JP5192134B2 - Waste treatment method and system - Google Patents

Description

  The present invention is a technology for treating waste containing fiber and oxidant-containing wastewater containing a peroxide-based oxidant, and in particular, biogas is produced by methane fermentation of waste discharged from a beverage / food factory. The present invention relates to a waste treatment method and system capable of collecting and treating oxidant-containing wastewater used for sterilization and washing in the factory.

  Waste discharged from beverage factories or food factories (hereinafter referred to as beverage and food factories) includes solid waste such as beverage and food processing residues, liquid waste such as product residue, There are cleaning wastewater used to clean equipment. A beverage factory will be described as an example. As shown in FIG. 5, in the product processing step, for example, in the step of extracting the liquid 101 from raw materials such as coffee beans and tea leaves and then preparing the extract 102, Processing residues such as tea leaves are generated. On the other hand, in the bottling process, the inside of the PET bottle is sterilized and washed 103 with oxidant-containing washing water, and then the extract is filled 104, the PET bottle is sealed 105, and then the outside screw portion of the PET bottle is watered inside the cap. Wash (106). Furthermore, since an oxidizing agent and washing water are used for washing various devices in the factory, an oxidizing agent-containing wastewater is generated here.

  Various chemicals are used to sterilize and clean containers for products and various equipment in factories. In conventional hot filling systems, chlorine-based chemicals such as hypochlorous acid were often used to clean the inside of containers, but in recent years, peroxide-based oxidizing agents such as peracetic acid and hydrogen peroxide have been added due to the extension of the aseptic filling system. It has been increasingly used. Therefore, there is a plant in which the peroxidation oxidant remains in the wastewater generated in the beverage / food factory. When treating oxidant-containing wastewater, neutralization with a reducing agent (see Patent Document 1 and the like), decomposition with catalytic activated carbon (see Patent Document 2 and the like), and the like are common.

In a beverage / food factory, a plurality of types of wastes are discharged, and therefore, a plurality of processing steps are provided. As shown in FIG. 6, solid waste such as food / food processing residue 60 is supplied to a methane fermentation tank 52 and subjected to methane fermentation after moisture adjustment, temperature adjustment, and the like in a mixing adjustment tank 51. The fermentation liquor is solid-liquid separated by the solid-liquid separation device 53. The separated liquid is subjected to treatment such as activated sludge treatment in the wastewater treatment facility 54. Other waste water 65 discharged from the factory is also treated at the same time. The sludge generated in the wastewater treatment is once stored in the sludge storage tank 58 and then dehydrated by the dehydrator 59 and separated into the dehydrated sludge and the separated liquid. The separated liquid is processed in the wastewater treatment facility 54. The dewatered sludge is treated by composting, incineration, landfill, etc.
On the other hand, the oxidant-containing waste water 61 containing a peroxide-based oxidant is reduced by the reduction facility 66 and sent to the discharge or wastewater treatment facility.

  As described above, conventionally, a plurality of processing systems have been individually provided, but a method of organically connecting them is disclosed in Patent Document 3 (Japanese Patent Laid-Open No. 2004-9017). In Patent Document 3, as a method for treating wastewater containing peroxides such as hydrogen peroxide and peracetic acid, wastewater to be biologically treated is anaerobically treated, and then the anaerobic treated water is mixed with peroxide-containing wastewater. Thus, a method for decomposing peroxide in the peroxide-containing waste water is disclosed. As a result, it is possible to biologically treat the peroxide in the wastewater by decomposing it without requiring a reducing agent, a catalyst, or the like.

On the other hand, solid waste discharged from beverage and food factories often contains a large amount of fiber. In the case of waste with high fiber content, biogas recovery is small because methane fermentation is difficult.
Therefore, in Patent Document 4 (Patent No. 36005626), as a method for methane fermentation of organic waste containing a hardly decomposable component and recovering biogas, sludge treated with methane fermentation is solubilized by ozone oxidation and solidified. A method of returning separated sludge to a methane fermentation tank after liquid separation has been proposed. Thus, by solubilizing the hardly decomposable substance, methane fermentation is promoted and the biogas recovery rate can be increased.

