JP2001002482A - Composting of organic waste - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently treat garbage, etc., and put them to effective use by treating organic waste with a wet pulverizing/selecting device, separating/ removing lightweight and heavyweight inadequate materials, treating the obtained slurry with a flocculating agent, subjecting it to solid-liquid separation and composting the solid content by fermentation. SOLUTION: The organic waste containing many composting components such as garbage, collected household waste, waste from a food industry or brewing industry and various kitchen waste is treated with the integrated or separated pulverizing/selecting device. The lightweight inadequate materials such as plastics and the heavyweight materials such as metal are separated and removed. The flocculating agent such as ferric chloride is added to the obtained slurry, which is, if necessary, treated with an alkaline agent to adjust the pH and then subjected to solid-liquid separation. The solid content is treated using a composting device to obtain the objective compost. It is preferable that the composting comprises fermenting using a fermentation tank after actinomycete or commercial compost is added to the solid content or fermenting by piling and cutting the solid content manually.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to garbage discharged from homes, factories, offices, etc., collected garbage including garbage,
The present invention relates to composting of organic waste (hereinafter, simply referred to as “garbage”) such as food industry waste, brewery industrial waste, and various types of kitchen waste.

[0002]

2. Description of the Related Art Conventionally, as a method of treating garbage and the like, incineration methods have been mainly adopted by local governments and the like. However, collected garbage contains plastics, etc., and if they are incinerated without completely removing them, dioxins and other harmful substances will be released, which may cause serious secondary disasters. However, there is a demand for an improvement in the processing. In addition, incineration of garbage requires not only a large amount of energy but also wasteful garbage, which is one of useful resources, without being effectively used.

On the other hand, garbage contains raw materials suitable for compost production and is therefore a suitable raw material for compost production. For household garbage and the like, small-scale composting treatment is performed at home. Have been done. However, in composting using raw garbage and the like collected on a large scale by local governments and the like, it is most efficient to completely remove impurities such as plastic, glass, and metal at the collection stage. However, except when a composting device is installed in a place such as a kitchen where garbage is generated, impurities are inevitably mixed when composting after collecting and transporting to a composting facility. In a conventional composting facility, municipal garbage containing impurities, business garbage, and the like are used as a pretreatment method for composting by using a combination of the following dry-type impurity sorting methods. Breaking bags, crushing Sieving separation Magnetic, electrical separation, etc.

[0004] However, when a lot of garbage is contained, kitchen garbage adheres to impurities (glass, metal, plastic, etc.) crushed and separated in these steps, generating odors and hindering recycling. You. In addition, the efficiency of the separation is poor, and impurities may enter the composting apparatus, and the quality of the final compost deteriorates, so that utilization may not proceed.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of such a state of the art, and has an object to treat garbage effectively without treating it by incineration. We re-focused on the point that composting is suitable as its use. The present invention has been made for the purpose of solving various problems in the conventional composting of garbage at once.

[0006]

DISCLOSURE OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and as a means for solving the above-mentioned problems, despite the processing of garbage and the like having a high water content, the conventional method has been proposed. Instead of dry treatment, which has been done, we focused on wet treatment, and as a result of intensive research, succeeded in completing and providing a new composting system based on wet treatment.

The means for solving the above problems have been completed by the following process. In other words, since garbage and the like have a high moisture content, instead of the current situation in which dry processing is exclusively used for the treatment, the idea is changed and instead of dehydrating the garbage with a high moisture content, Either as it is or reversely to the above to form a slurry into a porridge, which makes it possible to efficiently use both lightweight unsuitable materials such as plastic bags that are unsuitable for composting and heavy unsuitable materials such as broken glass bottles. Can be separated into
The obtained slurry can be very efficiently separated into solid and liquid by treating it with a coagulant, and the separated solid content does not contain any substances unsuitable for composting. Not only was it possible to confirm that the resulting compost was of very high quality because it used garbage, which was originally a suitable raw material for compost production. Based on these useful new findings, further studies have finally been completed.

That is, one of the features of the present invention is that a wet system incorporating a wet pulverizing and sorting apparatus is employed for compost production, while the conventional method employs a dry system. According to this system, garbage and the like can be pulverized and pulverized by a wet pulverizing / sorting device, and light and unsuitable substances can be separated and discharged (removal rate 95%), and a slurry can be obtained by screen separation and the like. This system is closed and operates with added water (about 0.7 times the garbage), so it has low odor. In addition, impurities in the separated slurry are small, and the slurry is condensed using a coagulant, and the solid content is collected by a dehydrator and subjected to composting. Is characterized by a good yield.

