JPH0840790A - Method for treating municipal waste and device therefor - Google Patents

Abstract

PURPOSE:To provide a method for treating municipal wastes by decomposing garbage in municipal wastes with a microorganism consisting essentially of an anaerobic synthetic microorganism group, almost eliminating an offensive smell component and generation of heat, separating most of water in the garbage as a fermentation solution, circulating and reusing part of the fermentation solution and utilizing part of the fermentation solution as a liquid fertilizer and a solid material as a solid fertilizer. CONSTITUTION:The method for treating municipal wastes comprises (a) a process for introducing municipal wastes into a separating device 14 and dividing the municipal wastes into at least combustible wastes, garbage and waste water, (b) a process for sending part of the separated garbage to a preculture tank 10, adding an organic substance decomposing microorganism group as a spawn or circulating and sending a fermentation solution from a reaction tank 12 mentioned later to the preculture tank 10 and carrying out preculture, (c) a process for introducing the rest of the garbage to the reaction tank 12, decomposing the previously cultured garbage from the preculture tank 10 with a microorganism and separating into a solid material and a fermentation solution and (d) a process for taking out the solid material from the reaction tank 12 and circulating part of the fermentation solution from the reaction tank 12 to the preculture tank 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for efficiently treating municipal solid waste including raw garbage, and an apparatus for carrying out this method.

[0002]

2. Description of the Related Art Currently, most of garbage is collected as municipal waste and is incinerated or landfilled, but there are many problems such as odor generation and hygiene problems. The method of composting raw garbage and returning it to farmland has also been implemented for a long time using composting equipment, but it is widely used due to problems such as odor generation, long residence time, and product distribution problems. The current situation is that there are none.

JP-A-5-170579 discloses that organic acid is added to organic waste to adjust the pH to 3.0 to 5.0, lactic acid is produced with anti-acidity, and butyric acid is not produced, which is pathogenic. A method for producing an organic fertilizer by treating with a microorganism having an antagonistic value of 50 or more in a closed and non-aerated state is described.

Further, Japanese Patent Publication No. 62-8236 discloses that
A method of producing textile and particulate matter from domestic, agricultural, forestry, organic and / or industrial waste, which comprises decomposing the waste to be treated and decomposing the decomposed waste into at least two parts, namely a machine. Mechanically crushable parts and mechanically difficult to crush parts, and crush these two parts separately to the desired final particle size, then combine and convey both parts, and in some cases intermediate treatment After that, both parts are heated, the water vapor generated at that time is extracted, dried to a predetermined maximum residual water content and sterilized, and then together divided into at least two parts depending on the particle size. Has been described.

[0005]

As described above, the method described in JP-A-5-170579 produces an organic fertilizer by adding an organic acid to organic waste and treating it with microorganisms. However, it is not economical to add organic acid to a large amount of garbage. In addition, it takes an extremely long time to sufficiently dry the product, and when discharged in the middle, it is necessary to immediately return to soil, which is also not suitable for large-scale treatment. Furthermore, a large amount of fermented liquor containing high organic matter is produced, which requires treatment.

The present invention has been made in view of the above points,
The object of the present invention is to make a part of the garbage into a pre-cultured garbage by reacting it with a group of organic matter-decomposing microorganisms in a pre-culture tank, and add this pre-cultured garbage to the rest of the garbage to carry out microbial decomposition. In view of the above, it is an object of the present invention to provide a method and a device for treating a large amount of raw garbage economically and efficiently with little generation of malodorous components and heat and making it available as solid fertilizer and liquid fertilizer.

[0007]

In order to achieve the above-mentioned object, the method of treating municipal solid waste of the present invention, as shown in FIG. 1, includes the following steps (a) to (c):
(A) A step of introducing a part of raw garbage into the pre-culture tank 10 and introducing an organic matter-decomposing microorganism group as seed bacteria, or circulatingly introducing a fermentation liquid from a microbial reaction tank 12 described below to perform pre-culture. b) a step of introducing the remainder of the raw garbage into the reaction tank 12 and introducing the pre-cultured raw garbage from the pre-culture tank 10 to perform microbial decomposition and separate into solid matter and fermentation liquid,
(C) Take out the solid matter from the reaction tank 12 and
Circulating a portion of the fermentation broth from 2 to the pre-incubator 10,
Is configured to include. When most of the municipal waste is raw garbage, it is processed by the above method.

