JPH09299906A - Organic waste treatment method - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] To provide an efficient and inexpensive method for biocombustion treatment of organic waste. In a method for treating organic waste by bioburning organic waste with microorganisms retained on a carrier, an animal-derived material such as a shell that is not easily bioburnable is used as a microbial carrier. With the above configuration, it is possible to efficiently, hygienically and inexpensively reduce the volume and harmlessness of organic wastes, particularly organic wastes containing animal-derived biocombustible materials.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for treating organic waste, and more particularly to a method for treating organic waste by bioburning the organic waste by microorganisms retained on a carrier.

[0002]

2. Description of the Related Art Conventionally, as a method for treating organic wastewater and / or organic waste containing organic solid matter, various organic carriers for these organic substances (those which inhabit and retain microorganisms) are used.
Biocombustion in the decomposition tank, that is, fermentation decomposition is carried out. According to such a method, the organic matter mixed with the carrier is bioburned by the microorganisms retained on the carrier and decomposed into carbon dioxide, water, etc., and the volume is reduced to be harmless.

At present, in a method of treating organic waste by bioburning it with microorganisms, wood chips such as cedar sawdust are used as a carrier of microorganisms (Japanese Patent Laid-Open No. 6-9).
1285, JP-A-6-294804), activated charcoal or charcoal (JP-A-6-91286), white sand which is a kind of volcanic ash (JP-A-6-246284).
And coffee liquid extraction residue of coffee beans (JP-A-6-3
No. 15694) has been proposed.

However, when wood chips are used as the carrier, the wood chips are also organic substances, and some of them are decomposed by the biocombustion action. For example, lignin will be included in the organic substance treatment residue, and it is necessary to perform a secondary treatment to remove it after disposal.

Further, although activated carbon can be used as a carrier by utilizing its adsorption action, it is necessary to remove the adsorbed substance to regenerate its adsorption ability, which requires time and labor such as incineration of the adsorbed component at high temperature. It has the disadvantage of being expensive. In the case of charcoal, it easily hardens when mixed with organic matter,
Since agglomerates are formed and impair the air permeability, the activity of aerobic microorganisms is hindered, and in order to solve this, a stirring means having a large stirring force is required.

Further, the conventional carrier needs to be purchased and procured, which causes a problem of cost. In particular, for example, in the treatment of seaweeds and shellfish trapped in the intakes of various plants such as nuclear power plants or thermal power plants, when treating an object to be treated including shells, the carrier itself as well as the treatment residue from the decomposition tank Since the carrier is taken out, the carrier needs to be replenished frequently and in a large amount, and the carrier purchase cost becomes a large cost factor. Further, in such a case, since the carrier to be treated is contained in the treated residue to be taken out in addition to the original treated residue, the effect of reducing the volume of waste by the biocombustion treatment cannot be expected so much. Become.

[0007] In order to avoid the above problems, it is necessary to separate the organic waste to be treated into ones that are difficult to bioburn (for example, shells) and other ones (for example, shellfish and seaweed). In addition, it is troublesome and expensive.

[0008]

An object of the present invention is to provide a treatment method capable of efficiently and inexpensively detoxifying and detoxifying an organic waste, particularly an organic waste containing a material which is hardly biocombustible. That is.

[0009]

Means for Solving the Problems As a result of intensive studies to solve the above-mentioned problems, the inventors of the present invention carry out biocombustion by using a biocombustible material of animal origin such as shell as a microorganism carrier. As a result, they have found that the organic waste can be reduced in volume and harmlessly in an efficient, hygienic and inexpensive manner, and the present invention has been completed.

