JP2004074093A - Organic waste treatment equipment and organic waste treatment method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic waste treatment equipment and an organic waste treatment method capable of saving energy and space and suppressing the generation of malodor. <P>SOLUTION: The organic waste treatment equipment has a closed type fermentor 1 for containing organic wastes and an oxygen enriching member module 2 constituting a part of the wall materials of the fermentor 1. The module 2 has a characteristic to permeate the gaseous oxygen in outdoor air into the fermentor 1 by the partial pressure difference between the gaseous oxygen in the outdoor air and the gaseous oxygen in the fermentor 1. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an organic waste treatment device and an organic waste treatment method.
[0002]
[Prior art]
Many types of processing equipment have been developed to ferment garbage from households, restaurants, supermarkets, etc., garbage and manure from fisheries markets, fruit and vegetable markets, poultry and pig farms, and garbage from food processors. It is used. For example, Japanese Patent Application Laid-Open No. 9-77581 discloses an apparatus for composting organic waste. This composting device appropriately changes and adjusts operating conditions such as temperature, humidity, and pH for fermentation treatment according to fluctuations in the amount and composition of waste. Thereby, a fermentation process can be performed stably.
[0003]
Further, with the aim of improving the decomposition treatment efficiency of the treatment device, a device has been developed which uses an oxygen enrichment device to prevent a decrease in the oxygen concentration in the treated fermenter. For example, JP-A-2001-334236 discloses an organic waste treatment device in which an oxygen enrichment device is connected to a treatment tank. According to this processing apparatus, since the oxygen-enriched air is sent into the processing tank, the decrease in the oxygen concentration in the processing tank can be compensated.
[0004]
[Problems to be solved by the invention]
However, the composting device disclosed in Japanese Patent Application Laid-Open No. 9-77581 is inevitably expensive because the device is complicated. Specifically, a pH sensor, a moisture content sensor, a humidity sensor, a control device for adjusting the addition of the pH adjusting liquid, and the like are required, so that an increase in cost cannot be avoided.
[0005]
In the organic waste treatment apparatus disclosed in Japanese Patent Application Laid-Open No. 2001-334236, a fan is required to send oxygen-enriched air generated by the oxygen enrichment apparatus to a treatment tank. Further, a pressure reducing means for reducing the pressure inside the oxygen-enriched membrane module of the oxygen-enriching apparatus is required. Therefore, there is a problem that the device becomes large.
[0006]
Further, in the organic waste treatment apparatus disclosed in Japanese Patent Application Laid-Open No. 2001-334236, oxygen-enriched air from the oxygen enrichment apparatus is introduced into the treatment tank, and decomposition gas generated by the treatment is exhausted to the atmosphere. You. Therefore, since the fermentation heat generated by the microbial decomposition of the organic waste is cooled by the introduced air and exhausted to the atmosphere, there is a problem that the effective use of heat is not sufficient.
[0007]
On the other hand, when treating organic waste, there is a problem that a bad odor is generated from the fermenter. For example, a bad smell of kitchen garbage brought in, a bad smell due to decomposition products such as organic acids, amines, and sulfur compounds generated in the fermentation process, and a putrid smell due to improper cleaning near the fermentation treatment tank are generated.
[0008]
The generation of offensive odors necessitates installation of the device outdoors, which limits the location where the device is installed. The offensive odor is mainly discharged from the exhaust port to the outside air together with carbon dioxide gas and water vapor generated in the fermentation process. In a conventional waste treatment apparatus, a deodorizing device or the like is provided at an exhaust port, and high initial costs and running costs are required for collecting bad odors. Further, in a household garbage disposer, the power required for deodorization is larger than the power required for fermentation, for example, the power required for stirring, so that from the viewpoint of energy saving, it is necessary to minimize the generation of offensive odors. Is desired.
