JP2006187681A - Treatment method and system for organic waste - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a treatment method and a system for organic waste where, in treatment for organic waste provided with a methane fermenter, soluble sludge can be removed without causing the reduction of pH, and further, the miniaturization of apparatus is made possible. <P>SOLUTION: In the treatment system for organic waste provided with: a regulation tank 11 for performing the acid production reaction or solubilization of organic waste; a methane fermenter 12 for performing the methane production reaction of the organic waste whose molecules are made low in the regulation tank; and activated sludge treatment equipment 13 for subjecting the treated liquid exhausted from the methane fermenter to activated sludge treatment, an iron electrolytic cell 17 into which the organic waste drawn out from the regulation tank 11 is introduced is provided, iron ions are eluted by electrolytic reaction in the electrolytic cell 17, the iron electrolytic solution containing the iron ions is returned to the regulation tank 11, and soluble sludge such as phosphorous and COD (Chemical Oxygen Demand) contained in the organic waste is subjected to flocculation separation by the iron ion. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an organic waste processing method and system for decomposing and removing pollutants such as organic matter, phosphorus and nitrogen contained in organic waste, and in particular, processing of organic waste provided with a methane fermentation facility. It relates to a method and a system.

For organic waste such as human waste, livestock manure, garbage, organic sludge, domestic wastewater, factory wastewater, SS (floating matter), nitrogen, phosphorus, BOD (biochemical oxygen demand), COD (chemical Contaminating substances that adversely affect the environment and the human body, such as oxygen demand, are contained, and various treatment methods have been developed and put to practical use in order to remove them.
Such organic waste treatment is appropriately combined with removal of SS by solid-liquid separation, organic matter utilizing the action of various microorganisms, decomposition and removal of nitrogen, removal of phosphorus and COD by agglomeration treatment, and the like. Is called.
In particular, in recent years, organic waste has not only been made harmless and discarded, but it has also been promoted to collect and reuse valuable materials in the waste as energy sources and recycled materials. One of them is methane fermentation, and the methane gas recovered by methane fermentation can be effectively used as fuel for driving equipment, power generation equipment and the like.

FIG. 10 shows a conventional general organic waste processing system equipped with a methane fermentation facility. As shown in the figure, this treatment system includes a methane treatment facility 100 that performs methane fermentation, and a water treatment facility 200 that performs detoxification treatment of treated water after methane fermentation.
In the treatment flow, first, pretreatment such as removal of fermentation incompatible materials is performed in the pretreatment facility 51, then an acid generation reaction is performed in the adjustment tank 52, and the organic waste reduced in molecular weight is further converted into a methane fermentation tank. It introduce | transduces into 53, performs methane production | generation reaction, decomposes and removes the organic substance in waste, and produces | generates methane gas. The generated methane gas is desulfurized in the desulfurization tower 62 and then sent to a power generation facility or the like. On the other hand, a part of the digested sludge generated in the methane fermentation tank 53 is returned to the adjustment tank 52 from the sludge return line 60, and the other part is introduced to the activated sludge treatment facility 54 via the sludge introduction line 61.

The treatment liquid from which BOD and nitrogen (including nitrogen compounds) have been removed by the action of aerobic bacteria in the activated sludge treatment facility 54 is guided to the solid-liquid separation facility 55 where it is separated into solid and liquid. The separated and separated liquid is supplied with a flocculant / pH adjuster 56 and introduced into a flocculent separation facility 57 to dissolve phosphorus (including phosphorus compounds such as phosphate ions) and COD contained in the liquid. Volatile contaminants are agglomerated and removed. Furthermore, after advanced treatments such as sterilization treatment and activated carbon adsorption were performed in the advanced treatment equipment 58, they were discharged. As the flocculant, aluminum sulfate (Al ₂ (SO ₄ ) ₃ ), ferric chloride (FeCl ₃ ), or the like has been used.
As another conventional example, as shown in FIG. 11, there is one provided with a solid-liquid separation facility 63 in the subsequent stage of the methane fermentation tank 53. The separated liquid is treated by the water treatment facility 200, and the separated sludge is returned to the adjustment tank 51 for circulation.

  However, these conventional treatment systems require activated sludge treatment and its solid-liquid separation equipment, and agglomeration separation equipment, respectively, in order to remove all of the organic matter, nitrogen and phosphorus contained in the organic waste. It was. Since the flocculant as described above has acidity, the addition of the flocculant lowers the pH of the water to be treated, resulting in activity inhibition in biological treatment. Therefore, in order to prevent this, it is necessary to perform biological treatment such as methane fermentation and activated sludge, and agglomeration treatment in separate steps. As a result, it is necessary to separately provide a solid-liquid separation device, and an increase in the size of the device has been a problem. In addition, pH adjustment must be performed after supplying the flocculant, and there is a problem in that the running cost is increased due to the use of an additive such as a pH adjuster, and the processing becomes complicated.

On the other hand, Patent Document 1 (Japanese Patent Application Laid-Open No. 2003-71454) discloses a technique for removing nitrogen and phosphorus in a water treatment apparatus that does not include a coagulation treatment facility. This water treatment apparatus has a configuration in which a first and second anaerobic filter bed tank, a contact aeration tank, a precipitation tank, and an electrolytic tank for phosphorus removal are circulated, and a nitrogen removal electrolytic tank is installed at the subsequent stage of the precipitation tank. In the electrolytic cell for removing phosphorus, metal ions are supplied by electrolysis, and the phosphorus compounds in the water to be treated are aggregated and removed by the metal ions.
An electrolytic cell for removing nitrogen and phosphorus is disclosed in, for example, Patent Document 2 (Japanese Patent Laid-Open No. 2003-230883). This electrolytic bath immerses a pair of electrodes in the water to be treated, elutes iron ions from the electrode constituting the anode, precipitates the phosphorus compound in the water to be treated as iron phosphate, and reduces the nitrogen compound at the cathode. It is what you do.

JP 2003-71454 A JP 2003-230883 A

  As described above, in the treatment of organic waste equipped with a methane fermentation tank, in addition to solid-liquid separation equipment after methane fermentation, solid-liquid separation equipment after biological treatment, agglomeration separation equipment, and a plurality of solid-liquid separation equipment Is necessary, and there is a problem that the facility becomes large. This is because the aggregation treatment and the biological treatment cannot be integrated when removing soluble pollutants such as phosphorus and COD. That is, when a flocculant is simply injected into a methane fermentation facility or an activated sludge treatment facility, the flocculant is generally acidic at about pH 2, so the pH of the liquid to be treated is extremely lowered, which impedes microbial activity. This is because the methane fermentation facility reduces the methane gas generation function, and the water treatment facility decreases the BOD and nitrogen removal function. In addition, when the flocculant is injected after the activated sludge treatment facility, the flocculant is generally acidic, so it is necessary to inject caustic soda as a pH adjuster after the flocculant treatment, which increases the running cost. there were.

Thus, water treatment facilities that do not use a flocculant as described in Patent Documents 1 and 2 have also been proposed, but this is not applied to methane fermentation, and is acidic in a treatment system equipped with a methane fermentation tank. Most of them used a flocculant.
Therefore, in view of the problems of the prior art described above, the present invention can remove soluble pollutants without causing a decrease in pH in the treatment of organic waste provided with a methane fermentation tank. An object of the present invention is to provide a method and system for treating organic waste that can be converted into an organic waste.

