JP2001300482A - Method for treating waste of food industry - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for treating waste of food industry, capable of making environmentally harmless the waste of food industry like a filter material comprising shells to which shellfish meat pieces are bonded or an inorganic substance to which an organic substance is bonded by a method advantageous from an aspect of cost to obtain a treated waste material which is used as a raw material for a building material without generating a malodor and capable of effectively putting the treated waste material to practical use in a building material manufacturing process without hindrance. SOLUTION: The method for treating the waste of the food industry, which contains an inorganic substance and an organic substance and of which the ignition residue at 650 deg.C is 90-99 mass % of the total solid, consists of the first process for decomposing and fermenting the organic substance in the waste of the food industry, the second process for introducing the decomposed and fermented waste obtained in the first process into a microorganism group and subjecting the same to aeration treatment under a predetermined solid concentration condition to oxidize and decompose the organic substance, the third process for subjecting the solid-containing liquid obtained in the second process to solid-liquid separation treatment to recover a solid and the fourth process for dehydrating the solid obtained in the third process to obtain a cake.

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 industry waste containing inorganic and organic substances.

[0002]

2. Description of the Related Art Conventionally, in the food industry, shells to which shell pieces are attached, crab shells to which meat pieces are attached,
Food industry waste such as filter media made of inorganic substances with organic substances attached, specifically used filter media generated from liquor and beer manufacturing plants, is simply dumped or landfilled as industrial waste. It is treated by methods such as waste, fertilizer, and incineration. For example, when piled up as industrial waste, if it is left at a disposal site for a long period of time, an odor associated with the decomposition of proteins such as shell pieces will be generated, and pollution measures will be required. Also,
Nowadays, the catch and cultivation of shellfish has become popular, and the amount of shellfish discarded after food processing has increased rapidly, and securing disposal sites has become a problem.

[0003] In order to reduce the occurrence of pollution such as bad smell, shells are also incinerated. However, incineration requires a large amount of energy costs, and a large amount of ash remains as a residue after incineration, and these must be disposed of by landfilling, which incurs secondary costs. There are various problems.

In view of such a situation, for example, Japanese Patent Laid-Open No.
In Japanese Patent No. 155653, it has been proposed that shells are incinerated and used as a raw material for lime-based refractories, focusing on the fact that when aragonite (aragonite) such as shells is calcined, it becomes calcite similar to limestone. ing. According to the publication, 125 shells such as shells, coral relics, and hailstones are used.
It is disclosed that calcining is performed by firing at 0 ° C. or higher. However, this method also requires a large energy cost, and some refractory raw materials that use a large amount of inexpensive raw materials are not cost-effective.

[0005] In the beer production process, in the beer filtration process, a filtering material such as diatomaceous earth or zeolite is used to remove beer residue. Organic materials mainly composed of proteins, such as plant waste and fibers, adhere to the used filter media. Like the shells, this filter material is also simply disposed of as industrial waste by landfill, landfill disposal, or incineration, etc., and the disposal cost is a great burden on beer manufacturers. I have. In addition, there is a problem such as a bad smell accompanying the decomposition of the organic substance.

Accordingly, it is an object of the present invention to provide a method which is advantageous in terms of cost reduction for food industry waste such as shells to which shell pieces are adhered and filter materials made of inorganic substances to which organic substances are adhered. It is an object of the present invention to provide a method for treating food industry waste which can be effectively used without generating odor when used as a raw material for building materials by eliminating pollution and without causing any trouble in the production process.

[0007]

That is, the method for treating food industry waste of the present invention comprises an inorganic substance and an organic substance, and comprises:
In a method for treating food industry waste in which the residue at 50 ° C. is 90 to 99% by mass or more of the total solids, a first step of decomposing and fermenting organic substances in the food industry waste; A second step of introducing microorganisms into the obtained decomposed and fermented waste and subjecting it to aeration treatment under a predetermined solid content condition to oxidatively decompose organic substances; and solid-liquid separation of the solid-containing liquid from the second step. A third step of separating and collecting a solid content; and a fourth step of dehydrating the solid content obtained in the third step to obtain a cake.