JP-A-11-267666 JP 2003-2111168 A JP 2004-9017 A Japanese Patent No. 36005626

Since the oxidizing agent has a high bactericidal effect, it cannot be directly put into wastewater treatment facilities such as activated sludge, and there is a problem that the treatment with an expensive reducing agent or activated carbon is required and the cost is increased. In addition, when the oxidizing agent is peracetic acid (CH ₃ COOOH), acetic acid (CH ₃ COOH) and hydrogen peroxide (H ₂ O ₂ ) are generated after the reduction treatment, which increases the load on the wastewater treatment facility. In Patent Document 3, a reducing agent, activated carbon, and the like are unnecessary, but the peroxide is merely decomposed and processed, and effective use cannot be achieved.
In addition, when wastes with high fiber content such as coffee cake and tea leaves are discharged, there is a problem that the amount of biogas recovered is small because methane fermentation is difficult. Solubilization as in Patent Document 4 is an effective means for methane fermentation, but oxidant-containing wastewater must be treated separately. In addition, when ozone is added in the solubilization process, the cost is high because it is generated by discharge. Moreover, since it was difficult to store, it was necessary to install an ozone generator in the hall. Furthermore, since it is a gaseous substance, there is a problem that exhaust gas treatment or containment is necessary so that it does not diffuse around, and an efficient solubilization treatment is required.

  Therefore, in view of the above-mentioned problems of the prior art, the present invention can increase the amount of biogas recovered when methane fermentation of fiber-containing waste, and reduce oxidant-containing wastewater without using a reducing agent or activated carbon An object of the present invention is to provide a waste treatment method and system capable of performing the treatment.

Therefore, in order to solve such a problem, the present invention treats a processing residue discharged from a beverage or food factory by methane fermentation, a solid-liquid separation step for solid-liquid separation of the methane fermentation liquid, A waste treatment method in which an oxidant-containing wastewater discharged from a beverage or food factory is fed into a processing residue treatment system for treating the activated liquid sludge with the solid-liquid separated liquid ,
Before turning on the processing residue to methane fermentation step, the pre-Symbol oxidant containing wastewater directly, or with the previous methane fermentation liquid to be introduced into the solid-liquid separation step, mixing an oxidizing agent-containing wastewater and the processing residue at the mixing section Then, the mixed waste is fed into a methane fermentation process .

In the present invention, the oxidant-containing wastewater introduced into the processing residue discharged from the beverage or food factory reduces the molecular weight of the fiber contained in the waste by its oxidizing power and solubilizes the waste. Solubilized waste tends to be methane-fermented, increasing biogas recovery. At the same time, since the oxidizing agent is reduced, it is not necessary to separately reduce the oxidizing agent, and a reducing agent, activated carbon and the like are unnecessary, and the running cost can be reduced.

That is, the pre-Symbol oxidant containing wastewater with methane fermentation liquid before introducing the (downstream side of the methane fermentation) solid-liquid separation step, the mixed waste by mixing an oxidizing agent-containing wastewater and the processing residue at the mixing section Is added to the methane fermentation liquid, the oxidant-containing wastewater is mixed with the methane fermentation liquid. Although the methane fermentation liquid itself has a low C / N ratio (carbon (C) / nitrogen (N)), the C / N ratio can be improved by oxidative decomposition. When processing, the amount of nutrient sources such as methanol added as a carbon source can be reduced.
In the present invention also with the previous SL oxidant containing waste water to solid-liquid separation step methane fermentation liquid before turning to, and so as to return from the methane fermentation of the upstream side to the mixing unit, the mixing of the oxidizing agent-containing wastewater Solubilized return sludge is introduced into methane fermentation, which promotes methane fermentation and increases the amount of biogas recovered. Furthermore, although throw off to oxidant-containing waste water is reduced, the methane fermentation liquid for anaerobic ingredients are contained many, a very high reduction effect.