In addition, in the method for treating municipal waste of the present invention, the following steps (a) to (d), that is, (a) introducing the municipal waste into the sorting apparatus 14, at least combustible garbage, garbage and A step of separating into waste water, (b) introducing a part of the separated raw garbage into the pre-culture tank 10 and introducing an organic matter-decomposing microorganism group as an inoculum, or introducing a fermentation solution from a reaction tank 12 described later in a circulating manner. And (c) introducing the rest of the garbage into the reaction tank 12 and introducing the pre-cultured garbage from the pre-culture tank 10 for microbial decomposition to separate solid matter and fermentation liquid. And (d) taking out the solid matter from the reaction tank 12 and circulating a part of the fermentation broth from the reaction tank 12 to the pre-culture tank 10. When municipal waste contains wastes other than raw garbage, this method is used.

In the above method, a part of the fermented liquor from the reaction tank 12 is supplied to the pre-culture tank 10, and another part of the fermented liquor is sprayed on the municipal waste in the separation step to generate odor during the separation step. Is preferably suppressed. Further, a part of the fermented liquor from the reaction tank 12 was supplied to the pre-culture tank 10, and the other part of the fermented liquor was adsorbed to the inorganic porous material or the organic porous material in the wastewater separated by the fractionation device. It is preferable to treat the wastewater by supplying it in a state of contact and contacting it. Furthermore, while supplying a part of the fermented liquid from the reaction tank 12 to the pre-culture tank 10, the other part of the fermented liquid is sprayed on the municipal waste in the separation process to suppress the generation of odor during the separation process, It is preferable to supply another part of the waste water to the waste water separated by the separation device to treat the waste water.

The combustible waste separated by the separating device 14 may be incinerated in the incinerator 16 so that the exhaust gas from the incinerator 16 dries and reduces the volume of the solid matter from the reaction tank 12. preferable. As microorganisms for decomposing food waste,
Although all microorganisms capable of decomposing organic substances can be used, it is preferable to use those mainly composed of anaerobic synthetic bacteria.

The municipal solid waste treating apparatus of the present invention comprises a pre-cultivation tank 10 for pre-culturing a part of raw garbage together with inoculum or fermentation liquid.
And a reaction tank 12 for reacting the remainder of the garbage with the pre-cultured garbage from the pre-culture tank 10 to decompose microorganisms and separate into a solid matter and a fermentation liquor, the reaction tank 12 and the pre-culture tank And a fermented liquid recycle pipe 18 for connecting 10 with each other.

Further, in the case of separating municipal waste, the apparatus of the present invention comprises a separating apparatus 14 for separating the municipal waste into at least combustible garbage, raw garbage and waste water, and a part of the separated raw garbage as an inoculum or a fermentation. Preculture tank 10 for preculture with liquid
And a reaction tank 12 for reacting the remainder of the garbage with the pre-cultured garbage from the pre-culture tank 10 to decompose microorganisms and separate into a solid matter and a fermentation liquor, the reaction tank 12 and the pre-culture tank And a fermented liquor recycle pipe 18 that connects 10 to the fermented liquid.

In the above apparatus, a wastewater treatment device 20 for treating wastewater from the separation device 14, a fermentation liquid pipe 22 connecting the reaction tank 12 and the upstream side of the separation device 14, the reaction tank 12 and the wastewater treatment device. A fermented liquid pipe 24 connecting 20 with
Incinerator 16 for incinerating combustible waste from the sorting device 14
And a drying / volume-reducing device 26 for drying / volume-reducing the solid matter from the reaction tank 12 by the waste heat from the incinerator 16.

A preferred embodiment of the present invention will be described below with reference to FIG. City waste including raw waste is introduced into the sorting apparatus 14 to sort into combustible waste, raw waste, recycled materials (paper, wood, plastic, metal, etc.) and waste water. The combustible waste is incinerated in the incinerator 16, and the wastewater is treated in the wastewater treatment device 20. A part (0.001 to 0.5 part by weight) of the separated garbage is introduced into the pre-culture tank 10, and a microorganism mainly composed of an anaerobic synthetic bacterium group is introduced as a pre-culture and pre-cultured. Remaining garbage (0.999-0.5
(Parts by weight) is introduced into the microbial reaction tank 12, and the pre-cultured raw garbage from the pre-culture tank 10 is introduced to carry out microbial decomposition and separate into solid matter and fermentation broth.

