JPH08290989A - Treatment of garbage - Google Patents

Abstract

PURPOSE: To effectively deodorize a smell-containing fermented exhaust occurring in making a solid particle component formed in crushing garbage and sludge prepared as a by-product in treatment of waste liquor with a bacterium into compost and to simultaneously clean both the waste liquor and a smell- containing drain rapidly. CONSTITUTION: Garbage 1 is crushed, transported 15 by water 2, subjected to sold-liquid separation 16-1, separated into a solid particle component 3 and waste liquor 5 and the solid particle component 3 is mixed with sludge 11 prepared as a by-product in aerobically treating the waste liquor 5 with a bacterium 8 into a compost 17. In the process, a smell-containing exhaust 7 prepared as a by product in forming the compost 17 is used as air supply for the aerobic bacterium treatment 18 of the waste liquor 5. Further, a drain 8 having a strong smell prepared as a by-product in another formation of compost different from the small-containing exhaust of the compost formation 17 is combined with the waste liquor 5 and deodorized and cleansed.

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 food waste without pollution.

[0002]

2. Description of the Related Art At present, food waste is treated by incineration or composting in a solid state. In recent years, for the convenience of transporting food waste, a technique for crushing food waste and transporting it with water has been developed and partially put into practical use overseas. However, if the crushed product is discharged as it is to sewage or the environment, it will impose a load on the sewage treatment facility and the environment. Therefore, it is desired to remove the polluted components of the crushed product. At that time, the elemental technology necessary for treating the crushed product, for example, solid-liquid separation, wastewater treatment, composting of solid particle components, sludge treatment, deodorization, etc., can be achieved as a total process simply by adding unit processes. The processing cost increases and it is difficult to put it into practical use in terms of economy.

[0003] Garbage is crushed by a means such as a disposer, conveyed with water and solid-liquid separated to separate a solid component and a waste liquid, and the solid component is combined with sludge produced as a by-product in the waste liquid treatment to form a compost. The process for doing so is already known (Japanese Patent Laid-Open No. 6-15794). Up to now, the sludge generated from the wastewater treatment facility has been extracted and separately disposed, but the above-mentioned process is economically advantageous in that it can be treated simultaneously with the solid component obtained by crushing the garbage.

However, with the composting, exhaust gas having a strong odor and drain having a strong odor and exhibiting acidity or alkalinity are produced as by-products. Pollution-free treatment of both is essential. If they are to be processed independently, the processing mechanism becomes complicated, and the operating cost increases, making it difficult for the process to be put to practical use. Among them, the latter drain is not neutral, and thus it is difficult to apply the aerobic microbial treatment, which is a general water purification technique, alone.

[0005]

DISCLOSURE OF THE INVENTION The object of the present invention is to improve the drawbacks of the food waste treatment process, which is centered on the crushing by a conventionally known disposer, and to exhaust the strong odor produced as a by-product during composting and to generate a strong odor and acidity. Alternatively, it is an economical pollution-free treatment of alkaline drainage.

[0006]

The first feature of the present invention is to:
Crush raw garbage, transport with water, separate solid and liquid to separate solid component and waste liquid, combine the solid component and sludge by-produced when aerobically treating the waste liquid with microorganisms In the method for composting, the odorous exhaust gas produced as a by-product during composting is used as the air supply for the waste liquid treatment.

The second feature of the present invention is that, in addition to the odorous exhaust gas for composting, the odorous drain by-produced during composting is treated together with the liquid waste.

The method of crushing food waste is not particularly limited as long as it can crush into substantially uniform particles such as using a disposer, a rotary hammer, a rotary roll. For transportation, a method is used in which water is supplied in an amount of 2 to 20 times the weight of raw garbage and is transferred mainly by gravity in an inclined pipe. The crushing and transportation means will be installed in each house of the housing complex, and more systems will be installed than the downstream elements. The method of separating the solid particle component and the waste liquid is not particularly limited, and conventionally known techniques such as sedimentation separation, screen filtration and centrifugation can be applied. The separated solid particle component is converted into compost by a conventionally known composting technique together with sludge produced as a by-product during aerobic microbial treatment of waste liquid described later. Fermentation conditions for composting, that is, fermentation temperature, aeration rate, mixing efficiency, etc. can be appropriately selected. The fermentation temperature is appropriately selected from the range of normal temperature to 70 ° C. The fermentation exhaust contains odorous components such as lower alcohols, aldehydes, ketones and organic acids, and also contains 15 to 20% by volume of oxygen and 90% or more relative humidity at the fermentation temperature. The temperature of the fermentation exhaust is approximately equal to the fermentation temperature.

On the other hand, the waste liquid treatment is not particularly limited as long as it is an aerobic microbial treatment, and an activated sludge method, a microbial fixed bed method, a water sprinkling bed method or the like can be used. The air flow rate is in the range of 5 to 100 m ³ / d for 1 kg / d of garbage processing capacity, which corresponds to several times the air flow rate in composting. In the waste liquid treatment, in addition to the waste liquid obtained by crushing food waste, other domestic waste water can be combined and treated at the same time. By-product sludge is a general term for so-called initial settled sludge, grease, surplus sludge, screen sludge, floating separation sludge, and other solid components associated with waste liquid treatment. The separating and concentrating method is not particularly limited, such as sedimentation separation, flotation separation, coagulation sedimentation and screen compression filtration, but if the water content can be 85% by weight or less of the solid particle component of crushed food waste, the water content in composting can be reduced. The heat supply required for evaporation can be saved.