According to the present invention, an organic waste is treated by a wet pulverizing and sorting apparatus, and the obtained slurry is treated with a flocculant.
Solid-liquid separation and composting of solids are based on the basic technical idea of a method for composting organic waste, and the present invention exemplifies the following as specific embodiments. ,
Included.

In the present invention, the organic waste includes:
Various organic wastes such as garbage, collected garbage including garbage, food industry waste, brewery industrial waste, and various kitchen wastes are widely included. Either the integrated type or the separated type can be used.

In practicing the present invention, the composting can be either mechanical composting using a fermenter or manual composting, wherein actinomycetes and / or product compost are added. These can be used as inoculum or starter to promote composting and shorten the compost production period. The present invention also relates to a product compost itself produced by such a composting method and having excellent characteristics as described above.

[0012]

Embodiments of the present invention will be described below in detail.

Please refer to FIG. FIG. 1 is a flow sheet illustrating an example of the method for producing compost according to the present invention. As raw materials, garbage and the like (collection including garbage, garbage, food industry waste, brewery industrial waste, various kitchen wastes, and other organic wastes) are used. First, garbage and the like are subjected to pretreatment such as bag breaking and crushing as necessary before being subjected to wet crushing and sorting. Next, a wet pulverizing and sorting process is performed.

The wet pulverizing and sorting process can be performed by a wet pulverizing and sorting apparatus such as a pulper. As the pulper, a type (separation type: Fig. 3) in which a light-weight unsuitable material separating section that separates and removes light-weight unsuitable materials (plastic bags, plastic films, various packaging materials, and other lightweight composting unsuitable materials) is separated from the main body. Any type (integral type: FIG. 2) in which the lightweight unsuitable object separating portion is integrated with the main body can be used.

The main body of the wet pulverizing and sorting apparatus, comprising a main body and a light-weight unsuitable material separating section, comprises a container provided with an impeller of a stirrer at a central portion, and a lower portion of the container is provided with or without a sieve portion. Provide an outlet for separating unsuitable materials (hereinafter referred to as "weight unsuitable materials").

The impeller is preferably conical and provided with a guide plate projecting at about 45 ° from the outside of the impeller and pivotally extending around the cone from the bottom end to the head end. The rotation of the impeller creates a stream of suspension in the form of a trogel or loop inside the body vessel. The flow is radially outward at the bottom and has a small lateral flow component. The flow obtained by the impeller provides a hydraulic cutting force acting on the suspension, so that garbage and the like can be completely slurried. The main body of the wet pulverizing and sorting apparatus is not limited to the above-mentioned type, and any type of apparatus can be used as appropriate as long as it is capable of pulverizing garbage and the like in a wet manner and making it into a slurry. By providing a weight-unsuitable material separating section, a wet pulverizing and sorting apparatus can be obtained.

In the case of the type in which the light-weight unsuitable material separating portion is integrated with the main body, the light-weight unsuitable material in the main body is grasped from above using a mesh, a net, a comb-like gripper, or the like. All types of separations, such as scooping, can be used. As an example, a case where a rake device is used (FIG. 2) will be described.

The raw garbage or the like is crushed or crushed, or is directly charged into the main body to be slurried. The tooth row is submerged in the slurry or the upper surface of the slurry is moved to grasp (and / or scoop) light-weight unsuitable materials (plastic bag, plastic film, various packaging materials, and other light-weight uncomfortable materials), The dentition which has been grasped is moved vertically by the dentition conveying device to reach the top of the container body, and then moved (turned) in the horizontal direction to separate the grasped lightweight unsuitable object. On the other hand, unsuitable materials (metal, glass, sand, pebbles, etc.) accumulate at the bottom of the container body,
Take this out as appropriate.

The slurry obtained by the above treatment is sent to a string tank through a sieve at the lower part of the container, and after removing unsuitable materials such as sand, the slurry is sent to a slurry storage tank.

In the case of a type in which the lightweight unsuitable material separating section is separated from the main body (for example, FIG. 3), the slurry is sent from the main body to the separation chamber. The separation chamber is provided with a cylindrical sieve having a hole formed by an elongated groove, and is rotated at a constant speed. The slurry containing the light-weight unsuitable material flows from the main body, the separated slurry is taken out through the sieve, and the light-weight unsuitable material is removed. If necessary, rinse water is supplied to wash the sieve. Further, sand and the like are taken out from the gravity separation unit provided below the sieve unit. On the other hand, unsuitable weight is taken out from the lower part of the container body as appropriate.

Next, the slurry is sent to a slurry storage tank.
In addition, if desired, the separation chamber may be integrated with the main body as described above, or may be provided separately from the main body via a pipe.