Therefore, in order to solve this problem, the present invention provides:
An adjustment step for performing an acid generation reaction or solubilization of organic waste, a methane fermentation step for performing a methane generation reaction of an organic waste reduced in molecular weight by the adjustment step, and a treatment liquid after the methane fermentation step An activated sludge treatment step for treating activated sludge, and a method for treating organic waste,
An iron electrolysis step for eluting iron ions by an electrolytic reaction is provided in the organic waste extracted from the adjustment step, and the iron electrolyte containing the eluted iron ions is returned to the adjustment step, It is characterized by aggregating soluble pollutants.

In the present invention, since an acidic flocculant is not used, agglomeration treatment of soluble pollutants such as phosphorus and COD can be performed without lowering the pH, and OH ⁻ is generated by an iron electrolysis reaction. The liquid moves to the alkali side, and a decrease in pH due to acid generation reaction or solubilization can be prevented. Therefore, it is possible to make the target liquid suitable for methane fermentation without supplying an additive such as an alkaline agent in methane fermentation. Moreover, since it is not necessary to provide a separate aggregating treatment facility as in the prior art, the apparatus can be miniaturized.
Iron ions eluted in the iron electrolysis step can also be used as a nutrient source for maintaining the activity of anaerobic microorganisms in methane fermentation.

In addition, an adjustment step for performing an acid generation reaction or solubilization of organic waste, a methane fermentation step for performing a methane generation reaction of organic waste having a low molecular weight by the adjustment step, and a treatment after the methane fermentation step An activated sludge treatment step for treating the liquid with activated sludge, and a method for treating organic waste comprising:
An iron electrolysis process for eluting iron ions by an electrolytic reaction is provided in the organic waste extracted from the methane fermentation process, and an iron electrolyte containing the eluted iron ions is returned to the methane fermentation process, and the iron It is characterized by aggregating soluble pollutants by ions.

In general, in the methane fermentation, hydrogen sulfide is generated along with the generation of methane gas. This hydrogen sulfide not only degrades the quality of methane gas but may also inhibit methane fermentation. According to the present invention, since iron ions eluted by the iron electrolysis are returned to the methane fermentation process, hardly soluble iron sulfide is generated, and generation of hydrogen sulfide can be minimized. Therefore, high-quality methane gas can be produced, and the recovered methane gas desulfurization equipment can be unnecessary or downsized.
Of course, also in the present invention, iron ions having an aggregating effect can be added without lowering the pH in the methane fermenter, and the subsequent water treatment facility can be simplified.

In addition, an adjustment step for performing an acid generation reaction or solubilization of organic waste, a methane fermentation step for performing a methane generation reaction of organic waste having a low molecular weight by the adjustment step, and a treatment after the methane fermentation step An activated sludge treatment step for treating the liquid with activated sludge, and a method for treating organic waste comprising:
An iron electrolysis step for eluting iron ions by an electrolytic reaction is provided in the treatment liquid extracted from the activated sludge treatment step, and the iron electrolyte containing the eluted iron ions is returned to the activated sludge treatment step, It is characterized by aggregating soluble pollutants by ions.

  According to the present invention, since most of the BOD contained in the organic waste is removed in the methane fermentation step, the activated sludge treatment step includes a treatment liquid having a high concentration of COD, phosphorus, and nitrogen. Supplied. Therefore, by providing an iron electrolysis step in this activated sludge treatment step, the concentration of phosphorus and COD can be reliably reduced and the removal efficiency of soluble pollutants can be improved.

  Furthermore, it is preferable to use at least a part of the iron electrolyte as dilution water in the adjustment step or the methane fermentation step. Since the iron electrolyte contains almost no organic matter, COD, nitrogen, and phosphorus, a part of this iron electrolyte is returned to the adjustment process or the methane fermentation process, so that it functions as dilution water. In addition, the iron ions remaining in the treated water bring about a further agglomeration effect, and can contribute to the suppression of the pH drop in the tank and the suppression of the generation of hydrogen sulfide.

  Furthermore, a first solid-liquid separation step is provided after the methane fermentation step, and the separated sludge separated by the first solid-liquid separation step is activated sludge treated in the activated sludge treatment step. And Thus, by providing the solid-liquid separation process after the methane fermentation process, the SS concentration in the activated sludge treatment process can be easily adjusted.

In addition, an adjustment process for performing an acid generation reaction or solubilization of organic waste, a methane fermentation process for performing a methane generation reaction of organic waste having a low molecular weight by the adjustment process, and a treatment liquid after the methane fermentation In a method for treating organic waste, comprising: a first solid-liquid separation step for solid-liquid separation; and an activated sludge treatment step for treating the separated liquid-liquid separation with activated sludge.
At least a part of the separated liquid-solid separated liquid is drawn out, and an iron electrolysis process is provided in the drawn-out separated liquid to elute iron ions by an electrolytic reaction, and the iron electrolyte containing the eluted iron ions is adjusted in the step And introduced into either the methane fermentation step or the activated sludge treatment step.
In this way, by performing iron electrolysis on a separated liquid with a low SS concentration after solid-liquid separation, it is possible to provide a highly safe process with low risk of clogging and foaming, stable operation, and high safety. It becomes.

In addition, an adjustment process for performing an acid generation reaction or solubilization of organic waste, a methane fermentation process for performing a methane generation reaction of organic waste having a low molecular weight by the adjustment process, and a treatment liquid after the methane fermentation A first solid-liquid separation step for solid-liquid separation, an activated sludge treatment step for treating the separated solid-liquid separation with activated sludge, and a second solid-liquid separation for solid-liquid separation of the treated liquid after activated sludge treatment And a method for treating organic waste comprising:
Iron from which at least a part of the separation liquid in the first solid-liquid separation step or the second solid-liquid separation step or process water is withdrawn, and iron ions are eluted by electrolytic reaction in the withdrawn separation liquid or process water. An electrolysis process is provided, and the iron electrolyte containing the eluted iron ions is introduced into the adjustment process, the methane fermentation process, or the activated sludge treatment process.

  As in the present invention, as a liquid supplied to the iron electrolysis step, a solid-liquid separation liquid after methane fermentation, a solid-liquid separation liquid after activated sludge treatment, or process water is used, so that the SS concentration and the nitrogen concentration are low. Thus, iron electrolysis can be carried out, the risk of blockage of the piping and foaming is low, stable operation is possible, and a highly safe treatment can be provided.

Furthermore, in the activated sludge treatment step, it is preferable to add liquid organic waste and perform the activated sludge treatment together with the treatment liquid. Thus, by supplying liquid organic waste to the activated sludge treatment step from the outside, it becomes possible to eliminate or reduce the supply of hydrogen donors in the activated sludge treatment.
Furthermore, the present invention is characterized in that an electrolytic denitrification step is provided in which the separated liquid separated by the second solid-liquid separation step provided after the activated sludge treatment step is denitrogenated by an electrolytic reaction. In general, the electrolytic denitrification treatment requires pH adjustment because the pH decreases due to the formation of hypochlorous acid-based HCl, but in the present invention, the pH is adjusted to shift to the alkali side by the iron electrolysis process. The amount of chemicals used for control can be reduced or eliminated.

Furthermore, the invention of the system includes an adjustment tank for performing an acid generation reaction or solubilization of organic waste, a methane fermentation tank for performing a methane generation reaction of organic waste having a low molecular weight in the adjustment tank, and the methane fermentation In an organic waste treatment system comprising activated sludge treatment equipment for treating activated sludge from a treatment liquid discharged from a tank,
An iron electrolytic cell for introducing the organic waste drawn out from the adjustment tank is provided, and the iron electrolytic cell has an anode containing iron and a conductive cathode disposed opposite to each other, and between the electrodes immersed in the organic waste. The iron ions are eluted by energizing the
The iron electrolyte containing the eluted iron ions is returned to the adjustment tank.