In these inventions, the processing residue is waste discharged from a beverage / food factory, the oxidizing agent-containing wastewater is a peroxide oxidizing agent, and the peroxide oxidizing agent is mainly peracetic acid. The waste water containing an oxidizing agent used for sterilization and washing in the beverage / food factory as a component .
In beverage and food factories, wastes containing a large amount of fiber such as beverage and food processing residues and oxidant-containing wastewater such as washing wastewater used for washing product containers and equipment are generated. Accordingly, the present invention can reduce the cost of chemicals supplied from the outside by organically linking the waste and wastewater discharged from the factory, and can improve the processing efficiency by enabling complex processing.

Furthermore, at least a part of the separated sludge that has been subjected to solid-liquid separation in the solid-liquid separation step is returned to a mixing unit that mixes the processing residue and oxidant-containing wastewater.
Thereby, since the surplus sludge after the activated sludge treatment is oxidized and solubilized, the surplus sludge generation amount is reduced, and at the same time, the oxidizing agent-containing waste water is reduced.
When the present invention is applied to a beverage / food factory, examples of the waste water include waste water such as concentrated waste water, general waste water, and diluted waste water discharged from the factory.

Further, the present invention is characterized in that the processing residue and oxidant-containing wastewater are mixed in a mixing section, and the mixed waste is put into a methane fermentation process .
In general, waste or methane fermentation liquid to be put into methane fermentation is subjected to moisture adjustment, temperature adjustment, etc. before methane fermentation. In the present invention, the processing residue and oxidizing agent-containing wastewater are further mixed in the mixing section. Therefore, the methane fermentation is promoted. At this time, it is preferable to use the waste heat and waste alkali generated in the treatment system of the present invention for the solubilization treatment, thereby promoting methane fermentation and providing energy-saving and low-cost treatment.

Furthermore, in these inventions, it is preferable that the peroxidic oxidant is mainly composed of peracetic acid.
When the peroxidic oxidant is mainly composed of peracetic acid, hydrogen peroxide and acetic acid are produced from peracetic acid, but the produced hydrogen peroxide functions as an oxidant and contributes to the reduction of waste molecules. On the other hand, since acetic acid produced by reduction of peracetic acid becomes a raw material for methane fermentation, the amount of biogas recovered can be further increased.

As an invention related to the waste treatment system of the invention,
A methane fermentation apparatus for processing a processing residue discharged from a beverage or food factory by methane fermentation, a solid-liquid separation apparatus for solid-liquid separation of the methane fermentation liquid, and a processing residue for processing activated sludge for the solid-liquid separated liquid A waste treatment system that incorporates an oxidant-containing wastewater treatment system that treats oxidant-containing wastewater discharged from beverages or food factories into the treatment system,
A mixing adjustment tank is provided in the input line for supplying the processing residue to the methane fermentation process , and the oxidizer-containing wastewater is input to the mixing adjustment tank directly or together with the methane fermentation liquid before being input to the solid-liquid separation process. A mixing line for mixing the processing residue and the oxidant-containing wastewater in the adjustment tank is provided.

Further, the mixing adjustment tank is provided with a return line for returning at least a part of the separated sludge solid-liquid separated by the solid-liquid separator to the upstream side of the methane fermentation tank.

Further comprising an active sludge treatment facility for activated sludge treatment pre Symbol methane fermentation liquor to solid-liquid separation was separated liquid after the methane fermentation,
The activated sludge treatment facility has an aeration tank and a settling tank, and includes a return line for returning at least a part of the excess sludge obtained in the settling tank to the aeration tank,
The return line is provided with means for mixing the oxidant-containing waste water with at least a part of the excess sludge.
In addition, a mixing adjustment tank is provided in the previous stage of the methane fermentation tank, and waste heat or waste alkali generated in the system is supplied to the mixing adjustment tank to solubilize the waste or the methane fermentation liquid. And
Furthermore, it is preferable that the peroxidic oxidant is mainly composed of peracetic acid.