[0010] That is, according to the present invention, in a method of treating organic waste by bioburning it with microorganisms retained on a carrier, a method of using an animal-derived biocombustible material as a microorganism carrier is used. Will be provided. Here, the term "animal-derived biomaterial that is difficult to burn" in the present specification is a material derived from an animal, and is a microorganism-derived organism within a normal treatment period under the conditions usually used in the present technical field. It means a material that undergoes no, or only little, combustion or fermentative decomposition.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The carrier used in the treatment method according to the present invention is a material of animal origin which is hard to bioburn, and has a material having pores in which microorganisms can live or can form such a material. It is a material. Examples of such a material include animal tissues mainly composed of hard proteins (bone, cancellous bone, fish scales, etc.), shells and crushed products thereof, among which shells and crushed products thereof are preferably used. To be Shell used in the present invention is a nuclear power plant, a thermal power plant or other various plants such as shells captured from the intake of shells or shells obtained from shells captured by the dredging of ports and rivers, or the food and drink industry,
It may be a shell or a crushed product thereof that is discharged as a waste from the food processing industry or other industries, and any kind of shellfish as a supply source may be used. In the treatment method of the present invention, both shells with or without body can be preferably used.

Hereinafter, an example of the processing method of the present invention will be described more specifically with reference to the processing step diagram shown in FIG. The organic waste treated by the present invention is carried in by a transportation means such as a truck (FIG. 1). Then, cleaning is performed by spraying (FIG. 1), but this step may be performed as necessary and can be omitted.

Next, the organic waste is sent to a crusher via a receiving conveyor and crushed to an appropriate size, if necessary (FIG. 1). At that time, if the organic waste contains an animal-derived material that can be used as a carrier, it can be crushed as it is without being separated (sorted) due to the difficulty of biological combustion, and the organic waste can be used as a carrier. When the obtained animal-derived material is not contained, the material that can be used as the carrier of the present invention, such as a shell, can be appropriately mixed and then crushed. It is also possible to mix the previously crushed carrier with the crushed organic waste. There is no limitation on the size to be crushed, but it is usually crushed to a size of several cm to several mm. As a matter of course, this step can be omitted if the object to be treated is liquid or crushed.

Then, the crushed object to be treated is put into the decomposition tank together with the microorganisms by the conveyer (FIGS. 1 and 2). There is no particular limitation on the microorganism that can be used in the method of the present invention, and any microorganism can be used as long as it can be usually used for fermentative decomposition of organic matter, but a thermophilic aerobic fermentation microorganism is preferably used. In addition, for example, when it is determined that such microorganisms are sufficiently attached to the organic waste to be treated by a known inspection means such as a dyeing microscope of an extracted sample, or when such microorganisms are sufficiently contained in the decomposition tank. If it is determined that a sufficient amount of surviving / surviving is required, it is not necessary to add a microorganism.

The decomposition tank that can be used in the present invention is not particularly limited, and any conventional decomposition tank may be used. There is no particular limitation on its size. In addition, conditions for biocombustion (decomposition) by microorganisms such as fermentation temperature range, fermentation period and stirring aeration can be changed depending on the material to be treated, the microorganisms used and the capacity of the decomposition tank, etc. It is a design item that can be set. Prevent the generation of secondary waste by discharging the residue that has been subjected to bio-combustion treatment by microorganisms in the decomposition tank on a regular basis and transferring it to the residue receiving tank, for example, by effectively using it as a special fertilizer or soil improvement material. be able to.

FIG. 2 and FIG. 3 respectively show a processing flow for treating organic waste consisting of seaweed and shellfish under the same conditions by the treatment method according to the present invention and the conventional treatment method. In these treatment flows, it is assumed that the total annual amount of organic waste generated is 800 m ³ and the proportion of seaweed and shellfish in the total amount is 50% by volume, and the capacity of the decomposition tank for treating this is 10 m. ^{There is as 3} . Therefore, if the facility availability is set to 50%, 1
Average daily required amount of seaweed and shellfish is 2.
It is 2 m ³ . If the volume reduction ratio when crushing 2.2 m ³ of seaweed and shellfish is estimated to be 1/3, the average biocombustion (decomposition) throughput of seaweed and shellfish after crushing is 0.73.
m ³ . Up to this point, the processing steps and conditions are common to both the method of the present invention and the conventional method.