Moreover, the adjustment tank which performs the acid production reaction or solubilization of organic waste, the methane fermentation tank which performs the methane production reaction of the organic waste having a low molecular weight in the adjustment tank, and the methane fermentation tank are discharged. In an organic waste treatment system comprising an activated sludge treatment facility for treating the treatment liquid with activated sludge,
An iron electrolytic cell for introducing organic waste extracted from the methane fermentation tank is provided, and the iron electrolytic cell is an electrode in which an anode containing iron and a conductive cathode are arranged opposite to each other and immersed in the organic waste The iron ions are eluted by energizing them in between,
The iron electrolyte containing the eluted iron ions is returned to the methane fermentation tank.

Moreover, the adjustment tank which performs the acid production reaction or solubilization of organic waste, the methane fermentation tank which performs the methane production reaction of the organic waste having a low molecular weight in the adjustment tank, and the methane fermentation tank are discharged. In an organic waste treatment system comprising an activated sludge treatment facility for treating the treatment liquid with activated sludge,
An iron electrolyzer is provided for introducing a treatment liquid extracted from the activated sludge treatment facility, and the iron electrolyzer is provided with an anode containing iron and a conductive cathode facing each other, and an electric current is passed between the electrodes immersed in the treatment liquid. To elute iron ions,
The iron electrolyte containing the eluted iron ions is returned to the activated sludge treatment facility.

Furthermore, it is preferable to use at least a part of the iron electrolyte as dilution water for the adjustment tank or the methane fermentation tank.
Furthermore, it is preferable that a first solid-liquid separation facility is provided after the methane fermentation tank, and the separated liquid separated is subjected to activated sludge treatment using the activated sludge treatment facility.

In addition, an acid generation reaction or solubilization of the organic waste, a methane fermentation tank for performing a methane generation reaction of the organic waste having a low molecular weight in the adjustment tank, and a treatment liquid after the methane fermentation In an organic waste treatment system comprising: a first solid-liquid separation facility for solid-liquid separation; and an activated sludge treatment facility for treating activated sludge for the separated liquid-liquid separation,
An iron electrolytic cell for introducing at least a part of the separated liquid-solid separated liquid is provided, and the iron electrolytic cell has an anode containing iron and a conductive cathode disposed opposite to each other, and between the electrodes immersed in the separated liquid. The iron ions are eluted by energization,
The iron electrolyte containing the eluted iron ions is introduced into the adjustment tank, the methane fermentation tank, or the activated sludge treatment facility.

In addition, an acid generation reaction or solubilization of the organic waste, a methane fermentation tank for performing a methane generation reaction of the organic waste having a low molecular weight in the adjustment tank, and a treatment liquid after the methane fermentation Solid-liquid separation first solid-liquid separation equipment, activated sludge treatment equipment for treating activated sludge with the solid-liquid separated separation liquid, and second solid-liquid separation equipment for solid-liquid separation of the treatment liquid treated with activated sludge In an organic waste treatment system comprising:
An iron electrolytic cell for introducing at least a part of the separation liquid of the first solid-liquid separation facility or the second solid-liquid separation facility or process water is provided, and the iron electrolytic cell is electrically conductive with an anode containing iron. The cathode is arranged oppositely, and iron ions are eluted by energizing between the electrodes immersed in the separation liquid or process water,
The iron electrolyte containing the eluted iron ions is introduced into the adjustment tank, the methane fermentation tank, or the activated sludge treatment facility.

Furthermore, it is preferable to introduce liquid organic waste into the activated sludge treatment facility and perform the activated sludge treatment together with the treatment liquid.
Furthermore, the present invention is characterized in that an electrolytic denitrification apparatus is provided that denitrifies the separated liquid from the second solid-liquid separation equipment provided at the subsequent stage of the activated sludge treatment equipment by an electrolytic reaction.
The first solid-liquid separation facility or the second solid-liquid separation facility preferably includes a membrane separation means.

  Further, the present invention is characterized in that a composting facility using a separated sludge separated as a raw material by the first solid-liquid separation facility or the second solid-liquid separation facility is provided. In the compost produced by this composting facility, Fe ions remaining in the separated sludge as a raw material are present, and therefore, high-quality compost containing Fe ions, which are essential elements of compost, can be obtained.

As described above, according to the present invention, iron ions as a coagulant can be added while transferring the liquid to be treated to the alkali side by iron electrolysis, and coagulation treatment can be performed without lowering the pH of the methane fermentation tank and activated sludge equipment. Therefore, it is possible to achieve a single-stage solid-liquid separation facility in the water treatment facility, thereby saving space.
Moreover, since the iron electrolyte which moved to the alkali side is used, fermentation inhibition due to pH reduction in the methane fermentation tank can be prevented.
Furthermore, the reaction of sulfide ions and added iron ions in methane fermentation can suppress the production of hydrogen sulfide, which is a harmful component in the recovered gas.
Furthermore, as an anaerobic microorganism nutrient source in methane fermentation, iron ions can be supplemented and the activity of microorganisms can be maintained.

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.
In this embodiment, for example, organic waste such as human waste, livestock manure, garbage, organic sludge, domestic wastewater, and factory wastewater is treated.
1 to 9 are diagrams showing organic waste processing systems according to Examples 1 to 9, respectively.

As shown in FIG. 1, the organic waste treatment system according to the first embodiment is roughly composed of a combination of a methane fermentation facility 100 and a water treatment facility 200.
The methane fermentation facility 100 includes a pretreatment facility 10 that makes organic waste suitable for methane fermentation, a conditioning tank 11 that performs an acid generation reaction and / or solubilization on the pretreated organic waste, A methane fermentation tank 12 for performing a methane generation reaction on the adjusted organic waste, and an iron electrolytic tank 17 for eluting iron ions by an electrolytic reaction using at least a part of the organic waste in the adjustment tank 11; ,including. A part of the treatment liquid (digested sludge) discharged from the methane fermentation tank 12 is returned to the adjustment tank 11 as a return sludge 21 and circulated.
The water treatment facility 200 includes an activated sludge treatment facility 13 that performs activated sludge treatment on the treatment liquid 22 discharged from the methane fermentation tank 12, and a second solid that separates the treatment liquid generated in the activated sludge treatment. It includes a liquid separation facility 14, an advanced treatment facility 15 that performs advanced treatment on the separated liquid-solid separation liquid, and a sludge treatment facility 16 that performs sludge treatment on the separated sludge after solid-liquid separation.

The pretreatment facility 10 includes various sorters for removing methane fermentation unsuitable materials or a crusher for homogenizing organic waste in a solid-liquid mixed state.
The said adjustment tank 11 performs the acid production | generation reaction and / or solubilization which are the pre-stages of a methane production | generation reaction to organic waste, Furthermore, water quantity adjustment of organic waste, density | concentration adjustment, mixing of waste, etc. are also carried out. Do.
The said methane fermentation tank 12 can use the well-known apparatus which reduces and decomposes organic waste into methane and a carbon dioxide by the effect | action of anaerobic bacteria, The intermediate temperature fermentation which made the inside of a tank 30-30 degreeC, 50-55 Any of high-temperature fermentation at ℃. In order to maintain the SS concentration in the methane fermentation tank 12 at a value suitable for methane fermentation, the return sludge 21 drawn from the methane fermentation tank 12 is returned to the adjustment tank 11 and circulated.
The methane gas 20 generated in the methane fermentation tank 12 is effectively used after removing hydrogen sulfide contained in the gas by a subsequent desulfurization facility (not shown). Examples of the desulfurization equipment include a desulfurization tower filled with an iron-based desulfurization agent. Examples of the methane gas usage destination include a drive facility using methane gas as fuel for a gas engine and boiler, a power generation facility, and the like.
The adjusting tank 11 and the methane fermentation tank 12 may be integrated. That is, these reactions can be performed sequentially in the same tank with a time difference.

