Processing system, power generation apparatus, desulfurization apparatus, power generation method, and desulfurization method

Abstract

To provide a treatment system, a power generator, a desulfurization treatment apparatus, a power generation method, and a desulfurization method that utilize emissions after anaerobic treatment of treated materials to enable further efficient energy recovery and utilization or desulfurization treatment.SOLUTION: A treatment system equipped with a digestion system that performs anaerobic treatment of treated materials generates electricity or performs desulfurization treatment by a reaction that uses a reducing substance in filtrate obtained by separating emissions after anaerobic treatment into solid and liquid, as an electron donor. There are also provided a power generator, a desulfurization treatment apparatus, a power generation method, and a desulfurization method. According to the present invention, power generation or desulfurization treatment can be performed by utilizing the emissions generated after anaerobic treatment through a reaction in which a reducing substance contained in filtrate is directly used as an electron donor, thereby reducing running costs related to anaerobic treatment and improving the treatment capacity of the entire treatment system.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a treatment system involving power generation or desulfurization treatment. Further, the present invention relates to a power generation device and a power generation method in anaerobic treatment. Furthermore, the present invention relates to a desulfurization treatment device and a desulfurization method in anaerobic treatment.

Background Art

[0002] Generally, as a method for treating a treatment object containing organic substances, biological treatment using various microorganisms is known. In particular, biological treatment in an anaerobic environment (hereinafter referred to as "anaerobic treatment") is widely used because of its high introduction merits such as no need for aeration power and almost no generation of excess sludge. For example, in the case of biomass containing a large amount of solid content as the treatment object, anaerobic treatment using a digester is known. In addition, various treatment steps and techniques are combined along with anaerobic treatment. For example, as one of the techniques associated with anaerobic treatment, it is known to use biogas such as methane generated by anaerobic treatment as fuel for power generation.

[0003] On the other hand, as a treatment using microorganisms, a microbial fuel cell that generates power using the oxidation-reduction reaction of microorganisms is known. A microbial fuel cell obtains electrical energy by utilizing the metabolic ability of microorganisms. More specifically, a microbial fuel cell has a configuration in which electrons generated during the process of oxidatively decomposing a substrate such as an organic substance by microorganisms are collected on the anode side and the electrons are transferred to the cathode side to obtain an electric current.

[0004] For example, Patent Document 1 describes a power generation device in which one electrode of a pair is used as an anode and is in contact with a solution (suspension) containing microorganisms that can grow under anaerobic conditions and organic matter, and the other electrode is formed as a cathode from a material with structural voids and is in contact with air, and the anode and cathode are electrically connected to form a closed circuit. Patent Document 1 also describes attaching microorganisms to the surface of the anode. Furthermore, Patent Document 1 describes a power generation method using this power generation device in which an oxidation reaction by microorganisms using the organic matter at the anode as an electron donor and a reduction reaction using oxygen at the cathode as an electron acceptor are carried out. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2004-442412 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] Power generation using microbial fuel cells, as described in Patent Document 1, has low energy conversion efficiency, and improving power output is a major challenge for practical application. This is presumed to be due to the fact that the transfer of mass to the electrodes is inhibited by the microorganisms, as the microorganisms are in direct contact with or supported on the electrodes, and the metabolic rate of the microorganisms becomes the rate-limiting factor.

[0007] Furthermore, in recent years, in order to reduce the power consumption of equipment used in treatment systems that perform various types of treatment on materials, not just anaerobic treatment, and to make them more energy-efficient, there is a demand for technologies that enable efficient energy recovery and utilization as an accessory to treatment systems. As one such technology, a technology that applies microbial fuel cells to treatment systems to perform treatment of materials and generate electricity simultaneously is being considered, but as mentioned above, there is a challenge in that it is difficult to obtain sufficient power output.

[0008] Furthermore, in addition to efficient energy recovery and utilization, technologies are also required to accompany the treatment of materials, such as technologies for efficiently removing harmful substances generated in the materials during treatment, including anaerobic treatment. In particular, there is a need for technologies to efficiently perform desulfurization to remove hydrogen sulfide generated during anaerobic treatment.

[0009] In particular, in anaerobic treatment, it may be necessary to subject the anaerobic waste to another anaerobic treatment or to perform additional treatment on the anaerobic waste. In this case, by utilizing the waste generated after anaerobic treatment for power generation or desulfurization, it is expected that the running costs related to the treatment of the treated material will be reduced and the overall treatment capacity will be improved.

[0010] The object of the present invention is to provide a treatment system, power generation apparatus, desulfurization apparatus, power generation method, and desulfurization method that utilize the waste products after anaerobic treatment of the material to be treated to enable more efficient energy recovery and utilization or desulfurization treatment. [Means for solving the problem]

[0011] As a result of diligent research into the above-mentioned problems, the inventors of the present invention have discovered that by using reducing substances in the filtrate obtained by solid-liquid separation of wastewater after anaerobic treatment as electron donors in a reaction, it becomes possible to efficiently recover and utilize energy through power generation and perform desulfurization treatment in wastewater treatment, thereby completing the present invention. In other words, the present invention relates to the following processing system, power generation apparatus, desulfurization apparatus, power generation method, and desulfurization method.

[0012] The present invention, which solves the above problems, is a processing system equipped with a digestion facility that performs anaerobic treatment on a material to be treated, and is characterized in that it generates electricity by a reaction in which a reducing substance in the filtrate obtained by solid-liquid separation of the waste after anaerobic treatment is used as an electron donor.

[0013] The present invention enables efficient power generation by directly using reducing substances contained in the filtrate obtained by solid-liquid separation of waste after anaerobic treatment as electron donors, thus avoiding inhibition of mass transfer by microorganisms. Furthermore, it allows for a smaller equipment size compared to power generation using microbial fuel cells. In addition, by utilizing the waste generated after anaerobic treatment to generate electricity, it is possible to reduce the running costs associated with anaerobic treatment and improve the overall treatment capacity of the treatment system.

[0014] Furthermore, another aspect of the processing system of the present invention for solving the above problems is a processing system equipped with a digestion facility that performs anaerobic treatment on the material to be processed, characterized in that desulfurization treatment is performed by a reaction in which a reducing substance in the filtrate obtained by solid-liquid separation of the waste after anaerobic treatment is used as an electron donor.

[0015] The treatment system of the present invention can convert hydrogen sulfide, a reducing substance, into sulfur by directly using a reducing substance contained in the filtrate obtained by solid-liquid separation of waste after anaerobic treatment as an electron donor, thereby enabling efficient removal of hydrogen sulfide from the material being treated. Furthermore, it is possible to perform desulfurization treatment on waste generated after anaerobic treatment, which reduces the running costs associated with anaerobic treatment and improves the overall treatment capacity of the treatment system.

[0016] Furthermore, one embodiment of the processing system of the present invention is characterized by having a power generation unit that generates electricity by bringing the filtrate into contact with an electrode. This feature allows for power generation during the processing of the material being treated by positioning electrodes in contact with the filtrate. This enables efficient power generation without increasing the size of the equipment. Furthermore, during this process, an electrode reaction proceeds using hydrogen sulfide contained in the filtrate as an electron donor, converting it to sulfur. Therefore, efficient desulfurization can be performed without the need for separate desulfurization equipment.

[0017] Furthermore, one embodiment of the processing system of the present invention is characterized by placing an ion exchanger between electrodes. This feature makes it possible to increase the efficiency of electron transfer between a pair of electrodes, thereby further improving power generation efficiency and desulfurization efficiency.

[0018] Furthermore, one embodiment of the processing system of the present invention is characterized by comprising contact efficiency improving means for improving the contact efficiency between the electrode surface of the power generation unit and the electrode reaction components containing reducing substances in the filtrate. This feature makes it possible to improve the contact efficiency between the electrode surface of the power generation section and the electrode reaction components. This suppresses a decrease in the efficiency of the electrode reaction, thereby improving the efficiency of power generation and desulfurization treatment.

[0019] Furthermore, in one embodiment of the processing system of the present invention, the contact efficiency improving means is characterized by comprising a movement speed control means that increases the movement speed of the electrode reaction component with respect to the electrode surface. This feature allows for the rapid supply of electrode reaction components to the electrode surface. By improving the contact efficiency between the electrode surface and the electrode reaction components, the decrease in electrode reaction efficiency is suppressed, and the efficiency of power generation and desulfurization treatment can be improved.

[0020] Furthermore, one embodiment of the processing system of the present invention is characterized by providing a temperature control means for a reaction in which a reducing substance in the filtrate is used as an electron donor, as a means for controlling the transfer speed. This characteristic makes it possible to control the temperature in reactions using reducing substances as electron donors to improve mass transfer rates and reaction efficiency. This, in turn, makes it possible to increase power generation efficiency and desulfurization efficiency.

[0021] Furthermore, in one embodiment of the processing system of the present invention, the contact efficiency improving means is characterized by comprising a concentration control means for controlling the concentration of electrode reaction components. According to this feature, it becomes possible to increase the amount of electrode reaction components involved in the electrode reaction. Thereby, by improving the contact efficiency between the electrode surface and the electrode reaction components, it is possible to suppress the decrease in the efficiency of the electrode reaction, and improve the efficiency of power generation and desulfurization treatment.

[0022] Moreover, as one embodiment of the treatment system of the present invention, as a concentration control means, it has a feature of providing a pH control means for dissolving a reducing substance in the filtrate in the filtrate. According to this feature, it becomes possible to retain more of the reducing substance whose solubility in the solution changes according to pH in the filtrate, and increase the amount of the reducing substance used as an electron donor for the reaction. Thereby, it becomes possible to increase the power generation efficiency and the desulfurization treatment efficiency.

[0023] Moreover, as one embodiment of the treatment system of the present invention, the contact efficiency improvement means has a feature of including a cleaning means for cleaning the deposits deposited on the electrode surface. According to this feature, it becomes possible to remove the deposits on the electrode surface. Thereby, the contact efficiency between the electrode surface and the electrode reaction components can be improved, the decrease in the efficiency of the electrode reaction can be suppressed, and the efficiency of power generation and desulfurization treatment can be improved.

[0024] Moreover, as one embodiment of the treatment system of the present invention, it has a feature of providing an exhaust gas supply means for supplying the exhaust gas generated by the combustion device to the power generation unit. According to this feature, by providing an exhaust gas supply means for supplying the exhaust gas generated by the combustion device to the power generation unit, it is possible to suppress the increase in pH on the cathode side in the electrode reaction. Thereby, it is possible to suppress the decrease in the efficiency of the electrode reaction, and improve the efficiency of power generation and desulfurization treatment.

[0025] Moreover, as one embodiment of the treatment system of the present invention, the combustion device has a feature of incinerating the solid matter obtained by solid-liquid separation of the discharge after anaerobic treatment and / or burning the gas generated by anaerobic treatment. This feature allows for easy acquisition of the material to be combusted, and enables the use of existing combustion equipment related to solid material processing and gas utilization. As a result, there is no need to install new combustion equipment for the processing system of the present invention, which significantly reduces initial costs.

[0026] Furthermore, one embodiment of the processing system of the present invention is characterized by comprising a degassing means for removing gas contained in the electrodes of the power generation unit. This feature allows for the removal of gases contained in the electrodes, thereby solving the problem of reduced specific surface area inside the electrodes. This suppresses a decrease in the efficiency of the electrode reaction, enabling improved efficiency in power generation and desulfurization treatment.

[0027] Furthermore, the present invention provides a power generation device for solving the above problems, which is installed in a processing system that performs anaerobic treatment on a material to be treated. This device is characterized by generating electricity using reducing substances in the filtrate obtained by solid-liquid separation of the waste material after anaerobic treatment as electron donors. The power generation device of the present invention generates electricity by directly using reducing substances contained in the filtrate obtained by solid-liquid separation of waste after anaerobic treatment as electron donors. This eliminates the inhibition of mass transfer by microorganisms, thus enabling efficient power generation. Furthermore, it allows for a smaller equipment size compared to power generation using microbial fuel cells. In addition, by utilizing waste generated after anaerobic treatment to generate electricity, it is possible to reduce the running costs associated with anaerobic treatment and improve the overall treatment capacity of the treatment system. Furthermore, by applying the power generation device of the present invention to an existing processing system, it becomes possible to upgrade the processing system to one that can generate electricity without having to extensively remodel the entire processing system.

[0028] Furthermore, the desulfurization apparatus of the present invention for solving the above problems is a desulfurization apparatus installed in a treatment system that performs anaerobic treatment of a material to be treated, and is characterized in that a reducing substance in the filtrate obtained by solid-liquid separation of the waste after anaerobic treatment is used as an electron donor for the desulfurization treatment. The desulfurization apparatus of the present invention performs desulfurization using reducing substances contained in the material to be treated as direct electron donors, thereby enabling efficient desulfurization without discharging hydrogen sulfide outside the system. Furthermore, it can perform desulfurization on the waste generated after anaerobic treatment, thereby reducing the running costs associated with anaerobic treatment and improving the overall processing capacity of the treatment system. Furthermore, by applying the desulfurization apparatus of the present invention to an existing processing system, it becomes possible to upgrade the entire processing system to one capable of performing desulfurization without extensively updating the entire system.

[0029] Furthermore, the present invention provides a power generation method for solving the above problems, which is a power generation method in wastewater treatment that performs anaerobic treatment on the material to be treated, and is characterized by comprising a step of generating electricity using reducing substances in the filtrate obtained by solid-liquid separation of the discharged material after anaerobic treatment as electron donors. The power generation method of the present invention generates electricity by directly using reducing substances contained in the filtrate obtained by solid-liquid separation of waste after anaerobic treatment as electron donors. This eliminates the inhibition of mass transfer by microorganisms, thus enabling efficient power generation. Furthermore, it allows for smaller equipment compared to power generation using microbial fuel cells. In addition, by utilizing waste generated after anaerobic treatment to generate electricity, it is possible to reduce the running costs associated with anaerobic treatment and improve the overall treatment capacity of the treatment system.

[0030] Furthermore, the present invention provides a desulfurization method for solving the above problems, which is a desulfurization method for wastewater treatment in which the material to be treated is subjected to anaerobic treatment, and is characterized by comprising a step of using a reducing substance in the filtrate obtained by solid-liquid separation of the discharged material after anaerobic treatment as an electron donor for desulfurization treatment. The desulfurization method of the present invention enables efficient desulfurization without discharging hydrogen sulfide outside the system by directly using a reducing substance contained in the material to be treated as an electron donor. Furthermore, it is possible to perform desulfurization on the waste generated after anaerobic treatment, which reduces the running costs associated with anaerobic treatment and improves the overall treatment capacity of the treatment system. [Effects of the Invention]

[0031] According to the present invention, it is possible to provide a treatment system, power generation apparatus, desulfurization apparatus, power generation method, and desulfurization method that utilize the waste products after anaerobic treatment of the material to be treated, enabling more efficient energy recovery and utilization or desulfurization treatment. [Brief explanation of the drawing]

[0032] [Figure 1] This is a schematic diagram illustrating the processing system in the first embodiment of the present invention. [Figure 2] This is a schematic diagram illustrating the processing system in a second embodiment of the present invention. [Figure 3] This is a schematic diagram illustrating another aspect of the processing system in the second embodiment of the present invention. [Figure 4] This is a schematic diagram illustrating the processing system in a third embodiment of the present invention. [Figure 5] This is a schematic diagram illustrating the means for improving contact efficiency (moving speed control means) in the processing system of the third embodiment of the present invention. [Figure 6] This is a schematic diagram illustrating another embodiment of the movement speed control means in the processing system of the third embodiment of the present invention. [Figure 7] This is a schematic diagram illustrating another embodiment of the movement speed control means in the processing system of the third embodiment of the present invention. [Figure 8] This is a schematic diagram illustrating another embodiment of the movement speed control means in the processing system of the third embodiment of the present invention. [Figure 9] This is a schematic diagram illustrating another embodiment of the movement speed control means in the processing system of the third embodiment of the present invention. [Figure 10] This is a schematic diagram illustrating another embodiment of the movement speed control means in the processing system of the third embodiment of the present invention. [Figure 11] This is a schematic diagram illustrating another aspect of the contact efficiency improvement means (concentration control means) in the processing system of the third embodiment of the present invention. [Figure 12]This is a schematic diagram illustrating another embodiment of the concentration control means in the processing system of the third embodiment of the present invention. [Figure 13] This is a schematic diagram illustrating another embodiment of the concentration control means in the processing system of the third embodiment of the present invention. [Figure 14] This is a schematic diagram illustrating another embodiment of the concentration control means in the processing system of the third embodiment of the present invention. [Figure 15] This is a schematic diagram illustrating a means for improving contact efficiency (cleaning means) in a processing system according to the fourth embodiment of the present invention. [Figure 16] This is a schematic diagram illustrating another embodiment of the cleaning means in the processing system of the fourth embodiment of the present invention. [Figure 17] This is a schematic diagram illustrating another embodiment of the cleaning means in the processing system of the fourth embodiment of the present invention. [Figure 18] This is a schematic diagram illustrating another embodiment of the cleaning means in the processing system of the fourth embodiment of the present invention. [Figure 19] This is a schematic diagram illustrating another embodiment of the cleaning means in the processing system of the fourth embodiment of the present invention. [Figure 20] This is a schematic diagram illustrating the processing system in a fifth embodiment of the present invention. [Figure 21] This is a schematic diagram illustrating another aspect of the processing system in the fifth embodiment of the present invention. [Figure 22] This is a schematic diagram illustrating a degassing means in a processing system according to a sixth embodiment of the present invention. [Figure 23] This is a schematic diagram illustrating another embodiment of the degassing means in the processing system of the sixth embodiment of the present invention. [Figure 24] This is a schematic diagram illustrating another embodiment of the degassing means in the processing system of the sixth embodiment of the present invention. [Figure 25] This is a schematic diagram illustrating the insulation mechanism in the processing system of the seventh embodiment of the present invention. [Figure 26] This is a schematic diagram illustrating another aspect of the insulation mechanism in the processing system of the seventh embodiment of the present invention. [Figure 27] This is a schematic diagram illustrating another aspect of the insulation mechanism in the processing system of the seventh embodiment of the present invention. [Figure 28] This is a schematic diagram illustrating the processing system in the eighth embodiment of the present invention. [Modes for carrying out the invention]

[0033] Hereinafter, embodiments of the processing system, power generation apparatus, desulfurization apparatus, power generation method, and desulfurization method according to the present invention will be described in detail with reference to the drawings. The power generation method and desulfurization method in the present invention will be replaced by the description of the operation of the processing system, power generation apparatus, and desulfurization apparatus in the present invention. The processing system, power generation apparatus, desulfurization apparatus, power generation method, and desulfurization method described in the embodiments are merely illustrative examples for illustrating the processing system, power generation apparatus, desulfurization apparatus, power generation method, and desulfurization method according to the present invention, and are not limited thereto.

