phosphorus, and strong rhodium necessary for plant growth and can be reused as compost. However, in many cases, the biomass cannot be used as compost as it is, and it is necessary to apply some treatment to the biomass. For example, waste such as livestock excrement and sewage surplus sludge cannot be disposed of as it is or reused as compost, for example. Removal of odorous components such as ammonia from waste, water in waste Treatment such as reduction of the content is required. In addition, when organic waste such as livestock excrement is simply left untreated, microorganisms are decomposed and fermented to organic waste, which further generates malodorous components such as fatty acids and amines. In order to reduce the odor of organic waste, treatment is necessary. Since it takes a long time to decompose microorganisms and leave them for fermentation, it is necessary to shorten the treatment time.

[0003] Generally, in a highly water-containing waste, in order to improve the transportability and breathability of the highly water-containing waste, natural water-absorbing fibrous materials such as bark, sardine waste, rice husk and the like are increased. A method of composting with microorganisms after reducing the water content of the highly hydrous waste by blending with hydrous waste is known. However, natural water-absorbing fibrous materials such as debris In order to absorb water sufficiently, it is necessary to mix water-absorbing fibrous material several times the amount of highly water-containing waste in order to absorb water sufficiently. There was a problem that it took time to compost. Thus, conventionally, treatment methods as described in Patent Documents 1 to 3 are known as biological treatment methods for composting organic high-water-containing waste by fermentation.

[0004] In Patent Document 1, composting is performed by mixing a cross-linked poly (sodium acrylate), which is a highly water-absorbing resin having high! / Water absorption capacity, with livestock excrement. Patent Document 2 discloses a method for promoting composting using poly-7-glutamic acid, which is a water-absorbing polymer having an extremely high water absorption capacity, as a composting aid. Patent Document 3 discloses a method for promoting composting of a highly hydrous raw material using a polysaccharide, for example, cellulose, which is a gelling material or a solidifying material. The method for treating compost raw materials disclosed in Patent Documents !! to 3 uses a water-absorbing polymer, for example, while suppressing an increase in the volume of the compost raw materials that are generated when sawdust is used. It is possible to improve the breathability of the composting process. Patent Document 1: JP-A-8-208362

Patent Document 2: JP 2001-261475 A

Patent Document 3: Japanese Unexamined Patent Publication No. 2003-342093

Disclosure of the invention

[0005] However, in the treatment method disclosed in Patent Document 1, the cross-linked sodium polyacrylate mixed with the excrement of livestock is hardly decomposed by microorganisms and heat of fermentation, and therefore remains as an impurity in compost. There was a problem. In the treatment method disclosed in Patent Document 2, polyγ-glutamic acid is easily decomposed by a protease produced from a microorganism. For this reason, the treatment method disclosed in Patent Document 2 has a problem that the amount of water in the compost raw material may increase excessively during the fermentation process, making it difficult to adjust the water content of the compost raw material. In the treatment method disclosed in Patent Document 3, since the cellulose blended as the gelling material is finally biodegraded after the composting treatment, there is no problem of remaining as impurities in the compost. However, since cellulose is decomposed mainly by cellulose-degrading bacteria that are active at temperatures below medium temperature, it is not fully decomposed during high-temperature treatment and gradually biodegraded after composting. Therefore, The treatment method disclosed in Patent Document 3 has a problem that it takes time until cellulose is finally biodegraded after composting treatment.

[0006] As a result of intensive studies by the present inventors, the present invention can reduce residual water-absorbing polymer after compost treatment by using a water-absorbing polymer comprising a polysaccharide or the like and a polysaccharide-degrading enzyme. Moreover, it was made by finding that moisture adjustment and composting can be performed in a short time. The object of the present invention is to reduce the residual amount of water-absorbing polymer after composting in a processing method for composting organic waste by fermentation treatment, and to adjust the moisture in a short time. An object is to provide a composting method capable of performing composting and a compost produced using the composting method.