[0008] The method of treating food industrial waste according to the present invention is characterized in that the method further comprises a fifth step of drying the inorganic substance cake obtained in the fourth step at a temperature of 40 ° C or lower.

Further, the method for treating food industry waste of the present invention is characterized in that humic substances are used in combination in the second step.

[0010] The method for treating food industry waste of the present invention is characterized in that the microorganisms used in the second step are activated sludge.

Further, the method for treating food industrial waste according to the present invention is characterized in that the solid content concentration in the second step is 1 to 15% by mass.

Further, the method for treating food industrial waste according to the present invention is characterized in that the solid content concentration in the second step is 5 to 12% by mass.

Further, in the method for treating food industrial waste according to the present invention, the food industrial waste may be one or two selected from diatomaceous earth, zeolite, shells, crab shells and bones as inorganic substances.
It is characterized by containing at least one species.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION In the method for treating food industrial waste according to the present invention, the food industrial waste to be treated contains an inorganic substance and an organic substance.
The waste is 0 to 99% by mass or more. That is, it is a waste containing 1 to 10% by mass of an organic substance and the like. Where 65
If the 0 ° C ignition residue is less than 90% by mass with respect to the total solid content, the efficiency of oxidative decomposition in the second step is extremely reduced, and the finally treated product emits offensive odor even at room temperature. Is not preferred because of the problem of In addition, various conditions must be adjusted, which is uneconomical. On the other hand, if the 650 ° C. ignition residue exceeds 99% by mass with respect to the total solid content, it becomes uneconomical and is not preferred. Such food industrial waste is not particularly limited, and examples thereof include shells, crab shells, bones of livestock products and fish, and filter media used in food and beverage manufacturing processes and the like. It is suitable for treating a filter medium containing protein used in a brewing process such as beer or beer.

Further, the food industrial waste to be treated in the food industrial waste treatment method of the present invention has a powder bulk specific gravity of 0.3 to 1.2 when dried into powder (at a temperature of 100 ° C.). Preferably, there is. This is because, during the aeration treatment in the second step, it is indispensable that the food industrial waste can be fluidized and dispersed by the introduced air or oxygen and gentle stirring (peripheral speed: 1.5 m / sec or less). For this reason,
When the size is too large or the bulk specific gravity is large, it is preferable to adjust the bulk specific gravity and the particle size to a preferable one by a pulverizing treatment or the like in advance.

The first step of the present invention comprises decomposing and fermenting organic substances adhering to food industry waste.
In the first step, the water content of food waste is usually set to 40 to
Adjusted to 65% by mass, and at room temperature, for example, 20 to 30 ° C., 24
It can be carried out by leaving the deposition for no more than 12 hours, preferably for 12 to 18 hours. Here, if the treatment temperature in the first step is lower than 20 ° C., it is not preferable because decomposition fermentation of organic substances is difficult to proceed, and if it exceeds 30 ° C., decay proceeds and remarkable odor is generated. In the following second step, a large amount of a pH adjuster must be used, which is not preferable. If the time exceeds 24 hours, rot proceeds even within the above-mentioned processing temperature range, causing unpleasant odor and the like, which is not preferable. Usually, it takes about several hours to 24 hours to be discharged from a food factory, transported, and carried into a processing facility, and this can be replaced with the first step.

Next, in the second step of the present invention, a microorganism group is introduced into the degraded and fermented waste subjected to the fermentation and decomposition treatment in the first step, and aerated under a predetermined solid content concentration condition. And further oxidatively decompose the organic substances fermented and decomposed by the activated sludge method. Here, in the second step, the microorganisms introduced into the degraded and fermented waste may be, for example, activated sludge.