[0034] In the processing system of the present invention, the material to be processed is not particularly limited. Preferably, the material to be processed generates reducing substances as the processing progresses in the processing system. Examples of specific materials to be processed include, for example, food waste and kitchen waste discharged from households and various factories, biomass such as wood, and excess sludge after processing of domestic wastewater such as industrial wastewater and sewage discharged from various factories. In the following embodiments, the material to be processed will mainly be described in which reducing substances are generated as a result of the processing, but it is not limited to this.

[0035] Furthermore, in the present invention, the reducing substance is not particularly limited, as long as it functions as an electron donor. Whether or not a substance functions as an electron donor is relatively determined by its combination with a substance that functions as an electron acceptor (hereinafter simply referred to as "electron acceptor"). In other words, the reducing substance in the present invention is one that releases electrons more easily than the electron acceptor, that is, one with a lower oxidation-reduction potential than the electron acceptor. For example, when oxygen is used as the electron acceptor, the reducing substance in the present invention is one with a lower oxidation-reduction potential than oxygen, and examples of such reducing substances include hydrogen sulfide, hydrogen, and ammonia.

[0036] [First Embodiment] (Processing system) Figure 1 is a schematic diagram illustrating the structure of a processing system in a first embodiment of the present invention. As shown in Figure 1, the processing system 1A in this embodiment comprises a processing tank 2, a solid-liquid separation unit 3, and a power generation unit 4. The processing system 1A also includes an introduction pipe L1 for introducing the material to be processed S into the processing tank 2, a connecting pipe L2 for connecting the processing tank 2 and the solid-liquid separation unit 3, an introduction pipe L3 for introducing the filtrate F separated in the solid-liquid separation unit 3 into the power generation unit 4, an discharge pipe L4 for discharging the solid matter separated in the solid-liquid separation unit 3 to the outside of the system, and an discharge pipe L5 for discharging the treated water W2 from the power generation unit 4 to the outside of the system.

[0037] In the processing system 1A shown in Figure 1, the material to be processed S is subjected to anaerobic treatment in the processing tank 2, and the waste product (processing liquid W1) after anaerobic treatment is separated into filtrate F and solid matter in the solid-liquid separation unit 3, and the filtrate F is introduced into the power generation unit 4. This makes it possible to utilize the waste product after anaerobic treatment of the material to be processed S to recover and use energy more efficiently or to perform desulfurization treatment. The following describes the various components of processing system 1A.

[0038] (Processing tank) Treatment tank 2 is a tank for performing anaerobic treatment on the material to be treated S. The treatment performed in treatment tank 2 is an anaerobic treatment appropriate to the target substance contained in the material to be treated S, and is not particularly limited as long as the discharged product (treatment liquid W1) after treatment contains reducing substances. Examples include methane fermentation by acid-producing bacteria and methane-producing bacteria, denitrification treatment in which nitrate and nitrite are reduced by denitrifying bacteria, and sulfate reduction treatment in which sulfuric acid is reduced by sulfate-reducing bacteria. In this embodiment, methane fermentation, which produces methane, is particularly preferred as the anaerobic treatment performed in the treatment tank 2, from the viewpoint of treatment cost and the usefulness of the produced gas. Therefore, it is preferable that the treatment tank 2 has a structure that functions as a digestion facility for digesting the material S to be treated. More specifically, it is preferable that the treatment tank 2 has a structure known as a digester, and the specific structure of the digester is not particularly limited.

[0039] In the treatment tank 2, when methane fermentation is performed as part of anaerobic treatment, the waste product (treatment liquid W1) after treating the material S contains not only methane but also hydrogen sulfide, hydrogen, ammonia, etc. These products correspond to the reducing substances in this invention.

[0040] The material to be treated S in the treatment tank 2 becomes waste (treatment liquid W1) containing reducing substances, which is introduced to the solid-liquid separation unit 3 via the connecting pipe L2.

[0041] (Solid-liquid separation section) The solid-liquid separation unit 3 is for separating the processing liquid W1 introduced from the processing tank 2 into solid matter and filtrate F. Here, the treatment liquid W1 separated in the solid-liquid separation unit 3 is the waste product after anaerobic treatment in the treatment tank 2, and is a solid-liquid mixture (sludge) containing muddy material such as excess sludge. In addition, the treatment liquid W1 contains reducing substances produced by methane fermentation. Therefore, by separating the processing liquid W1 in the solid-liquid separation unit 3, recovering the filtrate F containing reducing substances, and introducing it into the subsequent power generation unit 4, it becomes possible to carry out a reaction in which the reducing substances act as electron donors.

[0042] The solid-liquid separation unit 3 is not particularly limited and can be any unit capable of separating the solid matter contained in the processing liquid W1 from the filtrate F. Examples include sedimentation separation types such as coagulation-sedimentation tanks and sedimentation tanks, centrifugal separation types equipped with centrifugal separators, and pressurized filtration devices such as belt press dewatering machines and screw press dewatering machines.

[0043] The filtrate F separated in the solid-liquid separation unit 3 is introduced to the power generation unit 4 via the introduction pipe L3 as treated water W2 containing reducing substances. On the other hand, the solid matter separated in the solid-liquid separation unit 3 is discharged out of the system via the discharge pipe L4. In this case, a treatment facility for processing the solid matter may be provided downstream of the discharge pipe L4.

[0044] (Power Generation Section (Power Generation Equipment / Desulfurization Treatment Equipment)) The power generation unit 4 is for generating electricity using reducing substances in the filtrate F as electron donors. Furthermore, in this embodiment, the power generation unit 4 can also perform desulfurization by using sulfur-containing compounds such as hydrogen sulfide among the reducing substances in the filtrate F as electron donors. The structure of the power generation unit 4 of this embodiment will be described below from the perspective of power generation. Details of the desulfurization treatment by the power generation unit 4 of this embodiment will be described later.

[0045] As shown in Figure 1, the power generation unit 4 of this embodiment is located downstream of the solid-liquid separation unit 3 and comprises a first cell 41a and a second cell 41b, an ion exchanger 45 provided to partition the cells 41a and 41b, and electrodes 43a and 43b arranged in cells 41a and 41b, respectively. Here, the first cell 41a is formed so that the filtrate F introduced from the solid-liquid separation unit 3 via the introduction pipe L3 comes into contact with the electrode 43a, and the electrode 43a arranged in the first cell 41a functions as an anode. On the other hand, the second cell 41b is formed to store or supply electron acceptors, and the electrode 43b arranged in the second cell 41b functions as a cathode. Furthermore, electrodes 43a and 43b are connected to an external circuit by a conductor (not shown). This makes it possible to recover and utilize the electrical energy generated in the power generation unit 4 by the action of a reducing substance as an electron donor.

[0046] The first cell 41a is equipped with an electrode 43a and is formed so that the filtrate F comes into contact with the electrode 43a, and its material and shape are not particularly limited. For example, as shown in Figure 1, it may have a space that can temporarily store the filtrate F introduced from the inlet 42a via the introduction pipe L3, and a discharge pipe L5 for discharging the treated water W2 after it has come into contact with the electrode 43a from the discharge port 42b. As a result, the reducing substances in the filtrate F donate electrons to the electrode 43a as electron donors and are then quickly discharged via the discharge pipe L5. The positional relationship between the inlet 42a and the discharge port 42b is not particularly limited. For example, as shown in Figure 1, the inlet 42a is provided on the side of the first cell 41a and the discharge port 42b is provided on the bottom of the first cell 41a, or the inlet 42a and discharge port 42b are provided on the side of the first cell 41a and the discharge port 42b is located higher vertically than the inlet 42a.

[0047] Furthermore, flow rate adjustment mechanisms such as valves may be provided in the introduction pipe L3 and / or the discharge pipe L5. This makes it possible to adjust the amount and flow rate of the filtrate F that comes into contact with the electrode 43a, thereby controlling the mass transfer rate to the electrode 43a.

[0048] The treated water W2 discharged through the discharge pipe L5 can be discharged directly into rivers or other bodies of water if it meets the water quality requirements for discharge. Alternatively, a treatment facility may be installed downstream of the discharge pipe L5 to further treat the treated water W2 before discharging it from the system. Such a treatment facility is not particularly limited as long as it can treat the treated water W2 to a water quality suitable for discharge from the system or into rivers. Examples include aeration tanks and pH adjustment tanks.

[0049] The second cell 41b is equipped with an electrode 43b and is formed to store or supply electron acceptors to reducing substances in the filtrate F, and is not limited in terms of material or shape.

[0050] Here, the electron acceptor may be in the form of either a gas or a liquid. The liquid may be a solution in which a solid drug is dissolved, or a solution in which a gas is mixed (dissolved). In this embodiment, specific examples of electron acceptors include, for example, gases such as oxygen and oxygen-containing gases. Oxygen-containing gases include those that contain oxygen as a mixture, such as air, and those that contain oxygen as an element constituting a compound, such as carbon dioxide. When a gas is used as an electron acceptor, there are advantages such as the fact that the treatment of waste products after the reaction is unnecessary (or easy) and the cost of obtaining the gas can be reduced. In order to make the most of these advantages, it is particularly preferable to use air as the electron acceptor. Furthermore, other examples of electron acceptors in this embodiment include, for example, solutions containing dissolved oxygen or aqueous solutions of oxidizing agents such as potassium ferricyanide, as liquids. When a liquid is used as the electron acceptor, it has the advantage of making it easier to handle compounds (oxidizing agents) that are highly effective as electron acceptors, thereby further improving power generation efficiency. From the viewpoint of improving power generation efficiency, it is particularly preferable to use an aqueous solution of potassium ferricyanide as the electron acceptor.

[0051] As an example of the second cell 41b, as shown in Figure 1, the second cell 41b may be provided with an electron acceptor supply port 44a for supplying gas (oxygen, air, etc.) to the electrode 43b and an electron acceptor outlet 44b for discharging the gas after the reaction. Another example of the second cell 41b is to provide a space in the second cell 41b that can store liquid, and to provide an electron acceptor supply port 44a and an electron acceptor outlet 44b that can supply the electron acceptor solution and discharge the solution after the reaction, respectively. As a result, electrons from electrode 43a can be received by the electron acceptor via electrode 43b, and an electric current flows between electrode 43a and electrode 43b to generate electricity. The electron acceptor after the reaction is then quickly discharged to the outside of the power generation unit 4 via the electron acceptor outlet 44b. Furthermore, a flow rate adjustment mechanism such as a valve may be provided at the electron acceptor supply port 44a and / or electron acceptor outlet port 44b to adjust the concentration of electron acceptors in the second cell 41b. In addition, a control mechanism may be provided to control the flow rate adjustment mechanism so that the electron acceptor concentration is maintained in proportion to the amount of electrons generated by the reaction at electrode 43a. This makes it possible to suppress the decrease in reaction efficiency related to electron transfer between electrode 43a and electrode 43b, and thereby suppress the decrease in power generation efficiency.

[0052] In Figure 1, the electron acceptor supply port 44a and electron acceptor outlet 44b are shown as one each, but the design is not limited to this. For example, multiple electron acceptor supply ports 44a and electron acceptor outlets 44b may be provided. In particular, when an oxygen-containing gas is used as the electron acceptor, water is produced by the reaction at electrode 43b, as will be described later. Therefore, when multiple electron acceptor outlets 44b are provided, for example, one can be provided to discharge gas and the other to discharge liquid.

[0053] The ion exchanger 45 can be any known configuration that allows ions to pass through, and is not particularly limited. In particular, it is preferable to use a cation exchange membrane that can allow hydrogen ions generated at electrode 43a (anode side) to pass through. This allows hydrogen ions to move from electrode 43a (anode side) to electrode 43b (cathode side), thereby increasing the reaction efficiency of the electron acceptor at electrode 43b and improving power generation efficiency. Furthermore, it is more preferable that the ion exchanger 45 has low oxygen permeability. This suppresses the movement of electron acceptors (oxygen) supplied to electrode 43b (cathode side) to electrode 43a, and prevents the reaction efficiency of the electron donor at electrode 43a from decreasing due to oxygen. In Figure 1, the ion exchanger 45 is shown as being provided separately from electrodes 43a and 43b, but this is not the only option. For example, the ion exchange material can be integrated with electrodes 43a and / or 43b. This makes it possible to miniaturize the entire power generation unit 4 and reduce the time required for maintenance work.

[0054] Electrode 43a is an electrode that recovers electrons from reducing substances in the filtrate F and functions as a so-called anode. In this embodiment, electrode 43a is positioned in the first cell 41a so as to be in contact with the filtrate F introduced from the solid-liquid separation unit 3.

[0055] The electrode 43a can function as an anode, and its material and shape are not particularly limited. The material and shape of the electrode 43a can be appropriately selected considering the cost of material procurement and processing, the reaction efficiency of reducing substances in the electrode 43a, etc. Examples of materials for the electrode 43a include carbon and metals (stainless steel, platinum, copper, etc.) which are widely used as electrode materials in the field of electrochemistry. Examples of shapes for the electrode 43a include flat plates, rods, meshes, etc.

[0056] In this embodiment, the electrode 43a does not have microorganisms in contact with or supported on its surface. Therefore, the mass transfer of reducing substances is not inhibited by microorganisms, the reaction efficiency as an electron donor (the mass transfer rate of reducing substances to the electrode 43a) can be improved, and the power generation efficiency can be improved. Furthermore, in this embodiment, electrode 43a does not recover electrons generated by the metabolism of microorganisms, but rather recovers electrons directly from reducing substances. Therefore, the metabolism of microorganisms does not become the rate-limiting factor, the reaction efficiency as an electron donor (the rate of electron recovery at electrode 43a) is improved, and the power generation efficiency can be improved.

[0057] Furthermore, in this embodiment, the electrode 43a does not require processing to make its structure suitable for retaining microorganisms, thus reducing the cost associated with manufacturing the electrode 43a. Also, considering the amount of microorganisms that can be retained by the electrode 43a and the reaction efficiency by the microorganisms, there is no need to enlarge the electrode 43a, which allows for miniaturization of the equipment related to the processing system.

[0058] Electrode 43b is the counter electrode to electrode 43a and is the electrode that transfers electrons to the electron acceptor, functioning as a so-called cathode. In this embodiment, electrode 43b is located within the second cell 41b.

[0059] The electrode 43b can function as a cathode, and its material and shape are not particularly limited. The material and shape of the electrode 43b can be appropriately selected considering the costs associated with material procurement and processing, and the reaction efficiency of the electron acceptor in the electrode 43b. Examples of materials for the electrode 43b include carbon and metals (stainless steel, platinum, copper, etc.) that are widely used as electrode materials in the field of electrochemistry. Examples of shapes for the electrode 43b include flat plates, rods, and meshes.