  The activated sludge treatment facility 13 introduces the treatment liquid (digested sludge) 22 generated in the methane fermentation tank 12 and removes BOD, nitrogen, etc. contained in the treatment liquid by the action of microorganisms. For example, facilities combining an aeration tank and a precipitation tank, facilities equipped with a biofilm, facilities equipped with a nitrification tank, a denitrification tank and an aeration tank, and the like for nitrification and denitrification are included. The treatment liquid introduced into the activated sludge treatment facility 13 is adjusted in advance with pH, added with nutrients, and supplied with a hydrogen donor such as methanol, acetic acid, or BOD as necessary to obtain an appropriate BOD load. .

The second solid-liquid separation facility 14 is a facility for solid-liquid separation of the treatment liquid discharged from the activated sludge treatment facility 13, for example, a membrane separation method, a gravity sedimentation method, a flotation separation method, a mechanical separation method, Any combination of these may be mentioned, but membrane separation is particularly preferred. In this case, a separation membrane such as an immersion membrane, a tubular membrane, and a rotating flat membrane can be used, and an immersion type membrane module is particularly preferable. An MF membrane (microfiltration membrane), a UF membrane (ultrafiltration membrane) or the like can be used for the membrane module.
The advanced treatment facility 15 is a facility that further performs a treatment that meets the discharge standard on the separated liquid separated by the second solid-liquid separation facility 14, such as activated carbon adsorption, sand filtration, ozone oxidation, It is a facility that performs advanced processing such as disinfection.
The sludge treatment facility 16 is a facility that performs a composting treatment, a landfill treatment, or the like on the solid content separated from the treated water by the second solid-liquid separation facility 14.

Further, as a characteristic configuration of the present embodiment, an iron electrolysis tank 17 is attached to the adjustment tank 11. In the iron electrolysis tank 17, a pair of electrodes composed of an anode and a cathode are spaced apart from each other in the tank. A plurality of the electrodes may be provided. A power source for applying a current is connected to each of the anode and the cathode. These electrodes are made of a conductive material, and at least the anode side is a material containing iron or an iron-containing alloy.
At least a part of the organic waste in the adjustment tank 11 is extracted and introduced into the iron electrolysis tank 17. A current is applied between the electrodes immersed in the organic waste, and an electrolytic reaction occurs according to the following reaction formula.
(Anode) Fe → Fe ²⁺ + 2e ⁻
(Cathode) H ₂ O + 2e ⁻ → 2OH ⁻ + 2H ₂
By this reaction, the iron of the anode is eluted in the liquid as ferric ions (Fe ²⁺ ), and further oxidized to ferric ions (Fe ³⁺ ) by the action of dissolved oxygen in the liquid.

Most of the phosphorus contained in the organic waste introduced into the iron electrolyzer 17 is present as phosphate ions. Fe ³⁺ produced by the electrolysis reacts with the phosphate ions to produce iron phosphate according to the following reaction formula. Of course, Fe ²⁺ also contributes to the aggregation reaction of phosphate ions.
Fe ³⁺ + PO ₄ ³⁻ → FePO ₄
In the agglutination reaction using ferric ions, the required iron ions are Fe / P = 1.5 / 1 in molar equivalents, so that the potential difference is such that iron ions of 1.5 or more are supplied. It is preferable to give to an electrode. In addition, it is preferable that the iron electrolytic cell 17 maintain electrolytic efficiency by applying a reverse voltage every predetermined period in order to remove the substances adhering to the electrodes, or by stopping the treatment and washing.
The organic waste containing the produced iron phosphate and the remaining iron ions (Fe ³⁺ , Fe ²⁺ ) is returned to the adjustment tank 11.

  A processing flow in the first embodiment will be described. First, the organic waste is pretreated in the pretreatment facility 10 and then introduced into the adjustment tank 11 where acid generation reaction and / or solubilization is performed. Part or all of the organic waste in the adjustment tank 11 is introduced into the iron electrolysis tank 17, and phosphorus in the organic waste is removed by iron ions eluted in the iron electrolysis tank 17. By returning the iron electrolyte containing iron ions to the adjustment tank 11, aggregation of soluble pollutants such as phosphorus and COD in the adjustment tank 11 and the subsequent methane fermentation tank 12 and activated sludge treatment equipment 13. Progresses.

In the adjustment tank 11, a phenomenon occurs in which the pH is lowered in the process of hydrolyzing the organic waste due to the acid generation reaction and / or solubilization to lower the molecular weight. If the pH in the adjustment tank 11 is too low, an acid waste phenomenon may occur and reaction activity may be hindered. However, in this embodiment, OH ⁻ is generated from the cathode by the electrolytic reaction in the adjustment tank 11 and the liquid moves to the alkali side, so that the iron ion having an aggregating effect without lowering the pH in the adjustment tank 11. Can be supplied. Therefore, it can be set as the property suitable for methane fermentation, without supplying additives, such as an alkaline agent. Here, the agglomerates aggregated by the generated iron ions are separated and collected by the solid-liquid separation device 14 at the subsequent stage.

As in this embodiment, by attaching the iron electrolysis tank 17 to the adjustment tank 11, iron ions having an aggregating effect can be supplied without lowering the pH in the methane fermentation tank 17, and the subsequent water treatment Equipment (solid-liquid separation equipment) can be simplified.
The sludge treatment facility 16 is preferably a composting facility. In the compost produced by this composting facility, iron ions remaining in the separated sludge as a raw material are present, so that high quality compost containing Fe ions, which are essential elements of compost, can be obtained.

FIG. 2 shows a schematic configuration of an organic waste processing system according to the second embodiment. Hereinafter, in the second to ninth embodiments, detailed description of the same configurations as those of the first embodiment is omitted.
The processing system in the present Example 2 consists of the combination of the methane fermentation equipment 100 and the water treatment equipment 200, and the said methane fermentation equipment 100 is the pre-processing equipment 10 which pre-processes organic waste, and the pre-processed organic property. An adjustment tank 11 that performs acid generation reaction and / or solubilization on waste, a methane fermentation tank 12 that performs methane generation reaction on the adjusted organic waste, and organic waste in the methane fermentation tank 12 And an iron electrolytic cell 17 for eluting iron ions by an electrolytic reaction using at least a part of the product.
The water treatment facility 200 includes an activated sludge treatment facility 13 that performs activated sludge treatment on the treatment liquid generated in the methane fermentation tank 12, and a second solid that separates the treatment liquid generated in the activated sludge treatment. A liquid separation facility 14, an advanced treatment facility 15 that performs advanced treatment on the separated liquid, and a sludge treatment facility 16 that performs sludge treatment on the separated sludge are included.

  A processing flow in the second embodiment will be described. The organic waste is pretreated in the pretreatment facility 10 and then introduced into the adjustment tank 11 where acid generation reaction and / or solubilization is performed. The organic waste adjusted in the adjustment tank 11 is introduced into the methane fermentation tank 12, and a methane production reaction is performed. On the other hand, a part or all of the organic waste in the methane fermentation tank 12 is extracted and introduced into the iron electrolysis tank 17, and phosphorus ions in the organic waste are extracted by the iron ions eluted from the iron electrolysis tank 17. In the methane fermentation tank 12 and subsequent activated sludge treatment equipment 13, the soluble pollutant such as COD is agglomerated and the iron electrolyte containing the iron ions is returned to the methane fermentation tank 12. Aggregation reaction proceeds.

