JP2002336825A - Method for recycling organic waste - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for recycling organic wastes so that usable substances can be efficiently collected from organic wastes such as raw refuse, night soil, sludge in septic tanks or the like. SOLUTION: Raw refuse is roughly pulverized and classified by a centrifugal crushing and classifying machine 1 into crushed raw refuse and trash. The pulverized raw refuse is solubilized in a solubilizing process 2 and the solubilized material is subjected to the solid liquid separation in a solid liquid separating device 3. The obtained liquid component is used as a source material for a methane fermentation tank 4 or as an organic carbon source or a hydrogen donor in the waste water treatment. The solid component is used as a recycled source material for the production of compost, feed or the like 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for recycling organic waste, and more particularly to a technique for treating garbage and high-concentration organic wastewater in a sludge reprocessing center, a food waste recycling facility, and the like.

[0002]

2. Description of the Related Art Conventionally, as a pretreatment device for methane fermentation of garbage, a system combining a single-shaft or two-shaft coarse crusher and a compression separation machine is used to process garbage containing impurities in one or two shafts. There is a method in which a coarsely crushed material is coarsely crushed and then the coarsely crushed material is pasteurized by a compression fractionator and impurities in the coarsely crushed material are separated and removed.

Further, in a system combining a solubilization and a solid-liquid separation with a uniaxial or biaxial coarse crusher, garbage containing impurities is roughly crushed by a monoaxial or biaxial coarse crusher, and then the coarse crushed material is removed. In some cases, the solubilized material is solubilized and solid-liquid separated. Alternatively, there is a method in which garbage containing impurities is roughly crushed by a trommel-type apparatus and the garbage is separated from the impurities.

[0004]

By the way, in a system in which a single-shaft or twin-shaft coarse crusher and a compression separator are combined, all the non-paste impurities in the compression separator are discharged. In some cases, compostable materials such as vinyl and bone and vegetable fibers that are difficult to recycle are discharged as contaminants in a mixed state. Have difficulty.

In a system in which a solubilization process is combined with a single-shaft or twin-shaft coarse crusher, since the solubilized product in the solubilization process contains vinyls, impurities removed from the solubilized product by solid-liquid separation are It contains vinyls and is difficult to reuse by composting.

[0006] The trommel-type apparatus has a low separation ability, and a large amount of vinyl is mixed in the separated contaminants and the garbage used as a raw material for methane fermentation. The present invention solves the above-mentioned problems, and provides an organic waste recycling method capable of efficiently collecting usable materials from organic waste such as garbage, human waste, and septic tank sludge. Aim.

[0007]

According to a first aspect of the present invention, there is provided a method of recycling organic waste, comprising the steps of crushing garbage by roughly crushing and separating garbage with a centrifugal crusher / separator. And the contaminants, solubilize the garbage crushed material, and subject the solubilized product to solid-liquid separation with a solid-liquid separator to use the liquid as a raw material for methane fermentation, and use the solid as a raw material for recycling. Is what you do.

[0008] With the above-described configuration, the centrifugal crushing and sorting machine separates the crushed material by centrifugal force, so that it is possible to almost completely separate difficult-to-use impurities such as vinyls from the available garbage crushed material. In addition, difficult-to-use impurities such as vinyls do not flow into the solubilization process, so that the capacity of the solubilization tank can be reduced. An increase can be prevented, and vinyls and the like are not included in subsequent steps.

[0009] In the solubilization step, the solubilized portion of the garbage is solubilized into a liquid portion, and the bone and the fiber portion remain as a solid portion without being solubilized. Therefore, by solid-liquid separation of the solubilized product in the solubilization process with a solid-liquid separation device, the liquid content can be used for methane fermentation and the solid content can be used as a raw material for recycling such as composting and feed. To separate.

[0010] Since only bones and fibers are specifically obtained as a dehydrated cake by the solid-liquid separation, a composting or feed conversion step is not required in the subsequent stage. Since the dehydrated cake contains a large amount of calcium and fiber, compost and feed are high quality products. Since the temperature rises during the composting and feed conversion processes, various bacteria are killed and sanitary.

