JP2003260435A - Apparatus and method for treating nitrogen-containing organic waste - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus and method for treating nitrogen-containing organic waste, in which a liquid component in a methane-fermentation treated matter obtained by a methane-fermentation means is effectively treated and utilized, and the nitrogen-containing organic waste is efficiently treated. <P>SOLUTION: In this apparatus and method, there are included a methane- fermentation means for conducting methane-fermentation of a nitrogen-containing organic waste, an aeration-treatment means for aerating the methane- fermentation treated matter from the methane-fermentation means, and a line for returning a part or the whole of the methane-fermentation treated matter from the aeration-treatment means to the above methane-fermentation means. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an apparatus for treating nitrogen-containing organic waste and a method for treating nitrogen-containing organic waste.

[0002]

2. Description of the Related Art Conventionally, there has been known a technique of methane-fermenting organic waste such as garbage. Here, the object to be treated, which is the target of methane fermentation, may contain a large amount of nitrogen sources such as proteins. In such a case, NH ₃ —N (ammonia nitrogen) generated by the methane fermentation may accumulate in the methane fermentation tank, and it may be difficult to treat the organic waste due to NH ₃ —N inhibition. . As a countermeasure against this, a membrane separator is installed at the latter stage of the methane fermentation tank, the separated liquid containing a large amount of NH ₃ —N is discharged out of the system, and the solid matter is returned to the methane fermentation tank. Usually, the separated liquid cannot be discharged as it is, and it is necessary to treat the separated liquid. However, since the separated liquid has an extremely low C / N ratio, that is, the BOD component is low, when treating NH ₃ -N by a biological denitrification treatment method, a C component such as methanol must be added separately. There were also inconveniences such as not becoming. Further, the methane fermentation tank may require dilution water for keeping the concentration and pH of the object to be treated appropriately, but the separated liquid containing a large amount of NH ₃ —N could not be reused.

[0003]

In view of the above circumstances, the present invention effectively treats and utilizes the liquid component in the methane fermentation treated product obtained by the methane fermentation means to efficiently treat the nitrogen-containing organic waste. It is an object of the present invention to provide a treatment apparatus for nitrogen-containing organic waste and a method for treating nitrogen-containing organic waste, which enables to treat the wastewater.

[0004]

In order to achieve the above object, a nitrogen-containing organic waste treatment apparatus according to the present invention comprises a methane fermentation means for methane-fermenting a nitrogen-containing organic waste, It includes an aeration processing means for aerating the methane fermentation treatment product from the methane fermentation means, and a line for returning a part or all of the methane fermentation treatment product from the aeration treatment means to the methane fermentation means.

In one embodiment of the apparatus for treating nitrogen-containing organic waste according to the present invention, a membrane separation means for membrane-separating a methane fermentation treated product from the methane fermentation means is provided in the aeration treatment means. It is preferable that the membrane separation liquid separated by the membrane separation means is sent to the aeration treatment means in preparation for the former stage. Here, a denitrification means for introducing the aeration treatment liquid obtained by treating the membrane separation liquid by the aeration treatment means is provided, and the denitrification means is provided in the preceding stage of the methane fermentation means, and the denitrification means contains nitrogen-containing liquid. It can be configured to input a part or all of the organic waste.

Further, the nitrogen-containing organic waste treatment apparatus according to the present invention comprises a membrane separation means for membrane-separating the methane fermentation treatment product from the methane fermentation means, which is provided at a subsequent stage of the aeration treatment means. It is preferable that the aeration-processed material separated by the aeration processing means is sent to the membrane separation means. Here, a denitrification means for introducing the membrane separation liquid separated by the membrane separation means is provided, the denitrification means is provided in the preceding stage of the methane fermentation means, and the nitrogen-containing organic waste is provided in the denitrification means. It can be configured to input a part or all of the above.

Furthermore, in the nitrogen-containing organic waste treatment apparatus according to the present invention, a part or all of the methane fermentation treated product is taken out between the methane fermentation means and the aeration treatment means for solid-liquid separation. It is possible to provide a solid-liquid separation means for the purpose of composting the resulting dehydrated sludge.

[0008] The present invention, in another aspect, is a method for treating nitrogen-containing organic waste, which comprises subjecting the nitrogen-containing organic waste to methane fermentation by means of methane fermentation to produce methane and methane fermentation treatment. A step of obtaining a product, an aeration process for aerating the methane fermentation product with an aeration process means, and returning a part or all of the methane fermentation process product after the aeration process to the methane fermentation device.