[0060] When the electron acceptor supplied to the second cell 41b is a gas (air), one side of the electrode 43b is in contact with the gas, while the other side is in contact with the filtrate F. For this reason, it is preferable that the electrode 43b be in a form suitable as a so-called air cathode. A suitable form for an air cathode is, for example, one that possesses both gas permeability and water impermeability. By making the electrode 43b gas permeable, it becomes possible to effectively react the gas, which is the electron acceptor, at the electrode 43b. Furthermore, by making the electrode 43b water impermeable, it becomes possible to suppress the filtrate F in the first cell 41a from permeating through the electrode 43b and flowing into the second cell 41b. Specific examples of such an electrode 43b include one made of carbon fiber, or one in which a metal mesh surface has been treated by coating it with a material that has gas permeability and water impermeability, or by laminating a film. In this context, impermeability refers to the inability to allow water to pass through. For example, waterproofing, water-repellenting, hydrophobicating, or water-stopping the electrode 43b is also included in the definition of impermeability.

[0061] In this embodiment, the processing system 1A uses a reducing substance in the filtrate F as an electron donor and performs power generation or desulfurization treatment by electrochemical reaction (electrode reaction). Generally, when performing an electrochemical reaction, a problem arises in which the efficiency of the electrochemical reaction decreases due to the movement of electrons to areas other than the area where the electrochemical reaction actually takes place (power generation unit 4). Therefore, in this embodiment, it is preferable to insulate areas other than the area where the electrochemical reaction takes place (power generation unit 4) in the processing system 1A. Specific examples of insulation treatment include, for example, installing the processing tank 2 and the solid-liquid separation unit 3 on top of an insulator, constructing the outer or inner walls of the processing tank 2 and the solid-liquid separation unit 3 from an insulator, or coating the outer or inner walls of the processing tank 2 and the solid-liquid separation unit 3 with an insulating material. Furthermore, as for the insulation treatment of each pipe L1 to L5, for example, each pipe may be made of an insulator, or each pipe may be coated with an insulating material.

[0062] In the processing system 1A of the above embodiment, power generation or desulfurization can be performed by a reaction using a reducing substance in the filtrate F as an electron donor. The following describes in detail the power generation and desulfurization processes in processing system 1A.

[0063] (Power generation and desulfurization treatment in processing systems) Based on Figure 1, the reactions and processes related to power generation and desulfurization in the first embodiment of the present invention's treatment system 1A will be described. The reactions and processes related to power generation in the treatment system of this embodiment will be described in which a reducing substance contained in the filtrate F obtained by solid-liquid separation of the waste product (treatment liquid W1) after anaerobic treatment of the material to be treated S is used as an electron donor, and air (oxygen) is used as an electron acceptor. In particular, the use of hydrogen sulfide as an electron donor corresponds to the reactions and processes related to desulfurization in the treatment system of this embodiment. The description of the reactions and processes based on Figure 1 is an example of power generation and desulfurization treatment in this embodiment, and is not limited to this example. Furthermore, the following description concerns the reactions and processes from the treatment tank 2 to the power generation unit 4, and the reactions and processes related to other components (such as the inlet pipes L1 and L3, the connecting pipe L2, the discharge pipes L4 and L5, and the treatment equipment installed downstream of the discharge pipes L4 and L5) are omitted from the description. In addition, the notations for reactions R1 to R4 and processes S1 to S4 are assigned for explanatory purposes only and do not specify the order of the reactions and processes.

[0064] As shown in Figure 1, the material to be treated S introduced into the treatment tank 2 is subjected to anaerobic treatment by anaerobic microorganisms (acid-producing bacteria and methane-producing bacteria) in the treatment tank 2, and treatment liquid W1 is produced (step S1). At this time, in addition to methane, reducing substances (hydrogen, hydrogen sulfide, ammonia, etc.) are produced.

[0065] The waste (treatment liquid W1) treated in the treatment tank 2 is introduced into the solid-liquid separation unit 3 via the connecting pipe L2 as a solid-liquid mixture containing reducing substances (step S2). Here, the treatment liquid W1 is separated into solid matter and filtrate F.

[0066] Then, the filtrate F containing the reducing substance is introduced into the first cell 41a in the power generation unit 4 (step S3). Here, when the reducing substance (hydrogen, hydrogen sulfide, ammonia, etc.) comes into contact with the electrode 43a, the reducing substance functions as an electron donor and electrons are donated to the electrode 43a. Taking hydrogen sulfide as an example of the reducing substance that functions as an electron donor, the reaction at electrode 43a (reaction R1) is shown by the following reaction equation (equation 1).

number

[0067] Furthermore, some of the hydrogen sulfide reacts as hydrogen sulfide ions. This reaction is represented by the following reaction equation (Equation 2).

number

[0068] As shown in Equations 1 and 2, in reaction R1, the hydrogen sulfide contained in the filtrate F donates electrons to electrode 43a, and the hydrogen sulfide itself is oxidized, rendering it harmless and odorless. Therefore, the treatment system of this embodiment enables desulfurization and deodorization along with power generation. In addition, reducing substances (such as ammonia), which are harmful and odorous substances other than hydrogen sulfide, also function as electron donors, and as the reaction proceeds, they can be rendered harmless and odorless.

[0069] Based on the reaction equations shown in Equations 1 and 2, after the reaction at electrode 43a proceeds, electrons move from electrode 43a to electrode 43b via the wire (reaction R2). At this time, the hydrogen ions generated in the reaction at electrode 43a move to the second cell 41b side via the ion exchanger 45 (reaction R3).

[0070] Meanwhile, air (oxygen) is introduced into the second cell 41b from the electron acceptor supply port 44a as an electron acceptor (step S4). Here, in reaction R2, electrons that have moved from electrode 43a to electrode 43b are received by the electron acceptor via electrode 43b. At the same time, in reaction R3, hydrogen ions that have moved to the second cell 41b side via the ion exchanger 45 also react with the electron acceptor (oxygen). The reaction at electrode 43b at this time (reaction R4) is shown by the following reaction equation (equation 3).

number

[0071] Based on the reactions R1 to R4 and steps S1 to S4 described above, an electric current flows between electrodes 43a and 43b. This causes a reaction to proceed using the reducing substance in the filtrate F as an electron donor, and power generation and desulfurization treatment are performed in the treatment system 1A of this embodiment. Furthermore, the electrical energy obtained through power generation can be recovered and utilized through external circuits connected to electrodes 43a and 43b. The utilization of the electrical energy is not particularly limited. For example, it may be used to drive equipment in the processing system, or it may be used outside the processing system.

[0072] As described above, by using the processing system 1A of this embodiment, it is possible to utilize the waste products after anaerobic treatment of the material to be treated, and to efficiently recover and utilize energy through power generation and perform desulfurization treatment during anaerobic treatment. In particular, by enabling electrode reactions using reducing substances contained in the filtrate obtained by solid-liquid separation of the waste products after anaerobic treatment, it is possible to improve power generation efficiency and desulfurization treatment efficiency by eliminating inhibition of mass transfer by microorganisms and rate-limiting steps based on the metabolic rate of microorganisms. Furthermore, the equipment can be made smaller compared to power generation using microbial fuel cells. Moreover, it is possible to perform efficient desulfurization treatment without installing separate equipment for desulfurization treatment.

[0073] In conventional power generation using microbial fuel cells, increasing the concentration of microorganisms required for wastewater treatment further inhibits mass transfer to the electrodes, resulting in a trade-off between wastewater treatment efficiency and power generation efficiency. On the other hand, the treatment system and power generation method of this embodiment can separate the treatment of the material to be treated (anaerobic treatment) and power generation. Therefore, in the treatment system and power generation method of this embodiment, there is no trade-off between the treatment efficiency of the material to be treated and the power generation efficiency, enabling efficient power generation.

[0074] Furthermore, the configuration of the power generation unit 4 in this embodiment can be made independent as a power generation device or desulfurization treatment device according to the present invention. This power generation device or desulfurization treatment device can be applied to an existing treatment system. This makes it possible to provide the treatment system of the present invention without extensively updating the entire treatment system. In addition, a power generation method or desulfurization method using this treatment system can be provided.

[0075] [Second Embodiment] Figure 2 is a schematic diagram illustrating a processing system in a second embodiment of the present invention. The processing system 1B according to the second embodiment is configured such that the power generation unit 4 in the processing system 1A of the first embodiment is equipped with a storage unit 46 for treated water W2, and the treated water W2 is circulated between the first cell 41a and the storage unit 46. Note that the same configuration as that of the first embodiment will not be described.

[0076] In this embodiment, the power generation unit 4 of the processing system 1B is, as shown in Figure 2, the first embodiment In the power generation unit 4, there is a storage unit 46 for storing treated water W2, and the power generation unit 4 anode side (first It includes a circulation channel 47 connecting cell 41a) and storage section 46.

[0077] The storage unit 46 is not particularly limited and can be anything that can store treated water W2. For example, it can be a sealed tank. By storing the treated water W2 in the storage section 46 via the circulation channel 47, and then returning the treated water W2 to the first cell 41a, the treated water W2 can be repeatedly subjected to the electrode reaction. This allows reducing substances contained in the treated water W2 to be efficiently consumed in the electrode reaction, and in particular, the desulfurization treatment efficiency can be improved.

[0078] Furthermore, the storage unit 46 in this embodiment may have functions other than repeatedly subjecting the treated water W2 to the electrode reaction. Figure 3 is a schematic diagram illustrating another embodiment of the processing system 1B of this embodiment. As shown in Figure 3, another configuration of the processing system 1B involves providing a connecting pipe L6 that connects the processing tank 2 and the storage unit 46, and a discharge pipe L7 that discharges the gas G from the storage unit 46, in order to introduce the gas G (biogas) generated in the processing tank 2 into the storage unit 46 shown in Figure 2. By providing a connecting pipe L6 and bringing the biogas generated in the treatment tank 2 into contact with the treated water W2, it becomes possible to perform desulfurization to reduce the hydrogen sulfide contained in the biogas. Furthermore, by providing a discharge pipe L7, it becomes possible to discharge or recover the biogas after desulfurization. Thus, the storage unit 46 is equipped with functions related to the desulfurization and recovery of gas G (biogas) generated in the treatment tank 2. Furthermore, it is preferable to install equipment related to the utilization of biogas, such as gas storage facilities, downstream of the discharge piping L7 (not shown). This makes it easier to use the biogas recovered after desulfurization as an energy source.

[0079] As described above, by using the processing system 1B of this embodiment, the electrode reaction in the power generation section is After anode The treated water from the side can be repeatedly introduced into the power generation section, and reducing substances can be introduced into the electrons. This improves the reaction efficiency of the donor material, making it possible to carry out particularly efficient desulfurization treatment. Furthermore, the processing system 1B of this embodiment also performs desulfurization of the biogas generated in the processing tank 2. This also makes it possible to effectively recover the waste.

[0080] Furthermore, in the processing system 1B of this embodiment, power generation and desulfurization processing can be performed using the same process as in the first embodiment.

[0081] [Third Embodiment] Figure 4 is a schematic diagram illustrating a processing system in a third embodiment of the present invention. The processing system 1C according to the third embodiment further includes contact efficiency improving means 5 to improve the contact efficiency between the electrode surface of the power generation unit 4 and the electrode reaction components containing reducing substances in the filtrate F, compared to the structure of the processing system 1A in the first embodiment. Note that the same components as those in the first embodiment will not be described.

[0082] As described above, the electrode 43a in this embodiment directly recovers electrons from the reducing substance in the filtrate F. Therefore, by improving the contact efficiency of the reducing substance, which is an electrode reaction component, with respect to the electrode 43a, it is possible to suppress the decrease in electrode reaction efficiency and improve power generation efficiency. Similarly, by improving the contact efficiency of the electron acceptor, which is an electrode reaction component, with respect to the electrode 43b, it is possible to suppress the decrease in electrode reaction efficiency and improve power generation efficiency.

[0083] (Means for improving contact efficiency) The contact efficiency improvement means 5 is for improving the contact efficiency of the electrode reaction components with respect to the surfaces of electrodes 43a and / or electrodes 43b in the power generation unit 4.

[0084] The contact efficiency improving means 5 is not particularly limited, as long as it can improve the contact efficiency of the electrode reaction component with respect to the surfaces of electrode 43a and / or electrode 43b. Examples of the contact efficiency improving means 5 in this embodiment include increasing the migration speed of the electrode reaction component with respect to the surfaces of electrode 43a and / or electrode 43b, or increasing the concentration of the electrode reaction component. Furthermore, it is preferable that the contact efficiency improvement means 5 utilizes a processing step for processing the workpiece S. This allows the processing means for the workpiece S and the contact efficiency improvement means 5 to be used together, reducing the amount of auxiliary equipment related to improving the contact efficiency between the electrode and the electrode reaction components, and significantly lowering running costs.

[0085] The following describes a specific example of the contact efficiency improvement means 5. Note that the following description of the contact efficiency improvement means 5 is an example of the contact efficiency improvement means 5 in this embodiment, and is not limited to this example.

[0086] An example of the contact efficiency improvement means 5 in this embodiment is to provide a moving speed control means 6 on the surface of electrode 43a and / or electrode 43b to control the moving speed of the electrode reaction components.

[0087] Examples of the movement speed control means 6 include those that can control the movement speed of the electrode reaction components with respect to the surfaces of electrodes 43a and / or 43b, thereby increasing the movement speed of the electrode reaction components. Specifically, these include controlling the flow rate when supplying the filtrate F to the power generation unit 4, generating turbulence within the cells of the power generation unit 4 (first cell 41a, second cell 41b), and controlling the temperature related to the electrode reaction.

[0088] Here, if a means for controlling the flow velocity of the entire filtrate F is used as the moving velocity control means 6, considering the total volume of the filtrate F, it is assumed that this flow velocity control will require a great deal of power. Therefore, it is preferable that the moving velocity control means 6 is capable of creating turbulence within the cell of the power generation unit 4 and accelerating the movement velocity of the electrode reaction components. Furthermore, it is even more preferable that it is capable of creating turbulence near the electrode surface within the power generation unit 4. This makes it possible to suppress the power required to control the movement velocity of the electrode reaction components, thereby enabling energy saving and cost reduction.

[0089] A specific example of the movement speed control means 6 is to supply a fluid (gas or liquid) to the surfaces of electrodes 43a and 43b to form turbulence. Figure 5 is a schematic diagram illustrating the use of a device that supplies fluid to the surfaces of electrodes 43a and 43b as the moving speed control means 6 in this embodiment. Note that Figure 5 is an enlarged view of the area around the power generation unit 4 in the processing system 1C, and the processing tank 2 and solid-liquid separation unit 3 are not shown.

[0090] As shown in Figure 5, the movement speed control means 6 includes providing fluid supply ports 61a and 61b and a fluid supply means 62 in the first cell 41a and the second cell 41b, respectively, and arranging them so that fluid is supplied near the surfaces of electrodes 43a and 43b. The dashed arrows in Figure 5 indicate the direction of fluid movement.

[0091] The fluid supply means 62 is not particularly limited and can be any means capable of supplying fluid. Alternatively, the fluid supply means 62 may be a device capable of compressing fluid, supplying compressed fluid. Using compressed fluid makes it easier to control the flow velocity related to turbulence formation near the surfaces of electrodes 43a and 43b.

[0092] When gas is used as the fluid supplied from the fluid supply means 62, examples include supplying gas generated from the processing step for processing the material to be processed S, or partially reusing and supplying gas used in the processing step for processing the material to be processed S. More specifically, examples include recovering biogas generated in the processing tank 2 and supplying it from the fluid supply ports 61a and 61b, or supplying a portion of the aeration gas when an aeration tank is provided as a treatment facility for the treated water W2 from the fluid supply ports 61a and 61b. This makes it possible to use the same gas supply source for both the processing means for the material to be processed S and the moving speed control means 6, thereby reducing processing costs.

[0093] Furthermore, when a liquid is used as the fluid supplied from the fluid supply means 62, for example, a portion of the liquid used in the processing step for processing the material to be processed S may be reused and supplied. More specifically, a portion of the treated water W2 in the discharge pipe L5 may be supplied from the fluid supply ports 61a and 61b. This allows the processing means for the material to be processed S and the liquid supply source for the moving speed control means 6 to be used interchangeably, thereby reducing processing costs.

[0094] Another embodiment of the movement speed control means 6 is to use the treated water inlet 42a, treated water outlet 42b, electron acceptor supply inlet 44a, and electron acceptor outlet 44b as fluid supply inlets 61a and 61b, without providing the fluid supply inlets 61a and 61b shown in Figure 5 as separate components. This eliminates the need to provide a new structure as a contact efficiency improvement means 5 (movement speed control means 6) in the power generation unit 4, thereby reducing equipment costs.

[0095] Furthermore, in the moving speed control means 6, the fluid supplied to the first cell 41a and the second cell 41b may be discharged as is from the outlet 42b and the electron acceptor outlet 44b together with the treated water and electron acceptor, but a recovery means 63 for recovering the supplied fluid may also be provided. In particular, when biogas generated from the treatment tank 2 is used as the fluid for the moving speed control means 6, it is preferable to provide the fluid recovery means 63. This makes it possible to recover and reuse the biogas used in the power generation unit 4 as an energy source again, thereby increasing the energy recovery and utilization efficiency of the treatment system 1C.