[0009]
[Means for Solving the Problems]
The organic waste treatment apparatus of the present invention is an organic waste having an enclosed fermenter for containing organic waste and an oxygen-enriched membrane module constituting a part of a wall material of the enclosed fermenter. In the treatment apparatus, the oxygen-enriched membrane module transmits the oxygen gas in the outside air into the closed fermentation tank by a partial pressure difference between the oxygen gas in the outside air and the oxygen gas in the closed fermentation tank. It has the property to make it.
[0010]
The oxygen-enriched membrane module may have a laminated structure of an oxygen-enriched membrane and a heat-insulating ventilation member.
[0011]
The oxygen-enriched film is 1 cm in nitrogen gas.³Oxygen gas 1cm per second³It is desirable that the ratio of transmission seconds per unit is 2 or more.
[0012]
It is desirable that the heat-insulating ventilation member is formed of a continuous foam.
[0013]
The closed fermenter has an inlet for charging the organic waste, a stirrer for stirring the organic waste, an outlet for removing a residue of the organic waste, It may have a heat sensor for detecting the temperature of the type fermenter, and a heater controlled based on temperature information from the heat sensor.
[0014]
It is preferable that the oxygen-enriched membrane module has a water vapor permeability and is formed on an upper part of the closed fermenter.
[0015]
It is preferable that the oxygen-enriched membrane module is formed such that a surface on the closed fermenter side is inclined or perpendicular to a horizontal plane.
[0016]
The closed fermenter may have an airtight channel for discharging dew water generated on the surface of the oxygen-enriched membrane module on the closed fermenter side to the outside of the closed fermenter.
[0017]
In the oxygen-enriched membrane module, at least a part of the surface on the closed fermenter side may be subjected to a water-repellent treatment. Further, it is preferable that the oxygen-enriched film module is formed in a wavy shape. Further, the oxygen-enriched membrane module may be subjected to antibacterial and / or antifungal treatment.
[0018]
The organic waste treatment method of the present invention includes a step of charging an organic waste into a closed fermenter, and a step of aerobically decomposing the charged organic waste. Oxygen gas is introduced into the closed fermenter from outside the closed fermenter according to the oxygen gas partial pressure in the closed fermenter reduced by the decomposition step.
[0019]
The decomposition step is desirably performed in the presence of an aerobic organic matter-decomposing bacterium. Further, the aerobic organic matter-decomposing bacterium (hereinafter, also referred to as aerobic bacterium) may include a bacterium that assimilate (degrade) sugar and / or a cellulose-degrading bacterium.
[0020]
In the organic waste treatment apparatus of the present invention, the fermenter is configured with good airtightness, and a part of the wall material of the fermenter is configured with an oxygen-enriched membrane module. The oxygen-enriched membrane module has a property of transmitting oxygen gas, and preferably has a property of transmitting carbon dioxide gas and water vapor. The direction and speed of permeation of these gases are determined by the difference between the partial pressure of each gas in the outside air and the partial pressure of each gas in the fermenter.
[0021]
In the fermenter, the organic waste undergoes an aerobic decomposition action and is oxidized to carbon dioxide gas by microorganisms such as aerobic bacteria contaminating the organic waste as contaminating bacteria (rot bacteria). In the case of organic waste, particularly garbage, about 90% of its constituent ratio is water. In plant residues, for example, the cell walls of plant cells are damaged, thereby releasing water inside the cells. Soluble components such as sugars contained in the cells are oxidized and converted (fermented) into carbon dioxide by the decomposition of microorganisms, and the heat of the fermentation turns moisture into steam.
[0022]
The concentration of carbon dioxide in the atmosphere is about 350 ppm, and the humidity in the atmosphere is 50 to 70% RH. H. Therefore, the concentration and humidity of carbon dioxide in the fermenter are higher than the concentration and humidity of carbon in the atmosphere. Since the fermenter is a closed type, gas molecules of carbon dioxide and water vapor flow from the inside of the fermenter to the atmosphere via the oxygen-enriched membrane module. That is, the carbon dioxide gas and the water vapor pass through the oxygen-enriched membrane module and are released to the outside air.