In one embodiment of the method for treating nitrogen-containing organic waste according to the present invention, a membrane separation step for membrane-separating a methane fermentation treated product from the methane fermentation means is carried out in the aeration treatment step. It is preferable that the membrane separation liquid separated in the membrane separation step is aerated in the aeration treatment step. Here, the aeration treatment liquid obtained by treating the membrane separation liquid in the aeration treatment step is introduced into the denitrification means, and a part or all of the nitrogen-containing organic waste is introduced into the denitrification means to produce the membrane separation liquid. After being denitrified, it can be fed to the methane fermentation means as a mixture with a nitrogen-containing organic waste.

Further, in the method for treating a nitrogen-containing organic waste according to the present invention, in one embodiment thereof, a membrane separation step for membrane-separating a methane fermentation treated product from the methane fermentation means is aerated. It is preferable that the aeration treatment is carried out in the latter stage of the step and the aeration-treated product separated in the aeration treatment step is sent to the membrane separation step. Here, after the membrane separation liquid obtained in the above-mentioned membrane separation step is introduced into the denitrification means, and a part or all of the nitrogen-containing organic waste is introduced into the denitrification means to denitrify the membrane separation solution. , Can be added to the methane fermentation means as a mixture with nitrogen-containing organic waste.

Further, in the method for treating nitrogen-containing organic waste according to the present invention, a part or all of the methane fermentation treated product is taken out and solid-liquid separated between the methane fermentation process and the aeration treatment process. The resulting dehydrated sludge can be composted. Furthermore, in the method for treating nitrogen-containing organic waste according to the present invention,
The redox potential of the denitrification means is -250 to -150 m.
It is preferable to control the amount of aeration air and the amount of circulating liquid of the aeration processing means so as to be V.

[0012] Here, the significance of some of the terms used in the present specification will be clarified. The “nitrogen-containing organic waste” is an organic waste containing organic or ammoniacal nitrogen, and exists in various forms such as a liquid waste and a mixture of solid and liquid. Specifically, examples of waste liquid include human waste, a mixture of human waste and septic tank sludge, sewage, rural village drainage sludge and food processing waste liquid, marine product processing waste liquid, shochu waste liquid, soybean squeezed lees waste liquid, etc. It is characterized by containing or containing a slurry, having a high water content, and chemically containing a large amount of nitrogen (N). Furthermore, in the present invention, raw garbage, livestock excrement and the like are also included in the category of nitrogen-containing organic waste.

The "aeration processing means" is a means for performing aeration processing, and is generally carried out in the form of an "aeration tank". Further, it is embodied in the form of a "nitrification tank" depending on the embodiment. However, even if the other device is capable of exhibiting the same function, it is not limited to these.
It can be adopted unless it goes against the purpose of the present invention.
"Aeration treatment" generally involves contacting water with air to supply oxygen to accelerate the decomposition of pollutants by aerobic microorganisms, remove dissolved gases, and oxidize inorganic substances. Processing. In the organic waste water processing device according to the present invention, the aeration, by contacting the air to organic wastewater, the ammonium in the organic wastewater ion (NH ₄ ⁺⁾ nitrite ion ^- in (NO ₂₎ And oxidize nitrite ions (NO ₂ ⁻ ) to nitrate ions (NO ₃ ⁻ ). In addition, it is general that agitation in the tank is performed as a result of the aeration process.

The "methane fermentation means" is generally embodied as a "methane fermenter". The embodiment of the invention described below is also embodied as a methane fermentation tank. However, other device devices that can perform the same function are not limited to these, and can be adopted as long as they do not violate the object of the present invention. Methane fermentation is a process of anaerobically decomposing using organisms such as methane bacteria that decompose organic wastewater. In the methane fermentation tank, some of the C and H components contained in the organic wastewater are methane gasified,
It is discharged outside the system. In the methane fermentation tank, temperature, pH, etc. are set in an environment in which methane bacteria that generate methane from nitrogen-containing organic waste such as organic waste liquid can live. In the methane fermentation tank, the supplied organic waste is methane-fermented by the methane bacteria to obtain biogas containing methane, hydrogen sulfide and the like, and digested liquid after methane fermentation. The obtained biogas may be used as fuel or the like. Here, as an example of the methane-fermenting bacterium, Methanobacteri
um, Methanobacillus, Methan
It is an absolutely anaerobic bacterium such as ococcus, Methanosarcina.