The slurry is stored in a slurry storage tank, and then a coagulant is added to perform coagulation in a mixing tank. As the flocculant, a polymer or the like commonly used in the art can be appropriately used, and examples thereof include the following: ferric chloride, ferrous chloride, chlorinated bright ban, sodium aluminate, aluminum sulfate, Lime, sodium polyacrylate and other commonly used polymer flocculants. In the case of ferric chloride as an example, the amount used is 50 as Fe with respect to the slurry.
~ 4000mg / L, preferably 100 ~ 1500mg
/ L, more preferably 200 to 900 mg / L.
Taking a cationic polymer flocculant as an example, the flocculant is 0.3 to 1.0% (optimally 0.5 to
0.7%).

If necessary, the pH in the tank is raised to about 5.5 to 7 by adding an alkali, and iron and / or other solids also form flocs together with iron or alone. In addition, by alkali treatment,
The fat in the slurry can be saponified into a water-soluble form. As the alkali agent, alkali compounds such as sodium, potassium, calcium, and magnesium oxides and hydroxides are appropriately used.

The slurry treated with the coagulant (and the alkali agent) is subjected to a solid-liquid separation treatment. As the solid-liquid separator, a concentrator and a dehydrator are used, and various types (centrifugal type, pressurized type, etc.) are selectively used as necessary. The slurry treated with the coagulant has an extremely good dewatering property, and a screw press type dehydrator can provide dewatered sludge having a water content of about 60%.

By the solid-liquid separation treatment, a solid content and a liquid portion (water) are separated, and the solid content is used for compost production, and the liquid portion is sent to a water treatment facility. Known water treatment methods such as various biological treatment methods can be appropriately used as the water treatment equipment, and the required treated water quality can be obtained by combining advanced treatment equipment as needed.

The separated solids are composted with or without the addition of a secondary material including a moisture regulator. For composting, a method using a composting device using a fermenter, or a fermentation method by depositing and turning over, that is, either industrial composting by mechanical devices or manual composting by hand can be used.

In the case of industrial composting using a fermenter, as a seed inoculation for slurry solid content fermentation, preferably, a water content of 40% is used.
% Or less, more preferably about 20 to 30% (% by weight) after mixing the product compost, adjusting the water content, and, if diluting, in a mixer or other appropriate step.
It is also possible to adjust the water content by adding and mixing a water content adjusting material, and it is also possible to combine these methods. Rice husks, bran, bean husks, buckwheat hulls, rice straw, wheat straw, sawdust, wood chips, bark, and other commonly used moisture regulators can be used alone or in combination as appropriate.

In the present invention, composting can be sufficiently realized by using only the slurry solids as a raw material.
Secondary materials may be further added and mixed (mixing, fermentation or other appropriate places) for the purpose of smoothly fermenting the slurry solids or increasing the fertilizing effect. As auxiliary materials,
In addition to water conditioning materials, livestock (chicken) house excrement, rapeseed meal, bagasse, okara, fish meal, fish meal, shells, eggshells, non-carbonaceous materials,
Materials commonly used for composting can be used alone or in combination of two or more as appropriate.

In the above, the seed inoculation of the slurry solid content fermentation was performed in a step of returning and supplying and mixing a part of the product compost. However, if desired, the seed inoculation (culture) is directly inoculated. May be.

As the inoculum, Streptomyces griseolus I
FO 3403, Streptomyces griseus IFO 3122, Streptomyc
Streptomyces such as es olivaceus IFO 3152; Thermo
Thermoactinomyce such as actinomyces vulgaris IFO 13606
s sp .; Thermomonospora viridis IFO 12207 etc.Therm
omonospora spp .; Micromonospora spp., in addition to Micromonospora spp. such as Micromonospora fusca ATCC 15835 and VS34 manufactured by VS Kaiko, can be used.

The thus treated slurry solids are sent to a fermenter to be composted. The fermenter is equipped with a stirrer such as a vertical screw and a stirring blade inside the fermenter, and constitutes a fermenter together with its drive unit, air supply system, temperature control system, and these control systems. It can be used as appropriate.

As one example, the fermenter is of a vertical type and has a structure in which a rotating shaft with several stirring blades is located at the center, and an air supply pipe for supplying oxygen necessary for fermentation is provided at the lower part of the tank. . The rotating shaft with the stirring blade is slowly rotated so that the sludge introduced into the fermenter is not kneaded, and that the warm air supplied from the bottom of the fermenter flows evenly. In the fermenter, fermentation is performed in an aerobic environment for 3 days or more, for about 5 to 7 days, and compost is produced.