According to a second aspect of the present invention, there is provided a method for recycling organic waste, wherein the raw garbage is roughly crushed and separated by a centrifugal crushing / separating machine to separate crushed garbage and contaminants. The solubilized product, which is obtained by solid-liquid separation of the solubilized product by a solid-liquid separator, is supplied to a wastewater treatment system as an organic carbon source or a hydrogen donor.

According to the above-mentioned structure, when the BOD source becomes insufficient in a case where a high-concentration organic wastewater is subjected to a biological denitrification treatment, a liquid component of a solubilized substance is introduced instead of the conventional introduction of alcohol or the like. Thus, wastewater treatment costs can be reduced.

According to a third aspect of the present invention, there is provided a method for recycling organic waste, wherein high-concentration organic waste water is passed through a fine screen to separate the residue, and the separated residue is centrifugally crushed in the same manner as garbage. It is to be roughly crushed and separated by a separator.

With the above-mentioned structure, organic matter such as fibers in the residue contained in high-concentration organic wastewater such as night soil and septic tank sludge is effectively used. According to a fourth aspect of the present invention, there is provided the method for recycling organic waste, wherein a coagulant is added to the high-concentration organic wastewater before the fine screen to remove the BOD /
Adjust N ratio.

By adjusting the BOD / N ratio of the residue by the above-described configuration, the amount of BOD required for the biological denitrification treatment of the high-concentration organic wastewater in the subsequent step is ensured, and the excess BOD is obtained. And collect it together with the residue for effective use.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, garbage is roughly crushed and separated in a centrifugal crushing and separating machine 1 to separate crushed garbage and contaminants containing vinyls. Since the centrifugal crushing and sorting machine 1 separates the crushed material by centrifugal force, it is possible to almost completely separate the difficult-to-use impurities such as vinyls and the available garbage crushed material, solubilizing the next step. Difficult-to-use impurities such as vinyls do not flow into step 2.

The separated crushed food waste is solubilized in the solubilization step 2. In the solubilization step 2, impurities such as vinyls do not flow, so that the capacity of the solubilization tank can be reduced, and the pump for stirring in the solubilization tank is not blocked by vinyls, thereby increasing the load on the stirrer. It is possible to prevent such a situation, and the subsequent steps do not include vinyls and the like. In the solubilization step 2, the solubilized portion of the garbage is solubilized into a liquid portion, and bone, fiber, and the like remain as a solid portion without being solubilized.

The solubilized product is subjected to solid-liquid separation by a solid-liquid separation device 3. Screw press as solid-liquid separation device 3,
It is performed by a screen or a combination thereof, but a filter press, a centrifuge, a belt press, and the like can also be used. The solubilized product is separated into a liquid component and a solid component by the solid-liquid separation, and the liquid component is supplied to the membrane-type methane fermentation tank 4 as a raw material for methane fermentation, or is supplied to a biological denitrification treatment tank 7 described later. It is supplied as an organic carbon source or a hydrogen donor, and the solid content (dehydrated cake) is supplied to the composting / feed conversion step 5 as a raw material for recycling.

By this solid-liquid separation, only the bone and the fiber can be specifically obtained as a dehydrated cake.
Since the separation step at the latter stage of the feed conversion step 5 is not required, and the dewatered cake contains a large amount of calcium and fiber, compost and feed are high-quality products.

The composting / feed conversion step 5 uses a fermentation type, a drying type, and a fryer type apparatus, and the temperature is high (50 to 130 ° C.) in the step, so that various bacteria are killed and sanitary. The membrane-type methane fermentation tank 4 has a membrane separation device. Biogas generated by methane fermentation in the membrane-type methane fermentation tank 4 is used as a fuel or the like. Is used as a raw material for recycling in the composting / feed conversion step 5, and the dehydrated filtrate is supplied to a biological denitrification treatment tank 7 described later as an organic carbon source or a hydrogen donor.

The high-concentration organic wastewater such as human waste and septic tank sludge is added with a coagulant and then separated by a fine screen 8 to separate the residue, and then subjected to a biological treatment in a biological denitrification treatment tank 7. Separated residue is centrifugal crushing and sorting machine 1 like garbage.
And coarsely crushed.