Further, in the methane fermentation tank 12, together with the generation of methane gas, hydrogen sulfide from the sulfur component of the organic waste in (H 2 _S) is produced. This hydrogen sulfide not only causes deterioration in the quality of methane gas, but may also inhibit methane fermentation. However, according to the present embodiment, since iron ions eluted in the iron electrolyzer 17 are supplied into the methane fermentation tank 12, hardly soluble iron sulfide (FeS) is generated, and generation of hydrogen sulfide is minimized. It becomes possible to suppress.
Thus, according to the present Example 2, by attaching the iron electrolysis tank 17 to the methane fermentation tank 12, iron ions having an aggregating effect can be supplied without lowering the pH in the methane fermentation tank 12. In addition, it is possible to simplify the downstream water treatment facility and to suppress the generation of hydrogen sulfide in the methane fermentation tank 12.
If the generation of hydrogen sulfide in the methane fermentation tank 12 can be suppressed, high-quality methane gas can be produced, and desulfurization equipment for recovered methane gas can be eliminated or reduced in scale. Moreover, when the desulfurization tower filled with the desulfurization agent is provided, the replacement frequency of the desulfurization agent can be reduced, and the running cost can be reduced.

FIG. 3 shows a schematic configuration of an organic waste processing system according to the third embodiment.
The treatment system in the present Example 3 consists of a combination of a methane fermentation facility 100 and a water treatment facility 200, and the methane fermentation facility 100 includes a pretreatment facility 10 that pretreats organic waste, and a pretreated organic material. The adjustment tank 11 which performs an acid production | generation reaction and / or solubilization with respect to a waste, and the methane fermentation tank 12 which performs a methane production | generation reaction with respect to the adjusted organic waste are included.
The water treatment facility 200 includes an activated sludge treatment facility 13 that performs activated sludge treatment on the treatment liquid generated in the methane fermentation tank 12, and a second solid that separates the treatment liquid generated in the activated sludge treatment. Electrolytic reaction using at least part of the treatment liquid in the liquid separation equipment 14, the advanced treatment equipment 15 that performs advanced treatment on the separated liquid, the sludge treatment equipment 16 that performs sludge treatment on the separated sludge, and the activated sludge treatment equipment 13. And an iron electrolytic cell 17 for eluting iron ions.
Furthermore, at least a part of the separated liquid from the second solid-liquid separation facility 14 is branched and introduced as the dilution water 23 of the adjustment tank 11 or the methane fermentation tank 12.

  A processing flow in the third embodiment will be described. The organic waste is pretreated in the pretreatment facility 10 and then introduced into the adjustment tank 11 where acid generation reaction and / or solubilization is performed. The organic waste adjusted in the adjustment tank 11 is introduced into the methane fermentation tank 12, and a methane production reaction is performed. A part of the treatment liquid generated in the methane fermentation tank 12 is returned to the adjustment tank 11 as a return sludge 21, and the other treatment liquid 22 is introduced into the activated sludge treatment facility 13. In the activated sludge treatment facility 13, activated sludge treatment is performed, and at least a part of the treatment liquid is drawn out and introduced into the iron electrolysis tank 17, and iron ions are eluted by an electrolytic reaction in the iron electrolysis tank 17. To do. The iron electrolyte containing the iron ions is returned to the activated sludge treatment facility 13 so that soluble pollutants such as phosphorus and COD in the treatment liquid are aggregated and separated. The agglomerates are separated from the separated liquid by the subsequent solid-liquid separation equipment 14 and processed by the sludge treatment equipment 16.

Since most of the BOD contained in the organic waste is removed in the methane fermentation tank 12, the activated sludge treatment facility 13 is supplied with a treatment liquid having a high concentration of COD, phosphorus, and nitrogen. . Therefore, by attaching the iron electrolyzer 17 to the activated sludge treatment facility 13, the concentration of phosphorus and COD can be surely reduced, and the removal efficiency of soluble pollutants can be improved.
In addition, since most of the organic matter, COD, nitrogen, and phosphorus is removed from the separated liquid separated by the second solid-liquid separation facility 14, a part of the separated liquid is used as the dilution water 23, and the adjustment tank 11. And / or by returning to the methane fermentation tank 12, in addition to the function as dilution water, iron ions remaining in the separation liquid bring about a further agglomeration effect, suppression of pH drop in the tank, and hydrogen sulfide It can contribute to the generation suppression.

FIG. 4 shows a schematic configuration of an organic waste processing system according to the fourth embodiment.
The treatment system according to the fourth embodiment is composed of a combination of a methane fermentation facility 100 and a water treatment facility 200. The methane fermentation facility 100 includes a pretreatment facility 10 that pretreats organic waste and a pretreated organic material. The adjustment tank 11 that performs acid generation reaction and / or solubilization on the organic waste, the methane fermentation tank 12 that performs methane generation reaction on the adjusted organic waste, and the treatment liquid generated by methane fermentation are solidified. The first solid-liquid separation facility 18 for liquid separation, the sludge treatment facility 16 for subjecting the separated sludge separated to solid-liquid separation to composting, etc., and electrolysis using at least a part of the organic waste in the adjustment tank 11 And an iron electrolytic cell 17 for eluting iron ions. In addition, a part of the separation liquid 25 separated by the first solid-liquid separation facility 18 is returned to the adjustment tank 11 (or the methane fermentation tank 12), and another part of the separation liquid 25 is subjected to activated sludge treatment. It is designed to be introduced into the facility 13. Further, a part of the separated sludge from the first solid-liquid separation facility 18 is returned to the adjustment tank 11 as a return sludge 24.
The water treatment facility 200 performs solid-liquid separation of the activated sludge treatment facility 13 that performs the activated sludge treatment on the separated liquid 25 from the first solid-liquid separation facility 18 and the treatment liquid generated in the activated sludge treatment. 2 and the advanced treatment equipment 15 for subjecting the separated liquid to advanced treatment, and the separated sludge 26 is introduced into the sludge treatment equipment 16.

A processing flow in the fourth embodiment will be described. The organic waste is pretreated in the pretreatment facility 10 and then introduced into the adjustment tank 11 where acid generation reaction and / or solubilization is performed. At the same time, at least a part of the organic waste in the adjustment tank 11 is introduced into the iron electrolysis tank 17, and iron ions are eluted by an electrolytic reaction in the iron electrolysis tank 17, and an iron electrolyte containing the iron ions. Is introduced into the adjusting tank 11 and the soluble pollutant contained in the organic waste is agglomerated and separated.
Further, the organic waste discharged from the adjustment tank 11 is introduced into the methane fermentation tank 12 to perform a methane production reaction, and the treatment liquid generated here is solid-liquid separated by the first solid-liquid separation facility 18. After that, the sludge treatment facility 16 processes the separated sludge.
On the other hand, the solid-liquid separated separation liquid 25 is subjected to activated sludge treatment in the activated sludge treatment facility 13 and then solid-liquid separated in a second solid-liquid separation facility. The separated sludge 26 is introduced into the sludge treatment facility.

  As in the present embodiment, the SS concentration in the activated sludge treatment facility 13 can be easily adjusted by installing the first solid-liquid separation facility 18 in the subsequent stage of the methane fermentation tank 12. Further, by using the separation liquid 25 from which the phosphorus and SS discharged from the first solid-liquid separation facility 18 are partially removed as dilution water for the adjustment tank 11 (or the methane fermentation tank 12), a methane fermentation facility 100 loads can be reduced.