The "membrane separation means" is generally realized as a "membrane separation device". However, other device devices that can perform the same function are not limited to these, and can be adopted as long as they do not violate the object of the present invention. The "membrane separation device" is a separation means that uses a membrane such as a microfiltration membrane or an ultrafiltration membrane.

The "denitrification means" corresponds to those embodied as "denitrification tank", "denitrification tank" and "mixed denitrification tank" in the following embodiments. However, other device devices that can perform the same function are not limited to these, and can be adopted as long as they do not violate the object of the present invention.

The "solid-liquid separation means" is generally embodied in the form of a "solid-liquid separation device". A "mechanical solid-liquid separator" can be adopted. However, other device devices that can perform the same function are not limited to these, and can be adopted as long as they do not violate the object of the present invention. The “mechanical solid-liquid separation device” is, for example, a device that separates a substance to be treated (also referred to as raw water) by a physical action such as a screen or a centrifuge, and separates the substance from the separated liquid and sludge. It is a device for separating into and. Various precipitation methods that use a method that filters out solids contained in organic wastewater, etc. according to size (various screens, membranes, etc.), and a method that utilizes the difference in weight (that is, sedimentation velocity, inertial force, etc.), There are cyclones and centrifuges.

In a mechanical solid-liquid separator, a coagulant is often added. The flocculant flocculates or coagulates the suspension or dissolved components in the liquid to form large flocs capable of settling, and removes the precipitate. Examples of the aggregating agent include cationic, anionic, and nonionic organic polymer aggregating agents in addition to metal salts such as aluminum, iron, and calcium forming a colloid of metal hydroxide.

When the "solid-liquid separation means" is adopted to perform the solid-liquid separation, "dehydrated sludge" is produced. In biological treatment such as methane fermentation treatment performed in waste treatment, sewage treatment, various wastewater treatment, etc., the water phase is purified as a result of consumption of water-soluble nutrient sources for microbial propagation, and instead of microbial cells Is accumulated as sludge, which is always accompanied by sludge generation. This is called surplus sludge. On the other hand, in the treatment of sewage and night soil, septic tank sludge, and rural village sludge, sludge from the sedimentation site is also generated first. This is called the first settling sludge. These sludges have to be treated again. Generally, in order to reduce the volume, as in the case of the above-mentioned solid-liquid separation device, it is dehydrated using a flocculant (polymer, poly-iron sulfate, etc.) and discharged as sludge at a high concentration. There is. This is called "dehydrated sludge (high-concentration sludge)". High-concentration sludge not only has a low water content (about 75-90% water content), but is a decomposition product of organisms along with fine microbial carcass particles. Since water-soluble polymers such as polysaccharides and peptides are present as a binder, they exhibit a cake-like ultra-high viscosity.

In the following embodiments, "advanced processing means"
Some have adopted. This is an "advanced processing device"
Is generally embodied as The “advanced processing device” is a device for advanced processing of a liquid to be processed by a mechanical or chemical method. An example of an advanced treatment device is an ammonia stripping device.
As the ammonia stripping device, for example, a distillation column can be adopted. In such a distillation column, high-temperature steam is passed from the lower part through a plurality of shelf-shaped stages and brought into contact with the treated water introduced from the upper part. By this contact, wastewater is collected from the lower part of the tower and discharged to the outside of the system. Further, vapor containing ammonia can be recovered from the upper part.
Examples of other advanced treatment methods include a contact aeration treatment method, a coagulation separation treatment method, a sand filtration treatment method, and an activated carbon adsorption treatment method. These can be adopted as long as they are not against the object of the present invention.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION A nitrogen-containing organic waste treatment apparatus and a nitrogen-containing organic waste treatment method according to the present invention will be described in more detail below with reference to the embodiments shown in the accompanying drawings. To do.

FIG. 1 shows an embodiment of a treatment apparatus for nitrogen-containing organic waste according to the present invention. This nitrogen-containing organic waste treatment device is
Methane fermentation tank 102, membrane separation device 104, aeration tank 10
6. Includes a solid-liquid separator 108. In the following, regarding the embodiment in which the nitrogen-containing organic waste treatment apparatus 100 according to the present embodiment is operated to carry out the nitrogen-containing organic waste treatment method according to the present invention, the mechanism thereof will be described in each component device. The operation will be described.