[0096] The recovery means 63 is not particularly limited and can be any means capable of discharging and recovering the fluid in the moving speed control means 6 from the first cell 41a and the second cell 41b.

[0097] Figures 6 and 7 are schematic diagrams illustrating another embodiment of the processing system 1C in this embodiment. The processing system 1C in Figures 6 and 7 is a schematic diagram relating to a system in which a recovery means 63 is provided in the moving speed control means 6 shown in Figure 5.

[0098] As shown in Figure 6, one example of a fluid recovery means 63 is to provide fluid outlets 64a and 64b in the first cell 41a and the second cell 41b, and recover the biogas supplied into the first cell 41a and the second cell 41b from the fluid outlets 64a and 64b. Another example of the fluid recovery means 63 is to include a gas-liquid separation unit 65 that separates and recovers the fluid discharged from the treated water outlet 42b and the electron acceptor outlet 44b. For example, as shown in Figure 7, the gas-liquid separation unit 65 is provided on the discharge pipe L3 connected to the treated water outlet 42b to recover the biogas supplied to the first cell 41a. In this case, as shown in Figure 7, it is preferable to provide the inlet 42a and outlet 42b on the side of the first cell 41a, and to provide the outlet 42b at a position higher vertically than the inlet 42a. This makes it possible to efficiently recover the treated water W2 in a mixed state with the fluid (biogas). Furthermore, it is preferable to provide equipment related to the utilization of biogas, such as gas storage equipment, downstream of the recovery means 63 (fluid outlets 64a and 64b, or gas-liquid separation unit 65) (not shown). This makes it easier to utilize the biogas recovered by the recovery means 63 as an energy source.

[0099] Here, when biogas is supplied to the filtrate F in the first cell 41a or the solution in the second cell 41b and recovered via the recovery means 63, water-soluble components (especially hydrogen sulfide) contained in the biogas can be dissolved in the filtrate F, etc., and removed. This makes it possible to provide the treatment system 1C with the function of biogas purification in addition to wastewater treatment, power generation, and desulfurization treatment.

[0100] Another aspect of the movement speed control means 6 is to provide a stirring mechanism in the first cell 41a and the second cell 41b to create turbulence. This makes it possible to control the movement speed of the electrode reaction components relative to the electrode surface without providing a structure for supplying fluid from the outside. Furthermore, the movement speed of the electrode reaction components can be easily controlled by driving the stirring mechanism.

[0101] Furthermore, another embodiment of the movement speed control means 6 is the provision of a temperature control means 66. Figures 8 to 10 are schematic diagrams illustrating the configuration of this embodiment in which a temperature control means 66 is provided as the movement speed control means 6. Figures 8 to 10 are enlarged views of the area around the power generation unit 4 in the processing system 1C, and the processing tank 2 and solid-liquid separation unit 3 are not shown.

[0102] As described above, in the power generation section 4, an electrode reaction is proceeding with reducing substances in the filtrate F acting as electron donors. Furthermore, it is generally known that in electrode reactions, increasing the temperature leads to improvements in mass transfer rate and reaction efficiency. Therefore, by providing a temperature control means 66 as the movement speed control means 6, which controls the temperature related to the electrode reaction within the processing system 1C, it is possible to improve the efficiency of the electrode reaction and increase the power generation efficiency and desulfurization efficiency.

[0103] The temperature control means 66 is not particularly limited and can be any means capable of adjusting the temperature of the power generation unit 4. For example, it can adjust the temperature of the power generation unit 4 itself, or adjust the temperature of the solution (filtrate F, etc.) introduced into the power generation unit 4. Furthermore, as the temperature control means 66, new equipment related to the heat source may be installed, or a heat source may be brought in from outside the processing system 1C, but it is more preferable to use a heat source located within the processing system 1C. This makes it possible to reduce the initial cost and running cost of the equipment related to the processing system 1C.

[0104] In this embodiment, the temperature control means 66 can be made by utilizing the existing heat exchange equipment 67 that is provided to carry out anaerobic treatment in the treatment tank 2. For example, as shown in Figure 8, the power generation unit 4 is installed near the existing heat exchange equipment 67, and the cells (first cell 41a and second cell 41b), electrodes (electrodes 43a and electrodes 43b), introduction pipe L3, inlet 42a, and electron acceptor supply port 44a of the power generation unit 4 are arranged to be supplied with heat from the existing heat exchange equipment 67, thereby heating the power generation unit 4 itself and the filtrate F and electron acceptors introduced into the power generation unit 4. This makes it possible to control the temperature of the part of the reaction that uses reducing substances in the filtrate F as electron donors and the substances used in the reaction without installing new equipment related to temperature control, and makes it possible to control the migration speed of electrode reaction components to the electrode surface.

[0105] Another example of the temperature control means 66 is to provide pipes 68a and 68b connecting the existing heat exchange equipment 67 and the power generation unit 4, as shown in Figure 9, and supply heat from the existing heat exchange equipment 67 to the power generation unit 4 by moving a heat transfer medium such as air or water through the pipes 68a and 68b. This makes it possible to control the temperature of the power generation unit 4, control the temperature at the point where a reaction using reducing substances in the filtrate F as electron donors takes place, and control the movement rate of electrode reaction components to the electrode surface. The means of connecting the pipes 68a and 68b to the power generation unit 4 are not particularly limited. For example, the pipes 68a and 68b may be arranged to surround the entire power generation unit 4, or the pipes 68a and 68b may be arranged to be in contact with any one of the components of the power generation unit 4 (electrodes 43a and 43b, or the first cell 41a and the second cell 41b). Another example of the temperature control means 66 is to provide pipes 69a and 69b connecting the existing heat exchange equipment 67 and the introduction pipe L3, as shown in Figure 10, and supply heat from the existing heat exchange equipment 67 to the filtrate F in the introduction pipe L3 by moving a heat transfer medium such as air or water through the pipes 69a and 69b. This makes it possible to control the temperature of the filtrate F introduced into the power generation unit 4, control the temperature of the substance (reducing substance) used in the reaction that uses the reducing substance in the filtrate F as an electron donor, and control the migration rate of the electrode reaction components to the electrode surface. Furthermore, instead of the inlet pipe L3, the electron acceptor supply port 44a can be used as the connection point for pipes 69a and 69b. This allows heat from the existing heat exchange equipment 67 to be supplied to the electron acceptor, enabling control of the temperature of the substance (electron acceptor) used in the reaction where reducing substances in the filtrate F act as electron donors, and thus controlling the migration rate of the electrode reaction components to the electrode surface. The temperature control means 66 shown in Figures 9 and 10 may be provided individually or in combination. The appropriate configuration can be selected considering the temperature control efficiency and equipment costs associated with the temperature control means 66.

[0106] Furthermore, another example of the temperature control means 66 is to use the waste heat from gas power generation using biogas (such as methane generated by methane fermentation) produced from the treatment tank 2, instead of the existing heat exchange equipment 67. More specifically, by supplying heat to a heat transfer medium such as air or water heated using this waste heat and bringing it into contact with the power generation unit 4 and the introduction pipe L3 through piping, it becomes possible to control the temperature related to the reaction in which reducing substances in the filtrate F act as electron donors. This improves power generation efficiency and desulfurization efficiency, as well as enabling the effective utilization of waste heat related to methane gas power generation.

[0107] Another example of the contact efficiency improvement means 5 in this embodiment is the provision of a concentration control means 7 for controlling the concentration of electrode reaction components.

[0108] Concentration control means 7 include those that can control the concentration of electrode reaction components in the power generation unit 4 and increase the concentration of electrode reaction components at least. Specifically, this includes supplying additional electrode reaction components to the power generation unit 4, concentrating the electrode reaction components in the power generation unit 4 near electrodes 43a and 43b, and maintaining environmental conditions that allow electrode reaction components to dissolve in the filtrate F.

[0109] A specific example of the concentration control means 7 is the additional supply of electrode reaction components into the first cell 41a and the second cell 41b. Figure 11 is a schematic diagram illustrating the use of a concentration control means 7 in this embodiment that supplies additional electrode reaction components into the first cell 41a and the second cell 41b. Note that Figure 11 is an enlarged view of the area around the power generation unit 4 in the processing system 1C, and the processing tank 2 and solid-liquid separation unit 3 are not shown.

[0110] As shown in Figure 11, the concentration control means 7 includes providing electrode reaction component addition ports 71a and 71b and electrode reaction component addition means 72 in the first cell 41a and the second cell 41b, respectively.

[0111] The electrode reaction component adding means 72 is not particularly limited, as long as it can supply additional electrode reaction components to the first cell 41a and the second cell 41b. For example, the electrode reaction component adding means 72 may include a storage section for storing electrode reaction components, a control unit for determining and adjusting the amount of electrode reaction components added, etc.

[0112] The type of electrode reaction component added by the electrode reaction component addition means 72 is not particularly limited, as long as it allows the electrode reaction to proceed in both electrodes 43a and 43b. For example, a reducing substance may be added to the first cell 41a via the electrode reaction component addition means 72 as the electrode reaction component. On the other hand, an electron acceptor may be added to the second cell 41b via the electrode reaction component addition means 72 as the electrode reaction component.

[0113] Furthermore, by using the electrode reaction component as the fluid in the aforementioned movement speed control means 6, it may also serve the function of the electrode reaction component addition means 72. This makes it possible to further improve the contact efficiency between the electrode surface of the power generation unit 4 and the electrode reaction component. In particular, it is preferable to supply biogas from the treatment tank 2 to the first cell 41a of the power generation unit 4 and utilize it as the fluid in the movement speed control means 6 and as the electrode reaction component in the electrode reaction component addition means 72. In this case, water-soluble components (especially hydrogen sulfide) in the biogas dissolve in the filtrate F, increasing the concentration of reducing substances in the filtrate F, while hydrogen sulfide can be removed from the biogas. This has the effect of improving power generation efficiency and desulfurization efficiency, as well as providing a biogas purification function.

[0114] Another specific example of the concentration control means 7 is to concentrate the electrode reaction components within the power generation unit 4 near electrodes 43a and 43b. Figure 12 is a schematic diagram illustrating the use of a concentration control means 7 in this embodiment that concentrates the electrode reaction components near electrodes 43a and 43b. Note that Figure 12 is an enlarged view of the area around the power generation unit 4 in the processing system 1C, and the processing tank 2 and solid-liquid separation unit 3 are not shown.

[0115] As shown in Figure 12, one example of a concentration control means 7 is one in which an adsorbent 73 is provided in the first cell 41a and the second cell 41b.

[0116] The adsorbent 73 can be any material capable of adsorbing electrode reaction components, and its material and shape are not particularly limited. For example, the first cell 41a may be provided with an adsorbent 73 capable of adsorbing reducing substances as electrode reaction components. On the other hand, the second cell 41b may be provided with an adsorbent 73 capable of adsorbing electron acceptors as electrode reaction components. Furthermore, the adsorbent 73 may be provided in the vicinity of electrodes 43a and 43b, and electrodes 43a and 43b may be made of porous material, so that electrodes 43a and 43b themselves function as the adsorbent 73. This makes it possible to concentrate the electrode reaction components in the vicinity of electrodes 43a and 43b and control the concentration of the electrode reaction components.

[0117] Furthermore, another specific example of the concentration control means 7 is maintaining environmental conditions that allow electrode reaction components to remain dissolved in the filtrate F. Figure 13 is a schematic diagram illustrating the use of a concentration control means 7 in this embodiment that maintains environmental conditions for dissolving electrode reaction components in the filtrate F. Note that Figure 13 is an enlarged view of the area around the power generation unit 4 in the processing system 1C, and the processing tank 2 and solid-liquid separation unit 3 are not shown.

[0118] As described above, in treatment tank 2, hydrogen sulfide, a reducing substance, is generated as anaerobic treatment (such as methane fermentation) progresses. On the other hand, it is known that the solubility of hydrogen sulfide in a solution changes depending on the pH, and that increasing the pH to an alkaline level of 6 or higher increases its solubility and suppresses the release of hydrogen sulfide into the solution. Therefore, by providing a pH control means 74 that adjusts the pH of the treatment liquid W1 and filtrate F, it is possible to change the solubility of reducing substances (especially hydrogen sulfide) and maintain environmental conditions that allow reducing substances in filtrate F to remain dissolved in filtrate F. This increases the amount of reducing substances in filtrate F and increases the amount of electron donors used in the reaction, thereby improving the power generation efficiency and desulfurization efficiency in the power generation unit 4.

[0119] The pH control means 74 is not particularly limited and can be any means that adjusts the pH of the treatment liquid W1 or filtrate F and allows reducing substances in the filtrate F to dissolve in the filtrate F. As shown in Figure 12, the pH control means 74 includes a storage unit 75 for storing a pH adjusting agent, an addition unit 76 for adding the pH adjusting agent to the filtrate F, and a pH detection unit 77.

[0120] The storage section 75 can be any type capable of storing a pH adjusting agent and is not particularly limited. Furthermore, the pH adjusting agent stored in the storage section 75 is not particularly limited, and it is preferable to select the type of pH adjusting agent according to the pH dependence of the solubility of the reducing substance. For example, if the reducing substance is hydrogen sulfide, a pH adjusting agent that makes the pH of the filtrate F more alkaline can be used to increase the solubility of hydrogen sulfide. More specifically, hydroxides such as sodium hydroxide or calcium hydroxide can be used as pH adjusting agents. Acids such as hydrochloric acid or sulfuric acid may also be used as pH adjusting agents.

[0121] The additive section 76 is for adding the pH adjusting agent from the storage section 75 into the filtrate F. In this embodiment, the additive section 76 is provided on the introduction pipe L3, as shown in Figure 13. The additive section 76 is not particularly limited and only needs to have a structure that allows the pH adjusting agent to be added to the filtrate F in the introduction pipe L3. For example, it may consist of a pipe that connects the introduction pipe L3 and the storage section 75 and has a flow rate adjustment function.

[0122] The location of the additive unit 76 is not particularly limited, but it is preferable to select a location that can adjust the pH of the filtrate F and appropriately control the solubility of reducing substances. For example, as shown in Figure 13, in addition to providing the additive unit 76 on the introduction pipe L3, it can also be provided on the connecting pipe L2 between the treatment tank 2 and the solid-liquid separation unit 3. This allows hydrogen sulfide generated by anaerobic treatment in the treatment tank 2 to be dissolved in the treatment liquid W1 before being introduced into the solid-liquid separation unit 3. As a result, it becomes possible to introduce the filtrate F into the power generation unit 4 while maintaining environmental conditions that allow reducing substances in the filtrate F to remain dissolved in the filtrate F.

[0123] Another example of the pH control means 74 is the use of other equipment within the processing system. Figure 14 is a schematic diagram illustrating another embodiment of the pH control means in the concentration control means 7 of this embodiment. Note that Figure 14 is an enlarged view of the area around the power generation unit 4 in the processing system 1C, and the processing tank 2 and solid-liquid separation unit 3 are not shown. As shown in Figure 14, the pH control means 74 includes a storage unit 46 that circulates treated water W2 to the power generation unit 4 and a connecting pipe L6 that supplies gas G (biogas) generated in the treatment tank 2 to the storage unit 46 (see Figure 3), and the treated water W2 into which gas G has been introduced is used as a pH adjuster. In this case, the storage unit 46 also functions as the storage unit 75 described above. This eliminates the need to provide a new structure for the pH control means 74, improves power generation efficiency and desulfurization efficiency, and also makes it possible to purify the biogas generated in the treatment tank 2.

[0124] As shown in Figure 13, it is preferable to provide a pH detection unit 77 on the introduction pipe L3 and control the amount of pH adjusting agent added from the addition unit 76 according to the detection result of the pH detection unit 77. Alternatively, the pH detection unit 77 may be provided on the storage unit 75 (storage unit 46) or circulation channel 47 (not shown) as shown in Figure 14 to adjust the circulation rate of treated water W2. This makes it easier to adjust the pH of the filtrate F and to perform the adjustment at an appropriate timing. As a result, it is possible to increase the amount of reducing substances in the filtrate F introduced into the power generation unit 4 and increase the amount of electron donors used in the reaction, thereby improving the power generation efficiency and desulfurization treatment efficiency in the power generation unit 4. Furthermore, the control means for the additive unit 76 and the means for adjusting the circulation rate of the treated water W2 according to the detection result of the pH detection unit 77 are not particularly limited. For example, the detection result of the pH detection unit 77 could be visually confirmed by an operator, and the additive unit 76 and the circulation channel 47 of the treated water W2 could be operated manually according to the result, or the pH detection unit 77 and the additive unit 76 (or the circulation channel 47) could be connected in a controllable manner to automatically control the pH detection of the filtrate F and the addition of the pH adjusting agent (or the circulation rate of the treated water W2).

