JP2000218251A - Fermentation treatment of organic waste - Google Patents

Abstract

PROBLEM TO BE SOLVED: To recycle a subsidiary material by fermentation treating in the presence of a granular material formed from a biologically degradable fiber to excellently fermentation treat an organic waste in the treatment of the organic waste by fermentation. SOLUTION: The organic waste 4 such as garbage, leavings, food residue, activated sludge, fallen leaves, waste living things is introduced into a fermentor 1 and mixed with the granular material 6 formed from the fiber to perform primary fermentation. As the fiber forming the granular material 6, the one only having biologically degradable property is used without limiting and collagen, gelatin, fibrin, albumin, synthetic polypeptide or the like is cited. At the time that the primary fermentation is almost finished, the treated material 5 is introduced in a separation vessel 2 and the granular material 6 formed from the biologically degradable fiber is separated from the treated material 5 by a vibration screen in the separation vessel 2. The separated granular material 6 formed from the biologically degradable fiber is returned to the fermentor 1 to be used as the subsidiary material for fermentation. The separated treated material 7 is introduced into a fermentor 3 to be secondarily fermentation treated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a method for fermenting organic waste by utilizing the ability of microorganisms.

[0002]

2. Description of the Related Art Heretofore, some organic wastes such as garbage and sludge have been subjected to fermentation treatment by microorganisms and recycled as compost, feed or soil conditioner. Since these organic wastes generally have a high water content of about 70 to 95% and do not cause good aerobic fermentation as they are,
Sawdust, rice husk, rice straw, wood chips, etc. are added as auxiliary materials to the organic waste to adjust the water content to 40 to 60%, and then the microorganisms are proliferated by agitating and ventilating the organic waste. A method of fermenting a product is generally performed.

[0003] However, sawdust, rice husk, rice straw, wood chips and the like used as auxiliary materials are slowly decomposed by microorganisms, so that the time required for composting is prolonged and these auxiliary materials are completely contained in the processed material. Will remain. Furthermore, if the decomposition of these secondary materials in the fertilized soil progressed, it could cause nitrogen starvation and fever of the soil. In addition, since such secondary materials cannot be reused, storage sites for secondary materials are required when performing continuous composting, especially when using rice husk or rice straw. Due to the limited availability season, there was a need for a place to store large amounts of secondary materials.

[0004] Therefore, in facilities where it is difficult to use such organic sub-materials, it has been attempted to use hard-to-decompose plastics and rubbers as sub-materials and collect and reuse the sub-materials after fermentation. ing. However, in general, such hard-to-decompose plastics and rubbers are effective in terms of improving air permeability, but are inferior to organic auxiliary materials as a carrier for microorganisms, and furthermore, because they absorb less moisture,
There was a problem that it did not function sufficiently as a moisture regulator.

[0005]

The problem to be solved by the invention is disclosed in Japanese Patent Laid-Open No. 9-31.
Japanese Patent No. 4199 proposes using a porous material such as charcoal, wood chips, or a plastic porous material as a secondary material when the sludge is fermented, but these secondary materials are also separated from the processed material. However, there have been problems such as difficulty in carrying out the treatment and poor performance as a moisture adjusting material. An object of the present invention is to provide a fermentation treatment method for organic wastes, which can satisfactorily ferment organic wastes and can reuse secondary materials.

[0006]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve such problems, and as a result, the use of biodegradable fiber as a secondary material in the fermentation treatment of organic waste. It has been found that the treatment can be performed well by using the granular material, and the present invention has been completed.
That is, the present invention provides a biodegradable fiber (hereinafter referred to as a biodegradable fiber) for fermenting an organic waste.
A fermentation treatment method for an organic waste, wherein the fermentation treatment is performed in the presence of the particulate matter formed in the step (1).

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
Organic waste to be treated according to the present invention includes kitchen waste,
Food waste from food processing factories and fresh markets,
Activated sludge, pruned branches, fallen leaves, waste organisms (eg, livestock,
Carcasses such as pets and experimental animals). The fermentation treatment in the present invention refers to decomposing organic waste by the action of microorganisms, and the fermentation treatment can be used as compost or feed.

[0008] The fibers forming the particulate matter are not particularly limited as long as they have biodegradability, and collagen, gelatin, fibrin, albumin, synthetic polypeptides, polypeptides such as silk and wool, amylose ,
Dextran, alginic acid, chitin, chitosan, cotton,
Polysaccharides such as hemp, rayon, cellulose, polyglycolic acid, polylactic acid, polyglactin, polymalic acid, poly-
ε-caprolactone, poly-3-hydroxybutyric acid, poly-3-
Polyester fibers such as hydroxyvaleric acid, poly-4-hydroxybutyric acid, poly-6-hydroxyhexanoic acid, polybutylene succinate, and polyethylene succinate. These fibers may be used alone, mixed, or used as a copolymer. When used as a copolymer, if biodegradability is retained,
Any other copolymerized units can be used.