In the present embodiment, garbage is treated as the nitrogen-containing organic waste. Garbage is rich in nitrogen sources such as proteins, and with the fermentation of methane, NH
_It has a drawback that it produces _3- N and tends to cause ammonia inhibition. However, at the same time, there is a characteristic in composition that raw garbage, which is a raw material, simultaneously contains a carbon source. In this embodiment, first, the raw garbage is collected in the line 11
It is charged into the methane fermentation tank 102 from 0. In the methane fermentation tank 102, the methane fermentation represented by the chemical reaction formula (1) occurs by the methane fermentation bacterium. _{C n H a O b N c} + [n-0.25a-0.5b + 1.75c] H 2 O → [0.5n + 0.125a-0.25b-0.375c] CH 4 + [0.5n-0 _{.125a + 0.25b-0.625c] CO 2} + CNH 4 + cHCO 3 - (1)

Further, in the methane fermentation tank 102, the denitrification reaction represented by the chemical reaction formulas (2) and (3) occurs due to the action of the denitrifying bacteria at the same time as the methane fermentation. In the denitrification reaction, nitrite ion (NO ₂ ⁻ ) and nitrate ion (NO ₃ ⁻ ) are chemically converted into nitrogen gas (N ₂ ) and denitrified.

2NO ₂ ⁻ + 3H ₂ → N ₂ + 2OH ⁻ + 2H ₂ O (2) 2NO ₃ ⁻ + 5H ₂ → N ₂ + 2OH ⁻ + 4H ₂ O (3) As examples of denitrifiers, genus Psuedomonas, Micrococcu
s genus, Bacillus genus, Achromobacto
Examples thereof include microorganisms such as r genus. Chemical reaction formula (2),
The hydrogen (H ₂ ) source shown on the left side of (3) is supplied from organic matter such as food waste.

By the treatment in the methane fermentation tank 102, methane and other treated methane fermentation products can be obtained. this is,
Generally called digested sludge. In the present embodiment, this digested sludge is sent to the membrane separation device 104. Membrane separation device 104
Then, the digested liquid is removed from the digested sludge, and the other sludge is returned to the methane fermentation tank 102. As a result, the surviving methane fermentation bacterium can be returned to the methane fermentation tank 102, the concentration of the methane fermentation bacterium in the methane fermentation tank 102 can be maintained, and the fermentation performance of the methane fermentation tank 102 can be maintained.

The membrane separation liquid from the membrane separation device 104 is sent to the aeration tank 106. In the aeration tank 106, air is brought into contact with the membrane separation liquid to supply oxygen to accelerate the decomposition of pollutants by aerobic microorganisms and to remove dissolved gas.
A process of oxidizing an inorganic substance is performed. The method of oxygen supply is
For example, there are a mechanical stirring method in which the water surface is agitated by a turbine blade or a rotor, and an air diffusion method in which gas is dissolved by blowing air into water. The aeration operation maintains an aerobic condition as an environmental factor of the microorganisms responsible for the treatment, and also has a role of mixing a liquid in addition to supplying oxygen.

Aeration of the membrane separation liquid in the aeration tank 106 causes chemical reactions represented by the following equations (4) and (5). ^{_{NH 4 + + 3 / 2O 2}} → NO 2 - + 2H + + H 2 O (4) NO 2 - + 1 / 2O 2 → NO 3 - (5)

The chemical reaction formula (4) shows that ammonium ion (NH ₄ ⁺ ) is chemically changed to the nitrite ion (NO ₂ ⁻ ), and the chemical reaction formula (5) shows the nitrite ion (N ₄ ⁺ ).
O ₂ ⁻ ) chemically changes to nitrate ion (NO ₃ ⁻ ).

In the present embodiment, a pipe line 112 is provided for returning the aeration treatment liquid obtained by aerating the digested liquid which is a methane fermentation treatment product to the methane fermentation tank 102. By returning the aeration-treated solution to the methane fermentation tank 102 through this piping line 112, the diluted solution of the methane fermentation tank 102 can be secured. In addition, in this aeration treatment liquid, NH ₃
-N is nitrite ions (NO ₂ ^-) or nitrate (NO
₃ ^-) are converted into, not inhibit methane fermentation. Further, since these nitrite ions (NO ₂ ⁻ ) or nitrate ions (NO ₃ ⁻ ) are denitrogenated in the methane fermentation tank 102, the entire apparatus can be made compact. Moreover, raw garbage, which is a raw material, can be used instead of an additive component such as methanol for treating NH ₃ -N,
It is also excellent in cost.