FIG. 5 shows a schematic configuration of an organic waste processing system according to the fifth embodiment.
The treatment system in Example 5 is composed of a combination of a methane fermentation facility 100 and a water treatment facility 200. The methane fermentation facility 100 includes a pretreatment facility 10 that pretreats organic waste and a pretreated organic material. The adjustment tank 11 that performs acid generation reaction and / or solubilization on the organic waste, the methane fermentation tank 12 that performs methane generation reaction on the adjusted organic waste, and the treatment liquid generated by methane fermentation are solidified. The first solid-liquid separation facility 18 for liquid separation, the sludge treatment facility 16 for subjecting the separated sludge to composting and the like, and an electrolytic reaction using part or all of the separation liquid 25 are performed to elute iron ions. And an iron electrolytic cell 17. A part of the separation liquid 25 is returned to the adjustment tank 11 (or the methane fermentation tank 12), and the other part of the separation liquid 25 is introduced into the activated sludge treatment facility 13.
The water treatment facility 200 performs solid-liquid separation of the activated sludge treatment facility 13 that performs the activated sludge treatment on the separated liquid 25 from the first solid-liquid separation facility 18 and the treatment liquid generated in the activated sludge treatment. 2 solid-liquid separation equipment 14 and an advanced treatment equipment 15 for subjecting the separated liquid to advanced treatment.

A processing flow in the fifth embodiment will be described. The organic waste is pretreated in the pretreatment facility 10 and then introduced into the adjustment tank 11 where acid generation reaction and / or solubilization is performed. It is introduced and a methanogenesis reaction is performed. The treatment liquid generated in the methane fermentation tank 12 is solid-liquid separated by the first solid-liquid separation facility 18.
Part or all of the separated liquid 25 separated into solid and liquid is introduced into the iron electrolysis tank 17, and iron ions are eluted in the iron electrolysis tank 17 by an electrolytic reaction. The iron electrolyte containing the iron ions is introduced into the adjustment tank 11 (or methane fermentation tank 12) or the activated sludge treatment facility 13. Dissolved contaminants in the liquid are agglomerated and separated by the iron electrolyte, and the agglomerates are separated and removed from the treatment liquid by the first and second solid-liquid separation facilities 18 and 14.

  In the present embodiment, a first solid-liquid separation facility 18 is installed at a subsequent stage of the methane fermentation tank 12, and a separation liquid from the first solid-liquid separation facility 18 is further introduced into the iron electrolyzer 17. After the ions are eluted, they are introduced into the adjustment tank 11 (or methane fermentation tank 12) or the activated sludge treatment facility 13. In this way, by performing iron electrolysis on the separation liquid with a low SS concentration after solid-liquid separation, it is possible to provide a highly safe system with low risk of clogging and foaming, stable operation, and high safety. It becomes.

FIG. 6 shows a schematic configuration of an organic waste processing system according to the sixth embodiment.
The treatment system in Example 6 is composed of a combination of a methane fermentation facility 100 and a water treatment facility 200. The methane fermentation facility 100 includes a pretreatment facility 10 that pretreats organic waste and a pretreated organic material. The adjustment tank 11 that performs acid generation reaction and / or solubilization on the organic waste, the methane fermentation tank 12 that performs methane generation reaction on the adjusted organic waste, and the treatment liquid generated by methane fermentation are solidified. A first solid-liquid separation facility 18 for liquid separation and a sludge treatment facility 16 for subjecting the separated sludge to composting and the like are included. Further, the separation liquid 25 of the solid-liquid separation facility 18 is introduced into the activated sludge treatment facility 13, and a part of the separated sludge is returned to the adjustment tank 11 as a return sludge 24.

  The water treatment facility 200 performs solid-liquid separation of the activated sludge treatment facility 13 that performs the activated sludge treatment on the separated liquid 25 from the first solid-liquid separation facility 18 and the treatment liquid generated in the activated sludge treatment. The solid-liquid separation equipment 14, the advanced treatment equipment 15 for subjecting the separated solid-liquid separation to advanced treatment, and at least a part of the treatment liquid in the activated sludge treatment equipment 13 are subjected to an electrolytic reaction to produce iron ions. And an iron electrolytic cell 17 that elutes. In addition, at least a part of the iron electrolyte containing iron ions eluted in the iron electrolysis tank 17 is returned to the adjustment tank 11 and / or the methane fermentation tank 12 as dilution water 27. Further, the separated sludge 26 is introduced into the sludge treatment facility 16.

A processing flow in the sixth embodiment will be described. The organic waste is pretreated in the pretreatment facility 10 and then introduced into the adjustment tank 11 where acid generation reaction and / or solubilization is performed. It is introduced and a methanogenesis reaction is performed. The treatment liquid generated in the methane fermentation tank 12 is solid-liquid separated by the first solid-liquid separation facility 18. The separated liquid 25 separated into the solid and liquid is introduced into the activated sludge treatment facility 13.
In the activated sludge treatment facility 13, activated sludge treatment of the separation liquid 25 is performed, and at least a part thereof is drawn out and introduced into the iron electrolysis tank 17, and is eluted by an electrolytic reaction in the iron electrolysis tank 17. Phosphorus and COD in the organic waste are agglomerated and removed by the iron ions, and the iron electrolyte containing the iron ions is returned to the activated sludge treatment facility 13 to agglomerate and separate phosphorus and COD. Furthermore, at least a part of the iron electrolyte discharged from the iron electrolyzer 17 is returned to the adjustment tank 11 and / or the methane fermentation tank 12 as diluted water 27.

  According to the present embodiment, since the first solid-liquid separation facility 18 is installed at the subsequent stage of the methane fermentation tank 12, the SS concentration in the activated sludge treatment facility 13 can be easily managed, and at the same time, the activated sludge treatment facility. 13 is introduced into the adjustment tank 11 and / or the methane fermentation tank 12 because at least a part of the iron electrolyte discharged from the iron electrolytic tank 17 attached to 13 is high, and the aggregation efficiency of phosphorus, COD, etc. is high and reliably These soluble pollutants can be removed.

FIG. 7 shows a schematic configuration of an organic waste processing system according to the seventh embodiment.
The treatment system according to the seventh embodiment includes a combination of a methane fermentation facility 100 and a water treatment facility 200. The methane fermentation facility 100 includes a pretreatment facility 10 that pretreats organic waste, and a pretreated organic material. The adjustment tank 11 that performs acid generation reaction and / or solubilization on the organic waste, the methane fermentation tank 12 that performs methane generation reaction on the adjusted organic waste, and the treatment liquid generated by methane fermentation are solidified. A first solid-liquid separation facility 18 for liquid separation and a sludge treatment facility 16 for subjecting the separated sludge to composting and the like are included. In addition, a part of the separated sludge separated by the first solid-liquid separation facility 18 is returned to the adjustment tank 11 (or the methane fermentation tank 12) as a return sludge 24, and the separated liquid 25 is activated sludge treatment facility 13. To be introduced to.
The water treatment facility 200 includes an activated sludge treatment facility 13 that performs activated sludge treatment on the separation liquid 25, and a second solid-liquid separation facility 14 that solid-liquid separates the treatment liquid generated in the activated sludge treatment. In addition, at least a part of the separated liquid 28 separated and solid-liquid separated by the solid-liquid separation facilities 18, 14 is supplied to the iron electrolyzer 17.