The granular material formed of the biodegradable fiber used in the present invention is not particularly limited as long as it is formed of the above-mentioned fiber and is granular.
For example, a granular material in which fibers are entangled by water stirring or the like, a fiber bundle or a material obtained by heat-sealing these, and the like are mentioned. Therefore, it is preferable to use one obtained by heat-sealing the fibers, and particularly preferably to use one obtained by heat-sealing the fiber bundle.

[0010] In the case of performing heat fusion, for example, Japanese Patent Application Laid-Open No. 8-206675 so that the granular material has a sufficient bulk density.
As described in Japanese Patent Laid-Open Publication, a heat-shrinkable fiber and a heat-fusible fiber are mixed and used, or a heat-fusible composite comprising two or more fibers having different melting points or two or more polymers having different melting points Preferably, fibers are used. Specifically, a low-melting fiber for thermal fusion with a high-melting fiber, a core-sheath type heat-fusible conjugate fiber having a low-melting component on the outer periphery and a high-melting component on the inner periphery, and a low-melting fiber on one side of the cross section. At least 30% by weight or more of a so-called hot-melt type fiber such as a side-by-side type heat-fused conjugate fiber having a high melting point component on the opposite side;
It is preferable to use 50% by weight or more. In this case, polyglycolic acid, polylactic acid, poly-ε-caprolactone, poly-3-hydroxybutyric acid, poly-3-hydroxyvaleric acid, poly-4-hydroxybutyric acid, poly-6-hydroxyhexanoic acid, polybutylene By using a low-melting fiber such as succinate or polyethylene succinate as a binder, good heat fusion can be performed.

The size of the granular material is preferably 2 to 50 mm, more preferably 5 to 20 mm. 2 granules
If it is smaller than mm, it tends to be difficult to separate the processed material and the auxiliary material after the fermentation treatment, and if it is larger than 50 mm, it is not preferable in terms of improvement in air permeability, which is not preferable. The bulk density of the granular material is 0.03 to
It is preferably 0.3 g / ml. If the bulk density is too large, it cannot be mixed well with the processed product, which is not preferable.

The granular material formed of biodegradable fibers used as a secondary material cannot play a role as a secondary material if it undergoes rapid decomposition during the composting process.
In addition, since frequent replenishment is required, it is preferable to use a material that can maintain the function as an auxiliary material, at least 2 days or more under composting conditions, preferably 1 week or more, more preferably 1 month or more. . In addition, when the secondary material remains in the final treatment product, it is desirable that the residual material be eliminated within one year, preferably at the latest within three years so as not to cause a problem in the fertilized soil.

The amount of the particulate matter formed of fibers is preferably such that the organic waste has a water content of 20 to 80%, preferably 30 to 70%. The granular material formed of the fibers used in the present invention has an excellent water absorption / desorption property, and therefore has a water content of 30% or less or 7% or less.
Although fermentation proceeds favorably even at 0% or more, it is desirable to set the water content to 30 to 70% when performing continuous treatment.

The type of the fermenter for performing the fermentation treatment is not particularly limited.
In addition to a composting device of an auger type, a multi-stage type, a silo, a bottle type, and the like, a composting device with a small stirring device can be suitably used.

In the fermentation treatment, since a large amount of microorganisms are usually attached to the waste, the waste can be treated without adding seed bacteria or compost. In particular, when the secondary material is repeatedly used, the treatment proceeds promptly by the fermentation bacteria attached to the secondary material. However, in the initial stage where the amount of fermentation bacteria attached to the auxiliary material is small, improvement of the treatment speed can be expected by adding seed bacteria or seed compost.

Regarding the conditions of the fermentation treatment, if the water content in the fermenter becomes extremely low, it may be difficult to separate the treated product and the particulate matter formed of the biodegradable fibers later. Etc. to keep the water content in the fermenter from 20 to 80
% Is preferably maintained. As the fermentation progresses, the temperature of the processed product increases, reaches around 50 to 60 ° C., and when the primary fermentation ends, the temperature of the processed product gradually decreases.

In the present invention, it is preferable to separate the particulate matter formed of the biodegradable fiber when the primary fermentation is completed. Completion of the primary fermentation can be confirmed by the fact that the temperature of the processed material starts to decrease and the generation of carbon dioxide discharged by the fermentation stops.