The solid matter from the reaction tank 12 is introduced into the drying / volume-reducing device 26, and is dried / volume-reduced by the exhaust gas from the incinerator 16 to be used as a solid fertilizer. A part of the fermented liquid from the reaction tank 12 is introduced into the preculture tank 10 through the fermented liquid recycling pipe 18 and used in place of the inoculum. Therefore, when a part of the fermentation broth is introduced into the pre-culture tank 10, the inoculation of the inoculum is stopped. The other part of the fermented liquor from the reaction tank 12 is sprayed by the fermented liquor pipe 22 to the municipal waste on the upstream side of the sorting device 14 or the municipal waste at the inlet of the sorting device 14 to suppress odor generation during the sorting process. To be Further, another part of the fermented liquor from the reaction tank 12 is introduced into the wastewater treatment device 20 through the fermented liquor pipe 24, and the wastewater is biodegraded into water that can be discharged. The rest of the fermentation liquor is used as liquid fertilizer.

[0016]

EXAMPLES The present invention will be described in more detail based on the following examples, but the invention is not intended to be limited to the following examples, and various modifications can be made as appropriate. Example 1 70 g of fresh cabbage was filled in five 150 ml transparent containers, and anaerobic synthetic bacteria group EM-R (powder) 1 manufactured by EM Research Co., Ltd.
wt%, EM-R (powder) 5 wt%, EM-R (powder) 10 wt%
%, And 5% by weight of EM-R (liquid), respectively, and the mixture was sealed. Nothing was added to the remaining one container, which was hermetically sealed as it was to give a blank. Then, the time-dependent change in volume (volume reduction effect) was measured. The result was as shown in FIG. Figure 2
Therefore, when it was about 70 ml when it was filled, it was 4 after 20 days.
The volume decreased to around 0 ml, which shows that the volume-reducing effect of the anaerobic synthetic bacteria group is extremely large. In addition, a large amount of fermented liquid was produced. On the other hand, in the case of the blank, what was about 82 ml at the time of filling was about 68 after 20 days, which was not much reduced.

Then, 850 g of fresh cabbage was newly filled in each of four 2000 ml transparent containers and the above-mentioned EM-R was used.
Fermented liquid after 20 days when 10 wt% (powder) was added was extracted on fresh cabbage at 1 wt%, 5 wt%,
After spraying 10 wt%, it was sealed. The remaining one container was sealed as it was without spraying the fermented liquid and used as a blank. Then, the time-dependent change in volume (volume reduction effect) was measured. The result was as shown in FIG. From FIG. 3, it can be seen that what was around 87 ml at the time of filling decreased to around 60 after 7 days, and the volume reduction effect of the fermentation liquor recycling was extremely large. That is, it can be seen that the waste water and the solid matter are separated. In the case of blank, there is almost no change.

[0018]

Since the present invention is configured as described above, it has the following effects. (1) Since the garbage is decomposed by microorganisms mainly composed of synthetic bacteria, almost no odorous components and heat are generated, and most of the water in the garbage can be separated as a fermentation liquor. In particular, when those mainly composed of anaerobic synthetic bacteria are used, these actions,
The effect can be exhibited more suitably. (2) A high-concentration group of organic substance-decomposing microorganisms, for example, a group of anaerobic synthetic bacteria, live in the fermentation liquor, and can be recycled as a bacterial group and reused in the system. (3) The fermented liquor and solid matter, which are the processed products of raw garbage, can be effectively used as liquid fertilizer and solid fertilizer, respectively. (4) Since most of the water can be separated in the microbial reaction tank and the solid matter does not have a rotting odor, the load on the subsequent dryer (drying / volume reduction device) is small.

[Brief description of drawings]

FIG. 1 is an overall system diagram showing an embodiment of a municipal solid waste processing apparatus of the present invention.

FIG. 2 is a graph showing a volume reduction effect (volume change) by adding an anaerobic synthetic bacteria group in Examples.

FIG. 3 is a graph showing the volume reduction effect (volume change) by fermentation liquid recycling in Examples.