[0007] In order to achieve the above object, in one aspect of the present invention, a composting method for composting a compost raw material with an aerobic microorganism is provided. This composting method comprises the step of composting a compost raw material by blending the compost raw material with a polysaccharide-degrading enzyme and at least one water-absorbing polymer selected from polysaccharides and derivatives thereof.

[0008] In another aspect of the present invention, a compost produced using the composting method is provided.

Brief Description of Drawings

[0009] Fig. 1 is a graph showing the relationship between temperature and time during composting in Example 1 and each comparative example.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, an embodiment in which the present invention is embodied in compost produced using a composting method will be described in detail.

The composting treatment method according to the present embodiment is a processing method for composting compost raw materials by high-temperature decomposition treatment by mixing a water-absorbing polymer and a polysaccharide-degrading enzyme with compost raw materials. Specific examples of the compost raw material used in the present embodiment are not particularly limited as long as they are organic raw materials. Examples of such compost raw materials include excrement of livestock such as cattle, pigs, sheep, horses, and chickens (sewage), and sewage. Examples include treated sludge and food waste such as food waste. In this embodiment, the water content is sufficient using a large amount of natural water-absorbing fibrous material such as conventional sawdust. Even if it is a highly hydrous compost raw material that needs to absorb water, it can be used with the power S suitably.

[0011] The water-absorbing polymer blended in the compost raw material is a polymer composed of at least one selected from polysaccharides and derivatives thereof. Preferably, the water-absorbing polymer will eventually biodegrade even if it remains after composting. Examples of polysaccharides include starch, cellulose, hemicellulose, xylose, pectin, chitin, and chitosan. Examples of polysaccharide derivatives include starch derivatives, crosslinked starch derivatives, cellulose derivatives, crosslinked cellulose derivatives, hemicellulose derivatives, and crosslinked hemicellulose derivatives. More specifically, examples of the cellulose derivative and the crosslinked cellulose derivative include force carboxymethyl cellulose (CMC) and a crosslinked product thereof. Starch derivatives and cross-linked starch derivatives include carboxymethyl starch (CMS), acetylated adipic acid cross-linked starch, acetylated phosphoric acid cross-linked starch, hydroxypropylated phosphoric acid cross-linked starch, phosphoric acid monoesterified phosphoric acid cross-linked starch, phosphorus Examples include acid-crosslinked starch, sodium starch phosphate, and cross-linked products thereof. Preferably, since the water-absorbing polymer is easily available and has excellent biodegradability, starch, starch derivative, crosslinked starch derivative, cellulose, cellulose derivative, crosslinked cellulose derivative, hemicellulose, hemicellulose derivative, And at least one selected from crosslinked hemicellulose derivatives. More preferably, cross-linked CMC and phosphoric acid cross-linked starch are preferred because they remain less in the soil after composting. Most preferably, CMC having a high water absorption is used. These water-absorbing polymers can be blended alone in compost raw materials, or two or more can be combined in compost raw materials!

[0012] The polysaccharide can be crosslinked by a known method, for example, radiation treatment or a crosslinking agent. Examples of the cross-linking agent include polyhydric alcohols, polyamines, metaphosphates, phosphorus oxychloride, adipic anhydride, and epichlorohydrin. Examples of the polyhydric alcohol include polyethylene glycol, ethylene glycol diglycidyl ether, glycerin, and propylene glycol. Examples of the polyvalent amine include 1,4-diaminobutane.