Although there is no particular limitation on the method of separating the particulate matter formed of the biodegradable fiber from the treated product, it is easiest to use a vibrating sieve.
At this time, since the granular material formed of the biodegradable fiber used as the secondary material is decomposed by the secondary fermentation, it does not need to be completely separated, but a large amount of the granular material was not separated. In this case, the period of the secondary fermentation to be performed next may be long or may not be sufficiently decomposed by the secondary fermentation. The separated granular material can be reused as a secondary material for the fermentation treatment.

The separated product has a water content of 40%.
It is preferred to adjust to ~ 60% and further ferment.
The processed product obtained by fermentation in this way is compost,
It can be used as feed or soil conditioner.

An embodiment of the present invention will be described below with reference to FIG. FIG. 1 is a diagram showing an example of the process of the method for fermenting organic waste of the present invention. First,
The organic waste 4 is introduced into the first fermenter 1 and mixed with the granular material 6 formed of fibers to adjust the water content to 40 to 80% to perform primary fermentation. In the first fermenter 1, aerobic fermentation is always performed while maintaining the water content at 40 to 80%, and when the primary fermentation is almost completed, the treated product (including the particulate matter formed of biodegradable fibers) is processed. 5 is introduced into the separation tank 2, where it is separated into a treated material 7 and a granular material 6 formed of biodegradable fibers by a vibrating sieve. The granular material 6 formed of the separated biodegradable fibers is returned to the first fermenter 1 again and used as a secondary material for fermentation. Further, the separated processed product 7 is introduced into the second fermenter 3 to perform secondary fermentation.

[0021]

Next, the present invention will be described in detail with reference to examples.

Example 1 A polylactic acid fiber (fiber length of about 6 mm, fiber diameter of about 0.5 mm) was added to 5 kg of okara (water content: about 80%) and 1 kg of seed compost as granules formed of biodegradable fibers. 10 liters of granular material (diameter about 6 mm) formed by heat fusion was added, and the water content was 70%.
Was adjusted. This was fermented for 24 hours using a household garbage disposal machine (manufactured by Sanyo Electric Co., Ltd., trade name: Gomi Nice). After the treatment, the temperature rose, and after 8 hours, the temperature reached a maximum of 62 ° C., and good fermentation proceeded. The temperature then dropped to 40 ° C. after 24 hours.

After 24 hours, the whole processed material including the particulate matter formed of the biodegradable fiber is taken out of the garbage processing machine and
The granular material formed of the biodegradable fiber and the treated product were completely separated by a sieve having a diameter of mm. The separated granular material was returned to the garbage disposal machine, and the processed product was further aerated from the lower part in a 1 L container (secondary fermentation tank) to perform a fermentation treatment. In addition,
When fermentation is carried out using a small processing vessel, heat dissipation to the outside is large and it is difficult to detect temperature rise caused by fermentation heat. The temperature of the thermostat was adjusted so as to be always lower by 1 ° C. than the temperature in the processing vessel. The temperature of the treated product reached 63 ° C., which is the maximum temperature after one day, and then gradually decreased to 32 ° C. two days later. When the okara treatment was performed again using the granular material formed of the separated biodegradable fibers, it was possible to perform the treatment as well as the first time.

After the above operation was repeated 10 times (for 10 days), the granular material formed of the biodegradable fiber was thoroughly washed and dried, followed by observation and weight measurement. Compared to before the start of the test, after the test, a considerable amount of particulate matter was disintegrated, and a 12% weight loss was observed. Further, when the granular material was buried in a place of about 10 cm in the soil, the shape almost disappeared after 6 months and disappeared after 1 year.

[0025]

According to the present invention, organic waste can be satisfactorily fermented, and secondary materials can be reused. Therefore, it is not necessary to provide a storage for secondary materials, and the cost can be reduced. Reduction is possible. Furthermore, even when the secondary material remains in the final processed product, the decomposition proceeds in the processed product, so that a high-quality compost or fertilizer can be obtained.

[Brief description of the drawings]

FIG. 1 is a diagram showing an example of the process of the method for fermenting organic waste of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 First fermenter 2 Separation tank 3 Second fermenter 4 Organic waste 5 Treated material (including granular material formed of biodegradable fiber) 6 Granular material formed of biodegradable fiber 7 Treated material 8 Compost or fertilizer

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Takao Asano 23 Uji Kozakura, Uji City, Kyoto Prefecture Unitika Central Research Laboratory F-term (reference) 4D004 AA02 AC01 BA04 CA18 CB02 CC08 4D059 AA03 BA01 BA27 BK09 CC01 DB40

Claims (1)

[Claims] 1. A method for fermenting an organic waste, wherein the fermentation of the organic waste is performed in the presence of a particulate material formed of biodegradable fibers.