The solid content in the second step is 1 to 1 as the total amount of the degraded fermented waste and the microorganisms from the first step.
It is in the range of 5% by weight, preferably 5 to 12% by weight.
If the solid content is less than 1% by mass, the efficiency of oxidative decomposition (treatment) by the microorganisms decreases, which is not economical, and if it exceeds 15% by mass, the efficiency of oxidative decomposition (treatment) by the microorganisms decreases. It is not preferable because it is lowered. In addition, when introducing the microorganisms into the degraded and fermented waste from the first step, if the solid content cannot be adjusted to the above-mentioned solid content concentration by the water content accompanying the microorganisms, the solid content concentration is appropriately adjusted by adding water. Can be adjusted. Further, depending on the degree of fermentation decomposition in the first step, p
It may be preferable to adjust H.

In the second step, the aeration treatment is not particularly limited. For example, the aeration treatment can be performed by dispersing air sent from an air pump into the treatment system using an air stone. The dissolved oxygen concentration at this time is 0.5 to 2.5 mg / liter,
Preferably it is 1.0 to 2.0 mg / liter.

The aeration time in the second step is as follows:
Usually within the range of 4 to 28 hours, preferably 12 to 2 hours.
Within 4 hours. The temperature in the processing system is not particularly limited, but is preferably in the range of 18 to 28 ° C. In order to perform the aeration process more efficiently, it is effective to stir the inside of the processing system at a peripheral speed of 0.5 to 1.5 m / sec.

In the aeration treatment in the second step, humic substances (humus) can be added to the treatment system to further promote the oxidative decomposition of organic substances by the microorganisms.
The amount of humic substances added is in the range of 0.01 to 0.2% by mass on the basis of the mass of the decomposed and fermented waste subjected to the fermentation and decomposition treatment in the first step. If the added amount of humic substances is less than 0.01% by mass, the effect of adding the humic substances is not preferable, and if it exceeds 0.2% by mass, the effect of adding the humic substances is not preferable because it is saturated. The humic substances referred to in the present invention are brown or black amorphous organic substances in soil or calcareous substances, and are soil organic substances in which organic substances of animals and plants are slowly decomposed in the ground.

In the aeration treatment in the second step, an antifoaming agent can be added to the treatment system. As the defoaming agent, for example, an alcohol-based or silicone-based defoaming agent can be used.

The third step of the present invention comprises solid-liquid separation of the solid-containing liquid obtained by oxidatively decomposing the organic substance in the second step to recover the solid content. The solid-liquid separation can be performed by adding a flocculant to the treatment system and allowing the mixture to stand, thereby allowing the solid content to settle and removing the supernatant. As the coagulant, for example, a polymer coagulant, iron sulfate, aluminum sulfate, PAC, a polymer coagulant, or the like can be used.

The fourth step of the present invention is to obtain a cake by dewatering the solids obtained in the third step. The dehydration method is not particularly limited, and for example, a press dehydration method, a suction dehydration method, or the like can be used. The water content after dehydration is 6
The content is preferably 0% by mass or less because the drying time in the next step can be shortened.

In the fifth step of the present invention, if necessary, the cake obtained in the fourth step can be dried at a temperature of 40 ° C. or less. Here, the drying temperature is 4
If the temperature exceeds 0 ° C., the decomposition product is further thermally decomposed to generate an odor, which is not preferable. The drying time can be appropriately selected depending on the desired degree of drying. Further, as a preferred drying device, a fluidized bed dryer or a freeze dryer can be exemplified.

[0026]