[0013] A polysaccharide-degrading enzyme is a polysaccharide or a derivative thereof blended as a water-absorbing polymer. Eventually, it decomposes and disappears in compost or is easily biodegraded by microorganisms. Examples of polysaccharide-degrading enzymes include amylase (starch-degrading enzyme) that hydrolyzes starch or its derivatives, cellulase (cellulose-degrading enzyme) that hydrolyzes cellulose or its derivatives, and hemicellulose or its derivatives. Hemicellulase (hemicellulose-degrading enzyme), xylanase hydrolyzing xylose or its derivative (xylose-degrading enzyme), pectinase hydrolyzing pectin or its derivative (pectin-degrading enzyme), and chitin or A chitinase (chitin degrading enzyme) that hydrolyzes the derivative is mentioned. As the polysaccharide degrading enzyme, an enzyme capable of degrading the water-absorbing polymer compounded in the compost raw material is selected and applied. Compost raw materials usually contain cellulose or its derivatives, or hemicellulose or its derivatives. Therefore, preferably, the polysaccharide degrading enzyme is at least one selected from cellulase and hemicellulase. In this case, the polysaccharide-degrading enzyme can promote the composting treatment of the compost raw material by decomposing, for example, cellulose in the compost raw material.

[0014] As the polysaccharide-degrading enzyme, either an exo-type degrading enzyme that cleaves a specific number of sugar units from the end of the sugar chain or an endo-type degrading enzyme with a random cleavage mode force may be used. Examples of exo-type degrading enzymes include / 3-amylase and cellobiohydrolase. Examples of endo-type degrading enzymes include α-amylase and endoglucanase. Of the exo-type degrading enzymes and endo-type degrading enzymes, exo-type degrading enzymes are preferred for the following reasons. That is, the exo-type decomposing enzyme has a high effect of suppressing excessive decomposition of the water-absorbing polymer during composting and preventing an excessive amount of water in the compost raw material during compost processing. Furthermore, the exo-type decomposition enzyme can rapidly decompose the water-absorbing polymer or promote decomposition by microorganisms during and after the composting process. Composting with microorganisms is usually performed in the basic region due to the presence of basic substances such as ammonia in the compost raw material. Therefore, preferably, a degrading enzyme having activity in at least the neutral region to the basic region is used as the polysaccharide degrading enzyme.

[0015] The amount of the water-absorbing polymer and polysaccharide-degrading enzyme to be added to the compost raw material is appropriately determined depending on, for example, the type of the compound, the enzyme titer, and the compost raw material component and the water content Set to Preferably, the mixing ratio of the water-absorbing polymer and the polysaccharide-degrading enzyme is equal to the ratio of rapidly decomposing the water-absorbing polymer after composting treatment while suppressing excessive polymer degradation during composting treatment! /, .

The compost raw material may be further mixed with back compost or inoculum material in order to mix microorganisms (inoculum) necessary for composting the compost raw material with the compost raw material. Preferably, the back compost and the inoculum material contain at least one of a thermophilic aerobic bacterium and a mesophilic aerobic bacterium. Known bacteria existing in nature are used as thermophilic aerobic bacteria and mesophilic aerobic bacteria. As a mesophilic aerobic bacterium according to the present embodiment, that is, a mesophilic bacterium, in order to guide the compost raw material from the normal temperature (20 ° C.) to the intermediate temperature range (45 to 55 ° C. temperature range), 20 ° C. to 55 ° C. Bacteria that can grow at least in the range of ° C are preferred. As a thermophilic aerobic bacterium according to this embodiment, that is, a thermophilic bacterium, in order to guide the compost raw material from the middle temperature range to the high temperature range (temperature range of about 60 to 95 ° C), the temperature is about 55 ° C or higher. At least proliferating bacteria are preferred. Examples of mesophilic and thermophilic bacteria include, for example, Bacillus alvei, Bacillus amylolyticus, B. azotofixans, B. circula ns. ), Bacillus. Glucanolyticus (B. glucanolyticus), Notinoles. Labee (B. larvae), Bacillus. Lotus (B. lautus), Bacillus. Lentimorbus, Bacillus. Macerans ), Nochinores. Macquariensis (Β macquariensis), Nochinole Snow varieties (B. pabuli), Bacillus polymixer (Β · polymyxa), Bacillus popirie (Β · po pilliae), Nochinoles. Cyclosaccharo ricica (Β · psychrosaccharolyticus), Nochinolesno Norevuifaciens (B. pulvifaciens), Bacillus thiaminolyticus (B. thiaminolyticus), Bacillus .validus (B. validus), Bachi B. alcalophilus, B. nores. B. amyloliquefaciens, B. at rophaeus, B. at rophaeus, Nochinoles. Caroterum (Β carotarum, Nochinoles. firmus), B. flexus, B. laterosporus, B. lentus, B. licheniformis, B. megaterium , B. mycoides, B. nia cini, B. pantothenticus, B. pumilus, B. simplex, B. subtilis (B. subtilis) B. subtilis), Notils B. thuringiensis B. sphaericus B. sphaericus, Geobacillus thermodenitrificans, Geobacillus stearothermophilus, D. phyllaceus (G eobacillus kaustophilus), S. 7 "Norefunens (Geobacillus subterranens), S. monorenolance. (Geobacillus thermoleovorans), and S. dino chinoles. Caldoxylosilyticas In this embodiment, commercially available compost may be used as the back compost, and compost that has been composted in this embodiment may be used as the back compost. Thus, for example, Thermomaster, which is a trade name manufactured by Menicon, can be used.