As described above, according to the present invention, methane fermentation can be performed efficiently by effectively using waste water containing oxidant even if it is waste containing fiber, and the amount of biogas recovered is increased. be able to. In addition, since the oxidizing agent-containing waste water can be reduced at the same time, it is not necessary to supply a reducing agent or activated carbon, and the running cost can be reduced.
Furthermore, by introducing the oxidizing agent-containing wastewater into methane fermentation or both methane fermentation and activated sludge treatment, decomposition of biological treatment is promoted, so that the amount of sludge generated can be reduced and treatment costs can be reduced.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention unless otherwise specified, but are merely illustrative examples. Not too much.
FIG. 1 is a schematic diagram showing the main configuration of a waste treatment system according to an embodiment of the present invention, FIG. 2 is an overall configuration diagram of the waste treatment system according to Embodiment 1 of the present invention, and FIG. 3 is an embodiment of the present invention. FIG. 4 is an overall configuration diagram of a waste treatment system according to Embodiment 3 of the present invention.

The main configuration of the present embodiment will be described with reference to FIG. The object to be treated is waste containing fiber such as coffee / tea bowl, fruit squeezed fruit and other beverage / food processing residue 10 and the like, and an oxidizing agent containing an oxidizing agent used for sterilization and washing in the system. It is an agent-containing wastewater 11. Examples of the oxidizing agent include peroxidic oxidizing agents such as peracetic acid and hydrogen peroxide, but it is particularly preferable to apply to oxidizing agents containing peracetic acid.
In the present embodiment, as shown in the figure, a mixing adjustment tank 1 for adjusting the beverage / food processing residue 10 to a state suitable for methane fermentation, and methane for methane fermentation of the mixed beverage / food processing residue 10 Generated by the fermenter 2, the solid-liquid separation device 3 for solid-liquid separation of the methane fermentation liquid after the methane fermentation, the waste water treatment facility 4 for water treatment of the separated liquid obtained by solid-liquid separation, and the waste water treatment A sludge storage tank 8 for storing the sludge and a dehydrator 9 for dewatering the sludge.

In the mixing adjustment tank 1, moisture adjustment, temperature adjustment, and the like of the beverage / food processing residue 10 are performed, but in addition to the waste alkali 12 and waste heat 13 generated in the system, the beverage / food processing residue 10 May be solubilized.
In the methane fermentation tank 2, anaerobic microorganisms such as methane fermentation bacteria are propagated in the tank, and conditions such as temperature and pH are maintained in an environment in which the anaerobic microorganisms can prominently propagate. This is a well-known device that generates biogas by decomposing organic matter in the radioactive waste 20 mainly by gasification reaction.

The wastewater treatment facility 4 is a facility that performs water treatment mainly on biological treatment on the separated liquid obtained by solid-liquid separation, and activated sludge treatment is suitably used. In the activated sludge treatment, the aeration tank 5 and the sedimentation tank 6 connected in series and at least a part of the excess sludge obtained in the sedimentation tank 6 are returned to the aeration tank 5 as a return sludge 16. A mixing tank 7 is provided on the return line.
The separated liquid 17 separated in the settling tank 6 is discharged or sent to another water treatment system. On the other hand, the separated sludge 18 is once stored in the sludge storage tank 8, and then appropriately put into the dehydrator 9, where it is dehydrated. The dehydrated separation liquid is preferably treated in the wastewater treatment facility 4 together with other wastewater 15 generated in the factory.

Furthermore, in this embodiment, the oxidant-containing waste water 11 is introduced upstream from the methane fermentation tank 2 or downstream from the methane fermentation tank 2 and upstream from the solid-liquid separator 3.
When the oxidant-containing wastewater 11 is introduced upstream from the methane fermentation tank 2, it can be introduced between the mixing adjustment tank 1, the preceding stage of the mixing adjustment tank 1, or between the mixing adjustment tank 1 and the methane fermentation tank 2, This input position is not particularly limited. The oxidant-containing wastewater 11 put into the beverage / food processing residue 10 lowers the molecular weight of the fiber contained in the residue 10 by its oxidizing power and solubilizes the beverage / food processing residue 10. Since the solubilized waste is easily methane-fermented, the amount of biogas recovered increases. At the same time, the oxidizing agent is advantageously reduced.