[0023]
On the other hand, inside the fermenter, the organic waste is aerobically decomposed and oxygen is consumed as carbon dioxide is generated from the organic waste, so that the oxygen gas concentration in the fermenter decreases. Specifically, the oxygen gas concentration of 21% in the atmosphere is lower than 21% in the fermenter. In other words, a difference occurs in the oxygen gas partial pressure in proportion to the decrease in the oxygen gas concentration. Since the fermenter is closed, a flow of gas molecules of oxygen is generated from the atmosphere into the fermenter through the oxygen-enriched membrane module. That is, oxygen gas is introduced into the closed fermenter from outside the closed fermenter according to the oxygen gas partial pressure in the closed fermenter that has been reduced by the aerobic decomposition of the organic waste.
[0024]
Aerobic decomposition of organic waste proceeds continuously by agitating the organic waste in the fermenter and promoting the decomposition reaction of microorganisms. As the aerobic decomposition of organic waste continuously proceeds in the fermenter, the oxygen gas partial pressure in the fermenter is continuously reduced. Therefore, the oxygen gas permeation proceeds so that the oxygen gas partial pressure in the fermenter approaches the oxygen gas partial pressure in the atmosphere without externally applying power to the oxygen-enriched membrane module.
[0025]
Oxygen gas permeation occurs only by the decrease in the partial pressure of oxygen gas in the fermenter, so the outside air is introduced as compared to the case where air is forcibly sent from outside the fermenter to the fermenter. Temperature drop in the fermenter can be suppressed. In addition, since the gas exhausted from the fermenter via the oxygen-enriched membrane module is mainly a gas (carbon dioxide and water vapor) whose gas partial pressure has increased in the fermenter, the air is forcibly exhausted. As compared with the case, the temperature decrease in the fermenter due to the exhaust can be suppressed. In particular, by using an oxygen-enriched membrane module in which nitrogen gas occupying about 80% of the atmosphere is difficult to permeate, the nitrogen gas moves from outside the fermenter to the fermenter and from the fermenter to the outside of the fermenter. Can be suppressed, the heat balance accompanying the passage of nitrogen gas is improved, and the temperature drop in the fermenter can be further suppressed. Therefore, the fermentation heat can be effectively used, and external heating by a heater or the like can be suppressed as much as possible, which contributes to energy saving.
[0026]
According to the organic waste treatment apparatus of the present invention, a microbial reaction proceeds in an environment to which oxygen gas is supplied, so that aerobic bacteria act actively and the activity of anaerobic bacteria is suppressed. Therefore, generation of odorous substances generated by the anaerobic bacteria is suppressed, and generation of malodor such as putrefaction odor is reduced. Since the fermenter is a closed type, malodorous components cannot permeate through the wall material of the fermenter and hardly permeate through the oxygen-enriched membrane module. Is reduced. In addition, the generated malodor components can be decomposed by aerobic bacteria, so that the leakage of malodor is further reduced.
[0027]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present invention is not limited to the following embodiments.
[0028]
FIG. 1 is a cross-sectional view schematically showing an organic waste treatment apparatus of the present embodiment. The organic waste treatment apparatus according to the present embodiment includes a closed fermenter (hereinafter, also referred to as a fermenter) 1 for accommodating organic waste and oxygen enrichment forming a part of a wall material of the fermenter 1. And a membrane module 2.
[0029]
The fermenter 1 is a box-shaped fermenter having a height and width of about 1 m each, and has a heat insulating structure. The fermenter 1 has a metal container 1a in which organic waste stays, and a raw material input port provided at the upper front. The raw material inlet can be closed by the lid 3. The upper part of the lid 3 is attached to the wall material of the fermenter 1 via a hinge 4. Thereby, the material inlet can be freely opened and closed. The lid 3 has a structure capable of sealing the raw material inlet during operation. A fermentation residue outlet (not shown) is provided on the back of the fermenter 1. This outlet can also be sealed by a lid (not shown) that can be opened and closed. When the raw material inlet or the fermentation residue outlet is open, the sensor detects the opening and stops operations such as stirring and heating. Thereby, the safety of the worker is achieved.