[0017] The compost raw material may further contain a water-absorbing fibrous material in order to promote fermentation and growth of microorganisms within a range not impairing the effects of the present invention. Preferably, a natural organic material that is readily available and biodegradable after composting is used as the water-absorbing fibrous material. Examples of water-absorbing fibrous materials include organic wastes such as panolep, cotton lita, bark, sawdust, rice husk, rice straw, corn straw, bagasse, soybean meal, bran, rapeseed meal, and rice bran. Growth of mesophilic bacteria is promoted by using these organic materials as feed. These organic materials may be blended alone in compost raw materials, or two or more types may be combined in compost raw materials!

[0018] The amount of water in the compost raw material at the start of composting according to the present invention is not particularly limited, but is preferably 30 to 90% by mass, and more preferably 40 to 85% by mass. When the water content is 30% by mass or less, there is a possibility that microorganisms such as mesophilic bacteria do not grow sufficiently. Even when the amount of water in the compost raw material is high, that is, in the case of a highly hydrous compost raw material, the compost raw material can be gelled or solidified by blending the water-absorbing polymer. This increases the air permeability of the highly hydrous compost material and maintains or improves the aerobic metabolism of microorganisms.

[0019] In addition to the above-mentioned components, for example, organic waste or porous mineral may be blended with the compost raw material in order to ensure the breathability of the compost raw material. Examples of organic waste include rice husk and buckwheat husk. Examples of porous minerals include pearlite. [0020] Next, the operation of the compost manufactured using the composting method of the present embodiment configured as described above will be described. When, for example, livestock excrement is used as composting raw material, and CMC is added to the livestock excretion as a water-absorbing polymer and exo cellulase is added as a polysaccharide-degrading enzyme, for example, excretion of livestock The product is decomposed by the following reaction. First, when CMC is mixed with livestock excreta, the excess water contained in the livestock excreta is captured by the CMC, and the livestock excreta is gelled or solidified. As a result, air permeability in livestock excrement is ensured. As primary degradation, first, polysaccharides in livestock excreta are reduced in molecular weight by degrading enzymes, that is, for example, cellulose is reduced in molecular weight by cellulase to release sugars. Along with this, microorganisms that feed on low molecular weight cellulose such as cellooligosaccharides or glucose grow. As microorganisms grow, the temperature in the excreta of livestock rises to the highest temperature (medium temperature range to high temperature range: 50 to 85 ° C) in about 2 to 3 days. At this time, CMC blended as a water-absorbing polymer is gradually decomposed from the end of the sugar chain by exo-type cellulase. However, since the water retention capacity of CMC is still maintained, there is no risk that the amount of water in livestock excrement will become excessive during composting.