Further, in the present embodiment, a part of the digested sludge from the methane fermentation tank 102 is taken out to the solid-liquid separation device 108 and dehydration operation is performed. The dehydrated sludge obtained is
It can be composted and recycled as fuel.

According to the present embodiment, NH ₃ − produced when methane-fermenting a nitrogen-containing organic waste such as food waste is carried out.
The above-mentioned advantages are obtained while the problem of fermentation inhibition by N is solved.

FIG. 2 shows another embodiment of the apparatus for treating nitrogen-containing organic waste according to the present invention. The nitrogen-containing organic waste treatment apparatus 200 according to the present embodiment includes a methane fermentation tank 102, a membrane separation apparatus 104, an aeration tank 106, and a solid-liquid separation apparatus 108 as main components, and therefore FIG. This embodiment is common to the above embodiment. The basic operation of these devices is almost the same as described in FIG.

The embodiment of FIG. 2 is characterized in that a mixed denitrification tank 202 is provided in a stage preceding the methane fermentation tank 102, as compared with the embodiment 100 of FIG. The aeration treatment liquid is returned to the mixed denitrification tank 202. By this, the acid component in the aeration treatment liquid can be denitrified in advance, the pH of the substance to be put into the methane fermentation tank 102 can be adjusted, and the pH in the methane fermentation tank 102 can be kept stable. . The pH is an important factor for the growth of methane-fermenting bacteria, and its effect can be expected.

FIG. 3 shows still another embodiment of the apparatus for treating nitrogen-containing organic waste according to the present invention. The nitrogen-containing organic waste treatment device 300 includes a denitrification tank 302, a methane fermentation tank 304, and a nitrification tank 306 as main components. In this embodiment, livestock excreta is assumed as the nitrogen-containing organic waste to be treated.
After treating livestock manure, it is sprayed as liquid fertilizer, or the dehydrated solid matter is composted and the liquid portion is discharged. Such characteristics of livestock excreta include the fact that the original raw material contains a large amount of ammonia component in addition to the increase in ammonia component due to methane fermentation. Therefore, there is a problem that the carbon component is relatively small and methanol or the like must be added. In addition, when sprayed as liquid fertilizer, there was a problem that the excess nitrogen caused adverse effects on plants. This embodiment differs from the embodiments shown in FIGS. 1 and 2 in that the subject to be treated is livestock excrement. However, the operation of the methane fermenter 304 is substantially the same as that shown in FIGS.
It is the same as the methane fermentation tank 102 of FIG. The digested sludge (digested liquid) is aerated in the nitrification tank 306. The operation of the nitrification tank 306 is substantially the same as that of the aeration tank 106 shown in FIGS. That is, NH ₃ —N is converted to nitrite ion (N
O ₂ ⁻ ) or nitrate ion (NO ₃ ⁻ ).

In this embodiment, part of the aeration treatment liquid from the nitrification tank 306 is used as liquid fertilizer. On this occasion,
Since the TN of the fermented liquid is reduced, an excellent liquid fertilizer can be obtained. The rest of the aeration treatment liquid (nitrification liquid) from the nitrification tank 306 is sent to the denitrification tank 302 through a piping line 308. By this, nitrite ion (N
O ₂ ⁻ ) or nitrate ions (NO ₃ ⁻ ) are removed. That is, the acid component in the aeration treatment liquid can be denitrified in advance by utilizing easily decomposable organic matter contained in livestock manure. Therefore, it is possible to adjust the pH of the substance to be charged into the methane fermentation tank 302, and the pH in the methane fermentation tank 302 can be adjusted.
H can be kept stable. The pH is an important factor for the growth of methane-fermenting bacteria, and its effect can be expected. Also in this embodiment, the problem of fermentation inhibition due to NH ₃ —N generated when methane-fermenting a nitrogen-containing organic waste is solved, and at the same time, in addition components such as methanol for treating NH ₃ —N, Since it is possible to use livestock manure as a raw material, the cost is excellent.

FIG. 4 shows still another embodiment of the apparatus for treating nitrogen-containing organic waste according to the present invention. This nitrogen-containing organic waste treatment device 400 is similar to the embodiment 300 of FIG. 3 in that it includes a denitrification tank 302, a methane fermentation tank 304, and a nitrification tank 306 as main components. These operations are substantially the same as the embodiment of FIG. Also in this embodiment, livestock manure is assumed as the nitrogen-containing organic waste to be treated. In this embodiment, a solid-liquid separation device 402 is provided. Here, solid components are extracted from the digested sludge and composted. Furthermore, a part of the nitrification liquid that has passed through the nitrification tank 306 is
Since it does not contain NH ₃ —N, it can be discharged. Other than this, the basic effects of the embodiment of FIG. 3 can be expected.