[0030]
A part of the wall material of the fermenter 1 is constituted by the oxygen-enriched membrane module 2. In the present embodiment, an upper wall material of the fermenter 1 is constituted by the oxygen-enriched membrane module 2. The oxygen-enriched membrane module is not limited to the upper part of the fermenter 1 and may constitute a wall material on the side of the fermenter 1.
[0031]
The oxygen-enriched membrane module 2 has a structure in which an oxygen-enriched membrane 5 and a heat insulating ventilation member 6 are closely stacked. In the present embodiment, the oxygen-enriched membrane module 2 is formed such that the oxygen-enriched membrane 5 is located outside the fermenter 1 and the heat-insulating ventilation member 6 is located inside the fermenter 1. The oxygen-enriched membrane 5 may be formed inside the fermenter 1 and the heat-insulating ventilation member 6 may be formed outside the fermenter 1. Further, the oxygen-enriched membrane module 2 may have a structure in which the oxygen-enriched membrane 5 is sandwiched between two layers of the heat-insulating ventilation members 6. A structure that sandwiches the ventilation member 6 may be provided.
[0032]
The oxygen-enriched membrane 5 has an oxygen permeability coefficient of 1 × 10^-9cm³(STP) · cm / (cm²S · cmHg) or more is desirable. The oxygen permeability coefficient can be determined by using an oxygen-enriched film having a predetermined film thickness (for example, 10 μm), obtaining its oxygen permeability F, and dividing the oxygen permeability F by the film thickness.
[0033]
Further, it is desirable that the oxygen-enriched film 5 has a higher permeation amount of oxygen gas than a permeation amount of nitrogen gas, in other words, high oxygen gas separation characteristics. Specifically, the oxygen-enriched film 5 has a thickness of 1 cm of nitrogen gas.³Oxygen gas 1cm per second³Per second ratio, in other words, (oxygen gas 1 cm³Per second) / (1 cm of nitrogen gas)³(Per second) (hereinafter, also referred to as a separation coefficient) is preferably 2 or more, and more preferably 4 or more. In addition, the separation coefficient is 10.2 cm in area.²Can be obtained by measuring the time required for a fixed volume of oxygen and nitrogen to pass through the measurement piece, respectively.
[0034]
By using the oxygen-enriched membrane 5 having a high separation coefficient, the transfer of nitrogen gas between the inside and outside of the tank is suppressed, so that the transfer of heat due to the transfer of nitrogen gas is suppressed. Specifically, the nitrogen gas in the outside air having a lower temperature than that in the heated tank moves into the tank, or the heated nitrogen gas in the tank is discharged out of the tank, so that the inside of the tank is discharged. Temperature can be prevented from lowering.
[0035]
As the oxygen-enriched membrane 5, for example, a gas separation membrane disclosed in Japanese Patent Publication No. 7-77602 can be used. Specifically, polyphenylene oxide, poly-4-methylpentene-1,1,2-polybutadiene, 1,4-polybutadiene, polytrimethylsilylpropyne or one of copolymers having a polysiloxane structure as a main component or A gas separation membrane having the composition of these mixtures can be used. The oxygen-enriched film 5 may have either a single-layer structure or a multilayer structure.
[0036]
The film area of the oxygen-enriched film 5 required for the organic waste treatment (hereinafter, also referred to as a required film area) differs depending on the oxygen permeability coefficient of the oxygen-enriched film 5. For example, a gas separation membrane composed of a copolymer having a polysiloxane structure as a main component (a block copolymer of polyhydroxystyrene-polysulfone-organosiloxane) has an oxygen permeability F of 2.67 × 10^-3cm³/ Cm²・ S · cmHg. Assuming that the oxygen concentration in the atmosphere is 21%, when the oxygen concentration in the fermenter is 18%, the required film area can be estimated from the following calculation. The oxygen partial pressure difference between the inside and outside of the tank can be calculated by the following equation.