[0021] Next, aerobic fermentation is induced by, for example, agitation or aeration work by mixing with a blower to positively mix air with livestock excrement. Preferably, the aeration operation is continuously repeated until the processing is completed. Treatment at high temperatures can reduce water content, reduce the molecular weight of organic matter, decompose odorous compounds such as amines, suppress the generation of methane gas due to aerobic fermentation, and polymer fibers, proteins, etc. Reduction of molecular weight is performed. In addition, high-temperature treatment kills plant seeds and pathogenic bacteria derived from livestock excreta. Examples of pathogenic bacteria include coliform bacteria and Staphylococcus aureus known as cattle mastitis-causing bacteria. During the high-temperature treatment process, CMC is gradually degraded by microorganisms as the water content decreases.

[0022] Composting of compost raw materials is, for example, a force S that depends on the air supply amount, outside temperature, or moisture content in the compost raw materials, usually 2 to 3 months. It will be completed in about 6 months. Completion of the treatment is accompanied by a decrease in temperature due to the lower molecular weight of the macromolecular organic matter in the compost and the reduction of the water content. Malodorous components and moisture in compost produced after processing Has decreased significantly. CMC is reduced in molecular weight by the action of exo-type cellulase and microorganisms at the completion of compost treatment, so it is easily and quickly decomposed and disappeared by microorganisms in the compost after treatment or microorganisms in the soil. .

[0023] This embodiment has the following advantages!

(1) In this embodiment, a composting process is performed by mixing a water-absorbing polymer with a compost raw material. Therefore, when the amount of water in the compost raw material is excessively high for composting, natural water-absorbing fibrous materials such as bark, shredded waste, and rice husk are not included in the compost raw material, or the normal amount Even if a smaller amount of water-absorbing fibrous material is added, composting can be performed. Therefore, the increase in the bulk of the entire compost raw material can be significantly suppressed. In addition, the water balance in the compost raw material can be easily adjusted, and the power S can reduce the composting time.

(2) In this embodiment, preferably, a biodegradable polysaccharide such as cellulose or starch or a derivative thereof is used as the water-absorbing polymer. In this case, after the composting treatment, the water-absorbing polymer can be decomposed by microorganisms in the soil or compost to reduce the residue of the water-absorbing polymer.

[0025] (3) In this embodiment, the polysaccharide-degrading enzyme is blended in the compost material together with at least one water-absorbing polymer selected from polysaccharides and derivatives thereof. Therefore, the water-absorbing polymer is reduced in molecular weight to some extent during the composting process and is easily degraded by microorganisms after the composting process. As a result, the residue of the water-absorbing polymer can be extremely reduced in a short period of time.

[0026] (4) In this embodiment, an exo-type decomposing enzyme that cleaves a specific number of sugar units from the end of the sugar chain is preferably used as the polysaccharide degrading enzyme. When exo-type degrading enzymes are used, the rapid decrease in the molecular weight of the polysaccharide as a water-absorbing polymer is suppressed, so there is a risk that the amount of water in the composting material will become excessive during composting. Absent. In addition, since the water-absorbing polymer is decomposed to some extent, it is easily decomposed by microorganisms after composting treatment.

(5) In the present embodiment, preferably, crosslinked CMC is used as the water-absorbing polymer. At this time, cellobiohydrolase is used as a polysaccharide-degrading enzyme. In this case, the rack Since the bridge CMC has higher water absorption and the cross-linked CMC is biodegraded after composting, composting can be completed in a short period of time. Furthermore, the rapid depolymerization of polysaccharides is suppressed, there is no risk of excessive water content in the composting material during the composting process, and the water-absorbing polymer is decomposed to some extent after the composting process. Therefore, it is easily decomposed by microorganisms.

[0028] (6) In this embodiment, preferably, back compost or inoculum material containing at least one of thermophilic aerobic bacteria and mesophilic aerobic bacteria is further blended in the compost raw material. The In this case, it is possible to mix the inoculum with the compost raw material at a low cost and to facilitate the composting process.

[0029] (7) Since the composting process of the present embodiment is a decomposition and fermentation process using microorganisms, it is compared with a physical or chemical processing method such as a combustion method, a purification method, or an adsorption method. In addition, it does not require complicated equipment and a large amount of water, and requires a small amount of secondary processing products that require further processing, that is, by-products, and can reduce energy consumption of fossil fuels and the like.