  A processing flow in the seventh embodiment will be described. The organic waste is pretreated in the pretreatment facility 10 and then introduced into the adjustment tank 11 where acid generation reaction and / or solubilization is performed. After being introduced, a methane production reaction is performed, and the treatment liquid generated here is subjected to solid-liquid separation by the first solid-liquid separation facility 18 and then the separated sludge is treated by the sludge treatment facility 16. On the other hand, the separated liquid 25 is subjected to activated sludge treatment in the activated sludge treatment facility 13 and then separated into solid and liquid in the second solid-liquid separation facility 14, and the separated solution is introduced into the advanced treatment facility 15. The Further, at least a part of the separated liquid 28 separated by the solid-liquid separation equipment 18, 14 is branched and introduced into the iron electrolysis tank 17. Here, the iron electrolyte containing iron ions eluted by the electrolytic reaction is introduced into the adjustment tank 11 and / or the methane fermentation tank 12, and phosphorus and COD in the organic waste are agglomerated and removed.

By using a solid-liquid separation liquid after methane fermentation or a solid-liquid separation liquid in a water treatment facility as a supply liquid to the iron electrolysis tank 17 as in this embodiment, iron electrolysis is performed in a low SS concentration and nitrogen concentration. Therefore, it is possible to provide a highly safe system with low risk of blockage and foaming, stable operation, and high safety.
Moreover, the process water 29 can also be utilized for the supply liquid to the iron electrolyzer 17. Here, the process water refers to water that is made reusable in the system by improving the quality of the wastewater treated water. As described above, by using the process water 29 containing almost no SS and nitrogen, it is possible to supply iron ions stably. In the methane fermentation treatment, a system that uses process water as dilution water is conventionally used in many cases. However, it is most preferable to use this dilution water as a feed solution for the iron electrolyzer 17, thereby reducing running costs. Reduction is possible.

FIG. 8 shows a schematic configuration of an organic waste processing system according to the eighth embodiment.
The treatment system according to the eighth embodiment can be applied to the configurations of the above-described first to seventh embodiments. The characteristic configuration of the water treatment facility 200 is the separation at the first solid-liquid separation facility 18. The separated liquid 25 is introduced into the activated sludge treatment facility 13 together with other liquid organic waste, and activated sludge treatment is performed. The liquid organic waste can be, for example, organic waste such as human waste, livestock manure, organic sludge, domestic wastewater, and factory wastewater. The liquid organic waste is temporarily stored in the receiving storage facility 30 and then mixed with the separation liquid 25 in consideration of the SS concentration and the like, and processed in the activated sludge processing facility 13.

  Usually, in order to treat activated sludge with a treatment liquid generated by methane fermentation, a hydrogen donor such as methanol is often supplied before the activated sludge treatment. This is because most of the organic substances are removed by methane fermentation. However, according to the present embodiment, by supplying other liquid organic waste to the activated sludge treatment facility 13, the supply of the hydrogen donor can be unnecessary or reduced. In addition, the liquid organic waste processed together in the present embodiment preferably has a low nitrogen content and a high carbon content.

FIG. 9 shows a schematic configuration of an organic waste processing system according to the ninth embodiment.
The processing system according to the ninth embodiment can be applied to the configurations of the first to eighth embodiments. In the present embodiment, in the water treatment facility 200, the separated liquid separated by the second solid-liquid separation facility 14 is introduced into the electrolytic denitrification apparatus 31. In the electrolytic denitrification apparatus 31, electrolysis is performed to generate a hypochlorous acid-based strong oxidizing substance by electrolyzing the separated liquid, and to remove nitrogen contained in the separated liquid by the oxidizing action of the strong oxidizing substance. A tank is provided to stabilize the nitrogen removal function.
In the electrolytic denitrogenation treatment, the pH is lowered due to the generation of hypochlorous acid-based HCl, and thus pH adjustment is required. In this embodiment, since the iron electrolytic cell 17 is provided, the pH can be shifted to the alkali side, and the amount of chemicals used for pH adjustment can be suppressed or eliminated.

It is a schematic block diagram which shows the system which concerns on Example 1 of this invention, Comprising: It is the figure which attached the iron electrolyzer to the adjustment tank. It is a schematic block diagram which shows the system which concerns on Example 2 of this invention, Comprising: It is the figure which attached the iron electrolyzer to the methane fermentation tank. It is a schematic block diagram which shows the system which concerns on Example 3 of this invention, Comprising: It is the figure which attached the iron electrolyzer to the activated sludge processing equipment. It is a schematic block diagram which shows the system which concerns on Example 4 of this invention, Comprising: It is the figure which provided the solid-liquid separation equipment in the methane fermentation equipment side. It is a schematic block diagram which shows the system which concerns on Example 5 of this invention, Comprising: It is the figure which provided the solid-liquid separation equipment in the methane fermentation equipment side, and attached the iron electrolytic cell to the separation liquid line. It is a schematic block diagram which shows the system which concerns on Example 6 of this invention, Comprising: It is the figure which provided the line which introduces an iron electrolyte into an adjustment tank. It is a schematic block diagram which shows the system which concerns on Example 7 of this invention, Comprising: It is the figure which provided the line which introduces the solid-liquid separation liquid after methane fermentation or water treatment into an iron electrolyzer. It is a schematic block diagram which shows the system which concerns on Example 8 of this invention, Comprising: It is the figure which injected | thrown-in liquid organic waste to the activated sludge processing equipment. It is a schematic block diagram which shows the system which concerns on Example 9 of this invention, Comprising: It is the figure which provided the electrolytic denitrification apparatus in the water treatment facility. It is a figure which shows the processing system of the conventional organic waste. It is a figure which shows the processing system of the conventional organic waste.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Pretreatment equipment 11 Adjustment tank 12 Methane fermentation tank 13 Activated sludge treatment equipment 14 Second solid-liquid separation equipment 15 Advanced treatment equipment 16 Sludge treatment equipment 17 Iron electrolysis tank 18 First solid-liquid separation equipment 20 Methane gas 21, 24 Return Sludge 22 Treatment liquid 23 Partially diluted water 25, 28 Separation liquid 26 Separation sludge 27 Iron electrolyte 29 Process water 31 Electrolytic denitrification equipment 100 Methane fermentation equipment 200 Water treatment equipment

Claims (20)