[0125] In this embodiment, the contact efficiency improvement means 5 can have its operating conditions set as appropriate. For example, it may be set to operate constantly when the power generation unit 4 is driven (during power generation), or the operating interval and timing may be changed periodically or irregularly. This allows for setting operating conditions that enable efficient power generation and desulfurization treatment by the processing system 1C, making it possible to efficiently recover and utilize energy and improve the efficiency of the desulfurization treatment.

[0126] In this embodiment, the processing system 1C may set the operating conditions of the moving speed control means 6 and the concentration control means 7 in order to suppress the accumulation of deposits on the surfaces of electrodes 43a and 43b. Furthermore, the moving speed control means 6 and the concentration control means 7 themselves may also function as the cleaning means 8 described later, in order to remove deposits from the electrode surface. This allows the contact efficiency improvement means 5 to have multiple functions for improving the contact efficiency between the electrode surface and the electrode reaction components, thereby simplifying the apparatus configuration.

[0127] As described above, in the processing system 1C of this embodiment, by providing contact efficiency improving means that improve the contact efficiency between the electrode surface of the power generation unit and the electrode reaction components, it is possible to suppress a decrease in the efficiency of the electrode reaction and improve the efficiency of power generation and desulfurization treatment.

[0128] Furthermore, in the processing system 1C of this embodiment, power generation and desulfurization processing can be performed using the same process as in the first embodiment.

[0129] In particular, as a means for improving contact efficiency in the processing system 1C of this embodiment, by providing a movement speed control means for controlling the movement speed of the electrode reaction component with respect to the electrode surface, it becomes possible to quickly supply the electrode reaction component to the electrode surface. This improves the contact efficiency between the electrode surface and the electrode reaction component, suppresses the decrease in the efficiency of the electrode reaction, and enables an improvement in power generation efficiency.

[0130] Furthermore, by providing a concentration control means for controlling the concentration of electrode reaction components as a means for improving contact efficiency in the processing system 1C of this embodiment, it becomes possible to increase the amount of electrode reaction components involved in the electrode reaction. This improves the contact efficiency between the electrode surface and the electrode reaction components, suppresses the decrease in the efficiency of the electrode reaction, and enables an improvement in power generation efficiency.

[0131] Furthermore, by using a means that combines the above-mentioned movement speed limiting means and concentration control means as a means for improving contact efficiency in the processing system 1C of this embodiment, it becomes possible to further suppress the decrease in the efficiency of the electrode reaction. In particular, by utilizing the biogas generated in the processing tank and using it as a fluid for turbulence formation in the movement speed control means and as an electrode reaction component for additional supply in the concentration control means, it becomes possible to further improve the contact efficiency between the electrode surface of the power generation unit and the electrode reaction component, and to remove water-soluble components (especially hydrogen sulfide) in the biogas. Therefore, the processing system 1C of this embodiment also has the effect of providing a biogas purification function in addition to wastewater treatment, power generation, and desulfurization treatment.

[0132] [Fourth Embodiment] The processing system 1D according to the fourth embodiment is provided with a cleaning means 8 as a contact efficiency improvement means 5 for cleaning deposits accumulated on the surfaces of electrodes 43a and 43b, compared to the processing system 1A in the first embodiment. Note that the same components as those in the first and third embodiments will not be described.

[0133] As shown in Equations 1 and 2, products generated by the electrode reaction (such as sulfur) and microorganisms that partially enter the power generation unit 4 adhere to the surface of electrode 43a and accumulate as deposits. At this time, the mass transfer rate of reducing substances to electrode 43a is inhibited by the deposits, resulting in a problem of reduced electrode reaction efficiency. Similarly, at electrode 43b, substances introduced as electron acceptors and impurities that have been introduced adhere to electrode 43b and accumulate as deposits, resulting in a problem of reduced electrode reaction efficiency. Therefore, by providing a cleaning means 8 as a contact efficiency improvement means 5, deposits on the electrode surface can be removed and the contact efficiency between the electrode and the electrode reaction components can be improved. In addition, the decrease in electrode reaction efficiency in the power generation unit 4 can be suppressed, and the power generation efficiency and desulfurization treatment efficiency can be improved.

[0134] The cleaning means 8 is for cleaning the surfaces of electrodes 43a and 43b in the power generation unit 4 to suppress a decrease in electrode reaction efficiency. The cleaning means 8 is not particularly limited and can be any means capable of removing deposits accumulated on the surfaces of electrodes 43a and 43b. In this embodiment, the cleaning means 8 may be one in which electrodes 43a and 43b are cleaned while remaining inside the power generation unit 4, or one in which electrodes 43a and 43b are removed from the power generation unit 4 for cleaning. The appropriate method can be selected considering the cleaning effect and ease of operation.

[0135] The following describes specific examples of cleaning means. Note that the following description of cleaning means 8 is an example of cleaning means 8 in this embodiment and is not limited to this example.

[0136] One example of a cleaning means 8 in this embodiment is one that includes a peeling means 8A that applies an external force to peel off deposits accumulated on the electrode surface. The peeling means 8A can be any means that can peel off the deposit by applying an external force to it. Examples include means for mechanically rubbing the surfaces of electrodes 43a and 43b, or means for applying shear force using gas or liquid to the deposits accumulated on the surfaces of electrodes 43a and 43b. By using the peeling means 8A as the cleaning means 8, the deposits can be forcibly peeled off from the surfaces of electrodes 43a and 43b, and a high cleaning effect can be obtained regardless of the type of deposit. Furthermore, by using the peeling means 8A, cleaning can be performed without changing the environmental conditions (pH, concentration of various compounds, etc.) inside the first cell 41a and the second cell 41b by the cleaning means 8.

[0137] Specific examples of the peeling means 8A include providing a member that rubs the surfaces of electrodes 43a and 43b, such as a sponge or a scraper. An example of using a component to rub the surfaces of electrodes 43a and 43b is to provide a drive unit and control unit so that the surfaces of electrodes 43a and 43b can be automatically rubbed, and to set the frequency and timing of cleaning. This makes it easier to clean the deposits accumulated on the surfaces of electrodes 43a and 43b. In addition, by moving the component periodically, it is possible to suppress the accumulation of deposits on the surfaces of electrodes 43a and 43b in the first place. Another example of using a material to rub the surfaces of electrodes 43a and 43b is to have the worker directly clean the surfaces of electrodes 43a and 43b. This allows for both cleaning of the surfaces of electrodes 43a and 43b and visual maintenance by the worker.

[0138] Another specific example of the peeling means 8A is to apply bubbles or compressed fluid (gas or liquid) to the surfaces of electrodes 43a and 43b. Figure 15 is a schematic diagram illustrating the use of a peeling means 8A in this embodiment that applies a fluid (gas or liquid) to the surfaces of electrodes 43a and 43b. Note that Figure 15 is an enlarged view of the area around the power generation unit 4 in the processing system 1D, and the processing tank 2 and solid-liquid separation unit 3 are not shown.

[0139] As shown in Figure 15, the peeling means 8A is provided with fluid supply ports 81a and 81b and a fluid supply means 82 in the first cell 41a and the second cell 41b, respectively, and arranged so that the fluid comes into contact with the surfaces of electrodes 43a and 43b. The dashed arrows in Figure 15 indicate the direction of fluid movement. Furthermore, the fluid supply ports 81a and 81b and the fluid supply means 82 may have the same structure as the fluid supply ports 61a and 61b and the fluid supply means 62 in the aforementioned movement speed control means 6, and may combine the functions of the movement speed control means 6 and the peeling means 8A.

[0140] The fluid supply means 82 can be any means capable of supplying fluid, and is not particularly limited.

[0141] When gas is used as the fluid supplied from the fluid supply means 82, examples include supplying gas generated from the processing step for processing the material to be processed S, or partially reusing and supplying gas used in the processing step for processing the material to be processed S. More specifically, examples include recovering biogas generated in the processing tank 2 and supplying it from the fluid supply ports 81a and 81b, or supplying a portion of the aeration gas from the fluid supply ports 81a and 81b when an aeration tank is provided as a processing facility for processing the treated water W2. This makes it possible to use the same gas supply source for both the processing means for the material to be processed S and the washing means 8, thereby reducing processing costs. In this case, the fluid supply means 82 may also be equipped with equipment capable of compressing gas (blower, compressor, etc.) and supply compressed gas. By using compressed gas, the shear force on the deposits accumulated on the surfaces of electrodes 43a and 43b is increased, thereby improving the washing effect.

[0142] Furthermore, when a liquid is used as the fluid supplied from the fluid supply means 82, for example, a portion of the liquid used in the processing step for processing the workpiece S may be reused and supplied. More specifically, a portion of the treated water W2 in the discharge pipe L5 may be supplied from the fluid supply ports 81a and 81b. This allows the liquid supply source for the processing means of the workpiece S and the cleaning means 8 to be used interchangeably, thereby reducing processing costs. In this case, the fluid supply means 82 may be equipped with equipment capable of compressing liquid (such as a high-pressure pump) to supply high-pressure liquid. By using high-pressure liquid, the shear force on the deposits accumulated on the surfaces of electrodes 43a and 43b is increased, thereby enhancing the cleaning effect.

[0143] When fluid supply ports 81a, 81b and a fluid supply means 82 are provided as the peeling means 8A, it is preferable that the direction of fluid movement is opposite to the direction of movement of the filtrate F and electron acceptor, as shown in Figure 15. This applies a shear force in the opposite direction to the deposits accumulated on the surfaces of electrodes 43a and 43b along the direction of movement of the filtrate F and electron acceptor, thereby further enhancing the cleaning effect.

[0144] Another embodiment of the peeling means 8A is to use the inlet 42a, outlet 42b, electron acceptor supply port 44a, and electron acceptor outlet 44b as the fluid supply ports 81a and 81b, rather than providing the fluid supply ports 81a and 81b shown in Figure 15 as separate components. This eliminates the need to provide a new structure as a cleaning means 8 in the power generation unit 4, thereby reducing equipment costs.

[0145] Figure 16 is a schematic diagram illustrating another aspect of the peeling means 8A in this embodiment. Note that Figure 16 is an enlarged view of the area around the power generation unit 4 in the processing system 1D, and the processing tank 2 and solid-liquid separation unit 3 are omitted from the illustration. Also, the dashed arrows in Figure 16 indicate the direction of fluid movement.

[0146] As shown in Figure 16, the stripping means 8A may include, for example, pumps P1 and P2 capable of pressurizing liquid on the introduction pipe L3 and discharge pipe L5, and supplying high-pressure liquid toward the surface of the electrode 43a for cleaning. In this case, the high-pressure liquid may be supplied from the introduction pipe L3 side toward the inlet 42a, or from the discharge pipe L5 side toward the outlet 42b. In addition, as shown in Figure 16, a control unit 83 may be provided to switch the operation of pump P1 on the introduction pipe L3 and pump P2 on the discharge pipe L5. This makes it easy to switch between the normal wastewater treatment process and the cleaning process. Furthermore, it may be possible to supply high-pressure liquid alternately from the introduction pipe L3 side and the discharge pipe L5 side. This makes it possible to improve the cleaning effect on the surface of the electrode 43a.

[0147] Furthermore, as shown in Figure 16, the peeling means 8A may include, for example, cleaning the surface of the electrode 43b by supplying compressed fluid from the electron acceptor supply port 44a and the electron acceptor outlet 44b. In this case, gas generated from the processing step for processing the workpiece S, or fluid used in processing the workpiece S, may be compressed with a pump or the like and supplied (not shown). This makes it possible to minimize the structure newly provided as the peeling means 8A and reduce equipment costs.

[0148] Furthermore, in the peeling means 8A, the fluid supplied to the first cell 41a and the second cell 41b may be discharged from the outlet 42b and the electron acceptor outlet 44b after washing, or it may be discharged from a separate fluid outlet (not shown). In particular, when biogas generated from the treatment tank 2 is used as the fluid for the peeling means 8A, it is preferable to recover the fluid after washing from the fluid outlet. When recovering the fluid after washing, a structure similar to that of the recovery means 63 described above may be provided. This makes it possible to recover and reuse the fluid after washing as biogas, thereby increasing the energy recovery and utilization efficiency of the treatment system 1D.

[0149] Another embodiment of the cleaning means 8 in this embodiment includes a dissolving means 8B for dissolving deposits accumulated on the electrode surface. The dissolution means 8B can be any means capable of dissolving the sediment, and examples include means of adding a sediment-dissolving agent to electrodes 43a and 43b, or electrochemical means of controlling the voltage and current between electrodes 43a and 43b. By using the dissolution means 8B as the cleaning means 8, fewer new equipment configurations are required, and the equipment can be miniaturized. Furthermore, especially when the surfaces of electrodes 43a and 43b are porous, a high cleaning effect is achieved on the sediment accumulated on and inside the surfaces of electrodes 43a and 43b.

[0150] A specific example of the dissolution method 8B is the addition of a chemical agent that dissolves the sediment. Figure 17 is a schematic diagram illustrating the use of a dissolution means 8B in this embodiment, in which a chemical agent is added to the surfaces of electrodes 43a and 43b. Note that Figure 17 is an enlarged view of the area around the power generation unit 4 in the processing system 1D, and the processing tank 2 and solid-liquid separation unit 3 are not shown.

[0151] As shown in Figure 17, an example of using a dissolving means 8B that adds a drug is provided with drug addition ports 84a and 84b and a drug addition means 85 in the first cell 41a and the second cell 41b, respectively, and arranged so that the drug is supplied to the deposits accumulated on the surfaces of electrodes 43a and 43b. The dashed arrows in Figure 17 indicate the direction of drug addition.

[0152] The drug addition means 85 is not particularly limited, as long as it is capable of adding the drug to the first cell 41a and the second cell 41b. For example, the drug addition means 85 may include a storage section for storing the drug, a control unit for determining and adjusting the amount of drug to be added, etc.

[0153] The type of chemical added by the chemical addition means 85 is not particularly limited, as long as it can dissolve the sediment. Examples of chemicals include acids such as hydrochloric acid and sulfuric acid, and alkalis such as aqueous sodium hydroxide solution. Alternatively, chemicals such as pH adjusters used in the processing steps for treating the material S may be used. This eliminates the need to prepare new chemicals for the washing means 8, thereby reducing running costs.

[0154] When dissolving means 8B is provided with drug addition ports 84a and 84b and drug addition means 85, it is preferable that the direction of drug addition be from the top to the bottom of electrodes 43a and 43b, as shown in Figure 17. In particular, when the contents stored in the first cell 41a and the second cell 41b are liquid, adding the drug from the top of electrodes 43a and 43b allows the drug to diffuse rapidly into cells 41a and 41b. As a result, the drug is efficiently distributed across the entire surface of electrodes 43a and 43b, thereby enhancing the cleaning effect.

[0155] Alternatively, a drug addition means 85 may be connected to the introduction piping L3 to supply the drug to the electrode 43a from the inlet 42a. This eliminates the need to provide a separate drug addition port 84a, thus simplifying the device configuration.

[0156] Another embodiment of the dissolution means 8B involves providing a voltage / current control device connected to electrodes 43a and 43b and performing electrochemical treatment. More specifically, this may involve applying a high voltage between electrodes 43a and 43b, or passing a current in the opposite direction to the electrode reaction during power generation. This makes it possible to effectively dissolve deposits accumulated on the surface and within the porous structure of electrodes 43a and 43b, especially when electrodes 43a and 43b are porous. In particular, when the deposits consist mainly of those generated by electrode reactions, passing a current in the opposite direction to the electrode reaction during power generation forces the deposits to oxidize (or reduce), resulting in a high cleaning effect.

[0157] Another embodiment of the cleaning means 8 in this embodiment includes a dispersion means 8C for dispersing and freeing up deposits accumulated on the electrode surface. The dispersion means 8C can be any means that disperses the deposits on the electrode surface and thereby separates the deposits from the electrode surface. Examples include adding a chemical agent that has a deposit-dispersing effect to electrodes 43a and 43b, or applying vibration to the surfaces of electrodes 43a and 43b. By using the dispersion means 8C as the cleaning means 8, the deposits are dispersed once and separated from the surfaces of electrodes 43a and 43b, making it possible to clean with less load on the surfaces of electrodes 43a and 43b. Furthermore, if electrodes 43a and 43b are porous, a high cleaning effect is also achieved on deposits accumulated within the porous structure.

[0158] A specific example of dispersion method 8C is the addition of a chemical agent that has the effect of dispersing the sediment. Figure 18 is a schematic diagram illustrating the use of a dispersion means 8C in this embodiment in which a chemical agent is added to the surfaces of electrodes 43a and 43b. Note that Figure 18 is an enlarged view of the area around the power generation unit 4 in the processing system 1D, and the processing tank 2 and solid-liquid separation unit 3 are not shown.