[0030] (8) The compost obtained by the composting treatment of the present embodiment has a higher calorific value than the conventional compost obtained from the same compost raw material as the compost. See Examples and Comparative Examples). Therefore, when the compost according to the present embodiment is combusted, the amount of fuel required for compost combustion can be reduced as compared with the conventional compost.

[0031] The embodiment described above may be modified as follows.

In the above embodiment, the composting method is applied as a method for producing compost. However, the present invention is applied as a method for treating wastes such as livestock excrement and sewage treatment sludge that are simply discarded as they do not deteriorate the environment. May be. In this case, it becomes easy to appropriately dispose of the processed material processed in the present embodiment.

[0032] In the above embodiment, compost produced by using the composting method may be applied to livestock bedding as back compost.

Example

Next, the embodiment will be described more specifically with reference to examples and comparative examples.

Regarding the following Example 1 and each comparative example, temperature change in compost raw material, after composting treatment The presence or absence of the water-absorbing polymer residue and the calorific value of the compost were evaluated. As the temperature change, the temperature change 25 cm below the surface of the compost material was measured. The results are shown in Figure 1.

[0034] Regarding the water-absorbing polymer residue, compost after composting was visually observed. Table results

Shown in 1. In the “CMC residue” column of Table 1, “OO” indicates that no polymer residue was confirmed, and “◯” indicates that a slight amount of polymer residue was confirmed. Furthermore, “△” indicates that the water-absorbing polymer was confirmed to be slightly decomposed, “X” indicates that the polymer residue was hardly decomposed, and ““ Indicates that no compost was observed.

[0035] The calorific value of the compost after composting was measured according to Japanese Industrial Standard JIS Z7302-1: 1999. The calorific value of this compost was measured at the Tokai Technical Center, a Japanese foundation. The results are shown in Table 1. In the “Heat generation” column of Table 1, “” indicates that the heat generation was not measured.

[Example 1]

The mixture was prepared by blending and mixing the following components with dairy cow dung as compost raw material. That is, 13 kg of the dairy cow dung (water content: 86.7%), 130 g of cross-linked CMC (manufactured by Thienke East Japan) as a water-absorbing polymer, and cellobiohydrolase which is an exo-type degrading enzyme as a polysaccharide degrading enzyme Enzyme material (Toyota Roof Garden Co., Ltd.) approx. 8g, Inoculum material (Menicon Co., Ltd. product name: Thermomaster) 65ml, Slag as a water-absorbing fiber material (sawdust) 3. 9L and rice husk 1 Formulated with 3L. The composting test apparatus (Fujidaira Kogyo Co., Ltd .: trade name Kaguyahime) was charged with 13 L of the mixture and subjected to a composting treatment.

[0037] (Comparative Example 1)

The composting process was performed in the same manner as in Example 1 except that the enzyme material and the inoculum material were omitted.

[0038] (Comparative Example 2)

By mixing 10kg of dairy cow dung as raw material for compost (moisture content: 86.7%) with 10L of sawdust as a water-absorbent fibrous material and 1.0L of rice husk. mixture A product was prepared. In the preparation of the mixture, the total volume of sawdust and rice husk and the volume of dairy cow dung were set equal. The mixture 13L was charged into a composting test apparatus (manufactured by Fujidaira Kogyo Co., Ltd .: trade name Kaguyahime) and composted.

[Table 1] Table 1

[0040] As shown in Fig. 1, in Example 1, the fermentation temperature reached the maximum temperature of 52.1 ° C in about 60 hours from the start of the treatment. Thereafter, the temperature dropped rapidly and returned to room temperature after about 90 hours (not shown). In Comparative Example 1, the fermentation temperature reached the maximum temperature of 45.3 ° C in about 60 hours from the start of the treatment. Thereafter, the temperature dropped rapidly and returned to room temperature after about 120 hours (not shown). In Comparative Example 2, the fermentation temperature reached the maximum temperature of 44.7 ° C in about 80 hours from the start of the treatment. The temperature then dropped rapidly and returned to room temperature after 120 hours (not shown).