FIG. 5 shows still another embodiment of the apparatus for treating nitrogen-containing organic waste according to the present invention. This nitrogen-containing organic waste treatment device 500 is similar to the embodiment of FIG. 4 in that it includes a denitrification tank 302, a methane fermentation tank 304, a solid-liquid separation device 402, and a nitrification tank 306 as main components. Yes (however, some are omitted). These operations are substantially the same as the embodiment of FIG.
Also in this embodiment, livestock manure is assumed as the nitrogen-containing organic waste to be treated.

In this embodiment, a NOx-N concentrator 502 is provided. Here, NOx-N in the nitrification liquid (aeration treatment liquid) is concentrated. Concentration is performed using a reverse osmosis membrane or the like. Only the NOx-N concentrated water thus obtained is sent to the denitrification tank 302. As a result, the denitrification tank 302 can be made compact and efficient. Other than this, the basic effects of the embodiment of FIG. 4 can be expected.

The diluted water diluted with NOx-N is subjected to advanced treatment by the advanced treatment device 504 and then discharged. In addition, in the embodiment of FIG. 4, only this advanced processing device 504 is
It may be provided in the subsequent stage of the nitrification tank 306.

FIG. 6 shows still another embodiment of the apparatus for treating nitrogen-containing organic waste according to the present invention. This nitrogen-containing organic waste treatment device 600 has, as its main components, a methane fermentation tank 602, a membrane separation device 604, a nitrification tank 606, a condensation settling tank 608, an advanced treatment device 610,
A screen 612 and a denitrification tank 614 are included. In this embodiment, human waste or a mixture of human waste and septic tank sludge is assumed as the nitrogen-containing organic waste to be treated. Such nitrogen-containing organic waste is a soluble organic waste liquid, and it has conventionally been necessary to separately treat the liquid component and the solid component, and if the ammonia component is not removed, the liquid component after the treatment is removed. There was a problem that I couldn't release it.

In this embodiment, the object to be processed is different from that of the embodiment shown in FIGS. 1 and 2. But,
The operation of the methane fermentation tank 604 is substantially the same as that of the methane fermentation tank 102 in FIGS. 1 and 2. Similarly, the methane fermentation treated product (digested sludge) is aerated in the nitrification tank 606. The operation of the nitrification tank 606 is the same as that of the aeration tank 106 shown in FIGS.
Is substantially the same as. That is, NH ₃ —N is converted into nitrite ion (NO ₂ ⁻ ) or nitrate ion (NO ₃ ⁻ ). The operation of the membrane separation device 604 is the same as that of the membrane separation device 104. The sludge component of the digested sludge is returned to the methane fermentation tank 602 by the membrane separation device 104. Then, a part of the sludge can be further subjected to solid-liquid separation so that the solid content can be composted.

The function of the denitrification tank 614 is the same as that of the denitrification tank 302 shown in FIGS. 3 to 5, and the aeration treatment liquid is denitrified by the easily decomposable organic matter contained in the object to be treated in advance. As a result, the aeration treatment liquid is converted into the methane fermentation tank 602.
The pH adjustment in the methane fermentation tank 602 is facilitated when returning to the above. Further, the residual organic matter is effectively utilized for the denitrification process in the denitrification process in the denitrification tank 614. That is, it becomes possible to perform integrated treatment of water and sludge.

In this embodiment, human waste or a mixture of human waste and septic tank sludge is treated. Therefore, the screen 612 is provided before the methane fermentation tank 602. The screen 612 is a device for removing contaminants, and mechanically removes contaminants, suspended solids, or a mixture thereof that are being processed.

In this embodiment, a part of the aeration treatment liquid that has passed through the nitrification tank 606 is sent to the coagulation separation tank 608. Here, an aggregating agent (aluminum salt, iron salt, etc.) or a polymer aggregating agent (anionic polymer aggregating agent, nonionic polymer aggregating agent, etc.) is added to the aeration treatment liquid, and fine particles contained in the aeration treatment liquid are added. A floc that easily precipitates SS and the like is made, and a part of the organic matter which is a component of chromaticity and COD and phosphoric acid and the like are insolubilized to perform solid-liquid separation. The liquid component is further subjected to advanced treatment by an advanced treatment device 608 at the subsequent stage and then discharged.