[0159] As shown in Figure 18, an example of using a system in which a drug is added as the dispersion means 8C is to provide drug addition ports 86a and 86b and a drug addition means 87 in the first cell 41a and the second cell 41b, respectively, and arrange them so that the drug is supplied to the deposits accumulated on the surfaces of electrodes 43a and 43b. The dashed arrows in Figure 18 indicate the direction of drug addition.

[0160] The drug addition means 87 is not particularly limited, as long as it is capable of adding the drug to the first cell 41a and the second cell 41b. For example, the drug addition means 87 may include a storage section for storing the drug, a control unit for determining and adjusting the amount of drug to be added, etc.

[0161] The type of agent added by the agent addition means 87 is not particularly limited, as long as it can disperse the sediment. Examples of agents include surfactants and enzymes. The agent used in this case has the effect of having little corrosion or other effect on electrodes 43a and 43b, and does not place an unnecessary load on the surfaces of electrodes 43a and 43b. In particular, when the sediment mainly consists of microorganisms, using surfactants or enzymes makes it possible to disperse the microorganisms on the surfaces of electrodes 43a and 43b and detach them from the surfaces of electrodes 43a and 43b. This makes it possible to avoid dead microorganisms remaining as sediment on the surfaces of electrodes 43a and 43b and to suppress a decrease in electrode reaction efficiency.

[0162] When the dispersion means 8C includes drug addition ports 86a and 86b and a drug addition means 87, it is preferable that the direction of drug addition be from the top to the bottom of electrodes 43a and 43b, as shown in Figure 16. In particular, when the contents stored in the first cell 41a and the second cell 41b are liquid, adding the drug from the top of electrodes 43a and 43b allows the drug to diffuse rapidly into cells 41a and 41b. This allows the drug to efficiently spread across the entire surface of electrodes 43a and 43b, thereby enhancing the cleaning effect.

[0163] Alternatively, a drug addition means 87 may be connected to the introduction piping L3 to supply the drug to the electrode 43a from the inlet 42a. This eliminates the need to provide a separate drug addition port 86a, thus simplifying the device configuration.

[0164] Another aspect of the dispersion means 8C is to apply vibration to electrodes 43a and 43b. More specifically, this involves arranging an ultrasonic generator so that ultrasonic waves can be irradiated onto electrodes 43a and 43b. This makes it possible to subdivide and disperse the deposits accumulated on the surfaces of electrodes 43a and 43b, and to separate them from the surfaces of electrodes 43a and 43b. In particular, when the deposits are aggregates of microorganisms or when the products of electrode reactions are in the form of clumps, the deposits can be subdivided by ultrasonic waves, making it possible to easily peel off the deposits without putting stress on the surfaces of electrodes 43a and 43b.

[0165] Another embodiment of the cleaning means 8 in this embodiment includes a surrounding environment changing means 8D that changes the surrounding environment of the electrode surface. The means for changing the surrounding environment 8D can be anything that changes the environment surrounding the electrode surface, and examples include temperature control means such as heating and cooling, means for supplying additives that change the physical properties in the first cell 41a and the second cell 41b, and means for inflicting a certain amount of damage on the deposit. By using the means for changing the surrounding environment 8D as the cleaning means 8, if the deposit contains microorganisms, the microorganisms will not be able to withstand the environmental changes around the electrode surface, and will spontaneously move away from the electrode surface. This makes it possible to effectively remove microorganisms from the electrode surface and obtain a high cleaning effect on the electrode surface.

[0166] A specific example of the surrounding environment changing means 8D is supplying additives that change the physical properties within the first cell 41a and the second cell 41b. Figure 19 is a schematic diagram illustrating the use of a means 8D for changing the surrounding environment in this embodiment, which supplies additives to the surfaces of electrodes 43a and 43b. Note that Figure 19 is an enlarged view of the area around the power generation unit 4 in the processing system 1D, and the processing tank 2 and solid-liquid separation unit 3 are not shown.

[0167] As shown in Figure 19, an example of using an additive supply as the surrounding environment changing means 8D is to provide additive supply ports 88a and 88b and an additive supply means 89 in the first cell 41a and the second cell 41b, respectively, thereby changing the surrounding environment of the surface of electrodes 43a and 43b and the deposited deposits. The dashed arrows in Figure 19 indicate the direction of additive addition.

[0168] The additive supply means 89 is not particularly limited, as long as it is capable of supplying additives to the first cell 41a and the second cell 41b. For example, the additive supply means 89 may include a storage section for storing additives, a control unit for determining and adjusting the amount of additive supplied, and so on.

[0169] The type of additive supplied by the additive supply means 89 is not particularly limited, as long as it can change the physical properties within the first cell 41a and the second cell 41b. Examples of additives include salts such as sodium chloride and potassium chloride, and ion-free substances such as electrolyzed water. This changes the salt concentration within the first cell 41a and the second cell 41b, which in turn changes the osmotic pressure around the surfaces of electrodes 43a and 43b, thereby encouraging microorganisms to spontaneously move away from the surfaces of electrodes 43a and 43b.

[0170] When additive supply ports 88a, 88b and additive supply means 89 are provided as the surrounding environment changing means 8D, it is preferable that the direction of additive supply be from the top to the bottom of electrodes 43a and 43b, as shown in Figure 19. In particular, when the contents stored in the first cell 41a and the second cell 41b are liquid, supplying the additive from the top of electrodes 43a and 43b causes the additive to spread along the surface of electrodes 43a and 43b. This makes it possible to effectively change the physical properties around the surface of electrodes 43a and 43b, thereby enhancing the cleaning effect.

[0171] Another aspect of the surrounding environment alteration means 8D is to inflict a certain amount of damage on the sediment. More specifically, if the sediment on the surfaces of electrodes 43a and 43b consists of microorganisms, this may involve supplying chlorine or ozone to the microorganisms or irradiating them with ultraviolet light. This allows for a certain amount of damage to the sediment (microorganisms) accumulated on the surfaces of electrodes 43a and 43b. In this case, the microorganisms cannot withstand the environmental change of being damaged, and are encouraged to spontaneously move away from the surfaces of electrodes 43a and 43b. However, if the amount of chlorine or ozone supplied, or the amount of ultraviolet irradiation, is excessive, the microorganisms will die on the surfaces of electrodes 43a and 43b and remain as sediment. Therefore, it is preferable to limit the amount of chlorine or ozone supplied, or the amount of ultraviolet irradiation, which also has the effect of reducing running costs.

[0172] In the processing system 1D of this embodiment, the cleaning means 8 is not limited to performing the peeling means 8A, dissolving means 8B, dispersion means 8C, and surrounding environment alteration means 8D individually, but may be a combination of multiple means 8A to 8D. This makes it possible to select and implement a suitable cleaning means 8 depending on the type of sediment, thereby achieving a higher cleaning effect. In particular, in the configuration of means 8B to 8D of the cleaning means 8 in which chemicals and additives are added to the first cell 41a and the second cell 41b, it is possible to implement each of means 8B to 8D simply by changing the chemicals and additives added. Therefore, means 8B to 8D can be easily switched according to the type of sediment, making it possible to perform effective cleaning.

[0173] As described above, in the processing system 1D of this embodiment, by providing a cleaning means for cleaning deposits accumulated on the electrode surface as a means for improving contact efficiency, it is possible to suppress a decrease in the efficiency of the electrode reaction and improve the efficiency of power generation and desulfurization treatment.

[0174] Furthermore, in the processing system 1D of this embodiment, power generation and desulfurization processing can be performed using the same process as in the first embodiment.

[0175] Furthermore, in the power generation unit 4 of the processing system 1D of this embodiment, the accumulation of deposits on the electrode surface can lead to a reduction in the volume of the cells (first cell 41a and second cell 41b) within the power generation unit 4, as well as clogging inside the electrodes (electrodes 43a and electrodes 43b), which can cause pressure loss. Therefore, as in the processing system 1D of this embodiment, it is possible to suppress pressure loss within the device by providing a cleaning means as a means of improving contact efficiency and removing deposits from the electrode surface.

[0176] [Fifth Embodiment] Figure 20 is a schematic diagram illustrating a processing system in the fifth embodiment of the present invention. Figure 21 is a schematic diagram illustrating another aspect of the processing system in the fifth embodiment of the present invention. The fifth embodiment of the processing system 1E, as shown in Figures 20 and 21, is provided with an exhaust gas supply means 9 as a means to suppress the rise in pH on the cathode side, in addition to the processing system 1A of the first embodiment. Note that the same components as those in the first embodiment will not be described. Furthermore, Figures 20 and 21 are enlarged explanatory diagrams of the area around the power generation unit 4 of the processing system 1E, and the configurations of the processing tank 2 and the solid-liquid separation unit 3 are not shown.

[0177] As described above, in the electrode reaction in the processing system of this embodiment, reaction R3 generates hydrogen ions (H) on the cathode side. + The movement of ) allows reaction R4 based on equation 3 to proceed. However, in reaction R3, hydrogen ions move via the ion exchanger 45, so the electrode reaction may proceed before sufficient hydrogen ions are supplied to electrode 43b, which is the cathode side, in the reaction based on equation 3. In this case, at electrode 43b, instead of the reaction that produces water (H2O) based on equation 3, hydroxide ions (OH) are produced. - The reaction that produces ) proceeds, causing an increase in pH at electrode 43b (cathode side). This leads to the problem of reduced electrode reaction efficiency.

[0178] Therefore, it is preferable to provide the processing system with means to suppress the rise in pH on the cathode side of the power generation unit 4. One example of a means to suppress the rise in pH is to add an acidic component. Here, in addition to newly installing a means to add an acidic component as a chemical, a more preferable example of a means to suppress the rise in pH is to make it possible to utilize waste discharged from existing equipment, etc. This makes it possible to reduce costs and energy consumption of the processing system 1E. One way to utilize emissions from existing equipment and suppress pH increases is to supply exhaust gases generated by various combustion devices to the treatment system 1E. The exhaust gases generated by combustion devices include carbon dioxide (CO2) and sulfur oxides (SO2). X ), nitrogen oxides (NO X These include ), and it is known that these exhaust gas components exhibit acidity when dissolved in aqueous solution. Therefore, by utilizing the exhaust gas generated in the combustion device, it is possible to suppress the rise in pH in the power generation unit 4.

[0179] (Exhaust gas supply means) The exhaust gas supply means 9 supplies exhaust gas generated by the combustion device to the power generation unit 4, thereby suppressing the rise in pH and thus suppressing a decrease in electrode reaction efficiency. The exhaust gas supply means 9 is not particularly limited, as long as it can supply exhaust gas generated by the combustion device to the power generation unit 4. In this embodiment, it is particularly preferable that the exhaust gas supply means 9 supplies exhaust gas into the second cell 41b where the cathode electrode 43b is located. Examples of such exhaust gas supply means 9 include those that have a structure for directly supplying exhaust gas to the second cell 41b, and those that have a structure for supplying exhaust gas together with an electron acceptor.

[0180] A specific example of the exhaust gas supply means 9 is to directly provide a mechanism for supplying exhaust gas generated by the combustion device to the second cell 41b in the power generation unit 4. Figure 20 is a schematic diagram illustrating how the exhaust gas supply means 9 of this embodiment is directly provided with a mechanism for supplying exhaust gas to the second cell 41b.

[0181] As shown in Figure 20, the exhaust gas supply means 9 includes providing an exhaust gas supply port 91 in the second cell 41b and connecting a pipe 92 to the exhaust gas supply port 91 for supplying exhaust gas generated by a combustion device (not shown). Here, the dashed arrow in Figure 20 indicates the direction of exhaust gas inflow. Also, although Figure 20 illustrates an exhaust gas supply means 9 in which the exhaust gas supply port 91 is provided at the top of the second cell 41b to supply exhaust gas, it is not limited to this. Other examples of exhaust gas supply means 9 include providing the exhaust gas supply port 91 at the bottom of the second cell 41b and supplying the exhaust gas so that it rises from the bottom to the top of the second cell 41b.

[0182] The exhaust gas supply port 91 and piping 92 can use known configurations for gas supply and transfer, and their specific structure is not particularly limited. Furthermore, the piping 92 only needs to be for transporting exhaust gas generated in the combustion device, and may be directly connected to the combustion device or connected indirectly.

[0183] The exhaust gas supply means 9 is not limited to the configuration shown in Figure 20, which includes an exhaust gas supply port 91 and piping 92 connected to the power generation unit 4. For example, the exhaust gas supply means 9 may be configured by connecting piping 92 to the electron acceptor storage location or the line supplying the electron acceptor, and supplying exhaust gas from the electron acceptor supply port 44a to the electrode 43b. This eliminates the need to provide the exhaust gas supply port 91 as a separate component, thus simplifying the device configuration.

[0184] In this embodiment, the structure of the combustion device itself connected to the exhaust gas supply means 9, and the objects to be burned by the combustion device, are not particularly limited. As the combustion device, any known configuration capable of burning materials can be used. The combustion device may be newly installed for the processing system in this embodiment, but considering the cost, an existing combustion device may be used. Examples include combustion devices in waste incineration facilities, as well as combustion devices in power generation facilities that use gas combustion such as biogas. Furthermore, the substance to be burned in the combustion device may contain at least one of the following: carbon, sulfur, or nitrogen components, and after combustion, it may produce exhaust gas containing components that exhibit acidity when dissolved in an aqueous solution, such as carbon dioxide, sulfur oxides, and nitrogen oxides. The specific substance is not particularly limited.

[0185] An example of a combustion device is one that burns waste generated during the wastewater treatment process. This makes it possible to perform electrode reactions within the series of treatment processes in wastewater treatment, as well as to implement processes to suppress the decrease in electrode reaction efficiency. As a result, the treatment system 1E can be improved in terms of energy recovery and utilization efficiency, and costs can be reduced. Specific examples of such combustion devices include those that incinerate solid matter (sludge) separated in the solid-liquid separation unit 3, and those that burn gas (biogas) generated during anaerobic treatment in the treatment tank 2. This makes it easy to obtain the material to be burned, and allows the use of existing combustion devices for treating solid matter (sludge) discharged from the discharge pipe L4 and for biogas utilization. Furthermore, there is no need to install a new combustion device for the treatment system of the present invention, which makes it possible to significantly reduce initial costs. Furthermore, when sludge is used as the combustion target, the sludge contains a large amount of organic matter, resulting in exhaust gas containing a large amount of carbon dioxide during the combustion process. In recent years, regulations on carbon dioxide emissions have become stricter in light of the environmental impact. Therefore, supplying exhaust gas containing carbon dioxide to the power generation unit 4 suppresses the decrease in electrode reaction efficiency in the power generation unit 4, and also has the effect of suppressing the emission of carbon dioxide outside the system because the carbon dioxide dissolves in the electrolyte solution within the power generation unit 4. Furthermore, the combustion device is not limited to one unit; multiple units may be combined. For example, a unit that incinerates solid materials may be combined with a unit that burns gas. This allows for a stable supply of exhaust gas to the exhaust gas supply means 9, and enables low-cost treatment of the exhaust gas discharged from each combustion device.

[0186] Another embodiment of the exhaust gas supply means 9 in this embodiment may include a mechanism for adjusting the temperature of the exhaust gas. It is known that the temperature of exhaust gas produced in a combustion device can exceed 100 degrees Celsius. On the other hand, the power generation unit 4 of the processing system 1E in this embodiment performs an electrochemical reaction using electrodes placed in an aqueous solution. If exhaust gas exceeding 100 degrees Celsius is supplied as is, it will accelerate the deterioration of the electrodes and the electrolyte solution in the power generation unit 4 will evaporate (vaporize), potentially causing thermal problems such as a decrease in electrode reaction efficiency. Therefore, it is preferable to adjust the temperature of the exhaust gas before supplying it to the power generation unit 4.

[0187] Figure 21 is a schematic diagram illustrating the exhaust gas supply means 9 in this embodiment, which includes a mechanism for adjusting the temperature of the exhaust gas. As shown in Figure 21, a mechanism for adjusting the temperature of the exhaust gas is provided, which is a temperature adjustment mechanism 93 on the piping 92. More specifically, the temperature adjustment mechanism 93 cools the temperature of the exhaust gas to 100 degrees Celsius or lower. This makes it possible to suppress the occurrence of malfunctions due to heat when the exhaust gas is supplied to the power generation unit 4 (second cell 41b).

[0188] The temperature control mechanism 93 can be any device capable of controlling the temperature of the gas (exhaust gas), and known configurations can be used. An example of the temperature control mechanism 93 is a heat exchanger that uses a gas such as air or a liquid such as cooling water. Another example of the temperature control mechanism 93 is to arrange the exhaust gas piping, etc., so that the processing equipment such as the processing tank 2 in the processing system 1E of this embodiment can be heated using the exhaust gas. As a result, the exhaust gas that has been cooled after heating the processing equipment such as the processing tank 2 is supplied to the power generation unit 4 via the piping 92, thereby suppressing a decrease in electrode reaction efficiency and enabling energy saving for the entire processing system 1E.