When the oxidant-containing waste water 11 contains peracetic acid, since the peracetic acid exists in an equilibrium state as in the following formula (1), the generated hydrogen peroxide functions as an oxidant, and the beverage / food processing residue 10 Contributes to low molecular weight. On the other hand, acetic acid is produced by the reduction of peracetic acid. Since acetic acid is a raw material for methane fermentation, the amount of biogas recovered can be further increased.
CH ₃ COOOH + H ₂ O → CH ₃ COOH + H ₂ O ₂ (1)

When the oxidant-containing waste water 11 is introduced between the methane fermentation tank 2 and the solid-liquid separator 3, the oxidant-containing waste water 11 is mixed with the methane fermentation liquid after methane fermentation. Although the methane fermentation liquid itself has a low C / N ratio (carbon (C) / nitrogen (N)), it can be improved by oxidative decomposition, and denitrification treatment can be performed at the wastewater treatment facility 4 at the subsequent stage. When performing this, the amount of nutrient sources such as methanol added as a carbon source can be reduced.
Further, in this case, at least a part of the methane fermentation liquid mixed with the oxidant-containing waste water 11 and / or at least a part of the separated sludge obtained by solid-liquid separation of the methane fermentation liquid with the solid-liquid separator 3 are returned to the return sludge 14. 14 ′ is returned to the upstream side from the methane fermentation tank 2. For this reason, the return sludges 14, 14 ′ solubilized by the mixing of the oxidant-containing waste water 11 are introduced into the methane fermentation tank 2, methane fermentation is promoted, and the biogas recovery amount is increased. Furthermore, the oxidant-containing waste water 11 that has been input is reduced as in the above-described configuration, but since the methane fermentation liquid contains a large amount of anaerobic components, the reduction effect is extremely high. Therefore, it is preferable to adopt this configuration when the amount of the oxidant-containing wastewater 11 to be treated is large.
Of course, you may make it supply the oxidizing agent containing waste_water | drain 11 to both the upstream and downstream from the methane fermentation tank 2. FIG.

  In addition to any of the above-described configurations, the oxidant-containing waste water 11 may be input to the waste water treatment facility 4. At least a part of the excess sludge from the settling tank 6 is returned to the aeration tank 7 as the return sludge 16, the mixing tank 7 is provided on the return line, and the oxidizing agent-containing waste water 11 is put into the mixing tank 7. Thereby, since the surplus sludge after activated sludge processing is oxidized and solubilized, the surplus sludge generation amount reduces. Acetic acid generated when the oxidant-containing wastewater 11 contains peracetic acid is decomposed in the aeration tank.

Hereinafter, a specific configuration example of the present embodiment will be described with reference to Embodiments 1 to 3 shown in FIGS. These examples are intended for waste disposal in beverage factories as an example.
As shown in FIG. 2, in a general beverage factory, concentrated waste water, general waste water, diluted waste water, waste, and oxidizing agent-containing waste water are generated. Here, concentrated wastewater is product blow, primary wash wastewater, general wastewater is retort wastewater, pastorizer wastewater, bottle washer wastewater, CIP wastewater, utility wastewater, etc., lean wastewater is blend cooling wastewater, extraction cooling wastewater, rinser wastewater Waste water for washing water, wastes are coffee cakes, teacups, etc., and oxidant-containing wastewater is wastewater containing peracetic acid or hydrogen peroxide.

After the concentrated wastewater is once stored in the storage tank 20, it is appropriately subjected to acid fermentation 21 and subjected to an anaerobic biological treatment in the EGSB reactor 222. The EGSB (Expanded Granuler Sludge Bed) reactor is a biological treatment device that uses anaerobic bacteria and is suitable for concentrated wastewater because it can handle high loads.
The general waste water is subjected to neutralization 23 and then oil-separated 24 and stored in a storage tank 25. In the storage tank 25, the processing liquid after processing in the EGSB reactor 22 is also received. The wastewater in the storage tank 25 is appropriately subjected to biological treatment such as activated sludge treatment 26 to decompose organic matter, BOD, etc., and then inorganic matter, phosphorus, etc. are removed by agglomeration 27 and precipitation 28, and the precipitate separation liquid is sent to the storage tank 29. . Then, after processing, such as biofilm filtration 30, is stored in the storage tank 31, and treated water is discharged.