[0041] In Example 1, the maximum temperature is higher than the maximum temperature of Comparative Examples 1 and 2, so that the macromolecular organic matter necessary for fermentation is quickly withered and the fermentation treatment is completed early. I understand. In Comparative Example 1, the time to reach the maximum temperature was almost the same as in Example 1, but the maximum temperature itself was low and it took a long time to complete composting. From this result, it was found that composting is promoted by enzyme materials and inoculum materials. In Comparative Example 2, a water-absorbing fibrous material having the same volume as the compost material is blended in the compost material. For this reason, the time to reach the maximum temperature was longer than in Example 1, and it took a long time to complete composting. The maximum fermentation temperature and the time required for composting in the composting process depend on, for example, the amount of composting material to be processed. Therefore, when composting a large amount of compost raw material compared to the compost raw material according to Example 1, the maximum fermentation temperature is higher than that of Example 1, and it takes a long time for composting. There is a possibility of doing.

[0042] As shown in Table 1, in Example 1, crosslinked CMC formulated as a water-absorbing polymer. The polymer residue resulting from was not confirmed after composting treatment. In Comparative Example 1 where no enzyme material was blended, the water-absorbing polymer was only slightly degraded after composting. In order to sufficiently decompose the water-absorbing polymer in Comparative Example 1, it is necessary to leave the mixture for a longer period. Further, the calorific value of the compost according to Example 1 was higher than the calorific value of the compost according to Comparative Example 2. From this result, it was found that when compost obtained by the composting method according to the present invention is combusted, the amount of fuel used for compost combustion can be reduced as compared with conventional compost.

Claims

The scope of the claims

[1] In a composting method for composting a compost raw material with an aerobic microorganism, the compost raw material includes a polysaccharide-degrading enzyme and a water-absorbing polymer consisting of at least one selected from polysaccharides and derivatives thereof. A composting method comprising a step of composting a compost raw material by blending.

[2] The composting method according to claim 1, wherein the compost raw material is at least one selected from livestock excrement, sewage surplus sludge, and food waste.

[3] The composting method according to claim 1 or 2, wherein the polysaccharide-degrading enzyme has an activity in at least a neutral region force basic region.

[4] The composting treatment method according to any one of claims 1 to 3, wherein the polysaccharide-degrading enzyme is at least one selected from a cellulose-degrading enzyme and a hemicellulose-degrading enzyme. .

[5] The polysaccharide degrading enzyme according to any one of claims 1 to 4, wherein the polysaccharide degrading enzyme is an exolytic enzyme that cleaves a specific number of sugar units from the end of a sugar chain. Composting method.

[6] The water-absorbing polymer is at least selected from starch, starch derivatives, crosslinked starch derivatives, cellulose, cellulose derivatives, crosslinked cellulose derivatives, hemicellulose, hemicellulose derivatives, and crosslinked hemicellulose derivatives. 6. The composting method according to claim 1, wherein the composting method is one type.

[7] The step of composting the compost raw material further includes a step of blending the back compost or the inoculum material containing at least one of a thermophilic aerobic bacterium and a mesophilic aerobic bacterium into the compost raw material. The composting method according to any one of claims 1 to 6, characterized by:

[8] The composting process of compost raw material is at least selected from pulp, cotton rita, bark, sardine waste, rice husk, rice straw, corn straw, bagasse, soybean meal, bran, rapeseed meal, and rice straw. The composting method according to any one of claims 1 to 7, further comprising a step of blending a kind of water-absorbing fibrous material with compost raw material.

[9] The composting method according to any one of claims 1 to 8, wherein the water-absorbing polymer is crosslinked carboxymethylcellulose, and the polysaccharide-degrading enzyme is cellobiohydrolase. .

[10] A compost produced using the composting method according to any one of claims 1 to 9.