[0189] As described above, in the processing system 1E of this embodiment, by providing an exhaust gas supply means for supplying exhaust gas generated in the combustion device to the power generation unit, the rise in pH on the cathode side in the electrode reaction can be suppressed. This suppresses a decrease in the efficiency of the electrode reaction and makes it possible to improve the efficiency of power generation and desulfurization treatment.

[0190] Furthermore, in the processing system 1E of this embodiment, power generation and desulfurization processing can be performed using the same process as in the first embodiment.

[0191] [Sixth Embodiment] Figure 22 is a schematic diagram illustrating a processing system in the sixth embodiment of the present invention. Figures 23 and 24 are schematic diagrams illustrating other embodiments of the processing system in the sixth embodiment of the present invention. The processing system 1F according to the sixth embodiment, as shown in Figures 22 to 24, is provided with a degassing means 10 for degassing gas contained in the electrodes 41a and 41b of the power generation unit 4, in addition to the processing system 1A according to the first embodiment. Note that the same components as those in the first embodiment will not be explained. Furthermore, Figures 22 to 24 are enlarged explanatory diagrams of the area around the power generation unit 4 of the processing system 1F, and the configurations of the processing tank 2 and the solid-liquid separation unit 3 are not shown.

[0192] In this embodiment, electrode 43a directly recovers electrons from the reducing substance in the filtrate F. Therefore, by improving the contact efficiency between electrode 43a and the reducing substance, the reaction efficiency as an electron donor (the rate of electron recovery at electrode 43a) is improved, and the power generation efficiency can be improved. Similarly, in electrode 43b, by improving the contact efficiency between electrode 43b and the electron acceptor, the power generation efficiency can be improved.

[0193] On the other hand, if porous materials with a large specific surface area are used as electrodes 43a and 43b, considering power generation efficiency, there will be spaces inside the electrodes into which gas can enter. Therefore, if electrodes 43a and 43b made of porous materials are placed as they are in cells that store liquids such as treated water (first cell 41a, second cell 41b), air bubbles will be present inside electrodes 43a and 43b, and the contact area between the surface of electrodes 43a and 43b and the liquid such as filtrate F will decrease. In this case, a problem arises in electrodes 43a and 43b where the electrode reaction efficiency by reducing substances and electron acceptors decreases.

[0194] (Method of degassing) The degassing means 10 removes gas contained in electrodes 43a and 43b in the power generation unit 4, thereby suppressing a decrease in electrode reaction efficiency. The degassing means 10 is not particularly limited, as long as it can remove the gas contained in electrodes 43a and 43b. In this embodiment, the degassing means 10 may be one that performs degassing while electrodes 43a and 43b are installed inside the power generation unit 4, or one that performs degassing of electrodes 43a and 43b outside the power generation unit 4, such as before installation in the power generation unit 4 or after removal from the power generation unit 4. When degassing is performed on electrodes 43a and 43b inside the power generation unit 4, the transportation and installation of electrodes 43a and 43b can be carried out as usual, and the degassing process can be easily performed in between power generation processes. Therefore, it is possible to easily set the timing of operations related to the degassing process. On the other hand, when degassing is performed on electrodes 43a and 43b outside the power generation unit 4, multiple electrodes can be processed at once without adding degassing equipment to the power generation unit 4, thus reducing work costs. Therefore, the degassing means 10 may be performed either inside or outside the power generation unit 4, and can be appropriately selected in consideration of the degassing effect, work efficiency, etc.

[0195] In this embodiment, the degassing means 10 may include a drug adding means 10A for adding a drug to the electrode. The chemical addition means 10A can be any means that can remove gas contained in the electrodes by adding a chemical, for example, adding the chemical to electrodes 43a and 43b outside the power generation unit 4, or adding the chemical inside the power generation unit 4. By using the chemical addition means 10A as the degassing means 10, degassing of the electrodes can be performed by the relatively simple means of adding a chemical. In this case, it is possible to suppress the increase in size of ancillary equipment related to electrode degassing and reduce initial costs.

[0196] A specific example of the drug addition means 10A is to provide a mechanism for adding a drug to electrodes 43a and 43b installed in the power generation unit 4. Figure 22 is a schematic diagram illustrating the mechanism for adding a drug to electrodes 43a and 43b within the power generation unit 4, which is provided as the drug addition means 10A in this embodiment. As shown in Figure 22, the drug addition means 10A includes providing drug supply ports 101a and 101b and a drug supply means 102 in the first cell 41a and the second cell 41b, respectively, and arranging them so that the drug comes into contact with the surfaces of electrodes 43a and 43b. The dashed arrows in Figure 22 indicate the direction of drug inflow.

[0197] The drug supply means 102 is not particularly limited and can be any device capable of adding the drug. For example, the drug supply means 102 may include a storage section for storing the drug, a control unit for determining and adjusting the amount of drug to be added, etc.

[0198] The chemicals supplied from the chemical supply means 102 include those that replace the gas inside electrodes 43a and 43b and push the gas out of electrodes 43a and 43b, those that dissolve the gas inside electrodes 43a and 43b, and those that break the bubbles of the gas inside electrodes 43a and 43b. More specifically, these include organic solvents such as alcohol, as well as substances known as defoamers. This makes it possible to remove the gas contained in electrodes 43a and 43b located in the power generation unit 4.

[0199] The drug addition means 10A is not limited to the configuration shown in Figure 22, which includes drug supply ports 101a and 101b and a drug supply means 102 on the power generation unit 4. For example, the drug supply means 102 may be connected to the introduction piping L3, and the drug may be supplied to the electrode 43a from the introduction port 42a. This eliminates the need to provide the drug supply port 101a as a separate component, thus simplifying the device configuration.

[0200] Another embodiment of the drug addition means 10A is to provide equipment outside the power generation unit 4 for adding drugs to electrodes 43a and 43b, perform a degassing treatment all at once, and then transport and place the electrodes 43a and 43b, which have been placed in storage containers filled with a preservation solution, into the power generation unit 4.

[0201] In this case, the preservation solution can be any liquid that can suppress the re-inflow of gas into electrodes 43a and 43b after degassing, such as the chemical (solution) used in the degassing treatment, or pure water. Furthermore, it is preferable to use an aqueous solution such as pure water as the preservation solution. This makes it easier for the preservation solution to replace the treated water when electrodes 43a and 43b are placed in the power generation unit 4, and even if the preservation solution flows out into the treated water, it can minimize the impact on the environmental conditions inside the first cell 41a and the second cell 41b.

[0202] Furthermore, the storage container can be any container that can contain electrodes 43a and 43b and the storage solution, and that can prevent gas from flowing back into electrodes 43a and 43b after degassing. Examples of such containers include boxes or bags made of materials that are not permeable to air or water. Specific examples of such storage containers include bags made of plastic film or thin metal film, and boxes made of plastic or metal plates.

[0203] If the chemical addition means 10A is performed by carrying out degassing treatment with a chemical outside the power generation unit 4, the chemical is not directly introduced into the power generation unit 4. This results in less change in the environment inside the first cell 41a and the second cell 41b, which has the effect of suppressing the influence on the electrode reaction.

[0204] Another embodiment of the degassing means 10 in this embodiment includes an electrical processing means 10B that applies a voltage to an electrode. The electrical processing means 10B can be any device capable of applying voltage to electrodes while they are immersed in a solution such as treated water. Examples include providing an electrochemical device that controls the voltage and current between electrodes 43a and 43b located within the power generation unit 4, or providing equipment outside the power generation unit 4 equipped with an electrochemical device that controls the voltage and current applied between electrodes 43a and 43b. In particular, by providing the electrical processing means 10B within the power generation unit 4 as the degassing means 10, the number of newly added devices is reduced, making it possible to miniaturize the equipment.

[0205] Figure 23 is a schematic diagram illustrating the case in this embodiment where the electrical processing means 10B is one which applies a voltage between electrodes 43a and 43b in the power generation unit 4. As shown in Figure 23, the electrical processing means 10B includes a voltage / current control device 103 connected to electrodes 43a and 43b to perform electrochemical processing. More specifically, this involves applying a voltage to allow an electrode reaction to proceed, which generates gas from electrodes 43a and 43b. As a result, the gas contained in electrodes 43a and 43b is pushed out of electrodes 43a and 43b by the gas generated by the electrode reaction, thus enabling degassing of the electrodes. An example of an electrode reaction that generates gas is the electrolysis of an aqueous solution (water) stored in the first cell 41a and the second cell 41b. Hydrogen and oxygen are generated by the electrolysis of water in the power generation unit 4, and these are released outside electrodes 43a and 43b along with the gas contained in electrodes 43a and 43b, thereby enabling degassing of the electrodes. As a result, there is almost no need to add new equipment as a degassing means 10, making it possible to significantly reduce equipment costs.

[0206] Another embodiment of the degassing means 10 in this embodiment includes a depressurization means 10C that performs a depressurization process on the electrode. The degassing means 10C can be any means that can perform a degassing treatment on the electrodes and remove gas contained in the electrodes as a result. Examples include a means to depressurize the inside of the cells (first cell 41a and / or second cell 41b) with electrodes 43a and 43b placed inside the power generation unit 4, or a means to perform a degassing treatment on electrodes 43a and 43b outside the power generation unit 4 and then store them in a storage container while maintaining the depressurized state. By using the degassing means 10C as the degassing means 10, the electrodes can be degassed without changing the environmental conditions (pH, concentration of various compounds, etc.) inside the first cell 41a and the second cell 41b.

[0207] Figure 24 is a schematic diagram illustrating the case in this embodiment where the depressurization means 10C is one that depressurizes the inside of the first cell 41a and the second cell 41b with electrodes 43a and 43b arranged inside the power generation unit 4. As shown in Figure 24, the pressure reducing means 10C may include flow control valves 104a to 104d and a pressure reducing device 105. An example of the pressure reducing means 10C of this embodiment will be described based on Figure 24. The pressure reducing means 10C shown in Figure 24 is provided with flow control valves 104a and 104b on the introduction pipe L3 and discharge pipe L5 that introduce and discharge the filtrate F to the first cell 41a, and flow control valves 104c and 104d on pipes 106 and 107 that connect to the electron acceptor supply port 44a and electron acceptor discharge port 44b that introduce and discharge electron acceptors to the second cell 41b. As a result, by opening and closing the flow control valves 104a to 104d, the first cell 41a and the second cell 41 can be partitioned from other equipment related to the processing system 1F (such as the processing tank 2 and the solid-liquid separation unit 3). To reduce the pressure within the partitioned space, the pressure reducing means 10C shown in Figure 24 is provided with a pressure reducing device 105 connected to the first cell 41a and the second cell 41b. As a result, by driving the depressurization device 105, the pressure inside the partitioned spaces, the first cell 41a and the second cell 41b, is reduced. At this time, the gas contained in electrodes 43a and 43b is released outside electrodes 43a and 43b, so that the electrodes can be degassed.

[0208] The pressure reducing device 105 is not particularly limited, as long as it can reduce the pressure in the first cell 41a and the second cell 41b. For example, the pressure reducing device 105 can be a known pressure reducing pump.

[0209] The pressure reducing means 10C is not limited to the configuration shown in Figure 24. For example, if the electron acceptor supplied to the second cell 41b is a gas and degassing treatment is not required at electrode 43b, the pressure reducing means 10C may be provided only on the first cell side. In this case, the pressure reducing means 10C may consist of flow control valves 104a and 104b and a pressure reducing device 105 connected only to the first cell 41a. This allows degassing treatment to be performed only on the electrode 43a side, which is in contact with the filtrate F and requires gas removal, thereby simplifying the entire processing system 1F. On the other hand, if the degassing means 10C is provided in only one of the first cell 41a or the second cell 41b, and degassing is performed by degassing, there is a risk that the electrodes 43a, 43b and the ion exchanger 45 may be damaged due to the pressure difference between the cells. Therefore, when using the degassing means 10C as the degassing means 10, it is more preferable to provide flow control valves 104a to 104d, as shown in Figure 24, to partition the space to include both the first cell 41a and the second cell 41b, and to depressurize the partitioned space. This makes it possible to perform degassing of electrodes 43a and 43b stably.

[0210] Furthermore, when connecting the pressure reducing device 105 to the first cell 41a and the second cell 41b, new piping may be provided, or existing piping may be utilized. In particular, utilizing existing piping makes it possible to simplify the device configuration.

[0211] The degassing means 10 in the processing system 1F of this embodiment is not limited to the above-described chemical addition means 10A, electrical processing means 10B, and depressurization means 10C being performed individually, but may be a combination of multiple means 10A to 10C. This makes it possible to select and implement a suitable degassing means 10 according to the shape and arrangement of electrodes 43a and 43b, thereby obtaining a higher degassing effect.

[0212] The conditions for performing electrode degassing using the degassing means 10 in this embodiment (such as the number of times and timing of the degassing) are not particularly limited. For example, each degassing means 10 (means 10A to 10C) may be performed only once before or after installing the electrodes in the power generation unit 4, or it may be repeated multiple times. While repeating the degassing means 10 can increase the degassing efficiency, the number of times it is performed can be appropriately set considering the costs associated with driving the degassing means 10 (such as chemical costs and electricity costs). The timing for performing the degassing means 10 may include, for example, when replacing electrodes or when using new electrodes, or after electrode maintenance (such as cleaning).

[0213] Furthermore, electrodes 43a and 43b, which have undergone degassing treatment by the degassing means 10 of this embodiment, can be configured as independent electrodes of the present invention. The electrodes of the present invention only need to be those that have undergone degassing treatment by the degassing means 10, and are not particularly limited in form, etc. For example, they may be configured to undergo degassing treatment by the degassing means 10 provided outside the power generation unit 4 and be housed in a storage container or the like for transport. The electrode of the present invention is used as an electrode for generating electricity during a series of treatment processes in wastewater treatment, by contacting the filtrate F obtained by solid-liquid separation of waste (treatment liquid W1) after treatment by a treatment system (treatment system 1F in this embodiment) that performs anaerobic treatment on the material to be treated, and it can solve the problem of a decrease in the specific surface area inside the electrode. This suppresses a decrease in the efficiency of the electrode reaction and makes it possible to improve the efficiency of power generation and desulfurization treatment in the treatment system.

[0214] As described above, the processing system 1F of this embodiment is equipped with a degassing means for removing gas contained inside the electrode, thereby solving the problem of a decrease in the specific surface area inside the electrode. This suppresses a decrease in the efficiency of the electrode reaction and makes it possible to improve the efficiency of power generation and desulfurization treatment.

[0215] Furthermore, in the processing system 1F of this embodiment, power generation and desulfurization processing can be performed using the same process as in the first embodiment.

[0216] Furthermore, the electrodes of this embodiment suppress the decrease in specific surface area inside the electrodes, enabling improved efficiency of power generation and electrochemical treatment when power generation is performed as part of a series of treatment processes in wastewater treatment. In particular, when adding power generation or desulfurization functions to existing treatment systems, using the electrodes of this embodiment suppresses a decrease in the efficiency of the electrode reaction, making it possible to perform power generation and desulfurization treatment with high efficiency.

[0217] [Seventh Embodiment] Figure 25 is a schematic diagram illustrating a processing system in the seventh embodiment of the present invention. Figures 26 and 27 are schematic diagrams illustrating other embodiments of the processing system in the seventh embodiment of the present invention. The seventh embodiment of the processing system 1G, as shown in Figures 25 to 27, is provided with an insulating mechanism 11 for insulating the treated water W2 discharged from the first cell 41a in the processing system 1A of the first embodiment. Note that the same components as those in the first embodiment will not be described. Furthermore, Figures 25 to 27 are enlarged explanatory diagrams of the area around the power generation unit 4 of the processing system 1G, and the configurations of the processing tank 2 and the solid-liquid separation unit 3 are not shown.

[0218] As described above, when performing an electrode reaction, it is preferable to insulate areas other than the part where the electrode reaction takes place (power generation unit 4). The treatment system 1G in this embodiment is equipped with an insulating mechanism 11 that insulates the treated water W2. This prevents electrons generated in the power generation unit 4 from flowing anywhere other than between electrodes 43a and 43b, thereby improving the electrode reaction efficiency. As a result, both power generation efficiency and desulfurization treatment efficiency can be improved. The treatment system 1G in this embodiment may also incorporate insulation for the structures (treatment tank and piping) that constitute the treatment system as shown in the first embodiment. This can provide an even greater insulating effect and improve the electrode reaction efficiency in the power generation unit 4.

[0219] The insulating mechanism 11 is not particularly limited as long as it can insulate the treated water W2. Examples of means for insulating the treated water W2 by the insulating mechanism 11 include eliminating electrical contact (liquid junction) between the electrode 43a of the power generation unit 4 and the treated water W2, or shortening the liquid junction time. Examples of such liquid junction elimination means or liquid junction time shortening means include making the flow of the treated water W2 discontinuous (intermittent), interposing an insulator such as air in the treated water W2, or a combination of these means.