  Since dilute wastewater has an extremely low organic matter concentration, it is once stored in the storage tank 20 and then fed to the rear side of the general wastewater treatment process, that is, the storage tank 29 in this embodiment, and biofilm filtration 30 together with the precipitate separation liquid of general wastewater. It is released after being given. Depending on the quality of the diluted waste water, the waste water is recovered in the recovery facility 33. When the organic matter concentration is high, the waste water is supplied to the upstream side of the general waste water, in this embodiment, the storage tank 25, and the treatment starts from the activated sludge treatment 26. Further, the recovered water may be reused for other purposes.

The waste is temporarily stored in the hopper 34 and then pulverized 35 as necessary, adjusted 36 in the mixing adjustment tank 1 (see FIG. 1), and mixed with the oxidant-containing waste water. The waste is solubilized by the oxidizing power of the oxidizing agent-containing wastewater, and the oxidizing agent is neutralized. The solubilized waste is subjected to methane fermentation 37 in the methane fermentation tank 2.
The methane fermentation liquor generated by the methane fermentation 37 is dehydrated by a dehydrator (solid-liquid separation device 3), and the separated water is sent to the storage tank 25 in the general wastewater treatment process, and subjected to activated sludge treatment 26 and the like. On the other hand, the dewatered sludge is dried 39 and then used as a compost raw material, or is treated by incineration, landfilling or the like.
The biogas generated in the methane fermentation 37 is collected in the gas tank 40 and used as a fuel for the gas turbine 41 after performing a desulfurization process or the like as necessary. In the present embodiment, the gas turbine 41 and the boiler 42 are provided side by side, and it is preferable to effectively use the steam generated in the boiler 42 for drying 39 of the dewatered sludge. The electricity generated by the gas turbine is preferably used in the field.

  Thus, according to the present Example 1, methane fermentation is promoted by effectively combining the treatment process of waste generated in a beverage factory with the treatment process of oxidant-containing wastewater generated in the factory. It is possible to increase the amount of gas recovered and neutralize the oxidant-containing wastewater. In addition, the amount of sludge generated from the system can be reduced.

FIG. 3 shows the overall configuration of the waste treatment system according to the second embodiment. Hereinafter, in the second embodiment and the third embodiment, detailed description of the same configurations as those in the first embodiment is omitted.
In the second embodiment, the oxidizer-containing wastewater is not mixed with the oxidizer-containing wastewater before the methane fermentation 37 in the waste treatment process, but the oxidizer-containing wastewater is mixed 36 ′ with the methane fermentation liquid after the methane fermentation 37. At least a part of the methane fermentation liquid after the mixing 36 ′ is returned to the upstream side of the methane fermentation 37 and again subjected to methane fermentation. As a result, the solubilized methane fermentation broth is returned to promote the methane fermentation 37, and since the methane fermentation broth contains a large amount of anaerobic components, the reducing effect of the oxidizing agent becomes extremely high.

FIG. 4 shows the overall configuration of the waste treatment system according to the third embodiment.
In the third embodiment, in addition to the configuration of the first embodiment or the second embodiment described above, the oxidant-containing wastewater is input to the activated sludge treatment 26 in the general wastewater treatment process. The activated sludge treatment 26 includes an aeration 26a, a precipitate 26b, and a mixture 26c. The general waste water is aerated 26a in the aeration tank 5 (see FIG. 1) and then precipitated in the precipitation tank 6 to at least part of the separated liquid. Is returned to the aeration 26 a through the mixing tank 7. At this time, oxidant-containing wastewater is supplied to the mixing tank 7.
By mixing the excess sludge and the oxidizing agent-containing wastewater in the mixing tank 7, the excess sludge after the activated sludge treatment is oxidized and solubilized, so that the amount of excess sludge generated is reduced.