[0037]
P = 76 × 0.21-76 × 0.18 = 2.28 cmHg
[0038]
If 10 kg of kitchen garbage is put into the tank daily, assuming that about 90% of kitchen garbage is water, the weight of organic waste can be estimated to be about 1 kg. Average composition of organic waste is C₁₇H₂₉O₁₀Assuming that it is composed of the element ratio of N,
2C₁₇H₂₉O₁₀N + 77 / 2O₂→ 34CO₂+ 29H₂O + N₂
According to the reaction formula, 77/4 mol of oxygen is required for 1 mol of the organic waste. About 1 kg of organic waste is about 1000/407 mol. Therefore, assuming that the volume of one mole of gas is 22.4 mL, the amount of oxygen Q required to decompose about 1 kg of organic waste in one day is about 1059 L / day, that is, about 44 L / hr (about 12 cm³/ S). Since the required film area is determined by Q / (F × P), the required film area is about 0.2 m from the above result.²It becomes.
[0039]
In this embodiment, the film area is 1 m²The oxygen-enriched film 5 is formed into a wavy shape by folding the oxygen-enriched film 5. This allows the installation area to be 0.1 m²It can be. In the present embodiment, an opening is provided in the upper part (the ceiling part) of the fermenter 1, and the periphery of the oxygen-enriched membrane 5 is adhered to the wall material around the opening with good airtightness.
[0040]
It is desirable that the oxygen-enriched film 5 has high carbon dioxide and water vapor separation characteristics. Specifically, the oxygen-enriched film 5 is formed of (carbon dioxide gas 1 cm³Per second) / (1 cm of nitrogen gas)³Per second) is about 22 or more, and³Per second) / (1 cm of nitrogen gas)³(Per second) is preferably about 12 or more. Since carbon dioxide and steam are generated by fermentation of the organic waste, each partial pressure of the carbon dioxide and steam in the fermenter 1 increases. By using the oxygen-enriched membrane 5 having a high separation characteristic of carbon dioxide and water vapor, the carbon dioxide gas and water vapor in the fermenter 1 are substantially equilibrated with the respective partial pressures of carbon dioxide gas and water vapor outside the fermenter 1. , To the outside of the fermenter 1.
[0041]
A heat insulating ventilation member 6 is provided on a surface of the oxygen-enriched membrane 5 inside the fermenter 1. The heat-insulating ventilation member 6 has a structure that insulates heat inside the fermenter 1 and allows gas to pass through the oxygen-enriched membrane 5. The heat insulating ventilation member 6 is made of a continuous foam made of, for example, urethane resin. In this embodiment, a continuous foam having a thickness of 20 mm is used. The heat insulating ventilation member 6 also serves as a support for the oxygen-enriched membrane 5.
[0042]
The wall material (oxygen-enriched membrane module 2) in which the oxygen-enriched membrane 5 and the heat-insulating ventilation member 6 are laminated is always exposed to a high-humidity atmosphere, and thus is easily eroded by microorganisms. In order to avoid erosion damage, it is desirable to perform antibacterial and / or antifungal treatment on the inner surface 6a of the fermenter 1 of the heat insulating ventilation member 6. For example, a non-eluting, non-volatile antibacterial paint is applied to the inner surface 6a of the fermenter 1 of the heat insulating ventilation member 6. The antibacterial paint is a paint in which a mixture of a silver-based antibacterial agent and a zinc-based antibacterial agent is dispersed in an oil-based resin. Thereby, the antibacterial and antifungal effect can be exerted only on the microorganisms adhering to the heat insulating ventilation member 6 without affecting the microorganisms inside the fermenter 1.