[0220] Figure 25 is a schematic diagram illustrating the isolation mechanism 11 of the processing system 1G in this embodiment. As shown in Figure 25, the insulating mechanism 11 in this embodiment includes a storage tank 111 and a watering means 112 for spraying treated water W2 into the storage tank 111.

[0221] The storage tank 111 stores the treated water W2 discharged from the power generation unit 4 via the discharge pipe L5. The storage tank 111 is not particularly limited and can be any tank capable of storing the treated water W2. In addition, since the air present in the storage tank 111 acts as an insulator for the treated water W2, it is preferable to adjust the water level in the storage tank 111 so that the water level does not reach its maximum (full). This makes it possible to further enhance the insulating effect of the treated water W2.

[0222] The watering means 112 discharges the treated water W2 in droplet form. Since air from the storage tank 111 acts as an insulator between the droplets of treated water W2 discharged by the watering means 112, it is possible to eliminate liquid junctions or shorten the liquid junction time. The watering means 112 is not particularly limited and can be any device that can form the treated water W2 into droplets. A specific example of the watering means 112 is, for example, a structure connected to the outlet of the discharge pipe L5 and having multiple holes like a shower head, as shown in Figure 25. Another example of the watering means 112 is a flat, dish-shaped structure placed in the storage tank 111, facing the outlet of the discharge pipe L5 and spaced a predetermined distance apart.

[0223] Figure 26 is a schematic diagram illustrating another embodiment of the insulation mechanism 11 of the processing system 1G in this embodiment. As shown in Figure 26, the insulating mechanism 11 in this embodiment includes a storage tank 113 and a water discharge means 114 for intermittently releasing treated water W2 from the storage tank 113.

[0224] The storage tank 113 stores the treated water W2 discharged from the power generation unit 4 via the discharge pipe L5. The storage tank 113 is not particularly limited and can be any tank capable of storing the treated water W2. The water discharge means 114 is not particularly limited, as long as it can intermittently discharge the treated water W2 from the storage tank 113. An example of the water discharge means 114 is to install a solenoid valve 114a in the water discharge pipe 115 that discharges the treated water W2 from the storage tank 113, and to periodically open and close the solenoid valve 114a. This makes the flow of treated water W2 discharged from the storage tank 113 through the water discharge pipe 115 intermittent, thereby eliminating liquid entanglement of the treated water W2 or shortening the liquid entanglement time.

[0225] Figure 27 is a schematic diagram illustrating another embodiment of the insulation mechanism 11 of the processing system 1G in this embodiment. As shown in FIG. 27, in this embodiment, the insulation mechanism 11 includes a pipe diameter reduction means 116 for narrowing a part of the pipe diameter of the discharge pipe L5 on the discharge pipe L5, and a gas supply means 117 for supplying gas into the discharge pipe L5 from the upstream side of the pipe diameter reduction means 116.

[0226] The pipe diameter reduction means 116 may be any means that can narrow a part of the pipe diameter of the discharge pipe L5, and is not particularly limited. Examples of the pipe diameter reduction means 116 include providing a structure for narrowing the pipe diameter inside the discharge pipe L5, inserting a structure from the outside of the discharge pipe L5, and deforming the discharge pipe L5 itself by pressing from the outside of the discharge pipe L5. The gas supply means 117 may be any means that can supply gas into the discharge pipe L5 from the upstream side of the pipe diameter reduction means 116, and is not particularly limited. Examples of the gas supply means 117 include using a pump or the like that blows air by applying pressure to the air to supply air into the discharge pipe L5. The gas supplied by the gas supply means 117 is not limited to air. For example, in addition to air, biogas generated in the treatment tank 2 or exhaust gas after combustion of biogas can be used.

[0227] By supplying gas (air) from the upstream side of the pipe diameter reduction means 116 by the gas supply means 117, only gas intermittently flows at the location narrowed by the pipe diameter reduction means 116, and the flow of the treated water W2 in the discharge pipe L5 can be made discontinuous. Thereby, it is possible to eliminate the liquid contact or shorten the liquid contact time of the treated water W2 in the discharge pipe L5.

[0228] As described above, the treatment system 1G in this embodiment is provided with an insulation mechanism 11 for insulating the treated water W2, so that it is possible to eliminate the liquid contact or shorten the liquid contact time between the power generation unit 4 and the treated water W2. Thereby, it is possible to prevent electrons generated in the power generation unit 4 from flowing other than between the electrodes 43a and 43b and reduce the efficiency of the electrochemical reaction (electrode reaction), and improve the power generation efficiency and the desulfurization treatment efficiency.

[0229] Furthermore, in the processing system 1G of this embodiment, power generation and desulfurization processing can be performed using the same process as in the first embodiment.

[0230] [Eighth Embodiment] Figure 28 is a schematic diagram illustrating a processing system in the eighth embodiment of the present invention. As shown in Figure 28, the eighth embodiment of the processing system 1H is provided with an aeration tank 12 for processing the treated water W2 discharged from the discharge pipe L5 of the power generation unit 4, in addition to the processing system 1A of the first embodiment, and the aeration tank 12 and the electron acceptor supply port 44a provided in the second cell 41b of the power generation unit 4 are connected by a connecting pipe L8. The same components as those of the first embodiment will not be described.

[0231] In this embodiment, the treatment system 1H supplies treated water W2 from the aeration tank 12 to the power generation unit 4 and uses it as an electron acceptor in the power generation unit 4. Any treated water W2 other than that supplied to the power generation unit 4 via the connecting pipe L8 is discharged outside the system.

[0232] The aeration tank 12 uses an aeration device 12a to aerate the treated water W2 introduced into the tank with an oxygen-containing gas (oxygen, air, etc.), thereby promoting aerobic treatment by aerobic microorganisms and oxidation reactions by dissolved oxygen.

[0233] The aeration device 12a is not particularly limited, as long as it can supply oxygen-containing gas to the treated water W2 in the aeration tank 12. For example, a combination of a blower and an aeration pipe is widely used in aeration treatment.

[0234] Since oxygen-containing gas is introduced into the aeration tank 12 by the aeration device 12a, the treated water W2 in the aeration tank 12 is a liquid containing dissolved oxygen. Therefore, the treated water W2 introduced into the second cell 41b of the power generation unit 4 via the connecting pipe L8 becomes an electron acceptor in the power generation unit 4. This makes it possible to generate electricity by effectively utilizing the materials generated in the processing steps within the processing system 1H.

[0235] The treated water W2, after being used as an electron acceptor in the power generation unit 4, is discharged from the electron acceptor outlet 44b. At this time, if the discharged treated water W2 meets the water quality requirements for discharge into rivers or other bodies of water, it can be discharged as is. Alternatively, the discharged treated water W2 may be returned to the aeration tank 12 and subjected to aeration treatment again. This makes it possible to more reliably control the water quality of the treated water W2 discharged outside the system.

[0236] Furthermore, the treated water W2 in the aeration tank in the processing system of this embodiment may be utilized in the contact efficiency improvement means 5 described above. For example, the contact efficiency improvement means 5 may be the dissolving means 8B, which is the moving speed control means 6 shown in the third embodiment or the washing means 8 shown in the fourth embodiment. More specifically, for example, the treated water W2 in the aeration tank 12 may be introduced into the first cell 41a via the connecting pipe L8. In this case, the treated water W2 functions as a fluid in the moving speed control means 6. Also, as will be described later, since the treated water W2 contains microorganisms, the microorganisms in the treated water W2 function as a substitute for the chemical agent that dissolves the sediment in the dissolving means 8B.

[0237] As shown in Equations 1 and 2, precipitated sulfur has accumulated as a deposit on the surface of electrode 43a. Meanwhile, in the aeration tank 12, aerobic microorganisms that oxidize sulfur to sulfite ions are present under aerobic conditions (Equation 4).

number

[0238] Therefore, by introducing the treated water W2 in the aeration tank 12 to the electrode 43a side, the sulfur on the surface of the electrode 43a is dissolved and the surface of the electrode 43a is cleaned. Alternatively, as the cleaning means 8, the electrode 43a may be removed from the power generation unit 4 and immersed in the aeration tank 12. This allows the power generation and desulfurization treatment means using reducing substances in the filtrate F to be combined with the electrode cleaning means 8, reducing the amount of auxiliary equipment required for electrode cleaning and significantly lowering running costs.

[0239] Furthermore, in this embodiment, the treatment system 1H introduces treated water W2 from the aeration tank 12 into the power generation unit 4, so the surfaces of electrodes 43a and 43b are prone to the accumulation of deposits mainly consisting of microorganisms. Therefore, in addition to the dissolution means 8B described above, it is preferable to further include one of the peeling means 8A, dispersion means 8C, and surrounding environment changing means 8D to remove the microorganisms accumulated on the surfaces of electrodes 43a and 43b. This makes it possible to improve the cleaning efficiency of the surfaces of electrodes 43a and 43b.

[0240] As described above, in this embodiment, the processing system 1H can utilize the materials generated in the processing steps carried out within the processing system 1H as electron donors and electron acceptors in the power generation unit 4, thereby reducing the running costs related to power generation and desulfurization.

[0241] Furthermore, in the processing system 1H of this embodiment, power generation and desulfurization processing can be performed using the same process as in the first embodiment.

[0242] The embodiments described above are examples of processing systems, power generation devices, desulfurization treatment devices, power generation methods, and desulfurization methods. The processing systems, power generation devices, desulfurization treatment devices, power generation methods, and desulfurization methods according to the present invention are not limited to the embodiments described above, and the processing systems, power generation devices, desulfurization treatment devices, power generation methods, and desulfurization methods according to the embodiments described above may be modified without changing the gist of the claims.

[0243] For example, the processing system of this embodiment may select any one or more of the above-described contact efficiency improvement means (moving speed control means, concentration control means, cleaning means), exhaust gas supply means, degassing means, insulation mechanism, and aeration tank, and may be provided with a combination of a plurality of configurations. Thereby, it becomes possible to enhance the effect related to the improvement of the efficiency of the electrode reaction.

[0244] Also, for example, the processing system in this embodiment may be provided with a plurality of power generation units (power generation devices). Thereby, it becomes possible to perform electrode reactions using the processing within the processing system at multiple locations, and it also becomes possible to improve both the processing efficiency of the filtrate and the electrode reaction efficiency.

[0245] Also, for example, in the processing system of this embodiment, the electrode 43b may be provided in the aeration tank 12, and the aeration tank 12 may function as the second cell 41b of the power generation unit 4. Thereby, the power generation unit 4 and the aeration tank 12 can be integrated, and the equipment can be made even more compact.

[0246] Also, for example, the processing system in this embodiment may be provided with means for preventing the adhesion and deposition of microorganisms on the electrodes 43a and 43b. Examples of such means include coating the electrode surface with a material that prevents the adhesion of microorganisms, or having a shape such that the structure of the electrode itself makes it difficult for microorganisms to adhere. Thereby, even when microorganisms flow into the first cell 41a and the second cell 41b of the power generation unit 4, it becomes possible to suppress the inhibition of the electrode reaction by the microorganisms on the electrodes 43a and 43b.

[0247] Furthermore, for example, the processing system in this embodiment may omit some structures to simplify the device configuration. Examples of the structure that can be omitted include, for example, the ion exchanger 45. Thereby, it becomes possible to simplify the power generation unit 4 (power generation device·desulfurization treatment device), and the maintenance work becomes easier. Furthermore, other examples of structures that can be omitted include the electron acceptor supply port 44a and electron acceptor outlet port 44b in the second cell 41b. This makes it possible to further simplify the power generation unit 4 (power generation device / desulfurization treatment device). In this case, one surface of the electrode 43b is in contact with the filtrate F or ion exchanger 45, and the other surface is in direct contact with the outside air. In addition, it is preferable to provide a breathable material that is easy to replace or clean on the surface of the electrode 43b facing the outside air. This makes it possible to suppress the adhesion of solid impurities such as dust to the surface of the electrode 43b. [Industrial applicability]

[0248] The treatment system, power generation method, and desulfurization method of the present invention are used for anaerobic treatment of materials to be treated. In particular, they are suitably used in anaerobic treatment where reducing substances are contained in the waste products after anaerobic treatment of the materials to be treated.

[0249] By applying the power generation device of the present invention to an existing processing system, it is possible to provide the processing system and power generation method of the present invention without having to extensively remodel the entire processing system. Furthermore, by applying the desulfurization apparatus of the present invention to an existing treatment system, the treatment system and desulfurization method of the present invention can be provided without extensively updating the entire treatment system. [Explanation of symbols]

[0250] 1A,1B,1C,1D,1E,1F,1G,1H Processing system, 2 Processing tank, 3 Solid-liquid separation section, 4 Power generation section, 41a First cell, 41b Second cell, 42a Inlet, 42b Outlet, 43a,43b Electrodes, 44a Electron acceptor supply port, 44b Electron acceptor outlet, 45 Ion exchanger, 46 Storage section, 47 Circulation channel, 5 Contact efficiency improvement means, 6 Transfer speed control means, 61a,61b Fluid supply port, 62 Fluid supply means, 63 Recovery means, 64a,64b Fluid outlet, 65 Gas-liquid separation section, 66 Temperature control means, 67 Existing heat exchange equipment, 68a,68b,69a,69b Piping, 7 Concentration control means, 71a,71b Electrode reaction component addition port, 72 Electrode reaction component addition means, 73 Adsorbent, 74 pH control means, 75 Storage unit, 76 Addition unit, 77 pH detection unit, 8 Washing means, 8A Peeling means, 8B Dissolving means, 8C Dispersion means, 8D Surrounding environment changing means, 81a, 81b Fluid supply port, 82 Fluid supply means, 83 Control unit, 84a, 84b Chemical addition port, 85 Chemical addition means, 86a, 86b Chemical addition port, 87 Chemical addition means, 88a, 88b Additive supply port, 89 Additive supply means, 9 Exhaust gas supply means, 91 Exhaust gas supply port, 92 Piping, 93 Temperature adjustment mechanism, 10 Degassing means, 10A Chemical addition means, 10B Electrical processing means, 10C Pressure reduction means, 101a, 101b Chemical supply port, 102 Chemical supply means, 103 Voltage / current control device, 104a, 104b, 104c, 104d Flow control valve, 105 Pressure reducing device, 11 Insulation mechanism, 111, 113 Storage tank, 112 Spraying means, 114 Discharge means, 114a Solenoid valve, 115 Discharge piping, 116 Pipe diameter reduction means, 117 Gas supply means, 12 Aeration tank, 12a Aeration device, L1, L3 Inlet piping, L2, L6, L8 Connection piping, L4, L5, L7 Discharge piping, F Filtrate, S Material to be treated, W1 Treatment liquid, W2 Treated water

Claims

1. A processing system equipped with a digestion facility that performs anaerobic treatment on the material to be processed, A power generation unit receives a filtrate obtained by separating the solid and liquid from the waste after anaerobic treatment, and generates electricity or performs desulfurization treatment by a reaction in which reducing substances in the filtrate come into direct contact with electrodes and act as electron donors, A processing system characterized by comprising a storage unit that extracts the filtrate from the power generation unit and returns it directly to the power generation unit.

2. The processing system according to claim 1, characterized in that an ion exchanger is placed between the electrodes.

3. The processing system according to claim 1 or 2, further comprising means for improving the contact efficiency between the electrode surface of the power generation unit and the electrode reaction component containing a reducing substance in the filtrate.

4. The processing system according to claim 3, characterized in that the contact efficiency improving means includes a moving speed control means for increasing the moving speed of the electrode reaction component with respect to the electrode surface.

5. The processing system according to claim 4, characterized in that the transfer speed control means is provided with a temperature control means for a reaction in which the reducing substance in the filtrate is used as an electron donor.

6. The processing system according to claim 3, characterized in that the contact efficiency improving means includes a concentration control means for controlling the concentration of the electrode reaction component.

7. A desulfurization apparatus for a processing system that performs anaerobic treatment on a material to be processed, A power generation unit receives a filtrate obtained by separating the solid and liquid from the waste after anaerobic treatment, and performs desulfurization treatment by a reaction in which reducing substances in the filtrate come into direct contact with electrodes and act as electron donors, A desulfurization apparatus comprising a storage unit that extracts the filtrate from the power generation unit and returns it directly to the power generation unit.

8. A desulfurization method in anaerobic treatment of a material to be treated, A process of supplying the filtrate obtained by separating the solid and liquid from the waste after anaerobic treatment to the power generation unit, A step of performing a desulfurization treatment in the power generation section by a reaction in which the reducing substance in the filtrate is brought into direct contact with an electrode and acts as an electron donor, A desulfurization method characterized by comprising the steps of withdrawing the desulfurized filtrate from the power generation unit, storing it, and returning it directly to the power generation unit.

Images