EXAMPLES The method for treating food industry waste of the present invention will be further described below with reference to examples. Example 1 First Step Beer filter material waste discharged from the beer manufacturing process [filter material: diatomaceous earth, water content (100 ° C., 6 hours): 57% by mass, 650 ° C. ignition residue: 91% by mass, powder Body bulk specific gravity: 0.
38] was left at a temperature of 26 ° C. for 24 hours for decomposition fermentation. 2nd process 1.0k of beer filter material waste decomposed and fermented in 1st process
g was loaded into a treatment tank equipped with a stirrer having a diameter of 180 mm, a height of 650 mm and an effective volume of 14 liters, and then activated sludge (pH = 7.0, BOD = 320 pp) as a microorganism group
m, SS = 750 ppm)
The total amount of the treatment system was adjusted to 14 liters (solid content concentration: 8.6% by mass) by adding water. Next, 1 g of humic substances and a silicone-based antifoaming agent as an antifoaming agent were added to the treatment system.
g was added. The processing system obtained in this way is maintained at a temperature of 22.
° C, rotation speed of the stirrer 30 rpm (peripheral speed 0.8 m / sec),
The organic decomposition was oxidatively decomposed by aeration treatment for 18 hours under the condition of an air flow rate of 4.2 L / min. In addition, air was introduced by sending air discharged from an air pump to a processing system via an air stone. 3rd step Product name M as coagulant to treatment system aerated in 2nd step
0.5 g of K floc (polymer coagulant: manufactured by Mitsubishi Kakoki Co., Ltd.) was added, and the solid was precipitated and recovered by standing for 4 hours. The remaining 10 liters of supernatant was treated as normal wastewater. Fourth step A cake was obtained by press dewatering the solids recovered in the third step. Fifth Step The cake obtained in the fourth step was dried at a temperature of 35 ° C. for 3 hours. The water content (100 ° C., 6 hours) of the cake after drying was 43% by mass, and the residue at 650 ° C. on ignition was 95% by mass. Further, the cake after drying was put in a polycup and left open for 10 days, and the state of generation of odor during that time was investigated. As a result, no odor was generated.

Example 2 First Step Beer filter material waste discharged from the beer manufacturing process [filter material: diatomaceous earth, water content (100 ° C., 6 hours): 61% by mass, 650 ° C. Residue on ignition: 91% by mass %, Powder bulk specific gravity: 0.
35] at a temperature of 32 ° C. for 18 hours for decomposition fermentation. 2nd process 1.5k of beer filter material waste decomposed and fermented in 1st process
g was loaded into a treatment tank equipped with a stirrer having a diameter of 180 mm, a height of 650 mm and an effective volume of 14 liters, and then activated sludge (pH = 7.0, BOD = 320 pp) as a microorganism group
m, SS = 750 ppm)
By adding water, the total amount of the treatment system was adjusted to 14 liters (solid content concentration: 12.3% by mass). Next, 1 g of humic substances and 1 g of a silicon-based antifoaming agent as an antifoaming agent were added to the treatment system. The processing system obtained in this way was heated at a temperature of 2
4 ° C., rotation speed of stirrer 30 rpm (peripheral speed 0.8 m /
Second) and aeration treatment for 16 hours under the condition of an air flow rate of 6.0 liter / min to oxidatively decompose organic decomposition. In addition, air was introduced by sending air discharged from an air pump to a processing system via an air stone. 3rd step Product name M as coagulant to treatment system aerated in 2nd step
0.5 g of K floc (polymer flocculant: manufactured by Mitsubishi Kakoki Co., Ltd.) was added, and the mixture was allowed to stand for 6 hours to precipitate and collect solids. The remaining 10 liters of supernatant was treated as normal wastewater. Fourth step A cake was obtained by subjecting the solid content recovered in the third step to suction dehydration. The water content (100 ° C., 6 hours) of the obtained cake was 65% by mass, and the ignition residue at 650 ° C. was 94% by mass. When the cake after dehydration was put in a polycup and left open for 10 days, and the state of generation of odor during the period was investigated, no odor was generated.