[0043]
When a water film is formed on the inner side surface 6a of the fermenter 1 of the heat insulating ventilation member 6, the gas permeability of the oxygen-enriched film 5 is reduced. Therefore, it is desirable to perform treatment on the inner surface 6a of the fermenter 1 so that a water film is less likely to be formed on the inner surface 6a of the fermenter 1 of the heat insulating ventilation member 6. For example, a water-repellent treatment may be applied to at least a part of the inner surface 6a of the fermenter 1 of the heat-insulating ventilation member 6 by applying a silicone-based or fluorine-based water-repellent agent.
[0044]
Also, by providing the oxygen-enriched membrane module 2 so that the surface of the oxygen-enriched membrane module 2 on the side of the fermenter 1 is inclined or perpendicular to the horizontal plane, it is difficult to form a water film. In the present embodiment, the oxygen-enriched membrane module 2 is formed in a wavy shape, and the inner surface 6a of the fermenter 1 of the heat-insulating ventilation member 6 is inclined with respect to the horizontal plane. It flows down. Here, the wavy shape includes not only a case where the peaks and the valleys are angular, but also a case where the waveforms have a gentle curve. Further, not only the case of a sawtooth shape as shown in FIG. 1 but also the case of a rectangular wave shape is included.
[0045]
At the lower part of the wavy oxygen-enriched membrane module 2 (the valley on the fermenter 1 side), the condensate is discharged to the outside of the fermenter 1 so that the condensate does not drop and return to the organic waste. A water channel 7 such as a gutter is provided. The water channel 7 can discharge the dew water outside the fermenter 1 while maintaining the airtightness of the fermenter 1. As the water channel 7, for example, a water sealing mechanism using a U-shaped tube can be adopted. Specifically, one opening of the U-shaped tube is communicated with the inside of the fermenter 1, and the other opening is taken out of the fermenter 1. Water is stored in the U-shaped pipe in advance, and the U-shaped pipe communicating between the inside and the outside of the fermenter 1 is sealed with water. When water is injected into the U-tube from inside the fermenter 1, both water surfaces of the U-tube rise. When both water surfaces of the U-shaped tube reach a certain water level, the length of the outer tube is adjusted so that water overflows from the outer tube of the fermenter 1. Thereby, when the dew water is discharged out of the fermenter 1, the airtightness in the fermenter 1 is maintained. In addition, it is also possible to collect dew water in a sump provided in the fermentation tank 1 and drain the water accumulated in the sump to the outside of the fermentation tank 1 by regular maintenance.
[0046]
A stirring body 8 is provided at the center of the fermenter 1 according to the present embodiment. The stirrer 8 has a stirrer 8a such as a stirring blade or a stirrer, and a rotating shaft 8b connected to the stirrer 8a. A drive motor (not shown) for rotating the rotation shaft 8b is provided outside the fermenter 1. The rotating shaft 8b of the stirring body 8 is supported by a bearing (not shown) penetrating the wall material of the fermenter 1, and is connected to a drive motor. By stirring the inputted organic waste by the stirrer 8, the organic waste can be periodically and efficiently brought into contact with oxygen. The bearing is provided on the wall material of the fermenter 1 with good airtightness.
[0047]
The fermenter 1 has a heat sensor 9 for detecting the temperature in the fermenter 1, and a heater 10 controlled based on temperature information from the heat sensor 9. In this embodiment, the heat sensor 9 is provided in the container 1a of the fermenter 1, and can detect the temperature in the fermenter 1 by the heat conduction of the container 1a. The heater 10 is provided on the outer surface of the container 1a. The heater 10 is typically a planar heater or the like.