FIG. 7 shows a nitrogen-containing organic waste treatment apparatus 700 in which the membrane separation apparatus 604 is arranged at the subsequent stage of the nitrification tank 606 in the embodiment of FIG.

The embodiment shown in FIGS. 8 and 9 is a nitrogen-containing organic waste in which a part or all of the object to be treated is put into the denitrification tank 614 in the embodiment shown in FIG. 6 or 7, respectively. Processing devices 800, 900 of FIG. This makes it possible to directly utilize the easily decomposable BOD component contained in the treated human waste or the mixture of human waste and the septic tank sludge for denitrification. Other than that, in FIG. 8 and FIG. 9, the constituent elements shown by the same numbers in FIG. 6 or FIG. 7 perform substantially the same operations and functions as the embodiment of FIG. 6 or FIG.

In the embodiment shown in FIGS. 6 to 8,
The redox potential of the denitrification tank 614 is -250 to -150.
It is preferable to control the amount of aerated air and the amount of circulating liquid in the nitrification tank 606 so as to be mV. This is because denitrification is performed with a reducing atmosphere in the tank.

Other Embodiments The apparatus and method for treating nitrogen-containing organic waste according to the present invention have been described in the above embodiments, but the present invention is limited to such embodiments. Not something
All modifications, changes and additions that are obvious to those skilled in the art are included in the technical scope of the present invention.

[0050]

As is apparent from the above, according to the present invention, the liquid components in the methane fermentation treated product obtained by the methane fermentation means are effectively treated and utilized, and the nitrogen-containing organic waste is efficiently treated. Provided are a treatment apparatus for nitrogen-containing organic waste and a method for treating nitrogen-containing organic waste, which can be effectively treated.

[Brief description of drawings]

FIG. 1 is a conceptual diagram illustrating an embodiment of a treatment apparatus for nitrogen-containing organic waste according to the present invention.

FIG. 2 is a conceptual diagram illustrating another embodiment of the treatment apparatus for nitrogen-containing organic waste according to the present invention.

FIG. 3 is a conceptual diagram illustrating another embodiment of the nitrogen-containing organic waste treatment device according to the present invention.

FIG. 4 is a conceptual diagram illustrating another embodiment of the treatment apparatus for nitrogen-containing organic waste according to the present invention.

FIG. 5 is a conceptual diagram illustrating another embodiment of the treatment apparatus for nitrogen-containing organic waste according to the present invention.

FIG. 6 is a conceptual diagram illustrating another embodiment of the nitrogen-containing organic waste treatment device according to the present invention.

FIG. 7 is a conceptual diagram illustrating another embodiment of the treatment apparatus for nitrogen-containing organic waste according to the present invention.

FIG. 8 is a conceptual diagram illustrating another embodiment of the treatment apparatus for nitrogen-containing organic waste according to the present invention.

FIG. 9 is a conceptual diagram illustrating another embodiment of the nitrogen-containing organic waste treatment device according to the present invention.

[Explanation of symbols]

100,200 Nitrogen-containing organic waste treatment device 102 Methane fermentation tank 104 Membrane separation device 106 Aeration tank 108 Solid-liquid separation device 202 Mixed denitrification tank 300,400,500 Nitrogen-containing organic waste treatment device 302 Denitrification tank 304 Methane fermentation tank 306 Nitrification tank 402 Solid-liquid separation apparatus 502 NOx-N concentrator 504 Advanced processing apparatus 600,700,800,900 Nitrogen-containing organic waste processing apparatus 602 Methane fermentation tank 604 Membrane separation apparatus 606 Nitrification tank 608 Coagulation / separation device 610 Advanced processing device 612 Screen

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) B09B 3/00 C (72) Inventor Tomoaki Omura 1-8 Sachiura, Kanazawa-ku, Yokohama-shi, Kanagawa 1 Mitsubishi Heavy Industries Yokohama Institute Co., Ltd. (72) Inventor Yuji Yasuda 12 Nishiki-cho, Naka-ku, Yokohama-shi, Kanagawa Mitsubishi Heavy Industries, Ltd. Yokohama Works F-term (reference) 4D004 AA02 AA03 BA03 BA04 CA12 CA15 CA18 4D028 AB00 AC01 BB07 BD11 BD16 BD17 4D040 BB05 BB24 BB54 BB57 4D059 AA01 AA02 AA03 AA07 AA08 BA12 BE01 BE31 BE38 BE39 BE42 BE54 BE55 BE57 BE58 BE59 CA22 CA23 CC01 CC03 EB05