Example 3 First Step Beer filter material waste discharged from the beer manufacturing process [filter material: diatomaceous earth, water content (100 ° C., 6 hours): 60% by mass, 650 ° C. Residue on ignition: 90% by mass %, Powder bulk specific gravity: 0.
34] at a temperature of 28 ° C. for 24 hours for decomposition fermentation. 2nd process 1.5k of beer filter material waste decomposed and fermented in 1st process
g was loaded into a treatment tank equipped with a stirrer having a diameter of 180 mm, a height of 650 mm and an effective volume of 14 liters, and then activated sludge (pH = 7.0, BOD = 320 pp) as a microorganism group
m, SS = 750 ppm)
By adding water, the total amount of the treatment system was adjusted to 14 liters (solid content concentration: 12.0% by mass). Next, 1 g of a silicone-based antifoaming agent was added to the treatment system. The treatment system thus obtained was subjected to aeration treatment for 18 hours under the conditions of a temperature of 24 ° C., a rotation speed of a stirrer of 30 rpm (peripheral speed of 0.8 m / sec), and an air flow rate of 6.0 liter / min, for organic decomposition. Was oxidatively decomposed. In addition, air was introduced by sending air discharged from an air pump to a processing system via an air stone. 3rd step Product name M as coagulant to treatment system aerated in 2nd step
0.5 g of K floc (polymer flocculant: manufactured by Mitsubishi Kakoki Co., Ltd.) was added, and the mixture was allowed to stand for 6 hours to precipitate and collect solids. The remaining 10 liters of supernatant was treated as normal wastewater. Fourth step A cake was obtained by press dewatering the solids recovered in the third step. Fifth Step The cake obtained in the fourth step was dried by fluidized bed drying at a temperature of 30 ° C. for 3 hours. The water content of the cake after dehydration (100 ° C., 6 hours) was 48% by mass, the water content after drying (100 ° C., 6 hours) was 8% by mass, and the residue at 650 ° C. on ignition was 92% by mass. Was. The dried cake was placed in a polycup, left open for 10 days, and the state of odor generation during the period was investigated. As a result, a very slight odor was generated. there were.

REFERENCE EXAMPLE 9% by weight of the cake after drying selected in Example 1 above, 23% by weight of silica sand, 30% by weight of slaked lime, 5% by weight of calcium carbonate, 25% by weight of wollastonite, 7% by weight of pulp, 1% by mass of an additive is mixed with water to form a slurry, which is formed into a plate by a round-mesh papermaking method, further subjected to pressure molding, and hydrothermally cured at 180 ° C. for 6 hours in an autoclave to obtain calcium silicate. A molded article was obtained. At this time, there was no generation of offensive odor, and the calcium silicate molded body had a bulk specific gravity of 0.81 and a bending strength of 14.1 N / mm ² and had no problem as a building material.

[0030]

According to the method for treating food industrial wastes of the present invention, food industrial wastes composed of organic substances and inorganic substances such as shells and beer filter material wastes are not required at a great energy cost. This has the effect of enabling disposal of food industrial wastes that cause pollution problems such as odors when disposed of as such.

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Claims (7)

[Claims] 1. An inorganic and organic substance at 650 ° C.
In a method for treating food industry waste in which the residue on ignition is 90 to 99% by mass or more of the total solids, a first step of decomposing and fermenting organic substances in the food industry waste; A second step of introducing microorganisms into the decomposed and fermented waste and subjecting it to aeration treatment under a predetermined solid content concentration condition to oxidatively decompose organic substances; and solid-liquid separation of the solid-containing liquid obtained in the second step. A method for treating food industry waste, comprising: a third step of separating and collecting a solid content; and a fourth step of dehydrating the solid content obtained in the third step to obtain a cake. 2. The inorganic substance cake obtained in the fourth step is
The method for treating food industry waste according to claim 1, comprising a fifth step of drying at a temperature of 0 ° C or less. 3. The method for treating food industrial waste according to claim 1, wherein humic substances are used in the second step. 4. The method according to claim 1, wherein the microorganisms used in the second step are activated sludge. 5. The solid content concentration in the second step is 1 to 15% by mass.
The method for treating food industrial waste according to any one of claims 1 to 4, wherein 6. The solid content concentration in the second step is 5 to 12% by mass.
6. The method for treating food industrial waste according to claim 5, wherein 7. The food industrial waste is selected from diatomaceous earth, zeolite, shells, crab shells and bones as inorganic substances.
The method for treating food industrial waste according to any one of claims 1 to 6, comprising a seed or two or more kinds.