An adjustment step for performing an acid generation reaction or solubilization of organic waste, a methane fermentation step for performing a methane generation reaction of an organic waste reduced in molecular weight by the adjustment step, and a treatment liquid after the methane fermentation step An activated sludge treatment step for treating activated sludge, and a method for treating organic waste,
An iron electrolysis step for eluting iron ions by an electrolytic reaction is provided in the organic waste extracted from the adjustment step, and the iron electrolyte containing the eluted iron ions is returned to the adjustment step, A method for treating organic waste, comprising aggregating soluble pollutants. An adjustment step for performing an acid generation reaction or solubilization of organic waste, a methane fermentation step for performing a methane generation reaction of an organic waste reduced in molecular weight by the adjustment step, and a treatment liquid after the methane fermentation step An activated sludge treatment step for treating activated sludge, and a method for treating organic waste,
An iron electrolysis process for eluting iron ions by an electrolytic reaction is provided in the organic waste extracted from the methane fermentation process, and an iron electrolyte containing the eluted iron ions is returned to the methane fermentation process, and the iron A method for treating organic waste, comprising aggregating soluble pollutants with ions. An adjustment step for performing an acid generation reaction or solubilization of organic waste, a methane fermentation step for performing a methane generation reaction of an organic waste reduced in molecular weight by the adjustment step, and a treatment liquid after the methane fermentation step An activated sludge treatment step for treating activated sludge, and a method for treating organic waste,
An iron electrolysis step for eluting iron ions by an electrolytic reaction is provided in the treatment liquid extracted from the activated sludge treatment step, and the iron electrolyte containing the eluted iron ions is returned to the activated sludge treatment step, A method for treating organic waste, comprising aggregating soluble pollutants with ions.   The method for treating organic waste according to claim 3, wherein at least a part of the iron electrolyte is used as dilution water in the adjustment step or the methane fermentation step.   A first solid-liquid separation step is provided after the methane fermentation step, and the separated liquid separated by the first solid-liquid separation step is subjected to activated sludge treatment in the activated sludge treatment step. Item 4. A method for treating organic waste according to any one of Items 1 to 3. An adjustment process for acid generation reaction or solubilization of organic waste, a methane fermentation process for methane generation reaction of organic waste having a low molecular weight by the adjustment process, and a treatment liquid after the methane fermentation are solidified. In a method for treating organic waste, comprising: a first solid-liquid separation step for liquid separation; and an activated sludge treatment step for treating the separated liquid-liquid separation with activated sludge.
At least a part of the separated liquid-solid separated liquid is drawn out, and an iron electrolysis process is provided in the drawn-out separated liquid to elute iron ions by an electrolytic reaction, and the iron electrolyte containing the eluted iron ions is adjusted in the step A method for treating organic waste, which is introduced into either the methane fermentation step or the activated sludge treatment step. An adjustment process for acid generation reaction or solubilization of organic waste, a methane fermentation process for methane generation reaction of organic waste having a low molecular weight by the adjustment process, and a treatment liquid after the methane fermentation are solidified. A first solid-liquid separation step for liquid separation, an activated sludge treatment step for treating the separated liquid-liquid separation with activated sludge, and a second solid-liquid separation step for solid-liquid separation of the treated liquid after activated sludge treatment; In a method for treating organic waste comprising
Iron from which at least a part of the separation liquid in the first solid-liquid separation step or the second solid-liquid separation step or process water is withdrawn, and iron ions are eluted by electrolytic reaction in the withdrawn separation liquid or process water. An organic waste treatment method characterized by providing an electrolysis step and introducing an iron electrolyte containing the eluted iron ions into the adjustment step, the methane fermentation step, or the activated sludge treatment step.   The organic waste according to any one of claims 1, 2, 3, 6, and 7, wherein in the activated sludge treatment step, liquid organic waste is introduced and the activated sludge is treated together with the treatment liquid. How to handle things.   The electrolytic denitrification process of denitrifying the separated liquid separated by the second solid-liquid separation process provided after the activated sludge treatment process by an electrolytic reaction is provided. , 6, 7, or 8. The method for treating organic waste according to any one of the above. An adjustment tank that performs an acid generation reaction or solubilization of organic waste, a methane fermentation tank that performs a methane generation reaction of organic waste that has been reduced in molecular weight in the adjustment tank, and a treatment liquid that is discharged from the methane fermentation tank In an organic waste treatment system equipped with activated sludge treatment equipment for treating activated sludge,
An iron electrolytic cell for introducing the organic waste drawn out from the adjustment tank is provided, and the iron electrolytic cell has an anode containing iron and a conductive cathode disposed opposite to each other, and between the electrodes immersed in the organic waste. The iron ions are eluted by energizing the
An organic waste treatment system comprising a methane fermentation tank, wherein the iron electrolyte containing the eluted iron ions is returned to the adjustment tank. An adjustment tank that performs an acid generation reaction or solubilization of organic waste, a methane fermentation tank that performs a methane generation reaction of organic waste that has been reduced in molecular weight in the adjustment tank, and a treatment liquid that is discharged from the methane fermentation tank In an organic waste treatment system equipped with activated sludge treatment equipment for treating activated sludge,
An iron electrolytic cell for introducing organic waste extracted from the methane fermentation tank is provided, and the iron electrolytic cell is an electrode in which an anode containing iron and a conductive cathode are arranged opposite to each other and immersed in the organic waste The iron ions are eluted by energizing them in between,
An organic waste treatment system comprising a methane fermentation tank, wherein the iron electrolyte containing the eluted iron ions is returned to the methane fermentation tank. An adjustment tank that performs an acid generation reaction or solubilization of organic waste, a methane fermentation tank that performs a methane generation reaction of organic waste that has been reduced in molecular weight in the adjustment tank, and a treatment liquid that is discharged from the methane fermentation tank In an organic waste treatment system equipped with activated sludge treatment equipment for treating activated sludge,
An iron electrolyzer is provided for introducing a treatment liquid extracted from the activated sludge treatment facility, and the iron electrolyzer is provided with an anode containing iron and a conductive cathode facing each other, and an electric current is passed between the electrodes immersed in the treatment liquid. To elute iron ions,
An organic waste treatment system comprising a methane fermentation tank, wherein the iron electrolyte containing the eluted iron ions is returned to the activated sludge treatment facility.   The organic waste treatment system according to claim 12, wherein at least part of the iron electrolyte is used as dilution water in the adjustment tank or the methane fermentation tank.   The first solid-liquid separation facility is provided in the subsequent stage of the methane fermentation tank, and the activated sludge treatment is performed on the separated liquid-separated liquid in the activated sludge treatment facility. The organic waste treatment system described. A control tank that performs an acid generation reaction or solubilization of organic waste, a methane fermentation tank that performs a methane generation reaction of organic waste having a low molecular weight in the control tank, and a treatment liquid after the methane fermentation are solidified. In an organic waste treatment system comprising: a first solid-liquid separation facility for liquid separation; and an activated sludge treatment facility for treating activated sludge for the separated liquid-liquid separation,
An iron electrolytic cell for introducing at least a part of the separated liquid-solid separated liquid is provided, and the iron electrolytic cell has an anode containing iron and a conductive cathode disposed opposite to each other, and between the electrodes immersed in the separated liquid. The iron ions are eluted by energization,
Treatment of organic waste provided with a methane fermentation tank, wherein the iron electrolyte containing the eluted iron ions is introduced into the adjustment tank, the methane fermentation tank, or the activated sludge treatment facility system. A control tank that performs an acid generation reaction or solubilization of organic waste, a methane fermentation tank that performs a methane generation reaction of organic waste having a low molecular weight in the control tank, and a treatment liquid after the methane fermentation are solidified. A first solid-liquid separation facility for liquid separation, an activated sludge treatment facility for treating the separated liquid-liquid separation with activated sludge, a second solid-liquid separation facility for solid-liquid separation of the treated liquid treated with activated sludge, In the organic waste treatment system with
An iron electrolytic cell for introducing at least a part of the separation liquid of the first solid-liquid separation facility or the second solid-liquid separation facility or process water is provided, and the iron electrolytic cell is electrically conductive with an anode containing iron. The cathode is arranged oppositely, and iron ions are eluted by energizing between the electrodes immersed in the separation liquid or process water,
Treatment of organic waste provided with a methane fermentation tank, wherein the iron electrolyte containing the eluted iron ions is introduced into the adjustment tank, the methane fermentation tank, or the activated sludge treatment facility system.   The organic waste according to any one of claims 10, 11, 12, 15, and 16, wherein liquid organic waste is charged into the activated sludge treatment facility and activated sludge is treated together with the treatment liquid. Processing system.   The electrolytic denitrification apparatus which denitrifies the separated liquid from the 2nd solid-liquid separation equipment provided in the back | latter stage of the said activated sludge processing equipment by an electrolytic reaction was provided, , 16 or 17, an organic waste treatment system.   The organic waste treatment according to any one of claims 14, 15, and 16, wherein the first solid-liquid separation facility or the second solid-liquid separation facility includes a membrane separation means. system. 17. A composting facility using a separated sludge separated by solid-liquid separation in the first solid-liquid separation facility or the second solid-liquid separation facility as a raw material. Organic waste processing system according to crab.

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