[Explanation of symbols]

 10 Pre-culture tank 12 Microbial reaction tank 14 Separation device 16 Incinerator 18 Fermentation liquid recycling pipe 20 Waste water treatment device 22 Fermentation liquid pipe 24 Fermentation liquid pipe 26 Drying / volume reduction device

Continuation of front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location C05F 17/00 7537-4H 17/02 7537-4H (72) Inventor Hayami Ito 1 Kawasaki-cho, Akashi-shi, Hyogo No. 1 Kawasaki Heavy Industries Ltd. Akashi Plant (72) Inventor Hiroshi Fujiyama 1-3 1-3 Higashikawasaki-cho, Chuo-ku, Kobe-shi Kawasaki Heavy Industries Ltd. Kobe Head Office (72) Takeshi Suzuki 1 Higashi-kawasaki-cho, Chuo-ku, Kobe 1st-3rd Kawashige Environmental Engineering Co., Ltd.

Claims (10)

[Claims] 1. The following steps (a) to (c), that is, (a) a part of raw garbage is introduced into a preculture tank, and an organic matter-degrading microorganism group is added as an inoculum or a reaction described below. A step of circulating and introducing the fermentation broth from the tank to preculture, (b)
(C) Solid matter from the reaction tank, in which the remainder of the garbage is introduced into the reaction tank and the pre-cultured garbage from the pre-incubation tank is introduced to carry out microbial decomposition to separate into solid matter and fermentation liquid. And a step of circulating a part of the fermentation liquor from the reaction tank to the pre-culture tank. 2. The following steps (a) to (d), that is, (a) a step of introducing city waste into a separating apparatus and separating at least combustible waste, garbage and waste water, (b)
A step of introducing a part of the separated garbage into a pre-culture tank and introducing an organic matter-decomposing microorganism group as a seed bacterium, or circulatingly introducing a fermentation broth from a reaction tank to be described later to perform pre-culture, (c)
A step of introducing the remainder of the garbage into the reaction tank and introducing the pre-cultured garbage from the pre-culture tank to carry out microbial decomposition and separating into solid matter and fermentation liquid, (d) solid matter from the reaction tank And a step of circulating a part of the fermentation liquor from the reaction tank to the pre-culture tank. 3. A method of supplying a part of the fermentation broth from the reaction tank to the pre-culture tank, and spraying another part of the fermentation broth on municipal solid waste in the separation step to suppress odor generation during the separation step. The method for disposing of municipal waste as described in 2. 4. A part of the fermented liquor from the reaction tank is supplied to the pre-culture tank, and another part of the fermented liquor is adsorbed to the inorganic porous material or the organic porous material in the waste water separated by the fractionation device. 3. The method for treating municipal solid waste according to claim 2, wherein the waste water is treated by supplying it in contact with and contacting it. 5. Fermentation is performed by supplying a part of the fermented liquor from the reaction tank to the pre-culture tank and sprinkling another part of the fermented liquor on municipal waste in the separation step to suppress odor generation during the separation step. The method for treating municipal solid waste according to claim 2, wherein still another part of the liquid is supplied to the waste water separated by the separation device to treat the waste water. 6. The method according to claim 2, wherein the combustible waste separated by the separating device is incinerated in an incinerator, and the solid matter from the reaction tank is dried and reduced in volume by the exhaust gas from the incinerator. City waste disposal method. 7. The method of treating municipal solid waste according to claim 1, wherein a microorganism mainly composed of an anaerobic synthetic bacteria group is used as a microorganism for decomposing raw garbage. 8. A pre-incubator for pre-cultivating a part of the garbage with an inoculum or a fermented liquid, and a remaining portion of the garbage with the pre-incubated garbage from the pre-incubator for microbial decomposition to produce solid matter. An apparatus for treating municipal solid waste, comprising: a reaction tank for separating a fermentation solution and a fermentation solution; and a fermentation solution recycling pipe connecting the reaction tank and the pre-culture tank. 9. A sorting device for sorting municipal waste into at least combustible waste, raw garbage and wastewater, a pre-culture tank for pre-culturing a part of the sorted raw garbage together with an inoculum or a fermentation solution, and the rest of the raw garbage. A reaction tank for microbial decomposition by reacting with the pre-cultured garbage from the pre-culture tank and separating into a solid matter and a fermentation solution, and a fermentation solution recycling pipe connecting the reaction tank and the pre-culture tank A municipal solid waste treatment device comprising: 10. A wastewater treatment device for treating wastewater from the separation device, a fermentation liquid pipe connecting the reaction tank and an upstream side of the separation device, and a fermentation liquid pipe connecting the reaction tank and the wastewater treatment device. The city according to claim 9, comprising an incinerator that incinerates combustible waste from the separation device, and a drying / volume-reducing device that dries / volume-reduces solid matter from the reaction tank by waste heat from the incinerator. Garbage disposal equipment.