It is the schematic which shows the main structures of the waste disposal system which concerns on the Example of this invention. 1 is an overall configuration diagram of a waste disposal system according to Embodiment 1 of the present invention. It is a whole block diagram of the waste disposal system which concerns on Example 2 of this invention. It is a whole block diagram of the waste disposal system which concerns on Example 3 of this invention. It is a flowchart which shows the manufacture and washing process in a beverage factory. It is the schematic which shows the main structures of the conventional waste disposal system.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Mixing adjustment tank 2 Methane fermentation tank 3 Solid-liquid separator 4 Waste water treatment equipment 5 Aeration tank 6 Precipitation tank 7 Mixing tank 9 Dehydrator 26 Activated sludge treatment 26a Aeration 26b Precipitation 26c Mixing 36, 36 'Mixing 37 Methane fermentation

Claims (10)

A methane fermentation process for treating the processing residue discharged from a beverage or food factory by methane fermentation, a solid-liquid separation process for solid-liquid separation of the methane fermentation liquid, and a processing residue for treating the sludge separated liquid with activated sludge A waste treatment method in which oxidant-containing wastewater discharged from a beverage or food factory is put into a treatment system and treated,
Before introducing the processing residue into the methane fermentation process, the processing residue and the oxidizing agent-containing wastewater are mixed in the mixing unit directly or together with the methane fermentation liquid before being input into the solid-liquid separation process. The mixed waste is put into a methane fermentation process. 2. The waste treatment method according to claim 1, wherein at least a part of the separated sludge that has been subjected to solid-liquid separation in the solid-liquid separation step is returned to a mixing unit that mixes the processing residue and oxidant-containing wastewater.   The activated sludge treatment has an aeration process and a precipitation process, and at least a part of excess sludge obtained in the precipitation process is returned to the aeration process, and at least a part of the returned excess sludge is subjected to the oxidation. The waste treatment method according to claim 1 or 2, wherein the agent-containing waste water is mixed.   The waste to be introduced into the methane fermentation or the methane fermentation liquid to be returned to the methane fermentation is solubilized by waste heat or waste alkali generated in the treatment system. The waste disposal method described.   The waste treatment method according to claim 1, wherein the peroxidation-based oxidant contains peracetic acid as a main component. A methane fermentation apparatus for processing a processing residue discharged from a beverage or food factory by methane fermentation, a solid-liquid separation apparatus for solid-liquid separation of the methane fermentation liquid, and a processing residue for processing activated sludge for the solid-liquid separated liquid A waste treatment system that incorporates an oxidant-containing wastewater treatment system that treats oxidant-containing wastewater discharged from beverages or food factories into the treatment system,
A mixing adjustment tank is provided in the input line for supplying the processing residue to the methane fermentation process, and the oxidizer-containing wastewater is input to the mixing adjustment tank directly or together with the methane fermentation liquid before being input to the solid-liquid separation process. A waste treatment system comprising a mixing line for mixing the processing residue and oxidant-containing wastewater in a regulating tank.   The waste treatment according to claim 6, wherein the mixing adjustment tank is provided with a return line for returning at least a part of the separated sludge solid-liquid separated by a solid-liquid separator to the upstream side of the methane fermentation tank. system. An activated sludge treatment facility for treating activated sludge with a separated liquid obtained by solid-liquid separation of the methane fermentation liquid after the methane fermentation,
The activated sludge treatment facility has an aeration tank and a settling tank, and includes a return line for returning at least a part of the excess sludge obtained in the settling tank to the aeration tank,
The waste treatment system according to claim 6 or 7, wherein means for mixing the oxidant-containing waste water with at least a part of the excess sludge is provided on the return line.   The waste heat or waste alkali generated in the waste treatment system according to claim 6 is supplied to the mixing adjustment tank to solubilize the waste or the methane fermentation liquid. Waste treatment system.   The waste treatment system according to claim 6, wherein the peroxidic oxidant is mainly composed of peracetic acid.

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