As a result, organic substances such as human waste and fibers contained in the sediment contained in the septic tank sludge are effectively used as composting or methane fermentation raw materials. By adding a coagulant to the high-concentration organic wastewater and adjusting the BOD / N ratio of the residue, the necessary amount of BOD for the biological denitrification treatment of the high-concentration organic wastewater is secured, and excess The BOD is collected together with the residue, and is effectively used as a raw material for composting or methane fermentation. Excess sludge generated in the biological denitrification treatment tank 7 is supplied to the membrane methane fermentation tank 4 or supplied directly to the dehydrator 6.

[0023]

As described above, according to the present invention, garbage is hardly crushed and separated by the centrifugal crushing and separating machine, so that the difficult-to-use impurities such as vinyls and the crushed garbage can be almost completely separated. Pump that does not enter difficult-to-use impurities such as vinyls into the solubilization step and the subsequent steps, reduces the capacity of the solubilization tank, and performs stirring in the solubilization tank. Is not clogged with vinyls, thereby preventing an increase in load on the stirrer. Solid-liquid separation of the solubilized product into a liquid component that can be used for methane fermentation or wastewater treatment and a solid component that can be used as a raw material for recycling, such as composting and feed conversion, yields only bone and fiber components. Since it is obtained as a dehydrated cake, when composting or feed conversion is performed, a separation step in the subsequent stage is not required, and a high-quality compost or feed product containing a large amount of calcium and fiber can be obtained.

Organic matter such as fibers contained in high-concentration organic wastewater such as human waste and septic tank sludge can be effectively used, and the coagulant is added to adjust the BOD / N ratio of the residual. By doing so, it is possible to secure the required amount of BOD when biologically denitrifying high-concentration organic wastewater in a subsequent step, and to collect and effectively use excess BOD together with the residue.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a method for recycling organic waste according to an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Centrifugal crushing and sorting machine 2 Solubilization process 3 Solid-liquid separation device 4 Membrane methane fermentation tank 5 Composting and feed conversion process 6 Dehydrator 7 Biological denitrification treatment tank 8 Fine screen

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B02C 23/16 C02F 11/14 A C02F 11/04 C05F 7/00 11/14 9/00 C05F 7/00 B09B 3/00 ZABC 9/00 DZ (72) Inventor Masafumi Shiki 2-47 47 Shizitsuhigashi, Naniwa-ku, Osaka-shi, Osaka Kubota Co., Ltd. (72) Toshiyuki Shibata Toshiyuki Shibata, Osaka-shi, Osaka 1-47 Tsuto F-term in Kubota Corporation (Reference) 2B150 BA05 CD06 CD37 CD38 4D004 AA03 AC05 BA03 BA04 CA04 CA10 CA13 CA18 CB04 CB13 4D059 AA01 AA02 AA07 BA12 BA21 BE54 BF15 BK11 BK12 BK17 CC01 CC02 CC03 DD08 EE11 GA17 GA20 GB05 4H061 AA02 CC32 CC42 CC47 CC51 CC55 DD20 GG70

Claims (4)

[Claims] Claims 1. A garbage is coarsely crushed and separated by a centrifugal crushing and separating machine to separate crushed garbage and contaminants, solubilize the crushed garbage, and subject the solubilized product to a solid-liquid separation device. A method for recycling organic waste, characterized in that a liquid component obtained by solid-liquid separation is used as a raw material for methane fermentation and a solid component is used as a raw material for recycling. 2. The garbage is coarsely crushed and separated by a centrifugal crusher / separator to separate crushed garbage and contaminants. The crushed garbage is solubilized, and the solubilized product is separated by a solid-liquid separator. A method for recycling organic waste, comprising supplying a liquid fraction separated into solid and liquid to a wastewater treatment system as an organic carbon source or a hydrogen donor. 3. The method according to claim 1, wherein the high-concentration organic wastewater is passed through a fine screen to separate the residue, and the separated residue is roughly crushed and separated by a centrifugal crushing and separating machine. How to recycle organic waste. 4. The method for recycling organic waste according to claim 3, wherein a coagulant is added to the high-concentration organic wastewater before the fine screen to adjust the BOD / N ratio of the residue. .