Further, in both treatment methods, it is assumed that there is no difference in the rate and degree of biological combustion by microorganisms, and if the volume reduction ratio due to this biological combustion is 1/15, the seaweed that is easily biologically burned per day The average amount of residue generated is 0.
05M ³ next, and daily residues generated amount of hard shellfish is biologically burned average 0.73 ^3, and the total amount of residues occurring per day an average 0.78 m ^3.

Here, in the processing flow of the method of the present invention shown in FIG. 2, since the shell itself, which is the object to be treated, is used as the microorganism carrier, seaweed at the start of biocombustion (object of biocombustion). The mixture ratio of broth and mussels (microorganism carrier) is 1: 1, and the above 0.78 m ³ of residue is the net average amount of residue per day.

On the other hand, in the processing flow of the conventional method shown in FIG. 3, the same biocombustion target and microbial carrier mixing ratio as in the present invention is realized, and the biocombustion efficiency equivalent to that of the method of the present invention is realized. In order to obtain
It is necessary to separately charge a microbial carrier in a larger amount than 73 m ³ ), and the introduced microbial carrier is difficult to biocombust, so most of it remains as a residue. In order to avoid this, if the seaweed and shellfish are separated before crushing, supplementation of the above carrier is not necessary and the amount of residue is also equivalent to the method of the present invention, but for that purpose it is usually a manual work and a complicated separation work. Therefore, there remains a practical problem in terms of processing cost and workability. From this, it is understood that the treatment method of the present invention has an effect that the labor is saved and the amount of the treatment residue is remarkably reduced as compared with the conventional treatment method.

Further, in the conventional method shown in FIG. 3, it is necessary to realize the same biocombustion target and microbial carrier volume ratio as in the present invention and obtain the same biocombustion efficiency as in the method of the present invention. Even if the amount of the microbial carrier is estimated to be the same as the amount of the bio-burning object (0.73 m ³ ), the cost of purchasing the carrier is not negligible. For example, if cedar wood chips are used as a carrier, the unit price is about 75,000 yen / m ³ , so the annual cost to purchase the carrier is calculated by the following formula {(75,000 yen / m ³ ) ×
(0.78 m ³ / day) × (365/2 days)} to 10,000
It can be roughly estimated to be about 0,000 yen. Similarly, if activated carbon with a unit price of about 135,000 yen / m ³ is used, the annual cost of purchasing the carrier is 20,0
It can be estimated to be about 0000 yen. Thus, the treatment method of the present invention has an economic effect of reducing the cost of purchasing these carriers.

[0021]

As described above in detail, the treatment method of the present invention is a method of bioburning organic waste with microorganisms to reduce the volume and detoxify, and uses a material of animal origin that is difficult to bioburn as a microorganism carrier. By adopting a configuration of using, it reduces the burden on workers and reduces the amount of processing residue, particularly in the processing of organic waste containing materials that are difficult to bioburn.
And the remarkable effect of reducing the carrier purchase cost can be achieved.

[Brief description of drawings]

FIG. 1 is a process step diagram showing an example of a processing method of the present invention.

FIG. 2 is an explanatory diagram showing a processing flow of organic waste in which seaweed and shellfish are mixed according to the processing method of the present invention.

FIG. 3 is an explanatory diagram showing a processing flow of an organic waste mixed with seaweed and shellfish by a conventional processing method.

Claims (3)

[Claims] 1. A method for treating organic waste by bioburning organic waste with microorganisms retained on a carrier, characterized in that an animal-derived biocombustible material is used as a microorganism carrier. . 2. The method of claim 1, wherein the animal-derived biocombustible material is a shell. 3. The method according to claim 1, wherein the residue after bioburning the organic waste is used as a special fertilizer and / or a soil conditioner.