[0048]
In the initial stage of treating the organic waste, the temperature in the fermenter 1 has not reached the optimal temperature of the microorganisms, so the temperature sensor 9 indicates that the temperature in the fermenter 1 is lower than the optimal temperature of the microorganisms. The information is sent to the heater 10. Upon receiving this information, the heater 10 starts generating heat. Thereby, the temperature in the fermenter 1 rises. When the fermentation of the organic waste is started, the temperature in the fermenter 1 further increases due to the heat of fermentation. If the temperature in the fermenter 1 exceeds the optimal temperature of the microorganism, the microorganism will be killed or the fermentation by the microorganism will be stopped. Therefore, when the temperature in the fermenter 1 exceeds a certain temperature, the heat sensor 9 detects this. The heater 10 stops heating when it receives information from the heat sensor 9 that the temperature in the fermenter 1 is equal to or higher than a certain temperature. By the above operation, the temperature in the fermenter 1 can be appropriately controlled.
[0049]
Organic waste to be fermented usually has microorganisms such as aerobic bacteria contaminating as contaminating bacteria (septic bacteria), so it is possible to perform fermentation without adding aerobic bacteria. is there. However, since the concentration of aerobic bacteria in organic waste is unknown, sufficient fermentation may not be possible depending on the concentration of aerobic bacteria. Therefore, it is desirable to add aerobic bacteria to the organic waste during the fermentation treatment. Aerobic bacteria include sugar assimilating bacteria and cellulolytic bacteria. These can be used alone or in combination. Examples of the bacteria that assimilate sugar include Bacillus (Bacillus), Streptomyces (Streptomyces), and Staphylococcus (Staphylococcus). Examples of the cellulolytic bacteria include Bacillus. By using these microorganisms, organic waste can be decomposed while maintaining safety.
[0050]
It is desirable to add fermentation materials to the organic waste to promote fermentation. For example, it is desirable to add an accelerator composed of minerals or the like disclosed in JP-A-2001-334236 to organic waste.
[0051]
According to the organic waste treatment apparatus of the present embodiment, both the inflow of oxygen necessary for fermentation and the outflow of carbon dioxide and steam generated by fermentation are performed via the oxygen-enriched membrane module 2. This maintains the environmental conditions related to fermentation in the fermenter 1 and promotes the growth of aerobic bacteria, thereby suppressing the generation of offensive odors caused by anaerobic bacteria. Further, the malodorous component that may be generated is hardly leaked out of the fermenter 1 due to the low permeability of the oxygen-enriched membrane module 2, and the clean fermenter 1 with low off-odor can be realized.
[0052]
Regarding the gas permeation, since it operates by the difference in gas partial pressure generated by the microbial decomposition of organic waste, it does not require any special external power and can realize extremely high energy saving.
[0053]
The apparatus can be operated without causing the hygiene pests to be attracted by the putrefaction odor and without bringing the environment into an unsanitary state.
[0054]
(Example)
The organic waste was treated using the organic waste treatment apparatus of the embodiment. However, as the oxygen-enriched membrane 5, a gas separation membrane composed of a block copolymer of polyhydroxystyrene-polysulfone-organosiloxane was used.
[0055]
In processing 1 kg of organic waste (approximately 10 kg of garbage / day), first, 0.3 kg of organic waste (about 3 kg of garbage) was charged. Bacillus {subtilis} as a decomposing microorganism was added to an NB (nutrient broth) medium.⁷Acclimation was started by uniformly spraying 10 ml of the cfu / ml suspension over the organic waste. The NB medium is a medium in which 3 g of meat extract, 10 g of peptone, and 5 g of sodium chloride are dissolved per 1 L of pure water. Over the next 7 days, 0.3 kg / day of organic waste (approximately 3 kg / day as garbage) is continuously supplied, thereby processing a predetermined amount of 1 kg of organic waste (approximately 10 kg / day of garbage). You have reached the ability to do so.
[0056]
After reaching the predetermined operating state, the fermenter was able to operate stably without any fermentation abnormality such as a decrease in pH inside the fermenter. From this, it was confirmed that the oxygen-enriched membrane module 2 functioned effectively and maintained a good fermentation state.
[0057]
After feeding the fermentation raw materials (garbage), the vicinity of the input port was cleaned. No off-flavor or odor was felt near the organic waste treatment equipment. Therefore, it was confirmed that the fermenter of the embodiment was effective as a deodorant fermenter.