In the case of composting, a fermentation method is often employed in which the fermentation bed is circulated and ventilated, dehumidified in the middle to remove drainage, and fresh air is replenished by oxygen consumption. At this time, the drain produced as a by-product contains an acidic component mainly composed of an organic acid and has a pH of 3 to 5, or rarely contains ammonia, so that the pH reaches 8 or more. The amount of generation varies depending on the circulation and aeration conditions and the fermentation conditions, but it is in the range of 0.4 to 0.9 kg / d with a garbage disposal capacity of 1 kg / d. The drain is purified together with the waste liquid.

[0011]

Function: Garbage is crushed by a disposer, crushed to 10 mm or less, and moved in vertical and inclined pipes by a water flow to reach a solid-liquid separation device. Here, the solid particle component and the waste liquid are separated. The solid particle component is composted together with the sludge produced as a by-product in the aerobic biological treatment of the waste liquid. In composting, the air vented to the fermentation bed is dehumidified and circulated for exhaustion of oxygen consumption and replaced with fresh air. Odor-containing drain generated by dehumidification is introduced into a waste liquid treatment device together with a waste liquid, and dissolved organic components and odorous components are decomposed and purified.
On the other hand, the odorous and moisturized exhaust gas discharged from the composting device is used as an oxygen-containing air supply for purifying the waste liquid, and not only serves as a source of oxygen, but also the odorous components in the exhaust gas are decomposed and deodorized and A part is condensed and purified. Treated water and deodorized exhaust are discharged outside the system. Usually, the fermentation temperature, and hence the temperature of the fermentation exhaust gas and the temperature of the drain are higher than the ambient temperature, so the temperature of the waste liquid treatment also rises by 2 to 10 ° C., and the decomposition rate increases correspondingly, and the treatment efficiency improves. .

[0012]

【Example】

(Example 1) Fig. 1 shows a block diagram in which raw garbage 1 is crushed 14 by a disposer at each house of an apartment house and a plurality of units are combined and processed.

In the kitchen of each house, garbage 1 is crushed 14 using a disposer under the supply of water 2, water is conveyed 15 in the pipe, and solid-liquid separation 16-1 is carried out to obtain solid particle component 3 and waste liquid. 5 is generated. The solid particle component 3 is composted 17 under the supply of air 6 and converted into compost 10. The drain 8 produced as a by-product in composting 17 is a waste liquid 5 under the supply of air 6.
After the aerobic microbial treatment 18 together with the solid-liquid separation 16-2
Then, the treated water 12 and the sludge 11 are separated. The sludge 11 is returned to the composting 17 and composted together with the solid particle component 3. On the other hand, the odorous exhaust gas 7 generated by composting 17 is used as a part of the air supply of the aerobic microbial treatment 18,
Deodorizing exhaust 9 is obtained.

(Embodiment 2) FIG. 2 is a block diagram showing the aerobic microbial treatment 4 of domestic wastewater 13 in addition to the waste liquid 5 originating from the raw garbage treatment in the raw garbage treatment of the first embodiment.

During the processing of food waste 1, domestic wastewater 13 generated from other than the kitchen is transported by water 15 while containing solid components.
And the waste liquid 5 originating from food waste is subjected to aerobic microbial treatment 18 to obtain treated water 12 and sludge 11. The sludge 11 of this embodiment contains solid particle components derived from domestic wastewater in addition to raw garbage.

(Example 3) In Example 2, domestic wastewater 3 containing solid particle components is treated aerobically with microorganisms 4, whereas in this Example, garbage is crushed as shown in FIG. 1
After 4, the water is conveyed 15 together with the domestic wastewater 13, and the solid particle component 3 and the waste liquid 5 in both are separated and treated.

[0017]

EFFECT OF THE INVENTION According to the present invention, the dehumidification of the humid fermented exhaust gas generated during composting of the sludge by-produced by the aerobic microbial treatment of the solid particle component and the waste liquid produced during the crushing of the garbage is effectively deodorized, Moreover, the waste liquid and the odorous drain produced as a by-product can be purified simultaneously and at high speed.

[Brief description of drawings]

FIG. 1 is a block diagram of the process of one embodiment of the present invention.

FIG. 2 is a block diagram of the process of the second embodiment of the present invention.

FIG. 3 is a block diagram of the process of the third embodiment of the present invention.

[Explanation of symbols]

1 ... Garbage, 2 ... Water, 3 ... Solid particle component, 4 ... Aerobic microbial treatment, 5 ... Waste liquid, 6 ... Air, 7 ... Odor containing exhaust, 8 ... Drain, 9 ... Deodorizing exhaust, 10 ... Compost, 11 ... sludge,
12 ... Treated water, 13 ... Domestic wastewater, 14 ... Crushing, 15 ... Water conveyance, 16-1, 16-2 ... Solid-liquid separation.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location C05F 17/02 9356-4H C05F 17/02

Claims (3)

[Claims] 1. A by-product when crushing food waste, transporting it with water, performing solid-liquid separation to separate a solid component and a waste liquid, and subjecting the solid component and the waste liquid to aerobic microbial treatment. In the method of composting together with the sludge, the odor-containing exhaust gas produced as a by-product during composting is used as an air supply for the waste liquid treatment. 2. The method for treating food waste according to claim 1, wherein, in addition to the odorous exhaust gas for composting, odorous drain produced as a by-product during composting is treated together with the waste liquid. 3. The method for treating food waste according to claim 1, wherein the number of process lines is smaller than the number of process lines after crushing the garbage and transporting it with water.