Claims (13)

[Claims] 1. A methane fermentation means for methane-fermenting a nitrogen-containing organic waste, an aeration treatment means for aeration-treating a methane fermentation product from the methane fermentation means, and methane from the aeration treatment means. An apparatus for treating nitrogen-containing organic waste, comprising a line for returning a part or all of a fermented product to the methane fermentation means. 2. Membrane separation means for membrane-separating the methane fermentation treated product from the methane fermentation means is provided in the preceding stage of the aeration treatment means, and the membrane separation liquid separated by the membrane separation means is used as the aeration treatment means. The apparatus for treating nitrogen-containing organic waste according to claim 1, characterized in that it is configured to send. 3. A denitrification means for introducing the aeration treatment liquid obtained by treating the membrane separation liquid by the aeration treatment means, wherein the denitrification means is provided in the preceding stage of the methane fermentation means, and the denitrification means is provided. 3. The treatment apparatus for nitrogen-containing organic waste according to claim 2, wherein the nitrogen-containing organic waste is partly or wholly introduced. 4. A membrane separation means for membrane-separating the methane fermentation treated product from the methane fermentation means is provided at a stage subsequent to the aeration treatment means, and the aeration treated product from the aeration treatment means is sent to the membrane separation means. 2. The structure according to claim 1, wherein
Nitrogen-containing organic waste treatment equipment. 5. A denitrification means for introducing the membrane separation liquid separated by the membrane separation means is provided, the denitrification means is provided in the preceding stage of the methane fermentation means, and the denitrification means has a nitrogen-containing organic property. The apparatus for treating nitrogen-containing organic waste according to claim 4, characterized in that a part or all of the waste is introduced. 6. A solid-liquid separation means is provided between the methane fermentation means and the aeration treatment means for extracting a part or all of the methane fermentation-treated product for solid-liquid separation, and the resulting dehydrated sludge is composted. The apparatus for treating nitrogen-containing organic waste according to any one of claims 1 to 5, characterized in that 7. A step of methane-fermenting a nitrogen-containing organic waste by a methane fermentation means to obtain methane and a methane fermentation treated material, and an aeration treatment step for aerating the methane fermentation treated material with an aeration treatment means. And a method for treating a nitrogen-containing organic waste, which comprises returning a part or all of the methane fermentation treated product after the aeration treatment to the methane fermentation means. 8. A membrane separation step for membrane-separating a methane fermentation product from the methane fermentation means is carried out before the aeration treatment step, and the membrane separation liquid separated in the membrane separation step is aerated. The aeration process is performed according to claim 7.
Method for treatment of nitrogen-containing organic waste of. 9. The membrane, wherein the aeration treatment liquid obtained by treating the membrane separation liquid in the aeration treatment step is introduced into a denitrification means, and a part or all of the nitrogen-containing organic waste is introduced into the denitrification means. 9. The method for treating nitrogen-containing organic waste according to claim 8, wherein the separated liquid is denitrified and then introduced into the methane fermentation means as a mixture with the nitrogen-containing organic waste. 10. A membrane separation step for membrane-separating a methane fermentation product from the methane fermentation means is carried out after the aeration treatment step, and the aeration-treated product separated in the aeration treatment step is subjected to a membrane separation step. The method for treating nitrogen-containing organic waste according to claim 7, wherein 11. The membrane separation liquid obtained in the membrane separation step is charged into a denitrification unit, and a part or all of the nitrogen-containing organic waste is charged into the denitrification unit to denitrify the membrane separation liquid. The method for treating nitrogen-containing organic waste according to claim 10, wherein the mixture is added to the methane fermentation means as a mixture with the nitrogen-containing organic waste. 12. A dehydrated sludge obtained by performing a solid-liquid separation process for extracting a part or all of a methane fermentation-treated product and performing solid-liquid separation between the methane fermentation process and the aeration treatment process. The method for treating nitrogen-containing organic waste according to any one of claims 7 to 12, characterized by composting. 13. The redox potential of the denitrification means is −2.
13. The method for treating nitrogen-containing organic waste according to claim 9, 11 or 12, wherein the aeration air amount and the circulating liquid amount of the aeration treatment means are controlled so as to be 50 to −150 mV.