[0058]
According to the organic waste treatment apparatus of the embodiment, it is not necessary to provide a device that consumes a large amount of power, such as a deodorizing device or an electrocatalytic deodorizer. Thereby, power saving and space saving are achieved.
[0059]
Since the putrefaction odor did not spread to the surroundings, no hygienic pests such as flies were attracted. Therefore, it was also confirmed that the organic waste had such features that the organic waste could be decomposed extremely hygienically.
[0060]
【The invention's effect】
According to the organic waste treatment apparatus of the present invention, energy saving and space saving can be achieved. Further, since the generation of the bad odor is suppressed, the cost required for the treatment of the bad odor can be reduced. Since it is excellent in hygiene, the installation place is not limited.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view schematically showing an organic waste treatment apparatus according to an embodiment.
[Explanation of symbols]
1 closed fermenter
2. Oxygen-enriched membrane module
5 Oxygen enriched membrane
6 Insulated ventilation member
8 stirring body
9 Heat sensor
10 heater

Claims (14)

A closed fermenter containing organic waste;
An organic waste treatment apparatus having an oxygen-enriched membrane module constituting a part of the wall material of the closed fermenter,
The oxygen-enriched membrane module has a property of allowing oxygen gas in the outside air to permeate into the closed fermentation tank by a partial pressure difference between oxygen gas in the outside air and oxygen gas in the closed fermentation tank. Waste treatment equipment. The organic waste treatment apparatus according to claim 1, wherein the oxygen-enriched membrane module has a laminated structure of an oxygen-enriched membrane and a heat-insulating ventilation member. ^3. The organic waste treatment apparatus according to claim 2, wherein the oxygen-enriched film has a ratio of the number of seconds per 1 cm ³ of oxygen gas to the number of seconds per second per 1 cm ^{3 of} nitrogen gas of 2 or more. 4. The organic waste treatment device according to claim 2, wherein the heat-insulating ventilation member is formed from a continuous foam. The closed fermenter has an inlet for charging the organic waste, a stirrer for stirring the organic waste, an outlet for removing a residue of the organic waste, and a closed port. The organic waste treatment apparatus according to claim 1, further comprising: a heat sensor that detects a temperature of the type fermenter; and a heater that is controlled based on temperature information from the heat sensor. The organic waste treatment apparatus according to claim 1, wherein the oxygen-enriched membrane module has a water vapor permeability and is formed on an upper part of the closed fermenter. The organic waste treatment apparatus according to claim 1, wherein the oxygen-enriched membrane module is formed such that a surface on the closed fermenter side is inclined or perpendicular to a horizontal plane. 2. The hermetic fermenter according to claim 1, wherein the hermetic fermenter has an airtight channel for discharging dew water generated on a surface of the oxygen-enriched membrane module on the hermetic fermenter side outside the hermetic fermenter. 3. Organic waste treatment equipment. The organic waste treatment apparatus according to claim 1, wherein the oxygen-enriched membrane module has at least a part of a surface on the closed fermenter side that has been subjected to a water-repellent treatment. The organic waste treatment apparatus according to claim 1, wherein the oxygen-enriched membrane module is formed in a wavy shape. The organic waste treatment device according to claim 1, wherein the oxygen-enriched membrane module has been subjected to antibacterial and / or antifungal treatment. A step of charging organic waste into a closed fermenter,
And a step of aerobically decomposing the inputted organic waste, comprising:
An organic waste treatment method, wherein oxygen gas is introduced into the closed fermenter from outside the closed fermenter according to the oxygen gas partial pressure in the closed fermenter reduced by the decomposition step. The organic waste treatment method according to claim 12, wherein the decomposition step is performed in the presence of an aerobic organic matter decomposing bacterium. The method for treating an organic waste according to claim 13, wherein the aerobic organic matter-decomposing bacterium includes a bacterium that assimilates sugar and / or a cellulolytic bacterium.

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