The compost whose fermentation has been completed and whose water content has been reduced is periodically taken out from the bottom of the fermenter and then used as product compost. On the other hand, some of them can also be used for seeding. In this way, very good quality compost can be efficiently produced. Hereinafter, examples of the present invention will be described.

[0034]

Example 1 50 Kg of collected garbage was treated with a crusher, then treated with a separation type pulper to form a slurry, and at the same time, light weight and unsuitable materials were removed. After further removing the sand,
It was stored in a slurry storage tank.

The slurry was then transferred to a mixing tank.
A cationic polymer flocculant was used as a flocculant for this, and the polymer flocculant dry matter was 0.5
０．７0.7% is added so that caustic soda is added to adjust the pH in the mixing tank to 5７7.
The mixture was treated with a screw press type solid-liquid separator to separate a solid content and a liquid portion.

It has been confirmed that the liquid part can be discharged into a river by treating it with a biological treatment facility using activated sludge and then with an advanced treatment facility. On the other hand, the solid content has a water content of 5
It decreased to 7%, and was composted with a composting device without adding a moisture regulator.

That is, the product compost having a moisture content of 25% is mixed with the solid content at a ratio of 1: 1 by dry weight as a seed inoculation,
This mixture was fermented for 3.5 to 7 days in a vertical fermenter while supplying hot air at 50 ° C., and a high-quality compost having a moisture content of 40% or less with odor of mulch was able to be produced.

[0038]

According to the present invention, garbage and the like can be slurried by a wet system incorporating a wet crushing and sorting apparatus, and furthermore, by using a coagulant treatment together, it is possible to efficiently remove impurities such as plastic, glass and metal. Not only is the solid-liquid separation performed efficiently, but also good quality compost is obtained. Further, unlike the case of the dry treatment, the treatment system can be made a closed system, which is extremely sanitary, and is excellent as a pollution control technology.

Since the compost of the present invention uses raw materials such as garbage which are originally suitable as compost raw materials, extremely high quality can be obtained. Therefore, the present invention is not only excellent in terms of waste treatment, but also extremely unique in that waste can be effectively used as compost, and is excellent.

[Brief description of the drawings]

FIG. 1 shows a flow sheet for compost production according to the present invention.

FIG. 2 shows an integrated pulper.

FIG. 3 shows a separation type pulper.

 ──────────────────────────────────────────────────続 き Continuation of the front page (71) Applicant 000174965 Mitsui Mining Co., Ltd. 3-3-3 Toyosu, Koto-ku, Tokyo (71) Applicant 000176752 Mitsubishi Kakoki Machinery Co., Ltd. 2-1 Okawacho, Kawasaki-ku, Kawasaki-ku, Kawasaki-shi, Kanagawa No. (72) Inventor Takehiko Takano 579-1, Matsudo Sun Heights, Matsudo, Matsudo, Chiba 202 (72) Inventor Makito Ishihara 2-23-3, Osaka, Hino, Tokyo (72) Inventor Mitsuru Takishima Hongocho, Omiya, Saitama 1258-77 (72) Inventor Yoshinori Kuyoshi 1-5-25-203, Imaizumicho, Tochigi City, Tochigi Prefecture (72) Inventor Fumio Ide 2980-61 Hayakawa, Ayase City, Kanagawa Prefecture F-term (reference) 4D004 AA02 BA04 CA03 CA10 CA13 CA18 CB15 CC08 CC11 DA02 DA03 DA06 DA09 DA20 4H061 AA02 CC42 CC44 CC45 CC47 CC55 DD20 EE04 EE07 EE12 EE13 EE16 EE35 EE66 EE70 GG03 GG13 GG41 GG48 GG55

Claims (6)

[Claims] An organic waste, comprising: treating an organic waste with a wet pulverizing / sorting device; treating the obtained slurry with a coagulant; separating the mixture into solid and liquid; and composting the solid content. Composting method of goods. 2. The organic waste according to claim 1, wherein the organic waste is at least one selected from garbage, collected garbage including garbage, food industry waste, brewery industrial waste, and various kitchen wastes. The method described in. 3. A wet pulverizing / sorting device in which a light-weight unsuitable composting (hereinafter referred to as “light-weight unsuitable”) separating unit and a main body are integrated or a light-weight unsuitable separating unit and a main body are separated. 3. The method according to claim 1, wherein a type is used. 4. The method according to claim 1, wherein the composting is carried out by fermentation using a fermenter or manual fermentation by stacking and turning. 5. The method according to claim 4, wherein composting is performed by adding actinomycetes or product compost. 6. A compost produced by the method according to any one of claims 1 to 5.